JWT::decode() - Code Metrics - XOOPS/XoopsCore27 - Measure and Improve Code Quality continuously with Scrutinizer

JWT::decode() F
last analyzed 2025-09-22 08:00 UTC

↳ Parent: JWT

Complexity

Conditions	22
Paths	122

Size

Total Lines	86
Code Lines	46

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	22
eloc	46
nc	122
nop	3
dl	0
loc	86
rs	3.9833
c	0
b	0
f	0

How to fix Long Method Complexity

<?php

namespace Firebase\JWT;

use ArrayAccess;
use DateTime;
use DomainException;
use Exception;
use InvalidArgumentException;
use OpenSSLAsymmetricKey;
use OpenSSLCertificate;
use stdClass;
use UnexpectedValueException;

/**
 * JSON Web Token implementation, based on this spec:
 * https://tools.ietf.org/html/rfc7519
 *
 * PHP version 5
 *
 * @category Authentication
 * @package  Authentication_JWT
 * @author   Neuman Vong <[email protected]>
 * @author   Anant Narayanan <[email protected]>
 * @license  http://opensource.org/licenses/BSD-3-Clause 3-clause BSD
 * @link     https://github.com/firebase/php-jwt
 */
class JWT
{
    private const ASN1_INTEGER = 0x02;
    private const ASN1_SEQUENCE = 0x10;
    private const ASN1_BIT_STRING = 0x03;

    /**
     * When checking nbf, iat or expiration times,
     * we want to provide some extra leeway time to
     * account for clock skew.
     *
     * @var int
     */
    public static $leeway = 0;

    /**
     * Allow the current timestamp to be specified.
     * Useful for fixing a value within unit testing.
     * Will default to PHP time() value if null.
     *
     * @var ?int
     */
    public static $timestamp = null;

    /**
     * @var array<string, string[]>
     */
    public static $supported_algs = [
        'ES384' => ['openssl', 'SHA384'],
        'ES256' => ['openssl', 'SHA256'],
        'ES256K' => ['openssl', 'SHA256'],
        'HS256' => ['hash_hmac', 'SHA256'],
        'HS384' => ['hash_hmac', 'SHA384'],
        'HS512' => ['hash_hmac', 'SHA512'],
        'RS256' => ['openssl', 'SHA256'],
        'RS384' => ['openssl', 'SHA384'],
        'RS512' => ['openssl', 'SHA512'],
        'EdDSA' => ['sodium_crypto', 'EdDSA'],
    ];

    /**
     * Decodes a JWT string into a PHP object.
     *
     * @param string                 $jwt            The JWT
     * @param Key|ArrayAccess<string,Key>|array<string,Key> $keyOrKeyArray  The Key or associative array of key IDs
     *                                                                      (kid) to Key objects.
     *                                                                      If the algorithm used is asymmetric, this is
     *                                                                      the public key.
     *                                                                      Each Key object contains an algorithm and
     *                                                                      matching key.
     *                                                                      Supported algorithms are 'ES384','ES256',
     *                                                                      'HS256', 'HS384', 'HS512', 'RS256', 'RS384'
     *                                                                      and 'RS512'.
     * @param stdClass               $headers                               Optional. Populates stdClass with headers.
     *
     * @return stdClass The JWT's payload as a PHP object
     *
     * @throws InvalidArgumentException     Provided key/key-array was empty or malformed
     * @throws DomainException              Provided JWT is malformed
     * @throws UnexpectedValueException     Provided JWT was invalid
     * @throws SignatureInvalidException    Provided JWT was invalid because the signature verification failed
     * @throws BeforeValidException         Provided JWT is trying to be used before it's eligible as defined by 'nbf'
     * @throws BeforeValidException         Provided JWT is trying to be used before it's been created as defined by 'iat'
     * @throws ExpiredException             Provided JWT has since expired, as defined by the 'exp' claim
     *
     * @uses jsonDecode
     * @uses urlsafeB64Decode
     */
    public static function decode(
        string $jwt,
        $keyOrKeyArray,
        ?stdClass &$headers = null
    ): stdClass {
        // Validate JWT
        $timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp;

        if (empty($keyOrKeyArray)) {
            throw new InvalidArgumentException('Key may not be empty');
        }
        $tks = \explode('.', $jwt);
        if (\count($tks) !== 3) {
            throw new UnexpectedValueException('Wrong number of segments');
        }
        list($headb64, $bodyb64, $cryptob64) = $tks;
        $headerRaw = static::urlsafeB64Decode($headb64);
        if (null === ($header = static::jsonDecode($headerRaw))) {
            throw new UnexpectedValueException('Invalid header encoding');
        }
        if ($headers !== null) {
            $headers = $header;
        }
        $payloadRaw = static::urlsafeB64Decode($bodyb64);
        if (null === ($payload = static::jsonDecode($payloadRaw))) {
            throw new UnexpectedValueException('Invalid claims encoding');
        }
        if (\is_array($payload)) {
            // prevent PHP Fatal Error in edge-cases when payload is empty array
            $payload = (object) $payload;
        }
        if (!$payload instanceof stdClass) {
            throw new UnexpectedValueException('Payload must be a JSON object');
        }
        $sig = static::urlsafeB64Decode($cryptob64);
        if (empty($header->alg)) {
            throw new UnexpectedValueException('Empty algorithm');
        }
        if (empty(static::$supported_algs[$header->alg])) {
            throw new UnexpectedValueException('Algorithm not supported');
        }

        $key = self::getKey($keyOrKeyArray, property_exists($header, 'kid') ? $header->kid : null);

