| 1 |
<?php |
| 2 |
|
| 3 |
namespace Firebase\JWT; |
| 4 |
|
| 5 |
use ArrayAccess; |
| 6 |
use DomainException; |
| 7 |
use Exception; |
| 8 |
use InvalidArgumentException; |
| 9 |
use OpenSSLAsymmetricKey; |
| 10 |
use OpenSSLCertificate; |
| 11 |
use TypeError; |
| 12 |
use UnexpectedValueException; |
| 13 |
use DateTime; |
| 14 |
use stdClass; |
| 15 |
|
| 16 |
/** |
| 17 |
* JSON Web Token implementation, based on this spec: |
| 18 |
* https://tools.ietf.org/html/rfc7519 |
| 19 |
* |
| 20 |
* PHP version 5 |
| 21 |
* |
| 22 |
* @category Authentication |
| 23 |
* @package Authentication_JWT |
| 24 |
* @author Neuman Vong <neuman@twilio.com> |
| 25 |
* @author Anant Narayanan <anant@php.net> |
| 26 |
* @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD |
| 27 |
* @link https://github.com/firebase/php-jwt |
| 28 |
*/ |
| 29 |
class JWT |
| 30 |
{ |
| 31 |
private const ASN1_INTEGER = 0x02; |
| 32 |
private const ASN1_SEQUENCE = 0x10; |
| 33 |
private const ASN1_BIT_STRING = 0x03; |
| 34 |
|
| 35 |
/** |
| 36 |
* When checking nbf, iat or expiration times, |
| 37 |
* we want to provide some extra leeway time to |
| 38 |
* account for clock skew. |
| 39 |
* |
| 40 |
* @var int |
| 41 |
*/ |
| 42 |
public static $leeway = 0; |
| 43 |
|
| 44 |
/** |
| 45 |
* Allow the current timestamp to be specified. |
| 46 |
* Useful for fixing a value within unit testing. |
| 47 |
* Will default to PHP time() value if null. |
| 48 |
* |
| 49 |
* @var ?int |
| 50 |
*/ |
| 51 |
public static $timestamp = null; |
| 52 |
|
| 53 |
/** |
| 54 |
* @var array<string, string[]> |
| 55 |
*/ |
| 56 |
public static $supported_algs = [ |
| 57 |
'ES384' => ['openssl', 'SHA384'], |
| 58 |
'ES256' => ['openssl', 'SHA256'], |
| 59 |
'HS256' => ['hash_hmac', 'SHA256'], |
| 60 |
'HS384' => ['hash_hmac', 'SHA384'], |
| 61 |
'HS512' => ['hash_hmac', 'SHA512'], |
| 62 |
'RS256' => ['openssl', 'SHA256'], |
| 63 |
'RS384' => ['openssl', 'SHA384'], |
| 64 |
'RS512' => ['openssl', 'SHA512'], |
| 65 |
'EdDSA' => ['sodium_crypto', 'EdDSA'], |
| 66 |
]; |
| 67 |
|
| 68 |
/** |
| 69 |
* Decodes a JWT string into a PHP object. |
| 70 |
* |
| 71 |
* @param string $jwt The JWT |
| 72 |
* @param Key|array<string, Key> $keyOrKeyArray The Key or associative array of key IDs (kid) to Key objects. |
| 73 |
* If the algorithm used is asymmetric, this is the public key |
| 74 |
* Each Key object contains an algorithm and matching key. |
| 75 |
* Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', |
| 76 |
* 'HS512', 'RS256', 'RS384', and 'RS512' |
| 77 |
* |
| 78 |
* @return stdClass The JWT's payload as a PHP object |
| 79 |
* |
| 80 |
* @throws InvalidArgumentException Provided key/key-array was empty |
| 81 |
* @throws DomainException Provided JWT is malformed |
| 82 |
* @throws UnexpectedValueException Provided JWT was invalid |
| 83 |
* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed |
| 84 |
* @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' |
| 85 |
* @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' |
| 86 |
* @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim |
| 87 |
* |
| 88 |
* @uses jsonDecode |
| 89 |
* @uses urlsafeB64Decode |
| 90 |
*/ |
| 91 |
public static function decode( |
| 92 |
string $jwt, |
| 93 |
$keyOrKeyArray |
| 94 |
): stdClass { |
