Log failed IIS login (windows authentication)

Question

In our application, we offer the use of Windows authentication. For this, the browser pops-up a window. When a user is logged in correctly, I can log this in the code after this:

 if (HttpContext.Current.User.Identity.IsAuthenticated) c.Response.Redirect(General.PathPrefix() + "Default.aspx");

My question is, how can I log a user not getting authenticated, all code seems to stop when the login fails, and I get a 401 response.

Answer 1

You can log this error in the Global.asax file using the code below

public class CoolMvcApplication : System.Web.HttpApplication
{
    protected void Application_Error(object sender, EventArgs e)
    {
        Exception exception = Server.GetLastError();
        //check here if this exception is an unauthorized access error, if so
        Server.ClearError();
        Response.Redirect("/not_loggedin");
    }
}

Also you can achieve this by using filters and assert there if the error is unauthorized access and follow the same logic.