gravityview / GravityView

vendor/paragonie/sodium_compat/autoload.php

Indentation +51 added lines, -51 removed lines

@@ -1,72 +1,72 @@
 <?php
 
 if (PHP_VERSION_ID < 70000) {
-    if (!is_callable('sodiumCompatAutoloader')) {
-        /**
-         * Sodium_Compat autoloader.
-         *
-         * @param string $class Class name to be autoloaded.
-         *
-         * @return bool         Stop autoloading?
-         */
-        function sodiumCompatAutoloader($class)
-        {
-            $namespace = 'ParagonIE_Sodium_';
-            // Does the class use the namespace prefix?
-            $len = strlen($namespace);
-            if (strncmp($namespace, $class, $len) !== 0) {
-                // no, move to the next registered autoloader
-                return false;
-            }
+	if (!is_callable('sodiumCompatAutoloader')) {
+		/**
+		 * Sodium_Compat autoloader.
+		 *
+		 * @param string $class Class name to be autoloaded.
+		 *
+		 * @return bool         Stop autoloading?
+		 */
+		function sodiumCompatAutoloader($class)
+		{
+			$namespace = 'ParagonIE_Sodium_';
+			// Does the class use the namespace prefix?
+			$len = strlen($namespace);
+			if (strncmp($namespace, $class, $len) !== 0) {
+				// no, move to the next registered autoloader
+				return false;
+			}
 
-            // Get the relative class name
-            $relative_class = substr($class, $len);
+			// Get the relative class name
+			$relative_class = substr($class, $len);
 
-            // Replace the namespace prefix with the base directory, replace namespace
-            // separators with directory separators in the relative class name, append
-            // with .php
-            $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
-            // if the file exists, require it
-            if (file_exists($file)) {
-                require_once $file;
-                return true;
-            }
-            return false;
-        }
+			// Replace the namespace prefix with the base directory, replace namespace
+			// separators with directory separators in the relative class name, append
+			// with .php
+			$file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
+			// if the file exists, require it
+			if (file_exists($file)) {
+				require_once $file;
+				return true;
+			}
+			return false;
+		}
 
-        // Now that we have an autoloader, let's register it!
-        spl_autoload_register('sodiumCompatAutoloader');
-    }
+		// Now that we have an autoloader, let's register it!
+		spl_autoload_register('sodiumCompatAutoloader');
+	}
 } else {
-    require_once dirname(__FILE__) . '/autoload-php7.php';
+	require_once dirname(__FILE__) . '/autoload-php7.php';
 }
 
 /* Explicitly, always load the Compat class: */
 require_once dirname(__FILE__) . '/src/Compat.php';
 
 if (!class_exists('SodiumException', false)) {
-    require_once dirname(__FILE__) . '/src/SodiumException.php';
+	require_once dirname(__FILE__) . '/src/SodiumException.php';
 }
 if (PHP_VERSION_ID >= 50300) {
-    // Namespaces didn't exist before 5.3.0, so don't even try to use this
-    // unless PHP >= 5.3.0
-    require_once dirname(__FILE__) . '/lib/namespaced.php';
-    require_once dirname(__FILE__) . '/lib/sodium_compat.php';
+	// Namespaces didn't exist before 5.3.0, so don't even try to use this
+	// unless PHP >= 5.3.0
+	require_once dirname(__FILE__) . '/lib/namespaced.php';
+	require_once dirname(__FILE__) . '/lib/sodium_compat.php';
 } else {
-    require_once dirname(__FILE__) . '/src/PHP52/SplFixedArray.php';
+	require_once dirname(__FILE__) . '/src/PHP52/SplFixedArray.php';
 }
 if (PHP_VERSION_ID < 70200 || !extension_loaded('sodium')) {
-    if (PHP_VERSION_ID >= 50300 && !defined('SODIUM_CRYPTO_SCALARMULT_BYTES')) {
-        require_once dirname(__FILE__) . '/lib/php72compat_const.php';
-    }
-    if (PHP_VERSION_ID >= 70000) {
-        assert(class_exists('ParagonIE_Sodium_Compat'), 'Possible filesystem/autoloader bug?');
-    } else {
-        assert(class_exists('ParagonIE_Sodium_Compat'));
-    }
-    require_once(dirname(__FILE__) . '/lib/php72compat.php');
+	if (PHP_VERSION_ID >= 50300 && !defined('SODIUM_CRYPTO_SCALARMULT_BYTES')) {
+		require_once dirname(__FILE__) . '/lib/php72compat_const.php';
+	}
+	if (PHP_VERSION_ID >= 70000) {
+		assert(class_exists('ParagonIE_Sodium_Compat'), 'Possible filesystem/autoloader bug?');
+	} else {
+		assert(class_exists('ParagonIE_Sodium_Compat'));
+	}
+	require_once(dirname(__FILE__) . '/lib/php72compat.php');
 } elseif (!function_exists('sodium_crypto_stream_xchacha20_xor')) {
-    // Older versions of {PHP, ext/sodium} will not define these
-    require_once(dirname(__FILE__) . '/lib/php72compat.php');
+	// Older versions of {PHP, ext/sodium} will not define these
+	require_once(dirname(__FILE__) . '/lib/php72compat.php');
 }
 require_once(dirname(__FILE__) . '/lib/ristretto255.php');

vendor/paragonie/sodium_compat/autoload-php7.php

Indentation +20 added lines, -20 removed lines

@@ -3,29 +3,29 @@
  This file should only ever be loaded on PHP 7+
  */
 if (PHP_VERSION_ID < 70000) {
-    return;
+	return;
 }
 
 spl_autoload_register(function ($class) {
-    $namespace = 'ParagonIE_Sodium_';
-    // Does the class use the namespace prefix?
-    $len = strlen($namespace);
-    if (strncmp($namespace, $class, $len) !== 0) {
-        // no, move to the next registered autoloader
-        return false;
-    }
+	$namespace = 'ParagonIE_Sodium_';
+	// Does the class use the namespace prefix?
+	$len = strlen($namespace);
+	if (strncmp($namespace, $class, $len) !== 0) {
+		// no, move to the next registered autoloader
+		return false;
+	}
 
-    // Get the relative class name
-    $relative_class = substr($class, $len);
+	// Get the relative class name
+	$relative_class = substr($class, $len);
 
-    // Replace the namespace prefix with the base directory, replace namespace
-    // separators with directory separators in the relative class name, append
-    // with .php
-    $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
-    // if the file exists, require it
-    if (file_exists($file)) {
-        require_once $file;
-        return true;
-    }
-    return false;
+	// Replace the namespace prefix with the base directory, replace namespace
+	// separators with directory separators in the relative class name, append
+	// with .php
+	$file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
+	// if the file exists, require it
+	if (file_exists($file)) {
+		require_once $file;
+		return true;
+	}
+	return false;
 });

vendor/paragonie/sodium_compat/autoload-phpunit.php

Indentation +1 added lines, -1 removed lines

@@ -3,6 +3,6 @@
 require_once (dirname(__FILE__) . '/vendor/autoload.php');
 
 if (PHP_VERSION_ID >= 50300) {
-    require_once (dirname(__FILE__) . '/tests/phpunit-shim.php');
+	require_once (dirname(__FILE__) . '/tests/phpunit-shim.php');
 }
 require_once (dirname(__FILE__) . '/autoload.php');

vendor/paragonie/sodium_compat/src/Crypto.php

Indentation +1639 added lines, -1639 removed lines

@@ -1,7 +1,7 @@ 
 <?php
 
 if (class_exists('ParagonIE_Sodium_Crypto', false)) {
-    return;
+	return;
 }
 
 /**
@@ -14,1642 +14,1642 @@ 
  */
 abstract class ParagonIE_Sodium_Crypto
 {
-    const aead_chacha20poly1305_KEYBYTES = 32;
-    const aead_chacha20poly1305_NSECBYTES = 0;
-    const aead_chacha20poly1305_NPUBBYTES = 8;
-    const aead_chacha20poly1305_ABYTES = 16;
-
-    const aead_chacha20poly1305_IETF_KEYBYTES = 32;
-    const aead_chacha20poly1305_IETF_NSECBYTES = 0;
-    const aead_chacha20poly1305_IETF_NPUBBYTES = 12;
-    const aead_chacha20poly1305_IETF_ABYTES = 16;
-
-    const aead_xchacha20poly1305_IETF_KEYBYTES = 32;
-    const aead_xchacha20poly1305_IETF_NSECBYTES = 0;
-    const aead_xchacha20poly1305_IETF_NPUBBYTES = 24;
-    const aead_xchacha20poly1305_IETF_ABYTES = 16;
-
-    const box_curve25519xsalsa20poly1305_SEEDBYTES = 32;
-    const box_curve25519xsalsa20poly1305_PUBLICKEYBYTES = 32;
-    const box_curve25519xsalsa20poly1305_SECRETKEYBYTES = 32;
-    const box_curve25519xsalsa20poly1305_BEFORENMBYTES = 32;
-    const box_curve25519xsalsa20poly1305_NONCEBYTES = 24;
-    const box_curve25519xsalsa20poly1305_MACBYTES = 16;
-    const box_curve25519xsalsa20poly1305_BOXZEROBYTES = 16;
-    const box_curve25519xsalsa20poly1305_ZEROBYTES = 32;
-
-    const onetimeauth_poly1305_BYTES = 16;
-    const onetimeauth_poly1305_KEYBYTES = 32;
-
-    const secretbox_xsalsa20poly1305_KEYBYTES = 32;
-    const secretbox_xsalsa20poly1305_NONCEBYTES = 24;
-    const secretbox_xsalsa20poly1305_MACBYTES = 16;
-    const secretbox_xsalsa20poly1305_BOXZEROBYTES = 16;
-    const secretbox_xsalsa20poly1305_ZEROBYTES = 32;
-
-    const secretbox_xchacha20poly1305_KEYBYTES = 32;
-    const secretbox_xchacha20poly1305_NONCEBYTES = 24;
-    const secretbox_xchacha20poly1305_MACBYTES = 16;
-    const secretbox_xchacha20poly1305_BOXZEROBYTES = 16;
-    const secretbox_xchacha20poly1305_ZEROBYTES = 32;
-
-    const stream_salsa20_KEYBYTES = 32;
-
-    /**
-     * AEAD Decryption with ChaCha20-Poly1305
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_decrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $len - Length of message (ciphertext + MAC) */
-        $len = ParagonIE_Sodium_Core_Util::strlen($message);
-
-        /** @var int  $clen - Length of ciphertext */
-        $clen = $len - self::aead_chacha20poly1305_ABYTES;
-
-        /** @var int $adlen - Length of associated data */
-        $adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
-
-        /** @var string $mac - Message authentication code */
-        $mac = ParagonIE_Sodium_Core_Util::substr(
-            $message,
-            $clen,
-            self::aead_chacha20poly1305_ABYTES
-        );
-
-        /** @var string $ciphertext - The encrypted message (sans MAC) */
-        $ciphertext = ParagonIE_Sodium_Core_Util::substr($message, 0, $clen);
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core_ChaCha20::stream(
-            32,
-            $nonce,
-            $key
-        );
-
-        /* Recalculate the Poly1305 authentication tag (MAC): */
-        $state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-        $state->update($ad);
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
-        $state->update($ciphertext);
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($clen));
-        $computed_mac = $state->finish();
-
-        /* Compare the given MAC with the recalculated MAC: */
-        if (!ParagonIE_Sodium_Core_Util::verify_16($computed_mac, $mac)) {
-            throw new SodiumException('Invalid MAC');
-        }
-
-        // Here, we know that the MAC is valid, so we decrypt and return the plaintext
-        return ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
-            $ciphertext,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core_Util::store64_le(1)
-        );
-    }
-
-    /**
-     * AEAD Encryption with ChaCha20-Poly1305
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_encrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $len - Length of the plaintext message */
-        $len = ParagonIE_Sodium_Core_Util::strlen($message);
-
-        /** @var int $adlen - Length of the associated data */
-        $adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core_ChaCha20::stream(
-            32,
-            $nonce,
-            $key
-        );
-        $state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-
-        /** @var string $ciphertext - Raw encrypted data */
-        $ciphertext = ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
-            $message,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core_Util::store64_le(1)
-        );
-
-        $state->update($ad);
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
-        $state->update($ciphertext);
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($len));
-        return $ciphertext . $state->finish();
-    }
-
-    /**
-     * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_ietf_decrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $adlen - Length of associated data */
-        $adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
-
-        /** @var int $len - Length of message (ciphertext + MAC) */
-        $len = ParagonIE_Sodium_Core_Util::strlen($message);
-
-        /** @var int  $clen - Length of ciphertext */
-        $clen = $len - self::aead_chacha20poly1305_IETF_ABYTES;
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core_ChaCha20::ietfStream(
-            32,
-            $nonce,
-            $key
-        );
-
-        /** @var string $mac - Message authentication code */
-        $mac = ParagonIE_Sodium_Core_Util::substr(
-            $message,
-            $len - self::aead_chacha20poly1305_IETF_ABYTES,
-            self::aead_chacha20poly1305_IETF_ABYTES
-        );
-
-        /** @var string $ciphertext - The encrypted message (sans MAC) */
-        $ciphertext = ParagonIE_Sodium_Core_Util::substr(
-            $message,
-            0,
-            $len - self::aead_chacha20poly1305_IETF_ABYTES
-        );
-
-        /* Recalculate the Poly1305 authentication tag (MAC): */
-        $state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-        $state->update($ad);
-        $state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
-        $state->update($ciphertext);
-        $state->update(str_repeat("\x00", (0x10 - $clen) & 0xf));
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($clen));
-        $computed_mac = $state->finish();
-
-        /* Compare the given MAC with the recalculated MAC: */
-        if (!ParagonIE_Sodium_Core_Util::verify_16($computed_mac, $mac)) {
-            throw new SodiumException('Invalid MAC');
-        }
-
-        // Here, we know that the MAC is valid, so we decrypt and return the plaintext
-        return ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            $ciphertext,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core_Util::store64_le(1)
-        );
-    }
-
-    /**
-     * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_ietf_encrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $len - Length of the plaintext message */
-        $len = ParagonIE_Sodium_Core_Util::strlen($message);
-
-        /** @var int $adlen - Length of the associated data */
-        $adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core_ChaCha20::ietfStream(
-            32,
-            $nonce,
-            $key
-        );
-        $state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-
-        /** @var string $ciphertext - Raw encrypted data */
-        $ciphertext = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            $message,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core_Util::store64_le(1)
-        );
-
-        $state->update($ad);
-        $state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
-        $state->update($ciphertext);
-        $state->update(str_repeat("\x00", ((0x10 - $len) & 0xf)));
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
-        $state->update(ParagonIE_Sodium_Core_Util::store64_le($len));
-        return $ciphertext . $state->finish();
-    }
-
-    /**
-     * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_xchacha20poly1305_ietf_decrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        $subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16),
-            $key
-        );
-        $nonceLast = "\x00\x00\x00\x00" .
-            ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
-
-        return self::aead_chacha20poly1305_ietf_decrypt($message, $ad, $nonceLast, $subkey);
-    }
-
-    /**
-     * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_xchacha20poly1305_ietf_encrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        $subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16),
-            $key
-        );
-        $nonceLast = "\x00\x00\x00\x00" .
-            ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
-
-        return self::aead_chacha20poly1305_ietf_encrypt($message, $ad, $nonceLast, $subkey);
-    }
-
-    /**
-     * HMAC-SHA-512-256 (a.k.a. the leftmost 256 bits of HMAC-SHA-512)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $key
-     * @return string
-     * @throws TypeError
-     */
-    public static function auth($message, $key)
-    {
-        return ParagonIE_Sodium_Core_Util::substr(
-            hash_hmac('sha512', $message, $key, true),
-            0,
-            32
-        );
-    }
-
-    /**
-     * HMAC-SHA-512-256 validation. Constant-time via hash_equals().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $mac
-     * @param string $message
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function auth_verify($mac, $message, $key)
-    {
-        return ParagonIE_Sodium_Core_Util::hashEquals(
-            $mac,
-            self::auth($message, $key)
-        );
-    }
-
-    /**
-     * X25519 key exchange followed by XSalsa20Poly1305 symmetric encryption
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $plaintext
-     * @param string $nonce
-     * @param string $keypair
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box($plaintext, $nonce, $keypair)
-    {
-        $c = self::secretbox(
-            $plaintext,
-            $nonce,
-            self::box_beforenm(
-                self::box_secretkey($keypair),
-                self::box_publickey($keypair)
-            )
-        );
-        return $c;
-    }
-
-    /**
-     * X25519-XSalsa20-Poly1305 with one ephemeral X25519 keypair.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $publicKey
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seal($message, $publicKey)
-    {
-        /** @var string $ephemeralKeypair */
-        $ephemeralKeypair = self::box_keypair();
-
-        /** @var string $ephemeralSK */
-        $ephemeralSK = self::box_secretkey($ephemeralKeypair);
-
-        /** @var string $ephemeralPK */
-        $ephemeralPK = self::box_publickey($ephemeralKeypair);
-
-        /** @var string $nonce */
-        $nonce = self::generichash(
-            $ephemeralPK . $publicKey,
-            '',
-            24
-        );
-
-        /** @var string $keypair - The combined keypair used in crypto_box() */
-        $keypair = self::box_keypair_from_secretkey_and_publickey($ephemeralSK, $publicKey);
-
-        /** @var string $ciphertext Ciphertext + MAC from crypto_box */
-        $ciphertext = self::box($message, $nonce, $keypair);
-        try {
-            ParagonIE_Sodium_Compat::memzero($ephemeralKeypair);
-            ParagonIE_Sodium_Compat::memzero($ephemeralSK);
-            ParagonIE_Sodium_Compat::memzero($nonce);
-        } catch (SodiumException $ex) {
-            $ephemeralKeypair = null;
-            $ephemeralSK = null;
-            $nonce = null;
-        }
-        return $ephemeralPK . $ciphertext;
-    }
-
-    /**
-     * Opens a message encrypted via box_seal().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $keypair
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seal_open($message, $keypair)
-    {
-        /** @var string $ephemeralPK */
-        $ephemeralPK = ParagonIE_Sodium_Core_Util::substr($message, 0, 32);
-
-        /** @var string $ciphertext (ciphertext + MAC) */
-        $ciphertext = ParagonIE_Sodium_Core_Util::substr($message, 32);
-
-        /** @var string $secretKey */
-        $secretKey = self::box_secretkey($keypair);
-
-        /** @var string $publicKey */
-        $publicKey = self::box_publickey($keypair);
-
-        /** @var string $nonce */
-        $nonce = self::generichash(
-            $ephemeralPK . $publicKey,
-            '',
-            24
-        );
-
-        /** @var string $keypair */
-        $keypair = self::box_keypair_from_secretkey_and_publickey($secretKey, $ephemeralPK);
-
-        /** @var string $m */
-        $m = self::box_open($ciphertext, $nonce, $keypair);
-        try {
-            ParagonIE_Sodium_Compat::memzero($secretKey);
-            ParagonIE_Sodium_Compat::memzero($ephemeralPK);
-            ParagonIE_Sodium_Compat::memzero($nonce);
-        } catch (SodiumException $ex) {
-            $secretKey = null;
-            $ephemeralPK = null;
-            $nonce = null;
-        }
-        return $m;
-    }
-
-    /**
-     * Used by crypto_box() to get the crypto_secretbox() key.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sk
-     * @param string $pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_beforenm($sk, $pk)
-    {
-        return ParagonIE_Sodium_Core_HSalsa20::hsalsa20(
-            str_repeat("\x00", 16),
-            self::scalarmult($sk, $pk)
-        );
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @return string
-     * @throws Exception
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_keypair()
-    {
-        $sKey = random_bytes(32);
-        $pKey = self::scalarmult_base($sKey);
-        return $sKey . $pKey;
-    }
-
-    /**
-     * @param string $seed
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seed_keypair($seed)
-    {
-        $sKey = ParagonIE_Sodium_Core_Util::substr(
-            hash('sha512', $seed, true),
-            0,
-            32
-        );
-        $pKey = self::scalarmult_base($sKey);
-        return $sKey . $pKey;
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sKey
-     * @param string $pKey
-     * @return string
-     * @throws TypeError
-     */
-    public static function box_keypair_from_secretkey_and_publickey($sKey, $pKey)
-    {
-        return ParagonIE_Sodium_Core_Util::substr($sKey, 0, 32) .
-            ParagonIE_Sodium_Core_Util::substr($pKey, 0, 32);
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $keypair
-     * @return string
-     * @throws RangeException
-     * @throws TypeError
-     */
-    public static function box_secretkey($keypair)
-    {
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== 64) {
-            throw new RangeException(
-                'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
-            );
-        }
-        return ParagonIE_Sodium_Core_Util::substr($keypair, 0, 32);
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $keypair
-     * @return string
-     * @throws RangeException
-     * @throws TypeError
-     */
-    public static function box_publickey($keypair)
-    {
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new RangeException(
-                'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
-            );
-        }
-        return ParagonIE_Sodium_Core_Util::substr($keypair, 32, 32);
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sKey
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_publickey_from_secretkey($sKey)
-    {
-        if (ParagonIE_Sodium_Core_Util::strlen($sKey) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new RangeException(
-                'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES bytes long.'
-            );
-        }
-        return self::scalarmult_base($sKey);
-    }
-
-    /**
-     * Decrypt a message encrypted with box().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ciphertext
-     * @param string $nonce
-     * @param string $keypair
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_open($ciphertext, $nonce, $keypair)
-    {
-        return self::secretbox_open(
-            $ciphertext,
-            $nonce,
-            self::box_beforenm(
-                self::box_secretkey($keypair),
-                self::box_publickey($keypair)
-            )
-        );
-    }
-
-    /**
-     * Calculate a BLAKE2b hash.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string|null $key
-     * @param int $outlen
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash($message, $key = '', $outlen = 32)
-    {
-        // This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
-
-        $k = null;
-        if (!empty($key)) {
-            /** @var SplFixedArray $k */
-            $k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);
-            if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {
-                throw new RangeException('Invalid key size');
-            }
-        }
-
-        /** @var SplFixedArray $in */
-        $in = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($message);
-
-        /** @var SplFixedArray $ctx */
-        $ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outlen);
-        ParagonIE_Sodium_Core_BLAKE2b::update($ctx, $in, $in->count());
-
-        /** @var SplFixedArray $out */
-        $out = new SplFixedArray($outlen);
-        $out = ParagonIE_Sodium_Core_BLAKE2b::finish($ctx, $out);
-
-        /** @var array<int, int> */
-        $outArray = $out->toArray();
-        return ParagonIE_Sodium_Core_Util::intArrayToString($outArray);
-    }
-
-    /**
-     * Finalize a BLAKE2b hashing context, returning the hash.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ctx
-     * @param int $outlen
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_final($ctx, $outlen = 32)
-    {
-        if (!is_string($ctx)) {
-            throw new TypeError('Context must be a string');
-        }
-        $out = new SplFixedArray($outlen);
-
-        /** @var SplFixedArray $context */
-        $context = ParagonIE_Sodium_Core_BLAKE2b::stringToContext($ctx);
-
-        /** @var SplFixedArray $out */
-        $out = ParagonIE_Sodium_Core_BLAKE2b::finish($context, $out);
-
-        /** @var array<int, int> */
-        $outArray = $out->toArray();
-        return ParagonIE_Sodium_Core_Util::intArrayToString($outArray);
-    }
-
-    /**
-     * Initialize a hashing context for BLAKE2b.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $key
-     * @param int $outputLength
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_init($key = '', $outputLength = 32)
-    {
-        // This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
-
-        $k = null;
-        if (!empty($key)) {
-            $k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);
-            if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {
-                throw new RangeException('Invalid key size');
-            }
-        }
-
-        /** @var SplFixedArray $ctx */
-        $ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outputLength);
-
-        return ParagonIE_Sodium_Core_BLAKE2b::contextToString($ctx);
-    }
-
-    /**
-     * Initialize a hashing context for BLAKE2b.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $key
-     * @param int $outputLength
-     * @param string $salt
-     * @param string $personal
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_init_salt_personal(
-        $key = '',
-        $outputLength = 32,
-        $salt = '',
-        $personal = ''
-    ) {
-        // This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
-
-        $k = null;
-        if (!empty($key)) {
-            $k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);
-            if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {
-                throw new RangeException('Invalid key size');
-            }
-        }
-        if (!empty($salt)) {
-            $s = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($salt);
-        } else {
-            $s = null;
-        }
-        if (!empty($salt)) {
-            $p = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($personal);
-        } else {
-            $p = null;
-        }
-
-        /** @var SplFixedArray $ctx */
-        $ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outputLength, $s, $p);
-
-        return ParagonIE_Sodium_Core_BLAKE2b::contextToString($ctx);
-    }
-
-    /**
-     * Update a hashing context for BLAKE2b with $message
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ctx
-     * @param string $message
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_update($ctx, $message)
-    {
-        // This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
-
-        /** @var SplFixedArray $context */
-        $context = ParagonIE_Sodium_Core_BLAKE2b::stringToContext($ctx);
-
-        /** @var SplFixedArray $in */
-        $in = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($message);
-
-        ParagonIE_Sodium_Core_BLAKE2b::update($context, $in, $in->count());
-
-        return ParagonIE_Sodium_Core_BLAKE2b::contextToString($context);
-    }
-
-    /**
-     * Libsodium's crypto_kx().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $my_sk
-     * @param string $their_pk
-     * @param string $client_pk
-     * @param string $server_pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function keyExchange($my_sk, $their_pk, $client_pk, $server_pk)
-    {
-        return ParagonIE_Sodium_Compat::crypto_generichash(
-            ParagonIE_Sodium_Compat::crypto_scalarmult($my_sk, $their_pk) .
-            $client_pk .
-            $server_pk
-        );
-    }
-
-    /**
-     * ECDH over Curve25519
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sKey
-     * @param string $pKey
-     * @return string
-     *
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function scalarmult($sKey, $pKey)
-    {
-        $q = ParagonIE_Sodium_Core_X25519::crypto_scalarmult_curve25519_ref10($sKey, $pKey);
-        self::scalarmult_throw_if_zero($q);
-        return $q;
-    }
-
-    /**
-     * ECDH over Curve25519, using the basepoint.
-     * Used to get a secret key from a public key.
-     *
-     * @param string $secret
-     * @return string
-     *
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function scalarmult_base($secret)
-    {
-        $q = ParagonIE_Sodium_Core_X25519::crypto_scalarmult_curve25519_ref10_base($secret);
-        self::scalarmult_throw_if_zero($q);
-        return $q;
-    }
-
-    /**
-     * This throws an Error if a zero public key was passed to the function.
-     *
-     * @param string $q
-     * @return void
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function scalarmult_throw_if_zero($q)
-    {
-        $d = 0;
-        for ($i = 0; $i < self::box_curve25519xsalsa20poly1305_SECRETKEYBYTES; ++$i) {
-            $d |= ParagonIE_Sodium_Core_Util::chrToInt($q[$i]);
-        }
-
-        /* branch-free variant of === 0 */
-        if (-(1 & (($d - 1) >> 8))) {
-            throw new SodiumException('Zero public key is not allowed');
-        }
-    }
-
-    /**
-     * XSalsa20-Poly1305 authenticated symmetric-key encryption.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $plaintext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox($plaintext, $nonce, $key)
-    {
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $block0 */
-        $block0 = str_repeat("\x00", 32);
-
-        /** @var int $mlen - Length of the plaintext message */
-        $mlen = ParagonIE_Sodium_Core_Util::strlen($plaintext);
-        $mlen0 = $mlen;
-        if ($mlen0 > 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES) {
-            $mlen0 = 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES;
-        }
-        $block0 .= ParagonIE_Sodium_Core_Util::substr($plaintext, 0, $mlen0);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core_Salsa20::salsa20_xor(
-            $block0,
-            ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core_Util::substr(
-            $block0,
-            self::secretbox_xsalsa20poly1305_ZEROBYTES
-        );
-        if ($mlen > $mlen0) {
-            $c .= ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
-                ParagonIE_Sodium_Core_Util::substr(
-                    $plaintext,
-                    self::secretbox_xsalsa20poly1305_ZEROBYTES
-                ),
-                ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-                1,
-                $subkey
-            );
-        }
-        $state = new ParagonIE_Sodium_Core_Poly1305_State(
-            ParagonIE_Sodium_Core_Util::substr(
-                $block0,
-                0,
-                self::onetimeauth_poly1305_KEYBYTES
-            )
-        );
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-            ParagonIE_Sodium_Compat::memzero($subkey);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-            $subkey = null;
-        }
-
-        $state->update($c);
-
-        /** @var string $c - MAC || ciphertext */
-        $c = $state->finish() . $c;
-        unset($state);
-
-        return $c;
-    }
-
-    /**
-     * Decrypt a ciphertext generated via secretbox().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ciphertext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_open($ciphertext, $nonce, $key)
-    {
-        /** @var string $mac */
-        $mac = ParagonIE_Sodium_Core_Util::substr(
-            $ciphertext,
-            0,
-            self::secretbox_xsalsa20poly1305_MACBYTES
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core_Util::substr(
-            $ciphertext,
-            self::secretbox_xsalsa20poly1305_MACBYTES
-        );
-
-        /** @var int $clen */
-        $clen = ParagonIE_Sodium_Core_Util::strlen($c);
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core_Salsa20::salsa20(
-            64,
-            ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-        $verified = ParagonIE_Sodium_Core_Poly1305::onetimeauth_verify(
-            $mac,
-            $c,
-            ParagonIE_Sodium_Core_Util::substr($block0, 0, 32)
-        );
-        if (!$verified) {
-            try {
-                ParagonIE_Sodium_Compat::memzero($subkey);
-            } catch (SodiumException $ex) {
-                $subkey = null;
-            }
-            throw new SodiumException('Invalid MAC');
-        }
-
-        /** @var string $m - Decrypted message */
-        $m = ParagonIE_Sodium_Core_Util::xorStrings(
-            ParagonIE_Sodium_Core_Util::substr($block0, self::secretbox_xsalsa20poly1305_ZEROBYTES),
-            ParagonIE_Sodium_Core_Util::substr($c, 0, self::secretbox_xsalsa20poly1305_ZEROBYTES)
-        );
-        if ($clen > self::secretbox_xsalsa20poly1305_ZEROBYTES) {
-            // We had more than 1 block, so let's continue to decrypt the rest.
-            $m .= ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
-                ParagonIE_Sodium_Core_Util::substr(
-                    $c,
-                    self::secretbox_xsalsa20poly1305_ZEROBYTES
-                ),
-                ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-                1,
-                (string) $subkey
-            );
-        }
-        return $m;
-    }
-
-    /**
-     * XChaCha20-Poly1305 authenticated symmetric-key encryption.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $plaintext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_xchacha20poly1305($plaintext, $nonce, $key)
-    {
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16),
-            $key
-        );
-        $nonceLast = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
-
-        /** @var string $block0 */
-        $block0 = str_repeat("\x00", 32);
-
-        /** @var int $mlen - Length of the plaintext message */
-        $mlen = ParagonIE_Sodium_Core_Util::strlen($plaintext);
-        $mlen0 = $mlen;
-        if ($mlen0 > 64 - self::secretbox_xchacha20poly1305_ZEROBYTES) {
-            $mlen0 = 64 - self::secretbox_xchacha20poly1305_ZEROBYTES;
-        }
-        $block0 .= ParagonIE_Sodium_Core_Util::substr($plaintext, 0, $mlen0);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
-            $block0,
-            $nonceLast,
-            $subkey
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core_Util::substr(
-            $block0,
-            self::secretbox_xchacha20poly1305_ZEROBYTES
-        );
-        if ($mlen > $mlen0) {
-            $c .= ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
-                ParagonIE_Sodium_Core_Util::substr(
-                    $plaintext,
-                    self::secretbox_xchacha20poly1305_ZEROBYTES
-                ),
-                $nonceLast,
-                $subkey,
-                ParagonIE_Sodium_Core_Util::store64_le(1)
-            );
-        }
-        $state = new ParagonIE_Sodium_Core_Poly1305_State(
-            ParagonIE_Sodium_Core_Util::substr(
-                $block0,
-                0,
-                self::onetimeauth_poly1305_KEYBYTES
-            )
-        );
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-            ParagonIE_Sodium_Compat::memzero($subkey);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-            $subkey = null;
-        }
-
-        $state->update($c);
-
-        /** @var string $c - MAC || ciphertext */
-        $c = $state->finish() . $c;
-        unset($state);
-
-        return $c;
-    }
-
-    /**
-     * Decrypt a ciphertext generated via secretbox_xchacha20poly1305().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ciphertext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key)
-    {
-        /** @var string $mac */
-        $mac = ParagonIE_Sodium_Core_Util::substr(
-            $ciphertext,
-            0,
-            self::secretbox_xchacha20poly1305_MACBYTES
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core_Util::substr(
-            $ciphertext,
-            self::secretbox_xchacha20poly1305_MACBYTES
-        );
-
-        /** @var int $clen */
-        $clen = ParagonIE_Sodium_Core_Util::strlen($c);
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core_HChaCha20::hchacha20($nonce, $key);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core_ChaCha20::stream(
-            64,
-            ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-        $verified = ParagonIE_Sodium_Core_Poly1305::onetimeauth_verify(
-            $mac,
-            $c,
-            ParagonIE_Sodium_Core_Util::substr($block0, 0, 32)
-        );
-
-        if (!$verified) {
-            try {
-                ParagonIE_Sodium_Compat::memzero($subkey);
-            } catch (SodiumException $ex) {
-                $subkey = null;
-            }
-            throw new SodiumException('Invalid MAC');
-        }
-
-        /** @var string $m - Decrypted message */
-        $m = ParagonIE_Sodium_Core_Util::xorStrings(
-            ParagonIE_Sodium_Core_Util::substr($block0, self::secretbox_xchacha20poly1305_ZEROBYTES),
-            ParagonIE_Sodium_Core_Util::substr($c, 0, self::secretbox_xchacha20poly1305_ZEROBYTES)
-        );
-
-        if ($clen > self::secretbox_xchacha20poly1305_ZEROBYTES) {
-            // We had more than 1 block, so let's continue to decrypt the rest.
-            $m .= ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
-                ParagonIE_Sodium_Core_Util::substr(
-                    $c,
-                    self::secretbox_xchacha20poly1305_ZEROBYTES
-                ),
-                ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-                (string) $subkey,
-                ParagonIE_Sodium_Core_Util::store64_le(1)
-            );
-        }
-        return $m;
-    }
-
-    /**
-     * @param string $key
-     * @return array<int, string> Returns a state and a header.
-     * @throws Exception
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_init_push($key)
-    {
-        # randombytes_buf(out, crypto_secretstream_xchacha20poly1305_HEADERBYTES);
-        $out = random_bytes(24);
-
-        # crypto_core_hchacha20(state->k, out, k, NULL);
-        $subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20($out, $key);
-        $state = new ParagonIE_Sodium_Core_SecretStream_State(
-            $subkey,
-            ParagonIE_Sodium_Core_Util::substr($out, 16, 8) . str_repeat("\0", 4)
-        );
-
-        # _crypto_secretstream_xchacha20poly1305_counter_reset(state);
-        $state->counterReset();
-
-        # memcpy(STATE_INONCE(state), out + crypto_core_hchacha20_INPUTBYTES,
-        #        crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        # memset(state->_pad, 0, sizeof state->_pad);
-        return array(
-            $state->toString(),
-            $out
-        );
-    }
-
-    /**
-     * @param string $key
-     * @param string $header
-     * @return string Returns a state.
-     * @throws Exception
-     */
-    public static function secretstream_xchacha20poly1305_init_pull($key, $header)
-    {
-        # crypto_core_hchacha20(state->k, in, k, NULL);
-        $subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core_Util::substr($header, 0, 16),
-            $key
-        );
-        $state = new ParagonIE_Sodium_Core_SecretStream_State(
-            $subkey,
-            ParagonIE_Sodium_Core_Util::substr($header, 16)
-        );
-        $state->counterReset();
-        # memcpy(STATE_INONCE(state), in + crypto_core_hchacha20_INPUTBYTES,
-        #     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        # memset(state->_pad, 0, sizeof state->_pad);
-        # return 0;
-        return $state->toString();
-    }
-
-    /**
-     * @param string $state
-     * @param string $msg
-     * @param string $aad
-     * @param int $tag
-     * @return string
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_push(&$state, $msg, $aad = '', $tag = 0)
-    {
-        $st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);
-        # crypto_onetimeauth_poly1305_state poly1305_state;
-        # unsigned char                     block[64U];
-        # unsigned char                     slen[8U];
-        # unsigned char                    *c;
-        # unsigned char                    *mac;
-
-        $msglen = ParagonIE_Sodium_Core_Util::strlen($msg);
-        $aadlen = ParagonIE_Sodium_Core_Util::strlen($aad);
-
-        if ((($msglen + 63) >> 6) > 0xfffffffe) {
-            throw new SodiumException(
-                'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
-            );
-        }
-
-        # if (outlen_p != NULL) {
-        #     *outlen_p = 0U;
-        # }
-        # if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
-        #     sodium_misuse();
-        # }
-
-        # crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
-        # crypto_onetimeauth_poly1305_init(&poly1305_state, block);
-        # sodium_memzero(block, sizeof block);
-        $auth = new ParagonIE_Sodium_Core_Poly1305_State(
-            ParagonIE_Sodium_Core_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
-        );
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
-        $auth->update($aad);
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
-        #     (0x10 - adlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
-
-        # memset(block, 0, sizeof block);
-        # block[0] = tag;
-        # crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
-        #                                    state->nonce, 1U, state->k);
-        $block = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            ParagonIE_Sodium_Core_Util::intToChr($tag) . str_repeat("\0", 63),
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core_Util::store64_le(1)
-        );
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
-        $auth->update($block);
-
-        # out[0] = block[0];
-        $out = $block[0];
-        # c = out + (sizeof tag);
-        # crypto_stream_chacha20_ietf_xor_ic(c, m, mlen, state->nonce, 2U, state->k);
-        $cipher = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            $msg,
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core_Util::store64_le(2)
-        );
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
-        $auth->update($cipher);
-
-        $out .= $cipher;
-        unset($cipher);
-
-        # crypto_onetimeauth_poly1305_update
-        # (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
-
-        # STORE64_LE(slen, (uint64_t) adlen);
-        $slen = ParagonIE_Sodium_Core_Util::store64_le($aadlen);
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $auth->update($slen);
-
-        # STORE64_LE(slen, (sizeof block) + mlen);
-        $slen = ParagonIE_Sodium_Core_Util::store64_le(64 + $msglen);
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $auth->update($slen);
-
-        # mac = c + mlen;
-        # crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
-        $mac = $auth->finish();
-        $out .= $mac;
-
-        # sodium_memzero(&poly1305_state, sizeof poly1305_state);
-        unset($auth);
-
-
-        # XOR_BUF(STATE_INONCE(state), mac,
-        #     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        $st->xorNonce($mac);
-
-        # sodium_increment(STATE_COUNTER(state),
-        #     crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
-        $st->incrementCounter();
-        // Overwrite by reference:
-        $state = $st->toString();
-
-        /** @var bool $rekey */
-        $rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
-        # if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
-        #     sodium_is_zero(STATE_COUNTER(state),
-        #         crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
-        #     crypto_secretstream_xchacha20poly1305_rekey(state);
-        # }
-        if ($rekey || $st->needsRekey()) {
-            // DO REKEY
-            self::secretstream_xchacha20poly1305_rekey($state);
-        }
-        # if (outlen_p != NULL) {
-        #     *outlen_p = crypto_secretstream_xchacha20poly1305_ABYTES + mlen;
-        # }
-        return $out;
-    }
-
-    /**
-     * @param string $state
-     * @param string $cipher
-     * @param string $aad
-     * @return bool|array{0: string, 1: int}
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_pull(&$state, $cipher, $aad = '')
-    {
-        $st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);
-
-        $cipherlen = ParagonIE_Sodium_Core_Util::strlen($cipher);
-        #     mlen = inlen - crypto_secretstream_xchacha20poly1305_ABYTES;
-        $msglen = $cipherlen - ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES;
-        $aadlen = ParagonIE_Sodium_Core_Util::strlen($aad);
-
-        #     if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
-        #         sodium_misuse();
-        #     }
-        if ((($msglen + 63) >> 6) > 0xfffffffe) {
-            throw new SodiumException(
-                'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
-            );
-        }
-
-        #     crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
-        #     crypto_onetimeauth_poly1305_init(&poly1305_state, block);
-        #     sodium_memzero(block, sizeof block);
-        $auth = new ParagonIE_Sodium_Core_Poly1305_State(
-            ParagonIE_Sodium_Core_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
-        );
-
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
-        $auth->update($aad);
-
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
-        #         (0x10 - adlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
-
-
-        #     memset(block, 0, sizeof block);
-        #     block[0] = in[0];
-        #     crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
-        #                                        state->nonce, 1U, state->k);
-        $block = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            $cipher[0] . str_repeat("\0", 63),
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core_Util::store64_le(1)
-        );
-        #     tag = block[0];
-        #     block[0] = in[0];
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
-        $tag = ParagonIE_Sodium_Core_Util::chrToInt($block[0]);
-        $block[0] = $cipher[0];
-        $auth->update($block);
-
-
-        #     c = in + (sizeof tag);
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
-        $auth->update(ParagonIE_Sodium_Core_Util::substr($cipher, 1, $msglen));
-
-        #     crypto_onetimeauth_poly1305_update
-        #     (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
-
-        #     STORE64_LE(slen, (uint64_t) adlen);
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $slen = ParagonIE_Sodium_Core_Util::store64_le($aadlen);
-        $auth->update($slen);
-
-        #     STORE64_LE(slen, (sizeof block) + mlen);
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $slen = ParagonIE_Sodium_Core_Util::store64_le(64 + $msglen);
-        $auth->update($slen);
-
-        #     crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
-        #     sodium_memzero(&poly1305_state, sizeof poly1305_state);
-        $mac = $auth->finish();
-
-        #     stored_mac = c + mlen;
-        #     if (sodium_memcmp(mac, stored_mac, sizeof mac) != 0) {
-        #     sodium_memzero(mac, sizeof mac);
-        #         return -1;
-        #     }
-
-        $stored = ParagonIE_Sodium_Core_Util::substr($cipher, $msglen + 1, 16);
-        if (!ParagonIE_Sodium_Core_Util::hashEquals($mac, $stored)) {
-            return false;
-        }
-
-        #     crypto_stream_chacha20_ietf_xor_ic(m, c, mlen, state->nonce, 2U, state->k);
-        $out = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            ParagonIE_Sodium_Core_Util::substr($cipher, 1, $msglen),
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core_Util::store64_le(2)
-        );
-
-        #     XOR_BUF(STATE_INONCE(state), mac,
-        #         crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        $st->xorNonce($mac);
-
-        #     sodium_increment(STATE_COUNTER(state),
-        #         crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
-        $st->incrementCounter();
-
-        #     if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
-        #         sodium_is_zero(STATE_COUNTER(state),
-        #             crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
-        #         crypto_secretstream_xchacha20poly1305_rekey(state);
-        #     }
-
-        // Overwrite by reference:
-        $state = $st->toString();
-
-        /** @var bool $rekey */
-        $rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
-        if ($rekey || $st->needsRekey()) {
-            // DO REKEY
-            self::secretstream_xchacha20poly1305_rekey($state);
-        }
-        return array($out, $tag);
-    }
-
-    /**
-     * @param string $state
-     * @return void
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_rekey(&$state)
-    {
-        $st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);
-        # unsigned char new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES +
-        # crypto_secretstream_xchacha20poly1305_INONCEBYTES];
-        # size_t        i;
-        # for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
-        #     new_key_and_inonce[i] = state->k[i];
-        # }
-        $new_key_and_inonce = $st->getKey();
-
-        # for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
-        #     new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i] =
-        #         STATE_INONCE(state)[i];
-        # }
-        $new_key_and_inonce .= ParagonIE_Sodium_Core_Util::substR($st->getNonce(), 0, 8);
-
-        # crypto_stream_chacha20_ietf_xor(new_key_and_inonce, new_key_and_inonce,
-        #                                 sizeof new_key_and_inonce,
-        #                                 state->nonce, state->k);
-
-        $st->rekey(ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
-            $new_key_and_inonce,
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core_Util::store64_le(0)
-        ));
-
-        # for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
-        #     state->k[i] = new_key_and_inonce[i];
-        # }
-        # for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
-        #     STATE_INONCE(state)[i] =
-        #          new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i];
-        # }
-        # _crypto_secretstream_xchacha20poly1305_counter_reset(state);
-        $st->counterReset();
-
-        $state = $st->toString();
-    }
-
-    /**
-     * Detached Ed25519 signature.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $sk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign_detached($message, $sk)
-    {
-        return ParagonIE_Sodium_Core_Ed25519::sign_detached($message, $sk);
-    }
-
-    /**
-     * Attached Ed25519 signature. (Returns a signed message.)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $sk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign($message, $sk)
-    {
-        return ParagonIE_Sodium_Core_Ed25519::sign($message, $sk);
-    }
-
-    /**
-     * Opens a signed message. If valid, returns the message.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $signedMessage
-     * @param string $pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign_open($signedMessage, $pk)
-    {
-        return ParagonIE_Sodium_Core_Ed25519::sign_open($signedMessage, $pk);
-    }
-
-    /**
-     * Verify a detached signature of a given message and public key.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $signature
-     * @param string $message
-     * @param string $pk
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign_verify_detached($signature, $message, $pk)
-    {
-        return ParagonIE_Sodium_Core_Ed25519::verify_detached($signature, $message, $pk);
-    }
+	const aead_chacha20poly1305_KEYBYTES = 32;
+	const aead_chacha20poly1305_NSECBYTES = 0;
+	const aead_chacha20poly1305_NPUBBYTES = 8;
+	const aead_chacha20poly1305_ABYTES = 16;
+
+	const aead_chacha20poly1305_IETF_KEYBYTES = 32;
+	const aead_chacha20poly1305_IETF_NSECBYTES = 0;
+	const aead_chacha20poly1305_IETF_NPUBBYTES = 12;
+	const aead_chacha20poly1305_IETF_ABYTES = 16;
+
+	const aead_xchacha20poly1305_IETF_KEYBYTES = 32;
+	const aead_xchacha20poly1305_IETF_NSECBYTES = 0;
+	const aead_xchacha20poly1305_IETF_NPUBBYTES = 24;
+	const aead_xchacha20poly1305_IETF_ABYTES = 16;
+
+	const box_curve25519xsalsa20poly1305_SEEDBYTES = 32;
+	const box_curve25519xsalsa20poly1305_PUBLICKEYBYTES = 32;
+	const box_curve25519xsalsa20poly1305_SECRETKEYBYTES = 32;
+	const box_curve25519xsalsa20poly1305_BEFORENMBYTES = 32;
+	const box_curve25519xsalsa20poly1305_NONCEBYTES = 24;
+	const box_curve25519xsalsa20poly1305_MACBYTES = 16;
+	const box_curve25519xsalsa20poly1305_BOXZEROBYTES = 16;
+	const box_curve25519xsalsa20poly1305_ZEROBYTES = 32;
+
+	const onetimeauth_poly1305_BYTES = 16;
+	const onetimeauth_poly1305_KEYBYTES = 32;
+
+	const secretbox_xsalsa20poly1305_KEYBYTES = 32;
+	const secretbox_xsalsa20poly1305_NONCEBYTES = 24;
+	const secretbox_xsalsa20poly1305_MACBYTES = 16;
+	const secretbox_xsalsa20poly1305_BOXZEROBYTES = 16;
+	const secretbox_xsalsa20poly1305_ZEROBYTES = 32;
+
+	const secretbox_xchacha20poly1305_KEYBYTES = 32;
+	const secretbox_xchacha20poly1305_NONCEBYTES = 24;
+	const secretbox_xchacha20poly1305_MACBYTES = 16;
+	const secretbox_xchacha20poly1305_BOXZEROBYTES = 16;
+	const secretbox_xchacha20poly1305_ZEROBYTES = 32;
+
+	const stream_salsa20_KEYBYTES = 32;
+
+	/**
+	 * AEAD Decryption with ChaCha20-Poly1305
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_decrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $len - Length of message (ciphertext + MAC) */
+		$len = ParagonIE_Sodium_Core_Util::strlen($message);
+
+		/** @var int  $clen - Length of ciphertext */
+		$clen = $len - self::aead_chacha20poly1305_ABYTES;
+
+		/** @var int $adlen - Length of associated data */
+		$adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
+
+		/** @var string $mac - Message authentication code */
+		$mac = ParagonIE_Sodium_Core_Util::substr(
+			$message,
+			$clen,
+			self::aead_chacha20poly1305_ABYTES
+		);
+
+		/** @var string $ciphertext - The encrypted message (sans MAC) */
+		$ciphertext = ParagonIE_Sodium_Core_Util::substr($message, 0, $clen);
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core_ChaCha20::stream(
+			32,
+			$nonce,
+			$key
+		);
+
+		/* Recalculate the Poly1305 authentication tag (MAC): */
+		$state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+		$state->update($ad);
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
+		$state->update($ciphertext);
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($clen));
+		$computed_mac = $state->finish();
+
+		/* Compare the given MAC with the recalculated MAC: */
+		if (!ParagonIE_Sodium_Core_Util::verify_16($computed_mac, $mac)) {
+			throw new SodiumException('Invalid MAC');
+		}
+
+		// Here, we know that the MAC is valid, so we decrypt and return the plaintext
+		return ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
+			$ciphertext,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core_Util::store64_le(1)
+		);
+	}
+
+	/**
+	 * AEAD Encryption with ChaCha20-Poly1305
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_encrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $len - Length of the plaintext message */
+		$len = ParagonIE_Sodium_Core_Util::strlen($message);
+
+		/** @var int $adlen - Length of the associated data */
+		$adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core_ChaCha20::stream(
+			32,
+			$nonce,
+			$key
+		);
+		$state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+
+		/** @var string $ciphertext - Raw encrypted data */
+		$ciphertext = ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
+			$message,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core_Util::store64_le(1)
+		);
+
+		$state->update($ad);
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
+		$state->update($ciphertext);
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($len));
+		return $ciphertext . $state->finish();
+	}
+
+	/**
+	 * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_ietf_decrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $adlen - Length of associated data */
+		$adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
+
+		/** @var int $len - Length of message (ciphertext + MAC) */
+		$len = ParagonIE_Sodium_Core_Util::strlen($message);
+
+		/** @var int  $clen - Length of ciphertext */
+		$clen = $len - self::aead_chacha20poly1305_IETF_ABYTES;
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core_ChaCha20::ietfStream(
+			32,
+			$nonce,
+			$key
+		);
+
+		/** @var string $mac - Message authentication code */
+		$mac = ParagonIE_Sodium_Core_Util::substr(
+			$message,
+			$len - self::aead_chacha20poly1305_IETF_ABYTES,
+			self::aead_chacha20poly1305_IETF_ABYTES
+		);
+
+		/** @var string $ciphertext - The encrypted message (sans MAC) */
+		$ciphertext = ParagonIE_Sodium_Core_Util::substr(
+			$message,
+			0,
+			$len - self::aead_chacha20poly1305_IETF_ABYTES
+		);
+
+		/* Recalculate the Poly1305 authentication tag (MAC): */
+		$state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+		$state->update($ad);
+		$state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
+		$state->update($ciphertext);
+		$state->update(str_repeat("\x00", (0x10 - $clen) & 0xf));
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($clen));
+		$computed_mac = $state->finish();
+
+		/* Compare the given MAC with the recalculated MAC: */
+		if (!ParagonIE_Sodium_Core_Util::verify_16($computed_mac, $mac)) {
+			throw new SodiumException('Invalid MAC');
+		}
+
+		// Here, we know that the MAC is valid, so we decrypt and return the plaintext
+		return ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			$ciphertext,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core_Util::store64_le(1)
+		);
+	}
+
+	/**
+	 * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_ietf_encrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $len - Length of the plaintext message */
+		$len = ParagonIE_Sodium_Core_Util::strlen($message);
+
+		/** @var int $adlen - Length of the associated data */
+		$adlen = ParagonIE_Sodium_Core_Util::strlen($ad);
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core_ChaCha20::ietfStream(
+			32,
+			$nonce,
+			$key
+		);
+		$state = new ParagonIE_Sodium_Core_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+
+		/** @var string $ciphertext - Raw encrypted data */
+		$ciphertext = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			$message,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core_Util::store64_le(1)
+		);
+
+		$state->update($ad);
+		$state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
+		$state->update($ciphertext);
+		$state->update(str_repeat("\x00", ((0x10 - $len) & 0xf)));
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($adlen));
+		$state->update(ParagonIE_Sodium_Core_Util::store64_le($len));
+		return $ciphertext . $state->finish();
+	}
+
+	/**
+	 * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_xchacha20poly1305_ietf_decrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		$subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16),
+			$key
+		);
+		$nonceLast = "\x00\x00\x00\x00" .
+			ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
+
+		return self::aead_chacha20poly1305_ietf_decrypt($message, $ad, $nonceLast, $subkey);
+	}
+
+	/**
+	 * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_xchacha20poly1305_ietf_encrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		$subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16),
+			$key
+		);
+		$nonceLast = "\x00\x00\x00\x00" .
+			ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
+
+		return self::aead_chacha20poly1305_ietf_encrypt($message, $ad, $nonceLast, $subkey);
+	}
+
+	/**
+	 * HMAC-SHA-512-256 (a.k.a. the leftmost 256 bits of HMAC-SHA-512)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $key
+	 * @return string
+	 * @throws TypeError
+	 */
+	public static function auth($message, $key)
+	{
+		return ParagonIE_Sodium_Core_Util::substr(
+			hash_hmac('sha512', $message, $key, true),
+			0,
+			32
+		);
+	}
+
+	/**
+	 * HMAC-SHA-512-256 validation. Constant-time via hash_equals().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $mac
+	 * @param string $message
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function auth_verify($mac, $message, $key)
+	{
+		return ParagonIE_Sodium_Core_Util::hashEquals(
+			$mac,
+			self::auth($message, $key)
+		);
+	}
+
+	/**
+	 * X25519 key exchange followed by XSalsa20Poly1305 symmetric encryption
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $plaintext
+	 * @param string $nonce
+	 * @param string $keypair
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box($plaintext, $nonce, $keypair)
+	{
+		$c = self::secretbox(
+			$plaintext,
+			$nonce,
+			self::box_beforenm(
+				self::box_secretkey($keypair),
+				self::box_publickey($keypair)
+			)
+		);
+		return $c;
+	}
+
+	/**
+	 * X25519-XSalsa20-Poly1305 with one ephemeral X25519 keypair.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $publicKey
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seal($message, $publicKey)
+	{
+		/** @var string $ephemeralKeypair */
+		$ephemeralKeypair = self::box_keypair();
+
+		/** @var string $ephemeralSK */
+		$ephemeralSK = self::box_secretkey($ephemeralKeypair);
+
+		/** @var string $ephemeralPK */
+		$ephemeralPK = self::box_publickey($ephemeralKeypair);
+
+		/** @var string $nonce */
+		$nonce = self::generichash(
+			$ephemeralPK . $publicKey,
+			'',
+			24
+		);
+
+		/** @var string $keypair - The combined keypair used in crypto_box() */
+		$keypair = self::box_keypair_from_secretkey_and_publickey($ephemeralSK, $publicKey);
+
+		/** @var string $ciphertext Ciphertext + MAC from crypto_box */
+		$ciphertext = self::box($message, $nonce, $keypair);
+		try {
+			ParagonIE_Sodium_Compat::memzero($ephemeralKeypair);
+			ParagonIE_Sodium_Compat::memzero($ephemeralSK);
+			ParagonIE_Sodium_Compat::memzero($nonce);
+		} catch (SodiumException $ex) {
+			$ephemeralKeypair = null;
+			$ephemeralSK = null;
+			$nonce = null;
+		}
+		return $ephemeralPK . $ciphertext;
+	}
+
+	/**
+	 * Opens a message encrypted via box_seal().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $keypair
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seal_open($message, $keypair)
+	{
+		/** @var string $ephemeralPK */
+		$ephemeralPK = ParagonIE_Sodium_Core_Util::substr($message, 0, 32);
+
+		/** @var string $ciphertext (ciphertext + MAC) */
+		$ciphertext = ParagonIE_Sodium_Core_Util::substr($message, 32);
+
+		/** @var string $secretKey */
+		$secretKey = self::box_secretkey($keypair);
+
+		/** @var string $publicKey */
+		$publicKey = self::box_publickey($keypair);
+
+		/** @var string $nonce */
+		$nonce = self::generichash(
+			$ephemeralPK . $publicKey,
+			'',
+			24
+		);
+
+		/** @var string $keypair */
+		$keypair = self::box_keypair_from_secretkey_and_publickey($secretKey, $ephemeralPK);
+
+		/** @var string $m */
+		$m = self::box_open($ciphertext, $nonce, $keypair);
+		try {
+			ParagonIE_Sodium_Compat::memzero($secretKey);
+			ParagonIE_Sodium_Compat::memzero($ephemeralPK);
+			ParagonIE_Sodium_Compat::memzero($nonce);
+		} catch (SodiumException $ex) {
+			$secretKey = null;
+			$ephemeralPK = null;
+			$nonce = null;
+		}
+		return $m;
+	}
+
+	/**
+	 * Used by crypto_box() to get the crypto_secretbox() key.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sk
+	 * @param string $pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_beforenm($sk, $pk)
+	{
+		return ParagonIE_Sodium_Core_HSalsa20::hsalsa20(
+			str_repeat("\x00", 16),
+			self::scalarmult($sk, $pk)
+		);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_keypair()
+	{
+		$sKey = random_bytes(32);
+		$pKey = self::scalarmult_base($sKey);
+		return $sKey . $pKey;
+	}
+
+	/**
+	 * @param string $seed
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seed_keypair($seed)
+	{
+		$sKey = ParagonIE_Sodium_Core_Util::substr(
+			hash('sha512', $seed, true),
+			0,
+			32
+		);
+		$pKey = self::scalarmult_base($sKey);
+		return $sKey . $pKey;
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sKey
+	 * @param string $pKey
+	 * @return string
+	 * @throws TypeError
+	 */
+	public static function box_keypair_from_secretkey_and_publickey($sKey, $pKey)
+	{
+		return ParagonIE_Sodium_Core_Util::substr($sKey, 0, 32) .
+			ParagonIE_Sodium_Core_Util::substr($pKey, 0, 32);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $keypair
+	 * @return string
+	 * @throws RangeException
+	 * @throws TypeError
+	 */
+	public static function box_secretkey($keypair)
+	{
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== 64) {
+			throw new RangeException(
+				'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
+			);
+		}
+		return ParagonIE_Sodium_Core_Util::substr($keypair, 0, 32);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $keypair
+	 * @return string
+	 * @throws RangeException
+	 * @throws TypeError
+	 */
+	public static function box_publickey($keypair)
+	{
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new RangeException(
+				'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
+			);
+		}
+		return ParagonIE_Sodium_Core_Util::substr($keypair, 32, 32);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sKey
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_publickey_from_secretkey($sKey)
+	{
+		if (ParagonIE_Sodium_Core_Util::strlen($sKey) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new RangeException(
+				'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES bytes long.'
+			);
+		}
+		return self::scalarmult_base($sKey);
+	}
+
+	/**
+	 * Decrypt a message encrypted with box().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ciphertext
+	 * @param string $nonce
+	 * @param string $keypair
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_open($ciphertext, $nonce, $keypair)
+	{
+		return self::secretbox_open(
+			$ciphertext,
+			$nonce,
+			self::box_beforenm(
+				self::box_secretkey($keypair),
+				self::box_publickey($keypair)
+			)
+		);
+	}
+
+	/**
+	 * Calculate a BLAKE2b hash.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string|null $key
+	 * @param int $outlen
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash($message, $key = '', $outlen = 32)
+	{
+		// This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
+
+		$k = null;
+		if (!empty($key)) {
+			/** @var SplFixedArray $k */
+			$k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);
+			if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {
+				throw new RangeException('Invalid key size');
+			}
+		}
+
+		/** @var SplFixedArray $in */
+		$in = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($message);
+
+		/** @var SplFixedArray $ctx */
+		$ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outlen);
+		ParagonIE_Sodium_Core_BLAKE2b::update($ctx, $in, $in->count());
+
+		/** @var SplFixedArray $out */
+		$out = new SplFixedArray($outlen);
+		$out = ParagonIE_Sodium_Core_BLAKE2b::finish($ctx, $out);
+
+		/** @var array<int, int> */
+		$outArray = $out->toArray();
+		return ParagonIE_Sodium_Core_Util::intArrayToString($outArray);
+	}
+
+	/**
+	 * Finalize a BLAKE2b hashing context, returning the hash.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ctx
+	 * @param int $outlen
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_final($ctx, $outlen = 32)
+	{
+		if (!is_string($ctx)) {
+			throw new TypeError('Context must be a string');
+		}
+		$out = new SplFixedArray($outlen);
+
+		/** @var SplFixedArray $context */
+		$context = ParagonIE_Sodium_Core_BLAKE2b::stringToContext($ctx);
+
+		/** @var SplFixedArray $out */
+		$out = ParagonIE_Sodium_Core_BLAKE2b::finish($context, $out);
+
+		/** @var array<int, int> */
+		$outArray = $out->toArray();
+		return ParagonIE_Sodium_Core_Util::intArrayToString($outArray);
+	}
+
+	/**
+	 * Initialize a hashing context for BLAKE2b.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $key
+	 * @param int $outputLength
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_init($key = '', $outputLength = 32)
+	{
+		// This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
+
+		$k = null;
+		if (!empty($key)) {
+			$k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);
+			if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {
+				throw new RangeException('Invalid key size');
+			}
+		}
+
+		/** @var SplFixedArray $ctx */
+		$ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outputLength);
+
+		return ParagonIE_Sodium_Core_BLAKE2b::contextToString($ctx);
+	}
+
+	/**
+	 * Initialize a hashing context for BLAKE2b.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $key
+	 * @param int $outputLength
+	 * @param string $salt
+	 * @param string $personal
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_init_salt_personal(
+		$key = '',
+		$outputLength = 32,
+		$salt = '',
+		$personal = ''
+	) {
+		// This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
+
+		$k = null;
+		if (!empty($key)) {
+			$k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);
+			if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {
+				throw new RangeException('Invalid key size');
+			}
+		}
+		if (!empty($salt)) {
+			$s = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($salt);
+		} else {
+			$s = null;
+		}
+		if (!empty($salt)) {
+			$p = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($personal);
+		} else {
+			$p = null;
+		}
+
+		/** @var SplFixedArray $ctx */
+		$ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outputLength, $s, $p);
+
+		return ParagonIE_Sodium_Core_BLAKE2b::contextToString($ctx);
+	}
+
+	/**
+	 * Update a hashing context for BLAKE2b with $message
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ctx
+	 * @param string $message
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_update($ctx, $message)
+	{
+		// This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();
+
+		/** @var SplFixedArray $context */
+		$context = ParagonIE_Sodium_Core_BLAKE2b::stringToContext($ctx);
+
+		/** @var SplFixedArray $in */
+		$in = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($message);
+
+		ParagonIE_Sodium_Core_BLAKE2b::update($context, $in, $in->count());
+
+		return ParagonIE_Sodium_Core_BLAKE2b::contextToString($context);
+	}
+
+	/**
+	 * Libsodium's crypto_kx().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $my_sk
+	 * @param string $their_pk
+	 * @param string $client_pk
+	 * @param string $server_pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function keyExchange($my_sk, $their_pk, $client_pk, $server_pk)
+	{
+		return ParagonIE_Sodium_Compat::crypto_generichash(
+			ParagonIE_Sodium_Compat::crypto_scalarmult($my_sk, $their_pk) .
+			$client_pk .
+			$server_pk
+		);
+	}
+
+	/**
+	 * ECDH over Curve25519
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sKey
+	 * @param string $pKey
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function scalarmult($sKey, $pKey)
+	{
+		$q = ParagonIE_Sodium_Core_X25519::crypto_scalarmult_curve25519_ref10($sKey, $pKey);
+		self::scalarmult_throw_if_zero($q);
+		return $q;
+	}
+
+	/**
+	 * ECDH over Curve25519, using the basepoint.
+	 * Used to get a secret key from a public key.
+	 *
+	 * @param string $secret
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function scalarmult_base($secret)
+	{
+		$q = ParagonIE_Sodium_Core_X25519::crypto_scalarmult_curve25519_ref10_base($secret);
+		self::scalarmult_throw_if_zero($q);
+		return $q;
+	}
+
+	/**
+	 * This throws an Error if a zero public key was passed to the function.
+	 *
+	 * @param string $q
+	 * @return void
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function scalarmult_throw_if_zero($q)
+	{
+		$d = 0;
+		for ($i = 0; $i < self::box_curve25519xsalsa20poly1305_SECRETKEYBYTES; ++$i) {
+			$d |= ParagonIE_Sodium_Core_Util::chrToInt($q[$i]);
+		}
+
+		/* branch-free variant of === 0 */
+		if (-(1 & (($d - 1) >> 8))) {
+			throw new SodiumException('Zero public key is not allowed');
+		}
+	}
+
+	/**
+	 * XSalsa20-Poly1305 authenticated symmetric-key encryption.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $plaintext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox($plaintext, $nonce, $key)
+	{
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $block0 */
+		$block0 = str_repeat("\x00", 32);
+
+		/** @var int $mlen - Length of the plaintext message */
+		$mlen = ParagonIE_Sodium_Core_Util::strlen($plaintext);
+		$mlen0 = $mlen;
+		if ($mlen0 > 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES) {
+			$mlen0 = 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES;
+		}
+		$block0 .= ParagonIE_Sodium_Core_Util::substr($plaintext, 0, $mlen0);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core_Salsa20::salsa20_xor(
+			$block0,
+			ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core_Util::substr(
+			$block0,
+			self::secretbox_xsalsa20poly1305_ZEROBYTES
+		);
+		if ($mlen > $mlen0) {
+			$c .= ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
+				ParagonIE_Sodium_Core_Util::substr(
+					$plaintext,
+					self::secretbox_xsalsa20poly1305_ZEROBYTES
+				),
+				ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+				1,
+				$subkey
+			);
+		}
+		$state = new ParagonIE_Sodium_Core_Poly1305_State(
+			ParagonIE_Sodium_Core_Util::substr(
+				$block0,
+				0,
+				self::onetimeauth_poly1305_KEYBYTES
+			)
+		);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+			ParagonIE_Sodium_Compat::memzero($subkey);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+			$subkey = null;
+		}
+
+		$state->update($c);
+
+		/** @var string $c - MAC || ciphertext */
+		$c = $state->finish() . $c;
+		unset($state);
+
+		return $c;
+	}
+
+	/**
+	 * Decrypt a ciphertext generated via secretbox().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ciphertext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_open($ciphertext, $nonce, $key)
+	{
+		/** @var string $mac */
+		$mac = ParagonIE_Sodium_Core_Util::substr(
+			$ciphertext,
+			0,
+			self::secretbox_xsalsa20poly1305_MACBYTES
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core_Util::substr(
+			$ciphertext,
+			self::secretbox_xsalsa20poly1305_MACBYTES
+		);
+
+		/** @var int $clen */
+		$clen = ParagonIE_Sodium_Core_Util::strlen($c);
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core_Salsa20::salsa20(
+			64,
+			ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+		$verified = ParagonIE_Sodium_Core_Poly1305::onetimeauth_verify(
+			$mac,
+			$c,
+			ParagonIE_Sodium_Core_Util::substr($block0, 0, 32)
+		);
+		if (!$verified) {
+			try {
+				ParagonIE_Sodium_Compat::memzero($subkey);
+			} catch (SodiumException $ex) {
+				$subkey = null;
+			}
+			throw new SodiumException('Invalid MAC');
+		}
+
+		/** @var string $m - Decrypted message */
+		$m = ParagonIE_Sodium_Core_Util::xorStrings(
+			ParagonIE_Sodium_Core_Util::substr($block0, self::secretbox_xsalsa20poly1305_ZEROBYTES),
+			ParagonIE_Sodium_Core_Util::substr($c, 0, self::secretbox_xsalsa20poly1305_ZEROBYTES)
+		);
+		if ($clen > self::secretbox_xsalsa20poly1305_ZEROBYTES) {
+			// We had more than 1 block, so let's continue to decrypt the rest.
+			$m .= ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
+				ParagonIE_Sodium_Core_Util::substr(
+					$c,
+					self::secretbox_xsalsa20poly1305_ZEROBYTES
+				),
+				ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+				1,
+				(string) $subkey
+			);
+		}
+		return $m;
+	}
+
+	/**
+	 * XChaCha20-Poly1305 authenticated symmetric-key encryption.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $plaintext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_xchacha20poly1305($plaintext, $nonce, $key)
+	{
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16),
+			$key
+		);
+		$nonceLast = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
+
+		/** @var string $block0 */
+		$block0 = str_repeat("\x00", 32);
+
+		/** @var int $mlen - Length of the plaintext message */
+		$mlen = ParagonIE_Sodium_Core_Util::strlen($plaintext);
+		$mlen0 = $mlen;
+		if ($mlen0 > 64 - self::secretbox_xchacha20poly1305_ZEROBYTES) {
+			$mlen0 = 64 - self::secretbox_xchacha20poly1305_ZEROBYTES;
+		}
+		$block0 .= ParagonIE_Sodium_Core_Util::substr($plaintext, 0, $mlen0);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
+			$block0,
+			$nonceLast,
+			$subkey
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core_Util::substr(
+			$block0,
+			self::secretbox_xchacha20poly1305_ZEROBYTES
+		);
+		if ($mlen > $mlen0) {
+			$c .= ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
+				ParagonIE_Sodium_Core_Util::substr(
+					$plaintext,
+					self::secretbox_xchacha20poly1305_ZEROBYTES
+				),
+				$nonceLast,
+				$subkey,
+				ParagonIE_Sodium_Core_Util::store64_le(1)
+			);
+		}
+		$state = new ParagonIE_Sodium_Core_Poly1305_State(
+			ParagonIE_Sodium_Core_Util::substr(
+				$block0,
+				0,
+				self::onetimeauth_poly1305_KEYBYTES
+			)
+		);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+			ParagonIE_Sodium_Compat::memzero($subkey);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+			$subkey = null;
+		}
+
+		$state->update($c);
+
+		/** @var string $c - MAC || ciphertext */
+		$c = $state->finish() . $c;
+		unset($state);
+
+		return $c;
+	}
+
+	/**
+	 * Decrypt a ciphertext generated via secretbox_xchacha20poly1305().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ciphertext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key)
+	{
+		/** @var string $mac */
+		$mac = ParagonIE_Sodium_Core_Util::substr(
+			$ciphertext,
+			0,
+			self::secretbox_xchacha20poly1305_MACBYTES
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core_Util::substr(
+			$ciphertext,
+			self::secretbox_xchacha20poly1305_MACBYTES
+		);
+
+		/** @var int $clen */
+		$clen = ParagonIE_Sodium_Core_Util::strlen($c);
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core_HChaCha20::hchacha20($nonce, $key);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core_ChaCha20::stream(
+			64,
+			ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+		$verified = ParagonIE_Sodium_Core_Poly1305::onetimeauth_verify(
+			$mac,
+			$c,
+			ParagonIE_Sodium_Core_Util::substr($block0, 0, 32)
+		);
+
+		if (!$verified) {
+			try {
+				ParagonIE_Sodium_Compat::memzero($subkey);
+			} catch (SodiumException $ex) {
+				$subkey = null;
+			}
+			throw new SodiumException('Invalid MAC');
+		}
+
+		/** @var string $m - Decrypted message */
+		$m = ParagonIE_Sodium_Core_Util::xorStrings(
+			ParagonIE_Sodium_Core_Util::substr($block0, self::secretbox_xchacha20poly1305_ZEROBYTES),
+			ParagonIE_Sodium_Core_Util::substr($c, 0, self::secretbox_xchacha20poly1305_ZEROBYTES)
+		);
+
+		if ($clen > self::secretbox_xchacha20poly1305_ZEROBYTES) {
+			// We had more than 1 block, so let's continue to decrypt the rest.
+			$m .= ParagonIE_Sodium_Core_ChaCha20::streamXorIc(
+				ParagonIE_Sodium_Core_Util::substr(
+					$c,
+					self::secretbox_xchacha20poly1305_ZEROBYTES
+				),
+				ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+				(string) $subkey,
+				ParagonIE_Sodium_Core_Util::store64_le(1)
+			);
+		}
+		return $m;
+	}
+
+	/**
+	 * @param string $key
+	 * @return array<int, string> Returns a state and a header.
+	 * @throws Exception
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_init_push($key)
+	{
+		# randombytes_buf(out, crypto_secretstream_xchacha20poly1305_HEADERBYTES);
+		$out = random_bytes(24);
+
+		# crypto_core_hchacha20(state->k, out, k, NULL);
+		$subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20($out, $key);
+		$state = new ParagonIE_Sodium_Core_SecretStream_State(
+			$subkey,
+			ParagonIE_Sodium_Core_Util::substr($out, 16, 8) . str_repeat("\0", 4)
+		);
+
+		# _crypto_secretstream_xchacha20poly1305_counter_reset(state);
+		$state->counterReset();
+
+		# memcpy(STATE_INONCE(state), out + crypto_core_hchacha20_INPUTBYTES,
+		#        crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		# memset(state->_pad, 0, sizeof state->_pad);
+		return array(
+			$state->toString(),
+			$out
+		);
+	}
+
+	/**
+	 * @param string $key
+	 * @param string $header
+	 * @return string Returns a state.
+	 * @throws Exception
+	 */
+	public static function secretstream_xchacha20poly1305_init_pull($key, $header)
+	{
+		# crypto_core_hchacha20(state->k, in, k, NULL);
+		$subkey = ParagonIE_Sodium_Core_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core_Util::substr($header, 0, 16),
+			$key
+		);
+		$state = new ParagonIE_Sodium_Core_SecretStream_State(
+			$subkey,
+			ParagonIE_Sodium_Core_Util::substr($header, 16)
+		);
+		$state->counterReset();
+		# memcpy(STATE_INONCE(state), in + crypto_core_hchacha20_INPUTBYTES,
+		#     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		# memset(state->_pad, 0, sizeof state->_pad);
+		# return 0;
+		return $state->toString();
+	}
+
+	/**
+	 * @param string $state
+	 * @param string $msg
+	 * @param string $aad
+	 * @param int $tag
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_push(&$state, $msg, $aad = '', $tag = 0)
+	{
+		$st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);
+		# crypto_onetimeauth_poly1305_state poly1305_state;
+		# unsigned char                     block[64U];
+		# unsigned char                     slen[8U];
+		# unsigned char                    *c;
+		# unsigned char                    *mac;
+
+		$msglen = ParagonIE_Sodium_Core_Util::strlen($msg);
+		$aadlen = ParagonIE_Sodium_Core_Util::strlen($aad);
+
+		if ((($msglen + 63) >> 6) > 0xfffffffe) {
+			throw new SodiumException(
+				'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
+			);
+		}
+
+		# if (outlen_p != NULL) {
+		#     *outlen_p = 0U;
+		# }
+		# if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
+		#     sodium_misuse();
+		# }
+
+		# crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
+		# crypto_onetimeauth_poly1305_init(&poly1305_state, block);
+		# sodium_memzero(block, sizeof block);
+		$auth = new ParagonIE_Sodium_Core_Poly1305_State(
+			ParagonIE_Sodium_Core_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
+		);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
+		$auth->update($aad);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
+		#     (0x10 - adlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
+
+		# memset(block, 0, sizeof block);
+		# block[0] = tag;
+		# crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
+		#                                    state->nonce, 1U, state->k);
+		$block = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			ParagonIE_Sodium_Core_Util::intToChr($tag) . str_repeat("\0", 63),
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core_Util::store64_le(1)
+		);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
+		$auth->update($block);
+
+		# out[0] = block[0];
+		$out = $block[0];
+		# c = out + (sizeof tag);
+		# crypto_stream_chacha20_ietf_xor_ic(c, m, mlen, state->nonce, 2U, state->k);
+		$cipher = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			$msg,
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core_Util::store64_le(2)
+		);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
+		$auth->update($cipher);
+
+		$out .= $cipher;
+		unset($cipher);
+
+		# crypto_onetimeauth_poly1305_update
+		# (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
+
+		# STORE64_LE(slen, (uint64_t) adlen);
+		$slen = ParagonIE_Sodium_Core_Util::store64_le($aadlen);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$auth->update($slen);
+
+		# STORE64_LE(slen, (sizeof block) + mlen);
+		$slen = ParagonIE_Sodium_Core_Util::store64_le(64 + $msglen);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$auth->update($slen);
+
+		# mac = c + mlen;
+		# crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
+		$mac = $auth->finish();
+		$out .= $mac;
+
+		# sodium_memzero(&poly1305_state, sizeof poly1305_state);
+		unset($auth);
+
+
+		# XOR_BUF(STATE_INONCE(state), mac,
+		#     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		$st->xorNonce($mac);
+
+		# sodium_increment(STATE_COUNTER(state),
+		#     crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
+		$st->incrementCounter();
+		// Overwrite by reference:
+		$state = $st->toString();
+
+		/** @var bool $rekey */
+		$rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
+		# if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
+		#     sodium_is_zero(STATE_COUNTER(state),
+		#         crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
+		#     crypto_secretstream_xchacha20poly1305_rekey(state);
+		# }
+		if ($rekey || $st->needsRekey()) {
+			// DO REKEY
+			self::secretstream_xchacha20poly1305_rekey($state);
+		}
+		# if (outlen_p != NULL) {
+		#     *outlen_p = crypto_secretstream_xchacha20poly1305_ABYTES + mlen;
+		# }
+		return $out;
+	}
+
+	/**
+	 * @param string $state
+	 * @param string $cipher
+	 * @param string $aad
+	 * @return bool|array{0: string, 1: int}
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_pull(&$state, $cipher, $aad = '')
+	{
+		$st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);
+
+		$cipherlen = ParagonIE_Sodium_Core_Util::strlen($cipher);
+		#     mlen = inlen - crypto_secretstream_xchacha20poly1305_ABYTES;
+		$msglen = $cipherlen - ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES;
+		$aadlen = ParagonIE_Sodium_Core_Util::strlen($aad);
+
+		#     if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
+		#         sodium_misuse();
+		#     }
+		if ((($msglen + 63) >> 6) > 0xfffffffe) {
+			throw new SodiumException(
+				'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
+			);
+		}
+
+		#     crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
+		#     crypto_onetimeauth_poly1305_init(&poly1305_state, block);
+		#     sodium_memzero(block, sizeof block);
+		$auth = new ParagonIE_Sodium_Core_Poly1305_State(
+			ParagonIE_Sodium_Core_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
+		);
+
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
+		$auth->update($aad);
+
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
+		#         (0x10 - adlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
+
+
+		#     memset(block, 0, sizeof block);
+		#     block[0] = in[0];
+		#     crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
+		#                                        state->nonce, 1U, state->k);
+		$block = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			$cipher[0] . str_repeat("\0", 63),
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core_Util::store64_le(1)
+		);
+		#     tag = block[0];
+		#     block[0] = in[0];
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
+		$tag = ParagonIE_Sodium_Core_Util::chrToInt($block[0]);
+		$block[0] = $cipher[0];
+		$auth->update($block);
+
+
+		#     c = in + (sizeof tag);
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
+		$auth->update(ParagonIE_Sodium_Core_Util::substr($cipher, 1, $msglen));
+
+		#     crypto_onetimeauth_poly1305_update
+		#     (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
+
+		#     STORE64_LE(slen, (uint64_t) adlen);
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$slen = ParagonIE_Sodium_Core_Util::store64_le($aadlen);
+		$auth->update($slen);
+
+		#     STORE64_LE(slen, (sizeof block) + mlen);
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$slen = ParagonIE_Sodium_Core_Util::store64_le(64 + $msglen);
+		$auth->update($slen);
+
+		#     crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
+		#     sodium_memzero(&poly1305_state, sizeof poly1305_state);
+		$mac = $auth->finish();
+
+		#     stored_mac = c + mlen;
+		#     if (sodium_memcmp(mac, stored_mac, sizeof mac) != 0) {
+		#     sodium_memzero(mac, sizeof mac);
+		#         return -1;
+		#     }
+
+		$stored = ParagonIE_Sodium_Core_Util::substr($cipher, $msglen + 1, 16);
+		if (!ParagonIE_Sodium_Core_Util::hashEquals($mac, $stored)) {
+			return false;
+		}
+
+		#     crypto_stream_chacha20_ietf_xor_ic(m, c, mlen, state->nonce, 2U, state->k);
+		$out = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			ParagonIE_Sodium_Core_Util::substr($cipher, 1, $msglen),
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core_Util::store64_le(2)
+		);
+
+		#     XOR_BUF(STATE_INONCE(state), mac,
+		#         crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		$st->xorNonce($mac);
+
+		#     sodium_increment(STATE_COUNTER(state),
+		#         crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
+		$st->incrementCounter();
+
+		#     if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
+		#         sodium_is_zero(STATE_COUNTER(state),
+		#             crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
+		#         crypto_secretstream_xchacha20poly1305_rekey(state);
+		#     }
+
+		// Overwrite by reference:
+		$state = $st->toString();
+
+		/** @var bool $rekey */
+		$rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
+		if ($rekey || $st->needsRekey()) {
+			// DO REKEY
+			self::secretstream_xchacha20poly1305_rekey($state);
+		}
+		return array($out, $tag);
+	}
+
+	/**
+	 * @param string $state
+	 * @return void
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_rekey(&$state)
+	{
+		$st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);
+		# unsigned char new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES +
+		# crypto_secretstream_xchacha20poly1305_INONCEBYTES];
+		# size_t        i;
+		# for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
+		#     new_key_and_inonce[i] = state->k[i];
+		# }
+		$new_key_and_inonce = $st->getKey();
+
+		# for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
+		#     new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i] =
+		#         STATE_INONCE(state)[i];
+		# }
+		$new_key_and_inonce .= ParagonIE_Sodium_Core_Util::substR($st->getNonce(), 0, 8);
+
+		# crypto_stream_chacha20_ietf_xor(new_key_and_inonce, new_key_and_inonce,
+		#                                 sizeof new_key_and_inonce,
+		#                                 state->nonce, state->k);
+
+		$st->rekey(ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
+			$new_key_and_inonce,
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core_Util::store64_le(0)
+		));
+
+		# for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
+		#     state->k[i] = new_key_and_inonce[i];
+		# }
+		# for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
+		#     STATE_INONCE(state)[i] =
+		#          new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i];
+		# }
+		# _crypto_secretstream_xchacha20poly1305_counter_reset(state);
+		$st->counterReset();
+
+		$state = $st->toString();
+	}
+
+	/**
+	 * Detached Ed25519 signature.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $sk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign_detached($message, $sk)
+	{
+		return ParagonIE_Sodium_Core_Ed25519::sign_detached($message, $sk);
+	}
+
+	/**
+	 * Attached Ed25519 signature. (Returns a signed message.)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $sk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign($message, $sk)
+	{
+		return ParagonIE_Sodium_Core_Ed25519::sign($message, $sk);
+	}
+
+	/**
+	 * Opens a signed message. If valid, returns the message.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $signedMessage
+	 * @param string $pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign_open($signedMessage, $pk)
+	{
+		return ParagonIE_Sodium_Core_Ed25519::sign_open($signedMessage, $pk);
+	}
+
+	/**
+	 * Verify a detached signature of a given message and public key.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $signature
+	 * @param string $message
+	 * @param string $pk
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign_verify_detached($signature, $message, $pk)
+	{
+		return ParagonIE_Sodium_Core_Ed25519::verify_detached($signature, $message, $pk);
+	}
 }

