Elisa/Elisa.GameServer/ProxyControl.cs

using Serilog;
using System.Text.RegularExpressions;
using Titanium.Web.Proxy;
using Titanium.Web.Proxy.EventArguments;
using Titanium.Web.Proxy.Models;

namespace Elisa.GameServer;

public class ProxyControl
{
    static readonly Regex HostFilter = new Regex("(.*).(girlfrontline\\.co\\.kr|ppgame\\.com|txwy\\.tw|sunborngame\\.com|aihelp\\.net).*");
    static readonly Regex AWSFilter = new Regex(@"s3.*.amazonaws.com");
    static readonly Regex DLlistFilter = new Regex(@"dl.listdl.com");
    readonly string forwardIpAddress;
    readonly ProxyServer proxyServer;
    readonly ExplicitProxyEndPoint explicitEndPoint;

    public ProxyControl(string forwardIpAddress, int port = 9000)
    {
        this.forwardIpAddress = forwardIpAddress;
        proxyServer = new ProxyServer();
        explicitEndPoint = new ExplicitProxyEndPoint(System.Net.IPAddress.Any, port, true);
        
        proxyServer.BeforeRequest += OnRequest;
        //Ssl handling
        explicitEndPoint.BeforeTunnelConnectRequest += OnBeforeTunnelConnectRequest;
        
        
        proxyServer.ServerCertificateValidationCallback += OnCertificateValidation;
        proxyServer.ClientCertificateSelectionCallback += OnCertificateSelection;

    }

    public void Start()
    {
        proxyServer.AddEndPoint(explicitEndPoint);
        proxyServer.Start();

        //proxyServer.SetAsSystemHttpProxy(explicitEndPoint);
        //proxyServer.SetAsSystemHttpsProxy(explicitEndPoint);
    }

    public void Stop()
    {
        proxyServer.BeforeRequest -= OnRequest;
        //Ssl Handling
        proxyServer.ServerCertificateValidationCallback -= OnCertificateValidation;
        proxyServer.ClientCertificateSelectionCallback -= OnCertificateSelection;
        

        explicitEndPoint.BeforeTunnelConnectRequest -= OnBeforeTunnelConnectRequest;
        //proxyServer.DisableAllSystemProxies();
        proxyServer.Stop();
    }
    private async Task OnBeforeTunnelConnectRequest(object sender, TunnelConnectSessionEventArgs e)
    {
        string hostname = e.HttpClient.Request.RequestUri.Host;
        
        //show the hostname
        Log.Information($"Tunnel Connect Request for {hostname}");
        //Forward to our domain --this doesn't work

        if (HostFilter.IsMatch(hostname) || AWSFilter.IsMatch(hostname) || DLlistFilter.IsMatch(hostname))
        {
            Log.Information($"Forwarding tunnel connect request for {hostname} to {forwardIpAddress}");
            e.DecryptSsl = true;
            e.HttpClient.Request.RequestUri = new Uri("https://" + forwardIpAddress + e.HttpClient.Request.RequestUri.PathAndQuery, UriKind.Absolute);
            
            return;
        }

        if (hostname.Contains("gf-passport.sunborngame.com"))
        {
            // Exclude Https addresses you don't want to proxy
            // Useful for clients that use certificate pinning
            // for example dropbox.com
            e.DecryptSsl = false;
        }
        
    }
    public Task OnCertificateValidation(object sender, CertificateValidationEventArgs e)
    {
        // set IsValid to true/false based on Certificate Errors
        //if (e.SslPolicyErrors == System.Net.Security.SslPolicyErrors.None)
            e.IsValid = true;

        return Task.CompletedTask;
    }

// Allows overriding default client certificate selection logic during mutual authentication
    public Task OnCertificateSelection(object sender, CertificateSelectionEventArgs e)
    {
        // set e.clientCertificate to override
        return Task.CompletedTask;
    }

    private async Task OnRequest(object sender, SessionEventArgs e)
    {
        if (e.IsHttps)
        {
            Log.Information("HTTPS request detected, skipping");
            return;
        }
        Uri requestUri = e.HttpClient.Request.RequestUri;
        if (HostFilter.IsMatch(requestUri.Host))
        {
            Log.Information($"Forwarding request for {requestUri} to {forwardIpAddress}");

            Uri newUri = new Uri("http://" + forwardIpAddress + requestUri.PathAndQuery, UriKind.Absolute);
            Log.Information($"Forwarded request to {newUri}");

            e.HttpClient.Request.RequestUri = newUri;

            // Bubble it out to user
        }
        //Test for aws
        else if (AWSFilter.IsMatch(requestUri.Host))
        {
            Log.Information($"Forwarding AWS request for {requestUri} to {forwardIpAddress}");

            Uri newUri = new Uri("http://" + forwardIpAddress + requestUri.PathAndQuery, UriKind.Absolute);
            Log.Information($"Forwarded request to {newUri}");

            e.HttpClient.Request.RequestUri = newUri;
        }
        else if (DLlistFilter.IsMatch(requestUri.Host))
        {
            Log.Information($"Forwarding DLList request for {requestUri} to {forwardIpAddress}");

            Uri newUri = new Uri("http://" + forwardIpAddress + requestUri.PathAndQuery, UriKind.Absolute);
            Log.Information($"Forwarded request to {newUri}");

            e.HttpClient.Request.RequestUri = newUri;
        }
    }
}