Re: [jose] Stephen Farrell's Discuss on draft-ietf-jose-json-web-key-33: (with DISCUSS and COMMENT)

Mike Jones <Michael.Jones@microsoft.com> Tue, 07 October 2014 11:37 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 EA51E1A1B89; Tue, 7 Oct 2014 04:37:23 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.902
X-Spam-Level:
X-Spam-Status: No, score=-1.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, 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 To9Njr852VSa; Tue, 7 Oct 2014 04:37:21 -0700 (PDT)
Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1on0797.outbound.protection.outlook.com [IPv6:2a01:111:f400:fc10::797]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id D9F051A1B4E; Tue, 7 Oct 2014 04:37:20 -0700 (PDT)
Received: from CH1PR03CA008.namprd03.prod.outlook.com (10.255.156.153) by CY1PR0301MB0700.namprd03.prod.outlook.com (25.160.159.142) with Microsoft SMTP Server (TLS) id 15.0.1044.10; Tue, 7 Oct 2014 11:36:57 +0000
Received: from BY2FFO11FD026.protection.gbl (10.255.156.132) by CH1PR03CA008.outlook.office365.com (10.255.156.153) with Microsoft SMTP Server (TLS) id 15.0.1044.10 via Frontend Transport; Tue, 7 Oct 2014 11:36:56 +0000
Received: from mail.microsoft.com (131.107.125.37) by BY2FFO11FD026.mail.protection.outlook.com (10.1.15.215) with Microsoft SMTP Server (TLS) id 15.0.1039.16 via Frontend Transport; Tue, 7 Oct 2014 11:36:57 +0000
Received: from TK5EX14MBXC286.redmond.corp.microsoft.com ([169.254.1.93]) by TK5EX14MLTC104.redmond.corp.microsoft.com ([157.54.79.159]) with mapi id 14.03.0210.003; Tue, 7 Oct 2014 11:36:29 +0000
From: Mike Jones <Michael.Jones@microsoft.com>
To: Stephen Farrell <stephen.farrell@cs.tcd.ie>, Jim Schaad <ietf@augustcellars.com>, 'Ted Lemon' <Ted.Lemon@nominum.com>
Thread-Topic: [jose] Stephen Farrell's Discuss on draft-ietf-jose-json-web-key-33: (with DISCUSS and COMMENT)
Thread-Index: AQHP3jI0y2YQdh1++ku2NamIZ5KlrpwiPARQgAFPwQCAAAGVAIAADBaAgAAB+ACAAAMNgIAAAq0AgAA3FFCAABWNAIAAAScggACEiYCAABXTsA==
Date: Tue, 7 Oct 2014 11:36:28 +0000
Message-ID: <4E1F6AAD24975D4BA5B16804296739439BAF43CC@TK5EX14MBXC286.redmond.corp.microsoft.com>
References: <20141002111501.6046.52416.idtracker@ietfa.amsl.com> <4E1F6AAD24975D4BA5B16804296739439BAF0C1E@TK5EX14MBXC286.redmond.corp.microsoft.com> <00c601cfe1a4$15d32900$41797b00$@augustcellars.com> <7ABF79CB-61C8-490B-A727-465530222F0B@nominum.com> <00dd01cfe1aa$eba7db10$c2f79130$@augustcellars.com> <54330888.4090605@cs.tcd.ie> <00f101cfe1ad$6dc9fea0$495dfbe0$@augustcellars.com> <54330D56.507@cs.tcd.ie> <4E1F6AAD24975D4BA5B16804296739439BAF2783@TK5EX14MBXC286.redmond.corp.microsoft.com> <011b01cfe1d5$17f6d610$47e48230$@augustcellars.com> <4E1F6AAD24975D4BA5B16804296739439BAF321C@TK5EX14MBXC286.redmond.corp.microsoft.com> <5433BDC3.2050404@cs.tcd.ie>
