HttpClient, UseDefaultCredentials, Windows Authentication, .NET Core 2.0+ console application receives 401 Unauthorized

Question

I am trying to make an HTTP GET call from a .NET Core 3.0 console application. The endpoint expects Windows Authentication. The endpoint is an in-production .NET Framework 4.5.2

Answer 1

This workaround works for me add this before creating HttpClient / Handler:

AppContext.SetSwitch("System.Net.Http.UseSocketsHttpHandler", false);

Answer 2

So we are running into the same issue with HttpClient, but on the first request it is unauthorized, but if we do a another quick request call, it goes through just fine, and we get authorized.

If I do this on a .NET 4.7.1 console app, it works perfect. If I do it in a .NET 4.7.1 empty web app, it works fine, only if I do .NET Core 2.x do we get this issue.

var result = string.Empty;
var responseMessage = _client.GetAsync(url).Result;

if (responseMessage.IsSuccessStatusCode)
{
    result = await responseMessage.Content.ReadAsStringAsync();
}
else
{
    var responseMessage2 = _client.GetAsync(url).Result;

    if (responseMessage2.IsSuccessStatusCode)
    {
        result = await responseMessage2.Content.ReadAsStringAsync();
    }
}

return result;