| 1 |
<?php |
| 2 |
|
| 3 |
namespace Firebase\JWT; |
| 4 |
|
| 5 |
use \DomainException; |
| 6 |
use \InvalidArgumentException; |
| 7 |
use \UnexpectedValueException; |
| 8 |
use \DateTime; |
| 9 |
|
| 10 |
/** |
| 11 |
* JSON Web Token implementation, based on this spec: |
| 12 |
* https://tools.ietf.org/html/rfc7519 |
| 13 |
* |
| 14 |
* PHP version 5 |
| 15 |
* |
| 16 |
* @category Authentication |
| 17 |
* @package Authentication_JWT |
| 18 |
* @author Neuman Vong <neuman@twilio.com> |
| 19 |
* @author Anant Narayanan <anant@php.net> |
| 20 |
* @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD |
| 21 |
* @link https://github.com/firebase/php-jwt |
| 22 |
*/ |
| 23 |
class JWT |
| 24 |
{ |
| 25 |
const ASN1_INTEGER = 0x02; |
| 26 |
const ASN1_SEQUENCE = 0x10; |
| 27 |
const ASN1_BIT_STRING = 0x03; |
| 28 |
|
| 29 |
/** |
| 30 |
* When checking nbf, iat or expiration times, |
| 31 |
* we want to provide some extra leeway time to |
| 32 |
* account for clock skew. |
| 33 |
*/ |
| 34 |
public static $leeway = 0; |
| 35 |
|
| 36 |
/** |
| 37 |
* Allow the current timestamp to be specified. |
| 38 |
* Useful for fixing a value within unit testing. |
| 39 |
* |
| 40 |
* Will default to PHP time() value if null. |
| 41 |
*/ |
| 42 |
public static $timestamp = null; |
| 43 |
|
| 44 |
public static $supported_algs = array( |
| 45 |
'ES256' => array('openssl', 'SHA256'), |
| 46 |
'HS256' => array('hash_hmac', 'SHA256'), |
| 47 |
'HS384' => array('hash_hmac', 'SHA384'), |
| 48 |
'HS512' => array('hash_hmac', 'SHA512'), |
| 49 |
'RS256' => array('openssl', 'SHA256'), |
| 50 |
'RS384' => array('openssl', 'SHA384'), |
| 51 |
'RS512' => array('openssl', 'SHA512'), |
| 52 |
); |
| 53 |
|
| 54 |
/** |
| 55 |
* Decodes a JWT string into a PHP object. |
| 56 |
* |
| 57 |
* @param string $jwt The JWT |
| 58 |
* @param string|array|resource $key The key, or map of keys. |
| 59 |
* If the algorithm used is asymmetric, this is the public key |
| 60 |
* @param array $allowed_algs List of supported verification algorithms |
| 61 |
* Supported algorithms are 'ES256', 'HS256', 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512' |
| 62 |
* |
| 63 |
* @return object The JWT's payload as a PHP object |
| 64 |
* |
| 65 |
* @throws UnexpectedValueException Provided JWT was invalid |
| 66 |
* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed |
| 67 |
* @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' |
| 68 |
* @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' |
| 69 |
* @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim |
| 70 |
* |
| 71 |
* @uses jsonDecode |
| 72 |
* @uses urlsafeB64Decode |
| 73 |
*/ |
| 74 |
public static function decode($jwt, $key, array $allowed_algs = array()) |
| 75 |
{ |
| 76 |
$timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp; |
| 77 |
|
| 78 |
if (empty($key)) { |
| 79 |
throw new InvalidArgumentException('Key may not be empty'); |
| 80 |
} |
| 81 |
$tks = \explode('.', $jwt); |
| 82 |
if (\count($tks) != 3) { |
| 83 |
throw new UnexpectedValueException('Wrong number of segments'); |
| 84 |
} |
| 85 |
list($headb64, $bodyb64, $cryptob64) = $tks; |
| 86 |
