JWT.php
Demo Example:
<?php //namespace Firebase\JWT; //use \DomainException; //use \InvalidArgumentException; //use \UnexpectedValueException; //use \DateTime; /** * JSON Web Token implementation, based on this spec: * http://tools.ietf.org/html/draft-ietf-oauth-json-web-token-06 * * PHP version 5 * * @category Authentication * @package Authentication_JWT * @author Neuman Vong <neuman@twilio.com> * @author Anant Narayanan <anant@php.net> * @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD * @link https://github.com/firebase/php-jwt */ class JWT { /** * When checking nbf, iat or expiration times, * we want to provide some extra leeway time to * account for clock skew. */ public static $leeway = 0; public static $supported_algs = array( 'HS256' => array('hash_hmac', 'SHA256'), 'HS512' => array('hash_hmac', 'SHA512'), 'HS384' => array('hash_hmac', 'SHA384'), 'RS256' => array('openssl', 'SHA256'), ); /** * Decodes a JWT string into a PHP object. * * @param string $jwt The JWT * @param string|array|null $key The key, or map of keys. * If the algorithm used is asymmetric, this is the public key * @param array $allowed_algs List of supported verification algorithms * Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256' * * @return object The JWT's payload as a PHP object * * @throws DomainException Algorithm was not provided * @throws UnexpectedValueException Provided JWT was invalid * @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed * @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' * @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' * @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim * * @uses jsonDecode * @uses urlsafeB64Decode */ public static function decode($jwt, $key, $allowed_algs = array()) { if (empty($key)) { 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) = $tks; if (null === ($header = JWT::jsonDecode(JWT::urlsafeB64Decode($headb64)))) { throw new UnexpectedValueException('Invalid header encoding'); } if (null === $payload = JWT::jsonDecode(JWT::urlsafeB64Decode($bodyb64))) { throw new UnexpectedValueException('Invalid claims encoding'); } $sig = JWT::urlsafeB64Decode($cryptob64); if (empty($header->alg)) { throw new DomainException('Empty algorithm'); } if (empty(self::$supported_algs[$header->alg])) { throw new DomainException('Algorithm not supported'); } if (!is_array($allowed_algs) || !in_array($header->alg, $allowed_algs)) { throw new DomainException('Algorithm not allowed'); } if (is_array($key) || $key instanceof \ArrayAccess) { if (isset($header->kid)) { $key = $key[$header->kid]; } else { throw new DomainException('"kid" empty, unable to lookup correct key'); } } // Check the signature if (!JWT::verify("$headb64.$bodyb64", $sig, $key, $header->alg)) { throw new SignatureInvalidException('Signature verification failed'); } // Check if the nbf if it is defined. This is the time that the // token can actually be used. If it's not yet that time, abort. if (isset($payload->nbf) && $payload->nbf > (time() + self::$leeway)) { throw new BeforeValidException( 'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->nbf) ); } // Check that this token has been created before 'now'. This prevents // using tokens that have been created for later use (and haven't // correctly used the nbf claim). if (isset($payload->iat) && $payload->iat > (time() + self::$leeway)) { throw new BeforeValidException( 'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->iat) ); } // Check if this token has expired. if (isset($payload->exp) && (time() - self::$leeway) >= $payload->exp) { throw new ExpiredException('Expired token'); } return $payload; } /** * Converts and signs a PHP object or array into a JWT string. * * @param object|array $payload PHP object or array * @param string $key The secret key. * If the algorithm used is asymmetric, this is the private key * @param string $alg The signing algorithm. * Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256' * @param array $head An array with header elements to attach * * @return string A signed JWT * * @uses jsonEncode * @uses urlsafeB64Encode */ public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null) { $header = array('typ' => 'JWT', 'alg' => $alg); if ($keyId !== null) { $header['kid'] = $keyId; } if ( isset($head) && is_array($head) ) { $header = array_merge($head, $header); } $segments = array(); $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header)); $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload)); $signing_input = implode('.', $segments); $signature = JWT::sign($signing_input, $key, $alg); $segments[] = JWT::urlsafeB64Encode($signature); return implode('.', $segments); } /** * Sign a string with a given key and algorithm. * * @param string $msg The message to sign * @param string|resource $key The secret key * @param string $alg The signing algorithm. * Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256' * * @return string An encrypted message * * @throws DomainException Unsupported algorithm was specified */ public static function sign($msg, $key, $alg = 'HS256') { if (empty(self::$supported_algs[$alg])) { throw new DomainException('Algorithm not supported'); } list($function, $algorithm) = self::$supported_algs[$alg]; switch($function) { case 'hash_hmac': return hash_hmac($algorithm, $msg, $key, true); case 'openssl': $signature = ''; $success = openssl_sign($msg, $signature, $key, $algorithm); if (!