vendor/paragonie/sodium_compat/src/File.php

Indentation +1532 added lines, -1532 removed lines

@@ -1,1560 +1,1560 @@
 <?php
 
 if (class_exists('ParagonIE_Sodium_File', false)) {
-    return;
+	return;
 }
 /**
  * Class ParagonIE_Sodium_File
  */
 class ParagonIE_Sodium_File extends ParagonIE_Sodium_Core_Util
 {
-    /* PHP's default buffer size is 8192 for fread()/fwrite(). */
-    const BUFFER_SIZE = 8192;
-
-    /**
-     * Box a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_box(), but produces
-     * the same result.
-     *
-     * @param string $inputFile  Absolute path to a file on the filesystem
-     * @param string $outputFile Absolute path to a file on the filesystem
-     * @param string $nonce      Number to be used only once
-     * @param string $keyPair    ECDH secret key and ECDH public key concatenated
-     *
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box($inputFile, $outputFile, $nonce, $keyPair)
-    {
-        /* Type checks: */
-        if (!is_string($inputFile)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
-        }
-        if (!is_string($outputFile)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
-        }
-        if (!is_string($nonce)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
-        }
-
-        /* Input validation: */
-        if (!is_string($keyPair)) {
-            throw new TypeError('Argument 4 must be a string, ' . gettype($keyPair) . ' given.');
-        }
-        if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_NONCEBYTES) {
-            throw new TypeError('Argument 3 must be CRYPTO_BOX_NONCEBYTES bytes');
-        }
-        if (self::strlen($keyPair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new TypeError('Argument 4 must be CRYPTO_BOX_KEYPAIRBYTES bytes');
-        }
-
-        /** @var int $size */
-        $size = filesize($inputFile);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $ifp */
-        $ifp = fopen($inputFile, 'rb');
-        if (!is_resource($ifp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var resource $ofp */
-        $ofp = fopen($outputFile, 'wb');
-        if (!is_resource($ofp)) {
-            fclose($ifp);
-            throw new SodiumException('Could not open output file for writing');
-        }
-
-        $res = self::box_encrypt($ifp, $ofp, $size, $nonce, $keyPair);
-        fclose($ifp);
-        fclose($ofp);
-        return $res;
-    }
-
-    /**
-     * Open a boxed file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_box_open(), but produces
-     * the same result.
-     *
-     * Warning: Does not protect against TOCTOU attacks. You should
-     * just load the file into memory and use crypto_box_open() if
-     * you are worried about those.
-     *
-     * @param string $inputFile
-     * @param string $outputFile
-     * @param string $nonce
-     * @param string $keypair
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_open($inputFile, $outputFile, $nonce, $keypair)
-    {
-        /* Type checks: */
-        if (!is_string($inputFile)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
-        }
-        if (!is_string($outputFile)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
-        }
-        if (!is_string($nonce)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
-        }
-        if (!is_string($keypair)) {
-            throw new TypeError('Argument 4 must be a string, ' . gettype($keypair) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_NONCEBYTES) {
-            throw new TypeError('Argument 4 must be CRYPTO_BOX_NONCEBYTES bytes');
-        }
-        if (self::strlen($keypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new TypeError('Argument 4 must be CRYPTO_BOX_KEYPAIRBYTES bytes');
-        }
-
-        /** @var int $size */
-        $size = filesize($inputFile);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $ifp */
-        $ifp = fopen($inputFile, 'rb');
-        if (!is_resource($ifp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var resource $ofp */
-        $ofp = fopen($outputFile, 'wb');
-        if (!is_resource($ofp)) {
-            fclose($ifp);
-            throw new SodiumException('Could not open output file for writing');
-        }
-
-        $res = self::box_decrypt($ifp, $ofp, $size, $nonce, $keypair);
-        fclose($ifp);
-        fclose($ofp);
-        try {
-            ParagonIE_Sodium_Compat::memzero($nonce);
-            ParagonIE_Sodium_Compat::memzero($ephKeypair);
-        } catch (SodiumException $ex) {
-            if (isset($ephKeypair)) {
-                unset($ephKeypair);
-            }
-        }
-        return $res;
-    }
-
-    /**
-     * Seal a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_box_seal(), but produces
-     * the same result.
-     *
-     * @param string $inputFile  Absolute path to a file on the filesystem
-     * @param string $outputFile Absolute path to a file on the filesystem
-     * @param string $publicKey  ECDH public key
-     *
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seal($inputFile, $outputFile, $publicKey)
-    {
-        /* Type checks: */
-        if (!is_string($inputFile)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
-        }
-        if (!is_string($outputFile)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
-        }
-        if (!is_string($publicKey)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($publicKey) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($publicKey) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new TypeError('Argument 3 must be CRYPTO_BOX_PUBLICKEYBYTES bytes');
-        }
-
-        /** @var int $size */
-        $size = filesize($inputFile);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $ifp */
-        $ifp = fopen($inputFile, 'rb');
-        if (!is_resource($ifp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var resource $ofp */
-        $ofp = fopen($outputFile, 'wb');
-        if (!is_resource($ofp)) {
-            fclose($ifp);
-            throw new SodiumException('Could not open output file for writing');
-        }
-
-        /** @var string $ephKeypair */
-        $ephKeypair = ParagonIE_Sodium_Compat::crypto_box_keypair();
-
-        /** @var string $msgKeypair */
-        $msgKeypair = ParagonIE_Sodium_Compat::crypto_box_keypair_from_secretkey_and_publickey(
-            ParagonIE_Sodium_Compat::crypto_box_secretkey($ephKeypair),
-            $publicKey
-        );
-
-        /** @var string $ephemeralPK */
-        $ephemeralPK = ParagonIE_Sodium_Compat::crypto_box_publickey($ephKeypair);
-
-        /** @var string $nonce */
-        $nonce = ParagonIE_Sodium_Compat::crypto_generichash(
-            $ephemeralPK . $publicKey,
-            '',
-            24
-        );
-
-        /** @var int $firstWrite */
-        $firstWrite = fwrite(
-            $ofp,
-            $ephemeralPK,
-            ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES
-        );
-        if (!is_int($firstWrite)) {
-            fclose($ifp);
-            fclose($ofp);
-            ParagonIE_Sodium_Compat::memzero($ephKeypair);
-            throw new SodiumException('Could not write to output file');
-        }
-        if ($firstWrite !== ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES) {
-            ParagonIE_Sodium_Compat::memzero($ephKeypair);
-            fclose($ifp);
-            fclose($ofp);
-            throw new SodiumException('Error writing public key to output file');
-        }
-
-        $res = self::box_encrypt($ifp, $ofp, $size, $nonce, $msgKeypair);
-        fclose($ifp);
-        fclose($ofp);
-        try {
-            ParagonIE_Sodium_Compat::memzero($nonce);
-            ParagonIE_Sodium_Compat::memzero($ephKeypair);
-        } catch (SodiumException $ex) {
-            /** @psalm-suppress PossiblyUndefinedVariable */
-            unset($ephKeypair);
-        }
-        return $res;
-    }
-
-    /**
-     * Open a sealed file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_box_seal_open(), but produces
-     * the same result.
-     *
-     * Warning: Does not protect against TOCTOU attacks. You should
-     * just load the file into memory and use crypto_box_seal_open() if
-     * you are worried about those.
-     *
-     * @param string $inputFile
-     * @param string $outputFile
-     * @param string $ecdhKeypair
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seal_open($inputFile, $outputFile, $ecdhKeypair)
-    {
-        /* Type checks: */
-        if (!is_string($inputFile)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
-        }
-        if (!is_string($outputFile)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
-        }
-        if (!is_string($ecdhKeypair)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($ecdhKeypair) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($ecdhKeypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new TypeError('Argument 3 must be CRYPTO_BOX_KEYPAIRBYTES bytes');
-        }
-
-        $publicKey = ParagonIE_Sodium_Compat::crypto_box_publickey($ecdhKeypair);
-
-        /** @var int $size */
-        $size = filesize($inputFile);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $ifp */
-        $ifp = fopen($inputFile, 'rb');
-        if (!is_resource($ifp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var resource $ofp */
-        $ofp = fopen($outputFile, 'wb');
-        if (!is_resource($ofp)) {
-            fclose($ifp);
-            throw new SodiumException('Could not open output file for writing');
-        }
-
-        $ephemeralPK = fread($ifp, ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES);
-        if (!is_string($ephemeralPK)) {
-            throw new SodiumException('Could not read input file');
-        }
-        if (self::strlen($ephemeralPK) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES) {
-            fclose($ifp);
-            fclose($ofp);
-            throw new SodiumException('Could not read public key from sealed file');
-        }
-
-        $nonce = ParagonIE_Sodium_Compat::crypto_generichash(
-            $ephemeralPK . $publicKey,
-            '',
-            24
-        );
-        $msgKeypair = ParagonIE_Sodium_Compat::crypto_box_keypair_from_secretkey_and_publickey(
-            ParagonIE_Sodium_Compat::crypto_box_secretkey($ecdhKeypair),
-            $ephemeralPK
-        );
-
-        $res = self::box_decrypt($ifp, $ofp, $size, $nonce, $msgKeypair);
-        fclose($ifp);
-        fclose($ofp);
-        try {
-            ParagonIE_Sodium_Compat::memzero($nonce);
-            ParagonIE_Sodium_Compat::memzero($ephKeypair);
-        } catch (SodiumException $ex) {
-            if (isset($ephKeypair)) {
-                unset($ephKeypair);
-            }
-        }
-        return $res;
-    }
-
-    /**
-     * Calculate the BLAKE2b hash of a file.
-     *
-     * @param string      $filePath     Absolute path to a file on the filesystem
-     * @param string|null $key          BLAKE2b key
-     * @param int         $outputLength Length of hash output
-     *
-     * @return string                   BLAKE2b hash
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress FailedTypeResolution
-     */
-    public static function generichash($filePath, $key = '', $outputLength = 32)
-    {
-        /* Type checks: */
-        if (!is_string($filePath)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($filePath) . ' given.');
-        }
-        if (!is_string($key)) {
-            if (is_null($key)) {
-                $key = '';
-            } else {
-                throw new TypeError('Argument 2 must be a string, ' . gettype($key) . ' given.');
-            }
-        }
-        if (!is_int($outputLength)) {
-            if (!is_numeric($outputLength)) {
-                throw new TypeError('Argument 3 must be an integer, ' . gettype($outputLength) . ' given.');
-            }
-            $outputLength = (int) $outputLength;
-        }
-
-        /* Input validation: */
-        if (!empty($key)) {
-            if (self::strlen($key) < ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
-                throw new TypeError('Argument 2 must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes');
-            }
-            if (self::strlen($key) > ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
-                throw new TypeError('Argument 2 must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes');
-            }
-        }
-        if ($outputLength < ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_BYTES_MIN) {
-            throw new SodiumException('Argument 3 must be at least CRYPTO_GENERICHASH_BYTES_MIN');
-        }
-        if ($outputLength > ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_BYTES_MAX) {
-            throw new SodiumException('Argument 3 must be at least CRYPTO_GENERICHASH_BYTES_MAX');
-        }
-
-        /** @var int $size */
-        $size = filesize($filePath);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $fp */
-        $fp = fopen($filePath, 'rb');
-        if (!is_resource($fp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-        $ctx = ParagonIE_Sodium_Compat::crypto_generichash_init($key, $outputLength);
-        while ($size > 0) {
-            $blockSize = $size > 64
-                ? 64
-                : $size;
-            $read = fread($fp, $blockSize);
-            if (!is_string($read)) {
-                throw new SodiumException('Could not read input file');
-            }
-            ParagonIE_Sodium_Compat::crypto_generichash_update($ctx, $read);
-            $size -= $blockSize;
-        }
-
-        fclose($fp);
-        return ParagonIE_Sodium_Compat::crypto_generichash_final($ctx, $outputLength);
-    }
-
-    /**
-     * Encrypt a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_secretbox(), but produces
-     * the same result.
-     *
-     * @param string $inputFile  Absolute path to a file on the filesystem
-     * @param string $outputFile Absolute path to a file on the filesystem
-     * @param string $nonce      Number to be used only once
-     * @param string $key        Encryption key
-     *
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox($inputFile, $outputFile, $nonce, $key)
-    {
-        /* Type checks: */
-        if (!is_string($inputFile)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given..');
-        }
-        if (!is_string($outputFile)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
-        }
-        if (!is_string($nonce)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_NONCEBYTES) {
-            throw new TypeError('Argument 3 must be CRYPTO_SECRETBOX_NONCEBYTES bytes');
-        }
-        if (!is_string($key)) {
-            throw new TypeError('Argument 4 must be a string, ' . gettype($key) . ' given.');
-        }
-        if (self::strlen($key) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_KEYBYTES) {
-            throw new TypeError('Argument 4 must be CRYPTO_SECRETBOX_KEYBYTES bytes');
-        }
-
-        /** @var int $size */
-        $size = filesize($inputFile);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $ifp */
-        $ifp = fopen($inputFile, 'rb');
-        if (!is_resource($ifp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var resource $ofp */
-        $ofp = fopen($outputFile, 'wb');
-        if (!is_resource($ofp)) {
-            fclose($ifp);
-            throw new SodiumException('Could not open output file for writing');
-        }
-
-        $res = self::secretbox_encrypt($ifp, $ofp, $size, $nonce, $key);
-        fclose($ifp);
-        fclose($ofp);
-        return $res;
-    }
-    /**
-     * Seal a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_secretbox_open(), but produces
-     * the same result.
-     *
-     * Warning: Does not protect against TOCTOU attacks. You should
-     * just load the file into memory and use crypto_secretbox_open() if
-     * you are worried about those.
-     *
-     * @param string $inputFile
-     * @param string $outputFile
-     * @param string $nonce
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_open($inputFile, $outputFile, $nonce, $key)
-    {
-        /* Type checks: */
-        if (!is_string($inputFile)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
-        }
-        if (!is_string($outputFile)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
-        }
-        if (!is_string($nonce)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
-        }
-        if (!is_string($key)) {
-            throw new TypeError('Argument 4 must be a string, ' . gettype($key) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_NONCEBYTES) {
-            throw new TypeError('Argument 4 must be CRYPTO_SECRETBOX_NONCEBYTES bytes');
-        }
-        if (self::strlen($key) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_KEYBYTES) {
-            throw new TypeError('Argument 4 must be CRYPTO_SECRETBOXBOX_KEYBYTES bytes');
-        }
-
-        /** @var int $size */
-        $size = filesize($inputFile);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $ifp */
-        $ifp = fopen($inputFile, 'rb');
-        if (!is_resource($ifp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var resource $ofp */
-        $ofp = fopen($outputFile, 'wb');
-        if (!is_resource($ofp)) {
-            fclose($ifp);
-            throw new SodiumException('Could not open output file for writing');
-        }
-
-        $res = self::secretbox_decrypt($ifp, $ofp, $size, $nonce, $key);
-        fclose($ifp);
-        fclose($ofp);
-        try {
-            ParagonIE_Sodium_Compat::memzero($key);
-        } catch (SodiumException $ex) {
-            /** @psalm-suppress PossiblyUndefinedVariable */
-            unset($key);
-        }
-        return $res;
-    }
-
-    /**
-     * Sign a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_sign_detached(), but produces
-     * the same result.
-     *
-     * @param string $filePath  Absolute path to a file on the filesystem
-     * @param string $secretKey Secret signing key
-     *
-     * @return string           Ed25519 signature
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign($filePath, $secretKey)
-    {
-        /* Type checks: */
-        if (!is_string($filePath)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($filePath) . ' given.');
-        }
-        if (!is_string($secretKey)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($secretKey) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($secretKey) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_SECRETKEYBYTES) {
-            throw new TypeError('Argument 2 must be CRYPTO_SIGN_SECRETKEYBYTES bytes');
-        }
-        if (PHP_INT_SIZE === 4) {
-            return self::sign_core32($filePath, $secretKey);
-        }
-
-        /** @var int $size */
-        $size = filesize($filePath);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $fp */
-        $fp = fopen($filePath, 'rb');
-        if (!is_resource($fp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var string $az */
-        $az = hash('sha512', self::substr($secretKey, 0, 32), true);
-
-        $az[0] = self::intToChr(self::chrToInt($az[0]) & 248);
-        $az[31] = self::intToChr((self::chrToInt($az[31]) & 63) | 64);
-
-        $hs = hash_init('sha512');
-        self::hash_update($hs, self::substr($az, 32, 32));
-        /** @var resource $hs */
-        $hs = self::updateHashWithFile($hs, $fp, $size);
-
-        /** @var string $nonceHash */
-        $nonceHash = hash_final($hs, true);
-
-        /** @var string $pk */
-        $pk = self::substr($secretKey, 32, 32);
-
-        /** @var string $nonce */
-        $nonce = ParagonIE_Sodium_Core_Ed25519::sc_reduce($nonceHash) . self::substr($nonceHash, 32);
-
-        /** @var string $sig */
-        $sig = ParagonIE_Sodium_Core_Ed25519::ge_p3_tobytes(
-            ParagonIE_Sodium_Core_Ed25519::ge_scalarmult_base($nonce)
-        );
-
-        $hs = hash_init('sha512');
-        self::hash_update($hs, self::substr($sig, 0, 32));
-        self::hash_update($hs, self::substr($pk, 0, 32));
-        /** @var resource $hs */
-        $hs = self::updateHashWithFile($hs, $fp, $size);
-
-        /** @var string $hramHash */
-        $hramHash = hash_final($hs, true);
-
-        /** @var string $hram */
-        $hram = ParagonIE_Sodium_Core_Ed25519::sc_reduce($hramHash);
-
-        /** @var string $sigAfter */
-        $sigAfter = ParagonIE_Sodium_Core_Ed25519::sc_muladd($hram, $az, $nonce);
-
-        /** @var string $sig */
-        $sig = self::substr($sig, 0, 32) . self::substr($sigAfter, 0, 32);
-
-        try {
-            ParagonIE_Sodium_Compat::memzero($az);
-        } catch (SodiumException $ex) {
-            $az = null;
-        }
-        fclose($fp);
-        return $sig;
-    }
-
-    /**
-     * Verify a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_sign_verify_detached(), but
-     * produces the same result.
-     *
-     * @param string $sig       Ed25519 signature
-     * @param string $filePath  Absolute path to a file on the filesystem
-     * @param string $publicKey Signing public key
-     *
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     * @throws Exception
-     */
-    public static function verify($sig, $filePath, $publicKey)
-    {
-        /* Type checks: */
-        if (!is_string($sig)) {
-            throw new TypeError('Argument 1 must be a string, ' . gettype($sig) . ' given.');
-        }
-        if (!is_string($filePath)) {
-            throw new TypeError('Argument 2 must be a string, ' . gettype($filePath) . ' given.');
-        }
-        if (!is_string($publicKey)) {
-            throw new TypeError('Argument 3 must be a string, ' . gettype($publicKey) . ' given.');
-        }
-
-        /* Input validation: */
-        if (self::strlen($sig) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_BYTES) {
-            throw new TypeError('Argument 1 must be CRYPTO_SIGN_BYTES bytes');
-        }
-        if (self::strlen($publicKey) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_PUBLICKEYBYTES) {
-            throw new TypeError('Argument 3 must be CRYPTO_SIGN_PUBLICKEYBYTES bytes');
-        }
-        if (self::strlen($sig) < 64) {
-            throw new SodiumException('Signature is too short');
-        }
-
-        if (PHP_INT_SIZE === 4) {
-            return self::verify_core32($sig, $filePath, $publicKey);
-        }
-
-        /* Security checks */
-        if (
-            (ParagonIE_Sodium_Core_Ed25519::chrToInt($sig[63]) & 240)
-                &&
-            ParagonIE_Sodium_Core_Ed25519::check_S_lt_L(self::substr($sig, 32, 32))
-        ) {
-            throw new SodiumException('S < L - Invalid signature');
-        }
-        if (ParagonIE_Sodium_Core_Ed25519::small_order($sig)) {
-            throw new SodiumException('Signature is on too small of an order');
-        }
-        if ((self::chrToInt($sig[63]) & 224) !== 0) {
-            throw new SodiumException('Invalid signature');
-        }
-        $d = 0;
-        for ($i = 0; $i < 32; ++$i) {
-            $d |= self::chrToInt($publicKey[$i]);
-        }
-        if ($d === 0) {
-            throw new SodiumException('All zero public key');
-        }
-
-        /** @var int $size */
-        $size = filesize($filePath);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-
-        /** @var resource $fp */
-        $fp = fopen($filePath, 'rb');
-        if (!is_resource($fp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-
-        /** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */
-        $orig = ParagonIE_Sodium_Compat::$fastMult;
-
-        // Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.
-        ParagonIE_Sodium_Compat::$fastMult = true;
-
-        /** @var ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A */
-        $A = ParagonIE_Sodium_Core_Ed25519::ge_frombytes_negate_vartime($publicKey);
-
-        $hs = hash_init('sha512');
-        self::hash_update($hs, self::substr($sig, 0, 32));
-        self::hash_update($hs, self::substr($publicKey, 0, 32));
-        /** @var resource $hs */
-        $hs = self::updateHashWithFile($hs, $fp, $size);
-        /** @var string $hDigest */
-        $hDigest = hash_final($hs, true);
-
-        /** @var string $h */
-        $h = ParagonIE_Sodium_Core_Ed25519::sc_reduce($hDigest) . self::substr($hDigest, 32);
-
-        /** @var ParagonIE_Sodium_Core_Curve25519_Ge_P2 $R */
-        $R = ParagonIE_Sodium_Core_Ed25519::ge_double_scalarmult_vartime(
-            $h,
-            $A,
-            self::substr($sig, 32)
-        );
-
-        /** @var string $rcheck */
-        $rcheck = ParagonIE_Sodium_Core_Ed25519::ge_tobytes($R);
-
-        // Close the file handle
-        fclose($fp);
-
-        // Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.
-        ParagonIE_Sodium_Compat::$fastMult = $orig;
-        return self::verify_32($rcheck, self::substr($sig, 0, 32));
-    }
-
-    /**
-     * @param resource $ifp
-     * @param resource $ofp
-     * @param int      $mlen
-     * @param string   $nonce
-     * @param string   $boxKeypair
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function box_encrypt($ifp, $ofp, $mlen, $nonce, $boxKeypair)
-    {
-        if (PHP_INT_SIZE === 4) {
-            return self::secretbox_encrypt(
-                $ifp,
-                $ofp,
-                $mlen,
-                $nonce,
-                ParagonIE_Sodium_Crypto32::box_beforenm(
-                    ParagonIE_Sodium_Crypto32::box_secretkey($boxKeypair),
-                    ParagonIE_Sodium_Crypto32::box_publickey($boxKeypair)
-                )
-            );
-        }
-        return self::secretbox_encrypt(
-            $ifp,
-            $ofp,
-            $mlen,
-            $nonce,
-            ParagonIE_Sodium_Crypto::box_beforenm(
-                ParagonIE_Sodium_Crypto::box_secretkey($boxKeypair),
-                ParagonIE_Sodium_Crypto::box_publickey($boxKeypair)
-            )
-        );
-    }
-
-
-    /**
-     * @param resource $ifp
-     * @param resource $ofp
-     * @param int      $mlen
-     * @param string   $nonce
-     * @param string   $boxKeypair
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function box_decrypt($ifp, $ofp, $mlen, $nonce, $boxKeypair)
-    {
-        if (PHP_INT_SIZE === 4) {
-            return self::secretbox_decrypt(
-                $ifp,
-                $ofp,
-                $mlen,
-                $nonce,
-                ParagonIE_Sodium_Crypto32::box_beforenm(
-                    ParagonIE_Sodium_Crypto32::box_secretkey($boxKeypair),
-                    ParagonIE_Sodium_Crypto32::box_publickey($boxKeypair)
-                )
-            );
-        }
-        return self::secretbox_decrypt(
-            $ifp,
-            $ofp,
-            $mlen,
-            $nonce,
-            ParagonIE_Sodium_Crypto::box_beforenm(
-                ParagonIE_Sodium_Crypto::box_secretkey($boxKeypair),
-                ParagonIE_Sodium_Crypto::box_publickey($boxKeypair)
-            )
-        );
-    }
-
-    /**
-     * Encrypt a file
-     *
-     * @param resource $ifp
-     * @param resource $ofp
-     * @param int $mlen
-     * @param string $nonce
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function secretbox_encrypt($ifp, $ofp, $mlen, $nonce, $key)
-    {
-        if (PHP_INT_SIZE === 4) {
-            return self::secretbox_encrypt_core32($ifp, $ofp, $mlen, $nonce, $key);
-        }
-
-        $plaintext = fread($ifp, 32);
-        if (!is_string($plaintext)) {
-            throw new SodiumException('Could not read input file');
-        }
-        $first32 = self::ftell($ifp);
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $realNonce */
-        $realNonce = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
-
-        /** @var string $block0 */
-        $block0 = str_repeat("\x00", 32);
-
-        /** @var int $mlen - Length of the plaintext message */
-        $mlen0 = $mlen;
-        if ($mlen0 > 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES) {
-            $mlen0 = 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES;
-        }
-        $block0 .= ParagonIE_Sodium_Core_Util::substr($plaintext, 0, $mlen0);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core_Salsa20::salsa20_xor(
-            $block0,
-            $realNonce,
-            $subkey
-        );
-
-        $state = new ParagonIE_Sodium_Core_Poly1305_State(
-            ParagonIE_Sodium_Core_Util::substr(
-                $block0,
-                0,
-                ParagonIE_Sodium_Crypto::onetimeauth_poly1305_KEYBYTES
-            )
-        );
-
-        // Pre-write 16 blank bytes for the Poly1305 tag
-        $start = self::ftell($ofp);
-        fwrite($ofp, str_repeat("\x00", 16));
-
-        /** @var string $c */
-        $cBlock = ParagonIE_Sodium_Core_Util::substr(
-            $block0,
-            ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES
-        );
-        $state->update($cBlock);
-        fwrite($ofp, $cBlock);
-        $mlen -= 32;
-
-        /** @var int $iter */
-        $iter = 1;
-
-        /** @var int $incr */
-        $incr = self::BUFFER_SIZE >> 6;
-
-        /*
+	/* PHP's default buffer size is 8192 for fread()/fwrite(). */
+	const BUFFER_SIZE = 8192;
+
+	/**
+	 * Box a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_box(), but produces
+	 * the same result.
+	 *
+	 * @param string $inputFile  Absolute path to a file on the filesystem
+	 * @param string $outputFile Absolute path to a file on the filesystem
+	 * @param string $nonce      Number to be used only once
+	 * @param string $keyPair    ECDH secret key and ECDH public key concatenated
+	 *
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box($inputFile, $outputFile, $nonce, $keyPair)
+	{
+		/* Type checks: */
+		if (!is_string($inputFile)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
+		}
+		if (!is_string($outputFile)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
+		}
+		if (!is_string($nonce)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
+		}
+
+		/* Input validation: */
+		if (!is_string($keyPair)) {
+			throw new TypeError('Argument 4 must be a string, ' . gettype($keyPair) . ' given.');
+		}
+		if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_NONCEBYTES) {
+			throw new TypeError('Argument 3 must be CRYPTO_BOX_NONCEBYTES bytes');
+		}
+		if (self::strlen($keyPair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new TypeError('Argument 4 must be CRYPTO_BOX_KEYPAIRBYTES bytes');
+		}
+
+		/** @var int $size */
+		$size = filesize($inputFile);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $ifp */
+		$ifp = fopen($inputFile, 'rb');
+		if (!is_resource($ifp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var resource $ofp */
+		$ofp = fopen($outputFile, 'wb');
+		if (!is_resource($ofp)) {
+			fclose($ifp);
+			throw new SodiumException('Could not open output file for writing');
+		}
+
+		$res = self::box_encrypt($ifp, $ofp, $size, $nonce, $keyPair);
+		fclose($ifp);
+		fclose($ofp);
+		return $res;
+	}
+
+	/**
+	 * Open a boxed file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_box_open(), but produces
+	 * the same result.
+	 *
+	 * Warning: Does not protect against TOCTOU attacks. You should
+	 * just load the file into memory and use crypto_box_open() if
+	 * you are worried about those.
+	 *
+	 * @param string $inputFile
+	 * @param string $outputFile
+	 * @param string $nonce
+	 * @param string $keypair
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_open($inputFile, $outputFile, $nonce, $keypair)
+	{
+		/* Type checks: */
+		if (!is_string($inputFile)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
+		}
+		if (!is_string($outputFile)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
+		}
+		if (!is_string($nonce)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
+		}
+		if (!is_string($keypair)) {
+			throw new TypeError('Argument 4 must be a string, ' . gettype($keypair) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_NONCEBYTES) {
+			throw new TypeError('Argument 4 must be CRYPTO_BOX_NONCEBYTES bytes');
+		}
+		if (self::strlen($keypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new TypeError('Argument 4 must be CRYPTO_BOX_KEYPAIRBYTES bytes');
+		}
+
+		/** @var int $size */
+		$size = filesize($inputFile);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $ifp */
+		$ifp = fopen($inputFile, 'rb');
+		if (!is_resource($ifp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var resource $ofp */
+		$ofp = fopen($outputFile, 'wb');
+		if (!is_resource($ofp)) {
+			fclose($ifp);
+			throw new SodiumException('Could not open output file for writing');
+		}
+
+		$res = self::box_decrypt($ifp, $ofp, $size, $nonce, $keypair);
+		fclose($ifp);
+		fclose($ofp);
+		try {
+			ParagonIE_Sodium_Compat::memzero($nonce);
+			ParagonIE_Sodium_Compat::memzero($ephKeypair);
+		} catch (SodiumException $ex) {
+			if (isset($ephKeypair)) {
+				unset($ephKeypair);
+			}
+		}
+		return $res;
+	}
+
+	/**
+	 * Seal a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_box_seal(), but produces
+	 * the same result.
+	 *
+	 * @param string $inputFile  Absolute path to a file on the filesystem
+	 * @param string $outputFile Absolute path to a file on the filesystem
+	 * @param string $publicKey  ECDH public key
+	 *
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seal($inputFile, $outputFile, $publicKey)
+	{
+		/* Type checks: */
+		if (!is_string($inputFile)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
+		}
+		if (!is_string($outputFile)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
+		}
+		if (!is_string($publicKey)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($publicKey) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($publicKey) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new TypeError('Argument 3 must be CRYPTO_BOX_PUBLICKEYBYTES bytes');
+		}
+
+		/** @var int $size */
+		$size = filesize($inputFile);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $ifp */
+		$ifp = fopen($inputFile, 'rb');
+		if (!is_resource($ifp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var resource $ofp */
+		$ofp = fopen($outputFile, 'wb');
+		if (!is_resource($ofp)) {
+			fclose($ifp);
+			throw new SodiumException('Could not open output file for writing');
+		}
+
+		/** @var string $ephKeypair */
+		$ephKeypair = ParagonIE_Sodium_Compat::crypto_box_keypair();
+
+		/** @var string $msgKeypair */
+		$msgKeypair = ParagonIE_Sodium_Compat::crypto_box_keypair_from_secretkey_and_publickey(
+			ParagonIE_Sodium_Compat::crypto_box_secretkey($ephKeypair),
+			$publicKey
+		);
+
+		/** @var string $ephemeralPK */
+		$ephemeralPK = ParagonIE_Sodium_Compat::crypto_box_publickey($ephKeypair);
+
+		/** @var string $nonce */
+		$nonce = ParagonIE_Sodium_Compat::crypto_generichash(
+			$ephemeralPK . $publicKey,
+			'',
+			24
+		);
+
+		/** @var int $firstWrite */
+		$firstWrite = fwrite(
+			$ofp,
+			$ephemeralPK,
+			ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES
+		);
+		if (!is_int($firstWrite)) {
+			fclose($ifp);
+			fclose($ofp);
+			ParagonIE_Sodium_Compat::memzero($ephKeypair);
+			throw new SodiumException('Could not write to output file');
+		}
+		if ($firstWrite !== ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES) {
+			ParagonIE_Sodium_Compat::memzero($ephKeypair);
+			fclose($ifp);
+			fclose($ofp);
+			throw new SodiumException('Error writing public key to output file');
+		}
+
+		$res = self::box_encrypt($ifp, $ofp, $size, $nonce, $msgKeypair);
+		fclose($ifp);
+		fclose($ofp);
+		try {
+			ParagonIE_Sodium_Compat::memzero($nonce);
+			ParagonIE_Sodium_Compat::memzero($ephKeypair);
+		} catch (SodiumException $ex) {
+			/** @psalm-suppress PossiblyUndefinedVariable */
+			unset($ephKeypair);
+		}
+		return $res;
+	}
+
+	/**
+	 * Open a sealed file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_box_seal_open(), but produces
+	 * the same result.
+	 *
+	 * Warning: Does not protect against TOCTOU attacks. You should
+	 * just load the file into memory and use crypto_box_seal_open() if
+	 * you are worried about those.
+	 *
+	 * @param string $inputFile
+	 * @param string $outputFile
+	 * @param string $ecdhKeypair
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seal_open($inputFile, $outputFile, $ecdhKeypair)
+	{
+		/* Type checks: */
+		if (!is_string($inputFile)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
+		}
+		if (!is_string($outputFile)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
+		}
+		if (!is_string($ecdhKeypair)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($ecdhKeypair) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($ecdhKeypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new TypeError('Argument 3 must be CRYPTO_BOX_KEYPAIRBYTES bytes');
+		}
+
+		$publicKey = ParagonIE_Sodium_Compat::crypto_box_publickey($ecdhKeypair);
+
+		/** @var int $size */
+		$size = filesize($inputFile);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $ifp */
+		$ifp = fopen($inputFile, 'rb');
+		if (!is_resource($ifp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var resource $ofp */
+		$ofp = fopen($outputFile, 'wb');
+		if (!is_resource($ofp)) {
+			fclose($ifp);
+			throw new SodiumException('Could not open output file for writing');
+		}
+
+		$ephemeralPK = fread($ifp, ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES);
+		if (!is_string($ephemeralPK)) {
+			throw new SodiumException('Could not read input file');
+		}
+		if (self::strlen($ephemeralPK) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_PUBLICKEYBYTES) {
+			fclose($ifp);
+			fclose($ofp);
+			throw new SodiumException('Could not read public key from sealed file');
+		}
+
+		$nonce = ParagonIE_Sodium_Compat::crypto_generichash(
+			$ephemeralPK . $publicKey,
+			'',
+			24
+		);
+		$msgKeypair = ParagonIE_Sodium_Compat::crypto_box_keypair_from_secretkey_and_publickey(
+			ParagonIE_Sodium_Compat::crypto_box_secretkey($ecdhKeypair),
+			$ephemeralPK
+		);
+
+		$res = self::box_decrypt($ifp, $ofp, $size, $nonce, $msgKeypair);
+		fclose($ifp);
+		fclose($ofp);
+		try {
+			ParagonIE_Sodium_Compat::memzero($nonce);
+			ParagonIE_Sodium_Compat::memzero($ephKeypair);
+		} catch (SodiumException $ex) {
+			if (isset($ephKeypair)) {
+				unset($ephKeypair);
+			}
+		}
+		return $res;
+	}
+
+	/**
+	 * Calculate the BLAKE2b hash of a file.
+	 *
+	 * @param string      $filePath     Absolute path to a file on the filesystem
+	 * @param string|null $key          BLAKE2b key
+	 * @param int         $outputLength Length of hash output
+	 *
+	 * @return string                   BLAKE2b hash
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress FailedTypeResolution
+	 */
+	public static function generichash($filePath, $key = '', $outputLength = 32)
+	{
+		/* Type checks: */
+		if (!is_string($filePath)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($filePath) . ' given.');
+		}
+		if (!is_string($key)) {
+			if (is_null($key)) {
+				$key = '';
+			} else {
+				throw new TypeError('Argument 2 must be a string, ' . gettype($key) . ' given.');
+			}
+		}
+		if (!is_int($outputLength)) {
+			if (!is_numeric($outputLength)) {
+				throw new TypeError('Argument 3 must be an integer, ' . gettype($outputLength) . ' given.');
+			}
+			$outputLength = (int) $outputLength;
+		}
+
+		/* Input validation: */
+		if (!empty($key)) {
+			if (self::strlen($key) < ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
+				throw new TypeError('Argument 2 must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes');
+			}
+			if (self::strlen($key) > ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
+				throw new TypeError('Argument 2 must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes');
+			}
+		}
+		if ($outputLength < ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_BYTES_MIN) {
+			throw new SodiumException('Argument 3 must be at least CRYPTO_GENERICHASH_BYTES_MIN');
+		}
+		if ($outputLength > ParagonIE_Sodium_Compat::CRYPTO_GENERICHASH_BYTES_MAX) {
+			throw new SodiumException('Argument 3 must be at least CRYPTO_GENERICHASH_BYTES_MAX');
+		}
+
+		/** @var int $size */
+		$size = filesize($filePath);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $fp */
+		$fp = fopen($filePath, 'rb');
+		if (!is_resource($fp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+		$ctx = ParagonIE_Sodium_Compat::crypto_generichash_init($key, $outputLength);
+		while ($size > 0) {
+			$blockSize = $size > 64
+				? 64
+				: $size;
+			$read = fread($fp, $blockSize);
+			if (!is_string($read)) {
+				throw new SodiumException('Could not read input file');
+			}
+			ParagonIE_Sodium_Compat::crypto_generichash_update($ctx, $read);
+			$size -= $blockSize;
+		}
+
+		fclose($fp);
+		return ParagonIE_Sodium_Compat::crypto_generichash_final($ctx, $outputLength);
+	}
+
+	/**
+	 * Encrypt a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_secretbox(), but produces
+	 * the same result.
+	 *
+	 * @param string $inputFile  Absolute path to a file on the filesystem
+	 * @param string $outputFile Absolute path to a file on the filesystem
+	 * @param string $nonce      Number to be used only once
+	 * @param string $key        Encryption key
+	 *
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox($inputFile, $outputFile, $nonce, $key)
+	{
+		/* Type checks: */
+		if (!is_string($inputFile)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given..');
+		}
+		if (!is_string($outputFile)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
+		}
+		if (!is_string($nonce)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_NONCEBYTES) {
+			throw new TypeError('Argument 3 must be CRYPTO_SECRETBOX_NONCEBYTES bytes');
+		}
+		if (!is_string($key)) {
+			throw new TypeError('Argument 4 must be a string, ' . gettype($key) . ' given.');
+		}
+		if (self::strlen($key) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_KEYBYTES) {
+			throw new TypeError('Argument 4 must be CRYPTO_SECRETBOX_KEYBYTES bytes');
+		}
+
+		/** @var int $size */
+		$size = filesize($inputFile);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $ifp */
+		$ifp = fopen($inputFile, 'rb');
+		if (!is_resource($ifp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var resource $ofp */
+		$ofp = fopen($outputFile, 'wb');
+		if (!is_resource($ofp)) {
+			fclose($ifp);
+			throw new SodiumException('Could not open output file for writing');
+		}
+
+		$res = self::secretbox_encrypt($ifp, $ofp, $size, $nonce, $key);
+		fclose($ifp);
+		fclose($ofp);
+		return $res;
+	}
+	/**
+	 * Seal a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_secretbox_open(), but produces
+	 * the same result.
+	 *
+	 * Warning: Does not protect against TOCTOU attacks. You should
+	 * just load the file into memory and use crypto_secretbox_open() if
+	 * you are worried about those.
+	 *
+	 * @param string $inputFile
+	 * @param string $outputFile
+	 * @param string $nonce
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_open($inputFile, $outputFile, $nonce, $key)
+	{
+		/* Type checks: */
+		if (!is_string($inputFile)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($inputFile) . ' given.');
+		}
+		if (!is_string($outputFile)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($outputFile) . ' given.');
+		}
+		if (!is_string($nonce)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($nonce) . ' given.');
+		}
+		if (!is_string($key)) {
+			throw new TypeError('Argument 4 must be a string, ' . gettype($key) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($nonce) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_NONCEBYTES) {
+			throw new TypeError('Argument 4 must be CRYPTO_SECRETBOX_NONCEBYTES bytes');
+		}
+		if (self::strlen($key) !== ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_KEYBYTES) {
+			throw new TypeError('Argument 4 must be CRYPTO_SECRETBOXBOX_KEYBYTES bytes');
+		}
+
+		/** @var int $size */
+		$size = filesize($inputFile);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $ifp */
+		$ifp = fopen($inputFile, 'rb');
+		if (!is_resource($ifp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var resource $ofp */
+		$ofp = fopen($outputFile, 'wb');
+		if (!is_resource($ofp)) {
+			fclose($ifp);
+			throw new SodiumException('Could not open output file for writing');
+		}
+
+		$res = self::secretbox_decrypt($ifp, $ofp, $size, $nonce, $key);
+		fclose($ifp);
+		fclose($ofp);
+		try {
+			ParagonIE_Sodium_Compat::memzero($key);
+		} catch (SodiumException $ex) {
+			/** @psalm-suppress PossiblyUndefinedVariable */
+			unset($key);
+		}
+		return $res;
+	}
+
+	/**
+	 * Sign a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_sign_detached(), but produces
+	 * the same result.
+	 *
+	 * @param string $filePath  Absolute path to a file on the filesystem
+	 * @param string $secretKey Secret signing key
+	 *
+	 * @return string           Ed25519 signature
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign($filePath, $secretKey)
+	{
+		/* Type checks: */
+		if (!is_string($filePath)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($filePath) . ' given.');
+		}
+		if (!is_string($secretKey)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($secretKey) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($secretKey) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_SECRETKEYBYTES) {
+			throw new TypeError('Argument 2 must be CRYPTO_SIGN_SECRETKEYBYTES bytes');
+		}
+		if (PHP_INT_SIZE === 4) {
+			return self::sign_core32($filePath, $secretKey);
+		}
+
+		/** @var int $size */
+		$size = filesize($filePath);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $fp */
+		$fp = fopen($filePath, 'rb');
+		if (!is_resource($fp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var string $az */
+		$az = hash('sha512', self::substr($secretKey, 0, 32), true);
+
+		$az[0] = self::intToChr(self::chrToInt($az[0]) & 248);
+		$az[31] = self::intToChr((self::chrToInt($az[31]) & 63) | 64);
+
+		$hs = hash_init('sha512');
+		self::hash_update($hs, self::substr($az, 32, 32));
+		/** @var resource $hs */
+		$hs = self::updateHashWithFile($hs, $fp, $size);
+
+		/** @var string $nonceHash */
+		$nonceHash = hash_final($hs, true);
+
+		/** @var string $pk */
+		$pk = self::substr($secretKey, 32, 32);
+
+		/** @var string $nonce */
+		$nonce = ParagonIE_Sodium_Core_Ed25519::sc_reduce($nonceHash) . self::substr($nonceHash, 32);
+
+		/** @var string $sig */
+		$sig = ParagonIE_Sodium_Core_Ed25519::ge_p3_tobytes(
+			ParagonIE_Sodium_Core_Ed25519::ge_scalarmult_base($nonce)
+		);
+
+		$hs = hash_init('sha512');
+		self::hash_update($hs, self::substr($sig, 0, 32));
+		self::hash_update($hs, self::substr($pk, 0, 32));
+		/** @var resource $hs */
+		$hs = self::updateHashWithFile($hs, $fp, $size);
+
+		/** @var string $hramHash */
+		$hramHash = hash_final($hs, true);
+
+		/** @var string $hram */
+		$hram = ParagonIE_Sodium_Core_Ed25519::sc_reduce($hramHash);
+
+		/** @var string $sigAfter */
+		$sigAfter = ParagonIE_Sodium_Core_Ed25519::sc_muladd($hram, $az, $nonce);
+
+		/** @var string $sig */
+		$sig = self::substr($sig, 0, 32) . self::substr($sigAfter, 0, 32);
+
+		try {
+			ParagonIE_Sodium_Compat::memzero($az);
+		} catch (SodiumException $ex) {
+			$az = null;
+		}
+		fclose($fp);
+		return $sig;
+	}
+
+	/**
+	 * Verify a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_sign_verify_detached(), but
+	 * produces the same result.
+	 *
+	 * @param string $sig       Ed25519 signature
+	 * @param string $filePath  Absolute path to a file on the filesystem
+	 * @param string $publicKey Signing public key
+	 *
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @throws Exception
+	 */
+	public static function verify($sig, $filePath, $publicKey)
+	{
+		/* Type checks: */
+		if (!is_string($sig)) {
+			throw new TypeError('Argument 1 must be a string, ' . gettype($sig) . ' given.');
+		}
+		if (!is_string($filePath)) {
+			throw new TypeError('Argument 2 must be a string, ' . gettype($filePath) . ' given.');
+		}
+		if (!is_string($publicKey)) {
+			throw new TypeError('Argument 3 must be a string, ' . gettype($publicKey) . ' given.');
+		}
+
+		/* Input validation: */
+		if (self::strlen($sig) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_BYTES) {
+			throw new TypeError('Argument 1 must be CRYPTO_SIGN_BYTES bytes');
+		}
+		if (self::strlen($publicKey) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_PUBLICKEYBYTES) {
+			throw new TypeError('Argument 3 must be CRYPTO_SIGN_PUBLICKEYBYTES bytes');
+		}
+		if (self::strlen($sig) < 64) {
+			throw new SodiumException('Signature is too short');
+		}
+
+		if (PHP_INT_SIZE === 4) {
+			return self::verify_core32($sig, $filePath, $publicKey);
+		}
+
+		/* Security checks */
+		if (
+			(ParagonIE_Sodium_Core_Ed25519::chrToInt($sig[63]) & 240)
+				&&
+			ParagonIE_Sodium_Core_Ed25519::check_S_lt_L(self::substr($sig, 32, 32))
+		) {
+			throw new SodiumException('S < L - Invalid signature');
+		}
+		if (ParagonIE_Sodium_Core_Ed25519::small_order($sig)) {
+			throw new SodiumException('Signature is on too small of an order');
+		}
+		if ((self::chrToInt($sig[63]) & 224) !== 0) {
+			throw new SodiumException('Invalid signature');
+		}
+		$d = 0;
+		for ($i = 0; $i < 32; ++$i) {
+			$d |= self::chrToInt($publicKey[$i]);
+		}
+		if ($d === 0) {
+			throw new SodiumException('All zero public key');
+		}
