BeforeValidException.php
3 years ago
ExpiredException.php
3 years ago
JWT.php
3 years ago
SignatureInvalidException.php
3 years ago
JWT.php
380 lines
| 1 | <?php |
| 2 | |
| 3 | namespace AmeliaFirebase\JWT; |
| 4 | use \DomainException; |
| 5 | use \InvalidArgumentException; |
| 6 | use \UnexpectedValueException; |
| 7 | use \DateTime; |
| 8 | |
| 9 | /** |
| 10 | * JSON Web Token implementation, based on this spec: |
| 11 | * https://tools.ietf.org/html/rfc7519 |
| 12 | * |
| 13 | * PHP version 5 |
| 14 | * |
| 15 | * @category Authentication |
| 16 | * @package Authentication_JWT |
| 17 | * @author Neuman Vong <neuman@twilio.com> |
| 18 | * @author Anant Narayanan <anant@php.net> |
| 19 | * @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD |
| 20 | * @link https://github.com/firebase/php-jwt |
| 21 | */ |
| 22 | class JWT |
| 23 | { |
| 24 | |
| 25 | /** |
| 26 | * When checking nbf, iat or expiration times, |
| 27 | * we want to provide some extra leeway time to |
| 28 | * account for clock skew. |
| 29 | */ |
| 30 | public static $leeway = 0; |
| 31 | |
| 32 | /** |
| 33 | * Allow the current timestamp to be specified. |
| 34 | * Useful for fixing a value within unit testing. |
| 35 | * |
| 36 | * Will default to PHP time() value if null. |
| 37 | */ |
| 38 | public static $timestamp = null; |
| 39 | |
| 40 | public static $supported_algs = array( |
| 41 | 'HS256' => array('hash_hmac', 'SHA256'), |
| 42 | 'HS512' => array('hash_hmac', 'SHA512'), |
| 43 | 'HS384' => array('hash_hmac', 'SHA384'), |
| 44 | 'RS256' => array('openssl', 'SHA256'), |
| 45 | 'RS384' => array('openssl', 'SHA384'), |
| 46 | 'RS512' => array('openssl', 'SHA512'), |
| 47 | ); |
| 48 | |
| 49 | /** |
| 50 | * Decodes a JWT string into a PHP object. |
| 51 | * |
| 52 | * @param string $jwt The JWT |
| 53 | * @param string|array $key The key, or map of keys. |
| 54 | * If the algorithm used is asymmetric, this is the public key |
| 55 | * @param array $allowed_algs List of supported verification algorithms |
| 56 | * Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256' |
| 57 | * |
| 58 | * @return object The JWT's payload as a PHP object |
| 59 | * |
| 60 | * @throws UnexpectedValueException Provided JWT was invalid |
| 61 | * @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed |
| 62 | * @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' |
| 63 | * @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' |
| 64 | * @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim |
| 65 | * |
| 66 | * @uses jsonDecode |
| 67 | * @uses urlsafeB64Decode |
| 68 | */ |
| 69 | public static function decode($jwt, $key, array $allowed_algs = array()) |
| 70 | { |
| 71 | $timestamp = is_null(static::$timestamp) ? time() : static::$timestamp; |
| 72 | |
| 73 | if (empty($key)) { |
| 74 | throw new InvalidArgumentException('Key may not be empty'); |
| 75 | } |
| 76 | $tks = explode('.', $jwt); |
| 77 | if (count($tks) != 3) { |
| 78 | throw new UnexpectedValueException('Wrong number of segments'); |
| 79 | } |
| 80 | list($headb64, $bodyb64, $cryptob64) = $tks; |
| 81 | if (null === ($header = static::jsonDecode(static::urlsafeB64Decode($headb64)))) { |
| 82 | throw new UnexpectedValueException('Invalid header encoding'); |
| 83 | } |
| 84 | if (null === $payload = static::jsonDecode(static::urlsafeB64Decode($bodyb64))) { |
| 85 | throw new UnexpectedValueException('Invalid claims encoding'); |
| 86 | } |
| 87 | if (false === ($sig = static::urlsafeB64Decode($cryptob64))) { |
| 88 | throw new UnexpectedValueException('Invalid signature encoding'); |
| 89 | } |
| 90 | if (empty($header->alg)) { |
| 91 | throw new UnexpectedValueException('Empty algorithm'); |
