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  • Bug fixes for general core bugs in 4.0.x will end 8 May 2023 (12 months).
  • Bug fixes for security issues in 4.0.x will end 13 November 2023 (18 months).
  • PHP version: minimum PHP 7.3.0 Note: the minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is also supported.
<?php

namespace Firebase\JWT;

< use \DomainException; < use \InvalidArgumentException; < use \UnexpectedValueException; < use \DateTime;
> use ArrayAccess; > use DomainException; > use Exception; > use InvalidArgumentException; > use OpenSSLAsymmetricKey; > use UnexpectedValueException; > use DateTime;
/** * JSON Web Token implementation, based on this spec: * https://tools.ietf.org/html/rfc7519 * * PHP version 5 * * @category Authentication * @package Authentication_JWT * @author Neuman Vong <neuman@twilio.com> * @author Anant Narayanan <anant@php.net> * @license http://opensource.org/licenses/BSD-3-Clause 3-clause BSD * @link https://github.com/firebase/php-jwt */ class JWT {
< const ASN1_INTEGER = 0x02; < const ASN1_SEQUENCE = 0x10; < const ASN1_BIT_STRING = 0x03;
> // const ASN1_INTEGER = 0x02; > // const ASN1_SEQUENCE = 0x10; > // const ASN1_BIT_STRING = 0x03; > private static $asn1Integer = 0x02; > private static $asn1Sequence = 0x10; > private static $asn1BitString = 0x03;
/** * When checking nbf, iat or expiration times, * we want to provide some extra leeway time to * account for clock skew. */
< public static $leeway = 180;
> public static $leeway = 0;
/** * Allow the current timestamp to be specified. * Useful for fixing a value within unit testing. * * Will default to PHP time() value if null. */ public static $timestamp = null; public static $supported_algs = array(
> 'ES384' => array('openssl', 'SHA384'),
'ES256' => array('openssl', 'SHA256'), 'HS256' => array('hash_hmac', 'SHA256'), 'HS384' => array('hash_hmac', 'SHA384'), 'HS512' => array('hash_hmac', 'SHA512'), 'RS256' => array('openssl', 'SHA256'), 'RS384' => array('openssl', 'SHA384'), 'RS512' => array('openssl', 'SHA512'),
> 'EdDSA' => array('sodium_crypto', 'EdDSA'),
); /** * Decodes a JWT string into a PHP object. * * @param string $jwt The JWT
< * @param string|array|resource $key The key, or map of keys.
> * @param Key|array<string, Key> $keyOrKeyArray The Key or associative array of key IDs (kid) to Key objects.
* If the algorithm used is asymmetric, this is the public key
< * @param array $allowed_algs List of supported verification algorithms < * Supported algorithms are 'ES256', 'HS256', 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
> * Each Key object contains an algorithm and matching key. > * Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', > * 'HS512', 'RS256', 'RS384', and 'RS512'
* * @return object The JWT's payload as a PHP object *
> * @throws InvalidArgumentException Provided key/key-array was empty * @throws UnexpectedValueException Provided JWT was invalid > * @throws DomainException Provided JWT is malformed
* @throws SignatureInvalidException Provided JWT was invalid because the signature verification failed * @throws BeforeValidException Provided JWT is trying to be used before it's eligible as defined by 'nbf' * @throws BeforeValidException Provided JWT is trying to be used before it's been created as defined by 'iat' * @throws ExpiredException Provided JWT has since expired, as defined by the 'exp' claim * * @uses jsonDecode * @uses urlsafeB64Decode */
< public static function decode($jwt, $key, array $allowed_algs = array())
> public static function decode($jwt, $keyOrKeyArray)
{
> // Validate JWT
$timestamp = \is_null(static::$timestamp) ? \time() : static::$timestamp;
< if (empty($key)) {
> if (empty($keyOrKeyArray)) {
