draft-ietf-oauth-dyn-reg-30

[フレーム]

OAuth Working Group J. Richer, Ed.
Internet-Draft
Intended status: Standards Track M. Jones
Expires: November 29, 2015 Microsoft
 J. Bradley
 Ping Identity
 M. Machulak
 Newcastle University
 P. Hunt
 Oracle Corporation
 May 28, 2015
 OAuth 2.0 Dynamic Client Registration Protocol
 draft-ietf-oauth-dyn-reg-30
Abstract
 This specification defines mechanisms for dynamically registering
 OAuth 2.0 clients with authorization servers. Registration requests
 send a set of desired client metadata values to the authorization
 server. The resulting registration responses return a client
 identifier to use at the authorization server and the client metadata
 values registered for the client. The client can then use this
 registration information to communicate with the authorization server
 using the OAuth 2.0 protocol. This specification also defines a set
 of common client metadata fields and values for clients to use during
 registration.
Status of This Memo
 This Internet-Draft is submitted in full conformance with the
 provisions of BCP 78 and BCP 79.
 Internet-Drafts are working documents of the Internet Engineering
 Task Force (IETF). Note that other groups may also distribute
 working documents as Internet-Drafts. The list of current Internet-
 Drafts is at http://datatracker.ietf.org/drafts/current/.
 Internet-Drafts are draft documents valid for a maximum of six months
 and may be updated, replaced, or obsoleted by other documents at any
 time. It is inappropriate to use Internet-Drafts as reference
 material or to cite them other than as "work in progress."
 This Internet-Draft will expire on November 29, 2015.
Richer, et al. Expires November 29, 2015 [Page 1]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
Copyright Notice
 Copyright (c) 2015 IETF Trust and the persons identified as the
 document authors. All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document. Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document. Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.
Table of Contents
 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4
 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
 1.3. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 6
 2. Client Metadata . . . . . . . . . . . . . . . . . . . . . . . 7
 2.1. Relationship between Grant Types and Response Types . . . 11
 2.2. Human-Readable Client Metadata . . . . . . . . . . . . . 12
 2.3. Software Statement . . . . . . . . . . . . . . . . . . . 13
 3. Client Registration Endpoint . . . . . . . . . . . . . . . . 14
 3.1. Client Registration Request . . . . . . . . . . . . . . . 15
 3.1.1. Client Registration Request Using a Software
 Statement . . . . . . . . . . . . . . . . . . . . . . 17
 3.2. Responses . . . . . . . . . . . . . . . . . . . . . . . . 18
 3.2.1. Client Information Response . . . . . . . . . . . . . 18
 3.2.2. Client Registration Error Response . . . . . . . . . 20
 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
 4.1. OAuth Dynamic Client Registration Metadata Registry . . . 22
 4.1.1. Registration Template . . . . . . . . . . . . . . . . 23
 4.1.2. Initial Registry Contents . . . . . . . . . . . . . . 23
 4.2. OAuth Token Endpoint Authentication Methods Registry . . 26
 4.2.1. Registration Template . . . . . . . . . . . . . . . . 26
 4.2.2. Initial Registry Contents . . . . . . . . . . . . . . 27
 5. Security Considerations . . . . . . . . . . . . . . . . . . . 27
 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 30
 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 31
 7.1. Normative References . . . . . . . . . . . . . . . . . . 31
 7.2. Informative References . . . . . . . . . . . . . . . . . 33
 Appendix A. Use Cases . . . . . . . . . . . . . . . . . . . . . 33
 A.1. Open versus Protected Dynamic Client Registration . . . . 33
 A.1.1. Open Dynamic Client Registration . . . . . . . . . . 33
 A.1.2. Protected Dynamic Client Registration . . . . . . . . 33
Richer, et al. Expires November 29, 2015 [Page 2]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 A.2. Registration Without or With Software Statements . . . . 34
 A.2.1. Registration Without a Software Statement . . . . . . 34
 A.2.2. Registration With a Software Statement . . . . . . . 34
 A.3. Registration by the Client or Developer . . . . . . . . . 34
 A.3.1. Registration by the Client . . . . . . . . . . . . . 34
 A.3.2. Registration by the Developer . . . . . . . . . . . . 34
 A.4. Client ID per Client Instance or per Client Software . . 34
 A.4.1. Client ID per Client Software Instance . . . . . . . 34
 A.4.2. Client ID Shared Among All Instances of Client
 Software . . . . . . . . . . . . . . . . . . . . . . 35
 A.5. Stateful or Stateless Registration . . . . . . . . . . . 35
 A.5.1. Stateful Client Registration . . . . . . . . . . . . 35
 A.5.2. Stateless Client Registration . . . . . . . . . . . . 35
 Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 35
 Appendix C. Document History . . . . . . . . . . . . . . . . . . 36
 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 42
1. Introduction
 In order for an OAuth 2.0 [RFC6749] 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. This specification describes how an OAuth 2.0
 client can be dynamically registered with an authorization server to
 obtain this information.
 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 set of valid redirection URIs. This
 metadata can either be communicated in a self-asserted fashion or as
 a set of metadata called a software statement, which is digitally
 signed or MACed; in the case of a software statement, the issuer is
 vouching for the validity of the data about the client.
 Traditionally, registration of a client with an authorization server
 is performed manually. The mechanisms defined in this specification
 can be used either for a client to dynamically register itself with
 authorization servers or for a client developer to programmatically
 register the client with authorization servers. Multiple
 applications using OAuth 2.0 have previously developed mechanisms for
 accomplishing such registrations. This specification generalizes the
 registration mechanisms defined by the OpenID Connect Dynamic Client
 Registration 1.0 [OpenID.Registration] specification and used by the
 User Managed Access (UMA) Profile of OAuth 2.0
 [I-D.hardjono-oauth-umacore] specification in a way that is
 compatible with both, while being applicable to a wider set of OAuth
 2.0 use cases.
Richer, et al. Expires November 29, 2015 [Page 3]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
1.1. Notational Conventions
 The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT',
 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in this
 document are to be interpreted as described in [RFC2119].
 Unless otherwise noted, all the protocol parameter names and values
 are case sensitive.
1.2. Terminology
 This specification uses the terms "access token", "authorization
 code", "authorization endpoint", "authorization grant",
 "authorization server", "client", "client identifier", "client
 secret", "grant type", "protected resource", "redirection URI",
 "refresh token", "resource owner", "resource server", "response
 type", and "token endpoint" defined by OAuth 2.0 [RFC6749] and uses
 the term "Claim" defined by JSON Web Token (JWT) [RFC7519].
 This specification defines the following terms:
 Client Software
 Software implementing an OAuth 2.0 client.
 Client Instance
 A deployed instance of a piece of client software.
 Client Developer
 The person or organization that builds a client software package
 and prepares it for distribution. At the time of building the
 client, the developer is often not aware of who the deploying
 service provider organizations will be. Client developers will
 need to use dynamic registration when they are unable to predict
 aspects of the software, such as the deployment URLs, at compile
 time. For instance, this can occur when the software API
 publisher and the deploying organization are not the same.