In-Reply-To: <5433BDC3.2050404@cs.tcd.ie>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [157.54.51.33]
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-EOPAttributedMessage: 0
X-Forefront-Antispam-Report: CIP:131.107.125.37; CTRY:US; IPV:CAL; IPV:NLI; IPV:NLI; EFV:NLI; SFV:NSPM; SFS:(10019020)(6009001)(438002)(51704005)(13464003)(189002)(479174003)(377454003)(199003)(24454002)(104016003)(77096002)(85852003)(55846006)(47776003)(20776003)(97736003)(76176999)(54356999)(31966008)(87936001)(66066001)(85806002)(84676001)(92566001)(86362001)(2656002)(80022003)(46102003)(50986999)(64706001)(26826002)(44976005)(86612001)(19580395003)(68736004)(6806004)(33656002)(69596002)(23676002)(4396001)(106466001)(81156004)(106116001)(92726001)(120916001)(21056001)(19580405001)(107046002)(99396003)(95666004)(85306004)(76482002)(50466002)(230783001)(93886004); DIR:OUT; SFP:1102; SCL:1; SRVR:CY1PR0301MB0700; H:mail.microsoft.com; FPR:; MLV:ovrnspm; PTR:InfoDomainNonexistent; MX:1; A:1; LANG:en;
X-Microsoft-Antispam: UriScan:;
X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:CY1PR0301MB0700;
X-O365ENT-EOP-Header: Message processed by - O365_ENT: Allow from ranges (Engineering ONLY)
X-Forefront-PRVS: 035748864E
Received-SPF: Pass (protection.outlook.com: domain of microsoft.com designates 131.107.125.37 as permitted sender) receiver=protection.outlook.com; client-ip=131.107.125.37; helo=mail.microsoft.com;
Authentication-Results: spf=pass (sender IP is 131.107.125.37) smtp.mailfrom=Michael.Jones@microsoft.com;
X-OriginatorOrg: microsoft.onmicrosoft.com
Archived-At: http://mailarchive.ietf.org/arch/msg/jose/YsXvP51wAz6IdFE8CqzLpRSd5o8
Cc: "jose-chairs@tools.ietf.org" <jose-chairs@tools.ietf.org>, "draft-ietf-jose-json-web-key@tools.ietf.org" <draft-ietf-jose-json-web-key@tools.ietf.org>, 'The IESG' <iesg@ietf.org>, "jose@ietf.org" <jose@ietf.org>
Subject: Re: [jose] Stephen Farrell's Discuss on draft-ietf-jose-json-web-key-33: (with DISCUSS and COMMENT)
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: <http://www.ietf.org/mail-archive/web/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: Tue, 07 Oct 2014 11:37:24 -0000

