From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760016Ab3B1T0c (ORCPT ); Thu, 28 Feb 2013 14:26:32 -0500 Received: from ka.mail.enyo.de ([87.106.162.201]:47178 "EHLO ka.mail.enyo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759793Ab3B1T0a (ORCPT ); Thu, 28 Feb 2013 14:26:30 -0500 From: Florian Weimer To: Chris Friesen Cc: Greg KH , Matthew Garrett , 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 References: <87ppzo79in.fsf@mid.deneb.enyo.de> <30665.1361461678@warthog.procyon.org.uk> <20130221164244.GA19625@srcf.ucam.org> <18738.1361836265@warthog.procyon.org.uk> <20130226005955.GA19686@kroah.com> <20130226023332.GA29282@srcf.ucam.org> <20130226030249.GB23834@kroah.com> <20130226031338.GA29784@srcf.ucam.org> <20130226033156.GA24999@kroah.com> <8738wgsweq.fsf@mid.deneb.enyo.de> <512F7B0E.1030404@genband.com> Date: Thu, 28 Feb 2013 20:26:17 +0100 In-Reply-To: <512F7B0E.1030404@genband.com> (Chris Friesen's message of "Thu, 28 Feb 2013 09:43:10 -0600") Message-ID: <87lia8nsti.fsf@mid.deneb.enyo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Chris Friesen: > On 02/28/2013 01:57 AM, Florian Weimer wrote: > >> In any case, there's another reading of the UEFI Secure Boot >> requirements: you may run any code you wish after calling >> ExitBootServices(). That could be an unsigned, traditional GRUB. But >> this will not generally address the issue of dual-booting Windows 8 in >> such a way that Windows sees that the device has enabled Microsoft >> Secure Boot. > > Would it be possible to have a signed bootloader that allows booting > Win8 from within the secure environment, or it could exit the secure > environment and run unsigned grub? On systems where the firmware supports multiple boot loaders, this would work. On systems which support just one boot loader, the next-stage boot loader could be signed or not, it would not have access to the privileged Secure Boot environment. The decision to boot the Secure-Boot-capable operating system would have to be made before calling ExitBootServices(), otherwise that operating system will not see Secure Boot support.