| 95 |
// Validate JWT |
| 96 |
$timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp; |
| 97 |
|
| 98 |
if (empty($keyOrKeyArray)) { |
| 99 |
throw new InvalidArgumentException('Key may not be empty'); |
| 100 |
} |
| 101 |
$tks = \explode('.', $jwt); |
| 102 |
if (\count($tks) != 3) { |
| 103 |
throw new UnexpectedValueException('Wrong number of segments'); |
| 104 |
} |
| 105 |
list($headb64, $bodyb64, $cryptob64) = $tks; |
| 106 |
$headerRaw = static::urlsafeB64Decode($headb64); |
| 107 |
if (null === ($header = static::jsonDecode($headerRaw))) { |
| 108 |
throw new UnexpectedValueException('Invalid header encoding'); |
| 109 |
} |
| 110 |
$payloadRaw = static::urlsafeB64Decode($bodyb64); |
| 111 |
if (null === ($payload = static::jsonDecode($payloadRaw))) { |
| 112 |
throw new UnexpectedValueException('Invalid claims encoding'); |
| 113 |
} |
| 114 |
if (is_array($payload)) { |
| 115 |
// prevent PHP Fatal Error in edge-cases when payload is empty array |
| 116 |
$payload = (object) $payload; |
| 117 |
} |
| 118 |
if (!$payload instanceof stdClass) { |
| 119 |
throw new UnexpectedValueException('Payload must be a JSON object'); |
| 120 |
} |
| 121 |
$sig = static::urlsafeB64Decode($cryptob64); |
| 122 |
if (empty($header->alg)) { |
| 123 |
throw new UnexpectedValueException('Empty algorithm'); |
| 124 |
} |
| 125 |
if (empty(static::$supported_algs[$header->alg])) { |
| 126 |
throw new UnexpectedValueException('Algorithm not supported'); |
| 127 |
} |
| 128 |
|
| 129 |
$key = self::getKey($keyOrKeyArray, property_exists($header, 'kid') ? $header->kid : null); |
| 130 |
|
| 131 |
// Check the algorithm |
| 132 |
if (!self::constantTimeEquals($key->getAlgorithm(), $header->alg)) { |
| 133 |
// See issue #351 |
| 134 |
throw new UnexpectedValueException('Incorrect key for this algorithm'); |
| 135 |
} |
| 136 |
if ($header->alg === 'ES256' || $header->alg === 'ES384') { |
| 137 |
// OpenSSL expects an ASN.1 DER sequence for ES256/ES384 signatures |
| 138 |
$sig = self::signatureToDER($sig); |
| 139 |
} |
| 140 |
if (!self::verify("$headb64.$bodyb64", $sig, $key->getKeyMaterial(), $header->alg)) { |
| 141 |
throw new SignatureInvalidException('Signature verification failed'); |
| 142 |
} |
| 143 |
|
| 144 |
// Check the nbf if it is defined. This is the time that the |
| 145 |
// token can actually be used. If it's not yet that time, abort. |
| 146 |
if (isset($payload->nbf) && $payload->nbf > ($timestamp + static::$leeway)) { |
| 147 |
throw new BeforeValidException( |
| 148 |
'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->nbf) |
| 149 |
); |
| 150 |
} |
| 151 |
|
| 152 |
// Check that this token has been created before 'now'. This prevents |
| 153 |
// using tokens that have been created for later use (and haven't |
| 154 |
// correctly used the nbf claim). |
| 155 |
if (isset($payload->iat) && $payload->iat > ($timestamp + static::$leeway)) { |
| 156 |
throw new BeforeValidException( |
| 157 |
'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->iat) |
| 158 |
); |
| 159 |
} |
| 160 |
|
| 161 |
// Check if this token has expired. |
| 162 |
if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) { |
| 163 |
throw new ExpiredException('Expired token'); |
| 164 |
} |
| 165 |
|
| 166 |
return $payload; |
| 167 |
