I'm attempting to write a C# WebSocket server for an application that interacts upon browser input.
This is the code:
class Program {
static void Main(string[] args) {
var listener = new TcpListener(IPAddress.Parse("127.0.0.1"), 42001);
listener.Start();
using(var client = listener.AcceptTcpClient())
using(var stream = client.GetStream())
using(var reader = new StreamReader(stream))
using(var writer = new StreamWriter(stream)) {
while (!reader.EndOfStream) {
String line = reader.ReadLine();
if (new Regex("^GET").IsMatch(line)) {
line = reader.ReadLine();
if (new Regex("^Sec-WebSocket-Key: ").IsMatch(line)) {
String key = new Regex("(^Sec-WebSocket-Key\\: |\\r\\n)").Replace(line, "");
key = Convert.ToBase64String(SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes(key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")));
writer.WriteLine("HTTP/1.1 101 Switching Protocols");
writer.WriteLine("Upgrade: websocket");
writer.WriteLine("Connection: Upgrade");
writer.WriteLine("Sec-WebSocket-Accept: " + key);
writer.WriteLine("Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits");
writer.WriteLine("WebSocket-Origin: http://127.0.0.1");
writer.WriteLine("WebSocket-Location: ws://localhost:42001/websocket");
writer.WriteLine("");
}
}
}
}
listener.Stop();
}
}
... and:
var ws = new WebSocket('ws://localhost:42001/websocket');
ws.onopen = function() {
console.log('connected');
};
ws.onmessage = function(e) {
console.log(e.data);
};
ws.onerror = function(e) {
console.log(e);
};
ws.onclose = function() {
console.log("closed");
};
On execution, the TPCListener successfully accepts the TCPClient and reads the incoming HTTP request. It parses the Key, generates the correct Accept token, but the JS - window native - WebSocket seems to have gone flat out bonkers: it does not answer no matter what it receives.
I would expect it throwing an error upon sending a HTTP/1.1 400 Bad Request, but nothing at all happens. It just goes mute.
Checking out Chrome Dev Tools' Networking tab, I do only see the websocket outgoing GET request, but no incoming packets - is that supposed to happen?
If I forcefully close the application, WebSocket throws this exception:
WebSocket connection to 'ws://localhost:42001/websocket' failed: Error during WebSocket handshake: net::ERR_CONNECTION_RESET.
What am I missing here? Thank you all in advance.
Also, I'm not using Net.WebSockets because it is available since .NET 4.5, and my application targets systems from Windows 7 to the current build of Windows 10.