        // Check the algorithm
        if (!self::constantTimeEquals($key->getAlgorithm(), $header->alg)) {
            // See issue #351
            throw new UnexpectedValueException('Incorrect key for this algorithm');
        }
        if (\in_array($header->alg, ['ES256', 'ES256K', 'ES384'], true)) {
            // OpenSSL expects an ASN.1 DER sequence for ES256/ES256K/ES384 signatures
            $sig = self::signatureToDER($sig);
        }
        if (!self::verify("{$headb64}.{$bodyb64}", $sig, $key->getKeyMaterial(), $header->alg)) {
            throw new SignatureInvalidException('Signature verification failed');
        }

        // Check the nbf if it is defined. This is the time that the
        // token can actually be used. If it's not yet that time, abort.
        if (isset($payload->nbf) && floor($payload->nbf) > ($timestamp + static::$leeway)) {
            $ex = new BeforeValidException(
                'Cannot handle token with nbf prior to ' . \date(DateTime::ISO8601, (int) $payload->nbf)
            );
            $ex->setPayload($payload);
            throw $ex;
        }

        // Check that this token has been created before 'now'. This prevents
        // using tokens that have been created for later use (and haven't
        // correctly used the nbf claim).
        if (!isset($payload->nbf) && isset($payload->iat) && floor($payload->iat) > ($timestamp + static::$leeway)) {
            $ex = new BeforeValidException(
                'Cannot handle token with iat prior to ' . \date(DateTime::ISO8601, (int) $payload->iat)
            );
            $ex->setPayload($payload);
            throw $ex;
        }

        // Check if this token has expired.
        if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) {
            $ex = new ExpiredException('Expired token');
            $ex->setPayload($payload);
            throw $ex;
        }

        return $payload;
    }

    /**
     * Converts and signs a PHP array into a JWT string.
     *
     * @param array<mixed>          $payload PHP array
     * @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $key The secret key.
     * @param string                $alg     Supported algorithms are 'ES384','ES256', 'ES256K', 'HS256',
     *                                       'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
     * @param string                $keyId
     * @param array<string, string> $head    An array with header elements to attach
     *
     * @return string A signed JWT
     *
     * @uses jsonEncode
     * @uses urlsafeB64Encode
     */
    public static function encode(
        array $payload,
        $key,
        string $alg,
        ?string $keyId = null,
        ?array $head = null
    ): string {
        $header = ['typ' => 'JWT'];
        if (isset($head)) {
            $header = \array_merge($header, $head);
        }
        $header['alg'] = $alg;
        if ($keyId !== null) {
            $header['kid'] = $keyId;
        }
        $segments = [];
        $segments[] = static::urlsafeB64Encode((string) static::jsonEncode($header));
        $segments[] = static::urlsafeB64Encode((string) static::jsonEncode($payload));
        $signing_input = \implode('.', $segments);

        $signature = static::sign($signing_input, $key, $alg);
        $segments[] = static::urlsafeB64Encode($signature);

        return \implode('.', $segments);
    }

    /**
     * Sign a string with a given key and algorithm.
     *
     * @param string $msg  The message to sign
     * @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate  $key  The secret key.
     * @param string $alg  Supported algorithms are 'EdDSA', 'ES384', 'ES256', 'ES256K', 'HS256',
     *                    'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
     *
     * @return string An encrypted message
     *
     * @throws DomainException Unsupported algorithm or bad key was specified
     */
    public static function sign(
        string $msg,
        $key,
        string $alg
    ): string {
        if (empty(static::$supported_algs[$alg])) {
            throw new DomainException('Algorithm not supported');
        }
        list($function, $algorithm) = static::$supported_algs[$alg];
        switch ($function) {
            case 'hash_hmac':
                if (!\is_string($key)) {
                    throw new InvalidArgumentException('key must be a string when using hmac');
                }
                return \hash_hmac($algorithm, $msg, $key, true);
            case 'openssl':
                $signature = '';
                if (!\is_resource($key) && !openssl_pkey_get_private($key)) {
                    throw new DomainException('OpenSSL unable to validate key');
                }
                $success = \openssl_sign($msg, $signature, $key, $algorithm); // @phpstan-ignore-line
                if (!$success) {
                    throw new DomainException('OpenSSL unable to sign data');
                }
                if ($alg === 'ES256' || $alg === 'ES256K') {
                    $signature = self::signatureFromDER($signature, 256);
                } elseif ($alg === 'ES384') {
                    $signature = self::signatureFromDER($signature, 384);
                }
                return $signature;
            case 'sodium_crypto':
                if (!\function_exists('sodium_crypto_sign_detached')) {
                    throw new DomainException('libsodium is not available');
                }
                if (!\is_string($key)) {
                    throw new InvalidArgumentException('key must be a string when using EdDSA');
                }
                try {
                    // The last non-empty line is used as the key.
                    $lines = array_filter(explode("\n", $key));
                    $key = base64_decode((string) end($lines));
                    if (\strlen($key) === 0) {
                        throw new DomainException('Key cannot be empty string');
                    }
                    return sodium_crypto_sign_detached($msg, $key);
                } catch (Exception $e) {
                    throw new DomainException($e->getMessage(), 0, $e);
                }
        }

