[Lake] Re: Comments for remote attestation over EDHOC

[Michael Richardson <[e-mail]>]

Muhammad Usama Sardar <[e-mail]> wrote:
    > 1. /Clarify the EDHOC and RA combinations/: EDHOC has two participants
    > (Initiator and Responder) and RATS architecture (RFC9334) defines three roles
    > (Relying Party, Verifier and Attester). I think it is important to clarify
    > which combinations are not possible or otherwise possible but not covered by
    > the specs.

I don't see the conflict.
I don't expect two constrained devices to be able to perform remote
attestation on each other.  But, even if they were CRAYs with the padded
seats, it still makes no-sense.
In the context of lake-authz, the Attester is the new device (U), the Verifier is
W (or it's designate), and the Relying Party is V.

    > 2. /RATS topology (Background-check vs. Passport model)/: Sec. 3 states:
    > "More specifically, this specification supports the RATS background check
    > model." which gives rise to a few questions in my mind:

    > * Is this intended to mean draft-00 supports background-check model
    > only? i.e., will future drafts eventually contain the passport model
    > or will it remain out of scope?

background check would be perform as part of, or perhaps concurrent to
Voucher Request.

    > 3. /One-way vs. mutual attestation/: The draft describes Initiator as the
    > Attester. In some use cases, mutual attestation may be desired. I think the
    > spec should cover that.

Naw, it makes no sense, because neither device has a way to evaluate the
evidence in a way that scales to more than about three vendors.

{/me also RFC9334 editor}

I have a half-written document on putting EAT into the full BRSKI protocol.
A reason that I stopped is that I realized that doing security posture
evaluation at onboarding time (only) wasn't enough.  It has to be done
regularly.  So having a protocol used at onboarding time and another one
during normal operation meant that the onboarding one would have bugs that
never get fixed, since the code only runs once.

--
Michael Richardson <[e-mail]>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide