Re: [TLS] TLS 1.2 Long-term Support Profile vs HTTP/2.0

Yoav Nir <ynir.ietf@gmail.com> Sun, 03 April 2016 13:28 UTC

Return-Path: <ynir.ietf@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 BB09412D10D for <tls@ietfa.amsl.com>; Sun, 3 Apr 2016 06:28:08 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Level:
X-Spam-Status: No, score=-2.7 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, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-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 JtY2Dnjl30Y3 for <tls@ietfa.amsl.com>; Sun, 3 Apr 2016 06:28:07 -0700 (PDT)
Received: from mail-lf0-x233.google.com (mail-lf0-x233.google.com [IPv6:2a00:1450:4010:c07::233]) (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 B331F12D199 for <tls@ietf.org>; Sun, 3 Apr 2016 06:28:06 -0700 (PDT)
Received: by mail-lf0-x233.google.com with SMTP id p188so106064167lfd.0 for <tls@ietf.org>; Sun, 03 Apr 2016 06:28:06 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=rGleXm3GBCKvQNDcucASGf/26+d1Ejwsy541eUcYe8A=; b=uBIIYA9M/C5DdTCW5XdlenELvx9TGgD3TL7xiByXeUl9f4pWATpN2JFVidzy/o/DLy DHP5g06leAaHkbESOZJoZ2DJfYc/i1YJ+FQMA2HU8LymAYHox91Kn9G8JswIpXOFqSAL nPle+dGex8x0EzUeUKvemxZgsCvZThftzw4Tzz0FcXM+CmnSpGAtSlVN+mRkQLQqsP1g i2Lox+G8aHXEdrdgzUEleejHhDaWfLvImc3ligRN1p52eXL6cj9hDFKThy7uolotLlcz Xjl6ovtXe14oBlJd54v0l2awO1DNsnRY9MiRe34xFfa1DKw0y9QDI9puR9ygqs4VK/gy yBpg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=rGleXm3GBCKvQNDcucASGf/26+d1Ejwsy541eUcYe8A=; b=Hp4tFoI9a57lGX5kvBXiWvRZ2hsK4BWa2oJ3L1ZWQ4wfMkoFA9KwscERDcTYo5LzfE 8Ei+e6CxmC8c697uuXnLkLaJGn2JqOTZKeamopL0moo+FlaByyEOX6C38wmIGRdB8wMv bR14B76J77fnJHwWD5i3lkRU2eUWuJa7jq3ZF6qqHbFsQfX7GH0WM8K/MsoYiJrCzQ5m rIGIjKMFo77G6+Ox6xUafHynFx2zUu0UnDI/nRpAMKHXiY0UZ6KQDL3KaHSbEvhoYux+ HHeiCux4LHiffcHHGhzUdLpgWK6FQ7slJNMP/uH44a8N91lXMkVO69Vh1naYA9dJ5cUq K8kg==
X-Gm-Message-State: AD7BkJKj+DSobkunUx2yIpRtGOkPgW7xWAyl8eNHbMuIcLecfN5a9jabEmDZ6BXjGkO7cA==
X-Received: by 10.194.202.162 with SMTP id kj2mr4431174wjc.121.1459690084931; Sun, 03 Apr 2016 06:28:04 -0700 (PDT)
Received: from ?IPv6:2001:67c:370:160:edc2:3e9f:5b5d:546d? ([2001:67c:370:160:edc2:3e9f:5b5d:546d]) by smtp.gmail.com with ESMTPSA id yn10sm21809907wjc.45.2016.04.03.06.28.02 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 03 Apr 2016 06:28:04 -0700 (PDT)
Content-Type: text/plain; charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\))
From: Yoav Nir <ynir.ietf@gmail.com>
In-Reply-To: <CABkgnnUcOFaAdXc=mBnWg9=RFgQzVFjEdspgq_Bd30ei0f7sYQ@mail.gmail.com>
Date: Sun, 3 Apr 2016 10:27:59 -0300
Content-Transfer-Encoding: quoted-printable
Message-Id: <B842226B-C254-4BC1-864B-C5DA8E87BFD2@gmail.com>
References: <9A043F3CF02CD34C8E74AC1594475C73F4C2374E@uxcn10-tdc05.UoA.auckland.ac.nz> <1459497291.3034.20.camel@redhat.com> <9A043F3CF02CD34C8E74AC1594475C73F4C376E8@uxcn10-tdc05.UoA.auckland.ac.nz> <CABkgnnUcOFaAdXc=mBnWg9=RFgQzVFjEdspgq_Bd30ei0f7sYQ@mail.gmail.com>
To: Martin Thomson <martin.thomson@gmail.com>
X-Mailer: Apple Mail (2.3124)
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/-86SEO7Wj-qQAF0fxJ2EYdxX__I>
Cc: "<tls@ietf.org>" <tls@ietf.org>
Subject: Re: [TLS] TLS 1.2 Long-term Support Profile vs HTTP/2.0
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.17
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: Sun, 03 Apr 2016 13:28:09 -0000

> On 3 Apr 2016, at 8:44 AM, Martin Thomson <martin.thomson@gmail.com>; wrote:
> 
> On 3 April 2016 at 18:18, Peter Gutmann <pgut001@cs.auckland.ac.nz>; wrote:
>> I think the reason why there's no rationale is because there's no rational
>> explanation for lumping TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 in with the likes
>> of TLS_RSA_EXPORT_WITH_RC4_40_MD5.
> 
> You evidently believe that a decision to move to AEAD only is
> irrational.  Others, myself included, do not.
> 

Agree. TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 is fine if you also implement the EtM extension that nobody did. OTOH everybody implemented AES-GCM, so that’s better in the “yeah, we do that already” criterion. And as Dave McGrew’s draft showed us, you can fit CBC + HMAC into an AEAD in case you really, really like CBC and HMAC.

Yoav