 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 is obtained are out of scope for this specification.
 Initial Access Token
 OAuth 2.0 access token optionally issued by an authorization
 server to a developer or client 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
Richer, et al. Expires November 29, 2015 [Page 4]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 this token as well as the means by which the registration endpoint
 validates this token are out of scope for this specification. Use
 of an initial access token is required when the authorization
 server limits the parties that can register a client.
 Deployment Organization
 An administrative security domain under which a software API
 (service) is deployed and protected by an OAuth 2.0 framework. In
 some OAuth scenarios, the deployment organization and the software
 API publisher are the same. In these cases, the deploying
 organization will often have a close relationship with client
 software developers. In many other cases, the definer of the
 service may be an independent third-party publisher or a standards
 organization. When working to a published specification for an
 API, the client software developer is unable to have a prior
 relationship with the potentially many deployment organizations
 deploying the software API (service).
 Software API Deployment
 A deployed instance of a software API that is protected by OAuth
 2.0 (a protected resource) in a particular deployment organization
 domain. For any particular software API, there may be one or more
 deployments. A software API deployment typically has an
 associated OAuth 2.0 authorization server as well as a client
 registration endpoint. The means by which endpoints are obtained
 are out of scope for this specification.
 Software API Publisher
 The organization that defines a particular web accessible API that
 may be deployed in one or more deployment environments. A
 publisher may be any standards body, commercial, public, private,
 or open source organization that is responsible for publishing and
 distributing software and API specifications that may be protected
 via OAuth 2.0. In some cases, a software API publisher and a
 client developer may be the same organization. At the time of
 publication of a web accessible API, the software publisher often
 does not have a prior relationship with the deploying
 organizations.
 Software Statement
 Digitally signed or MACed JSON Web Token (JWT) [RFC7519] that
 asserts metadata values about the client software. In some cases,
 a software statement will be issued directly by the client
 developer. In other cases, a software statement will be issued by
 a third party organization for use by the client developer. In
 both cases, the trust relationship the authorization server has
 with the issuer of the software statement is intended to be used
 as an input to the evaluation of whether the registration request
Richer, et al. Expires November 29, 2015 [Page 5]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 is accepted. A software statement can be presented to an
 authorization server as part of a client registration request.
1.3. Protocol Flow
 +--------(A)- Initial Access Token (OPTIONAL)
 |
 | +----(B)- Software Statement (OPTIONAL)
 | |
 v v
 +-----------+ +---------------+
 | |--(C)- Client Registration Request -->| Client |
 | Client or | | Registration |
 | Developer |<-(D)- Client Information Response ---| Endpoint |
 | | or Client Error Response +---------------+
 +-----------+
 Figure 1: Abstract Dynamic Client Registration Flow
 The abstract OAuth 2.0 client dynamic registration flow illustrated
 in Figure 1 describes the interaction between the client or developer
 and the endpoint defined in this specification. This figure does not
 demonstrate error conditions. This flow includes the following
 steps:
 (A) Optionally, the client or developer is issued an initial access
 token giving access to the client registration endpoint. The
 method by which the initial access token is issued to the client
 or developer is out of scope for this specification.
 (B) Optionally, the client or developer is issued a software
 statement for use with the client registration endpoint. The
 method by which the software statement is issued to the client or
 developer is out of scope for this specification.
 (C) The client or developer calls the client registration endpoint
 with the client's desired registration metadata, optionally
 including the initial access token from (A) if one is required by
 the authorization server.
 (D) The authorization server registers the client and returns:
 * the client's registered metadata,
 * a client identifier that is unique at the server, and
Richer, et al. Expires November 29, 2015 [Page 6]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 * a set of client credentials such as a client secret, if
 applicable for this client.
 Examples of different configurations and usages are included in
 Appendix A.
2. Client Metadata
 Registered clients have a set of metadata values associated with
 their client identifier at an authorization server, such as the list
 of valid redirection URIs or a display name.
 These client metadata values are used in two ways:
 o as input values to registration requests, and
 o as output values in registration responses.
 The following client metadata fields are defined by this
 specification. The implementation and use of all client metadata
 fields is OPTIONAL, unless stated otherwise. All data member types
 (strings, arrays, numbers) are defined in terms of their JSON
 [RFC7159] representations.
 redirect_uris
 Array of redirection URI strings for use in redirect-based flows
 such as the authorization code and implicit flows. As required by
 Section 2 of OAuth 2.0 [RFC6749], clients using flows with
 redirection MUST register their redirection URI values.
 Authorization servers that support dynamic registration for
 redirect-based flows MUST implement support for this metadata
 value.
 token_endpoint_auth_method
 String indicator of the requested authentication method for the
 token endpoint. Values defined by this specification are:
 * "none": The client is a public client as defined in OAuth 2.0
 and does not have a client secret.
 * "client_secret_post": The client uses the HTTP POST parameters
 defined in OAuth 2.0 section 2.3.1.
 * "client_secret_basic": the client uses HTTP Basic defined in
 OAuth 2.0 section 2.3.1
 Additional values can be defined via the IANA OAuth Token Endpoint
 Authentication Methods Registry established in Section 4.2.
Richer, et al. Expires November 29, 2015 [Page 7]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 Absolute URIs can also be used as values for this parameter
 without being registered. If unspecified or omitted, the default
 is "client_secret_basic", denoting HTTP Basic Authentication
 Scheme as specified in Section 2.3.1 of OAuth 2.0.
 grant_types
 Array of OAuth 2.0 grant type strings that the client can use at
 the token endpoint. These grant types are defined as follows:
 * "authorization_code": The Authorization Code Grant described in
 OAuth 2.0 Section 4.1
 * "implicit": The Implicit Grant described in OAuth 2.0
 Section 4.2
 * "password": The Resource Owner Password Credentials Grant
 described in OAuth 2.0 Section 4.3
 * "client_credentials": The Client Credentials Grant described in
 OAuth 2.0 Section 4.4
 * "refresh_token": The Refresh Token Grant described in OAuth 2.0
 Section 6.
 * "urn:ietf:params:oauth:grant-type:jwt-bearer": The JWT Bearer
 Grant defined in OAuth JWT Bearer Token Profiles [RFC7523].
 * "urn:ietf:params:oauth:grant-type:saml2-bearer": The SAML 2
 Bearer Grant defined in OAuth SAML 2 Bearer Token Profiles
 [RFC7522].
 If the token endpoint is used in the grant type, the value of this
 parameter MUST be the same as the value of the "grant_type"
 parameter passed to the token endpoint defined in the grant type
 definition. Authorization servers MAY allow for other values as
 defined in the grant type extension process described in OAuth 2.0
 Section 2.5. If omitted, the default behavior is that the client
 will use only the "authorization_code" Grant Type.
 response_types
 Array of the OAuth 2.0 response type strings that the client can
 use at the authorization endpoint. These response types are
 defined as follows:
 * "code": The authorization code response described in OAuth 2.0
 Section 4.1.
