OAuth 2.0
Dynamic Client Registration Management Protocolietf@justin.richer.orgMicrosoftmbj@microsoft.comhttp://self-issued.info/Ping Identityve7jtb@ve7jtb.comNewcastle Universitymaciej.machulak@gmail.com
Security
OAuth Working GroupThis 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.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 at that
server. The OAuth 2.0 Dynamic Client
Registration Protocol 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 server, and methods for the
client to be unregistered from the authorization server.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 .Unless otherwise noted, all the protocol parameter names and values
are case sensitive.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 and the terms
defined by the OAuth 2.0 Client
Dynamic Registration Protocol.This specification defines the following terms: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.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.This extends the flow in the OAuth 2.0 Dynamic Client Registration
Protocol specification as follows:| 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
FlowThe 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: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.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.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.The authorization server registers the client
and returns:the client's registered metadata,a client identifier that is unique at 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, anda registration access token to be used when calling the
client configuration endpoint.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.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.The client or developer optionally calls the
client configuration endpoint with a delete request using the
registration access token issued in (D).The authorization server deprovisions the client
and responds with a confirmation that the deletion has taken
place.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 . The client MUST use its registration
access token in all calls to this endpoint as an OAuth 2.0 Bearer Token
.The client configuration endpoint MUST be protected by a
transport-layer security mechanism, as described in .Operations on this endpoint are switched through the use of different
HTTP methods. If an authorization server
does not support a particular method on the client configuration
endpoint, it MUST respond with the appropriate error code.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):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 . 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.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.This operation updates a previously-registered client with new
metadata at the authorization server. This request is authenticated by
the registration access token issued to the client.The client sends an HTTP PUT to the client configuration endpoint
with a content type of application/json.
The HTTP entity payload is a JSON
document consisting of a JSON object and all parameters as top- level
members of that JSON object.This request MUST include all client metadata fields as returned to
the client from a previous registration, read, or update operation.
The client MUST NOT include the registration_access_token,
registration_client_uri, client_secret_expires_at, or client_id_issued_at
fields described in .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:Following is a non-normative example request (with line
wraps for display purposes only):This example uses client metadata values defined in .Upon successful update, the authorization server responds with an
HTTP 200 OK Message with content type application/json
and a payload, as described in .
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.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.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 .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 .Following is a non-normative example request (with line
wraps for display purposes only):A successful delete action will invalidate the client_id,
client_secret, and registration_access_token
for this client, thereby preventing the client_id
from being used at either the authorization endpoint or token endpoint
of the authorization server. If possible, the authorization server
SHOULD immediately invalidate all existing authorization grants and
currently-active access tokens, refresh tokens, and other tokens
associated with this client.If a client has been successfully deprovisioned, the authorization
server MUST respond with an HTTP 204 No Content message.If the server does not support the delete method, the server MUST
respond with an HTTP 405 Not Supported.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.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
possible.If the client is not allowed to delete itself, the server MUST
respond with HTTP 403 Forbidden.Following is a non-normative example response:This specification extends the client information response defined in
OAuth 2.0 Client Dynamic
Registration, which states that the response contains the client
identifier as well as the client secret, if the client is a confidential
client. When used with this specification, the client information
response also contains the fully qualified URL of the client configuration endpoint for
