Archive for the 'JSON' Category

November 15, 2017
OAuth Authorization Server Metadata spec incorporating IETF last call feedback

OAuth logoThe OAuth Authorization Server Metadata specification has been updated to incorporate feedback received during IETF last call. Thanks to Shwetha Bhandari, Brian Carpenter, Donald Eastlake, Dick Hardt, and Mark Nottingham for their reviews. See the Document History appendix for clarifications applied. No normative changes were made.

The specification is available at:

An HTML-formatted version is also available at:

July 27, 2017
Initial working group draft of JSON Web Token Best Current Practices

OAuth logoI’m happy to announce that the OAuth working group adopted the JSON Web Token Best Current Practices (JWT BCP) draft that Yaron Sheffer, Dick Hardt, and I had worked on, following discussions at IETF 99 in Prague and on the working group mailing list.

The specification is available at:

An HTML-formatted version is also available at:

July 4, 2017
JSON Web Token Best Current Practices draft describing Explicit Typing

OAuth logoThe JWT BCP draft has been updated to describe the use of explicit typing of JWTs as one of the ways to prevent confusion among different kinds of JWTs. This is accomplished by including an explicit type for the JWT in the “typ” header parameter. For instance, the Security Event Token (SET) specification now uses the “application/secevent+jwt” content type to explicitly type SETs.

The specification is available at:

An HTML-formatted version is also available at:

June 30, 2017
Security Event Token (SET) specification preventing token confusion

IETF logoA new version of the Security Event Token (SET) specification has been published containing measures that prevent any possibility of confusion between ID Tokens and SETs. Preventing confusion between SETs, access tokens, and other kinds of JWTs is also covered. Changes were:

  • Added the Requirements for SET Profiles section.
  • Expanded the Security Considerations section to describe how to prevent confusion of SETs with ID Tokens, access tokens, and other kinds of JWTs.
  • Registered the application/secevent+jwt media type and defined how to use it for explicit typing of SETs.
  • Clarified the misleading statement that used to say that a SET conveys a single security event.
  • Added a note explicitly acknowledging that some SET profiles may choose to convey event subject information in the event payload.
  • Corrected an encoded claims set example.
  • Applied grammar corrections.

This draft is intended to provide solutions to the issues that had been discussed in IETF 98 in Chicago and subsequently on the working group mailing list. Thanks for all the great discussions that informed this draft!

The specification is available at:

An HTML-formatted version is also available at:

June 16, 2017
Authentication Method Reference Values is now RFC 8176

IETF logoThe Authentication Method Reference Values specification is now RFC 8176. The abstract describes the specification as:

The amr (Authentication Methods References) claim is defined and registered in the IANA “JSON Web Token Claims” registry, but no standard Authentication Method Reference values are currently defined. This specification establishes a registry for Authentication Method Reference values and defines an initial set of Authentication Method Reference values.

The specification defines and registers some Authentication Method Reference values such as the following, which are already in use by some Google and Microsoft products and OpenID specifications:

  • face” – Facial recognition
  • fpt” – Fingerprint
  • hwk” – Proof-of-possession of a hardware-secured key
  • otp” – One-time password
  • pin” – Personal Identification Number
  • pwd” – Password
  • swk” – Proof-of-possession of a software-secured key
  • sms” – Confirmation using SMS
  • user” – User presence test
  • wia” – Windows Integrated Authentication

See https://www.iana.org/assignments/authentication-method-reference-values/ for the full list of registered values.

Thanks to Caleb Baker, Phil Hunt, Tony Nadalin, and William Denniss, all of whom substantially contributed to the specification. Thanks also to the OAuth working group members, chairs, area directors, and other IETF members who helped refine the specification.

June 4, 2017
Initial JSON Web Token Best Current Practices Draft

OAuth logoJSON Web Tokens (JWTs) and the JSON Object Signing and Encryption (JOSE) functions underlying them are now being widely used in diverse sets of applications. During IETF 98 in Chicago, we discussed reports of people implementing and using JOSE and JWTs insecurely, the causes of these problems, and ways to address them. Part of this discussion was an invited JOSE/JWT Security Update presentation that I gave to two working groups, which included links to problem reports and described mitigations. Citing the widespread use of JWTs in new IETF applications, Security Area Director Kathleen Moriarty suggested during these discussions that a Best Current Practices (BCP) document be written for JSON Web Tokens (JWTs).

I’m happy to report that Yaron Sheffer, Dick Hardt, and myself have produced an initial draft of a JWT BCP. Its abstract is:

JSON Web Tokens, also known as JWTs [RFC7519], are URL-safe JSON-based security tokens that contain a set of claims that can be signed and/or encrypted. JWTs are being widely used and deployed as a simple security token format in numerous protocols and applications, both in the area of digital identity, and in other application areas. The goal of this Best Current Practices document is to provide actionable guidance leading to secure implementation and deployment of JWTs.

