WordPoints / wordpoints

     * @param string $key

     * @return string

     */

    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 (Error $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)

     * @param string $key

     * @return string

     */

    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 (Error $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)