OpenID Connect Back-Channel Logout 1.0 incorporating errata set 1

Abstract

OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol. It enables Clients to verify the identity of the End-User based on the authentication performed by an Authorization Server, as well as to obtain basic profile information about the End-User in an interoperable and REST-like manner.

This specification defines a logout mechanism that uses direct back-channel communication between the OP and RPs being logged out; this differs from front-channel logout mechanisms, which communicate logout requests from the OP to RPs via the User Agent.

Table of Contents

1.  Introduction
    1.1.  Requirements Notation and Conventions
    1.2.  Terminology
2.  Back-Channel Logout
    2.1.  Indicating OP Support for Back-Channel Logout
    2.2.  Indicating RP Support for Back-Channel Logout
    2.3.  Remembering Logged-In RPs
    2.4.  Logout Token
    2.5.  Back-Channel Logout Request
    2.6.  Logout Token Validation
    2.7.  Back-Channel Logout Actions
    2.8.  Back-Channel Logout Response
3.  Implementation Considerations
4.  Security Considerations
    4.1.  Cross-JWT Confusion
5.  IANA Considerations
    5.1.  OAuth Dynamic Client Registration Metadata Registration
        5.1.1.  Registry Contents
    5.2.  OAuth Authorization Server Metadata Registry
        5.2.1.  Registry Contents
    5.3.  Media Type Registration
        5.3.1.  Registry Contents
6.  References
    6.1.  Normative References
    6.2.  Informative References
Appendix A.  Acknowledgements
Appendix B.  Notices
§  Authors' Addresses

1.  Introduction

OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 [RFC6749] (Hardt, D., Ed., “The OAuth 2.0 Authorization Framework,” October 2012.) protocol. It enables Clients to verify the identity of the End-User based on the authentication performed by an Authorization Server, as well as to obtain basic profile information about the End-User in an interoperable and REST-like manner.

This specification defines a logout mechanism that uses direct back-channel communication between the OP and RPs being logged out; this differs from front-channel logout mechanisms, which communicate logout requests from the OP to RPs via the User Agent.

An upside of back-channel communication is that it can be more reliable than communication through the User Agent, since in the front-channel, the RP's browser session must be active for the communication to succeed. (If the RP's browser tab was subsequently used to navigate to an unrelated page, the RP session will be active unless the user uses the back button to return to it.) Both the OpenID Connect Session Management 1.0 (de Medeiros, B., Agarwal, N., Sakimura, N., Bradley, J., and M. Jones, “OpenID Connect Session Management 1.0,” September 2022.) [OpenID.Session] and OpenID Connect Front-Channel Logout 1.0 (Jones, M., “OpenID Connect Front-Channel Logout 1.0,” September 2022.) [OpenID.FrontChannel] specifications use front-channel communication, which communicate logout requests from the OP to RPs via the User Agent.

A downside of back-channel communication is that the session state maintained between the OP and RP over the front-channel, such as cookies and HTML5 local storage, are not available when using back-channel communication. As a result, all needed state must be explicitly communicated between the parties. Furthermore, RPs must implement an application-specific method of terminating RP sessions with the OP upon receiving back-channel logout requests; this can be more complicated than simply clearing cookies and HTML5 local storage state, which is often all that has to happen to implement logout in response to front-channel logout requests.

Another significant limitation of back-channel logout is that the RP's back-channel logout URI must be reachable from all the OPs used. This means, for instance, that the RP cannot be behind a firewall or NAT when used with public OPs.

The OpenID Connect RP-Initiated Logout 1.0 (Jones, M., de Medeiros, B., Agarwal, N., Sakimura, N., and J. Bradley, “OpenID Connect RP-Initiated Logout 1.0,” September 2022.) [OpenID.RPInitiated] specification complements these specifications by defining a mechanism for a Relying Party to request that an OpenID Provider log out the End-User.

This specification can be used separately from or in combination with OpenID Connect RP-Initiated Logout 1.0, OpenID Connect Session Management 1.0, and/or OpenID Connect Front-Channel Logout 1.0.

The previous version of this specification is:

• OpenID Connect Back-Channel Logout 1.0 (final) (Jones, M. and J. Bradley, “OpenID Connect Back-Channel Logout 1.0 (final),” September 2022.) [OpenID.BackChannel.Final]

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 RFC 2119 (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.) [RFC2119].