| 92 | } |
| 93 | if (empty(static::$supported_algs[$header->alg])) { |
| 94 | throw new UnexpectedValueException('Algorithm not supported'); |
| 95 | } |
| 96 | if (!in_array($header->alg, $allowed_algs)) { |
| 97 | throw new UnexpectedValueException('Algorithm not allowed'); |
| 98 | } |
| 99 | if (is_array($key) || $key instanceof \ArrayAccess) { |
| 100 | if (isset($header->kid)) { |
| 101 | if (!isset($key[$header->kid])) { |
| 102 | throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key'); |
| 103 | } |
| 104 | $key = $key[$header->kid]; |
| 105 | } else { |
| 106 | throw new UnexpectedValueException('"kid" empty, unable to lookup correct key'); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | // Check the signature |
| 111 | if (!static::verify("$headb64.$bodyb64", $sig, $key, $header->alg)) { |
| 112 | throw new SignatureInvalidException('Signature verification failed'); |
| 113 | } |
| 114 | |
| 115 | // Check if the nbf if it is defined. This is the time that the |
| 116 | // token can actually be used. If it's not yet that time, abort. |
| 117 | if (isset($payload->nbf) && $payload->nbf > ($timestamp + static::$leeway)) { |
| 118 | throw new BeforeValidException( |
| 119 | 'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->nbf) |
| 120 | ); |
| 121 | } |
| 122 | |
| 123 | // Check that this token has been created before 'now'. This prevents |
| 124 | // using tokens that have been created for later use (and haven't |
| 125 | // correctly used the nbf claim). |
| 126 | if (isset($payload->iat) && $payload->iat > ($timestamp + static::$leeway)) { |
| 127 | throw new BeforeValidException( |
| 128 | 'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->iat) |
| 129 | ); |
| 130 | } |
| 131 | |
| 132 | // Check if this token has expired. |
| 133 | if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) { |
| 134 | throw new ExpiredException('Expired token'); |
| 135 | } |
| 136 | |
| 137 | return $payload; |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Converts and signs a PHP object or array into a JWT string. |
| 142 | * |
| 143 | * @param object|array $payload PHP object or array |
| 144 | * @param string $key The secret key. |
| 145 | * If the algorithm used is asymmetric, this is the private key |
| 146 | * @param string $alg The signing algorithm. |
| 147 | * Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256' |
| 148 | * @param mixed $keyId |
| 149 | * @param array $head An array with header elements to attach |
| 150 | * |
| 151 | * @return string A signed JWT |
| 152 | * |
| 153 | * @uses jsonEncode |
| 154 | * @uses urlsafeB64Encode |
| 155 | */ |
| 156 | public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null) |
| 157 | { |
| 158 | $header = array('typ' => 'JWT', 'alg' => $alg); |
| 159 | if ($keyId !== null) { |
| 160 | $header['kid'] = $keyId; |
| 161 | } |
| 162 | if ( isset($head) && is_array($head) ) { |
| 163 | $header = array_merge($head, $header); |
| 164 | } |
| 165 | $segments = array(); |
| 166 | $segments[] = static::urlsafeB64Encode(static::jsonEncode($header)); |
| 167 | $segments[] = static::urlsafeB64Encode(static::jsonEncode($payload)); |
| 168 | $signing_input = implode('.', $segments); |
| 169 | |
| 170 | $signature = static::sign($signing_input, $key, $alg); |
| 171 | $segments[] = static::urlsafeB64Encode($signature); |
| 172 | |
| 173 | return implode('.', $segments); |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * Sign a string with a given key and algorithm. |
| 178 | * |
| 179 | * @param string $msg The message to sign |
| 180 | * @param string|resource $key The secret key |
| 181 | * @param string $alg The signing algorithm. |
