private static async Task <string> TestSslProtocol(string hostName, int port, SslProtocols p, string testDescription)
        {
            //Console.WriteLine($"P:{p}");
            await Task.Yield();

            var       sb             = new StringBuilder();
            Stopwatch sw             = Stopwatch.StartNew();
            var       actualProtocol = SslProtocols.None;

            try
            {
                using (var socket = new Socket(SocketType.Stream, ProtocolType.Tcp))
                {
                    socket.Connect(hostName, port);
                    var networkStream = new NetworkStream(socket, false);

                    var sslStream   = new SslStream(networkStream);
                    var clientCerts = new System.Security.Cryptography.X509Certificates.X509CertificateCollection();



                    sslStream.AuthenticateAsClient(hostName, clientCerts, p, true);

                    actualProtocol = sslStream.SslProtocol;

                    sw.Stop();
                    sb.AppendLine($"{testDescription}: Allowed, Duration={sw.ElapsedMilliseconds}ms, Protocols Allowed: {p.ToStringExpanded()}, Protocol Used: {actualProtocol}");

                    sb.AppendLine($"  Cipher: {sslStream.CipherAlgorithm}, strength {sslStream.CipherStrength} bits");
                    sb.AppendLine($"  Hash: {sslStream.HashAlgorithm}, strength {sslStream.HashStrength} bits");
                    sb.AppendLine($"  Key exchange: {sslStream.KeyExchangeAlgorithm}, strength {sslStream.KeyExchangeStrength} bits");
                }
            }
            catch (Exception)
            {
                sb.AppendLine($"{testDescription}: BLOCKED, Duration={sw.ElapsedMilliseconds}ms, Protocols Attempted: {p.ToStringExpanded()}");
            }

            return(sb.ToString());
        }