        throw new DomainException('Algorithm not supported');
    }

    /**
     * Verify a signature with the message, key and method. Not all methods
     * are symmetric, so we must have a separate verify and sign method.
     *
     * @param string $msg         The original message (header and body)
     * @param string $signature   The original signature
     * @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate  $keyMaterial For Ed*, ES*, HS*, a string key works. for RS*, must be an instance of OpenSSLAsymmetricKey
     * @param string $alg         The algorithm
     *
     * @return bool
     *
     * @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure
     */
    private static function verify(
        string $msg,
        string $signature,
        $keyMaterial,
        string $alg
    ): bool {
        if (empty(static::$supported_algs[$alg])) {
            throw new DomainException('Algorithm not supported');
        }

        list($function, $algorithm) = static::$supported_algs[$alg];
        switch ($function) {
            case 'openssl':
                $success = \openssl_verify($msg, $signature, $keyMaterial, $algorithm); // @phpstan-ignore-line
                if ($success === 1) {
                    return true;
                }
                if ($success === 0) {
                    return false;
                }
                // returns 1 on success, 0 on failure, -1 on error.
                throw new DomainException(
                    'OpenSSL error: ' . \openssl_error_string()
                );
            case 'sodium_crypto':
                if (!\function_exists('sodium_crypto_sign_verify_detached')) {
                    throw new DomainException('libsodium is not available');
                }
                if (!\is_string($keyMaterial)) {
                    throw new InvalidArgumentException('key must be a string when using EdDSA');
                }
                try {
                    // The last non-empty line is used as the key.
                    $lines = array_filter(explode("\n", $keyMaterial));
                    $key = base64_decode((string) end($lines));
                    if (\strlen($key) === 0) {
                        throw new DomainException('Key cannot be empty string');
                    }
                    if (\strlen($signature) === 0) {
                        throw new DomainException('Signature cannot be empty string');
                    }
                    return sodium_crypto_sign_verify_detached($signature, $msg, $key);
                } catch (Exception $e) {
                    throw new DomainException($e->getMessage(), 0, $e);
                }
            case 'hash_hmac':
            default:
                if (!\is_string($keyMaterial)) {
                    throw new InvalidArgumentException('key must be a string when using hmac');
                }
                $hash = \hash_hmac($algorithm, $msg, $keyMaterial, true);
                return self::constantTimeEquals($hash, $signature);
        }
    }

    /**
     * Decode a JSON string into a PHP object.
     *
     * @param string $input JSON string
     *
     * @return mixed The decoded JSON string
     *
     * @throws DomainException Provided string was invalid JSON
     */
    public static function jsonDecode(string $input)
    {
        $obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING);

        if ($errno = \json_last_error()) {
            self::handleJsonError($errno);
        } elseif ($obj === null && $input !== 'null') {
            throw new DomainException('Null result with non-null input');
        }
        return $obj;
    }

    /**
     * Encode a PHP array into a JSON string.
     *
     * @param array<mixed> $input A PHP array
     *
     * @return string JSON representation of the PHP array
     *
     * @throws DomainException Provided object could not be encoded to valid JSON
     */
    public static function jsonEncode(array $input): string
    {
        $json = \json_encode($input, \JSON_UNESCAPED_SLASHES);
        if ($errno = \json_last_error()) {
            self::handleJsonError($errno);
        } elseif ($json === 'null') {
            throw new DomainException('Null result with non-null input');
        }
        if ($json === false) {
            throw new DomainException('Provided object could not be encoded to valid JSON');
        }
        return $json;
    }

    /**
     * Decode a string with URL-safe Base64.
     *
     * @param string $input A Base64 encoded string
     *
     * @return string A decoded string
     *
     * @throws InvalidArgumentException invalid base64 characters
     */
    public static function urlsafeB64Decode(string $input): string
    {
        return \base64_decode(self::convertBase64UrlToBase64($input));
    }

    /**
     * Convert a string in the base64url (URL-safe Base64) encoding to standard base64.
     *
     * @param string $input A Base64 encoded string with URL-safe characters (-_ and no padding)
     *
     * @return string A Base64 encoded string with standard characters (+/) and padding (=), when
     * needed.
     *
     * @see https://www.rfc-editor.org/rfc/rfc4648
     */
    public static function convertBase64UrlToBase64(string $input): string
    {
        $remainder = \strlen($input) % 4;
        if ($remainder) {
            $padlen = 4 - $remainder;
            $input .= \str_repeat('=', $padlen);
        }
        return \strtr($input, '-_', '+/');
    }

    /**
     * Encode a string with URL-safe Base64.
     *
     * @param string $input The string you want encoded
     *
     * @return string The base64 encode of what you passed in
     */
    public static function urlsafeB64Encode(string $input): string
    {
        return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_'));
    }


    /**
     * Determine if an algorithm has been provided for each Key
     *
     * @param Key|ArrayAccess<string,Key>|array<string,Key> $keyOrKeyArray
     * @param string|null            $kid
     *
     * @throws UnexpectedValueException
     *
     * @return Key
     */
    private static function getKey(
        $keyOrKeyArray,
        ?string $kid
    ): Key {
        if ($keyOrKeyArray instanceof Key) {
            return $keyOrKeyArray;
        }

        if (empty($kid) && $kid !== '0') {
            throw new UnexpectedValueException('"kid" empty, unable to lookup correct key');
        }

        if ($keyOrKeyArray instanceof CachedKeySet) {
            // Skip "isset" check, as this will automatically refresh if not set
            return $keyOrKeyArray[$kid];
        }

        if (!isset($keyOrKeyArray[$kid])) {
            throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key');
        }

        return $keyOrKeyArray[$kid];
    }

    /**
     * @param string $left  The string of known length to compare against
     * @param string $right The user-supplied string
     * @return bool
     */
    public static function constantTimeEquals(string $left, string $right): bool
    {
        if (\function_exists('hash_equals')) {
            return \hash_equals($left, $right);
        }
        $len = \min(self::safeStrlen($left), self::safeStrlen($right));

