OAuth Working Group                                       J. Richer, Ed.
Internet-Draft
Intended status: Experimental                                   M. Jones
Expires: September 24, 2015                                    Microsoft
                                                              J. Bradley
                                                           Ping Identity
                                                             M. Machulak
                                                    Newcastle University
                                                          March 23, 2015


       OAuth 2.0 Dynamic Client Registration Management Protocol
                 draft-ietf-oauth-dyn-reg-management-11

Abstract

   This specification defines methods for management of dynamic OAuth
   2.0 client registrations for use cases in which the properties of a
   registered client may need to be changed during the lifetime of the
   client.  Not all authorization servers supporting dynamic client
   registration will support these management methods.

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 September 24, 2015.

Copyright Notice

   Copyright (c) 2015 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



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   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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Notational Conventions  . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Protocol Flow . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Client Configuration Endpoint . . . . . . . . . . . . . . . .   5
     2.1.  Client Read Request . . . . . . . . . . . . . . . . . . .   6
     2.2.  Client Update Request . . . . . . . . . . . . . . . . . .   6
     2.3.  Client Delete Request . . . . . . . . . . . . . . . . . .   9
   3.  Client Information Response . . . . . . . . . . . . . . . . .  10
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   6.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  13
   7.  Normative References  . . . . . . . . . . . . . . . . . . . .  13
   Appendix A.  Acknowledgments  . . . . . . . . . . . . . . . . . .  13
   Appendix B.  Registration Tokens and Client Credentials . . . . .  14
     B.1.  Credential Rotation . . . . . . . . . . . . . . . . . . .  15
   Appendix C.  Forming the Client Configuration Endpoint URL  . . .  15
   Appendix D.  Document History . . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   In order for an OAuth 2.0 client to utilize an OAuth 2.0
   authorization server, the client needs specific information to
   interact with the server, including an OAuth 2.0 client identifier to
   use with that server.  The OAuth 2.0 Dynamic Client Registration
   Protocol [OAuth.Registration] specification describes how an OAuth
   2.0 client can be dynamically registered with an authorization server
   to obtain this information and how metadata about the client can be
   registered with the server.

   This specification extends the core registration specification by
   defining a set of methods for management of dynamic OAuth 2.0 client
   registrations beyond those defined in the core registration
   specification.  In some situations, the registered metadata of a
   client can change over time, either by modification at the
   authorization server or by a change in the client software itself.
   This specification provides methods for the current registration
   state of a client to be queried at the authorization server, methods
   for the registration of a client to be updated at the authorization



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   server, and methods for the client to be unregistered from the
   authorization server.

1.1.  Notational Conventions

   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 [RFC2119].

   Unless otherwise noted, all the protocol parameter names and values
   are case sensitive.

1.2.  Terminology

   This specification uses the terms "access token", "authorization
   code", "authorization endpoint", "authorization grant",
   "authorization server", "client", "client identifier", "client
   secret", "grant type", "protected resource", "redirection URI",
   "refresh token", "resource owner", "resource server", "response
   type", and "token endpoint" defined by OAuth 2.0 [RFC6749] and the
   terms defined by the OAuth 2.0 Client Dynamic Registration Protocol
   [OAuth.Registration].

   This specification defines the following terms:

   Client Configuration Endpoint
      OAuth 2.0 endpoint through which registration information for a
      registered client can be managed.  This URL for this endpoint is
      returned by the authorization server in the client information
      response.

   Registration Access Token
      OAuth 2.0 bearer token issued by the authorization server through
      the client registration endpoint that is used to authenticate the
      caller when accessing the client's registration information at the
      client configuration endpoint.  This access token is associated
      with a particular registered client.

