IETF Logo Mail Archive

Re: [TLS] draft-ietf-tls-session-hash-04 and session resumption

Martin Thomson <martin.thomson@gmail.com> Wed, 15 April 2015 16:40 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 358651B360E for <tls@ietfa.amsl.com>; Wed, 15 Apr 2015 09:40:04 -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 fzjJ4wAsYT0c for <tls@ietfa.amsl.com>; Wed, 15 Apr 2015 09:39:58 -0700 (PDT)
Received: from mail-ob0-x229.google.com (mail-ob0-x229.google.com [IPv6:2607:f8b0:4003:c01::229]) (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 14E3A1B2DE1 for <tls@ietf.org>; Wed, 15 Apr 2015 09:39:58 -0700 (PDT)
Received: by oblw8 with SMTP id w8so28076103obl.0 for <tls@ietf.org>; Wed, 15 Apr 2015 09:39:57 -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:content-transfer-encoding; bh=+Gtm9H7Yedpx+0N1licwcDJC93y13SeqH7H+4rrXG5w=; b=qfD4LuLvk6HT0cd/asP8sb4fJO4tpuGeqrTBtV88qLjAZlb6DrEtkJvvX103qgq11z XpJcnZ6840vNI458/Km1XsF/bNs39N7xdc8Kq5Cm4KkzpFsTCVg5gxf+N6CrYUF6L+3G cCQkwW7n7XHxKHI3ZnbYW056lYdLebLSOXdAvXhsbqLZEf3bcteSoOOfC2weHdw4iSxB BQVTbBfQyddYFjWXg5JJUKL13P8fn9EtgYb7p38JgUpiDk4u27Id76iD8OMtHHgdSpUb 5HXKr7ipf4hVoAhP76I0Cb4JjQAbEk/uelQKA0bR+tPVBomqVakJwNeBmywsfMbXNupA c1pg==
MIME-Version: 1.0
X-Received: by 10.202.0.75 with SMTP id 72mr16529452oia.131.1429115971499; Wed, 15 Apr 2015 09:39:31 -0700 (PDT)
Received: by 10.202.212.212 with HTTP; Wed, 15 Apr 2015 09:39:31 -0700 (PDT)
In-Reply-To: <56BA5F9C-E1CE-402F-831C-0D3AF3D336AE@gmail.com>
References: <20150415015313.357751B28A@ld9781.wdf.sap.corp> <53BB8A96-8CFE-4275-9562-336D60B567B3@gmail.com> <56BA5F9C-E1CE-402F-831C-0D3AF3D336AE@gmail.com>
Date: Wed, 15 Apr 2015 09:39:31 -0700
Message-ID: <CABkgnnXKU0nMQpgeUdVTTUY1K-m3_geeDO0a+0sk966X6HyxBw@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Karthikeyan Bhargavan <karthik.bhargavan@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/_lnhAwH_bNVYVe9ktOuMi3w6LrM>
Cc: "tls@ietf.org" <tls@ietf.org>, Bill Cox <waywardgeek@google.com>
Subject: Re: [TLS] draft-ietf-tls-session-hash-04 and session resumption
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: Wed, 15 Apr 2015 16:40:04 -0000

On 15 April 2015 at 00:38, Karthikeyan Bhargavan
<karthik.bhargavan@gmail.com> wrote:
> I guess my question is whether “SHOULD perform a full handshake” is strong enough,
> leaving the server the option of aborting the handshake, or is MUST preferable
> as a clearer indication to implementers?


This is fine with me.  Though I think David's concerns are worth
taking into account.  You might instead say:

   Instead, it MUST either perform a full handshake or abort the connection.

That leaves plenty of options open.

Given that this only arises if you have a busted client, we shouldn't
worry too much about which option people take.  If this were an
expected situation somehow, I'd be arguing more strongly for the full
handshake option.

v2.23.0 | Report a Bug | By Email