static class Server
{
    static void Main()
    {
        TcpListener L = new TcpListener(IPAddress.Parse("127.1.2.3"), 4300);
        L.Start();
        TcpClient C = L.AcceptTcpClient();
        X509Certificate Cert = new X509Certificate("public.pfx", "Password");
        SslServerStream S = new SslServerStream
            (C.GetStream(), Cert, false, true,
            Mono.Security.Protocol.Tls.SecurityProtocolType.Ssl3);
        byte[] Buff = new byte[C.Available];
        S.Read(Buff);
        Console.WriteLine("C: " + Encoding.UTF8.GetString(Buff));
        string Reply = "LoooL";
        S.Write(Encoding.UTF8.GetBytes(Reply));
        Console.WriteLine("S: " + Reply);
        S.Close();
        C.Close();
        L.Stop();
        Console.ReadKey(true);
    }
}

static class Client
{
    static void Main()
    {
        TcpClient C = new TcpClient("127.1.2.3", 4300);
        SslClientStream S = new SslClientStream
            (C.GetStream(), "ServerNameFromCertFile", true, SecurityProtocolType.Ssl3);
        string Messsage = "LoL";
        S.Write(Encoding.UTF8.GetBytes(Messsage));
        Console.WriteLine("C: " + Messsage);
        byte[] Buff = new byte[C.Available];
        S.Read(Buff);
        Console.WriteLine("S: " + Encoding.UTF8.GetString(Buff));
        S.Close();
        C.Close();
        Console.ReadKey(true);
    }
}