Windows Authentication succeeds but IsAuthenticated == false - asp.net

Question

Environment is IIS 7 integrated pipeline, ASP.NET 4.0. I have a .aspx page configured without anonymous authentication and with windows authentication:
<location path="auth/windows">
<system.webServer>
<security>
<authentication>
<anonymousAuthentication enabled="false" />
<windowsAuthentication enabled="true" />
</authentication>
</security>
</system.webServer>
</location>
When I request the page, a normal Windows auth (NTLM/Negotiate) challenge response happens, and ultimately the page is returned.
I have an HttpModule in which I handle the PostAuthorize event. As expected, this event is only raised once the challenge-response authentication has succeeded and access to the page has been authorized.
However, the Request.IsAuthenticated property is false; and HttpContext.Current.User.Identity reflects an unauthenticated user (.Name returns the empty string). Interestingly, Request.ServerVariables["LOGON_USER"] does return the value of the authenticated Windows user.
I'd have thought that once the user was authenticated (and authorized, for that matter), the request would reflect being authenticated; and the User / Identity for the request would have been properly set.
Any thoughts on why this is not the case?
Thanks,
Donnie

Answer 1

It turns out that the native handling of Windows authentication works when you have Forms authentication enabled in Web.config. But the managed part of Windows authentication - associating the authenticated Windows user with an IIdentity-derived object representing that user - only happens if Windows authentication is enabled in Web.config. Looks like I'll have to rely on the Request.ServerVariables["LOGON_USER"] value.

Answer 2

windows Authentication is enabled in IIS and authentication mode set to windows in my web.config file.
<authentication mode="Windows">
</authentication>
My site is asking for credentials and it's working fine. but when check using
HttpContext.User.Identity.Name
is empty string
Or
HttpContext.User.Identity.IsAuthenticated is false;
I used Request.ServerVariables["LOGON_USER"].Tostring(); to get logged in user credentials.
It worked for me, Thanks for Posting soccerdad.