1.3.  Protocol Flow












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   This extends the flow in the OAuth 2.0 Dynamic Client Registration
   Protocol [OAuth.Registration] specification as follows:

        +--------(A)- Initial Access Token (OPTIONAL)
        |
        |   +----(B)- Software Statement (OPTIONAL)
        |   |
        v   v
    +-----------+                                      +---------------+
    |           |--(C)- Client Registration Request -->|    Client     |
    |           |                                      | Registration  |
    |           |<-(D)- Client Information Response ---|   Endpoint    |
    |           |                                      +---------------+
    |           |
    |           |                                      +---------------+
    | Client or |--(E)- Read or Update Request ------->|               |
    | Developer |                                      |               |
    |           |<-(F)- Client Information Response ---|    Client     |
    |           |                                      | Configuration |
    |           |                                      |   Endpoint    |
    |           |                                      |               |
    |           |--(G)- Delete Request --------------->|               |
    |           |                                      |               |
    |           |<-(H)- Delete Confirmation -----------|               |
    +-----------+                                      +---------------+

   Figure 1: Abstract Extended Dynamic Client Registration Flow

   The abstract OAuth 2.0 client dynamic registration flow illustrated
   in Figure 1 describes the interaction between the client or developer
   and the endpoints defined in this specification and its parent.  This
   figure does not demonstrate error conditions.  This flow includes the
   following steps:

   (A)  Optionally, the client or developer is issued an initial access
      token for use with the client registration endpoint.  The method
      by which the initial access token is issued to the client or
      developer is out of scope for this specification.

   (B)  Optionally, the client or developer is issued a software
      statement for use with the client registration endpoint.  The
      method by which the software statement is issued to the client or
      developer is out of scope for this specification.

   (C)  The client or developer calls the client registration endpoint
      with its desired registration metadata, optionally including the
      initial access token from (A) if one is required by the
      authorization server.



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   (D)  The authorization server registers the client and returns:

      *  the client's registered metadata,

      *  a client identifier that is unique to the server,

      *  a set of client credentials such as a client secret, if
         applicable for this client,

      *  a URI pointing to the client configuration endpoint, and

      *  a registration access token to be used when calling the client
         configuration endpoint.

   (E)  The client or developer optionally calls the client
      configuration endpoint with a read or update request using the
      registration access token issued in (D).  An update request
      contains all of the client's registered metadata.

   (F)  The authorization server responds with the client's current
      configuration, potentially including a new registration access
      token and a new set of client credentials such as a client secret
      if applicable for this client.  If a new registration access token
      is issued, it replaces the token issued in (D) for all subsequent
      calls to the client configuration endpoint.

   (G)  The client or developer optionally calls the client
      configuration endpoint with a delete request using the
      registration access token issued in (D) or (F).

   (H)  The authorization server deprovisions the client and responds
      with a confirmation that the deletion has taken place.

2.  Client Configuration Endpoint

   The client configuration endpoint is an OAuth 2.0 protected resource
   that is provisioned by the server to facilitate viewing, updating,
   and deleting a client's registered information.  The location of this
   endpoint is communicated to the client through the
   "registration_client_uri" member of the client information response,
   as specified in Section 3.  The client MUST use its registration
   access token in all calls to this endpoint as an OAuth 2.0 Bearer
   Token [RFC6750].

   The client configuration endpoint MUST be protected by a transport-
   layer security mechanism, as described in Section 5.





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   Operations on this endpoint are switched through the use of different
   HTTP methods [RFC7231].  If an authorization server does not support
   a particular method on the client configuration endpoint, it MUST
   respond with the appropriate error code.

2.1.  Client Read Request

   To read the current configuration of the client on the authorization
   server, the client makes an HTTP GET request to the client
   configuration endpoint, authenticating with its registration access
   token.

   Following is a non-normative example request (with line wraps for
   display purposes only):

     GET /register/s6BhdRkqt3 HTTP/1.1
     Accept: application/json
     Host: server.example.com
     Authorization: Bearer reg-23410913-abewfq.123483

   Upon successful read of the information for a currently active
   client, the authorization server responds with an HTTP 200 OK with
   content type of "application/json" and a payload, as described in
   Section 3.  Some values in the response, including the
   "client_secret" and "registration_access_token", MAY be different
   from those in the initial registration response.  If the
   authorization server includes a new client secret and/or registration
   access token in its response, the client MUST immediately discard its
   previous client secret and/or registration access token.  The value
   of the "client_id" MUST NOT change from the initial registration
   response.

