Category: IETF Page 1 of 7

On August 2, 2024

Orie Steele and I have updated the “Fully-Specified Algorithms for JOSE and COSE” specification to incorporate feedback from IETF 120 in Vancouver. Specifically, the registrations for fully-specified Elliptic Curve Diffie-Hellman (ECDH) algorithms in draft 03 were removed, along with the previously proposed fully-specified ECDH algorithm identifiers, while continuing to describe how to create fully-specified ECDH algorithms in the future, if needed.

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-jose-fully-specified-algorithms-04.html

Fully-Specified Algorithms Specification Addressing Working Group Last Call Comments

On July 11, 2024

Orie Steele and I have updated the “Fully-Specified Algorithms for JOSE and COSE” specification to incorporate working group last call (WGLC) feedback. Thanks to all who took the time to comment on the draft. Your feedback was exceptionally actionable and helped to substantially improve the specification. Responses to each WGLC comment thread were sent on the IETF JOSE working group mailing list.

The updated draft attempts to discuss the full range of the problems created by polymorphic algorithm identifiers. Guided by working group feedback, it strikes an engineering balance between which of these problems to fix immediately in the specification and which to describe how future specifications can fix later as the need arises.

I look forward to discussing next steps for the specification at IETF 120 in Vancouver.

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-jose-fully-specified-algorithms-03.html

OAuth 2.0 Protected Resource Metadata draft addressing shepherd comments

On July 10, 2024

In IETF, OAuth, Specifications

OAuth logo The “OAuth 2.0 Protected Resource Metadata” specification has been updated to address feedback from our document shepherd Rifaat Shekh-Yusef in advance of IETF 120 in Vancouver. All changes were strictly editorial.

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-oauth-resource-metadata-06.html

CBOR Web Token (CWT) Claims in COSE Headers is now RFC 9597

On June 24, 2024

The CBOR Web Token (CWT) Claims in COSE Headers specification has been published as RFC 9597! This closes a gap for COSE relative to JOSE, adding the ability to use CWT claims in COSE header parameters, just as JWT claims can be used in JOSE header parameters.

The specification abstract is:

This document describes how to include CBOR Web Token (CWT) claims in the header parameters of any CBOR Object Signing and Encryption (COSE) structure. This functionality helps to facilitate applications that wish to make use of 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. Another use case is using CWT claims with payloads that are not CWT Claims Sets, including payloads that are not CBOR at all.

Special thanks to my co-author Tobias Looker, who had a use case for this functionality and wrote an RFC with me defining it (his first!). It was a pleasure working with Tobias on the draft as we navigated the ins and outs of working group feedback and IETF processes. The spec was refined by the journey we took together. And as with CBOR Object Signing and Encryption (COSE) “typ” (type) Header Parameter (now RFC 9596) that immediately preceded it, I believe the CBOR and COSE ecosystems are better for it.

COSE “typ” (type) Header Parameter is now RFC 9596

On June 11, 2024

The CBOR Object Signing and Encryption (COSE) “typ” (type) Header Parameter specification has been published as RFC 9596! This closes a gap for COSE relative to JOSE, adding the ability to use media types to declare the content of the complete COSE object.

The specification abstract is:

This specification adds the equivalent of the JSON Object Signing and Encryption (JOSE) “typ” (type) header parameter to CBOR Object Signing and Encryption (COSE). This enables the benefits of explicit typing (as defined in RFC 8725, “JSON Web Token Best Current Practices”) to be brought to COSE objects. The syntax of the COSE type header parameter value is the same as the existing COSE content type header parameter.

Special thanks to my co-author Orie Steele, who pointed out the gap and proposed that we close it. He was an active participant and insightful partner in making this RFC happen (his first!). The CBOR and COSE ecosystems are better for it.

Standards are About Making Choices

On June 9, 2024

In CBOR, Claims, Cryptography, Events, FIDO, IETF, Interoperability, JSON, OAuth, OpenID, Phishing Resistance, Specifications, W3C

EIC 2024 Logo I was honored to give the keynote presentation Standards are About Making Choices at the 2024 European Identity and Cloud Conference (PowerPoint) (PDF). The abstract was:

When building machines, we take for granted being able to use nuts, bolts, wires, light bulbs, and countless other parts made to industry standards. Standards contain choices about dimensions of screw threads, nut sizes, etc., enabling a marketplace of interoperable parts from multiple suppliers. Without these choices, every part would be custom manufactured. The same is true of the identity and security standards we use to build identity systems.

