Subject: [Trans] making progress on precertificate discussion

From: Melinda Shore <[email-masked]>
Date: Fri, 03 Oct 2014 02:48:28 -0800

Hi, all:

Problems around precertificate contents and formats were among
the things we first discussed when the working group was chartered,
and here we are, still at it.  There are basically two problems
that fall under the "precertificate" rubric: 1) whether or not
it's possible/reasonable to include a certificate's serial number
(as this implies that the issuer will know in advance what the
serial number will be), and 2) encoding/representation.  There's
a general sense that the first *seems* like it ought to be a
problem, but we haven't had CAs stepping forward saying that
this would prevent them from being able to implement and
would be unacceptably onerous for them.  Instead, we're hearing
reports of at least one major CA solving the problem by
simultaneously issuing precertificates and certs.

Given the lack of new information and lack of new technical
arguments, I think we need to close the serial number aspect of
the discussion and go ahead with continuing to include it in
precertificates.  This is the IETF and nearly any decision can
be revisited with the introduction of new information or a new,
compelling argument.  But in the meantime we need to move forward,
so let's close this one and move on to trying to close the encoding
discussion.

Many thanks for the careful thought that's gone into the
deliberations so far,

Melinda

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From: Stephen Kent <[email-masked]>
Date: Fri, 03 Oct 2014 15:26:51 -0400

Melinda,

> simultaneously issuing precertificates and certs.
I'm confused by the last sentence above. One can issue a cert at the
same time a pre-cert is issued, but the cert does not contain the
SCT that will be generated by the log, so the parallel issuance seems 
redundant,
and I'm not sure how it helps.
> so let's close this one and move on to trying to close the encoding
I'd feel more comfortable on this topic if we had the results
of the CABF member poll I suggested. Is there any progress on
that front?

Steve

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From: Melinda Shore <[email-masked]>
Date: Fri, 03 Oct 2014 11:58:28 -0800

> and I'm not sure how it helps.

This goes to the question of whether or not the serial number
is knowable at the time at the precertificate is constructed.
I don't know much beyond that; this is based on implementation
reports from an American CA.

> of the CABF member poll I suggested. Is there any progress on

It's underway, and so far nobody is saying that the serial number
issue is a block to implementation.  I'm very concerned that
we have not been able to close this issue for over six months,
and that while several people have raised concerns on
principle nobody who's actually implementing this on the CA side
has said that this is a show-stopper, or even enough of a difficulty
to raise it with us.  We're very open to revisiting this if there's
new information.

Melinda

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From: Jeremy.Rowley <[email-masked]>
Date: Fri, 3 Oct 2014 14:14:06 -0600

For us, it's actually more difficult to generate per-certificates 
without a serial number or with a different serial number.  I'd prefer 
to keep it as-is.

Jeremy

On 10/3/2014 1:58 PM, Melinda Shore wrote:
> _______________________________________________
> Trans mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/trans
> .
>

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From: Stephen Kent <[email-masked]>
Date: Wed, 08 Oct 2014 11:05:06 -0400

Melinda,

> reports from an American CA.
I still don't understand the answer that was provided to you, as
it does not address the issue of mechanisms that prevent serial number
reuse. Never mind ...

> issue is a block to implementation.
Are you also getting responses to the "are you tracking the TRNAS WG"
question I suggested?
> I'm very concerned that
That's a fair appraisal. If we get an thorough accounting of the poll,
and it covers the vast majority of "root" CAs, then I will rescind by 
objection.

Steve