In Section 2, we describe threats and vulnerabilities. In Section 3, we describe best practices addressing those threats and vulnerabilities. We believe that the best practices in Sections 3.1 through 3.8 are ready to apply today. Section 3.9 (Use Mutually Exclusive Validation Rules for Different Kinds of JWTs) describes several possible best practices on that topic to serve as a starting point for a discussion on which of them we want to recommend under what circumstances.

We invite input from the OAuth Working Group and other interested parties on what best practices for JSON Web Tokens and the JOSE functions underlying them should be. We look forward to hearing your thoughts and working on this specification together.

The specification is available at:

An HTML-formatted version is also available at:

March 13, 2017
AMR Values specification addressing Stephen Farrell’s comments

OAuth logoSecurity area director Stephen Farrell had asked us to make it as clear as possible to people who might be registering new “amr” values that names can identify families of closely-related authentication methods. This is now said right in the IANA Registration Template, so that people who might not have read the spec can’t miss it.

FYI, all the previous IESG DISCUSSes have now been cleared, so hopefully that means this is the last version to be published before the Authentication Method Reference Values specification becomes an RFC.

Thanks again to Stephen for his always-thorough reviews of the specification.

The specification is available at:

An HTML-formatted version is also available at:

March 10, 2017
OAuth Authorization Server Metadata spec incorporating WGLC feedback

OAuth logoThe OAuth Authorization Server Metadata specification has been updated to incorporate the working group last call feedback received. Thanks to William Denniss and Hannes Tschofenig for their reviews. Use of the “https” scheme for the “jwks_uri” URL is now required. The precedence of signed metadata values over unsigned values was clarified. Unused references were removed.

The specification is available at:

An HTML-formatted version is also available at:

February 28, 2017
AMR Values specification addressing IESG comments

OAuth logoThe Authentication Method Reference Values specification has been updated to address feedback from the IESG. Identifiers are now restricted to using only printable JSON-friendly ASCII characters. All the “amr” value definitions now include specification references.

Thanks to Stephen Farrell, Alexey Melnikov, Ben Campbell, and Jari Arkko for their reviews.

The specification is available at:

An HTML-formatted version is also available at:

January 24, 2017
“amr” Values specification addressing IETF last call comments

OAuth logoDraft -05 of the Authentication Method Reference Values specification addresses the IETF last call comments received. Changes were:

  • Specified characters allowed in “amr” values, reusing the IANA Considerations language on this topic from RFC 7638.
  • Added several individuals to the acknowledgements.

Thanks to Linda Dunbar, Catherine Meadows, and Paul Kyzivat for their reviews.

The specification is available at:

An HTML-formatted version is also available at:

January 19, 2017
OAuth Authorization Server Metadata decoupled from OAuth Protected Resource Metadata

OAuth logoThe IETF OAuth working group decided at IETF 97 to proceed with standardizing the OAuth Authorization Server Metadata specification, which is already in widespread use, and to stop work on the OAuth Protected Resource Metadata specification, which is more speculative. Accordingly, a new version of the AS Metadata spec has been published that removes its dependencies upon the Resource Metadata spec. In particular, the “protected_resources” AS Metadata element has been removed. Its definition has been moved to the Resource Metadata spec for archival purposes. Note that the Resource Metadata specification authors intend to let it expire unless the working group decides to resume work on it at some point in the future.

The specifications are available at:

HTML-formatted versions are also available at:

November 23, 2016
Security Event Token (SET) Specification and IETF Security Events Working Group

IETF logoAs those of you who have been following the id-event@ietf.org mailing list or attended the inaugural meeting of the new IETF Security Events working group know, Phil Hunt and co-authors (including myself) have been working on a Security Event Token (SET) specification. A SET is a JSON Web Token (JWT) with an “events” claim that contains one or more event identifiers (which are URIs) that say what event the SET describes.

This work isn’t being done in isolation. Among others, the OpenID Risk and Incident Sharing and Coordination (RISC) working group, the OpenID Back-Channel Logout specification, and the SCIM Provisioning Events work intend to use the Security Event Token format.

To make this concrete, the claims in an example OpenID Connect Back-Channel Logout token (which is a SET) are:

{
  "iss": "https://server.example.com",
  "sub": "248289761001",
  "aud": "s6BhdRkqt3",
  "iat": 1471566154,
  "jti": "bWJq",
  "sid": "08a5019c-17e1-4977-8f42-65a12843ea02",
  "events": {
    "http://schemas.openid.net/event/backchannel-logout": {}
  }
}

You’ll see that this a normal JWT, with the issuer, subject, and session ID identifying the target of the logout, and the “events” value identifying the JWT as a logout SET.

Today, we published an updated SET spec based on discussions at IETF 97, which simplifies the SET parsing. Thanks to Phil Hunt or Oracle, William Denniss of Google, Morteza Ansari of Cisco, and the numerous other contributors who’ve gotten us to this point. We now believe that this specification is ready for adoption by the Security Events working group.