} |
| 168 |
|
| 169 |
/** |
| 170 |
* Converts and signs a PHP object or array into a JWT string. |
| 171 |
* |
| 172 |
* @param array<mixed> $payload PHP array |
| 173 |
* @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $key The secret key. |
| 174 |
* @param string $alg Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', |
| 175 |
* 'HS512', 'RS256', 'RS384', and 'RS512' |
| 176 |
* @param string $keyId |
| 177 |
* @param array<string, string> $head An array with header elements to attach |
| 178 |
* |
| 179 |
* @return string A signed JWT |
| 180 |
* |
| 181 |
* @uses jsonEncode |
| 182 |
* @uses urlsafeB64Encode |
| 183 |
*/ |
| 184 |
public static function encode( |
| 185 |
array $payload, |
| 186 |
$key, |
| 187 |
string $alg, |
| 188 |
string $keyId = null, |
| 189 |
array $head = null |
| 190 |
): string { |
| 191 |
$header = ['typ' => 'JWT', 'alg' => $alg]; |
| 192 |
if ($keyId !== null) { |
| 193 |
$header['kid'] = $keyId; |
| 194 |
} |
| 195 |
if (isset($head) && \is_array($head)) { |
| 196 |
$header = \array_merge($head, $header); |
| 197 |
} |
| 198 |
$segments = []; |
| 199 |
$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($header)); |
| 200 |
$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($payload)); |
| 201 |
$signing_input = \implode('.', $segments); |
| 202 |
|
| 203 |
$signature = static::sign($signing_input, $key, $alg); |
| 204 |
$segments[] = static::urlsafeB64Encode($signature); |
| 205 |
|
| 206 |
return \implode('.', $segments); |
| 207 |
} |
| 208 |
|
| 209 |
/** |
| 210 |
* Sign a string with a given key and algorithm. |
| 211 |
* |
| 212 |
* @param string $msg The message to sign |
| 213 |
* @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $key The secret key. |
| 214 |
* @param string $alg Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', |
| 215 |
* 'HS512', 'RS256', 'RS384', and 'RS512' |
| 216 |
* |
| 217 |
* @return string An encrypted message |
| 218 |
* |
| 219 |
* @throws DomainException Unsupported algorithm or bad key was specified |
| 220 |
*/ |
| 221 |
public static function sign( |
| 222 |
string $msg, |
| 223 |
$key, |
| 224 |
string $alg |
| 225 |
): string { |
| 226 |
if (empty(static::$supported_algs[$alg])) { |
| 227 |
throw new DomainException('Algorithm not supported'); |
| 228 |
} |
| 229 |
list($function, $algorithm) = static::$supported_algs[$alg]; |
| 230 |
switch ($function) { |
| 231 |
case 'hash_hmac': |
| 232 |
if (!is_string($key)) { |
| 233 |
throw new InvalidArgumentException('key must be a string when using hmac'); |
| 234 |
} |
| 235 |
return \hash_hmac($algorithm, $msg, $key, true); |
| 236 |
case 'openssl': |
| 237 |
$signature = ''; |
| 238 |
$success = \openssl_sign($msg, $signature, $key, $algorithm); // @phpstan-ignore-line |
| 239 |
if (!$success) { |
| 240 |
throw new DomainException("OpenSSL unable to sign data"); |
| 241 |
} |
| 242 |
if ($alg === 'ES256') { |
| 243 |
$signature = self::signatureFromDER($signature, 256); |
| 244 |
} elseif ($alg === 'ES384') { |
| 245 |
$signature = self::signatureFromDER($signature, 384); |
| 246 |
} |
| 247 |
return $signature; |
| 248 |
case 'sodium_crypto': |
| 249 |
if (!function_exists('sodium_crypto_sign_detached')) { |
| 250 |
throw new DomainException('libsodium is not available'); |
| 251 |