this specific client that the client or developer may use to manage the
client's registration configuration, as well as a registration access
token that is to be used by the client or developer to perform
subsequent operations at the client configuration endpoint. REQUIRED. Access
token used at the client configuration endpoint to perform
subsequent operations upon the client registration. REQUIRED. Fully
qualified URL of the client configuration endpoint for this
client.Additionally, the authorization server MUST return all registered
metadata about this client, including any fields provisioned by the
authorization server itself. The authorization server MAY reject or
replace any of the client's requested metadata values submitted during
the registration or update requests and substitute them with suitable
values.The response is an application/json
document with all parameters as top-level members of a JSON object.Following is a non-normative example response:This specification requests that IANA extend the OAuth Dynamic Client
Metadata registry with the following entries:Client Metadata Name: registration_access_tokenClient Metadata Description: OAuth 2.0 bearer token used to
access the client configuration endpointChange controller: IESGSpecification document(s): [[ this document ]]Client Metadata Name: registration_client_uriClient Metadata Description: Fully qualified URI of the client
registration endpointChange controller: IESGSpecification document(s): [[ this document ]]While the client secret can expire, the registration access token
SHOULD NOT expire while a client is still actively registered. If this
token were to expire, a developer or client could be left in a situation
where they have no means of retrieving or updating the client's
registration information. Were that the case, a new registration would
be required, thereby generating a new client identifier. However, to
limit the exposure surface of the registration access token, the
registration access token MAY be rotated when the developer or client
does a read or update operation on the client's client configuration
endpoint. As the registration access tokens are relatively long-term
credentials, and since the registration access token is a Bearer token
and acts as the sole authentication for use at the client configuration
endpoint, it MUST be protected by the developer or client as described
in OAuth 2.0 Bearer Token Usage.Since requests to the client configuration endpoint result in the
transmission of clear-text credentials (in the HTTP request and
response), the authorization server MUST require the use of a
transport-layer security mechanism when sending requests to the
endpoint. The server MUST support TLS 1.2 RFC
5246 and MAY support additional transport-layer mechanisms
meeting its security requirements. When using TLS, the client MUST
perform a TLS/SSL server certificate check, per RFC 6125. Implementation security considerations
can be found in Recommendations for Secure Use of
TLS and DTLS.Since the client configuration endpoint is an OAuth 2.0 protected
resource, it SHOULD have some rate limiting on failures to prevent the
registration access token from being disclosed though repeated access
attempts.If a client is deprovisioned from a server, any outstanding
registration access token for that client MUST be invalidated at the
same time. Otherwise, this can lead to an inconsistent state wherein a
client could make requests to the client configuration endpoint where
the authentication would succeed but the action would fail because the
client is no longer valid. To prevent accidental disclosure from such an
erroneous situation, the authorization server MUST treat all such
requests as if the registration access token was invalid (by returning
an HTTP 401 Unauthorized error, as described).This specification poses no additional privacy considerations beyond
those described in the core OAuth 2.0
Dynamic Client Registration specification.Recommendations for Secure Use of TLS and DTLSPorticor29 HaHarash St.Hod HaSharon4501303Israelyaronf.ietf@gmail.comTechnische Universitaet MuenchenBoltzmannstr. 3Garching85748Germanyralph.ietf@gmail.com&yetpeter@andyet.comhttps://andyet.com/OAuth 2.0 Dynamic
Client Registration ProtocolThe MITRE Corporationjricher@mitre.orgMicrosoftmbj@microsoft.comhttp://self-issued.info/Ping Identityve7jtb@ve7jtb.comNewcastle Universitym.p.machulak@ncl.ac.ukhttp://ncl.ac.uk/Oracle Corporationphil.hunt@yahoo.comThe authors thank the OAuth Working Group, the User-Managed Access
Working Group, and the OpenID Connect Working Group participants for
their input to this document. In particular, the following individuals
have been instrumental in their review and contribution to various
versions of this document: Amanda Anganes, Derek Atkins, Tim Bray,
Domenico Catalano, Donald Coffin, Vladimir Dzhuvinov, George Fletcher,
Thomas Hardjono, Phil Hunt, William Kim, Torsten Lodderstedt, Eve Maler,
Josh Mandel, Nov Matake, Tony Nadalin, Nat Sakimura, Christian Scholz,
and Hannes Tschofenig.Throughout the course of the dynamic registration protocol, there are
three different classes of credentials in play, each with different
properties and targets.The initial access token is optionally used by the client or
developer at the registration endpoint. This is an OAuth 2.0 token
that is used to authorize the initial client registration request.