        $status = 0;
        for ($i = 0; $i < $len; $i++) {
            $status |= (\ord($left[$i]) ^ \ord($right[$i]));
        }
        $status |= (self::safeStrlen($left) ^ self::safeStrlen($right));

        return ($status === 0);
    }

    /**
     * Helper method to create a JSON error.
     *
     * @param int $errno An error number from json_last_error()
     *
     * @throws DomainException
     *
     * @return void
     */
    private static function handleJsonError(int $errno): void
    {
        $messages = [
            JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
            JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON',
            JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
            JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON',
            JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3
        ];
        throw new DomainException(
            isset($messages[$errno])
            ? $messages[$errno]
            : 'Unknown JSON error: ' . $errno
        );
    }

    /**
     * Get the number of bytes in cryptographic strings.
     *
     * @param string $str
     *
     * @return int
     */
    private static function safeStrlen(string $str): int
    {
        if (\function_exists('mb_strlen')) {
            return \mb_strlen($str, '8bit');
        }
        return \strlen($str);
    }

    /**
     * Convert an ECDSA signature to an ASN.1 DER sequence
     *
     * @param   string $sig The ECDSA signature to convert
     * @return  string The encoded DER object
     */
    private static function signatureToDER(string $sig): string
    {
        // Separate the signature into r-value and s-value
        $length = max(1, (int) (\strlen($sig) / 2));
        list($r, $s) = \str_split($sig, $length);

        // Trim leading zeros
        $r = \ltrim($r, "\x00");
        $s = \ltrim($s, "\x00");

        // Convert r-value and s-value from unsigned big-endian integers to
        // signed two's complement
        if (\ord($r[0]) > 0x7f) {
            $r = "\x00" . $r;
        }
        if (\ord($s[0]) > 0x7f) {
            $s = "\x00" . $s;
        }

        return self::encodeDER(
            self::ASN1_SEQUENCE,
            self::encodeDER(self::ASN1_INTEGER, $r) .
            self::encodeDER(self::ASN1_INTEGER, $s)
        );
    }

    /**
     * Encodes a value into a DER object.
     *
     * @param   int     $type DER tag
     * @param   string  $value the value to encode
     *
     * @return  string  the encoded object
     */
    private static function encodeDER(int $type, string $value): string
    {
        $tag_header = 0;
        if ($type === self::ASN1_SEQUENCE) {
            $tag_header |= 0x20;
        }

        // Type
        $der = \chr($tag_header | $type);

        // Length
        $der .= \chr(\strlen($value));

        return $der . $value;
    }

    /**
     * Encodes signature from a DER object.
     *
     * @param   string  $der binary signature in DER format
     * @param   int     $keySize the number of bits in the key
     *
     * @return  string  the signature
     */
    private static function signatureFromDER(string $der, int $keySize): string
    {
        // OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE
        list($offset, $_) = self::readDER($der);
        list($offset, $r) = self::readDER($der, $offset);
        list($offset, $s) = self::readDER($der, $offset);

        // Convert r-value and s-value from signed two's compliment to unsigned
        // big-endian integers
        $r = \ltrim($r, "\x00");
        $s = \ltrim($s, "\x00");

        // Pad out r and s so that they are $keySize bits long
        $r = \str_pad($r, $keySize / 8, "\x00", STR_PAD_LEFT);
        $s = \str_pad($s, $keySize / 8, "\x00", STR_PAD_LEFT);

        return $r . $s;
    }

    /**
     * Reads binary DER-encoded data and decodes into a single object
     *
     * @param string $der the binary data in DER format
     * @param int $offset the offset of the data stream containing the object
     * to decode
     *
     * @return array{int, string|null} the new offset and the decoded object

     */
    private static function readDER(string $der, int $offset = 0): array
    {
        $pos = $offset;
        $size = \strlen($der);
        $constructed = (\ord($der[$pos]) >> 5) & 0x01;
        $type = \ord($der[$pos++]) & 0x1f;

        // Length
        $len = \ord($der[$pos++]);
        if ($len & 0x80) {
            $n = $len & 0x1f;
            $len = 0;
            while ($n-- && $pos < $size) {
                $len = ($len << 8) | \ord($der[$pos++]);
            }
        }

        // Value
        if ($type === self::ASN1_BIT_STRING) {
            $pos++; // Skip the first contents octet (padding indicator)
            $data = \substr($der, $pos, $len - 1);
            $pos += $len - 1;
        } elseif (!$constructed) {
            $data = \substr($der, $pos, $len);
            $pos += $len;
        } else {
            $data = null;
        }

