phpseclib\Crypt\AES::setKey PHP Метод

    function setKey($key)
    {
        switch (strlen($key)) {
            case 16:
            case 24:
            case 32:
                break;
            default:
                throw new \LengthException('Key of size ' . strlen($key) . ' not supported by this algorithm. Only keys of sizes 16, 24 or 32 supported');
        }
        parent::setKey($key);
    }

 public static function decrypt($data, $k, $iv)
 {
     $aes = new AES(MCRYPT_MODE_CBC);
     $aes->setKey($k);
     $aes->setIV($iv);
     return $aes->decrypt($data);
 }