if (null === ($header = static::jsonDecode(static::urlsafeB64Decode($headb64)))) { |
| 87 |
throw new UnexpectedValueException('Invalid header encoding'); |
| 88 |
} |
| 89 |
if (null === $payload = static::jsonDecode(static::urlsafeB64Decode($bodyb64))) { |
| 90 |
throw new UnexpectedValueException('Invalid claims encoding'); |
| 91 |
} |
| 92 |
if (false === ($sig = static::urlsafeB64Decode($cryptob64))) { |
| 93 |
throw new UnexpectedValueException('Invalid signature encoding'); |
| 94 |
} |
| 95 |
if (empty($header->alg)) { |
| 96 |
throw new UnexpectedValueException('Empty algorithm'); |
| 97 |
} |
| 98 |
if (empty(static::$supported_algs[$header->alg])) { |
| 99 |
throw new UnexpectedValueException('Algorithm not supported'); |
| 100 |
} |
| 101 |
if (!\in_array($header->alg, $allowed_algs)) { |
| 102 |
throw new UnexpectedValueException('Algorithm not allowed'); |
| 103 |
} |
| 104 |
if ($header->alg === 'ES256') { |
| 105 |
// OpenSSL expects an ASN.1 DER sequence for ES256 signatures |
| 106 |
$sig = self::signatureToDER($sig); |
| 107 |
} |
| 108 |
|
| 109 |
if (\is_array($key) || $key instanceof \ArrayAccess) { |
| 110 |
if (isset($header->kid)) { |
| 111 |
if (!isset($key[$header->kid])) { |
| 112 |
throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key'); |
| 113 |
} |
| 114 |
$key = $key[$header->kid]; |
| 115 |
} else { |
| 116 |
throw new UnexpectedValueException('"kid" empty, unable to lookup correct key'); |
| 117 |
} |
| 118 |
} |
| 119 |
|
| 120 |
// Check the signature |
| 121 |
if (!static::verify("$headb64.$bodyb64", $sig, $key, $header->alg)) { |
| 122 |
throw new SignatureInvalidException('Signature verification failed'); |
| 123 |
} |
| 124 |
|
| 125 |
// Check the nbf if it is defined. This is the time that the |
| 126 |
// token can actually be used. If it's not yet that time, abort. |
| 127 |
if (isset($payload->nbf) && $payload->nbf > ($timestamp + static::$leeway)) { |
| 128 |
throw new BeforeValidException( |
| 129 |
'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->nbf) |
| 130 |
); |
| 131 |
} |
| 132 |
|
| 133 |
// Check that this token has been created before 'now'. This prevents |
| 134 |
// using tokens that have been created for later use (and haven't |
| 135 |
// correctly used the nbf claim). |
| 136 |
if (isset($payload->iat) && $payload->iat > ($timestamp + static::$leeway)) { |
| 137 |
throw new BeforeValidException( |
| 138 |
'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->iat) |
| 139 |
); |
| 140 |
} |
| 141 |
|
| 142 |
// Check if this token has expired. |
| 143 |
if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) { |
| 144 |
throw new ExpiredException('Expired token'); |
| 145 |
} |
| 146 |
|
| 147 |
return $payload; |
| 148 |
} |
| 149 |
|
| 150 |
/** |
| 151 |
* Converts and signs a PHP object or array into a JWT string. |
| 152 |
* |
| 153 |
* @param object|array $payload PHP object or array |
| 154 |
* @param string $key The secret key. |
| 155 |
* If the algorithm used is asymmetric, this is the private key |
| 156 |
* @param string $alg The signing algorithm. |
| 157 |
* Supported algorithms are 'ES256', 'HS256', 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512' |
| 158 |
