SSL ALPN Negotiation with .NET Core 2.1 Preview

ssl-alpn-test.txt

using System;
using System.Threading;
using System.Collections.Generic;
using System.Net.Security;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.Threading.Tasks;

namespace ssltest
{
    class Program
    {
        const int TIMEOUT_MSEC = 10000;

        const string TargetHost = "[YOUR TARGET HOST]";

        static void Main(string[] args)
        {
            DoConnectAsync();
         
            Console.WriteLine("Press any key to exit...");
            Console.ReadKey();
        }

        // The following method is invoked by the RemoteCertificateValidationDelegate.
        public static bool ValidateServerCertificate(
              object sender,
              X509Certificate certificate,
              X509Chain chain,
              SslPolicyErrors sslPolicyErrors)
        {
            if (sslPolicyErrors == SslPolicyErrors.None)
                return true;

            Console.WriteLine("Certificate error: {0}", sslPolicyErrors);

            // Do not allow this client to communicate with unauthenticated servers.
            return false;
        }

        private static async void DoConnectAsync()
        {
            // let exceptions bubble up to console UI for now.
            //try
            //{
            TcpClient tcpClient = new TcpClient();
            Task task = tcpClient.ConnectAsync(TargetHost, 443);
            await task;

            SslStream sslStream = new SslStream(tcpClient.GetStream(), false);

            X509Certificate2 certificate = new X509Certificate2("[FILENAME OF CERTIFICATE GOES HERE]");
            X509Certificate2Collection certColl = new X509Certificate2Collection(certificate);

            SslClientAuthenticationOptions authOptions = new SslClientAuthenticationOptions();
            authOptions.ApplicationProtocols = new List<SslApplicationProtocol>() { SslApplicationProtocol.Http2 };
            authOptions.EnabledSslProtocols = SslProtocols.Tls12;
            authOptions.TargetHost = TargetHost;
            //authOptions.AllowRenegotiation = true;
            authOptions.ClientCertificates = certColl;
            authOptions.RemoteCertificateValidationCallback = new RemoteCertificateValidationCallback(ValidateServerCertificate);

            await sslStream.AuthenticateAsClientAsync(authOptions, new CancellationToken(false));

            // At this point we made a Grpc channel and client and connected using the GRPC protocol.
            // Not including with this sample.

            //}
            //catch(Exception e)
            //{
            //    Console.WriteLine("DoConnect exception: {0}", e.Message);
            //}
        }
    }
}