One document matched: draft-ietf-oauth-dyn-reg-13.xml
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<front>
<title abbrev="oauth-dyn-reg">OAuth 2.0 Dynamic Client Registration
Protocol</title>
<author fullname="Justin Richer" initials="J" role="editor"
surname="Richer">
<organization>The MITRE Corporation</organization>
<address>
<postal>
<street/>
<city/>
<region/>
<code/>
<country/>
</postal>
<phone/>
<facsimile/>
<email>jricher@mitre.org</email>
<uri/>
</address>
</author>
<author fullname="John Bradley" initials="J." surname="Bradley">
<organization abbrev="Ping Identity">Ping Identity</organization>
<address>
<email>ve7jtb@ve7jtb.com</email>
</address>
</author>
<author fullname="Michael B. Jones" initials="M.B." surname="Jones">
<organization abbrev="Microsoft">Microsoft</organization>
<address>
<email>mbj@microsoft.com</email>
<uri>http://self-issued.info/</uri>
</address>
</author>
<author fullname="Maciej Machulak" initials="M" surname="Machulak">
<organization>Newcastle University</organization>
<address>
<email>m.p.machulak@ncl.ac.uk</email>
<uri>http://ncl.ac.uk/</uri>
</address>
</author>
<date day="2" month="July" year="2013"/>
<area>Security</area>
<workgroup>OAuth Working Group</workgroup>
<abstract>
<t>This specification defines an endpoint and protocol for dynamic
registration of OAuth 2.0 clients at an authorization server and methods
for the dynamically registered client to manage its registration through
an OAuth 2.0 protected web API.</t>
</abstract>
</front>
<middle>
<section anchor="Introduction" title="Introduction">
<t>In some use-case scenarios, it is desirable or necessary to allow
OAuth 2.0 clients to obtain authorization from an OAuth 2.0
authorization server without requiring the two parties to interact
beforehand. Nevertheless, for the authorization server to accurately and
securely represent to end-users which client is seeking authorization to
access the end-user's resources, a method for automatic and unique
registration of clients is needed. The OAuth 2.0 authorization framework
does not define how the relationship between the client and the
authorization server is initialized, or how a given client is assigned a
unique client identifier. Historically, this has happened out-of-band
from the OAuth 2.0 protocol. This draft provides a mechanism for a
client to register itself with the authorization server, which can be
used to dynamically provision a client identifier, and optionally a
client secret. Additionally, the mechanisms in this draft may can be
used by a client developer to register the client with the authorization
server in a programmatic fashion.</t>
<t>As part of the registration process, this specification also defines
a mechanism for the client to present the authorization server with a
set of metadata, such as a display name and icon to be presented to the
user during the authorization step. This draft also provides a mechanism
for the client to read and update this information after the initial
registration action. This draft protects these actions through the use
of an OAuth 2.0 bearer access token that is issued to the client during
registration explicitly for this purpose.</t>
<section anchor="Notation" title="Notational Conventions">
<t>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 <xref
target="RFC2119"/>.</t>
<t>Unless otherwise noted, all the protocol parameter names and values
are case sensitive.</t>
</section>
<section anchor="terminology" title="Terminology">
<t>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 <xref target="RFC6749">OAuth
2.0</xref>.</t>
<t>This specification defines the following additional terms:</t>
<t><list style="hanging">
<t hangText="Client Registration Endpoint">OAuth 2.0 endpoint
through which a client can be registered at an authorization
server. The means by which the URL for this endpoint are obtained
are out of scope for this specification.</t>
<t hangText="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.</t>
<t hangText="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.</t>
<t hangText="Initial Access Token">OAuth 2.0 access token
optionally issued by an Authorization Server and used to authorize
calls to the client registration endpoint. The type and format of
this token are likely service-specific and are out of scope for
this specification. The means by which the authorization server
issues this token as well as the means by which the registration
endpoint validates this token are out of scope for this
specification.</t>
</list></t>
</section>
<section anchor="protocol-flow" title="Protocol Flow">
<figure>
<preamble>(preamble)</preamble>
<artwork><![CDATA[
+--------(A)- Initial Access Token
|
v
+-----------+ +---------------+
| |--(B)- Client Registration Request -->| Client |
| | | Registration |
| |<-(C)- Client Information Response ---| Endpoint |
| | +---------------+
| |
| | +---------------+
| Client or |--(D)- Read or Update Request ------->| |
| Developer | | |
| |<-(E)- Client Information Response ---| Client |
| | | Configuration |
| | | Endpoint |
| | | |
| |--(F)- Delete Request --------------->| |
| | | |
| |<-(G)- Delete Confirmation -----------| |
+-----------+ +---------------+
]]></artwork>
<postamble>Figure 1: Abstract Protocol Flow</postamble>
</figure>
<t>The abstract OAuth 2.0 Client dynamic registration flow illustrated
in Figure 1 describes the interaction between the client or developer
and the two endpoints defined in this specification. This figure does
not demonstrate error conditions. This flow includes the following
steps:</t>
<t><list style="hanging">
<t hangText="(A)"><vspace blankLines="0"/>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.</t>
<t hangText="(B)"><vspace blankLines="0"/>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.</t>
<t hangText="(C)"><vspace blankLines="0"/>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, and a
registration access token to be used when calling the client
configuration endpoint.</t>
<t hangText="(D)"><vspace blankLines="0"/>The client or developer
optionally calls the client configuration endpoint with a read or
update request using the registration access token issued in (C).
An update request contains all of the client's registered
metadata.</t>
<t hangText="(E)"><vspace blankLines="0"/>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 (C) for all subsequent calls to the client
configuration endpoint.</t>
<t hangText="(F)"><vspace blankLines="0"/>The client or developer
optionally calls the client configuration endpoint with a delete
request using the registration access token issued in (C).</t>
<t hangText="(G)"><vspace blankLines="0"/>The authorization server
deprovisions the client and responds with a confirmation that the
deletion has taken place.</t>
</list>Further discussion of possible example lifecycles are found
in the Appendix to this specification, <xref
target="client-lifecycle-examples">Client Lifecycle
Examples</xref>.</t>
</section>
<section anchor="Credentials"
title="Registration Tokens and Client Credentials">
<t>Throughout the course of the dynamic registration protocol, there
are three different classes of credentials in play, each with
different properties and targets.</t>
<t><list style="symbols">
<t>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 between
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 should be used only at the client
registration endpoint.</t>
<t>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 and should not be shared between instances of a client
(otherwise, one instance could change or delete registration
values for all instances of the client). The registration access
token can be rotated through the use of the client read and update
methods on the client configuration endpoint. The registration
access token should be used only at the client configuration
endpoint.</t>
<t>The client credentials (such as <spanx style="verb">client_secret</spanx>)
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 and update methods on
the client configuration endpoint. The client credentials can not
be used for authentication at the client registration endpoint or
at the client configuration endpoint.</t>
</list></t>
<section anchor="credential-rotation" title="Credential Rotation">
<t>The Authorization Server MAY rotate the client's registration
access token and/or client credentials (such as a <spanx
style="verb">client_secret</spanx>) throughout the lifetime of the
client. The client is informed of the changed values changing by
making either read or update requests to the client configuration
endpoint, and the new values of the registration access token and
the client credentials will be included in the client information
response.</t>
<t>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 SHOULD be discarded by
both parties. If the registration access token to expire or be
rotated outside of such requests, the client or developer may be
locked out of managing the client's configuration.</t>
</section>
</section>
</section>
<section anchor="client-metadata" title="Client Metadata">
<t>Clients generally have an array of metadata associated with their
unique client identifier at the authorization server. These can range
from human-facing display strings, such as a client name, to items that
impact the security of the protocol, such as the list of valid redirect
URIs.</t>
<t>The client metadata values serve two parallel purposes in the overall
OAuth 2.0 dynamic client registration protocol:</t>
<t><list style="symbols">
<t>the client requesting its desired values for each parameter to
the authorization server in a <xref
target="RegistrationRequest">register</xref> or <xref
target="UpdateRequest">update</xref> request, and</t>
<t>the authorization server informing the client of the current
values of each parameter that the client has been registered to use
through a <xref target="client-info-response">client information
response</xref>.</t>
</list></t>
<t>An authorization server MAY override any value that a client requests
during the registration process (including any omitted values) and
replace the requested value with a default at the server's discretion.