The specification is available at:

An HTML-formatted version is also available at:

The OpenID Connect Back-Channel Logout specification should be updated soon (after the US Thanksgiving holiday) to utilize the simplified SET syntax. Happy Thanksgiving, everyone!

November 13, 2016
“amr” Values specification addressing area director comments

OAuth logoDraft -04 of the Authentication Method Reference Values specification addresses comments by our security area director Kathleen Moriarty. Changes were:

  • Added “amr” claim examples with both single and multiple values.
  • Clarified that the actual credentials referenced are not part of this specification to avoid additional privacy concerns for biometric data.
  • Clarified that the OAuth 2.0 Threat Model [RFC6819] applies to applications using this specification.

The specification is available at:

An HTML-formatted version is also available at:

October 14, 2016
“amr” Values specification addressing shepherd comments

OAuth logoDraft -03 of the Authentication Method Reference Values specification addresses the shepherd comments. It changes the references providing information about specific “amr” values to be informative, rather than normative. A reference to ISO/IEC 29115 was also added. No normative changes were made.

The specification is available at:

An HTML-formatted version is also available at:

September 9, 2016
“amr” Values specification addressing WGLC comments

OAuth logoDraft -02 of the Authentication Method Reference Values specification addresses the Working Group Last Call (WGLC) comments received. It adds an example to the multiple-channel authentication description and moves the “amr” definition into the introduction. No normative changes were made.

The specification is available at:

An HTML-formatted version is also available at:

August 3, 2016
OAuth Metadata Specifications Enhanced

OAuth logoThe existing OAuth 2.0 Authorization Server Metadata specification has now been joined by a related OAuth 2.0 Protected Resource Metadata specification. This means that JSON metadata formats are now defined for all the OAuth 2.0 parties: clients, authorization servers, and protected resources.

The most significant addition to the OAuth 2.0 Authorization Server Metadata specification is enabling signed metadata, represented as claims in a JSON Web Token (JWT). This is analogous to the role that the Software Statement plays in OAuth Dynamic Client Registration. Signed metadata can also be used for protected resource metadata.

For use cases in which the set of protected resources used with an authorization server are enumerable, the authorization server metadata specification now defines the “protected_resources” metadata value to list them. Likewise, the protected resource metadata specification defines an “authorization_servers” metadata value to list the authorization servers that can be used with a protected resource, for use cases in which those are enumerable.

The specifications are available at:

HTML-formatted versions are also available at:

July 8, 2016
“amr” Values specification distinguishing between iris and retina scan biometrics

OAuth logoThis draft distinguishes between iris and retina scan biometrics, as requested by NIST, and adds a paragraph providing readers more context at the end of the introduction, which was requested by the chairs during the call for adoption. The OpenID Connect MODRNA Authentication Profile 1.0 specification, which uses “amr” values defined by this specification, is now also referenced.

The specification is available at:

An HTML formatted version is also available at:

July 4, 2016
Token Binding for Access Tokens, Refresh Tokens, and ID Tokens

IETF logoTwo new related specifications define syntax and semantics for applying Token Binding to OAuth Access Tokens and Refresh Tokens and to OpenID Connect ID Tokens. draft-jones-oauth-token-binding contains the OAuth portions. openid-connect-token-bound-authentication-1_0 contains the OpenID Connect portions.

These are being submitted now to hopefully enable end-to-end implementations and interop testing of Token Bound Access Tokens, Refresh Tokens, and ID Tokens across multiple platforms before the Token Binding specifications are finalized.

The OAuth specification is available at:

The OpenID Connect specification is available at:

Thanks to Andrei Popov, Yordan Rouskov, John Bradley, and Brian Campbell for reviews of earlier versions of these specifications and to Dirk Balfanz and William Denniss for some earlier discussions providing input to these specifications.

April 6, 2016
Proof-of-Possession Key Semantics for JSON Web Tokens (JWTs) is now RFC 7800

IETF logoThe Proof-of-Possession Key Semantics for JSON Web Tokens (JWTs) specification is now RFC 7800 – an IETF standard. The abstract describes the specification as:

This specification describes how to declare in a JSON Web Token (JWT) that the presenter of the JWT possesses a particular proof-of-possession key and how the recipient can cryptographically confirm proof of possession of the key by the presenter. Being able to prove possession of a key is also sometimes described as the presenter being a holder-of-key.

Thanks to John Bradley, Hannes Tschofenig, and the OAuth working group for their work on this specification.

March 4, 2016
OAuth 2.0 Token Exchange draft -04

OAuth logoA new draft of “OAuth 2.0 Token Exchange” has been published addressing review comments on the prior draft. The changes from -03 are listed here:

The specification is available at:

An HTML-formatted version is also available at:

Thanks to Brian Campbell for doing most of the edits for this release.

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