protected function encrypt($str, $key){
        $str = serialize($str);
        $iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC), MCRYPT_DEV_URANDOM);
        $key = pack('H*', $key);
        $mac = hash_hmac('sha256', $str, substr(bin2hex($key), -32));
        $passcrypt = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $str.$mac, MCRYPT_MODE_CBC, $iv);
        $encrypted = base64_encode($passcrypt).'|'.base64_encode($iv);
        return $encrypted;
    }

    protected function decrypt($str, $key){
        $str = explode('|', $str.'|');
        $decoded = base64_decode($str[0]);
        $iv = base64_decode($str[1]);
        if(strlen($iv)!==mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC)){ return false; }
        $key = pack('H*', $key);
        $decrypted = trim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $decoded, MCRYPT_MODE_CBC, $iv));
        $mac = substr($decrypted, -64);
        $decrypted = substr($decrypted, 0, -64);
        $calcmac = hash_hmac('sha256', $decrypted, substr(bin2hex($key), -32));
        if($calcmac!==$mac){ return false; }
        $decrypted = unserialize($decrypted);
        return $decrypted;
    }