+
+		/** @var int $size */
+		$size = filesize($filePath);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+
+		/** @var resource $fp */
+		$fp = fopen($filePath, 'rb');
+		if (!is_resource($fp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+
+		/** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */
+		$orig = ParagonIE_Sodium_Compat::$fastMult;
+
+		// Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.
+		ParagonIE_Sodium_Compat::$fastMult = true;
+
+		/** @var ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A */
+		$A = ParagonIE_Sodium_Core_Ed25519::ge_frombytes_negate_vartime($publicKey);
+
+		$hs = hash_init('sha512');
+		self::hash_update($hs, self::substr($sig, 0, 32));
+		self::hash_update($hs, self::substr($publicKey, 0, 32));
+		/** @var resource $hs */
+		$hs = self::updateHashWithFile($hs, $fp, $size);
+		/** @var string $hDigest */
+		$hDigest = hash_final($hs, true);
+
+		/** @var string $h */
+		$h = ParagonIE_Sodium_Core_Ed25519::sc_reduce($hDigest) . self::substr($hDigest, 32);
+
+		/** @var ParagonIE_Sodium_Core_Curve25519_Ge_P2 $R */
+		$R = ParagonIE_Sodium_Core_Ed25519::ge_double_scalarmult_vartime(
+			$h,
+			$A,
+			self::substr($sig, 32)
+		);
+
+		/** @var string $rcheck */
+		$rcheck = ParagonIE_Sodium_Core_Ed25519::ge_tobytes($R);
+
+		// Close the file handle
+		fclose($fp);
+
+		// Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.
+		ParagonIE_Sodium_Compat::$fastMult = $orig;
+		return self::verify_32($rcheck, self::substr($sig, 0, 32));
+	}
+
+	/**
+	 * @param resource $ifp
+	 * @param resource $ofp
+	 * @param int      $mlen
+	 * @param string   $nonce
+	 * @param string   $boxKeypair
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function box_encrypt($ifp, $ofp, $mlen, $nonce, $boxKeypair)
+	{
+		if (PHP_INT_SIZE === 4) {
+			return self::secretbox_encrypt(
+				$ifp,
+				$ofp,
+				$mlen,
+				$nonce,
+				ParagonIE_Sodium_Crypto32::box_beforenm(
+					ParagonIE_Sodium_Crypto32::box_secretkey($boxKeypair),
+					ParagonIE_Sodium_Crypto32::box_publickey($boxKeypair)
+				)
+			);
+		}
+		return self::secretbox_encrypt(
+			$ifp,
+			$ofp,
+			$mlen,
+			$nonce,
+			ParagonIE_Sodium_Crypto::box_beforenm(
+				ParagonIE_Sodium_Crypto::box_secretkey($boxKeypair),
+				ParagonIE_Sodium_Crypto::box_publickey($boxKeypair)
+			)
+		);
+	}
+
+
+	/**
+	 * @param resource $ifp
+	 * @param resource $ofp
+	 * @param int      $mlen
+	 * @param string   $nonce
+	 * @param string   $boxKeypair
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function box_decrypt($ifp, $ofp, $mlen, $nonce, $boxKeypair)
+	{
+		if (PHP_INT_SIZE === 4) {
+			return self::secretbox_decrypt(
+				$ifp,
+				$ofp,
+				$mlen,
+				$nonce,
+				ParagonIE_Sodium_Crypto32::box_beforenm(
+					ParagonIE_Sodium_Crypto32::box_secretkey($boxKeypair),
+					ParagonIE_Sodium_Crypto32::box_publickey($boxKeypair)
+				)
+			);
+		}
+		return self::secretbox_decrypt(
+			$ifp,
+			$ofp,
+			$mlen,
+			$nonce,
+			ParagonIE_Sodium_Crypto::box_beforenm(
+				ParagonIE_Sodium_Crypto::box_secretkey($boxKeypair),
+				ParagonIE_Sodium_Crypto::box_publickey($boxKeypair)
+			)
+		);
+	}
+
+	/**
+	 * Encrypt a file
+	 *
+	 * @param resource $ifp
+	 * @param resource $ofp
+	 * @param int $mlen
+	 * @param string $nonce
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function secretbox_encrypt($ifp, $ofp, $mlen, $nonce, $key)
+	{
+		if (PHP_INT_SIZE === 4) {
+			return self::secretbox_encrypt_core32($ifp, $ofp, $mlen, $nonce, $key);
+		}
+
+		$plaintext = fread($ifp, 32);
+		if (!is_string($plaintext)) {
+			throw new SodiumException('Could not read input file');
+		}
+		$first32 = self::ftell($ifp);
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $realNonce */
+		$realNonce = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
+
+		/** @var string $block0 */
+		$block0 = str_repeat("\x00", 32);
+
+		/** @var int $mlen - Length of the plaintext message */
+		$mlen0 = $mlen;
+		if ($mlen0 > 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES) {
+			$mlen0 = 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES;
+		}
+		$block0 .= ParagonIE_Sodium_Core_Util::substr($plaintext, 0, $mlen0);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core_Salsa20::salsa20_xor(
+			$block0,
+			$realNonce,
+			$subkey
+		);
+
+		$state = new ParagonIE_Sodium_Core_Poly1305_State(
+			ParagonIE_Sodium_Core_Util::substr(
+				$block0,
+				0,
+				ParagonIE_Sodium_Crypto::onetimeauth_poly1305_KEYBYTES
+			)
+		);
+
+		// Pre-write 16 blank bytes for the Poly1305 tag
+		$start = self::ftell($ofp);
+		fwrite($ofp, str_repeat("\x00", 16));
+
+		/** @var string $c */
+		$cBlock = ParagonIE_Sodium_Core_Util::substr(
+			$block0,
+			ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES
+		);
+		$state->update($cBlock);
+		fwrite($ofp, $cBlock);
+		$mlen -= 32;
+
+		/** @var int $iter */
+		$iter = 1;
+
+		/** @var int $incr */
+		$incr = self::BUFFER_SIZE >> 6;
+
+		/*
          * Set the cursor to the end of the first half-block. All future bytes will
          * generated from salsa20_xor_ic, starting from 1 (second block).
          */
-        fseek($ifp, $first32, SEEK_SET);
-
-        while ($mlen > 0) {
-            $blockSize = $mlen > self::BUFFER_SIZE
-                ? self::BUFFER_SIZE
-                : $mlen;
-            $plaintext = fread($ifp, $blockSize);
-            if (!is_string($plaintext)) {
-                throw new SodiumException('Could not read input file');
-            }
-            $cBlock = ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
-                $plaintext,
-                $realNonce,
-                $iter,
-                $subkey
-            );
-            fwrite($ofp, $cBlock, $blockSize);
-            $state->update($cBlock);
-
-            $mlen -= $blockSize;
-            $iter += $incr;
-        }
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-            ParagonIE_Sodium_Compat::memzero($subkey);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-            $subkey = null;
-        }
-        $end = self::ftell($ofp);
-
-        /*
+		fseek($ifp, $first32, SEEK_SET);
+
+		while ($mlen > 0) {
+			$blockSize = $mlen > self::BUFFER_SIZE
+				? self::BUFFER_SIZE
+				: $mlen;
+			$plaintext = fread($ifp, $blockSize);
+			if (!is_string($plaintext)) {
+				throw new SodiumException('Could not read input file');
+			}
+			$cBlock = ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
+				$plaintext,
+				$realNonce,
+				$iter,
+				$subkey
+			);
+			fwrite($ofp, $cBlock, $blockSize);
+			$state->update($cBlock);
+
+			$mlen -= $blockSize;
+			$iter += $incr;
+		}
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+			ParagonIE_Sodium_Compat::memzero($subkey);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+			$subkey = null;
+		}
+		$end = self::ftell($ofp);
+
+		/*
          * Write the Poly1305 authentication tag that provides integrity
          * over the ciphertext (encrypt-then-MAC)
          */
-        fseek($ofp, $start, SEEK_SET);
-        fwrite($ofp, $state->finish(), ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_MACBYTES);
-        fseek($ofp, $end, SEEK_SET);
-        unset($state);
-
-        return true;
-    }
-
-    /**
-     * Decrypt a file
-     *
-     * @param resource $ifp
-     * @param resource $ofp
-     * @param int $mlen
-     * @param string $nonce
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function secretbox_decrypt($ifp, $ofp, $mlen, $nonce, $key)
-    {
-        if (PHP_INT_SIZE === 4) {
-            return self::secretbox_decrypt_core32($ifp, $ofp, $mlen, $nonce, $key);
-        }
-        $tag = fread($ifp, 16);
-        if (!is_string($tag)) {
-            throw new SodiumException('Could not read input file');
-        }
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $realNonce */
-        $realNonce = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core_Salsa20::salsa20(
-            64,
-            ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-
-        /* Verify the Poly1305 MAC -before- attempting to decrypt! */
-        $state = new ParagonIE_Sodium_Core_Poly1305_State(self::substr($block0, 0, 32));
-        if (!self::onetimeauth_verify($state, $ifp, $tag, $mlen)) {
-            throw new SodiumException('Invalid MAC');
-        }
-
-        /*
+		fseek($ofp, $start, SEEK_SET);
+		fwrite($ofp, $state->finish(), ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_MACBYTES);
+		fseek($ofp, $end, SEEK_SET);
+		unset($state);
+
+		return true;
+	}
+
+	/**
+	 * Decrypt a file
+	 *
+	 * @param resource $ifp
+	 * @param resource $ofp
+	 * @param int $mlen
+	 * @param string $nonce
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function secretbox_decrypt($ifp, $ofp, $mlen, $nonce, $key)
+	{
+		if (PHP_INT_SIZE === 4) {
+			return self::secretbox_decrypt_core32($ifp, $ofp, $mlen, $nonce, $key);
+		}
+		$tag = fread($ifp, 16);
+		if (!is_string($tag)) {
+			throw new SodiumException('Could not read input file');
+		}
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $realNonce */
+		$realNonce = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core_Salsa20::salsa20(
+			64,
+			ParagonIE_Sodium_Core_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+
+		/* Verify the Poly1305 MAC -before- attempting to decrypt! */
+		$state = new ParagonIE_Sodium_Core_Poly1305_State(self::substr($block0, 0, 32));
+		if (!self::onetimeauth_verify($state, $ifp, $tag, $mlen)) {
+			throw new SodiumException('Invalid MAC');
+		}
+
+		/*
          * Set the cursor to the end of the first half-block. All future bytes will
          * generated from salsa20_xor_ic, starting from 1 (second block).
          */
-        $first32 = fread($ifp, 32);
-        if (!is_string($first32)) {
-            throw new SodiumException('Could not read input file');
-        }
-        $first32len = self::strlen($first32);
-        fwrite(
-            $ofp,
-            self::xorStrings(
-                self::substr($block0, 32, $first32len),
-                self::substr($first32, 0, $first32len)
-            )
-        );
-        $mlen -= 32;
-
-        /** @var int $iter */
-        $iter = 1;
-
-        /** @var int $incr */
-        $incr = self::BUFFER_SIZE >> 6;
-
-        /* Decrypts ciphertext, writes to output file. */
-        while ($mlen > 0) {
-            $blockSize = $mlen > self::BUFFER_SIZE
-                ? self::BUFFER_SIZE
-                : $mlen;
-            $ciphertext = fread($ifp, $blockSize);
-            if (!is_string($ciphertext)) {
-                throw new SodiumException('Could not read input file');
-            }
-            $pBlock = ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
-                $ciphertext,
-                $realNonce,
-                $iter,
-                $subkey
-            );
-            fwrite($ofp, $pBlock, $blockSize);
-            $mlen -= $blockSize;
-            $iter += $incr;
-        }
-        return true;
-    }
-
-    /**
-     * @param ParagonIE_Sodium_Core_Poly1305_State $state
-     * @param resource $ifp
-     * @param string $tag
-     * @param int $mlen
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function onetimeauth_verify(
-        ParagonIE_Sodium_Core_Poly1305_State $state,
-        $ifp,
-        $tag = '',
-        $mlen = 0
-    ) {
-        /** @var int $pos */
-        $pos = self::ftell($ifp);
-
-        /** @var int $iter */
-        $iter = 1;
-
-        /** @var int $incr */
-        $incr = self::BUFFER_SIZE >> 6;
-
-        while ($mlen > 0) {
-            $blockSize = $mlen > self::BUFFER_SIZE
-                ? self::BUFFER_SIZE
-                : $mlen;
-            $ciphertext = fread($ifp, $blockSize);
-            if (!is_string($ciphertext)) {
-                throw new SodiumException('Could not read input file');
-            }
-            $state->update($ciphertext);
-            $mlen -= $blockSize;
-            $iter += $incr;
-        }
-        $res = ParagonIE_Sodium_Core_Util::verify_16($tag, $state->finish());
-
-        fseek($ifp, $pos, SEEK_SET);
-        return $res;
-    }
-
-    /**
-     * Update a hash context with the contents of a file, without
-     * loading the entire file into memory.
-     *
-     * @param resource|HashContext $hash
-     * @param resource $fp
-     * @param int $size
-     * @return resource|object Resource on PHP < 7.2, HashContext object on PHP >= 7.2
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress PossiblyInvalidArgument
-     *                 PHP 7.2 changes from a resource to an object,
-     *                 which causes Psalm to complain about an error.
-     * @psalm-suppress TypeCoercion
-     *                 Ditto.
-     */
-    public static function updateHashWithFile($hash, $fp, $size = 0)
-    {
-        /* Type checks: */
-        if (PHP_VERSION_ID < 70200) {
-            if (!is_resource($hash)) {
-                throw new TypeError('Argument 1 must be a resource, ' . gettype($hash) . ' given.');
-            }
-        } else {
-            if (!is_object($hash)) {
-                throw new TypeError('Argument 1 must be an object (PHP 7.2+), ' . gettype($hash) . ' given.');
-            }
-        }
-
-        if (!is_resource($fp)) {
-            throw new TypeError('Argument 2 must be a resource, ' . gettype($fp) . ' given.');
-        }
-        if (!is_int($size)) {
-            throw new TypeError('Argument 3 must be an integer, ' . gettype($size) . ' given.');
-        }
-
-        /** @var int $originalPosition */
-        $originalPosition = self::ftell($fp);
-
-        // Move file pointer to beginning of file
-        fseek($fp, 0, SEEK_SET);
-        for ($i = 0; $i < $size; $i += self::BUFFER_SIZE) {
-            /** @var string|bool $message */
-            $message = fread(
-                $fp,
-                ($size - $i) > self::BUFFER_SIZE
-                    ? $size - $i
-                    : self::BUFFER_SIZE
-            );
-            if (!is_string($message)) {
-                throw new SodiumException('Unexpected error reading from file.');
-            }
-            /** @var string $message */
-            /** @psalm-suppress InvalidArgument */
-            self::hash_update($hash, $message);
-        }
-        // Reset file pointer's position
-        fseek($fp, $originalPosition, SEEK_SET);
-        return $hash;
-    }
-
-    /**
-     * Sign a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_sign_detached(), but produces
-     * the same result. (32-bit)
-     *
-     * @param string $filePath  Absolute path to a file on the filesystem
-     * @param string $secretKey Secret signing key
-     *
-     * @return string           Ed25519 signature
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    private static function sign_core32($filePath, $secretKey)
-    {
-        /** @var int|bool $size */
-        $size = filesize($filePath);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-        /** @var int $size */
-
-        /** @var resource|bool $fp */
-        $fp = fopen($filePath, 'rb');
-        if (!is_resource($fp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-        /** @var resource $fp */
-
-        /** @var string $az */
-        $az = hash('sha512', self::substr($secretKey, 0, 32), true);
-
-        $az[0] = self::intToChr(self::chrToInt($az[0]) & 248);
-        $az[31] = self::intToChr((self::chrToInt($az[31]) & 63) | 64);
-
-        $hs = hash_init('sha512');
-        self::hash_update($hs, self::substr($az, 32, 32));
-        /** @var resource $hs */
-        $hs = self::updateHashWithFile($hs, $fp, $size);
-
-        /** @var string $nonceHash */
-        $nonceHash = hash_final($hs, true);
-
-        /** @var string $pk */
-        $pk = self::substr($secretKey, 32, 32);
-
-        /** @var string $nonce */
-        $nonce = ParagonIE_Sodium_Core32_Ed25519::sc_reduce($nonceHash) . self::substr($nonceHash, 32);
-
-        /** @var string $sig */
-        $sig = ParagonIE_Sodium_Core32_Ed25519::ge_p3_tobytes(
-            ParagonIE_Sodium_Core32_Ed25519::ge_scalarmult_base($nonce)
-        );
-
-        $hs = hash_init('sha512');
-        self::hash_update($hs, self::substr($sig, 0, 32));
-        self::hash_update($hs, self::substr($pk, 0, 32));
-        /** @var resource $hs */
-        $hs = self::updateHashWithFile($hs, $fp, $size);
-
-        /** @var string $hramHash */
-        $hramHash = hash_final($hs, true);
-
-        /** @var string $hram */
-        $hram = ParagonIE_Sodium_Core32_Ed25519::sc_reduce($hramHash);
-
-        /** @var string $sigAfter */
-        $sigAfter = ParagonIE_Sodium_Core32_Ed25519::sc_muladd($hram, $az, $nonce);
-
-        /** @var string $sig */
-        $sig = self::substr($sig, 0, 32) . self::substr($sigAfter, 0, 32);
-
-        try {
-            ParagonIE_Sodium_Compat::memzero($az);
-        } catch (SodiumException $ex) {
-            $az = null;
-        }
-        fclose($fp);
-        return $sig;
-    }
-
-    /**
-     *
-     * Verify a file (rather than a string). Uses less memory than
-     * ParagonIE_Sodium_Compat::crypto_sign_verify_detached(), but
-     * produces the same result. (32-bit)
-     *
-     * @param string $sig       Ed25519 signature
-     * @param string $filePath  Absolute path to a file on the filesystem
-     * @param string $publicKey Signing public key
-     *
-     * @return bool
-     * @throws SodiumException
-     * @throws Exception
-     */
-    public static function verify_core32($sig, $filePath, $publicKey)
-    {
-        /* Security checks */
-        if (ParagonIE_Sodium_Core32_Ed25519::check_S_lt_L(self::substr($sig, 32, 32))) {
-            throw new SodiumException('S < L - Invalid signature');
-        }
-        if (ParagonIE_Sodium_Core32_Ed25519::small_order($sig)) {
-            throw new SodiumException('Signature is on too small of an order');
-        }
-        if ((self::chrToInt($sig[63]) & 224) !== 0) {
-            throw new SodiumException('Invalid signature');
-        }
-        $d = 0;
-        for ($i = 0; $i < 32; ++$i) {
-            $d |= self::chrToInt($publicKey[$i]);
-        }
-        if ($d === 0) {
-            throw new SodiumException('All zero public key');
-        }
-
-        /** @var int|bool $size */
-        $size = filesize($filePath);
-        if (!is_int($size)) {
-            throw new SodiumException('Could not obtain the file size');
-        }
-        /** @var int $size */
-
-        /** @var resource|bool $fp */
-        $fp = fopen($filePath, 'rb');
-        if (!is_resource($fp)) {
-            throw new SodiumException('Could not open input file for reading');
-        }
-        /** @var resource $fp */
-
-        /** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */
-        $orig = ParagonIE_Sodium_Compat::$fastMult;
-
-        // Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.
-        ParagonIE_Sodium_Compat::$fastMult = true;
-
-        /** @var ParagonIE_Sodium_Core32_Curve25519_Ge_P3 $A */
-        $A = ParagonIE_Sodium_Core32_Ed25519::ge_frombytes_negate_vartime($publicKey);
-
-        $hs = hash_init('sha512');
-        self::hash_update($hs, self::substr($sig, 0, 32));
-        self::hash_update($hs, self::substr($publicKey, 0, 32));
-        /** @var resource $hs */
-        $hs = self::updateHashWithFile($hs, $fp, $size);
-        /** @var string $hDigest */
-        $hDigest = hash_final($hs, true);
-
-        /** @var string $h */
-        $h = ParagonIE_Sodium_Core32_Ed25519::sc_reduce($hDigest) . self::substr($hDigest, 32);
-
-        /** @var ParagonIE_Sodium_Core32_Curve25519_Ge_P2 $R */
-        $R = ParagonIE_Sodium_Core32_Ed25519::ge_double_scalarmult_vartime(
-            $h,
-            $A,
-            self::substr($sig, 32)
-        );
-
-        /** @var string $rcheck */
-        $rcheck = ParagonIE_Sodium_Core32_Ed25519::ge_tobytes($R);
-
-        // Close the file handle
-        fclose($fp);
-
-        // Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.
-        ParagonIE_Sodium_Compat::$fastMult = $orig;
-        return self::verify_32($rcheck, self::substr($sig, 0, 32));
-    }
-
-    /**
-     * Encrypt a file (32-bit)
-     *
-     * @param resource $ifp
-     * @param resource $ofp
-     * @param int $mlen
-     * @param string $nonce
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function secretbox_encrypt_core32($ifp, $ofp, $mlen, $nonce, $key)
-    {
-        $plaintext = fread($ifp, 32);
-        if (!is_string($plaintext)) {
-            throw new SodiumException('Could not read input file');
-        }
-        $first32 = self::ftell($ifp);
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $realNonce */
-        $realNonce = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
-
-        /** @var string $block0 */
-        $block0 = str_repeat("\x00", 32);
-
-        /** @var int $mlen - Length of the plaintext message */
-        $mlen0 = $mlen;
-        if ($mlen0 > 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES) {
-            $mlen0 = 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES;
-        }
-        $block0 .= ParagonIE_Sodium_Core32_Util::substr($plaintext, 0, $mlen0);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor(
-            $block0,
-            $realNonce,
-            $subkey
-        );
-
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State(
-            ParagonIE_Sodium_Core32_Util::substr(
-                $block0,
-                0,
-                ParagonIE_Sodium_Crypto::onetimeauth_poly1305_KEYBYTES
-            )
-        );
-
-        // Pre-write 16 blank bytes for the Poly1305 tag
-        $start = self::ftell($ofp);
-        fwrite($ofp, str_repeat("\x00", 16));
-
-        /** @var string $c */
-        $cBlock = ParagonIE_Sodium_Core32_Util::substr(
-            $block0,
-            ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES
-        );
-        $state->update($cBlock);
-        fwrite($ofp, $cBlock);
-        $mlen -= 32;
-
-        /** @var int $iter */
-        $iter = 1;
-
-        /** @var int $incr */
-        $incr = self::BUFFER_SIZE >> 6;
-
-        /*
+		$first32 = fread($ifp, 32);
+		if (!is_string($first32)) {
+			throw new SodiumException('Could not read input file');
+		}
+		$first32len = self::strlen($first32);
+		fwrite(
+			$ofp,
+			self::xorStrings(
+				self::substr($block0, 32, $first32len),
+				self::substr($first32, 0, $first32len)
+			)
+		);
+		$mlen -= 32;
+
+		/** @var int $iter */
+		$iter = 1;
+
+		/** @var int $incr */
+		$incr = self::BUFFER_SIZE >> 6;
+
+		/* Decrypts ciphertext, writes to output file. */
+		while ($mlen > 0) {
+			$blockSize = $mlen > self::BUFFER_SIZE
+				? self::BUFFER_SIZE
+				: $mlen;
+			$ciphertext = fread($ifp, $blockSize);
+			if (!is_string($ciphertext)) {
+				throw new SodiumException('Could not read input file');
+			}
+			$pBlock = ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic(
+				$ciphertext,
+				$realNonce,
+				$iter,
+				$subkey
+			);
+			fwrite($ofp, $pBlock, $blockSize);
+			$mlen -= $blockSize;
+			$iter += $incr;
+		}
+		return true;
+	}
+
+	/**
+	 * @param ParagonIE_Sodium_Core_Poly1305_State $state
+	 * @param resource $ifp
+	 * @param string $tag
+	 * @param int $mlen
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function onetimeauth_verify(
+		ParagonIE_Sodium_Core_Poly1305_State $state,
+		$ifp,
+		$tag = '',
+		$mlen = 0
+	) {
+		/** @var int $pos */
+		$pos = self::ftell($ifp);
+
+		/** @var int $iter */
+		$iter = 1;
+
+		/** @var int $incr */
+		$incr = self::BUFFER_SIZE >> 6;
+
+		while ($mlen > 0) {
+			$blockSize = $mlen > self::BUFFER_SIZE
+				? self::BUFFER_SIZE
+				: $mlen;
+			$ciphertext = fread($ifp, $blockSize);
+			if (!is_string($ciphertext)) {
+				throw new SodiumException('Could not read input file');
+			}
+			$state->update($ciphertext);
+			$mlen -= $blockSize;
+			$iter += $incr;
+		}
+		$res = ParagonIE_Sodium_Core_Util::verify_16($tag, $state->finish());
+
+		fseek($ifp, $pos, SEEK_SET);
+		return $res;
+	}
+
+	/**
+	 * Update a hash context with the contents of a file, without
+	 * loading the entire file into memory.
+	 *
+	 * @param resource|HashContext $hash
+	 * @param resource $fp
+	 * @param int $size
+	 * @return resource|object Resource on PHP < 7.2, HashContext object on PHP >= 7.2
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress PossiblyInvalidArgument
+	 *                 PHP 7.2 changes from a resource to an object,
+	 *                 which causes Psalm to complain about an error.
+	 * @psalm-suppress TypeCoercion
+	 *                 Ditto.
+	 */
+	public static function updateHashWithFile($hash, $fp, $size = 0)
+	{
+		/* Type checks: */
+		if (PHP_VERSION_ID < 70200) {
+			if (!is_resource($hash)) {
+				throw new TypeError('Argument 1 must be a resource, ' . gettype($hash) . ' given.');
+			}
+		} else {
+			if (!is_object($hash)) {
+				throw new TypeError('Argument 1 must be an object (PHP 7.2+), ' . gettype($hash) . ' given.');
+			}
+		}
+
+		if (!is_resource($fp)) {
+			throw new TypeError('Argument 2 must be a resource, ' . gettype($fp) . ' given.');
+		}
+		if (!is_int($size)) {
+			throw new TypeError('Argument 3 must be an integer, ' . gettype($size) . ' given.');
+		}
+
+		/** @var int $originalPosition */
+		$originalPosition = self::ftell($fp);
+
+		// Move file pointer to beginning of file
+		fseek($fp, 0, SEEK_SET);
+		for ($i = 0; $i < $size; $i += self::BUFFER_SIZE) {
+			/** @var string|bool $message */
+			$message = fread(
+				$fp,
+				($size - $i) > self::BUFFER_SIZE
+					? $size - $i
+					: self::BUFFER_SIZE
+			);
+			if (!is_string($message)) {
+				throw new SodiumException('Unexpected error reading from file.');
+			}
+			/** @var string $message */
+			/** @psalm-suppress InvalidArgument */
+			self::hash_update($hash, $message);
+		}
+		// Reset file pointer's position
+		fseek($fp, $originalPosition, SEEK_SET);
+		return $hash;
+	}
+
+	/**
+	 * Sign a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_sign_detached(), but produces
+	 * the same result. (32-bit)
+	 *
+	 * @param string $filePath  Absolute path to a file on the filesystem
+	 * @param string $secretKey Secret signing key
+	 *
+	 * @return string           Ed25519 signature
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	private static function sign_core32($filePath, $secretKey)
+	{
+		/** @var int|bool $size */
+		$size = filesize($filePath);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+		/** @var int $size */
+
+		/** @var resource|bool $fp */
+		$fp = fopen($filePath, 'rb');
+		if (!is_resource($fp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+		/** @var resource $fp */
+
+		/** @var string $az */
+		$az = hash('sha512', self::substr($secretKey, 0, 32), true);
+
+		$az[0] = self::intToChr(self::chrToInt($az[0]) & 248);
+		$az[31] = self::intToChr((self::chrToInt($az[31]) & 63) | 64);
+
+		$hs = hash_init('sha512');
+		self::hash_update($hs, self::substr($az, 32, 32));
+		/** @var resource $hs */
+		$hs = self::updateHashWithFile($hs, $fp, $size);
+
+		/** @var string $nonceHash */
+		$nonceHash = hash_final($hs, true);
+
+		/** @var string $pk */
+		$pk = self::substr($secretKey, 32, 32);
+
+		/** @var string $nonce */
+		$nonce = ParagonIE_Sodium_Core32_Ed25519::sc_reduce($nonceHash) . self::substr($nonceHash, 32);
+
+		/** @var string $sig */
+		$sig = ParagonIE_Sodium_Core32_Ed25519::ge_p3_tobytes(
+			ParagonIE_Sodium_Core32_Ed25519::ge_scalarmult_base($nonce)
+		);
+
+		$hs = hash_init('sha512');
+		self::hash_update($hs, self::substr($sig, 0, 32));
+		self::hash_update($hs, self::substr($pk, 0, 32));
+		/** @var resource $hs */
+		$hs = self::updateHashWithFile($hs, $fp, $size);
+
+		/** @var string $hramHash */
+		$hramHash = hash_final($hs, true);
+
+		/** @var string $hram */
+		$hram = ParagonIE_Sodium_Core32_Ed25519::sc_reduce($hramHash);
+
+		/** @var string $sigAfter */
+		$sigAfter = ParagonIE_Sodium_Core32_Ed25519::sc_muladd($hram, $az, $nonce);
+
+		/** @var string $sig */
+		$sig = self::substr($sig, 0, 32) . self::substr($sigAfter, 0, 32);
+
+		try {
+			ParagonIE_Sodium_Compat::memzero($az);
+		} catch (SodiumException $ex) {
+			$az = null;
+		}
+		fclose($fp);
+		return $sig;
+	}
+
+	/**
+	 *
+	 * Verify a file (rather than a string). Uses less memory than
+	 * ParagonIE_Sodium_Compat::crypto_sign_verify_detached(), but
+	 * produces the same result. (32-bit)
+	 *
+	 * @param string $sig       Ed25519 signature
+	 * @param string $filePath  Absolute path to a file on the filesystem
+	 * @param string $publicKey Signing public key
+	 *
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws Exception
+	 */
+	public static function verify_core32($sig, $filePath, $publicKey)
+	{
+		/* Security checks */
+		if (ParagonIE_Sodium_Core32_Ed25519::check_S_lt_L(self::substr($sig, 32, 32))) {
+			throw new SodiumException('S < L - Invalid signature');
+		}
+		if (ParagonIE_Sodium_Core32_Ed25519::small_order($sig)) {
+			throw new SodiumException('Signature is on too small of an order');
+		}
+		if ((self::chrToInt($sig[63]) & 224) !== 0) {
+			throw new SodiumException('Invalid signature');
+		}
+		$d = 0;
+		for ($i = 0; $i < 32; ++$i) {
+			$d |= self::chrToInt($publicKey[$i]);
+		}
+		if ($d === 0) {
+			throw new SodiumException('All zero public key');
+		}
+
+		/** @var int|bool $size */
+		$size = filesize($filePath);
+		if (!is_int($size)) {
+			throw new SodiumException('Could not obtain the file size');
+		}
+		/** @var int $size */
+
+		/** @var resource|bool $fp */
+		$fp = fopen($filePath, 'rb');
+		if (!is_resource($fp)) {
+			throw new SodiumException('Could not open input file for reading');
+		}
+		/** @var resource $fp */
+
+		/** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */
+		$orig = ParagonIE_Sodium_Compat::$fastMult;
+
+		// Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.
+		ParagonIE_Sodium_Compat::$fastMult = true;
+
+		/** @var ParagonIE_Sodium_Core32_Curve25519_Ge_P3 $A */
+		$A = ParagonIE_Sodium_Core32_Ed25519::ge_frombytes_negate_vartime($publicKey);
+
+		$hs = hash_init('sha512');
+		self::hash_update($hs, self::substr($sig, 0, 32));
+		self::hash_update($hs, self::substr($publicKey, 0, 32));
+		/** @var resource $hs */
+		$hs = self::updateHashWithFile($hs, $fp, $size);
+		/** @var string $hDigest */
+		$hDigest = hash_final($hs, true);
+
+		/** @var string $h */
+		$h = ParagonIE_Sodium_Core32_Ed25519::sc_reduce($hDigest) . self::substr($hDigest, 32);
+
+		/** @var ParagonIE_Sodium_Core32_Curve25519_Ge_P2 $R */
+		$R = ParagonIE_Sodium_Core32_Ed25519::ge_double_scalarmult_vartime(
+			$h,
+			$A,
+			self::substr($sig, 32)
+		);
+
+		/** @var string $rcheck */
+		$rcheck = ParagonIE_Sodium_Core32_Ed25519::ge_tobytes($R);
+
+		// Close the file handle
+		fclose($fp);
+
+		// Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.
+		ParagonIE_Sodium_Compat::$fastMult = $orig;
+		return self::verify_32($rcheck, self::substr($sig, 0, 32));
+	}
+
+	/**
+	 * Encrypt a file (32-bit)
+	 *
+	 * @param resource $ifp
+	 * @param resource $ofp
+	 * @param int $mlen
+	 * @param string $nonce
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function secretbox_encrypt_core32($ifp, $ofp, $mlen, $nonce, $key)
+	{
+		$plaintext = fread($ifp, 32);
+		if (!is_string($plaintext)) {
+			throw new SodiumException('Could not read input file');
+		}
+		$first32 = self::ftell($ifp);
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $realNonce */
+		$realNonce = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
+
+		/** @var string $block0 */
+		$block0 = str_repeat("\x00", 32);
+
+		/** @var int $mlen - Length of the plaintext message */
+		$mlen0 = $mlen;
+		if ($mlen0 > 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES) {
+			$mlen0 = 64 - ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES;
+		}
+		$block0 .= ParagonIE_Sodium_Core32_Util::substr($plaintext, 0, $mlen0);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor(
+			$block0,
+			$realNonce,
+			$subkey
+		);
+
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State(
+			ParagonIE_Sodium_Core32_Util::substr(
+				$block0,
+				0,
+				ParagonIE_Sodium_Crypto::onetimeauth_poly1305_KEYBYTES
+			)
+		);
+
+		// Pre-write 16 blank bytes for the Poly1305 tag
+		$start = self::ftell($ofp);
+		fwrite($ofp, str_repeat("\x00", 16));
+
+		/** @var string $c */
+		$cBlock = ParagonIE_Sodium_Core32_Util::substr(
+			$block0,
+			ParagonIE_Sodium_Crypto::secretbox_xsalsa20poly1305_ZEROBYTES
+		);
+		$state->update($cBlock);
+		fwrite($ofp, $cBlock);
+		$mlen -= 32;
+
+		/** @var int $iter */
+		$iter = 1;
+
+		/** @var int $incr */
+		$incr = self::BUFFER_SIZE >> 6;
+
+		/*
          * Set the cursor to the end of the first half-block. All future bytes will
          * generated from salsa20_xor_ic, starting from 1 (second block).
          */
-        fseek($ifp, $first32, SEEK_SET);
-
-        while ($mlen > 0) {
-            $blockSize = $mlen > self::BUFFER_SIZE
-                ? self::BUFFER_SIZE
-                : $mlen;
-            $plaintext = fread($ifp, $blockSize);
-            if (!is_string($plaintext)) {
-                throw new SodiumException('Could not read input file');
-            }
-            $cBlock = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
-                $plaintext,
-                $realNonce,
-                $iter,
-                $subkey
-            );
-            fwrite($ofp, $cBlock, $blockSize);
-            $state->update($cBlock);
-
-            $mlen -= $blockSize;
-            $iter += $incr;
-        }
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-            ParagonIE_Sodium_Compat::memzero($subkey);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-            $subkey = null;
-        }
-        $end = self::ftell($ofp);
-
-        /*
+		fseek($ifp, $first32, SEEK_SET);
+
+		while ($mlen > 0) {
+			$blockSize = $mlen > self::BUFFER_SIZE
+				? self::BUFFER_SIZE
+				: $mlen;
+			$plaintext = fread($ifp, $blockSize);
+			if (!is_string($plaintext)) {
+				throw new SodiumException('Could not read input file');
+			}
+			$cBlock = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
+				$plaintext,
+				$realNonce,
+				$iter,
+				$subkey
+			);
+			fwrite($ofp, $cBlock, $blockSize);
+			$state->update($cBlock);
+
+			$mlen -= $blockSize;
+			$iter += $incr;
+		}
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+			ParagonIE_Sodium_Compat::memzero($subkey);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+			$subkey = null;
+		}
+		$end = self::ftell($ofp);
+
+		/*
          * Write the Poly1305 authentication tag that provides integrity
          * over the ciphertext (encrypt-then-MAC)
          */
-        fseek($ofp, $start, SEEK_SET);
-        fwrite($ofp, $state->finish(), ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_MACBYTES);
-        fseek($ofp, $end, SEEK_SET);
-        unset($state);
-
-        return true;
-    }
-
-    /**
-     * Decrypt a file (32-bit)
-     *
-     * @param resource $ifp
-     * @param resource $ofp
-     * @param int $mlen
-     * @param string $nonce
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function secretbox_decrypt_core32($ifp, $ofp, $mlen, $nonce, $key)
-    {
-        $tag = fread($ifp, 16);
-        if (!is_string($tag)) {
-            throw new SodiumException('Could not read input file');
-        }
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $realNonce */
-        $realNonce = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20(
-            64,
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-
-        /* Verify the Poly1305 MAC -before- attempting to decrypt! */
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State(self::substr($block0, 0, 32));
-        if (!self::onetimeauth_verify_core32($state, $ifp, $tag, $mlen)) {
-            throw new SodiumException('Invalid MAC');
-        }
-
-        /*
+		fseek($ofp, $start, SEEK_SET);
+		fwrite($ofp, $state->finish(), ParagonIE_Sodium_Compat::CRYPTO_SECRETBOX_MACBYTES);
+		fseek($ofp, $end, SEEK_SET);
+		unset($state);
+
+		return true;
+	}
+
+	/**
+	 * Decrypt a file (32-bit)
+	 *
+	 * @param resource $ifp
+	 * @param resource $ofp
+	 * @param int $mlen
+	 * @param string $nonce
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function secretbox_decrypt_core32($ifp, $ofp, $mlen, $nonce, $key)
+	{
+		$tag = fread($ifp, 16);
+		if (!is_string($tag)) {
+			throw new SodiumException('Could not read input file');
+		}
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $realNonce */
+		$realNonce = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20(
+			64,
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+
+		/* Verify the Poly1305 MAC -before- attempting to decrypt! */
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State(self::substr($block0, 0, 32));
+		if (!self::onetimeauth_verify_core32($state, $ifp, $tag, $mlen)) {
+			throw new SodiumException('Invalid MAC');
+		}
+
+		/*
          * Set the cursor to the end of the first half-block. All future bytes will
          * generated from salsa20_xor_ic, starting from 1 (second block).
          */
-        $first32 = fread($ifp, 32);
-        if (!is_string($first32)) {
-            throw new SodiumException('Could not read input file');
-        }
-        $first32len = self::strlen($first32);
-        fwrite(
-            $ofp,
-            self::xorStrings(
-                self::substr($block0, 32, $first32len),
-                self::substr($first32, 0, $first32len)
-            )
-        );
-        $mlen -= 32;
-
-        /** @var int $iter */
-        $iter = 1;
-
-        /** @var int $incr */
-        $incr = self::BUFFER_SIZE >> 6;
-
-        /* Decrypts ciphertext, writes to output file. */
-        while ($mlen > 0) {
-            $blockSize = $mlen > self::BUFFER_SIZE
-                ? self::BUFFER_SIZE
-                : $mlen;
-            $ciphertext = fread($ifp, $blockSize);
-            if (!is_string($ciphertext)) {
-                throw new SodiumException('Could not read input file');
-            }
-            $pBlock = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
-                $ciphertext,
-                $realNonce,
-                $iter,
-                $subkey
-            );
-            fwrite($ofp, $pBlock, $blockSize);
-            $mlen -= $blockSize;
-            $iter += $incr;
-        }
-        return true;
-    }
-
-    /**
-     * One-time message authentication for 32-bit systems
-     *
-     * @param ParagonIE_Sodium_Core32_Poly1305_State $state
-     * @param resource $ifp
-     * @param string $tag
-     * @param int $mlen
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function onetimeauth_verify_core32(
-        ParagonIE_Sodium_Core32_Poly1305_State $state,
-        $ifp,
-        $tag = '',
-        $mlen = 0
-    ) {
-        /** @var int $pos */
-        $pos = self::ftell($ifp);
-
-        while ($mlen > 0) {
-            $blockSize = $mlen > self::BUFFER_SIZE
-                ? self::BUFFER_SIZE
-                : $mlen;
-            $ciphertext = fread($ifp, $blockSize);
-            if (!is_string($ciphertext)) {
-                throw new SodiumException('Could not read input file');
-            }
-            $state->update($ciphertext);
-            $mlen -= $blockSize;
-        }
-        $res = ParagonIE_Sodium_Core32_Util::verify_16($tag, $state->finish());
-
-        fseek($ifp, $pos, SEEK_SET);
-        return $res;
-    }
-
-    /**
-     * @param resource $resource
-     * @return int
-     * @throws SodiumException
-     */
-    private static function ftell($resource)
-    {
-        $return = ftell($resource);
-        if (!is_int($return)) {
-            throw new SodiumException('ftell() returned false');
-        }
-        return (int) $return;
-    }
+		$first32 = fread($ifp, 32);
+		if (!is_string($first32)) {
+			throw new SodiumException('Could not read input file');
+		}
+		$first32len = self::strlen($first32);
+		fwrite(
+			$ofp,
+			self::xorStrings(
+				self::substr($block0, 32, $first32len),
+				self::substr($first32, 0, $first32len)
+			)
+		);
+		$mlen -= 32;
+
+		/** @var int $iter */
+		$iter = 1;
+
+		/** @var int $incr */
+		$incr = self::BUFFER_SIZE >> 6;
+
+		/* Decrypts ciphertext, writes to output file. */
+		while ($mlen > 0) {
+			$blockSize = $mlen > self::BUFFER_SIZE
+				? self::BUFFER_SIZE
+				: $mlen;
+			$ciphertext = fread($ifp, $blockSize);
+			if (!is_string($ciphertext)) {
+				throw new SodiumException('Could not read input file');
+			}
+			$pBlock = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
+				$ciphertext,
+				$realNonce,
+				$iter,
+				$subkey
+			);
+			fwrite($ofp, $pBlock, $blockSize);
+			$mlen -= $blockSize;
+			$iter += $incr;
+		}
+		return true;
+	}
+
+	/**
+	 * One-time message authentication for 32-bit systems
+	 *
+	 * @param ParagonIE_Sodium_Core32_Poly1305_State $state
+	 * @param resource $ifp
+	 * @param string $tag
+	 * @param int $mlen
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function onetimeauth_verify_core32(
+		ParagonIE_Sodium_Core32_Poly1305_State $state,
+		$ifp,
+		$tag = '',
+		$mlen = 0
+	) {
+		/** @var int $pos */
+		$pos = self::ftell($ifp);
+
+		while ($mlen > 0) {
+			$blockSize = $mlen > self::BUFFER_SIZE
+				? self::BUFFER_SIZE
+				: $mlen;
+			$ciphertext = fread($ifp, $blockSize);
+			if (!is_string($ciphertext)) {
+				throw new SodiumException('Could not read input file');
+			}
+			$state->update($ciphertext);
+			$mlen -= $blockSize;
+		}
+		$res = ParagonIE_Sodium_Core32_Util::verify_16($tag, $state->finish());
+
+		fseek($ifp, $pos, SEEK_SET);
+		return $res;
+	}
+
+	/**
+	 * @param resource $resource
+	 * @return int
+	 * @throws SodiumException
+	 */
+	private static function ftell($resource)
+	{
+		$return = ftell($resource);
+		if (!is_int($return)) {
+			throw new SodiumException('ftell() returned false');
+		}
+		return (int) $return;
+	}
 }

vendor/paragonie/sodium_compat/src/PHP52/SplFixedArray.php

Indentation +174 added lines, -174 removed lines

@@ -1,7 +1,7 @@ 
 <?php
 
 if (class_exists('SplFixedArray')) {
-    return;
+	return;
 }
 
 /**
@@ -13,177 +13,177 @@ 
  */
 class SplFixedArray implements Iterator, ArrayAccess, Countable
 {
-    /** @var array<int, mixed> */
-    private $internalArray = array();
-
-    /** @var int $size */
-    private $size = 0;
-
-    /**
-     * SplFixedArray constructor.
-     * @param int $size
-     */
-    public function __construct($size = 0)
-    {
-        $this->size = $size;
-        $this->internalArray = array();
-    }
-
-    /**
-     * @return int
-     */
-    public function count()
-    {
-        return count($this->internalArray);
-    }
-
-    /**
-     * @return array
-     */
-    public function toArray()
-    {
-        ksort($this->internalArray);
-        return (array) $this->internalArray;
-    }
-
-    /**
-     * @param array $array
-     * @param bool $save_indexes
-     * @return SplFixedArray
-     * @psalm-suppress MixedAssignment
-     */
-    public static function fromArray(array $array, $save_indexes = true)
-    {
-        $self = new SplFixedArray(count($array));
-        if($save_indexes) {
-            foreach($array as $key => $value) {
-                $self[(int) $key] = $value;
-            }
-        } else {
-            $i = 0;
-            foreach (array_values($array) as $value) {
-                $self[$i] = $value;
-                $i++;
-            }
-        }
-        return $self;
-    }
-
-    /**
-     * @return int
-     */
-    public function getSize()
-    {
-        return $this->size;
-    }
-
-    /**
-     * @param int $size
-     * @return bool
-     */
-    public function setSize($size)
-    {
-        $this->size = $size;
-        return true;
-    }
-
-    /**
-     * @param string|int $index
-     * @return bool
-     */
-    public function offsetExists($index)
-    {
-        return array_key_exists((int) $index, $this->internalArray);
-    }
-
-    /**
-     * @param string|int $index
-     * @return mixed
-     */
-    public function offsetGet($index)
-    {
-        /** @psalm-suppress MixedReturnStatement */
-        return $this->internalArray[(int) $index];
-    }
-
-    /**
-     * @param string|int $index
-     * @param mixed $newval
-     * @psalm-suppress MixedAssignment
-     */
-    public function offsetSet($index, $newval)
-    {
-        $this->internalArray[(int) $index] = $newval;
-    }
-
-    /**
-     * @param string|int $index
-     */
-    public function offsetUnset($index)
-    {
-        unset($this->internalArray[(int) $index]);
-    }
-
-    /**
-     * Rewind iterator back to the start
-     * @link https://php.net/manual/en/splfixedarray.rewind.php
-     * @return void
-     * @since 5.3.0
-     */
-    public function rewind()
-    {
-        reset($this->internalArray);
-    }
-
-    /**
-     * Return current array entry
-     * @link https://php.net/manual/en/splfixedarray.current.php
-     * @return mixed The current element value.
-     * @since 5.3.0
-     */
-    public function current()
-    {
-        /** @psalm-suppress MixedReturnStatement */
-        return current($this->internalArray);
-    }
-
-    /**
-     * Return current array index
-     * @return int The current array index.
-     */
-    public function key()
-    {
-        return key($this->internalArray);
-    }
-
-    /**
-     * @return void
-     */
-    public function next()
-    {
-        next($this->internalArray);
-    }
-
-    /**
-     * Check whether the array contains more elements
-     * @link https://php.net/manual/en/splfixedarray.valid.php
-     * @return bool true if the array contains any more elements, false otherwise.
-     */
-    public function valid()
-    {
-        if (empty($this->internalArray)) {
-            return false;
-        }
-        $result = next($this->internalArray) !== false;
-        prev($this->internalArray);
-        return $result;
-    }
-
-    /**
-     * Do nothing.
-     */
-    public function __wakeup()
-    {
-        // NOP
-    }
+	/** @var array<int, mixed> */
+	private $internalArray = array();
+
+	/** @var int $size */
+	private $size = 0;
+
+	/**
+	 * SplFixedArray constructor.
+	 * @param int $size
+	 */
+	public function __construct($size = 0)
+	{
+		$this->size = $size;
+		$this->internalArray = array();
+	}
+
+	/**
+	 * @return int
+	 */
+	public function count()
+	{
+		return count($this->internalArray);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function toArray()
+	{
+		ksort($this->internalArray);
+		return (array) $this->internalArray;
+	}
+
+	/**
+	 * @param array $array
+	 * @param bool $save_indexes
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedAssignment
+	 */
+	public static function fromArray(array $array, $save_indexes = true)
+	{
+		$self = new SplFixedArray(count($array));
+		if($save_indexes) {
+			foreach($array as $key => $value) {
+				$self[(int) $key] = $value;
+			}
+		} else {
+			$i = 0;
+			foreach (array_values($array) as $value) {
+				$self[$i] = $value;
+				$i++;
+			}
+		}
+		return $self;
+	}
+
+	/**
+	 * @return int
+	 */
+	public function getSize()
+	{
+		return $this->size;
+	}
+
+	/**
+	 * @param int $size
+	 * @return bool
+	 */
+	public function setSize($size)
+	{
+		$this->size = $size;
+		return true;
+	}
+
+	/**
+	 * @param string|int $index
+	 * @return bool
+	 */
+	public function offsetExists($index)
+	{
+		return array_key_exists((int) $index, $this->internalArray);
+	}
+
+	/**
+	 * @param string|int $index
+	 * @return mixed
+	 */
+	public function offsetGet($index)
+	{
+		/** @psalm-suppress MixedReturnStatement */
+		return $this->internalArray[(int) $index];
+	}
+
+	/**
+	 * @param string|int $index
+	 * @param mixed $newval
+	 * @psalm-suppress MixedAssignment
+	 */
+	public function offsetSet($index, $newval)
+	{
+		$this->internalArray[(int) $index] = $newval;
+	}
+
+	/**
+	 * @param string|int $index
+	 */
+	public function offsetUnset($index)
+	{
+		unset($this->internalArray[(int) $index]);
+	}
+
+	/**
+	 * Rewind iterator back to the start
+	 * @link https://php.net/manual/en/splfixedarray.rewind.php
+	 * @return void
+	 * @since 5.3.0
+	 */
+	public function rewind()
+	{
+		reset($this->internalArray);
+	}
+
+	/**
+	 * Return current array entry
+	 * @link https://php.net/manual/en/splfixedarray.current.php
+	 * @return mixed The current element value.
+	 * @since 5.3.0
+	 */
+	public function current()
+	{
+		/** @psalm-suppress MixedReturnStatement */
+		return current($this->internalArray);
+	}
+
+	/**
+	 * Return current array index
+	 * @return int The current array index.
+	 */
+	public function key()
+	{
+		return key($this->internalArray);
+	}
+
+	/**
+	 * @return void
+	 */
+	public function next()
+	{
+		next($this->internalArray);
+	}
+
+	/**
+	 * Check whether the array contains more elements
+	 * @link https://php.net/manual/en/splfixedarray.valid.php
+	 * @return bool true if the array contains any more elements, false otherwise.
+	 */
+	public function valid()
+	{
+		if (empty($this->internalArray)) {
+			return false;
+		}
+		$result = next($this->internalArray) !== false;
+		prev($this->internalArray);
+		return $result;
+	}
+
+	/**
+	 * Do nothing.
+	 */
+	public function __wakeup()
+	{
+		// NOP
+	}
 }
\ No newline at end of file

