From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759927Ab3BYPmm (ORCPT ); Mon, 25 Feb 2013 10:42:42 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:45578 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759908Ab3BYPml (ORCPT ); Mon, 25 Feb 2013 10:42:41 -0500 Date: Mon, 25 Feb 2013 15:42:36 +0000 From: Matthew Garrett To: Florian Weimer Cc: David Howells , Linus Torvalds , Josh Boyer , Peter Jones , Vivek Goyal , Kees Cook , keyrings@linux-nfs.org, Linux Kernel Mailing List Subject: Re: [GIT PULL] Load keys from signed PE binaries Message-ID: <20130225154236.GC13605@srcf.ucam.org> References: <30665.1361461678@warthog.procyon.org.uk> <20130221164244.GA19625@srcf.ucam.org> <567.1361470653@warthog.procyon.org.uk> <20130221182511.GA22156@srcf.ucam.org> <878v6c79av.fsf@mid.deneb.enyo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878v6c79av.fsf@mid.deneb.enyo.de> User-Agent: Mutt/1.5.20 (2009-06-14) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@cavan.codon.org.uk X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 25, 2013 at 03:33:12PM +0100, Florian Weimer wrote: > * Matthew Garrett: > > > I don't think that's a problem. Just put the original binary hash in the > > certificate before signing it, and extend the X.509 parser to refuse > > certificates that have a tag that's present in dbx. > > Why would Microsoft put a hash of something into dbx which they > haven't signed? Wouldn't this make them subject to a > denial-of-service attack on their platform if they revoke something > with surprising consequences? ? The entire point is that the key is in a binary that Microsoft have signed. -- Matthew Garrett | mjg59@srcf.ucam.org