The authorization server SHOULD provide documentation for any fields
that it requires to be filled in by the client or to have particular
values or formats. An authorization server MAY ignore the values
provided by the client for any field in this list.</t>
<t>Extensions and profiles of this specification MAY expand this list,
and authorization servers MUST accept all fields in this list. The
authorization server MUST ignore any additional parameters sent by the
Client that it does not understand.</t>
<t><list style="hanging">
<t hangText="redirect_uris"><vspace blankLines="0"/>Array of
redirect URIs for use in redirect-based flows such as the
authorization code and implicit grant types. It is RECOMMENDED that
clients using these flows register this parameter, and an
authorization server SHOULD require registration of valid redirect
URIs for all clients that use these grant types to protect against
token and credential theft attacks.</t>
<t hangText="client_name"><vspace blankLines="0"/>Human-readable
name of the client to be presented to the user. If omitted, the
authorization server MAY display the raw <spanx style="verb">client_id</spanx>
value to the user instead. It is RECOMMENDED that clients always
send this field. The value of this field MAY be internationalized as
described in <xref target="HumanReadableClientMetadata">Human
Readable Client Metadata</xref>.</t>
<t hangText="client_uri"><vspace/>URL of the homepage of the client.
If present, the server SHOULD display this URL to the end user in a
clickable fashion. It is RECOMMENDED that clients always send this
field. The value of this field MUST point to a valid web page. The
value of this field MAY be internationalized as described in <xref
target="HumanReadableClientMetadata">Human Readable Client
Metadata</xref>.</t>
<t hangText="logo_uri"><vspace blankLines="0"/>URL that references a
logo for the client. If present, the server SHOULD display this
image to the end user during approval. The value of this field MUST
point to a valid image file. The value of this field MAY be
internationalized as described in <xref
target="HumanReadableClientMetadata">Human Readable Client
Metadata</xref>.</t>
<t hangText="contacts"><vspace blankLines="0"/>Array of email
addresses for people responsible for this client. The authorization
server MAY make these addresses available to end users for support
requests for the client. An authorization server MAY use these email
addresses as identifiers for an administrative page for this
client.</t>
<t hangText="tos_uri"><vspace blankLines="0"/>URL that points to a
human-readable Terms of Service document for the client. The
Authorization Server SHOULD display this URL to the end-user if it
is given. The Terms of Service usually describe a contractual
relationship between the end-user and the client that the end-user
accepts when authorizing the client. The value of this field MUST
point to a valid web page. The value of this field MAY be
internationalized as described in <xref
target="HumanReadableClientMetadata">Human Readable Client
Metadata</xref>.</t>
<t hangText="policy_uri"><vspace blankLines="0"/>URL that points to
a human-readable Policy document for the client. The authorization
server SHOULD display this URL to the end-user if it is given. The
policy usually describes how an end-user's data will be used by the
client. The value of this field MUST point to a valid web page. The
value of this field MAY be internationalized as described in <xref
target="HumanReadableClientMetadata">Human Readable Client
Metadata</xref>.</t>
<t hangText="token_endpoint_auth_method"><vspace blankLines="0"/>The
requested authentication method for the token endpoint. Values
defined by this specification are: <list style="symbols">
<t><spanx style="verb">none</spanx>: The client is a public
client as defined in OAuth 2.0 and does not have a client
secret.</t>
<t><spanx style="verb">client_secret_post</spanx>: The client
uses the HTTP POST parameters defined in OAuth 2.0 section
2.3.1.</t>
<t><spanx style="verb">client_secret_basic</spanx>: the client
uses HTTP Basic defined in OAuth 2.0 section 2.3.1</t>
</list> Additional values can be defined via the IANA OAuth Token
Endpoint Authentication Methods Registry <xref
target="team-registry"/>. Absolute URIs can also be used as values
for this parameter without being registered. If unspecified or
omitted, the default is <spanx style="verb">client_secret_basic</spanx>,
denoting HTTP Basic Authentication Scheme as specified in Section
2.3.1 of OAuth 2.0.</t>
<t hangText="scope"><vspace blankLines="0"/>Space separated list of
scope values (as described in <xref target="RFC6749">OAuth 2.0
Section 3.3</xref>) that the client can use when requesting access
tokens. The semantics of values in this list is service specific. If
omitted, an authorization server MAY register a Client with a
default set of scopes.</t>
<t hangText="grant_types"><vspace blankLines="0"/>Array of OAuth 2.0
grant types that the Client may use. These grant types are defined
as follows:<list style="symbols">
<t><spanx style="verb">authorization_code</spanx>: The
Authorization Code Grant described in OAuth 2.0 Section 4.1</t>
<t><spanx style="verb">implicit</spanx>: The Implicit Grant
described in OAuth 2.0 Section 4.2</t>
<t><spanx style="verb">password</spanx>: The Resource Owner
Password Credentials Grant described in OAuth 2.0 Section
4.3</t>
<t><spanx style="verb">client_credentials</spanx>: The Client
Credentials Grant described in OAuth 2.0 Section 4.4</t>
<t><spanx style="verb">refresh_token</spanx>: The Refresh Token
Grant described in OAuth 2.0 Section 6.</t>
<t><spanx style="verb">urn:ietf:params:oauth:grant-type:jwt-bearer</spanx>:
The JWT Bearer Grant defined in <xref target="OAuth.JWT">OAuth
JWT Bearer Token Profiles</xref>.</t>
<t><spanx style="verb">urn:ietf:params:oauth:grant-type:saml2-bearer</spanx>:
The SAML 2 Bearer Grant defined in <xref
target="OAuth.SAML2">OAuth SAML 2 Bearer Token
Profiles</xref>.</t>
</list>Authorization Servers MAY allow for other values as defined
in grant type extensions to OAuth 2.0. The extension process is
described in OAuth 2.0 Section 2.5. If the token endpoint is used in
the grant type, the value of this parameter MUST be the same as the
value of the <spanx style="verb">grant_type</spanx> parameter passed
to the token endpoint defined in the extension.</t>
<t hangText="response_types"><vspace blankLines="0"/>Array of the
OAuth 2.0 response types that the Client may use. These response
types are defined as follows:<list style="symbols">
<t><spanx style="verb">code</spanx>: The Authorization Code
response described in OAuth 2.0 Section 4.1.</t>
<t><spanx style="verb">token</spanx>: The Implicit response
described in OAuth 2.0 Section 4.2.</t>
</list>Authorization servers MAY allow for other values as defined
in response type extensions to OAuth 2.0. The extension process is
described in OAuth 2.0 Section 2.5. If the authorization endpoint is
used by the grant type, the value of this parameter MUST be the same
as the value of the <spanx style="verb">response_type</spanx>
parameter passed to the authorization endpoint defined in the
extension.</t>
<t hangText="jwks_uri"><vspace blankLines="0"/>URL for the Client's
<xref target="JWK">JSON Web Key Set</xref> document representing the
client's public keys. The value of this field MUST point to a valid
JWK Set. These keys MAY be used for higher level protocols that
