Re: Benjamin Kaduk's Discuss on draft-ietf-httpbis-header-structure-18: (with DISCUSS and COMMENT)

Benjamin Kaduk <kaduk@mit.edu> Wed, 20 May 2020 16:23 UTC

Return-Path: <ietf-http-wg-request+bounce-httpbisa-archive-bis2juki=lists.ie@listhub.w3.org>
X-Original-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Delivered-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 965D83A0C6E for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Wed, 20 May 2020 09:23:44 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.65
X-Spam-Level:
X-Spam-Status: No, score=-2.65 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, MAILING_LIST_MULTI=-1, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001] autolearn=unavailable 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 iNw1Baj_AOY9 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Wed, 20 May 2020 09:23:43 -0700 (PDT)
Received: from lyra.w3.org (lyra.w3.org [128.30.52.18]) (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 55BB93A0C6D for <httpbisa-archive-bis2Juki@lists.ietf.org>; Wed, 20 May 2020 09:23:43 -0700 (PDT)
Received: from lists by lyra.w3.org with local (Exim 4.92) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1jbRVD-0005Zj-50 for ietf-http-wg-dist@listhub.w3.org; Wed, 20 May 2020 16:23:31 +0000
Resent-Date: Wed, 20 May 2020 16:23:31 +0000
Resent-Message-Id: <E1jbRVD-0005Zj-50@lyra.w3.org>
Received: from titan.w3.org ([128.30.52.76]) by lyra.w3.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from <kaduk@mit.edu>) id 1jbRVC-0005Z1-Gi for ietf-http-wg@listhub.w3.org; Wed, 20 May 2020 16:23:30 +0000
Received: from outgoing-auth-1.mit.edu ([18.9.28.11] helo=outgoing.mit.edu) by titan.w3.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from <kaduk@mit.edu>) id 1jbRVA-0003AW-Uf for ietf-http-wg@w3.org; Wed, 20 May 2020 16:23:30 +0000
Received: from kduck.mit.edu ([24.16.140.251]) (authenticated bits=56) (User authenticated as kaduk@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 04KGN5aj002042 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 May 2020 12:23:07 -0400
Date: Wed, 20 May 2020 09:23:05 -0700
From: Benjamin Kaduk <kaduk@mit.edu>
To: Mark Nottingham <mnot@mnot.net>
Cc: The IESG <iesg@ietf.org>, draft-ietf-httpbis-header-structure@ietf.org, httpbis-chairs@ietf.org, HTTP Working Group <ietf-http-wg@w3.org>, Tommy Pauly <tpauly@apple.com>
Message-ID: <20200520162305.GA58497@kduck.mit.edu>
References: <158985680600.32294.14997877272521602557@ietfa.amsl.com> <CFC9B0CA-6125-4705-A13E-F2260F3EC3A5@mnot.net> <20200519170036.GN58497@kduck.mit.edu> <FB915609-4CD1-416A-98AD-3950BF3BE09C@mnot.net> <20200520153858.GZ58497@kduck.mit.edu>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20200520153858.GZ58497@kduck.mit.edu>
User-Agent: Mutt/1.12.1 (2019-06-15)
X-W3C-Hub-Spam-Status: No, score=-7.2
X-W3C-Hub-Spam-Report: BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, W3C_AA=-1, W3C_IRA=-1, W3C_WL=-1
X-W3C-Scan-Sig: titan.w3.org 1jbRVA-0003AW-Uf aee3e3af4f176398778c49ed3726a549
X-Original-To: ietf-http-wg@w3.org
Subject: Re: Benjamin Kaduk's Discuss on draft-ietf-httpbis-header-structure-18: (with DISCUSS and COMMENT)
Archived-At: <https://www.w3.org/mid/20200520162305.GA58497@kduck.mit.edu>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/37682
X-Loop: ietf-http-wg@w3.org
Resent-Sender: ietf-http-wg-request@w3.org
Precedence: list
List-Id: <ietf-http-wg.w3.org>
List-Help: <https://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>

On Wed, May 20, 2020 at 08:39:03AM -0700, Benjamin Kaduk wrote:
> 
> > >>> Section 6
> > >>> 
> > >>> It seems worth mentioning the handling for duplicated key names (e.g.,
> > >>> in parameters and dictionaries) w.r.t. overwrite or must-be-unique, and
> > >>> how there have been previous vulnerabilities relating to different
> > >>> implementations choosing "first one wins" vs. "last one wins".
> > >> 
> > >> That doesn't seem to apply to a correct implementation, only to headers that *aren't* structured fields.
> > > 
> > > It's still motivation for why we are making the choices we did and a
> > > benefit that structured headers have over the existing mechanisms.
> > 
> > Right, but that doesn't seem appropriate in Security Considerations; it's more Introduction / motivating material.
> > 
> > > Also, it seems to explicitly apply to parameter map keys (per the earlier
> > > discussion).
> > 
> > I've added a note to this effect in the Dictionary and Parameter parsing algorithms; see latest commit.

Hmm, the note says this discards duplicates after the first one, but the
procedures say to overwrite an existing value.  Shouldn't the note say
something else?

-Ben