lkml.org 
[lkml]   [2023]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Linux guest kernel threat model for Confidential Computing
* Richard Weinberger (richard.weinberger@gmail.com) wrote:
> On Thu, Jan 26, 2023 at 3:58 PM Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
> >
> > * Richard Weinberger (richard.weinberger@gmail.com) wrote:
> > > On Wed, Jan 25, 2023 at 3:22 PM Daniel P. Berrangé <berrange@redhat.com> wrote:
> > > > Any virtual device exposed to the guest that can transfer potentially
> > > > sensitive data needs to have some form of guest controlled encryption
> > > > applied. For disks this is easy with FDE like LUKS, for NICs this is
> > > > already best practice for services by using TLS. Other devices may not
> > > > have good existing options for applying encryption.
> > >
> > > I disagree wrt. LUKS. The cryptography behind LUKS protects persistent data
> > > but not transport. If an attacker can observe all IO you better
> > > consult a cryptographer.
> > > LUKS has no concept of session keys or such, so the same disk sector will
> > > always get encrypted with the very same key/iv.
> >
> > Are you aware of anything that you'd use instead?
>
> Well, I'd think towards iSCSI over TLS to protect the IO transport.

Yeh, that's not entirely crazy for VMs which tend to come off some
remote storage system.

> > Are you happy with dm-verity for protection against modification?
>
> Like LUKS (actually dm-crypt) the crypto behind is designed to protect
> persistent data not transport.
> My fear is that an attacker who is able to observe IOs can do bad things.

Hmm, OK, I'd assumed dm-crypt was OK since it's more hashlike and
unchanging.

Dave

--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

\
 
 \ /
  Last update: 2023-03-26 23:57    [W:0.140 / U:0.552 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site