File indexing completed on 2022-11-29 20:29:23

0001 <?php
0002 
0003 /**
0004  * JSON Web Token implementation, based on this spec:
0005  * http://tools.ietf.org/html/draft-ietf-oauth-json-web-token-06
0006  *
0007  * PHP version 5
0008  *
0009  * @category Authentication
0010  * @package  Authentication_JWT
0011  * @author   Neuman Vong <neuman@twilio.com>
0012  * @author   Anant Narayanan <anant@php.net>
0013  * @license  http://opensource.org/licenses/BSD-3-Clause 3-clause BSD
0014  * @link     https://github.com/firebase/php-jwt
0015  */
0016 class JWT
0017 {
0018     /**
0019      * Decodes a JWT string into a PHP object.
0020      *
0021      * @param string      $jwt The JWT
0022      * @param string|null $key The secret key
0023      * @param bool        $verify Don't skip verification process
0024      *
0025      * @return object      The JWT's payload as a PHP object
0026      * @throws UnexpectedValueException Provided JWT was invalid
0027      * @throws DomainException          Algorithm was not provided
0028      *
0029      * @uses jsonDecode
0030      * @uses urlsafeB64Decode
0031      */
0032     public static function decode($jwt, $key = null, $verify = true)
0033     {
0034         $tks = explode('.', $jwt);
0035         if (count($tks) != 3) {
0036             throw new UnexpectedValueException('Wrong number of segments');
0037         }
0038         list($headb64, $bodyb64, $cryptob64) = $tks;
0039         if (null === ($header = JWT::jsonDecode(JWT::urlsafeB64Decode($headb64)))) {
0040             throw new UnexpectedValueException('Invalid segment encoding');
0041         }
0042         if (null === $payload = JWT::jsonDecode(JWT::urlsafeB64Decode($bodyb64))) {
0043             throw new UnexpectedValueException('Invalid segment encoding');
0044         }
0045         $sig = JWT::urlsafeB64Decode($cryptob64);
0046         if ($verify) {
0047             if (empty($header->alg)) {
0048                 throw new DomainException('Empty algorithm');
0049             }
0050             if ($sig != JWT::sign("$headb64.$bodyb64", $key, $header->alg)) {
0051                 throw new UnexpectedValueException('Signature verification failed');
0052             }
0053         }
0054 
0055         return $payload;
0056     }
0057 
0058     /**
0059      * Decode a JSON string into a PHP object.
0060      *
0061      * @param string $input JSON string
0062      *
0063      * @return object          Object representation of JSON string
0064      * @throws DomainException Provided string was invalid JSON
0065      */
0066     public static function jsonDecode($input)
0067     {
0068         $obj = json_decode($input);
0069         if (function_exists('json_last_error') && $errno = json_last_error()) {
0070             JWT::_handleJsonError($errno);
0071         } else {
0072             if ($obj === null && $input !== 'null') {
0073                 throw new DomainException('Null result with non-null input');
0074             }
0075         }
0076 
0077         return $obj;
0078     }
0079 
0080     /**
0081      * Helper method to create a JSON error.
0082      *
0083      * @param int $errno An error number from json_last_error()
0084      *
0085      * @return void
0086      */
0087     private static function _handleJsonError($errno)
0088     {
0089         $messages = array(
0090             JSON_ERROR_DEPTH     => 'Maximum stack depth exceeded',
0091             JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
0092             JSON_ERROR_SYNTAX    => 'Syntax error, malformed JSON'
0093         );
0094         throw new DomainException(isset($messages[$errno]) ? $messages[$errno] : 'Unknown JSON error: ' . $errno);
0095     }
0096 
0097     /**
0098      * Decode a string with URL-safe Base64.
0099      *
0100      * @param string $input A Base64 encoded string
0101      *
0102      * @return string A decoded string
0103      */
0104     public static function urlsafeB64Decode($input)
0105     {
0106         $remainder = strlen($input) % 4;
0107         if ($remainder) {
0108             $padlen = 4 - $remainder;
0109             $input .= str_repeat('=', $padlen);
0110         }
0111 
0112         return base64_decode(strtr($input, '-_', '+/'));
0113     }
0114 
0115     /**
0116      * Sign a string with a given key and algorithm.
0117      *
0118      * @param string $msg The message to sign
0119      * @param string $key The secret key
0120      * @param string $method The signing algorithm. Supported
0121      *                       algorithms are 'HS256', 'HS384' and 'HS512'
0122      *
0123      * @return string          An encrypted message
0124      * @throws DomainException Unsupported algorithm was specified
0125      */
0126     public static function sign($msg, $key, $method = 'HS256')
0127     {
0128         $methods = array(
0129             'HS256' => 'sha256',
0130             'HS384' => 'sha384',
0131             'HS512' => 'sha512',
0132         );
0133         if (empty($methods[$method])) {
0134             throw new DomainException('Algorithm not supported');
0135         }
0136 
0137         return hash_hmac($methods[$method], $msg, $key, true);
0138     }
0139 
0140     /**
0141      * Converts and signs a PHP object or array into a JWT string.
0142      *
0143      * @param object|array $payload PHP object or array
0144      * @param string       $key The secret key
0145      * @param string       $algo The signing algorithm. Supported
0146      *                              algorithms are 'HS256', 'HS384' and 'HS512'
0147      *
0148      * @return string      A signed JWT
0149      * @uses jsonEncode
0150      * @uses urlsafeB64Encode
0151      */
0152     public static function encode($payload, $key, $algo = 'HS256')
0153     {
0154         $header = array('typ' => 'JWT', 'alg' => $algo);
0155         $segments = array();
0156         $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header));
0157         $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload));
0158         $signing_input = implode('.', $segments);
0159         $signature = JWT::sign($signing_input, $key, $algo);
0160         $segments[] = JWT::urlsafeB64Encode($signature);
0161 
0162         return implode('.', $segments);
0163     }
0164 
0165     /**
0166      * Encode a string with URL-safe Base64.
0167      *
0168      * @param string $input The string you want encoded
0169      *
0170      * @return string The base64 encode of what you passed in
0171      */
0172     public static function urlsafeB64Encode($input)
0173     {
0174         return str_replace('=', '', strtr(base64_encode($input), '+/', '-_'));
0175     }
0176 
0177     /**
0178      * Encode a PHP object into a JSON string.
0179      *
0180      * @param object|array $input A PHP object or array
0181      *
0182      * @return string          JSON representation of the PHP object or array
0183      * @throws DomainException Provided object could not be encoded to valid JSON
0184      */
0185     public static function jsonEncode($input)
0186     {
0187         $json = json_encode($input);
0188         if (function_exists('json_last_error') && $errno = json_last_error()) {
0189             JWT::_handleJsonError($errno);
0190         } else {
0191             if ($json === 'null' && $input !== null) {
0192                 throw new DomainException('Null result with non-null input');
0193             }
0194         }
0195 
0196         return $json;
0197     }
0198 
0199     public static function hashCode($a)
0200     {
0201         if ($a == null) {
0202             return 0;
0203         }
0204 
0205         $result = crc32($a);
0206 
0207         return $result;
0208     }
0209 
0210 }