Re: [kitten] Kerberos preauth negotiation techniques

Nico Williams <nico@cryptonector.com> Mon, 23 February 2015 22:23 UTC

Return-Path: <nico@cryptonector.com>
X-Original-To: kitten@ietfa.amsl.com
Delivered-To: kitten@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5CCA91A01F2 for <kitten@ietfa.amsl.com>; Mon, 23 Feb 2015 14:23:22 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.044
X-Spam-Level:
X-Spam-Status: No, score=-1.044 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FM_FORGED_GMAIL=0.622, IP_NOT_FRIENDLY=0.334, RCVD_IN_DNSWL_NONE=-0.0001] autolearn=no
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 vtmZhIaJZcyZ for <kitten@ietfa.amsl.com>; Mon, 23 Feb 2015 14:23:21 -0800 (PST)
Received: from homiemail-a66.g.dreamhost.com (sub4.mail.dreamhost.com [69.163.253.135]) by ietfa.amsl.com (Postfix) with ESMTP id 730061A0018 for <kitten@ietf.org>; Mon, 23 Feb 2015 14:23:21 -0800 (PST)
Received: from homiemail-a66.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a66.g.dreamhost.com (Postfix) with ESMTP id 4EF4D350078 for <kitten@ietf.org>; Mon, 23 Feb 2015 14:23:21 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=cryptonector.com; h= mime-version:in-reply-to:references:date:message-id:subject:from :to:cc:content-type; s=cryptonector.com; bh=8HfIwwmE+mmyr/f9EUFm hWU4iVY=; b=p5pIj+met6L0r7mGZtX2vw3lsIr7FbnJjCrdn/9Y6fXZpZ97ufRG KPVnxruOSpN00IfB2j8KSvt5a8AoGPRND4K1vUJ6JYEK/gnDIwPlXHIpIvgQ4sUS AWeUAEiUluSpOxxt33d5/iYcRBQ6FXpqH9u6XURY9YeCd/diRz/YnBs=
Received: from mail-ie0-f182.google.com (mail-ie0-f182.google.com [209.85.223.182]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: nico@cryptonector.com) by homiemail-a66.g.dreamhost.com (Postfix) with ESMTPSA id 15D2035005B for <kitten@ietf.org>; Mon, 23 Feb 2015 14:23:21 -0800 (PST)
Received: by iecrd18 with SMTP id rd18so27332690iec.8 for <kitten@ietf.org>; Mon, 23 Feb 2015 14:23:20 -0800 (PST)
MIME-Version: 1.0
X-Received: by 10.107.27.143 with SMTP id b137mr16787518iob.76.1424730200528; Mon, 23 Feb 2015 14:23:20 -0800 (PST)
Received: by 10.64.130.66 with HTTP; Mon, 23 Feb 2015 14:23:20 -0800 (PST)
In-Reply-To: <1424728786.2604.88.camel@redhat.com>
References: <x7da90k47ox.fsf@equal-rites.mit.edu> <1424189675.2645.23.camel@redhat.com> <54E4F31D.5080103@mit.edu> <20150218204339.GR5246@localhost> <1424722422.2604.77.camel@redhat.com> <54EB9A91.6040007@mit.edu> <CAK3OfOhkNdhAUNeKMqqBvkMspM3pCtvA_AOFKB-Zb7UXh4w9aw@mail.gmail.com> <1424728786.2604.88.camel@redhat.com>
Date: Mon, 23 Feb 2015 16:23:20 -0600
Message-ID: <CAK3OfOhEPAR4v8U1yiGzBR4yJAxVv=g7N2dO78WxV8TT2rbXTA@mail.gmail.com>
From: Nico Williams <nico@cryptonector.com>
To: Nathaniel McCallum <npmccallum@redhat.com>
Content-Type: text/plain; charset=UTF-8
Archived-At: <http://mailarchive.ietf.org/arch/msg/kitten/HE67j2dEAnRhwZzuFOt2Rrw071M>
Cc: "kitten@ietf.org" <kitten@ietf.org>
Subject: Re: [kitten] Kerberos preauth negotiation techniques
X-BeenThere: kitten@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Common Authentication Technologies - Next Generation <kitten.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/kitten>, <mailto:kitten-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/kitten/>
List-Post: <mailto:kitten@ietf.org>
List-Help: <mailto:kitten-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/kitten>, <mailto:kitten-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 23 Feb 2015 22:23:22 -0000

On Mon, Feb 23, 2015 at 3:59 PM, Nathaniel McCallum
<npmccallum@redhat.com> wrote:
> On Mon, 2015-02-23 at 15:41 -0600, Nico Williams wrote:
>> On Mon, Feb 23, 2015 at 3:24 PM, Greg Hudson <ghudson@mit.edu> wrote:
>> > On 02/23/2015 03:13 PM, Nathaniel McCallum wrote:
>> > > We also discussed making group negotiation have a note in the
>> > > RFC about being careful regarding the number of groups exposed. I
>> > > suspect sensible defaults will be:
>> > > * P-256
>> > > * P-384
>> > > * P-521
>> > > * Curve25519
>> >
>> > I would prefer an even more limited offering, but this decision
>> > can wait until later.
>>
>> I think two for the 128-bit level and one or two (preferably one)
>> each for the 192- and 256-bit levels.
>
> I think this is an implementation detail that will change over time. :)

This is what we do here: we specify what must be implemented to get interop.

We can argue about whether some group that you can't implement _now_
should be required to implement.  We can argue about other groups that
others can't implement _now_.  We can't really have no
required-to-implement groups.  Well, we could, but not as an
Standards-Track RFC.

Nico
--