private void DropRequest(ServerResponse res, ushort code, string reason, string body, params Header[] otherHeaders)
{
res.SetHead(code, reason, new Header("Content-Length", body.Length.ToString()), new Header("Connection", "close"));
foreach (Header h in otherHeaders)
{
res.SetHeader(h.Name, h.Value);
}
res.Write(body);
res.End();
}
private void OnRequest(ClientRequest req, ServerResponse res)
{
if (req.HttpVersion != "HTTP/1.1")
{
// bad http version
DropRequest(res, 505, "HTTP Version Not Supported", "Use HTTP/1.1");
return;
}
if (req.Method != "GET")
{
// bad http version
DropRequest(res, 405, "Method Not Allowed", "Use GET");
return;
}
if (req["Transfer-Encoding"] != null || req["Content-Encoding"] != null || req["Content-Length"] != null)
{
// has body
DropRequest(res, 400, "Bad Request", "No body allowed");
return;
}
if (req["Connection"] != "Upgrade")
{
// not upgrading
DropRequest(res, 426, "Upgrade Required", "Upgrade required");
return;
}
if (req["Upgrade"] != "websocket")
{
// not upgrading to websocket
DropRequest(res, 400, "Bad Request", "Upgrade to websocket");
return;
}
if (req["Sec-WebSocket-Version"] != "13")
{
// bad websocket version
DropRequest(res, 400, "Bad Request", "Unsupported WebSocket version", new Header("Sec-WebSocket-Version", "13"));
return;
}
if (req["Sec-WebSocket-Key"] == null)
{
// Sec-WebSocket-Key not given
DropRequest(res, 400, "Bad Request", "Sec-WebSocket-Key not given");
return;
}
if (ClientVerifier != null && !ClientVerifier(req.Head))
{
// rejected
DropRequest(res, 403, "Forbidden", "");
return;
}
SHA1 hasher = SHA1.Create();
byte[] result = hasher.ComputeHash(Encoding.UTF8.GetBytes(req["Sec-WebSocket-Key"] + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"));
string str = Convert.ToBase64String(result, Base64FormattingOptions.None);
hasher.Dispose();
res.SetHead(101, "Switching Protocols");
res["Connection"] = "upgrade";
res["Upgrade"] = "websocket";
res["Sec-WebSocket-Version"] = "13";
res["Sec-WebSocket-Accept"] = str;
byte[] trail = res.Upgrade();
ServerWebSocket ws = new ServerWebSocket(req.Connection.Base, req.Head, trail);
OnConnection?.Invoke(ws);
ws.Base.Resume();
}