woocommerce-pos / vendor_prefixed / firebase / php-jwt / src / JWT.php

JWT.php in WCPOS – Point of Sale (POS) plugin for WooCommerce 1.10.16, at vendor_prefixed/firebase/php-jwt/src/JWT.php

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1	<?php
2
3	namespace WCPOS\Vendor\Firebase\JWT;
4
5	use ArrayAccess;
6	use DateTime;
7	use DomainException;
8	use Exception;
9	use InvalidArgumentException;
10	use OpenSSLAsymmetricKey;
11	use OpenSSLCertificate;
12	use stdClass;
13	use UnexpectedValueException;
14	/**
15	* JSON Web Token implementation, based on this spec:
16	* https://tools.ietf.org/html/rfc7519
17	*
18	* PHP version 5
19	*
20	* @category Authentication
21	* @package Authentication_JWT
22	* @author Neuman Vong <neuman@twilio.com>
23	* @author Anant Narayanan <anant@php.net>
24	* @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD
25	* @link https://github.com/firebase/php-jwt
26	*/
27	class JWT
28	{
29	private const ASN1_INTEGER = 0x2;
30	private const ASN1_SEQUENCE = 0x10;
31	private const ASN1_BIT_STRING = 0x3;
32	/**
33	* When checking nbf, iat or expiration times,
34	* we want to provide some extra leeway time to
35	* account for clock skew.
36	*
37	* @var int
38	*/
39	public static $leeway = 0;
40	/**
41	* Allow the current timestamp to be specified.
42	* Useful for fixing a value within unit testing.
43	* Will default to PHP time() value if null.
44	*
45	* @var ?int
46	*/
47	public static $timestamp = null;
48	/**
49	* @var array<string, string[]>
50	*/
51	public static $supported_algs = ['ES384' => ['openssl', 'SHA384'], 'ES256' => ['openssl', 'SHA256'], 'ES256K' => ['openssl', 'SHA256'], 'HS256' => ['hash_hmac', 'SHA256'], 'HS384' => ['hash_hmac', 'SHA384'], 'HS512' => ['hash_hmac', 'SHA512'], 'RS256' => ['openssl', 'SHA256'], 'RS384' => ['openssl', 'SHA384'], 'RS512' => ['openssl', 'SHA512'], 'EdDSA' => ['sodium_crypto', 'EdDSA']];
52	/**
53	* Decodes a JWT string into a PHP object.
54	*
55	* @param string $jwt The JWT
56	* @param Key\|ArrayAccess<string,Key>\|array<string,Key> $keyOrKeyArray The Key or associative array of key IDs
57	* (kid) to Key objects.
58	* If the algorithm used is asymmetric, this is
59	* the public key.
60	* Each Key object contains an algorithm and
61	* matching key.
62	* Supported algorithms are 'ES384','ES256',
63	* 'HS256', 'HS384', 'HS512', 'RS256', 'RS384'
64	* and 'RS512'.
65	* @param stdClass $headers Optional. Populates stdClass with headers.
66	*
67	* @return stdClass The JWT's payload as a PHP object
68	*
69	* @throws InvalidArgumentException Provided key/key-array was empty or malformed
70	* @throws DomainException Provided JWT is malformed
71	* @throws UnexpectedValueException Provided JWT was invalid
72	* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed
73	* @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf'
74	* @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat'
75	* @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim
76	*
77	* @uses jsonDecode
78	* @uses urlsafeB64Decode
79	*/
80	public static function decode(string $jwt, $keyOrKeyArray, stdClass &$headers = null) : stdClass
81	{
82	// Validate JWT
83	$timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp;
84	if (empty($keyOrKeyArray)) {
85	throw new InvalidArgumentException('Key may not be empty');
86	}
87	$tks = \explode('.', $jwt);
88	if (\count($tks) !== 3) {
89	throw new UnexpectedValueException('Wrong number of segments');
90	}
91	list($headb64, $bodyb64, $cryptob64) = $tks;
92	$headerRaw = static::urlsafeB64Decode($headb64);
93	if (null === ($header = static::jsonDecode($headerRaw))) {
94	throw new UnexpectedValueException('Invalid header encoding');
95	}
96	if ($headers !== null) {
97	$headers = $header;
98	}
99	$payloadRaw = static::urlsafeB64Decode($bodyb64);
100	if (null === ($payload = static::jsonDecode($payloadRaw))) {