* @param mixed $keyId |
| 159 |
* @param array $head An array with header elements to attach |
| 160 |
* |
| 161 |
* @return string A signed JWT |
| 162 |
* |
| 163 |
* @uses jsonEncode |
| 164 |
* @uses urlsafeB64Encode |
| 165 |
*/ |
| 166 |
public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null) |
| 167 |
{ |
| 168 |
$header = array('typ' => 'JWT', 'alg' => $alg); |
| 169 |
if ($keyId !== null) { |
| 170 |
$header['kid'] = $keyId; |
| 171 |
} |
| 172 |
if (isset($head) && \is_array($head)) { |
| 173 |
$header = \array_merge($head, $header); |
| 174 |
} |
| 175 |
$segments = array(); |
| 176 |
$segments[] = static::urlsafeB64Encode(static::jsonEncode($header)); |
| 177 |
$segments[] = static::urlsafeB64Encode(static::jsonEncode($payload)); |
| 178 |
$signing_input = \implode('.', $segments); |
| 179 |
|
| 180 |
$signature = static::sign($signing_input, $key, $alg); |
| 181 |
$segments[] = static::urlsafeB64Encode($signature); |
| 182 |
|
| 183 |
return \implode('.', $segments); |
| 184 |
} |
| 185 |
|
| 186 |
/** |
| 187 |
* Sign a string with a given key and algorithm. |
| 188 |
* |
| 189 |
* @param string $msg The message to sign |
| 190 |
* @param string|resource $key The secret key |
| 191 |
* @param string $alg The signing algorithm. |
| 192 |
* Supported algorithms are 'ES256', 'HS256', 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512' |
| 193 |
* |
| 194 |
* @return string An encrypted message |
| 195 |
* |
| 196 |
* @throws DomainException Unsupported algorithm was specified |
| 197 |
*/ |
| 198 |
public static function sign($msg, $key, $alg = 'HS256') |
| 199 |
{ |
| 200 |
if (empty(static::$supported_algs[$alg])) { |
| 201 |
throw new DomainException('Algorithm not supported'); |
| 202 |
} |
| 203 |
list($function, $algorithm) = static::$supported_algs[$alg]; |
| 204 |
switch ($function) { |
| 205 |
case 'hash_hmac': |
| 206 |
return \hash_hmac($algorithm, $msg, $key, true); |
| 207 |
case 'openssl': |
| 208 |
$signature = ''; |
| 209 |
$success = \openssl_sign($msg, $signature, $key, $algorithm); |
| 210 |
if (!$success) { |
| 211 |
throw new DomainException("OpenSSL unable to sign data"); |
| 212 |
} else { |
| 213 |
if ($alg === 'ES256') { |
| 214 |
$signature = self::signatureFromDER($signature, 256); |
| 215 |
} |
| 216 |
return $signature; |
| 217 |
} |
| 218 |
} |
| 219 |
} |
| 220 |
|
| 221 |
/** |
| 222 |
* Verify a signature with the message, key and method. Not all methods |
| 223 |
* are symmetric, so we must have a separate verify and sign method. |
| 224 |
* |
| 225 |
* @param string $msg The original message (header and body) |
| 226 |
* @param string $signature The original signature |
| 227 |
* @param string|resource $key For HS*, a string key works. for RS*, must be a resource of an openssl public key |
| 228 |
* @param string $alg The algorithm |
| 229 |
* |
| 230 |
* @return bool |
| 231 |
* |
| 232 |
* @throws DomainException Invalid Algorithm or OpenSSL failure |
| 233 |
*/ |
| 234 |
private static function verify($msg, $signature, $key, $alg) |
| 235 |
{ |
| 236 |
if (empty(static::$supported_algs[$alg])) { |
| 237 |
throw new DomainException('Algorithm not supported'); |
| 238 |
} |
| 239 |
