From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757371Ab3CZXsy (ORCPT ); Tue, 26 Mar 2013 19:48:54 -0400 Received: from cantor2.suse.de ([195.135.220.15]:50786 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755824Ab3CZXsZ (ORCPT ); Tue, 26 Mar 2013 19:48:25 -0400 Message-ID: <515233C8.40205@suse.cz> Date: Wed, 27 Mar 2013 00:48:24 +0100 From: Michal Marek User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130105 Thunderbird/17.0.2 MIME-Version: 1.0 To: David Howells Cc: Rusty Russell , linux-kernel@vger.kernel.org Subject: Re: [PATCH] MODSIGN: Discard previous signature when signing modules References: <1364338701-24306-1-git-send-email-mmarek@suse.cz> <960.1364340890@warthog.procyon.org.uk> In-Reply-To: <960.1364340890@warthog.procyon.org.uk> Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27.3.2013 00:34, David Howells wrote: > Michal Marek wrote: > >> The format only supports one signature, so discard any previous >> signature before signing the module. > > That's not totally true. The format does not preclude multiple signatures. > You can just add another signature block on the end that signs everything > inside of that, including all previous signatures. The alteration to the code > to check all of them would be very small, I think. The question is if this would be useful and desired, as opposed to supporting a list of signatures that all sign the *same* message. My bet is that such chain of signatures is more likely going to indicate error than intention. But I don't care much, I haven't run into this myself, I just thought that others migh do. Michal