101	throw new UnexpectedValueException('Invalid claims encoding');
102	}
103	if (\is_array($payload)) {
104	// prevent PHP Fatal Error in edge-cases when payload is empty array
105	$payload = (object) $payload;
106	}
107	if (!$payload instanceof stdClass) {
108	throw new UnexpectedValueException('Payload must be a JSON object');
109	}
110	$sig = static::urlsafeB64Decode($cryptob64);
111	if (empty($header->alg)) {
112	throw new UnexpectedValueException('Empty algorithm');
113	}
114	if (empty(static::$supported_algs[$header->alg])) {
115	throw new UnexpectedValueException('Algorithm not supported');
116	}
117	$key = self::getKey($keyOrKeyArray, \property_exists($header, 'kid') ? $header->kid : null);
118	// Check the algorithm
119	if (!self::constantTimeEquals($key->getAlgorithm(), $header->alg)) {
120	// See issue #351
121	throw new UnexpectedValueException('Incorrect key for this algorithm');
122	}
123	if (\in_array($header->alg, ['ES256', 'ES256K', 'ES384'], \true)) {
124	// OpenSSL expects an ASN.1 DER sequence for ES256/ES256K/ES384 signatures
125	$sig = self::signatureToDER($sig);
126	}
127	if (!self::verify("{$headb64}.{$bodyb64}", $sig, $key->getKeyMaterial(), $header->alg)) {
128	throw new SignatureInvalidException('Signature verification failed');
129	}
130	// Check the nbf if it is defined. This is the time that the
131	// token can actually be used. If it's not yet that time, abort.
132	if (isset($payload->nbf) && \floor($payload->nbf) > $timestamp + static::$leeway) {
133	$ex = new BeforeValidException('Cannot handle token with nbf prior to ' . \date(DateTime::ISO8601, (int) $payload->nbf));
134	$ex->setPayload($payload);
135	throw $ex;
136	}
137	// Check that this token has been created before 'now'. This prevents
138	// using tokens that have been created for later use (and haven't
139	// correctly used the nbf claim).
140	if (!isset($payload->nbf) && isset($payload->iat) && \floor($payload->iat) > $timestamp + static::$leeway) {
141	$ex = new BeforeValidException('Cannot handle token with iat prior to ' . \date(DateTime::ISO8601, (int) $payload->iat));
142	$ex->setPayload($payload);
143	throw $ex;
144	}
145	// Check if this token has expired.
146	if (isset($payload->exp) && $timestamp - static::$leeway >= $payload->exp) {
147	$ex = new ExpiredException('Expired token');
148	$ex->setPayload($payload);
149	throw $ex;
150	}
151	return $payload;
152	}
153	/**
154	* Converts and signs a PHP array into a JWT string.
155	*
156	* @param array<mixed> $payload PHP array
157	* @param string\|resource\|OpenSSLAsymmetricKey\|OpenSSLCertificate $key The secret key.
158	* @param string $alg Supported algorithms are 'ES384','ES256', 'ES256K', 'HS256',
159	* 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
160	* @param string $keyId
161	* @param array<string, string> $head An array with header elements to attach
162	*
163	* @return string A signed JWT
164	*
165	* @uses jsonEncode
166	* @uses urlsafeB64Encode
167	*/
168	public static function encode(array $payload, $key, string $alg, string $keyId = null, array $head = null) : string
169	{
170	$header = ['typ' => 'JWT'];
171	if (isset($head) && \is_array($head)) {
172	$header = \array_merge($header, $head);
173	}
174	$header['alg'] = $alg;
175	if ($keyId !== null) {
176	$header['kid'] = $keyId;
177	}
178	$segments = [];
179	$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($header));
180	$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($payload));
181	$signing_input = \implode('.', $segments);
182	$signature = static::sign($signing_input, $key, $alg);
183	$segments[] = static::urlsafeB64Encode($signature);
184	return \implode('.', $segments);
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\|OpenSSLAsymmetricKey\|OpenSSLCertificate $key The secret key.