The content, structure, generation, and validation of this token are
out of scope for this specification. The authorization server can
use this token to verify that the presenter is allowed to
dynamically register new clients. This token may be shared among
multiple instances of a client to allow them to each register
separately, thereby letting the authorization server use this token
to tie multiple instances of registered clients (each with their own
distinct client identifier) back to the party to whom the initial
access token was issued, usually an application developer. This
token is usually intended to be used only at the client registration
endpoint.The registration access token is used by the client or developer
at the client configuration endpoint and represents the holder's
authorization to manage the registration of a client. This is an
OAuth 2.0 bearer token that is issued from the client registration
endpoint in response to a client registration request and is
returned in a client information response. The registration access
token is uniquely bound to the client identifier and is required to
be presented with all calls to the client configuration endpoint.
The registration access token should be protected as described in
and should not be shared between instances
of a client. If a registration access token is shared between client
instances, one instance could change or delete registration values
for all other instances of the client. The registration access token
can be rotated through the use of the client read or update method
on the client configuration endpoint. The registration access token
is intended to be used only at the client configuration
endpoint.The client credentials (such as client_secret)
are optional depending on the type of client and are used to
retrieve OAuth tokens. Client credentials are most often bound to
particular instances of a client and should not be shared between
instances. Note that since not all types of clients have client
credentials, they cannot be used to manage client registrations at
the client configuration endpoint. The client credentials can be
rotated through the use of the client read or update method on the
client configuration endpoint. The client credentials are intended
to be used only at the token endpoint.The authorization server may be configured to issue new
registration access token and/or client credentials (such as a client_secret) throughout the lifetime of the
client. This map help minimize the impact of exposed credentials. The
authorization server conveys new registration access tokens and client
credentials (if applicable) to the client in the client information
response of either a read or update request to the client
configuration endpoint. The client's current registration access token
and client credentials (if applicable) MUST be included in the client
information response.The registration access token SHOULD be rotated only in response to
a read or update request to the client configuration endpoint, at
which point the new registration access token is returned to the
client and the old registration access token MUST be discarded by the
client and SHOULD be discarded by the server, if possible. If instead
the registration access token were to expire or be invalidated outside
of such requests, the client or developer might be locked out of
managing the client's configuration.Note that the authorization server decides the frequency of the
credential rotation and not the client. Methods by which the client
can request credential rotation are outside the scope of this
document.The authorization server MUST provide the client with the fully
qualified URL in the registration_client_uri
element of the Client Information Response, as specified in . The authorization server MUST NOT expect
the client to construct or discover this URL on its own. The client MUST
use the URL as given by the server and MUST NOT construct this URL from
component pieces.Depending on deployment characteristics, the client configuration
endpoint URL may take any number of forms. It is RECOMMENDED that this
endpoint URL be formed through the use of a server-constructed URL
string which combines the client registration endpoint's URL and the
issued client_id for this client, with the
latter as either a path parameter or a query parameter. For example, a
client with the client identifier s6BhdRkqt3
could be given a client configuration endpoint URL of https://server.example.com/register/s6BhdRkqt3
(path parameter) or of https://server.example.com/register?client_id=s6BhdRkqt3
(query parameter). In both of these cases, the client simply uses the
URL as given by the authorization server.These common patterns can help the server to more easily determine
the client to which the request pertains, which MUST be matched against
the client to which the registration access token was issued. If
desired, the server MAY simply return the client registration endpoint
URL as the client configuration endpoint URL and change behavior based
on the authentication context provided by the registration access
token.[[ to be removed by the RFC editor before publication as an RFC
]]-10Updated author information.Updated TLS information, imported from Dynamic Registration
core.Expanded introduction.Reformatted diagram text.Added privacy considerations section.-09Updated author information.-08Updated HTTP RFC reference.-07Editorial clarifications due to document shepherd feedback.-06Removed TLS 1.0.Moved several explanatory sections to the appendix.Clarified read operations.Added IANA request.-05Removed Phil Hunt from authors list, per request.Applied various minor editorial changes from working group
comments.-04Incorrect XML uploaded for -03-03Changed draft to be Experimental instead of Standards Track.-02 Added more context information to the abstract.-01 Addressed issues that arose from last call comments on
draft-ietf-oauth-dyn-reg and draft-ietf-oauth-dyn-reg-metadata.-00 Created from draft-jones-oauth-dyn-reg-management-00.