Re: [TLS] SHA-3 in SignatureScheme

Eric Rescorla <ekr@rtfm.com> Fri, 02 September 2016 19:22 UTC

Return-Path: <ekr@rtfm.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 4B8A612B036 for <tls@ietfa.amsl.com>; Fri, 2 Sep 2016 12:22:56 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=rtfm-com.20150623.gappssmtp.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 Z35eSFLmXLl6 for <tls@ietfa.amsl.com>; Fri, 2 Sep 2016 12:22:54 -0700 (PDT)
Received: from mail-yw0-x22d.google.com (mail-yw0-x22d.google.com [IPv6:2607:f8b0:4002:c05::22d]) (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 28E7612B071 for <tls@ietf.org>; Fri, 2 Sep 2016 12:22:54 -0700 (PDT)
Received: by mail-yw0-x22d.google.com with SMTP id l8so8087241ywb.0 for <tls@ietf.org>; Fri, 02 Sep 2016 12:22:54 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rtfm-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=dP+bMpFF6QFentXKNCtclCoEuUMDNKhrG+Kw1uYkrUo=; b=unLmX53uTQuHCXtqtLjyiaV2Dt1dSUHzP621Mgk3TseuqjAsNgfCwy6jLczgj/PYA2 iljrQyUipSsZ/ji+gwPGPgxuKf/rk7gVH6uRImrpb4AN4gd51ORDwF6WFeTQPhC4YXJd ddgQWAw/1XmRMPKbMaofCx45KP0iWPUyAKYEqZNYPeStJjAaB4A9TePEj4pln+UZ7hie jWqAaAYiUqnSxaThj8YqdwtscdCz2daxtrfqvHxao+p2/IX2kGTVr4f9Qqz/zID3Gx5R Ukjpq9qh+gR8ccgehOFVgAjCxhW2buG8cTCCOsugzbPy7AHmoesFiNNWV50mTvVoJvmw OcwQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=dP+bMpFF6QFentXKNCtclCoEuUMDNKhrG+Kw1uYkrUo=; b=ewkejp/XWb+Z9Z8Gg/OCrJUCLjB+MDhqWiox8LpSp4y4068YhLW04nbCvxCxb9OJcT eTs6YMre6gGKHZ8xAQvNxM8+BTXWc14fz3nSQzNIKcFr78t7tkhEFpGKsP/jpNVncJBE iL24oKjvwl/sXAxt6uYO6RPaaIC62RD/0kgZ2RiASHCAqLrU7YiKI1x8pVwwy9dECjBU cg829aerrcbxACsBtGjLFLS7GNl6znBbnBgvMbxikRjJ6xjjVY7MkSEpqWWjEL6eBaKc sMFdsXQ1XsicBvNBNUjKK1sX/XidUlvQ2R4D3NY2tYF6MUl6GTdK+mEoki4NABIvpEN+ XT0g==
X-Gm-Message-State: AE9vXwNhW4qWZ/kcfb6GEi7GcXeIFKLaxFwFFxiEij+ZmeaGvP6k0TlhFSOThR4OEh1Yc515ZmipxsD72rB7lg==
X-Received: by 10.129.125.135 with SMTP id y129mr20422050ywc.107.1472844173358; Fri, 02 Sep 2016 12:22:53 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.129.48.193 with HTTP; Fri, 2 Sep 2016 12:22:12 -0700 (PDT)
In-Reply-To: <1489216.MHQYH3hEiU@pintsize.usersys.redhat.com>
References: <7755682.Cma8FBTrvx@pintsize.usersys.redhat.com> <4536302.2GJhFoeUiN@pintsize.usersys.redhat.com> <BC6013EC-26EF-4EF7-AE5C-37D70D9CFF50@gmail.com> <1489216.MHQYH3hEiU@pintsize.usersys.redhat.com>
From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 2 Sep 2016 12:22:12 -0700
Message-ID: <CABcZeBNJaKSNSWko+zCKURTNHS0iAcmFtm4keQrFLwoZazM4cg@mail.gmail.com>
To: Hubert Kario <hkario@redhat.com>
Content-Type: multipart/alternative; boundary=001a11492ce8c36741053b8b4114
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/uHEwEJZqCVH8lk8sdXgcmcPPulo>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] SHA-3 in SignatureScheme
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: Fri, 02 Sep 2016 19:22:56 -0000

On Fri, Sep 2, 2016 at 12:21 PM, Hubert Kario <hkario@redhat.com> wrote:

> On Friday, 2 September 2016 21:38:33 CEST Yoav Nir wrote:
> > > On 2 Sep 2016, at 8:27 PM, Hubert Kario <hkario@redhat.com> wrote:
> > >
> > > On Friday, 2 September 2016 12:06:55 CEST Benjamin Kaduk wrote:
> > >> On 09/02/2016 12:04 PM, Eric Rescorla wrote:
> > >>> On Fri, Sep 2, 2016 at 8:25 AM, Dave Garrett <davemgarrett@gmail.com
> > >>>
> > >>> <mailto:davemgarrett@gmail.com>> wrote:
> > >>>    On Friday, September 02, 2016 07:32:06 am Eric Rescorla wrote:
> > >>>> On Fri, Sep 2, 2016 at 3:42 AM, Ilari Liusvaara
> > >>>>
> > >>>    <ilariliusvaara@welho.com <mailto:ilariliusvaara@welho.com>>
> wrote:
> > >>>>> I also don't see why this should be in TLS 1.3 spec, instead of
> > >>>>> being
> > >>>>> its own spec (I looked up how much process BS it would be to
> > >>>>>
> > >>>    get the
> > >>>>>
> > >>>>> needed registrations: informative RFC would do).
> > >>>>
> > >>>> I also am not following why we need to do this now. The reason
> > >>>>
> > >>>    we defined SHA-2 in
> > >>>>
> > >>>> a new RFC was because (a) SHA-1 was looking weak and (b) we had
> > >>>>
> > >>>    to make significant
> > >>>>
> > >>>> changes to TLS to allow the use of SHA-2. This does not seem to
> > >>>>
> > >>>    be that case.
> > >>>
> > >>>    I don't think we strictly _need_ to do this now, however I think
> > >>>    it's a good idea given that we'll need to do it eventually
> > >>>
> > >>> I'm not sure that that's true.
> > >>
> > >> Predicting future needs is not always reliable, yes.
> > >>
> > >>> From a release-engineering (standards-engineering?) perspective, I
> still
> > >>
> > >> don't see any reasons to add it now, and do see reasons to not add it
> > >> now.
> > >
> > > what would be the reasons not to add it now?
> >
> > Several reasons:
> >  - This is a core spec. Those don’t traditionally specify new algorithms
> > unless they’re MTI (like SHA-256 is TLS 1.2 and RSAPSS here)
> > - For now,
> > SHA-3 is yet another national algorithm. Why add this and not Streebog?
> [1]
> > - Who’s to tell whether SHA-2 breaks earlier than SHA-3?
>
> But then we have:
> * AES and ChaCha (two modes for the former one even)
> * RSA and ECDSA
> * NIST curves and Bernstein curves
> * ECDHE key exchange an DHE key exchange
>
> only the SHA-2 stands alone...
>

We have SHA-256 and SHA-384.

-Ekr


>
> --
> Regards,
> Hubert Kario
> Senior Quality Engineer, QE BaseOS Security team
> Web: www.cz.redhat.com
> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic
>
> _______________________________________________
> TLS mailing list
> TLS@ietf.org
> https://www.ietf.org/mailman/listinfo/tls
>
>