vendor/paragonie/sodium_compat/src/Compat.php

Indentation +3914 added lines, -3914 removed lines

@@ -22,3926 +22,3926 @@
  */
 
 if (class_exists('ParagonIE_Sodium_Compat', false)) {
-    return;
+	return;
 }
 
 class ParagonIE_Sodium_Compat
 {
-    /**
-     * This parameter prevents the use of the PECL extension.
-     * It should only be used for unit testing.
-     *
-     * @var bool
-     */
-    public static $disableFallbackForUnitTests = false;
-
-    /**
-     * Use fast multiplication rather than our constant-time multiplication
-     * implementation. Can be enabled at runtime. Only enable this if you
-     * are absolutely certain that there is no timing leak on your platform.
-     *
-     * @var bool
-     */
-    public static $fastMult = false;
-
-    const LIBRARY_MAJOR_VERSION = 9;
-    const LIBRARY_MINOR_VERSION = 1;
-    const LIBRARY_VERSION_MAJOR = 9;
-    const LIBRARY_VERSION_MINOR = 1;
-    const VERSION_STRING = 'polyfill-1.0.8';
-
-    // From libsodium
-    const BASE64_VARIANT_ORIGINAL = 1;
-    const BASE64_VARIANT_ORIGINAL_NO_PADDING = 3;
-    const BASE64_VARIANT_URLSAFE = 5;
-    const BASE64_VARIANT_URLSAFE_NO_PADDING = 7;
-    const CRYPTO_AEAD_AES256GCM_KEYBYTES = 32;
-    const CRYPTO_AEAD_AES256GCM_NSECBYTES = 0;
-    const CRYPTO_AEAD_AES256GCM_NPUBBYTES = 12;
-    const CRYPTO_AEAD_AES256GCM_ABYTES = 16;
-    const CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES = 32;
-    const CRYPTO_AEAD_CHACHA20POLY1305_NSECBYTES = 0;
-    const CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES = 8;
-    const CRYPTO_AEAD_CHACHA20POLY1305_ABYTES = 16;
-    const CRYPTO_AEAD_CHACHA20POLY1305_IETF_KEYBYTES = 32;
-    const CRYPTO_AEAD_CHACHA20POLY1305_IETF_NSECBYTES = 0;
-    const CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES = 12;
-    const CRYPTO_AEAD_CHACHA20POLY1305_IETF_ABYTES = 16;
-    const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES = 32;
-    const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NSECBYTES = 0;
-    const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES = 24;
-    const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES = 16;
-    const CRYPTO_AUTH_BYTES = 32;
-    const CRYPTO_AUTH_KEYBYTES = 32;
-    const CRYPTO_BOX_SEALBYTES = 16;
-    const CRYPTO_BOX_SECRETKEYBYTES = 32;
-    const CRYPTO_BOX_PUBLICKEYBYTES = 32;
-    const CRYPTO_BOX_KEYPAIRBYTES = 64;
-    const CRYPTO_BOX_MACBYTES = 16;
-    const CRYPTO_BOX_NONCEBYTES = 24;
-    const CRYPTO_BOX_SEEDBYTES = 32;
-    const CRYPTO_CORE_RISTRETTO255_BYTES = 32;
-    const CRYPTO_CORE_RISTRETTO255_SCALARBYTES = 32;
-    const CRYPTO_CORE_RISTRETTO255_HASHBYTES = 64;
-    const CRYPTO_CORE_RISTRETTO255_NONREDUCEDSCALARBYTES = 64;
-    const CRYPTO_KDF_BYTES_MIN = 16;
-    const CRYPTO_KDF_BYTES_MAX = 64;
-    const CRYPTO_KDF_CONTEXTBYTES = 8;
-    const CRYPTO_KDF_KEYBYTES = 32;
-    const CRYPTO_KX_BYTES = 32;
-    const CRYPTO_KX_PRIMITIVE = 'x25519blake2b';
-    const CRYPTO_KX_SEEDBYTES = 32;
-    const CRYPTO_KX_KEYPAIRBYTES = 64;
-    const CRYPTO_KX_PUBLICKEYBYTES = 32;
-    const CRYPTO_KX_SECRETKEYBYTES = 32;
-    const CRYPTO_KX_SESSIONKEYBYTES = 32;
-    const CRYPTO_GENERICHASH_BYTES = 32;
-    const CRYPTO_GENERICHASH_BYTES_MIN = 16;
-    const CRYPTO_GENERICHASH_BYTES_MAX = 64;
-    const CRYPTO_GENERICHASH_KEYBYTES = 32;
-    const CRYPTO_GENERICHASH_KEYBYTES_MIN = 16;
-    const CRYPTO_GENERICHASH_KEYBYTES_MAX = 64;
-    const CRYPTO_PWHASH_SALTBYTES = 16;
-    const CRYPTO_PWHASH_STRPREFIX = '$argon2id$';
-    const CRYPTO_PWHASH_ALG_ARGON2I13 = 1;
-    const CRYPTO_PWHASH_ALG_ARGON2ID13 = 2;
-    const CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE = 33554432;
-    const CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE = 4;
-    const CRYPTO_PWHASH_MEMLIMIT_MODERATE = 134217728;
-    const CRYPTO_PWHASH_OPSLIMIT_MODERATE = 6;
-    const CRYPTO_PWHASH_MEMLIMIT_SENSITIVE = 536870912;
-    const CRYPTO_PWHASH_OPSLIMIT_SENSITIVE = 8;
-    const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_SALTBYTES = 32;
-    const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_STRPREFIX = '$7$';
-    const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_INTERACTIVE = 534288;
-    const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_INTERACTIVE = 16777216;
-    const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_SENSITIVE = 33554432;
-    const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_SENSITIVE = 1073741824;
-    const CRYPTO_SCALARMULT_BYTES = 32;
-    const CRYPTO_SCALARMULT_SCALARBYTES = 32;
-    const CRYPTO_SCALARMULT_RISTRETTO255_BYTES = 32;
-    const CRYPTO_SCALARMULT_RISTRETTO255_SCALARBYTES = 32;
-    const CRYPTO_SHORTHASH_BYTES = 8;
-    const CRYPTO_SHORTHASH_KEYBYTES = 16;
-    const CRYPTO_SECRETBOX_KEYBYTES = 32;
-    const CRYPTO_SECRETBOX_MACBYTES = 16;
-    const CRYPTO_SECRETBOX_NONCEBYTES = 24;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES = 17;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_HEADERBYTES = 24;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_KEYBYTES = 32;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_PUSH = 0;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_PULL = 1;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY = 2;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_FINAL = 3;
-    const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX = 0x3fffffff80;
-    const CRYPTO_SIGN_BYTES = 64;
-    const CRYPTO_SIGN_SEEDBYTES = 32;
-    const CRYPTO_SIGN_PUBLICKEYBYTES = 32;
-    const CRYPTO_SIGN_SECRETKEYBYTES = 64;
-    const CRYPTO_SIGN_KEYPAIRBYTES = 96;
-    const CRYPTO_STREAM_KEYBYTES = 32;
-    const CRYPTO_STREAM_NONCEBYTES = 24;
-    const CRYPTO_STREAM_XCHACHA20_KEYBYTES = 32;
-    const CRYPTO_STREAM_XCHACHA20_NONCEBYTES = 24;
-
-    /**
-     * Add two numbers (little-endian unsigned), storing the value in the first
-     * parameter.
-     *
-     * This mutates $val.
-     *
-     * @param string $val
-     * @param string $addv
-     * @return void
-     * @throws SodiumException
-     */
-    public static function add(&$val, $addv)
-    {
-        $val_len = ParagonIE_Sodium_Core_Util::strlen($val);
-        $addv_len = ParagonIE_Sodium_Core_Util::strlen($addv);
-        if ($val_len !== $addv_len) {
-            throw new SodiumException('values must have the same length');
-        }
-        $A = ParagonIE_Sodium_Core_Util::stringToIntArray($val);
-        $B = ParagonIE_Sodium_Core_Util::stringToIntArray($addv);
-
-        $c = 0;
-        for ($i = 0; $i < $val_len; $i++) {
-            $c += ($A[$i] + $B[$i]);
-            $A[$i] = ($c & 0xff);
-            $c >>= 8;
-        }
-        $val = ParagonIE_Sodium_Core_Util::intArrayToString($A);
-    }
-
-    /**
-     * @param string $encoded
-     * @param int $variant
-     * @param string $ignore
-     * @return string
-     * @throws SodiumException
-     */
-    public static function base642bin($encoded, $variant, $ignore = '')
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($encoded, 'string', 1);
-
-        /** @var string $encoded */
-        $encoded = (string) $encoded;
-        if (ParagonIE_Sodium_Core_Util::strlen($encoded) === 0) {
-            return '';
-        }
-
-        // Just strip before decoding
-        if (!empty($ignore)) {
-            $encoded = str_replace($ignore, '', $encoded);
-        }
-
-        try {
-            switch ($variant) {
-                case self::BASE64_VARIANT_ORIGINAL:
-                    return ParagonIE_Sodium_Core_Base64_Original::decode($encoded, true);
-                case self::BASE64_VARIANT_ORIGINAL_NO_PADDING:
-                    return ParagonIE_Sodium_Core_Base64_Original::decode($encoded, false);
-                case self::BASE64_VARIANT_URLSAFE:
-                    return ParagonIE_Sodium_Core_Base64_UrlSafe::decode($encoded, true);
-                case self::BASE64_VARIANT_URLSAFE_NO_PADDING:
-                    return ParagonIE_Sodium_Core_Base64_UrlSafe::decode($encoded, false);
-                default:
-                    throw new SodiumException('invalid base64 variant identifier');
-            }
-        } catch (Exception $ex) {
-            if ($ex instanceof SodiumException) {
-                throw $ex;
-            }
-            throw new SodiumException('invalid base64 string');
-        }
-    }
-
-    /**
-     * @param string $decoded
-     * @param int $variant
-     * @return string
-     * @throws SodiumException
-     */
-    public static function bin2base64($decoded, $variant)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($decoded, 'string', 1);
-        /** @var string $decoded */
-        $decoded = (string) $decoded;
-        if (ParagonIE_Sodium_Core_Util::strlen($decoded) === 0) {
-            return '';
-        }
-
-        switch ($variant) {
-            case self::BASE64_VARIANT_ORIGINAL:
-                return ParagonIE_Sodium_Core_Base64_Original::encode($decoded);
-            case self::BASE64_VARIANT_ORIGINAL_NO_PADDING:
-                return ParagonIE_Sodium_Core_Base64_Original::encodeUnpadded($decoded);
-            case self::BASE64_VARIANT_URLSAFE:
-                return ParagonIE_Sodium_Core_Base64_UrlSafe::encode($decoded);
-            case self::BASE64_VARIANT_URLSAFE_NO_PADDING:
-                return ParagonIE_Sodium_Core_Base64_UrlSafe::encodeUnpadded($decoded);
-            default:
-                throw new SodiumException('invalid base64 variant identifier');
-        }
-    }
-
-    /**
-     * Cache-timing-safe implementation of bin2hex().
-     *
-     * @param string $string A string (probably raw binary)
-     * @return string        A hexadecimal-encoded string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function bin2hex($string)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($string, 'string', 1);
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_bin2hex($string);
-        }
-        if (self::use_fallback('bin2hex')) {
-            return (string) call_user_func('\\Sodium\\bin2hex', $string);
-        }
-        return ParagonIE_Sodium_Core_Util::bin2hex($string);
-    }
-
-    /**
-     * Compare two strings, in constant-time.
-     * Compared to memcmp(), compare() is more useful for sorting.
-     *
-     * @param string $left  The left operand; must be a string
-     * @param string $right The right operand; must be a string
-     * @return int          If < 0 if the left operand is less than the right
-     *                      If = 0 if both strings are equal
-     *                      If > 0 if the right operand is less than the left
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function compare($left, $right)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($left, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($right, 'string', 2);
-
-        if (self::useNewSodiumAPI()) {
-            return (int) sodium_compare($left, $right);
-        }
-        if (self::use_fallback('compare')) {
-            return (int) call_user_func('\\Sodium\\compare', $left, $right);
-        }
-        return ParagonIE_Sodium_Core_Util::compare($left, $right);
-    }
-
-    /**
-     * Is AES-256-GCM even available to use?
-     *
-     * @return bool
-     * @psalm-suppress UndefinedFunction
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_aead_aes256gcm_is_available()
-    {
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_aead_aes256gcm_is_available();
-        }
-        if (self::use_fallback('crypto_aead_aes256gcm_is_available')) {
-            return call_user_func('\\Sodium\\crypto_aead_aes256gcm_is_available');
-        }
-        if (PHP_VERSION_ID < 70100) {
-            // OpenSSL doesn't support AEAD before 7.1.0
-            return false;
-        }
-        if (!is_callable('openssl_encrypt') || !is_callable('openssl_decrypt')) {
-            // OpenSSL isn't installed
-            return false;
-        }
-        return (bool) in_array('aes-256-gcm', openssl_get_cipher_methods());
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data: Decryption
-     *
-     * Algorithm:
-     *     AES-256-GCM
-     *
-     * This mode uses a 64-bit random nonce with a 64-bit counter.
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     *
-     * @param string $ciphertext Encrypted message (with Poly1305 MAC appended)
-     * @param string $assocData  Authenticated Associated Data (unencrypted)
-     * @param string $nonce      Number to be used only Once; must be 8 bytes
-     * @param string $key        Encryption key
-     *
-     * @return string|bool       The original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_aead_aes256gcm_decrypt(
-        $ciphertext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        if (!self::crypto_aead_aes256gcm_is_available()) {
-            throw new SodiumException('AES-256-GCM is not available');
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_AES256GCM_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_AES256GCM_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_AES256GCM_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_AES256GCM_KEYBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_AES256GCM_ABYTES) {
-            throw new SodiumException('Message must be at least CRYPTO_AEAD_AES256GCM_ABYTES long');
-        }
-        if (!is_callable('openssl_decrypt')) {
-            throw new SodiumException('The OpenSSL extension is not installed, or openssl_decrypt() is not available');
-        }
-
-        /** @var string $ctext */
-        $ctext = ParagonIE_Sodium_Core_Util::substr($ciphertext, 0, -self::CRYPTO_AEAD_AES256GCM_ABYTES);
-        /** @var string $authTag */
-        $authTag = ParagonIE_Sodium_Core_Util::substr($ciphertext, -self::CRYPTO_AEAD_AES256GCM_ABYTES, 16);
-        return openssl_decrypt(
-            $ctext,
-            'aes-256-gcm',
-            $key,
-            OPENSSL_RAW_DATA,
-            $nonce,
-            $authTag,
-            $assocData
-        );
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data: Encryption
-     *
-     * Algorithm:
-     *     AES-256-GCM
-     *
-     * @param string $plaintext Message to be encrypted
-     * @param string $assocData Authenticated Associated Data (unencrypted)
-     * @param string $nonce     Number to be used only Once; must be 8 bytes
-     * @param string $key       Encryption key
-     *
-     * @return string           Ciphertext with a 16-byte GCM message
-     *                          authentication code appended
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_aead_aes256gcm_encrypt(
-        $plaintext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        if (!self::crypto_aead_aes256gcm_is_available()) {
-            throw new SodiumException('AES-256-GCM is not available');
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_AES256GCM_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_AES256GCM_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_AES256GCM_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_AES256GCM_KEYBYTES long');
-        }
-
-        if (!is_callable('openssl_encrypt')) {
-            throw new SodiumException('The OpenSSL extension is not installed, or openssl_encrypt() is not available');
-        }
-
-        $authTag = '';
-        $ciphertext = openssl_encrypt(
-            $plaintext,
-            'aes-256-gcm',
-            $key,
-            OPENSSL_RAW_DATA,
-            $nonce,
-            $authTag,
-            $assocData
-        );
-        return $ciphertext . $authTag;
-    }
-
-    /**
-     * Return a secure random key for use with the AES-256-GCM
-     * symmetric AEAD interface.
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_aead_aes256gcm_keygen()
-    {
-        return random_bytes(self::CRYPTO_AEAD_AES256GCM_KEYBYTES);
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data: Decryption
-     *
-     * Algorithm:
-     *     ChaCha20-Poly1305
-     *
-     * This mode uses a 64-bit random nonce with a 64-bit counter.
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     *
-     * @param string $ciphertext Encrypted message (with Poly1305 MAC appended)
-     * @param string $assocData  Authenticated Associated Data (unencrypted)
-     * @param string $nonce      Number to be used only Once; must be 8 bytes
-     * @param string $key        Encryption key
-     *
-     * @return string            The original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_aead_chacha20poly1305_decrypt(
-        $ciphertext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_CHACHA20POLY1305_ABYTES) {
-            throw new SodiumException('Message must be at least CRYPTO_AEAD_CHACHA20POLY1305_ABYTES long');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            /**
-             * @psalm-suppress InvalidReturnStatement
-             * @psalm-suppress FalsableReturnStatement
-             */
-            return sodium_crypto_aead_chacha20poly1305_decrypt(
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (self::use_fallback('crypto_aead_chacha20poly1305_decrypt')) {
-            return call_user_func(
-                '\\Sodium\\crypto_aead_chacha20poly1305_decrypt',
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_decrypt(
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_decrypt(
-            $ciphertext,
-            $assocData,
-            $nonce,
-            $key
-        );
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data
-     *
-     * Algorithm:
-     *     ChaCha20-Poly1305
-     *
-     * This mode uses a 64-bit random nonce with a 64-bit counter.
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     *
-     * @param string $plaintext Message to be encrypted
-     * @param string $assocData Authenticated Associated Data (unencrypted)
-     * @param string $nonce     Number to be used only Once; must be 8 bytes
-     * @param string $key       Encryption key
-     *
-     * @return string           Ciphertext with a 16-byte Poly1305 message
-     *                          authentication code appended
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_aead_chacha20poly1305_encrypt(
-        $plaintext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_aead_chacha20poly1305_encrypt(
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (self::use_fallback('crypto_aead_chacha20poly1305_encrypt')) {
-            return (string) call_user_func(
-                '\\Sodium\\crypto_aead_chacha20poly1305_encrypt',
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_encrypt(
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_encrypt(
-            $plaintext,
-            $assocData,
-            $nonce,
-            $key
-        );
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data: Decryption
-     *
-     * Algorithm:
-     *     ChaCha20-Poly1305
-     *
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     * Regular mode uses a 64-bit random nonce with a 64-bit counter.
-     *
-     * @param string $ciphertext Encrypted message (with Poly1305 MAC appended)
-     * @param string $assocData  Authenticated Associated Data (unencrypted)
-     * @param string $nonce      Number to be used only Once; must be 12 bytes
-     * @param string $key        Encryption key
-     *
-     * @return string            The original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_aead_chacha20poly1305_ietf_decrypt(
-        $ciphertext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_CHACHA20POLY1305_ABYTES) {
-            throw new SodiumException('Message must be at least CRYPTO_AEAD_CHACHA20POLY1305_ABYTES long');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            /**
-             * @psalm-suppress InvalidReturnStatement
-             * @psalm-suppress FalsableReturnStatement
-             */
-            return sodium_crypto_aead_chacha20poly1305_ietf_decrypt(
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (self::use_fallback('crypto_aead_chacha20poly1305_ietf_decrypt')) {
-            return call_user_func(
-                '\\Sodium\\crypto_aead_chacha20poly1305_ietf_decrypt',
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_ietf_decrypt(
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_ietf_decrypt(
-            $ciphertext,
-            $assocData,
-            $nonce,
-            $key
-        );
-    }
-
-    /**
-     * Return a secure random key for use with the ChaCha20-Poly1305
-     * symmetric AEAD interface.
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_aead_chacha20poly1305_keygen()
-    {
-        return random_bytes(self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES);
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data
-     *
-     * Algorithm:
-     *     ChaCha20-Poly1305
-     *
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     * Regular mode uses a 64-bit random nonce with a 64-bit counter.
-     *
-     * @param string $plaintext Message to be encrypted
-     * @param string $assocData Authenticated Associated Data (unencrypted)
-     * @param string $nonce Number to be used only Once; must be 8 bytes
-     * @param string $key Encryption key
-     *
-     * @return string           Ciphertext with a 16-byte Poly1305 message
-     *                          authentication code appended
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_aead_chacha20poly1305_ietf_encrypt(
-        $plaintext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        if (!is_null($assocData)) {
-            ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_aead_chacha20poly1305_ietf_encrypt(
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (self::use_fallback('crypto_aead_chacha20poly1305_ietf_encrypt')) {
-            return (string) call_user_func(
-                '\\Sodium\\crypto_aead_chacha20poly1305_ietf_encrypt',
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_ietf_encrypt(
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_ietf_encrypt(
-            $plaintext,
-            $assocData,
-            $nonce,
-            $key
-        );
-    }
-
-    /**
-     * Return a secure random key for use with the ChaCha20-Poly1305
-     * symmetric AEAD interface. (IETF version)
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_aead_chacha20poly1305_ietf_keygen()
-    {
-        return random_bytes(self::CRYPTO_AEAD_CHACHA20POLY1305_IETF_KEYBYTES);
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data: Decryption
-     *
-     * Algorithm:
-     *     XChaCha20-Poly1305
-     *
-     * This mode uses a 64-bit random nonce with a 64-bit counter.
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     *
-     * @param string $ciphertext   Encrypted message (with Poly1305 MAC appended)
-     * @param string $assocData    Authenticated Associated Data (unencrypted)
-     * @param string $nonce        Number to be used only Once; must be 8 bytes
-     * @param string $key          Encryption key
-     * @param bool   $dontFallback Don't fallback to ext/sodium
-     *
-     * @return string|bool         The original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_aead_xchacha20poly1305_ietf_decrypt(
-        $ciphertext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = '',
-        $dontFallback = false
-    ) {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        if (!is_null($assocData)) {
-            ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        } else {
-            $assocData = '';
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES) {
-            throw new SodiumException('Message must be at least CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES long');
-        }
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            if (is_callable('sodium_crypto_aead_xchacha20poly1305_ietf_decrypt')) {
-                return sodium_crypto_aead_xchacha20poly1305_ietf_decrypt(
-                    $ciphertext,
-                    $assocData,
-                    $nonce,
-                    $key
-                );
-            }
-        }
-
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::aead_xchacha20poly1305_ietf_decrypt(
-                $ciphertext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        return ParagonIE_Sodium_Crypto::aead_xchacha20poly1305_ietf_decrypt(
-            $ciphertext,
-            $assocData,
-            $nonce,
-            $key
-        );
-    }
-
-    /**
-     * Authenticated Encryption with Associated Data
-     *
-     * Algorithm:
-     *     XChaCha20-Poly1305
-     *
-     * This mode uses a 64-bit random nonce with a 64-bit counter.
-     * IETF mode uses a 96-bit random nonce with a 32-bit counter.
-     *
-     * @param string $plaintext    Message to be encrypted
-     * @param string $assocData    Authenticated Associated Data (unencrypted)
-     * @param string $nonce        Number to be used only Once; must be 8 bytes
-     * @param string $key          Encryption key
-     * @param bool   $dontFallback Don't fallback to ext/sodium
-     *
-     * @return string           Ciphertext with a 16-byte Poly1305 message
-     *                          authentication code appended
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_aead_xchacha20poly1305_ietf_encrypt(
-        $plaintext = '',
-        $assocData = '',
-        $nonce = '',
-        $key = '',
-        $dontFallback = false
-    ) {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        if (!is_null($assocData)) {
-            ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
-        } else {
-            $assocData = '';
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES) {
-            throw new SodiumException('Nonce must be CRYPTO_AEAD_XCHACHA20POLY1305_NPUBBYTES long');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES) {
-            throw new SodiumException('Key must be CRYPTO_AEAD_XCHACHA20POLY1305_KEYBYTES long');
-        }
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            if (is_callable('sodium_crypto_aead_xchacha20poly1305_ietf_encrypt')) {
-                return sodium_crypto_aead_xchacha20poly1305_ietf_encrypt(
-                    $plaintext,
-                    $assocData,
-                    $nonce,
-                    $key
-                );
-            }
-        }
-
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::aead_xchacha20poly1305_ietf_encrypt(
-                $plaintext,
-                $assocData,
-                $nonce,
-                $key
-            );
-        }
-        return ParagonIE_Sodium_Crypto::aead_xchacha20poly1305_ietf_encrypt(
-            $plaintext,
-            $assocData,
-            $nonce,
-            $key
-        );
-    }
-
-    /**
-     * Return a secure random key for use with the XChaCha20-Poly1305
-     * symmetric AEAD interface.
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_aead_xchacha20poly1305_ietf_keygen()
-    {
-        return random_bytes(self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES);
-    }
-
-    /**
-     * Authenticate a message. Uses symmetric-key cryptography.
-     *
-     * Algorithm:
-     *     HMAC-SHA512-256. Which is HMAC-SHA-512 truncated to 256 bits.
-     *     Not to be confused with HMAC-SHA-512/256 which would use the
-     *     SHA-512/256 hash function (uses different initial parameters
-     *     but still truncates to 256 bits to sidestep length-extension
-     *     attacks).
-     *
-     * @param string $message Message to be authenticated
-     * @param string $key Symmetric authentication key
-     * @return string         Message authentication code
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_auth($message, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AUTH_KEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_AUTH_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_auth($message, $key);
-        }
-        if (self::use_fallback('crypto_auth')) {
-            return (string) call_user_func('\\Sodium\\crypto_auth', $message, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::auth($message, $key);
-        }
-        return ParagonIE_Sodium_Crypto::auth($message, $key);
-    }
-
-    /**
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_auth_keygen()
-    {
-        return random_bytes(self::CRYPTO_AUTH_KEYBYTES);
-    }
-
-    /**
-     * Verify the MAC of a message previously authenticated with crypto_auth.
-     *
-     * @param string $mac Message authentication code
-     * @param string $message Message whose authenticity you are attempting to
-     *                        verify (with a given MAC and key)
-     * @param string $key Symmetric authentication key
-     * @return bool           TRUE if authenticated, FALSE otherwise
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_auth_verify($mac, $message, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($mac, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($mac) !== self::CRYPTO_AUTH_BYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_AUTH_BYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AUTH_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_AUTH_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (bool) sodium_crypto_auth_verify($mac, $message, $key);
-        }
-        if (self::use_fallback('crypto_auth_verify')) {
-            return (bool) call_user_func('\\Sodium\\crypto_auth_verify', $mac, $message, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::auth_verify($mac, $message, $key);
-        }
-        return ParagonIE_Sodium_Crypto::auth_verify($mac, $message, $key);
-    }
-
-    /**
-     * Authenticated asymmetric-key encryption. Both the sender and recipient
-     * may decrypt messages.
-     *
-     * Algorithm: X25519-XSalsa20-Poly1305.
-     *     X25519: Elliptic-Curve Diffie Hellman over Curve25519.
-     *     XSalsa20: Extended-nonce variant of salsa20.
-     *     Poyl1305: Polynomial MAC for one-time message authentication.
-     *
-     * @param string $plaintext The message to be encrypted
-     * @param string $nonce A Number to only be used Once; must be 24 bytes
-     * @param string $keypair Your secret key and your recipient's public key
-     * @return string           Ciphertext with 16-byte Poly1305 MAC
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box($plaintext, $nonce, $keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_BOX_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_BOX_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box($plaintext, $nonce, $keypair);
-        }
-        if (self::use_fallback('crypto_box')) {
-            return (string) call_user_func('\\Sodium\\crypto_box', $plaintext, $nonce, $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box($plaintext, $nonce, $keypair);
-        }
-        return ParagonIE_Sodium_Crypto::box($plaintext, $nonce, $keypair);
-    }
-
-    /**
-     * Anonymous public-key encryption. Only the recipient may decrypt messages.
-     *
-     * Algorithm: X25519-XSalsa20-Poly1305, as with crypto_box.
-     *     The sender's X25519 keypair is ephemeral.
-     *     Nonce is generated from the BLAKE2b hash of both public keys.
-     *
-     * This provides ciphertext integrity.
-     *
-     * @param string $plaintext Message to be sealed
-     * @param string $publicKey Your recipient's public key
-     * @return string           Sealed message that only your recipient can
-     *                          decrypt
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box_seal($plaintext, $publicKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_seal($plaintext, $publicKey);
-        }
-        if (self::use_fallback('crypto_box_seal')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_seal', $plaintext, $publicKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_seal($plaintext, $publicKey);
-        }
-        return ParagonIE_Sodium_Crypto::box_seal($plaintext, $publicKey);
-    }
-
-    /**
-     * Opens a message encrypted with crypto_box_seal(). Requires
-     * the recipient's keypair (sk || pk) to decrypt successfully.
-     *
-     * This validates ciphertext integrity.
-     *
-     * @param string $ciphertext Sealed message to be opened
-     * @param string $keypair    Your crypto_box keypair
-     * @return string            The original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_box_seal_open($ciphertext, $keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            /**
-             * @psalm-suppress InvalidReturnStatement
-             * @psalm-suppress FalsableReturnStatement
-             */
-            return sodium_crypto_box_seal_open($ciphertext, $keypair);
-        }
-        if (self::use_fallback('crypto_box_seal_open')) {
-            return call_user_func('\\Sodium\\crypto_box_seal_open', $ciphertext, $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_seal_open($ciphertext, $keypair);
-        }
-        return ParagonIE_Sodium_Crypto::box_seal_open($ciphertext, $keypair);
-    }
-
-    /**
-     * Generate a new random X25519 keypair.
-     *
-     * @return string A 64-byte string; the first 32 are your secret key, while
-     *                the last 32 are your public key. crypto_box_secretkey()
-     *                and crypto_box_publickey() exist to separate them so you
-     *                don't accidentally get them mixed up!
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box_keypair()
-    {
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_keypair();
-        }
-        if (self::use_fallback('crypto_box_keypair')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_keypair');
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_keypair();
-        }
-        return ParagonIE_Sodium_Crypto::box_keypair();
-    }
-
-    /**
-     * Combine two keys into a keypair for use in library methods that expect
-     * a keypair. This doesn't necessarily have to be the same person's keys.
-     *
-     * @param string $secretKey Secret key
-     * @param string $publicKey Public key
-     * @return string    Keypair
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box_keypair_from_secretkey_and_publickey($secretKey, $publicKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_keypair_from_secretkey_and_publickey($secretKey, $publicKey);
-        }
-        if (self::use_fallback('crypto_box_keypair_from_secretkey_and_publickey')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_keypair_from_secretkey_and_publickey', $secretKey, $publicKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_keypair_from_secretkey_and_publickey($secretKey, $publicKey);
-        }
-        return ParagonIE_Sodium_Crypto::box_keypair_from_secretkey_and_publickey($secretKey, $publicKey);
-    }
-
-    /**
-     * Decrypt a message previously encrypted with crypto_box().
-     *
-     * @param string $ciphertext Encrypted message
-     * @param string $nonce      Number to only be used Once; must be 24 bytes
-     * @param string $keypair    Your secret key and the sender's public key
-     * @return string            The original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_box_open($ciphertext, $nonce, $keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_BOX_MACBYTES) {
-            throw new SodiumException('Argument 1 must be at least CRYPTO_BOX_MACBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_BOX_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_BOX_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            /**
-             * @psalm-suppress InvalidReturnStatement
-             * @psalm-suppress FalsableReturnStatement
-             */
-            return sodium_crypto_box_open($ciphertext, $nonce, $keypair);
-        }
-        if (self::use_fallback('crypto_box_open')) {
-            return call_user_func('\\Sodium\\crypto_box_open', $ciphertext, $nonce, $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_open($ciphertext, $nonce, $keypair);
-        }
-        return ParagonIE_Sodium_Crypto::box_open($ciphertext, $nonce, $keypair);
-    }
-
-    /**
-     * Extract the public key from a crypto_box keypair.
-     *
-     * @param string $keypair Keypair containing secret and public key
-     * @return string         Your crypto_box public key
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box_publickey($keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_publickey($keypair);
-        }
-        if (self::use_fallback('crypto_box_publickey')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_publickey', $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_publickey($keypair);
-        }
-        return ParagonIE_Sodium_Crypto::box_publickey($keypair);
-    }
-
-    /**
-     * Calculate the X25519 public key from a given X25519 secret key.
-     *
-     * @param string $secretKey Any X25519 secret key
-     * @return string           The corresponding X25519 public key
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box_publickey_from_secretkey($secretKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_publickey_from_secretkey($secretKey);
-        }
-        if (self::use_fallback('crypto_box_publickey_from_secretkey')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_publickey_from_secretkey', $secretKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_publickey_from_secretkey($secretKey);
-        }
-        return ParagonIE_Sodium_Crypto::box_publickey_from_secretkey($secretKey);
-    }
-
-    /**
-     * Extract the secret key from a crypto_box keypair.
-     *
-     * @param string $keypair
-     * @return string         Your crypto_box secret key
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_box_secretkey($keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_secretkey($keypair);
-        }
-        if (self::use_fallback('crypto_box_secretkey')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_secretkey', $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_secretkey($keypair);
-        }
-        return ParagonIE_Sodium_Crypto::box_secretkey($keypair);
-    }
-
-    /**
-     * Generate an X25519 keypair from a seed.
-     *
-     * @param string $seed
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress UndefinedFunction
-     */
-    public static function crypto_box_seed_keypair($seed)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($seed, 'string', 1);
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_box_seed_keypair($seed);
-        }
-        if (self::use_fallback('crypto_box_seed_keypair')) {
-            return (string) call_user_func('\\Sodium\\crypto_box_seed_keypair', $seed);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::box_seed_keypair($seed);
-        }
-        return ParagonIE_Sodium_Crypto::box_seed_keypair($seed);
-    }
-
-    /**
-     * Calculates a BLAKE2b hash, with an optional key.
-     *
-     * @param string      $message The message to be hashed
-     * @param string|null $key     If specified, must be a string between 16
-     *                             and 64 bytes long
-     * @param int         $length  Output length in bytes; must be between 16
-     *                             and 64 (default = 32)
-     * @return string              Raw binary
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_generichash($message, $key = '', $length = self::CRYPTO_GENERICHASH_BYTES)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        if (is_null($key)) {
-            $key = '';
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 3);
-
-        /* Input validation: */
-        if (!empty($key)) {
-            if (ParagonIE_Sodium_Core_Util::strlen($key) < self::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
-                throw new SodiumException('Unsupported key size. Must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes long.');
-            }
-            if (ParagonIE_Sodium_Core_Util::strlen($key) > self::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
-                throw new SodiumException('Unsupported key size. Must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes long.');
-            }
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_generichash($message, $key, $length);
-        }
-        if (self::use_fallback('crypto_generichash')) {
-            return (string) call_user_func('\\Sodium\\crypto_generichash', $message, $key, $length);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::generichash($message, $key, $length);
-        }
-        return ParagonIE_Sodium_Crypto::generichash($message, $key, $length);
-    }
-
-    /**
-     * Get the final BLAKE2b hash output for a given context.
-     *
-     * @param string $ctx BLAKE2 hashing context. Generated by crypto_generichash_init().
-     * @param int $length Hash output size.
-     * @return string     Final BLAKE2b hash.
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress ReferenceConstraintViolation
-     * @psalm-suppress ConflictingReferenceConstraint
-     */
-    public static function crypto_generichash_final(&$ctx, $length = self::CRYPTO_GENERICHASH_BYTES)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ctx, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 2);
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_generichash_final($ctx, $length);
-        }
-        if (self::use_fallback('crypto_generichash_final')) {
-            $func = '\\Sodium\\crypto_generichash_final';
-            return (string) $func($ctx, $length);
-        }
-        if ($length < 1) {
-            try {
-                self::memzero($ctx);
-            } catch (SodiumException $ex) {
-                unset($ctx);
-            }
-            return '';
-        }
-        if (PHP_INT_SIZE === 4) {
-            $result = ParagonIE_Sodium_Crypto32::generichash_final($ctx, $length);
-        } else {
-            $result = ParagonIE_Sodium_Crypto::generichash_final($ctx, $length);
-        }
-        try {
-            self::memzero($ctx);
-        } catch (SodiumException $ex) {
-            unset($ctx);
-        }
-        return $result;
-    }
-
-    /**
-     * Initialize a BLAKE2b hashing context, for use in a streaming interface.
-     *
-     * @param string|null $key If specified must be a string between 16 and 64 bytes
-     * @param int $length      The size of the desired hash output
-     * @return string          A BLAKE2 hashing context, encoded as a string
-     *                         (To be 100% compatible with ext/libsodium)
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_generichash_init($key = '', $length = self::CRYPTO_GENERICHASH_BYTES)
-    {
-        /* Type checks: */
-        if (is_null($key)) {
-            $key = '';
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 2);
-
-        /* Input validation: */
-        if (!empty($key)) {
-            if (ParagonIE_Sodium_Core_Util::strlen($key) < self::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
-                throw new SodiumException('Unsupported key size. Must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes long.');
-            }
-            if (ParagonIE_Sodium_Core_Util::strlen($key) > self::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
-                throw new SodiumException('Unsupported key size. Must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes long.');
-            }
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_generichash_init($key, $length);
-        }
-        if (self::use_fallback('crypto_generichash_init')) {
-            return (string) call_user_func('\\Sodium\\crypto_generichash_init', $key, $length);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::generichash_init($key, $length);
-        }
-        return ParagonIE_Sodium_Crypto::generichash_init($key, $length);
-    }
-
-    /**
-     * Initialize a BLAKE2b hashing context, for use in a streaming interface.
-     *
-     * @param string|null $key If specified must be a string between 16 and 64 bytes
-     * @param int $length      The size of the desired hash output
-     * @param string $salt     Salt (up to 16 bytes)
-     * @param string $personal Personalization string (up to 16 bytes)
-     * @return string          A BLAKE2 hashing context, encoded as a string
-     *                         (To be 100% compatible with ext/libsodium)
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_generichash_init_salt_personal(
-        $key = '',
-        $length = self::CRYPTO_GENERICHASH_BYTES,
-        $salt = '',
-        $personal = ''
-    ) {
-        /* Type checks: */
-        if (is_null($key)) {
-            $key = '';
-        }
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($salt, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($personal, 'string', 4);
-        $salt = str_pad($salt, 16, "\0", STR_PAD_RIGHT);
-        $personal = str_pad($personal, 16, "\0", STR_PAD_RIGHT);
-
-        /* Input validation: */
-        if (!empty($key)) {
-            /*
+	/**
+	 * This parameter prevents the use of the PECL extension.
+	 * It should only be used for unit testing.
+	 *
+	 * @var bool
+	 */
+	public static $disableFallbackForUnitTests = false;
+
+	/**
+	 * Use fast multiplication rather than our constant-time multiplication
+	 * implementation. Can be enabled at runtime. Only enable this if you
+	 * are absolutely certain that there is no timing leak on your platform.
+	 *
+	 * @var bool
+	 */
+	public static $fastMult = false;
+
+	const LIBRARY_MAJOR_VERSION = 9;
+	const LIBRARY_MINOR_VERSION = 1;
+	const LIBRARY_VERSION_MAJOR = 9;
+	const LIBRARY_VERSION_MINOR = 1;
+	const VERSION_STRING = 'polyfill-1.0.8';
+
+	// From libsodium
+	const BASE64_VARIANT_ORIGINAL = 1;
+	const BASE64_VARIANT_ORIGINAL_NO_PADDING = 3;
+	const BASE64_VARIANT_URLSAFE = 5;
+	const BASE64_VARIANT_URLSAFE_NO_PADDING = 7;
+	const CRYPTO_AEAD_AES256GCM_KEYBYTES = 32;
+	const CRYPTO_AEAD_AES256GCM_NSECBYTES = 0;
+	const CRYPTO_AEAD_AES256GCM_NPUBBYTES = 12;
+	const CRYPTO_AEAD_AES256GCM_ABYTES = 16;
+	const CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES = 32;
+	const CRYPTO_AEAD_CHACHA20POLY1305_NSECBYTES = 0;
+	const CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES = 8;
+	const CRYPTO_AEAD_CHACHA20POLY1305_ABYTES = 16;
+	const CRYPTO_AEAD_CHACHA20POLY1305_IETF_KEYBYTES = 32;
+	const CRYPTO_AEAD_CHACHA20POLY1305_IETF_NSECBYTES = 0;
+	const CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES = 12;
+	const CRYPTO_AEAD_CHACHA20POLY1305_IETF_ABYTES = 16;
+	const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES = 32;
+	const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NSECBYTES = 0;
+	const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES = 24;
+	const CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES = 16;
+	const CRYPTO_AUTH_BYTES = 32;
+	const CRYPTO_AUTH_KEYBYTES = 32;
+	const CRYPTO_BOX_SEALBYTES = 16;
+	const CRYPTO_BOX_SECRETKEYBYTES = 32;
+	const CRYPTO_BOX_PUBLICKEYBYTES = 32;
+	const CRYPTO_BOX_KEYPAIRBYTES = 64;
+	const CRYPTO_BOX_MACBYTES = 16;
+	const CRYPTO_BOX_NONCEBYTES = 24;
+	const CRYPTO_BOX_SEEDBYTES = 32;
+	const CRYPTO_CORE_RISTRETTO255_BYTES = 32;
+	const CRYPTO_CORE_RISTRETTO255_SCALARBYTES = 32;
+	const CRYPTO_CORE_RISTRETTO255_HASHBYTES = 64;
+	const CRYPTO_CORE_RISTRETTO255_NONREDUCEDSCALARBYTES = 64;
+	const CRYPTO_KDF_BYTES_MIN = 16;
+	const CRYPTO_KDF_BYTES_MAX = 64;
+	const CRYPTO_KDF_CONTEXTBYTES = 8;
+	const CRYPTO_KDF_KEYBYTES = 32;
+	const CRYPTO_KX_BYTES = 32;
+	const CRYPTO_KX_PRIMITIVE = 'x25519blake2b';
+	const CRYPTO_KX_SEEDBYTES = 32;
+	const CRYPTO_KX_KEYPAIRBYTES = 64;
+	const CRYPTO_KX_PUBLICKEYBYTES = 32;
+	const CRYPTO_KX_SECRETKEYBYTES = 32;
+	const CRYPTO_KX_SESSIONKEYBYTES = 32;
+	const CRYPTO_GENERICHASH_BYTES = 32;
+	const CRYPTO_GENERICHASH_BYTES_MIN = 16;
+	const CRYPTO_GENERICHASH_BYTES_MAX = 64;
+	const CRYPTO_GENERICHASH_KEYBYTES = 32;
+	const CRYPTO_GENERICHASH_KEYBYTES_MIN = 16;
+	const CRYPTO_GENERICHASH_KEYBYTES_MAX = 64;
+	const CRYPTO_PWHASH_SALTBYTES = 16;
+	const CRYPTO_PWHASH_STRPREFIX = '$argon2id$';
+	const CRYPTO_PWHASH_ALG_ARGON2I13 = 1;
+	const CRYPTO_PWHASH_ALG_ARGON2ID13 = 2;
+	const CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE = 33554432;
+	const CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE = 4;
+	const CRYPTO_PWHASH_MEMLIMIT_MODERATE = 134217728;
+	const CRYPTO_PWHASH_OPSLIMIT_MODERATE = 6;
+	const CRYPTO_PWHASH_MEMLIMIT_SENSITIVE = 536870912;
+	const CRYPTO_PWHASH_OPSLIMIT_SENSITIVE = 8;
+	const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_SALTBYTES = 32;
+	const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_STRPREFIX = '$7$';
+	const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_INTERACTIVE = 534288;
+	const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_INTERACTIVE = 16777216;
+	const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_SENSITIVE = 33554432;
+	const CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_SENSITIVE = 1073741824;
+	const CRYPTO_SCALARMULT_BYTES = 32;
+	const CRYPTO_SCALARMULT_SCALARBYTES = 32;
+	const CRYPTO_SCALARMULT_RISTRETTO255_BYTES = 32;
+	const CRYPTO_SCALARMULT_RISTRETTO255_SCALARBYTES = 32;
+	const CRYPTO_SHORTHASH_BYTES = 8;
+	const CRYPTO_SHORTHASH_KEYBYTES = 16;
+	const CRYPTO_SECRETBOX_KEYBYTES = 32;
+	const CRYPTO_SECRETBOX_MACBYTES = 16;
+	const CRYPTO_SECRETBOX_NONCEBYTES = 24;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES = 17;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_HEADERBYTES = 24;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_KEYBYTES = 32;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_PUSH = 0;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_PULL = 1;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY = 2;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_FINAL = 3;
+	const CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX = 0x3fffffff80;
+	const CRYPTO_SIGN_BYTES = 64;
+	const CRYPTO_SIGN_SEEDBYTES = 32;
+	const CRYPTO_SIGN_PUBLICKEYBYTES = 32;
+	const CRYPTO_SIGN_SECRETKEYBYTES = 64;
+	const CRYPTO_SIGN_KEYPAIRBYTES = 96;
+	const CRYPTO_STREAM_KEYBYTES = 32;
+	const CRYPTO_STREAM_NONCEBYTES = 24;
+	const CRYPTO_STREAM_XCHACHA20_KEYBYTES = 32;
+	const CRYPTO_STREAM_XCHACHA20_NONCEBYTES = 24;
+
+	/**
+	 * Add two numbers (little-endian unsigned), storing the value in the first
+	 * parameter.
+	 *
+	 * This mutates $val.
+	 *
+	 * @param string $val
+	 * @param string $addv
+	 * @return void
+	 * @throws SodiumException
+	 */
+	public static function add(&$val, $addv)
+	{
+		$val_len = ParagonIE_Sodium_Core_Util::strlen($val);
+		$addv_len = ParagonIE_Sodium_Core_Util::strlen($addv);
+		if ($val_len !== $addv_len) {
+			throw new SodiumException('values must have the same length');
+		}
+		$A = ParagonIE_Sodium_Core_Util::stringToIntArray($val);
+		$B = ParagonIE_Sodium_Core_Util::stringToIntArray($addv);
+
+		$c = 0;
+		for ($i = 0; $i < $val_len; $i++) {
+			$c += ($A[$i] + $B[$i]);
+			$A[$i] = ($c & 0xff);
+			$c >>= 8;
+		}
+		$val = ParagonIE_Sodium_Core_Util::intArrayToString($A);
+	}
+
+	/**
+	 * @param string $encoded
+	 * @param int $variant
+	 * @param string $ignore
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function base642bin($encoded, $variant, $ignore = '')
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($encoded, 'string', 1);
+
+		/** @var string $encoded */
+		$encoded = (string) $encoded;
+		if (ParagonIE_Sodium_Core_Util::strlen($encoded) === 0) {
+			return '';
+		}
+
+		// Just strip before decoding
+		if (!empty($ignore)) {
+			$encoded = str_replace($ignore, '', $encoded);
+		}
+
+		try {
+			switch ($variant) {
+				case self::BASE64_VARIANT_ORIGINAL:
+					return ParagonIE_Sodium_Core_Base64_Original::decode($encoded, true);
+				case self::BASE64_VARIANT_ORIGINAL_NO_PADDING:
+					return ParagonIE_Sodium_Core_Base64_Original::decode($encoded, false);
+				case self::BASE64_VARIANT_URLSAFE:
+					return ParagonIE_Sodium_Core_Base64_UrlSafe::decode($encoded, true);
+				case self::BASE64_VARIANT_URLSAFE_NO_PADDING:
+					return ParagonIE_Sodium_Core_Base64_UrlSafe::decode($encoded, false);
+				default:
+					throw new SodiumException('invalid base64 variant identifier');
+			}
+		} catch (Exception $ex) {
+			if ($ex instanceof SodiumException) {
+				throw $ex;
+			}
+			throw new SodiumException('invalid base64 string');
+		}
+	}
+
+	/**
+	 * @param string $decoded
+	 * @param int $variant
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function bin2base64($decoded, $variant)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($decoded, 'string', 1);
+		/** @var string $decoded */
+		$decoded = (string) $decoded;
+		if (ParagonIE_Sodium_Core_Util::strlen($decoded) === 0) {
+			return '';
+		}
+
+		switch ($variant) {
+			case self::BASE64_VARIANT_ORIGINAL:
+				return ParagonIE_Sodium_Core_Base64_Original::encode($decoded);
+			case self::BASE64_VARIANT_ORIGINAL_NO_PADDING:
+				return ParagonIE_Sodium_Core_Base64_Original::encodeUnpadded($decoded);
+			case self::BASE64_VARIANT_URLSAFE:
+				return ParagonIE_Sodium_Core_Base64_UrlSafe::encode($decoded);
+			case self::BASE64_VARIANT_URLSAFE_NO_PADDING:
+				return ParagonIE_Sodium_Core_Base64_UrlSafe::encodeUnpadded($decoded);
+			default:
+				throw new SodiumException('invalid base64 variant identifier');
+		}
+	}
+
+	/**
+	 * Cache-timing-safe implementation of bin2hex().
+	 *
+	 * @param string $string A string (probably raw binary)
+	 * @return string        A hexadecimal-encoded string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function bin2hex($string)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($string, 'string', 1);
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_bin2hex($string);
+		}
+		if (self::use_fallback('bin2hex')) {
+			return (string) call_user_func('\\Sodium\\bin2hex', $string);
+		}
+		return ParagonIE_Sodium_Core_Util::bin2hex($string);
+	}
+
+	/**
+	 * Compare two strings, in constant-time.
+	 * Compared to memcmp(), compare() is more useful for sorting.
+	 *
+	 * @param string $left  The left operand; must be a string
+	 * @param string $right The right operand; must be a string
+	 * @return int          If < 0 if the left operand is less than the right
+	 *                      If = 0 if both strings are equal
+	 *                      If > 0 if the right operand is less than the left
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function compare($left, $right)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($left, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($right, 'string', 2);
+
+		if (self::useNewSodiumAPI()) {
+			return (int) sodium_compare($left, $right);
+		}
+		if (self::use_fallback('compare')) {
+			return (int) call_user_func('\\Sodium\\compare', $left, $right);
+		}
+		return ParagonIE_Sodium_Core_Util::compare($left, $right);
+	}
+
+	/**
+	 * Is AES-256-GCM even available to use?
+	 *
+	 * @return bool
+	 * @psalm-suppress UndefinedFunction
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_aead_aes256gcm_is_available()
+	{
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_aead_aes256gcm_is_available();
+		}
+		if (self::use_fallback('crypto_aead_aes256gcm_is_available')) {
+			return call_user_func('\\Sodium\\crypto_aead_aes256gcm_is_available');
+		}
+		if (PHP_VERSION_ID < 70100) {
+			// OpenSSL doesn't support AEAD before 7.1.0
+			return false;
+		}
+		if (!is_callable('openssl_encrypt') || !is_callable('openssl_decrypt')) {
+			// OpenSSL isn't installed
+			return false;
+		}
+		return (bool) in_array('aes-256-gcm', openssl_get_cipher_methods());
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data: Decryption
+	 *
+	 * Algorithm:
+	 *     AES-256-GCM
+	 *
+	 * This mode uses a 64-bit random nonce with a 64-bit counter.
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 *
+	 * @param string $ciphertext Encrypted message (with Poly1305 MAC appended)
+	 * @param string $assocData  Authenticated Associated Data (unencrypted)
+	 * @param string $nonce      Number to be used only Once; must be 8 bytes
+	 * @param string $key        Encryption key
+	 *
+	 * @return string|bool       The original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_aead_aes256gcm_decrypt(
+		$ciphertext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = ''
+	) {
+		if (!self::crypto_aead_aes256gcm_is_available()) {
+			throw new SodiumException('AES-256-GCM is not available');
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_AES256GCM_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_AES256GCM_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_AES256GCM_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_AES256GCM_KEYBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_AES256GCM_ABYTES) {
+			throw new SodiumException('Message must be at least CRYPTO_AEAD_AES256GCM_ABYTES long');
+		}
+		if (!is_callable('openssl_decrypt')) {
+			throw new SodiumException('The OpenSSL extension is not installed, or openssl_decrypt() is not available');
+		}
+
+		/** @var string $ctext */
+		$ctext = ParagonIE_Sodium_Core_Util::substr($ciphertext, 0, -self::CRYPTO_AEAD_AES256GCM_ABYTES);
+		/** @var string $authTag */
+		$authTag = ParagonIE_Sodium_Core_Util::substr($ciphertext, -self::CRYPTO_AEAD_AES256GCM_ABYTES, 16);
+		return openssl_decrypt(
+			$ctext,
+			'aes-256-gcm',
+			$key,
+			OPENSSL_RAW_DATA,
+			$nonce,
+			$authTag,
+			$assocData
+		);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data: Encryption
+	 *
+	 * Algorithm:
+	 *     AES-256-GCM
+	 *
+	 * @param string $plaintext Message to be encrypted
+	 * @param string $assocData Authenticated Associated Data (unencrypted)
+	 * @param string $nonce     Number to be used only Once; must be 8 bytes
+	 * @param string $key       Encryption key
+	 *
+	 * @return string           Ciphertext with a 16-byte GCM message
+	 *                          authentication code appended
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_aead_aes256gcm_encrypt(
+		$plaintext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = ''
+	) {
+		if (!self::crypto_aead_aes256gcm_is_available()) {
+			throw new SodiumException('AES-256-GCM is not available');
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_AES256GCM_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_AES256GCM_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_AES256GCM_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_AES256GCM_KEYBYTES long');
+		}
+
+		if (!is_callable('openssl_encrypt')) {
+			throw new SodiumException('The OpenSSL extension is not installed, or openssl_encrypt() is not available');
+		}
+
+		$authTag = '';
+		$ciphertext = openssl_encrypt(
+			$plaintext,
+			'aes-256-gcm',
+			$key,
+			OPENSSL_RAW_DATA,
+			$nonce,
+			$authTag,
+			$assocData
+		);
+		return $ciphertext . $authTag;
+	}
+
+	/**
+	 * Return a secure random key for use with the AES-256-GCM
+	 * symmetric AEAD interface.
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_aead_aes256gcm_keygen()
+	{
+		return random_bytes(self::CRYPTO_AEAD_AES256GCM_KEYBYTES);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data: Decryption
+	 *
+	 * Algorithm:
+	 *     ChaCha20-Poly1305
+	 *
+	 * This mode uses a 64-bit random nonce with a 64-bit counter.
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 *
+	 * @param string $ciphertext Encrypted message (with Poly1305 MAC appended)
+	 * @param string $assocData  Authenticated Associated Data (unencrypted)
+	 * @param string $nonce      Number to be used only Once; must be 8 bytes
+	 * @param string $key        Encryption key
+	 *
+	 * @return string            The original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_aead_chacha20poly1305_decrypt(
+		$ciphertext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_CHACHA20POLY1305_ABYTES) {
+			throw new SodiumException('Message must be at least CRYPTO_AEAD_CHACHA20POLY1305_ABYTES long');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			/**
+			 * @psalm-suppress InvalidReturnStatement
+			 * @psalm-suppress FalsableReturnStatement
+			 */
+			return sodium_crypto_aead_chacha20poly1305_decrypt(
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (self::use_fallback('crypto_aead_chacha20poly1305_decrypt')) {
+			return call_user_func(
+				'\\Sodium\\crypto_aead_chacha20poly1305_decrypt',
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_decrypt(
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_decrypt(
+			$ciphertext,
+			$assocData,
+			$nonce,
+			$key
+		);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data
+	 *
+	 * Algorithm:
+	 *     ChaCha20-Poly1305
+	 *
+	 * This mode uses a 64-bit random nonce with a 64-bit counter.
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 *
+	 * @param string $plaintext Message to be encrypted
+	 * @param string $assocData Authenticated Associated Data (unencrypted)
+	 * @param string $nonce     Number to be used only Once; must be 8 bytes
+	 * @param string $key       Encryption key
+	 *
+	 * @return string           Ciphertext with a 16-byte Poly1305 message
+	 *                          authentication code appended
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_aead_chacha20poly1305_encrypt(
+		$plaintext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_aead_chacha20poly1305_encrypt(
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (self::use_fallback('crypto_aead_chacha20poly1305_encrypt')) {
+			return (string) call_user_func(
+				'\\Sodium\\crypto_aead_chacha20poly1305_encrypt',
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_encrypt(
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_encrypt(
+			$plaintext,
+			$assocData,
+			$nonce,
+			$key
+		);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data: Decryption
+	 *
+	 * Algorithm:
+	 *     ChaCha20-Poly1305
+	 *
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 * Regular mode uses a 64-bit random nonce with a 64-bit counter.
+	 *
+	 * @param string $ciphertext Encrypted message (with Poly1305 MAC appended)
+	 * @param string $assocData  Authenticated Associated Data (unencrypted)
+	 * @param string $nonce      Number to be used only Once; must be 12 bytes
+	 * @param string $key        Encryption key
+	 *
+	 * @return string            The original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_aead_chacha20poly1305_ietf_decrypt(
+		$ciphertext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_CHACHA20POLY1305_ABYTES) {
+			throw new SodiumException('Message must be at least CRYPTO_AEAD_CHACHA20POLY1305_ABYTES long');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			/**
+			 * @psalm-suppress InvalidReturnStatement
+			 * @psalm-suppress FalsableReturnStatement
+			 */
+			return sodium_crypto_aead_chacha20poly1305_ietf_decrypt(
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (self::use_fallback('crypto_aead_chacha20poly1305_ietf_decrypt')) {
+			return call_user_func(
+				'\\Sodium\\crypto_aead_chacha20poly1305_ietf_decrypt',
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_ietf_decrypt(
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_ietf_decrypt(
+			$ciphertext,
+			$assocData,
+			$nonce,
+			$key
+		);
+	}
+
+	/**
+	 * Return a secure random key for use with the ChaCha20-Poly1305
+	 * symmetric AEAD interface.
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_aead_chacha20poly1305_keygen()
+	{
+		return random_bytes(self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data
+	 *
+	 * Algorithm:
+	 *     ChaCha20-Poly1305
+	 *
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 * Regular mode uses a 64-bit random nonce with a 64-bit counter.
+	 *
+	 * @param string $plaintext Message to be encrypted
+	 * @param string $assocData Authenticated Associated Data (unencrypted)
+	 * @param string $nonce Number to be used only Once; must be 8 bytes
+	 * @param string $key Encryption key
+	 *
+	 * @return string           Ciphertext with a 16-byte Poly1305 message
+	 *                          authentication code appended
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_aead_chacha20poly1305_ietf_encrypt(
+		$plaintext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		if (!is_null($assocData)) {
+			ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_CHACHA20POLY1305_KEYBYTES long');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_aead_chacha20poly1305_ietf_encrypt(
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (self::use_fallback('crypto_aead_chacha20poly1305_ietf_encrypt')) {
+			return (string) call_user_func(
+				'\\Sodium\\crypto_aead_chacha20poly1305_ietf_encrypt',
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::aead_chacha20poly1305_ietf_encrypt(
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		return ParagonIE_Sodium_Crypto::aead_chacha20poly1305_ietf_encrypt(
+			$plaintext,
+			$assocData,
+			$nonce,
+			$key
+		);
+	}
+
+	/**
+	 * Return a secure random key for use with the ChaCha20-Poly1305
+	 * symmetric AEAD interface. (IETF version)
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_aead_chacha20poly1305_ietf_keygen()
+	{
+		return random_bytes(self::CRYPTO_AEAD_CHACHA20POLY1305_IETF_KEYBYTES);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data: Decryption
+	 *
+	 * Algorithm:
+	 *     XChaCha20-Poly1305
+	 *
+	 * This mode uses a 64-bit random nonce with a 64-bit counter.
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 *
+	 * @param string $ciphertext   Encrypted message (with Poly1305 MAC appended)
+	 * @param string $assocData    Authenticated Associated Data (unencrypted)
+	 * @param string $nonce        Number to be used only Once; must be 8 bytes
+	 * @param string $key          Encryption key
+	 * @param bool   $dontFallback Don't fallback to ext/sodium
+	 *
+	 * @return string|bool         The original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_aead_xchacha20poly1305_ietf_decrypt(
+		$ciphertext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = '',
+		$dontFallback = false
+	) {
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		if (!is_null($assocData)) {
+			ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		} else {
+			$assocData = '';
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES) {
+			throw new SodiumException('Message must be at least CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES long');
+		}
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			if (is_callable('sodium_crypto_aead_xchacha20poly1305_ietf_decrypt')) {
+				return sodium_crypto_aead_xchacha20poly1305_ietf_decrypt(
+					$ciphertext,
+					$assocData,
+					$nonce,
+					$key
+				);
+			}
+		}
+
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::aead_xchacha20poly1305_ietf_decrypt(
+				$ciphertext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		return ParagonIE_Sodium_Crypto::aead_xchacha20poly1305_ietf_decrypt(
+			$ciphertext,
+			$assocData,
+			$nonce,
+			$key
+		);
+	}
+
+	/**
+	 * Authenticated Encryption with Associated Data
+	 *
+	 * Algorithm:
+	 *     XChaCha20-Poly1305
+	 *
+	 * This mode uses a 64-bit random nonce with a 64-bit counter.
+	 * IETF mode uses a 96-bit random nonce with a 32-bit counter.
+	 *
+	 * @param string $plaintext    Message to be encrypted
+	 * @param string $assocData    Authenticated Associated Data (unencrypted)
+	 * @param string $nonce        Number to be used only Once; must be 8 bytes
+	 * @param string $key          Encryption key
+	 * @param bool   $dontFallback Don't fallback to ext/sodium
+	 *
+	 * @return string           Ciphertext with a 16-byte Poly1305 message
+	 *                          authentication code appended
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_aead_xchacha20poly1305_ietf_encrypt(
+		$plaintext = '',
+		$assocData = '',
+		$nonce = '',
+		$key = '',
+		$dontFallback = false
+	) {
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		if (!is_null($assocData)) {
+			ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
+		} else {
+			$assocData = '';
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES) {
+			throw new SodiumException('Nonce must be CRYPTO_AEAD_XCHACHA20POLY1305_NPUBBYTES long');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES) {
+			throw new SodiumException('Key must be CRYPTO_AEAD_XCHACHA20POLY1305_KEYBYTES long');
+		}
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			if (is_callable('sodium_crypto_aead_xchacha20poly1305_ietf_encrypt')) {
+				return sodium_crypto_aead_xchacha20poly1305_ietf_encrypt(
+					$plaintext,
+					$assocData,
+					$nonce,
+					$key
+				);
+			}
+		}
+
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::aead_xchacha20poly1305_ietf_encrypt(
+				$plaintext,
+				$assocData,
+				$nonce,
+				$key
+			);
+		}
+		return ParagonIE_Sodium_Crypto::aead_xchacha20poly1305_ietf_encrypt(
+			$plaintext,
+			$assocData,
+			$nonce,
+			$key
+		);
+	}
+
+	/**
+	 * Return a secure random key for use with the XChaCha20-Poly1305
+	 * symmetric AEAD interface.
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_aead_xchacha20poly1305_ietf_keygen()
+	{
+		return random_bytes(self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES);
+	}
+
+	/**
+	 * Authenticate a message. Uses symmetric-key cryptography.
+	 *
+	 * Algorithm:
+	 *     HMAC-SHA512-256. Which is HMAC-SHA-512 truncated to 256 bits.
+	 *     Not to be confused with HMAC-SHA-512/256 which would use the
+	 *     SHA-512/256 hash function (uses different initial parameters
+	 *     but still truncates to 256 bits to sidestep length-extension
+	 *     attacks).
+	 *
+	 * @param string $message Message to be authenticated
+	 * @param string $key Symmetric authentication key
+	 * @return string         Message authentication code
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_auth($message, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AUTH_KEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_AUTH_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_auth($message, $key);
+		}
+		if (self::use_fallback('crypto_auth')) {
+			return (string) call_user_func('\\Sodium\\crypto_auth', $message, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::auth($message, $key);
+		}
+		return ParagonIE_Sodium_Crypto::auth($message, $key);
+	}
+
+	/**
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_auth_keygen()
+	{
+		return random_bytes(self::CRYPTO_AUTH_KEYBYTES);
+	}
+
+	/**
+	 * Verify the MAC of a message previously authenticated with crypto_auth.
+	 *
+	 * @param string $mac Message authentication code
+	 * @param string $message Message whose authenticity you are attempting to
+	 *                        verify (with a given MAC and key)
+	 * @param string $key Symmetric authentication key
+	 * @return bool           TRUE if authenticated, FALSE otherwise
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_auth_verify($mac, $message, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($mac, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($mac) !== self::CRYPTO_AUTH_BYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_AUTH_BYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AUTH_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_AUTH_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (bool) sodium_crypto_auth_verify($mac, $message, $key);
+		}
+		if (self::use_fallback('crypto_auth_verify')) {
+			return (bool) call_user_func('\\Sodium\\crypto_auth_verify', $mac, $message, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::auth_verify($mac, $message, $key);
+		}
+		return ParagonIE_Sodium_Crypto::auth_verify($mac, $message, $key);
+	}
+
+	/**
+	 * Authenticated asymmetric-key encryption. Both the sender and recipient
+	 * may decrypt messages.
+	 *
+	 * Algorithm: X25519-XSalsa20-Poly1305.
+	 *     X25519: Elliptic-Curve Diffie Hellman over Curve25519.
+	 *     XSalsa20: Extended-nonce variant of salsa20.
+	 *     Poyl1305: Polynomial MAC for one-time message authentication.
+	 *
+	 * @param string $plaintext The message to be encrypted
+	 * @param string $nonce A Number to only be used Once; must be 24 bytes
+	 * @param string $keypair Your secret key and your recipient's public key
+	 * @return string           Ciphertext with 16-byte Poly1305 MAC