Richer, et al. Expires November 29, 2015 [Page 8]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 * "token": The implicit response described in OAuth 2.0
 Section 4.2.
 If the authorization endpoint is used by the grant type, the value
 of this parameter MUST be the same as the value of the
 "response_type" parameter passed to the authorization endpoint
 defined in the grant type definition. Authorization servers MAY
 allow for other values as defined in the grant type extension
 process is described in OAuth 2.0 Section 2.5. If omitted, the
 default is that the client will use only the "code" response type.
 client_name
 Human-readable string name of the client to be presented to the
 end-user during authorization. If omitted, the authorization
 server MAY display the raw "client_id" value to the end-user
 instead. It is RECOMMENDED that clients always send this field.
 The value of this field MAY be internationalized, as described in
 Section 2.2.
 client_uri
 URL string of a web page providing information about 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 Section 2.2.
 logo_uri
 URL string 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
 Section 2.2.
 scope
 String containing a space separated list of scope values (as
 described in Section 3.3 of OAuth 2.0 [RFC6749]) 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.
 contacts
 Array of strings representing ways to contact people responsible
 for this client, typically email addresses. The authorization
 server MAY make these contact addresses available to end-users for
 support requests for the client. See Section 6 for information on
 Privacy Considerations.
Richer, et al. Expires November 29, 2015 [Page 9]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 tos_uri
 URL string that points to a human-readable terms of service
 document for the client that describes a contractual relationship
 between the end-user and the client that the end-user accepts when
 authorizing the client. The authorization server SHOULD display
 this URL to the end-user if it is provided. The value of this
 field MUST point to a valid web page. The value of this field MAY
 be internationalized, as described in Section 2.2.
 policy_uri
 URL string that points to a human-readable privacy policy document
 that describes how the deployment organization collects, uses,
 retains, and discloses personal data. The authorization server
 SHOULD display this URL to the end-user if it is provided. The
 value of this field MUST point to a valid web page. The value of
 this field MAY be internationalized, as described in Section 2.2.
 jwks_uri
 URL string referencing the client's JSON Web Key Set [RFC7517]
 document, which contains the client's public keys. The value of
 this field MUST point to a valid JWK Set document. These keys can
 be used by higher level protocols that use signing or encryption.
 For instance, these keys might be used by some applications for
 validating signed requests made to the token endpoint when using
 JWTs for client authentication [RFC7523]. Use of this parameter
 is preferred over the "jwks" parameter, as it allows for easier
 key rotation. The "jwks_uri" and "jwks" parameters MUST NOT both
 be present in the same request or response.
 jwks
 Client's JSON Web Key Set [RFC7517] document value, which contains
 the client's public keys. The value of this field MUST be a JSON
 object containing a valid JWK Set. These keys can be used by
 higher level protocols that use signing or encryption. This
 parameter is intended to be used by clients that cannot use the
 "jwks_uri" parameter, such as native clients that cannot host
 public URLs. The "jwks_uri" and "jwks" parameters MUST NOT both
 be present in the same request or response.
 software_id
 A unique identifier string (e.g. a UUID) assigned by the client
 developer or software publisher used by registration endpoints to
 identify the client software to be dynamically registered. Unlike
 "client_id", which is issued by the authorization server and
 SHOULD vary between instances, the "software_id" SHOULD remain the
 same for all instances of the client software. The "software_id"
 SHOULD remain the same across multiple updates or versions of the
 same piece of software. The value of this field is not intended
Richer, et al. Expires November 29, 2015 [Page 10]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 to be human-readable and is usually opaque to the client and
 authorization server.
 software_version
 A version identifier string for the client software identified by
 "software_id". The value of the "software_version" SHOULD change
 on any update to the client software identified by the same
 "software_id". The value of this field is intended to be compared
 using string equality matching and no other comparison semantics
 are defined by this specification. The value of this field is
 outside the scope of this speicification, but it is not intended
 to be human readable and is usually opaque to the client and
 authorization server. The definition of what constitutes an
 update to client software that would trigger a change to this
 value is specific to the software itself and is outside the scope
 of this specification.
 Extensions and profiles of this specification can expand this list
 with metadata names and descriptions registered in accordance with
 the IANA Considerations in Section 4 of this document. The
 authorization server MUST ignore any client metadata sent by the
 client that it does not understand (for instance, by silently
 removing unknown metadata from the client's registration record
 during processing). The authorization server MAY reject any
 requested client metadata values by replacing requested values with
 suitable defaults as described in Section 3.2.1 or by returning an
 error response as described in Section 3.2.2.
 Client metadata values can either be communicated directly in the
 body of a registration request, as described in Section 3.1, or
 included as claims in a software statement, as described in
 Section 2.3, or a mixture of both. If the same client metadata name
 is present in both locations and the software statement is trusted by
 the authorization server, the value of a claim in the software
 statement MUST take precedence.
2.1. Relationship between Grant Types and Response Types
 The "grant_types" and "response_types" 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 "grant_types" available to a client influence the
 "response_types" that the client is allowed to use, and vice versa.
 For instance, a "grant_types" value that includes
 "authorization_code" implies a "response_types" value that includes
 "code", 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
Richer, et al. Expires November 29, 2015 [Page 11]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 an inconsistent state, for example by returning an
 "invalid_client_metadata" error response to an inconsistent
 registration request.
 The correlation between the two fields is listed in the table below.
 +-----------------------------------------------+-------------------+
 | grant_types value includes: | response_types |
 | | value includes: |
 +-----------------------------------------------+-------------------+
 | authorization_code | code |
 | implicit | token |
 | password | (none) |
 | client_credentials | (none) |
 | refresh_token | (none) |
 | urn:ietf:params:oauth:grant-type:jwt-bearer | (none) |
 | urn:ietf:params:oauth:grant-type:saml2-bearer | (none) |
 +-----------------------------------------------+-------------------+
 Extensions and profiles of this document that introduce new values to
 either the "grant_types" or "response_types" parameter MUST document
 all correspondences between these two parameter types.
2.2. Human-Readable Client Metadata
 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
 "client_name", "tos_uri", "policy_uri", "logo_uri", and "client_uri"
 might have multiple locale-specific values in some client
 registrations to facilitate use in different locations.
 To specify the languages and scripts, BCP47 [RFC5646] language tags
 are added to client metadata member names, delimited by a #
 character. Since JSON [RFC7159] 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 IANA Language Subtag Registry [IANA.Language]. 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
 "fr" might be sufficient in many contexts, rather than "fr-CA" or
 "fr-FR".
Richer, et al. Expires November 29, 2015 [Page 12]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 For example, a client could represent its name in English as
 ""client_name#en": "My Client"" and its name in Japanese as
 ""client_name#ja-Jpan-JP":
 "\u30AF\u30E9\u30A4\u30A2\u30F3\u30C8\u540D"" 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.
 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.
 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
 "#" 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, "var j =
 JSON.parse(json);", then as a workaround the member "client_name#en-
 us" can be accessed using the JavaScript syntax "j["client_name#en-
 us"]".