        return [$pos, $data];
    }
}


1			<?php
2
3			namespace Firebase\JWT;
4
5			use ArrayAccess;
6			use DateTime;
7			use DomainException;
8			use Exception;
9			use InvalidArgumentException;
10			use OpenSSLAsymmetricKey;
11			use OpenSSLCertificate;
12			use stdClass;
13			use UnexpectedValueException;
14
15			/**
16			* JSON Web Token implementation, based on this spec:
17			* https://tools.ietf.org/html/rfc7519
18			*
19			* PHP version 5
20			*
21			* @category Authentication
22			* @package Authentication_JWT
23			* @author Neuman Vong <[email protected]>
24			* @author Anant Narayanan <[email protected]>
25			* @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD
26			* @link https://github.com/firebase/php-jwt
27			*/
28			class JWT
29			{
30			private const ASN1_INTEGER = 0x02;
31			private const ASN1_SEQUENCE = 0x10;
32			private const ASN1_BIT_STRING = 0x03;
33
34			/**
35			* When checking nbf, iat or expiration times,
36			* we want to provide some extra leeway time to
37			* account for clock skew.
38			*
39			* @var int
40			*/
41			public static $leeway = 0;
42
43			/**
44			* Allow the current timestamp to be specified.
45			* Useful for fixing a value within unit testing.
46			* Will default to PHP time() value if null.
47			*
48			* @var ?int
49			*/
50			public static $timestamp = null;
51
52			/**
53			* @var array<string, string[]>
54			*/
55			public static $supported_algs = [
56			'ES384' => ['openssl', 'SHA384'],
57			'ES256' => ['openssl', 'SHA256'],
58			'ES256K' => ['openssl', 'SHA256'],
59			'HS256' => ['hash_hmac', 'SHA256'],
60			'HS384' => ['hash_hmac', 'SHA384'],
61			'HS512' => ['hash_hmac', 'SHA512'],
62			'RS256' => ['openssl', 'SHA256'],
63			'RS384' => ['openssl', 'SHA384'],
64			'RS512' => ['openssl', 'SHA512'],
65			'EdDSA' => ['sodium_crypto', 'EdDSA'],
66			];
67
68			/**
69			* Decodes a JWT string into a PHP object.
70			*
71			* @param string $jwt The JWT
72			* @param Key\|ArrayAccess<string,Key>\|array<string,Key> $keyOrKeyArray The Key or associative array of key IDs
73			* (kid) to Key objects.
74			* If the algorithm used is asymmetric, this is
75			* the public key.
76			* Each Key object contains an algorithm and
77			* matching key.
78			* Supported algorithms are 'ES384','ES256',
79			* 'HS256', 'HS384', 'HS512', 'RS256', 'RS384'
80			* and 'RS512'.
81			* @param stdClass $headers Optional. Populates stdClass with headers.
82			*
83			* @return stdClass The JWT's payload as a PHP object
84			*
85			* @throws InvalidArgumentException Provided key/key-array was empty or malformed
86			* @throws DomainException Provided JWT is malformed
87			* @throws UnexpectedValueException Provided JWT was invalid
88			* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed
89			* @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf'
90			* @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat'
91			* @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim
92			*
93			* @uses jsonDecode
94			* @uses urlsafeB64Decode
95			*/
96			public static function decode(
97			string $jwt,
98			$keyOrKeyArray,
99			?stdClass &$headers = null
100			): stdClass {
101			// Validate JWT
102			$timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp;
103
104			if (empty($keyOrKeyArray)) {
105			throw new InvalidArgumentException('Key may not be empty');
106			}
107			$tks = \explode('.', $jwt);
108			if (\count($tks) !== 3) {
109			throw new UnexpectedValueException('Wrong number of segments');
110			}
111			list($headb64, $bodyb64, $cryptob64) = $tks;
112			$headerRaw = static::urlsafeB64Decode($headb64);
113			if (null === ($header = static::jsonDecode($headerRaw))) {
114			throw new UnexpectedValueException('Invalid header encoding');
115			}
116			if ($headers !== null) {
117			$headers = $header;
118			}
119			$payloadRaw = static::urlsafeB64Decode($bodyb64);
120			if (null === ($payload = static::jsonDecode($payloadRaw))) {
121			throw new UnexpectedValueException('Invalid claims encoding');
122			}
123			if (\is_array($payload)) {
124			// prevent PHP Fatal Error in edge-cases when payload is empty array
125			$payload = (object) $payload;
126			}
127			if (!$payload instanceof stdClass) {
128			throw new UnexpectedValueException('Payload must be a JSON object');
129			}
130			$sig = static::urlsafeB64Decode($cryptob64);
131			if (empty($header->alg)) {
132			throw new UnexpectedValueException('Empty algorithm');
133			}
134			if (empty(static::$supported_algs[$header->alg])) {
135			throw new UnexpectedValueException('Algorithm not supported');
136			}
137
138			$key = self::getKey($keyOrKeyArray, property_exists($header, 'kid') ? $header->kid : null);
139
140			// Check the algorithm
141			if (!self::constantTimeEquals($key->getAlgorithm(), $header->alg)) {
142			// See issue #351
143			throw new UnexpectedValueException('Incorrect key for this algorithm');
144			}
145			if (\in_array($header->alg, ['ES256', 'ES256K', 'ES384'], true)) {
146			// OpenSSL expects an ASN.1 DER sequence for ES256/ES256K/ES384 signatures
147			$sig = self::signatureToDER($sig);
148			}
149			if (!self::verify("{$headb64}.{$bodyb64}", $sig, $key->getKeyMaterial(), $header->alg)) {
150			throw new SignatureInvalidException('Signature verification failed');
151			}
152
153			// Check the nbf if it is defined. This is the time that the
154			// token can actually be used. If it's not yet that time, abort.
155			if (isset($payload->nbf) && floor($payload->nbf) > ($timestamp + static::$leeway)) {
156			$ex = new BeforeValidException(