throw new InvalidArgumentException('Key may not be empty'); } $tks = \explode('.', $jwt); if (\count($tks) != 3) { throw new UnexpectedValueException('Wrong number of segments'); } list($headb64, $bodyb64, $cryptob64) = $tks; if (null === ($header = static::jsonDecode(static::urlsafeB64Decode($headb64)))) { throw new UnexpectedValueException('Invalid header encoding'); } if (null === $payload = static::jsonDecode(static::urlsafeB64Decode($bodyb64))) { throw new UnexpectedValueException('Invalid claims encoding'); } if (false === ($sig = static::urlsafeB64Decode($cryptob64))) { throw new UnexpectedValueException('Invalid signature encoding'); } if (empty($header->alg)) { throw new UnexpectedValueException('Empty algorithm'); } if (empty(static::$supported_algs[$header->alg])) { throw new UnexpectedValueException('Algorithm not supported'); }
< if (!\in_array($header->alg, $allowed_algs)) { < throw new UnexpectedValueException('Algorithm not allowed'); < } < if ($header->alg === 'ES256') { < // OpenSSL expects an ASN.1 DER sequence for ES256 signatures < $sig = self::signatureToDER($sig); < }
< if (\is_array($key) || $key instanceof \ArrayAccess) { < if (isset($header->kid)) { < if (!isset($key[$header->kid])) { < throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key'); < } < $key = $key[$header->kid]; < } else { < throw new UnexpectedValueException('"kid" empty, unable to lookup correct key');
> $key = self::getKey($keyOrKeyArray, empty($header->kid) ? null : $header->kid); > > // Check the algorithm > if (!self::constantTimeEquals($key->getAlgorithm(), $header->alg)) { > // See issue #351 > throw new UnexpectedValueException('Incorrect key for this algorithm');
}
> if ($header->alg === 'ES256' || $header->alg === 'ES384') { } > // OpenSSL expects an ASN.1 DER sequence for ES256/ES384 signatures > $sig = self::signatureToDER($sig);
< < // Check the signature < if (!static::verify("$headb64.$bodyb64", $sig, $key, $header->alg)) {
> if (!static::verify("$headb64.$bodyb64", $sig, $key->getKeyMaterial(), $header->alg)) {
} // Check the nbf if it is defined. This is the time that the // token can actually be used. If it's not yet that time, abort. if (isset($payload->nbf) && $payload->nbf > ($timestamp + static::$leeway)) { throw new BeforeValidException( 'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->nbf) ); } // Check that this token has been created before 'now'. This prevents // using tokens that have been created for later use (and haven't // correctly used the nbf claim). if (isset($payload->iat) && $payload->iat > ($timestamp + static::$leeway)) { throw new BeforeValidException( 'Cannot handle token prior to ' . \date(DateTime::ISO8601, $payload->iat) ); } // Check if this token has expired. if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) { throw new ExpiredException('Expired token'); } return $payload; } /** * Converts and signs a PHP object or array into a JWT string. * * @param object|array $payload PHP object or array
< * @param string $key The secret key.
> * @param string|resource $key The secret key.
* If the algorithm used is asymmetric, this is the private key * @param string $alg The signing algorithm.
< * Supported algorithms are 'ES256', 'HS256', 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
> * Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', > * 'HS512', 'RS256', 'RS384', and 'RS512'
* @param mixed $keyId * @param array $head An array with header elements to attach * * @return string A signed JWT * * @uses jsonEncode * @uses urlsafeB64Encode */
< public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null)
> public static function encode($payload, $key, $alg, $keyId = null, $head = null)
{ $header = array('typ' => 'JWT', 'alg' => $alg); if ($keyId !== null) { $header['kid'] = $keyId; } if (isset($head) && \is_array($head)) { $header = \array_merge($head, $header); } $segments = array(); $segments[] = static::urlsafeB64Encode(static::jsonEncode($header)); $segments[] = static::urlsafeB64Encode(static::jsonEncode($payload)); $signing_input = \implode('.', $segments); $signature = static::sign($signing_input, $key, $alg); $segments[] = static::urlsafeB64Encode($signature); return \implode('.', $segments); } /** * Sign a string with a given key and algorithm. * * @param string $msg The message to sign * @param string|resource $key The secret key * @param string $alg The signing algorithm.
