Re: [TLS] comments on draft-ietf-tls-tls13-19

[Ryan Sleevi <[e-mail]>]

On Mon, Apr 24, 2017 at 3:58 AM, Nikos Mavrogiannopoulos <[e-mail]>
wrote:

>
> That's intentional.


And misguided. It violates the layering.


> Not every application is firefox or chrome and thus
> application writers cannot be expected to set sane defaults for OCSP
> validity time _when the nextUpdate field is missing_.


Not every TLS implementation should be required to process the PKI.


> The reason they
> cannot be expected to do that, is that it is not by way obvious what to
> do. Ilari's implentation closes the connection, mine sets a limit of 15
> days, and I guess each and every other one behaves differently. It is
> the role of the standards to clarify uncertainties for implementers or
> forbid such options (I'd equally be happy if we have a text that
> forbids an empty nextUpdate field in OCSP responses to be used in the
> context of TLS 1.3 ocsp stapling).
>

Can you point to where the spec supports your behaviours? That is, where
it's a valid reading of the spec to close the connection or to set a limit
of 15 days.

The point is that it's not a valid reading of the spec. It is, instead, an
application profile. And that's great. I don't think anyone would
realistically be arguing that applications or other specifications cannot
profile the spec to their needs. While I remain unconvinced that TLS is the
right thing, what you're describing here is simply a decision you've made
for your community. That doesn't mean that because you and Ilari have made
different decisions, that should be imposed on the spec.


> >  Given that stapling "issues" exist even without stapling, it does
> > seem an unnecessary reach to include within the spec.
>
> There is a usability and interoperability issue there.


Not within the spec. Within the profile you've done for your community.


> Given that there
> is no common interpretation of what the missing nextUpdate field means
> in terms of validity, there some equally valid interpretations:
>  1. the response is invalid for use in TLS 1.3
>

That's not an equally valid interpretation. A missing nextUpdate is defined
in the relevant OCSP specs.


>  2. the response is valid for a limited amount of time 1, 7, 8, 9, 15
> days
>

That's not an equally valid interpretation. A missing nextUpdate is defined
in the relevant OCSP specs.


>  3. the response is valid for an unlimited amount of time (which raises
>  the question of why staple at all in that case?)
>

A missing nextU... you get the idea.