2.3. Software Statement
 A software statement is a JSON Web Token (JWT) [RFC7519] that asserts
 metadata values about the client software as a bundle. A set of
 claims that can be used in a software statement are defined in
 Section 2. When presented to the authorization server as part of a
 client registration request, the software statement MUST be digitally
 signed or MACed using JWS [RFC7515] and MUST contain an "iss"
 (issuer) claim denoting the party attesting to the claims in the
 software statement. It is RECOMMENDED that software statements be
 digitally signed using the "RS256" signature algorithm, although
 particular applications MAY specify the use of different algorithms.
 It is RECOMMENDED that software statements contain the "software_id"
 claim to allow authorization servers to correlate different instances
 of software using the same software statement.
 For example, a software statement could contain the following claims:
Richer, et al. Expires November 29, 2015 [Page 13]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 {
 "software_id": "4NRB1-0XZABZI9E6-5SM3R",
 "client_name": "Example Statement-based Client",
 "client_uri": "https://client.example.net/"
 }
 The following non-normative example JWT includes these claims and has
 been asymmetrically signed using RS256:
 Line breaks are for display purposes only
 eyJhbGciOiJSUzI1NiJ9.
 eyJzb2Z0d2FyZV9pZCI6IjROUkIxLTBYWkFCWkk5RTYtNVNNM1IiLCJjbGll
 bnRfbmFtZSI6IkV4YW1wbGUgU3RhdGVtZW50LWJhc2VkIENsaWVudCIsImNs
 aWVudF91cmkiOiJodHRwczovL2NsaWVudC5leGFtcGxlLm5ldC8ifQ.
 GHfL4QNIrQwL18BSRdE595T9jbzqa06R9BT8w409x9oIcKaZo_mt15riEXHa
 zdISUvDIZhtiyNrSHQ8K4TvqWxH6uJgcmoodZdPwmWRIEYbQDLqPNxREtYn0
 5X3AR7ia4FRjQ2ojZjk5fJqJdQ-JcfxyhK-P8BAWBd6I2LLA77IG32xtbhxY
 fHX7VhuU5ProJO8uvu3Ayv4XRhLZJY4yKfmyjiiKiPNe-Ia4SMy_d_QSWxsk
 U5XIQl5Sa2YRPMbDRXttm2TfnZM1xx70DoYi8g6czz-CPGRi4SW_S2RKHIJf
 IjoI3zTJ0Y2oe0_EJAiXbL6OyF9S5tKxDXV8JIndSA
 The means by which a client or developer obtains a software statement
 are outside the scope of this specification. Some common methods
 could include a client developer generating a client-specific JWT by
 registering with a software API publisher to obtain a software
 statement for a class of clients. The software statement is
 typically distributed with all instances of a client application.
 The criteria by which authorization servers determine whether to
 trust and utilize the information in a software statement are beyond
 the scope of this specification.
 In some cases, authorization servers MAY choose to accept a software
 statement value directly as a client identifier in an authorization
 request, without a prior dynamic client registration having been
 performed. The circumstances under which an authorization server
 would do so, and the specific software statement characteristics
 required in this case, are beyond the scope of this specification.
3. Client Registration Endpoint
 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 "application/json" format. The client
Richer, et al. Expires November 29, 2015 [Page 14]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 registration endpoint MUST be protected by a transport-layer security
 mechanism, as described in Section 5.
 The client registration endpoint MAY be an OAuth 2.0 protected
 resource and accept an initial access token in the form of an OAuth
 2.0 [RFC6749] access token to limit registration to only previously
 authorized parties. The method by which the initial access token is
 obtained by the client or developer 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.
 To support open registration and facilitate wider interoperability,
 the client registration endpoint SHOULD allow registration requests
 with no authorization (which is to say, with no initial 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.
3.1. Client Registration Request
 This operation registers a client with the authorization server. The
 authorization server assigns this client a unique client identifier,
 optionally assigns a client secret, and associates the metadata
 provided in the request with the issued client identifier. The
 request includes any client metadata parameters being specified for
 the client during the registration. The authorization server MAY
 provision default values for any items omitted in the client
 metadata.
 To register, the client or developer sends an HTTP POST to the client
 registration endpoint with a content type of "application/json". The
 HTTP Entity Payload is a JSON [RFC7159] document consisting of a JSON
 object and all requested client metadata values as top-level members
 of that JSON object.
 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:
Richer, et al. Expires November 29, 2015 [Page 15]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 The following is a non-normative example request not using an initial
 access token (with line wraps within values for display purposes
 only):
 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",
 "logo_uri":"https://client.example.org/logo.png",
 "jwks_uri":"https://client.example.org/my_public_keys.jwks",
 "example_extension_parameter": "example_value"
 }
 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 OAuth 2.0 Bearer Token [RFC6750], but any OAuth
 2.0 token type could be used by an authorization server.
Richer, et al. Expires November 29, 2015 [Page 16]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 The following is a non-normative example request using an initial
 access token and registering a JWK set by value (with line wraps
 within values for display purposes only):
 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",
 "policy_uri":"https://client.example.org/policy.html",
 "jwks":{"keys":[{
 "e": "AQAB",
 "n": "nj3YJwsLUFl9BmpAbkOswCNVx17Eh9wMO-_AReZwBqfaWFcfG
 HrZXsIV2VMCNVNU8Tpb4obUaSXcRcQ-VMsfQPJm9IzgtRdAY8NN8Xb7PEcYyk
 lBjvTtuPbpzIaqyiUepzUXNDFuAOOkrIol3WmflPUUgMKULBN0EUd1fpOD70p
 RM0rlp_gg_WNUKoW1V-3keYUJoXH9NztEDm_D2MQXj9eGOJJ8yPgGL8PAZMLe
 2R7jb9TxOCPDED7tY_TU4nFPlxptw59A42mldEmViXsKQt60s1SLboazxFKve
 qXC_jpLUt22OC6GUG63p-REw-ZOr3r845z50wMuzifQrMI9bQ",
 "kty": "RSA"
 }]},
 "example_extension_parameter": "example_value"
 }
3.1.1. Client Registration Request Using a Software Statement
 In addition to JSON elements, client metadata values MAY also be
 provided in a software statement, as described in Section 2.3. The
 authorization server MAY ignore the software statement if it does not
 support this feature. If the server supports software statements,
 client metadata values conveyed in the software statement MUST take
 precedence over those conveyed using plain JSON elements.
 Software statements are included in the requesting JSON object using
 this OPTIONAL member:
 software_statement
 A software statement containing client metadata values about the
 client software as claims. This is a string value containing the
 entire signed JWT.
Richer, et al. Expires November 29, 2015 [Page 17]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 In the following example, some registration parameters are conveyed
 as claims in a software statement from the example in Section 2.3,
 while some values specific to the client instance are conveyed as
 regular parameters (with line wraps within values for display
 purposes only):
 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"
 ],
 "software_statement":"eyJhbGciOiJSUzI1NiJ9.
 eyJzb2Z0d2FyZV9pZCI6IjROUkIxLTBYWkFCWkk5RTYtNVNNM1IiLCJjbGll
 bnRfbmFtZSI6IkV4YW1wbGUgU3RhdGVtZW50LWJhc2VkIENsaWVudCIsImNs
 aWVudF91cmkiOiJodHRwczovL2NsaWVudC5leGFtcGxlLm5ldC8ifQ.
