public WebSocketFrame Read(Stream stream, Socket socket)
{
byte byte1;
try
{
byte1 = (byte)stream.ReadByte();
}
catch (IOException)
{
if (socket.Connected)
{
throw;
}
else
{
return(null);
}
}
// process first byte
byte finBitFlag = 0x80;
byte opCodeFlag = 0x0F;
bool isFinBitSet = (byte1 & finBitFlag) == finBitFlag;
WebSocketOpCode opCode = (WebSocketOpCode)(byte1 & opCodeFlag);
// read and process second byte
byte byte2 = (byte)stream.ReadByte();
byte maskFlag = 0x80;
bool isMaskBitSet = (byte2 & maskFlag) == maskFlag;
uint len = ReadLength(byte2, stream);
byte[] payload;
// use the masking key to decode the data if needed
if (isMaskBitSet)
{
byte[] maskKey = BinaryReaderWriter.ReadExactly(WebSocketFrameCommon.MaskKeyLength, stream);
payload = BinaryReaderWriter.ReadExactly((int)len, stream);
// apply the mask key to the payload (which will be mutated)
WebSocketFrameCommon.ToggleMask(maskKey, payload);
}
else
{
payload = BinaryReaderWriter.ReadExactly((int)len, stream);
}
WebSocketFrame frame = new WebSocketFrame(isFinBitSet, opCode, payload, true);
return(frame);
}
public void Write(WebSocketOpCode opCode, byte[] payload, bool isLastFrame)
{
// best to write everything to a memory stream before we push it onto the wire
// not really necessary but I like it this way
using (MemoryStream memoryStream = new MemoryStream())
{
byte finBitSetAsByte = isLastFrame ? (byte)0x80 : (byte)0x00;
byte byte1 = (byte)(finBitSetAsByte | (byte)opCode);
memoryStream.WriteByte(byte1);
// NB, set the mask flag if we are constructing a client frame
byte maskBitSetAsByte = _isClient ? (byte)0x80 : (byte)0x00;
// depending on the size of the length we want to write it as a byte, ushort or ulong
if (payload.Length < 126)
{
byte byte2 = (byte)(maskBitSetAsByte | (byte)payload.Length);
memoryStream.WriteByte(byte2);
}
else if (payload.Length <= ushort.MaxValue)
{
byte byte2 = (byte)(maskBitSetAsByte | 126);
memoryStream.WriteByte(byte2);
BinaryReaderWriter.WriteUShort((ushort)payload.Length, memoryStream, false);
}
else
{
byte byte2 = (byte)(maskBitSetAsByte | 127);
memoryStream.WriteByte(byte2);
BinaryReaderWriter.WriteULong((ulong)payload.Length, memoryStream, false);
}
// if we are creating a client frame then we MUST mack the payload as per the spec
if (_isClient)
{
byte[] maskKey = new byte[WebSocketFrameCommon.MaskKeyLength];
_random.NextBytes(maskKey);
memoryStream.Write(maskKey, 0, maskKey.Length);
// mask the payload
WebSocketFrameCommon.ToggleMask(maskKey, payload);
}
memoryStream.Write(payload, 0, payload.Length);
byte[] buffer = memoryStream.ToArray();
_stream.Write(buffer, 0, buffer.Length);
}
}
