linux-kernel - Re: [RFC PATCH v2] x86/boot: add .sbat section to the bzImage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <caec9522f981393e6fd0f8e36ff495781828406f.camel@HansenPartnership.com>
Date:   Fri, 21 Jul 2023 09:33:56 -0400
From:   James Bottomley <James.Bottomley@...senPartnership.com>
To:     Luca Boccassi <bluca@...ian.org>
Cc:     Eric Snowberg <eric.snowberg@...cle.com>,
        Ard Biesheuvel <ardb@...nel.org>,
        "Daniel P." Berrangé <berrange@...hat.com>,
        Emanuele Giuseppe Esposito <eesposit@...hat.com>,
        "x86@...nel.org" <x86@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "lennart@...ttering.net" <lennart@...ttering.net>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Alexander Potapenko <glider@...gle.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        open list <linux-kernel@...r.kernel.org>,
        "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        "keyrings@...r.kernel.org" <keyrings@...r.kernel.org>,
        Jarkko Sakkinen <jarkko@...nel.org>
Subject: Re: [RFC PATCH v2] x86/boot: add .sbat section to the bzImage

On Fri, 2023-07-21 at 14:10 +0100, Luca Boccassi wrote:
> On Fri, 21 Jul 2023 at 14:01, James Bottomley
> <James.Bottomley@...senpartnership.com> wrote:
[...]
> > Well, my job is to be concerned about how individuals who want to
> > own their own keys, either in MoK or db, participate in this, so I
> > am mostly thinking about local signing.  Whatever we decide, there
> > must be a local workflow pathway.
> 
> Sure but for local signing via MoK that's obviously fine, as one gets
> to keep the pieces. AFAIK it's a different flow in Shim whether
> something is authorized by MoK, DB or the built-in cert, so having
> different policies built-in for those different cases should be
> doable. Actually at the moment even if Shim loads the image, if it
> gets authorized by DB .sbat isn't checked at all.

So let's be sure we mean the same thing here.  There is really no third
party CA.  Microsoft gives the distributions a signing key to allow
them to sign their version of shim.  Some distributions, like Red Hat,
also embed their signing certificates in shim, so shim can distinguish
between a RH key and another key added to MokList.  However, some
distributions, like SUSE, insist that all signing keys be approved by
the machine owner (so no embedded shim certs for non-enterprise) and
their shim can't distinguish between SUSE keys and machine owner
additions.  Given the variances in key handling, I think trying to
distinguish between official and developer keys is a huge addition of
complexity we don't need, so there has to be a workflow that functions
for both and that workflow would seem to be allowing non-existent or
empty sbat sections.  Official key holders  would *always* add sbat
sections, so there's really no problem that needs a solution to be
mandated here.

James