Re: [jose] Gen-Art LC review: draft-ietf-jose-jws-signing-input-options-06

Mike Jones <Michael.Jones@microsoft.com> Sun, 13 December 2015 05:24 UTC

Return-Path: <Michael.Jones@microsoft.com>
X-Original-To: jose@ietfa.amsl.com
Delivered-To: jose@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C1CE61AC39C; Sat, 12 Dec 2015 21:24:46 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.002
X-Spam-Level:
X-Spam-Status: No, score=-2.002 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_NONE=-0.0001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] 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 v-BEb-cEVcIG; Sat, 12 Dec 2015 21:24:42 -0800 (PST)
Received: from na01-bl2-obe.outbound.protection.outlook.com (mail-bl2on0111.outbound.protection.outlook.com [65.55.169.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 007031ABD3E; Sat, 12 Dec 2015 21:24:41 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=selector1; h=From:To:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=jcO2kXoioVbVpf3KyughqXLtd27GzwR4l66y69Fe/Pc=; b=AH7J1vGbGP3IxQx+g5+r3GSenecBVZ1un+4qIr3S+LDpuqrt5v7O2eXU3RGG+pSXrz1cnRieW2CwuShuqTm4XkRFWQyYxiFJWWwyfpWP/Kz1wXYAAKyHobCBMEd3ifWFpFOsUxSi2geZLTMEtQywPe33yXf5T2zyT8TClVOSGXA=
Received: from BY2PR03MB442.namprd03.prod.outlook.com (10.141.141.145) by BY2PR03MB442.namprd03.prod.outlook.com (10.141.141.145) with Microsoft SMTP Server (TLS) id 15.1.355.16; Sun, 13 Dec 2015 05:24:37 +0000
Received: from BY2PR03MB442.namprd03.prod.outlook.com ([10.141.141.145]) by BY2PR03MB442.namprd03.prod.outlook.com ([10.141.141.145]) with mapi id 15.01.0355.012; Sun, 13 Dec 2015 05:24:37 +0000
From: Mike Jones <Michael.Jones@microsoft.com>
To: Jim Schaad <ietf@augustcellars.com>, 'Robert Sparks' <rjsparks@nostrum.com>, 'General Area Review Team' <gen-art@ietf.org>, "ietf@ietf.org" <ietf@ietf.org>, "jose@ietf.org" <jose@ietf.org>, "draft-ietf-jose-jws-signing-input-options@ietf.org" <draft-ietf-jose-jws-signing-input-options@ietf.org>
Thread-Topic: [jose] Gen-Art LC review: draft-ietf-jose-jws-signing-input-options-06
Thread-Index: AQHRNWSs/Gcqi23qp0uKS19nw77Ev57IX8HQ
Date: Sun, 13 Dec 2015 05:24:37 +0000
Message-ID: <BY2PR03MB442CE011B790A802AF470E7F5EC0@BY2PR03MB442.namprd03.prod.outlook.com>
References: <5661E491.9050007@nostrum.com> <BY2PR03MB442B4D7B1E70A9957D43590F5EC0@BY2PR03MB442.namprd03.prod.outlook.com> <04f801d13564$4711ddd0$d5359970$@augustcellars.com>
In-Reply-To: <04f801d13564$4711ddd0$d5359970$@augustcellars.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
authentication-results: spf=none (sender IP is ) smtp.mailfrom=Michael.Jones@microsoft.com;
x-originating-ip: [12.130.119.128]
x-microsoft-exchange-diagnostics: 1; BY2PR03MB442; 5:FSnrJ24FQ4F7dfyxBcHA8zN7LzgrSSSAFERWzJ1Zyplhva5tHZiH3Sz+Pvx9y2JBTrRpkEniyzWOSkujYafOuLTMgB8m9taff1ynQh27wys8d9wEj5qbQwfnGt8opRN7Vjv8jsqxbyOHzMjHd6KRcw==; 24:+aHoDV40e3mb1qv0ecORTLcpI+Nu/iiNqDZ0uSpkmh+kzoqq/gTewXo210j5+w8Tj5cG3s2oNk4TPw7tFvhvKehn8iqt9uEOFS2wLbHO7Co=
x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:BY2PR03MB442;
x-microsoft-antispam-prvs: <BY2PR03MB442D55975E0D0A8A4E8C626F5EC0@BY2PR03MB442.namprd03.prod.outlook.com>
x-exchange-antispam-report-test: UriScan:;
x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:(61425038)(601004)(2401047)(5005006)(520078)(8121501046)(3002001)(10201501046)(61426038)(61427038); SRVR:BY2PR03MB442; BCL:0; PCL:0; RULEID:; SRVR:BY2PR03MB442;
x-forefront-prvs: 07891BF289
x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(6009001)(51914003)(13464003)(199003)(43784003)(189002)(377454003)(51444003)(66066001)(92566002)(5008740100001)(54356999)(2950100001)(15975445007)(2900100001)(87936001)(2501003)(76576001)(77096005)(6116002)(102836003)(3846002)(122556002)(1220700001)(586003)(1096002)(40100003)(86612001)(50986999)(189998001)(97736004)(5001770100001)(81156007)(107886002)(101416001)(33656002)(5001960100002)(2201001)(5002640100001)(11100500001)(106356001)(106116001)(76176999)(105586002)(99286002)(74316001)(19580395003)(230783001)(10090500001)(19580405001)(5003600100002)(10290500002)(8990500004)(5005710100001)(86362001)(5004730100002)(10400500002); DIR:OUT; SFP:1102; SCL:1; SRVR:BY2PR03MB442; H:BY2PR03MB442.namprd03.prod.outlook.com; FPR:; SPF:None; PTR:InfoNoRecords; A:1; MX:1; LANG:en;
received-spf: None (protection.outlook.com: microsoft.com does not designate permitted sender hosts)
spamdiagnosticoutput: 1:23
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: microsoft.com
X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Dec 2015 05:24:37.4975 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY2PR03MB442
Archived-At: <http://mailarchive.ietf.org/arch/msg/jose/6GGz_XGOmW1Zk9iKcIu-TF4gOgs>
Subject: Re: [jose] Gen-Art LC review: draft-ietf-jose-jws-signing-input-options-06
X-BeenThere: jose@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Javascript Object Signing and Encryption <jose.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/jose>, <mailto:jose-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/jose/>
List-Post: <mailto:jose@ietf.org>
List-Help: <mailto:jose-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/jose>, <mailto:jose-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 13 Dec 2015 05:24:47 -0000