} |
| 252 |
if (!is_string($key)) { |
| 253 |
throw new InvalidArgumentException('key must be a string when using EdDSA'); |
| 254 |
} |
| 255 |
try { |
| 256 |
// The last non-empty line is used as the key. |
| 257 |
$lines = array_filter(explode("\n", $key)); |
| 258 |
$key = base64_decode((string) end($lines)); |
| 259 |
return sodium_crypto_sign_detached($msg, $key); |
| 260 |
} catch (Exception $e) { |
| 261 |
throw new DomainException($e->getMessage(), 0, $e); |
| 262 |
} |
| 263 |
} |
| 264 |
|
| 265 |
throw new DomainException('Algorithm not supported'); |
| 266 |
} |
| 267 |
|
| 268 |
/** |
| 269 |
* Verify a signature with the message, key and method. Not all methods |
| 270 |
* are symmetric, so we must have a separate verify and sign method. |
| 271 |
* |
| 272 |
* @param string $msg The original message (header and body) |
| 273 |
* @param string $signature The original signature |
| 274 |
* @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $keyMaterial For HS*, a string key works. for RS*, must be an instance of OpenSSLAsymmetricKey |
| 275 |
* @param string $alg The algorithm |
| 276 |
* |
| 277 |
* @return bool |
| 278 |
* |
| 279 |
* @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure |
| 280 |
*/ |
| 281 |
private static function verify( |
| 282 |
string $msg, |
| 283 |
string $signature, |
| 284 |
$keyMaterial, |
| 285 |
string $alg |
| 286 |
): bool { |
| 287 |
if (empty(static::$supported_algs[$alg])) { |
| 288 |
throw new DomainException('Algorithm not supported'); |
| 289 |
} |
| 290 |
|
| 291 |
list($function, $algorithm) = static::$supported_algs[$alg]; |
| 292 |
switch ($function) { |
| 293 |
case 'openssl': |
| 294 |
$success = \openssl_verify($msg, $signature, $keyMaterial, $algorithm); // @phpstan-ignore-line |
| 295 |
if ($success === 1) { |
| 296 |
return true; |
| 297 |
} elseif ($success === 0) { |
| 298 |
return false; |
| 299 |
} |
| 300 |
// returns 1 on success, 0 on failure, -1 on error. |
| 301 |
throw new DomainException( |
| 302 |
'OpenSSL error: ' . \openssl_error_string() |
| 303 |
); |
| 304 |
case 'sodium_crypto': |
| 305 |
if (!function_exists('sodium_crypto_sign_verify_detached')) { |
| 306 |
throw new DomainException('libsodium is not available'); |
| 307 |
} |
| 308 |
if (!is_string($keyMaterial)) { |
| 309 |
throw new InvalidArgumentException('key must be a string when using EdDSA'); |
| 310 |
} |
| 311 |
try { |
| 312 |
// The last non-empty line is used as the key. |
| 313 |
$lines = array_filter(explode("\n", $keyMaterial)); |
| 314 |
$key = base64_decode((string) end($lines)); |
| 315 |
return sodium_crypto_sign_verify_detached($signature, $msg, $key); |
| 316 |
} catch (Exception $e) { |
| 317 |
throw new DomainException($e->getMessage(), 0, $e); |
| 318 |
} |
| 319 |
case 'hash_hmac': |
| 320 |
default: |
| 321 |
if (!is_string($keyMaterial)) { |
| 322 |
throw new InvalidArgumentException('key must be a string when using hmac'); |
| 323 |
} |
| 324 |
$hash = \hash_hmac($algorithm, $msg, $keyMaterial, true); |
| 325 |
return self::constantTimeEquals($hash, $signature); |
| 326 |
} |
| 327 |
} |
| 328 |
|
| 329 |
/** |
| 330 |
* Decode a JSON string into a PHP object. |
| 331 |
* |
| 332 |
* @param string $input JSON string |
| 333 |
* |
| 334 |
* @return mixed The decoded JSON string |