However, the identity and security standards at our disposal differ wildly in the degree to which they do and don’t make choices. Some consistently define ONE way to do things, resulting in everyone doing it that way (interoperability!). Others leave critical choices unmade, passing the buck to implementers and applications (your mileage may vary).

In this talk, I’ll name names and take prisoners, critiquing existing and emerging standards through the lens of the choices they made and failed to make. Hold on to your hats as we examine the pros and cons of the choices made by OAuth, SAML, X.509, OpenID Connect, Verifiable Credentials, DIDs, WebCrypto, JOSE, COSE, and many others through this lens!

I believe you’ll agree with me that making choices matters.

The conference keynote description includes a recording of the presentation.

Thanks to MATTR for providing a designer to work with me on the presentation, enabling the visual design to transcend my usual black-text-on-white-background design style!

Using Standards: Some Assembly Required

On May 30, 2024

In CBOR, Claims, Cryptography, Events, FIDO, IETF, Interoperability, JSON, OAuth, OpenID, Phishing Resistance, Specifications, W3C

Identiverse Logo I gave the following presentation in the session Using Standards: Some Assembly Required at the 2024 Identiverse conference (PowerPoint) (PDF). The abstract was:

Standards are about making choices. When building machines, we take for granted being able to use nuts, bolts, wires, light bulbs, and countless other parts made to industry standards. Standards contain choices about dimensions of screw threads, nut sizes, etc., enabling a marketplace of interoperable parts from multiple suppliers. Without these choices, every part would be custom-manufactured. The same is true of the identity and security standards we use to build the Identity Engine. However, the identity and security standards at our disposal differ wildly in the degree to which they do and don’t make choices. Some consistently define ONE way to do things, resulting in everyone doing it that way (interoperability!). Others leave critical choices unmade, passing the buck to implementers and applications (your mileage may vary). In this talk, I’ll name names and take prisoners, critiquing existing and emerging standards through the lens of the choices they made and failed to make. Hold on to your hats as we examine the pros and cons of the choices made by OAuth, SAML, X.509, OpenID Connect, Verifiable Credentials, DIDs, WebCrypto, JOSE, COSE, and many others through this lens! I believe you’ll agree with me that making choices matters.

The audience was highly engaged by the process of giving existing and emerging standards letter grades based on the choices they made (or failed to make)!

Fully-Specified Algorithms Presentation at 2024 OAuth Security Workshop

On April 12, 2024

In Cryptography, Events, IETF, Specifications

OAuth Security Workshop I gave a presentation on Fully-Specified Algorithms for JOSE and COSE at the 2024 OAuth Security Workshop in Rome. The slides used to update participants on the progress of the work are available as PowerPoint and PDF.

Thanks to the organizers for another great OAuth Security Workshop! And special thanks to the colleagues from Fondazione Bruno Kessler who did a great job with local arrangements in Rome!

COSE “typ” (type) Header Parameter Specification in RFC Editor Queue

On April 12, 2024

I’m pleased to report that the COSE “typ” (type) Header Parameter Specification has been approved by the IESG and is now in the RFC Editor queue.

The version approved by the IESG and sent to the RFC Editor is:

https://www.ietf.org/archive/id/draft-ietf-cose-typ-header-parameter-05.html

It joins CBOR Web Token (CWT) Claims in COSE Headers in the RFC Editor queue. Because of the reference to this spec by CWT Claims in Headers, they form a cluster, and therefore will become RFCs at the same time.

Eight Specifications Published in Preparation for IETF 119

On March 20, 2024

In CBOR, Claims, Cryptography, Events, IETF, JSON, Specifications

My co-authors and I published updated versions of eight specifications in preparation for IETF 119 in Brisbane. The specifications span three working groups: JOSE, COSE, and OAuth. The updated specifications and outcomes when discussed at IETF 119 are as follows.

