New file |
0,0 → 1,326 |
<?php |
|
/** |
* 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 |
{ |
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 secret key, or map of keys |
* @param Array $allowed_algs List of supported verification algorithms |
* |
* @return object The JWT's payload as a PHP object |
* |
* @throws DomainException Algorithm was not provided |
* @throws UnexpectedValueException Provided JWT was invalid |
* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed |
* @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' |
* @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' |
* @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim |
* |
* @uses jsonDecode |
* @uses urlsafeB64Decode |
*/ |
public static function decode($jwt, $key = null, $allowed_algs = array()) |
{ |
$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 (isset($key)) { |
if (empty($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)) { |
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()) { |
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()) { |
throw new BeforeValidException( |
'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->iat) |
); |
} |
|
// Check if this token has expired. |
if (isset($payload->exp) && time() >= $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 |
* @param string $alg The signing algorithm. Supported |
* algorithms are 'HS256', 'HS384' and 'HS512' |
* |
* @return string A signed JWT |
* @uses jsonEncode |
* @uses urlsafeB64Encode |
*/ |
public static function encode($payload, $key, $alg = 'HS256', $keyId = null) |
{ |
$header = array('typ' => 'JWT', 'alg' => $alg); |
if ($keyId !== null) { |
$header['kid'] = $keyId; |
} |
$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 mesage, key and method. Not all methods |
* are symmetric, so we must have a separate verify and sign method. |
* @param string $msg the original message |
* @param string $signature |
* @param string|resource $key for HS*, a string key works. for RS*, must be a resource of an openssl public key |
* @param string $alg |
* @return bool |
* @throws DomainException Invalid Algorithm or OpenSSL failure |
*/ |
private static function verify($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); |
} |
} |