CBOR Web Token (CWT) Claims in COSE Headers
draft-ietf-cose-cwt-claims-in-headers-10

[Ballot comment]
It may be that I'm unfamiliar with this aspect of COSE, but I note that Section 2 says:

"The following is a non-normative description for the value type of the CWT claim header parameter using CDDL [RFC8610]."

It's curious to have a Standards Track document with only a non-normative description of the thing it purports to standardize.

[Ballot comment]
Thank you for the work on this document.

Many thanks to Claudio Allocchio for his ART ART review: https://mailarchive.ietf.org/arch/msg/art/kuLLKsPo04s22kyXIIV7AsKkgZM/, and to Carsten Bormann for his review and contribution to the text, following his review as IANA Designated Expert of the COSE Header Parameters registry.

[Ballot comment]
Thanks for working on this specification. No objection from transport point of view, however, I noticed the IANA is not OK at the time I was reviewing but the AD has assured the issues has been resolved, that means the IANA review is pending.

[Ballot comment]
# Éric Vyncke, INT AD, comments for draft-ietf-cose-cwt-claims-in-headers-09

Thank you for the work put into this document.

Please find below one non-blocking COMMENT points.

Special thanks to Orie Steele for the shepherd's detailed write-up including the WG consensus *but it lacks* the justification of the intended status.

Other thanks to Hannes Tschofenig, the IoT directorate reviewer (at my request), please consider this int-dir review:
https://datatracker.ietf.org/doc/review-ietf-cose-cwt-claims-in-headers-07-iotdir-telechat-tschofenig-2023-10-31/ (and I have read the email discussions with the authors, thanks to all)

I hope that this review helps to improve the document,

Regards,

-éric


# COMMENTS (non-blocking)


## Section 3

Is there a reason for using a non-normative "should" in `applications and protocols using them *should* ensure that these COSE objects are only made visible` ?

[Ballot comment]
Thank you to Peter Yee for the SECDIR Review.

Thank you to Hannes Tschofenig for the security-focused IOTDIR review, and to the WG for discussing and resolving this feedback.

I have a major issue with this registration: this is basically a duplicate of an existing registration, called "kccs". "kccs" is described as follows:


> A CWT Claims Set (CCS) containing a COSE_Key in a 'cnf' claim and possibly other claims. CCS is defined in [RFC8392].



If my understanding is correct, this is almost exactly what draft-ietf-cose-cwt-claims-in-headers wants, with the exception that draft-ietf-cose-cwt-claims-in-headers doesn't give any specification about which claims are included. I believe registering another parameter, as requested by draft-ietf-cose-cwt-claims-in-headers, goes against the guidance given by the Expert Review Instructions of RFC 9052, Section 11.6:



> Reviewers are encouraged to get sufficient information for registration requests to ensure that the usage is not going to duplicate an existing registration



I note that "kccs" is registered by the EDHOC document in lake: https://datatracker.ietf.org/doc/draft-ietf-lake-edhoc/ which is not yet published (it is however in EDIT state in the RFC Editor queue). I suggest that that document's COSE Header Parameter is changed so that the description is more general and cover this case as well.



This could be done by a small change of the name "kccs" to "ccs" and the following change in the description:



OLD

A CWT Claims Set (CCS) containing a COSE_Key in a 'cnf' claim and possibly other claims. CCS is defined in [RFC8392].

NEW

A CWT Claims Set (CCS) as defined in [RFC8392].



(And if that is done, I suggest the same modification is done for "kcwt").



Then draft-ietf-cose-cwt-claims-in-headers would not need to be published at all.

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-cose-cwt-claims-in-headers-06. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there is a single action which we must complete.

In the COSE Header Parameters registry in the CBOR Object Signing and Encryption (COSE) registry group located at:

https://www.iana.org/assignments/cose/

a single new registration is to be made as follows:

Name: CWT Claims
Label: [ TBD-at-Registration ]
Value Type: map
Value Registry: [ TBD-at-Registration ]
Description: location for CWT Claims in COSE Header Parameters
Reference: [ RFC-to-be ]

We note that the authors have requested label 13, which has already been registered by another assignment. Assuming that the authors would like the next available label in this range (15 currently), this will require Expert Review; we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

We understand that this is the only action required to be completed upon approval of this document.

NOTE: The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2023-10-20):

From: The IESG
To: IETF-Announce
CC: cose-chairs@ietf.org, cose@ietf.org, draft-ietf-cose-cwt-claims-in-headers@ietf.org, mprorock@mesur.io, orie@transmute.industries, paul.wouters@aiven.io
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (CBOR Web Token (CWT) Claims in COSE Headers) to Proposed Standard


The IESG has received a request from the CBOR Object Signing and Encryption
WG (cose) to consider the following document: - 'CBOR Web Token (CWT) Claims
in COSE Headers'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2023-10-20. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document describes how to include CBOR Web Token (CWT) claims in
  the header parameters of any COSE structure.  This functionality
  helps to facilitate applications that wish to make use of CBOR Web
  Token (CWT) claims in encrypted COSE structures and/or COSE
  structures featuring detached signatures, while having some of those
  claims be available before decryption and/or without inspecting the
  detached payload.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-cose-cwt-claims-in-headers/



No IPR declarations have been submitted directly on this I-D.

Document Shepherd Write-Up for https://datatracker.ietf.org/doc/draft-ietf-cose-cwt-claims-in-headers
Based on: https://datatracker.ietf.org/doc/shepherdwriteup-template/workinggroup

Document History
1. Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?

The document received good feedback on the mailing list. It seems well supported by the working group.

2. Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?

There were no major controversies. The document is very simple.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)

I am not aware of any discontent regarding the document.