|
| 240 |
list($function, $algorithm) = static::$supported_algs[$alg]; |
| 241 |
switch ($function) { |
| 242 |
case 'openssl': |
| 243 |
$success = \openssl_verify($msg, $signature, $key, $algorithm); |
| 244 |
if ($success === 1) { |
| 245 |
return true; |
| 246 |
} elseif ($success === 0) { |
| 247 |
return false; |
| 248 |
} |
| 249 |
// returns 1 on success, 0 on failure, -1 on error. |
| 250 |
throw new DomainException( |
| 251 |
'OpenSSL error: ' . \openssl_error_string() |
| 252 |
); |
| 253 |
case 'hash_hmac': |
| 254 |
default: |
| 255 |
$hash = \hash_hmac($algorithm, $msg, $key, true); |
| 256 |
if (\function_exists('hash_equals')) { |
| 257 |
return \hash_equals($signature, $hash); |
| 258 |
} |
| 259 |
$len = \min(static::safeStrlen($signature), static::safeStrlen($hash)); |
| 260 |
|
| 261 |
$status = 0; |
| 262 |
for ($i = 0; $i < $len; $i++) { |
| 263 |
$status |= (\ord($signature[$i]) ^ \ord($hash[$i])); |
| 264 |
} |
| 265 |
$status |= (static::safeStrlen($signature) ^ static::safeStrlen($hash)); |
| 266 |
|
| 267 |
return ($status === 0); |
| 268 |
} |
| 269 |
} |
| 270 |
|
| 271 |
/** |
| 272 |
* Decode a JSON string into a PHP object. |
| 273 |
* |
| 274 |
* @param string $input JSON string |
| 275 |
* |
| 276 |
* @return object Object representation of JSON string |
| 277 |
* |
| 278 |
* @throws DomainException Provided string was invalid JSON |
| 279 |
*/ |
| 280 |
public static function jsonDecode($input) |
| 281 |
{ |
| 282 |
if (\version_compare(PHP_VERSION, '5.4.0', '>=') && !(\defined('JSON_C_VERSION') && PHP_INT_SIZE > 4)) { |
| 283 |
/** In PHP >=5.4.0, json_decode() accepts an options parameter, that allows you |
| 284 |
* to specify that large ints (like Steam Transaction IDs) should be treated as |
| 285 |
* strings, rather than the PHP default behaviour of converting them to floats. |
| 286 |
*/ |
| 287 |
$obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING); |
| 288 |
} else { |
| 289 |
/** Not all servers will support that, however, so for older versions we must |
| 290 |
* manually detect large ints in the JSON string and quote them (thus converting |
| 291 |
*them to strings) before decoding, hence the preg_replace() call. |
| 292 |
*/ |
| 293 |
$max_int_length = \strlen((string) PHP_INT_MAX) - 1; |
| 294 |
$json_without_bigints = \preg_replace('/:\s*(-?\d{'.$max_int_length.',})/', ': "$1"', $input); |
| 295 |
$obj = \json_decode($json_without_bigints); |
| 296 |
} |
| 297 |
|
| 298 |
if ($errno = \json_last_error()) { |
| 299 |
static::handleJsonError($errno); |
| 300 |
} elseif ($obj === null && $input !== 'null') { |
| 301 |
throw new DomainException('Null result with non-null input'); |
| 302 |
} |
| 303 |
return $obj; |
| 304 |
} |
| 305 |
|
| 306 |
/** |
| 307 |
* Encode a PHP object into a JSON string. |
| 308 |
* |
| 309 |
* @param object|array $input A PHP object or array |
| 310 |
* |
| 311 |
* @return string JSON representation of the PHP object or array |
| 312 |
* |
| 313 |
* @throws DomainException Provided object could not be encoded to valid JSON |
| 314 |
*/ |
| 315 |
public static function jsonEncode($input) |
| 316 |
{ |
| 317 |
$json = \json_encode($input); |
| 318 |
