From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1Ld95m-00048N-Aj for mharc-grub-devel@gnu.org; Fri, 27 Feb 2009 15:13:54 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Ld95j-00044D-GJ for grub-devel@gnu.org; Fri, 27 Feb 2009 15:13:51 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Ld95h-00041i-5K for grub-devel@gnu.org; Fri, 27 Feb 2009 15:13:50 -0500 Received: from [199.232.76.173] (port=53928 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ld95g-00041E-G2 for grub-devel@gnu.org; Fri, 27 Feb 2009 15:13:48 -0500 Received: from aybabtu.com ([69.60.117.155]:35045) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Ld95g-0001DP-42 for grub-devel@gnu.org; Fri, 27 Feb 2009 15:13:48 -0500 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1Ld8yY-0006Wu-H3 for grub-devel@gnu.org; Fri, 27 Feb 2009 21:06:27 +0100 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1Ld8rg-0008G4-Dk for grub-devel@gnu.org; Fri, 27 Feb 2009 20:59:20 +0100 Date: Fri, 27 Feb 2009 20:59:20 +0100 From: Robert Millan To: The development of GRUB 2 Message-ID: <20090227195920.GC31629@thorin> References: <499DB343.9020301@gmail.com> <499DF97E.1080800@student.ethz.ch> <499E6007.9050902@student.ethz.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: free as in freedom X-Message-Flag: Worried about Outlook viruses? Switch to Thunderbird! www.mozilla.com/thunderbird X-Debbugs-No-Ack: true User-Agent: Mutt/1.5.18 (2008-05-17) X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. Subject: Re: A _good_ and valid use for TPM X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Feb 2009 20:13:52 -0000 On Sun, Feb 22, 2009 at 03:14:07AM +0200, Alex Besogonov wrote: > Jan Alsenz wrote: >>>> Yeah, but an attacker could patch that out too. >>> Not if we first measure the MBR. It can be done without any >>> TPM-specific code in the MBR if I'm not very mistaken. >> Could you elaborate on that? >> E.g. where do you measure the MBR from? > MBR is automatically measured by the TPM module, it requires no > intervention from GRUB. Well, that is true, but for GRUB to measure all of its own stages it gets quite complicated. Overall, from a technical POV it looks like a lousy approach. It makes a lot more sense to simply have the firmware load GRUB as an executable image and measure that IMO. You can do that easily when you're in a legacy-free environment. -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all."