require signing or encryption.</t>
</list></t>
<section anchor="GrantTypesAndResponseTypes"
title="Relationship Between Grant Types and Response Types">
<t>The <spanx style="verb">grant_types</spanx> and <spanx
style="verb">response_types</spanx> values described above are
partially orthogonal, as they refer to arguments passed to different
endpoints in the OAuth protocol. However, they are related in that the
<spanx style="verb">grant_types</spanx> available to a client
influence the <spanx style="verb">response_types</spanx> that the
client is allowed to use, and vice versa. For instance, a <spanx
style="verb">grant_types</spanx> value that includes <spanx
style="verb">authorization_code</spanx> implies a <spanx style="verb">response_types</spanx>
value that includes <spanx style="verb">code</spanx>, as both values
are defined as part of the OAuth 2.0 authorization code grant. As
such, a server supporting these fields SHOULD take steps to ensure
that a client cannot register itself into an inconsistent state.</t>
<t>The correlation between the two fields is listed in the table
below.</t>
<texttable>
<ttcol>grant_types value includes:</ttcol>
<ttcol>response_types value includes:</ttcol>
<c>authorization_code</c>
<c>code</c>
<c>implicit</c>
<c>token</c>
<c>password</c>
<c>(none)</c>
<c>client_credentials</c>
<c>(none)</c>
<c>refresh_token</c>
<c>(none)</c>
<c>urn:ietf:params:oauth:grant-type:jwt-bearer</c>
<c>(none)</c>
<c>urn:ietf:params:oauth:grant-type:saml2-bearer</c>
<c>(none)</c>
</texttable>
<t>Extensions and profiles of this document that introduce new values
to either the <spanx style="verb">grant_types</spanx> or <spanx
style="verb">response_types</spanx> parameter MUST document all
correspondences between these two parameter types.</t>
</section>
<section anchor="HumanReadableClientMetadata"
title="Human Readable Client Metadata">
<t>Human-readable client metadata values and client metadata values
that reference human-readable values MAY be represented in multiple
languages and scripts. For example, the values of fields such as
<spanx style="verb">client_name</spanx>, <spanx style="verb">tos_uri</spanx>,
<spanx style="verb">policy_uri</spanx>, <spanx style="verb">logo_uri</spanx>,
and <spanx style="verb">client_uri</spanx> might have multiple
locale-specific values in some client registrations.</t>
<t>To specify the languages and scripts, <xref
target="RFC5646">BCP47</xref> language tags are added to client
metadata member names, delimited by a # character. Since JSON member
names are case sensitive, it is RECOMMENDED that language tag values
used in Claim Names be spelled using the character case with which
they are registered in the <xref target="IANA.Language">IANA Language
Subtag Registry</xref>. In particular, normally language names are
spelled with lowercase characters, region names are spelled with
uppercase characters, and languages are spelled with mixed case
characters. However, since BCP47 language tag values are case
insensitive, implementations SHOULD interpret the language tag values
supplied in a case insensitive manner. Per the recommendations in
BCP47, language tag values used in metadata member names should only
be as specific as necessary. For instance, using <spanx style="verb">fr</spanx>
might be sufficient in many contexts, rather than <spanx style="verb">fr-CA</spanx>
or <spanx style="verb">fr-FR</spanx>.</t>
<t>For example, a client could represent its name in English as <spanx
style="verb">"client_name#en": "My Client"</spanx> and its name in
Japanese as <spanx style="verb">"client_name#ja-Jpan-JP": "\u30AF\u30E9\u30A4\u30A2\u30F3\u30C8\u540D"</spanx>
within the same registration request. The authorization server MAY
display any or all of these names to the resource owner during the
authorization step, choosing which name to display based on system
configuration, user preferences or other factors.</t>
<t>If any human-readable field is sent without a language tag, parties
using it MUST NOT make any assumptions about the language, character
set, or script of the string value, and the string value MUST be used
as-is wherever it is presented in a user interface. To facilitate
interoperability, it is RECOMMENDED that clients and servers use a
human-readable field without any language tags in addition to any
language-specific fields, and it is RECOMMENDED that any
human-readable fields sent without language tags contain values
suitable for display on a wide variety of systems.</t>
<t>Implementer's Note: Many JSON libraries make it possible to
reference members of a JSON object as members of an object construct
in the native programming environment of the library. However, while
the <spanx style="verb">#</spanx> character is a valid character
inside of a JSON object's member names, it is not a valid character
for use in an object member name in many programming environments.
Therefore, implementations will need to use alternative access forms
for these claims. For instance, in JavaScript, if one parses the JSON
as follows, <spanx style="verb">var j = JSON.parse(json);</spanx>,
then the member <spanx style="verb">client_name#en-us</spanx> can be
accessed using the JavaScript syntax <spanx style="verb">j["client_name#en-us"]</spanx>.</t>
</section>
</section>
<section anchor="RegistrationEndpoint"
title="Client Registration Endpoint">
<t>The client registration endpoint is an OAuth 2.0 endpoint defined in
this document that is designed to allow a client to be registered with
the authorization server. The client registration Endpoint MUST accept
HTTP POST messages with request parameters encoded in the entity body
using the <spanx style="verb">application/json</spanx> format. The
client registration endpoint MUST be protected by a transport-layer
security mechanism, and the server MUST support TLS 1.2 <xref
target="RFC5246">RFC 5246</xref> and/or TLS 1.0 <xref target="RFC2246"/>
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 <xref target="RFC6125">RFC
6125</xref>.</t>
<t>The client registration endpoint MAY be an OAuth 2.0 protected
resource and accept an initial access token in the form of an <xref
target="RFC6749">OAuth 2.0 </xref> access token to limit registration to
only previously authorized parties. The method by which the initial
access token is obtained by the registrant is generally out-of-band and
is out of scope for this specification. The method by which the initial
access token is verified and validated by the client registration
endpoint is out of scope for this specification.</t>
<t>To support open registration and facilitate wider interoperability,
the client registration endpoint SHOULD allow initial registration
requests with no authorization (which is to say, with no OAuth 2.0
access token in the request). These requests MAY be rate-limited or
otherwise limited to prevent a denial-of-service attack on the client
registration endpoint.</t>
<t>To allow the registrant to manage the client's information, the
client registration endpoint issues a request access token as an <xref
target="RFC6750">OAuth 2.0 Bearer Token</xref> to securely authorize
calls to the <xref target="AccessEndpoint">client configuration
endpoint</xref>.</t>
<t>The client registration endpoint MUST ignore all parameters it does
not understand.</t>
<section anchor="RegistrationRequest"
title="Client Registration Request">
<t>This operation registers a new client to the authorization server.
