From owner-freebsd-security Wed Jul 19 7:59:21 2000 Delivered-To: freebsd-security@freebsd.org Received: from faith.cs.utah.edu (faith.cs.utah.edu [155.99.198.108]) by hub.freebsd.org (Postfix) with ESMTP id A88D937B7FD for ; Wed, 19 Jul 2000 07:59:17 -0700 (PDT) (envelope-from danderse@cs.utah.edu) Received: (from danderse@localhost) by faith.cs.utah.edu (8.9.3/8.9.3) id IAA08077; Wed, 19 Jul 2000 08:58:51 -0600 (MDT) Message-Id: <200007191458.IAA08077@faith.cs.utah.edu> Subject: Re: Status of FreeBSD security work? Audit, regression and crypto swap? To: sheldonh@uunet.co.za (Sheldon Hearn) Date: Wed, 19 Jul 2000 08:58:51 -0600 (MDT) Cc: silby@silby.com (Mike Silbersack), watchman@ludd.luth.se (Joachim =?iso-8859-1?Q?Str=F6mbergson?=), glewis@trc.adelaide.edu.au (Greg Lewis), freebsd-security@FreeBSD.ORG In-Reply-To: <30869.963985360@axl.ops.uunet.co.za> from "Sheldon Hearn" at Jul 19, 2000 07:42:40 AM From: "David G. Andersen" X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Lo and behold, Sheldon Hearn once said: > > On Tue, 18 Jul 2000 18:44:28 EST, Mike Silbersack wrote: > > > Hence, one obtaining access to the swap file does have greater > > knowledge than they would with a crypted swap. His paper seems well > > written, I suggest that you read it. > > I read some of it. Two things occur to me: > > 1) It's close to a waste of time in the absence of crypted filesystems. > > 2) The kind of access required to read the swap device usually implies a > much more serious issue than a crypted swap is going to help you > with. That's not really true, actually. If someone breaks into your apartment and snags your hard disks, they may potentially be able to get a lot more information out of it if you have available swap. For instance, grepping through my swap partition last night, I noticed that the contents of some of my xterm scrollback buffers were stored in there - that's not information someone would be able to obtain ordinarily if you'd shut your computer down. > That said, it _does_ provide some kind of damage control. It's just not > as useful as people sometimes assume. :-) Few things are. There's likely more information stored on filesystems that people don't want lingering around even after repeated overwrites, but swap has the potential to store things behind your back - even if you and your programs are careful to never write them to disk. -Dave -- work: dga@lcs.mit.edu me: dga@pobox.com MIT Laboratory for Computer Science http://www.angio.net/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message