DemoValidateServerCertificate.cs

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

namespace ServerCertificateValidationDemo
{
  public class Program
  {
    private static string _defaultUrl = @"https://www.google.com";

    public static void Main(string[] args)
    {
      // Set the URL value. If no argument is given, use the default URL.
      string url = _defaultUrl;
      if (args != null && args.Length > 0)
      {
        url = args[0];
      }
      Console.WriteLine("Using URL: {0}{1}", url, Environment.NewLine);
    
      // Create a new web request and set up a validation callback.
      HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
      request.ServerCertificateValidationCallback += OnCertificateValidation;
      try
      {
        // Get the response. If the certificate fails to validate, a
        // WebException will be thrown.
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        Console.WriteLine("Response status: {0} ({1})", response.StatusCode, response.StatusDescription);
      }
      catch (WebException e)
      {
        Console.WriteLine("Exception: {0}", e.Message);
      }
            
      Console.WriteLine("Press ENTER to close.");
      Console.ReadLine();
    }

    public static bool OnCertificateValidation(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
    {
      Console.WriteLine("Subject: {0}", certificate.Subject);
      Console.WriteLine("Effective date: {0}", certificate.GetEffectiveDateString());
      Console.WriteLine("Expiration date: {0}", certificate.GetExpirationDateString());
      Console.WriteLine("Issuer: {0}", certificate.Issuer);
      Console.WriteLine("Key algorithm: {0}", certificate.GetKeyAlgorithm());
      Console.WriteLine("Certificate hash: {0}", certificate.GetCertHashString());
      Console.WriteLine("Public key: {0}", certificate.GetPublicKeyString());
      Console.WriteLine("Serial number: {0}", certificate.GetSerialNumberString());
      Console.WriteLine("SSL policy errors: {0}", errors);
      return (errors == SslPolicyErrors.None);
    }
  }
}