191	* @param string $alg Supported algorithms are 'EdDSA', 'ES384', 'ES256', 'ES256K', 'HS256',
192	* 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
193	*
194	* @return string An encrypted message
195	*
196	* @throws DomainException Unsupported algorithm or bad key was specified
197	*/
198	public static function sign(string $msg, $key, string $alg) : string
199	{
200	if (empty(static::$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	if (!\is_string($key)) {
207	throw new InvalidArgumentException('key must be a string when using hmac');
208	}
209	return \hash_hmac($algorithm, $msg, $key, \true);
210	case 'openssl':
211	$signature = '';
212	$success = \openssl_sign($msg, $signature, $key, $algorithm);
213	// @phpstan-ignore-line
214	if (!$success) {
215	throw new DomainException('OpenSSL unable to sign data');
216	}
217	if ($alg === 'ES256' \|\| $alg === 'ES256K') {
218	$signature = self::signatureFromDER($signature, 256);
219	} elseif ($alg === 'ES384') {
220	$signature = self::signatureFromDER($signature, 384);
221	}
222	return $signature;
223	case 'sodium_crypto':
224	if (!\function_exists('sodium_crypto_sign_detached')) {
225	throw new DomainException('libsodium is not available');
226	}
227	if (!\is_string($key)) {
228	throw new InvalidArgumentException('key must be a string when using EdDSA');
229	}
230	try {
231	// The last non-empty line is used as the key.
232	$lines = \array_filter(\explode("\n", $key));
233	$key = \base64_decode((string) \end($lines));
234	if (\strlen($key) === 0) {
235	throw new DomainException('Key cannot be empty string');
236	}
237	return \sodium_crypto_sign_detached($msg, $key);
238	} catch (Exception $e) {
239	throw new DomainException($e->getMessage(), 0, $e);
240	}
241	}
242	throw new DomainException('Algorithm not supported');
243	}
244	/**
245	* Verify a signature with the message, key and method. Not all methods
246	* are symmetric, so we must have a separate verify and sign method.
247	*
248	* @param string $msg The original message (header and body)
249	* @param string $signature The original signature
250	* @param string\|resource\|OpenSSLAsymmetricKey\|OpenSSLCertificate $keyMaterial For Ed, ES, HS, a string key works. for RS, must be an instance of OpenSSLAsymmetricKey
251	* @param string $alg The algorithm
252	*
253	* @return bool
254	*
255	* @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure
256	*/
257	private static function verify(string $msg, string $signature, $keyMaterial, string $alg) : bool
258	{
259	if (empty(static::$supported_algs[$alg])) {
260	throw new DomainException('Algorithm not supported');
261	}
262	list($function, $algorithm) = static::$supported_algs[$alg];
263	switch ($function) {
264	case 'openssl':
265	$success = \openssl_verify($msg, $signature, $keyMaterial, $algorithm);
266	// @phpstan-ignore-line
267	if ($success === 1) {
268	return \true;
269	}
270	if ($success === 0) {
271	return \false;
272	}
273	// returns 1 on success, 0 on failure, -1 on error.
274	throw new DomainException('OpenSSL error: ' . \openssl_error_string());
275	case 'sodium_crypto':
276	if (!\function_exists('sodium_crypto_sign_verify_detached')) {
277	throw new DomainException('libsodium is not available');
278	}
279	if (!\is_string($keyMaterial)) {
280	throw new InvalidArgumentException('key must be a string when using EdDSA');
281	}
282	try {
283	// The last non-empty line is used as the key.
284	$lines = \array_filter(\explode("\n", $keyMaterial));
285	$key = \base64_decode((string) \end($lines));
286	if (\strlen($key) === 0) {
287	throw new DomainException('Key cannot be empty string');
288	}
289	if (\strlen($signature) === 0) {
290	throw new DomainException('Signature cannot be empty string');
291	}
292	return \sodium_crypto_sign_verify_detached($signature, $msg, $key);
293	} catch (Exception $e) {
294	throw new DomainException($e->getMessage(), 0, $e);
295	}
296	case 'hash_hmac':
297	default:
298	if (!\is_string($keyMaterial)) {
299	throw new InvalidArgumentException('key must be a string when using hmac');
300	}
301	$hash = \hash_hmac($algorithm, $msg, $keyMaterial, \true);
302	return self::constantTimeEquals($hash, $signature);
303	}
304	}
305	/**
306	* Decode a JSON string into a PHP object.
307	*
308	* @param string $input JSON string
309	*
310	* @return mixed The decoded JSON string
311	*
312	* @throws DomainException Provided string was invalid JSON
313	*/
314	public static function jsonDecode(string $input)
315	{
316	$obj = \json_decode($input, \false, 512, \JSON_BIGINT_AS_STRING);
317	if ($errno = \json_last_error()) {
318	self::handleJsonError($errno);
319	} elseif ($obj === null && $input !== 'null') {
320	throw new DomainException('Null result with non-null input');
321	}
322	return $obj;
323	}
324	/**
325	* Encode a PHP array into a JSON string.
