No effect of SE_BACKUP_NAME privilege on cygwin?

[Christian Franke]

Corinna Vinschen wrote:
> On Mar  1 20:28, Christian Franke wrote:
>   
>> Enabling SE_BACKUP_NAME has no effect for cygwin programs.
>>     
>
> You're expecting that you can use Windows functions in a POSIX
> application without disturbing the way Cygwin works.  That's a bit
> dangerous.

Agree.

(I tried to add a "regtool save ..." action to allow backup of registry 
hives from scripts.
This calls RegSaveKey which needs SE_BACKUP_NAME.)


>   A Cygwin application's main thread is not running under the
> process token, but under a derived impersonation token.  This is true
> for every thread in Cygwin.  So, instead of using OpenProcessToken, you
> should be able to accomplish what you want by calling OpenThreadToken.
>   

Yes, it works, thanks!

Already tried this before but gave up too early, because it didn't work 
in the non-cygwin version ;-)
I didn't realize that the main thread has no token by default...


> However, I'm wondering if a Cygwin application should always try by
> itself to request the SE_BACKUP_NAME privilege.  It would simplify file
> access for all privileged processes.  Hmm.
>   

Sounds reasonable.
SE_RESTORE_NAME is requested somewhere in the code, but not SE_BACKUP_NAME.

Christian


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