The authorization server assigns this client a unique client
identifier, optionally assigns a client secret, and associates the
metadata given in the request with the issued client identifier. The
request includes any parameters described in <xref
target="client-metadata">Client Metadata</xref> that the client wishes
to specify for itself during the registration. The authorization
server MAY provision default values for any items omitted in the
client metadata.</t>
<t>To register, the client or developer sends an HTTP POST to the
client registration endpoint with a content type of <spanx
style="verb">application/json</spanx>. The HTTP Entity Payload is a
<xref target="RFC4627">JSON</xref> document consisting of a JSON
object and all parameters as top-level members of that JSON
object.</t>
<t>For example, if the server supports open registration (with no
initial access token), the client could send the following
registration request to the client registration endpoint:</t>
<figure>
<preamble>Following is a non-normative example request (with line
wraps for display purposes only):</preamble>
<artwork><![CDATA[
POST /register HTTP/1.1
Content-Type: application/json
Accept: application/json
Host: server.example.com
{
"redirect_uris":["https://client.example.org/callback",
"https://client.example.org/callback2"],
"client_name":"My Example Client",
"client_name#ja-Jpan-JP":
"\u30AF\u30E9\u30A4\u30A2\u30F3\u30C8\u540D",
"token_endpoint_auth_method":"client_secret_basic",
"scope":"read write dolphin",
"logo_uri":"https://client.example.org/logo.png",
"jwks_uri":"https://client.example.org/my_public_keys.jwks"
}
]]></artwork>
</figure>
<t/>
<t>Alternatively, if the server supports authorized registration, the
developer or the client will be provisioned with an initial access
token (the method by which the initial access token is obtained is out
of scope for this specification). The developer or client sends the
following authorized registration request to the client registration
endpoint. Note that the initial access token sent in this example as
an <xref target="RFC6750">OAuth 2.0 Bearer Token</xref>, but any OAuth
2.0 token type could be used by an authorization server:</t>
<figure>
<preamble>Following is a non-normative example request (with line
wraps for display purposes only):</preamble>
<artwork><![CDATA[
POST /register HTTP/1.1
Content-Type: application/json
Accept: application/json
Authorization: Bearer ey23f2.adfj230.af32-developer321
Host: server.example.com
{
"redirect_uris":["https://client.example.org/callback",
"https://client.example.org/callback2"],
"client_name":"My Example Client",
"client_name#ja-Jpan-JP":
"\u30AF\u30E9\u30A4\u30A2\u30F3\u30C8\u540D",
"token_endpoint_auth_method":"client_secret_basic",
"scope":"read write dolphin",
"logo_uri":"https://client.example.org/logo.png",
"jwks_uri":"https://client.example.org/my_public_keys.jwks"
}
]]></artwork>
</figure>
<t/>
</section>
<section anchor="RegistrationResponse"
title="Client Registration Response">
<t>Upon successful registration, the authorization server generates a
new client identifier for the client. This client identifier MUST be
unique at the server and MUST NOT be in use by any other client. The
server responds with an HTTP 201 Created code and a body of type
<spanx style="verb">application/json</spanx> with content described in
<xref target="client-info-response">Client Information
Response</xref>.</t>
<t>Upon an unsuccessful registration, the authorization server
responds with an error as described in <xref
target="client-registration-error">Client Registration
Error</xref>.</t>
</section>
</section>
<section anchor="AccessEndpoint" title="Client Configuration Endpoint">
<t>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 <spanx style="verb">registration_client_uri</spanx>
member of the <xref target="client-info-response">Client Information
Response</xref>. The client MUST use its registration access token in
all calls to this endpoint as an <xref target="RFC6750">OAuth 2.0 Bearer
Token</xref>.</t>
<t>Operations on this endpoint are switched through the use of different
<xref target="RFC2616">HTTP methods</xref>. If an authorization server
does not support a particular method on the client configuration
endpoint, it MUST respond with the appropriate error code.</t>
<section anchor="client-configuration-endpoint-uri"
title="Forming the Client Configuration Endpoint URL">
<t>The authorization server MUST provide the client with the fully
qualified URL in the <spanx style="verb">registration_client_uri</spanx>
element of the <xref target="client-info-response">Client Information
Response</xref>. 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.</t>
<t>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 <spanx style="verb">client_id</spanx> for this client, with the
latter as either a path parameter or a query parameter. For example, a
client with the client identifier <spanx style="verb">s6BhdRkqt3</spanx>
could be given a client configuration endpoint URL of <spanx
style="verb">https://server.example.com/register/s6BhdRkqt3</spanx>
(path parameter) or of <spanx style="verb">https://server.example.com/register?client_id=s6BhdRkqt3</spanx>
(query parameter). In both of these cases, the client simply uses the
URL as given by the authorization server.</t>
<t>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.</t>
</section>
<section anchor="ReadRequest" title="Client Read Request">
<t>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.</t>
<figure>
<preamble>Following is a non-normative example request (with line
wraps for display purposes only):</preamble>
<artwork><![CDATA[GET /register/s6BhdRkqt3 HTTP/1.1
Accept: application/json
Host: server.example.com
Authorization: Bearer reg-23410913-abewfq.123483
]]></artwork>
</figure>
<t/>
<t>Upon successful read of the information for a currently active
client, the authorization server responds with an HTTP 200 OK with
content type of <spanx style="verb">application/json</spanx> and a
payload as described in <xref target="client-info-response">Client
Information Response</xref>. Some values in the response, including
the <spanx style="verb">client_secret</spanx> and <spanx style="verb">registration_access_token</spanx>,
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 <spanx style="verb">client_id</spanx> MUST NOT change
from the initial registration response.</t>
<t>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.</t>
<t>If the client does not have permission to read its record, the
server MUST return an HTTP 403 Forbidden.</t>
</section>
<section anchor="UpdateRequest" title="Client Update Request">
<t>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.</t>
<t>The client sends an HTTP PUT to the client configuration endpoint
with a content type of <spanx style="verb">application/json</spanx>.
The HTTP entity payload is a <xref target="RFC4627">JSON</xref>
document consisting of a JSON object and all parameters as top- level
members of that JSON object.</t>
<t>This request MUST include all fields described in <xref
target="client-metadata">Client Metadata</xref> as returned to the
client from a previous register, read, or update operation. The client
MUST NOT include the <spanx style="verb">registration_access_token</spanx>,
<spanx style="verb">registration_client_uri</spanx>, <spanx
style="verb">client_secret_expires_at</spanx>, or <spanx style="verb">client_id_issued_at</spanx>
fields described in <xref target="client-info-response">Client
Information Response</xref>.</t>
<t>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.</t>
<t>The client MUST include its <spanx style="verb">client_id</spanx>
field in the request, and it MUST be the same as its currently-issued
client identifier. If the client includes the <spanx style="verb">client_secret</spanx>
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.</t>
<t>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.</t>
<t>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:</t>
<figure>
<preamble>Following is a non-normative example request (with line
wraps for display purposes only):</preamble>
<artwork><![CDATA[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"],
"scope": "read write dolphin",
"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"
}
]]></artwork>
</figure>
<t/>
<t>Upon successful update, the authorization server responds with an
HTTP 200 OK Message with content type <spanx style="verb">application/json</spanx>
and a payload as described in <xref
target="client-info-response">Client Information Response</xref>. Some
values in the response, including the <spanx style="verb">client_secret</spanx>
and r<spanx style="verb">egistration_access_token</spanx>, 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 <spanx style="verb">client_id</spanx> MUST NOT change from the
initial registration response.</t>
<t>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.</t>
<t>If the client is not allowed to update its records, the server MUST
respond with HTTP 403 Forbidden.</t>
<t>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 <xref
target="client-registration-error">Client Registration Error
Response</xref>.</t>
</section>
<section anchor="DeleteRequest" title="Client Delete Request">
<t>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.</t>
<figure>
<preamble>Following is a non-normative example request (with line
wraps for display purposes only):</preamble>
<artwork><![CDATA[DELETE /register/s6BhdRkqt3 HTTP/1.1
Host: server.example.com
Authorization: Bearer reg-23410913-abewfq.123483
]]></artwork>
</figure>
<t/>
<t>A successful delete action will invalidate the <spanx style="verb">client_id</spanx>,
<spanx style="verb">client_secret</spanx>, and <spanx style="verb">registration_access_token</spanx>
for this client, thereby preventing the <spanx style="verb">client_id</spanx>
from being used at either the authorization endpoint or token endpoint
of the authorization server. The authorization server SHOULD
immediately invalidate all existing authorization grants and
currently-active tokens associated with this client.</t>
<t>If a client has been successfully deprovisioned, the authorization
server responds with an HTTP 204 No Content message.</t>
<t>If the server does not support the delete method, the server MUST
respond with an HTTP 405 Not Supported.</t>
<t>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.</t>
<t>If the client is not allowed to delete itself, the server MUST
respond with HTTP 403 Forbidden.</t>
<figure>
<preamble>Following is a non-normative example response:</preamble>
<artwork><![CDATA[HTTP/1.1 204 No Content
Cache-Control: no-store
Pragma: no-cache
]]></artwork>
</figure>
</section>
</section>
<section anchor="Responses" title="Responses">
<t>In response to certain requests from the client to either the client
registration endpoint or the client configuration endpoint as described
in this specification, the authorization server sends the following
response bodies.</t>
<section anchor="client-info-response"
title="Client Information Response">
<t>The response contains the client identifier as well as the client
secret, if the client is a confidential client. The response also
contains the fully qualified URL to the client configuration endpoint
for this specific client that the client may use to obtain and update
information about itself. The response also contains a registration
access token that is to be used by the client to perform subsequent
operations at the client configuration endpoint.</t>
<t><list style="hanging">
<t hangText="client_id"><vspace/>REQUIRED. The unique client
identifier, MUST NOT be currently valid for any other registered
client.</t>
<t hangText="client_secret"><vspace/>OPTIONAL. The client secret.
