/// <summary>
/// Connect with a stream that has already been opened and HTTP websocket upgrade request sent
/// This function will check the handshake response from the server and proceed if successful
/// Use this function if you have specific requirements to open a conenction like using special http headers and cookies
/// You will have to build your own HTTP websocket upgrade request
/// You may not even choose to use TCP/IP and this function will allow you to do that
/// </summary>
/// <param name="responseStream">The full duplex response stream from the server</param>
/// <param name="secWebSocketKey">The secWebSocketKey you used in the handshake request</param>
/// <param name="options">The WebSocket client options</param>
/// <param name="token">The optional cancellation token</param>
/// <returns></returns>
public async Task <WebSocket> ConnectAsync(System.IO.Stream responseStream, string secWebSocketKey,
WebSocketClientOptions options, CancellationToken token = default(CancellationToken))
{
Guid guid = Guid.NewGuid();
return(await ConnectAsync(guid, responseStream, secWebSocketKey, options.KeepAliveInterval,
options.SecWebSocketExtensions, options.IncludeExceptionInCloseResponse, token));
}
/// <summary>
/// Connect with options specified
/// </summary>
/// <param name="uri">The WebSocket uri to connect to (e.g. ws://example.com or wss://example.com for SSL)</param>
/// <param name="options">The WebSocket client options</param>
/// <param name="token">The optional cancellation token</param>
/// <returns>A connected web socket instance</returns>
public async Task <WebSocket> ConnectAsync(Uri uri, WebSocketClientOptions options, CancellationToken token = default(CancellationToken))
{
Guid guid = Guid.NewGuid();
string host = uri.Host;
int port = uri.Port;
string uriScheme = uri.Scheme.ToLower();
bool useSsl = uriScheme == "wss" || uriScheme == "https";
System.IO.Stream stream = await GetStream(guid, useSsl, options.NoDelay, host, port, token);
return(await PerformHandshake(guid, uri, stream, options, token));
}
private async Task <WebSocket> PerformHandshake(Guid guid, Uri uri, System.IO.Stream stream,
WebSocketClientOptions options, CancellationToken token)
{
Random rand = new Random();
byte[] keyAsBytes = new byte[16];
rand.NextBytes(keyAsBytes);
string secWebSocketKey = Convert.ToBase64String(keyAsBytes);
string additionalHeaders = GetAdditionalHeaders(options.AdditionalHttpHeaders);
string handshakeHttpRequest = $"GET {uri.PathAndQuery} HTTP/1.1\r\n" +
$"Host: {uri.Host}:{uri.Port}\r\n" +
"Upgrade: websocket\r\n" +
"Connection: Upgrade\r\n" +
$"Sec-WebSocket-Key: {secWebSocketKey}\r\n" +
$"Origin: http://{uri.Host}:{uri.Port}\r\n" +
$"Sec-WebSocket-Protocol: {options.SecWebSocketProtocol}\r\n" +
additionalHeaders +
"Sec-WebSocket-Version: 13\r\n\r\n";
byte[] httpRequest = Encoding.UTF8.GetBytes(handshakeHttpRequest);
stream.Write(httpRequest, 0, httpRequest.Length);
return(await ConnectAsync(stream, secWebSocketKey, options, token));
}