In the .txt version of this specification, values are quoted to indicate that they are to be taken literally. When using these values in protocol messages, the quotes MUST NOT be used as part of the value. In the HTML version of this specification, values to be taken literally are indicated by the use of this fixed-width font.

1.2.  Terminology

This specification uses the terms "Authorization Server", "Client", and "Client Identifier" defined by OAuth 2.0 (Hardt, D., Ed., “The OAuth 2.0 Authorization Framework,” October 2012.) [RFC6749], the term "User Agent" defined by RFC 7230 (Fielding, R., Ed. and J. Reschke, Ed., “Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing,” June 2014.) [RFC7230], the terms "Session" and "Session ID" defined by OpenID Connect Front-Channel Logout 1.0 (Jones, M., “OpenID Connect Front-Channel Logout 1.0,” September 2022.) [OpenID.FrontChannel] and the terms defined by OpenID Connect Core 1.0 (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.) [OpenID.Core] and JSON Web Token (JWT) (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” May 2015.) [JWT].

This specification also defines the following term:

Logout Token

JSON Web Token (JWT) (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” May 2015.) [JWT] similar to an ID Token that contains Claims about the logout action being requested.

2.  Back-Channel Logout

2.1.  Indicating OP Support for Back-Channel Logout

If the OpenID Provider supports OpenID Connect Discovery 1.0 (Sakimura, N., Bradley, J., Jones, M., and E. Jay, “OpenID Connect Discovery 1.0,” December 2023.) [OpenID.Discovery], it uses this metadata value to advertise its support for back-channel logout:

backchannel_logout_supported

OPTIONAL. Boolean value specifying whether the OP supports back-channel logout, with true indicating support. If omitted, the default value is false.

It SHOULD also register this related metadata value:

backchannel_logout_session_supported

OPTIONAL. Boolean value specifying whether the OP can pass a sid (session ID) Claim in the Logout Token to identify the RP session with the OP. If supported, the sid Claim is also included in ID Tokens issued by the OP. If omitted, the default value is false.

The sid (session ID) Claim used in ID Tokens and as a Logout Token parameter has the following definition (which is identical to the corresponding definition in OpenID Connect Front-Channel Logout 1.0 (Jones, M., “OpenID Connect Front-Channel Logout 1.0,” September 2022.) [OpenID.FrontChannel]):

sid

OPTIONAL. Session ID - String identifier for a Session. This represents a Session of a User Agent or device for a logged-in End-User at an RP. Different sid values are used to identify distinct sessions at an OP. The sid value need only be unique in the context of a particular issuer. Its contents are opaque to the RP. Its syntax is the same as an OAuth 2.0 Client Identifier.

2.2.  Indicating RP Support for Back-Channel Logout

Relying Parties supporting back-channel-based logout register a back-channel logout URI with the OP as part of their client registration.

The back-channel logout URI MUST be an absolute URI as defined by Section 4.3 of [RFC3986] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.). The back-channel logout URI MAY include an application/x-www-form-urlencoded formatted query component, per Section 3.4 of [RFC3986] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.), which MUST be retained when adding additional query parameters. The back-channel logout URI MUST NOT include a fragment component.

If the RP supports OpenID Connect Dynamic Client Registration 1.0 (Sakimura, N., Bradley, J., and M. Jones, “OpenID Connect Dynamic Client Registration 1.0,” December 2023.) [OpenID.Registration], it uses this metadata value to register the back-channel logout URI:

backchannel_logout_uri

OPTIONAL. RP URL that will cause the RP to log itself out when sent a Logout Token by the OP. This URL SHOULD use the https scheme and MAY contain port, path, and query parameter components; however, it MAY use the http scheme, provided that the Client Type is confidential, as defined in Section 2.1 of OAuth 2.0 (Hardt, D., Ed., “The OAuth 2.0 Authorization Framework,” October 2012.) [RFC6749], and provided the OP allows the use of http RP URIs.

It SHOULD also register this related metadata value:

backchannel_logout_session_required

OPTIONAL. Boolean value specifying whether the RP requires that a sid (session ID) Claim be included in the Logout Token to identify the RP session with the OP when the backchannel_logout_uri is used. If omitted, the default value is false.