If issued, this MUST be unique for each <spanx style="verb">client_id</spanx>.
This value is used by confidential clients to authenticate to the
token endpoint as described in OAuth 2.0 Section 2.3.1.</t>
<t hangText="client_id_issued_at"><vspace/>OPTIONAL. Time at which
the Client Identifier was issued. The time is represented as the
number of seconds from 1970-01-01T0:0:0Z as measured in UTC until
the date/time.</t>
<t hangText="client_secret_expires_at"><vspace/>REQUIRED if <spanx
style="verb">client_secret</spanx> is issued. Time at which the
<spanx style="verb">client_secret</spanx> will expire or 0 if it
will not expire. The time is represented as the number of seconds
from 1970-01-01T0:0:0Z as measured in UTC until the date/time.</t>
<t hangText="registration_access_token"><vspace/>REQUIRED. Access
token that is used at the client configuration endpoint to perform
subsequent operations upon the client registration.</t>
<t hangText="registration_client_uri"><vspace
blankLines="0"/>REQUIRED. The fully qualified URL of the client
configuration endpoint for this client. The client MUST use this
URL as given when communicating with the client configuration
endpoint.</t>
</list></t>
<t>Additionally, the Authorization Server MUST return all registered
<xref target="client-metadata">metadata</xref> 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.</t>
<t>The response is an <spanx style="verb">application/json</spanx>
document with all parameters as top-level members of a <xref
target="RFC4627">JSON object</xref>.</t>
<figure>
<preamble>Following is a non-normative example response:</preamble>
<artwork><![CDATA[HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-store
Pragma: no-cache
{
"registration_access_token": "reg-23410913-abewfq.123483",
"registration_client_uri":
"https://server.example.com/register/s6BhdRkqt3",
"client_id":"s6BhdRkqt3",
"client_secret": "cf136dc3c1fc93f31185e5885805d",
"client_id_issued_at":2893256800
"client_secret_expires_at":2893276800
"client_name":"My Example Client",
"client_name#ja-Jpan-JP":
"\u30AF\u30E9\u30A4\u30A2\u30F3\u30C8\u540D",
"redirect_uris":["https://client.example.org/callback",
"https://client.example.org/callback2"]
"scope": "read write dolphin",
"grant_types": ["authorization_code", "refresh_token"]
"token_endpoint_auth_method": "client_secret_basic",
"logo_uri": "https://client.example.org/logo.png",
"jwks_uri": "https://client.example.org/my_public_keys.jwks"
}]]></artwork>
</figure>
</section>
<section anchor="client-registration-error"
title="Client Registration Error Response">
<t>When an OAuth 2.0 error condition occurs, such as the client
presenting an invalid registration access token, the authorization
server returns an error response appropriate to the OAuth 2.0 token
type. For the registration access token, which is an OAuth 2.0 bearer
token, this error response is defined in Section 3 of <xref
target="RFC6750">OAuth 2.0 Bearer Token Usage</xref>.</t>
<t>When a registration error condition occurs, the authorization
server returns an HTTP 400 status code (unless otherwise specified)
with content type <spanx style="verb">application/json</spanx>
consisting of a <xref target="RFC4627">JSON object</xref> describing
the error in the response body.</t>
<t>The JSON object contains two members:</t>
<t><list style="hanging">
<t hangText="error"><vspace/>The error code, a single ASCII
string.</t>
<t hangText="error_description"><vspace/>A human-readable text
description of the error for debugging.</t>
</list></t>
<t>This specification defines the following error codes:</t>
<t><list style="hanging">
<t hangText="invalid_redirect_uri"><vspace/>The value of one or
more <spanx style="verb">redirect_uris</spanx> is invalid.</t>
<t hangText="invalid_client_metadata"><vspace/>The value of one of
the <xref target="client-metadata">client metadata</xref> fields
is invalid and the server has rejected this request. Note that an
Authorization server MAY choose to substitute a valid value for
any requested parameter of a client's metadata.</t>
<t hangText="invalid_client_id"><vspace/> The value of <spanx
style="verb">client_id</spanx> does not match the one assigned to
this client.</t>
</list></t>
<figure>
<preamble>Following is a non-normative example of an error response
(with line wraps for display purposes only):</preamble>
<artwork><![CDATA[HTTP/1.1 400 Bad Request
Content-Type: application/json
Cache-Control: no-store
Pragma: no-cache
{
"error":"invalid_redirect_uri",
"error_description":"The redirect URI of http://sketchy.example.com
is not allowed for this server."
}]]></artwork>
</figure>
</section>
</section>
<section anchor="IANA" title="IANA Considerations">
<section anchor="team-registry"
title="OAuth Token Endpoint Authentication Methods Registry">
<t>This specification establishes the OAuth Token Endpoint
Authentication Methods registry.</t>
<t>Additional values for use as <spanx style="verb">token_endpoint_auth_method</spanx>
metadata values are registered with a Specification Required (<xref
target="RFC5226"/>) after a two-week review period on the
oauth-ext-review@ietf.org mailing list, on the advice of one or more
Designated Experts. However, to allow for the allocation of values
prior to publication, the Designated Expert(s) may approve
registration once they are satisfied that such a specification will be
published.</t>
<t>Registration requests must be sent to the oauth-ext-review@ietf.org
mailing list for review and comment, with an appropriate subject
(e.g., "Request to register token_endpoint_auth_method value:
example").</t>
<t>Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request
successful.</t>
<t>IANA must only accept registry updates from the Designated
Expert(s) and should direct all requests for registration to the
review mailing list.</t>
<section anchor="team-template" title="Registration Template">
<t><list style="hanging">
<t
hangText="Token Endpoint Authorization Method name:"><vspace/>The
name requested (e.g., "example"). This name is case sensitive.
