Session Date/Time: 28 Jan 2025 17:00

LAKE

Summary

This interim meeting of the LAKE Working Group covered updates on several adopted drafts (GREASE, ODS, AP-PROFILES, PSK), formalized the adoption of the LAKE-RA draft, and discussed planning for IETF 122. A significant announcement was the transition of co-chairmanship from Stephen Farrell to Renzo Comin.

Key Discussion Points

Co-chair Transition: Stephen Farrell stepped down as co-chair, and Renzo Comin officially joined as the new co-chair. The working group thanked Stephen for his contributions.
GREASE (draft-ietf-lake-grease) Update:
- The document was recently adopted. Its purpose is to exercise EDHOC extension points to prevent them from becoming ossified.
- Two main questions arose during the adoption call:
  1. Whether better mechanisms can be implemented for greasing cipher suites, especially given that only the initiator might be a constrained device. The current protocol simplicity might limit flexibility here.
  2. How to exercise the extension point for ad-hoc authentication credential types within a COSE header map. Uncertainty exists regarding the semantics of unknown items in COSE header maps – specifically, if they are mandatory to understand or can be ignored by default. If they cannot be ignored, greasing would break functionality, defeating its purpose.
- Christian expressed willingness to run interoperability tests, noting that current EDHOC implementations would likely fail.
- An email discussion on the mailing list has been initiated to gather input on these questions.
ODS (draft-ietf-lake-ods) Update (on behalf of Jovan Marojevic):
- The intent is to broaden the scope of the draft to cover generic notarization of ad-hoc rather than being constrained only to the enrollment use case.
- Proposed changes include:
  - Adding a new subsection in Section 4 to generically describe the protocol in both forward and reverse flows.
  - Moving the network enrollment use case to a dedicated Section 5.
  - Instantiating optimization strategies from the current draft within the enrollment use case.
- These next steps were supported by Christian.
Application Profiles (draft-ietf-lake-ap-profiles) Update:
- The draft was adopted and is undergoing editor's copy work on GitHub, targeting a version 1 revision for IETF 122.
- Updates in the editor's copy include:
  - Moving definitions of several information elements (e.g., COAP-CF corrected to COAP-CT, URI-PATH) to the ACE WG's draft-ietf-ace-cose-info-obj, as they pertain better to the COSE Information Object.
  - The AProf parameter definition remains in this document.
  - Incorporated features from draft-ietf-lake-ta-hint related to advertising supported trust anchors (references only, not values), defining a corresponding trust-anchors parameter and link target attributes.
- A major point of work is on advertising supported EDHOC features and profiles within EDHOC messages themselves. This includes using a new EAD item for EDHOC Message 1 and 2, and a new error code/info for an EDHOC error message in reply to Message 1. This EAD item will be a COER sequence (byte string wrapping a COER sequence for Msg1/Msg2) or directly a COER sequence (for error messages), capable of conveying profile identifiers, arrays of EAD labels, or piece-by-piece indication of supported features via an EDHOC Information Object.
PSK (draft-ietf-lake-psk) Update:
- The draft was adopted and has undergone several corrections and clarifications.
- PSK1 variant has been removed, only PSK2 remains.
- Corrections include: adding hyperlinks, referencing concepts and terms, reformulating ID_cred_PSK and Cred_PSK definitions, correcting a typo in K_SK_3 derivation (key length vs. credential identifier length), and a title change for Section 5.
- A key point of discussion is the structure of Ciphertext 3 in EDHOC Message 3. Two options are being considered:
  1. Defining Ciphertext 3 as a COER sequence composed of two elements (Ciphertext_3A and Ciphertext_3B). This would be a deviation from RFC 9528.
  2. Defining Ciphertext 3 as a COER sequence of one element (which itself is a COER sequence composed of two elements), implying an extra wrapping that adds bytes.
- Marco expressed support for Option 1, despite it being a deviation, provided it is clearly highlighted.
LAKE-RA (draft-ietf-lake-ra) Adoption Call Summary:
- The adoption call concluded, with a clear sense of consensus for adoption.
- Comments were received from Michael Richardson and the RATs Working Group, which included technical remarks.
IETF 122 Planning (Bangkok):
- A poll of those present indicated that while many would be attending remotely, several key contributors (e.g., Marco, Richard, John) plan to be on-site.
- A sense of those present was to request a physical meeting for IETF 122.
CDDL Rata for EDHOC:
- A rata for the EDHOC CDDL was submitted by Brian Seos. Discussion on this will be pursued on the mailing list.

Decisions and Action Items

Decision: Stephen Farrell stepped down as co-chair, Renzo Comin officially takes over as co-chair.
Decision: draft-ietf-lake-ra is adopted as a Working Group document.
Decision: The chairs will request a 1-hour hybrid session for the LAKE Working Group at IETF 122 in Bangkok.
Action Item (Christian): Continue email discussion on the mailing list regarding GREASE questions (semantics of COSE header map elements).
Action Item (Christian): Run interoperability tests for GREASE, particularly to observe potential breaking changes.
Action Item (Jovan): Update draft-ietf-lake-ods to reflect generic notarization, including new sections for generic protocol flow and dedicated enrollment use cases.
Action Item (Marco): Prepare draft-ietf-lake-ap-profiles version 1, focusing on in-message advertisement of profiles/features and addressing adoption call comments.
Action Item (Ela and PSK authors): Conduct another round of protocol review for draft-ietf-lake-psk, aiming for a stable version by IETF 122, before calling for formal analysis.
Action Item (Chairs): Send an official announcement on the mailing list regarding the adoption of draft-ietf-lake-ra.
Action Item (Yuan): Lead discussions to address technical comments received from Michael Richardson and the RATs Working Group for draft-ietf-lake-ra once the ietf-lake version is published.
Action Item (Yuan): Pursue discussion on the mailing list regarding the submitted CDDL rata for EDHOC.

Next Steps

Continue working on GREASE, ODS, AP-PROFILES, and PSK drafts to address open questions and incorporate feedback.
Formal analysis of draft-ietf-lake-psk will be initiated once the protocol is deemed stable by the authors.
The LAKE Working Group will meet for a 1-hour hybrid session at IETF 122 in Bangkok.
Discuss and resolve the CDDL rata on the mailing list.
Address comments on draft-ietf-lake-ra after its publication as a WG draft.