C#: sslStream and local proxy

问题

![enter image description here][1]Hi,

We have a server which accepts ssl connection. Say if I request for https://gmail.com then the server first checks if i have logged in to it, if yes then it connects to gmail and sends the response back. If I have not logged in then it redirects to our login page. my requirement is the following:

I have to write a TCPListener which listens to the local proxy (say 127.0.0.1:13000). When ever a request comes from browser, I have to create a ssl connection to our server and pass the request to it.

The server will either reply with login url or success Then I should do the same with the browser.

The Code I have written is as follows:

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Collections.Generic;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

class MyTcpListener
{
    public static void Main()
    {
        TcpListener server = null;
        try
        {
            // Set the TcpListener on port 13000.
            Int32 port = 13000;
            IPAddress localAddr = IPAddress.Parse("127.0.0.1");

            // TcpListener server = new TcpListener(port);
            server = new TcpListener(localAddr, port);

            // Start listening for client requests.
            server.Start();

            // Buffer for reading data
            Byte[] bytes = new Byte[256];
            String data = null;

            // Buffer for reading data
            Byte[] bytes1 = new Byte[256];
            String data1 = null;

            string serverName = "xxxxxxxxxxxxxxxx";//This is the server of my company


            TcpClient sslClient = new TcpClient();
            sslClient.Connect(serverName, 8080);
            SslStream sslStream = new SslStream(sslClient.GetStream(), false, new RemoteCertificateValidationCallback(CertificateValidationCallback));
            sslStream.AuthenticateAsClient(serverName);

            // Enter the listening loop.
            while (true)
            {
                Console.Write("Waiting for a connection... ");

                // Perform a blocking call to accept requests.
                // You could also user server.AcceptSocket() here.
                TcpClient client = server.AcceptTcpClient();
                Console.WriteLine("Connected!");
                data = null;

                // Get a stream object for reading and writing
                NetworkStream stream = client.GetStream();

                int i;
                int j;
                bool firstTime = true;
                // Loop to receive all the data sent by the client.
                while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
                {
                    // Translate data bytes to a ASCII string.
                    data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
                    Console.WriteLine("Received: {0}", data);
                    Console.WriteLine("----------------------------------------------");
                    // Process the data sent by the client.
                    data = data.ToUpper();


                    byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
                    byte[] msg1 = null;
                    sslStream.Write(msg, 0, msg.Length);
                    Console.WriteLine("written to sslchannel: {0}", msg.Length);
                    if (firstTime)
                    {
                        j = sslStream.Read(bytes1, 0, bytes1.Length);

                        firstTime = false;
                        // Translate data bytes to a ASCII string.
                        data1 = System.Text.Encoding.ASCII.GetString(bytes1, 0, j);
                        Console.WriteLine("Received from ssl: {0}", data1);
                        Console.WriteLine("----------------------------------------------");
                        // Process the data sent by the client.


                        data1 = data1.ToUpper();
                        msg1 = System.Text.Encoding.ASCII.GetBytes(data1);
                        Console.WriteLine("Sent from ssl: {0}", data1);
                        Console.WriteLine("----------------------------------------------");
                        sslStream.Write(msg1, 0, msg1.Length);
                       // stream.Write(msg1, 0, msg1.Length);

                    }
                    // Send back a response.
                    stream.Write(msg1, 0, msg1.Length);
                    Console.WriteLine("Sent: {0}", data);
                    Console.WriteLine("----------------------------------------------");
                }

                Console.WriteLine("sslStream Block");

                // Shutdown and end connection
                client.Close();
            }
        }
        catch (SocketException e)
        {
            Console.WriteLine("SocketException: {0}", e);
        }


        finally
        {
            // Stop listening for new clients.
            server.Stop();
        }


        Console.WriteLine("\nHit enter to continue...");
        Console.Read();
    }

    static bool CertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
    {
        if (sslPolicyErrors != SslPolicyErrors.None)
        {
            Console.WriteLine("SSL Certificate Validation Error!");
            Console.WriteLine(sslPolicyErrors.ToString());
            return false;
        }
        else
            return true;
    }
}

When I run the code I get the output that I have attached. (The blocked text shows the login url of my company)

Can someone tell me why the browser is not redirecting to login page.

Thanks Irfan

来源：https://stackoverflow.com/questions/6356070/c-sslstream-and-local-proxy