Re: [secdir] secdir review of draft-ietf-isis-sbfd-discriminator-02

"Les Ginsberg (ginsberg)" <ginsberg@cisco.com> Wed, 18 November 2015 04:31 UTC

Return-Path: <ginsberg@cisco.com>
X-Original-To: secdir@ietfa.amsl.com
Delivered-To: secdir@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1FB251AC429; Tue, 17 Nov 2015 20:31:56 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -15.086
X-Spam-Level:
X-Spam-Status: No, score=-15.086 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-0.585, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] 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 GgNntX6MF6oq; Tue, 17 Nov 2015 20:31:54 -0800 (PST)
Received: from alln-iport-5.cisco.com (alln-iport-5.cisco.com [173.37.142.92]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id BF71D1AC425; Tue, 17 Nov 2015 20:31:54 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=2443; q=dns/txt; s=iport; t=1447821114; x=1449030714; h=from:to:subject:date:message-id:references:in-reply-to: content-transfer-encoding:mime-version; bh=QaqU088Vk7l+z28qhE6MWH0squ1PPeHiILDIyE+0KZA=; b=K5F4KL6tG9KU21Pp6v1Eux3KDDJKrTapWoUn6Vc7d5WRi6M0+5/CYhFX Prwm6wZqX5ABxuFghv40pe3/Ms3W8r9Tgxhv0/W0uhw97IUreUpsiNByV otkMqlxe3aMR3HTCdV8GJefTDjisyZrvvifFeLJg0cWT3hXeYP+oKzZcC w=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0D0AQCq/UtW/4UNJK1eDoMtgUIGvmEBD?= =?us-ascii?q?YFlhg8CgUs4FAEBAQEBAQGBCoQ0AQEBBDpLBAIBCA4DBAEBHwkHMhQJCAIEARI?= =?us-ascii?q?IiCa9WAEBAQEBAQEBAQEBAQEBAQEBAQEahlSEfok5BZJng2IBjSOcSwEfAQFCg?= =?us-ascii?q?0Y+cgGEBIEHAQEB?=
X-IronPort-AV: E=Sophos;i="5.20,311,1444694400"; d="scan'208";a="209339238"
Received: from alln-core-11.cisco.com ([173.36.13.133]) by alln-iport-5.cisco.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 18 Nov 2015 04:31:53 +0000
Received: from XCH-ALN-003.cisco.com (xch-aln-003.cisco.com [173.36.7.13]) by alln-core-11.cisco.com (8.14.5/8.14.5) with ESMTP id tAI4VrYs002131 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Wed, 18 Nov 2015 04:31:53 GMT
Received: from xch-aln-001.cisco.com (173.36.7.11) by XCH-ALN-003.cisco.com (173.36.7.13) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Tue, 17 Nov 2015 22:31:53 -0600
Received: from xch-aln-001.cisco.com ([173.36.7.11]) by XCH-ALN-001.cisco.com ([173.36.7.11]) with mapi id 15.00.1104.000; Tue, 17 Nov 2015 22:31:53 -0600
From: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
To: Tom Yu <tlyu@mit.edu>, "iesg@ietf.org" <iesg@ietf.org>, "secdir@ietf.org" <secdir@ietf.org>, "draft-ietf-isis-sbfd-discriminator.all@tools.ietf.org" <draft-ietf-isis-sbfd-discriminator.all@tools.ietf.org>
Thread-Topic: secdir review of draft-ietf-isis-sbfd-discriminator-02
Thread-Index: AQHRIa4iUTgfB7Eo3kutQLFKONAxpp6hL5qA
Date: Wed, 18 Nov 2015 04:31:53 +0000
Message-ID: <f13edbe3b383420b9f029361f4b81a3b@XCH-ALN-001.cisco.com>
References: <ldv4mgk2ehg.fsf@sarnath.mit.edu>
In-Reply-To: <ldv4mgk2ehg.fsf@sarnath.mit.edu>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.24.121.24]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: <http://mailarchive.ietf.org/arch/msg/secdir/NDB8-_Q70E_kizyAVLjJxdH9jnQ>
X-Mailman-Approved-At: Tue, 17 Nov 2015 23:10:35 -0800
Subject: Re: [secdir] secdir review of draft-ietf-isis-sbfd-discriminator-02
X-BeenThere: secdir@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Security Area Directorate <secdir.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/secdir>, <mailto:secdir-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/secdir/>
List-Post: <mailto:secdir@ietf.org>
List-Help: <mailto:secdir-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/secdir>, <mailto:secdir-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 18 Nov 2015 04:31:56 -0000

Tom -

Thanx for the review.

If you are not happy with the Security section of the base S-BFD draft it seems to me it makes the most sense to address any issues in that document. Trying to make up for any shortcomings in S-BFD draft by adding to  the IGP drafts (there is a similar OSPF S-BFD draft) when the IGPs are merely acting as a transport for opaque information (as you say) does not seem appropriate to me.

Can we close on this issue?

   Les


> -----Original Message-----
> From: Tom Yu [mailto:tlyu@mit.edu]
> Sent: Tuesday, November 17, 2015 7:06 PM
> To: iesg@ietf.org; secdir@ietf.org; draft-ietf-isis-sbfd-
> discriminator.all@tools.ietf.org
> Subject: secdir review of draft-ietf-isis-sbfd-discriminator-02
> 
> I have reviewed this document as part of the security directorate's ongoing
> effort to review all IETF documents being processed by the IESG.  These
> comments were written primarily for the benefit of the security area
> directors.  Document editors and WG chairs should treat these comments
> just like any other last call comments.
> 
> Summary: ready with nits
> 
> I agree with the first paragraph of the Security Considerations, in that I think
> it's unlikely that this document introduces security risks for IS-IS, which as I
> understand it, effectively transports the proposed S-BFD discriminators as an
> uninterpreted opaque payload.
> 
> The second paragraph
> 
>    Advertisement of the S-BFD discriminators does make it possible for
>    attackers to initiate S-BFD sessions using the advertised
>    information.  The vulnerabilities this poses and how to mitigate them
>    are discussed in the Security Considerations section of [S-BFD].
> 
> refers to the Security Considerations of the [S-BFD] base document.  The [S-
> BFD] Security Considerations describe some strengthening practices, but
> doesn't seem to describe the vulnerabilities in significant detail.
> [S-BFD] Security Considerations seems to describe an attack where someone
> impersonates the responder, but not one where someone impersonates an
> initiator.
> 
> Other sections of [S-BFD] might imply the existence of this sort of
> vulnerability, but the Security considerations seems not to mention it
> explicitly.  I'm not sure whether it's best to leave things alone, revise this
> document, or revise [S-BFD].
> 
> -Tom