Names that match other registered names in a case insensitive
manner SHOULD NOT be accepted.</t>
<t hangText="Change controller:"><vspace/>For Standards Track
RFCs, state "IETF". For others, give the name of the responsible
party. Other details (e.g., postal address, email address, home
page URI) may also be included.</t>
<t hangText="Specification document(s):"><vspace/>Reference to
the document(s) that specify the token endpoint authorization
method, preferably including a URI that can be used to retrieve
a copy of the document(s). An indication of the relevant
sections may also be included but is not required.</t>
</list></t>
</section>
<section anchor="team-contents" title="Initial Registry Contents">
<t>The OAuth Token Endpoint Authentication Methods registry's
initial contents are:</t>
<t><?rfc subcompact="yes"?> <list style="symbols">
<t>Token Endpoint Authorization Method name: <spanx
style="verb">none</spanx></t>
<t>Change controller: IETF</t>
<t>Specification document(s): [[ this document ]]</t>
</list></t>
<t><list style="symbols">
<t>Token Endpoint Authorization Method name: <spanx
style="verb">client_secret_post</spanx></t>
<t>Change controller: IETF</t>
<t>Specification document(s): [[ this document ]]</t>
</list></t>
<t><list style="symbols">
<t>Token Endpoint Authorization Method name: <spanx
style="verb">client_secret_basic</spanx></t>
<t>Change controller: IETF</t>
<t>Specification document(s): [[ this document ]]</t>
</list></t>
</section>
<?rfc subcompact="no"?>
</section>
</section>
<section anchor="Security" title="Security Considerations">
<t>Since requests to the client registration 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
registration endpoint. The server MUST support TLS 1.2 <xref
target="RFC5246">RFC 5246</xref> and/or TLS 1.0 <xref target="RFC2246"/>
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 <xref target="RFC6125">RFC
6125</xref>.</t>
<t>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.</t>
<t>For clients that use redirect-based grant types such as <spanx
style="verb">authorization_code</spanx> and <spanx style="verb">implicit</spanx>,
authorization servers SHOULD require clients to register their <spanx
style="verb">redirect_uris</spanx>. Requiring clients to do so can help
mitigate attacks where rogue actors inject and impersonate a validly
registered client and intercept its authorization code or tokens through
an invalid redirect URI.</t>
<t>The authorization server MUST treat all client metadata as
self-asserted. A rogue client might use the name and logo for the
legitimate client, which it is trying to impersonate. An authorization
server needs to take steps to mitigate this phishing risk, since the
logo could confuse users into thinking they're logging in to the
legitimate client. For instance, an authorization server could warn if
the domain/site of the logo doesn't match the domain/site of redirect
URIs. An authorization server can also present warning messages to end
users about untrusted clients in all cases, especially if such clients
have been recently registered and have not been trusted by any users at
the authorization server before.</t>
<t>In a situation where the authorization server is supporting open
client registration, it must be extremely careful with any URL provided
by the client that will be displayed to the user (e.g. <spanx
style="verb">logo_uri</spanx>, <spanx style="verb">tos_uri</spanx>,
<spanx style="verb">client_uri</spanx>, and <spanx style="verb">policy_uri</spanx>).
For instance, a rogue client could specify a registration request with a
reference to a drive-by download in the <spanx style="verb">policy_uri</spanx>.
The authorization server SHOULD check to see if the <spanx style="verb">logo_uri</spanx>,
<spanx style="verb">tos_uri</spanx>, <spanx style="verb">client_uri</spanx>,
and <spanx style="verb">policy_uri</spanx> have the same host and scheme
as the those defined in the array of <spanx style="verb">redirect_uris</spanx>
and that all of these resolve to valid web pages.</t>
<t>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 <xref target="RFC6750">OAuth 2.0 Bearer Token Usage</xref>.</t>
<t>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).</t>
<t>Public clients MAY register with an authorization server using this
protocol, if the authorization server's policy allows them. Public
clients use a <spanx style="verb">none</spanx> value for the <spanx
style="verb">token_endpoint_auth_method</spanx> metadata field and are
generally used with the <spanx style="verb">implicit</spanx> grant type.
Often these clients will be short-lived in-browser applications
requesting access to a user's resources and access is tied to a user's
active session at the authorization server. Since such clients often do
not have long-term storage, it's possible that such clients would need
to re-register every time the browser application is loaded.
Additionally, such clients may not have ample opportunity to unregister
themselves using the delete action before the browser closes. To avoid
the resulting proliferation of dead client identifiers, an authorization
server MAY decide to expire registrations for existing clients meeting
certain criteria after a period of time has elapsed.</t>
<t>Since different OAuth 2.0 grant types have different security and
usage parameters, an authorization server MAY require separate
registrations for a piece of software to support multiple grant types.
For instance, an authorization server might require that all clients
using the <spanx style="verb">authorization_code</spanx> grant type make
use of a client secret for the <spanx style="verb">token_endpoint_auth_method</spanx>,
but any clients using the <spanx style="verb">implicit</spanx> grant
type do not use any authentication at the token endpoint. In such a
situation, a server MAY disallow clients from registering for both the
<spanx style="verb">authorization_code</spanx> and <spanx style="verb">implicit</spanx>
grant types simultaneously. Similarly, the <spanx style="verb">authorization_code</spanx>
grant type is used to represent access on behalf of an end user, but the
<spanx style="verb">client_credentials</spanx> grant type represents
access on behalf of the client itself. For security reasons, an
authorization server could require that different scopes be used for
these different use cases, and as a consequence it MAY disallow these
two grant types from being registered together by the same client. In
all of these cases, the authorization server would respond with an
<spanx style="verb">invalid_client_metadata</spanx> <xref
target="client-registration-error">error response</xref>.</t>
</section>
</middle>
<back>
<references title="Normative References">
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml' ?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.2246.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.2616.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.4627.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.5226.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.5246.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.5646.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.6125.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.6749.xml'?>
<?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.6750.xml'?>
<reference anchor="JWK">
<front>
<title>JSON Web Key (JWK)</title>
<author fullname="Michael B. Jones" initials="M.B." surname="Jones">
<organization>Microsoft</organization>
<address>
<email>mbj@microsoft.com</email>
<uri>http://self-issued.info/</uri>
</address>
</author>
<date day="8" month="May" year="2013"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-jose-json-web-key"/>
<format target="http://tools.ietf.org/html/draft-ietf-jose-json-web-key"
type="HTML"/>
</reference>
<reference anchor="OAuth.JWT">
<front>
<title abbrev="OAuth JWT Bearer Token Profiles">JSON Web Token (JWT)
Bearer Token Profiles for OAuth 2.0</title>
<author fullname="Michael B. Jones" initials="M.B." surname="Jones">
<!-- role="editor" -->
<organization>Microsoft</organization>
</author>
<author fullname="Brian Campbell" initials="B." surname="Campbell">
<organization abbrev="Ping Identity">Ping Identity
Corp.</organization>
</author>
<author fullname="Chuck Mortimore" initials="C." surname="Mortimore">
<organization>Salesforce</organization>
</author>
<date day="29" month="March" year="2013"/>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-oauth-jwt-bearer"/>
<format target="http://tools.ietf.org/html/draft-ietf-oauth-jwt-bearer"
type="HTML"/>
</reference>
<reference anchor="OAuth.SAML2">
<front>
<title abbrev="OAuth JWT Bearer Token Profiles">SAML 2.0 Bearer
Assertion Profiles for OAuth 2.0</title>
<author fullname="Brian Campbell" initials="B." surname="Campbell">
<organization abbrev="Ping Identity">Ping Identity
Corp.</organization>
</author>
<author fullname="Chuck Mortimore" initials="C." surname="Mortimore">
<organization>Salesforce</organization>
</author>
<author fullname="Michael B. Jones" initials="M.B." surname="Jones">
<organization>Microsoft</organization>
</author>
<date day="29" month="March" year="2013"/>
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-oauth-saml2-bearer"/>
<format target="http://tools.ietf.org/html/draft-ietf-oauth-saml2-bearer"
type="HTML"/>
</reference>
<reference anchor="IANA.Language">
<front>
<title>Language Subtag Registry</title>
<author>
<organization>Internet Assigned Numbers Authority
(IANA)</organization>
</author>