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box($plaintext, $nonce, $keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_BOX_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_BOX_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box($plaintext, $nonce, $keypair);
+		}
+		if (self::use_fallback('crypto_box')) {
+			return (string) call_user_func('\\Sodium\\crypto_box', $plaintext, $nonce, $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box($plaintext, $nonce, $keypair);
+		}
+		return ParagonIE_Sodium_Crypto::box($plaintext, $nonce, $keypair);
+	}
+
+	/**
+	 * Anonymous public-key encryption. Only the recipient may decrypt messages.
+	 *
+	 * Algorithm: X25519-XSalsa20-Poly1305, as with crypto_box.
+	 *     The sender's X25519 keypair is ephemeral.
+	 *     Nonce is generated from the BLAKE2b hash of both public keys.
+	 *
+	 * This provides ciphertext integrity.
+	 *
+	 * @param string $plaintext Message to be sealed
+	 * @param string $publicKey Your recipient's public key
+	 * @return string           Sealed message that only your recipient can
+	 *                          decrypt
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box_seal($plaintext, $publicKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_seal($plaintext, $publicKey);
+		}
+		if (self::use_fallback('crypto_box_seal')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_seal', $plaintext, $publicKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_seal($plaintext, $publicKey);
+		}
+		return ParagonIE_Sodium_Crypto::box_seal($plaintext, $publicKey);
+	}
+
+	/**
+	 * Opens a message encrypted with crypto_box_seal(). Requires
+	 * the recipient's keypair (sk || pk) to decrypt successfully.
+	 *
+	 * This validates ciphertext integrity.
+	 *
+	 * @param string $ciphertext Sealed message to be opened
+	 * @param string $keypair    Your crypto_box keypair
+	 * @return string            The original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_box_seal_open($ciphertext, $keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			/**
+			 * @psalm-suppress InvalidReturnStatement
+			 * @psalm-suppress FalsableReturnStatement
+			 */
+			return sodium_crypto_box_seal_open($ciphertext, $keypair);
+		}
+		if (self::use_fallback('crypto_box_seal_open')) {
+			return call_user_func('\\Sodium\\crypto_box_seal_open', $ciphertext, $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_seal_open($ciphertext, $keypair);
+		}
+		return ParagonIE_Sodium_Crypto::box_seal_open($ciphertext, $keypair);
+	}
+
+	/**
+	 * Generate a new random X25519 keypair.
+	 *
+	 * @return string A 64-byte string; the first 32 are your secret key, while
+	 *                the last 32 are your public key. crypto_box_secretkey()
+	 *                and crypto_box_publickey() exist to separate them so you
+	 *                don't accidentally get them mixed up!
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box_keypair()
+	{
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_keypair();
+		}
+		if (self::use_fallback('crypto_box_keypair')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_keypair');
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_keypair();
+		}
+		return ParagonIE_Sodium_Crypto::box_keypair();
+	}
+
+	/**
+	 * Combine two keys into a keypair for use in library methods that expect
+	 * a keypair. This doesn't necessarily have to be the same person's keys.
+	 *
+	 * @param string $secretKey Secret key
+	 * @param string $publicKey Public key
+	 * @return string    Keypair
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box_keypair_from_secretkey_and_publickey($secretKey, $publicKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_keypair_from_secretkey_and_publickey($secretKey, $publicKey);
+		}
+		if (self::use_fallback('crypto_box_keypair_from_secretkey_and_publickey')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_keypair_from_secretkey_and_publickey', $secretKey, $publicKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_keypair_from_secretkey_and_publickey($secretKey, $publicKey);
+		}
+		return ParagonIE_Sodium_Crypto::box_keypair_from_secretkey_and_publickey($secretKey, $publicKey);
+	}
+
+	/**
+	 * Decrypt a message previously encrypted with crypto_box().
+	 *
+	 * @param string $ciphertext Encrypted message
+	 * @param string $nonce      Number to only be used Once; must be 24 bytes
+	 * @param string $keypair    Your secret key and the sender's public key
+	 * @return string            The original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_box_open($ciphertext, $nonce, $keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_BOX_MACBYTES) {
+			throw new SodiumException('Argument 1 must be at least CRYPTO_BOX_MACBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_BOX_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_BOX_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			/**
+			 * @psalm-suppress InvalidReturnStatement
+			 * @psalm-suppress FalsableReturnStatement
+			 */
+			return sodium_crypto_box_open($ciphertext, $nonce, $keypair);
+		}
+		if (self::use_fallback('crypto_box_open')) {
+			return call_user_func('\\Sodium\\crypto_box_open', $ciphertext, $nonce, $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_open($ciphertext, $nonce, $keypair);
+		}
+		return ParagonIE_Sodium_Crypto::box_open($ciphertext, $nonce, $keypair);
+	}
+
+	/**
+	 * Extract the public key from a crypto_box keypair.
+	 *
+	 * @param string $keypair Keypair containing secret and public key
+	 * @return string         Your crypto_box public key
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box_publickey($keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_publickey($keypair);
+		}
+		if (self::use_fallback('crypto_box_publickey')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_publickey', $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_publickey($keypair);
+		}
+		return ParagonIE_Sodium_Crypto::box_publickey($keypair);
+	}
+
+	/**
+	 * Calculate the X25519 public key from a given X25519 secret key.
+	 *
+	 * @param string $secretKey Any X25519 secret key
+	 * @return string           The corresponding X25519 public key
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box_publickey_from_secretkey($secretKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_publickey_from_secretkey($secretKey);
+		}
+		if (self::use_fallback('crypto_box_publickey_from_secretkey')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_publickey_from_secretkey', $secretKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_publickey_from_secretkey($secretKey);
+		}
+		return ParagonIE_Sodium_Crypto::box_publickey_from_secretkey($secretKey);
+	}
+
+	/**
+	 * Extract the secret key from a crypto_box keypair.
+	 *
+	 * @param string $keypair
+	 * @return string         Your crypto_box secret key
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_box_secretkey($keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_secretkey($keypair);
+		}
+		if (self::use_fallback('crypto_box_secretkey')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_secretkey', $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_secretkey($keypair);
+		}
+		return ParagonIE_Sodium_Crypto::box_secretkey($keypair);
+	}
+
+	/**
+	 * Generate an X25519 keypair from a seed.
+	 *
+	 * @param string $seed
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress UndefinedFunction
+	 */
+	public static function crypto_box_seed_keypair($seed)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($seed, 'string', 1);
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_box_seed_keypair($seed);
+		}
+		if (self::use_fallback('crypto_box_seed_keypair')) {
+			return (string) call_user_func('\\Sodium\\crypto_box_seed_keypair', $seed);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::box_seed_keypair($seed);
+		}
+		return ParagonIE_Sodium_Crypto::box_seed_keypair($seed);
+	}
+
+	/**
+	 * Calculates a BLAKE2b hash, with an optional key.
+	 *
+	 * @param string      $message The message to be hashed
+	 * @param string|null $key     If specified, must be a string between 16
+	 *                             and 64 bytes long
+	 * @param int         $length  Output length in bytes; must be between 16
+	 *                             and 64 (default = 32)
+	 * @return string              Raw binary
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_generichash($message, $key = '', $length = self::CRYPTO_GENERICHASH_BYTES)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		if (is_null($key)) {
+			$key = '';
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 3);
+
+		/* Input validation: */
+		if (!empty($key)) {
+			if (ParagonIE_Sodium_Core_Util::strlen($key) < self::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
+				throw new SodiumException('Unsupported key size. Must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes long.');
+			}
+			if (ParagonIE_Sodium_Core_Util::strlen($key) > self::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
+				throw new SodiumException('Unsupported key size. Must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes long.');
+			}
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_generichash($message, $key, $length);
+		}
+		if (self::use_fallback('crypto_generichash')) {
+			return (string) call_user_func('\\Sodium\\crypto_generichash', $message, $key, $length);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::generichash($message, $key, $length);
+		}
+		return ParagonIE_Sodium_Crypto::generichash($message, $key, $length);
+	}
+
+	/**
+	 * Get the final BLAKE2b hash output for a given context.
+	 *
+	 * @param string $ctx BLAKE2 hashing context. Generated by crypto_generichash_init().
+	 * @param int $length Hash output size.
+	 * @return string     Final BLAKE2b hash.
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress ReferenceConstraintViolation
+	 * @psalm-suppress ConflictingReferenceConstraint
+	 */
+	public static function crypto_generichash_final(&$ctx, $length = self::CRYPTO_GENERICHASH_BYTES)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ctx, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 2);
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_generichash_final($ctx, $length);
+		}
+		if (self::use_fallback('crypto_generichash_final')) {
+			$func = '\\Sodium\\crypto_generichash_final';
+			return (string) $func($ctx, $length);
+		}
+		if ($length < 1) {
+			try {
+				self::memzero($ctx);
+			} catch (SodiumException $ex) {
+				unset($ctx);
+			}
+			return '';
+		}
+		if (PHP_INT_SIZE === 4) {
+			$result = ParagonIE_Sodium_Crypto32::generichash_final($ctx, $length);
+		} else {
+			$result = ParagonIE_Sodium_Crypto::generichash_final($ctx, $length);
+		}
+		try {
+			self::memzero($ctx);
+		} catch (SodiumException $ex) {
+			unset($ctx);
+		}
+		return $result;
+	}
+
+	/**
+	 * Initialize a BLAKE2b hashing context, for use in a streaming interface.
+	 *
+	 * @param string|null $key If specified must be a string between 16 and 64 bytes
+	 * @param int $length      The size of the desired hash output
+	 * @return string          A BLAKE2 hashing context, encoded as a string
+	 *                         (To be 100% compatible with ext/libsodium)
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_generichash_init($key = '', $length = self::CRYPTO_GENERICHASH_BYTES)
+	{
+		/* Type checks: */
+		if (is_null($key)) {
+			$key = '';
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 2);
+
+		/* Input validation: */
+		if (!empty($key)) {
+			if (ParagonIE_Sodium_Core_Util::strlen($key) < self::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
+				throw new SodiumException('Unsupported key size. Must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes long.');
+			}
+			if (ParagonIE_Sodium_Core_Util::strlen($key) > self::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
+				throw new SodiumException('Unsupported key size. Must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes long.');
+			}
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_generichash_init($key, $length);
+		}
+		if (self::use_fallback('crypto_generichash_init')) {
+			return (string) call_user_func('\\Sodium\\crypto_generichash_init', $key, $length);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::generichash_init($key, $length);
+		}
+		return ParagonIE_Sodium_Crypto::generichash_init($key, $length);
+	}
+
+	/**
+	 * Initialize a BLAKE2b hashing context, for use in a streaming interface.
+	 *
+	 * @param string|null $key If specified must be a string between 16 and 64 bytes
+	 * @param int $length      The size of the desired hash output
+	 * @param string $salt     Salt (up to 16 bytes)
+	 * @param string $personal Personalization string (up to 16 bytes)
+	 * @return string          A BLAKE2 hashing context, encoded as a string
+	 *                         (To be 100% compatible with ext/libsodium)
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_generichash_init_salt_personal(
+		$key = '',
+		$length = self::CRYPTO_GENERICHASH_BYTES,
+		$salt = '',
+		$personal = ''
+	) {
+		/* Type checks: */
+		if (is_null($key)) {
+			$key = '';
+		}
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($length, 'int', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($salt, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($personal, 'string', 4);
+		$salt = str_pad($salt, 16, "\0", STR_PAD_RIGHT);
+		$personal = str_pad($personal, 16, "\0", STR_PAD_RIGHT);
+
+		/* Input validation: */
+		if (!empty($key)) {
+			/*
             if (ParagonIE_Sodium_Core_Util::strlen($key) < self::CRYPTO_GENERICHASH_KEYBYTES_MIN) {
                 throw new SodiumException('Unsupported key size. Must be at least CRYPTO_GENERICHASH_KEYBYTES_MIN bytes long.');
             }
             */
-            if (ParagonIE_Sodium_Core_Util::strlen($key) > self::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
-                throw new SodiumException('Unsupported key size. Must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes long.');
-            }
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::generichash_init_salt_personal($key, $length, $salt, $personal);
-        }
-        return ParagonIE_Sodium_Crypto::generichash_init_salt_personal($key, $length, $salt, $personal);
-    }
-
-    /**
-     * Update a BLAKE2b hashing context with additional data.
-     *
-     * @param string $ctx    BLAKE2 hashing context. Generated by crypto_generichash_init().
-     *                       $ctx is passed by reference and gets updated in-place.
-     * @param-out string $ctx
-     * @param string $message The message to append to the existing hash state.
-     * @return void
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress ReferenceConstraintViolation
-     */
-    public static function crypto_generichash_update(&$ctx, $message)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ctx, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 2);
-
-        if (self::useNewSodiumAPI()) {
-            sodium_crypto_generichash_update($ctx, $message);
-            return;
-        }
-        if (self::use_fallback('crypto_generichash_update')) {
-            $func = '\\Sodium\\crypto_generichash_update';
-            $func($ctx, $message);
-            return;
-        }
-        if (PHP_INT_SIZE === 4) {
-            $ctx = ParagonIE_Sodium_Crypto32::generichash_update($ctx, $message);
-        } else {
-            $ctx = ParagonIE_Sodium_Crypto::generichash_update($ctx, $message);
-        }
-    }
-
-    /**
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_generichash_keygen()
-    {
-        return random_bytes(self::CRYPTO_GENERICHASH_KEYBYTES);
-    }
-
-    /**
-     * @param int $subkey_len
-     * @param int $subkey_id
-     * @param string $context
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     */
-    public static function crypto_kdf_derive_from_key(
-        $subkey_len,
-        $subkey_id,
-        $context,
-        $key
-    ) {
-        ParagonIE_Sodium_Core_Util::declareScalarType($subkey_len, 'int', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($subkey_id, 'int', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($context, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
-        $subkey_id = (int) $subkey_id;
-        $subkey_len = (int) $subkey_len;
-        $context = (string) $context;
-        $key = (string) $key;
-
-        if ($subkey_len < self::CRYPTO_KDF_BYTES_MIN) {
-            throw new SodiumException('subkey cannot be smaller than SODIUM_CRYPTO_KDF_BYTES_MIN');
-        }
-        if ($subkey_len > self::CRYPTO_KDF_BYTES_MAX) {
-            throw new SodiumException('subkey cannot be larger than SODIUM_CRYPTO_KDF_BYTES_MAX');
-        }
-        if ($subkey_id < 0) {
-            throw new SodiumException('subkey_id cannot be negative');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($context) !== self::CRYPTO_KDF_CONTEXTBYTES) {
-            throw new SodiumException('context should be SODIUM_CRYPTO_KDF_CONTEXTBYTES bytes');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_KDF_KEYBYTES) {
-            throw new SodiumException('key should be SODIUM_CRYPTO_KDF_KEYBYTES bytes');
-        }
-
-        $salt = ParagonIE_Sodium_Core_Util::store64_le($subkey_id);
-        $state = self::crypto_generichash_init_salt_personal(
-            $key,
-            $subkey_len,
-            $salt,
-            $context
-        );
-        return self::crypto_generichash_final($state, $subkey_len);
-    }
-
-    /**
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_kdf_keygen()
-    {
-        return random_bytes(self::CRYPTO_KDF_KEYBYTES);
-    }
-
-    /**
-     * Perform a key exchange, between a designated client and a server.
-     *
-     * Typically, you would designate one machine to be the client and the
-     * other to be the server. The first two keys are what you'd expect for
-     * scalarmult() below, but the latter two public keys don't swap places.
-     *
-     * | ALICE                          | BOB                                 |
-     * | Client                         | Server                              |
-     * |--------------------------------|-------------------------------------|
-     * | shared = crypto_kx(            | shared = crypto_kx(                 |
-     * |     alice_sk,                  |     bob_sk,                         | <- contextual
-     * |     bob_pk,                    |     alice_pk,                       | <- contextual
-     * |     alice_pk,                  |     alice_pk,                       | <----- static
-     * |     bob_pk                     |     bob_pk                          | <----- static
-     * | )                              | )                                   |
-     *
-     * They are used along with the scalarmult product to generate a 256-bit
-     * BLAKE2b hash unique to the client and server keys.
-     *
-     * @param string $my_secret
-     * @param string $their_public
-     * @param string $client_public
-     * @param string $server_public
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_kx($my_secret, $their_public, $client_public, $server_public, $dontFallback = false)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($my_secret, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($their_public, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($client_public, 'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($server_public, 'string', 4);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($my_secret) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($their_public) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($client_public) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($server_public) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 4 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            if (is_callable('sodium_crypto_kx')) {
-                return (string) sodium_crypto_kx(
-                    $my_secret,
-                    $their_public,
-                    $client_public,
-                    $server_public
-                );
-            }
-        }
-        if (self::use_fallback('crypto_kx')) {
-            return (string) call_user_func(
-                '\\Sodium\\crypto_kx',
-                $my_secret,
-                $their_public,
-                $client_public,
-                $server_public
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::keyExchange(
-                $my_secret,
-                $their_public,
-                $client_public,
-                $server_public
-            );
-        }
-        return ParagonIE_Sodium_Crypto::keyExchange(
-            $my_secret,
-            $their_public,
-            $client_public,
-            $server_public
-        );
-    }
-
-    /**
-     * @param string $seed
-     * @return string
-     * @throws SodiumException
-     */
-    public static function crypto_kx_seed_keypair($seed)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($seed, 'string', 1);
-
-        $seed = (string) $seed;
-
-        if (ParagonIE_Sodium_Core_Util::strlen($seed) !== self::CRYPTO_KX_SEEDBYTES) {
-            throw new SodiumException('seed must be SODIUM_CRYPTO_KX_SEEDBYTES bytes');
-        }
-
-        $sk = self::crypto_generichash($seed, '', self::CRYPTO_KX_SECRETKEYBYTES);
-        $pk = self::crypto_scalarmult_base($sk);
-        return $sk . $pk;
-    }
-
-    /**
-     * @return string
-     * @throws Exception
-     */
-    public static function crypto_kx_keypair()
-    {
-        $sk = self::randombytes_buf(self::CRYPTO_KX_SECRETKEYBYTES);
-        $pk = self::crypto_scalarmult_base($sk);
-        return $sk . $pk;
-    }
-
-    /**
-     * @param string $keypair
-     * @param string $serverPublicKey
-     * @return array{0: string, 1: string}
-     * @throws SodiumException
-     */
-    public static function crypto_kx_client_session_keys($keypair, $serverPublicKey)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($serverPublicKey, 'string', 2);
-
-        $keypair = (string) $keypair;
-        $serverPublicKey = (string) $serverPublicKey;
-
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_KX_KEYPAIRBYTES) {
-            throw new SodiumException('keypair should be SODIUM_CRYPTO_KX_KEYPAIRBYTES bytes');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($serverPublicKey) !== self::CRYPTO_KX_PUBLICKEYBYTES) {
-            throw new SodiumException('public keys must be SODIUM_CRYPTO_KX_PUBLICKEYBYTES bytes');
-        }
-
-        $sk = self::crypto_kx_secretkey($keypair);
-        $pk = self::crypto_kx_publickey($keypair);
-        $h = self::crypto_generichash_init(null, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
-        self::crypto_generichash_update($h, self::crypto_scalarmult($sk, $serverPublicKey));
-        self::crypto_generichash_update($h, $pk);
-        self::crypto_generichash_update($h, $serverPublicKey);
-        $sessionKeys = self::crypto_generichash_final($h, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
-        return array(
-            ParagonIE_Sodium_Core_Util::substr(
-                $sessionKeys,
-                0,
-                self::CRYPTO_KX_SESSIONKEYBYTES
-            ),
-            ParagonIE_Sodium_Core_Util::substr(
-                $sessionKeys,
-                self::CRYPTO_KX_SESSIONKEYBYTES,
-                self::CRYPTO_KX_SESSIONKEYBYTES
-            )
-        );
-    }
-
-    /**
-     * @param string $keypair
-     * @param string $clientPublicKey
-     * @return array{0: string, 1: string}
-     * @throws SodiumException
-     */
-    public static function crypto_kx_server_session_keys($keypair, $clientPublicKey)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($clientPublicKey, 'string', 2);
-
-        $keypair = (string) $keypair;
-        $clientPublicKey = (string) $clientPublicKey;
-
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_KX_KEYPAIRBYTES) {
-            throw new SodiumException('keypair should be SODIUM_CRYPTO_KX_KEYPAIRBYTES bytes');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($clientPublicKey) !== self::CRYPTO_KX_PUBLICKEYBYTES) {
-            throw new SodiumException('public keys must be SODIUM_CRYPTO_KX_PUBLICKEYBYTES bytes');
-        }
-
-        $sk = self::crypto_kx_secretkey($keypair);
-        $pk = self::crypto_kx_publickey($keypair);
-        $h = self::crypto_generichash_init(null, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
-        self::crypto_generichash_update($h, self::crypto_scalarmult($sk, $clientPublicKey));
-        self::crypto_generichash_update($h, $clientPublicKey);
-        self::crypto_generichash_update($h, $pk);
-        $sessionKeys = self::crypto_generichash_final($h, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
-        return array(
-            ParagonIE_Sodium_Core_Util::substr(
-                $sessionKeys,
-                self::CRYPTO_KX_SESSIONKEYBYTES,
-                self::CRYPTO_KX_SESSIONKEYBYTES
-            ),
-            ParagonIE_Sodium_Core_Util::substr(
-                $sessionKeys,
-                0,
-                self::CRYPTO_KX_SESSIONKEYBYTES
-            )
-        );
-    }
-
-    /**
-     * @param string $kp
-     * @return string
-     * @throws SodiumException
-     */
-    public static function crypto_kx_secretkey($kp)
-    {
-        return ParagonIE_Sodium_Core_Util::substr(
-            $kp,
-            0,
-            self::CRYPTO_KX_SECRETKEYBYTES
-        );
-    }
-
-    /**
-     * @param string $kp
-     * @return string
-     * @throws SodiumException
-     */
-    public static function crypto_kx_publickey($kp)
-    {
-        return ParagonIE_Sodium_Core_Util::substr(
-            $kp,
-            self::CRYPTO_KX_SECRETKEYBYTES,
-            self::CRYPTO_KX_PUBLICKEYBYTES
-        );
-    }
-
-    /**
-     * @param int $outlen
-     * @param string $passwd
-     * @param string $salt
-     * @param int $opslimit
-     * @param int $memlimit
-     * @param int|null $alg
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_pwhash($outlen, $passwd, $salt, $opslimit, $memlimit, $alg = null)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($outlen, 'int', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($salt,  'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 4);
-        ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 5);
-
-        if (self::useNewSodiumAPI()) {
-            if (!is_null($alg)) {
-                ParagonIE_Sodium_Core_Util::declareScalarType($alg, 'int', 6);
-                return sodium_crypto_pwhash($outlen, $passwd, $salt, $opslimit, $memlimit, $alg);
-            }
-            return sodium_crypto_pwhash($outlen, $passwd, $salt, $opslimit, $memlimit);
-        }
-        if (self::use_fallback('crypto_pwhash')) {
-            return (string) call_user_func('\\Sodium\\crypto_pwhash', $outlen, $passwd, $salt, $opslimit, $memlimit);
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented, as it is not possible to implement Argon2i with acceptable performance in pure-PHP'
-        );
-    }
-
-    /**
-     * !Exclusive to sodium_compat!
-     *
-     * This returns TRUE if the native crypto_pwhash API is available by libsodium.
-     * This returns FALSE if only sodium_compat is available.
-     *
-     * @return bool
-     */
-    public static function crypto_pwhash_is_available()
-    {
-        if (self::useNewSodiumAPI()) {
-            return true;
-        }
-        if (self::use_fallback('crypto_pwhash')) {
-            return true;
-        }
-        return false;
-    }
-
-    /**
-     * @param string $passwd
-     * @param int $opslimit
-     * @param int $memlimit
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_pwhash_str($passwd, $opslimit, $memlimit)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 3);
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_pwhash_str($passwd, $opslimit, $memlimit);
-        }
-        if (self::use_fallback('crypto_pwhash_str')) {
-            return (string) call_user_func('\\Sodium\\crypto_pwhash_str', $passwd, $opslimit, $memlimit);
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented, as it is not possible to implement Argon2i with acceptable performance in pure-PHP'
-        );
-    }
-
-    /**
-     * Do we need to rehash this password?
-     *
-     * @param string $hash
-     * @param int $opslimit
-     * @param int $memlimit
-     * @return bool
-     * @throws SodiumException
-     */
-    public static function crypto_pwhash_str_needs_rehash($hash, $opslimit, $memlimit)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($hash, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 3);
-
-        // Just grab the first 4 pieces.
-        $pieces = explode('$', (string) $hash);
-        $prefix = implode('$', array_slice($pieces, 0, 4));
-
-        // Rebuild the expected header.
-        /** @var int $ops */
-        $ops = (int) $opslimit;
-        /** @var int $mem */
-        $mem = (int) $memlimit >> 10;
-        $encoded = self::CRYPTO_PWHASH_STRPREFIX . 'v=19$m=' . $mem . ',t=' . $ops . ',p=1';
-
-        // Do they match? If so, we don't need to rehash, so return false.
-        return !ParagonIE_Sodium_Core_Util::hashEquals($encoded, $prefix);
-    }
-
-    /**
-     * @param string $passwd
-     * @param string $hash
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_pwhash_str_verify($passwd, $hash)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($hash, 'string', 2);
-
-        if (self::useNewSodiumAPI()) {
-            return (bool) sodium_crypto_pwhash_str_verify($passwd, $hash);
-        }
-        if (self::use_fallback('crypto_pwhash_str_verify')) {
-            return (bool) call_user_func('\\Sodium\\crypto_pwhash_str_verify', $passwd, $hash);
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented, as it is not possible to implement Argon2i with acceptable performance in pure-PHP'
-        );
-    }
-
-    /**
-     * @param int $outlen
-     * @param string $passwd
-     * @param string $salt
-     * @param int $opslimit
-     * @param int $memlimit
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function crypto_pwhash_scryptsalsa208sha256($outlen, $passwd, $salt, $opslimit, $memlimit)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($outlen, 'int', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($salt,  'string', 3);
-        ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 4);
-        ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 5);
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_pwhash_scryptsalsa208sha256(
-                (int) $outlen,
-                (string) $passwd,
-                (string) $salt,
-                (int) $opslimit,
-                (int) $memlimit
-            );
-        }
-        if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256')) {
-            return (string) call_user_func(
-                '\\Sodium\\crypto_pwhash_scryptsalsa208sha256',
-                (int) $outlen,
-                (string) $passwd,
-                (string) $salt,
-                (int) $opslimit,
-                (int) $memlimit
-            );
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented, as it is not possible to implement Scrypt with acceptable performance in pure-PHP'
-        );
-    }
-
-    /**
-     * !Exclusive to sodium_compat!
-     *
-     * This returns TRUE if the native crypto_pwhash API is available by libsodium.
-     * This returns FALSE if only sodium_compat is available.
-     *
-     * @return bool
-     */
-    public static function crypto_pwhash_scryptsalsa208sha256_is_available()
-    {
-        if (self::useNewSodiumAPI()) {
-            return true;
-        }
-        if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256')) {
-            return true;
-        }
-        return false;
-    }
-
-    /**
-     * @param string $passwd
-     * @param int $opslimit
-     * @param int $memlimit
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function crypto_pwhash_scryptsalsa208sha256_str($passwd, $opslimit, $memlimit)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 3);
-
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_crypto_pwhash_scryptsalsa208sha256_str(
-                (string) $passwd,
-                (int) $opslimit,
-                (int) $memlimit
-            );
-        }
-        if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256_str')) {
-            return (string) call_user_func(
-                '\\Sodium\\crypto_pwhash_scryptsalsa208sha256_str',
-                (string) $passwd,
-                (int) $opslimit,
-                (int) $memlimit
-            );
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented, as it is not possible to implement Scrypt with acceptable performance in pure-PHP'
-        );
-    }
-
-    /**
-     * @param string $passwd
-     * @param string $hash
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function crypto_pwhash_scryptsalsa208sha256_str_verify($passwd, $hash)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($hash, 'string', 2);
-
-        if (self::useNewSodiumAPI()) {
-            return (bool) sodium_crypto_pwhash_scryptsalsa208sha256_str_verify(
-                (string) $passwd,
-                (string) $hash
-            );
-        }
-        if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256_str_verify')) {
-            return (bool) call_user_func(
-                '\\Sodium\\crypto_pwhash_scryptsalsa208sha256_str_verify',
-                (string) $passwd,
-                (string) $hash
-            );
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented, as it is not possible to implement Scrypt with acceptable performance in pure-PHP'
-        );
-    }
-
-    /**
-     * Calculate the shared secret between your secret key and your
-     * recipient's public key.
-     *
-     * Algorithm: X25519 (ECDH over Curve25519)
-     *
-     * @param string $secretKey
-     * @param string $publicKey
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_scalarmult($secretKey, $publicKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_scalarmult($secretKey, $publicKey);
-        }
-        if (self::use_fallback('crypto_scalarmult')) {
-            return (string) call_user_func('\\Sodium\\crypto_scalarmult', $secretKey, $publicKey);
-        }
-
-        /* Output validation: Forbid all-zero keys */
-        if (ParagonIE_Sodium_Core_Util::hashEquals($secretKey, str_repeat("\0", self::CRYPTO_BOX_SECRETKEYBYTES))) {
-            throw new SodiumException('Zero secret key is not allowed');
-        }
-        if (ParagonIE_Sodium_Core_Util::hashEquals($publicKey, str_repeat("\0", self::CRYPTO_BOX_PUBLICKEYBYTES))) {
-            throw new SodiumException('Zero public key is not allowed');
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::scalarmult($secretKey, $publicKey);
-        }
-        return ParagonIE_Sodium_Crypto::scalarmult($secretKey, $publicKey);
-    }
-
-    /**
-     * Calculate an X25519 public key from an X25519 secret key.
-     *
-     * @param string $secretKey
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress TooFewArguments
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_scalarmult_base($secretKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_scalarmult_base($secretKey);
-        }
-        if (self::use_fallback('crypto_scalarmult_base')) {
-            return (string) call_user_func('\\Sodium\\crypto_scalarmult_base', $secretKey);
-        }
-        if (ParagonIE_Sodium_Core_Util::hashEquals($secretKey, str_repeat("\0", self::CRYPTO_BOX_SECRETKEYBYTES))) {
-            throw new SodiumException('Zero secret key is not allowed');
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::scalarmult_base($secretKey);
-        }
-        return ParagonIE_Sodium_Crypto::scalarmult_base($secretKey);
-    }
-
-    /**
-     * Authenticated symmetric-key encryption.
-     *
-     * Algorithm: XSalsa20-Poly1305
-     *
-     * @param string $plaintext The message you're encrypting
-     * @param string $nonce A Number to be used Once; must be 24 bytes
-     * @param string $key Symmetric encryption key
-     * @return string           Ciphertext with Poly1305 MAC
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_secretbox($plaintext, $nonce, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_secretbox($plaintext, $nonce, $key);
-        }
-        if (self::use_fallback('crypto_secretbox')) {
-            return (string) call_user_func('\\Sodium\\crypto_secretbox', $plaintext, $nonce, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretbox($plaintext, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Crypto::secretbox($plaintext, $nonce, $key);
-    }
-
-    /**
-     * Decrypts a message previously encrypted with crypto_secretbox().
-     *
-     * @param string $ciphertext Ciphertext with Poly1305 MAC
-     * @param string $nonce      A Number to be used Once; must be 24 bytes
-     * @param string $key        Symmetric encryption key
-     * @return string            Original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_secretbox_open($ciphertext, $nonce, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            /**
-             * @psalm-suppress InvalidReturnStatement
-             * @psalm-suppress FalsableReturnStatement
-             */
-            return sodium_crypto_secretbox_open($ciphertext, $nonce, $key);
-        }
-        if (self::use_fallback('crypto_secretbox_open')) {
-            return call_user_func('\\Sodium\\crypto_secretbox_open', $ciphertext, $nonce, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretbox_open($ciphertext, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Crypto::secretbox_open($ciphertext, $nonce, $key);
-    }
-
-    /**
-     * Return a secure random key for use with crypto_secretbox
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_secretbox_keygen()
-    {
-        return random_bytes(self::CRYPTO_SECRETBOX_KEYBYTES);
-    }
-
-    /**
-     * Authenticated symmetric-key encryption.
-     *
-     * Algorithm: XChaCha20-Poly1305
-     *
-     * @param string $plaintext The message you're encrypting
-     * @param string $nonce     A Number to be used Once; must be 24 bytes
-     * @param string $key       Symmetric encryption key
-     * @return string           Ciphertext with Poly1305 MAC
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_secretbox_xchacha20poly1305($plaintext, $nonce, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretbox_xchacha20poly1305($plaintext, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Crypto::secretbox_xchacha20poly1305($plaintext, $nonce, $key);
-    }
-    /**
-     * Decrypts a message previously encrypted with crypto_secretbox_xchacha20poly1305().
-     *
-     * @param string $ciphertext Ciphertext with Poly1305 MAC
-     * @param string $nonce      A Number to be used Once; must be 24 bytes
-     * @param string $key        Symmetric encryption key
-     * @return string            Original plaintext message
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
-        }
-
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Crypto::secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key);
-    }
-
-    /**
-     * @param string $key
-     * @return array<int, string> Returns a state and a header.
-     * @throws Exception
-     * @throws SodiumException
-     */
-    public static function crypto_secretstream_xchacha20poly1305_init_push($key)
-    {
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_init_push($key);
-        }
-        return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_init_push($key);
-    }
-
-    /**
-     * @param string $header
-     * @param string $key
-     * @return string Returns a state.
-     * @throws Exception
-     */
-    public static function crypto_secretstream_xchacha20poly1305_init_pull($header, $key)
-    {
-        if (ParagonIE_Sodium_Core_Util::strlen($header) < self::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_HEADERBYTES) {
-            throw new SodiumException(
-                'header size should be SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_HEADERBYTES bytes'
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_init_pull($key, $header);
-        }
-        return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_init_pull($key, $header);
-    }
-
-    /**
-     * @param string $state
-     * @param string $msg
-     * @param string $aad
-     * @param int $tag
-     * @return string
-     * @throws SodiumException
-     */
-    public static function crypto_secretstream_xchacha20poly1305_push(&$state, $msg, $aad = '', $tag = 0)
-    {
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_push(
-                $state,
-                $msg,
-                $aad,
-                $tag
-            );
-        }
-        return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_push(
-            $state,
-            $msg,
-            $aad,
-            $tag
-        );
-    }
-
-    /**
-     * @param string $state
-     * @param string $msg
-     * @param string $aad
-     * @return bool|array{0: string, 1: int}
-     * @throws SodiumException
-     */
-    public static function crypto_secretstream_xchacha20poly1305_pull(&$state, $msg, $aad = '')
-    {
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_pull(
-                $state,
-                $msg,
-                $aad
-            );
-        }
-        return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_pull(
-            $state,
-            $msg,
-            $aad
-        );
-    }
-
-    /**
-     * @return string
-     * @throws Exception
-     */
-    public static function crypto_secretstream_xchacha20poly1305_keygen()
-    {
-        return random_bytes(self::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_KEYBYTES);
-    }
-
-    /**
-     * @param string $state
-     * @return void
-     * @throws SodiumException
-     */
-    public static function crypto_secretstream_xchacha20poly1305_rekey(&$state)
-    {
-        if (PHP_INT_SIZE === 4) {
-            ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_rekey($state);
-        } else {
-            ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_rekey($state);
-        }
-    }
-
-    /**
-     * Calculates a SipHash-2-4 hash of a message for a given key.
-     *
-     * @param string $message Input message
-     * @param string $key SipHash-2-4 key
-     * @return string         Hash
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_shorthash($message, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SHORTHASH_KEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SHORTHASH_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_shorthash($message, $key);
-        }
-        if (self::use_fallback('crypto_shorthash')) {
-            return (string) call_user_func('\\Sodium\\crypto_shorthash', $message, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_SipHash::sipHash24($message, $key);
-        }
-        return ParagonIE_Sodium_Core_SipHash::sipHash24($message, $key);
-    }
-
-    /**
-     * Return a secure random key for use with crypto_shorthash
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_shorthash_keygen()
-    {
-        return random_bytes(self::CRYPTO_SHORTHASH_KEYBYTES);
-    }
-
-    /**
-     * Returns a signed message. You probably want crypto_sign_detached()
-     * instead, which only returns the signature.
-     *
-     * Algorithm: Ed25519 (EdDSA over Curve25519)
-     *
-     * @param string $message Message to be signed.
-     * @param string $secretKey Secret signing key.
-     * @return string           Signed message (signature is prefixed).
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_sign($message, $secretKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SIGN_SECRETKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign($message, $secretKey);
-        }
-        if (self::use_fallback('crypto_sign')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign', $message, $secretKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::sign($message, $secretKey);
-        }
-        return ParagonIE_Sodium_Crypto::sign($message, $secretKey);
-    }
-
-    /**
-     * Validates a signed message then returns the message.
-     *
-     * @param string $signedMessage A signed message
-     * @param string $publicKey A public key
-     * @return string               The original message (if the signature is
-     *                              valid for this public key)
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress MixedReturnStatement
-     */
-    public static function crypto_sign_open($signedMessage, $publicKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($signedMessage, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($signedMessage) < self::CRYPTO_SIGN_BYTES) {
-            throw new SodiumException('Argument 1 must be at least CRYPTO_SIGN_BYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_SIGN_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SIGN_PUBLICKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            /**
-             * @psalm-suppress InvalidReturnStatement
-             * @psalm-suppress FalsableReturnStatement
-             */
-            return sodium_crypto_sign_open($signedMessage, $publicKey);
-        }
-        if (self::use_fallback('crypto_sign_open')) {
-            return call_user_func('\\Sodium\\crypto_sign_open', $signedMessage, $publicKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::sign_open($signedMessage, $publicKey);
-        }
-        return ParagonIE_Sodium_Crypto::sign_open($signedMessage, $publicKey);
-    }
-
-    /**
-     * Generate a new random Ed25519 keypair.
-     *
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function crypto_sign_keypair()
-    {
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_keypair();
-        }
-        if (self::use_fallback('crypto_sign_keypair')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_keypair');
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_Ed25519::keypair();
-        }
-        return ParagonIE_Sodium_Core_Ed25519::keypair();
-    }
-
-    /**
-     * @param string $sk
-     * @param string $pk
-     * @return string
-     * @throws SodiumException
-     */
-    public static function crypto_sign_keypair_from_secretkey_and_publickey($sk, $pk)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($sk, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($pk, 'string', 1);
-        $sk = (string) $sk;
-        $pk = (string) $pk;
-
-        if (ParagonIE_Sodium_Core_Util::strlen($sk) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
-            throw new SodiumException('secretkey should be SODIUM_CRYPTO_SIGN_SECRETKEYBYTES bytes');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($pk) !== self::CRYPTO_SIGN_PUBLICKEYBYTES) {
-            throw new SodiumException('publickey should be SODIUM_CRYPTO_SIGN_PUBLICKEYBYTES bytes');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_keypair_from_secretkey_and_publickey($sk, $pk);
-        }
-        return $sk . $pk;
-    }
-
-    /**
-     * Generate an Ed25519 keypair from a seed.
-     *
-     * @param string $seed Input seed
-     * @return string      Keypair
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_seed_keypair($seed)
-    {
-        ParagonIE_Sodium_Core_Util::declareScalarType($seed, 'string', 1);
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_seed_keypair($seed);
-        }
-        if (self::use_fallback('crypto_sign_keypair')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_seed_keypair', $seed);
-        }
-        $publicKey = '';
-        $secretKey = '';
-        if (PHP_INT_SIZE === 4) {
-            ParagonIE_Sodium_Core32_Ed25519::seed_keypair($publicKey, $secretKey, $seed);
-        } else {
-            ParagonIE_Sodium_Core_Ed25519::seed_keypair($publicKey, $secretKey, $seed);
-        }
-        return $secretKey . $publicKey;
-    }
-
-    /**
-     * Extract an Ed25519 public key from an Ed25519 keypair.
-     *
-     * @param string $keypair Keypair
-     * @return string         Public key
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_publickey($keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_SIGN_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_SIGN_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_publickey($keypair);
-        }
-        if (self::use_fallback('crypto_sign_publickey')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_publickey', $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_Ed25519::publickey($keypair);
-        }
-        return ParagonIE_Sodium_Core_Ed25519::publickey($keypair);
-    }
-
-    /**
-     * Calculate an Ed25519 public key from an Ed25519 secret key.
-     *
-     * @param string $secretKey Your Ed25519 secret key
-     * @return string           The corresponding Ed25519 public key
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_publickey_from_secretkey($secretKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_SIGN_SECRETKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_publickey_from_secretkey($secretKey);
-        }
-        if (self::use_fallback('crypto_sign_publickey_from_secretkey')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_publickey_from_secretkey', $secretKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_Ed25519::publickey_from_secretkey($secretKey);
-        }
-        return ParagonIE_Sodium_Core_Ed25519::publickey_from_secretkey($secretKey);
-    }
-
-    /**
-     * Extract an Ed25519 secret key from an Ed25519 keypair.
-     *
-     * @param string $keypair Keypair
-     * @return string         Secret key
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_secretkey($keypair)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_SIGN_KEYPAIRBYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_SIGN_KEYPAIRBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_secretkey($keypair);
-        }
-        if (self::use_fallback('crypto_sign_secretkey')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_secretkey', $keypair);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_Ed25519::secretkey($keypair);
-        }
-        return ParagonIE_Sodium_Core_Ed25519::secretkey($keypair);
-    }
-
-    /**
-     * Calculate the Ed25519 signature of a message and return ONLY the signature.
-     *
-     * Algorithm: Ed25519 (EdDSA over Curve25519)
-     *
-     * @param string $message Message to be signed
-     * @param string $secretKey Secret signing key
-     * @return string           Digital signature
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_detached($message, $secretKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 2);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SIGN_SECRETKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_detached($message, $secretKey);
-        }
-        if (self::use_fallback('crypto_sign_detached')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_detached', $message, $secretKey);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::sign_detached($message, $secretKey);
-        }
-        return ParagonIE_Sodium_Crypto::sign_detached($message, $secretKey);
-    }
-
-    /**
-     * Verify the Ed25519 signature of a message.
-     *
-     * @param string $signature Digital sginature
-     * @param string $message Message to be verified
-     * @param string $publicKey Public key
-     * @return bool             TRUE if this signature is good for this public key;
-     *                          FALSE otherwise
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_verify_detached($signature, $message, $publicKey)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($signature, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($signature) !== self::CRYPTO_SIGN_BYTES) {
-            throw new SodiumException('Argument 1 must be CRYPTO_SIGN_BYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_SIGN_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SIGN_PUBLICKEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_sign_verify_detached($signature, $message, $publicKey);
-        }
-        if (self::use_fallback('crypto_sign_verify_detached')) {
-            return (bool) call_user_func(
-                '\\Sodium\\crypto_sign_verify_detached',
-                $signature,
-                $message,
-                $publicKey
-            );
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Crypto32::sign_verify_detached($signature, $message, $publicKey);
-        }
-        return ParagonIE_Sodium_Crypto::sign_verify_detached($signature, $message, $publicKey);
-    }
-
-    /**
-     * Convert an Ed25519 public key to a Curve25519 public key
-     *
-     * @param string $pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_ed25519_pk_to_curve25519($pk)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($pk, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($pk) < self::CRYPTO_SIGN_PUBLICKEYBYTES) {
-            throw new SodiumException('Argument 1 must be at least CRYPTO_SIGN_PUBLICKEYBYTES long.');
-        }
-        if (self::useNewSodiumAPI()) {
-            if (is_callable('crypto_sign_ed25519_pk_to_curve25519')) {
-                return (string) sodium_crypto_sign_ed25519_pk_to_curve25519($pk);
-            }
-        }
-        if (self::use_fallback('crypto_sign_ed25519_pk_to_curve25519')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_ed25519_pk_to_curve25519', $pk);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_Ed25519::pk_to_curve25519($pk);
-        }
-        return ParagonIE_Sodium_Core_Ed25519::pk_to_curve25519($pk);
-    }
-
-    /**
-     * Convert an Ed25519 secret key to a Curve25519 secret key
-     *
-     * @param string $sk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_sign_ed25519_sk_to_curve25519($sk)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($sk, 'string', 1);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($sk) < self::CRYPTO_SIGN_SEEDBYTES) {
-            throw new SodiumException('Argument 1 must be at least CRYPTO_SIGN_SEEDBYTES long.');
-        }
-        if (self::useNewSodiumAPI()) {
-            if (is_callable('crypto_sign_ed25519_sk_to_curve25519')) {
-                return sodium_crypto_sign_ed25519_sk_to_curve25519($sk);
-            }
-        }
-        if (self::use_fallback('crypto_sign_ed25519_sk_to_curve25519')) {
-            return (string) call_user_func('\\Sodium\\crypto_sign_ed25519_sk_to_curve25519', $sk);
-        }
-
-        $h = hash('sha512', ParagonIE_Sodium_Core_Util::substr($sk, 0, 32), true);
-        $h[0] = ParagonIE_Sodium_Core_Util::intToChr(
-            ParagonIE_Sodium_Core_Util::chrToInt($h[0]) & 248
-        );
-        $h[31] = ParagonIE_Sodium_Core_Util::intToChr(
-            (ParagonIE_Sodium_Core_Util::chrToInt($h[31]) & 127) | 64
-        );
-        return ParagonIE_Sodium_Core_Util::substr($h, 0, 32);
-    }
-
-    /**
-     * Expand a key and nonce into a keystream of pseudorandom bytes.
-     *
-     * @param int $len Number of bytes desired
-     * @param string $nonce Number to be used Once; must be 24 bytes
-     * @param string $key XSalsa20 key
-     * @return string       Pseudorandom stream that can be XORed with messages
-     *                      to provide encryption (but not authentication; see
-     *                      Poly1305 or crypto_auth() for that, which is not
-     *                      optional for security)
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_stream($len, $nonce, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($len, 'int', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_STREAM_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_stream($len, $nonce, $key);
-        }
-        if (self::use_fallback('crypto_stream')) {
-            return (string) call_user_func('\\Sodium\\crypto_stream', $len, $nonce, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_XSalsa20::xsalsa20($len, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Core_XSalsa20::xsalsa20($len, $nonce, $key);
-    }
-
-    /**
-     * DANGER! UNAUTHENTICATED ENCRYPTION!
-     *
-     * Unless you are following expert advice, do not use this feature.
-     *
-     * Algorithm: XSalsa20
-     *
-     * This DOES NOT provide ciphertext integrity.
-     *
-     * @param string $message Plaintext message
-     * @param string $nonce Number to be used Once; must be 24 bytes
-     * @param string $key Encryption key
-     * @return string         Encrypted text which is vulnerable to chosen-
-     *                        ciphertext attacks unless you implement some
-     *                        other mitigation to the ciphertext (i.e.
-     *                        Encrypt then MAC)
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_stream_xor($message, $nonce, $key)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_crypto_stream_xor($message, $nonce, $key);
-        }
-        if (self::use_fallback('crypto_stream_xor')) {
-            return (string) call_user_func('\\Sodium\\crypto_stream_xor', $message, $nonce, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_XSalsa20::xsalsa20_xor($message, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Core_XSalsa20::xsalsa20_xor($message, $nonce, $key);
-    }
-
-    /**
-     * Return a secure random key for use with crypto_stream
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_stream_keygen()
-    {
-        return random_bytes(self::CRYPTO_STREAM_KEYBYTES);
-    }
-
-
-    /**
-     * Expand a key and nonce into a keystream of pseudorandom bytes.
-     *
-     * @param int $len Number of bytes desired
-     * @param string $nonce Number to be used Once; must be 24 bytes
-     * @param string $key XChaCha20 key
-     * @param bool $dontFallback
-     * @return string       Pseudorandom stream that can be XORed with messages
-     *                      to provide encryption (but not authentication; see
-     *                      Poly1305 or crypto_auth() for that, which is not
-     *                      optional for security)
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_stream_xchacha20($len, $nonce, $key, $dontFallback = false)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($len, 'int', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_XCHACHA20_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_XCHACHA20_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_XCHACHA20_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_STREAM_XCHACHA20_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_stream_xchacha20($len, $nonce, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_XChaCha20::stream($len, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Core_XChaCha20::stream($len, $nonce, $key);
-    }
-
-    /**
-     * DANGER! UNAUTHENTICATED ENCRYPTION!
-     *
-     * Unless you are following expert advice, do not use this feature.
-     *
-     * Algorithm: XChaCha20
-     *
-     * This DOES NOT provide ciphertext integrity.
-     *
-     * @param string $message Plaintext message
-     * @param string $nonce Number to be used Once; must be 24 bytes
-     * @param string $key Encryption key
-     * @return string         Encrypted text which is vulnerable to chosen-
-     *                        ciphertext attacks unless you implement some
-     *                        other mitigation to the ciphertext (i.e.
-     *                        Encrypt then MAC)
-     * @param bool $dontFallback
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function crypto_stream_xchacha20_xor($message, $nonce, $key, $dontFallback = false)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
-        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
-
-        /* Input validation: */
-        if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_XCHACHA20_NONCEBYTES) {
-            throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_XCHACHA20_NONCEBYTES long.');
-        }
-        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_XCHACHA20_KEYBYTES) {
-            throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_XCHACHA20_KEYBYTES long.');
-        }
-
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_stream_xchacha20_xor($message, $nonce, $key);
-        }
-        if (PHP_INT_SIZE === 4) {
-            return ParagonIE_Sodium_Core32_XChaCha20::streamXorIc($message, $nonce, $key);
-        }
-        return ParagonIE_Sodium_Core_XChaCha20::streamXorIc($message, $nonce, $key);
-    }
-
-    /**
-     * Return a secure random key for use with crypto_stream_xchacha20
-     *
-     * @return string
-     * @throws Exception
-     * @throws Error
-     */
-    public static function crypto_stream_xchacha20_keygen()
-    {
-        return random_bytes(self::CRYPTO_STREAM_XCHACHA20_KEYBYTES);
-    }
-
-    /**
-     * Cache-timing-safe implementation of hex2bin().
-     *
-     * @param string $string Hexadecimal string
-     * @return string        Raw binary string
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress TooFewArguments
-     * @psalm-suppress MixedArgument
-     */
-    public static function hex2bin($string)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($string, 'string', 1);
-
-        if (self::useNewSodiumAPI()) {
-            if (is_callable('sodium_hex2bin')) {
-                return (string) sodium_hex2bin($string);
-            }
-        }
-        if (self::use_fallback('hex2bin')) {
-            return (string) call_user_func('\\Sodium\\hex2bin', $string);
-        }
-        return ParagonIE_Sodium_Core_Util::hex2bin($string);
-    }
-
-    /**
-     * Increase a string (little endian)
-     *
-     * @param string $var
-     *
-     * @return void
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function increment(&$var)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($var, 'string', 1);
-
-        if (self::useNewSodiumAPI()) {
-            sodium_increment($var);
-            return;
-        }
-        if (self::use_fallback('increment')) {
-            $func = '\\Sodium\\increment';
-            $func($var);
-            return;
-        }
-
-        $len = ParagonIE_Sodium_Core_Util::strlen($var);
-        $c = 1;
-        $copy = '';
-        for ($i = 0; $i < $len; ++$i) {
-            $c += ParagonIE_Sodium_Core_Util::chrToInt(
-                ParagonIE_Sodium_Core_Util::substr($var, $i, 1)
-            );
-            $copy .= ParagonIE_Sodium_Core_Util::intToChr($c);
-            $c >>= 8;
-        }
-        $var = $copy;
-    }
-
-    /**
-     * @param string $str
-     * @return bool
-     *
-     * @throws SodiumException
-     */
-    public static function is_zero($str)
-    {
-        $d = 0;
-        for ($i = 0; $i < 32; ++$i) {
-            $d |= ParagonIE_Sodium_Core_Util::chrToInt($str[$i]);
-        }
-        return ((($d - 1) >> 31) & 1) === 1;
-    }
-
-    /**
-     * The equivalent to the libsodium minor version we aim to be compatible
-     * with (sans pwhash and memzero).
-     *
-     * @return int
-     */
-    public static function library_version_major()
-    {
-        if (self::useNewSodiumAPI() && defined('SODIUM_LIBRARY_MAJOR_VERSION')) {
-            return SODIUM_LIBRARY_MAJOR_VERSION;
-        }
-        if (self::use_fallback('library_version_major')) {
-            /** @psalm-suppress UndefinedFunction */
-            return (int) call_user_func('\\Sodium\\library_version_major');
-        }
-        return self::LIBRARY_VERSION_MAJOR;
-    }
-
-    /**
-     * The equivalent to the libsodium minor version we aim to be compatible
-     * with (sans pwhash and memzero).
-     *
-     * @return int
-     */
-    public static function library_version_minor()
-    {
-        if (self::useNewSodiumAPI() && defined('SODIUM_LIBRARY_MINOR_VERSION')) {
-            return SODIUM_LIBRARY_MINOR_VERSION;
-        }
-        if (self::use_fallback('library_version_minor')) {
-            /** @psalm-suppress UndefinedFunction */
-            return (int) call_user_func('\\Sodium\\library_version_minor');
-        }
-        return self::LIBRARY_VERSION_MINOR;
-    }
-
-    /**
-     * Compare two strings.
-     *
-     * @param string $left
-     * @param string $right
-     * @return int
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     */
-    public static function memcmp($left, $right)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($left, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($right, 'string', 2);
-
-        if (self::useNewSodiumAPI()) {
-            return sodium_memcmp($left, $right);
-        }
-        if (self::use_fallback('memcmp')) {
-            return (int) call_user_func('\\Sodium\\memcmp', $left, $right);
-        }
-        /** @var string $left */
-        /** @var string $right */
-        return ParagonIE_Sodium_Core_Util::memcmp($left, $right);
-    }
-
-    /**
-     * It's actually not possible to zero memory buffers in PHP. You need the
-     * native library for that.
-     *
-     * @param string|null $var
-     * @param-out string|null $var
-     *
-     * @return void
-     * @throws SodiumException (Unless libsodium is installed)
-     * @throws TypeError
-     * @psalm-suppress TooFewArguments
-     */
-    public static function memzero(&$var)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($var, 'string', 1);
-
-        if (self::useNewSodiumAPI()) {
-            /** @psalm-suppress MixedArgument */
-            sodium_memzero($var);
-            return;
-        }
-        if (self::use_fallback('memzero')) {
-            $func = '\\Sodium\\memzero';
-            $func($var);
-            if ($var === null) {
-                return;
-            }
-        }
-        // This is the best we can do.
-        throw new SodiumException(
-            'This is not implemented in sodium_compat, as it is not possible to securely wipe memory from PHP. ' .
-            'To fix this error, make sure libsodium is installed and the PHP extension is enabled.'
-        );
-    }
-
-    /**
-     * @param string $unpadded
-     * @param int $blockSize
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function pad($unpadded, $blockSize, $dontFallback = false)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($unpadded, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($blockSize, 'int', 2);
-
-        $unpadded = (string) $unpadded;
-        $blockSize = (int) $blockSize;
-
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return (string) sodium_pad($unpadded, $blockSize);
-        }
-
-        if ($blockSize <= 0) {
-            throw new SodiumException(
-                'block size cannot be less than 1'
-            );
-        }
-        $unpadded_len = ParagonIE_Sodium_Core_Util::strlen($unpadded);
-        $xpadlen = ($blockSize - 1);
-        if (($blockSize & ($blockSize - 1)) === 0) {
-            $xpadlen -= $unpadded_len & ($blockSize - 1);
-        } else {
-            $xpadlen -= $unpadded_len % $blockSize;
-        }
-
-        $xpadded_len = $unpadded_len + $xpadlen;
-        $padded = str_repeat("\0", $xpadded_len - 1);
-        if ($unpadded_len > 0) {
-            $st = 1;
-            $i = 0;
-            $k = $unpadded_len;
-            for ($j = 0; $j <= $xpadded_len; ++$j) {
-                $i = (int) $i;
-                $k = (int) $k;
-                $st = (int) $st;
-                if ($j >= $unpadded_len) {
-                    $padded[$j] = "\0";
-                } else {
-                    $padded[$j] = $unpadded[$j];
-                }
-                /** @var int $k */
-                $k -= $st;
-                $st = (int) (~(
-                            (
-                                (
-                                    ($k >> 48)
-                                        |
-                                    ($k >> 32)
-                                        |
-                                    ($k >> 16)
-                                        |
-                                    $k
-                                ) - 1
-                            ) >> 16
-                        )
-                    ) & 1;
-                $i += $st;
-            }
-        }
-
-        $mask = 0;
-        $tail = $xpadded_len;
-        for ($i = 0; $i < $blockSize; ++$i) {
-            # barrier_mask = (unsigned char)
-            #     (((i ^ xpadlen) - 1U) >> ((sizeof(size_t) - 1U) * CHAR_BIT));
-            $barrier_mask = (($i ^ $xpadlen) -1) >> ((PHP_INT_SIZE << 3) - 1);
-            # tail[-i] = (tail[-i] & mask) | (0x80 & barrier_mask);
-            $padded[$tail - $i] = ParagonIE_Sodium_Core_Util::intToChr(
-                (ParagonIE_Sodium_Core_Util::chrToInt($padded[$tail - $i]) & $mask)
-                    |
-                (0x80 & $barrier_mask)
-            );
-            # mask |= barrier_mask;
-            $mask |= $barrier_mask;
-        }
-        return $padded;
-    }
-
-    /**
-     * @param string $padded
-     * @param int $blockSize
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function unpad($padded, $blockSize, $dontFallback = false)
-    {
-        /* Type checks: */
-        ParagonIE_Sodium_Core_Util::declareScalarType($padded, 'string', 1);
-        ParagonIE_Sodium_Core_Util::declareScalarType($blockSize, 'int', 2);
-
-        $padded = (string) $padded;
-        $blockSize = (int) $blockSize;
-
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return (string) sodium_unpad($padded, $blockSize);
-        }
-        if ($blockSize <= 0) {
-            throw new SodiumException('block size cannot be less than 1');
-        }
-        $padded_len = ParagonIE_Sodium_Core_Util::strlen($padded);
-        if ($padded_len < $blockSize) {
-            throw new SodiumException('invalid padding');
-        }
-
-        # tail = &padded[padded_len - 1U];
-        $tail = $padded_len - 1;
-
-        $acc = 0;
-        $valid = 0;
-        $pad_len = 0;
-
-        $found = 0;
-        for ($i = 0; $i < $blockSize; ++$i) {
-            # c = tail[-i];
-            $c = ParagonIE_Sodium_Core_Util::chrToInt($padded[$tail - $i]);
-
-            # is_barrier =
-            #     (( (acc - 1U) & (pad_len - 1U) & ((c ^ 0x80) - 1U) ) >> 8) & 1U;
-            $is_barrier = (
-                (
-                    ($acc - 1) & ($pad_len - 1) & (($c ^ 80) - 1)
-                ) >> 7
-            ) & 1;
-            $is_barrier &= ~$found;
-            $found |= $is_barrier;
-
-            # acc |= c;
-            $acc |= $c;
-
-            # pad_len |= i & (1U + ~is_barrier);
-            $pad_len |= $i & (1 + ~$is_barrier);
-
-            # valid |= (unsigned char) is_barrier;
-            $valid |= ($is_barrier & 0xff);
-        }
-        # unpadded_len = padded_len - 1U - pad_len;
-        $unpadded_len = $padded_len - 1 - $pad_len;
-        if ($valid !== 1) {
-            throw new SodiumException('invalid padding');
-        }
-        return ParagonIE_Sodium_Core_Util::substr($padded, 0, $unpadded_len);
-    }
-
-    /**
-     * Will sodium_compat run fast on the current hardware and PHP configuration?
-     *
-     * @return bool
-     */
-    public static function polyfill_is_fast()
-    {
-        if (extension_loaded('sodium')) {
-            return true;
-        }
-        if (extension_loaded('libsodium')) {
-            return true;
-        }
-        return PHP_INT_SIZE === 8;
-    }
-
-    /**
-     * Generate a string of bytes from the kernel's CSPRNG.
-     * Proudly uses /dev/urandom (if getrandom(2) is not available).
-     *
-     * @param int $numBytes
-     * @return string
-     * @throws Exception
-     * @throws TypeError
-     */
-    public static function randombytes_buf($numBytes)
-    {
-        /* Type checks: */
-        if (!is_int($numBytes)) {
-            if (is_numeric($numBytes)) {
-                $numBytes = (int) $numBytes;
-            } else {
-                throw new TypeError(
-                    'Argument 1 must be an integer, ' . gettype($numBytes) . ' given.'
-                );
