[lamps] Martin Duke's Discuss on draft-ietf-lamps-cmp-updates-20: (with DISCUSS and COMMENT)

[Martin Duke via Datatracker <[e-mail]>]

Martin Duke has entered the following ballot position for
draft-ietf-lamps-cmp-updates-20: Discuss

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DISCUSS:
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As far as I can tell, CMP provides multiple optional levels of encryption and
authentication to protect its messages and components of that message. However,
I gather that the transport substrate is allowed to be HTTP without TLS.

Given that, how does this protocol defend against version downgrade attacks? If
an on-path attacker responds to a client message with an error message
requiring an older version, do all configurations of CMP detect the
intervention?


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COMMENT:
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I support Paul's DISCUSS.

(2.13) IIUC, this section should also require the cmp2021 version.

I found it quite confusing that this document is specifying two different
versions, with version 3 diffs scattered throughout the draft. It would be much
cleaner to have a clean definition of the revised v2, and then a new section
that defines v3 with the small diff from v2.