public void Write(WebSocketOpCode opCode, byte[] payload, bool isLastFrame)
{
using (var memoryStream = new MemoryStream()) {
var finBitSetAsByte = isLastFrame ? (byte)0x80 : (byte)0x00;
var byte1 = (byte)(finBitSetAsByte | (byte)opCode);
memoryStream.WriteByte(byte1);
if (payload.Length < 126)
{
var byte2 = (byte)payload.Length;
memoryStream.WriteByte(byte2);
}
else if (payload.Length <= ushort.MaxValue)
{
byte byte2 = 126;
memoryStream.WriteByte(byte2);
BinaryReaderWriter.WriteUShort((ushort)payload.Length, memoryStream);
}
else
{
byte byte2 = 127;
memoryStream.WriteByte(byte2);
BinaryReaderWriter.WriteULong((ulong)payload.Length, memoryStream);
}
memoryStream.Write(payload, 0, payload.Length);
var buffer = memoryStream.ToArray();
_stream.Write(buffer, 0, buffer.Length);
}
}
private static uint ReadLength(byte byte2, Stream stream)
{
const byte payloadLenFlag = 0x7F;
var lenght = (uint)(byte2 & payloadLenFlag);
const uint maxLen = 2147483648;
if (lenght > maxLen)
{
throw new ArgumentOutOfRangeException($"Payload length out of range. Min 0 max 2GB. Actual {lenght:#,##0} bytes.");
}
if (lenght == 126)
{
var lenBuffer = BinaryReaderWriter.ReadExactly(2, stream);
lenght = BitConverter.ToUInt16(lenBuffer, 0);
}
else if (lenght == 127)
{
var lenBuffer = BinaryReaderWriter.ReadExactly(8, stream);
lenght = (uint)BitConverter.ToUInt64(lenBuffer, 0);
}
return(lenght);
}
public WebSocketFrame Read(NetworkStream stream)
{
var byte1 = (byte)stream.ReadByte();
if (!stream.DataAvailable && byte1 == 0xFF)
{
return(new WebSocketFrame(true, WebSocketOpCode.ConnectionClose, new byte[0], false));
}
const byte finBitFlag = 0x80;
const byte opCodeFlag = 0x0F;
var isFinBitSet = (byte1 & finBitFlag) == finBitFlag;
var opCode = (WebSocketOpCode)(byte1 & opCodeFlag);
var byte2 = (byte)stream.ReadByte();
const byte maskFlag = 0x80;
var isMaskBitSet = (byte2 & maskFlag) == maskFlag;
var len = ReadLength(byte2, stream);
byte[] decodedPayload;
if (isMaskBitSet)
{
const int maskKeyLen = 4;
var maskKey = BinaryReaderWriter.ReadExactly(maskKeyLen, stream);
var encodedPayload = BinaryReaderWriter.ReadExactly((int)len, stream);
decodedPayload = new byte[len];
for (var i = 0; i < encodedPayload.Length; i++)
{
decodedPayload[i] = (byte)(encodedPayload[i] ^ maskKey[i % maskKeyLen]);
}
}
else
{
decodedPayload = BinaryReaderWriter.ReadExactly((int)len, stream);
}
var frame = new WebSocketFrame(isFinBitSet, opCode, decodedPayload, true);
return(frame);
}