157			'Cannot handle token with nbf prior to ' . \date(DateTime::ISO8601, (int) $payload->nbf)
158			);
159			$ex->setPayload($payload);
160			throw $ex;
161			}
162
163			// Check that this token has been created before 'now'. This prevents
164			// using tokens that have been created for later use (and haven't
165			// correctly used the nbf claim).
166			if (!isset($payload->nbf) && isset($payload->iat) && floor($payload->iat) > ($timestamp + static::$leeway)) {
167			$ex = new BeforeValidException(
168			'Cannot handle token with iat prior to ' . \date(DateTime::ISO8601, (int) $payload->iat)
169			);
170			$ex->setPayload($payload);
171			throw $ex;
172			}
173
174			// Check if this token has expired.
175			if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) {
176			$ex = new ExpiredException('Expired token');
177			$ex->setPayload($payload);
178			throw $ex;
179			}
180
181			return $payload;
182			}
183
184			/**
185			* Converts and signs a PHP array into a JWT string.
186			*
187			* @param array<mixed> $payload PHP array
188			* @param string\|resource\|OpenSSLAsymmetricKey\|OpenSSLCertificate $key The secret key.
189			* @param string $alg Supported algorithms are 'ES384','ES256', 'ES256K', 'HS256',
190			* 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
191			* @param string $keyId
192			* @param array<string, string> $head An array with header elements to attach
193			*
194			* @return string A signed JWT
195			*
196			* @uses jsonEncode
197			* @uses urlsafeB64Encode
198			*/
199			public static function encode(
200			array $payload,
201			$key,
202			string $alg,
203			?string $keyId = null,
204			?array $head = null
205			): string {
206			$header = ['typ' => 'JWT'];
207			if (isset($head)) {
208			$header = \array_merge($header, $head);
209			}
210			$header['alg'] = $alg;
211			if ($keyId !== null) {
212			$header['kid'] = $keyId;
213			}
214			$segments = [];
215			$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($header));
216			$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($payload));
217			$signing_input = \implode('.', $segments);
218
219			$signature = static::sign($signing_input, $key, $alg);
220			$segments[] = static::urlsafeB64Encode($signature);
221
222			return \implode('.', $segments);
223			}
224
225			/**
226			* Sign a string with a given key and algorithm.
227			*
228			* @param string $msg The message to sign
229			* @param string\|resource\|OpenSSLAsymmetricKey\|OpenSSLCertificate $key The secret key.
230			* @param string $alg Supported algorithms are 'EdDSA', 'ES384', 'ES256', 'ES256K', 'HS256',
231			* 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
232			*
233			* @return string An encrypted message
234			*
235			* @throws DomainException Unsupported algorithm or bad key was specified
236			*/
237			public static function sign(
238			string $msg,
239			$key,
240			string $alg
241			): string {
242			if (empty(static::$supported_algs[$alg])) {
243			throw new DomainException('Algorithm not supported');
244			}
245			list($function, $algorithm) = static::$supported_algs[$alg];
246			switch ($function) {
247			case 'hash_hmac':
248			if (!\is_string($key)) {
249			throw new InvalidArgumentException('key must be a string when using hmac');
250			}
251			return \hash_hmac($algorithm, $msg, $key, true);
252			case 'openssl':
253			$signature = '';
254			if (!\is_resource($key) && !openssl_pkey_get_private($key)) {
255			throw new DomainException('OpenSSL unable to validate key');
256			}
257			$success = \openssl_sign($msg, $signature, $key, $algorithm); // @phpstan-ignore-line
258			if (!$success) {
259			throw new DomainException('OpenSSL unable to sign data');
260			}
261			if ($alg === 'ES256' \|\| $alg === 'ES256K') {
262			$signature = self::signatureFromDER($signature, 256);
263			} elseif ($alg === 'ES384') {
264			$signature = self::signatureFromDER($signature, 384);
265			}
266			return $signature;
267			case 'sodium_crypto':
268			if (!\function_exists('sodium_crypto_sign_detached')) {
269			throw new DomainException('libsodium is not available');
270			}
271			if (!\is_string($key)) {
272			throw new InvalidArgumentException('key must be a string when using EdDSA');
273			}
274			try {
275			// The last non-empty line is used as the key.
276			$lines = array_filter(explode("\n", $key));
277			$key = base64_decode((string) end($lines));
278			if (\strlen($key) === 0) {
279			throw new DomainException('Key cannot be empty string');
280			}
281			return sodium_crypto_sign_detached($msg, $key);
282			} catch (Exception $e) {
283			throw new DomainException($e->getMessage(), 0, $e);
284			}
285			}
286
287			throw new DomainException('Algorithm not supported');
288			}
289
290			/**
291			* Verify a signature with the message, key and method. Not all methods
292			* are symmetric, so we must have a separate verify and sign method.
293			*
294			* @param string $msg The original message (header and body)
295			* @param string $signature The original signature
296			* @param string\|resource\|OpenSSLAsymmetricKey\|OpenSSLCertificate $keyMaterial For Ed, ES, HS, a string key works. for RS, must be an instance of OpenSSLAsymmetricKey
297			* @param string $alg The algorithm
298			*
299			* @return bool
300			*
301			* @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure
302			*/
303			private static function verify(
304			string $msg,
305			string $signature,
306			$keyMaterial,
307			string $alg
308			): bool {
309			if (empty(static::$supported_algs[$alg])) {
310			throw new DomainException('Algorithm not supported');
311			}
312