| 182 | * Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256' |
| 183 | * |
| 184 | * @return string An encrypted message |
| 185 | * |
| 186 | * @throws DomainException Unsupported algorithm was specified |
| 187 | */ |
| 188 | public static function sign($msg, $key, $alg = 'HS256') |
| 189 | { |
| 190 | if (empty(static::$supported_algs[$alg])) { |
| 191 | throw new DomainException('Algorithm not supported'); |
| 192 | } |
| 193 | list($function, $algorithm) = static::$supported_algs[$alg]; |
| 194 | switch($function) { |
| 195 | case 'hash_hmac': |
| 196 | return hash_hmac($algorithm, $msg, $key, true); |
| 197 | case 'openssl': |
| 198 | $signature = ''; |
| 199 | $success = openssl_sign($msg, $signature, $key, $algorithm); |
| 200 | if (!$success) { |
| 201 | throw new DomainException("OpenSSL unable to sign data"); |
| 202 | } else { |
| 203 | return $signature; |
| 204 | } |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Verify a signature with the message, key and method. Not all methods |
| 210 | * are symmetric, so we must have a separate verify and sign method. |
| 211 | * |
| 212 | * @param string $msg The original message (header and body) |
| 213 | * @param string $signature The original signature |
| 214 | * @param string|resource $key For HS*, a string key works. for RS*, must be a resource of an openssl public key |
| 215 | * @param string $alg The algorithm |
| 216 | * |
| 217 | * @return bool |
| 218 | * |
| 219 | * @throws DomainException Invalid Algorithm or OpenSSL failure |
| 220 | */ |
| 221 | private static function verify($msg, $signature, $key, $alg) |
| 222 | { |
| 223 | if (empty(static::$supported_algs[$alg])) { |
| 224 | throw new DomainException('Algorithm not supported'); |
| 225 | } |
| 226 | |
| 227 | list($function, $algorithm) = static::$supported_algs[$alg]; |
| 228 | switch($function) { |
| 229 | case 'openssl': |
| 230 | $success = openssl_verify($msg, $signature, $key, $algorithm); |
| 231 | if ($success === 1) { |
| 232 | return true; |
| 233 | } elseif ($success === 0) { |
| 234 | return false; |
| 235 | } |
| 236 | // returns 1 on success, 0 on failure, -1 on error. |
| 237 | throw new DomainException( |
| 238 | 'OpenSSL error: ' . openssl_error_string() |
| 239 | ); |
| 240 | case 'hash_hmac': |
| 241 | default: |
| 242 | $hash = hash_hmac($algorithm, $msg, $key, true); |
| 243 | if (function_exists('hash_equals')) { |
| 244 | return hash_equals($signature, $hash); |
| 245 | } |
| 246 | $len = min(static::safeStrlen($signature), static::safeStrlen($hash)); |
| 247 | |
| 248 | $status = 0; |
| 249 | for ($i = 0; $i < $len; $i++) { |
| 250 | $status |= (ord($signature[$i]) ^ ord($hash[$i])); |
| 251 | } |
| 252 | $status |= (static::safeStrlen($signature) ^ static::safeStrlen($hash)); |
| 253 | |
| 254 | return ($status === 0); |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * Decode a JSON string into a PHP object. |
| 260 | * |
| 261 | * @param string $input JSON string |
| 262 | * |
| 263 | * @return object Object representation of JSON string |
| 264 | * |
| 265 | * @throws DomainException Provided string was invalid JSON |
| 266 | */ |
| 267 | public static function jsonDecode($input) |
| 268 | { |
| 269 | if (version_compare(PHP_VERSION, '5.4.0', '>=') && !(defined('JSON_C_VERSION') && PHP_INT_SIZE > 4)) { |
| 270 | /** In PHP >=5.4.0, json_decode() accepts an options parameter, that allows you |
| 271 | * to specify that large ints (like Steam Transaction IDs) should be treated as |
| 272 | * strings, rather than the PHP default behaviour of converting them to floats. |
| 273 | */ |
| 274 | $obj = json_decode($input, false, 512, JSON_BIGINT_AS_STRING); |
| 275 | } else { |
