Re: [TLS] Making post-handshake messages optional in TLS 1.3 (#676)

Eric Rescorla <ekr@rtfm.com> Tue, 11 October 2016 17:22 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Tue, 11 Oct 2016 10:21:50 -0700
Message-ID: <CABcZeBPooVXfF_fG8-QOfS+tkJDmGJ8uHioOkMo-GbUKOmNO0Q@mail.gmail.com>
To: Hannes Tschofenig <hannes.tschofenig@gmx.net>
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Cc: "tls@ietf.org" <TLS@ietf.org>
Subject: Re: [TLS] Making post-handshake messages optional in TLS 1.3 (#676)
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I think it would be simpler (and deal with most cases) to only allow this
for specific application
profiles (we would then allow it in HTTP/H2, perhaps with some small -bis
RFC).

Here is a PR for this:
https://github.com/tlswg/tls13-spec/pull/680

Andrei, would this cause you any problem? My impression was that this use
case was only
about HTTP/H2.

Thanks,
-Ekr



On Tue, Oct 11, 2016 at 9:37 AM, Hannes Tschofenig <
hannes.tschofenig@gmx.net>; wrote:

> Hi Nick,
>
> given my discussion with Martin in this thread
> https://www.ietf.org/mail-archive/web/tls/current/msg21481.html I like
> your idea of making the post-handshake messages optional since it allows
> me to develop a TLS 1.3 client that is smaller in code size.
>
> Ciao
> Hannes
>
>
> On 10/08/2016 03:03 AM, Nick Sullivan wrote:
> > There has been a lot of discussion lately about post-handshake messages
> > that do not contain application data and how to handle them. This PR is
> > an attempt to make the story more explicit by adding a new
> > post_handshake extension to TLS 1.3.
> >
> > Supporting all types of post-handshake messages can require extra
> > complexity and logic, even when the features that these messages enable
> > are not needed. Some types of connections/implementations don't need to
> > support key updates (some unidirectional connections), session tickets
> > (pure PSK implementations) and post-handshake client auth (most
> > browsers). These are all currently SHOULDs in the spec and they don't
> > need to be.
> >
> > In order to simplify the logic around dealing with post-handshake
> > messages, this proposal makes support for each of these modes explicit
> > via a new handshake extension. This change also makes the path to
> > introducing other types of post-handshake messages in future drafts more
> > explicit.
> >
> > PR:
> > https://github.com/tlswg/tls13-spec/pull/676
> >
> > Nick
> >
> >
> > _______________________________________________
> > TLS mailing list
> > TLS@ietf.org
> > https://www.ietf.org/mailman/listinfo/tls
> >
>
>
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