1, 2, & 3: JSON Web Proof, JSON Proof Algorithms, and JSON Proof Token. Updates were:

Normatively defined header parameters used
Populated IANA Considerations sections
Allowed proof representations to contain multiple base64url-encoded parts
Specified representation of zero-length disclosed payloads
Added Terminology sections
Updated to use draft-irtf-cfrg-bbs-signatures-05
Updated to use draft-ietf-cose-bls-key-representations-04
More and better examples
Improvements resulting from a full proofreading

Continued reviews and feedback from implementations are requested.

4: Fully-Specified Algorithms for JOSE and COSE. Updates were:

Published initial working group document following adoption
Added text on fully-specified computations using multiple algorithms
Added text on KEMs and encapsulated keys
Updated instructions to the designated experts

It was agreed during the JOSE meeting to describe what fully-specified algorithms for ECDH would look like, for consideration by the working group.

5: OAuth 2.0 Protected Resource Metadata. Updates were:

Switched from concatenating .well-known to the end of the resource identifier to inserting it between the host and path components of it
Have WWW-Authenticate return resource_metadata URL rather than resource identifier

It was decided to start working group last call during the OAuth meeting.

6: COSE “typ” (type) Header Parameter. Updates were:

Added language about media type parameters
Addressed working group last call comments
Changed requested assignment from 14 to 16 due to conflict with a new assignment
Addressed GENART, OPSDIR, and SECDIR review comments

This document is scheduled for the April 4, 2024 IESG telechat.

7: Barreto-Lynn-Scott Elliptic Curve Key Representations for JOSE and COSE. Updates were:

Changed to use key type EC for JOSE and equivalent EC2 for COSE for uncompressed key representations
Changed identifier spellings from “Bls” to “BLS”, since these letters are people’s initials

We received feedback to not add compressed key representations to the draft.

8: Use of Hybrid Public-Key Encryption (HPKE) with JavaScript Object Signing and Encryption (JOSE). Updates were:

Use existing "alg": "dir" value for HPKE Direct Encryption mode
Aligned choices more closely with those of Use of Hybrid Public-Key Encryption (HPKE) with CBOR Object Signing and Encryption (COSE)
Defined both Integrated Encryption mode and Key Encryption mode
Added IANA Considerations section
Removed Post-Quantum Considerations

It was decided to start a working group call for adoption during the JOSE meeting.

Thanks to all who contributed to the progress made on these specifications, both before and during IETF 119!

COSE “typ” (type) Header Parameter Specification Addressing IETF Last Call Feedback

On February 26, 2024

Orie Steele and I have updated the COSE “typ” (type) Header Parameter Specification to address feedback received during IETF Last Call. No normative changes were made.

Thanks to those that reviewed the specification!

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-cose-typ-header-parameter-03.html

Besides the spec being useful on its own, it’s worth noting that the CBOR Web Token (CWT) Claims in COSE Headers specification references this spec, and so won’t exit the RFC Editor queue as an RFC until this one also does.

Fully-Specified Algorithms adopted by JOSE working group

On January 31, 2024

The “Fully-Specified Algorithms for JOSE and COSE” specification has been adopted by the JOSE working group. See my original post about the spec for why fully-specified algorithms matter. Thanks to all who supported adoption and also thanks to those who provided useful detailed feedback that we can address in future working group drafts.

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-jose-fully-specified-algorithms-00.html

Hybrid Public Key Encryption (HPKE) for JOSE

On October 31, 2023

In Cryptography, IETF, JSON, Specifications

The new “Use of Hybrid Public-Key Encryption (HPKE) with Javascript Object Signing and Encryption (JOSE)” specification has been published. Its abstract is:

This specification defines Hybrid public-key encryption (HPKE) for use with Javascript Object Signing and Encryption (JOSE). HPKE offers a variant of public-key encryption of arbitrary-sized plaintexts for a recipient public key.

HPKE works for any combination of an asymmetric key encapsulation mechanism (KEM), key derivation function (KDF), and authenticated encryption with additional data (AEAD) function. Authentication for HPKE in JOSE is provided by JOSE-native security mechanisms or by one of the authenticated variants of HPKE.

This document defines the use of the HPKE with JOSE.

Hybrid Public Key Encryption (HPKE) is defined by RFC 9180. There’s a whole new generation of specifications using it for encryption. The Messaging Layer Security (MLS) Protocol [RFC 9420] uses it. TLS Encrypted Client Hello uses it. Use of Hybrid Public-Key Encryption (HPKE) with CBOR Object Signing and Encryption (COSE) brings it to COSE. And this specification brings it to JOSE.

