Registries for Web Authentication (WebAuthn)
draft-hodges-webauthn-registries-09

Abstract

This specification defines IANA registries for W3C Web Authentication attestation statement format identifiers and extension identifiers.

Note to Readers

RFC EDITOR: please remove this section before publication

This is a work-in-progress.

The issues list can be found at https://github.com/w3c/webauthn/issues?q=is%3Aopen+is%3Aissue+label%3Aspec%3Awebauthn-registries .

The most recent _published_ draft revision is at https://tools.ietf.org/html/draft-hodges-webauthn-registries.

The editors' draft is at https://github.com/w3c/webauthn/blob/master/draft-hodges-webauthn-registries.txt

Changes in the editors' draft, both proposed and incorporated, are listed at https://github.com/w3c/webauthn/pulls?q=is%3Apr+label%3Aspec%3Awebauthn-registries

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on November 23, 2020.

Copyright Notice

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Table of Contents

• 1. Introduction
• 1.1. Requirements Notation and Conventions
• 2. IANA Considerations
• 2.1. WebAuthn Attestation Statement Format Identifier Registry
• 2.1.1. Registering Attestation Statement Format Identifiers
• 2.1.2. Registration Request Processing
• 2.1.3. Initial WebAuthn Attestation Statement Format Identifier Registry Values
• 2.2. WebAuthn Extension Identifier Registry
• 2.2.1. Registering Extension Identifiers
• 2.2.2. Registration Request Processing
• 2.2.3. Initial WebAuthn Extension Identifier Registry Values
• 3. Security Considerations
• 4. Acknowledgements
• 5. Document History
• 6. Normative References
• Authors' Addresses

1. Introduction

This specification establishes IANA registries for W3C Web Authentication [WebAuthn] attestation statement format identifiers and extension identifiers. The initial values for these registries are in the IANA Considerations section of the [WebAuthn] specification.

1.1. Requirements Notation and Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2. IANA Considerations

This specification establishes two registries:

• the "WebAuthn Attestation Statement Format Identifier" registry; see Section 2.1.
• the "WebAuthn Extension Identifier" registry; see Section 2.2.

[[ Per discussions in an email thread between the authors and IANA ( "[IANA #1154148]" ), it is requested that the registries be located at <https://www.iana.org/assignments/webauthn>. RFC Editor - please delete this request after the registries have been created. ]]

Any additional processes established by the expert(s) after the publication of this document will be recorded on the registry Web page at the expert(s)' discretion.

2.1. WebAuthn Attestation Statement Format Identifier Registry

WebAuthn attestation statement format identifiers are strings whose semantic, syntactic, and string-matching criteria are specified in [WebAuthn] "Attestation Statement Format Identifiers", along with the concepts of attestation and attestation statement formats.

Registered attestation statement format identifiers are those that have been added to the registry by following the procedure in Section 2.1.1.

Each attestation statement format identifier added to this registry MUST be unique amongst the set of registered attestation statement format identifiers.

Registered attestation statement format identifiers MUST be a maximum of 32 octets in length and MUST consist only of printable ASCII [RFC20] characters, excluding backslash and doublequote, i.e., VCHAR as defined in [RFC5234] but without %x22 and %x5c. Attestation statement format identifiers are case sensitive and may not match other registered identifiers in a case-insensitive manner unless the Designated Experts determine that there is a compelling reason to allow an exception.

2.1.1. Registering Attestation Statement Format Identifiers

WebAuthn attestation statement format identifiers are registered using the Specification Required policy (see Section 4.6 of [RFC8126]).

The WebAuthn attestation statement format identifiers registry is located at https://www.iana.org/assignments/webauthn. Registration requests can be made by following the instructions located there, or by sending an e-mail to the webauthn-reg-review@ietf.org mailing list.

Registration requests consist of at least the following information:

• WebAuthn Attestation Statement Format Identifier:
  An identifier meeting the requirements given above in Section 2.1.
• Description:
  A relatively short description of the attestation format.
• Specification Document(s):
  Reference to the document or documents that specify the attestation statement format.
• Change Controller:
  For Standards Track RFCs, list the "IESG". For others, give the name of the responsible party. Other details (e.g., postal address, email address, home page URI) may also be included.
• Notes:
  [optional]

Registrations MUST reference a freely available, stable specification, e.g., as described in Section 4.6 of [RFC8126]. This specification MUST include security and privacy considerations relevant to the attestation statement format.

Note that WebAuthn attestation statement format identifiers can be registered by third parties (including the expert(s) themselves), if the expert(s) determine that an unregistered attestation statement format is widely deployed and not likely to be registered in a timely manner otherwise. Such registrations still are subject to the requirements defined, including the need to reference a specification.

2.1.2. Registration Request Processing

As noted in Section 2.1.1, WebAuthn attestation statement format identifiers are registered using the Specification Required policy.

The expert(s) will clearly identify any issues that cause a registration to be refused, such as an incompletely specified attestation format.

When a request is approved, the expert(s) will inform IANA, and the registration will be processed. The IESG is the arbiter of any objection.

