From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755890Ab3AUQnQ (ORCPT ); Mon, 21 Jan 2013 11:43:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39825 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752052Ab3AUQnO (ORCPT ); Mon, 21 Jan 2013 11:43:14 -0500 Date: Mon, 21 Jan 2013 10:45:01 -0500 From: Vivek Goyal To: Mimi Zohar Cc: linux-kernel@vger.kernel.org, ebiederm@xmission.com, pjones@redhat.com, hpa@zytor.com, dhowells@redhat.com, jwboyer@redhat.com Subject: Re: [PATCH 2/3] binfmt_elf: Verify signature of signed elf binary Message-ID: <20130121154501.GA27617@redhat.com> References: <1358285695-26173-1-git-send-email-vgoyal@redhat.com> <1358285695-26173-3-git-send-email-vgoyal@redhat.com> <1358437021.2689.52.camel@falcor1> <20130117155154.GC12165@redhat.com> <1358440365.2689.72.camel@falcor1> <20130117173605.GB2237@redhat.com> <1358702400.2406.103.camel@falcor1.watson.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1358702400.2406.103.camel@falcor1.watson.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 20, 2013 at 12:20:00PM -0500, Mimi Zohar wrote: > On Thu, 2013-01-17 at 12:36 -0500, Vivek Goyal wrote: > > On Thu, Jan 17, 2013 at 11:32:45AM -0500, Mimi Zohar wrote: > > > > [..] > > > > > At this point, why would you want yet another method for signing files? > > > > > > > > Are you saying that append signature instead of putting them in a section > > > > or are you saying that just use IMA. > > > > > > > > - For the first, I am fine with appending too if that works better. So > > > > what's wrong with current implementation. Just because we append the > > > > signatures in case of modules, we should follow the same thing for > > > > executables too? > > > > > > No, I was saying that if this patch set were to be upstreamed, then the > > > signature verification, at least for ELF modules and ELF executables, > > > should be the same. The patch would then be a lot smaller. > > > > I don't think that patch is lot smaller. Initially I had written code > > where signatures were appended. Parsing the signature is little different > > from module. In case of modules, whole file is already in memory and > > in case of executables, we are reading selected portions of file in > > buffer. > > Have you looked at the original kernel module signature verification > code as posted by David? It did something similar, but was not > upstreamed. I have. I think keeping code in a section makes stripping of section easy. Anyway, these sections are not loaded in memory at file exec time so it should be fine. So appending signature is easy and I can change the implementation to do it like modules. But please give a more stronger reason that why it should be appened to executable then put in a section. Thanks Vivek