Yes, you can make it fail if you're using library not supporting the extension by using "crit".  The spec already says that and the new paragraph goes into it further.  But using library not supporting functionality needed by the application seems like a pretty poor choice - all-up.  This is something that would be caught during debugging - well before production deployment.

If the application needs support for "b64":false to work correctly and doesn't have it, the application will be broken and is incorrect, no matter what, just like it would if it didn't have an implementation of RFC 7515 at all.  Yes, particular applications can send "crit":["b64"] if they want to guarantee a particular kind of failure if the recipient is incorrectly implemented but has a working implementation of RFC 7515, but that seems like a real corner case - nonetheless, one that is already covered in the specification, should applications want to achieve that.

I'm not aware of any cases that aren't already covered - especially once the new paragraph is added.

				-- Mike

-----Original Message-----
From: Jim Schaad [mailto:ietf@augustcellars.com] 
Sent: Saturday, December 12, 2015 9:08 PM
To: Mike Jones <Michael.Jones@microsoft.com>om>; 'Robert Sparks' <rjsparks@nostrum.com>om>; 'General Area Review Team' <gen-art@ietf.org>rg>; ietf@ietf.org; jose@ietf.org; draft-ietf-jose-jws-signing-input-options@ietf.org
Subject: RE: [jose] Gen-Art LC review: draft-ietf-jose-jws-signing-input-options-06

Mike,

I think that the text is somewhat tone deaf to the issue that Robert raises, and which I have said many times.

The question is not how to I make sure it will work, but how do I make sure that it will fail when it is not supposed to work.  Use of 'crit' does that quite well.  It is not clear that your favored method 1 would do this.

