C# - Windows authentication - How to get from HttpContext user's Full doMain name (FQDN)

Question

Assume there is Active Directory domain: " chiled.root.f1dm.com "

Netbios name: " CHILED1F1 "

Given this code:

if (HttpContext.Current == null || HttpContext.Current.User == null ||
            !HttpContext.Current.User.Identity.IsAuthenticated)
        {
            throw new MyException(WRONG_USERNAME_OR_PASSWORD_ERROR_CODE, WRONG_USERNAME_OR_PASSWORD_ERROR_MESSAGE);
        }

I'm looking for a way to reach from the HttpContext the user's Fully qualified domain name (FQDN). Currently I'm getting from the context the user's domain in the Netbios form (Like: CHILED1F1\\user_name) but I need this: chiled.root.f1dm.com\\user_name

I there a way to do it? I need it for the Windows current user only (So the Machine's domain name will not help me). Thanks!

Answer 1

If your user as logged in his using AD, you can try to get his name via ServerVariables. Exemple:

string username = Request.ServerVariables["AUTH_USER"].ToString();