Why DuplicateToken

[Ed]

Anybody know the reason the call to DuplicateToken is
needed in the Impersonation sample found at:
[url]http://msdn.microsoft.com/library/default.asp?[/url]
url=/library/en-
us/cpref/html/frlrfSystemSecurityPrincipalWindowsIdentityCl
assImpersonateTopic.asp

Since the underlying Win32 ImpersonateLoggedOnUser can
take the handle directly from the LogonUser. Why Duplicate
it?

----- Ed

[Lior Amar]

Hmm...good question. The only time you would need to call DuplicateToken
after a LogonUser is if the returned Token is not a Primary token. The only
tokens that can be impersonated are primary tokens. I would bet that
removing the DuplicateToken and using the token acquired with LogonUser
would still work.

Lior,

"Ed" <nowhere@nospam.com> wrote in message
news:192901c37941$835d22a0$a501280a@phx.gbl...

> Anybody know the reason the call to DuplicateToken is
> needed in the Impersonation sample found at:
> [url]http://msdn.microsoft.com/library/default.asp?[/url]
> url=/library/en-
> us/cpref/html/frlrfSystemSecurityPrincipalWindowsIdentityCl
> assImpersonateTopic.asp
>
> Since the underlying Win32 ImpersonateLoggedOnUser can
> take the handle directly from the LogonUser. Why Duplicate
> it?
>
> ----- Ed
>