Google

breno@google.com

Google

naa@google.com

Nomura Research Institute, Ltd.

n-sakimura@nri.co.jp

Ping Identity

ve7jtb@ve7jtb.com

Microsoft

mbj@microsoft.com

OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol. It allows 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 document describes how to manage sessions for OpenID Connect, including when to log out the user.

This specification complements the OpenID Connect Messages 1.0 and OpenID Connect Standard 1.0 specifications by defining how to monitor the user's login status at the OpenID Provider on an ongoing basis so that the Relying Party can log out the user once the user has logged out of the OpenID Provider.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. Throughout this document, 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.

This specification uses the terms "Access Token", "Refresh Token", "Authorization Code", "Authorization Grant", "Authorization Server", "Authorization Endpoint", "Client", "Client Identifier", "Client Secret", "Protected Resource", "Resource Owner", "Resource Server", and "Token Endpoint" defined by OAuth 2.0, and the terms defined by OpenID Connect Messages 1.0. This specification also defines the following term: Instance of an interactive logged-in session at a Relying Party with a particular OpenID Provider and End-User identity.

To support OpenID Connect session management, the RP needs to obtain the session management related endpoint URLs. This can either be communicated out of band or through the OP configuration file, as described in OpenID Connect Discovery 1.0. The OP endpoints defined in this specification are as follows: URL of an OP iframe that supports cross-origin communications for session state information with the RP Client, using the HTML 5 postMessage API. The page is loaded from an invisible iframe embedded in an RP page so that it can run in the OP's security context. It accepts postMessage requests from the relevant RP iframe and uses postMessage to post back the login status of the user at the OP. URL at the OP that an RP can redirect the user to log out at the OP.

In OpenID Connect, the session at the RP typically starts when the RP validates the user's ID Token. Refer to the OpenID Connect Messages 1.0 and OpenID Connect Standard 1.0 specifications to find out how to obtain an ID Token and validate it. When the OP supports session management, it MUST also return the Session State as an additional session_state parameter in the Authorization Response. An OpenID Connect Authorization Response is specified in Section 2.1.2 of OpenID Connect Messages 1.0. This parameter is: Session State. JSON string that represents the user's login state at the OP. This string is opaque to the RP. This is REQUIRED if session management is supported.

ID Token typically comes with the expiry date. The RP MAY rely on it to expire the RP session. However, it is entirely possible that the user may have logged out of the OP before the expiry date. Therefore, it is highly desirable to be able to find out the login status of the user at the OP. To do so, it is possible to repeat the authentication request with prompt=none. However, this causes network traffic and this is problematic on the mobile devices that are increasingly becoming popular. Therefore, once the session is established with the authentication request and response, it is desirable to be able to check the login status at the OP without causing network traffic by polling the hidden OP iframe from a RP iframe with origin restricted postMessage as follows.

The RP typically loads an invisible OP iframe in the page from the OP's check_session_iframe. The RP MUST assign an id attribute to the iframe so that it can address it later. The OP iframe MUST enforce that the caller has the same origin as its parent frame. It MUST reject postMessage requests from any other source origin. The postMessage from the RP iframe delivers the concatenation of the following, as the data: Client ID + " " + Session State The OP frame has access to Browser state at the OP (in a cookie or in HTML5 storage) that it uses to calculate and compare the OP session state that was passed by the RP. The OP iframe MUST recalculate it from the previously obtained Client ID, the source origin URL (from the postMessage), and the current OP Browser state. If the received value and the calculated value do not match, then the OP iframe MUST postMessage the string changed back to the source. If it matched, then it MUST postMessage the string unchanged. Following is non-normative example pseudo-code for the OP iframe:

The OP browser state is typically going to be stored in a cookie or HTML5 local storage. It is origin bound to the Authorization Server. It captures meaningful events such as logins, logouts, change of user, change of authorization status for Clients being used by the end-user, etc. Thus, the OP should update the value of the browser state in response to such meaningful events. As a result, the next call to check_session() after such an event will return the value changed. It is recommended that the OP do not update the browser state too frequently in the absence of meaningful events so as to spare excessive network traffic at the Client in response to spurious changed events. The computation of the session state returned in response to unsuccessful Authorization Requests should, in addition to the browser state, incorporate sufficient randomness in the form of a salt so as to prevent identification of a user across successive calls to the OP's Authorization Endpoint. In the case of an authorized Client (successful Authorization Response), the OP should change the value of the session state returned to the Client under one of the following events: The set of users authenticated to the browser changes (login, logout, session add). The authorization status of Clients being used by the end-user changes. In addition, the browser state used to verify the session state should change with such events. Calls to check_session() will return changed against earlier versions of session state after such events. It is recommended that the browser state should not vary too frequently in the absence of such events to minimize network traffic caused by the Client's response to changed notifications. In the case of an unsuccessful Authorization Request, the value of the session state returned should vary with each request. However, the browser session state need not change unless a meaningful event happens. In particular, many values of session state can be simultaneously valid, for instance by the introduction of random salt in the session states issued in response to unsuccessful Authorization Requests.