if ($errno = \json_last_error()) { |
| 319 |
static::handleJsonError($errno); |
| 320 |
} elseif ($json === 'null' && $input !== null) { |
| 321 |
throw new DomainException('Null result with non-null input'); |
| 322 |
} |
| 323 |
return $json; |
| 324 |
} |
| 325 |
|
| 326 |
/** |
| 327 |
* Decode a string with URL-safe Base64. |
| 328 |
* |
| 329 |
* @param string $input A Base64 encoded string |
| 330 |
* |
| 331 |
* @return string A decoded string |
| 332 |
*/ |
| 333 |
public static function urlsafeB64Decode($input) |
| 334 |
{ |
| 335 |
$remainder = \strlen($input) % 4; |
| 336 |
if ($remainder) { |
| 337 |
$padlen = 4 - $remainder; |
| 338 |
$input .= \str_repeat('=', $padlen); |
| 339 |
} |
| 340 |
return \base64_decode(\strtr($input, '-_', '+/')); |
| 341 |
} |
| 342 |
|
| 343 |
/** |
| 344 |
* Encode a string with URL-safe Base64. |
| 345 |
* |
| 346 |
* @param string $input The string you want encoded |
| 347 |
* |
| 348 |
* @return string The base64 encode of what you passed in |
| 349 |
*/ |
| 350 |
public static function urlsafeB64Encode($input) |
| 351 |
{ |
| 352 |
return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_')); |
| 353 |
} |
| 354 |
|
| 355 |
/** |
| 356 |
* Helper method to create a JSON error. |
| 357 |
* |
| 358 |
* @param int $errno An error number from json_last_error() |
| 359 |
* |
| 360 |
* @return void |
| 361 |
*/ |
| 362 |
private static function handleJsonError($errno) |
| 363 |
{ |
| 364 |
$messages = array( |
| 365 |
JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', |
| 366 |
JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON', |
| 367 |
JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', |
| 368 |
JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON', |
| 369 |
JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3 |
| 370 |
); |
| 371 |
throw new DomainException( |
| 372 |
isset($messages[$errno]) |
| 373 |
? $messages[$errno] |
| 374 |
: 'Unknown JSON error: ' . $errno |
| 375 |
); |
| 376 |
} |
| 377 |
|
| 378 |
/** |
| 379 |
* Get the number of bytes in cryptographic strings. |
| 380 |
* |
| 381 |
* @param string $str |
| 382 |
* |
| 383 |
* @return int |
| 384 |
*/ |
| 385 |
private static function safeStrlen($str) |
| 386 |
{ |
| 387 |
if (\function_exists('mb_strlen')) { |
| 388 |
return \mb_strlen($str, '8bit'); |
| 389 |
} |
| 390 |
return \strlen($str); |
| 391 |
} |
| 392 |
|
| 393 |
/** |
| 394 |
* Convert an ECDSA signature to an ASN.1 DER sequence |
| 395 |
* |
| 396 |
* @param string $sig The ECDSA signature to convert |
| 397 |
* @return string The encoded DER object |
| 398 |
*/ |
| 399 |
private static function signatureToDER($sig) |
| 400 |
{ |
| 401 |
// Separate the signature into r-value and s-value |
| 402 |
list($r, $s) = \str_split($sig, (int) (\strlen($sig) / 2)); |
| 403 |
|
| 404 |
// Trim leading zeros |
| 405 |
$r = \ltrim($r, "\x00"); |
| 406 |
$s = \ltrim($s, "\x00"); |
| 407 |
|
| 408 |
// Convert r-value and s-value from unsigned big-endian integers to |
| 409 |
// signed two's complement |
| 410 |
if (\ord($r[0]) > 0x7f) { |
| 411 |
$r = "\x00" . $r; |
| 412 |
} |
| 413 |
if (\ord($s[0]) > 0x7f) { |
| 414 |
$s = "\x00" . $s; |
