Re: [homenet] Benjamin Kaduk's No Objection on draft-ietf-homenet-babel-profile-06: (with COMMENT)

Juliusz Chroboczek <jch@irif.fr> Wed, 18 July 2018 14:30 UTC

Return-Path: <jch@irif.fr>
X-Original-To: homenet@ietfa.amsl.com
Delivered-To: homenet@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1C989130E28; Wed, 18 Jul 2018 07:30:25 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=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 UIeb1k-HLSIe; Wed, 18 Jul 2018 07:30:23 -0700 (PDT)
Received: from korolev.univ-paris7.fr (korolev.univ-paris7.fr [IPv6:2001:660:3301:8000::1:2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4970C12F1A2; Wed, 18 Jul 2018 07:30:23 -0700 (PDT)
Received: from potemkin.univ-paris7.fr (potemkin.univ-paris7.fr [IPv6:2001:660:3301:8000::1:1]) by korolev.univ-paris7.fr (8.14.4/8.14.4/relay1/75695) with ESMTP id w6IETbWs016717 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 18 Jul 2018 16:29:37 +0200
Received: from mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [81.194.30.253]) by potemkin.univ-paris7.fr (8.14.4/8.14.4/relay2/75695) with ESMTP id w6IEToax005970; Wed, 18 Jul 2018 16:29:50 +0200
Received: from mailhub.math.univ-paris-diderot.fr (localhost [127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTP id 98DEBEB22D; Wed, 18 Jul 2018 16:30:18 +0200 (CEST)
X-Virus-Scanned: amavisd-new at math.univ-paris-diderot.fr
Received: from mailhub.math.univ-paris-diderot.fr ([127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id M6dd-azojm34; Wed, 18 Jul 2018 16:30:17 +0200 (CEST)
Received: from pirx.irif.fr (unknown [78.194.40.74]) (Authenticated sender: jch) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTPSA id 83D7AEB22E; Wed, 18 Jul 2018 16:30:17 +0200 (CEST)
Date: Wed, 18 Jul 2018 16:30:17 +0200
Message-ID: <877els39c6.wl-jch@irif.fr>
From: Juliusz Chroboczek <jch@irif.fr>
To: Benjamin Kaduk <kaduk@mit.edu>
Cc: "The IESG" <iesg@ietf.org>, homenet-chairs@ietf.org, homenet@ietf.org, draft-ietf-homenet-babel-profile@ietf.org, bs7652@att.com
In-Reply-To: <152578801016.16097.3912115934408683828.idtracker@ietfa.amsl.com>
References: <152578801016.16097.3912115934408683828.idtracker@ietfa.amsl.com>
User-Agent: Wanderlust/2.15.9
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (korolev.univ-paris7.fr [IPv6:2001:660:3301:8000::1:2]); Wed, 18 Jul 2018 16:29:37 +0200 (CEST)
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (potemkin.univ-paris7.fr [194.254.61.141]); Wed, 18 Jul 2018 16:29:50 +0200 (CEST)
X-Miltered: at korolev with ID 5B4F4ED1.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)!
X-Miltered: at potemkin with ID 5B4F4EDE.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)!
X-j-chkmail-Enveloppe: 5B4F4ED1.000 from potemkin.univ-paris7.fr/potemkin.univ-paris7.fr/null/potemkin.univ-paris7.fr/<jch@irif.fr>
X-j-chkmail-Enveloppe: 5B4F4EDE.000 from mailhub.math.univ-paris-diderot.fr/mailhub.math.univ-paris-diderot.fr/null/mailhub.math.univ-paris-diderot.fr/<jch@irif.fr>
X-j-chkmail-Score: MSGID : 5B4F4ED1.000 on korolev.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000
X-j-chkmail-Score: MSGID : 5B4F4EDE.000 on potemkin.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000
X-j-chkmail-Status: Ham
X-j-chkmail-Status: Ham
Archived-At: <https://mailarchive.ietf.org/arch/msg/homenet/f8J0KQejA7K54g0Lx3ITbRQi6GI>
Subject: Re: [homenet] Benjamin Kaduk's No Objection on draft-ietf-homenet-babel-profile-06: (with COMMENT)
X-BeenThere: homenet@ietf.org
X-Mailman-Version: 2.1.27
Precedence: list
List-Id: IETF Homenet WG mailing list <homenet.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/homenet>, <mailto:homenet-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/homenet/>
List-Post: <mailto:homenet@ietf.org>
List-Help: <mailto:homenet-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/homenet>, <mailto:homenet-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 18 Jul 2018 14:30:25 -0000

>    REQ5: a Homenet implementation of Babel MUST use metrics that are of
>    a similar magnitude to the values suggested in Appendix A of
>    RFC 6126bis.

> "MUST" and "similar magnitude" are not a great pairing.

Fixed.  This is now "must", the exact values are still SHOULD.

> I agree with the secdir reviewer that the link classification is
> important, and would suggest a that SHOULD become MUST for "if it is
> unable to determine whether a link is wired or wireless, it MUST
> make the worst-case hypothesis".

I most humbly disagree.  Babel is sufficiently robust to survive
misassignment, the consequence will be sub-optimal routing, and only if
mis-assignment happens on both ends of a wireless link, and only in
non-trivial topologies.

I think the consequences are sufficiently benign for us to afford leaving
some latitude to implementers.

> Section 4

> I always worry a little bit about the ability to classify links as
> "trusted", but there are probably cases where it's valid to do so.

I agree that HNCP edge detection is not satisfactory, but that's the best
we've got right now, and it's time we moved forward.  Hopefully the
security work will progress so that we can make crypto the default at some
point, thus making this issue moot, but I request that this document
should not be held up waiting for the security work to complete.

> I do wonder whether it's worth enumerating the "upper-layer security
> protocol"s that HNCP and Babel support, as there are tradeoffs among
> the PSK/PKI/TOFU options that the implementor may need to consider.

Since this document is intended for standards track, I worry that an
enumeration will be taken as exhaustive, and limit the choices of the WG.

-- Juliusz