BaseMtpValidationMode

Example Usage

The following C# code demonstrates how to use the BaseMtpValidationMode enum to configure certificate validation for an MTP connection.

using System;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

public class MtpClient
{
    public static void Connect(string serverName, X509Certificate2 clientCertificate)
    {
        // Configure the SslStream for MTP validation
        // For demonstration purposes, we'll use 'Full' validation.
        // In a real application, choose the mode appropriate for your security needs.
        SslProtocols protocols = SslProtocols.Tls12; // Or other appropriate protocols
        LocalCertificateSelectionCallback certificateSelectionCallback = (sender, targetHost, localCertificates, remoteCertificate, acceptableIssuers) =>
        {
            return clientCertificate;
        };

        // Create a RemoteCertificateValidationCallback to handle certificate validation
        RemoteCertificateValidationCallback validationCallback = (sender, certificate, chain, sslPolicyErrors) =>
        {
            // Use the BaseMtpValidationMode to determine validation behavior
            BaseMtpValidationMode validationMode = BaseMtpValidationMode.Full; // Example setting

            if (validationMode == BaseMtpValidationMode.Full)
            {
                if (sslPolicyErrors != SslPolicyErrors.None)
                {
                    Console.WriteLine($"SSL Policy Errors: {sslPolicyErrors}");
                    // Further detailed validation can be performed here
                    return false; // Reject if there are policy errors
                }
                if (certificate == null)
                {
                    Console.WriteLine("Remote certificate is null.");
                    return false;
                }
                try
                {
                    X509Chain ch = new X509Chain();
                    ch.ChainPolicy.RevocationFlag = X509RevocationFlag.EntireChain;
                    ch.ChainPolicy.RevocationMode = X509RevocationMode.Online;
                    ch.ChainPolicy.VerificationFlags = X509VerificationFlags.AllFlags;
                    ch.ChainPolicy.ExtraStore.Add(clientCertificate); // Add client cert if needed for chain building

                    if (!ch.Build((X509Certificate2)certificate))
                    {
                        Console.WriteLine("Certificate chain build failed.");
                        foreach (X509ChainStatus status in ch.ChainStatus)
                        {
                            Console.WriteLine($"Status: {status.Status} - {status.StatusInformation}");
                        }
                        return false;
                    }

                    foreach (X509ChainStatus status in ch.ChainStatus)
                    {
                        if (status.Status != X509ChainStatusFlags.NoError)
                        {
                            Console.WriteLine($"Certificate validation error: {status.Status} - {status.StatusInformation}");
                            return false;
                        }
                    }
                    Console.WriteLine("Certificate validation succeeded.");
                    return true; // Certificate is valid
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"Error during certificate validation: {ex.Message}");
                    return false;
                }
            }
            else if (validationMode == BaseMtpValidationMode.None)
            {
                Console.WriteLine("Certificate validation is disabled.");
                return true; // Bypass validation
            }
            else // Default mode
            {
                // For default, we can rely on the system's default behavior or implement custom logic
                if (sslPolicyErrors == SslPolicyErrors.None)
                {
                    return true;
                }
                Console.WriteLine($"SSL Policy Errors (Default): {sslPolicyErrors}");
                return false;
            }
        };

        // Use the callbacks when creating an SslStream or establishing a connection
        // Example: using (var client = new TcpClient(serverName, port))
        //          using (var sslStream = new SslStream(client.GetStream(), false, validationCallback, certificateSelectionCallback))
        //          {
        //              sslStream.AuthenticateAsClient(serverName);
        //              // ... use sslStream ...
        //          }
        Console.WriteLine($"MTP client configured for {validationMode}.");
    }

    public static void Main(string[] args)
    {
        // Dummy client certificate for example
        X509Certificate2 dummyCert = new X509Certificate2("path/to/your/certificate.pfx", "password");
        Connect("example.com", dummyCert);
    }
}