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.netactive-directorycross-domainimpersonation

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


I have two Active Directory domains, A and B. Users in domain A need to run an application on their desktops to view and manipulate a resource located on a server in domain B. Each user also has an account in domain B. Is it possible to impersonate each user's domain B identity to perform operations on the domain B resource programatically?

Example Workflow:

  1. User logs in to domain A.
  2. User launches desktop application.
  3. User specifies resource in domain B.
  4. Application prompts user for domain B credentials.
  5. Application impersonates user's domain B identity to access specified resource.
  6. User manipulates domain B resource using application.

Solution

  • I'm going to speak in terms of Win32 APIs, but I'm pretty sure you can p/invoke to these from .NET. Check http://pinvoke.net.

    You need to call the LogonUser API to create an access token that represents the user's domain B credentials.

    Then you call ImpersonateLoggedOnUser, passing in that access token. The calling thread will impersonate the domain B credentials until you impersonate a different set of credentials or call the RevertToSelf API.

    I guess it goes without saying that, for the LogonUser call to succeed, the machine you're running on will need to trust domain B.