Re: caps in elf, next itteration (the hack get's bigger)

Pavel Machek (pavel@bug.ucw.cz)
Sun, 11 Apr 1999 12:01:16 +0200


Hi!

> The problem is, to get good semantics, there are a lot of repercussions
> which all need to be thought out. For instance, I now find that besides
> needing to store the true owner of the file in the headers, we also need
> to store the true value of the setuid bit, to determine whether the file
> actually executes as the owner or not. (group info is _not_ needed)

If you took a look at patch, you'd realize that this is already
done. 2 lines of c ;-).

Pavel
PS: Patch actually does not change semantics of almost anything:
Setuid root can do _anything_...

...which for example means it can volunteerily give up its
rights. What capelf does is that instead of dropping it at beggining
of main (which is doable _right now_), it drops them even sooner _AND_
external program like lscap can verify that it is really going to drop
privileges.

-- 
I'm really pavel@atrey.karlin.mff.cuni.cz. 	   Pavel
Look at http://atrey.karlin.mff.cuni.cz/~pavel/ ;-).

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