 GHfL4QNIrQwL18BSRdE595T9jbzqa06R9BT8w409x9oIcKaZo_mt15riEXHa
 zdISUvDIZhtiyNrSHQ8K4TvqWxH6uJgcmoodZdPwmWRIEYbQDLqPNxREtYn0
 5X3AR7ia4FRjQ2ojZjk5fJqJdQ-JcfxyhK-P8BAWBd6I2LLA77IG32xtbhxY
 fHX7VhuU5ProJO8uvu3Ayv4XRhLZJY4yKfmyjiiKiPNe-Ia4SMy_d_QSWxsk
 U5XIQl5Sa2YRPMbDRXttm2TfnZM1xx70DoYi8g6czz-CPGRi4SW_S2RKHIJf
 IjoI3zTJ0Y2oe0_EJAiXbL6OyF9S5tKxDXV8JIndSA",
 "scope":"read write",
 "example_extension_parameter":"example_value"
 }
3.2. Responses
 Upon a successful registration request, the authorization server
 returns a client identifier for the client. The server responds with
 an HTTP 201 Created code and a body of type "application/json" with
 content as described in Section 3.2.1.
 Upon an unsuccessful registration request, the authorization server
 responds with an error, as described in Section 3.2.2.
3.2.1. Client Information Response
 The response contains the client identifier as well as the client
 secret, if the client is a confidential client. The response MAY
 contain additional fields as specified by extensions to this
 specification.
 client_id
Richer, et al. Expires November 29, 2015 [Page 18]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 REQUIRED. OAuth 2.0 client identifier string. It SHOULD NOT be
 currently valid for any other registered client, though an
 authorization server MAY issue the same client identifier to
 multiple instances of a registered client at its discretion.
 client_secret
 OPTIONAL. OAuth 2.0 client secret string. If issued, this MUST
 be unique for each "client_id" and SHOULD be unique for multiple
 instances of a client using the same "client_id". This value is
 used by confidential clients to authenticate to the token endpoint
 as described in OAuth 2.0 [RFC6749] Section 2.3.1.
 client_id_issued_at
 OPTIONAL. Time at which the client identifier was issued. The
 time is represented as the number of seconds from
 1970年01月01日T0:0:0Z as measured in UTC until the date/time of
 issuance.
 client_secret_expires_at
 REQUIRED if "client_secret" is issued. Time at which the client
 secret will expire or 0 if it will not expire. The time is
 represented as the number of seconds from 1970年01月01日T0:0:0Z as
 measured in UTC until the date/time of expiration.
 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 and substitute them with suitable values.
 The client or developer can check the values in the response to
 determine if the registration is sufficient for use (e.g., the
 registered "token_endpoint_auth_method" is supported by the client
 software) and determine a course of action appropriate for the client
 software. The response to such a situation is out of scope for this
 specification but could include filing a report with the application
 developer or authorization server provider, attempted re-registration
 with different metadata values, or various other methods. For
 instance, if the server also supports a registration management
 mechanism such as that defined in [OAuth.Registration.Management],
 the client or developer could attempt to update the registration with
 different metadata values. This process could also be aided by a
 service discovery protocol such as [OpenID.Discovery] which can list
 a server's capabilities, allowing a client to make a more informed
 registration request. The use of any such management or discovery
 system is optional and outside the scope of this specification.
 The successful registration response uses an HTTP 201 Created status
 code with a body of type "application/json" consisting of a single
Richer, et al. Expires November 29, 2015 [Page 19]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 JSON object [RFC7159] with all parameters as top-level members of the
 object.
 If a software statement was used as part of the registration, its
 value MUST be returned unmodified in the response along with other
 metadata using the "software_statement" member name. Client metadata
 elements used from the software statement MUST also be returned
 directly as top-level client metadata values in the registration
 response (possibly with different values, since the values requested
 and the values used may differ).
 Following is a non-normative example response of a successful
 registration:
 HTTP/1.1 201 Created
 Content-Type: application/json
 Cache-Control: no-store
 Pragma: no-cache
 {
 "client_id":"s6BhdRkqt3",
 "client_secret": "cf136dc3c1fc93f31185e5885805d",
 "client_id_issued_at":2893256800,
 "client_secret_expires_at":2893276800,
 "redirect_uris":[
 "https://client.example.org/callback",
 "https://client.example.org/callback2"],
 "grant_types": ["authorization_code", "refresh_token"],
 "client_name":"My Example Client",
 "client_name#ja-Jpan-JP":
 "\u30AF\u30E9\u30A4\u30A2\u30F3\u30C8\u540D",
 "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",
 "example_extension_parameter": "example_value"
 }
3.2.2. Client Registration Error Response
 When an OAuth 2.0 error condition occurs, such as the client
 presenting an invalid initial access token, the authorization server
 returns an error response appropriate to the OAuth 2.0 token type.
 When a registration error condition occurs, the authorization server
 returns an HTTP 400 status code (unless otherwise specified) with
 content type "application/json" consisting of a JSON object [RFC7159]
 describing the error in the response body.
Richer, et al. Expires November 29, 2015 [Page 20]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 Two members are defined for inclusion in the JSON object:
 error
 REQUIRED. Single ASCII error code string.
 error_description
 OPTIONAL. Human-readable ASCII text description of the error used
 for debugging.
 Other members MAY also be included, and if not understood, MUST be
 ignored.
 This specification defines the following error codes:
 invalid_redirect_uri
 The value of one or more redirection URIs is invalid.
 invalid_client_metadata
 The value of one of the client metadata 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.
 invalid_software_statement
 The software statement presented is invalid.
 unapproved_software_statement
 The software statement presented is not approved for use by this
 authorization server.
 Following is a non-normative example of an error response resulting
 from a redirection URI that has been blacklisted by the authorization
 server (with line wraps within values for display purposes only):
 HTTP/1.1 400 Bad Request
 Content-Type: application/json
 Cache-Control: no-store
 Pragma: no-cache
 {
 "error": "invalid_redirect_uri",
 "error_description": "The redirection URI
 http://sketchy.example.com is not allowed by this server."
 }
Richer, et al. Expires November 29, 2015 [Page 21]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 Following is a non-normative example of an error response resulting
 from an inconsistent combination of "response_types" and
 "grant_types" values (with line wraps within values for display
 purposes only):
 HTTP/1.1 400 Bad Request
 Content-Type: application/json
 Cache-Control: no-store
 Pragma: no-cache
 {
 "error": "invalid_client_metadata",
 "error_description": "The grant type 'authorization_code' must be
 registered along with the response type 'code' but found only
 'implicit' instead."
 }
4. IANA Considerations
4.1. OAuth Dynamic Client Registration Metadata Registry
 This specification establishes the OAuth Dynamic Client Registration
 Metadata registry.
