[secdir] secdir review of draft-ietf-tcpm-tcpmss-04

Klaas Wierenga <klaas@cisco.com> Wed, 30 May 2012 15:05 UTC

Return-Path: <klaas@cisco.com>
X-Original-To: secdir@ietfa.amsl.com
Delivered-To: secdir@ietfa.amsl.com
Received: from localhost (localhost []) by ietfa.amsl.com (Postfix) with ESMTP id 98A0E21F8672; Wed, 30 May 2012 08:05:25 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.243
X-Spam-Status: No, score=-10.243 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8, SARE_SUB_6CONS_WORD=0.356]
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id BAoPXFMYslvk; Wed, 30 May 2012 08:05:24 -0700 (PDT)
Received: from rcdn-iport-7.cisco.com (rcdn-iport-7.cisco.com []) by ietfa.amsl.com (Postfix) with ESMTP id B612021F8671; Wed, 30 May 2012 08:05:24 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=klaas@cisco.com; l=1689; q=dns/txt; s=iport; t=1338390324; x=1339599924; h=message-id:date:from:mime-version:to:subject: content-transfer-encoding; bh=7uKGvV6ccnKNxb2+p/wZPTKadSWOdesd23LbsfQKTIM=; b=S04j7TuvcA0CN0SU5dU4TA+ZrCAS2+5kKbd+/6NbxApyqh6RC5ZoKeRz Njw6ZvxseLtk+dw6wbdoXZhMKEdRfC2h04jOQwFwzeqydlMxNh6wCltgX FOnYBlSOYeqZ/sQGhI9gcdnacIP6/4u9eLnZT85IY80ymUue1mTjhbng1 g=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: Av0EACc2xk+tJV2b/2dsb2JhbABEtA2BB4IwAWU9FhgDAgECAUsBDAgBAR6HaZkRn3+QRwOVGIEPjH6BZoJi
X-IronPort-AV: E=Sophos;i="4.75,685,1330905600"; d="scan'208";a="87941284"
Received: from rcdn-core-4.cisco.com ([]) by rcdn-iport-7.cisco.com with ESMTP; 30 May 2012 15:05:24 +0000
Received: from macmini.wierenga.net (rtp-kwiereng-87110.cisco.com []) by rcdn-core-4.cisco.com (8.14.5/8.14.5) with ESMTP id q4UF5MSv031834; Wed, 30 May 2012 15:05:22 GMT
Message-ID: <4FC63731.7060409@cisco.com>
Date: Wed, 30 May 2012 17:05:21 +0200
From: Klaas Wierenga <klaas@cisco.com>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:12.0) Gecko/20120428 Thunderbird/12.0.1
MIME-Version: 1.0
To: The IESG <iesg@ietf.org>, secdir@ietf.org, draft-ietf-tcpm-tcpmss.all@tools.ietf.org
X-Enigmail-Version: 1.4.1
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
Subject: [secdir] secdir review of draft-ietf-tcpm-tcpmss-04
X-BeenThere: secdir@ietf.org
X-Mailman-Version: 2.1.12
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: <http://www.ietf.org/mail-archive/web/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, 30 May 2012 15:05:25 -0000

Hash: SHA1


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.

General comments:

This is a short, clear and to the point draft. I have only a few
general comments

1 (introduction)
- ----------------

- - Please expand MSS on first use

- - "(see appendix A)" and "but there still seems to be some confusion"

This sounds pretty vague to me. I thought Appendix A would be a
verbatim copy of the text from 1122, but it is much more, and I
appreciated the discussion. I propose to make that explicit:

"RFC1122 clarified the MSS option, but confusion remains as discussed
in Appendix A"

Security Considerations:
I don't really think what you have written down here qualifies as
security considerations. It sort of hints to a denial-of-service, but
I don't see any evil, just an operational problem. What I wonder about
(but I am not knowledgable to judge) is whether wrong MSS size
settings could be exploited for for example buffer overflow attacks.


Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
Comment: GPGTools - http://gpgtools.org
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/