From: David Howells Subject: Re: [PATCH 5/6] MODSIGN: Export module signature definitions. Date: Thu, 20 Apr 2017 15:37:37 +0100 Message-ID: <21102.1492699057@warthog.procyon.org.uk> References: <1492691712.3081.85.camel@linux.vnet.ibm.com> <1492546666-16615-1-git-send-email-bauerman@linux.vnet.ibm.com> <1492546666-16615-6-git-send-email-bauerman@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Cc: dhowells@redhat.com, Thiago Jung Bauermann , linux-security-module@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Dmitry Kasatkin , Herbert Xu , "David S. Miller" , Claudio Carvalho To: Mimi Zohar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37008 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S946424AbdDTOhl (ORCPT ); Thu, 20 Apr 2017 10:37:41 -0400 In-Reply-To: <1492691712.3081.85.camel@linux.vnet.ibm.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: Mimi Zohar wrote: > On Tue, 2017-04-18 at 17:17 -0300, Thiago Jung Bauermann wrote: > > IMA will use the module_signature format for append signatures, so export > > the relevant definitions and factor out the code which verifies that the > > appended signature trailer is valid. > > > > Also, create a CONFIG_MODULE_SIG_FORMAT option so that IMA can select it > > and be able to use validate_module_signature without having to depend on > > CONFIG_MODULE_SIG. > > Basically we want to generalize the concept of an appended signature. >  Referring to it as a "module signature format" seems a bit confusing. > > David, would you have a problem with changing the appended string from > "~Module signature appended~\n" to something more generic? Conceptually, no. Is it possible that doing so could break someone's module that they load on multiple versions of the kernel? Say a module that only exports things and doesn't use anything from the core or any other module. Also, it needs to reasonably long and distinct enough to prevent a false positive match. David