 OAuth registration client metadata names and descriptions are
 registered with a Specification Required ([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 names prior to publication, the Designated Expert(s)
 may approve registration once they are satisfied that such a
 specification will be published, per [RFC7120].
 Registration requests sent to the mailing list for review should use
 an appropriate subject (e.g., "Request to register OAuth Dynamic
 Client Registration Metadata name: example").
 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.
 IANA must only accept registry updates from the Designated Expert(s)
 and should direct all requests for registration to the review mailing
 list.
Richer, et al. Expires November 29, 2015 [Page 22]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
4.1.1. Registration Template
 Client Metadata Name:
 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.
 Client Metadata Description:
 Brief description of the metadata value (e.g., "Example
 description").
 Change controller:
 For Standards Track RFCs, state "IESG". For others, give the name
 of the responsible party. Other details (e.g., postal address,
 email address, home page URI) may also be included.
 Specification document(s):
 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.
4.1.2. Initial Registry Contents
 The initial contents of the OAuth Dynamic Client Registration
 Metadata registry are:
 o Client Metadata Name: "redirect_uris"
 o Client Metadata Description: Array of redirection URIs for use in
 redirect-based flows
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
 o Client Metadata Name: "token_endpoint_auth_method"
 o Client Metadata Description: Requested authentication method for
 the token endpoint
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
 o Client Metadata Name: "grant_types"
 o Client Metadata Description: Array of OAuth 2.0 grant types that
 the client may use
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
 o Client Metadata Name: "response_types"
 o Client Metadata Description: Array of the OAuth 2.0 response types
 that the client may use
Richer, et al. Expires November 29, 2015 [Page 23]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
 o Client Metadata Name: "client_name"
 o Client Metadata Description: Human-readable name of the client to
 be presented to the user
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "client_uri"
 o Client Metadata Description: URL of a Web page providing
 information about the client
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "logo_uri"
 o Client Metadata Description: URL that references a logo for the
 client
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "scope"
 o Client Metadata Description: Space separated list of OAuth 2.0
 scope values
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "contacts"
 o Client Metadata Description: Array of strings representing ways to
 contact people responsible for this client, typically email
 addresses
 o Change Controller: IESG
 o Specification document(s): [[ this document ]]
 o Client Metadata Name: "tos_uri"
 o Client Metadata Description: URL that points to a human-readable
 Terms of Service document for the client
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "policy_uri"
 o Client Metadata Description: URL that points to a human-readable
 Policy document for the client
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "jwks_uri"
Richer, et al. Expires November 29, 2015 [Page 24]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o Client Metadata Description: URL referencing the client's JSON Web
 Key Set [RFC7517] document representing the client's public keys
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "jwks"
 o Client Metadata Description: Client's JSON Web Key Set [RFC7517]
 document representing the client's public keys
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "software_id"
 o Client Metadata Description: Identifier for the software that
 comprises a client
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "software_version"
 o Client Metadata Description: Version identifier for the software
 that comprises a client
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "client_id"
 o Client Metadata Description: Client identifier
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "client_secret"
 o Client Metadata Description: Client secret
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "client_id_issued_at"
 o Client Metadata Description: Time at which the client identifier
 was issued
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
 o Client Metadata Name: "client_secret_expires_at"
 o Client Metadata Description: Time at which the client secret will
 expire
 o Change Controller: IESG
 o Specification Document(s): [[ this document ]]
Richer, et al. Expires November 29, 2015 [Page 25]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
4.2. OAuth Token Endpoint Authentication Methods Registry
 This specification establishes the OAuth Token Endpoint
 Authentication Methods registry.
 Additional values for use as "token_endpoint_auth_method" values are
 registered with a Specification Required ([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, per [RFC7120].
 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").
 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.
 IANA must only accept registry updates from the Designated Expert(s)
 and should direct all requests for registration to the review mailing
 list.
4.2.1. Registration Template
 Token Endpoint Authorization Method Name:
 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.
 Change controller:
 For Standards Track RFCs, state "IESG". For others, give the name
 of the responsible party. Other details (e.g., postal address,
 email address, home page URI) may also be included.
 Specification document(s):
 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.
Richer, et al. Expires November 29, 2015 [Page 26]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
4.2.2. Initial Registry Contents
 The initial contents of the OAuth Token Endpoint Authentication
 Methods registry are:
 o Token Endpoint Authorization Method Name: "none"
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
 o Token Endpoint Authorization Method Name: "client_secret_post"
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
 o Token Endpoint Authorization Method Name: "client_secret_basic"
 o Change controller: IESG
 o Specification document(s): [[ this document ]]
5. Security Considerations
 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 RFC 5246
 [RFC5246] 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 [RFC6125].
 Implementation security considerations can be found in
 Recommendations for Secure Use of TLS and DTLS [RFC7525].
 For clients that use redirect-based grant types such as
 "authorization_code" and "implicit", authorization servers MUST
 require clients to register their redirection URI values. This can
 help mitigate attacks where rogue actors inject and impersonate a
 validly registered client and intercept its authorization code or
 tokens through an invalid redirection URI or open redirector.
 Additionally, in order to prevent hijacking of the return values of
 the redirection, registered redirection URI values MUST be one of:
 o A remote web site protected by TLS (e.g.,
 https://client.example.com/oauth_redirect)
 o A web site hosted on the local machine using an HTTP URI (e.g.,
 http://localhost:8080/oauth_redirect)
 o A non-HTTP application-specific URL that is available only to the
 client application (e.g., exampleapp://oauth_redirect)
 Public clients MAY register with an authorization server using this
 protocol, if the authorization server's policy allows them. Public
Richer, et al. Expires November 29, 2015 [Page 27]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 clients use a "none" value for the "token_endpoint_auth_method"
 metadata field and are generally used with the "implicit" 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 is possible that such
 clients would need to re-register every time the browser application
 is loaded. 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. Alternatively, such clients could be
 registered on the server where the in-browser application's code is
 served from, and the client's configuration pushed to the browser
 along side the code.
 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 "authorization_code" grant type make use of a
 client secret for the "token_endpoint_auth_method", but any clients
 using the "implicit" 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 "authorization_code" and "implicit"
 grant types simultaneously. Similarly, the "authorization_code"
 grant type is used to represent access on behalf of an end-user, but
 the "client_credentials" 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
 "invalid_client_metadata" error response.
 Unless used as a claim in a software statement, the authorization
 server MUST treat all client metadata as self-asserted. For
 instance, a rogue client might use the name and logo of a legitimate
 client that it is trying to impersonate. Additionally, a rogue
 client might try to use the software identifier or software version
 of a legitimate client to attempt to associate itself on the
 authorization server with instances of the legitimate client. To
 counteract this, an authorization server MUST take appropriate steps
 to mitigate this risk by looking at the entire registration request
 and client configuration. For instance, an authorization server
 could issue a warning if the domain/site of the logo doesn't match
 the domain/site of redirection URIs. An authorization server could
 also refuse registration requests from a known software identifier
 that is requesting different redirection URIs or a different client
Richer, et al. Expires November 29, 2015 [Page 28]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 URI. An authorization server can also present warning messages to
 end-users about dynamically registered clients in all cases,
 especially if such clients have been recently registered or have not
 been trusted by any users at the authorization server before.