The RP also loads an invisible iframe from itself in the same page. This iframe MUST know the ID of the OP iframe so that it can postMessage to the OP iframe. RP iframe polls OP iframe with postMessage with certain interval suitable for the RP application. With each postMessage, it sends the session state defined in Section 4.1. It also has to be able to receive the postMessage back from the OP iframe. The received data would either be changed or unchanged. Upon receipt of changed, the RP MUST perform the re-authentication with prompt=none to find the current session state at the OP. Following is non-normative example pseudo-code for the RP iframe:

When the RP detects a session state change, it should first try an immediate mode request within an iframe to obtain a new ID Token and session state, sending the old ID Token as the id_token_hint. If the RP receives an ID token for the same user, it should simply update the value of the session state. If it doesn't receive an ID token or receives an ID token for another user, then it needs to handle this case as a logout for the original user. Note that the session state is origin bound. Session state SHOULD be returned upon an authorization failure.

Sometimes, the RP may want to notify the OP that the user has logged out of the site, and he may want to logout of the OP as well. In this case, the RP, after having logged out the user, sends the user to the OP's logout endpoint URL that is either advertised through OP's provider configuration information or via out of band knowledge. Upon receipt of such message, the OP SHOULD prompt the user whether he wants to logout of the OP as well. If the user says "yes", then the OP MUST log the user out.

In some cases, the RP may want the user to be redirected back to the RP after a logout has been performed. This specification defines an additional dynamic registration parameter for this purpose, per Section 2.1 of OpenID Connect Dynamic Client Registration 1.0. OPTIONAL. URL supplied by the RP to request that the user be redirected to this location after a logout has been performed. If supplied, the OP SHOULD honor this request following a logout initiated from this RP.

If any of the validation procedures defined in this specification fail, any operations requiring the information that failed to correctly validate MUST be aborted and the information that failed to validate MUST NOT be used.

This specification defines features used by both Relying Parties and OpenID Providers that choose to implement Session Management. 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 Session Management are defined by this specification.

The OP iframe MUST enforce that the caller has the same origin as its parent frame. It MUST reject postMessage requests from any other source origin, to prevent cross-site scripting attacks.

This specification registers the following parameters in the IANA OAuth Parameters registry defined in RFC 6749.

Parameter name: session_state Parameter usage location: Authorization Response, Access Token Response Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None

Nomura Research Institute, Ltd. Ping Identity Microsoft Google Salesforce Illumila Nomura Research Institute, Ltd. Ping Identity Microsoft Google Salesforce Illumila Nomura Research Institute, Ltd. Ping Identity Microsoft Illumila Nomura Research Institute, Ltd. Ping Identity Microsoft

Naveen Agarwal, Amanda Anganes, John Bradley, Breno de Medeiros, George Fletcher, Edmund Jay, Michael B. Jones, Torsten Lodderstedt, Tony Nadalin, Axel Nennker, Justin Richer, and Nat Sakimura contributed to the design of this specification.

Copyright (c) 2013 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.

[[ To be removed from the final specification ]] -12 Fixed #364 - Term "Session" not defined. State that when any validations fail, any operations requiring the information that failed to correctly validate MUST be aborted and the information that failed to validate MUST NOT be used. Fixed #779 - Parameters missing from IANA Considerations. Fixed #782 - Changed uses of "_url" in identifiers to "_uri". -11 Applied changes from October 24, 2012 editing session at the Internet Identity Workshop (IIW). This separates the session state from the ID Token, adding the new session_state parameter to the authorization response. These identifiers also changed: check_session_endpoint to check_session_iframe_url and end_session_endpoint to end_session_endpoint_url. Fixed #605 - op_logout_url description. Added Implementation Considerations section. Fixed #698 - Inconsistent use of articles. Naming consistency changes. Renamed check_session_iframe_url to check_session_iframe and end_session_endpoint_url back to end_session_endpoint. -10 Fixed #689 - Track JWT change that allows JWTs to have multiple audiences. -09 Changed user_hint to id_token_hint for consistency with Messages. Fixed #666 - JWS signature validation vs. verification. Referenced OAuth 2.0 RFC -- RFC 6749. -08 Complete rewrite based on the decisions made at the May 5, 2012 face to face working group meeting. -07 Added warning about the significant revisions planned to session management to the abstract and introduction. Changed client.example.com to client.example.org, per issue #251 Listed author of ISO29115 as "International Telecommunication Union and International Organization for Standardization", per issue #589 Use standards track version of JSON Web Token spec (draft-ietf-oauth-json-web-token) -06 Updated Notices Updated References -05 Removed Check Session Endpoint Updated ID Token claims to reflect changes in Messages -04 Changes associated with renaming "Lite" to "Basic Client" and replacing "Core" and "Framework" with "Messages" and "Standard". Numerous cleanups, including updating references. -03 Corrected examples. -02 Correct issues raised by Johnny Bufu and discussed on the 7-Jul-11 working group call. -01 Consistency and cleanup pass, including removing unused references. -00 Split from core when all optional features were removed.