< * Supported algorithms are 'ES256', 'HS256', 'HS384', 'HS512', 'RS256', 'RS384', and 'RS512'
> * Supported algorithms are 'ES384','ES256', 'HS256', 'HS384', > * 'HS512', 'RS256', 'RS384', and 'RS512'
* * @return string An encrypted message *
< * @throws DomainException Unsupported algorithm was specified
> * @throws DomainException Unsupported algorithm or bad key was specified
*/
< public static function sign($msg, $key, $alg = 'HS256')
> public static function sign($msg, $key, $alg)
{ if (empty(static::$supported_algs[$alg])) { throw new DomainException('Algorithm not supported'); } list($function, $algorithm) = static::$supported_algs[$alg]; switch ($function) { case 'hash_hmac': return \hash_hmac($algorithm, $msg, $key, true); case 'openssl': $signature = ''; $success = \openssl_sign($msg, $signature, $key, $algorithm); if (!$success) { throw new DomainException("OpenSSL unable to sign data");
< } else {
> }
if ($alg === 'ES256') { $signature = self::signatureFromDER($signature, 256);
> } elseif ($alg === 'ES384') { } > $signature = self::signatureFromDER($signature, 384);
return $signature;
> case 'sodium_crypto': } > if (!function_exists('sodium_crypto_sign_detached')) { } > throw new DomainException('libsodium is not available'); } > } > try { /** > // The last non-empty line is used as the key. * Verify a signature with the message, key and method. Not all methods > $lines = array_filter(explode("\n", $key)); * are symmetric, so we must have a separate verify and sign method. > $key = base64_decode(end($lines)); * > return sodium_crypto_sign_detached($msg, $key); * @param string $msg The original message (header and body) > } catch (Exception $e) { * @param string $signature The original signature > throw new DomainException($e->getMessage(), 0, $e);
* @param string|resource $key For HS*, a string key works. for RS*, must be a resource of an openssl public key * @param string $alg The algorithm * * @return bool *
< * @throws DomainException Invalid Algorithm or OpenSSL failure
> * @throws DomainException Invalid Algorithm, bad key, or OpenSSL failure
*/ private static function verify($msg, $signature, $key, $alg) { if (empty(static::$supported_algs[$alg])) { throw new DomainException('Algorithm not supported'); } list($function, $algorithm) = static::$supported_algs[$alg]; switch ($function) { case 'openssl': $success = \openssl_verify($msg, $signature, $key, $algorithm); if ($success === 1) { return true; } elseif ($success === 0) { return false; } // returns 1 on success, 0 on failure, -1 on error. throw new DomainException( 'OpenSSL error: ' . \openssl_error_string() );
> case 'sodium_crypto': case 'hash_hmac': > if (!function_exists('sodium_crypto_sign_verify_detached')) { default: > throw new DomainException('libsodium is not available'); $hash = \hash_hmac($algorithm, $msg, $key, true); > } if (\function_exists('hash_equals')) { > try { return \hash_equals($signature, $hash); > // The last non-empty line is used as the key. } > $lines = array_filter(explode("\n", $key)); $len = \min(static::safeStrlen($signature), static::safeStrlen($hash)); > $key = base64_decode(end($lines)); > return sodium_crypto_sign_verify_detached($signature, $msg, $key); $status = 0; > } catch (Exception $e) { for ($i = 0; $i < $len; $i++) { > throw new DomainException($e->getMessage(), 0, $e); $status |= (\ord($signature[$i]) ^ \ord($hash[$i])); > }
< if (\function_exists('hash_equals')) { < return \hash_equals($signature, $hash); < } < $len = \min(static::safeStrlen($signature), static::safeStrlen($hash)); < < $status = 0; < for ($i = 0; $i < $len; $i++) { < $status |= (\ord($signature[$i]) ^ \ord($hash[$i])); < } < $status |= (static::safeStrlen($signature) ^ static::safeStrlen($hash)); < < return ($status === 0);
> return self::constantTimeEquals($signature, $hash);
* @return object Object representation of JSON string * * @throws DomainException Provided string was invalid JSON */ public static function jsonDecode($input) { if (\version_compare(PHP_VERSION, '5.4.0', '>=') && !(\defined('JSON_C_VERSION') && PHP_INT_SIZE > 4)) { /** In PHP >=5.4.0, json_decode() accepts an options parameter, that allows you * to specify that large ints (like Steam Transaction IDs) should be treated as * strings, rather than the PHP default behaviour of converting them to floats. */ $obj = \json_decode($input, false, 512, JSON_BIGINT_AS_STRING); } else { /** Not all servers will support that, however, so for older versions we must * manually detect large ints in the JSON string and quote them (thus converting *them to strings) before decoding, hence the preg_replace() call. */ $max_int_length = \strlen((string) PHP_INT_MAX) - 1; $json_without_bigints = \preg_replace('/:\s*(-?\d{'.$max_int_length.',})/', ': "$1"', $input); $obj = \json_decode($json_without_bigints); } if ($errno = \json_last_error()) { static::handleJsonError($errno); } elseif ($obj === null && $input !== 'null') { throw new DomainException('Null result with non-null input'); } return $obj; } /** * Encode a PHP object into a JSON string. * * @param object|array $input A PHP object or array * * @return string JSON representation of the PHP object or array * * @throws DomainException Provided object could not be encoded to valid JSON */ public static function jsonEncode($input) {