<date year="2005"/>
</front>
<format target="http://www.iana.org/assignments/language-subtag-registry"
type="TXT"/>
</reference>
</references>
<section anchor="Acknowledgments" title="Acknowledgments">
<t>The 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, Nat Sakimura, Christian Scholz, and Hannes
Tschofenig.</t>
</section>
<section anchor="client-lifecycle-examples"
title="Client Lifecycle Examples">
<t>In the <xref target="RFC6749">OAuth 2.0 specification</xref>, a
client is identified by its own unique Client identifier (<spanx
style="verb">client_id</spanx>) at each authorization server that it
associates with. Dynamic registration as defined in this document is one
way for a client to get a client identifier and associate a set of
metadata with that identifier. Lack of such a client identifier is the
expected trigger for a client registration operation.</t>
<t>In many cases, this client identifier is a unique, pairwise
association between a particular running instance of a piece of client
software and a particular running instance of an authorization server
software. In particular:</t>
<t><list style="symbols">
<t>A single instance of client software (such as a Web server)
talking to multiple authorization servers will need to register with
each authorization server separately, creating a distinct client
identifier with each authorization server. The client can not make
any assumption that the authorization servers are correlating
separate registrations of the client software together without
further profiles and extensions to this specification document. The
means by which a client discovers and differentiates between
multiple authorization servers is out of scope for this
specification.</t>
<t>Multiple instances of client software (such as a native
application installed on multiple devices simultaneously) talking to
the same authorization server will need to each register with that
authorization server separately, creating a distinct client
identifier for each copy of the application. The authorization
server cannot make any assumption of correlation between these
clients without further specifications, profiles, and extensions to
this specification. The client can not make any assumption that the
authorization server will correlate separate registrations of the
client software together without further profiles and extensions to
this specification document.</t>
</list></t>
<t>A client identifier (and its associated credentials) could also be
shared between multiple instances of a client. Mechanisms for sharing
client identifiers between multiple instances of a piece of software
(either client or authorization server) are outside the scope of this
specification, as it is expected that every successful <xref
target="RegistrationRequest">registration request</xref> results in the
issuance of a new client identifier.</t>
<t>There are several patterns of OAuth client registration that dynamic
registration protocol can enable. The following non-normative example
lifecycle descriptions are not intended to be an exhaustive list. It is
assumed that the authorization server supports the dynamic registration
protocol and that all necessary discovery steps (which are out of scope
for this specification) have already been performed.</t>
<section anchor="OpenRegistration" title="Open Registration">
<t>Open registration, with no authorization required on the client
registration endpoint, works as follows:</t>
<t><list style="letters">
<t>A client needs to get OAuth 2.0 tokens from an authorization
server, but the client does not have a client identifier for that
authorization server.</t>
<t>The client sends an HTTP POST request to the client
registration endpoint at the authorization server and includes its
metadata.</t>
<t>The authorization server issues a client identifier and returns
it to the client along with a registration access token and a
reference to the client's client configuration endpoint.</t>
<t>The client stores the returned response from the authorization
server. At a minimum, it should remember the values of <spanx
style="verb">client_id</spanx>, <spanx style="verb">client_secret</spanx>
(if present), <spanx style="verb">registration_access_token</spanx>,
and <spanx style="verb">registration_client_uri</spanx>.</t>
<t>The client uses the its <spanx style="verb">client_id</spanx>
and <spanx style="verb">client_secret</spanx> (if provided) to
request OAuth 2.0 tokens using any valid OAuth 2.0 flow for which
it is authorized.</t>
<t>If the client's <spanx style="verb">client_secret</spanx>
expires or otherwise stops working, the client sends an HTTP GET
request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This response will contain the client's
refreshed <spanx style="verb">client_secret</spanx> along with any
changed metadata values. Its <spanx style="verb">client_id</spanx>
will remain the same.</t>
<t>If the client needs to update its configuration on the
authorization server, it sends an HTTP PUT request to the <spanx
style="verb">registration_client_uri</spanx> with the <spanx
style="verb">registration_access_token</spanx> as its
authorization. This response will contain the client's changed
metadata values. Its <spanx style="verb">client_id</spanx> will
remain the same.</t>
<t>If the client is uninstalled or otherwise deprovisioned, it can
send an HTTP DELETE request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This will effectively deprovision the client
from the authorization server.</t>
</list></t>
</section>
<section anchor="ProtectedRegistration" title="Protected Registration">
<t>An authorization server may require an initial access token for
requests to its registration endpoint. While the method by which a
client receives this initial Access token and the method by which the
authorization server validates this initial access token are out of
scope for this specification, a common approach is for the developer
to use a manual pre-registration portal at the authorization server
that issues an initial access token to the developer. This allows the
developer to package the initial access token with different instances
of the client application. While each copy of the application would
get its own client identifier (and registration access token), all
instances of the application would be tied back to the developer by
their shared use of this initial access token.</t>
<t><list style="letters">
<t>A developer is creating a client to use an authorization server
and knows that instances of the client will dynamically register
at runtime, but that the authorization server requires
authorization at the registration endpoint.</t>
<t>The developer visits a manual pre-registration page at the
authorization server and is issued an initial access token in the
form of an <xref target="RFC6750">OAuth 2.0 Bearer
Token</xref>.</t>
<t>The developer packages that token with all instances of the
client application.</t>
<t>The client needs to get OAuth 2.0 tokens from an authorization
server, but the client does not have a client identifier for that
authorization server.</t>
<t>The client sends an HTTP POST request to the client
registration endpoint at the authorization server with its
metadata, and the initial access token as its authorization.</t>
<t>The authorization server issues a client identifier and returns
it to the client along with a registration access token and a
reference to the client's client configuration endpoint.</t>
<t>The client stores the returned response from the authorization
server. At a minimum, it should know the values of <spanx
style="verb">client_id</spanx>, <spanx style="verb">client_secret</spanx>
(if present), <spanx style="verb">registration_access_token</spanx>,
and <spanx style="verb">registration_client_uri</spanx>.</t>
<t>The client uses the its <spanx style="verb">client_id</spanx>
and <spanx style="verb">client_secret</spanx> (if provided) to
request OAuth 2.0 tokens using any supported OAuth 2.0 flow for
which this client is authorized.</t>
<t>If the client's <spanx style="verb">client_secret</spanx>
expires or otherwise stops working, the client sends an HTTP GET
request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This response will contain the client's
refreshed <spanx style="verb">client_secret</spanx> along with any
metadata values registered to that client, some of which may have
changed. Its <spanx style="verb">client_id</spanx> will remain the
same.</t>
<t>If the client needs to update its configuration on the
authorization server, it sends an HTTP PUT request to the <spanx
style="verb">registration_client_uri</spanx> with the <spanx
style="verb">registration_access_token</spanx> as its
authorization. The response will contain the client's changed
metadata values. Its <spanx style="verb">client_id</spanx> will
remain the same.</t>
<t>If the client is uninstalled or otherwise deprovisioned, it can
send an HTTP DELETE request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This will effectively deprovision the client
from the Authorization Server.</t>
</list></t>
</section>
<section anchor="DeveloperAutomation" title="Developer Automation">
<t>The dynamic registration protocol can also be used in place of a
manual registration portal, for instance as part of an automated build
and deployment process. In this scenario, the authorization server may
require an initial access token for requests to its registration
endpoint, as described in <xref
target="ProtectedRegistration">Protected Registration </xref>.
