Re: [TLS] WGLC for draft-ietf-tls-ticketrequests

Rob Sayre <sayrer@gmail.com> Thu, 21 November 2019 05:01 UTC

Return-Path: <sayrer@gmail.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id EE3D0120963 for <tls@ietfa.amsl.com>; Wed, 20 Nov 2019 21:01:55 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.997
X-Spam-Level:
X-Spam-Status: No, score=-1.997 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vIjsdLHsdxpI for <tls@ietfa.amsl.com>; Wed, 20 Nov 2019 21:01:53 -0800 (PST)
Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 7182D120959 for <tls@ietf.org>; Wed, 20 Nov 2019 21:01:53 -0800 (PST)
Received: by mail-il1-x12f.google.com with SMTP id p6so2048737ilp.1 for <tls@ietf.org>; Wed, 20 Nov 2019 21:01:53 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EBglmM6/24dF/AIWb/EK+TAmFEXPahfr0IamULQvEwY=; b=fvW9gbfy6Oli7fqUqWPU7KGPx325D2SoMuGONQVFStB7HpvmWbsOPinratoPmegVfK B6pQA98sxABfMdnYnBCvxFU8nBxd8IwFl5755toBQeOcgVqR/ajEAbSrJz3auSILO+1Q wMTw1wnUEaChldhCohsaMSz0kwXTNMzrRvOuQuXYxHSezLY+QrKjuCCQekiqcUiKsybI cGiC2vulNvtRB+atxGjVP/sEyfL2Q/r/MSgpKcfqaQbQqusV4k33ljhtbXvKZS+gYLQt gKmfjuY9Dgq+5jdCy1UJF2jm7ltpsoeQoU+ROfxFPEqlwjBxxubaC1Kdbri+ObzLYe/Z uj2A==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EBglmM6/24dF/AIWb/EK+TAmFEXPahfr0IamULQvEwY=; b=AAVLLmdNVw9OdXLV1vE5zbnjmJ3DVlcpmVpLITnZOx3ivG1XlHuoFEfjWgw7RMo1EY KDpR8NH1w5krK8O3EDo4gEH8jHiWgZYfC93Y/D7WPOmLGBQw3F1+fLrP3waow6j0/fr8 R5btuo8SXaRfFXOalylk294J+IhpqgEGM39ZYaxj8QBYcdhhXt6EfyPvyYJ10cdY48Ix gP5JOW7r2zw6ZUbFIViUKHH0cEHwPYyGxDDwMO9JPOWv23aT4dmqx2WY9KNeIwsWdckK dlcZOv5xJlhYQwkBWwgGW5GiZIOEoJkK3TioowsHViqs9Lb4viL/1XG+0gmLwxkyop7g o4IA==
X-Gm-Message-State: APjAAAWE4tmAArUpEJP3vzcuwVKt333ynYVQZHmmgF9Rrx9/l8QqnIqq Um584DVdY6kz1efF3z4+6/Ruz18jZsSfPcIlGsk=
X-Google-Smtp-Source: APXvYqxfdkl4v+Ru/YjSBJGXGERcMMzLzGj3qciVd6PfQ0m0h5MyW2TdomUzcRyWaaFV47E+jysZW8rEHbu6qnXGTjs=
X-Received: by 2002:a92:8394:: with SMTP id p20mr8224512ilk.73.1574312512424; Wed, 20 Nov 2019 21:01:52 -0800 (PST)
MIME-Version: 1.0
References: <20191116103855.GQ20609@akamai.com> <20191116110425.GR34850@straasha.imrryr.org> <556d2210-4af7-b398-fbd7-eab2685d7c62@wizmail.org> <20191116210617.GS34850@straasha.imrryr.org> <20191116235952.GR20609@akamai.com> <20191117002249.GV34850@straasha.imrryr.org> <CADZyTkmaUVj=sFdgg93MuM2au0B=1M1k3yCA1XDoaAneVDmnNw@mail.gmail.com> <14690874-E301-4BC0-B385-00DEBCBA94C2@apple.com> <20191120034812.GQ34850@straasha.imrryr.org> <5FBFE820-8C53-4B32-9520-343279C1A6CC@apple.com> <20191120064819.GR34850@straasha.imrryr.org> <CAPDSy+6DFJ+OYRtYK6eEiUt1noiik4KxqrGFx0ro_RL2Mft_VA@mail.gmail.com>
In-Reply-To: <CAPDSy+6DFJ+OYRtYK6eEiUt1noiik4KxqrGFx0ro_RL2Mft_VA@mail.gmail.com>
From: Rob Sayre <sayrer@gmail.com>
Date: Wed, 20 Nov 2019 21:01:39 -0800
Message-ID: <CAChr6SzWruw9VT-+3xOYLTxkvqC0Y890FVGMcuTxwz8WS5rP_w@mail.gmail.com>
To: David Schinazi <dschinazi.ietf@gmail.com>
Cc: "TLS@ietf.org" <tls@ietf.org>
Content-Type: multipart/alternative; boundary="000000000000118ef10597d43285"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/_bWpklpipuDNiNsdv5YIcOqlt8s>
Subject: Re: [TLS] WGLC for draft-ietf-tls-ticketrequests
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tls/>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 21 Nov 2019 05:01:56 -0000

On Wed, Nov 20, 2019 at 7:20 PM David Schinazi <dschinazi.ietf@gmail.com>;
wrote:

> Hi folks,
>
> I've chatted with Daniel and Chris offline, and I think there might
> have been some miscommunication here. Please allow me to
> rephrase what I think is going on, and please let me know if
> this accurately represents your views.
>
> Daniel has a IoT use-case where due to memory constraints,
> a client knows it can only handle a certain number of tickets,
> and therefore Daniel was wondering if it would make sense to
> make the requested number of tickets a required maximum
> (as in a RFC 2119 MUST). However, server operators on this
> thread have indicated that a MUST would get in the way of
> implementing this, due to STEK rotation for example. Daniel
> understands this, and is OK with the current mindset of the
> document (which is only a hint, not a MUST). Additionally,
> Daniel would prefer to see the document move forward.
>
> In order to try to address Daniel's comments, I attempted
> to rephrase the normative section to suggest in more
> stronger terms that servers really shouldn't be sending
> more than the client's request, but keeping it a SHOULD.
>
> Here is the PR with the rephrase:
> https://github.com/tlswg/draft-ietf-tls-ticketrequest/pull/10
>
> Here's a copy of the updated paragraph in the PR:
>    Clients can use TicketRequestContents.count to indicate the number of
>    tickets they would prefer to receive.  Servers SHOULD NOT send more
>    tickets than TicketRequestContents.count, as clients will most likely
>    discard any additional tickets.  Servers SHOULD additionally place a
>    limit on the number of tickets they are willing to send to save
>    resources.  Therefore, the number of NewSessionTicket messages sent
>    SHOULD be the minimum of the server's self-imposed limit and
>    TicketRequestContents.count.
>

This sounds pretty close to the "MAY option" I sent on Oct 2 here:

https://mailarchive.ietf.org/arch/msg/tls/YogBUOC0ZujSAxHVp8H0oIjJm3Y

The latter half of the patch's paragraph still uses "SHOULD"
interoperability requirements to remark on quality-of-implementation
issues, rather than just explain them. That's not great, but also not a
dealbreaker.

thanks,
Rob