One of our goals for the JOSE HPKE specification is to keep it closely aligned with the COSE HPKE specification. That should be facilitated by having multiple authors in common, with Hannes Tschofenig and Orie Steele being authors of both, and me being a COSE co-chair.

Aritra Banerjee will be presenting the draft to the JOSE working group at IETF 118 in Prague. I’m hoping to see many of you there!

The specification is available at:

https://www.ietf.org/archive/id/draft-rha-jose-hpke-encrypt-01.html

BLS Key Representations for JOSE and COSE updated for IETF 118

On October 24, 2023

In CBOR, Claims, IETF, JSON, Privacy, Specifications

Tobias Looker and I have published an updated Barreto-Lynn-Scott Elliptic Curve Key Representations for JOSE and COSE specification in preparation for IETF 118 in Prague. This one of suite of IETF and IRTF specifications, including BLS Signatures and JSON Web Proofs that are coming together to enable standards for the use of JSON-based and CBOR-based tokens utilizing zero-knowledge proofs.

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-cose-bls-key-representations-03.html

CBOR Web Token (CWT) Claims in COSE Headers Draft Addressing IETF Last Call Comments

On October 24, 2023

Tobias Looker and I have published an updated CBOR Web Token (CWT) Claims in COSE Headers specification that addresses the IETF Last Call (WGLC) comments received. Changes made were:

Added Privacy Consideration about unencrypted claims in header parameters.
Added Security Consideration about detached content.
Added Security Consideration about claims that are present both in the payload and the header of a CWT.
Changed requested IANA COSE Header Parameter assignment number from 13 to 15 due to subsequent assignments of 13 and 14.
Acknowledged last call reviewers.

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-cose-cwt-claims-in-headers-07.html

The specification is scheduled for the IESG telechat on November 30, 2023.

JSON Web Proofs specifications updated in preparation for IETF 118

On October 22, 2023

In Claims, Cryptography, IETF, JSON, Privacy, Specifications

David Waite and I have updated the “JSON Web Proof”, “JSON Proof Algorithms”, and “JSON Proof Token” specifications in preparation for presentation and discussions in the JOSE working group at IETF 118 in Prague. The primary updates were to align the BBS algorithm text and examples with the current CFRG BBS Signature Scheme draft. We also applied improvements suggested by Brent Zundel and Alberto Solavagione.

The specifications are available at:

Thanks to David Waite for doing the heavy lifting to update the BBS content. Thanks to MATTR for publishing their Pairing Cryptography software, which was used to generate the examples. And thanks to Alberto Solavagione for validating the specifications with his implementation.

OAuth 2.0 Protected Resource Metadata updated in preparation for IETF 118

On October 21, 2023

In IETF, OAuth, Specifications

OAuth logo Aaron Parecki and I have updated the “OAuth 2.0 Protected Resource Metadata” specification in preparation for presentation and discussions at IETF 118 in Prague. The updates address comments received during the discussions at IETF 117 and afterwards. As described in the History entry, the changes were:

Renamed scopes_provided to scopes_supported
Added security consideration for scopes_supported
Use BCP 195 for TLS recommendations
Clarified that resource metadata can be used by clients and authorization servers
Added security consideration recommending audience-restricted access tokens
Mention FAPI Message Signing as a use case for publishing signing keys
Updated references

The specification is available at:

https://www.ietf.org/archive/id/draft-ietf-oauth-resource-metadata-01.html

Fully-Specified Algorithms updated in preparation for IETF 118

On October 20, 2023

Orie Steele and I have updated the “Fully-Specified Algorithms for JOSE and COSE” specification in preparation for presentation and discussions at IETF 118 in Prague. The updates address comments received during the discussions at IETF 117 and afterwards. Specifically, this draft adds descriptions of key representations and of algorithms not updated by the specification. See my original post about the spec for why fully-specified algorithms matter.

Hopefully working group adoption will be considered by the JOSE working group during IETF 118.

The specification is available at:

https://www.ietf.org/archive/id/draft-jones-jose-fully-specified-algorithms-02.html

OAuth 2.0 Demonstrating Proof of Possession (DPoP) is now RFC 9449