Re: [TLS] Working Group Last Call for draft-ietf-tls-downgrade-scsv-00

Martin Thomson <martin.thomson@gmail.com> Fri, 26 September 2014 07:22 UTC

Return-Path: <martin.thomson@gmail.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 125121A1A75 for <tls@ietfa.amsl.com>; Fri, 26 Sep 2014 00:22:30 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 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, SPF_PASS=-0.001] autolearn=ham
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 9UlJfTekfeu8 for <tls@ietfa.amsl.com>; Fri, 26 Sep 2014 00:22:28 -0700 (PDT)
Received: from mail-la0-x22f.google.com (mail-la0-x22f.google.com [IPv6:2a00:1450:4010:c03::22f]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 8C6AB1A1A6E for <tls@ietf.org>; Fri, 26 Sep 2014 00:22:28 -0700 (PDT)
Received: by mail-la0-f47.google.com with SMTP id mc6so13761309lab.6 for <tls@ietf.org>; Fri, 26 Sep 2014 00:22:26 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=pVKy3Xq9SNpI/y4g2u4cwkXrHFwQFZOCfJe7E+eCWpQ=; b=RlaAsmJxQIuxkjiJYjv8/8O11FV06vVPlXsJQ3k4PQKdIso8dIOIChAeN5GeNSiWMf TWU9LmXbojZh/yIhWhF43GrpAPjS4x/IewVbcXPkHvegWNmNIZGmCo3ZAYHf5mrOIGfg meHz6tG9eZPJNkLXdvsdMJY6cwiv9G9zv6B+3+1w/JR6RHHaC+m0OZQBZykPFFUs+1Lr /VUXBQDPxFWnDOAuTCTeYxwK7eSJE6heAjwUdjV+41zh6Dln/eumz2SuE9VXYwy5sTSL er1DmivEL4aZdEo+AWv0ML+S/91JKgeAM3/ZG1CQfFcpTv9smASFRZqbojLcwbkv3lct 6oiA==
MIME-Version: 1.0
X-Received: by 10.112.148.170 with SMTP id tt10mr17689261lbb.61.1411716146755; Fri, 26 Sep 2014 00:22:26 -0700 (PDT)
Received: by 10.25.166.75 with HTTP; Fri, 26 Sep 2014 00:22:26 -0700 (PDT)
In-Reply-To: <CADMpkcJpHeKGV-xc4Uon8KWj=+p=6nQO1_rxb6sRN04nFX--gQ@mail.gmail.com>
References: <2112FCAD-4820-49D9-9871-6501C83A554D@cisco.com> <CABkgnnUxeouqDNhYFGDC2xqUaT8r7zFvAT5U1OUGJwHwCOuOwA@mail.gmail.com> <CADMpkcJKJiTCQXdDbepyiAf22J9VC03DDgiE521n3NsNnFmALA@mail.gmail.com> <CABkgnnWo9KGMkRrmA0wkJ5Dfnzh2Vo-cveCe_UeH71F8K_4oWw@mail.gmail.com> <CADMpkcJpHeKGV-xc4Uon8KWj=+p=6nQO1_rxb6sRN04nFX--gQ@mail.gmail.com>
Date: Fri, 26 Sep 2014 08:22:26 +0100
Message-ID: <CABkgnnU8DyzRvvq1e24bUsZdwx48mFOC6KstZaUCbvyQ-WwesQ@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Bodo Moeller <bmoeller@acm.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: http://mailarchive.ietf.org/arch/msg/tls/kAsquRM8BEF6hT-l06Xz8FiY5HM
Cc: "<tls@ietf.org>" <tls@ietf.org>
Subject: Re: [TLS] Working Group Last Call for draft-ietf-tls-downgrade-scsv-00
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.15
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: <http://www.ietf.org/mail-archive/web/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: Fri, 26 Sep 2014 07:22:30 -0000

On 26 September 2014 08:08, Bodo Moeller <bmoeller@acm.org> wrote:
>
> The main thinking behind the draft, however, is that the server-side logic
> should be as simple as possible, because I want *every* server to do this.
> (What's more, I want every server to do it *correctly*.) The client-side
> logic, in contrast, can be a bit more complicated: if your client never does
> those fallback retries, you don't have to do anything.

I'm OK with that, but if this is the real reason for the MUST, then
it's not particularly clear.