Re: [Gen-art] [Ace] Genart last call review of draft-ietf-ace-oauth-params-06

elwynd <> Thu, 19 December 2019 20:24 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id A7E50120A96; Thu, 19 Dec 2019 12:24:00 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -4.194
X-Spam-Status: No, score=-4.194 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id VEWIVCR6hzfa; Thu, 19 Dec 2019 12:23:57 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id C36561200C7; Thu, 19 Dec 2019 12:23:56 -0800 (PST)
Received: from ([2001:8b0:bf:1:5532:6d1b:9399:b05b]) by with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from <>) id 1ii2Kx-0000RA-1P; Thu, 19 Dec 2019 20:23:55 +0000
Date: Thu, 19 Dec 2019 20:23:50 +0000
In-Reply-To: <>
Importance: normal
From: elwynd <>
To: Ludwig Seitz <>,
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary=""
Message-ID: <>
Archived-At: <>
Subject: Re: [Gen-art] [Ace] Genart last call review of draft-ietf-ace-oauth-params-06
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "GEN-ART: General Area Review Team" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Thu, 19 Dec 2019 20:24:01 -0000

Hi, Ludwig.Thanks for the prompt response.Regarding he major issue, I understand what the intention of the split was, but as far as early implementations are concerned, there is no such thing as a 'minimal breakage'; unless there is some cunning mechanism in the basic ace-oauth-authz protocol, changes to the structure of the items defined here will break the protocol.  One possibility that I could see is the addition of extra keys in the COSE_Key dictionary structure: In this case you could add some extra words (in the ace-oauth-authz document) to indicate that unrecognized keys should be ignored.  This is associated with the editorial comments I made about s3.1 that would allow any other keys to be present in the COSE_Key object structure.  Similarly, the obects defined here are effectively JSON/CBOR dictionaries.  The changes could be accomodated by adding comments in ace-oauth that extra keys in the items defined would be ignored.  In my opinion, it would be best to remove the comments about possible changes and just state that they have been separated out because they might be used in other contexts.  The possible 'changes to the definitions' issue is just a matter of 'institutional memory'.  If there is some mechanism, such as I mentioned above, to accommodate changes without neeeding an update to the ace-oauth-authz (or other protocols using these items), this should be explained.Regarding the h vs b64 representations, since they are only examples (and the strings are essentially arbitrary as the actual keys aren't in the document), I'd be inclined to put in h representations to avoid my question arisng.   Otherwise I think we are done.Cheers and best wishes for the Festive Season,ElwynSent from Samsung tablet.
-------- Original message --------From: Ludwig Seitz <> Date: 17/12/2019  16:53  (GMT+00:00) To: Cc:,, Subject: Re: [Gen-art] [Ace] Genart last call review of
  draft-ietf-ace-oauth-params-06 Hello Elwyn,thank you for your review. Comments inline./LudwigOn 2019-12-14 23:46, Elwyn Davies via Datatracker wrote:> Reviewer: Elwyn Davies> Review result: Not Ready>> 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>> <>.>> Document: draft-ietf-ace-oauth-params-06> Reviewer: Elwyn Davies> Review Date: 2019-12-14> IETF LC End Date: 2019-12-13> IESG Telechat date: Not scheduled for a telechat>> 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>> <">>;.>> Document: draft-ietf-ace-oauth-params-06> Reviewer: Elwyn Davies> Review Date: 2019/12/14> IETF LC End Date: 2019/2/13> IESG Telechat date: (if known) N/A>> Summary: Not ready.  In particular there seems to be some doubt as to whether> the definitions in this document are actually stable - or alternatively that it> lacks a versioning mechanism to cope with changes that the might be.>> Major issues:> Dealing with possible updates to items defined here:> In s1 the following appears:>>      These parameters and claims can also be used in other contexts, and may>      need to be updated to align them with ongoing OAuth work. Therefore, these>      parameters and claims have been put into a dedicated document, to>      facilitate their use and any potential updates in a manner independent of>      [I-D.ietf-ace-oauth-authz].