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Date:      Wed, 12 Feb 1997 22:23:14 +0200 (EET)
From:      Alexander Snarskii <snar@lucky.net>
To:        michaelh@cet.co.jp (Michael Hancock)
Cc:        dk+@ua.net, snar@lucky.net, freebsd-hackers@FreeBSD.org
Subject:   Re: Increasing overall security....
Message-ID:  <199702122023.WAA21544@burka.carrier.kiev.ua>
In-Reply-To: <Pine.SV4.3.95.970212103543.5799C-100000@parkplace.cet.co.jp> from "Michael Hancock" at Feb 12, 97 11:28:24 am

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> 
> On Mon, 10 Feb 1997, Dmitry Kohmanyuk wrote:
> > > 'Why don't rewrite that functions to check the stack integrity
> > > before return?' says Oleg Panaschenko sometimes ago, and after
> > > some reflections i found that that is not so bad idea. Yes, we're
> > > getting some overhead with using these functions rather than
> > > with standard ones, but, as for me, this overhead is not so big
> > > and a reason, that i can sleep without nightmares about another
> > > stack overflow exploits is much important for me.
> > 
> > that's very good idea.  I don't understand the reasons from other people
> > responding to this negatively.
> 
> Speaking for myself.  The author's original argument for this patch seemed
> to be because there was no "Theo" in the FreeBSD group.  He was unaware of
> the current situation and I informed him.

The fact that "Theo" is not in the FreeBSD-team was just one of my
arguments :)

> 
> To play devil's advocate...
> 
> 1) It requires assembler which is harder to understand.  Less people are
> qualified to review it.  Relying on something harder to understand for
> security is questionable. 

Yes, it is. But there are about 51 functions in standard libc, realized
on assembler, so, i think there are someone, who wrote it, and knew
assembler well to review .... 
 
> 
> 2) We don't know if it operates correctly.  Sendmail 8.8.5 has around 106
> strcpy's in it and we don't know what the patch's effect will be in a
> production environment. 

Mike, do you think that i published this patches without correct
check of working ? These patches are applied on my main computers
about week or so, and i have no problems with... 
( Well, sendmail 8.8.5 - no problems, too... )
 
> 
> The author should probably instead try to get people to apply it in their
> own environments and test it for him.  If there is enough popular demand
> then people might make more effort to commit it. 
> 
> Just out of curiosity has this patch been submitted to OpenBSD?

Not. Right now i have no time, but on the next week i'll port
it to OpenBSD/i386.

-- 
Alexander Snarskii
the source code is included.



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