> -----Original Message-----
> From: Stephen Farrell [mailto:stephen.farrell@cs.tcd.ie]
> Sent: Tuesday, October 07, 2014 3:18 AM
> To: Mike Jones; Jim Schaad; 'Ted Lemon'
> Cc: jose-chairs@tools.ietf.org; draft-ietf-jose-json-web-key@tools.ietf.org; 'The
> IESG'; jose@ietf.org
> Subject: Re: [jose] Stephen Farrell's Discuss on draft-ietf-jose-json-web-key-33:
> (with DISCUSS and COMMENT)
> 
> 
> 
> On 07/10/14 03:23, Mike Jones wrote:
> >> -----Original Message-----
> >> From: Jim Schaad [mailto:ietf@augustcellars.com]
> >> Sent: Monday, October 06, 2014 7:19 PM
> >> To: Mike Jones; 'Stephen Farrell'; 'Ted Lemon'
> >> Cc: jose-chairs@tools.ietf.org; 'The IESG'; jose@ietf.org;
> >> draft-ietf-jose-json- web-key@tools.ietf.org
> >> Subject: RE: [jose] Stephen Farrell's Discuss on draft-ietf-jose-json-web-key-
> 33:
> >> (with DISCUSS and COMMENT)
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: Mike Jones [mailto:Michael.Jones@microsoft.com]
> >>> Sent: Monday, October 06, 2014 6:12 PM
> >>> To: Stephen Farrell; Jim Schaad; 'Ted Lemon'
> >>> Cc: jose-chairs@tools.ietf.org; 'The IESG'; jose@ietf.org;
> >>> draft-ietf-jose-json- web-key@tools.ietf.org
> >>> Subject: RE: [jose] Stephen Farrell's Discuss on
> >>> draft-ietf-jose-json-web-key-
> >>> 33: (with DISCUSS and COMMENT)
> >>>
> >>>>>>>>> I worry that if we starting providing guidance to DNS names,
> >>>>>>>>> then we need to worry about the I18N implications.  I don't
> >>>>>>>>> remember if these are both case sensitive and easy to do the
> >>>>>>>>> case conversion on.
> >>>>>>>>
> >>>>>>>> Isn't this a solved problem?   You convert to the unicode
> >>>>>>>> presentation and then convert to the canonical case as defined
> >>>>>>>> in the unicode standard.
> >>>>>>> The
> >>>>>>>> worst case scenario is that you encounter some script where
> >>>>>>>> this rule
> >>>>>>> doesn't
> >>>>>>>> work, and that script is then in the position that all scripts
> >>>>>>>> are in now.
> >>>>>>>
> >>>>>>> It may be it is, however this makes an assumption that clients
> >>>>>>> are up on how to do this.  I.e. that JavaScript is going to do
> >>>>>>> it right when I do a strlower function on a string.  I don't
> >>>>>>> know that this is really the case. I would hope so but am unsure.
> >>>>>>
> >>>>>> So we're talking about key ids here. In most case where those
> >>>>>> would use DNS names, the code that creates the key id would know
> >>>>>> what its doing and dumber code would be presented with the key id
> >>>>>> and would not have to do the tolower().
> >>>>>>
> >>>>>> So I would say its safe to add something like "When creating a
> >>>>>> key id, if the code doing so is aware that it is dealing with a
> >>>>>> DNS name, then that code should tolower() the DNS name before
> >>>>>> including those bytes in the key id."
> >>>>>
> >>>>> Yes, but if that is the case, then why does it need to be
> >>>>> lower-cased at all?  If I say my key id is "JimSchaad.foobar" and
> >>>>> that is my DNS address why does it need to be lowercased? Jim
> >>>>
> >>>> Because there will be cases where two different implementations
> >>>> with code try to create the same key id from its components and get
> >>>> it wrong otherwise. Not all cases, but some.
> >>>>
> >>>> S.
> >>>
> >>> All of this is making me think that saying anything specifically
> >>> about the use of DNS names in Key IDs is opening up a can of worms -
> >>> particularly
> >> I18N worms.
> >>> ;-)
> >>>
> >>> In my initial response, I'd proposed that we add more generic text
> >>> like the following.  Would that work for you, Stephen?
> >>>
> >>> "If case-insensitive values, such as DNS names, are included in "kid"
> >>> values, then the application specifying their inclusion needs to
> >>> define a canonical case-sensitive representation to use for the
> >>> case-insensitive portions inside the "kid", such as lowercasing them."
> >>>
> >>> 				-- Mike
> >>
> >> In cases where applications assign semantics to the kid field,
> >> applications may need to define canonicalization routines for these
> >> values.  For example, if DNS names are to be used as a "kid" value,
> >> then it applications should probably specify that it be converted to lowercase
> before using it as a value.
> >>
> >> I kind of like using the assumption that this is important only when
> >> applications assign semantics to the field.  Otherwise it is just
> >> going to be some random string.
> >
> > I agree - thanks Jim.
> 
> I disagree. There is no assignment of semantics if two different implementations
> are written to read a DNS name from somewhere and then use that as part of a
> kid. The issue is nothing to do with semantics but all do to with whether those
> two chunks of code both do or do not include a tolower() call.
> 
> The text suggested above is almost ok however, but I'd prefer it more like:
> 
>    If case-insensitive values, such as DNS names, are included
>    in "kid" values, then the application including those needs
>    to ensure that a canonical case-sensitive representation is
>    used as otherwise different implementations will be highly
>    likely to suffer interoperability problems. In the case of
>    DNS names, the common approach taken is lowercasing."
> 
> I'd prefer "SHOULD be lowercased" myself but can live with the above.

Works for me.

> S.

				-- Mike