-            }
-        }
-        if (self::use_fallback('randombytes_buf')) {
-            return (string) call_user_func('\\Sodium\\randombytes_buf', $numBytes);
-        }
-        return random_bytes($numBytes);
-    }
-
-    /**
-     * Generate an integer between 0 and $range (non-inclusive).
-     *
-     * @param int $range
-     * @return int
-     * @throws Exception
-     * @throws Error
-     * @throws TypeError
-     */
-    public static function randombytes_uniform($range)
-    {
-        /* Type checks: */
-        if (!is_int($range)) {
-            if (is_numeric($range)) {
-                $range = (int) $range;
-            } else {
-                throw new TypeError(
-                    'Argument 1 must be an integer, ' . gettype($range) . ' given.'
-                );
-            }
-        }
-        if (self::use_fallback('randombytes_uniform')) {
-            return (int) call_user_func('\\Sodium\\randombytes_uniform', $range);
-        }
-        return random_int(0, $range - 1);
-    }
-
-    /**
-     * Generate a random 16-bit integer.
-     *
-     * @return int
-     * @throws Exception
-     * @throws Error
-     * @throws TypeError
-     */
-    public static function randombytes_random16()
-    {
-        if (self::use_fallback('randombytes_random16')) {
-            return (int) call_user_func('\\Sodium\\randombytes_random16');
-        }
-        return random_int(0, 65535);
-    }
-
-    /**
-     * @param string $p
-     * @param bool $dontFallback
-     * @return bool
-     * @throws SodiumException
-     */
-    public static function ristretto255_is_valid_point($p, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_is_valid_point($p);
-        }
-        try {
-            $r = ParagonIE_Sodium_Core_Ristretto255::ristretto255_frombytes($p);
-            return $r['res'] === 0 &&
-                ParagonIE_Sodium_Core_Ristretto255::ristretto255_point_is_canonical($p) === 1;
-        } catch (SodiumException $ex) {
-            if ($ex->getMessage() === 'S is not canonical') {
-                return false;
-            }
-            throw $ex;
-        }
-    }
-
-    /**
-     * @param string $p
-     * @param string $q
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_add($p, $q, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_add($p, $q);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_add($p, $q);
-    }
-
-    /**
-     * @param string $p
-     * @param string $q
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_sub($p, $q, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_sub($p, $q);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_sub($p, $q);
-    }
-
-    /**
-     * @param string $r
-     * @param bool $dontFallback
-     * @return string
-     *
-     * @throws SodiumException
-     */
-    public static function ristretto255_from_hash($r, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_from_hash($r);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_from_hash($r);
-    }
-
-    /**
-     * @param bool $dontFallback
-     * @return string
-     *
-     * @throws SodiumException
-     */
-    public static function ristretto255_random($dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_random();
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_random();
-    }
-
-    /**
-     * @param bool $dontFallback
-     * @return string
-     *
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_random($dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_random();
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_random();
-    }
-
-    /**
-     * @param string $s
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_invert($s, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_invert($s);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_invert($s);
-    }
-    /**
-     * @param string $s
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_negate($s, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_negate($s);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_negate($s);
-    }
-
-    /**
-     * @param string $s
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_complement($s, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_complement($s);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_complement($s);
-    }
-
-    /**
-     * @param string $x
-     * @param string $y
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_add($x, $y, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_add($x, $y);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_add($x, $y);
-    }
-
-    /**
-     * @param string $x
-     * @param string $y
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_sub($x, $y, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_sub($x, $y);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_sub($x, $y);
-    }
-
-    /**
-     * @param string $x
-     * @param string $y
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_mul($x, $y, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_mul($x, $y);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_mul($x, $y);
-    }
-
-    /**
-     * @param string $n
-     * @param string $p
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function scalarmult_ristretto255($n, $p, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_scalarmult_ristretto255($n, $p);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::scalarmult_ristretto255($n, $p);
-    }
-
-    /**
-     * @param string $n
-     * @param string $p
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function scalarmult_ristretto255_base($n, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_scalarmult_ristretto255_base($n);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::scalarmult_ristretto255_base($n);
-    }
-
-    /**
-     * @param string $s
-     * @param bool $dontFallback
-     * @return string
-     * @throws SodiumException
-     */
-    public static function ristretto255_scalar_reduce($s, $dontFallback = false)
-    {
-        if (self::useNewSodiumAPI() && !$dontFallback) {
-            return sodium_crypto_core_ristretto255_scalar_reduce($s);
-        }
-        return ParagonIE_Sodium_Core_Ristretto255::sc_reduce($s);
-    }
-
-    /**
-     * Runtime testing method for 32-bit platforms.
-     *
-     * Usage: If runtime_speed_test() returns FALSE, then our 32-bit
-     *        implementation is to slow to use safely without risking timeouts.
-     *        If this happens, install sodium from PECL to get acceptable
-     *        performance.
-     *
-     * @param int $iterations Number of multiplications to attempt
-     * @param int $maxTimeout Milliseconds
-     * @return bool           TRUE if we're fast enough, FALSE is not
-     * @throws SodiumException
-     */
-    public static function runtime_speed_test($iterations, $maxTimeout)
-    {
-        if (self::polyfill_is_fast()) {
-            return true;
-        }
-        /** @var float $end */
-        $end = 0.0;
-        /** @var float $start */
-        $start = microtime(true);
-        /** @var ParagonIE_Sodium_Core32_Int64 $a */
-        $a = ParagonIE_Sodium_Core32_Int64::fromInt(random_int(3, 1 << 16));
-        for ($i = 0; $i < $iterations; ++$i) {
-            /** @var ParagonIE_Sodium_Core32_Int64 $b */
-            $b = ParagonIE_Sodium_Core32_Int64::fromInt(random_int(3, 1 << 16));
-            $a->mulInt64($b);
-        }
-        /** @var float $end */
-        $end = microtime(true);
-        /** @var int $diff */
-        $diff = (int) ceil(($end - $start) * 1000);
-        return $diff < $maxTimeout;
-    }
-
-    /**
-     * Add two numbers (little-endian unsigned), storing the value in the first
-     * parameter.
-     *
-     * This mutates $val.
-     *
-     * @param string $val
-     * @param string $addv
-     * @return void
-     * @throws SodiumException
-     */
-    public static function sub(&$val, $addv)
-    {
-        $val_len = ParagonIE_Sodium_Core_Util::strlen($val);
-        $addv_len = ParagonIE_Sodium_Core_Util::strlen($addv);
-        if ($val_len !== $addv_len) {
-            throw new SodiumException('values must have the same length');
-        }
-        $A = ParagonIE_Sodium_Core_Util::stringToIntArray($val);
-        $B = ParagonIE_Sodium_Core_Util::stringToIntArray($addv);
-
-        $c = 0;
-        for ($i = 0; $i < $val_len; $i++) {
-            $c = ($A[$i] - $B[$i] - $c);
-            $A[$i] = ($c & 0xff);
-            $c = ($c >> 8) & 1;
-        }
-        $val = ParagonIE_Sodium_Core_Util::intArrayToString($A);
-    }
-
-    /**
-     * This emulates libsodium's version_string() function, except ours is
-     * prefixed with 'polyfill-'.
-     *
-     * @return string
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress UndefinedFunction
-     */
-    public static function version_string()
-    {
-        if (self::useNewSodiumAPI()) {
-            return (string) sodium_version_string();
-        }
-        if (self::use_fallback('version_string')) {
-            return (string) call_user_func('\\Sodium\\version_string');
-        }
-        return (string) self::VERSION_STRING;
-    }
-
-    /**
-     * Should we use the libsodium core function instead?
-     * This is always a good idea, if it's available. (Unless we're in the
-     * middle of running our unit test suite.)
-     *
-     * If ext/libsodium is available, use it. Return TRUE.
-     * Otherwise, we have to use the code provided herein. Return FALSE.
-     *
-     * @param string $sodium_func_name
-     *
-     * @return bool
-     */
-    protected static function use_fallback($sodium_func_name = '')
-    {
-        static $res = null;
-        if ($res === null) {
-            $res = extension_loaded('libsodium') && PHP_VERSION_ID >= 50300;
-        }
-        if ($res === false) {
-            // No libsodium installed
-            return false;
-        }
-        if (self::$disableFallbackForUnitTests) {
-            // Don't fallback. Use the PHP implementation.
-            return false;
-        }
-        if (!empty($sodium_func_name)) {
-            return is_callable('\\Sodium\\' . $sodium_func_name);
-        }
-        return true;
-    }
-
-    /**
-     * Libsodium as implemented in PHP 7.2
-     * and/or ext/sodium (via PECL)
-     *
-     * @ref https://wiki.php.net/rfc/libsodium
-     * @return bool
-     */
-    protected static function useNewSodiumAPI()
-    {
-        static $res = null;
-        if ($res === null) {
-            $res = PHP_VERSION_ID >= 70000 && extension_loaded('sodium');
-        }
-        if (self::$disableFallbackForUnitTests) {
-            // Don't fallback. Use the PHP implementation.
-            return false;
-        }
-        return (bool) $res;
-    }
+			if (ParagonIE_Sodium_Core_Util::strlen($key) > self::CRYPTO_GENERICHASH_KEYBYTES_MAX) {
+				throw new SodiumException('Unsupported key size. Must be at most CRYPTO_GENERICHASH_KEYBYTES_MAX bytes long.');
+			}
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::generichash_init_salt_personal($key, $length, $salt, $personal);
+		}
+		return ParagonIE_Sodium_Crypto::generichash_init_salt_personal($key, $length, $salt, $personal);
+	}
+
+	/**
+	 * Update a BLAKE2b hashing context with additional data.
+	 *
+	 * @param string $ctx    BLAKE2 hashing context. Generated by crypto_generichash_init().
+	 *                       $ctx is passed by reference and gets updated in-place.
+	 * @param-out string $ctx
+	 * @param string $message The message to append to the existing hash state.
+	 * @return void
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress ReferenceConstraintViolation
+	 */
+	public static function crypto_generichash_update(&$ctx, $message)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ctx, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 2);
+
+		if (self::useNewSodiumAPI()) {
+			sodium_crypto_generichash_update($ctx, $message);
+			return;
+		}
+		if (self::use_fallback('crypto_generichash_update')) {
+			$func = '\\Sodium\\crypto_generichash_update';
+			$func($ctx, $message);
+			return;
+		}
+		if (PHP_INT_SIZE === 4) {
+			$ctx = ParagonIE_Sodium_Crypto32::generichash_update($ctx, $message);
+		} else {
+			$ctx = ParagonIE_Sodium_Crypto::generichash_update($ctx, $message);
+		}
+	}
+
+	/**
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_generichash_keygen()
+	{
+		return random_bytes(self::CRYPTO_GENERICHASH_KEYBYTES);
+	}
+
+	/**
+	 * @param int $subkey_len
+	 * @param int $subkey_id
+	 * @param string $context
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function crypto_kdf_derive_from_key(
+		$subkey_len,
+		$subkey_id,
+		$context,
+		$key
+	) {
+		ParagonIE_Sodium_Core_Util::declareScalarType($subkey_len, 'int', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($subkey_id, 'int', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($context, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
+		$subkey_id = (int) $subkey_id;
+		$subkey_len = (int) $subkey_len;
+		$context = (string) $context;
+		$key = (string) $key;
+
+		if ($subkey_len < self::CRYPTO_KDF_BYTES_MIN) {
+			throw new SodiumException('subkey cannot be smaller than SODIUM_CRYPTO_KDF_BYTES_MIN');
+		}
+		if ($subkey_len > self::CRYPTO_KDF_BYTES_MAX) {
+			throw new SodiumException('subkey cannot be larger than SODIUM_CRYPTO_KDF_BYTES_MAX');
+		}
+		if ($subkey_id < 0) {
+			throw new SodiumException('subkey_id cannot be negative');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($context) !== self::CRYPTO_KDF_CONTEXTBYTES) {
+			throw new SodiumException('context should be SODIUM_CRYPTO_KDF_CONTEXTBYTES bytes');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_KDF_KEYBYTES) {
+			throw new SodiumException('key should be SODIUM_CRYPTO_KDF_KEYBYTES bytes');
+		}
+
+		$salt = ParagonIE_Sodium_Core_Util::store64_le($subkey_id);
+		$state = self::crypto_generichash_init_salt_personal(
+			$key,
+			$subkey_len,
+			$salt,
+			$context
+		);
+		return self::crypto_generichash_final($state, $subkey_len);
+	}
+
+	/**
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_kdf_keygen()
+	{
+		return random_bytes(self::CRYPTO_KDF_KEYBYTES);
+	}
+
+	/**
+	 * Perform a key exchange, between a designated client and a server.
+	 *
+	 * Typically, you would designate one machine to be the client and the
+	 * other to be the server. The first two keys are what you'd expect for
+	 * scalarmult() below, but the latter two public keys don't swap places.
+	 *
+	 * | ALICE                          | BOB                                 |
+	 * | Client                         | Server                              |
+	 * |--------------------------------|-------------------------------------|
+	 * | shared = crypto_kx(            | shared = crypto_kx(                 |
+	 * |     alice_sk,                  |     bob_sk,                         | <- contextual
+	 * |     bob_pk,                    |     alice_pk,                       | <- contextual
+	 * |     alice_pk,                  |     alice_pk,                       | <----- static
+	 * |     bob_pk                     |     bob_pk                          | <----- static
+	 * | )                              | )                                   |
+	 *
+	 * They are used along with the scalarmult product to generate a 256-bit
+	 * BLAKE2b hash unique to the client and server keys.
+	 *
+	 * @param string $my_secret
+	 * @param string $their_public
+	 * @param string $client_public
+	 * @param string $server_public
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_kx($my_secret, $their_public, $client_public, $server_public, $dontFallback = false)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($my_secret, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($their_public, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($client_public, 'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($server_public, 'string', 4);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($my_secret) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($their_public) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($client_public) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($server_public) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 4 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			if (is_callable('sodium_crypto_kx')) {
+				return (string) sodium_crypto_kx(
+					$my_secret,
+					$their_public,
+					$client_public,
+					$server_public
+				);
+			}
+		}
+		if (self::use_fallback('crypto_kx')) {
+			return (string) call_user_func(
+				'\\Sodium\\crypto_kx',
+				$my_secret,
+				$their_public,
+				$client_public,
+				$server_public
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::keyExchange(
+				$my_secret,
+				$their_public,
+				$client_public,
+				$server_public
+			);
+		}
+		return ParagonIE_Sodium_Crypto::keyExchange(
+			$my_secret,
+			$their_public,
+			$client_public,
+			$server_public
+		);
+	}
+
+	/**
+	 * @param string $seed
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function crypto_kx_seed_keypair($seed)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($seed, 'string', 1);
+
+		$seed = (string) $seed;
+
+		if (ParagonIE_Sodium_Core_Util::strlen($seed) !== self::CRYPTO_KX_SEEDBYTES) {
+			throw new SodiumException('seed must be SODIUM_CRYPTO_KX_SEEDBYTES bytes');
+		}
+
+		$sk = self::crypto_generichash($seed, '', self::CRYPTO_KX_SECRETKEYBYTES);
+		$pk = self::crypto_scalarmult_base($sk);
+		return $sk . $pk;
+	}
+
+	/**
+	 * @return string
+	 * @throws Exception
+	 */
+	public static function crypto_kx_keypair()
+	{
+		$sk = self::randombytes_buf(self::CRYPTO_KX_SECRETKEYBYTES);
+		$pk = self::crypto_scalarmult_base($sk);
+		return $sk . $pk;
+	}
+
+	/**
+	 * @param string $keypair
+	 * @param string $serverPublicKey
+	 * @return array{0: string, 1: string}
+	 * @throws SodiumException
+	 */
+	public static function crypto_kx_client_session_keys($keypair, $serverPublicKey)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($serverPublicKey, 'string', 2);
+
+		$keypair = (string) $keypair;
+		$serverPublicKey = (string) $serverPublicKey;
+
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_KX_KEYPAIRBYTES) {
+			throw new SodiumException('keypair should be SODIUM_CRYPTO_KX_KEYPAIRBYTES bytes');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($serverPublicKey) !== self::CRYPTO_KX_PUBLICKEYBYTES) {
+			throw new SodiumException('public keys must be SODIUM_CRYPTO_KX_PUBLICKEYBYTES bytes');
+		}
+
+		$sk = self::crypto_kx_secretkey($keypair);
+		$pk = self::crypto_kx_publickey($keypair);
+		$h = self::crypto_generichash_init(null, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
+		self::crypto_generichash_update($h, self::crypto_scalarmult($sk, $serverPublicKey));
+		self::crypto_generichash_update($h, $pk);
+		self::crypto_generichash_update($h, $serverPublicKey);
+		$sessionKeys = self::crypto_generichash_final($h, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
+		return array(
+			ParagonIE_Sodium_Core_Util::substr(
+				$sessionKeys,
+				0,
+				self::CRYPTO_KX_SESSIONKEYBYTES
+			),
+			ParagonIE_Sodium_Core_Util::substr(
+				$sessionKeys,
+				self::CRYPTO_KX_SESSIONKEYBYTES,
+				self::CRYPTO_KX_SESSIONKEYBYTES
+			)
+		);
+	}
+
+	/**
+	 * @param string $keypair
+	 * @param string $clientPublicKey
+	 * @return array{0: string, 1: string}
+	 * @throws SodiumException
+	 */
+	public static function crypto_kx_server_session_keys($keypair, $clientPublicKey)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($clientPublicKey, 'string', 2);
+
+		$keypair = (string) $keypair;
+		$clientPublicKey = (string) $clientPublicKey;
+
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_KX_KEYPAIRBYTES) {
+			throw new SodiumException('keypair should be SODIUM_CRYPTO_KX_KEYPAIRBYTES bytes');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($clientPublicKey) !== self::CRYPTO_KX_PUBLICKEYBYTES) {
+			throw new SodiumException('public keys must be SODIUM_CRYPTO_KX_PUBLICKEYBYTES bytes');
+		}
+
+		$sk = self::crypto_kx_secretkey($keypair);
+		$pk = self::crypto_kx_publickey($keypair);
+		$h = self::crypto_generichash_init(null, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
+		self::crypto_generichash_update($h, self::crypto_scalarmult($sk, $clientPublicKey));
+		self::crypto_generichash_update($h, $clientPublicKey);
+		self::crypto_generichash_update($h, $pk);
+		$sessionKeys = self::crypto_generichash_final($h, self::CRYPTO_KX_SESSIONKEYBYTES * 2);
+		return array(
+			ParagonIE_Sodium_Core_Util::substr(
+				$sessionKeys,
+				self::CRYPTO_KX_SESSIONKEYBYTES,
+				self::CRYPTO_KX_SESSIONKEYBYTES
+			),
+			ParagonIE_Sodium_Core_Util::substr(
+				$sessionKeys,
+				0,
+				self::CRYPTO_KX_SESSIONKEYBYTES
+			)
+		);
+	}
+
+	/**
+	 * @param string $kp
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function crypto_kx_secretkey($kp)
+	{
+		return ParagonIE_Sodium_Core_Util::substr(
+			$kp,
+			0,
+			self::CRYPTO_KX_SECRETKEYBYTES
+		);
+	}
+
+	/**
+	 * @param string $kp
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function crypto_kx_publickey($kp)
+	{
+		return ParagonIE_Sodium_Core_Util::substr(
+			$kp,
+			self::CRYPTO_KX_SECRETKEYBYTES,
+			self::CRYPTO_KX_PUBLICKEYBYTES
+		);
+	}
+
+	/**
+	 * @param int $outlen
+	 * @param string $passwd
+	 * @param string $salt
+	 * @param int $opslimit
+	 * @param int $memlimit
+	 * @param int|null $alg
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_pwhash($outlen, $passwd, $salt, $opslimit, $memlimit, $alg = null)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($outlen, 'int', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($salt,  'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 4);
+		ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 5);
+
+		if (self::useNewSodiumAPI()) {
+			if (!is_null($alg)) {
+				ParagonIE_Sodium_Core_Util::declareScalarType($alg, 'int', 6);
+				return sodium_crypto_pwhash($outlen, $passwd, $salt, $opslimit, $memlimit, $alg);
+			}
+			return sodium_crypto_pwhash($outlen, $passwd, $salt, $opslimit, $memlimit);
+		}
+		if (self::use_fallback('crypto_pwhash')) {
+			return (string) call_user_func('\\Sodium\\crypto_pwhash', $outlen, $passwd, $salt, $opslimit, $memlimit);
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented, as it is not possible to implement Argon2i with acceptable performance in pure-PHP'
+		);
+	}
+
+	/**
+	 * !Exclusive to sodium_compat!
+	 *
+	 * This returns TRUE if the native crypto_pwhash API is available by libsodium.
+	 * This returns FALSE if only sodium_compat is available.
+	 *
+	 * @return bool
+	 */
+	public static function crypto_pwhash_is_available()
+	{
+		if (self::useNewSodiumAPI()) {
+			return true;
+		}
+		if (self::use_fallback('crypto_pwhash')) {
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * @param string $passwd
+	 * @param int $opslimit
+	 * @param int $memlimit
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_pwhash_str($passwd, $opslimit, $memlimit)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 3);
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_pwhash_str($passwd, $opslimit, $memlimit);
+		}
+		if (self::use_fallback('crypto_pwhash_str')) {
+			return (string) call_user_func('\\Sodium\\crypto_pwhash_str', $passwd, $opslimit, $memlimit);
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented, as it is not possible to implement Argon2i with acceptable performance in pure-PHP'
+		);
+	}
+
+	/**
+	 * Do we need to rehash this password?
+	 *
+	 * @param string $hash
+	 * @param int $opslimit
+	 * @param int $memlimit
+	 * @return bool
+	 * @throws SodiumException
+	 */
+	public static function crypto_pwhash_str_needs_rehash($hash, $opslimit, $memlimit)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($hash, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 3);
+
+		// Just grab the first 4 pieces.
+		$pieces = explode('$', (string) $hash);
+		$prefix = implode('$', array_slice($pieces, 0, 4));
+
+		// Rebuild the expected header.
+		/** @var int $ops */
+		$ops = (int) $opslimit;
+		/** @var int $mem */
+		$mem = (int) $memlimit >> 10;
+		$encoded = self::CRYPTO_PWHASH_STRPREFIX . 'v=19$m=' . $mem . ',t=' . $ops . ',p=1';
+
+		// Do they match? If so, we don't need to rehash, so return false.
+		return !ParagonIE_Sodium_Core_Util::hashEquals($encoded, $prefix);
+	}
+
+	/**
+	 * @param string $passwd
+	 * @param string $hash
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_pwhash_str_verify($passwd, $hash)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($hash, 'string', 2);
+
+		if (self::useNewSodiumAPI()) {
+			return (bool) sodium_crypto_pwhash_str_verify($passwd, $hash);
+		}
+		if (self::use_fallback('crypto_pwhash_str_verify')) {
+			return (bool) call_user_func('\\Sodium\\crypto_pwhash_str_verify', $passwd, $hash);
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented, as it is not possible to implement Argon2i with acceptable performance in pure-PHP'
+		);
+	}
+
+	/**
+	 * @param int $outlen
+	 * @param string $passwd
+	 * @param string $salt
+	 * @param int $opslimit
+	 * @param int $memlimit
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function crypto_pwhash_scryptsalsa208sha256($outlen, $passwd, $salt, $opslimit, $memlimit)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($outlen, 'int', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($salt,  'string', 3);
+		ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 4);
+		ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 5);
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_pwhash_scryptsalsa208sha256(
+				(int) $outlen,
+				(string) $passwd,
+				(string) $salt,
+				(int) $opslimit,
+				(int) $memlimit
+			);
+		}
+		if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256')) {
+			return (string) call_user_func(
+				'\\Sodium\\crypto_pwhash_scryptsalsa208sha256',
+				(int) $outlen,
+				(string) $passwd,
+				(string) $salt,
+				(int) $opslimit,
+				(int) $memlimit
+			);
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented, as it is not possible to implement Scrypt with acceptable performance in pure-PHP'
+		);
+	}
+
+	/**
+	 * !Exclusive to sodium_compat!
+	 *
+	 * This returns TRUE if the native crypto_pwhash API is available by libsodium.
+	 * This returns FALSE if only sodium_compat is available.
+	 *
+	 * @return bool
+	 */
+	public static function crypto_pwhash_scryptsalsa208sha256_is_available()
+	{
+		if (self::useNewSodiumAPI()) {
+			return true;
+		}
+		if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256')) {
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * @param string $passwd
+	 * @param int $opslimit
+	 * @param int $memlimit
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function crypto_pwhash_scryptsalsa208sha256_str($passwd, $opslimit, $memlimit)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($opslimit, 'int', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($memlimit, 'int', 3);
+
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_crypto_pwhash_scryptsalsa208sha256_str(
+				(string) $passwd,
+				(int) $opslimit,
+				(int) $memlimit
+			);
+		}
+		if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256_str')) {
+			return (string) call_user_func(
+				'\\Sodium\\crypto_pwhash_scryptsalsa208sha256_str',
+				(string) $passwd,
+				(int) $opslimit,
+				(int) $memlimit
+			);
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented, as it is not possible to implement Scrypt with acceptable performance in pure-PHP'
+		);
+	}
+
+	/**
+	 * @param string $passwd
+	 * @param string $hash
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function crypto_pwhash_scryptsalsa208sha256_str_verify($passwd, $hash)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($passwd, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($hash, 'string', 2);
+
+		if (self::useNewSodiumAPI()) {
+			return (bool) sodium_crypto_pwhash_scryptsalsa208sha256_str_verify(
+				(string) $passwd,
+				(string) $hash
+			);
+		}
+		if (self::use_fallback('crypto_pwhash_scryptsalsa208sha256_str_verify')) {
+			return (bool) call_user_func(
+				'\\Sodium\\crypto_pwhash_scryptsalsa208sha256_str_verify',
+				(string) $passwd,
+				(string) $hash
+			);
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented, as it is not possible to implement Scrypt with acceptable performance in pure-PHP'
+		);
+	}
+
+	/**
+	 * Calculate the shared secret between your secret key and your
+	 * recipient's public key.
+	 *
+	 * Algorithm: X25519 (ECDH over Curve25519)
+	 *
+	 * @param string $secretKey
+	 * @param string $publicKey
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_scalarmult($secretKey, $publicKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_scalarmult($secretKey, $publicKey);
+		}
+		if (self::use_fallback('crypto_scalarmult')) {
+			return (string) call_user_func('\\Sodium\\crypto_scalarmult', $secretKey, $publicKey);
+		}
+
+		/* Output validation: Forbid all-zero keys */
+		if (ParagonIE_Sodium_Core_Util::hashEquals($secretKey, str_repeat("\0", self::CRYPTO_BOX_SECRETKEYBYTES))) {
+			throw new SodiumException('Zero secret key is not allowed');
+		}
+		if (ParagonIE_Sodium_Core_Util::hashEquals($publicKey, str_repeat("\0", self::CRYPTO_BOX_PUBLICKEYBYTES))) {
+			throw new SodiumException('Zero public key is not allowed');
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::scalarmult($secretKey, $publicKey);
+		}
+		return ParagonIE_Sodium_Crypto::scalarmult($secretKey, $publicKey);
+	}
+
+	/**
+	 * Calculate an X25519 public key from an X25519 secret key.
+	 *
+	 * @param string $secretKey
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress TooFewArguments
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_scalarmult_base($secretKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_scalarmult_base($secretKey);
+		}
+		if (self::use_fallback('crypto_scalarmult_base')) {
+			return (string) call_user_func('\\Sodium\\crypto_scalarmult_base', $secretKey);
+		}
+		if (ParagonIE_Sodium_Core_Util::hashEquals($secretKey, str_repeat("\0", self::CRYPTO_BOX_SECRETKEYBYTES))) {
+			throw new SodiumException('Zero secret key is not allowed');
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::scalarmult_base($secretKey);
+		}
+		return ParagonIE_Sodium_Crypto::scalarmult_base($secretKey);
+	}
+
+	/**
+	 * Authenticated symmetric-key encryption.
+	 *
+	 * Algorithm: XSalsa20-Poly1305
+	 *
+	 * @param string $plaintext The message you're encrypting
+	 * @param string $nonce A Number to be used Once; must be 24 bytes
+	 * @param string $key Symmetric encryption key
+	 * @return string           Ciphertext with Poly1305 MAC
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_secretbox($plaintext, $nonce, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_secretbox($plaintext, $nonce, $key);
+		}
+		if (self::use_fallback('crypto_secretbox')) {
+			return (string) call_user_func('\\Sodium\\crypto_secretbox', $plaintext, $nonce, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretbox($plaintext, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Crypto::secretbox($plaintext, $nonce, $key);
+	}
+
+	/**
+	 * Decrypts a message previously encrypted with crypto_secretbox().
+	 *
+	 * @param string $ciphertext Ciphertext with Poly1305 MAC
+	 * @param string $nonce      A Number to be used Once; must be 24 bytes
+	 * @param string $key        Symmetric encryption key
+	 * @return string            Original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_secretbox_open($ciphertext, $nonce, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			/**
+			 * @psalm-suppress InvalidReturnStatement
+			 * @psalm-suppress FalsableReturnStatement
+			 */
+			return sodium_crypto_secretbox_open($ciphertext, $nonce, $key);
+		}
+		if (self::use_fallback('crypto_secretbox_open')) {
+			return call_user_func('\\Sodium\\crypto_secretbox_open', $ciphertext, $nonce, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretbox_open($ciphertext, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Crypto::secretbox_open($ciphertext, $nonce, $key);
+	}
+
+	/**
+	 * Return a secure random key for use with crypto_secretbox
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_secretbox_keygen()
+	{
+		return random_bytes(self::CRYPTO_SECRETBOX_KEYBYTES);
+	}
+
+	/**
+	 * Authenticated symmetric-key encryption.
+	 *
+	 * Algorithm: XChaCha20-Poly1305
+	 *
+	 * @param string $plaintext The message you're encrypting
+	 * @param string $nonce     A Number to be used Once; must be 24 bytes
+	 * @param string $key       Symmetric encryption key
+	 * @return string           Ciphertext with Poly1305 MAC
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_secretbox_xchacha20poly1305($plaintext, $nonce, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($plaintext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretbox_xchacha20poly1305($plaintext, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Crypto::secretbox_xchacha20poly1305($plaintext, $nonce, $key);
+	}
+	/**
+	 * Decrypts a message previously encrypted with crypto_secretbox_xchacha20poly1305().
+	 *
+	 * @param string $ciphertext Ciphertext with Poly1305 MAC
+	 * @param string $nonce      A Number to be used Once; must be 24 bytes
+	 * @param string $key        Symmetric encryption key
+	 * @return string            Original plaintext message
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_SECRETBOX_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SECRETBOX_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
+		}
+
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Crypto::secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key);
+	}
+
+	/**
+	 * @param string $key
+	 * @return array<int, string> Returns a state and a header.
+	 * @throws Exception
+	 * @throws SodiumException
+	 */
+	public static function crypto_secretstream_xchacha20poly1305_init_push($key)
+	{
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_init_push($key);
+		}
+		return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_init_push($key);
+	}
+
+	/**
+	 * @param string $header
+	 * @param string $key
+	 * @return string Returns a state.
+	 * @throws Exception
+	 */
+	public static function crypto_secretstream_xchacha20poly1305_init_pull($header, $key)
+	{
+		if (ParagonIE_Sodium_Core_Util::strlen($header) < self::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_HEADERBYTES) {
+			throw new SodiumException(
+				'header size should be SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_HEADERBYTES bytes'
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_init_pull($key, $header);
+		}
+		return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_init_pull($key, $header);
+	}
+
+	/**
+	 * @param string $state
+	 * @param string $msg
+	 * @param string $aad
+	 * @param int $tag
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function crypto_secretstream_xchacha20poly1305_push(&$state, $msg, $aad = '', $tag = 0)
+	{
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_push(
+				$state,
+				$msg,
+				$aad,
+				$tag
+			);
+		}
+		return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_push(
+			$state,
+			$msg,
+			$aad,
+			$tag
+		);
+	}
+
+	/**
+	 * @param string $state
+	 * @param string $msg
+	 * @param string $aad
+	 * @return bool|array{0: string, 1: int}
+	 * @throws SodiumException
+	 */
+	public static function crypto_secretstream_xchacha20poly1305_pull(&$state, $msg, $aad = '')
+	{
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_pull(
+				$state,
+				$msg,
+				$aad
+			);
+		}
+		return ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_pull(
+			$state,
+			$msg,
+			$aad
+		);
+	}
+
+	/**
+	 * @return string
+	 * @throws Exception
+	 */
+	public static function crypto_secretstream_xchacha20poly1305_keygen()
+	{
+		return random_bytes(self::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_KEYBYTES);
+	}
+
+	/**
+	 * @param string $state
+	 * @return void
+	 * @throws SodiumException
+	 */
+	public static function crypto_secretstream_xchacha20poly1305_rekey(&$state)
+	{
+		if (PHP_INT_SIZE === 4) {
+			ParagonIE_Sodium_Crypto32::secretstream_xchacha20poly1305_rekey($state);
+		} else {
+			ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_rekey($state);
+		}
+	}
+
+	/**
+	 * Calculates a SipHash-2-4 hash of a message for a given key.
+	 *
+	 * @param string $message Input message
+	 * @param string $key SipHash-2-4 key
+	 * @return string         Hash
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_shorthash($message, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_SHORTHASH_KEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SHORTHASH_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_shorthash($message, $key);
+		}
+		if (self::use_fallback('crypto_shorthash')) {
+			return (string) call_user_func('\\Sodium\\crypto_shorthash', $message, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_SipHash::sipHash24($message, $key);
+		}
+		return ParagonIE_Sodium_Core_SipHash::sipHash24($message, $key);
+	}
+
+	/**
+	 * Return a secure random key for use with crypto_shorthash
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_shorthash_keygen()
+	{
+		return random_bytes(self::CRYPTO_SHORTHASH_KEYBYTES);
+	}
+
+	/**
+	 * Returns a signed message. You probably want crypto_sign_detached()
+	 * instead, which only returns the signature.
+	 *
+	 * Algorithm: Ed25519 (EdDSA over Curve25519)
+	 *
+	 * @param string $message Message to be signed.
+	 * @param string $secretKey Secret signing key.
+	 * @return string           Signed message (signature is prefixed).
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_sign($message, $secretKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SIGN_SECRETKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign($message, $secretKey);
+		}
+		if (self::use_fallback('crypto_sign')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign', $message, $secretKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::sign($message, $secretKey);
+		}
+		return ParagonIE_Sodium_Crypto::sign($message, $secretKey);
+	}
+
+	/**
+	 * Validates a signed message then returns the message.
+	 *
+	 * @param string $signedMessage A signed message
+	 * @param string $publicKey A public key
+	 * @return string               The original message (if the signature is
+	 *                              valid for this public key)
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress MixedReturnStatement
+	 */
+	public static function crypto_sign_open($signedMessage, $publicKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($signedMessage, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($signedMessage) < self::CRYPTO_SIGN_BYTES) {
+			throw new SodiumException('Argument 1 must be at least CRYPTO_SIGN_BYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_SIGN_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SIGN_PUBLICKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			/**
+			 * @psalm-suppress InvalidReturnStatement
+			 * @psalm-suppress FalsableReturnStatement
+			 */
+			return sodium_crypto_sign_open($signedMessage, $publicKey);
+		}
+		if (self::use_fallback('crypto_sign_open')) {
+			return call_user_func('\\Sodium\\crypto_sign_open', $signedMessage, $publicKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::sign_open($signedMessage, $publicKey);
+		}
+		return ParagonIE_Sodium_Crypto::sign_open($signedMessage, $publicKey);
+	}
+
+	/**
+	 * Generate a new random Ed25519 keypair.
+	 *
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function crypto_sign_keypair()
+	{
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_keypair();
+		}
+		if (self::use_fallback('crypto_sign_keypair')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_keypair');
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_Ed25519::keypair();
+		}
+		return ParagonIE_Sodium_Core_Ed25519::keypair();
+	}
+
+	/**
+	 * @param string $sk
+	 * @param string $pk
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function crypto_sign_keypair_from_secretkey_and_publickey($sk, $pk)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($sk, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($pk, 'string', 1);
+		$sk = (string) $sk;
+		$pk = (string) $pk;
+
+		if (ParagonIE_Sodium_Core_Util::strlen($sk) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
+			throw new SodiumException('secretkey should be SODIUM_CRYPTO_SIGN_SECRETKEYBYTES bytes');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($pk) !== self::CRYPTO_SIGN_PUBLICKEYBYTES) {
+			throw new SodiumException('publickey should be SODIUM_CRYPTO_SIGN_PUBLICKEYBYTES bytes');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_keypair_from_secretkey_and_publickey($sk, $pk);
+		}
+		return $sk . $pk;
+	}
+
+	/**
+	 * Generate an Ed25519 keypair from a seed.
+	 *
+	 * @param string $seed Input seed
+	 * @return string      Keypair
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_seed_keypair($seed)
+	{
+		ParagonIE_Sodium_Core_Util::declareScalarType($seed, 'string', 1);
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_seed_keypair($seed);
+		}
+		if (self::use_fallback('crypto_sign_keypair')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_seed_keypair', $seed);
+		}
+		$publicKey = '';
+		$secretKey = '';
+		if (PHP_INT_SIZE === 4) {
+			ParagonIE_Sodium_Core32_Ed25519::seed_keypair($publicKey, $secretKey, $seed);
+		} else {
+			ParagonIE_Sodium_Core_Ed25519::seed_keypair($publicKey, $secretKey, $seed);
+		}
+		return $secretKey . $publicKey;
+	}
+
+	/**
+	 * Extract an Ed25519 public key from an Ed25519 keypair.
+	 *
+	 * @param string $keypair Keypair
+	 * @return string         Public key
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_publickey($keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_SIGN_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_SIGN_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_publickey($keypair);
+		}
+		if (self::use_fallback('crypto_sign_publickey')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_publickey', $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_Ed25519::publickey($keypair);
+		}
+		return ParagonIE_Sodium_Core_Ed25519::publickey($keypair);
+	}
+
+	/**
+	 * Calculate an Ed25519 public key from an Ed25519 secret key.
+	 *
+	 * @param string $secretKey Your Ed25519 secret key
+	 * @return string           The corresponding Ed25519 public key
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_publickey_from_secretkey($secretKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_SIGN_SECRETKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_publickey_from_secretkey($secretKey);
+		}
+		if (self::use_fallback('crypto_sign_publickey_from_secretkey')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_publickey_from_secretkey', $secretKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_Ed25519::publickey_from_secretkey($secretKey);
+		}
+		return ParagonIE_Sodium_Core_Ed25519::publickey_from_secretkey($secretKey);
+	}
+
+	/**
+	 * Extract an Ed25519 secret key from an Ed25519 keypair.
+	 *
+	 * @param string $keypair Keypair
+	 * @return string         Secret key
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_secretkey($keypair)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_SIGN_KEYPAIRBYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_SIGN_KEYPAIRBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_secretkey($keypair);
+		}
+		if (self::use_fallback('crypto_sign_secretkey')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_secretkey', $keypair);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_Ed25519::secretkey($keypair);
+		}
+		return ParagonIE_Sodium_Core_Ed25519::secretkey($keypair);
+	}
+
+	/**
+	 * Calculate the Ed25519 signature of a message and return ONLY the signature.
+	 *
+	 * Algorithm: Ed25519 (EdDSA over Curve25519)
+	 *
+	 * @param string $message Message to be signed
+	 * @param string $secretKey Secret signing key
+	 * @return string           Digital signature
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_detached($message, $secretKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 2);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_SIGN_SECRETKEYBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SIGN_SECRETKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_detached($message, $secretKey);
+		}
+		if (self::use_fallback('crypto_sign_detached')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_detached', $message, $secretKey);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::sign_detached($message, $secretKey);
+		}
+		return ParagonIE_Sodium_Crypto::sign_detached($message, $secretKey);
+	}
+
+	/**
+	 * Verify the Ed25519 signature of a message.
+	 *
+	 * @param string $signature Digital sginature
+	 * @param string $message Message to be verified
+	 * @param string $publicKey Public key
+	 * @return bool             TRUE if this signature is good for this public key;
+	 *                          FALSE otherwise
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_verify_detached($signature, $message, $publicKey)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($signature, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($signature) !== self::CRYPTO_SIGN_BYTES) {
+			throw new SodiumException('Argument 1 must be CRYPTO_SIGN_BYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_SIGN_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SIGN_PUBLICKEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_sign_verify_detached($signature, $message, $publicKey);
+		}
+		if (self::use_fallback('crypto_sign_verify_detached')) {
+			return (bool) call_user_func(
+				'\\Sodium\\crypto_sign_verify_detached',
+				$signature,
+				$message,
+				$publicKey
+			);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Crypto32::sign_verify_detached($signature, $message, $publicKey);
+		}
+		return ParagonIE_Sodium_Crypto::sign_verify_detached($signature, $message, $publicKey);
+	}
+
+	/**
+	 * Convert an Ed25519 public key to a Curve25519 public key
+	 *
+	 * @param string $pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_ed25519_pk_to_curve25519($pk)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($pk, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($pk) < self::CRYPTO_SIGN_PUBLICKEYBYTES) {
+			throw new SodiumException('Argument 1 must be at least CRYPTO_SIGN_PUBLICKEYBYTES long.');
+		}
+		if (self::useNewSodiumAPI()) {
+			if (is_callable('crypto_sign_ed25519_pk_to_curve25519')) {
+				return (string) sodium_crypto_sign_ed25519_pk_to_curve25519($pk);
+			}
+		}
+		if (self::use_fallback('crypto_sign_ed25519_pk_to_curve25519')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_ed25519_pk_to_curve25519', $pk);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_Ed25519::pk_to_curve25519($pk);
+		}
+		return ParagonIE_Sodium_Core_Ed25519::pk_to_curve25519($pk);
+	}
+
+	/**
+	 * Convert an Ed25519 secret key to a Curve25519 secret key
+	 *
+	 * @param string $sk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_sign_ed25519_sk_to_curve25519($sk)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($sk, 'string', 1);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($sk) < self::CRYPTO_SIGN_SEEDBYTES) {
+			throw new SodiumException('Argument 1 must be at least CRYPTO_SIGN_SEEDBYTES long.');
+		}
+		if (self::useNewSodiumAPI()) {
+			if (is_callable('crypto_sign_ed25519_sk_to_curve25519')) {
+				return sodium_crypto_sign_ed25519_sk_to_curve25519($sk);
+			}
+		}
+		if (self::use_fallback('crypto_sign_ed25519_sk_to_curve25519')) {
+			return (string) call_user_func('\\Sodium\\crypto_sign_ed25519_sk_to_curve25519', $sk);
+		}
+
+		$h = hash('sha512', ParagonIE_Sodium_Core_Util::substr($sk, 0, 32), true);
+		$h[0] = ParagonIE_Sodium_Core_Util::intToChr(
+			ParagonIE_Sodium_Core_Util::chrToInt($h[0]) & 248
+		);
+		$h[31] = ParagonIE_Sodium_Core_Util::intToChr(
+			(ParagonIE_Sodium_Core_Util::chrToInt($h[31]) & 127) | 64
+		);
+		return ParagonIE_Sodium_Core_Util::substr($h, 0, 32);
+	}
+
+	/**
+	 * Expand a key and nonce into a keystream of pseudorandom bytes.
+	 *
+	 * @param int $len Number of bytes desired
+	 * @param string $nonce Number to be used Once; must be 24 bytes
+	 * @param string $key XSalsa20 key
+	 * @return string       Pseudorandom stream that can be XORed with messages
+	 *                      to provide encryption (but not authentication; see
+	 *                      Poly1305 or crypto_auth() for that, which is not
+	 *                      optional for security)
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_stream($len, $nonce, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($len, 'int', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_STREAM_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_stream($len, $nonce, $key);
+		}
+		if (self::use_fallback('crypto_stream')) {
+			return (string) call_user_func('\\Sodium\\crypto_stream', $len, $nonce, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_XSalsa20::xsalsa20($len, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Core_XSalsa20::xsalsa20($len, $nonce, $key);
+	}
+
+	/**
+	 * DANGER! UNAUTHENTICATED ENCRYPTION!
+	 *
+	 * Unless you are following expert advice, do not use this feature.
+	 *
+	 * Algorithm: XSalsa20
+	 *
+	 * This DOES NOT provide ciphertext integrity.
+	 *
+	 * @param string $message Plaintext message
+	 * @param string $nonce Number to be used Once; must be 24 bytes
+	 * @param string $key Encryption key
+	 * @return string         Encrypted text which is vulnerable to chosen-
+	 *                        ciphertext attacks unless you implement some
+	 *                        other mitigation to the ciphertext (i.e.
+	 *                        Encrypt then MAC)
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_stream_xor($message, $nonce, $key)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_crypto_stream_xor($message, $nonce, $key);
+		}
+		if (self::use_fallback('crypto_stream_xor')) {
+			return (string) call_user_func('\\Sodium\\crypto_stream_xor', $message, $nonce, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_XSalsa20::xsalsa20_xor($message, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Core_XSalsa20::xsalsa20_xor($message, $nonce, $key);
+	}
+
+	/**
+	 * Return a secure random key for use with crypto_stream
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_stream_keygen()
+	{
+		return random_bytes(self::CRYPTO_STREAM_KEYBYTES);
+	}
+
+
+	/**
+	 * Expand a key and nonce into a keystream of pseudorandom bytes.
+	 *
+	 * @param int $len Number of bytes desired
+	 * @param string $nonce Number to be used Once; must be 24 bytes
+	 * @param string $key XChaCha20 key
+	 * @param bool $dontFallback
+	 * @return string       Pseudorandom stream that can be XORed with messages
+	 *                      to provide encryption (but not authentication; see
+	 *                      Poly1305 or crypto_auth() for that, which is not
+	 *                      optional for security)
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_stream_xchacha20($len, $nonce, $key, $dontFallback = false)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($len, 'int', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_XCHACHA20_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_XCHACHA20_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_XCHACHA20_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_STREAM_XCHACHA20_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_stream_xchacha20($len, $nonce, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_XChaCha20::stream($len, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Core_XChaCha20::stream($len, $nonce, $key);
+	}
+
+	/**
+	 * DANGER! UNAUTHENTICATED ENCRYPTION!
+	 *
+	 * Unless you are following expert advice, do not use this feature.
+	 *
+	 * Algorithm: XChaCha20
+	 *
+	 * This DOES NOT provide ciphertext integrity.
+	 *
+	 * @param string $message Plaintext message
+	 * @param string $nonce Number to be used Once; must be 24 bytes
+	 * @param string $key Encryption key
+	 * @return string         Encrypted text which is vulnerable to chosen-
+	 *                        ciphertext attacks unless you implement some
+	 *                        other mitigation to the ciphertext (i.e.
+	 *                        Encrypt then MAC)
+	 * @param bool $dontFallback
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function crypto_stream_xchacha20_xor($message, $nonce, $key, $dontFallback = false)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($message, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 2);
+		ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 3);
+
+		/* Input validation: */
+		if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_STREAM_XCHACHA20_NONCEBYTES) {
+			throw new SodiumException('Argument 2 must be CRYPTO_SECRETBOX_XCHACHA20_NONCEBYTES long.');
+		}
+		if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_STREAM_XCHACHA20_KEYBYTES) {
+			throw new SodiumException('Argument 3 must be CRYPTO_SECRETBOX_XCHACHA20_KEYBYTES long.');
+		}
+
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_stream_xchacha20_xor($message, $nonce, $key);
+		}
+		if (PHP_INT_SIZE === 4) {
+			return ParagonIE_Sodium_Core32_XChaCha20::streamXorIc($message, $nonce, $key);
+		}
+		return ParagonIE_Sodium_Core_XChaCha20::streamXorIc($message, $nonce, $key);
+	}
+
+	/**
+	 * Return a secure random key for use with crypto_stream_xchacha20
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws Error
+	 */
+	public static function crypto_stream_xchacha20_keygen()
+	{
+		return random_bytes(self::CRYPTO_STREAM_XCHACHA20_KEYBYTES);
+	}
+
+	/**
+	 * Cache-timing-safe implementation of hex2bin().
+	 *
+	 * @param string $string Hexadecimal string
+	 * @return string        Raw binary string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress TooFewArguments
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function hex2bin($string)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($string, 'string', 1);
+
+		if (self::useNewSodiumAPI()) {
+			if (is_callable('sodium_hex2bin')) {
+				return (string) sodium_hex2bin($string);
+			}
+		}
+		if (self::use_fallback('hex2bin')) {
+			return (string) call_user_func('\\Sodium\\hex2bin', $string);
+		}
+		return ParagonIE_Sodium_Core_Util::hex2bin($string);
+	}
+
+	/**
+	 * Increase a string (little endian)
+	 *
+	 * @param string $var
+	 *
+	 * @return void
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function increment(&$var)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($var, 'string', 1);
+
+		if (self::useNewSodiumAPI()) {
+			sodium_increment($var);
+			return;
+		}
+		if (self::use_fallback('increment')) {
+			$func = '\\Sodium\\increment';
+			$func($var);
+			return;
+		}
+
+		$len = ParagonIE_Sodium_Core_Util::strlen($var);
+		$c = 1;
+		$copy = '';
+		for ($i = 0; $i < $len; ++$i) {
+			$c += ParagonIE_Sodium_Core_Util::chrToInt(
+				ParagonIE_Sodium_Core_Util::substr($var, $i, 1)
+			);
+			$copy .= ParagonIE_Sodium_Core_Util::intToChr($c);
+			$c >>= 8;
+		}
+		$var = $copy;
+	}
+
+	/**
+	 * @param string $str
+	 * @return bool
+	 *
+	 * @throws SodiumException
+	 */
+	public static function is_zero($str)
+	{
+		$d = 0;
+		for ($i = 0; $i < 32; ++$i) {
+			$d |= ParagonIE_Sodium_Core_Util::chrToInt($str[$i]);
+		}
+		return ((($d - 1) >> 31) & 1) === 1;
+	}
+
+	/**
+	 * The equivalent to the libsodium minor version we aim to be compatible
+	 * with (sans pwhash and memzero).
+	 *
+	 * @return int
+	 */
+	public static function library_version_major()
+	{
+		if (self::useNewSodiumAPI() && defined('SODIUM_LIBRARY_MAJOR_VERSION')) {
+			return SODIUM_LIBRARY_MAJOR_VERSION;
+		}
+		if (self::use_fallback('library_version_major')) {
+			/** @psalm-suppress UndefinedFunction */
+			return (int) call_user_func('\\Sodium\\library_version_major');
+		}
+		return self::LIBRARY_VERSION_MAJOR;
+	}
+
+	/**
+	 * The equivalent to the libsodium minor version we aim to be compatible
+	 * with (sans pwhash and memzero).
+	 *
+	 * @return int
+	 */
+	public static function library_version_minor()
+	{
+		if (self::useNewSodiumAPI() && defined('SODIUM_LIBRARY_MINOR_VERSION')) {
+			return SODIUM_LIBRARY_MINOR_VERSION;
+		}
+		if (self::use_fallback('library_version_minor')) {
+			/** @psalm-suppress UndefinedFunction */
+			return (int) call_user_func('\\Sodium\\library_version_minor');
+		}
+		return self::LIBRARY_VERSION_MINOR;
+	}
+
+	/**
+	 * Compare two strings.
+	 *
+	 * @param string $left
+	 * @param string $right
+	 * @return int
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 */
+	public static function memcmp($left, $right)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($left, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($right, 'string', 2);
+
+		if (self::useNewSodiumAPI()) {
+			return sodium_memcmp($left, $right);
+		}
+		if (self::use_fallback('memcmp')) {
+			return (int) call_user_func('\\Sodium\\memcmp', $left, $right);
+		}
+		/** @var string $left */
+		/** @var string $right */
+		return ParagonIE_Sodium_Core_Util::memcmp($left, $right);
+	}
+
+	/**
+	 * It's actually not possible to zero memory buffers in PHP. You need the
+	 * native library for that.
+	 *
+	 * @param string|null $var
+	 * @param-out string|null $var
+	 *
+	 * @return void
+	 * @throws SodiumException (Unless libsodium is installed)
+	 * @throws TypeError
+	 * @psalm-suppress TooFewArguments
+	 */
+	public static function memzero(&$var)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($var, 'string', 1);
+
+		if (self::useNewSodiumAPI()) {
+			/** @psalm-suppress MixedArgument */
+			sodium_memzero($var);
+			return;
+		}
+		if (self::use_fallback('memzero')) {
+			$func = '\\Sodium\\memzero';
+			$func($var);
+			if ($var === null) {
+				return;
+			}
+		}
+		// This is the best we can do.
+		throw new SodiumException(
+			'This is not implemented in sodium_compat, as it is not possible to securely wipe memory from PHP. ' .
+			'To fix this error, make sure libsodium is installed and the PHP extension is enabled.'
+		);
+	}
+
+	/**
+	 * @param string $unpadded
+	 * @param int $blockSize
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function pad($unpadded, $blockSize, $dontFallback = false)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($unpadded, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($blockSize, 'int', 2);
+
+		$unpadded = (string) $unpadded;
+		$blockSize = (int) $blockSize;
+
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return (string) sodium_pad($unpadded, $blockSize);
+		}
+
+		if ($blockSize <= 0) {
+			throw new SodiumException(
+				'block size cannot be less than 1'
+			);
+		}
+		$unpadded_len = ParagonIE_Sodium_Core_Util::strlen($unpadded);
+		$xpadlen = ($blockSize - 1);
+		if (($blockSize & ($blockSize - 1)) === 0) {
+			$xpadlen -= $unpadded_len & ($blockSize - 1);
+		} else {
+			$xpadlen -= $unpadded_len % $blockSize;
+		}
+
+		$xpadded_len = $unpadded_len + $xpadlen;
+		$padded = str_repeat("\0", $xpadded_len - 1);
+		if ($unpadded_len > 0) {
+			$st = 1;
+			$i = 0;
+			$k = $unpadded_len;
+			for ($j = 0; $j <= $xpadded_len; ++$j) {
+				$i = (int) $i;
+				$k = (int) $k;
+				$st = (int) $st;
+				if ($j >= $unpadded_len) {
+					$padded[$j] = "\0";
+				} else {
+					$padded[$j] = $unpadded[$j];
+				}
+				/** @var int $k */
+				$k -= $st;
+				$st = (int) (~(
+							(
+								(
+									($k >> 48)
+										|
+									($k >> 32)
+										|
+									($k >> 16)
+										|
+									$k
+								) - 1
+							) >> 16
+						)
+					) & 1;
+				$i += $st;
+			}
+		}
+
+		$mask = 0;
+		$tail = $xpadded_len;
+		for ($i = 0; $i < $blockSize; ++$i) {
+			# barrier_mask = (unsigned char)
+			#     (((i ^ xpadlen) - 1U) >> ((sizeof(size_t) - 1U) * CHAR_BIT));
+			$barrier_mask = (($i ^ $xpadlen) -1) >> ((PHP_INT_SIZE << 3) - 1);
+			# tail[-i] = (tail[-i] & mask) | (0x80 & barrier_mask);
+			$padded[$tail - $i] = ParagonIE_Sodium_Core_Util::intToChr(
+				(ParagonIE_Sodium_Core_Util::chrToInt($padded[$tail - $i]) & $mask)
+					|
+				(0x80 & $barrier_mask)
+			);
+			# mask |= barrier_mask;
+			$mask |= $barrier_mask;
+		}
+		return $padded;
+	}
+
+	/**
+	 * @param string $padded
+	 * @param int $blockSize
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function unpad($padded, $blockSize, $dontFallback = false)
+	{
+		/* Type checks: */
+		ParagonIE_Sodium_Core_Util::declareScalarType($padded, 'string', 1);
+		ParagonIE_Sodium_Core_Util::declareScalarType($blockSize, 'int', 2);
+
+		$padded = (string) $padded;
+		$blockSize = (int) $blockSize;
+
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return (string) sodium_unpad($padded, $blockSize);
+		}
+		if ($blockSize <= 0) {
+			throw new SodiumException('block size cannot be less than 1');
+		}
+		$padded_len = ParagonIE_Sodium_Core_Util::strlen($padded);
+		if ($padded_len < $blockSize) {
+			throw new SodiumException('invalid padding');
+		}
+
+		# tail = &padded[padded_len - 1U];
+		$tail = $padded_len - 1;
+
+		$acc = 0;
+		$valid = 0;
+		$pad_len = 0;
+
+		$found = 0;
+		for ($i = 0; $i < $blockSize; ++$i) {
+			# c = tail[-i];
+			$c = ParagonIE_Sodium_Core_Util::chrToInt($padded[$tail - $i]);
+
+			# is_barrier =
+			#     (( (acc - 1U) & (pad_len - 1U) & ((c ^ 0x80) - 1U) ) >> 8) & 1U;
+			$is_barrier = (
+				(
+					($acc - 1) & ($pad_len - 1) & (($c ^ 80) - 1)
+				) >> 7
+			) & 1;
+			$is_barrier &= ~$found;
+			$found |= $is_barrier;
+
+			# acc |= c;
+			$acc |= $c;
+
+			# pad_len |= i & (1U + ~is_barrier);
+			$pad_len |= $i & (1 + ~$is_barrier);
+
+			# valid |= (unsigned char) is_barrier;
+			$valid |= ($is_barrier & 0xff);
+		}
+		# unpadded_len = padded_len - 1U - pad_len;
+		$unpadded_len = $padded_len - 1 - $pad_len;
+		if ($valid !== 1) {
+			throw new SodiumException('invalid padding');
+		}
+		return ParagonIE_Sodium_Core_Util::substr($padded, 0, $unpadded_len);
+	}
+
+	/**
+	 * Will sodium_compat run fast on the current hardware and PHP configuration?
+	 *
+	 * @return bool
+	 */
+	public static function polyfill_is_fast()
+	{
+		if (extension_loaded('sodium')) {
+			return true;
+		}
+		if (extension_loaded('libsodium')) {
+			return true;
+		}
+		return PHP_INT_SIZE === 8;
+	}
+
+	/**
+	 * Generate a string of bytes from the kernel's CSPRNG.
+	 * Proudly uses /dev/urandom (if getrandom(2) is not available).
+	 *
+	 * @param int $numBytes
+	 * @return string
+	 * @throws Exception
+	 * @throws TypeError
+	 */
+	public static function randombytes_buf($numBytes)
+	{
+		/* Type checks: */
+		if (!is_int($numBytes)) {
+			if (is_numeric($numBytes)) {
+				$numBytes = (int) $numBytes;
+			} else {
+				throw new TypeError(
+					'Argument 1 must be an integer, ' . gettype($numBytes) . ' given.'
+				);
+			}
+		}
+		if (self::use_fallback('randombytes_buf')) {
+			return (string) call_user_func('\\Sodium\\randombytes_buf', $numBytes);
+		}
+		return random_bytes($numBytes);
+	}
+
+	/**
+	 * Generate an integer between 0 and $range (non-inclusive).
+	 *
+	 * @param int $range
+	 * @return int
+	 * @throws Exception
+	 * @throws Error
+	 * @throws TypeError
+	 */
+	public static function randombytes_uniform($range)
+	{
+		/* Type checks: */
+		if (!is_int($range)) {
+			if (is_numeric($range)) {
+				$range = (int) $range;
+			} else {
+				throw new TypeError(
+					'Argument 1 must be an integer, ' . gettype($range) . ' given.'
+				);
+			}
+		}
+		if (self::use_fallback('randombytes_uniform')) {
+			return (int) call_user_func('\\Sodium\\randombytes_uniform', $range);
+		}
+		return random_int(0, $range - 1);
+	}
+
+	/**
+	 * Generate a random 16-bit integer.
+	 *
+	 * @return int
+	 * @throws Exception
+	 * @throws Error
+	 * @throws TypeError
+	 */
+	public static function randombytes_random16()
+	{
+		if (self::use_fallback('randombytes_random16')) {
+			return (int) call_user_func('\\Sodium\\randombytes_random16');
+		}
+		return random_int(0, 65535);
+	}
+
+	/**
+	 * @param string $p
+	 * @param bool $dontFallback
+	 * @return bool
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_is_valid_point($p, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_is_valid_point($p);
+		}
+		try {
+			$r = ParagonIE_Sodium_Core_Ristretto255::ristretto255_frombytes($p);
+			return $r['res'] === 0 &&
+				ParagonIE_Sodium_Core_Ristretto255::ristretto255_point_is_canonical($p) === 1;
+		} catch (SodiumException $ex) {
+			if ($ex->getMessage() === 'S is not canonical') {
+				return false;
+			}
+			throw $ex;
+		}
+	}
+
+	/**
+	 * @param string $p
+	 * @param string $q
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_add($p, $q, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_add($p, $q);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_add($p, $q);
+	}
+
+	/**
+	 * @param string $p
+	 * @param string $q
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_sub($p, $q, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_sub($p, $q);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_sub($p, $q);
+	}
+
+	/**
+	 * @param string $r
+	 * @param bool $dontFallback
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_from_hash($r, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_from_hash($r);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_from_hash($r);
+	}
+
+	/**
+	 * @param bool $dontFallback
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_random($dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_random();
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_random();
+	}
+
+	/**
+	 * @param bool $dontFallback
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_random($dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_random();
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_random();
+	}
+
+	/**
+	 * @param string $s
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_invert($s, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_invert($s);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_invert($s);
+	}
+	/**
+	 * @param string $s
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_negate($s, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_negate($s);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_negate($s);
+	}
+
+	/**
+	 * @param string $s
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_complement($s, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_complement($s);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_complement($s);
+	}
+
+	/**
+	 * @param string $x
+	 * @param string $y
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_add($x, $y, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_add($x, $y);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_add($x, $y);
+	}
+
+	/**
+	 * @param string $x
+	 * @param string $y
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_sub($x, $y, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_sub($x, $y);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_sub($x, $y);
+	}
+
+	/**
+	 * @param string $x
+	 * @param string $y
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_mul($x, $y, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_mul($x, $y);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::ristretto255_scalar_mul($x, $y);
+	}
+
+	/**
+	 * @param string $n
+	 * @param string $p
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function scalarmult_ristretto255($n, $p, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_scalarmult_ristretto255($n, $p);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::scalarmult_ristretto255($n, $p);
+	}
+
+	/**
+	 * @param string $n
+	 * @param string $p
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function scalarmult_ristretto255_base($n, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_scalarmult_ristretto255_base($n);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::scalarmult_ristretto255_base($n);
+	}
+
+	/**
+	 * @param string $s
+	 * @param bool $dontFallback
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function ristretto255_scalar_reduce($s, $dontFallback = false)
+	{
+		if (self::useNewSodiumAPI() && !$dontFallback) {
+			return sodium_crypto_core_ristretto255_scalar_reduce($s);
+		}
+		return ParagonIE_Sodium_Core_Ristretto255::sc_reduce($s);
+	}
+
+	/**
+	 * Runtime testing method for 32-bit platforms.
+	 *
+	 * Usage: If runtime_speed_test() returns FALSE, then our 32-bit
+	 *        implementation is to slow to use safely without risking timeouts.
+	 *        If this happens, install sodium from PECL to get acceptable
+	 *        performance.
+	 *
+	 * @param int $iterations Number of multiplications to attempt
+	 * @param int $maxTimeout Milliseconds
+	 * @return bool           TRUE if we're fast enough, FALSE is not
+	 * @throws SodiumException
+	 */
+	public static function runtime_speed_test($iterations, $maxTimeout)
+	{
+		if (self::polyfill_is_fast()) {
+			return true;
+		}
+		/** @var float $end */
+		$end = 0.0;
+		/** @var float $start */
+		$start = microtime(true);
+		/** @var ParagonIE_Sodium_Core32_Int64 $a */
+		$a = ParagonIE_Sodium_Core32_Int64::fromInt(random_int(3, 1 << 16));
+		for ($i = 0; $i < $iterations; ++$i) {
+			/** @var ParagonIE_Sodium_Core32_Int64 $b */
+			$b = ParagonIE_Sodium_Core32_Int64::fromInt(random_int(3, 1 << 16));
+			$a->mulInt64($b);
+		}
+		/** @var float $end */
+		$end = microtime(true);
+		/** @var int $diff */
+		$diff = (int) ceil(($end - $start) * 1000);
+		return $diff < $maxTimeout;
+	}
+
+	/**
+	 * Add two numbers (little-endian unsigned), storing the value in the first
+	 * parameter.
+	 *
+	 * This mutates $val.
+	 *
+	 * @param string $val
+	 * @param string $addv
+	 * @return void
+	 * @throws SodiumException
+	 */
+	public static function sub(&$val, $addv)
+	{
+		$val_len = ParagonIE_Sodium_Core_Util::strlen($val);
+		$addv_len = ParagonIE_Sodium_Core_Util::strlen($addv);
+		if ($val_len !== $addv_len) {
+			throw new SodiumException('values must have the same length');
+		}
+		$A = ParagonIE_Sodium_Core_Util::stringToIntArray($val);
+		$B = ParagonIE_Sodium_Core_Util::stringToIntArray($addv);
+
+		$c = 0;
+		for ($i = 0; $i < $val_len; $i++) {
+			$c = ($A[$i] - $B[$i] - $c);
+			$A[$i] = ($c & 0xff);
+			$c = ($c >> 8) & 1;
+		}
+		$val = ParagonIE_Sodium_Core_Util::intArrayToString($A);
+	}
+
+	/**
+	 * This emulates libsodium's version_string() function, except ours is
+	 * prefixed with 'polyfill-'.
+	 *
+	 * @return string
+	 * @psalm-suppress MixedInferredReturnType
+	 * @psalm-suppress UndefinedFunction
+	 */
+	public static function version_string()
+	{
+		if (self::useNewSodiumAPI()) {
+			return (string) sodium_version_string();
+		}
+		if (self::use_fallback('version_string')) {
+			return (string) call_user_func('\\Sodium\\version_string');
+		}
+		return (string) self::VERSION_STRING;
+	}
+
+	/**
+	 * Should we use the libsodium core function instead?
+	 * This is always a good idea, if it's available. (Unless we're in the
+	 * middle of running our unit test suite.)
+	 *
+	 * If ext/libsodium is available, use it. Return TRUE.
+	 * Otherwise, we have to use the code provided herein. Return FALSE.
+	 *
+	 * @param string $sodium_func_name
+	 *
+	 * @return bool
+	 */
+	protected static function use_fallback($sodium_func_name = '')
+	{
+		static $res = null;
+		if ($res === null) {
+			$res = extension_loaded('libsodium') && PHP_VERSION_ID >= 50300;
+		}
+		if ($res === false) {
+			// No libsodium installed
+			return false;
+		}
+		if (self::$disableFallbackForUnitTests) {
+			// Don't fallback. Use the PHP implementation.
+			return false;
+		}
+		if (!empty($sodium_func_name)) {
+			return is_callable('\\Sodium\\' . $sodium_func_name);
+		}
+		return true;
+	}
+
+	/**
+	 * Libsodium as implemented in PHP 7.2
+	 * and/or ext/sodium (via PECL)
+	 *
+	 * @ref https://wiki.php.net/rfc/libsodium
+	 * @return bool
+	 */
+	protected static function useNewSodiumAPI()
+	{
+		static $res = null;
+		if ($res === null) {
+			$res = PHP_VERSION_ID >= 70000 && extension_loaded('sodium');
+		}
+		if (self::$disableFallbackForUnitTests) {
+			// Don't fallback. Use the PHP implementation.
+			return false;
+		}
+		return (bool) $res;
+	}
 }

