National foreword

This British Standard is the UK implementation of ISO/IEC 26136:2024.

The UK participation in its preparation was entrusted to Technical Committee ICT/1, Information systems co-ordination.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2024.

Foreword

ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of document should be noted (see www.iso.org/directives or www.iec.ch/members_experts/refdocs).

ISO and IEC draw attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents and https://patents.iec.ch. ISO and IEC shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.

This document was prepared by the OpenID Foundation (OIDF) (as OpenID Connect Front-Channel Logout 1.0) and drafted in accordance with its editorial rules. It was adopted, under the JTC 1 PAS procedure, by Joint Technical Committee ISO/IEC JTC 1, Information technology.

Any feedback or questions on this document should be directed to the user's national standards body. A complete listing of these bodies can be found at www.iso.org/members.html and www.iec.ch/national-committees.

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 front-channel communication via the User Agent between the OP and RPs being logged out that does not need an OpenID Provider iframe on Relying Party pages. Other protocols have used HTTP GETs to RP URLs that clear login state to achieve this. This specification does the same thing.

1 Introduction

OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 [RFC6749] 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 front-channel communication via the User Agent between the OP and RPs being logged out that does not need an OpenID Provider iframe on Relying Party pages, as OpenID Connect Session Management 1.0 [OpenID.Session] does. Other protocols have used HTTP GETs to RP URLs that clear login state to achieve this; this specification does the same thing.

In contrast, the OpenID Connect Back-Channel Logout 1.0 [OpenID.BackChannel] specification 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. The OpenID Connect RP-Initiated Logout 1.0 [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 Back-Channel Logout 1.0.

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 [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", "Client Identifier", and "Redirection URI" defined by OAuth 2.0 [RFC6749], the term "User Agent" defined by RFC 7230 [RFC7230], and the terms defined by OpenID Connect Core 1.0 [OpenID.Core].

This specification also defines the following terms:

Session
- Continuous period of time during which an End-User accesses a Relying Party relying on the Authentication of the End-User performed by the OpenID Provider.
Session ID
- Identifier for a Session.

2 Relying Party Logout Functionality

3 OpenID Provider Logout Functionality

3.1 Example Front-Channel Logout URL Usage

4 Implementation Considerations

4.1 User Agents Blocking Access to Third-Party Content

5 Security Considerations

6 IANA Considerations

6.1 JSON Web Token Claims Registration

6.2 OAuth Dynamic Client Registration Metadata Registration

6.3 OAuth Authorization Server Metadata Registry

7 References

7.1 Normative References

7.2 Informative References

BS ISO/IEC 26136:2024

Information technology. OpenID connect. OpenID connect front-channel logout 1.0

Current

Published:

30 Nov 2024