 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.
 "logo_uri", "tos_uri", "client_uri", and "policy_uri"). For
 instance, a rogue client could specify a registration request with a
 reference to a drive-by download in the "policy_uri", enticing the
 user to click on it during the authorization. The authorization
 server SHOULD check to see if the "logo_uri", "tos_uri",
 "client_uri", and "policy_uri" have the same host and scheme as the
 those defined in the array of "redirect_uris" and that all of these
 URIs resolve to valid web pages. Since these URI values that are
 intended to be displayed to the user at the authorization page, the
 authorization server SHOULD protect the user from malicious content
 hosted at the URLs where possible. For instance, before presenting
 the URLs to the user at the authorization page, the authorization
 server could download the content hosted at the URLs, check the
 content against a malware scanner and blacklist filter, determine
 whether or not there is mixed secure and non-secure content at the
 URL, and other possible server-side mitigations. Note that the
 content in these URLs can change at any time and the authorization
 server cannot provide complete confidence in the safety of the URLs,
 but these practices could help. To further mitigate this kind of
 threat, the authorization server can also warn the user that the URL
 links have been provided by a third party, should be treated with
 caution, and are not hosted by the authorization server itself. For
 instance, instead of providing the links directly in an HTML anchor,
 the authorization server can direct the user to an interstitial
 warning page before allowing the user to continue to the target URL.
 Clients MAY use both the direct JSON object and the JWT-encoded
 software statement to present client metadata to the authorization
 server as part of the registration request. A software statement is
 cryptographically protected and represents claims made by the issuer
 of the statement, while the JSON object represents the self-asserted
 claims made by the client or developer directly. If the software
 statement is valid and signed by an acceptable authority (such as the
 software API publisher), the values of client metadata within the
 software statement MUST take precedence over those metadata values
 presented in the plain JSON object, which could have been intercepted
 and modified.
 Like all metadata values, the software statement is an item that is
 self-asserted by the client, even though its contents have been
Richer, et al. Expires November 29, 2015 [Page 29]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 digitally signed or MACed by the issuer of the software statement.
 As such, presentation of the software statement is not sufficient in
 most cases to fully identify a piece of client software. An initial
 access token, in contrast, does not necessarily contain information
 about a particular piece of client software but instead represents
 authorization to use the registration endpoint. An authorization
 server MUST consider the full registration request, including the
 software statement, initial access token, and JSON client metadata
 values, when deciding whether to honor a given registration request.
 If an authorization server receives a registration request for a
 client that is not intended to have multiple instances registered
 simultaneously and the authorization server can infer a duplication
 of registration (e.g., it uses the same "software_id" and
 "software_version" values as another existing client), the server
 SHOULD treat the new registration as being suspect and reject the
 registration. It is possible that the new client is trying to
 impersonate the existing client in order to trick users into
 authorizing it, or that the original registration is no longer valid.
 The details of managing this situation are specific to the
 authorization server deployment and outside the scope of this
 specification.
 Since a client identifier is a public value that can be used to
 impersonate a client at the authorization endpoint, an authorization
 server that decides to issue the same client identifier to multiple
 instances of a registered client needs to be very particular about
 the circumstances under which this occurs. For instance, the
 authorization server can limit a given client identifier to clients
 using the same redirect-based flow and the same redirection URIs. An
 authorization server SHOULD NOT issue the same client secret to
 multiple instances of a registered client, even if they are issued
 the same client identifier, or else the client secret could be
 leaked, allowing malicious impostors to impersonate a confidential
 client.
6. Privacy Considerations
 As the protocol described in this specification deals almost
 exclusively with information about software and not about people,
 there are very few privacy concerns for its use. The notable
 exception is the "contacts" field as defined in Client Metadata
 (Section 2), which contains contact information for the developers or
 other parties responsible for the client software. These values are
 intended to be displayed to end-users and will be available to the
 administrators of the authorization server. As such, the developer
 may wish to provide an email address or other contact information
 expressly dedicated to the purpose of supporting the client instead
Richer, et al. Expires November 29, 2015 [Page 30]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 of using their personal or professional addresses. Alternatively,
 the developer may wish to provide a collective email address for the
 client to allow for continuing contact and support of the client
 software after the developer moves on and someone else takes over
 that responsibility.
 In general, the metadata for a client, such as the client name and
 software identifier, are common across all instances of a piece of
 client software and therefore pose no privacy issues for end-users.
 Client identifiers, on the other hand, are often unique to a specific
 instance of a client. For clients such as web sites that are used by
 many users, there may not be significant privacy concerns regarding
 the client identifier, but for clients such as native applications
 that are installed on a single end-user's device, the client
 identifier could be uniquely tracked during OAuth 2.0 transactions
 and its use tied to that single end-user. However, as the client
 software still needs to be authorized by a resource owner through an
 OAuth 2.0 authorization grant, this type of tracking can occur
 whether or not the client identifier is unique by correlating the
 authenticated resource owner with the requesting client identifier.
 Note that clients are forbidden by this specification from creating
 their own client identifier. If the client were able to do so, an
 individual client instance could be tracked across multiple colluding
 authorization servers, leading to privacy and security issues.
 Additionally, client identifiers are generally issued uniquely per
 registration request, even for the same instance of software. In
 this way, an application could marginally improve privacy by
 registering multiple times and appearing to be completely separate
 applications. However, this technique does incur significant
 usability cost in the form of requiring multiple authorizations per
 resource owner and is therefore unlikely to be used in practice.
7. References
7.1. Normative References
 [IANA.Language]
 Internet Assigned Numbers Authority (IANA), "Language
 Subtag Registry", <http://www.iana.org/assignments/
 language-subtag-registry>.
 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
 Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
 IANA Considerations Section in RFCs", BCP 26, RFC 5226,
 May 2008.
Richer, et al. Expires November 29, 2015 [Page 31]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
 (TLS) Protocol Version 1.2", RFC 5246, August 2008.
 [RFC5646] Phillips, A. and M. Davis, "Tags for Identifying
 Languages", BCP 47, RFC 5646, September 2009.
 [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
 Verification of Domain-Based Application Service Identity
 within Internet Public Key Infrastructure Using X.509
 (PKIX) Certificates in the Context of Transport Layer
 Security (TLS)", RFC 6125, March 2011.
 [RFC6749] Hardt, D., "The OAuth 2.0 Authorization Framework", RFC
 6749, October 2012.
 [RFC6750] Jones, M. and D. Hardt, "The OAuth 2.0 Authorization
 Framework: Bearer Token Usage", RFC 6750, October 2012.
 [RFC7120] Cotton, M., "Early IANA Allocation of Standards Track Code
 Points", BCP 100, RFC 7120, January 2014.
 [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data
 Interchange Format", RFC 7159, March 2014.
 [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
 Signature (JWS)", RFC 7515, May 2015.
 [RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517, May 2015.
