Encryption 如何从dll文件中检索加密密钥？

我有一个dll文件，它向Web服务器发出http post请求，请求如下所示：

UmdUsFrEB3wGMuuAz1Znywuedx6+ee9cHDyzqM3Gc0FW8TxKFitPfkoC23aJeW39rPhAIpkg7vyzYzRwsloEfUM3y1LnehrJVR5tQuoZ8EUa6uFgzFauuaiP1Ea9+lRg5OU

我不是什么专家，但对我来说它看起来像Base64，但当我尝试使用在线解码器解码它时，大多数解码器只是给出了一个错误，即它不是Base64格式，而其他解码器给出了汉字

有些给出了如下结果：

RgT°ZÄ|2ë€ÏVgËžw¾yï\<³¨ÍÆsAVñ<J+O~JÛv‰ymý¬ø@"™ îü³c4p²Z}C7ËRçzÉUmBêðEêá`ÌV®¹¨ÔF½úT`äå

RgT°Z|2ÏVgËžw¾yï\
    private byte[] (byte[] u0002, byte[] u0003)
    {
        byte[] numArray;
        byte[] numArray1 = new byte[89];
        ((Array)u0003).CopyTo((Array)numArray1, 0);
        ((Array)u0002).CopyTo((Array)numArray1, 16);
        if (0 == 0)
        {
            ((Array)Encoding.ASCII.GetBytes("MTRandom")).CopyTo(numArray1, 80);
        }
        do
        {
            numArray = (new MD5CryptoServiceProvider()).ComputeHash(numArray1);
        }
        while (3 == 0);
        return numArray;
    }

    private new unsafe void (byte[] u0002)
    {
        void* length = (void*)stackalloc IntPtr[9];
        this. = (ulong)0;
        *(length + 4) = this. <= 1101;
        if ((sbyte)(*(length + 4)) == 0)
        {
            . _u0001 = new .();
            byte[] numArray = base.(8);
            _u0001. = BitConverter.ToUInt16(numArray, 0);
            _u0001. = BitConverter.ToUInt16(numArray, 2);
            _u0001. = BitConverter.ToUInt16(numArray, 4);
            _u0001. = BitConverter.ToUInt16(numArray, 6);
            byte[] numArray1 = base.((int)_u0001.);
            byte[] numArray2 = this.(numArray1, u0002, _u0001);
            *length = null;
            while (true)
            {
                if (((int)(*length) >= (int)numArray2.Length ? true : (int)numArray2.Length - (int)(*length) < 8))
                {
                    return;
                }
                byte[] numArray3 = new byte[8];
                Array.Copy(numArray2, (int)(*length), numArray3, 0, 8);
                *length = (int)(*length) + 8;
                _u0001 = this.(numArray3, u0002);
                *(length + 5) = (int)numArray2.Length - (int)(*length) < _u0001.;
                if ((sbyte)(*(length + 5)) != 0)