Messages in this thread | | | Date | Thu, 26 Jan 2023 15:22:09 +0000 | From | "Dr. David Alan Gilbert" <> | Subject | Re: Linux guest kernel threat model for Confidential Computing |
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* 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
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