663 lines
23 KiB
PHP
663 lines
23 KiB
PHP
<?php
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namespace Firebase\JWT;
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use ArrayAccess;
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use DateTime;
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use DomainException;
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use Exception;
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use InvalidArgumentException;
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use OpenSSLAsymmetricKey;
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use OpenSSLCertificate;
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use stdClass;
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use UnexpectedValueException;
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/**
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* JSON Web Token implementation, based on this spec:
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* https://tools.ietf.org/html/rfc7519
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*
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* PHP version 5
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*
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* @category Authentication
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* @package Authentication_JWT
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* @author Neuman Vong <neuman@twilio.com>
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* @author Anant Narayanan <anant@php.net>
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* @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD
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* @link https://github.com/firebase/php-jwt
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*/
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class JWT
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{
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private const ASN1_INTEGER = 0x02;
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private const ASN1_SEQUENCE = 0x10;
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private const ASN1_BIT_STRING = 0x03;
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/**
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* When checking nbf, iat or expiration times,
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* we want to provide some extra leeway time to
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* account for clock skew.
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*
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* @var int
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*/
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public static $leeway = 0;
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/**
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* Allow the current timestamp to be specified.
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* Useful for fixing a value within unit testing.
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* Will default to PHP time() value if null.
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*
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* @var ?int
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*/
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public static $timestamp = null;
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/**
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* @var array<string, string[]>
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*/
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public static $supported_algs = [
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'ES384' => ['openssl', 'SHA384'],
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'ES256' => ['openssl', 'SHA256'],
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'ES256K' => ['openssl', 'SHA256'],
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'HS256' => ['hash_hmac', 'SHA256'],
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'HS384' => ['hash_hmac', 'SHA384'],
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'HS512' => ['hash_hmac', 'SHA512'],
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'RS256' => ['openssl', 'SHA256'],
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'RS384' => ['openssl', 'SHA384'],
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'RS512' => ['openssl', 'SHA512'],
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'EdDSA' => ['sodium_crypto', 'EdDSA'],
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];
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/**
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* Decodes a JWT string into a PHP object.
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*
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* @param string $jwt The JWT
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* @param Key|ArrayAccess<string,Key>|array<string,Key> $keyOrKeyArray The Key or associative array of key IDs
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* (kid) to Key objects.
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* If the algorithm used is asymmetric, this is
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* the public key.
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* Each Key object contains an algorithm and
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* matching key.
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* Supported algorithms are 'ES384','ES256',
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* 'HS256', 'HS384', 'HS512', 'RS256', 'RS384'
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* and 'RS512'.
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* @param stdClass $headers Optional. Populates stdClass with headers.
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*
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* @return stdClass The JWT's payload as a PHP object
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*
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* @throws InvalidArgumentException Provided key/key-array was empty or malformed
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* @throws DomainException Provided JWT is malformed
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* @throws UnexpectedValueException Provided JWT was invalid
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* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed
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* @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf'
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* @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat'
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* @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim
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*
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* @uses jsonDecode
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* @uses urlsafeB64Decode
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*/
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public static function decode(
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string $jwt,
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$keyOrKeyArray,
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stdClass &$headers = null
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): stdClass {
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// Validate JWT
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$timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp;
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if (empty($keyOrKeyArray)) {
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throw new InvalidArgumentException('Key may not be empty');
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}
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$tks = \explode('.', $jwt);
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if (\count($tks) !== 3) {
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throw new UnexpectedValueException('Wrong number of segments');
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}
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list($headb64, $bodyb64, $cryptob64) = $tks;
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$headerRaw = static::urlsafeB64Decode($headb64);
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if (null === ($header = static::jsonDecode($headerRaw))) {
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throw new UnexpectedValueException('Invalid header encoding');
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}
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if ($headers !== null) {
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$headers = $header;
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}
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$payloadRaw = static::urlsafeB64Decode($bodyb64);
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if (null === ($payload = static::jsonDecode($payloadRaw))) {
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throw new UnexpectedValueException('Invalid claims encoding');
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}
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if (\is_array($payload)) {
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// prevent PHP Fatal Error in edge-cases when payload is empty array
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$payload = (object) $payload;
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}
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if (!$payload instanceof stdClass) {
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throw new UnexpectedValueException('Payload must be a JSON object');
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}
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$sig = static::urlsafeB64Decode($cryptob64);
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if (empty($header->alg)) {
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throw new UnexpectedValueException('Empty algorithm');
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}
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if (empty(static::$supported_algs[$header->alg])) {
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throw new UnexpectedValueException('Algorithm not supported');
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}
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$key = self::getKey($keyOrKeyArray, property_exists($header, 'kid') ? $header->kid : null);
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// Check the algorithm
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if (!self::constantTimeEquals($key->getAlgorithm(), $header->alg)) {
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// See issue #351
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throw new UnexpectedValueException('Incorrect key for this algorithm');
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}
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if (\in_array($header->alg, ['ES256', 'ES256K', 'ES384'], true)) {
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// OpenSSL expects an ASN.1 DER sequence for ES256/ES256K/ES384 signatures
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$sig = self::signatureToDER($sig);
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}
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if (!self::verify("{$headb64}.{$bodyb64}", $sig, $key->getKeyMaterial(), $header->alg)) {
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throw new SignatureInvalidException('Signature verification failed');
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}
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// Check the nbf if it is defined. This is the time that the
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// token can actually be used. If it's not yet that time, abort.