2.3.  Remembering Logged-In RPs

OPs supporting back-channel logout need to keep track of the set of logged-in RPs so that they know what RPs to contact at their back-channel logout URIs to cause them to log out. Some OPs track this state using a "visited sites" cookie. OPs are encouraged to send logout requests to them in parallel.

2.4.  Logout Token

OPs send a JWT similar to an ID Token to RPs called a Logout Token to request that they log out. ID Tokens are defined in Section 2 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

The following Claims are used within the Logout Token:

iss

REQUIRED. Issuer Identifier, as specified in Section 2 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

sub

OPTIONAL. Subject Identifier, as specified in Section 2 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

aud

REQUIRED. Audience(s), as specified in Section 2 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

iat

REQUIRED. Issued at time, as specified in Section 2 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

exp

REQUIRED. Expiration time, as specified in Section 2 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

jti

REQUIRED. Unique identifier for the token, as specified in Section 9 of [OpenID.Core] (Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, “OpenID Connect Core 1.0,” December 2023.).

events

REQUIRED. Claim whose value is a JSON object containing the member name http://schemas.openid.net/event/backchannel-logout. This declares that the JWT is a Logout Token. The corresponding member value MUST be a JSON object and SHOULD be the empty JSON object {}.

sid

OPTIONAL. Session ID - String identifier for a Session. This represents a Session of a User Agent or device for a logged-in End-User at an RP. Different sid values are used to identify distinct sessions at an OP. The sid value need only be unique in the context of a particular issuer. Its contents are opaque to the RP. Its syntax is the same as an OAuth 2.0 Client Identifier.

A Logout Token MUST contain either a sub or a sid Claim, and MAY contain both. If a sid Claim is not present, the intent is that all sessions at the RP for the End-User identified by the iss and sub Claims be logged out.

The following Claim MUST NOT be used within the Logout Token:

nonce

PROHIBITED. A nonce Claim MUST NOT be present. Its use is prohibited to make a Logout Token syntactically invalid if used in a forged Authentication Response in place of an ID Token.

Logout Tokens MAY contain other Claims. Any Claims used that are not understood MUST be ignored.

A Logout Token MUST be signed and MAY also be encrypted. The same keys are used to sign and encrypt Logout Tokens as are used for ID Tokens. If the Logout Token is encrypted, it SHOULD replicate the iss (issuer) claim in the JWT Header Parameters, as specified in Section 5.3 of [JWT] (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” May 2015.).

It is RECOMMENDED that Logout Tokens be explicitly typed. This is accomplished by including a typ (type) Header Parameter with a value of logout+jwt in the Logout Token. See Section 4.1 (Cross-JWT Confusion) for a discussion of the security and interoperability considerations of using explicit typing.

NOTE: The Logout Token is compatible with the Security Event Token (SET) [RFC8417] (Hunt, P., Ed., Jones, M., Denniss, W., and M. Ansari, “Security Event Token (SET),” July 2018.) specification, but uses a more specific typ (type) value.

A non-normative example JWT Claims Set for a Logout Token follows:

  {
   "iss": "https://server.example.com",
   "sub": "248289761001",
   "aud": "s6BhdRkqt3",
   "iat": 1471566154,
   "exp": 1471569754,
   "jti": "bWJq",
   "sid": "08a5019c-17e1-4977-8f42-65a12843ea02",
   "events": {
     "http://schemas.openid.net/event/backchannel-logout": {}
     }
  }

2.5.  Back-Channel Logout Request

The OP uses an HTTP POST to the registered back-channel logout URI to trigger the logout actions by the RP. The POST body uses the application/x-www-form-urlencoded encoding and must include a logout_token parameter containing a Logout Token from the OP for the RP identifying the End-User to be logged out.

The POST body MAY contain other values in addition to logout_token. Values that are not understood by the implementation MUST be ignored.

The following is a non-normative example of such a logout request (with most of the Logout Token contents omitted for brevity):

  POST /backchannel_logout HTTP/1.1
  Host: rp.example.org
  Content-Type: application/x-www-form-urlencoded

  logout_token=eyJhbGci ... .eyJpc3Mi ... .T3BlbklE ...