Jim


> -----Original Message-----
> From: jose [mailto:jose-bounces@ietf.org] On Behalf Of Mike Jones
> Sent: Saturday, December 12, 2015 6:33 PM
> To: Robert Sparks <rjsparks@nostrum.com>om>; General Area Review Team 
> <gen- art@ietf.org>gt;; ietf@ietf.org; jose@ietf.org;
draft-ietf-jose-jws-signing-input-
> options@ietf.org
> Subject: Re: [jose] Gen-Art LC review:
draft-ietf-jose-jws-signing-input-options-
> 06
> 
> Hi Robert.  Thanks for the useful review.  Replies are inline below...
> 
> > -----Original Message-----
> > From: Robert Sparks [mailto:rjsparks@nostrum.com]
> > Sent: Friday, December 4, 2015 11:08 AM
> > To: General Area Review Team <gen-art@ietf.org>rg>; ietf@ietf.org; 
> > jose@ietf.org; draft-ietf-jose-jws-signing-input-options@ietf.org
> > Subject: Gen-Art LC review:
> > draft-ietf-jose-jws-signing-input-options-06
> >
> > I am the assigned Gen-ART reviewer for this draft. The General Area 
> > Review Team (Gen-ART) reviews all IETF documents being processed by 
> > the IESG for the IETF Chair.  Please treat these comments just like 
> > any other last call comments.
> >
> > For more information, please see the FAQ at
> >
> > <http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
> >
> > Document: draft-ietf-jose-jws-signing-input-options-06
> > Reviewer: Robert Sparks
> > Review Date: 4Dec2015
> > IETF LC End Date: 9Dec2015
> > IESG Telechat date: 17Dec2015
> >
> > Summary: Almost ready for publication as Proposed Standard, but with 
> > a minor issue that should be addressed before publication.
> >
> > Minor issues:
> >
> > This document explicitly provides a way for interoperability to 
> > fail, but does not motivate _why_ leaving this failure mode in the 
> > protocol is a good tradeoff.
> >
> > Specifically, as the security considerations section points out, it 
> > is possible for an existing implementation to receive a JWS that has 
> > b64=false, which it will ignore as an unknown parameter, and 
> > (however
> > unlikely) successfully decode the payload, and hence believe it has 
> > a valid JWS that is not what was sent.
> >
> > The idea that this failure can be avoided by making sure the 
> > endpoints all play nice through some unspecified agreement is dangerous.
> > Specifically, I don't think you can rule out the case that the JWS 
> > escapes the controlled set of actors you are positing in option 1 
> > from the list in the security considerations..
> >
> > I would have been much more comfortable with a consensus to require
'crit'.
> > (Count me in the rough if this proceeds with crit being optional).
> >
> > I assume there is a strong reason to allow for option 1. Please add 
> > the motivation for it to the draft, and consider adding a SHOULD use
'crit'
> > requirement if option 1 remains.
> 
> It's a reasonable request to have the draft say why "crit" isn't required.
My
> working draft adds the following new paragraph at the end of the 
> security considerations section to do this.  Unless I hear objections, 
> I'll plan on
publishing
> an updated draft with the paragraph shortly.
> 
> "Note that methods 2 and 3 are sufficient to cause JWSs using this
extension to
> be rejected by implementations not supporting this extension but they 
> are
not
> sufficient to enable JWSs using this extension to be successfully used 
> by applications. Thus, method 1 - requiring support for this extension 
> - is
the
> preferred approach and the only means for this extension to be 
> practically
useful
> to applications. Method 2 - requiring the use of <spanx 
> style="verb">crit</spanx> - while theoretically useful to ensure that
confusion
> between encoded and unencoded payloads cannot occur, is not 
> particularly useful in practice, since method 1 is still required for 
> the extension to
be usable.
> When method 1 is employed, method 2 doesn't add any value and since it 
> increases the size of the JWS, its use is not required by this
specification."
> 
> > Nits/editorial comments:
> >
> > In the security considerations, the last sentence of the first 
> > paragraph needs to be simplified. I suggest replacing it with:
> >
> > "It then becomes the responsibility of the application to ensure 
> > that payloads only contain characters that will not cause parsing 
> > problems for the serialization used, as described in Section 5. The 
> > application also incurs the responsibility to ensure that the 
> > payload will not be modified during retransmission.
> 
> I have simplified this in the manner that you suggested.
> 
> 				Thanks again,
> 				-- Mike
> _______________________________________________
> jose mailing list
> jose@ietf.org
> https://www.ietf.org/mailman/listinfo/jose