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baubyte/jwt_decode.php

Forked from ahgood/jwt_decode.php
Created March 1, 2024 16:49
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  1. @ahgood ahgood created this gist Jun 20, 2016.
    156 changes: 156 additions & 0 deletions jwt_decode.php
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,156 @@
    <?php
    /**
    * JSON Web Token implementation
    *
    * Minimum implementation used by Realtime auth, based on this spec:
    * http://self-issued.info/docs/draft-jones-json-web-token-01.html.
    *
    * @author Neuman Vong <[email protected]>
    */
    class JWT
    {
    /**
    * @param string $jwt The JWT
    * @param string|null $key The secret key
    * @param bool $verify Don't skip verification process
    *
    * @return object The JWT's payload as a PHP object
    */
    public static function decode($jwt, $key = null, $verify = true)
    {
    $tks = explode('.', $jwt);
    if (count($tks) != 3) {
    throw new UnexpectedValueException('Wrong number of segments');
    }
    list($headb64, $payloadb64, $cryptob64) = $tks;
    if (null === ($header = JWT::jsonDecode(JWT::urlsafeB64Decode($headb64)))
    ) {
    throw new UnexpectedValueException('Invalid segment encoding');
    }
    if (null === $payload = JWT::jsonDecode(JWT::urlsafeB64Decode($payloadb64))
    ) {
    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.$payloadb64", $key, $header->alg)) {
    throw new UnexpectedValueException('Signature verification failed');
    }
    }
    return $payload;
    }
    /**
    * @param object|array $payload PHP object or array
    * @param string $key The secret key
    * @param string $algo The signing algorithm
    *
    * @return string A JWT
    */
    public static function encode($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);
    }
    /**
    * @param string $msg The message to sign
    * @param string $key The secret key
    * @param string $method The signing algorithm
    *
    * @return string An encrypted message
    */
    public static function sign($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);
    }
    /**
    * @param string $input JSON string
    *
    * @return object Object representation of JSON string
    */
    public static function jsonDecode($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;
    }
    /**
    * @param object|array $input A PHP object or array
    *
    * @return string JSON representation of the PHP object or array
    */
    public static function jsonEncode($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;
    }
    /**
    * @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, '-_', '+/'));
    }
    /**
    * @param string $input Anything really
    *
    * @return string The base64 encode of what you passed in
    */
    public static function urlsafeB64Encode($input)
    {
    return str_replace('=', '', strtr(base64_encode($input), '+/', '-_'));
    }
    /**
    * @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
    );
    }
    }

    $payload_data = JWT::decode($jwt_token, JWT_AUTH_SECRET_KEY, false);