313			list($function, $algorithm) = static::$supported_algs[$alg];
314			switch ($function) {
315			case 'openssl':
316			$success = \openssl_verify($msg, $signature, $keyMaterial, $algorithm); // @phpstan-ignore-line
317			if ($success === 1) {
318			return true;
319			}
320			if ($success === 0) {
321			return false;
322			}
323			// returns 1 on success, 0 on failure, -1 on error.
324			throw new DomainException(
325			'OpenSSL error: ' . \openssl_error_string()
326			);
327			case 'sodium_crypto':
328			if (!\function_exists('sodium_crypto_sign_verify_detached')) {
329			throw new DomainException('libsodium is not available');
330			}
331			if (!\is_string($keyMaterial)) {
332			throw new InvalidArgumentException('key must be a string when using EdDSA');
333			}
334			try {
335			// The last non-empty line is used as the key.
336			$lines = array_filter(explode("\n", $keyMaterial));
337			$key = base64_decode((string) end($lines));
338			if (\strlen($key) === 0) {
339			throw new DomainException('Key cannot be empty string');
340			}
341			if (\strlen($signature) === 0) {
342			throw new DomainException('Signature cannot be empty string');
343			}
344			return sodium_crypto_sign_verify_detached($signature, $msg, $key);
345			} catch (Exception $e) {
346			throw new DomainException($e->getMessage(), 0, $e);
347			}
348			case 'hash_hmac':
349			default:
350			if (!\is_string($keyMaterial)) {
351			throw new InvalidArgumentException('key must be a string when using hmac');
352			}
353			$hash = \hash_hmac($algorithm, $msg, $keyMaterial, true);
354			return self::constantTimeEquals($hash, $signature);
355			}
356			}
357
358			/**
359			* Decode a JSON string into a PHP object.
360			*
361			* @param string $input JSON string
362			*
363			* @return mixed The decoded JSON string
364			*
365			* @throws DomainException Provided string was invalid JSON
366			*/
367			public static function jsonDecode(string $input)
368			{
369			$obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING);
370
371			if ($errno = \json_last_error()) {
372			self::handleJsonError($errno);
373			} elseif ($obj === null && $input !== 'null') {
374			throw new DomainException('Null result with non-null input');
375			}
376			return $obj;
377			}
378
379			/**
380			* Encode a PHP array into a JSON string.
381			*
382			* @param array<mixed> $input A PHP array
383			*
384			* @return string JSON representation of the PHP array
385			*
386			* @throws DomainException Provided object could not be encoded to valid JSON
387			*/
388			public static function jsonEncode(array $input): string
389			{
390			$json = \json_encode($input, \JSON_UNESCAPED_SLASHES);
391			if ($errno = \json_last_error()) {
392			self::handleJsonError($errno);
393			} elseif ($json === 'null') {
394			throw new DomainException('Null result with non-null input');
395			}
396			if ($json === false) {
397			throw new DomainException('Provided object could not be encoded to valid JSON');
398			}
399			return $json;
400			}
401
402			/**
403			* Decode a string with URL-safe Base64.
404			*
405			* @param string $input A Base64 encoded string
406			*
407			* @return string A decoded string
408			*
409			* @throws InvalidArgumentException invalid base64 characters
410			*/
411			public static function urlsafeB64Decode(string $input): string
412			{
413			return \base64_decode(self::convertBase64UrlToBase64($input));
414			}
415
416			/**
417			* Convert a string in the base64url (URL-safe Base64) encoding to standard base64.
418			*
419			* @param string $input A Base64 encoded string with URL-safe characters (-_ and no padding)
420			*
421			* @return string A Base64 encoded string with standard characters (+/) and padding (=), when
422			* needed.
423			*
424			* @see https://www.rfc-editor.org/rfc/rfc4648
425			*/
426			public static function convertBase64UrlToBase64(string $input): string
427			{
428			$remainder = \strlen($input) % 4;
429			if ($remainder) {
430			$padlen = 4 - $remainder;
431			$input .= \str_repeat('=', $padlen);
432			}
433			return \strtr($input, '-_', '+/');
434			}
435
436			/**
437			* Encode a string with URL-safe Base64.
438			*
439			* @param string $input The string you want encoded
440			*
441			* @return string The base64 encode of what you passed in
442			*/
443			public static function urlsafeB64Encode(string $input): string
444			{
445			return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_'));
446			}
447
448
449			/**
450			* Determine if an algorithm has been provided for each Key
451			*
452			* @param Key\|ArrayAccess<string,Key>\|array<string,Key> $keyOrKeyArray
453			* @param string\|null $kid
454			*
455			* @throws UnexpectedValueException
456			*
457			* @return Key
458			*/
459			private static function getKey(
460			$keyOrKeyArray,
461			?string $kid
462			): Key {
463			if ($keyOrKeyArray instanceof Key) {
464			return $keyOrKeyArray;
465			}
466
467			if (empty($kid) && $kid !== '0') {
468			throw new UnexpectedValueException('"kid" empty, unable to lookup correct key');
469			}
470
471			if ($keyOrKeyArray instanceof CachedKeySet) {
472			// Skip "isset" check, as this will automatically refresh if not set
473			return $keyOrKeyArray[$kid];
474			}
475
476			if (!isset($keyOrKeyArray[$kid])) {
477			throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key');
478			}
479
480			return $keyOrKeyArray[$kid];
481			}
482
483			/**
484			* @param string $left The string of known length to compare against
485			* @param string $right The user-supplied string
486			* @return bool
487			*/
