using System;

using System.Net.Security;

using System.Security.Cryptography.X509Certificates;

using System.Net.Sockets;

using log4net;

using log4net.Repository.Hierarchy;

using log4net.Core;

using log4net.Appender;

using log4net.Layout;

​

public class Program

{

    private static readonly ILog Logger = LogManager.GetLogger(typeof(Program));

    public class Log

    {

        public static void Setup()

        {

            Hierarchy hierarchy = (Hierarchy)LogManager.GetRepository();

​

            PatternLayout patternLayout = new PatternLayout();

            patternLayout.ConversionPattern = "%date [%thread] %-5level %logger - %message%newline";

            patternLayout.ActivateOptions();

​

            ConsoleAppender appender = new ConsoleAppender();

            appender.Name = "Console";

            appender.Layout = patternLayout;           

            appender.ActivateOptions();

            hierarchy.Root.AddAppender(appender);

​

            MemoryAppender memory = new MemoryAppender();

            memory.ActivateOptions();

            hierarchy.Root.AddAppender(memory);

​

            hierarchy.Root.Level = Level.Info;

            hierarchy.Configured = true;

        }

    }

    public static void Main(string[] args)

    {

        Log.Setup();

        // Valid Chain

        Connect("www.google.com");

        // Invalid Chain

        Connect("incomplete-chain.badssl.com");

    }

​

    private static void Connect(string url)

    {

        try

        {

            new SslStream(new TcpClient(url, 443).GetStream(), false,

            new RemoteCertificateValidationCallback(ServerCertificateValidationCallback))

            .AuthenticateAsClient(url);

        }

        catch { }

    }

    private static bool ServerCertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)

        {

            // If the certificate is a valid, signed certificate, return true.

            if (sslPolicyErrors == SslPolicyErrors.None)

            {

                return true;

            }

            else

            {

                // Log info

                Logger.Error("SSL Policy Error: " + sslPolicyErrors);

                Logger.Error("Certificate:\n" + certificate.ToString(true));

                foreach (var element in chain.ChainElements)

                    Logger.Error("Parent Cert:\n" + element.Certificate.ToString(true));

                foreach (var status in chain.ChainStatus)

                    Logger.Error("Chain Status: " + status.StatusInformation);

                return false;

            }

        }   

}