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
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   This Internet-Draft will expire on March 12, 2011.

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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










































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.  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.


.  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 ]].




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   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.








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.  Acknowledgements

   I would like to thank Stefanie Dronia, Sebastian Ebling, and
   Christian Stuebner for their valuable feedback.


.  IANA Considerations

   This draft includes no request to IANA.


.  Security Considerations

   All relevant security considerations have been given in the
   functional specification.


.  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,
              <http://tools.ietf.org/html/draft-ietf-oauth-v2-10>.


Author's Address

   Dr.-Ing. Torsten Lodderstedt
   Deutsche Telekom AG

   Email: torsten@lodderstedt.net




















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