> if (PHP_VERSION_ID >= 50400) { $json = \json_encode($input); > $json = \json_encode($input, \JSON_UNESCAPED_SLASHES); if ($errno = \json_last_error()) { > } else { static::handleJsonError($errno); > // PHP 5.3 only
} elseif ($json === 'null' && $input !== null) {
> }
throw new DomainException('Null result with non-null input'); } return $json; } /** * Decode a string with URL-safe Base64. * * @param string $input A Base64 encoded string * * @return string A decoded string */ public static function urlsafeB64Decode($input) { $remainder = \strlen($input) % 4; if ($remainder) { $padlen = 4 - $remainder; $input .= \str_repeat('=', $padlen); } return \base64_decode(\strtr($input, '-_', '+/')); } /** * Encode a string with URL-safe Base64. * * @param string $input The string you want encoded * * @return string The base64 encode of what you passed in */ public static function urlsafeB64Encode($input) { return \str_replace('=', '', \strtr(\base64_encode($input), '+/', '-_')); }
> /** > /** * Helper method to create a JSON error. > * Determine if an algorithm has been provided for each Key * > * * @param int $errno An error number from json_last_error() > * @param Key|array<string, Key> $keyOrKeyArray * > * @param string|null $kid * @return void > * */ > * @throws UnexpectedValueException private static function handleJsonError($errno) > * { > * @return array containing the keyMaterial and algorithm $messages = array( > */ JSON_ERROR_DEPTH => 'Maximum stack depth exceeded', > private static function getKey($keyOrKeyArray, $kid = null) JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON', > { JSON_ERROR_CTRL_CHAR => 'Unexpected control character found', > if ($keyOrKeyArray instanceof Key) { JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON', > return $keyOrKeyArray; JSON_ERROR_UTF8 => 'Malformed UTF-8 characters' //PHP >= 5.3.3 > } ); > throw new DomainException( > if (is_array($keyOrKeyArray) || $keyOrKeyArray instanceof ArrayAccess) { isset($messages[$errno]) > foreach ($keyOrKeyArray as $keyId => $key) { ? $messages[$errno] > if (!$key instanceof Key) { : 'Unknown JSON error: ' . $errno > throw new UnexpectedValueException( ); > '$keyOrKeyArray must be an instance of Firebase\JWT\Key key or an ' } > . 'array of Firebase\JWT\Key keys' > ); /** > } * Get the number of bytes in cryptographic strings. > } * > if (!isset($kid)) { * @param string $str > throw new UnexpectedValueException('"kid" empty, unable to lookup correct key'); * > } * @return int > if (!isset($keyOrKeyArray[$kid])) { */ > throw new UnexpectedValueException('"kid" invalid, unable to lookup correct key'); private static function safeStrlen($str) > } { > if (\function_exists('mb_strlen')) { > return $keyOrKeyArray[$kid]; return \mb_strlen($str, '8bit'); > } } > return \strlen($str); > throw new UnexpectedValueException( } > '$keyOrKeyArray must be an instance of Firebase\JWT\Key key or an ' > . 'array of Firebase\JWT\Key keys' /** > ); * Convert an ECDSA signature to an ASN.1 DER sequence > } * > * @param string $sig The ECDSA signature to convert > /** * @return string The encoded DER object > * @param string $left */ > * @param string $right private static function signatureToDER($sig) > * @return bool { > */ // Separate the signature into r-value and s-value > public static function constantTimeEquals($left, $right) list($r, $s) = \str_split($sig, (int) (\strlen($sig) / 2)); > { > if (\function_exists('hash_equals')) { // Trim leading zeros > return \hash_equals($left, $right); $r = \ltrim($r, "\x00"); > } $s = \ltrim($s, "\x00"); > $len = \min(static::safeStrlen($left), static::safeStrlen($right)); > // Convert r-value and s-value from unsigned big-endian integers to > $status = 0; // signed two's complement > for ($i = 0; $i < $len; $i++) { if (\ord($r[0]) > 0x7f) { > $status |= (\ord($left[$i]) ^ \ord($right[$i])); $r = "\x00" . $r; > } } > $status |= (static::safeStrlen($left) ^ static::safeStrlen($right)); if (\ord($s[0]) > 0x7f) { > $s = "\x00" . $s; > return ($status === 0); } > } >
return self::encodeDER(
< self::ASN1_SEQUENCE, < self::encodeDER(self::ASN1_INTEGER, $r) . < self::encodeDER(self::ASN1_INTEGER, $s)
> self::$asn1Sequence, > self::encodeDER(self::$asn1Integer, $r) . > self::encodeDER(self::$asn1Integer, $s)
); } /** * Encodes a value into a DER object. * * @param int $type DER tag * @param string $value the value to encode * @return string the encoded object */ private static function encodeDER($type, $value) { $tag_header = 0;
< if ($type === self::ASN1_SEQUENCE) {
> if ($type === self::$asn1Sequence) {
$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 $keySize the number of bits in the key * @return string the signature */ private static function signatureFromDER($der, $keySize) { // OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE list($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 $offset the offset of the data stream containing the object * to decode * @return array [$offset, $data] the new offset and the decoded object */ private static function readDER($der, $offset = 0) { $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 ($type == self::ASN1_BIT_STRING) {
> if ($type == self::$asn1BitString) {
$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 { $data = null; } return array($pos, $data); } }