//This is called when client is aware of proxy
private static void HandleClient(ExplicitProxyEndPoint endPoint, TcpClient client)
{
Stream clientStream = client.GetStream();
var clientStreamReader = new CustomBinaryReader(clientStream, Encoding.ASCII);
var clientStreamWriter = new StreamWriter(clientStream);
Uri httpRemoteUri;
try
{
//read the first line HTTP command
var httpCmd = clientStreamReader.ReadLine();
if (string.IsNullOrEmpty(httpCmd))
{
Dispose(client, clientStream, clientStreamReader, clientStreamWriter, null);
return;
}
//break up the line into three components (method, remote URL & Http Version)
var httpCmdSplit = httpCmd.Split(SpaceSplit, 3);
var httpVerb = httpCmdSplit[0];
if (httpVerb.ToUpper() == "CONNECT")
httpRemoteUri = new Uri("http://" + httpCmdSplit[1]);
else
httpRemoteUri = new Uri(httpCmdSplit[1]);
var httpVersion = httpCmdSplit[2];
var excluded = endPoint.ExcludedHttpsHostNameRegex != null ? endPoint.ExcludedHttpsHostNameRegex.Any(x => Regex.IsMatch(httpRemoteUri.Host, x)) : false;
//Client wants to create a secure tcp tunnel (its a HTTPS request)
if (httpVerb.ToUpper() == "CONNECT" && !excluded && httpRemoteUri.Port != 80)
{
httpRemoteUri = new Uri("https://" + httpCmdSplit[1]);
clientStreamReader.ReadAllLines();
WriteConnectResponse(clientStreamWriter, httpVersion);
var certificate = CertManager.CreateCertificate(httpRemoteUri.Host);
SslStream sslStream = null;
try
{
sslStream = new SslStream(clientStream, true);
//Successfully managed to authenticate the client using the fake certificate
sslStream.AuthenticateAsServer(certificate, false,
SupportedProtocols, false);
clientStreamReader = new CustomBinaryReader(sslStream, Encoding.ASCII);
clientStreamWriter = new StreamWriter(sslStream);
//HTTPS server created - we can now decrypt the client's traffic
clientStream = sslStream;
}
catch
{
if (sslStream != null)
sslStream.Dispose();
Dispose(client, clientStream, clientStreamReader, clientStreamWriter, null);
return;
}
httpCmd = clientStreamReader.ReadLine();
}
else if (httpVerb.ToUpper() == "CONNECT")
{
clientStreamReader.ReadAllLines();
WriteConnectResponse(clientStreamWriter, httpVersion);
TcpHelper.SendRaw(clientStream, null, null, httpRemoteUri.Host, httpRemoteUri.Port,
false);
Dispose(client, clientStream, clientStreamReader, clientStreamWriter, null);
return;
}
//Now create the request
HandleHttpSessionRequest(client, httpCmd, clientStream, clientStreamReader, clientStreamWriter,
httpRemoteUri.Scheme == Uri.UriSchemeHttps ? true : false);
}
catch
{
Dispose(client, clientStream, clientStreamReader, clientStreamWriter, null);
}
}
public void StartProxy()
{
ProxyServer.BeforeRequest += OnRequest;
ProxyServer.BeforeResponse += OnResponse;
//Exclude Https addresses you don't want to proxy
//Usefull for clients that use certificate pinning
//for example dropbox.com
var explicitEndPoint = new ExplicitProxyEndPoint(IPAddress.Any, 8000, true){
ExcludedHttpsHostNameRegex = new List<string>() { "dropbox.com" }
};
//An explicit endpoint is where the client knows about the existance of a proxy
//So client sends request in a proxy friendly manner
ProxyServer.AddEndPoint(explicitEndPoint);
ProxyServer.Start();
//Transparent endpoint is usefull for reverse proxying (client is not aware of the existance of proxy)
//A transparent endpoint usually requires a network router port forwarding HTTP(S) packets to this endpoint
//Currently do not support Server Name Indication (It is not currently supported by SslStream class)
//That means that the transparent endpoint will always provide the same Generic Certificate to all HTTPS requests
//In this example only google.com will work for HTTPS requests
//Other sites will receive a certificate mismatch warning on browser
//Please read about it before asking questions!
var transparentEndPoint = new TransparentProxyEndPoint(IPAddress.Any, 8001, true) {
GenericCertificateName = "google.com"
};
ProxyServer.AddEndPoint(transparentEndPoint);
foreach (var endPoint in ProxyServer.ProxyEndPoints)
Console.WriteLine("Listening on '{0}' endpoint at Ip {1} and port: {2} ",
endPoint.GetType().Name, endPoint.IpAddress, endPoint.Port);
//You can also add/remove end points after proxy has been started
ProxyServer.RemoveEndPoint(transparentEndPoint);
//Only explicit proxies can be set as system proxy!
ProxyServer.SetAsSystemHttpProxy(explicitEndPoint);
ProxyServer.SetAsSystemHttpsProxy(explicitEndPoint);
}