HybiEncode

gistfile1.cs

public byte[] HybiEncode(string message)
{
    if (message.Length > 125)
    {
        message = message.Substring(0, 125);
    }

    byte[] payload = Encoding.UTF8.GetBytes(message);
    List<int> frameHead = new List<int>();
    int payloadLength = payload.Length;
    
    frameHead.Add(129); // 1000 0001 FIN and opcode of text
    frameHead.Add(payloadLength + 128); // 128 for masking

    Random random = new Random();
    List<int> mask = new List<int>();
    for(int i = 0; i < 4; i++)
    {
        mask.Add(random.Next(0, 255));
    }
    frameHead.AddRange(mask);

    for (int i = 0; i < payloadLength; i++)
    {
        frameHead.Add(payload[i] ^ mask[i % 4]);
    }

    return frameHead.Select(e => (byte)e).ToArray();
}