The OP should not retransmit a Back-Channel Logout Request unless the OP suspects that previous transmissions may have failed due to potentially recoverable errors (such as network outage or temporary service interruption at either the OP or RP). In this case, the OP SHOULD delay retransmission for an appropriate amount of time to avoid overwhelming the RP. In all other cases, the OP SHOULD NOT retransmit a Back-Channel Logout Request. (Note that this is the same retransmission logic as specified in Push-Based Security Event Token (SET) Delivery Using HTTP (Backman, A., Ed., Jones, M., Ed., Scurtescu, M., Ansari, M., and A. Nadalin, “Push-Based Security Event Token (SET) Delivery Using HTTP,” November 2020.) [RFC8935].)

2.6.  Logout Token Validation

Upon receiving a logout request at the back-channel logout URI, the RP MUST validate the Logout Token as follows:

1. If the Logout Token is encrypted, decrypt it using the keys and algorithms that the Client specified during Registration that the OP was to use to encrypt ID Tokens. If ID Token encryption was negotiated with the OP at Registration time and the Logout Token is not encrypted, the RP SHOULD reject it.
2. Validate the Logout Token signature in the same way that an ID Token signature is validated, with the following refinements.
3. Validate the alg (algorithm) Header Parameter in the same way it is validated for ID Tokens. Like ID Tokens, selection of the algorithm used is governed by the id_token_signing_alg_values_supported Discovery parameter and the id_token_signed_response_alg Registration parameter when they are used; otherwise, the value SHOULD be the default of RS256. Additionally, an alg with the value none MUST NOT be used for Logout Tokens.
4. Validate the iss, aud, iat, and exp Claims in the same way they are validated in ID Tokens.
5. Verify that the Logout Token contains a sub Claim, a sid Claim, or both.
6. Verify that the Logout Token contains an events Claim whose value is JSON object containing the member name http://schemas.openid.net/event/backchannel-logout.
7. Verify that the Logout Token does not contain a nonce Claim.
8. Optionally verify that another Logout Token with the same jti value has not been recently received.
9. Optionally verify that the iss Logout Token Claim matches the iss Claim in an ID Token issued for the current session or a recent session of this RP with the OP.
10. Optionally verify that any sub Logout Token Claim matches the sub Claim in an ID Token issued for the current session or a recent session of this RP with the OP.
11. Optionally verify that any sid Logout Token Claim matches the sid Claim in an ID Token issued for the current session or a recent session of this RP with the OP.

If any of the validation steps fails, reject the Logout Token and return an HTTP 400 Bad Request error. Otherwise, proceed to perform the logout actions.

2.7.  Back-Channel Logout Actions

After receiving a valid Logout Token from the OpenID Provider, the RP locates the session(s) identified by the iss and sub Claims and/or the sid Claim. The RP then clears any state associated with the identified session(s). The mechanism by which the RP achieves this is implementation specific. If the identified End-User is already logged out at the RP when the logout request is received, the logout is considered to have succeeded.

In the case that the RP is also an OP serving as an identity provider to downstream logged-in sessions, it is desirable for the logout request to the RP to likewise trigger downstream logout requests. This is achieved by having the RP/OP send logout requests to its downstream RPs as part of its logout actions.

Refresh tokens issued without the offline_access property to a session being logged out SHOULD be revoked. Refresh tokens issued with the offline_access property normally SHOULD NOT be revoked.

2.8.  Back-Channel Logout Response

If the logout succeeded, the RP MUST respond with HTTP 200 OK. However, note that some Web frameworks will substitute an HTTP 204 No Content response for an HTTP 200 OK when the HTTP body is empty. Therefore, OPs should be prepared to also process an HTTP 204 No Content response as a successful response.

If the logout request was invalid or the logout failed, the RP MUST respond with HTTP 400 Bad Request. The response MAY include an HTTP body consisting of a JSON object with error and error_description parameters conveying the nature of the error that occurred, which can assist with debugging. These error response parameters are used as specified in Section 5.2 of OAuth 2.0 (Hardt, D., Ed., “The OAuth 2.0 Authorization Framework,” October 2012.) [RFC6749]. Like in OAuth 2.0, the parameters are included in the entity-body of the HTTP response using the application/json media type. Also like in OAuth 2.0, the error parameter is REQUIRED when a response body is present and the error_description parameter is OPTIONAL. An error value of invalid_request MAY be used to indicate that there was a problem with the syntax of the logout request. Note that the information conveyed in the response body is intended to help debug deployments; it is not intended that implementations use different error values to trigger different runtime behaviors.