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if (isset($payload->nbf) && floor($payload->nbf) > ($timestamp + static::$leeway)) {
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throw new BeforeValidException(
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'Cannot handle token with nbf prior to ' . \date(DateTime::ISO8601, (int) $payload->nbf)
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);
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}
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// Check that this token has been created before 'now'. This prevents
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// using tokens that have been created for later use (and haven't
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// correctly used the nbf claim).
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if (!isset($payload->nbf) && isset($payload->iat) && floor($payload->iat) > ($timestamp + static::$leeway)) {
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throw new BeforeValidException(
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'Cannot handle token with iat prior to ' . \date(DateTime::ISO8601, (int) $payload->iat)
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);
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}
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// Check if this token has expired.
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if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) {
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throw new ExpiredException('Expired token');
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}
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return $payload;
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}
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/**
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* Converts and signs a PHP array into a JWT string.
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*
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* @param array<mixed> $payload PHP array
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* @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $key The secret key.
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* @param string $alg Supported algorithms are 'ES384','ES256', 'ES256K', 'HS256',
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* 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
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* @param string $keyId
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* @param array<string, string> $head An array with header elements to attach
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*
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* @return string A signed JWT
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*
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* @uses jsonEncode
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* @uses urlsafeB64Encode
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*/
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public static function encode(
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array $payload,
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$key,
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string $alg,
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string $keyId = null,
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array $head = null
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): string {
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$header = ['typ' => 'JWT', 'alg' => $alg];
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if ($keyId !== null) {
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$header['kid'] = $keyId;
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}
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if (isset($head) && \is_array($head)) {
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$header = \array_merge($head, $header);
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}
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$segments = [];
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$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($header));
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$segments[] = static::urlsafeB64Encode((string) static::jsonEncode($payload));
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$signing_input = \implode('.', $segments);
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$signature = static::sign($signing_input, $key, $alg);
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$segments[] = static::urlsafeB64Encode($signature);
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return \implode('.', $segments);
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}
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/**
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* Sign a string with a given key and algorithm.
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*
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* @param string $msg The message to sign
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* @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $key The secret key.
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* @param string $alg Supported algorithms are 'EdDSA', 'ES384', 'ES256', 'ES256K', 'HS256',
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* 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
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*
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* @return string An encrypted message
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*
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* @throws DomainException Unsupported algorithm or bad key was specified
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*/
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public static function sign(
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string $msg,
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$key,
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string $alg
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): string {
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if (empty(static::$supported_algs[$alg])) {
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throw new DomainException('Algorithm not supported');
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}
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list($function, $algorithm) = static::$supported_algs[$alg];
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switch ($function) {
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case 'hash_hmac':
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if (!\is_string($key)) {
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throw new InvalidArgumentException('key must be a string when using hmac');
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}
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return \hash_hmac($algorithm, $msg, $key, true);
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case 'openssl':
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$signature = '';
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$success = \openssl_sign($msg, $signature, $key, $algorithm); // @phpstan-ignore-line
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if (!$success) {
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throw new DomainException('OpenSSL unable to sign data');
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}
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if ($alg === 'ES256' || $alg === 'ES256K') {
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$signature = self::signatureFromDER($signature, 256);
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} elseif ($alg === 'ES384') {
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$signature = self::signatureFromDER($signature, 384);
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}
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return $signature;
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case 'sodium_crypto':
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if (!\function_exists('sodium_crypto_sign_detached')) {
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throw new DomainException('libsodium is not available');
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}
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if (!\is_string($key)) {
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throw new InvalidArgumentException('key must be a string when using EdDSA');
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}
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try {
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// The last non-empty line is used as the key.
