/// <summary>
/// Perform WebSocket server upgrade
/// </summary>
/// <param name="request">WebSocket upgrade HTTP request</param>
/// <param name="response">WebSocket upgrade HTTP response</param>
/// <returns>'true' if the WebSocket was successfully upgrade, 'false' if the WebSocket was not upgrade</returns>
public Boolean PerformServerUpgrade(HttpNetworkRequest request, HttpNetworkResponse response)
{
if (request.Method != "GET")
{
return(false);
}
Boolean error = false;
Boolean connection = false;
Boolean upgrade = false;
Boolean wsKey = false;
Boolean wsVersion = false;
String accept = "";
// Validate WebSocket handshake headers
for (Int32 i = 0; i < request.Headers; ++i)
{
Tuple <String, String> header = request.Header(i);
String key = header.Item1;
String value = header.Item2;
if (key == "Connection")
{
if (value != "Upgrade" && value != "keep-alive, Upgrade")
{
error = true;
response.MakeErrorResponse("Invalid WebSocket handshaked request: 'Connection' header value must be 'Upgrade' or 'keep-alive, Upgrade'", 400);
break;
}
connection = true;
}
else if (key == "Upgrade")
{
if (value != "websocket")
{
error = true;
response.MakeErrorResponse("Invalid WebSocket handshaked request: 'Upgrade' header value must be 'websocket'", 400);
break;
}
upgrade = true;
}
else if (key == "Sec-WebSocket-Key")
{
if (String.IsNullOrEmpty(value))
{
error = true;
response.MakeErrorResponse("Invalid WebSocket handshaked request: 'Sec-WebSocket-Key' header value must be non empty", 400);
break;
}
// Calculate the original WebSocket hash
String wskey = value + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
Byte[] wshash;
using (SHA1Managed sha1 = new SHA1Managed())
{
wshash = sha1.ComputeHash(Encoding.UTF8.GetBytes(wskey));
}
accept = Convert.ToBase64String(wshash);
wsKey = true;
}
else if (key == "Sec-WebSocket-Version")
{
if (value != "13")
{
error = true;
response.MakeErrorResponse("Invalid WebSocket handshaked request: 'Sec-WebSocket-Version' header value must be '13'", 400);
break;
}
wsVersion = true;
}
}
// Filter out non WebSocket handshake requests
if (!connection && !upgrade && !wsKey && !wsVersion)
{
return(false);
}
// Failed to perform WebSocket handshake
if (!connection || !upgrade || !wsKey || !wsVersion)
{
if (!error)
{
response.MakeErrorResponse("Invalid WebSocket response", 400);
}
_wsHandler.SendResponse(response);
return(false);
}
// Prepare WebSocket upgrade success response
response.Clear();
response.SetBegin(101);
response.SetHeader("Connection", "Upgrade");
response.SetHeader("Upgrade", "websocket");
response.SetHeader("Sec-WebSocket-Accept", accept);
response.SetBody();
// Validate WebSocket upgrade request and response
if (!_wsHandler.OnWsConnecting(request, response))
{
return(false);
}
// Send WebSocket upgrade response
_wsHandler.SendResponse(response);
// WebSocket successfully handshaked!
WsHandshaked = true;
Array.Fill(WsSendMask, (Byte)0);
_wsHandler.OnWsConnected(request);
return(true);
}
