Impersonate a Active Directory user in MVC application with Windows Authentication - asp.net-mvc

Question

I am building an admin module for an intranet MVC application. This application implements Windows Authentication (users are automatically logged in).
Currently I base all the user experience based around their HttpContext.User.Identity data.
What I need to do is to be able to impersonate an user so I can replicate their experience if they are having problems.
With Forms Authentication this is very straight forward...
I tried replacing the IPrincipal.User object in the HttpContext but this only has a getter not a setter.
any pointers would be greatly appreciated.
Thanks.

Answer 1

using (new Impersonation()){
// now working in context of whatever user you want
}
and this is the class
[PermissionSet(SecurityAction.Demand, Name = "FullTrust")]
public class Impersonation : IDisposable
{
private readonly SafeTokenHandle _handle;
private readonly WindowsImpersonationContext _context;
//const int Logon32LogonNewCredentials = 9;
private const int Logon32LogonInteractive = 2;
public Impersonation()
{
var domain = "your domain;
var username = "the user";
var password = "their password";
var ok = LogonUser(username, domain, password, Logon32LogonInteractive, 0, out _handle);
if (!ok)
{
var errorCode = Marshal.GetLastWin32Error();
throw new ApplicationException(string.Format("Could not impersonate the elevated user. LogonUser returned error code {0}.", errorCode));
}
_context = WindowsIdentity.Impersonate(_handle.DangerousGetHandle());
}
public void Dispose()
{
_context.Dispose();
_handle.Dispose();
}
[DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
private static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword, int dwLogonType, int dwLogonProvider, out SafeTokenHandle phToken);
public sealed class SafeTokenHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private SafeTokenHandle()
: base(true) { }
[DllImport("kernel32.dll")]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
[SuppressUnmanagedCodeSecurity]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool CloseHandle(IntPtr handle);
protected override bool ReleaseHandle()
{
return CloseHandle(handle);
}
}
}