   If the registration access token used to make this request is not
   valid, the server MUST respond with an error as described in OAuth
   Bearer Token Usage [RFC6750].

   If the client does not exist on this server, the server MUST respond
   with HTTP 401 Unauthorized and the registration access token used to
   make this request SHOULD be immediately revoked.

   If the client does not have permission to read its record, the server
   MUST return an HTTP 403 Forbidden.

2.2.  Client Update Request

   To update previously-registered client's registration with an
   authorization server, the client makes an HTTP PUT request to the
   client configuration endpoint with a content type of "application/



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   json".  The HTTP entity payload is a JSON [RFC7159] document
   consisting of a JSON object and all parameters as top-level members
   of that JSON object.  This request is authenticated by the
   registration access token issued to the client.

   This request MUST include all client metadata fields as returned to
   the client from a previous registration, read, or update operation.
   The updated client metadata fields request MUST NOT include the
   "registration_access_token", "registration_client_uri",
   "client_secret_expires_at", or "client_id_issued_at" fields described
   in Section 3.

   Valid values of client metadata fields in this request MUST replace,
   not augment, the values previously associated with this client.
   Omitted fields MUST be treated as null or empty values by the server,
   indicating the client's request to delete them from the client's
   registration.  The authorization server MAY ignore any null or empty
   value in the request just as any other value.

   The client MUST include its "client_id" field in the request, and it
   MUST be the same as its currently-issued client identifier.  If the
   client includes the "client_secret" field in the request, the value
   of this field MUST match the currently-issued client secret for that
   client.  The client MUST NOT be allowed to overwrite its existing
   client secret with its own chosen value.

   For all metadata fields, the authorization server MAY replace any
   invalid values with suitable default values, and it MUST return any
   such fields to the client in the response.

   For example, a client could send the following request to the client
   registration endpoint to update the client registration in the above
   example with new information:


















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   Following is a non-normative example request (with line wraps for
   display purposes only):

     PUT /register/s6BhdRkqt3 HTTP/1.1
     Accept: application/json
     Host: server.example.com
     Authorization: Bearer reg-23410913-abewfq.123483

     {
      "client_id":"s6BhdRkqt3",
      "client_secret": "cf136dc3c1fc93f31185e5885805d",
      "redirect_uris":[
        "https://client.example.org/callback",
        "https://client.example.org/alt"],
      "grant_types": ["authorization_code", "refresh_token"],
      "token_endpoint_auth_method": "client_secret_basic",
      "jwks_uri": "https://client.example.org/my_public_keys.jwks",
      "client_name":"My New Example",
      "client_name#fr":"Mon Nouvel Exemple",
      "logo_uri":"https://client.example.org/newlogo.png",
      "logo_uri#fr":"https://client.example.org/fr/newlogo.png"
     }

   This example uses client metadata values defined in
   [OAuth.Registration].

   Upon successful update, the authorization server responds with an
   HTTP 200 OK Message with content type "application/json" and a
   payload, as described in Section 3.  Some values in the response,
   including the "client_secret" and "registration_access_token", MAY be
   different from those in the initial registration response.  If the
   authorization server includes a new client secret and/or registration
   access token in its response, the client MUST immediately discard its
   previous client secret and/or registration access token.  The value
   of the "client_id" MUST NOT change from the initial registration
   response.

   If the registration access token used to make this request is not
   valid, the server MUST respond with an error as described in OAuth
   Bearer Token Usage [RFC6750].

   If the client does not exist on this server, the server MUST respond
   with HTTP 401 Unauthorized, and the registration access token used to
   make this request SHOULD be immediately revoked.

   If the client is not allowed to update its records, the server MUST
   respond with HTTP 403 Forbidden.




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   If the client attempts to set an invalid metadata field and the
   authorization server does not set a default value, the authorization
   server responds with an error as described in [OAuth.Registration].

2.3.  Client Delete Request

   To deprovision itself on the authorization server, the client makes
   an HTTP DELETE request to the client configuration endpoint.  This
   request is authenticated by the registration access token issued to
   the client as described in [