326	*
327	* @param array<mixed> $input A PHP array
328	*
329	* @return string JSON representation of the PHP array
330	*
331	* @throws DomainException Provided object could not be encoded to valid JSON
332	*/
333	public static function jsonEncode(array $input) : string
334	{
335	if (\PHP_VERSION_ID >= 50400) {
336	$json = \json_encode($input, \JSON_UNESCAPED_SLASHES);
337	} else {
338	// PHP 5.3 only
339	$json = \json_encode($input);
340	}
341	if ($errno = \json_last_error()) {
342	self::handleJsonError($errno);
343	} elseif ($json === 'null') {
344	throw new DomainException('Null result with non-null input');
345	}
346	if ($json === \false) {
347	throw new DomainException('Provided object could not be encoded to valid JSON');
348	}
349	return $json;
350	}
351	/**
352	* Decode a string with URL-safe Base64.
353	*
354	* @param string $input A Base64 encoded string
355	*
356	* @return string A decoded string
357	*
358	* @throws InvalidArgumentException invalid base64 characters
359	*/
360	public static function urlsafeB64Decode(string $input) : string
361	{
362	return \base64_decode(self::convertBase64UrlToBase64($input));
363	}
364	/**
365	* Convert a string in the base64url (URL-safe Base64) encoding to standard base64.
366	*
367	* @param string $input A Base64 encoded string with URL-safe characters (-_ and no padding)
368	*
369	* @return string A Base64 encoded string with standard characters (+/) and padding (=), when
370	* needed.
371	*
372	* @see https://www.rfc-editor.org/rfc/rfc4648
373	*/
374	public static function convertBase64UrlToBase64(string $input) : string
375	{
376	$remainder = \strlen($input) % 4;
377	if ($remainder) {
378	$padlen = 4 - $remainder;
379	$input .= \str_repeat('=', $padlen);
380	}
381	return \strtr($input, '-_', '+/');
382	}
383	/**
384	* Encode a string with URL-safe Base64.
385	*
386	* @param string $input The string you want encoded
387	*
388	* @return string The base64 encode of what you passed in
389	*/
390	public static function urlsafeB64Encode(string $input) : string
391	{
392	return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_'));
393	}
394	/**
395	* Determine if an algorithm has been provided for each Key
396	*
397	* @param Key\|ArrayAccess<string,Key>\|array<string,Key> $keyOrKeyArray
398	* @param string\|null $kid
399	*
400	* @throws UnexpectedValueException
401	*
402	* @return Key
403	*/
404	private static function getKey($keyOrKeyArray, ?string $kid) : Key
405	{
406	if ($keyOrKeyArray instanceof Key) {
407	return $keyOrKeyArray;
408	}
409	if (empty($kid) && $kid !== '0') {
410	throw new UnexpectedValueException('"kid" empty, unable to lookup correct key');
411	}
412	if ($keyOrKeyArray instanceof CachedKeySet) {
413	// Skip "isset" check, as this will automatically refresh if not set
414	return $keyOrKeyArray[$kid];
415	}
416	if (!isset($keyOrKeyArray[$kid])) {
417	throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key');
418	}
419	return $keyOrKeyArray[$kid];
420	}
421	/**
422	* @param string $left The string of known length to compare against
423	* @param string $right The user-supplied string
424	* @return bool
425	*/
426	public static function constantTimeEquals(string $left, string $right) : bool
427	{
428	if (\function_exists('hash_equals')) {
429	return \hash_equals($left, $right);
430	}
431	$len = \min(self::safeStrlen($left), self::safeStrlen($right));
432	$status = 0;
433	for ($i = 0; $i < $len; $i++) {
434	$status \|= \ord($left[$i]) ^ \ord($right[$i]);
435	}
436	$status \|= self::safeStrlen($left) ^ self::safeStrlen($right);
437	return $status === 0;
438	}
439	/**
440	* Helper method to create a JSON error.
