Asp.net-core – Asp.net Core Web API – Current user & Windows Authentication

I have a Windows 2008 server that I'm working on, so my answer is not completely the same as what the OP has on a Windows 2003 server.

Here is what I did (recording this here so I can find it later).

I was having this same issue:

In my Web.config file, I had this section:

<system.web>
    <authentication mode="Windows" />
    <authorization>
        <allow users="*" />
        <deny users="?" />
    </authorization>
</system.web>

Under IIS, all of these seems to be solved under the Authentication icon.

1. Edit Permissions: Make sure your ASP.NET account has permission. Mine was not originally added.

Now go into the features of Authentication:

Enable Anonymous Authentication with the IUSR:

Enable Windows Authentication, then Right-Click to set the Providers.

NTLM needs to be FIRST!

Next, check that under Advanced Settings... the Extended Protection is Accept and Enable Kernel-mode authentication is CHECKED:

Once I did this, I went back to my web application, clicked the Browse link, and logged in without having to provide my credentials again.

I hope this proves beneficial to many of you, and I hope it is useful for me later as well.

You can get the user's WindowsIdentity object under Windows Authentication by:

WindowsIdentity identity = HttpContext.Current.Request.LogonUserIdentity;

and then you can get the information about the user like identity.Name.

Please note you need to have HttpContext for these code.