Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751422Ab3IZEkK (ORCPT ); Thu, 26 Sep 2013 00:40:10 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:44623 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751211Ab3IZEkH (ORCPT ); Thu, 26 Sep 2013 00:40:07 -0400 Subject: Re: [RFC V4 PATCH 00/15] Signature verification of hibernate snapshot From: joeyli To: Pavel Machek Cc: James Bottomley , Alan Stern , David Howells , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org, linux-pm@vger.kernel.org, linux-crypto@vger.kernel.org, opensuse-kernel@opensuse.org, "Rafael J. Wysocki" , Matthew Garrett , Len Brown , Josh Boyer , Vojtech Pavlik , Matt Fleming , Greg KH , JKosina@suse.com, Rusty Russell , Herbert Xu , "David S. Miller" , "H. Peter Anvin" , Michal Marek , Gary Lin , Vivek Goyal In-Reply-To: <20130926002730.GA26857@amd.pavel.ucw.cz> References: <1380147414.18835.36.camel@dabdike.int.hansenpartnership.com> <20130926002730.GA26857@amd.pavel.ucw.cz> Content-Type: text/plain; charset="UTF-8" Date: Thu, 26 Sep 2013 12:40:03 +0800 Message-ID: <1380170403.32302.52.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2045 Lines: 54 於 四，2013-09-26 於 02:27 +0200，Pavel Machek 提到： > On Wed 2013-09-25 15:16:54, James Bottomley wrote: > > On Wed, 2013-09-25 at 17:25 -0400, Alan Stern wrote: > > > On Wed, 25 Sep 2013, David Howells wrote: > > > > > > > I have pushed some keyrings patches that will likely affect this to: > > > > > > > > http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-devel > > > > > > > > I intend to ask James to pull these into his next branch. If he's happy to do > > > > so, I can look at pulling at least your asymmetric keys patch on top of them. > > > > > > This suggests a point that I raised at the Linux Plumbers conference: > > > > > > Why are asymmetric keys used for verifying the hibernation image? It > > > seems that a symmetric key would work just as well. And it would be a > > > lot quicker to generate, because it wouldn't need any high-precision > > > integer computations. > > > > The reason is the desire to validate that the previous kernel created > > something which it passed on to the current kernel (in this case, the > > hibernation image) untampered with. To do that, something must be > > passed to the prior kernel that can be validated but *not* recreated by > > the current kernel. > > I don't get this. Why is it important that current kernel can't > recreate the signature? > > Current kernel is not considered malicious (if it were, you have worse > problems). > Current boot kernel should not malicious especially when UEFI secure boot enabled. > Pavel > > PS: And yes, it would be nice to have > Documentation/power/swsusp-uefi.txt (or something) explaining the > design. > Thanks for your suggestion, I will write the swsusp-uefi.txt to explaining the design in next version. Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/