Re: [PATCH] Capabilities, this time in elf section

Robert Minichino (linuxkrn@pasture.net)
Tue, 13 Apr 1999 09:49:41 -0400 (EDT)

On Tue, 13 Apr 1999, Horst von Brand wrote:
> > I've implemented this in another operating system before. Permissions are
> > handled by a security manager daemon which holds the various keys that the
> > machine trusts and what they are trusted with. Executables are signed by
> > one or more keys, and the executable contains the permission
> > information.
>
> And each time a random executable is run the hash for the executable and
> any libraries it might use are computed? Sounds expensive...

Provided the executable remains unmodified (security model in OS this was
implemented on was quite different; no access to raw devices or filesystem
change times) the security info is cached. One method I see is attaching
watchdogs to privledged files to trap modifications or just flat out
prevent (+i) modifications to a privledged executable to make caching more
effective. But how many executables are you going to have with elevated
permissions anyway? 

--
Robert Minichino
Chief Engineer
Denarius Enterprises, Inc.
http://www.denarius.com/




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