2.1.3. Initial WebAuthn Attestation Statement Format Identifier Registry Values

The initial values for the WebAuthn Attestation Statement Format Identifier Registry are to be populated from the values listed in "WebAuthn Attestation Statement Format Identifier Registrations" of [WebAuthn]. Also, the Change Controller entry to be used for each of those registrations is:

• Change Controller: W3C Web Authentication Working Group - public‑webauthn@w3.org

2.2. WebAuthn Extension Identifier Registry

WebAuthn extension identifiers are strings whose semantic, syntactic, and string-matching criteria are specified in [WebAuthn] "Extension Identifiers" .

Registered extension identifiers are those that have been added to the registry by following the procedure in Section 2.2.1.

Each extension identifier added to this registry MUST be unique amongst the set of registered extension identifiers.

Registered extension identifiers MUST be a maximum of 32 octets in length and MUST consist only of printable ASCII characters, excluding backslash and doublequote, i.e., VCHAR as defined in [RFC5234] but without %x22 and %x5c. Extension identifiers are case sensitive and may not match other registered identifiers in a case-insensitive manner unless the Designated Experts determine that there is a compelling reason to allow an exception.

2.2.1. Registering Extension Identifiers

WebAuthn extension identifiers registry are registered using the Specification Required policy (see Section 4.6 of [RFC8126]).

The WebAuthn extension identifiers registry is located at https://www.iana.org/assignments/webauthn. Registration requests can be made by following the instructions located there, or by sending an e-mail to the webauthn-reg-review@ietf.org mailing list.

Registration requests consist of at least the following information:

• WebAuthn Extension Identifier:
  An identifier meeting the requirements given above in Section 2.2.
• Description:
  A relatively short description of the extension.
• Specification Document(s):
  Reference to the document or documents that specify the extension.
• Change Controller:
  For Standards Track RFCs, list the "IESG". For others, give the name of the responsible party. Other details (e.g., postal address, email address, home page URI) may also be included.
• Notes:
  [optional]

Registrations MUST reference a freely available, stable specification, e.g., as described in Section 4.6 of [RFC8126]. This specification MUST include security and privacy considerations relevant to the extension.

Note that WebAuthn extensions can be registered by third parties (including the expert(s) themselves), if the expert(s) determine that an unregistered extension is widely deployed and not likely to be registered in a timely manner otherwise. Such registrations still are subject to the requirements defined, including the need to reference a specification.

2.2.2. Registration Request Processing

As noted in Section 2.2.1, WebAuthn extension identifiers are registered using the Specification Required policy.

The expert(s) will clearly identify any issues that cause a registration to be refused, such as an incompletely specified extension.

When a request is approved, the expert(s) will inform IANA, and the registration will be processed. The IESG is the arbiter of any objection.

2.2.3. Initial WebAuthn Extension Identifier Registry Values

The initial values for the WebAuthn Extension Identifier Registry are to be populated from the values listed in "WebAuthn Extension Identifier Registrations" of [WebAuthn]. Also, the Change Controller entry to be used for each of those registrations is:

• Change Controller: W3C Web Authentication Working Group - public‑webauthn@w3.org

3. Security Considerations

See [WebAuthn] for relevant security considerations.

4. Acknowledgements

Thanks to Mark Nottingham for valuable comments and suggestions. Thanks to Kathleen Moriarty and Benjamin Kaduk for their Area Director sponsorship of this specification. Thanks to Amanda Baber, Sarah Banks, Alissa Cooper, Roman Danyliw, Murray Kucherawy, Paul Kyzivat, Barry Leiba, Hilarie Orman, Magnus Westerlund, and Robert Wilton for their reviews.

5. Document History

[[ to be removed by the RFC Editor before publication as an RFC ]]

-09

• Added Change Controller fields to registries, per suggestion by Magnus Westerlund.
• Applied editorial suggestions by Amanda Baber, Murray Kucherawy, and Barry Leiba.

-08

• Addressed review feedback by Murray Kucherawy.
• Added BCP 14 Requirements Notation and Conventions section.
• Referenced RFC 20, which defines ASCII characters.
• Applied editorial cleanups.

-07

• Removed a duplicate URI listing pointed out by Hilarie Orman.

-06

• Addressed Gen-Art review comments by Paul Kyzivat by deleting text about designated experts defining additional registry fields.
• Addressed Ops-Dir review comments by Sarah Banks by deleting text that duplicated requirements already specified in RFC 8126.
• Addressed Security review comments by Hilarie Orman by deleting unnecessary text about attestation statement formats lacking complete specifications.
• Replaced uses of the URL https://www.w3.org/TR/webauthn/ with https://www.w3.org/TR/2019/REC-webauthn-1-20190304/ so that the reference remains stable after the level 2 WebAuthn specification is published.

-05

• Updated to address the solicited IANA review comments, per discussions in an email thread between the authors and IANA ( "[IANA #1154148]" ).

-04

• Update per Benjamin Kaduk's further AD review: Remove 'final' wrt IESG arbitrating objections; Add explicit requirement for extension or attestation specs to include security and privacy considerations.
• Update per IANA review: Move "IANA considerations section up in doc to encompass (former) sections 2 and 3.

-03

• Update per Benjamin Kaduk's AD review. Align with RFC 8288, rather than draft-nottingham-rfc5988bis.

-02

• Refresh now that the WebAuthn spec is at Recommendation (REC) maturity level.

-01

• Refresh now that the WebAuthn Committee Recommendation (CR) draft is pending.

-00

• Initial version, based on draft-nottingham-rfc5988bis.

6. Normative References

Authors' Addresses