| 335 |
* |
| 336 |
* @throws DomainException Provided string was invalid JSON |
| 337 |
*/ |
| 338 |
public static function jsonDecode(string $input) |
| 339 |
{ |
| 340 |
$obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING); |
| 341 |
|
| 342 |
if ($errno = \json_last_error()) { |
| 343 |
self::handleJsonError($errno); |
| 344 |
} elseif ($obj === null && $input !== 'null') { |
| 345 |
throw new DomainException('Null result with non-null input'); |
| 346 |
} |
| 347 |
return $obj; |
| 348 |
} |
| 349 |
|
| 350 |
/** |
| 351 |
* Encode a PHP array into a JSON string. |
| 352 |
* |
| 353 |
* @param array<mixed> $input A PHP array |
| 354 |
* |
| 355 |
* @return string JSON representation of the PHP array |
| 356 |
* |
| 357 |
* @throws DomainException Provided object could not be encoded to valid JSON |
| 358 |
*/ |
| 359 |
public static function jsonEncode(array $input): string |
| 360 |
{ |
| 361 |
if (PHP_VERSION_ID >= 50400) { |
| 362 |
$json = \json_encode($input, \JSON_UNESCAPED_SLASHES); |
| 363 |
} else { |
| 364 |
// PHP 5.3 only |
| 365 |
$json = \json_encode($input); |
| 366 |
} |
| 367 |
if ($errno = \json_last_error()) { |
| 368 |
self::handleJsonError($errno); |
| 369 |
} elseif ($json === 'null' && $input !== null) { |
| 370 |
throw new DomainException('Null result with non-null input'); |
| 371 |
} |
| 372 |
if ($json === false) { |
| 373 |
throw new DomainException('Provided object could not be encoded to valid JSON'); |
| 374 |
} |
| 375 |
return $json; |
| 376 |
} |
| 377 |
|
| 378 |
/** |
| 379 |
* Decode a string with URL-safe Base64. |
| 380 |
* |
| 381 |
* @param string $input A Base64 encoded string |
| 382 |
* |
| 383 |
* @return string A decoded string |
| 384 |
* |
| 385 |
* @throws InvalidArgumentException invalid base64 characters |
| 386 |
*/ |
| 387 |
public static function urlsafeB64Decode(string $input): string |
| 388 |
{ |
| 389 |
$remainder = \strlen($input) % 4; |
| 390 |
if ($remainder) { |
| 391 |
$padlen = 4 - $remainder; |
| 392 |
$input .= \str_repeat('=', $padlen); |
| 393 |
} |
| 394 |
return \base64_decode(\strtr($input, '-_', '+/')); |
| 395 |
} |
| 396 |
|
| 397 |
/** |
| 398 |
* Encode a string with URL-safe Base64. |
| 399 |
* |
| 400 |
* @param string $input The string you want encoded |
| 401 |
* |
| 402 |
* @return string The base64 encode of what you passed in |
| 403 |
*/ |
| 404 |
public static function urlsafeB64Encode(string $input): string |
| 405 |
{ |
| 406 |
return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_')); |
| 407 |
} |
| 408 |
|
| 409 |
|
| 410 |
/** |
| 411 |
* Determine if an algorithm has been provided for each Key |
| 412 |
* |
| 413 |
* @param Key|array<string, Key> $keyOrKeyArray |
| 414 |
* @param string|null $kid |
| 415 |
* |
| 416 |
* @throws UnexpectedValueException |
| 417 |
* |
| 418 |
* @return Key |
| 419 |
*/ |
| 420 |
private static function getKey( |
| 421 |
$keyOrKeyArray, |
| 422 |
?string $kid |
| 423 |
): Key { |
| 424 |
if ($keyOrKeyArray instanceof Key) { |
| 425 |
return $keyOrKeyArray; |
| 426 |
} |
| 427 |
|
| 428 |
foreach ($keyOrKeyArray as $keyId => $key) { |
| 429 |
if (!$key instanceof Key) { |
| 430 |
throw new TypeError( |
| 431 |
'$keyOrKeyArray must be an instance of Firebase\JWT\Key key or an ' |