488			public static function constantTimeEquals(string $left, string $right): bool
489			{
490			if (\function_exists('hash_equals')) {
491			return \hash_equals($left, $right);
492			}
493			$len = \min(self::safeStrlen($left), self::safeStrlen($right));
494
495			$status = 0;
496			for ($i = 0; $i < $len; $i++) {
497			$status \|= (\ord($left[$i]) ^ \ord($right[$i]));
498			}
499			$status \|= (self::safeStrlen($left) ^ self::safeStrlen($right));
500
501			return ($status === 0);
502			}
503
504			/**
505			* Helper method to create a JSON error.
506			*
507			* @param int $errno An error number from json_last_error()
508			*
509			* @throws DomainException
510			*
511			* @return void
512			*/
513			private static function handleJsonError(int $errno): void
514			{
515			$messages = [
516			JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
517			JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON',
518			JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
519			JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON',
520			JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3
521			];
522			throw new DomainException(
523			isset($messages[$errno])
524			? $messages[$errno]
525			: 'Unknown JSON error: ' . $errno
526			);
527			}
528
529			/**
530			* Get the number of bytes in cryptographic strings.
531			*
532			* @param string $str
533			*
534			* @return int
535			*/
536			private static function safeStrlen(string $str): int
537			{
538			if (\function_exists('mb_strlen')) {
539			return \mb_strlen($str, '8bit');
540			}
541			return \strlen($str);
542			}
543
544			/**
545			* Convert an ECDSA signature to an ASN.1 DER sequence
546			*
547			* @param string $sig The ECDSA signature to convert
548			* @return string The encoded DER object
549			*/
550			private static function signatureToDER(string $sig): string
551			{
552			// Separate the signature into r-value and s-value
553			$length = max(1, (int) (\strlen($sig) / 2));
554			list($r, $s) = \str_split($sig, $length);
555
556			// Trim leading zeros
557			$r = \ltrim($r, "\x00");
558			$s = \ltrim($s, "\x00");
559
560			// Convert r-value and s-value from unsigned big-endian integers to
561			// signed two's complement
562			if (\ord($r[0]) > 0x7f) {
563			$r = "\x00" . $r;
564			}
565			if (\ord($s[0]) > 0x7f) {
566			$s = "\x00" . $s;
567			}
568
569			return self::encodeDER(
570			self::ASN1_SEQUENCE,
571			self::encodeDER(self::ASN1_INTEGER, $r) .
572			self::encodeDER(self::ASN1_INTEGER, $s)
573			);
574			}
575
576			/**
577			* Encodes a value into a DER object.
578			*
579			* @param int $type DER tag
580			* @param string $value the value to encode
581			*
582			* @return string the encoded object
583			*/
584			private static function encodeDER(int $type, string $value): string
585			{
586			$tag_header = 0;
587			if ($type === self::ASN1_SEQUENCE) {
588			$tag_header \|= 0x20;
589			}
590
591			// Type
592			$der = \chr($tag_header \| $type);
593
594			// Length
595			$der .= \chr(\strlen($value));
596
597			return $der . $value;
598			}
599
600			/**
601			* Encodes signature from a DER object.
602			*
603			* @param string $der binary signature in DER format
604			* @param int $keySize the number of bits in the key
605			*
606			* @return string the signature
607			*/
608			private static function signatureFromDER(string $der, int $keySize): string
609			{
610			// OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE
611			list($offset, $_) = self::readDER($der);
612			list($offset, $r) = self::readDER($der, $offset);
613			list($offset, $s) = self::readDER($der, $offset);
614
615			// Convert r-value and s-value from signed two's compliment to unsigned
616			// big-endian integers
617			$r = \ltrim($r, "\x00");
618			$s = \ltrim($s, "\x00");
619
620			// Pad out r and s so that they are $keySize bits long
621			$r = \str_pad($r, $keySize / 8, "\x00", STR_PAD_LEFT);
622			$s = \str_pad($s, $keySize / 8, "\x00", STR_PAD_LEFT);
623
624			return $r . $s;
625			}
626
627			/**
628			* Reads binary DER-encoded data and decodes into a single object
629			*
630			* @param string $der the binary data in DER format
631			* @param int $offset the offset of the data stream containing the object
632			* to decode
633			*
634			* @return array{int, string\|null} the new offset and the decoded object
			0 ignored issues – show Documentation Bug introduced 2025-03-22 13:57 UTC by Report Bug Copy Issue Report The doc comment `array{int, string\|null}` at position `2` could not be parsed: Expected ':' at position 2, but found 'int'. Loading history...
635			*/
636			private static function readDER(string $der, int $offset = 0): array
637			{
638			$pos = $offset;
639			$size = \strlen($der);
640			$constructed = (\ord($der[$pos]) >> 5) & 0x01;
641			$type = \ord($der[$pos++]) & 0x1f;
642
643			// Length
644			$len = \ord($der[$pos++]);
645			if ($len & 0x80) {
646			$n = $len & 0x1f;
647			$len = 0;
648			while ($n-- && $pos < $size) {
649			$len = ($len << 8) \| \ord($der[$pos++]);
650			}
651			}
652
653			// Value
654			if ($type === self::ASN1_BIT_STRING) {
655			$pos++; // Skip the first contents octet (padding indicator)
656			$data = \substr($der, $pos, $len - 1);
657			$pos += $len - 1;
658			} elseif (!$constructed) {
659			$data = \substr($der, $pos, $len);
660			$pos += $len;
661			} else {
662			$data = null;
663			}
664
665			return [$pos, $data];
666			}
667			}
668

XOOPS / XoopsCore27

JWT::decode() F last analyzed 2025-09-22 08:00 UTC

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JWT::decode() F
last analyzed 2025-09-22 08:00 UTC