web-base/core/External/JWT.class.php
2020-02-09 23:30:26 +01:00

200 lines
5.6 KiB
PHP

<?php
/**
* JSON Web Token implementation, based on this spec:
* http://tools.ietf.org/html/draft-ietf-oauth-json-web-token-06
*
* 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
*/
namespace External;
class JWT
{
/**
* Decodes a JWT string into a PHP object.
*
* @param string $jwt The JWT
* @param string|null $key The secret key
* @param bool $verify Don't skip verification process
*
* @return object The JWT's payload as a PHP object
* @throws UnexpectedValueException Provided JWT was invalid
* @throws DomainException Algorithm was not provided
*
* @uses jsonDecode
* @uses urlsafeB64Decode
*/
public static function decode($jwt, $key = null, $verify = true)
{
$tks = explode('.', $jwt);
if (count($tks) != 3) {
throw new UnexpectedValueException('Wrong number of segments');
}
list($headb64, $bodyb64, $cryptob64) = $tks;
if (null === ($header = JWT::jsonDecode(JWT::urlsafeB64Decode($headb64)))) {
throw new UnexpectedValueException('Invalid segment encoding');
}
if (null === $payload = JWT::jsonDecode(JWT::urlsafeB64Decode($bodyb64))) {
throw new UnexpectedValueException('Invalid segment encoding');
}
$sig = JWT::urlsafeB64Decode($cryptob64);
if ($verify) {
if (empty($header->alg)) {
throw new DomainException('Empty algorithm');
}
if ($sig != JWT::sign("$headb64.$bodyb64", $key, $header->alg)) {
throw new UnexpectedValueException('Signature verification failed');
}
}
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 $algo The signing algorithm. Supported
* algorithms are 'HS256', 'HS384' and 'HS512'
*
* @return string A signed JWT
* @uses jsonEncode
* @uses urlsafeB64Encode
*/
public static function encode($payload, $key, $algo = 'HS256')
{
$header = array('typ' => 'JWT', 'alg' => $algo);
$segments = array();
$segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header));
$segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload));
$signing_input = implode('.', $segments);
$signature = JWT::sign($signing_input, $key, $algo);
$segments[] = JWT::urlsafeB64Encode($signature);
return implode('.', $segments);
}
/**
* Sign a string with a given key and algorithm.
*
* @param string $msg The message to sign
* @param string $key The secret key
* @param string $method The signing algorithm. Supported
* algorithms are 'HS256', 'HS384' and 'HS512'
*
* @return string An encrypted message
* @throws DomainException Unsupported algorithm was specified
*/
public static function sign($msg, $key, $method = 'HS256')
{
$methods = array(
'HS256' => 'sha256',
'HS384' => 'sha384',
'HS512' => 'sha512',
);
if (empty($methods[$method])) {
throw new DomainException('Algorithm not supported');
}
return hash_hmac($methods[$method], $msg, $key, true);
}
/**
* Decode a JSON string into a PHP object.
*
* @param string $input JSON string
*
* @return object Object representation of JSON string
* @throws DomainException Provided string was invalid JSON
*/
public static function jsonDecode($input)
{
$obj = json_decode($input);
if (function_exists('json_last_error') && $errno = json_last_error()) {
JWT::_handleJsonError($errno);
} else if ($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)
{
$json = json_encode($input);
if (function_exists('json_last_error') && $errno = json_last_error()) {
JWT::_handleJsonError($errno);
} else if ($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.
*
* @param int $errno An error number from json_last_error()
*
* @return void
*/
private static function _handleJsonError($errno)
{
$messages = array(
JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON'
);
throw new DomainException(
isset($messages[$errno])
? $messages[$errno]
: 'Unknown JSON error: ' . $errno
);
}
}