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$lines = array_filter(explode("\n", $key));
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$key = base64_decode((string) end($lines));
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if (\strlen($key) === 0) {
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throw new DomainException('Key cannot be empty string');
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}
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return sodium_crypto_sign_detached($msg, $key);
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} catch (Exception $e) {
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throw new DomainException($e->getMessage(), 0, $e);
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}
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}
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throw new DomainException('Algorithm not supported');
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}
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/**
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* Verify a signature with the message, key and method. Not all methods
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* are symmetric, so we must have a separate verify and sign method.
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*
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* @param string $msg The original message (header and body)
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* @param string $signature The original signature
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* @param string|resource|OpenSSLAsymmetricKey|OpenSSLCertificate $keyMaterial For Ed*, ES*, HS*, a string key works. for RS*, must be an instance of OpenSSLAsymmetricKey
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* @param string $alg The algorithm
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*
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* @return bool
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*
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* @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure
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*/
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private static function verify(
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string $msg,
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string $signature,
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$keyMaterial,
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string $alg
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): bool {
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if (empty(static::$supported_algs[$alg])) {
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throw new DomainException('Algorithm not supported');
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}
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list($function, $algorithm) = static::$supported_algs[$alg];
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switch ($function) {
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case 'openssl':
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$success = \openssl_verify($msg, $signature, $keyMaterial, $algorithm); // @phpstan-ignore-line
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if ($success === 1) {
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return true;
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}
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if ($success === 0) {
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return false;
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}
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// returns 1 on success, 0 on failure, -1 on error.
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throw new DomainException(
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'OpenSSL error: ' . \openssl_error_string()
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);
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case 'sodium_crypto':
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if (!\function_exists('sodium_crypto_sign_verify_detached')) {
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throw new DomainException('libsodium is not available');
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}
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if (!\is_string($keyMaterial)) {
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throw new InvalidArgumentException('key must be a string when using EdDSA');
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}
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try {
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// The last non-empty line is used as the key.
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$lines = array_filter(explode("\n", $keyMaterial));
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$key = base64_decode((string) end($lines));
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if (\strlen($key) === 0) {
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throw new DomainException('Key cannot be empty string');
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}
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if (\strlen($signature) === 0) {
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throw new DomainException('Signature cannot be empty string');
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}
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return sodium_crypto_sign_verify_detached($signature, $msg, $key);
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} catch (Exception $e) {
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throw new DomainException($e->getMessage(), 0, $e);
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}
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case 'hash_hmac':
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default:
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if (!\is_string($keyMaterial)) {
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throw new InvalidArgumentException('key must be a string when using hmac');
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}
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$hash = \hash_hmac($algorithm, $msg, $keyMaterial, true);
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return self::constantTimeEquals($hash, $signature);
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}
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}
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/**
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* Decode a JSON string into a PHP object.
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*
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* @param string $input JSON string
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*
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* @return mixed The decoded JSON string
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*
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* @throws DomainException Provided string was invalid JSON
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*/
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public static function jsonDecode(string $input)
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{
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$obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING);
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if ($errno = \json_last_error()) {
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self::handleJsonError($errno);
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} elseif ($obj === null && $input !== 'null') {
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throw new DomainException('Null result with non-null input');
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}
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return $obj;
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}
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/**
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* Encode a PHP array into a JSON string.