The RP's response SHOULD include the Cache-Control HTTP response header field with a no-store value, keeping the response from being cached to prevent cached responses from interfering with future logout requests. An example of this is:

  Cache-Control: no-store

3.  Implementation Considerations

This specification defines features used by both Relying Parties and OpenID Providers that choose to implement Back-Channel Logout. All of these Relying Parties and OpenID Providers MUST implement the features that are listed in this specification as being "REQUIRED" or are described with a "MUST". No other implementation considerations for implementations of Back-Channel Logout are defined by this specification.

4.  Security Considerations

The signed Logout Token is required in the logout request to prevent denial of service attacks by enabling the RP to verify that the logout request is coming from a legitimate party.

The kinds of Relying Parties that can be logged out by different implementations will vary. Implementations should make it clear, for instance, whether they are capable of logging out native applications or only Web RPs.

OPs are encouraged to use short expiration times in Logout Tokens, preferably at most two minutes in the future, to prevent captured Logout Tokens from being replayable.

4.1.  Cross-JWT Confusion

As described in Section 2.8 of [RFC8725] (Sheffer, Y., Hardt, D., and M. Jones, “JSON Web Token Best Current Practices,” February 2020.), attackers may attempt to use a JWT issued for one purpose in a context that it was not intended for. The mitigations described for these attacks can be applied to Logout Tokens.

One way that an attacker might attempt to repurpose a Logout Token is to try to use it as an ID Token. As described in Section 2.4 (Logout Token), inclusion of a nonce Claim in a Logout Token is prohibited to prevent its misuse as an ID Token.

Another way to prevent cross-JWT confusion is to use explicit typing, as described in Section 3.11 of [RFC8725] (Sheffer, Y., Hardt, D., and M. Jones, “JSON Web Token Best Current Practices,” February 2020.). One would explicitly type a Logout Token by including a typ (type) Header Parameter with a value of logout+jwt (which is registered in Section 5.3.1 (Registry Contents). Note that the application/ portion of the application/logout+jwt media type name is omitted when used as a typ Header Parameter value, as described in the typ definition in Section 4.1.9 [JWS] (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Signature (JWS),” May 2015.). Including an explicit type in issued Logout Tokens is a best practice. Note however, that requiring explicitly typed Logout Tokens will break most existing deployments, as existing OPs and RPs are already commonly using untyped Logout Tokens. However, requiring explicit typing would be a good idea for new deployment profiles where compatibility with existing deployments is not a consideration.

5.  IANA Considerations

5.1.  OAuth Dynamic Client Registration Metadata Registration

This specification registers the following client metadata definitions in the IANA "OAuth Dynamic Client Registration Metadata" registry [IANA.OAuth.Parameters] (IANA, “OAuth Parameters,” .) established by [RFC7591] (Richer, J., Ed., Jones, M., Bradley, J., Machulak, M., and P. Hunt, “OAuth 2.0 Dynamic Client Registration Protocol,” July 2015.):

5.1.1.  Registry Contents

• Client Metadata Name: backchannel_logout_uri
• Client Metadata Description: RP URL that will cause the RP to log itself out when sent a Logout Token by the OP
• Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Specification Document(s): Section 2.2 (Indicating RP Support for Back-Channel Logout) of this specification

• Client Metadata Name: backchannel_logout_session_required
• Client Metadata Description: Boolean value specifying whether the RP requires that a sid (session ID) Claim be included in the Logout Token to identify the RP session with the OP when the backchannel_logout_uri is used
• Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Specification Document(s): Section 2.2 (Indicating RP Support for Back-Channel Logout) of this specification

5.2.  OAuth Authorization Server Metadata Registry

This specification registers the following metadata names in the IANA "OAuth Authorization Server Metadata" registry [IANA.OAuth.Parameters] (IANA, “OAuth Parameters,” .) established by [RFC8414] (Jones, M., Sakimura, N., and J. Bradley, “OAuth 2.0 Authorization Server Metadata,” June 2018.).