vendor/paragonie/sodium_compat/src/Crypto32.php

Indentation +1638 added lines, -1638 removed lines

@@ -1,7 +1,7 @@ 
 <?php
 
 if (class_exists('ParagonIE_Sodium_Crypto32', false)) {
-    return;
+	return;
 }
 
 /**
@@ -14,1641 +14,1641 @@ 
  */
 abstract class ParagonIE_Sodium_Crypto32
 {
-    const aead_chacha20poly1305_KEYBYTES = 32;
-    const aead_chacha20poly1305_NSECBYTES = 0;
-    const aead_chacha20poly1305_NPUBBYTES = 8;
-    const aead_chacha20poly1305_ABYTES = 16;
-
-    const aead_chacha20poly1305_IETF_KEYBYTES = 32;
-    const aead_chacha20poly1305_IETF_NSECBYTES = 0;
-    const aead_chacha20poly1305_IETF_NPUBBYTES = 12;
-    const aead_chacha20poly1305_IETF_ABYTES = 16;
-
-    const aead_xchacha20poly1305_IETF_KEYBYTES = 32;
-    const aead_xchacha20poly1305_IETF_NSECBYTES = 0;
-    const aead_xchacha20poly1305_IETF_NPUBBYTES = 24;
-    const aead_xchacha20poly1305_IETF_ABYTES = 16;
-
-    const box_curve25519xsalsa20poly1305_SEEDBYTES = 32;
-    const box_curve25519xsalsa20poly1305_PUBLICKEYBYTES = 32;
-    const box_curve25519xsalsa20poly1305_SECRETKEYBYTES = 32;
-    const box_curve25519xsalsa20poly1305_BEFORENMBYTES = 32;
-    const box_curve25519xsalsa20poly1305_NONCEBYTES = 24;
-    const box_curve25519xsalsa20poly1305_MACBYTES = 16;
-    const box_curve25519xsalsa20poly1305_BOXZEROBYTES = 16;
-    const box_curve25519xsalsa20poly1305_ZEROBYTES = 32;
-
-    const onetimeauth_poly1305_BYTES = 16;
-    const onetimeauth_poly1305_KEYBYTES = 32;
-
-    const secretbox_xsalsa20poly1305_KEYBYTES = 32;
-    const secretbox_xsalsa20poly1305_NONCEBYTES = 24;
-    const secretbox_xsalsa20poly1305_MACBYTES = 16;
-    const secretbox_xsalsa20poly1305_BOXZEROBYTES = 16;
-    const secretbox_xsalsa20poly1305_ZEROBYTES = 32;
-
-    const secretbox_xchacha20poly1305_KEYBYTES = 32;
-    const secretbox_xchacha20poly1305_NONCEBYTES = 24;
-    const secretbox_xchacha20poly1305_MACBYTES = 16;
-    const secretbox_xchacha20poly1305_BOXZEROBYTES = 16;
-    const secretbox_xchacha20poly1305_ZEROBYTES = 32;
-
-    const stream_salsa20_KEYBYTES = 32;
-
-    /**
-     * AEAD Decryption with ChaCha20-Poly1305
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_decrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $len - Length of message (ciphertext + MAC) */
-        $len = ParagonIE_Sodium_Core32_Util::strlen($message);
-
-        /** @var int  $clen - Length of ciphertext */
-        $clen = $len - self::aead_chacha20poly1305_ABYTES;
-
-        /** @var int $adlen - Length of associated data */
-        $adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
-
-        /** @var string $mac - Message authentication code */
-        $mac = ParagonIE_Sodium_Core32_Util::substr(
-            $message,
-            $clen,
-            self::aead_chacha20poly1305_ABYTES
-        );
-
-        /** @var string $ciphertext - The encrypted message (sans MAC) */
-        $ciphertext = ParagonIE_Sodium_Core32_Util::substr($message, 0, $clen);
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core32_ChaCha20::stream(
-            32,
-            $nonce,
-            $key
-        );
-
-        /* Recalculate the Poly1305 authentication tag (MAC): */
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-        $state->update($ad);
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
-        $state->update($ciphertext);
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($clen));
-        $computed_mac = $state->finish();
-
-        /* Compare the given MAC with the recalculated MAC: */
-        if (!ParagonIE_Sodium_Core32_Util::verify_16($computed_mac, $mac)) {
-            throw new SodiumException('Invalid MAC');
-        }
-
-        // Here, we know that the MAC is valid, so we decrypt and return the plaintext
-        return ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
-            $ciphertext,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core32_Util::store64_le(1)
-        );
-    }
-
-    /**
-     * AEAD Encryption with ChaCha20-Poly1305
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_encrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $len - Length of the plaintext message */
-        $len = ParagonIE_Sodium_Core32_Util::strlen($message);
-
-        /** @var int $adlen - Length of the associated data */
-        $adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core32_ChaCha20::stream(
-            32,
-            $nonce,
-            $key
-        );
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-
-        /** @var string $ciphertext - Raw encrypted data */
-        $ciphertext = ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
-            $message,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core32_Util::store64_le(1)
-        );
-
-        $state->update($ad);
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
-        $state->update($ciphertext);
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($len));
-        return $ciphertext . $state->finish();
-    }
-
-    /**
-     * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_ietf_decrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $adlen - Length of associated data */
-        $adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
-
-        /** @var int $len - Length of message (ciphertext + MAC) */
-        $len = ParagonIE_Sodium_Core32_Util::strlen($message);
-
-        /** @var int  $clen - Length of ciphertext */
-        $clen = $len - self::aead_chacha20poly1305_IETF_ABYTES;
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core32_ChaCha20::ietfStream(
-            32,
-            $nonce,
-            $key
-        );
-
-        /** @var string $mac - Message authentication code */
-        $mac = ParagonIE_Sodium_Core32_Util::substr(
-            $message,
-            $len - self::aead_chacha20poly1305_IETF_ABYTES,
-            self::aead_chacha20poly1305_IETF_ABYTES
-        );
-
-        /** @var string $ciphertext - The encrypted message (sans MAC) */
-        $ciphertext = ParagonIE_Sodium_Core32_Util::substr(
-            $message,
-            0,
-            $len - self::aead_chacha20poly1305_IETF_ABYTES
-        );
-
-        /* Recalculate the Poly1305 authentication tag (MAC): */
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-        $state->update($ad);
-        $state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
-        $state->update($ciphertext);
-        $state->update(str_repeat("\x00", (0x10 - $clen) & 0xf));
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($clen));
-        $computed_mac = $state->finish();
-
-        /* Compare the given MAC with the recalculated MAC: */
-        if (!ParagonIE_Sodium_Core32_Util::verify_16($computed_mac, $mac)) {
-            throw new SodiumException('Invalid MAC');
-        }
-
-        // Here, we know that the MAC is valid, so we decrypt and return the plaintext
-        return ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            $ciphertext,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core32_Util::store64_le(1)
-        );
-    }
-
-    /**
-     * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_chacha20poly1305_ietf_encrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        /** @var int $len - Length of the plaintext message */
-        $len = ParagonIE_Sodium_Core32_Util::strlen($message);
-
-        /** @var int $adlen - Length of the associated data */
-        $adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
-
-        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
-        $block0 = ParagonIE_Sodium_Core32_ChaCha20::ietfStream(
-            32,
-            $nonce,
-            $key
-        );
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-        }
-
-        /** @var string $ciphertext - Raw encrypted data */
-        $ciphertext = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            $message,
-            $nonce,
-            $key,
-            ParagonIE_Sodium_Core32_Util::store64_le(1)
-        );
-
-        $state->update($ad);
-        $state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
-        $state->update($ciphertext);
-        $state->update(str_repeat("\x00", ((0x10 - $len) & 0xf)));
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
-        $state->update(ParagonIE_Sodium_Core32_Util::store64_le($len));
-        return $ciphertext . $state->finish();
-    }
-
-    /**
-     * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_xchacha20poly1305_ietf_decrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        $subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 0, 16),
-            $key
-        );
-        $nonceLast = "\x00\x00\x00\x00" .
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
-
-        return self::aead_chacha20poly1305_ietf_decrypt($message, $ad, $nonceLast, $subkey);
-    }
-
-    /**
-     * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $ad
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function aead_xchacha20poly1305_ietf_encrypt(
-        $message = '',
-        $ad = '',
-        $nonce = '',
-        $key = ''
-    ) {
-        $subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 0, 16),
-            $key
-        );
-        $nonceLast = "\x00\x00\x00\x00" .
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
-
-        return self::aead_chacha20poly1305_ietf_encrypt($message, $ad, $nonceLast, $subkey);
-    }
-
-    /**
-     * HMAC-SHA-512-256 (a.k.a. the leftmost 256 bits of HMAC-SHA-512)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $key
-     * @return string
-     * @throws TypeError
-     */
-    public static function auth($message, $key)
-    {
-        return ParagonIE_Sodium_Core32_Util::substr(
-            hash_hmac('sha512', $message, $key, true),
-            0,
-            32
-        );
-    }
-
-    /**
-     * HMAC-SHA-512-256 validation. Constant-time via hash_equals().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $mac
-     * @param string $message
-     * @param string $key
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function auth_verify($mac, $message, $key)
-    {
-        return ParagonIE_Sodium_Core32_Util::hashEquals(
-            $mac,
-            self::auth($message, $key)
-        );
-    }
-
-    /**
-     * X25519 key exchange followed by XSalsa20Poly1305 symmetric encryption
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $plaintext
-     * @param string $nonce
-     * @param string $keypair
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box($plaintext, $nonce, $keypair)
-    {
-        return self::secretbox(
-            $plaintext,
-            $nonce,
-            self::box_beforenm(
-                self::box_secretkey($keypair),
-                self::box_publickey($keypair)
-            )
-        );
-    }
-
-    /**
-     * X25519-XSalsa20-Poly1305 with one ephemeral X25519 keypair.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $publicKey
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seal($message, $publicKey)
-    {
-        /** @var string $ephemeralKeypair */
-        $ephemeralKeypair = self::box_keypair();
-
-        /** @var string $ephemeralSK */
-        $ephemeralSK = self::box_secretkey($ephemeralKeypair);
-
-        /** @var string $ephemeralPK */
-        $ephemeralPK = self::box_publickey($ephemeralKeypair);
-
-        /** @var string $nonce */
-        $nonce = self::generichash(
-            $ephemeralPK . $publicKey,
-            '',
-            24
-        );
-
-        /** @var string $keypair - The combined keypair used in crypto_box() */
-        $keypair = self::box_keypair_from_secretkey_and_publickey($ephemeralSK, $publicKey);
-
-        /** @var string $ciphertext Ciphertext + MAC from crypto_box */
-        $ciphertext = self::box($message, $nonce, $keypair);
-        try {
-            ParagonIE_Sodium_Compat::memzero($ephemeralKeypair);
-            ParagonIE_Sodium_Compat::memzero($ephemeralSK);
-            ParagonIE_Sodium_Compat::memzero($nonce);
-        } catch (SodiumException $ex) {
-            $ephemeralKeypair = null;
-            $ephemeralSK = null;
-            $nonce = null;
-        }
-        return $ephemeralPK . $ciphertext;
-    }
-
-    /**
-     * Opens a message encrypted via box_seal().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $keypair
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seal_open($message, $keypair)
-    {
-        /** @var string $ephemeralPK */
-        $ephemeralPK = ParagonIE_Sodium_Core32_Util::substr($message, 0, 32);
-
-        /** @var string $ciphertext (ciphertext + MAC) */
-        $ciphertext = ParagonIE_Sodium_Core32_Util::substr($message, 32);
-
-        /** @var string $secretKey */
-        $secretKey = self::box_secretkey($keypair);
-
-        /** @var string $publicKey */
-        $publicKey = self::box_publickey($keypair);
-
-        /** @var string $nonce */
-        $nonce = self::generichash(
-            $ephemeralPK . $publicKey,
-            '',
-            24
-        );
-
-        /** @var string $keypair */
-        $keypair = self::box_keypair_from_secretkey_and_publickey($secretKey, $ephemeralPK);
-
-        /** @var string $m */
-        $m = self::box_open($ciphertext, $nonce, $keypair);
-        try {
-            ParagonIE_Sodium_Compat::memzero($secretKey);
-            ParagonIE_Sodium_Compat::memzero($ephemeralPK);
-            ParagonIE_Sodium_Compat::memzero($nonce);
-        } catch (SodiumException $ex) {
-            $secretKey = null;
-            $ephemeralPK = null;
-            $nonce = null;
-        }
-        return $m;
-    }
-
-    /**
-     * Used by crypto_box() to get the crypto_secretbox() key.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sk
-     * @param string $pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_beforenm($sk, $pk)
-    {
-        return ParagonIE_Sodium_Core32_HSalsa20::hsalsa20(
-            str_repeat("\x00", 16),
-            self::scalarmult($sk, $pk)
-        );
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @return string
-     * @throws Exception
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_keypair()
-    {
-        $sKey = random_bytes(32);
-        $pKey = self::scalarmult_base($sKey);
-        return $sKey . $pKey;
-    }
-
-    /**
-     * @param string $seed
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_seed_keypair($seed)
-    {
-        $sKey = ParagonIE_Sodium_Core32_Util::substr(
-            hash('sha512', $seed, true),
-            0,
-            32
-        );
-        $pKey = self::scalarmult_base($sKey);
-        return $sKey . $pKey;
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sKey
-     * @param string $pKey
-     * @return string
-     * @throws TypeError
-     */
-    public static function box_keypair_from_secretkey_and_publickey($sKey, $pKey)
-    {
-        return ParagonIE_Sodium_Core32_Util::substr($sKey, 0, 32) .
-            ParagonIE_Sodium_Core32_Util::substr($pKey, 0, 32);
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $keypair
-     * @return string
-     * @throws RangeException
-     * @throws TypeError
-     */
-    public static function box_secretkey($keypair)
-    {
-        if (ParagonIE_Sodium_Core32_Util::strlen($keypair) !== 64) {
-            throw new RangeException(
-                'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
-            );
-        }
-        return ParagonIE_Sodium_Core32_Util::substr($keypair, 0, 32);
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $keypair
-     * @return string
-     * @throws RangeException
-     * @throws TypeError
-     */
-    public static function box_publickey($keypair)
-    {
-        if (ParagonIE_Sodium_Core32_Util::strlen($keypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
-            throw new RangeException(
-                'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
-            );
-        }
-        return ParagonIE_Sodium_Core32_Util::substr($keypair, 32, 32);
-    }
-
-    /**
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sKey
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_publickey_from_secretkey($sKey)
-    {
-        if (ParagonIE_Sodium_Core32_Util::strlen($sKey) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES) {
-            throw new RangeException(
-                'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES bytes long.'
-            );
-        }
-        return self::scalarmult_base($sKey);
-    }
-
-    /**
-     * Decrypt a message encrypted with box().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ciphertext
-     * @param string $nonce
-     * @param string $keypair
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function box_open($ciphertext, $nonce, $keypair)
-    {
-        return self::secretbox_open(
-            $ciphertext,
-            $nonce,
-            self::box_beforenm(
-                self::box_secretkey($keypair),
-                self::box_publickey($keypair)
-            )
-        );
-    }
-
-    /**
-     * Calculate a BLAKE2b hash.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string|null $key
-     * @param int $outlen
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash($message, $key = '', $outlen = 32)
-    {
-        // This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
-
-        $k = null;
-        if (!empty($key)) {
-            /** @var SplFixedArray $k */
-            $k = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($key);
-            if ($k->count() > ParagonIE_Sodium_Core32_BLAKE2b::KEYBYTES) {
-                throw new RangeException('Invalid key size');
-            }
-        }
-
-        /** @var SplFixedArray $in */
-        $in = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($message);
-
-        /** @var SplFixedArray $ctx */
-        $ctx = ParagonIE_Sodium_Core32_BLAKE2b::init($k, $outlen);
-        ParagonIE_Sodium_Core32_BLAKE2b::update($ctx, $in, $in->count());
-
-        /** @var SplFixedArray $out */
-        $out = new SplFixedArray($outlen);
-        $out = ParagonIE_Sodium_Core32_BLAKE2b::finish($ctx, $out);
-
-        /** @var array<int, int> */
-        $outArray = $out->toArray();
-        return ParagonIE_Sodium_Core32_Util::intArrayToString($outArray);
-    }
-
-    /**
-     * Finalize a BLAKE2b hashing context, returning the hash.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ctx
-     * @param int $outlen
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_final($ctx, $outlen = 32)
-    {
-        if (!is_string($ctx)) {
-            throw new TypeError('Context must be a string');
-        }
-        $out = new SplFixedArray($outlen);
-
-        /** @var SplFixedArray $context */
-        $context = ParagonIE_Sodium_Core32_BLAKE2b::stringToContext($ctx);
-
-        /** @var SplFixedArray $out */
-        $out = ParagonIE_Sodium_Core32_BLAKE2b::finish($context, $out);
-
-        /** @var array<int, int> */
-        $outArray = $out->toArray();
-        return ParagonIE_Sodium_Core32_Util::intArrayToString($outArray);
-    }
-
-    /**
-     * Initialize a hashing context for BLAKE2b.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $key
-     * @param int $outputLength
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_init($key = '', $outputLength = 32)
-    {
-        // This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
-
-        $k = null;
-        if (!empty($key)) {
-            $k = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($key);
-            if ($k->count() > ParagonIE_Sodium_Core32_BLAKE2b::KEYBYTES) {
-                throw new RangeException('Invalid key size');
-            }
-        }
-
-        /** @var SplFixedArray $ctx */
-        $ctx = ParagonIE_Sodium_Core32_BLAKE2b::init($k, $outputLength);
-
-        return ParagonIE_Sodium_Core32_BLAKE2b::contextToString($ctx);
-    }
-
-    /**
-     * Initialize a hashing context for BLAKE2b.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $key
-     * @param int $outputLength
-     * @param string $salt
-     * @param string $personal
-     * @return string
-     * @throws RangeException
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_init_salt_personal(
-        $key = '',
-        $outputLength = 32,
-        $salt = '',
-        $personal = ''
-    ) {
-        // This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
-
-        $k = null;
-        if (!empty($key)) {
-            $k = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($key);
-            if ($k->count() > ParagonIE_Sodium_Core32_BLAKE2b::KEYBYTES) {
-                throw new RangeException('Invalid key size');
-            }
-        }
-        if (!empty($salt)) {
-            $s = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($salt);
-        } else {
-            $s = null;
-        }
-        if (!empty($salt)) {
-            $p = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($personal);
-        } else {
-            $p = null;
-        }
-
-        /** @var SplFixedArray $ctx */
-        $ctx = ParagonIE_Sodium_Core32_BLAKE2b::init($k, $outputLength, $s, $p);
-
-        return ParagonIE_Sodium_Core32_BLAKE2b::contextToString($ctx);
-    }
-
-    /**
-     * Update a hashing context for BLAKE2b with $message
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ctx
-     * @param string $message
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function generichash_update($ctx, $message)
-    {
-        // This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
-        ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
-
-        /** @var SplFixedArray $context */
-        $context = ParagonIE_Sodium_Core32_BLAKE2b::stringToContext($ctx);
-
-        /** @var SplFixedArray $in */
-        $in = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($message);
-
-        ParagonIE_Sodium_Core32_BLAKE2b::update($context, $in, $in->count());
-
-        return ParagonIE_Sodium_Core32_BLAKE2b::contextToString($context);
-    }
-
-    /**
-     * Libsodium's crypto_kx().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $my_sk
-     * @param string $their_pk
-     * @param string $client_pk
-     * @param string $server_pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function keyExchange($my_sk, $their_pk, $client_pk, $server_pk)
-    {
-        return self::generichash(
-            self::scalarmult($my_sk, $their_pk) .
-            $client_pk .
-            $server_pk
-        );
-    }
-
-    /**
-     * ECDH over Curve25519
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $sKey
-     * @param string $pKey
-     * @return string
-     *
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function scalarmult($sKey, $pKey)
-    {
-        $q = ParagonIE_Sodium_Core32_X25519::crypto_scalarmult_curve25519_ref10($sKey, $pKey);
-        self::scalarmult_throw_if_zero($q);
-        return $q;
-    }
-
-    /**
-     * ECDH over Curve25519, using the basepoint.
-     * Used to get a secret key from a public key.
-     *
-     * @param string $secret
-     * @return string
-     *
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function scalarmult_base($secret)
-    {
-        $q = ParagonIE_Sodium_Core32_X25519::crypto_scalarmult_curve25519_ref10_base($secret);
-        self::scalarmult_throw_if_zero($q);
-        return $q;
-    }
-
-    /**
-     * This throws an Error if a zero public key was passed to the function.
-     *
-     * @param string $q
-     * @return void
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function scalarmult_throw_if_zero($q)
-    {
-        $d = 0;
-        for ($i = 0; $i < self::box_curve25519xsalsa20poly1305_SECRETKEYBYTES; ++$i) {
-            $d |= ParagonIE_Sodium_Core32_Util::chrToInt($q[$i]);
-        }
-
-        /* branch-free variant of === 0 */
-        if (-(1 & (($d - 1) >> 8))) {
-            throw new SodiumException('Zero public key is not allowed');
-        }
-    }
-
-    /**
-     * XSalsa20-Poly1305 authenticated symmetric-key encryption.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $plaintext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox($plaintext, $nonce, $key)
-    {
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $block0 */
-        $block0 = str_repeat("\x00", 32);
-
-        /** @var int $mlen - Length of the plaintext message */
-        $mlen = ParagonIE_Sodium_Core32_Util::strlen($plaintext);
-        $mlen0 = $mlen;
-        if ($mlen0 > 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES) {
-            $mlen0 = 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES;
-        }
-        $block0 .= ParagonIE_Sodium_Core32_Util::substr($plaintext, 0, $mlen0);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor(
-            $block0,
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core32_Util::substr(
-            $block0,
-            self::secretbox_xsalsa20poly1305_ZEROBYTES
-        );
-        if ($mlen > $mlen0) {
-            $c .= ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
-                ParagonIE_Sodium_Core32_Util::substr(
-                    $plaintext,
-                    self::secretbox_xsalsa20poly1305_ZEROBYTES
-                ),
-                ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-                1,
-                $subkey
-            );
-        }
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State(
-            ParagonIE_Sodium_Core32_Util::substr(
-                $block0,
-                0,
-                self::onetimeauth_poly1305_KEYBYTES
-            )
-        );
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-            ParagonIE_Sodium_Compat::memzero($subkey);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-            $subkey = null;
-        }
-
-        $state->update($c);
-
-        /** @var string $c - MAC || ciphertext */
-        $c = $state->finish() . $c;
-        unset($state);
-
-        return $c;
-    }
-
-    /**
-     * Decrypt a ciphertext generated via secretbox().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ciphertext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_open($ciphertext, $nonce, $key)
-    {
-        /** @var string $mac */
-        $mac = ParagonIE_Sodium_Core32_Util::substr(
-            $ciphertext,
-            0,
-            self::secretbox_xsalsa20poly1305_MACBYTES
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core32_Util::substr(
-            $ciphertext,
-            self::secretbox_xsalsa20poly1305_MACBYTES
-        );
-
-        /** @var int $clen */
-        $clen = ParagonIE_Sodium_Core32_Util::strlen($c);
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20(
-            64,
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-        $verified = ParagonIE_Sodium_Core32_Poly1305::onetimeauth_verify(
-            $mac,
-            $c,
-            ParagonIE_Sodium_Core32_Util::substr($block0, 0, 32)
-        );
-        if (!$verified) {
-            try {
-                ParagonIE_Sodium_Compat::memzero($subkey);
-            } catch (SodiumException $ex) {
-                $subkey = null;
-            }
-            throw new SodiumException('Invalid MAC');
-        }
-
-        /** @var string $m - Decrypted message */
-        $m = ParagonIE_Sodium_Core32_Util::xorStrings(
-            ParagonIE_Sodium_Core32_Util::substr($block0, self::secretbox_xsalsa20poly1305_ZEROBYTES),
-            ParagonIE_Sodium_Core32_Util::substr($c, 0, self::secretbox_xsalsa20poly1305_ZEROBYTES)
-        );
-        if ($clen > self::secretbox_xsalsa20poly1305_ZEROBYTES) {
-            // We had more than 1 block, so let's continue to decrypt the rest.
-            $m .= ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
-                ParagonIE_Sodium_Core32_Util::substr(
-                    $c,
-                    self::secretbox_xsalsa20poly1305_ZEROBYTES
-                ),
-                ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-                1,
-                (string) $subkey
-            );
-        }
-        return $m;
-    }
-
-    /**
-     * XChaCha20-Poly1305 authenticated symmetric-key encryption.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $plaintext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_xchacha20poly1305($plaintext, $nonce, $key)
-    {
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 0, 16),
-            $key
-        );
-        $nonceLast = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
-
-        /** @var string $block0 */
-        $block0 = str_repeat("\x00", 32);
-
-        /** @var int $mlen - Length of the plaintext message */
-        $mlen = ParagonIE_Sodium_Core32_Util::strlen($plaintext);
-        $mlen0 = $mlen;
-        if ($mlen0 > 64 - self::secretbox_xchacha20poly1305_ZEROBYTES) {
-            $mlen0 = 64 - self::secretbox_xchacha20poly1305_ZEROBYTES;
-        }
-        $block0 .= ParagonIE_Sodium_Core32_Util::substr($plaintext, 0, $mlen0);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
-            $block0,
-            $nonceLast,
-            $subkey
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core32_Util::substr(
-            $block0,
-            self::secretbox_xchacha20poly1305_ZEROBYTES
-        );
-        if ($mlen > $mlen0) {
-            $c .= ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
-                ParagonIE_Sodium_Core32_Util::substr(
-                    $plaintext,
-                    self::secretbox_xchacha20poly1305_ZEROBYTES
-                ),
-                $nonceLast,
-                $subkey,
-                ParagonIE_Sodium_Core32_Util::store64_le(1)
-            );
-        }
-        $state = new ParagonIE_Sodium_Core32_Poly1305_State(
-            ParagonIE_Sodium_Core32_Util::substr(
-                $block0,
-                0,
-                self::onetimeauth_poly1305_KEYBYTES
-            )
-        );
-        try {
-            ParagonIE_Sodium_Compat::memzero($block0);
-            ParagonIE_Sodium_Compat::memzero($subkey);
-        } catch (SodiumException $ex) {
-            $block0 = null;
-            $subkey = null;
-        }
-
-        $state->update($c);
-
-        /** @var string $c - MAC || ciphertext */
-        $c = $state->finish() . $c;
-        unset($state);
-
-        return $c;
-    }
-
-    /**
-     * Decrypt a ciphertext generated via secretbox_xchacha20poly1305().
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $ciphertext
-     * @param string $nonce
-     * @param string $key
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key)
-    {
-        /** @var string $mac */
-        $mac = ParagonIE_Sodium_Core32_Util::substr(
-            $ciphertext,
-            0,
-            self::secretbox_xchacha20poly1305_MACBYTES
-        );
-
-        /** @var string $c */
-        $c = ParagonIE_Sodium_Core32_Util::substr(
-            $ciphertext,
-            self::secretbox_xchacha20poly1305_MACBYTES
-        );
-
-        /** @var int $clen */
-        $clen = ParagonIE_Sodium_Core32_Util::strlen($c);
-
-        /** @var string $subkey */
-        $subkey = ParagonIE_Sodium_Core32_HChaCha20::hchacha20($nonce, $key);
-
-        /** @var string $block0 */
-        $block0 = ParagonIE_Sodium_Core32_ChaCha20::stream(
-            64,
-            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-            $subkey
-        );
-        $verified = ParagonIE_Sodium_Core32_Poly1305::onetimeauth_verify(
-            $mac,
-            $c,
-            ParagonIE_Sodium_Core32_Util::substr($block0, 0, 32)
-        );
-
-        if (!$verified) {
-            try {
-                ParagonIE_Sodium_Compat::memzero($subkey);
-            } catch (SodiumException $ex) {
-                $subkey = null;
-            }
-            throw new SodiumException('Invalid MAC');
-        }
-
-        /** @var string $m - Decrypted message */
-        $m = ParagonIE_Sodium_Core32_Util::xorStrings(
-            ParagonIE_Sodium_Core32_Util::substr($block0, self::secretbox_xchacha20poly1305_ZEROBYTES),
-            ParagonIE_Sodium_Core32_Util::substr($c, 0, self::secretbox_xchacha20poly1305_ZEROBYTES)
-        );
-
-        if ($clen > self::secretbox_xchacha20poly1305_ZEROBYTES) {
-            // We had more than 1 block, so let's continue to decrypt the rest.
-            $m .= ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
-                ParagonIE_Sodium_Core32_Util::substr(
-                    $c,
-                    self::secretbox_xchacha20poly1305_ZEROBYTES
-                ),
-                ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
-                (string) $subkey,
-                ParagonIE_Sodium_Core32_Util::store64_le(1)
-            );
-        }
-        return $m;
-    }
-
-    /**
-     * @param string $key
-     * @return array<int, string> Returns a state and a header.
-     * @throws Exception
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_init_push($key)
-    {
-        # randombytes_buf(out, crypto_secretstream_xchacha20poly1305_HEADERBYTES);
-        $out = random_bytes(24);
-
-        # crypto_core_hchacha20(state->k, out, k, NULL);
-        $subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20($out, $key);
-        $state = new ParagonIE_Sodium_Core32_SecretStream_State(
-            $subkey,
-            ParagonIE_Sodium_Core32_Util::substr($out, 16, 8) . str_repeat("\0", 4)
-        );
-
-        # _crypto_secretstream_xchacha20poly1305_counter_reset(state);
-        $state->counterReset();
-
-        # memcpy(STATE_INONCE(state), out + crypto_core_hchacha20_INPUTBYTES,
-        #        crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        # memset(state->_pad, 0, sizeof state->_pad);
-        return array(
-            $state->toString(),
-            $out
-        );
-    }
-
-    /**
-     * @param string $key
-     * @param string $header
-     * @return string Returns a state.
-     * @throws Exception
-     */
-    public static function secretstream_xchacha20poly1305_init_pull($key, $header)
-    {
-        # crypto_core_hchacha20(state->k, in, k, NULL);
-        $subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
-            ParagonIE_Sodium_Core32_Util::substr($header, 0, 16),
-            $key
-        );
-        $state = new ParagonIE_Sodium_Core32_SecretStream_State(
-            $subkey,
-            ParagonIE_Sodium_Core32_Util::substr($header, 16)
-        );
-        $state->counterReset();
-        # memcpy(STATE_INONCE(state), in + crypto_core_hchacha20_INPUTBYTES,
-        #     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        # memset(state->_pad, 0, sizeof state->_pad);
-        # return 0;
-        return $state->toString();
-    }
-
-    /**
-     * @param string $state
-     * @param string $msg
-     * @param string $aad
-     * @param int $tag
-     * @return string
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_push(&$state, $msg, $aad = '', $tag = 0)
-    {
-        $st = ParagonIE_Sodium_Core32_SecretStream_State::fromString($state);
-        # crypto_onetimeauth_poly1305_state poly1305_state;
-        # unsigned char                     block[64U];
-        # unsigned char                     slen[8U];
-        # unsigned char                    *c;
-        # unsigned char                    *mac;
-
-        $msglen = ParagonIE_Sodium_Core32_Util::strlen($msg);
-        $aadlen = ParagonIE_Sodium_Core32_Util::strlen($aad);
-
-        if ((($msglen + 63) >> 6) > 0xfffffffe) {
-            throw new SodiumException(
-                'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
-            );
-        }
-
-        # if (outlen_p != NULL) {
-        #     *outlen_p = 0U;
-        # }
-        # if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
-        #     sodium_misuse();
-        # }
-
-        # crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
-        # crypto_onetimeauth_poly1305_init(&poly1305_state, block);
-        # sodium_memzero(block, sizeof block);
-        $auth = new ParagonIE_Sodium_Core32_Poly1305_State(
-            ParagonIE_Sodium_Core32_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
-        );
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
-        $auth->update($aad);
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
-        #     (0x10 - adlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
-
-        # memset(block, 0, sizeof block);
-        # block[0] = tag;
-        # crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
-        #                                    state->nonce, 1U, state->k);
-        $block = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            ParagonIE_Sodium_Core32_Util::intToChr($tag) . str_repeat("\0", 63),
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core32_Util::store64_le(1)
-        );
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
-        $auth->update($block);
-
-        # out[0] = block[0];
-        $out = $block[0];
-        # c = out + (sizeof tag);
-        # crypto_stream_chacha20_ietf_xor_ic(c, m, mlen, state->nonce, 2U, state->k);
-        $cipher = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            $msg,
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core32_Util::store64_le(2)
-        );
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
-        $auth->update($cipher);
-
-        $out .= $cipher;
-        unset($cipher);
-
-        # crypto_onetimeauth_poly1305_update
-        # (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
-
-        # STORE64_LE(slen, (uint64_t) adlen);
-        $slen = ParagonIE_Sodium_Core32_Util::store64_le($aadlen);
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $auth->update($slen);
-
-        # STORE64_LE(slen, (sizeof block) + mlen);
-        $slen = ParagonIE_Sodium_Core32_Util::store64_le(64 + $msglen);
-
-        # crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $auth->update($slen);
-
-        # mac = c + mlen;
-        # crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
-        $mac = $auth->finish();
-        $out .= $mac;
-
-        # sodium_memzero(&poly1305_state, sizeof poly1305_state);
-        unset($auth);
-
-
-        # XOR_BUF(STATE_INONCE(state), mac,
-        #     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        $st->xorNonce($mac);
-
-        # sodium_increment(STATE_COUNTER(state),
-        #     crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
-        $st->incrementCounter();
-        // Overwrite by reference:
-        $state = $st->toString();
-
-        /** @var bool $rekey */
-        $rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
-        # if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
-        #     sodium_is_zero(STATE_COUNTER(state),
-        #         crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
-        #     crypto_secretstream_xchacha20poly1305_rekey(state);
-        # }
-        if ($rekey || $st->needsRekey()) {
-            // DO REKEY
-            self::secretstream_xchacha20poly1305_rekey($state);
-        }
-        # if (outlen_p != NULL) {
-        #     *outlen_p = crypto_secretstream_xchacha20poly1305_ABYTES + mlen;
-        # }
-        return $out;
-    }
-
-    /**
-     * @param string $state
-     * @param string $cipher
-     * @param string $aad
-     * @return bool|array{0: string, 1: int}
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_pull(&$state, $cipher, $aad = '')
-    {
-        $st = ParagonIE_Sodium_Core32_SecretStream_State::fromString($state);
-
-        $cipherlen = ParagonIE_Sodium_Core32_Util::strlen($cipher);
-        #     mlen = inlen - crypto_secretstream_xchacha20poly1305_ABYTES;
-        $msglen = $cipherlen - ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES;
-        $aadlen = ParagonIE_Sodium_Core32_Util::strlen($aad);
-
-        #     if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
-        #         sodium_misuse();
-        #     }
-        if ((($msglen + 63) >> 6) > 0xfffffffe) {
-            throw new SodiumException(
-                'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
-            );
-        }
-
-        #     crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
-        #     crypto_onetimeauth_poly1305_init(&poly1305_state, block);
-        #     sodium_memzero(block, sizeof block);
-        $auth = new ParagonIE_Sodium_Core32_Poly1305_State(
-            ParagonIE_Sodium_Core32_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
-        );
-
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
-        $auth->update($aad);
-
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
-        #         (0x10 - adlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
-
-
-        #     memset(block, 0, sizeof block);
-        #     block[0] = in[0];
-        #     crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
-        #                                        state->nonce, 1U, state->k);
-        $block = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            $cipher[0] . str_repeat("\0", 63),
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core32_Util::store64_le(1)
-        );
-        #     tag = block[0];
-        #     block[0] = in[0];
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
-        $tag = ParagonIE_Sodium_Core32_Util::chrToInt($block[0]);
-        $block[0] = $cipher[0];
-        $auth->update($block);
-
-
-        #     c = in + (sizeof tag);
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
-        $auth->update(ParagonIE_Sodium_Core32_Util::substr($cipher, 1, $msglen));
-
-        #     crypto_onetimeauth_poly1305_update
-        #     (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
-        $auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
-
-        #     STORE64_LE(slen, (uint64_t) adlen);
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $slen = ParagonIE_Sodium_Core32_Util::store64_le($aadlen);
-        $auth->update($slen);
-
-        #     STORE64_LE(slen, (sizeof block) + mlen);
-        #     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
-        $slen = ParagonIE_Sodium_Core32_Util::store64_le(64 + $msglen);
-        $auth->update($slen);
-
-        #     crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
-        #     sodium_memzero(&poly1305_state, sizeof poly1305_state);
-        $mac = $auth->finish();
-
-        #     stored_mac = c + mlen;
-        #     if (sodium_memcmp(mac, stored_mac, sizeof mac) != 0) {
-        #     sodium_memzero(mac, sizeof mac);
-        #         return -1;
-        #     }
-
-        $stored = ParagonIE_Sodium_Core32_Util::substr($cipher, $msglen + 1, 16);
-        if (!ParagonIE_Sodium_Core32_Util::hashEquals($mac, $stored)) {
-            return false;
-        }
-
-        #     crypto_stream_chacha20_ietf_xor_ic(m, c, mlen, state->nonce, 2U, state->k);
-        $out = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            ParagonIE_Sodium_Core32_Util::substr($cipher, 1, $msglen),
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core32_Util::store64_le(2)
-        );
-
-        #     XOR_BUF(STATE_INONCE(state), mac,
-        #         crypto_secretstream_xchacha20poly1305_INONCEBYTES);
-        $st->xorNonce($mac);
-
-        #     sodium_increment(STATE_COUNTER(state),
-        #         crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
-        $st->incrementCounter();
-
-        #     if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
-        #         sodium_is_zero(STATE_COUNTER(state),
-        #             crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
-        #         crypto_secretstream_xchacha20poly1305_rekey(state);
-        #     }
-
-        // Overwrite by reference:
-        $state = $st->toString();
-
-        /** @var bool $rekey */
-        $rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
-        if ($rekey || $st->needsRekey()) {
-            // DO REKEY
-            self::secretstream_xchacha20poly1305_rekey($state);
-        }
-        return array($out, $tag);
-    }
-
-    /**
-     * @param string $state
-     * @return void
-     * @throws SodiumException
-     */
-    public static function secretstream_xchacha20poly1305_rekey(&$state)
-    {
-        $st = ParagonIE_Sodium_Core32_SecretStream_State::fromString($state);
-        # unsigned char new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES +
-        # crypto_secretstream_xchacha20poly1305_INONCEBYTES];
-        # size_t        i;
-        # for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
-        #     new_key_and_inonce[i] = state->k[i];
-        # }
-        $new_key_and_inonce = $st->getKey();
-
-        # for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
-        #     new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i] =
-        #         STATE_INONCE(state)[i];
-        # }
-        $new_key_and_inonce .= ParagonIE_Sodium_Core32_Util::substR($st->getNonce(), 0, 8);
-
-        # crypto_stream_chacha20_ietf_xor(new_key_and_inonce, new_key_and_inonce,
-        #                                 sizeof new_key_and_inonce,
-        #                                 state->nonce, state->k);
-
-        $st->rekey(ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
-            $new_key_and_inonce,
-            $st->getCombinedNonce(),
-            $st->getKey(),
-            ParagonIE_Sodium_Core32_Util::store64_le(0)
-        ));
-
-        # for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
-        #     state->k[i] = new_key_and_inonce[i];
-        # }
-        # for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
-        #     STATE_INONCE(state)[i] =
-        #          new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i];
-        # }
-        # _crypto_secretstream_xchacha20poly1305_counter_reset(state);
-        $st->counterReset();
-
-        $state = $st->toString();
-    }
-
-    /**
-     * Detached Ed25519 signature.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $sk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign_detached($message, $sk)
-    {
-        return ParagonIE_Sodium_Core32_Ed25519::sign_detached($message, $sk);
-    }
-
-    /**
-     * Attached Ed25519 signature. (Returns a signed message.)
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $message
-     * @param string $sk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign($message, $sk)
-    {
-        return ParagonIE_Sodium_Core32_Ed25519::sign($message, $sk);
-    }
-
-    /**
-     * Opens a signed message. If valid, returns the message.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $signedMessage
-     * @param string $pk
-     * @return string
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign_open($signedMessage, $pk)
-    {
-        return ParagonIE_Sodium_Core32_Ed25519::sign_open($signedMessage, $pk);
-    }
-
-    /**
-     * Verify a detached signature of a given message and public key.
-     *
-     * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
-     *
-     * @param string $signature
-     * @param string $message
-     * @param string $pk
-     * @return bool
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    public static function sign_verify_detached($signature, $message, $pk)
-    {
-        return ParagonIE_Sodium_Core32_Ed25519::verify_detached($signature, $message, $pk);
-    }
+	const aead_chacha20poly1305_KEYBYTES = 32;
+	const aead_chacha20poly1305_NSECBYTES = 0;
+	const aead_chacha20poly1305_NPUBBYTES = 8;
+	const aead_chacha20poly1305_ABYTES = 16;
+
+	const aead_chacha20poly1305_IETF_KEYBYTES = 32;
+	const aead_chacha20poly1305_IETF_NSECBYTES = 0;
+	const aead_chacha20poly1305_IETF_NPUBBYTES = 12;
+	const aead_chacha20poly1305_IETF_ABYTES = 16;
+
+	const aead_xchacha20poly1305_IETF_KEYBYTES = 32;
+	const aead_xchacha20poly1305_IETF_NSECBYTES = 0;
+	const aead_xchacha20poly1305_IETF_NPUBBYTES = 24;
+	const aead_xchacha20poly1305_IETF_ABYTES = 16;
+
+	const box_curve25519xsalsa20poly1305_SEEDBYTES = 32;
+	const box_curve25519xsalsa20poly1305_PUBLICKEYBYTES = 32;
+	const box_curve25519xsalsa20poly1305_SECRETKEYBYTES = 32;
+	const box_curve25519xsalsa20poly1305_BEFORENMBYTES = 32;
+	const box_curve25519xsalsa20poly1305_NONCEBYTES = 24;
+	const box_curve25519xsalsa20poly1305_MACBYTES = 16;
+	const box_curve25519xsalsa20poly1305_BOXZEROBYTES = 16;
+	const box_curve25519xsalsa20poly1305_ZEROBYTES = 32;
+
+	const onetimeauth_poly1305_BYTES = 16;
+	const onetimeauth_poly1305_KEYBYTES = 32;
+
+	const secretbox_xsalsa20poly1305_KEYBYTES = 32;
+	const secretbox_xsalsa20poly1305_NONCEBYTES = 24;
+	const secretbox_xsalsa20poly1305_MACBYTES = 16;
+	const secretbox_xsalsa20poly1305_BOXZEROBYTES = 16;
+	const secretbox_xsalsa20poly1305_ZEROBYTES = 32;
+
+	const secretbox_xchacha20poly1305_KEYBYTES = 32;
+	const secretbox_xchacha20poly1305_NONCEBYTES = 24;
+	const secretbox_xchacha20poly1305_MACBYTES = 16;
+	const secretbox_xchacha20poly1305_BOXZEROBYTES = 16;
+	const secretbox_xchacha20poly1305_ZEROBYTES = 32;
+
+	const stream_salsa20_KEYBYTES = 32;
+
+	/**
+	 * AEAD Decryption with ChaCha20-Poly1305
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_decrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $len - Length of message (ciphertext + MAC) */
+		$len = ParagonIE_Sodium_Core32_Util::strlen($message);
+
+		/** @var int  $clen - Length of ciphertext */
+		$clen = $len - self::aead_chacha20poly1305_ABYTES;
+
+		/** @var int $adlen - Length of associated data */
+		$adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
+
+		/** @var string $mac - Message authentication code */
+		$mac = ParagonIE_Sodium_Core32_Util::substr(
+			$message,
+			$clen,
+			self::aead_chacha20poly1305_ABYTES
+		);
+
+		/** @var string $ciphertext - The encrypted message (sans MAC) */
+		$ciphertext = ParagonIE_Sodium_Core32_Util::substr($message, 0, $clen);
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core32_ChaCha20::stream(
+			32,
+			$nonce,
+			$key
+		);
+
+		/* Recalculate the Poly1305 authentication tag (MAC): */
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+		$state->update($ad);
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
+		$state->update($ciphertext);
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($clen));
+		$computed_mac = $state->finish();
+
+		/* Compare the given MAC with the recalculated MAC: */
+		if (!ParagonIE_Sodium_Core32_Util::verify_16($computed_mac, $mac)) {
+			throw new SodiumException('Invalid MAC');
+		}
+
+		// Here, we know that the MAC is valid, so we decrypt and return the plaintext
+		return ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
+			$ciphertext,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core32_Util::store64_le(1)
+		);
+	}
+
+	/**
+	 * AEAD Encryption with ChaCha20-Poly1305
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_encrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $len - Length of the plaintext message */
+		$len = ParagonIE_Sodium_Core32_Util::strlen($message);
+
+		/** @var int $adlen - Length of the associated data */
+		$adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core32_ChaCha20::stream(
+			32,
+			$nonce,
+			$key
+		);
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+
+		/** @var string $ciphertext - Raw encrypted data */
+		$ciphertext = ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
+			$message,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core32_Util::store64_le(1)
+		);
+
+		$state->update($ad);
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
+		$state->update($ciphertext);
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($len));
+		return $ciphertext . $state->finish();
+	}
+
+	/**
+	 * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_ietf_decrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $adlen - Length of associated data */
+		$adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
+
+		/** @var int $len - Length of message (ciphertext + MAC) */
+		$len = ParagonIE_Sodium_Core32_Util::strlen($message);
+
+		/** @var int  $clen - Length of ciphertext */
+		$clen = $len - self::aead_chacha20poly1305_IETF_ABYTES;
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core32_ChaCha20::ietfStream(
+			32,
+			$nonce,
+			$key
+		);
+
+		/** @var string $mac - Message authentication code */
+		$mac = ParagonIE_Sodium_Core32_Util::substr(
+			$message,
+			$len - self::aead_chacha20poly1305_IETF_ABYTES,
+			self::aead_chacha20poly1305_IETF_ABYTES
+		);
+
+		/** @var string $ciphertext - The encrypted message (sans MAC) */
+		$ciphertext = ParagonIE_Sodium_Core32_Util::substr(
+			$message,
+			0,
+			$len - self::aead_chacha20poly1305_IETF_ABYTES
+		);
+
+		/* Recalculate the Poly1305 authentication tag (MAC): */
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+		$state->update($ad);
+		$state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
+		$state->update($ciphertext);
+		$state->update(str_repeat("\x00", (0x10 - $clen) & 0xf));
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($clen));
+		$computed_mac = $state->finish();
+
+		/* Compare the given MAC with the recalculated MAC: */
+		if (!ParagonIE_Sodium_Core32_Util::verify_16($computed_mac, $mac)) {
+			throw new SodiumException('Invalid MAC');
+		}
+
+		// Here, we know that the MAC is valid, so we decrypt and return the plaintext
+		return ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			$ciphertext,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core32_Util::store64_le(1)
+		);
+	}
+
+	/**
+	 * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_chacha20poly1305_ietf_encrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		/** @var int $len - Length of the plaintext message */
+		$len = ParagonIE_Sodium_Core32_Util::strlen($message);
+
+		/** @var int $adlen - Length of the associated data */
+		$adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);
+
+		/** @var string The first block of the chacha20 keystream, used as a poly1305 key */
+		$block0 = ParagonIE_Sodium_Core32_ChaCha20::ietfStream(
+			32,
+			$nonce,
+			$key
+		);
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State($block0);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+		}
+
+		/** @var string $ciphertext - Raw encrypted data */
+		$ciphertext = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			$message,
+			$nonce,
+			$key,
+			ParagonIE_Sodium_Core32_Util::store64_le(1)
+		);
+
+		$state->update($ad);
+		$state->update(str_repeat("\x00", ((0x10 - $adlen) & 0xf)));
+		$state->update($ciphertext);
+		$state->update(str_repeat("\x00", ((0x10 - $len) & 0xf)));
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($adlen));
+		$state->update(ParagonIE_Sodium_Core32_Util::store64_le($len));
+		return $ciphertext . $state->finish();
+	}
+
+	/**
+	 * AEAD Decryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_xchacha20poly1305_ietf_decrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		$subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 0, 16),
+			$key
+		);
+		$nonceLast = "\x00\x00\x00\x00" .
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
+
+		return self::aead_chacha20poly1305_ietf_decrypt($message, $ad, $nonceLast, $subkey);
+	}
+
+	/**
+	 * AEAD Encryption with ChaCha20-Poly1305, IETF mode (96-bit nonce)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $ad
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function aead_xchacha20poly1305_ietf_encrypt(
+		$message = '',
+		$ad = '',
+		$nonce = '',
+		$key = ''
+	) {
+		$subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 0, 16),
+			$key
+		);
+		$nonceLast = "\x00\x00\x00\x00" .
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
+
+		return self::aead_chacha20poly1305_ietf_encrypt($message, $ad, $nonceLast, $subkey);
+	}
+
+	/**
+	 * HMAC-SHA-512-256 (a.k.a. the leftmost 256 bits of HMAC-SHA-512)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $key
+	 * @return string
+	 * @throws TypeError
+	 */
+	public static function auth($message, $key)
+	{
+		return ParagonIE_Sodium_Core32_Util::substr(
+			hash_hmac('sha512', $message, $key, true),
+			0,
+			32
+		);
+	}
+
+	/**
+	 * HMAC-SHA-512-256 validation. Constant-time via hash_equals().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $mac
+	 * @param string $message
+	 * @param string $key
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function auth_verify($mac, $message, $key)
+	{
+		return ParagonIE_Sodium_Core32_Util::hashEquals(
+			$mac,
+			self::auth($message, $key)
+		);
+	}
+
+	/**
+	 * X25519 key exchange followed by XSalsa20Poly1305 symmetric encryption
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $plaintext
+	 * @param string $nonce
+	 * @param string $keypair
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box($plaintext, $nonce, $keypair)
+	{
+		return self::secretbox(
+			$plaintext,
+			$nonce,
+			self::box_beforenm(
+				self::box_secretkey($keypair),
+				self::box_publickey($keypair)
+			)
+		);
+	}
+
+	/**
+	 * X25519-XSalsa20-Poly1305 with one ephemeral X25519 keypair.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $publicKey
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seal($message, $publicKey)
+	{
+		/** @var string $ephemeralKeypair */
+		$ephemeralKeypair = self::box_keypair();
+
+		/** @var string $ephemeralSK */
+		$ephemeralSK = self::box_secretkey($ephemeralKeypair);
+
+		/** @var string $ephemeralPK */
+		$ephemeralPK = self::box_publickey($ephemeralKeypair);
+
+		/** @var string $nonce */
+		$nonce = self::generichash(
+			$ephemeralPK . $publicKey,
+			'',
+			24
+		);
+
+		/** @var string $keypair - The combined keypair used in crypto_box() */
+		$keypair = self::box_keypair_from_secretkey_and_publickey($ephemeralSK, $publicKey);
+
+		/** @var string $ciphertext Ciphertext + MAC from crypto_box */
+		$ciphertext = self::box($message, $nonce, $keypair);
+		try {
+			ParagonIE_Sodium_Compat::memzero($ephemeralKeypair);
+			ParagonIE_Sodium_Compat::memzero($ephemeralSK);
+			ParagonIE_Sodium_Compat::memzero($nonce);
+		} catch (SodiumException $ex) {
+			$ephemeralKeypair = null;
+			$ephemeralSK = null;
+			$nonce = null;
+		}
+		return $ephemeralPK . $ciphertext;
+	}
+
+	/**
+	 * Opens a message encrypted via box_seal().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $keypair
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seal_open($message, $keypair)
+	{
+		/** @var string $ephemeralPK */
+		$ephemeralPK = ParagonIE_Sodium_Core32_Util::substr($message, 0, 32);
+
+		/** @var string $ciphertext (ciphertext + MAC) */
+		$ciphertext = ParagonIE_Sodium_Core32_Util::substr($message, 32);
+
+		/** @var string $secretKey */
+		$secretKey = self::box_secretkey($keypair);
+
+		/** @var string $publicKey */
+		$publicKey = self::box_publickey($keypair);
+
+		/** @var string $nonce */
+		$nonce = self::generichash(
+			$ephemeralPK . $publicKey,
+			'',
+			24
+		);
+
+		/** @var string $keypair */
+		$keypair = self::box_keypair_from_secretkey_and_publickey($secretKey, $ephemeralPK);
+
+		/** @var string $m */
+		$m = self::box_open($ciphertext, $nonce, $keypair);
+		try {
+			ParagonIE_Sodium_Compat::memzero($secretKey);
+			ParagonIE_Sodium_Compat::memzero($ephemeralPK);
+			ParagonIE_Sodium_Compat::memzero($nonce);
+		} catch (SodiumException $ex) {
+			$secretKey = null;
+			$ephemeralPK = null;
+			$nonce = null;
+		}
+		return $m;
+	}
+
+	/**
+	 * Used by crypto_box() to get the crypto_secretbox() key.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sk
+	 * @param string $pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_beforenm($sk, $pk)
+	{
+		return ParagonIE_Sodium_Core32_HSalsa20::hsalsa20(
+			str_repeat("\x00", 16),
+			self::scalarmult($sk, $pk)
+		);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @return string
+	 * @throws Exception
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_keypair()
+	{
+		$sKey = random_bytes(32);
+		$pKey = self::scalarmult_base($sKey);
+		return $sKey . $pKey;
+	}
+
+	/**
+	 * @param string $seed
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_seed_keypair($seed)
+	{
+		$sKey = ParagonIE_Sodium_Core32_Util::substr(
+			hash('sha512', $seed, true),
+			0,
+			32
+		);
+		$pKey = self::scalarmult_base($sKey);
+		return $sKey . $pKey;
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sKey
+	 * @param string $pKey
+	 * @return string
+	 * @throws TypeError
+	 */
+	public static function box_keypair_from_secretkey_and_publickey($sKey, $pKey)
+	{
+		return ParagonIE_Sodium_Core32_Util::substr($sKey, 0, 32) .
+			ParagonIE_Sodium_Core32_Util::substr($pKey, 0, 32);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $keypair
+	 * @return string
+	 * @throws RangeException
+	 * @throws TypeError
+	 */
+	public static function box_secretkey($keypair)
+	{
+		if (ParagonIE_Sodium_Core32_Util::strlen($keypair) !== 64) {
+			throw new RangeException(
+				'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
+			);
+		}
+		return ParagonIE_Sodium_Core32_Util::substr($keypair, 0, 32);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $keypair
+	 * @return string
+	 * @throws RangeException
+	 * @throws TypeError
+	 */
+	public static function box_publickey($keypair)
+	{
+		if (ParagonIE_Sodium_Core32_Util::strlen($keypair) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES) {
+			throw new RangeException(
+				'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_KEYPAIRBYTES bytes long.'
+			);
+		}
+		return ParagonIE_Sodium_Core32_Util::substr($keypair, 32, 32);
+	}
+
+	/**
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sKey
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_publickey_from_secretkey($sKey)
+	{
+		if (ParagonIE_Sodium_Core32_Util::strlen($sKey) !== ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES) {
+			throw new RangeException(
+				'Must be ParagonIE_Sodium_Compat::CRYPTO_BOX_SECRETKEYBYTES bytes long.'
+			);
+		}
+		return self::scalarmult_base($sKey);
+	}
+
+	/**
+	 * Decrypt a message encrypted with box().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ciphertext
+	 * @param string $nonce
+	 * @param string $keypair
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function box_open($ciphertext, $nonce, $keypair)
+	{
+		return self::secretbox_open(
+			$ciphertext,
+			$nonce,
+			self::box_beforenm(
+				self::box_secretkey($keypair),
+				self::box_publickey($keypair)
+			)
+		);
+	}
+
+	/**
+	 * Calculate a BLAKE2b hash.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string|null $key
+	 * @param int $outlen
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash($message, $key = '', $outlen = 32)
+	{
+		// This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
+
+		$k = null;
+		if (!empty($key)) {
+			/** @var SplFixedArray $k */
+			$k = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($key);
+			if ($k->count() > ParagonIE_Sodium_Core32_BLAKE2b::KEYBYTES) {
+				throw new RangeException('Invalid key size');
+			}
+		}
+
+		/** @var SplFixedArray $in */
+		$in = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($message);
+
+		/** @var SplFixedArray $ctx */
+		$ctx = ParagonIE_Sodium_Core32_BLAKE2b::init($k, $outlen);
+		ParagonIE_Sodium_Core32_BLAKE2b::update($ctx, $in, $in->count());
+
+		/** @var SplFixedArray $out */
+		$out = new SplFixedArray($outlen);
+		$out = ParagonIE_Sodium_Core32_BLAKE2b::finish($ctx, $out);
+
+		/** @var array<int, int> */
+		$outArray = $out->toArray();
+		return ParagonIE_Sodium_Core32_Util::intArrayToString($outArray);
+	}
+
+	/**
+	 * Finalize a BLAKE2b hashing context, returning the hash.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ctx
+	 * @param int $outlen
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_final($ctx, $outlen = 32)
+	{
+		if (!is_string($ctx)) {
+			throw new TypeError('Context must be a string');
+		}
+		$out = new SplFixedArray($outlen);
+
+		/** @var SplFixedArray $context */
+		$context = ParagonIE_Sodium_Core32_BLAKE2b::stringToContext($ctx);
+
+		/** @var SplFixedArray $out */
+		$out = ParagonIE_Sodium_Core32_BLAKE2b::finish($context, $out);
+
+		/** @var array<int, int> */
+		$outArray = $out->toArray();
+		return ParagonIE_Sodium_Core32_Util::intArrayToString($outArray);
+	}
+
+	/**
+	 * Initialize a hashing context for BLAKE2b.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $key
+	 * @param int $outputLength
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_init($key = '', $outputLength = 32)
+	{
+		// This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
+
+		$k = null;
+		if (!empty($key)) {
+			$k = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($key);
+			if ($k->count() > ParagonIE_Sodium_Core32_BLAKE2b::KEYBYTES) {
+				throw new RangeException('Invalid key size');
+			}
+		}
+
+		/** @var SplFixedArray $ctx */
+		$ctx = ParagonIE_Sodium_Core32_BLAKE2b::init($k, $outputLength);
+
+		return ParagonIE_Sodium_Core32_BLAKE2b::contextToString($ctx);
+	}
+
+	/**
+	 * Initialize a hashing context for BLAKE2b.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $key
+	 * @param int $outputLength
+	 * @param string $salt
+	 * @param string $personal
+	 * @return string
+	 * @throws RangeException
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_init_salt_personal(
+		$key = '',
+		$outputLength = 32,
+		$salt = '',
+		$personal = ''
+	) {
+		// This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
+
+		$k = null;
+		if (!empty($key)) {
+			$k = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($key);
+			if ($k->count() > ParagonIE_Sodium_Core32_BLAKE2b::KEYBYTES) {
+				throw new RangeException('Invalid key size');
+			}
+		}
+		if (!empty($salt)) {
+			$s = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($salt);
+		} else {
+			$s = null;
+		}
+		if (!empty($salt)) {
+			$p = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($personal);
+		} else {
+			$p = null;
+		}
+
+		/** @var SplFixedArray $ctx */
+		$ctx = ParagonIE_Sodium_Core32_BLAKE2b::init($k, $outputLength, $s, $p);
+
+		return ParagonIE_Sodium_Core32_BLAKE2b::contextToString($ctx);
+	}
+
+	/**
+	 * Update a hashing context for BLAKE2b with $message
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ctx
+	 * @param string $message
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function generichash_update($ctx, $message)
+	{
+		// This ensures that ParagonIE_Sodium_Core32_BLAKE2b::$iv is initialized
+		ParagonIE_Sodium_Core32_BLAKE2b::pseudoConstructor();
+
+		/** @var SplFixedArray $context */
+		$context = ParagonIE_Sodium_Core32_BLAKE2b::stringToContext($ctx);
+
+		/** @var SplFixedArray $in */
+		$in = ParagonIE_Sodium_Core32_BLAKE2b::stringToSplFixedArray($message);
+
+		ParagonIE_Sodium_Core32_BLAKE2b::update($context, $in, $in->count());
+
+		return ParagonIE_Sodium_Core32_BLAKE2b::contextToString($context);
+	}
+
+	/**
+	 * Libsodium's crypto_kx().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $my_sk
+	 * @param string $their_pk
+	 * @param string $client_pk
+	 * @param string $server_pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function keyExchange($my_sk, $their_pk, $client_pk, $server_pk)
+	{
+		return self::generichash(
+			self::scalarmult($my_sk, $their_pk) .
+			$client_pk .
+			$server_pk
+		);
+	}
+
+	/**
+	 * ECDH over Curve25519
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $sKey
+	 * @param string $pKey
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function scalarmult($sKey, $pKey)
+	{
+		$q = ParagonIE_Sodium_Core32_X25519::crypto_scalarmult_curve25519_ref10($sKey, $pKey);
+		self::scalarmult_throw_if_zero($q);
+		return $q;
+	}
+
+	/**
+	 * ECDH over Curve25519, using the basepoint.
+	 * Used to get a secret key from a public key.
+	 *
+	 * @param string $secret
+	 * @return string
+	 *
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function scalarmult_base($secret)
+	{
+		$q = ParagonIE_Sodium_Core32_X25519::crypto_scalarmult_curve25519_ref10_base($secret);
+		self::scalarmult_throw_if_zero($q);
+		return $q;
+	}
+
+	/**
+	 * This throws an Error if a zero public key was passed to the function.
+	 *
+	 * @param string $q
+	 * @return void
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function scalarmult_throw_if_zero($q)
+	{
+		$d = 0;
+		for ($i = 0; $i < self::box_curve25519xsalsa20poly1305_SECRETKEYBYTES; ++$i) {
+			$d |= ParagonIE_Sodium_Core32_Util::chrToInt($q[$i]);
+		}
+
+		/* branch-free variant of === 0 */
+		if (-(1 & (($d - 1) >> 8))) {
+			throw new SodiumException('Zero public key is not allowed');
+		}
+	}
+
+	/**
+	 * XSalsa20-Poly1305 authenticated symmetric-key encryption.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $plaintext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox($plaintext, $nonce, $key)
+	{
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $block0 */
+		$block0 = str_repeat("\x00", 32);
+
+		/** @var int $mlen - Length of the plaintext message */
+		$mlen = ParagonIE_Sodium_Core32_Util::strlen($plaintext);
+		$mlen0 = $mlen;
+		if ($mlen0 > 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES) {
+			$mlen0 = 64 - self::secretbox_xsalsa20poly1305_ZEROBYTES;
+		}
+		$block0 .= ParagonIE_Sodium_Core32_Util::substr($plaintext, 0, $mlen0);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor(
+			$block0,
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core32_Util::substr(
+			$block0,
+			self::secretbox_xsalsa20poly1305_ZEROBYTES
+		);
+		if ($mlen > $mlen0) {
+			$c .= ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
+				ParagonIE_Sodium_Core32_Util::substr(
+					$plaintext,
+					self::secretbox_xsalsa20poly1305_ZEROBYTES
+				),
+				ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+				1,
+				$subkey
+			);
+		}
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State(
+			ParagonIE_Sodium_Core32_Util::substr(
+				$block0,
+				0,
+				self::onetimeauth_poly1305_KEYBYTES
+			)
+		);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+			ParagonIE_Sodium_Compat::memzero($subkey);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+			$subkey = null;
+		}
+
+		$state->update($c);
+
+		/** @var string $c - MAC || ciphertext */
+		$c = $state->finish() . $c;
+		unset($state);
+
+		return $c;
+	}
+
+	/**
+	 * Decrypt a ciphertext generated via secretbox().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ciphertext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_open($ciphertext, $nonce, $key)
+	{
+		/** @var string $mac */
+		$mac = ParagonIE_Sodium_Core32_Util::substr(
+			$ciphertext,
+			0,
+			self::secretbox_xsalsa20poly1305_MACBYTES
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core32_Util::substr(
+			$ciphertext,
+			self::secretbox_xsalsa20poly1305_MACBYTES
+		);
+
+		/** @var int $clen */
+		$clen = ParagonIE_Sodium_Core32_Util::strlen($c);
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20(
+			64,
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+		$verified = ParagonIE_Sodium_Core32_Poly1305::onetimeauth_verify(
+			$mac,
+			$c,
+			ParagonIE_Sodium_Core32_Util::substr($block0, 0, 32)
+		);
+		if (!$verified) {
+			try {
+				ParagonIE_Sodium_Compat::memzero($subkey);
+			} catch (SodiumException $ex) {
+				$subkey = null;
+			}
+			throw new SodiumException('Invalid MAC');
+		}
+
+		/** @var string $m - Decrypted message */
+		$m = ParagonIE_Sodium_Core32_Util::xorStrings(
+			ParagonIE_Sodium_Core32_Util::substr($block0, self::secretbox_xsalsa20poly1305_ZEROBYTES),
+			ParagonIE_Sodium_Core32_Util::substr($c, 0, self::secretbox_xsalsa20poly1305_ZEROBYTES)
+		);
+		if ($clen > self::secretbox_xsalsa20poly1305_ZEROBYTES) {
+			// We had more than 1 block, so let's continue to decrypt the rest.
+			$m .= ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(
+				ParagonIE_Sodium_Core32_Util::substr(
+					$c,
+					self::secretbox_xsalsa20poly1305_ZEROBYTES
+				),
+				ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+				1,
+				(string) $subkey
+			);
+		}
+		return $m;
+	}
+
+	/**
+	 * XChaCha20-Poly1305 authenticated symmetric-key encryption.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $plaintext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_xchacha20poly1305($plaintext, $nonce, $key)
+	{
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 0, 16),
+			$key
+		);
+		$nonceLast = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);
+
+		/** @var string $block0 */
+		$block0 = str_repeat("\x00", 32);
+
+		/** @var int $mlen - Length of the plaintext message */
+		$mlen = ParagonIE_Sodium_Core32_Util::strlen($plaintext);
+		$mlen0 = $mlen;
+		if ($mlen0 > 64 - self::secretbox_xchacha20poly1305_ZEROBYTES) {
+			$mlen0 = 64 - self::secretbox_xchacha20poly1305_ZEROBYTES;
+		}
+		$block0 .= ParagonIE_Sodium_Core32_Util::substr($plaintext, 0, $mlen0);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
+			$block0,
+			$nonceLast,
+			$subkey
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core32_Util::substr(
+			$block0,
+			self::secretbox_xchacha20poly1305_ZEROBYTES
+		);
+		if ($mlen > $mlen0) {
+			$c .= ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
+				ParagonIE_Sodium_Core32_Util::substr(
+					$plaintext,
+					self::secretbox_xchacha20poly1305_ZEROBYTES
+				),
+				$nonceLast,
+				$subkey,
+				ParagonIE_Sodium_Core32_Util::store64_le(1)
+			);
+		}
+		$state = new ParagonIE_Sodium_Core32_Poly1305_State(
+			ParagonIE_Sodium_Core32_Util::substr(
+				$block0,
+				0,
+				self::onetimeauth_poly1305_KEYBYTES
+			)
+		);
+		try {
+			ParagonIE_Sodium_Compat::memzero($block0);
+			ParagonIE_Sodium_Compat::memzero($subkey);
+		} catch (SodiumException $ex) {
+			$block0 = null;
+			$subkey = null;
+		}
+
+		$state->update($c);
+
+		/** @var string $c - MAC || ciphertext */
+		$c = $state->finish() . $c;
+		unset($state);
+
+		return $c;
+	}
+
+	/**
+	 * Decrypt a ciphertext generated via secretbox_xchacha20poly1305().
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $ciphertext
+	 * @param string $nonce
+	 * @param string $key
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function secretbox_xchacha20poly1305_open($ciphertext, $nonce, $key)
+	{
+		/** @var string $mac */
+		$mac = ParagonIE_Sodium_Core32_Util::substr(
+			$ciphertext,
+			0,
+			self::secretbox_xchacha20poly1305_MACBYTES
+		);
+
+		/** @var string $c */
+		$c = ParagonIE_Sodium_Core32_Util::substr(
+			$ciphertext,
+			self::secretbox_xchacha20poly1305_MACBYTES
+		);
+
+		/** @var int $clen */
+		$clen = ParagonIE_Sodium_Core32_Util::strlen($c);
+
+		/** @var string $subkey */
+		$subkey = ParagonIE_Sodium_Core32_HChaCha20::hchacha20($nonce, $key);
+
+		/** @var string $block0 */
+		$block0 = ParagonIE_Sodium_Core32_ChaCha20::stream(
+			64,
+			ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+			$subkey
+		);
+		$verified = ParagonIE_Sodium_Core32_Poly1305::onetimeauth_verify(
+			$mac,
+			$c,
+			ParagonIE_Sodium_Core32_Util::substr($block0, 0, 32)
+		);
+
+		if (!$verified) {
+			try {
+				ParagonIE_Sodium_Compat::memzero($subkey);
+			} catch (SodiumException $ex) {
+				$subkey = null;
+			}
+			throw new SodiumException('Invalid MAC');
+		}
+
+		/** @var string $m - Decrypted message */
+		$m = ParagonIE_Sodium_Core32_Util::xorStrings(
+			ParagonIE_Sodium_Core32_Util::substr($block0, self::secretbox_xchacha20poly1305_ZEROBYTES),
+			ParagonIE_Sodium_Core32_Util::substr($c, 0, self::secretbox_xchacha20poly1305_ZEROBYTES)
+		);
+
+		if ($clen > self::secretbox_xchacha20poly1305_ZEROBYTES) {
+			// We had more than 1 block, so let's continue to decrypt the rest.
+			$m .= ParagonIE_Sodium_Core32_ChaCha20::streamXorIc(
+				ParagonIE_Sodium_Core32_Util::substr(
+					$c,
+					self::secretbox_xchacha20poly1305_ZEROBYTES
+				),
+				ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),
+				(string) $subkey,
+				ParagonIE_Sodium_Core32_Util::store64_le(1)
+			);
+		}
+		return $m;
+	}
+
+	/**
+	 * @param string $key
+	 * @return array<int, string> Returns a state and a header.
+	 * @throws Exception
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_init_push($key)
+	{
+		# randombytes_buf(out, crypto_secretstream_xchacha20poly1305_HEADERBYTES);
+		$out = random_bytes(24);
+
+		# crypto_core_hchacha20(state->k, out, k, NULL);
+		$subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20($out, $key);
+		$state = new ParagonIE_Sodium_Core32_SecretStream_State(
+			$subkey,
+			ParagonIE_Sodium_Core32_Util::substr($out, 16, 8) . str_repeat("\0", 4)
+		);
+
+		# _crypto_secretstream_xchacha20poly1305_counter_reset(state);
+		$state->counterReset();
+
+		# memcpy(STATE_INONCE(state), out + crypto_core_hchacha20_INPUTBYTES,
+		#        crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		# memset(state->_pad, 0, sizeof state->_pad);
+		return array(
+			$state->toString(),
+			$out
+		);
+	}
+
+	/**
+	 * @param string $key
+	 * @param string $header
+	 * @return string Returns a state.
+	 * @throws Exception
+	 */
+	public static function secretstream_xchacha20poly1305_init_pull($key, $header)
+	{
+		# crypto_core_hchacha20(state->k, in, k, NULL);
+		$subkey = ParagonIE_Sodium_Core32_HChaCha20::hChaCha20(
+			ParagonIE_Sodium_Core32_Util::substr($header, 0, 16),
+			$key
+		);
+		$state = new ParagonIE_Sodium_Core32_SecretStream_State(
+			$subkey,
+			ParagonIE_Sodium_Core32_Util::substr($header, 16)
+		);
+		$state->counterReset();
+		# memcpy(STATE_INONCE(state), in + crypto_core_hchacha20_INPUTBYTES,
+		#     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		# memset(state->_pad, 0, sizeof state->_pad);
+		# return 0;
+		return $state->toString();
+	}
+
+	/**
+	 * @param string $state
+	 * @param string $msg
+	 * @param string $aad
+	 * @param int $tag
+	 * @return string
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_push(&$state, $msg, $aad = '', $tag = 0)
+	{
+		$st = ParagonIE_Sodium_Core32_SecretStream_State::fromString($state);
+		# crypto_onetimeauth_poly1305_state poly1305_state;
+		# unsigned char                     block[64U];
+		# unsigned char                     slen[8U];
+		# unsigned char                    *c;
+		# unsigned char                    *mac;
+
+		$msglen = ParagonIE_Sodium_Core32_Util::strlen($msg);
+		$aadlen = ParagonIE_Sodium_Core32_Util::strlen($aad);
+
+		if ((($msglen + 63) >> 6) > 0xfffffffe) {
+			throw new SodiumException(
+				'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
+			);
+		}
+
+		# if (outlen_p != NULL) {
+		#     *outlen_p = 0U;
+		# }
+		# if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
+		#     sodium_misuse();
+		# }
+
+		# crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
+		# crypto_onetimeauth_poly1305_init(&poly1305_state, block);
+		# sodium_memzero(block, sizeof block);
+		$auth = new ParagonIE_Sodium_Core32_Poly1305_State(
+			ParagonIE_Sodium_Core32_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
+		);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
+		$auth->update($aad);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
+		#     (0x10 - adlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
+
+		# memset(block, 0, sizeof block);
+		# block[0] = tag;
+		# crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
+		#                                    state->nonce, 1U, state->k);
+		$block = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			ParagonIE_Sodium_Core32_Util::intToChr($tag) . str_repeat("\0", 63),
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core32_Util::store64_le(1)
+		);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
+		$auth->update($block);
+
+		# out[0] = block[0];
+		$out = $block[0];
+		# c = out + (sizeof tag);
+		# crypto_stream_chacha20_ietf_xor_ic(c, m, mlen, state->nonce, 2U, state->k);
+		$cipher = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			$msg,
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core32_Util::store64_le(2)
+		);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
+		$auth->update($cipher);
+
+		$out .= $cipher;
+		unset($cipher);
+
+		# crypto_onetimeauth_poly1305_update
+		# (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
+
+		# STORE64_LE(slen, (uint64_t) adlen);
+		$slen = ParagonIE_Sodium_Core32_Util::store64_le($aadlen);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$auth->update($slen);
+
+		# STORE64_LE(slen, (sizeof block) + mlen);
+		$slen = ParagonIE_Sodium_Core32_Util::store64_le(64 + $msglen);
+
+		# crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$auth->update($slen);
+
+		# mac = c + mlen;
+		# crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
+		$mac = $auth->finish();
+		$out .= $mac;
+
+		# sodium_memzero(&poly1305_state, sizeof poly1305_state);
+		unset($auth);
+
+
+		# XOR_BUF(STATE_INONCE(state), mac,
+		#     crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		$st->xorNonce($mac);
+
+		# sodium_increment(STATE_COUNTER(state),
+		#     crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
+		$st->incrementCounter();
+		// Overwrite by reference:
+		$state = $st->toString();
+
+		/** @var bool $rekey */
+		$rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
+		# if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
+		#     sodium_is_zero(STATE_COUNTER(state),
+		#         crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
+		#     crypto_secretstream_xchacha20poly1305_rekey(state);
+		# }
+		if ($rekey || $st->needsRekey()) {
+			// DO REKEY
+			self::secretstream_xchacha20poly1305_rekey($state);
+		}
+		# if (outlen_p != NULL) {
+		#     *outlen_p = crypto_secretstream_xchacha20poly1305_ABYTES + mlen;
+		# }
+		return $out;
+	}
+
+	/**
+	 * @param string $state
+	 * @param string $cipher
+	 * @param string $aad
+	 * @return bool|array{0: string, 1: int}
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_pull(&$state, $cipher, $aad = '')
+	{
+		$st = ParagonIE_Sodium_Core32_SecretStream_State::fromString($state);
+
+		$cipherlen = ParagonIE_Sodium_Core32_Util::strlen($cipher);
+		#     mlen = inlen - crypto_secretstream_xchacha20poly1305_ABYTES;
+		$msglen = $cipherlen - ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES;
+		$aadlen = ParagonIE_Sodium_Core32_Util::strlen($aad);
+
+		#     if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
+		#         sodium_misuse();
+		#     }
+		if ((($msglen + 63) >> 6) > 0xfffffffe) {
+			throw new SodiumException(
+				'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
+			);
+		}
+
+		#     crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
+		#     crypto_onetimeauth_poly1305_init(&poly1305_state, block);
+		#     sodium_memzero(block, sizeof block);
+		$auth = new ParagonIE_Sodium_Core32_Poly1305_State(
+			ParagonIE_Sodium_Core32_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
+		);
+
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
+		$auth->update($aad);
+
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
+		#         (0x10 - adlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));
+
+
+		#     memset(block, 0, sizeof block);
+		#     block[0] = in[0];
+		#     crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
+		#                                        state->nonce, 1U, state->k);
+		$block = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			$cipher[0] . str_repeat("\0", 63),
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core32_Util::store64_le(1)
+		);
+		#     tag = block[0];
+		#     block[0] = in[0];
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
+		$tag = ParagonIE_Sodium_Core32_Util::chrToInt($block[0]);
+		$block[0] = $cipher[0];
+		$auth->update($block);
+
+
+		#     c = in + (sizeof tag);
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
+		$auth->update(ParagonIE_Sodium_Core32_Util::substr($cipher, 1, $msglen));
+
+		#     crypto_onetimeauth_poly1305_update
+		#     (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
+		$auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));
+
+		#     STORE64_LE(slen, (uint64_t) adlen);
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$slen = ParagonIE_Sodium_Core32_Util::store64_le($aadlen);
+		$auth->update($slen);
+
+		#     STORE64_LE(slen, (sizeof block) + mlen);
+		#     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
+		$slen = ParagonIE_Sodium_Core32_Util::store64_le(64 + $msglen);
+		$auth->update($slen);
+
+		#     crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
+		#     sodium_memzero(&poly1305_state, sizeof poly1305_state);
+		$mac = $auth->finish();
+
+		#     stored_mac = c + mlen;
+		#     if (sodium_memcmp(mac, stored_mac, sizeof mac) != 0) {
+		#     sodium_memzero(mac, sizeof mac);
+		#         return -1;
+		#     }
+
+		$stored = ParagonIE_Sodium_Core32_Util::substr($cipher, $msglen + 1, 16);
+		if (!ParagonIE_Sodium_Core32_Util::hashEquals($mac, $stored)) {
+			return false;
+		}
+
+		#     crypto_stream_chacha20_ietf_xor_ic(m, c, mlen, state->nonce, 2U, state->k);
+		$out = ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			ParagonIE_Sodium_Core32_Util::substr($cipher, 1, $msglen),
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core32_Util::store64_le(2)
+		);
+
+		#     XOR_BUF(STATE_INONCE(state), mac,
+		#         crypto_secretstream_xchacha20poly1305_INONCEBYTES);
+		$st->xorNonce($mac);
+
+		#     sodium_increment(STATE_COUNTER(state),
+		#         crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
+		$st->incrementCounter();
+
+		#     if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
+		#         sodium_is_zero(STATE_COUNTER(state),
+		#             crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
+		#         crypto_secretstream_xchacha20poly1305_rekey(state);
+		#     }
+
+		// Overwrite by reference:
+		$state = $st->toString();
+
+		/** @var bool $rekey */
+		$rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
+		if ($rekey || $st->needsRekey()) {
+			// DO REKEY
+			self::secretstream_xchacha20poly1305_rekey($state);
+		}
+		return array($out, $tag);
+	}
+
+	/**
+	 * @param string $state
+	 * @return void
+	 * @throws SodiumException
+	 */
+	public static function secretstream_xchacha20poly1305_rekey(&$state)
+	{
+		$st = ParagonIE_Sodium_Core32_SecretStream_State::fromString($state);
+		# unsigned char new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES +
+		# crypto_secretstream_xchacha20poly1305_INONCEBYTES];
+		# size_t        i;
+		# for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
+		#     new_key_and_inonce[i] = state->k[i];
+		# }
+		$new_key_and_inonce = $st->getKey();
+
+		# for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
+		#     new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i] =
+		#         STATE_INONCE(state)[i];
+		# }
+		$new_key_and_inonce .= ParagonIE_Sodium_Core32_Util::substR($st->getNonce(), 0, 8);
+
+		# crypto_stream_chacha20_ietf_xor(new_key_and_inonce, new_key_and_inonce,
+		#                                 sizeof new_key_and_inonce,
+		#                                 state->nonce, state->k);
+
+		$st->rekey(ParagonIE_Sodium_Core32_ChaCha20::ietfStreamXorIc(
+			$new_key_and_inonce,
+			$st->getCombinedNonce(),
+			$st->getKey(),
+			ParagonIE_Sodium_Core32_Util::store64_le(0)
+		));
+
+		# for (i = 0U; i < crypto_stream_chacha20_ietf_KEYBYTES; i++) {
+		#     state->k[i] = new_key_and_inonce[i];
+		# }
+		# for (i = 0U; i < crypto_secretstream_xchacha20poly1305_INONCEBYTES; i++) {
+		#     STATE_INONCE(state)[i] =
+		#          new_key_and_inonce[crypto_stream_chacha20_ietf_KEYBYTES + i];
+		# }
+		# _crypto_secretstream_xchacha20poly1305_counter_reset(state);
+		$st->counterReset();
+
+		$state = $st->toString();
+	}
+
+	/**
+	 * Detached Ed25519 signature.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $sk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign_detached($message, $sk)
+	{
+		return ParagonIE_Sodium_Core32_Ed25519::sign_detached($message, $sk);
+	}
+
+	/**
+	 * Attached Ed25519 signature. (Returns a signed message.)
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $message
+	 * @param string $sk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign($message, $sk)
+	{
+		return ParagonIE_Sodium_Core32_Ed25519::sign($message, $sk);
+	}
+
+	/**
+	 * Opens a signed message. If valid, returns the message.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $signedMessage
+	 * @param string $pk
+	 * @return string
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign_open($signedMessage, $pk)
+	{
+		return ParagonIE_Sodium_Core32_Ed25519::sign_open($signedMessage, $pk);
+	}
+
+	/**
+	 * Verify a detached signature of a given message and public key.
+	 *
+	 * @internal Do not use this directly. Use ParagonIE_Sodium_Compat.
+	 *
+	 * @param string $signature
+	 * @param string $message
+	 * @param string $pk
+	 * @return bool
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	public static function sign_verify_detached($signature, $message, $pk)
+	{
+		return ParagonIE_Sodium_Core32_Ed25519::verify_detached($signature, $message, $pk);
+	}
 }

