How to pass impersonated user in Web API call from Console App with Windows Authentication?

Question

I have a Console App and a Web API 2 project, both run on the same server. I have setup my Console App to call a RESTful endpoint in my Web API using HttpClient while impersonating a domain account.

            Console.WriteLine("Setting up impersonator.");
            using (new Impersonator(accountUsername, accountDomain, accountPwd))
            {
                Console.WriteLine("Impersonator set up.");

                HttpClientHandler handler = new HttpClientHandler();
                handler.UseDefaultCredentials = true;

                Console.WriteLine("Executing as: " + System.Security.Principal.WindowsIdentity.GetCurrent().Name);

                using (var client = new HttpClient(handler))
                {
                    client.BaseAddress = new Uri(serviceBaseUrl);
                    client.DefaultRequestHeaders.Accept.Clear();
                    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                    HttpResponseMessage response = await client.GetAsync("api/resource/3/");
                    Console.WriteLine(response.ToString());
                    if (response.IsSuccessStatusCode)
                    {
                        result = await response.Content.ReadAsAsync<ResourceType>();
                    }
                }

                if (result != null)
                {
                    // Do something...
                }
            }

I don't think the actual endpoint is relevant to this question, as the Http Request never makes it to this point (even without any authorization attribute). When I run the two projects locally, the Console App is successful when making the call. However, when I run it on the server, the Console App receives a 401 unauthorized. I added some logging to my Web API pipeline to log the HttpContext.Current.User information.

    protected void Application_BeginRequest()
    {
        var currentContext = HttpContext.Current;
        ILogHelper _logger = new LogHelper("System");

        _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "BeginRequest System Principal Name: " + System.Security.Principal.WindowsIdentity.GetCurrent().Name);
        _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "BeginRequest Is User Null? " + (currentContext.User == null? "YES":"NO"));

        if (currentContext.User != null)
        {
            _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "BeginRequest User: " + currentContext.User.Identity.Name);
            _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "BeginRequest User Authenticated: " + currentContext.User.Identity.IsAuthenticated.ToString());
        }
    }

    protected void Application_AuthenticateRequest()
    {
        var currentContext = HttpContext.Current;
        ILogHelper _logger = new LogHelper("System");

        _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthenticateRequest System Principal Name: " + System.Security.Principal.WindowsIdentity.GetCurrent().Name);
        _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthenticateRequest Is User Null? " + (currentContext.User == null ? "YES" : "NO"));

        if (currentContext.User != null)
        {
            _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthenticateRequest User: " + currentContext.User.Identity.Name);
            _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthenticateRequest User Authenticated: " + currentContext.User.Identity.IsAuthenticated.ToString());
        }
    }

    protected void Application_AuthorizeRequest()
    {
        var currentContext = HttpContext.Current;
        ILogHelper _logger = new LogHelper("System");

        _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthorizeRequest System Principal Name: " + System.Security.Principal.WindowsIdentity.GetCurrent().Name);
        _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthorizeRequest Is User Null? " + (currentContext.User == null ? "YES" : "NO"));

        if (currentContext.User != null)
        {
            _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthorizeRequest User: " + currentContext.User.Identity.Name);
            _logger.LogLine(NLog.LogLevel.Info, LogHelper.Tier.Business, "AuthorizeRequest User Authenticated: " + currentContext.User.Identity.IsAuthenticated.ToString());
        }
    }

When ran locally, the impersonated user is logged in the 'AuthenticateRequest' and 'AuthorizeRequest'. But, when ran on the server, the user is null the whole way through the pipeline.

I have Windows Authentication and Impersonation Enabled in IIS (everything else disabled). I have been working on this for 40+ hours and feel like I haven't made any progress. Any help with this issue would be huge!

Answer 1

From this SO question, I determined that it is, in fact, a FQDN problem. To "fix", I just had to change out the "servername.com/service/" base URL in my Web.config with "localhost/service/". Once I did this, it ran flawlessly. I don't like the thought of using localhost as the URL, but I am unable to edit the server Registry values, so the fix provided by Microsoft wouldn't work for me.

Also, it turns out that I don't need Impersonation Enabled on my Web API site in IIS. Now, I only have Windows Authentication enabled.