5.2.1.  Registry Contents

• Metadata Name: backchannel_logout_supported
• Metadata Description: Boolean value specifying whether the OP supports back-channel logout, with true indicating support
• Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Specification Document(s): Section 2.1 (Indicating OP Support for Back-Channel Logout) of this specification

• Metadata Name: backchannel_logout_session_supported
• Metadata Description: Boolean value specifying whether the OP can pass a sid (session ID) Claim in the Logout Token to identify the RP session with the OP
• Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Specification Document(s): Section 2.1 (Indicating OP Support for Back-Channel Logout) of this specification

5.3.  Media Type Registration

5.3.1.  Registry Contents

This section registers the application/logout+jwt media type [RFC2046] (Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types,” November 1996.) in the IANA "Media Types" registry [IANA.MediaTypes] (IANA, “Media Types,” .) in the manner described in [RFC6838] (Freed, N., Klensin, J., and T. Hansen, “Media Type Specifications and Registration Procedures,” January 2013.), which can be used to indicate that the content is a Logout Token.

• Type name: application
• Subtype name: logout+jwt
• Required parameters: n/a
• Optional parameters: n/a
• Encoding considerations: binary; A Logout Token is a JWT; JWT values are encoded as a series of base64url-encoded values (some of which may be the empty string) separated by period ('.') characters.
• Security considerations: See Section 4.1 (Cross-JWT Confusion) of this specification
• Interoperability considerations: n/a
• Published specification: Section 2.4 (Logout Token) of this specification
• Applications that use this media type: Applications that use Logout Tokens to achieve back-channel logout
• Fragment identifier considerations: n/a
• Additional information:

  Magic number(s): n/a

  File extension(s): n/a

  Macintosh file type code(s): n/a

  
  
• Person & email address to contact for further information:
  OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Intended usage: COMMON
• Restrictions on usage: none
• Author: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net
• Provisional registration? No

6.  References

6.1. Normative References

6.2. Informative References

Appendix A.  Acknowledgements

The OpenID Community would like to thank the following people for their contributions to this specification:

John Bradley (ve7jtb@ve7jtb.com), Yubico

Brian Campbell (bcampbell@pingidentity.com), Ping Identity

Andrii Deinega (andrii.deinega@gmail.com), GlobalLogic

Vladimir Dzhuvinov (vladimir@connect2id.com), Connect2id

Pedro Felix (pmhsfelix@gmail.com), individual

Joseph Heenan (joseph@authlete.com), Authlete

Phil Hunt (phil.hunt@independentid.com), Independent Identity, Inc.

Michael B. Jones (michael_b_jones@hotmail.com), Self-Issued Consulting (was at Microsoft)

Todd Lainhart (lainhart@us.ibm.com), IBM

Torsten Lodderstedt (torsten@lodderstedt.net), independent (was at yes.com)

Nat Sakimura (nat@nat.consulting), NAT.Consulting

Filip Skokan (panva.ip@gmail.com), Auth0

Hans Zandbelt (hans.zandbelt@zmartzone.eu), ZmartZone

Appendix B.  Notices

Copyright (c) 2023 The OpenID Foundation.

The OpenID Foundation (OIDF) grants to any Contributor, developer, implementer, or other interested party a non-exclusive, royalty free, worldwide copyright license to reproduce, prepare derivative works from, distribute, perform and display, this Implementers Draft or Final Specification solely for the purposes of (i) developing specifications, and (ii) implementing Implementers Drafts and Final Specifications based on such documents, provided that attribution be made to the OIDF as the source of the material, but that such attribution does not indicate an endorsement by the OIDF.

The technology described in this specification was made available from contributions from various sources, including members of the OpenID Foundation and others. Although the OpenID Foundation has taken steps to help ensure that the technology is available for distribution, it takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this specification or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any independent effort to identify any such rights. The OpenID Foundation and the contributors to this specification make no (and hereby expressly disclaim any) warranties (express, implied, or otherwise), including implied warranties of merchantability, non-infringement, fitness for a particular purpose, or title, related to this specification, and the entire risk as to implementing this specification is assumed by the implementer. The OpenID Intellectual Property Rights policy requires contributors to offer a patent promise not to assert certain patent claims against other contributors and against implementers. The OpenID Foundation invites any interested party to bring to its attention any copyrights, patents, patent applications, or other proprietary rights that may cover technology that may be required to practice this specification.

Authors' Addresses