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*
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* @param array<mixed> $input A PHP array
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*
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* @return string JSON representation of the PHP array
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*
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* @throws DomainException Provided object could not be encoded to valid JSON
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*/
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public static function jsonEncode(array $input): string
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{
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if (PHP_VERSION_ID >= 50400) {
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$json = \json_encode($input, \JSON_UNESCAPED_SLASHES);
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} else {
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// PHP 5.3 only
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$json = \json_encode($input);
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}
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if ($errno = \json_last_error()) {
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self::handleJsonError($errno);
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} elseif ($json === 'null') {
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throw new DomainException('Null result with non-null input');
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}
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if ($json === false) {
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throw new DomainException('Provided object could not be encoded to valid JSON');
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}
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return $json;
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}
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/**
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* Decode a string with URL-safe Base64.
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*
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* @param string $input A Base64 encoded string
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*
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* @return string A decoded string
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*
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* @throws InvalidArgumentException invalid base64 characters
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*/
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public static function urlsafeB64Decode(string $input): string
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{
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return \base64_decode(self::convertBase64UrlToBase64($input));
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}
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/**
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* Convert a string in the base64url (URL-safe Base64) encoding to standard base64.
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*
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* @param string $input A Base64 encoded string with URL-safe characters (-_ and no padding)
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*
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* @return string A Base64 encoded string with standard characters (+/) and padding (=), when
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* needed.
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*
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* @see https://www.rfc-editor.org/rfc/rfc4648
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*/
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public static function convertBase64UrlToBase64(string $input): string
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{
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$remainder = \strlen($input) % 4;
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if ($remainder) {
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$padlen = 4 - $remainder;
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$input .= \str_repeat('=', $padlen);
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}
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return \strtr($input, '-_', '+/');
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}
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/**
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* Encode a string with URL-safe Base64.
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*
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* @param string $input The string you want encoded
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*
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* @return string The base64 encode of what you passed in
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*/
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public static function urlsafeB64Encode(string $input): string
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{
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return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_'));
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}
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/**
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* Determine if an algorithm has been provided for each Key
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*
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* @param Key|ArrayAccess<string,Key>|array<string,Key> $keyOrKeyArray
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* @param string|null $kid
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*
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* @throws UnexpectedValueException
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*
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* @return Key
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*/
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private static function getKey(
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$keyOrKeyArray,
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?string $kid
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): Key {
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if ($keyOrKeyArray instanceof Key) {
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return $keyOrKeyArray;
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}
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if (empty($kid) && $kid !== '0') {
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throw new UnexpectedValueException('"kid" empty, unable to lookup correct key');
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}
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if ($keyOrKeyArray instanceof CachedKeySet) {
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// Skip "isset" check, as this will automatically refresh if not set
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return $keyOrKeyArray[$kid];
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}
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if (!isset($keyOrKeyArray[$kid])) {
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throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key');
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}
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return $keyOrKeyArray[$kid];
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}
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/**
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* @param string $left The string of known length to compare against
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* @param string $right The user-supplied string
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* @return bool
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*/
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public static function constantTimeEquals(string $left, string $right): bool
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{
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if (\function_exists('hash_equals')) {
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return \hash_equals($left, $right);
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}
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$len = \min(self::safeStrlen($left), self::safeStrlen($right));
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$status = 0;
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for ($i = 0; $i < $len; $i++) {
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$status |= (\ord($left[$i]) ^ \ord($right[$i]));
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}
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$status |= (self::safeStrlen($left) ^ self::safeStrlen($right));
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return ($status === 0);
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}
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/**
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* Helper method to create a JSON error.
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*
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* @param int $errno An error number from json_last_error()
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*
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* @throws DomainException
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*
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* @return void
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*/
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private static function handleJsonError(int $errno): void
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{
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$messages = [
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JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
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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' //PHP >= 5.3.3
|
|
];
|
|
throw new DomainException(
|
|
isset($messages[$errno])
|
|
? $messages[$errno]
|
|
: 'Unknown JSON error: ' . $errno
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Get the number of bytes in cryptographic strings.
