I have a ASP.NET Core 8 Application which is being dockerized and deployed in Openshift.

The problem is that I cant authenticate to an endpoint using NTLM.
From my windows machine i can use it just fine, as expected, considering its both windows.

This is the output of the logged request inside the pod:
Request:
Method: GET
Target:
Request Headers:

Response:
Status Code: ServiceUnavailable
Response Headers:
Cache-Control: no-cache
X-XSS-Protection: 1
Connection: close
Pragma: no-cache
Content-Type: text/html; charset=utf-8
Content-Length: 768

I can call the endpoint manually by using curl with the –ntlm flag inside of the pods terminal. So connectivity should’nt be the problem.

I’ve tried using the standard aspnet:8.0 base image and also an alpine:latest
I’ve tried installing the gss-ntlmssp onto the aspnet base image, cant get it to install tho:

E: The repository 'http://deb.debian.org/debian bookworm InRelease' is not signed.
E: Failed to fetch http://deb.debian.org/debian/dists/bookworm/InRelease  403  Forbidden 

I’ve tried installing the krb5-libs when using the alpine base image (gss-ntlmssp isnt available on alpine).

And i’ve also tried setting the UseManagedNtlm

``<ItemGroup>
  <RuntimeHostConfiguration Include="System.Net.Security.UseManagedNtlm" Value="true"/>
</ItemGroup>` `

both in the .csproj and in the Program.cs with:

AppContext.SetSwitch("System.Net.Security.UseManagedNtlm", true);

as suggested by the various GitHub threads regarding this topic.

This is my HttpClient:

...
private static HttpClient s_client;

    private static void CreateHttpClientWithNtlmAuth(IConfiguration configuration)
    {
        var aDUser = configuration["SRV_USER"];
        var aDPassword = configuration["SRV_PASSWORD"];

        HttpClientHandler hand = new HttpClientHandler
        {
            UseDefaultCredentials = false,
            Credentials = new NetworkCredential(aDUser, aDPassword, "<domain>"),
            PreAuthenticate = true,

        };

        s_client = new HttpClient(new LoggingHandler(hand));
    }

...

I think that i’ve tried every possbile permutation of requested fixes but cant seem to get it to work. So there must be something I am missing. Appreciate any help.