/// <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 bool PerformServerUpgrade(HttpRequest request, HttpResponse response)
{
if (request.Method != "GET")
{
return(false);
}
bool error = false;
bool connection = false;
bool upgrade = false;
bool wsKey = false;
bool wsVersion = false;
string accept = "";
// Validate WebSocket handshake headers
for (int i = 0; i < request.Headers; ++i)
{
var header = request.Header(i);
var key = header.Item1;
var value = header.Item2;
if (string.Compare(key, "Connection", StringComparison.OrdinalIgnoreCase) == 0)
{
if ((string.Compare(value, "Upgrade", StringComparison.OrdinalIgnoreCase) != 0) && (string.Compare(value, "keep-alive, Upgrade", StringComparison.OrdinalIgnoreCase) != 0))
{
error = true;
response.MakeErrorResponse("Invalid WebSocket handshaked request: 'Connection' header value must be 'Upgrade' or 'keep-alive, Upgrade'", 400);
break;
}
connection = true;
}
else if (string.Compare(key, "Upgrade", StringComparison.OrdinalIgnoreCase) == 0)
{
if (string.Compare(value, "websocket", StringComparison.OrdinalIgnoreCase) != 0)
{
error = true;
response.MakeErrorResponse("Invalid WebSocket handshaked request: 'Upgrade' header value must be 'websocket'", 400);
break;
}
upgrade = true;
}
else if (string.Compare(key, "Sec-WebSocket-Key", StringComparison.OrdinalIgnoreCase) == 0)
{
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 (string.Compare(key, "Sec-WebSocket-Version", StringComparison.OrdinalIgnoreCase) == 0)
{
if (string.Compare(value, "13", StringComparison.OrdinalIgnoreCase) != 0)
{
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;
for (int i = 0; i < WsSendMask.Length; i++)
{
WsSendMask[i] = (byte)0;
}
// Array.Fill(WsSendMask, (byte)0);
_wsHandler.OnWsConnected(request);
return(true);
}
