Re: [openpgp] 1PA3PC: first-party attested third-party certifications (making Key Server Prefs no-modify actionable)

Daniel Kahn Gillmor <dkg@fifthhorseman.net> Fri, 30 August 2019 17:48 UTC

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From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
To: Werner Koch <wk@gnupg.org>
Cc: Ángel <angel@16bits.net>, openpgp@ietf.org
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Date: Fri, 30 Aug 2019 13:47:57 -0400
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Subject: Re: [openpgp] 1PA3PC: first-party attested third-party certifications (making Key Server Prefs no-modify actionable)
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On Fri 2019-08-30 09:28:49 +0200, Werner Koch wrote:
> On Fri, 30 Aug 2019 01:15, dkg@fifthhorseman.net said:
>> If there's a broader consensus on the list that we shouldn't explicitly
>> associate no-modify with a 1PA3PC mechanism, then i can drop that part
>
> I can't yet decide on this because I have no clear vision on how to
> implement the workflow to create the new attestation.  Probably they
> should be handled like a local signature and only exported when needed.
> Older versions need to be dropped to avoid cluttering the keyblock with
> lots of old and useless attestations.

I agree that any OpenPGP keystore (local keyring, keyserver, whatever)
should be able to legitimately discard all superseded Attestation Key
Signatures, keeping only the most recent one.  I think this is true
regardless of whether we explicitly tie keyserver-prefs no-modify to
this mechanism.

   [ Digging into the weird corner cases: there is a question about what
     to do when one receives an Attestation Key Signature with a
     Signature Creation Time that is in the future. I think it is
     acceptable to drop/discard these objects (perhaps with some window
     of allowance for possible clock skew) ]

If you're generally ok with the protocol mechanism for attestations
proposed here, i'd be happy to share my notes for what i think a initial
interface for managing attestations with GnuPG might look like -- i can
do that on https://dev.gnupg.org/, or on gnupg-devel@gnupg.org, wherever
you prefer.

All the best,

            --dkg