Tuya protocop

public byte[] CreatePayload(Command command, string data)
{
    byte[] payload = Encoding.UTF8.GetBytes(data);

    if (Version == ProtocolVersion.V33)
    {
        payload = Encrypt(payload); // Encrypt
        // Add protocol 3.3 header
        if ((command != Command.DP_QUERY) && (command != Command.UPDATED_PS))
            payload = Enumerable.Concat(PROTOCOL_33_HEADER, payload).ToArray();
    }
    else if (command == Command.CONTROL)
    {
        // Encrypt
        payload = Encrypt(payload);
        // Encode to base64
        string data64 = Convert.ToBase64String(payload);
        // Make string
        payload = Encoding.UTF8.GetBytes($"data={data64}||lpv=3.1||");
        using (var md5 = MD5.Create())
        using (var ms = new MemoryStream())
        {
            // Calculate MD5 of data
            ms.Write(payload, 0, payload.Length);
            // ...and encryption key
            var binaryKey = Encoding.UTF8.GetBytes(LocalKey);
            ms.Write(binaryKey, 0, binaryKey.Length);

            string md5s =
                BitConverter.ToString( // Make string from MD5
                    md5.ComputeHash(ms.ToArray()) // Calculate MD5
                )
                .Replace("-", string.Empty) // Remove '-'
                .Substring(8, 16)   // Get part of it
                .ToLower();         // Lowercase
            // Data with version & MD5 hash/signature
            payload = Encoding.UTF8.GetBytes($"3.1{md5s}{data64}");
        }
    }

    using (var ms = new MemoryStream())
    {
        byte[] seqNo = BitConverter.GetBytes(SeqNo++);
        if (BitConverter.IsLittleEndian) Array.Reverse(seqNo); // Make big-endian
        byte[] dataLength = BitConverter.GetBytes(payload.Length + 8);
        if (BitConverter.IsLittleEndian) Array.Reverse(dataLength); // Make big-endian

        ms.Write(PREFIX_VALUE, 0, 4);   // Prefix
        ms.Write(seqNo, 0, 4);          // Packet number
        ms.Write(new byte[] { 0, 0, 0, (byte) command }, 0, 4); // Command number
        ms.Write(dataLength, 0, 4);     // Length of data + length of suffix
        ms.Write(payload, 0, payload.Length);   // Data
        var crc32 = new Crc32();
        var crc = crc32.Get(ms.ToArray());
        byte[] crcBin = BitConverter.GetBytes(crc);
        if (BitConverter.IsLittleEndian) Array.Reverse(crcBin); // Make big-endian
        ms.Write(crcBin, 0, 4);         // CRC32 checksum
        ms.Write(SUFFIX_VALUE, 0, 4);   // Suffix
        payload = ms.ToArray();
    }

    return payload;
}