why certificates are null using .NET Core 2 but it works just fine with .NET Framework 4.6.2?

Question

I have been doing some test migrating .NET Framework 4.6.2 apps to .NET Core 2. I noticed that this particular app, a monitoring http is not working fine with Net Core 2. Can you please help me to verify what is happening?

static void Main(string[] args)
        {
            try
            {
                HttpWebRequest myhttpWebReqest = (HttpWebRequest)WebRequest.Create("https://www.google.com.mx/");
            System.Diagnostics.Stopwatch timer = new System.Diagnostics.Stopwatch();
            timer.Start();
            HttpWebResponse myHttpWebResponse = (HttpWebResponse)myhttpWebReqest.GetResponse();
            timer.Stop();
            TimeSpan timeSpan = timer.Elapsed;
            Console.WriteLine(timeSpan.ToString());
            Console.WriteLine();
            Console.WriteLine(myHttpWebResponse.StatusCode);
            Console.WriteLine((int)myHttpWebResponse.StatusCode);
            Console.WriteLine();
            Console.WriteLine(myhttpWebReqest.ServicePoint.Certificate.GetEffectiveDateString());
            Console.WriteLine();
            Console.WriteLine(myhttpWebReqest.ServicePoint.Certificate.GetExpirationDateString());
            Console.WriteLine();
            Console.WriteLine(myhttpWebReqest.ServicePoint.Certificate.Issuer);
            Console.WriteLine();
            Console.WriteLine(myhttpWebReqest.ServicePoint.Certificate.Subject);                
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
            if(ex.InnerException !=null)
            {
                Console.WriteLine(ex.InnerException);
            }
        }
        Console.ReadLine();
    }
}

in the .NET Framework 4.6.2 i see the certificate data, in the .NET Core 2 i see myhttpWebReqest.ServicePoint.Certificate null ... do you know why?

Answer 1

See discussion of this here: https://github.com/dotnet/corefx/issues/36979

ServicePointManager and ServicePoint classes are no-op on .NET Core. But you can do a similar thing with HttpClient. HttpClient is the more modern and preferred HTTP API in .NET Framework and .NET Core.

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

namespace NetCoreConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var handler = new HttpClientHandler();
            handler.ServerCertificateCustomValidationCallback = CustomCallback;
            var client = new HttpClient(handler);

            HttpResponseMessage response = client.GetAsync("https://www.google.com.mx/").GetAwaiter().GetResult();
            Console.WriteLine(response.StatusCode);
            Console.WriteLine((int)response.StatusCode);
        }

        private static bool CustomCallback(HttpRequestMessage arg1, X509Certificate2 arg2, X509Chain arg3, SslPolicyErrors arg4)
        {
            Console.WriteLine(arg2.GetEffectiveDateString());
            Console.WriteLine(arg2.GetExpirationDateString());
            Console.WriteLine(arg2.Issuer);
            Console.WriteLine(arg2.Subject);

            return arg4 == SslPolicyErrors.None;
        }
    }
}