vendor/paragonie/sodium_compat/src/Core/BLAKE2b.php

Indentation +773 added lines, -773 removed lines

@@ -1,7 +1,7 @@ 
 <?php
 
 if (class_exists('ParagonIE_Sodium_Core_BLAKE2b', false)) {
-    return;
+	return;
 }
 
 /**
@@ -11,780 +11,780 @@ 
  */
 abstract class ParagonIE_Sodium_Core_BLAKE2b extends ParagonIE_Sodium_Core_Util
 {
-    /**
-     * @var SplFixedArray
-     */
-    protected static $iv;
-
-    /**
-     * @var array<int, array<int, int>>
-     */
-    protected static $sigma = array(
-        array(  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15),
-        array( 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3),
-        array( 11,  8, 12,  0,  5,  2, 15, 13, 10, 14,  3,  6,  7,  1,  9,  4),
-        array(  7,  9,  3,  1, 13, 12, 11, 14,  2,  6,  5, 10,  4,  0, 15,  8),
-        array(  9,  0,  5,  7,  2,  4, 10, 15, 14,  1, 11, 12,  6,  8,  3, 13),
-        array(  2, 12,  6, 10,  0, 11,  8,  3,  4, 13,  7,  5, 15, 14,  1,  9),
-        array( 12,  5,  1, 15, 14, 13,  4, 10,  0,  7,  6,  3,  9,  2,  8, 11),
-        array( 13, 11,  7, 14, 12,  1,  3,  9,  5,  0, 15,  4,  8,  6,  2, 10),
-        array(  6, 15, 14,  9, 11,  3,  0,  8, 12,  2, 13,  7,  1,  4, 10,  5),
-        array( 10,  2,  8,  4,  7,  6,  1,  5, 15, 11,  9, 14,  3, 12, 13 , 0),
-        array(  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15),
-        array( 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3)
-    );
-
-    const BLOCKBYTES = 128;
-    const OUTBYTES   = 64;
-    const KEYBYTES   = 64;
-
-    /**
-     * Turn two 32-bit integers into a fixed array representing a 64-bit integer.
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @param int $high
-     * @param int $low
-     * @return SplFixedArray
-     * @psalm-suppress MixedAssignment
-     */
-    public static function new64($high, $low)
-    {
-        $i64 = new SplFixedArray(2);
-        $i64[0] = $high & 0xffffffff;
-        $i64[1] = $low & 0xffffffff;
-        return $i64;
-    }
-
-    /**
-     * Convert an arbitrary number into an SplFixedArray of two 32-bit integers
-     * that represents a 64-bit integer.
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @param int $num
-     * @return SplFixedArray
-     */
-    protected static function to64($num)
-    {
-        list($hi, $lo) = self::numericTo64BitInteger($num);
-        return self::new64($hi, $lo);
-    }
-
-    /**
-     * Adds two 64-bit integers together, returning their sum as a SplFixedArray
-     * containing two 32-bit integers (representing a 64-bit integer).
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @param SplFixedArray $y
-     * @return SplFixedArray
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedOperand
-     */
-    protected static function add64($x, $y)
-    {
-        $l = ($x[1] + $y[1]) & 0xffffffff;
-        return self::new64(
-            (int) ($x[0] + $y[0] + (
-                ($l < $x[1]) ? 1 : 0
-            )),
-            (int) $l
-        );
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @param SplFixedArray $y
-     * @param SplFixedArray $z
-     * @return SplFixedArray
-     */
-    protected static function add364($x, $y, $z)
-    {
-        return self::add64($x, self::add64($y, $z));
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @param SplFixedArray $y
-     * @return SplFixedArray
-     * @throws SodiumException
-     * @throws TypeError
-     */
-    protected static function xor64(SplFixedArray $x, SplFixedArray $y)
-    {
-        if (!is_numeric($x[0])) {
-            throw new SodiumException('x[0] is not an integer');
-        }
-        if (!is_numeric($x[1])) {
-            throw new SodiumException('x[1] is not an integer');
-        }
-        if (!is_numeric($y[0])) {
-            throw new SodiumException('y[0] is not an integer');
-        }
-        if (!is_numeric($y[1])) {
-            throw new SodiumException('y[1] is not an integer');
-        }
-        return self::new64(
-            (int) (($x[0] ^ $y[0]) & 0xffffffff),
-            (int) (($x[1] ^ $y[1]) & 0xffffffff)
-        );
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @param int $c
-     * @return SplFixedArray
-     * @psalm-suppress MixedAssignment
-     */
-    public static function rotr64($x, $c)
-    {
-        if ($c >= 64) {
-            $c %= 64;
-        }
-        if ($c >= 32) {
-            /** @var int $tmp */
-            $tmp = $x[0];
-            $x[0] = $x[1];
-            $x[1] = $tmp;
-            $c -= 32;
-        }
-        if ($c === 0) {
-            return $x;
-        }
-
-        $l0 = 0;
-        $c = 64 - $c;
-
-        if ($c < 32) {
-            /** @var int $h0 */
-            $h0 = ((int) ($x[0]) << $c) | (
-                (
-                    (int) ($x[1]) & ((1 << $c) - 1)
-                        <<
-                    (32 - $c)
-                ) >> (32 - $c)
-            );
-            /** @var int $l0 */
-            $l0 = (int) ($x[1]) << $c;
-        } else {
-            /** @var int $h0 */
-            $h0 = (int) ($x[1]) << ($c - 32);
-        }
-
-        $h1 = 0;
-        $c1 = 64 - $c;
-
-        if ($c1 < 32) {
-            /** @var int $h1 */
-            $h1 = (int) ($x[0]) >> $c1;
-            /** @var int $l1 */
-            $l1 = ((int) ($x[1]) >> $c1) | ((int) ($x[0]) & ((1 << $c1) - 1)) << (32 - $c1);
-        } else {
-            /** @var int $l1 */
-            $l1 = (int) ($x[0]) >> ($c1 - 32);
-        }
-
-        return self::new64($h0 | $h1, $l0 | $l1);
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @return int
-     * @psalm-suppress MixedOperand
-     */
-    protected static function flatten64($x)
-    {
-        return (int) ($x[0] * 4294967296 + $x[1]);
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @param int $i
-     * @return SplFixedArray
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedArrayOffset
-     */
-    protected static function load64(SplFixedArray $x, $i)
-    {
-        /** @var int $l */
-        $l = (int) ($x[$i])
-             | ((int) ($x[$i+1]) << 8)
-             | ((int) ($x[$i+2]) << 16)
-             | ((int) ($x[$i+3]) << 24);
-        /** @var int $h */
-        $h = (int) ($x[$i+4])
-             | ((int) ($x[$i+5]) << 8)
-             | ((int) ($x[$i+6]) << 16)
-             | ((int) ($x[$i+7]) << 24);
-        return self::new64($h, $l);
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $x
-     * @param int $i
-     * @param SplFixedArray $u
-     * @return void
-     * @psalm-suppress MixedAssignment
-     */
-    protected static function store64(SplFixedArray $x, $i, SplFixedArray $u)
-    {
-        $maxLength = $x->getSize() - 1;
-        for ($j = 0; $j < 8; ++$j) {
-            /*
+	/**
+	 * @var SplFixedArray
+	 */
+	protected static $iv;
+
+	/**
+	 * @var array<int, array<int, int>>
+	 */
+	protected static $sigma = array(
+		array(  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15),
+		array( 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3),
+		array( 11,  8, 12,  0,  5,  2, 15, 13, 10, 14,  3,  6,  7,  1,  9,  4),
+		array(  7,  9,  3,  1, 13, 12, 11, 14,  2,  6,  5, 10,  4,  0, 15,  8),
+		array(  9,  0,  5,  7,  2,  4, 10, 15, 14,  1, 11, 12,  6,  8,  3, 13),
+		array(  2, 12,  6, 10,  0, 11,  8,  3,  4, 13,  7,  5, 15, 14,  1,  9),
+		array( 12,  5,  1, 15, 14, 13,  4, 10,  0,  7,  6,  3,  9,  2,  8, 11),
+		array( 13, 11,  7, 14, 12,  1,  3,  9,  5,  0, 15,  4,  8,  6,  2, 10),
+		array(  6, 15, 14,  9, 11,  3,  0,  8, 12,  2, 13,  7,  1,  4, 10,  5),
+		array( 10,  2,  8,  4,  7,  6,  1,  5, 15, 11,  9, 14,  3, 12, 13 , 0),
+		array(  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15),
+		array( 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3)
+	);
+
+	const BLOCKBYTES = 128;
+	const OUTBYTES   = 64;
+	const KEYBYTES   = 64;
+
+	/**
+	 * Turn two 32-bit integers into a fixed array representing a 64-bit integer.
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param int $high
+	 * @param int $low
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedAssignment
+	 */
+	public static function new64($high, $low)
+	{
+		$i64 = new SplFixedArray(2);
+		$i64[0] = $high & 0xffffffff;
+		$i64[1] = $low & 0xffffffff;
+		return $i64;
+	}
+
+	/**
+	 * Convert an arbitrary number into an SplFixedArray of two 32-bit integers
+	 * that represents a 64-bit integer.
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param int $num
+	 * @return SplFixedArray
+	 */
+	protected static function to64($num)
+	{
+		list($hi, $lo) = self::numericTo64BitInteger($num);
+		return self::new64($hi, $lo);
+	}
+
+	/**
+	 * Adds two 64-bit integers together, returning their sum as a SplFixedArray
+	 * containing two 32-bit integers (representing a 64-bit integer).
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @param SplFixedArray $y
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedOperand
+	 */
+	protected static function add64($x, $y)
+	{
+		$l = ($x[1] + $y[1]) & 0xffffffff;
+		return self::new64(
+			(int) ($x[0] + $y[0] + (
+				($l < $x[1]) ? 1 : 0
+			)),
+			(int) $l
+		);
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @param SplFixedArray $y
+	 * @param SplFixedArray $z
+	 * @return SplFixedArray
+	 */
+	protected static function add364($x, $y, $z)
+	{
+		return self::add64($x, self::add64($y, $z));
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @param SplFixedArray $y
+	 * @return SplFixedArray
+	 * @throws SodiumException
+	 * @throws TypeError
+	 */
+	protected static function xor64(SplFixedArray $x, SplFixedArray $y)
+	{
+		if (!is_numeric($x[0])) {
+			throw new SodiumException('x[0] is not an integer');
+		}
+		if (!is_numeric($x[1])) {
+			throw new SodiumException('x[1] is not an integer');
+		}
+		if (!is_numeric($y[0])) {
+			throw new SodiumException('y[0] is not an integer');
+		}
+		if (!is_numeric($y[1])) {
+			throw new SodiumException('y[1] is not an integer');
+		}
+		return self::new64(
+			(int) (($x[0] ^ $y[0]) & 0xffffffff),
+			(int) (($x[1] ^ $y[1]) & 0xffffffff)
+		);
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @param int $c
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedAssignment
+	 */
+	public static function rotr64($x, $c)
+	{
+		if ($c >= 64) {
+			$c %= 64;
+		}
+		if ($c >= 32) {
+			/** @var int $tmp */
+			$tmp = $x[0];
+			$x[0] = $x[1];
+			$x[1] = $tmp;
+			$c -= 32;
+		}
+		if ($c === 0) {
+			return $x;
+		}
+
+		$l0 = 0;
+		$c = 64 - $c;
+
+		if ($c < 32) {
+			/** @var int $h0 */
+			$h0 = ((int) ($x[0]) << $c) | (
+				(
+					(int) ($x[1]) & ((1 << $c) - 1)
+						<<
+					(32 - $c)
+				) >> (32 - $c)
+			);
+			/** @var int $l0 */
+			$l0 = (int) ($x[1]) << $c;
+		} else {
+			/** @var int $h0 */
+			$h0 = (int) ($x[1]) << ($c - 32);
+		}
+
+		$h1 = 0;
+		$c1 = 64 - $c;
+
+		if ($c1 < 32) {
+			/** @var int $h1 */
+			$h1 = (int) ($x[0]) >> $c1;
+			/** @var int $l1 */
+			$l1 = ((int) ($x[1]) >> $c1) | ((int) ($x[0]) & ((1 << $c1) - 1)) << (32 - $c1);
+		} else {
+			/** @var int $l1 */
+			$l1 = (int) ($x[0]) >> ($c1 - 32);
+		}
+
+		return self::new64($h0 | $h1, $l0 | $l1);
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @return int
+	 * @psalm-suppress MixedOperand
+	 */
+	protected static function flatten64($x)
+	{
+		return (int) ($x[0] * 4294967296 + $x[1]);
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @param int $i
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedArrayOffset
+	 */
+	protected static function load64(SplFixedArray $x, $i)
+	{
+		/** @var int $l */
+		$l = (int) ($x[$i])
+			 | ((int) ($x[$i+1]) << 8)
+			 | ((int) ($x[$i+2]) << 16)
+			 | ((int) ($x[$i+3]) << 24);
+		/** @var int $h */
+		$h = (int) ($x[$i+4])
+			 | ((int) ($x[$i+5]) << 8)
+			 | ((int) ($x[$i+6]) << 16)
+			 | ((int) ($x[$i+7]) << 24);
+		return self::new64($h, $l);
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $x
+	 * @param int $i
+	 * @param SplFixedArray $u
+	 * @return void
+	 * @psalm-suppress MixedAssignment
+	 */
+	protected static function store64(SplFixedArray $x, $i, SplFixedArray $u)
+	{
+		$maxLength = $x->getSize() - 1;
+		for ($j = 0; $j < 8; ++$j) {
+			/*
                [0, 1, 2, 3, 4, 5, 6, 7]
                     ... becomes ...
                [0, 0, 0, 0, 1, 1, 1, 1]
             */
-            /** @var int $uIdx */
-            $uIdx = ((7 - $j) & 4) >> 2;
-            $x[$i]   = ((int) ($u[$uIdx]) & 0xff);
-            if (++$i > $maxLength) {
-                return;
-            }
-            /** @psalm-suppress MixedOperand */
-            $u[$uIdx] >>= 8;
-        }
-    }
-
-    /**
-     * This just sets the $iv static variable.
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @return void
-     */
-    public static function pseudoConstructor()
-    {
-        static $called = false;
-        if ($called) {
-            return;
-        }
-        self::$iv = new SplFixedArray(8);
-        self::$iv[0] = self::new64(0x6a09e667, 0xf3bcc908);
-        self::$iv[1] = self::new64(0xbb67ae85, 0x84caa73b);
-        self::$iv[2] = self::new64(0x3c6ef372, 0xfe94f82b);
-        self::$iv[3] = self::new64(0xa54ff53a, 0x5f1d36f1);
-        self::$iv[4] = self::new64(0x510e527f, 0xade682d1);
-        self::$iv[5] = self::new64(0x9b05688c, 0x2b3e6c1f);
-        self::$iv[6] = self::new64(0x1f83d9ab, 0xfb41bd6b);
-        self::$iv[7] = self::new64(0x5be0cd19, 0x137e2179);
-
-        $called = true;
-    }
-
-    /**
-     * Returns a fresh BLAKE2 context.
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @return SplFixedArray
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     */
-    protected static function context()
-    {
-        $ctx    = new SplFixedArray(6);
-        $ctx[0] = new SplFixedArray(8);   // h
-        $ctx[1] = new SplFixedArray(2);   // t
-        $ctx[2] = new SplFixedArray(2);   // f
-        $ctx[3] = new SplFixedArray(256); // buf
-        $ctx[4] = 0;                      // buflen
-        $ctx[5] = 0;                      // last_node (uint8_t)
-
-        for ($i = 8; $i--;) {
-            $ctx[0][$i] = self::$iv[$i];
-        }
-        for ($i = 256; $i--;) {
-            $ctx[3][$i] = 0;
-        }
-
-        $zero = self::new64(0, 0);
-        $ctx[1][0] = $zero;
-        $ctx[1][1] = $zero;
-        $ctx[2][0] = $zero;
-        $ctx[2][1] = $zero;
-
-        return $ctx;
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $ctx
-     * @param SplFixedArray $buf
-     * @return void
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     * @psalm-suppress MixedArrayOffset
-     */
-    protected static function compress(SplFixedArray $ctx, SplFixedArray $buf)
-    {
-        $m = new SplFixedArray(16);
-        $v = new SplFixedArray(16);
-
-        for ($i = 16; $i--;) {
-            $m[$i] = self::load64($buf, $i << 3);
-        }
-
-        for ($i = 8; $i--;) {
-            $v[$i] = $ctx[0][$i];
-        }
-
-        $v[ 8] = self::$iv[0];
-        $v[ 9] = self::$iv[1];
-        $v[10] = self::$iv[2];
-        $v[11] = self::$iv[3];
-
-        $v[12] = self::xor64($ctx[1][0], self::$iv[4]);
-        $v[13] = self::xor64($ctx[1][1], self::$iv[5]);
-        $v[14] = self::xor64($ctx[2][0], self::$iv[6]);
-        $v[15] = self::xor64($ctx[2][1], self::$iv[7]);
-
-        for ($r = 0; $r < 12; ++$r) {
-            $v = self::G($r, 0, 0, 4, 8, 12, $v, $m);
-            $v = self::G($r, 1, 1, 5, 9, 13, $v, $m);
-            $v = self::G($r, 2, 2, 6, 10, 14, $v, $m);
-            $v = self::G($r, 3, 3, 7, 11, 15, $v, $m);
-            $v = self::G($r, 4, 0, 5, 10, 15, $v, $m);
-            $v = self::G($r, 5, 1, 6, 11, 12, $v, $m);
-            $v = self::G($r, 6, 2, 7, 8, 13, $v, $m);
-            $v = self::G($r, 7, 3, 4, 9, 14, $v, $m);
-        }
-
-        for ($i = 8; $i--;) {
-            $ctx[0][$i] = self::xor64(
-                $ctx[0][$i], self::xor64($v[$i], $v[$i+8])
-            );
-        }
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param int $r
-     * @param int $i
-     * @param int $a
-     * @param int $b
-     * @param int $c
-     * @param int $d
-     * @param SplFixedArray $v
-     * @param SplFixedArray $m
-     * @return SplFixedArray
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedArrayOffset
-     */
-    public static function G($r, $i, $a, $b, $c, $d, SplFixedArray $v, SplFixedArray $m)
-    {
-        $v[$a] = self::add364($v[$a], $v[$b], $m[self::$sigma[$r][$i << 1]]);
-        $v[$d] = self::rotr64(self::xor64($v[$d], $v[$a]), 32);
-        $v[$c] = self::add64($v[$c], $v[$d]);
-        $v[$b] = self::rotr64(self::xor64($v[$b], $v[$c]), 24);
-        $v[$a] = self::add364($v[$a], $v[$b], $m[self::$sigma[$r][($i << 1) + 1]]);
-        $v[$d] = self::rotr64(self::xor64($v[$d], $v[$a]), 16);
-        $v[$c] = self::add64($v[$c], $v[$d]);
-        $v[$b] = self::rotr64(self::xor64($v[$b], $v[$c]), 63);
-        return $v;
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $ctx
-     * @param int $inc
-     * @return void
-     * @throws SodiumException
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     */
-    public static function increment_counter($ctx, $inc)
-    {
-        if ($inc < 0) {
-            throw new SodiumException('Increasing by a negative number makes no sense.');
-        }
-        $t = self::to64($inc);
-        # S->t is $ctx[1] in our implementation
-
-        # S->t[0] = ( uint64_t )( t >> 0 );
-        $ctx[1][0] = self::add64($ctx[1][0], $t);
-
-        # S->t[1] += ( S->t[0] < inc );
-        if (self::flatten64($ctx[1][0]) < $inc) {
-            $ctx[1][1] = self::add64($ctx[1][1], self::to64(1));
-        }
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $ctx
-     * @param SplFixedArray $p
-     * @param int $plen
-     * @return void
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     * @psalm-suppress MixedArrayOffset
-     * @psalm-suppress MixedOperand
-     */
-    public static function update(SplFixedArray $ctx, SplFixedArray $p, $plen)
-    {
-        self::pseudoConstructor();
-
-        $offset = 0;
-        while ($plen > 0) {
-            $left = $ctx[4];
-            $fill = 256 - $left;
-
-            if ($plen > $fill) {
-                # memcpy( S->buf + left, in, fill ); /* Fill buffer */
-                for ($i = $fill; $i--;) {
-                    $ctx[3][$i + $left] = $p[$i + $offset];
-                }
-
-                # S->buflen += fill;
-                $ctx[4] += $fill;
-
-                # blake2b_increment_counter( S, BLAKE2B_BLOCKBYTES );
-                self::increment_counter($ctx, 128);
-
-                # blake2b_compress( S, S->buf ); /* Compress */
-                self::compress($ctx, $ctx[3]);
-
-                # memcpy( S->buf, S->buf + BLAKE2B_BLOCKBYTES, BLAKE2B_BLOCKBYTES ); /* Shift buffer left */
-                for ($i = 128; $i--;) {
-                    $ctx[3][$i] = $ctx[3][$i + 128];
-                }
-
-                # S->buflen -= BLAKE2B_BLOCKBYTES;
-                $ctx[4] -= 128;
-
-                # in += fill;
-                $offset += $fill;
-
-                # inlen -= fill;
-                $plen -= $fill;
-            } else {
-                for ($i = $plen; $i--;) {
-                    $ctx[3][$i + $left] = $p[$i + $offset];
-                }
-                $ctx[4] += $plen;
-                $offset += $plen;
-                $plen -= $plen;
-            }
-        }
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $ctx
-     * @param SplFixedArray $out
-     * @return SplFixedArray
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     * @psalm-suppress MixedArrayOffset
-     * @psalm-suppress MixedOperand
-     */
-    public static function finish(SplFixedArray $ctx, SplFixedArray $out)
-    {
-        self::pseudoConstructor();
-        if ($ctx[4] > 128) {
-            self::increment_counter($ctx, 128);
-            self::compress($ctx, $ctx[3]);
-            $ctx[4] -= 128;
-            if ($ctx[4] > 128) {
-                throw new SodiumException('Failed to assert that buflen <= 128 bytes');
-            }
-            for ($i = $ctx[4]; $i--;) {
-                $ctx[3][$i] = $ctx[3][$i + 128];
-            }
-        }
-
-        self::increment_counter($ctx, $ctx[4]);
-        $ctx[2][0] = self::new64(0xffffffff, 0xffffffff);
-
-        for ($i = 256 - $ctx[4]; $i--;) {
-            $ctx[3][$i+$ctx[4]] = 0;
-        }
-
-        self::compress($ctx, $ctx[3]);
-
-        $i = (int) (($out->getSize() - 1) / 8);
-        for (; $i >= 0; --$i) {
-            self::store64($out, $i << 3, $ctx[0][$i]);
-        }
-        return $out;
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray|null $key
-     * @param int $outlen
-     * @param SplFixedArray|null $salt
-     * @param SplFixedArray|null $personal
-     * @return SplFixedArray
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     * @psalm-suppress MixedArrayOffset
-     */
-    public static function init(
-        $key = null,
-        $outlen = 64,
-        $salt = null,
-        $personal = null
-    ) {
-        self::pseudoConstructor();
-        $klen = 0;
-
-        if ($key !== null) {
-            if (count($key) > 64) {
-                throw new SodiumException('Invalid key size');
-            }
-            $klen = count($key);
-        }
-
-        if ($outlen > 64) {
-            throw new SodiumException('Invalid output size');
-        }
-
-        $ctx = self::context();
-
-        $p = new SplFixedArray(64);
-        // Zero our param buffer...
-        for ($i = 64; --$i;) {
-            $p[$i] = 0;
-        }
-
-        $p[0] = $outlen; // digest_length
-        $p[1] = $klen;   // key_length
-        $p[2] = 1;       // fanout
-        $p[3] = 1;       // depth
-
-        if ($salt instanceof SplFixedArray) {
-            // salt: [32] through [47]
-            for ($i = 0; $i < 16; ++$i) {
-                $p[32 + $i] = (int) $salt[$i];
-            }
-        }
-        if ($personal instanceof SplFixedArray) {
-            // personal: [48] through [63]
-            for ($i = 0; $i < 16; ++$i) {
-                $p[48 + $i] = (int) $personal[$i];
-            }
-        }
-
-        $ctx[0][0] = self::xor64(
-            $ctx[0][0],
-            self::load64($p, 0)
-        );
-        if ($salt instanceof SplFixedArray || $personal instanceof SplFixedArray) {
-            // We need to do what blake2b_init_param() does:
-            for ($i = 1; $i < 8; ++$i) {
-                $ctx[0][$i] = self::xor64(
-                    $ctx[0][$i],
-                    self::load64($p, $i << 3)
-                );
-            }
-        }
-
-        if ($klen > 0 && $key instanceof SplFixedArray) {
-            $block = new SplFixedArray(128);
-            for ($i = 128; $i--;) {
-                $block[$i] = 0;
-            }
-            for ($i = $klen; $i--;) {
-                $block[$i] = $key[$i];
-            }
-            self::update($ctx, $block, 128);
-            $ctx[4] = 128;
-        }
-
-        return $ctx;
-    }
-
-    /**
-     * Convert a string into an SplFixedArray of integers
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @param string $str
-     * @return SplFixedArray
-     * @psalm-suppress MixedArgumentTypeCoercion
-     */
-    public static function stringToSplFixedArray($str = '')
-    {
-        $values = unpack('C*', $str);
-        return SplFixedArray::fromArray(array_values($values));
-    }
-
-    /**
-     * Convert an SplFixedArray of integers into a string
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $a
-     * @return string
-     * @throws TypeError
-     */
-    public static function SplFixedArrayToString(SplFixedArray $a)
-    {
-        /**
-         * @var array<int, int|string> $arr
-         */
-        $arr = $a->toArray();
-        $c = $a->count();
-        array_unshift($arr, str_repeat('C', $c));
-        return (string) (call_user_func_array('pack', $arr));
-    }
-
-    /**
-     * @internal You should not use this directly from another application
-     *
-     * @param SplFixedArray $ctx
-     * @return string
-     * @throws TypeError
-     * @psalm-suppress MixedArgument
-     * @psalm-suppress MixedAssignment
-     * @psalm-suppress MixedArrayAccess
-     * @psalm-suppress MixedArrayAssignment
-     * @psalm-suppress MixedArrayOffset
-     * @psalm-suppress MixedMethodCall
-     */
-    public static function contextToString(SplFixedArray $ctx)
-    {
-        $str = '';
-        /** @var array<int, array<int, int>> $ctxA */
-        $ctxA = $ctx[0]->toArray();
-
-        # uint64_t h[8];
-        for ($i = 0; $i < 8; ++$i) {
-            $str .= self::store32_le($ctxA[$i][1]);
-            $str .= self::store32_le($ctxA[$i][0]);
-        }
-
-        # uint64_t t[2];
-        # uint64_t f[2];
-        for ($i = 1; $i < 3; ++$i) {
-            $ctxA = $ctx[$i]->toArray();
-            $str .= self::store32_le($ctxA[0][1]);
-            $str .= self::store32_le($ctxA[0][0]);
-            $str .= self::store32_le($ctxA[1][1]);
-            $str .= self::store32_le($ctxA[1][0]);
-        }
-
-        # uint8_t buf[2 * 128];
-        $str .= self::SplFixedArrayToString($ctx[3]);
-
-        /** @var int $ctx4 */
-        $ctx4 = (int) $ctx[4];
-
-        # size_t buflen;
-        $str .= implode('', array(
-            self::intToChr($ctx4 & 0xff),
-            self::intToChr(($ctx4 >> 8) & 0xff),
-            self::intToChr(($ctx4 >> 16) & 0xff),
-            self::intToChr(($ctx4 >> 24) & 0xff),
-            self::intToChr(($ctx4 >> 32) & 0xff),
-            self::intToChr(($ctx4 >> 40) & 0xff),
-            self::intToChr(($ctx4 >> 48) & 0xff),
-            self::intToChr(($ctx4 >> 56) & 0xff)
-        ));
-        # uint8_t last_node;
-        return $str . self::intToChr($ctx[5]) . str_repeat("\x00", 23);
-    }
-
-    /**
-     * Creates an SplFixedArray containing other SplFixedArray elements, from
-     * a string (compatible with \Sodium\crypto_generichash_{init, update, final})
-     *
-     * @internal You should not use this directly from another application
-     *
-     * @param string $string
-     * @return SplFixedArray
-     * @throws SodiumException
-     * @throws TypeError
-     * @psalm-suppress MixedArrayAssignment
-     */
-    public static function stringToContext($string)
-    {
-        $ctx = self::context();
-
-        # uint64_t h[8];
-        for ($i = 0; $i < 8; ++$i) {
-            $ctx[0][$i] = SplFixedArray::fromArray(
-                array(
-                    self::load_4(
-                        self::substr($string, (($i << 3) + 4), 4)
-                    ),
-                    self::load_4(
-                        self::substr($string, (($i << 3) + 0), 4)
-                    )
-                )
-            );
-        }
-
-        # uint64_t t[2];
-        # uint64_t f[2];
-        for ($i = 1; $i < 3; ++$i) {
-            $ctx[$i][1] = SplFixedArray::fromArray(
-                array(
-                    self::load_4(self::substr($string, 76 + (($i - 1) << 4), 4)),
-                    self::load_4(self::substr($string, 72 + (($i - 1) << 4), 4))
-                )
-            );
-            $ctx[$i][0] = SplFixedArray::fromArray(
-                array(
-                    self::load_4(self::substr($string, 68 + (($i - 1) << 4), 4)),
-                    self::load_4(self::substr($string, 64 + (($i - 1) << 4), 4))
-                )
-            );
-        }
-
-        # uint8_t buf[2 * 128];
-        $ctx[3] = self::stringToSplFixedArray(self::substr($string, 96, 256));
-
-        # uint8_t buf[2 * 128];
-        $int = 0;
-        for ($i = 0; $i < 8; ++$i) {
-            $int |= self::chrToInt($string[352 + $i]) << ($i << 3);
-        }
-        $ctx[4] = $int;
-
-        return $ctx;
-    }
+			/** @var int $uIdx */
+			$uIdx = ((7 - $j) & 4) >> 2;
+			$x[$i]   = ((int) ($u[$uIdx]) & 0xff);
+			if (++$i > $maxLength) {
+				return;
+			}
+			/** @psalm-suppress MixedOperand */
+			$u[$uIdx] >>= 8;
+		}
+	}
+
+	/**
+	 * This just sets the $iv static variable.
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @return void
+	 */
+	public static function pseudoConstructor()
+	{
+		static $called = false;
+		if ($called) {
+			return;
+		}
+		self::$iv = new SplFixedArray(8);
+		self::$iv[0] = self::new64(0x6a09e667, 0xf3bcc908);
+		self::$iv[1] = self::new64(0xbb67ae85, 0x84caa73b);
+		self::$iv[2] = self::new64(0x3c6ef372, 0xfe94f82b);
+		self::$iv[3] = self::new64(0xa54ff53a, 0x5f1d36f1);
+		self::$iv[4] = self::new64(0x510e527f, 0xade682d1);
+		self::$iv[5] = self::new64(0x9b05688c, 0x2b3e6c1f);
+		self::$iv[6] = self::new64(0x1f83d9ab, 0xfb41bd6b);
+		self::$iv[7] = self::new64(0x5be0cd19, 0x137e2179);
+
+		$called = true;
+	}
+
+	/**
+	 * Returns a fresh BLAKE2 context.
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 */
+	protected static function context()
+	{
+		$ctx    = new SplFixedArray(6);
+		$ctx[0] = new SplFixedArray(8);   // h
+		$ctx[1] = new SplFixedArray(2);   // t
+		$ctx[2] = new SplFixedArray(2);   // f
+		$ctx[3] = new SplFixedArray(256); // buf
+		$ctx[4] = 0;                      // buflen
+		$ctx[5] = 0;                      // last_node (uint8_t)
+
+		for ($i = 8; $i--;) {
+			$ctx[0][$i] = self::$iv[$i];
+		}
+		for ($i = 256; $i--;) {
+			$ctx[3][$i] = 0;
+		}
+
+		$zero = self::new64(0, 0);
+		$ctx[1][0] = $zero;
+		$ctx[1][1] = $zero;
+		$ctx[2][0] = $zero;
+		$ctx[2][1] = $zero;
+
+		return $ctx;
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $ctx
+	 * @param SplFixedArray $buf
+	 * @return void
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 * @psalm-suppress MixedArrayOffset
+	 */
+	protected static function compress(SplFixedArray $ctx, SplFixedArray $buf)
+	{
+		$m = new SplFixedArray(16);
+		$v = new SplFixedArray(16);
+
+		for ($i = 16; $i--;) {
+			$m[$i] = self::load64($buf, $i << 3);
+		}
+
+		for ($i = 8; $i--;) {
+			$v[$i] = $ctx[0][$i];
+		}
+
+		$v[ 8] = self::$iv[0];
+		$v[ 9] = self::$iv[1];
+		$v[10] = self::$iv[2];
+		$v[11] = self::$iv[3];
+
+		$v[12] = self::xor64($ctx[1][0], self::$iv[4]);
+		$v[13] = self::xor64($ctx[1][1], self::$iv[5]);
+		$v[14] = self::xor64($ctx[2][0], self::$iv[6]);
+		$v[15] = self::xor64($ctx[2][1], self::$iv[7]);
+
+		for ($r = 0; $r < 12; ++$r) {
+			$v = self::G($r, 0, 0, 4, 8, 12, $v, $m);
+			$v = self::G($r, 1, 1, 5, 9, 13, $v, $m);
+			$v = self::G($r, 2, 2, 6, 10, 14, $v, $m);
+			$v = self::G($r, 3, 3, 7, 11, 15, $v, $m);
+			$v = self::G($r, 4, 0, 5, 10, 15, $v, $m);
+			$v = self::G($r, 5, 1, 6, 11, 12, $v, $m);
+			$v = self::G($r, 6, 2, 7, 8, 13, $v, $m);
+			$v = self::G($r, 7, 3, 4, 9, 14, $v, $m);
+		}
+
+		for ($i = 8; $i--;) {
+			$ctx[0][$i] = self::xor64(
+				$ctx[0][$i], self::xor64($v[$i], $v[$i+8])
+			);
+		}
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param int $r
+	 * @param int $i
+	 * @param int $a
+	 * @param int $b
+	 * @param int $c
+	 * @param int $d
+	 * @param SplFixedArray $v
+	 * @param SplFixedArray $m
+	 * @return SplFixedArray
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedArrayOffset
+	 */
+	public static function G($r, $i, $a, $b, $c, $d, SplFixedArray $v, SplFixedArray $m)
+	{
+		$v[$a] = self::add364($v[$a], $v[$b], $m[self::$sigma[$r][$i << 1]]);
+		$v[$d] = self::rotr64(self::xor64($v[$d], $v[$a]), 32);
+		$v[$c] = self::add64($v[$c], $v[$d]);
+		$v[$b] = self::rotr64(self::xor64($v[$b], $v[$c]), 24);
+		$v[$a] = self::add364($v[$a], $v[$b], $m[self::$sigma[$r][($i << 1) + 1]]);
+		$v[$d] = self::rotr64(self::xor64($v[$d], $v[$a]), 16);
+		$v[$c] = self::add64($v[$c], $v[$d]);
+		$v[$b] = self::rotr64(self::xor64($v[$b], $v[$c]), 63);
+		return $v;
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $ctx
+	 * @param int $inc
+	 * @return void
+	 * @throws SodiumException
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 */
+	public static function increment_counter($ctx, $inc)
+	{
+		if ($inc < 0) {
+			throw new SodiumException('Increasing by a negative number makes no sense.');
+		}
+		$t = self::to64($inc);
+		# S->t is $ctx[1] in our implementation
+
+		# S->t[0] = ( uint64_t )( t >> 0 );
+		$ctx[1][0] = self::add64($ctx[1][0], $t);
+
+		# S->t[1] += ( S->t[0] < inc );
+		if (self::flatten64($ctx[1][0]) < $inc) {
+			$ctx[1][1] = self::add64($ctx[1][1], self::to64(1));
+		}
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $ctx
+	 * @param SplFixedArray $p
+	 * @param int $plen
+	 * @return void
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 * @psalm-suppress MixedArrayOffset
+	 * @psalm-suppress MixedOperand
+	 */
+	public static function update(SplFixedArray $ctx, SplFixedArray $p, $plen)
+	{
+		self::pseudoConstructor();
+
+		$offset = 0;
+		while ($plen > 0) {
+			$left = $ctx[4];
+			$fill = 256 - $left;
+
+			if ($plen > $fill) {
+				# memcpy( S->buf + left, in, fill ); /* Fill buffer */
+				for ($i = $fill; $i--;) {
+					$ctx[3][$i + $left] = $p[$i + $offset];
+				}
+
+				# S->buflen += fill;
+				$ctx[4] += $fill;
+
+				# blake2b_increment_counter( S, BLAKE2B_BLOCKBYTES );
+				self::increment_counter($ctx, 128);
+
+				# blake2b_compress( S, S->buf ); /* Compress */
+				self::compress($ctx, $ctx[3]);
+
+				# memcpy( S->buf, S->buf + BLAKE2B_BLOCKBYTES, BLAKE2B_BLOCKBYTES ); /* Shift buffer left */
+				for ($i = 128; $i--;) {
+					$ctx[3][$i] = $ctx[3][$i + 128];
+				}
+
+				# S->buflen -= BLAKE2B_BLOCKBYTES;
+				$ctx[4] -= 128;
+
+				# in += fill;
+				$offset += $fill;
+
+				# inlen -= fill;
+				$plen -= $fill;
+			} else {
+				for ($i = $plen; $i--;) {
+					$ctx[3][$i + $left] = $p[$i + $offset];
+				}
+				$ctx[4] += $plen;
+				$offset += $plen;
+				$plen -= $plen;
+			}
+		}
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $ctx
+	 * @param SplFixedArray $out
+	 * @return SplFixedArray
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 * @psalm-suppress MixedArrayOffset
+	 * @psalm-suppress MixedOperand
+	 */
+	public static function finish(SplFixedArray $ctx, SplFixedArray $out)
+	{
+		self::pseudoConstructor();
+		if ($ctx[4] > 128) {
+			self::increment_counter($ctx, 128);
+			self::compress($ctx, $ctx[3]);
+			$ctx[4] -= 128;
+			if ($ctx[4] > 128) {
+				throw new SodiumException('Failed to assert that buflen <= 128 bytes');
+			}
+			for ($i = $ctx[4]; $i--;) {
+				$ctx[3][$i] = $ctx[3][$i + 128];
+			}
+		}
+
+		self::increment_counter($ctx, $ctx[4]);
+		$ctx[2][0] = self::new64(0xffffffff, 0xffffffff);
+
+		for ($i = 256 - $ctx[4]; $i--;) {
+			$ctx[3][$i+$ctx[4]] = 0;
+		}
+
+		self::compress($ctx, $ctx[3]);
+
+		$i = (int) (($out->getSize() - 1) / 8);
+		for (; $i >= 0; --$i) {
+			self::store64($out, $i << 3, $ctx[0][$i]);
+		}
+		return $out;
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray|null $key
+	 * @param int $outlen
+	 * @param SplFixedArray|null $salt
+	 * @param SplFixedArray|null $personal
+	 * @return SplFixedArray
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 * @psalm-suppress MixedArrayOffset
+	 */
+	public static function init(
+		$key = null,
+		$outlen = 64,
+		$salt = null,
+		$personal = null
+	) {
+		self::pseudoConstructor();
+		$klen = 0;
+
+		if ($key !== null) {
+			if (count($key) > 64) {
+				throw new SodiumException('Invalid key size');
+			}
+			$klen = count($key);
+		}
+
+		if ($outlen > 64) {
+			throw new SodiumException('Invalid output size');
+		}
+
+		$ctx = self::context();
+
+		$p = new SplFixedArray(64);
+		// Zero our param buffer...
+		for ($i = 64; --$i;) {
+			$p[$i] = 0;
+		}
+
+		$p[0] = $outlen; // digest_length
+		$p[1] = $klen;   // key_length
+		$p[2] = 1;       // fanout
+		$p[3] = 1;       // depth
+
+		if ($salt instanceof SplFixedArray) {
+			// salt: [32] through [47]
+			for ($i = 0; $i < 16; ++$i) {
+				$p[32 + $i] = (int) $salt[$i];
+			}
+		}
+		if ($personal instanceof SplFixedArray) {
+			// personal: [48] through [63]
+			for ($i = 0; $i < 16; ++$i) {
+				$p[48 + $i] = (int) $personal[$i];
+			}
+		}
+
+		$ctx[0][0] = self::xor64(
+			$ctx[0][0],
+			self::load64($p, 0)
+		);
+		if ($salt instanceof SplFixedArray || $personal instanceof SplFixedArray) {
+			// We need to do what blake2b_init_param() does:
+			for ($i = 1; $i < 8; ++$i) {
+				$ctx[0][$i] = self::xor64(
+					$ctx[0][$i],
+					self::load64($p, $i << 3)
+				);
+			}
+		}
+
+		if ($klen > 0 && $key instanceof SplFixedArray) {
+			$block = new SplFixedArray(128);
+			for ($i = 128; $i--;) {
+				$block[$i] = 0;
+			}
+			for ($i = $klen; $i--;) {
+				$block[$i] = $key[$i];
+			}
+			self::update($ctx, $block, 128);
+			$ctx[4] = 128;
+		}
+
+		return $ctx;
+	}
+
+	/**
+	 * Convert a string into an SplFixedArray of integers
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param string $str
+	 * @return SplFixedArray
+	 * @psalm-suppress MixedArgumentTypeCoercion
+	 */
+	public static function stringToSplFixedArray($str = '')
+	{
+		$values = unpack('C*', $str);
+		return SplFixedArray::fromArray(array_values($values));
+	}
+
+	/**
+	 * Convert an SplFixedArray of integers into a string
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $a
+	 * @return string
+	 * @throws TypeError
+	 */
+	public static function SplFixedArrayToString(SplFixedArray $a)
+	{
+		/**
+		 * @var array<int, int|string> $arr
+		 */
+		$arr = $a->toArray();
+		$c = $a->count();
+		array_unshift($arr, str_repeat('C', $c));
+		return (string) (call_user_func_array('pack', $arr));
+	}
+
+	/**
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param SplFixedArray $ctx
+	 * @return string
+	 * @throws TypeError
+	 * @psalm-suppress MixedArgument
+	 * @psalm-suppress MixedAssignment
+	 * @psalm-suppress MixedArrayAccess
+	 * @psalm-suppress MixedArrayAssignment
+	 * @psalm-suppress MixedArrayOffset
+	 * @psalm-suppress MixedMethodCall
+	 */
+	public static function contextToString(SplFixedArray $ctx)
+	{
+		$str = '';
+		/** @var array<int, array<int, int>> $ctxA */
+		$ctxA = $ctx[0]->toArray();
+
+		# uint64_t h[8];
+		for ($i = 0; $i < 8; ++$i) {
+			$str .= self::store32_le($ctxA[$i][1]);
+			$str .= self::store32_le($ctxA[$i][0]);
+		}
+
+		# uint64_t t[2];
+		# uint64_t f[2];
+		for ($i = 1; $i < 3; ++$i) {
+			$ctxA = $ctx[$i]->toArray();
+			$str .= self::store32_le($ctxA[0][1]);
+			$str .= self::store32_le($ctxA[0][0]);
+			$str .= self::store32_le($ctxA[1][1]);
+			$str .= self::store32_le($ctxA[1][0]);
+		}
+
+		# uint8_t buf[2 * 128];
+		$str .= self::SplFixedArrayToString($ctx[3]);
+
+		/** @var int $ctx4 */
+		$ctx4 = (int) $ctx[4];
+
+		# size_t buflen;
+		$str .= implode('', array(
+			self::intToChr($ctx4 & 0xff),
+			self::intToChr(($ctx4 >> 8) & 0xff),
+			self::intToChr(($ctx4 >> 16) & 0xff),
+			self::intToChr(($ctx4 >> 24) & 0xff),
+			self::intToChr(($ctx4 >> 32) & 0xff),
+			self::intToChr(($ctx4 >> 40) & 0xff),
+			self::intToChr(($ctx4 >> 48) & 0xff),
+			self::intToChr(($ctx4 >> 56) & 0xff)
+		));
+		# uint8_t last_node;
+		return $str . self::intToChr($ctx[5]) . str_repeat("\x00", 23);
+	}
+
+	/**
+	 * Creates an SplFixedArray containing other SplFixedArray elements, from
+	 * a string (compatible with \Sodium\crypto_generichash_{init, update, final})
+	 *
+	 * @internal You should not use this directly from another application
+	 *
+	 * @param string $string
+	 * @return SplFixedArray
+	 * @throws SodiumException
+	 * @throws TypeError
+	 * @psalm-suppress MixedArrayAssignment
+	 */
+	public static function stringToContext($string)
+	{
+		$ctx = self::context();
+
+		# uint64_t h[8];
+		for ($i = 0; $i < 8; ++$i) {
+			$ctx[0][$i] = SplFixedArray::fromArray(
+				array(
+					self::load_4(
+						self::substr($string, (($i << 3) + 4), 4)
+					),
+					self::load_4(
+						self::substr($string, (($i << 3) + 0), 4)
+					)
+				)
+			);
+		}
+
+		# uint64_t t[2];
+		# uint64_t f[2];
+		for ($i = 1; $i < 3; ++$i) {
+			$ctx[$i][1] = SplFixedArray::fromArray(
+				array(
+					self::load_4(self::substr($string, 76 + (($i - 1) << 4), 4)),
+					self::load_4(self::substr($string, 72 + (($i - 1) << 4), 4))
+				)
+			);
+			$ctx[$i][0] = SplFixedArray::fromArray(
+				array(
+					self::load_4(self::substr($string, 68 + (($i - 1) << 4), 4)),
+					self::load_4(self::substr($string, 64 + (($i - 1) << 4), 4))
+				)
+			);
+		}
+
+		# uint8_t buf[2 * 128];
+		$ctx[3] = self::stringToSplFixedArray(self::substr($string, 96, 256));
+
+		# uint8_t buf[2 * 128];
+		$int = 0;
+		for ($i = 0; $i < 8; ++$i) {
+			$int |= self::chrToInt($string[352 + $i]) << ($i << 3);
+		}
+		$ctx[4] = $int;
+
+		return $ctx;
+	}
 }