class Program
    {
        static bool ValidateServerCertificate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            if (sslPolicyErrors == SslPolicyErrors.None) return true;
            Console.WriteLine("Certificate error: {0}", sslPolicyErrors);
            return false;
        }

        static void Main()
        {
            var tcpListener = new TcpListener(IPAddress.Parse("127.0.0.1"), 8080);
            tcpListener.Start();
            var clientAccept = tcpListener.AcceptTcpClient();
            Thread.Sleep(1000);

            if (clientAccept.Available > 0)
            {
                var sslStream = new SslStream(clientAccept.GetStream(), false, new RemoteCertificateValidationCallback(ValidateServerCertificate), null);
                var certificate = new X509Certificate(@"C:\Users\orlov_000\Desktop\server.pfx");
                sslStream.AuthenticateAsServer(certificate);
            }

            Console.ReadLine();
        }
    }