>> I am unclear whether this implies that it is intended that these potential> updates would alter the definitions here after they have been standardized or> alternatively that the standardization of this document should be delayed until> the alternative usage is defined.  If the first case applies, I do not see any> versioning mechanism that would allow early implementations to cope with later> updates of the items defined here.  In the second case, I have to ask myself> why this document has been submitted for standardization before the usages have> stabilized.>The intention with this document was to place certain parameters(req_cnf, cnf, rs_cnf) needed for draft-ietf-ace-oauth-authz into aseparate document, that could be updated or obsoleted by other draftswithout obsoleting or updating draft-ietf-ace-oauth-authz.This is mainly due to some work in the OAuth WG which has been runningin parallel, especially this is not a high priority item for OAuth (the draft named abovehas expired), the feeling in ACE was (@ACE please correct me if Imisrepresent) that going forward with this document was a goodcompromise to get these parameters standardized, while causing minimalbreakage if OAuth at some later point finalized the pop key distributionwork.> Minor issues:> ss3.1, 3.2 and 4.1:  The COSE_Key type 'EC' used in several kty fields is not> defined.  I assume it should be 'EC2'.>Correct, will fix> ss3.1, 3.2 and 4.1:  Does it matter that the definitions of the x and y> parameters in an EC2 key are given as 'h' encodings in RFC8152 but are given as> 'b64' in this document?  I am very much not an expert here.This is just a matter of the diagnostic representation used here forhuman readability. On the wire this will be the same binary string.Note that the hex encoding h'....' renders a much longer string than theBase64 encoding b64'...' so I prefer b64 for readability.>> s6: This section starts with 'If CBOR is used...': The main ACE draft> draft-ietf-ace-oauth-authz is apparently intended to cover both JSON and CBOR> encodings of payloads, although CBOR is recommended.  This is not made explicit> in this addition to that specification and the use of CBOR diagnostic> representation and the prominence of COSE_Key items could make it appear up> until s6 that this specification is intended just for CBOR encoding.  A few> words at the beginning would clarify the dual alternatives.>I will add a clarification. The intention is to cover both JSON and CBOR.> Nits/editorial comments:Will fix.> General: s/e.g./e.g.,/ (3 places)>> Abstract, 2nd sentence: s/whishes/wishes/>> Abstract: Need to expand AS and RS.>> s2:  RS, AS and (probably) various other terms are defined in RFC 6749 and need> to be expanded on  first use.  Adding something like the para from> draft-ietf-ace-oauth-authz would solve this (except for the abstract).>>      Terminology for entities in the architecture is defined in OAuth 2.0>      [RFC6749] such as client (C), resource server (RS), and authorization>      server (AS).s2, para 3: Need to expand CoAP on first use.>> s3:  This section needs a reference to RFC 8152 for the specification of the> CWT COSE_Key item that is used extensively.>> s3/s4: Some introductory text for each section is desirable.>> s3.1, para 2 (definition of req_cnf):: Possibly add a note that the> recommendation against symmetric keys implies currently kty being 'Symmetric'.> Will it ever be anything else?>> s3.1:  The text in s3.2 of draft-ietf-ace-cwt-proof-of-possession-03 contans> the following>>     The COSE_Key MUST contain the required key members for a COSE_Key of that>     key type and MAY contain other COSE_Key members, including the "kid" (Key>     ID) member.>>     The "COSE_Key" member MAY also be used for a COSE_Key representing a>     symmetric key, provided that the CWT is encrypted so that the key is not>     revealed to unintended parties. The means of encrypting a CWT is explained>     in [RFC8392]. If the CWT is not encrypted, the symmetric key MUST be>     encrypted as described in Section 3.3.>> These riders probably apply to all the subsectons of s3 and to s4.1 and could> be included in the currently empty main section text.>> s4.1, rs_cnf - DTLS-RPK: This term needs a reference (RFC 7250). Also all other> uses do not hyphenate and RPK needs to be expanded.>     s/DTLS-RPK handshake/DTLS Raw Public Key (RPK) handshake [RFC7250]/>>> _______________________________________________> Ace mailing list>>>_______________________________________________Gen-art mailing listGen-art@ietf.org