How to get TLS/SSL related information in ASP.NET Core?

Question

I would like to gain more information of a current TLS/SSL request in an ASP.NET Core MVC Controller.

using Microsoft.AspNetCore.Mvc;

namespace WebApp.Controllers
{
    public class HomeController : Controller
    {        
        public IActionResult About()
        {
            if (HttpContext.Request.IsHttps)
            {
                // How to get more information about the transport layer ?

                ViewData["Message"] = "Connection via TLS/SSL - ... missing details ...";
            }

            return View();
        }        
    }
}

Is there a way to access the properties like used TLS version, cipher and so on ?

I know that this is not possible in ASP.NET MVC as stated in Check ssl protocol, cipher & other properties in an asp.net mvc 4 application. Perhaps the new framework with Kestrel offers this kind of information I was not able to find so far.

Answer 1

You can get those values using the Features property from the HttpContext. If you call:

var tlsHandshakeFeature = request.HttpContext.Features.Get<ITlsHandshakeFeature>();

ITlsHandshakeFeature will give you the TLS version (Protocol property), the CipherAlgorithm, among many other things.
You can also Get the ITlsConnectionFeature which will give you the certificates.