| 276 | /** Not all servers will support that, however, so for older versions we must |
| 277 | * manually detect large ints in the JSON string and quote them (thus converting |
| 278 | *them to strings) before decoding, hence the preg_replace() call. |
| 279 | */ |
| 280 | $max_int_length = strlen((string) PHP_INT_MAX) - 1; |
| 281 | $json_without_bigints = preg_replace('/:\s*(-?\d{'.$max_int_length.',})/', ': "$1"', $input); |
| 282 | $obj = json_decode($json_without_bigints); |
| 283 | } |
| 284 | |
| 285 | if (function_exists('json_last_error') && $errno = json_last_error()) { |
| 286 | static::handleJsonError($errno); |
| 287 | } elseif ($obj === null && $input !== 'null') { |
| 288 | throw new DomainException('Null result with non-null input'); |
| 289 | } |
| 290 | return $obj; |
| 291 | } |
| 292 | |
| 293 | /** |
| 294 | * Encode a PHP object into a JSON string. |
| 295 | * |
| 296 | * @param object|array $input A PHP object or array |
| 297 | * |
| 298 | * @return string JSON representation of the PHP object or array |
| 299 | * |
| 300 | * @throws DomainException Provided object could not be encoded to valid JSON |
| 301 | */ |
| 302 | public static function jsonEncode($input) |
| 303 | { |
| 304 | $json = json_encode($input); |
| 305 | if (function_exists('json_last_error') && $errno = json_last_error()) { |
| 306 | static::handleJsonError($errno); |
| 307 | } elseif ($json === 'null' && $input !== null) { |
| 308 | throw new DomainException('Null result with non-null input'); |
| 309 | } |
| 310 | return $json; |
| 311 | } |
| 312 | |
| 313 | /** |
| 314 | * Decode a string with URL-safe Base64. |
| 315 | * |
| 316 | * @param string $input A Base64 encoded string |
| 317 | * |
| 318 | * @return string A decoded string |
| 319 | */ |
| 320 | public static function urlsafeB64Decode($input) |
| 321 | { |
| 322 | $remainder = strlen($input) % 4; |
| 323 | if ($remainder) { |
| 324 | $padlen = 4 - $remainder; |
| 325 | $input .= str_repeat('=', $padlen); |
| 326 | } |
| 327 | return base64_decode(strtr($input, '-_', '+/')); |
| 328 | } |
| 329 | |
| 330 | /** |
| 331 | * Encode a string with URL-safe Base64. |
| 332 | * |
| 333 | * @param string $input The string you want encoded |
| 334 | * |
| 335 | * @return string The base64 encode of what you passed in |
| 336 | */ |
| 337 | public static function urlsafeB64Encode($input) |
| 338 | { |
| 339 | return str_replace('=', '', strtr(base64_encode($input), '+/', '-_')); |
| 340 | } |
| 341 | |
| 342 | /** |
| 343 | * Helper method to create a JSON error. |
| 344 | * |
| 345 | * @param int $errno An error number from json_last_error() |
| 346 | * |
| 347 | * @return void |
| 348 | */ |
| 349 | private static function handleJsonError($errno) |
| 350 | { |
| 351 | $messages = array( |
| 352 | JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', |
| 353 | JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON', |
| 354 | JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', |
| 355 | JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON', |
| 356 | JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3 |
| 357 | ); |
| 358 | throw new DomainException( |
| 359 | isset($messages[$errno]) |
| 360 | ? $messages[$errno] |
| 361 | : 'Unknown JSON error: ' . $errno |
| 362 | ); |
| 363 | } |
| 364 | |
| 365 | /** |
| 366 | * Get the number of bytes in cryptographic strings. |
| 367 | * |
| 368 | * @param string |
| 369 | * |
| 370 | * @return int |
| 371 | */ |
| 372 | private static function safeStrlen($str) |
| 373 | { |
| 374 | if (function_exists('mb_strlen')) { |
| 375 | return mb_strlen($str, '8bit'); |
| 376 | } |
| 377 | return strlen($str); |
| 378 | } |
| 379 | } |
| 380 |