/// <summary>
/// Check for an upgrade to a web socket connection.
/// </summary>
/// <param name="request"></param>
/// <param name="response"></param>
/// <returns></returns>
private IWebSocketRequestHandler UpgradeToWebsocket(HttpRequest request, HttpResponse response)
{
// Check for required headers
if (!(request.Headers.ContainsKey(HttpHeaders.Connection) && request.Headers[HttpHeaders.Connection].ToLower().Contains("upgrade")))
{
return(null);
}
if (!(request.Headers.ContainsKey(HttpHeaders.Upgrade) && request.Headers[HttpHeaders.Upgrade].ToLower().Contains("websocket")))
{
return(null);
}
if (!request.Headers.ContainsKey(SecWebSocketVersion))
{
return(null);
}
int version;
if (!(int.TryParse(request.Headers[SecWebSocketVersion], out version) && (version == 13)))
{
return(null);
}
if (!request.Headers.ContainsKey(SecWebSocketKey))
{
return(null);
}
// Make sure we have a handler for the URI
string partial;
IWebSocketRequestHandler handler = m_server.GetHandlerForWebSocket(request.URI, out partial);
if (handler == null)
{
return(null);
}
// Do we support the protocols requested?
string protocol = null;
if (request.Headers.ContainsKey(SecWebSocketProtocol))
{
foreach (string proto in request.Headers[SecWebSocketProtocol].Split(WebSocketProtocolSeparator))
{
if (handler.WillAcceptRequest(partial, proto.Trim()))
{
protocol = proto.Trim();
break;
}
}
}
else if (handler.WillAcceptRequest(partial, ""))
{
protocol = "";
}
if (protocol == null)
{
return(null);
}
// Finish the handshake
byte[] security = Encoding.UTF8.GetBytes(request.Headers[SecWebSocketKey].Trim() + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11");
SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
sha1.Initialize();
sha1.HashCore(security, 0, security.Length);
security = sha1.HashFinal();
response.Headers[SecWebSocketAccept] = Convert.ToBase64String(security);
response.Headers[HttpHeaders.Upgrade] = "websocket";
response.Headers[HttpHeaders.Connection] = "Upgrade";
response.ResponseCode = HttpResponseCode.SwitchingProtocols;
if (protocol.Length > 0)
{
response.Headers[SecWebSocketProtocol] = protocol;
}
// And we are done
return(handler);
}