protected virtual async Task FireEventAsync(object sender, WSAuthorizeEventArgs args)
{
if (_authorizeEvent != null)
{
await _authorizeEvent?.Invoke(sender, args);
}
}
public virtual async Task <bool> UpgradeConnectionCallbackAsync(WSAuthorizeEventArgs args)
{
Console.WriteLine("=====Handshaking from client=====\n{0}", args.UpgradeData);
// 1. Obtain the value of the "Sec-WebSocket-Key" request header without any leading or trailing whitespace
// 2. Concatenate it with "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" (a special GUID specified by RFC 6455)
// 3. Compute SHA-1 and Base64 hash of the new value
// 4. Write the hash back as the value of "Sec-WebSocket-Accept" response header in an HTTP response
var swk = Regex.Match(args.UpgradeData, $"{HttpKnownHeaderNames.SecWebSocketKey}: (.*)").Groups[1].Value.Trim();
var swka = swk + Statics.WS_SERVER_GUID;
var swkaSha1 = System.Security.Cryptography.SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes(swka));
var swkaSha1Base64 = Convert.ToBase64String(swkaSha1);
var requestedSubprotocols = Regex.Match(args.UpgradeData, $"{HttpKnownHeaderNames.SecWebSocketProtocol}: (.*)").Groups[1].Value.Trim().Split(",");
if (requestedSubprotocols.Where(x => !string.IsNullOrWhiteSpace(x)).ToArray().Length > 0)
{
if (!AreSubprotocolsRequestedValid(requestedSubprotocols))
{
var bytes = Encoding.UTF8.GetBytes("Invalid subprotocols requested");
await args.Connection.Stream.WriteAsync(bytes);
await DisconnectConnectionAsync(args.Connection);
return(false);
}
}
var selectedSubProtocol = requestedSubprotocols.Where(x => !string.IsNullOrWhiteSpace(x)).ToArray().Length > 0 ? $"{HttpKnownHeaderNames.SecWebSocketProtocol}: {requestedSubprotocols[0]}\r\n" : string.Empty;
// HTTP/1.1 defines the sequence CR LF as the end-of-line marker
var response = Encoding.UTF8.GetBytes(
"HTTP/1.1 101 Switching Protocols\r\n" +
$"{HttpKnownHeaderNames.Connection}: Upgrade\r\n" +
$"{HttpKnownHeaderNames.Upgrade}: websocket\r\n" +
$"{HttpKnownHeaderNames.SecWebSocketAccept}: {swkaSha1Base64}\r\n" +
$"{selectedSubProtocol}\r\n");
args.Connection.SubProtocols = requestedSubprotocols;
await args.Connection.Stream.WriteAsync(response, 0, response.Length);
_numberOfConnections++;
await SendRawAsync(_parameters.ConnectionSuccessString, args.Connection);
return(true);
}