|
|
*
|
|
* @param string $str
|
|
*
|
|
* @return int
|
|
*/
|
|
private static function safeStrlen(string $str): int
|
|
{
|
|
if (\function_exists('mb_strlen')) {
|
|
return \mb_strlen($str, '8bit');
|
|
}
|
|
return \strlen($str);
|
|
}
|
|
|
|
/**
|
|
* Convert an ECDSA signature to an ASN.1 DER sequence
|
|
*
|
|
* @param string $sig The ECDSA signature to convert
|
|
* @return string The encoded DER object
|
|
*/
|
|
private static function signatureToDER(string $sig): string
|
|
{
|
|
// Separate the signature into r-value and s-value
|
|
$length = max(1, (int) (\strlen($sig) / 2));
|
|
list($r, $s) = \str_split($sig, $length);
|
|
|
|
// Trim leading zeros
|
|
$r = \ltrim($r, "\x00");
|
|
$s = \ltrim($s, "\x00");
|
|
|
|
// Convert r-value and s-value from unsigned big-endian integers to
|
|
// signed two's complement
|
|
if (\ord($r[0]) > 0x7f) {
|
|
$r = "\x00" . $r;
|
|
}
|
|
if (\ord($s[0]) > 0x7f) {
|
|
$s = "\x00" . $s;
|
|
}
|
|
|
|
return self::encodeDER(
|
|
self::ASN1_SEQUENCE,
|
|
self::encodeDER(self::ASN1_INTEGER, $r) .
|
|
self::encodeDER(self::ASN1_INTEGER, $s)
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Encodes a value into a DER object.
|
|
*
|
|
* @param int $type DER tag
|
|
* @param string $value the value to encode
|
|
*
|
|
* @return string the encoded object
|
|
*/
|
|
private static function encodeDER(int $type, string $value): string
|
|
{
|
|
$tag_header = 0;
|
|
if ($type === self::ASN1_SEQUENCE) {
|
|
$tag_header |= 0x20;
|
|
}
|
|
|
|
// Type
|
|
$der = \chr($tag_header | $type);
|
|
|
|
// Length
|
|
$der .= \chr(\strlen($value));
|
|
|
|
return $der . $value;
|
|
}
|
|
|
|
/**
|
|
* Encodes signature from a DER object.
|
|
*
|
|
* @param string $der binary signature in DER format
|
|
* @param int $keySize the number of bits in the key
|
|
*
|
|
* @return string the signature
|
|
*/
|
|
private static function signatureFromDER(string $der, int $keySize): string
|
|
{
|
|
// OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE
|
|
list($offset, $_) = self::readDER($der);
|
|
list($offset, $r) = self::readDER($der, $offset);
|
|
list($offset, $s) = self::readDER($der, $offset);
|
|
|
|
// Convert r-value and s-value from signed two's compliment to unsigned
|
|
// big-endian integers
|
|
$r = \ltrim($r, "\x00");
|
|
$s = \ltrim($s, "\x00");
|
|
|
|
// Pad out r and s so that they are $keySize bits long
|
|
$r = \str_pad($r, $keySize / 8, "\x00", STR_PAD_LEFT);
|
|
$s = \str_pad($s, $keySize / 8, "\x00", STR_PAD_LEFT);
|
|
|
|
return $r . $s;
|
|
}
|
|
|
|
/**
|
|
* Reads binary DER-encoded data and decodes into a single object
|
|
*
|
|
* @param string $der the binary data in DER format
|
|
* @param int $offset the offset of the data stream containing the object
|
|
* to decode
|
|
*
|
|
* @return array{int, string|null} the new offset and the decoded object
|
|
*/
|
|
private static function readDER(string $der, int $offset = 0): array
|
|
{
|
|
$pos = $offset;
|
|
$size = \strlen($der);
|
|
$constructed = (\ord($der[$pos]) >> 5) & 0x01;
|
|
$type = \ord($der[$pos++]) & 0x1f;
|
|
|
|
// Length
|
|
$len = \ord($der[$pos++]);
|
|
if ($len & 0x80) {
|
|
$n = $len & 0x1f;
|
|
$len = 0;
|
|
while ($n-- && $pos < $size) {
|
|
$len = ($len << 8) | \ord($der[$pos++]);
|
|
}
|
|
}
|
|
|
|
// Value
|
|
if ($type === self::ASN1_BIT_STRING) {
|
|
$pos++; // Skip the first contents octet (padding indicator)
|
|
$data = \substr($der, $pos, $len - 1);
|
|
$pos += $len - 1;
|
|
} elseif (!$constructed) {
|
|
$data = \substr($der, $pos, $len);
|
|
$pos += $len;
|
|
} else {
|
|
$data = null;
|
|
}
|
|
|
|
return [$pos, $data];
|
|
}
|
|
}
|