C# – How to use LogonUser properly to impersonate domain user from workgroup client

cc#-2.0impersonationnetwinforms

ASP.NET: Impersonate against a domain on VMWare

This question is what I am asking, but the answer does not provide details on how the _token is derived. It seems to only use WindowsIdentity.GetCurrent().Token so there's no impersonation happening.

Can I impersonate a user on a different Active Directory domain in .NET?

This next question has conflicting answers, with the accepted one bearing a comment "I'm beginning to suspect that my problem lies elsewhere." Not helpful.

LogonUser works only for my domain

This next question seems to imply it is not possible, but it deals with 2 domains so I am not sure if it is relevant.

My real question is:

  • Is it possible? And if so,
  • How? or Where did I go wrong?

What I have tried so far is, using the code from http://msdn.microsoft.com/en-us/library/chf6fbt4%28v=VS.80%29.aspx

bool returnValue = LogonUser(user, domain, password,
            LOGON32_LOGON_NETWORK, LOGON32_PROVIDER_DEFAULT,
            ref tokenHandle);
// after this point, returnValue = false

The Win32 error is

Logon failure: unknown user name or bad password

Best Answer

Very few posts suggest using LOGON_TYPE_NEW_CREDENTIALS instead of LOGON_TYPE_NETWORK or LOGON_TYPE_INTERACTIVE. I had an impersonation issue with one machine connected to a domain and one not, and this fixed it. The last code snippet in this post suggests that impersonating across a forest does work, but it doesn't specifically say anything about trust being set up. So this may be worth trying:

const int LOGON_TYPE_NEW_CREDENTIALS = 9;
const int LOGON32_PROVIDER_WINNT50 = 3;
bool returnValue = LogonUser(user, domain, password,
            LOGON_TYPE_NEW_CREDENTIALS, LOGON32_PROVIDER_WINNT50,
            ref tokenHandle);

MSDN says that LOGON_TYPE_NEW_CREDENTIALS only works when using LOGON32_PROVIDER_WINNT50.

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