Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 20 Aug 1998 19:40:39 -0500 (EST)
From:      Alfred Perlstein <bright@www.hotjobs.com>
To:        Mike Smith <mike@smith.net.au>
Cc:        freebsd-hackers@FreeBSD.ORG
Subject:   Re: Trapping memory 
Message-ID:  <Pine.BSF.3.96.980820193404.305J-100000@bright.fx.genx.net>
In-Reply-To: <199808201558.PAA00613@dingo.cdrom.com>

next in thread | previous in thread | raw e-mail | index | archive | help
baring physical access to the machine couldn't you compile in the
secureflags option?

then make sure to chflags the kernel, and startup scripts properly.

btw, perhaps a sysctl that could be set but not cleared in securemode to
suppress lkm loading. properly chflag'd  startup scripts could
load lkms, then set the flag to prevent a kernel trojan/virus lkm from
being loaded.

Alfred Perlstein - Programmer, HotJobs Inc. - www.hotjobs.com
-- There are operating systems, and then there's BSD.
-- http://www.freebsd.org/

On Thu, 20 Aug 1998, Mike Smith wrote:

> > Is there some way to trap or detect when some other program is trying to
> > read memory used by another program?
> 
> You could implement a kernel extension to provide this support.
> 
> > For example, I have an encryption/decryption daemon that holds its key in
> > memory.  I have been told that there is really no way to protect the memory
> > used by the daemon in the case of a root compromise.  However, if I could
> > somehow detect another program trying to access my daemon's memory space,
> > then I could have the daemon dump the key and shutdown.
> > 
> > Any insight would be greatly appreciated.
> 
> A root compromise would be able to defeat the detection mechanism.
> 
> You could increase the difficulty of recovering the key slightly by 
> obfuscating its storage, but protecting it completely would require 
> kernel modifications which could be reversed/removed/faked around by a 
> sufficiently persistent attacker.
> 
> -- 
> \\  Sometimes you're ahead,       \\  Mike Smith
> \\  sometimes you're behind.      \\  mike@smith.net.au
> \\  The race is long, and in the  \\  msmith@freebsd.org
> \\  end it's only with yourself.  \\  msmith@cdrom.com
> 
> 
> 
> To Unsubscribe: send mail to majordomo@FreeBSD.org
> with "unsubscribe freebsd-hackers" in the body of the message
> 


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.96.980820193404.305J-100000>