Open Authentication Protocol T. Lodderstedt Internet-Draft Deutsche Telekom AG Intended status: Standards Track September 8, 2010 Expires: March 12, 2011 Token Revocation draft-lodderstedt-oauth-revocation-00 Abstract This draft proposes an additional endpoint for OAuth authorization servers for revoking tokens. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on March 12, 2011. Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Lodderstedt Expires March 12, 2011 [Page 1] Internet-Draft token revocation September 2010 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Token Revocation . . . . . . . . . . . . . . . . . . . . . . . 3 3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. Informative References . . . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 5 Lodderstedt Expires March 12, 2011 [Page 2] Internet-Draft token revocation September 2010 1. Introduction The current OAuth 2.0 draft [draft-ietf-oauth-v2-10] defines several ways for a client to obtain refresh and access tokens. This specification supplements the draft with a mechanism to finalize the life cycle of both types of tokens. From an end user's perspective, this mechanism is used to realize application logout or the removal of a persistent application's permission to access the user's resources. By using an additional endpoint, the token revocation endpoint, clients can request the revocation of a particular token. Compliant implementation must support the revocation of refresh tokens, access token revocation is an optional feature. 2. Token Revocation The client requests the revocation of a particular token by making an HTTP "POST" request to the token revocation endpoint. The location of the token revocation endpoint can be found in the authorization servers documentation, or can be obtained by using [[OAuth Discovery ]]. The token endpoint URI MAY include a query component. Since requests to the token revocation endpoint result in the transmission of plain text credentials in the HTTP request, the authorization server MUST require the use of a transport-layer security mechanism when sending requests to the token revocation endpoints. Authorization servers MUST support TLS 1.2 as defined in [RFC5246], and MAY support additional transport-layer security mechanisms. The client authenticates with the authorization server by adding its client credentials to the request as described in Section 2 of [draft-ietf-oauth-v2-10]. The client constructs the request by including the following parameters using the "application/x-www-form-urlencoded" format in the HTTP request entity-body: token REQUIRED. The token that the client wants to get revoked. token_type REQUIRED. The type of the token to be revoked, either "refresh_token" or "access_token". Information about the supported token types can be found in the authorization server's documentation, or can be obtained by using [[OAuth Discovery ]]. Lodderstedt Expires March 12, 2011 [Page 3] Internet-Draft token revocation September 2010 For example, a client may request the revocation of a refresh token with the following request (line breaks are for display purposes only): POST /revoke HTTP/1.1 Host: server.example.com Content-Type: application/x-www-form-urlencoded token=45ghiukldjahdnhzdauz&token_type=refresh_token& client_id=s6BhdRkqt3&client_secret=gX1fBat3bV The authorization server first verifies whether the client is authorized to revoke the particular token based on the client credentials and its policy. For example, only the client the token has been issued for might be allowed to revoke it. It is also conceivable to allow a dedicated user self-care portal to revoke all kinds of tokens. In the next step, the authorization server invalidates the token. Whether the revocation takes effect instantly or with some delay depends on the architecture of the particular deployment. The client shall not make any assumption about the timing and MUST NOT use the token again. If the processed token is a refresh token and the authorization server supports the revocation of access tokens, then the authorization server must also invalidate all access tokens issued for that refresh token. The authorization server indicates a successful processing of the request by a HTTP status code 204. Status code 401 indicates a failed client authentication, whereas a status code 403 is used if the client is not authorized to revoke the particular token. For all other error conditions, a status code 400 is used along with an error response as defined in section 4.3. of [draft-ietf-oauth-v2-10]. The following error codes are defined for the token revocation endpoint: unsupported_token_type The authorization server does not support the revocation of the presented token type. i.e. the client tried to revoke an access token on a server not supporting this feature. invalid_token The presented token is invalid. Lodderstedt Expires March 12, 2011 [Page 4] Internet-Draft token revocation September 2010 3. Acknowledgements I would like to thank Stefanie Dronia, Sebastian Ebling, and Christian Stuebner for their valuable feedback. 4. IANA Considerations This draft includes no request to IANA. 5. Security Considerations All relevant security considerations have been given in the functional specification. 6. Informative References [draft-ietf-oauth-v2-10] Hammer-Lahav, E., Ed., Recordon, D., and D. Hardt, "The OAuth 2.0 Protocol draft-ietf-oauth-v2-10", July 2010, . Author's Address Dr.-Ing. Torsten Lodderstedt Deutsche Telekom AG Email: torsten@lodderstedt.net Lodderstedt Expires March 12, 2011 [Page 5]