| 432 |
. 'array of Firebase\JWT\Key keys' |
| 433 |
); |
| 434 |
} |
| 435 |
} |
| 436 |
if (!isset($kid)) { |
| 437 |
throw new UnexpectedValueException('"kid" empty, unable to lookup correct key'); |
| 438 |
} |
| 439 |
if (!isset($keyOrKeyArray[$kid])) { |
| 440 |
throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key'); |
| 441 |
} |
| 442 |
|
| 443 |
return $keyOrKeyArray[$kid]; |
| 444 |
} |
| 445 |
|
| 446 |
/** |
| 447 |
* @param string $left The string of known length to compare against |
| 448 |
* @param string $right The user-supplied string |
| 449 |
* @return bool |
| 450 |
*/ |
| 451 |
public static function constantTimeEquals(string $left, string $right): bool |
| 452 |
{ |
| 453 |
if (\function_exists('hash_equals')) { |
| 454 |
return \hash_equals($left, $right); |
| 455 |
} |
| 456 |
$len = \min(self::safeStrlen($left), self::safeStrlen($right)); |
| 457 |
|
| 458 |
$status = 0; |
| 459 |
for ($i = 0; $i < $len; $i++) { |
| 460 |
$status |= (\ord($left[$i]) ^ \ord($right[$i])); |
| 461 |
} |
| 462 |
$status |= (self::safeStrlen($left) ^ self::safeStrlen($right)); |
| 463 |
|
| 464 |
return ($status === 0); |
| 465 |
} |
| 466 |
|
| 467 |
/** |
| 468 |
* Helper method to create a JSON error. |
| 469 |
* |
| 470 |
* @param int $errno An error number from json_last_error() |
| 471 |
* |
| 472 |
* @throws DomainException |
| 473 |
* |
| 474 |
* @return void |
| 475 |
*/ |
| 476 |
private static function handleJsonError(int $errno): void |
| 477 |
{ |
| 478 |
$messages = [ |
| 479 |
JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', |
| 480 |
JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON', |
| 481 |
JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', |
| 482 |
JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON', |
| 483 |
JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3 |
| 484 |
]; |
| 485 |
throw new DomainException( |
| 486 |
isset($messages[$errno]) |
| 487 |
? $messages[$errno] |
| 488 |
: 'Unknown JSON error: ' . $errno |
| 489 |
); |
| 490 |
} |
| 491 |
|
| 492 |
/** |
| 493 |
* Get the number of bytes in cryptographic strings. |
| 494 |
* |
| 495 |
* @param string $str |
| 496 |
* |
| 497 |
* @return int |
| 498 |
*/ |
| 499 |
private static function safeStrlen(string $str): int |
| 500 |
{ |
| 501 |
if (\function_exists('mb_strlen')) { |
| 502 |
return \mb_strlen($str, '8bit'); |
| 503 |
} |
| 504 |
return \strlen($str); |
| 505 |
} |
| 506 |
|
| 507 |
/** |
| 508 |
* Convert an ECDSA signature to an ASN.1 DER sequence |
| 509 |
* |
| 510 |
* @param string $sig The ECDSA signature to convert |
| 511 |
* @return string The encoded DER object |
| 512 |
*/ |
| 513 |
private static function signatureToDER(string $sig): string |
| 514 |
{ |
| 515 |
// Separate the signature into r-value and s-value |
| 516 |
$length = max(1, (int) (\strlen($sig) / 2)); |
| 517 |
list($r, $s) = \str_split($sig, $length > 0 ? $length : 1); |
| 518 |
|
| 519 |
// Trim leading zeros |
| 520 |
$r = \ltrim($r, "\x00"); |
| 521 |
$s = \ltrim($s, "\x00"); |
| 522 |
|
| 523 |
// Convert r-value and s-value from unsigned big-endian integers to |
| 524 |
// signed two's complement |
| 525 |
if (\ord($r[0]) > 0x7f) { |
| 526 |
$r = "\x00" . $r; |
| 527 |
} |
| 528 |
if (\ord($s[0]) > 0x7f) { |
| 529 |