However, here the developer manages the client's registration instead
of the client itself. Therefore, the initial registration token and
registration access token all remain with the developer. The developer
packages the client identifier with the client as part of the client's
build process. <list style="letters">
<t>A developer is creating a client to use an authorization server
and knows that instances of the client will not dynamically
register at runtime.</t>
<t>If required for registrations at the authorization server, the
developer performs an OAuth 2.0 authorization of his build
environment against the authorization server using any valid OAuth
2.0 flow. The authorization server and is issues an initial access
token to the developer's build environment in the form of an <xref
target="RFC6750">OAuth 2.0 Bearer Token</xref>.</t>
<t>The developer configures his build environment to send an HTTP
POST request to the client registration endpoint at the
authorization server with the client's metadata, using the initial
access token obtained the previous step as an <xref
target="RFC6750">OAuth 2.0 Bearer Token</xref>.</t>
<t>The authorization server issues a client identifier and returns
it to the developer along with a registration access token and a
reference to the client's client configuration endpoint.</t>
<t>The developer packages the client identifier with the client
and stores the <spanx style="verb">registration_access_token</spanx>,
and <spanx style="verb">registration_client_uri</spanx> in the
deployment system.</t>
<t>The client uses the its <spanx style="verb">client_id</spanx>
and <spanx style="verb">client_secret</spanx> (if provided) to
request OAuth 2.0 tokens using any supported OAuth 2.0 flow.</t>
<t>If the client's <spanx style="verb">client_secret</spanx>
expires or otherwise stops working, the developer's deployment
system sends an HTTP GET request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This response will contain the client's
refreshed <spanx style="verb">client_secret</spanx> along with any
changed metadata values. Its <spanx style="verb">client_id</spanx>
will remain the same. These new values will then be packaged and
shipped to or retrieved by instances of the client, if
necessary.</t>
<t>If the developer needs to update its configuration on the
authorization server, the deployment system sends an HTTP PUT
request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This response will contain the client's changed
metadata values. Its <spanx style="verb">client_id</spanx> will
remain the same. These new values will then be packaged and
shipped to or retrieved by instances of the client, if
necessary.</t>
<t>If the client is deprovisioned, the developer's deployment
system can send an HTTP DELETE request to the <spanx style="verb">registration_client_uri</spanx>
with the <spanx style="verb">registration_access_token</spanx> as
its authorization. This will effectively deprovision the client
from the authorization server and prevent any instances of the
client from functioning.</t>
</list></t>
</section>
</section>
<section anchor="History" title="Document History">
<t>[[ to be removed by the RFC editor before publication as an RFC
]]</t>
<t>-13</t>
<t><list style="symbols">
<t>Fixed broken example text in registration request and in delete
request</t>
<t>Added security discussion of separating clients of different
grant types</t>
<t>Fixed error reference to point to RFC6750 instead of RFC6749</t>
<t>Clarified that servers must respond to all requests to
configuration endpoint, even if it's just an error code</t>
<t>Lowercased all Terms to conform to style used in RFC6750</t>
</list></t>
<t>-12</t>
<t><list style="symbols">
<t>Improved definition of Initial Access Token</t>
<t>Changed developer registration scenario to have the Initial
Access Token gotten through a normal OAuth 2.0 flow</t>
<t>Moved non-normative client lifecycle examples to appendix</t>
<t>Marked differentiating between auth servers as out of scope</t>
<t>Added protocol flow diagram</t>
<t>Added credential rotation discussion</t>
<t>Called out Client Registration Endpoint as an OAuth 2.0 Protected
Resource</t>
<t>Cleaned up several pieces of text</t>
</list></t>
<t>-11</t>
<t><list style="symbols">
<t>Added localized text to registration request and response
examples.</t>
<t>Removed <spanx style="verb">client_secret_jwt</spanx> and <spanx
style="verb">private_key_jwt</spanx>.</t>
<t>Clarified <spanx style="verb">tos_uri</spanx> and <spanx
style="verb">policy_uri</spanx> definitions.</t>
<t>Added the OAuth Token Endpoint Authentication Methods registry
for registering <spanx style="verb">token_endpoint_auth_method</spanx>
metadata values.</t>
<t>Removed uses of non-ASCII characters, per RFC formatting
rules.</t>
<t>Changed <spanx style="verb">expires_at</spanx> to <spanx
style="verb">client_secret_expires_at</spanx> and <spanx
style="verb">issued_at</spanx> to <spanx style="verb">client_id_issued_at</spanx>
for greater clarity.</t>
<t>Added explanatory text for different credentials (Initial Access
Token, Registration Access Token, Client Credentials) and what
they're used for.</t>
<t>Added Client Lifecycle discussion and examples.</t>
<t>Defined Initial Access Token in Terminology section.</t>
</list></t>
<t>-10</t>
<t><list style="symbols">
<t>Added language to point out that scope values are
service-specific</t>
<t>Clarified normative language around client metadata</t>
<t>Added extensibility to token_endpoint_auth_method using absolute
URIs</t>
<t>Added security consideration about registering redirect URIs</t>
<t>Changed erroneous 403 responses to 401's with notes about token
handling</t>
<t>Added example for initial registration credential</t>
</list></t>
<t>-09</t>
<t><list style="symbols">
<t>Added method of internationalization for Client Metadata
values</t>
<t>Fixed SAML reference</t>
</list></t>
<t>-08</t>
<t><list style="symbols">
<t>Collapsed jwk_uri, jwk_encryption_uri, x509_uri, and
x509_encryption_uri into a single jwks_uri parameter</t>
<t>Renamed grant_type to grant_types since it's a plural value</t>
<t>Formalized name of "OAuth 2.0" throughout document</t>
<t>Added JWT Bearer Assertion and SAML 2 Bearer Assertion to example
grant types</t>
<t>Added response_types parameter and explanatory text on its use
with and relationship to grant_types</t>
</list></t>
<t>-07</t>
<t><list style="symbols">
<t>Changed registration_access_url to registration_client_uri</t>
<t>Fixed missing text in 5.1</t>
<t>Added Pragma: no-cache to examples</t>
<t>Changed "no such client" error to 403</t>
<t>Renamed Client Registration Access Endpoint to Client
Configuration Endpoint</t>
<t>Changed all the parameter names containing "_url" to instead use
"_uri"</t>
<t>Updated example text for forming Client Configuration Endpoint
URL</t>
</list></t>
<t>-06</t>
<t><list style="symbols">
<t>Removed secret_rotation as a client-initiated action, including
removing client secret rotation endpoint and parameters.</t>
<t>Changed _links structure to single value
registration_access_url.</t>
<t>Collapsed create/update/read responses into client info
response.</t>
<t>Changed return code of create action to 201.</t>
<t>Added section to describe suggested generation and composition of
Client Registration Access URL.</t>
<t>Added clarifying text to PUT and POST requests to specify JSON in
the body.</t>
<t>Added Editor's Note to DELETE operation about its inclusion.</t>
<t>Added Editor's Note to registration_access_url about alternate
syntax proposals.</t>
</list></t>
<t>-05</t>
<t><list style="symbols">
<t>changed redirect_uri and contact to lists instead of space
delimited strings</t>
<t>removed operation parameter</t>
<t>added _links structure</t>
<t>made client update management more RESTful</t>
<t>split endpoint into three parts</t>
<t>changed input to JSON from form-encoded</t>
<t>added READ and DELETE operations</t>
<t>removed Requirements section</t>
<t>changed token_endpoint_auth_type back to
token_endpoint_auth_method to match OIDC who changed to match us</t>
</list></t>
<t>-04</t>
<t><list style="symbols">
<t>removed default_acr, too undefined in the general OAuth2 case</t>
<t>removed default_max_auth_age, since there's no mechanism for
supplying a non-default max_auth_age in OAuth2</t>
<t>clarified signing and encryption URLs</t>
<t>changed token_endpoint_auth_method to token_endpoint_auth_type to
match OIDC</t>
</list></t>
<t>-03</t>
<t><list style="symbols">
<t>added scope and grant_type claims</t>
<t>fixed various typos and changed wording for better clarity</t>
<t>endpoint now returns the full set of client information</t>
<t>operations on client_update allow for three actions on metadata:
leave existing value, clear existing value, replace existing value
with new value</t>
</list></t>
<t>-02</t>
<t><list style="symbols">
<t>Reorganized contributors and references</t>
<t>Moved OAuth references to RFC</t>
<t>Reorganized model/protocol sections for clarity</t>
<t>Changed terminology to "client register" instead of "client
associate"</t>
<t>Specified that client_id must match across all subsequent
requests</t>
<t>Fixed RFC2XML formatting, especially on lists</t>
</list></t>
<t>-01</t>
<t><list style="symbols">
<t>Merged UMA and OpenID Connect registrations into a single
document</t>
<t>Changed to form-paramter inputs to endpoint</t>
<t>Removed pull-based registration</t>
</list></t>
<t>-00</t>
<t><list style="symbols">
<t>Imported original UMA draft specification</t>
</list></t>
</section>
</back>
</rfc>
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