441	*
442	* @param int $errno An error number from json_last_error()
443	*
444	* @throws DomainException
445	*
446	* @return void
447	*/
448	private static function handleJsonError(int $errno) : void
449	{
450	$messages = [\JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', \JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON', \JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', \JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON', \JSON_ERROR_UTF8 => 'Malformed UTF-8 characters'];
451	throw new DomainException(isset($messages[$errno]) ? $messages[$errno] : 'Unknown JSON error: ' . $errno);
452	}
453	/**
454	* Get the number of bytes in cryptographic strings.
455	*
456	* @param string $str
457	*
458	* @return int
459	*/
460	private static function safeStrlen(string $str) : int
461	{
462	if (\function_exists('mb_strlen')) {
463	return \mb_strlen($str, '8bit');
464	}
465	return \strlen($str);
466	}
467	/**
468	* Convert an ECDSA signature to an ASN.1 DER sequence
469	*
470	* @param string $sig The ECDSA signature to convert
471	* @return string The encoded DER object
472	*/
473	private static function signatureToDER(string $sig) : string
474	{
475	// Separate the signature into r-value and s-value
476	$length = \max(1, (int) (\strlen($sig) / 2));
477	list($r, $s) = \str_split($sig, $length);
478	// Trim leading zeros
479	$r = \ltrim($r, "\x00");
480	$s = \ltrim($s, "\x00");
481	// Convert r-value and s-value from unsigned big-endian integers to
482	// signed two's complement
483	if (\ord($r[0]) > 0x7f) {
484	$r = "\x00" . $r;
485	}
486	if (\ord($s[0]) > 0x7f) {
487	$s = "\x00" . $s;
488	}
489	return self::encodeDER(self::ASN1_SEQUENCE, self::encodeDER(self::ASN1_INTEGER, $r) . self::encodeDER(self::ASN1_INTEGER, $s));
490	}
491	/**
492	* Encodes a value into a DER object.
493	*
494	* @param int $type DER tag
495	* @param string $value the value to encode
496	*
497	* @return string the encoded object
498	*/
499	private static function encodeDER(int $type, string $value) : string
500	{
501	$tag_header = 0;
502	if ($type === self::ASN1_SEQUENCE) {
503	$tag_header \|= 0x20;
504	}
505	// Type
506	$der = \chr($tag_header \| $type);
507	// Length
508	$der .= \chr(\strlen($value));
509	return $der . $value;
510	}
511	/**
512	* Encodes signature from a DER object.
513	*
514	* @param string $der binary signature in DER format
515	* @param int $keySize the number of bits in the key
516	*
517	* @return string the signature
518	*/
519	private static function signatureFromDER(string $der, int $keySize) : string
520	{
521	// OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE
522	list($offset, $_) = self::readDER($der);
523	list($offset, $r) = self::readDER($der, $offset);
524	list($offset, $s) = self::readDER($der, $offset);
525	// Convert r-value and s-value from signed two's compliment to unsigned
526	// big-endian integers
527	$r = \ltrim($r, "\x00");
528	$s = \ltrim($s, "\x00");
529	// Pad out r and s so that they are $keySize bits long
530	$r = \str_pad($r, $keySize / 8, "\x00", \STR_PAD_LEFT);
531	$s = \str_pad($s, $keySize / 8, "\x00", \STR_PAD_LEFT);
532	return $r . $s;
533	}
534	/**
535	* Reads binary DER-encoded data and decodes into a single object
536	*
537	* @param string $der the binary data in DER format
538	* @param int $offset the offset of the data stream containing the object
539	* to decode
540	*
541	* @return array{int, string\|null} the new offset and the decoded object
542	*/
543	private static function readDER(string $der, int $offset = 0) : array
544	{
545	$pos = $offset;
546	$size = \strlen($der);
547	$constructed = \ord($der[$pos]) >> 5 & 0x1;
548	$type = \ord($der[$pos++]) & 0x1f;
549	// Length
550	$len = \ord($der[$pos++]);
551	if ($len & 0x80) {
552	$n = $len & 0x1f;
553	$len = 0;
554	while ($n-- && $pos < $size) {
555	$len = $len << 8 \| \ord($der[$pos++]);
556	}
557	}
558	// Value
559	if ($type === self::ASN1_BIT_STRING) {
560	$pos++;
561	// Skip the first contents octet (padding indicator)
562	$data = \substr($der, $pos, $len - 1);
563	$pos += $len - 1;
564	} elseif (!$constructed) {
565	$data = \substr($der, $pos, $len);
566	$pos += $len;
567	} else {
568	$data = null;
569	}
570	return [$pos, $data];
571	}
572	}
573