$s = "\x00" . $s; |
| 530 |
} |
| 531 |
|
| 532 |
return self::encodeDER( |
| 533 |
self::ASN1_SEQUENCE, |
| 534 |
self::encodeDER(self::ASN1_INTEGER, $r) . |
| 535 |
self::encodeDER(self::ASN1_INTEGER, $s) |
| 536 |
); |
| 537 |
} |
| 538 |
|
| 539 |
/** |
| 540 |
* Encodes a value into a DER object. |
| 541 |
* |
| 542 |
* @param int $type DER tag |
| 543 |
* @param string $value the value to encode |
| 544 |
* |
| 545 |
* @return string the encoded object |
| 546 |
*/ |
| 547 |
private static function encodeDER(int $type, string $value): string |
| 548 |
{ |
| 549 |
$tag_header = 0; |
| 550 |
if ($type === self::ASN1_SEQUENCE) { |
| 551 |
$tag_header |= 0x20; |
| 552 |
} |
| 553 |
|
| 554 |
// Type |
| 555 |
$der = \chr($tag_header | $type); |
| 556 |
|
| 557 |
// Length |
| 558 |
$der .= \chr(\strlen($value)); |
| 559 |
|
| 560 |
return $der . $value; |
| 561 |
} |
| 562 |
|
| 563 |
/** |
| 564 |
* Encodes signature from a DER object. |
| 565 |
* |
| 566 |
* @param string $der binary signature in DER format |
| 567 |
* @param int $keySize the number of bits in the key |
| 568 |
* |
| 569 |
* @return string the signature |
| 570 |
*/ |
| 571 |
private static function signatureFromDER(string $der, int $keySize): string |
| 572 |
{ |
| 573 |
// OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE |
| 574 |
list($offset, $_) = self::readDER($der); |
| 575 |
list($offset, $r) = self::readDER($der, $offset); |
| 576 |
list($offset, $s) = self::readDER($der, $offset); |
| 577 |
|
| 578 |
// Convert r-value and s-value from signed two's compliment to unsigned |
| 579 |
// big-endian integers |
| 580 |
$r = \ltrim($r, "\x00"); |
| 581 |
$s = \ltrim($s, "\x00"); |
| 582 |
|
| 583 |
// Pad out r and s so that they are $keySize bits long |
| 584 |
$r = \str_pad($r, $keySize / 8, "\x00", STR_PAD_LEFT); |
| 585 |
$s = \str_pad($s, $keySize / 8, "\x00", STR_PAD_LEFT); |
| 586 |
|
| 587 |
return $r . $s; |
| 588 |
} |
| 589 |
|
| 590 |
/** |
| 591 |
* Reads binary DER-encoded data and decodes into a single object |
| 592 |
* |
| 593 |
* @param string $der the binary data in DER format |
| 594 |
* @param int $offset the offset of the data stream containing the object |
| 595 |
* to decode |
| 596 |
* |
| 597 |
* @return array{int, string|null} the new offset and the decoded object |
| 598 |
*/ |
| 599 |
private static function readDER(string $der, int $offset = 0): array |
| 600 |
{ |
| 601 |
$pos = $offset; |
| 602 |
$size = \strlen($der); |
| 603 |
$constructed = (\ord($der[$pos]) >> 5) & 0x01; |
| 604 |
$type = \ord($der[$pos++]) & 0x1f; |
| 605 |
|
| 606 |
// Length |
| 607 |
$len = \ord($der[$pos++]); |
| 608 |
if ($len & 0x80) { |
| 609 |
$n = $len & 0x1f; |
| 610 |
$len = 0; |
| 611 |
while ($n-- && $pos < $size) { |
| 612 |
$len = ($len << 8) | \ord($der[$pos++]); |
| 613 |
} |
| 614 |
} |
| 615 |
|
| 616 |
// Value |
| 617 |
if ($type == self::ASN1_BIT_STRING) { |
| 618 |
$pos++; // Skip the first contents octet (padding indicator) |
| 619 |
$data = \substr($der, $pos, $len - 1); |
| 620 |
$pos += $len - 1; |
| 621 |
} elseif (!$constructed) { |
| 622 |
$data = \substr($der, $pos, $len); |
| 623 |
$pos += $len; |
| 624 |
} else { |
| 625 |
$data = null; |
| 626 |
} |
| 627 |
|
| 628 |
return [$pos, $data]; |
| 629 |
} |
| 630 |
} |
| 631 |
|