$success) { throw new DomainException("OpenSSL unable to sign data"); } else { return $signature; } } } /** * 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 $key For HS*, a string key works. for RS*, must be a resource of an openssl public key * @param string $alg The algorithm * * @return bool * * @throws DomainException Invalid Algorithm or OpenSSL failure */ private static function verify($msg, $signature, $key, $alg) { if (empty(self::$supported_algs[$alg])) { throw new DomainException('Algorithm not supported'); } list($function, $algorithm) = self::$supported_algs[$alg]; switch($function) { case 'openssl': $success = openssl_verify($msg, $signature, $key, $algorithm); if (!$success) { throw new DomainException("OpenSSL unable to verify data: " . openssl_error_string()); } else { return $signature; } case 'hash_hmac': default: $hash = hash_hmac($algorithm, $msg, $key, true); if (function_exists('hash_equals')) { return hash_equals($signature, $hash); } $len = min(self::safeStrlen($signature), self::safeStrlen($hash)); $status = 0; for ($i = 0; $i < $len; $i++) { $status |= (ord($signature[$i]) ^ ord($hash[$i])); } $status |= (self::safeStrlen($signature) ^ self::safeStrlen($hash)); return ($status === 0); } } /** * Decode a JSON string into a PHP object. * * @param string $input JSON string * * @return object Object representation of JSON string * * @throws DomainException Provided string was invalid JSON */ public static function jsonDecode($input) { if (version_compare(PHP_VERSION, '5.4.0', '>=') && !(defined('JSON_C_VERSION') && PHP_INT_SIZE > 4)) { /** In PHP >=5.4.0, json_decode() accepts an options parameter, that allows you * to specify that large ints (like Steam Transaction IDs) should be treated as * strings, rather than the PHP default behaviour of converting them to floats. */ $obj = json_decode($input, false, 512, JSON_BIGINT_AS_STRING); } else { /** Not all servers will support that, however, so for older versions we must * manually detect large ints in the JSON string and quote them (thus converting *them to strings) before decoding, hence the preg_replace() call. */ $max_int_length = strlen((string) PHP_INT_MAX) - 1; $json_without_bigints = preg_replace('/:\s*(-?\d{'.$max_int_length.',})/', ': "$1"', $input); $obj = json_decode($json_without_bigints); } if (function_exists('json_last_error') && $errno = json_last_error()) { JWT::handleJsonError($errno); } elseif ($obj === null && $input !== 'null') { throw new DomainException('Null result with non-null input'); } return $obj; } /** * Encode a PHP object into a JSON string. * * @param object|array $input A PHP object or array * * @return string JSON representation of the PHP object or array * * @throws DomainException Provided object could not be encoded to valid JSON */ public static function jsonEncode($input) { $json = json_encode($input); if (function_exists('json_last_error') && $errno = json_last_error()) { JWT::handleJsonError($errno); } elseif ($json === 'null' && $input !== null) { throw new DomainException('Null result with non-null input'); } return $json; } /** * Decode a string with URL-safe Base64. * * @param string $input A Base64 encoded string * * @return string A decoded string */ public static function urlsafeB64Decode($input) { $remainder = strlen($input) % 4; if ($remainder) { $padlen = 4 - $remainder; $input .= str_repeat('=', $padlen); } return base64_decode(strtr($input, '-_', '+/')); } /** * Encode a string with URL-safe Base64. * * @param string $input The string you want encoded * * @return string The base64 encode of what you passed in */ public static function urlsafeB64Encode($input) { return str_replace('=', '', strtr(base64_encode($input), '+/', '-_')); } /** * Helper method to create a JSON error. * * @param int $errno An error number from json_last_error() * * @return void */ private static function handleJsonError($errno) { $messages = array( JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON' ); throw new DomainException( isset($messages[$errno]) ? $messages[$errno] : 'Unknown JSON error: ' . $errno ); } /** * Get the number of bytes in cryptographic strings. * * @param string * * @return int */ private static function safeStrlen($str) { if (function_exists('mb_strlen')) { return mb_strlen($str, '8bit'); } return strlen($str); } }
Demo Example:
<?php use \Firebase\JWT\JWT; $key = "example_key"; $token = array( "iss" => "http://example.org", "aud" => "http://example.com", "iat" => 1356999524, "nbf" => 1357000000 ); /** * IMPORTANT: * You must specify supported algorithms for your application. See * https://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-40 * for a list of spec-compliant algorithms. */ $jwt = JWT::encode($token, $key); $decoded = JWT::decode($jwt, $key, array('HS256')); print_r($decoded); /* NOTE: This will now be an object instead of an associative array. To get an associative array, you will need to cast it as such: */ $decoded_array = (array) $decoded; /** * You can add a leeway to account for when there is a clock skew times between * the signing and verifying servers. It is recommended that this leeway should * not be bigger than a few minutes. * * Source: http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html#nbfDef */ JWT::$leeway = 60; // $leeway in seconds $decoded = JWT::decode($jwt, $key, array('HS256')); ?>