4. For protocol documents, are there existing implementations of the contents of
the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as RFC 7942 recommends) or elsewhere
(where)?

I am not aware of any implementations of this specific document, but many implementations of COSE headers exist, in particular:

- https://github.com/erdtman/cose-js
- https://github.com/veraison/go-cose  (plans to implement)
- https://github.com/transmute-industries/cose  (plans to implement)
Additional Reviews
  5. Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.

Yes, this document is particularly relevant to RATS, SCITT and OAUTH at IETF and VCWG at W3C. It’s clear from discussions on the list that reviews have taken place from members who are active in these groups.

However the data tracker does not contain any directorate related reviews.

I don’t believe it is necessary to obtain additional reviews.

  6. Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A

  7. If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in RFC 8342?

N/A

  8. Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.

There is only a small fragment of CDDL and it is very similar to the examples described in https://datatracker.ietf.org/doc/draft-ietf-rats-eat/
Document Shepherd Checks
      9. Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?

Yes

      10. Several IETF Areas have assembled lists of common issues that their
reviewers encounter. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
reviews?

The tracker does not document reviews formally, but it's clear from the list discussions that there were reviews from OAUTH and RATS members. I don’t believe additional reviews are necessary.

      11. What type of RFC publication is being requested on the IETF stream (Best
Current Practice, Proposed Standard, Internet Standard,
Informational, Experimental or Historic)? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard, intended RFC status needs to be updated in data tracker.

      12. Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? To
the best of your knowledge, have all required disclosures been filed? If
not, explain why. If yes, summarize any relevant discussion, including links
to publicly-available messages when applicable.

I have asked the authors and they confirmed privately that they are not aware of any IPR disclosure obligations.

      13. Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.

Yes

      14. Document any remaining I-D nits in this document. Simply running the idnits
tool is not enough; please review the "Content Guidelines" on
authors.ietf.org. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)

I am not aware of any remaining I-D nits. The document is short and was easy to review manually.


      15. Should any informative references be normative or vice-versa? See the IESG
Statement on Normative and Informative References.

It's debatable if RFC8392 should be normative, but I don’t feel strongly that it should be.

      16. List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?

N/A

      17. Are there any normative downward references (see RFC 3967 and BCP
97) that are not already listed in the DOWNREF registry? If so,
list them.

None

      18. Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?

None

      19. Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.

The document does not update any existing RFCs.

      20. Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see RFC 8126).

This is the main point of the document. It seems clear to me, however a reservation entry being present in https://www.iana.org/assignments/cose/cose.xhtml#header-parameters might further clarify the intention. I’m not sure if that's possible for this specific registry.

      21. List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.

No new registries are requested.

Document Shepherd Write-Up for https://datatracker.ietf.org/doc/draft-ietf-cose-cwt-claims-in-headers
Based on: https://datatracker.ietf.org/doc/shepherdwriteup-template/workinggroup

Document History
1. Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?

The document received good feedback on the mailing list. It seems well supported by the working group.

2. Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?

There were no major controversies. The document is very simple.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)

I am not aware of any discontent regarding the document.

4. For protocol documents, are there existing implementations of the contents of
the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as RFC 7942 recommends) or elsewhere
(where)?

I am not aware of any implementations of this specific document, but many implementations of COSE headers exist, in particular:

- https://github.com/erdtman/cose-js
- https://github.com/veraison/go-cose  (plans to implement)
- https://github.com/transmute-industries/cose  (plans to implement)
Additional Reviews
  5. Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.

Yes, this document is particularly relevant to RATS, SCITT and OAUTH at IETF and VCWG at W3C. It’s clear from discussions on the list that reviews have taken place from members who are active in these groups.

However the data tracker does not contain any directorate related reviews.

I don’t believe it is necessary to obtain additional reviews.

  6. Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A

  7. If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in RFC 8342?

N/A

  8. Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.

There is only a small fragment of CDDL and it is very similar to the examples described in https://datatracker.ietf.org/doc/draft-ietf-rats-eat/
Document Shepherd Checks
      9. Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?

Yes

      10. Several IETF Areas have assembled lists of common issues that their
reviewers encounter. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
reviews?

The tracker does not document reviews formally, but it's clear from the list discussions that there were reviews from OAUTH and RATS members. I don’t believe additional reviews are necessary.

      11. What type of RFC publication is being requested on the IETF stream (Best
Current Practice, Proposed Standard, Internet Standard,
Informational, Experimental or Historic)? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard, intended RFC status needs to be updated in data tracker.

      12. Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? To
the best of your knowledge, have all required disclosures been filed? If
not, explain why. If yes, summarize any relevant discussion, including links
to publicly-available messages when applicable.

I have asked the authors and they confirmed privately that they are not aware of any IPR disclosure obligations.

      13. Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.

Yes

      14. Document any remaining I-D nits in this document. Simply running the idnits
tool is not enough; please review the "Content Guidelines" on
authors.ietf.org. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)

I am not aware of any remaining I-D nits. The document is short and was easy to review manually.


      15. Should any informative references be normative or vice-versa? See the IESG
Statement on Normative and Informative References.

It's debatable if RFC8392 should be normative, but I don’t feel strongly that it should be.

      16. List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?

N/A

      17. Are there any normative downward references (see RFC 3967 and BCP
97) that are not already listed in the DOWNREF registry? If so,
list them.

None

      18. Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?

None

      19. Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.

The document does not update any existing RFCs.

      20. Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see RFC 8126).

This is the main point of the document. It seems clear to me, however a reservation entry being present in https://www.iana.org/assignments/cose/cose.xhtml#header-parameters might further clarify the intention. I’m not sure if that's possible for this specific registry.

      21. List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.

No new registries are requested.