tls-spy.cs

using System;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Security.Cryptography.X509Certificates;
using System.Threading;
using System.Threading.Tasks;

namespace TlsSpy
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length != 5)
            {
                Console.WriteLine(@"TLS Spy Proxy usage:
tlspy.exe listen-port forward-host-and-port server-cert-path client-cert-path dir-name
");
                return;
            }

            if(int.TryParse(args[0], out var listenPort) == false)
            {
                Console.WriteLine("Unable to parse listen port: " + args[0]);
                return;
            }
            var forwardParts = args[1].Split(':');
            if(forwardParts.Length != 2)
            {
                Console.WriteLine("Unable to parse forward host and port: " + args[1]);
                return;
            }
            string forwardHost = forwardParts[0];
            if (int.TryParse(forwardParts[1], out var forwardPort) == false)
            {
                Console.WriteLine("Unable to parse forward port: " + forwardParts[1]);
                return;
            }
            X509Certificate2 serverCert, clientCert;
            try
            {
                serverCert = new X509Certificate2(args[2]);
            }
            catch (Exception e)
            {
                Console.WriteLine("Unable to open server cert: " + args[2]);
                Console.WriteLine(e);
                return;
            }
            try
            {
                clientCert = new X509Certificate2(args[3]);
            }
            catch (Exception e)
            {
                Console.WriteLine("Unable to open client cert: " + args[3]);
                Console.WriteLine(e);
                return;
            }

            string outputDir;
            try
            {
                if(!Directory.Exists(args[4]))
                    Directory.CreateDirectory(args[4]);
                outputDir = args[4];
            }
            catch (Exception e)
            {
                Console.WriteLine("Unable to create directory: " + args[4]);
                Console.WriteLine(e);
                return;
            }

            TcpListener tcpListener;
            try
            {
                tcpListener = new TcpListener(IPAddress.Any, listenPort);
                tcpListener.Start();
            }
            catch (Exception e)
            {
                Console.WriteLine("Unable to listen to port: " + listenPort);
                Console.WriteLine(e);
                return;
            }

            
        }

        private static int counter;

        private static async Task ForwardAndClone(TcpClient client, string forwardHost, int forwardPort, X509Certificate2 serverCert, X509Certificate2 clientCert, string outputDir)
        {
            var current = Interlocked.Increment(ref counter);
            using (var output = File.Create(Path.Combine(outputDir, DateTime.Now.ToString("o") + "-" + current)))
            using(var src = new SslStream(client.GetStream(), false,
                (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) => true))
            {
                await src.AuthenticateAsServerAsync(serverCert);

                using (var server = new TcpClient())
                {
                    await server.ConnectAsync(forwardHost, forwardPort);

                    using (var dst = new SslStream(server.GetStream(), false,
                        (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) => true))
                    {
                        await dst.AuthenticateAsClientAsync(forwardHost, new X509CertificateCollection{ clientCert }, false);

                        var a = dst.CopyToAsync(src);
                        var b = src.CopyToAsync(dst);

                        await Task.WhenAll(a, b);
                    }
                }
            }
        }
    }
}