| 415 |
} |
| 416 |
|
| 417 |
return self::encodeDER( |
| 418 |
self::ASN1_SEQUENCE, |
| 419 |
self::encodeDER(self::ASN1_INTEGER, $r) . |
| 420 |
self::encodeDER(self::ASN1_INTEGER, $s) |
| 421 |
); |
| 422 |
} |
| 423 |
|
| 424 |
/** |
| 425 |
* Encodes a value into a DER object. |
| 426 |
* |
| 427 |
* @param int $type DER tag |
| 428 |
* @param string $value the value to encode |
| 429 |
* @return string the encoded object |
| 430 |
*/ |
| 431 |
private static function encodeDER($type, $value) |
| 432 |
{ |
| 433 |
$tag_header = 0; |
| 434 |
if ($type === self::ASN1_SEQUENCE) { |
| 435 |
$tag_header |= 0x20; |
| 436 |
} |
| 437 |
|
| 438 |
// Type |
| 439 |
$der = \chr($tag_header | $type); |
| 440 |
|
| 441 |
// Length |
| 442 |
$der .= \chr(\strlen($value)); |
| 443 |
|
| 444 |
return $der . $value; |
| 445 |
} |
| 446 |
|
| 447 |
/** |
| 448 |
* Encodes signature from a DER object. |
| 449 |
* |
| 450 |
* @param string $der binary signature in DER format |
| 451 |
* @param int $keySize the number of bits in the key |
| 452 |
* @return string the signature |
| 453 |
*/ |
| 454 |
private static function signatureFromDER($der, $keySize) |
| 455 |
{ |
| 456 |
// OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE |
| 457 |
list($offset, $_) = self::readDER($der); |
| 458 |
list($offset, $r) = self::readDER($der, $offset); |
| 459 |
list($offset, $s) = self::readDER($der, $offset); |
| 460 |
|
| 461 |
// Convert r-value and s-value from signed two's compliment to unsigned |
| 462 |
// big-endian integers |
| 463 |
$r = \ltrim($r, "\x00"); |
| 464 |
$s = \ltrim($s, "\x00"); |
| 465 |
|
| 466 |
// Pad out r and s so that they are $keySize bits long |
| 467 |
$r = \str_pad($r, $keySize / 8, "\x00", STR_PAD_LEFT); |
| 468 |
$s = \str_pad($s, $keySize / 8, "\x00", STR_PAD_LEFT); |
| 469 |
|
| 470 |
return $r . $s; |
| 471 |
} |
| 472 |
|
| 473 |
/** |
| 474 |
* Reads binary DER-encoded data and decodes into a single object |
| 475 |
* |
| 476 |
* @param string $der the binary data in DER format |
| 477 |
* @param int $offset the offset of the data stream containing the object |
| 478 |
* to decode |
| 479 |
* @return array [$offset, $data] the new offset and the decoded object |
| 480 |
*/ |
| 481 |
private static function readDER($der, $offset = 0) |
| 482 |
{ |
| 483 |
$pos = $offset; |
| 484 |
$size = \strlen($der); |
| 485 |
$constructed = (\ord($der[$pos]) >> 5) & 0x01; |
| 486 |
$type = \ord($der[$pos++]) & 0x1f; |
| 487 |
|
| 488 |
// Length |
| 489 |
$len = \ord($der[$pos++]); |
| 490 |
if ($len & 0x80) { |
| 491 |
$n = $len & 0x1f; |
| 492 |
$len = 0; |
| 493 |
while ($n-- && $pos < $size) { |
| 494 |
$len = ($len << 8) | \ord($der[$pos++]); |
| 495 |
} |
| 496 |
} |
| 497 |
|
| 498 |
// Value |
| 499 |
if ($type == self::ASN1_BIT_STRING) { |
| 500 |
$pos++; // Skip the first contents octet (padding indicator) |
| 501 |
$data = \substr($der, $pos, $len - 1); |
| 502 |
$pos += $len - 1; |
| 503 |
} elseif (!$constructed) { |
| 504 |
$data = \substr($der, $pos, $len); |
| 505 |
$pos += $len; |
| 506 |
} else { |
| 507 |
$data = null; |
| 508 |
} |
| 509 |
|
| 510 |
return array($pos, $data); |
| 511 |
} |
| 512 |
} |
| 513 |
|
