internal async Task InvokeTunnectConnectRequest(ProxyServer proxyServer, TunnelConnectSessionEventArgs connectArgs, Action <Exception> exceptionFunc)
{
if (TunnelConnectRequest != null)
{
await TunnelConnectRequest.InvokeAsync(proxyServer, connectArgs, exceptionFunc);
}
}
/// <summary>
/// This is called when client is aware of proxy
/// So for HTTPS requests client would send CONNECT header to negotiate a secure tcp tunnel via proxy
/// </summary>
/// <param name="endPoint"></param>
/// <param name="tcpClient"></param>
/// <returns></returns>
private async Task HandleClient(ExplicitProxyEndPoint endPoint, TcpClient tcpClient)
{
bool disposed = false;
var clientStream = new CustomBufferedStream(tcpClient.GetStream(), BufferSize);
var clientStreamReader = new CustomBinaryReader(clientStream, BufferSize);
var clientStreamWriter = new HttpResponseWriter(clientStream, BufferSize);
Uri httpRemoteUri;
try
{
//read the first line HTTP command
string httpCmd = await clientStreamReader.ReadLineAsync();
if (string.IsNullOrEmpty(httpCmd))
{
return;
}
Request.ParseRequestLine(httpCmd, out string httpMethod, out string httpUrl, out var version);
httpRemoteUri = httpMethod == "CONNECT" ? new Uri("http://" + httpUrl) : new Uri(httpUrl);
//filter out excluded host names
bool excluded = false;
if (endPoint.ExcludedHttpsHostNameRegex != null)
{
excluded = endPoint.ExcludedHttpsHostNameRegexList.Any(x => x.IsMatch(httpRemoteUri.Host));
}
if (endPoint.IncludedHttpsHostNameRegex != null)
{
excluded = !endPoint.IncludedHttpsHostNameRegexList.Any(x => x.IsMatch(httpRemoteUri.Host));
}
ConnectRequest connectRequest = null;
//Client wants to create a secure tcp tunnel (probably its a HTTPS or Websocket request)
if (httpMethod == "CONNECT")
{
connectRequest = new ConnectRequest
{
RequestUri = httpRemoteUri,
OriginalUrl = httpUrl,
HttpVersion = version,
};
await HeaderParser.ReadHeaders(clientStreamReader, connectRequest.Headers);
var connectArgs = new TunnelConnectSessionEventArgs(BufferSize, endPoint, connectRequest, ExceptionFunc);
connectArgs.ProxyClient.TcpClient = tcpClient;
connectArgs.ProxyClient.ClientStream = clientStream;
if (TunnelConnectRequest != null)
{
await TunnelConnectRequest.InvokeAsync(this, connectArgs, ExceptionFunc);
}
if (await CheckAuthorization(clientStreamWriter, connectArgs) == false)
{
if (TunnelConnectResponse != null)
{
await TunnelConnectResponse.InvokeAsync(this, connectArgs, ExceptionFunc);
}
return;
}
//write back successfull CONNECT response
connectArgs.WebSession.Response = ConnectResponse.CreateSuccessfullConnectResponse(version);
await clientStreamWriter.WriteResponseAsync(connectArgs.WebSession.Response);
var clientHelloInfo = await SslTools.PeekClientHello(clientStream);
bool isClientHello = clientHelloInfo != null;
if (isClientHello)
{
connectRequest.ClientHelloInfo = clientHelloInfo;
}
if (TunnelConnectResponse != null)
{
connectArgs.IsHttpsConnect = isClientHello;
await TunnelConnectResponse.InvokeAsync(this, connectArgs, ExceptionFunc);
}
if (!excluded && isClientHello)
{
httpRemoteUri = new Uri("https://" + httpUrl);
connectRequest.RequestUri = httpRemoteUri;
SslStream sslStream = null;
try
{
sslStream = new SslStream(clientStream);
string certName = HttpHelper.GetWildCardDomainName(httpRemoteUri.Host);
var certificate = endPoint.GenericCertificate ?? CertificateManager.CreateCertificate(certName, false);
//Successfully managed to authenticate the client using the fake certificate
await sslStream.AuthenticateAsServerAsync(certificate, false, SupportedSslProtocols, false);
//HTTPS server created - we can now decrypt the client's traffic
clientStream = new CustomBufferedStream(sslStream, BufferSize);
clientStreamReader.Dispose();
clientStreamReader = new CustomBinaryReader(clientStream, BufferSize);
clientStreamWriter = new HttpResponseWriter(clientStream, BufferSize);
}
catch
{
sslStream?.Dispose();
return;
}
if (await CanBeHttpMethod(clientStream))
{
//Now read the actual HTTPS request line
httpCmd = await clientStreamReader.ReadLineAsync();
}
else
{
// It can be for example some Google (Cloude Messaging for Chrome) magic
excluded = true;
}
}
//Hostname is excluded or it is not an HTTPS connect
if (excluded || !isClientHello)
{
//create new connection
using (var connection = await GetServerConnection(connectArgs, true))
{
if (isClientHello)
{
int available = clientStream.Available;
if (available > 0)
{
//send the buffered data
var data = BufferPool.GetBuffer(BufferSize);
try
{
// clientStream.Available sbould be at most BufferSize because it is using the same buffer size
await clientStream.ReadAsync(data, 0, available);
await connection.StreamWriter.WriteAsync(data, 0, available, true);
}
finally
{
BufferPool.ReturnBuffer(data);
}
}
var serverHelloInfo = await SslTools.PeekServerHello(connection.Stream);
((ConnectResponse)connectArgs.WebSession.Response).ServerHelloInfo = serverHelloInfo;
}
await TcpHelper.SendRaw(clientStream, connection.Stream, BufferSize,
(buffer, offset, count) => { connectArgs.OnDataSent(buffer, offset, count); },
(buffer, offset, count) => { connectArgs.OnDataReceived(buffer, offset, count); },
ExceptionFunc);
}
return;
}
}
//Now create the request
disposed = await HandleHttpSessionRequest(tcpClient, httpCmd, clientStream, clientStreamReader, clientStreamWriter,
httpRemoteUri.Scheme == UriSchemeHttps?httpRemoteUri.Host : null, endPoint, connectRequest);
}
catch (IOException e)
{
ExceptionFunc(new Exception("Connection was aborted", e));
}
catch (SocketException e)
{
ExceptionFunc(new Exception("Could not connect", e));
}
catch (Exception e)
{
// is this the correct error message?
ExceptionFunc(new Exception("Error whilst authorizing request", e));
}
finally
{
if (!disposed)
{
Dispose(clientStream, clientStreamReader, clientStreamWriter, null);
}
}
}