From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1LavGM-0000Ez-1J for mharc-grub-devel@gnu.org; Sat, 21 Feb 2009 12:03:38 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LavGK-0000EM-D7 for grub-devel@gnu.org; Sat, 21 Feb 2009 12:03:36 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LavGI-0000DU-6B for grub-devel@gnu.org; Sat, 21 Feb 2009 12:03:35 -0500 Received: from [199.232.76.173] (port=35895 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LavGH-0000DP-Tn for grub-devel@gnu.org; Sat, 21 Feb 2009 12:03:34 -0500 Received: from fg-out-1718.google.com ([72.14.220.159]:33009) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LavGH-0000Gb-78 for grub-devel@gnu.org; Sat, 21 Feb 2009 12:03:33 -0500 Received: by fg-out-1718.google.com with SMTP id l27so1676238fgb.30 for ; Sat, 21 Feb 2009 09:03:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=xcPcIy350oudWbposuGysxbSWVe01L0IvYfcGi86irc=; b=qla53zhbGS4ws2McF/ZoA8fYHa11YeMf457xr6bzq8pK2CpamAUOZrtFLsvtr+FNzm ODPWCEC6xeFg+e3sp6boX2BU/WnhwpOtT5B9eiJw8WUjukVXkjho9EDDv4DzmFDDLdD1 /O7PXJ/vdIiRB2j75L15A4nDpSkq+ufjdV+sA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; b=W0/TnoGFOaG8zVP+V1/QXvKHRpK5mc/mbEtmX30MQIlkg/UdTzRFKeMojxAg9tMND9 yG05LYXq+zeaa9isvpswhc+L1uKu0XBhNVSzcj7e+CVxUw1QtSY9xns7goS8ns6wxiVh 2/ZY3NLRGuDKUXZNsfPkFRO9LgYPskjN6CQ3k= Received: by 10.86.57.9 with SMTP id f9mr1806851fga.38.1235235812523; Sat, 21 Feb 2009 09:03:32 -0800 (PST) Received: from ?192.168.1.25? (166-90.62-81.cust.bluewin.ch [81.62.90.166]) by mx.google.com with ESMTPS id d6sm1404687fga.29.2009.02.21.09.03.31 (version=SSLv3 cipher=RC4-MD5); Sat, 21 Feb 2009 09:03:32 -0800 (PST) Message-ID: <49A033E2.6060904@gmail.com> Date: Sat, 21 Feb 2009 18:03:30 +0100 From: phcoder User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: The development of GRUB 2 References: <499DB343.9020301@gmail.com> <499DF97E.1080800@student.ethz.ch> <20090221134607.GJ16068@thorin> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 2) 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: Sat, 21 Feb 2009 17:03:36 -0000 Well I don't understand you. When someone speaks about an attack on tpm you always consider it not-applicable in your environment. Most of them actually are. Like power analysis is able to recover keys in $1000 margin. With firewire attack you can do it with $10. You can't seriously assume an attacker which has less then $100 budget in any application. Reading directly from tpm in its current state is just a matter of time. However you consider any attack on the scheme coreboot+grub+boot or boot virus protection+sha-1+grub+boot with the encryption key in flash memory relevant. In both of these scenarios an attacker is unable to read the key without a hardware tampering level comparable to the one required to recover the key from tpm. TPM is dangerous and once we use it it's difficult to come back. If it could provide something over the two mentioned schemes then I would say that it's worth investigating. But as it isn't I say smash you tpm chip. The only thing that tpm offers over other possibilities is a claim to achieve something that is theoretically impossible. Such claims are often the case in computer industry. I call it "marketing security". I suppose companies and engineers know that their claims are false still say it because their salaries depend on how well their product is sold Regards Vladimir 'phcoder' Serbinenko Alex Besogonov wrote: > On Sat, Feb 21, 2009 at 3:46 PM, Robert Millan wrote: >>> Yes, I'm trying to do remote attestation. >> You're confusing things. I think you simply want to ensure data integrity, and >> the TPM doesn't even do that: it simply puts the problem in hands of a third >> party. > No, I'm not confusing anything. > >> "remote attestation" is only useful when you want to coerce others into >> running your (generaly proprietary) software. I hope this is not what you >> want to do. > It's exactly what I want to do (minus the 'coercing' part). I want to > ensure that devices run only my unmodified software (which I consider > secure) and only in this case provide decryption keys for sensitive > data. Of course, it done not for DRM purposes, but rather to protect > sensitive data from theft (real theft, not copyright infringement). > >>> Well, I spoke phcoder on Jabber - there might be a way to do this. >>> He's going to investigate it. >> This is unnecessary. Once GRUB supports crypto, it can simply load >> itself from an encrypted filesystem on disk. An image can be of >> arbitrary size. > Nope. Still no way to test system integrity. > > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/grub-devel