On Thu, 24 Aug 2006, Neal Becker wrote:
Ralf Ertzinger wrote:
> Hi.
>
> On Thu, 24 Aug 2006 11:04:26 -0400, Neal Becker wrote:
>
>>
http://www.openwall.com/presentations/Owl/mgp00020.html
>
> Hmmm. What is the advantage of this scheme? The first disadvantage
> that springs to my mind is that any attacker that gains user privileges
> (browser bug or whatever) can suddenly change the user password.
>
How is that a disadvantage, compared to existing systems? With previous
systems, if you gain user priv you can also change user password. I think
the idea of tcb is that's all you can do. No suid root stuff is used.
(Honestly, I don't know much about tcb - I just thought it might be of
interest)
I think Ralf was thinking that tcb would permit something conceptually
along the lines of
$ vi /etc/tcb/`id -un`/shadow
to change your existing passwd w/o having to know it
The permissions on /etc/tcb should prevent that though -- only an sgid
shadow app (the passwd command) can be used....
later,
chris