 [RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
 (JWT)", RFC 7519, May 2015.
 [RFC7522] Campbell, B., Mortimore, C., and M. Jones, "Security
 Assertion Markup Language (SAML) 2.0 Profile for OAuth 2.0
 Client Authentication and Authorization Grants", RFC 7522,
 May 2015.
 [RFC7523] Jones, M., Campbell, B., and C. Mortimore, "JSON Web Token
 (JWT) Profile for OAuth 2.0 Client Authentication and
 Authorization Grants", RFC 7523, May 2015.
 [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
 "Recommendations for Secure Use of Transport Layer
 Security (TLS) and Datagram Transport Layer Security
 (DTLS)", BCP 195, RFC 7525, May 2015.
Richer, et al. Expires November 29, 2015 [Page 32]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
7.2. Informative References
 [I-D.hardjono-oauth-umacore]
 Hardjono, T., Maler, E., Machulak, M., and D. Catalano,
 "User-Managed Access (UMA) Profile of OAuth 2.0", draft-
 hardjono-oauth-umacore-13 (work in progress), April 2015.
 [OAuth.Registration.Management]
 Richer, J., Jones, M., Bradley, J., and M. Machulak,
 "OAuth 2.0 Dynamic Client Registration Management
 Protocol", draft-ietf-oauth-dyn-reg-management (work in
 progress), May 2015.
 [OpenID.Discovery]
 Sakimura, N., Bradley, J., Jones, M., and E. Jay, "OpenID
 Connect Discovery 1.0", November 2014.
 [OpenID.Registration]
 Sakimura, N., Bradley, J., and M. Jones, "OpenID Connect
 Dynamic Client Registration 1.0", November 2014.
Appendix A. Use Cases
 This appendix describes different ways that this specification can be
 utilized, including describing some of the choices that may need to
 be made. Some of the choices are independent and can be used in
 combination, whereas some of the choices are interrelated.
A.1. Open versus Protected Dynamic Client Registration
A.1.1. Open Dynamic Client Registration
 Authorization servers that support open registration allow
 registrations to be made with no initial access token. This allows
 all client software to register with the authorization server.
A.1.2. Protected Dynamic Client Registration
 Authorization servers that support protected registration require
 that an initial access token be used when making registration
 requests. While the method by which a client or developer 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.
Richer, et al. Expires November 29, 2015 [Page 33]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
A.2. Registration Without or With Software Statements
A.2.1. Registration Without a Software Statement
 When a software statement is not used in the registration request,
 the authorization server must be willing to use client metadata
 values without them being digitally signed or MACed (and thereby
 attested to) by any authority. (Note that this choice is independent
 of the Open versus Protected choice, and that an initial access token
 is another possible form of attestation.)
A.2.2. Registration With a Software Statement
 A software statement can be used in a registration request to provide
 attestation by an authority for a set of client metadata values.
 This can be useful when the authorization server wants to restrict
 registration to client software attested to by a set of authorities
 or when it wants to know that multiple registration requests refer to
 the same piece of client software.
A.3. Registration by the Client or Developer
A.3.1. Registration by the Client
 In some use cases, client software will dynamically register itself
 with an authorization server to obtain a client identifier and other
 information needed to interact with the authorization server. In
 this case, no client identifier for the authorization server is
 packaged with the client software.
A.3.2. Registration by the Developer
 In some cases, the developer (or development software being used by
 the developer) will pre-register the client software with the
 authorization server or a set of authorization servers. In this
 case, the client identifier value(s) for the authorization server(s)
 can be packaged with the client software.
A.4. Client ID per Client Instance or per Client Software
A.4.1. Client ID per Client Software Instance
 In some cases, each deployed instance of a piece of client software
 will dynamically register and obtain distinct client identifier
 values. This can be advantageous, for instance, if the code flow is
 being used, as it also enables each client instance to have its own
 client secret. This can be useful for native clients, which cannot
 maintain the secrecy of a client secret value packaged with the
Richer, et al. Expires November 29, 2015 [Page 34]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 software, but which may be able to maintain the secrecy of a per-
 instance client secret.
A.4.2. Client ID Shared Among All Instances of Client Software
 In some cases, each deployed instance of a piece of client software
 will share a common client identifier value. For instance, this is
 often the case for in-browser clients using the implicit flow, when
 no client secret is involved. Particular authorization servers might
 choose, for instance, to maintain a mapping between software
 statement values and client identifier values, and return the same
 client identifier value for all registration requests for a
 particular piece of software. The circumstances under which an
 authorization server would do so, and the specific software statement
 characteristics required in this case, are beyond the scope of this
 specification.
A.5. Stateful or Stateless Registration
A.5.1. Stateful Client Registration
 In some cases, authorization servers will maintain state about
 registered clients, typically indexing this state using the client
 identifier value. This state would typically include the client
 metadata values associated with the client registration, and possibly
 other state specific to the authorization server's implementation.
 When stateful registration is used, operations to support retrieving
 and/or updating this state may be supported. One possible set of
 operations upon stateful registrations is described in the
 [OAuth.Registration.Management] specification.
A.5.2. Stateless Client Registration
 In some cases, authorization servers will be implemented in a manner
 the enables them to not maintain any local state about registered
 clients. One means of doing this is to encode all the registration
 state in the returned client identifier value, and possibly
 encrypting the state to the authorization server to maintain the
 confidentiality and integrity of the state.
Appendix B. Acknowledgments
 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,
Richer, et al. Expires November 29, 2015 [Page 35]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 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.
Appendix C. Document History
 [[ to be removed by the RFC editor before publication as an RFC ]]
 -30
 o Updated JOSE, JWT, and OAuth Assertion draft references to final
 RFC numbers.
 -29
 o Descrbed more possible client responses to the metadata fields
 returned by the server being different than those requested.
 o Added RFC 7120/BCP 100 references.
 o Added RFC 7525/BCP 195 reference to replace draft reference.
 -28
 o Clarified all client metadata as JSON arrays, strings, or numbers.
 o Expanded security considerations advice around external URLs.
 o Added text to say what happens if the client doesn't get back the
 registration it expected in the response.
 o Added more explicit references to HTTP 201 response from
 registration.
 o Clarified client version definition.
 o Removed spurious reference to "delete action".
 o Fixed intended normative and non-normative language in several
 sections.
 o Stated what a server should do if a suspected duplicate client
 tries to register.
 -27
 o Changed a registry name missed in -26.
 -26
 o Used consistent registry name.
 -25
 o Updated author information.
 o Clarified registry contents.
 o Added forward pointer to IANA from metadata section.
Richer, et al. Expires November 29, 2015 [Page 36]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o Clarified how to silently ignore errors.
 o Reformatted diagram text.
 -24
 o Clarified some party definitions.
 o Clarified the opaqueness of software_id and software_statement.
 o Created a forward pointer to the Security Considerations section
 for TLS requirements on the registration endpoint.
 o Added a forward pointer to the Privacy Considerations section for
 the contacts field.
 o Wrote privacy considerations about client_id tracking.
 -23
 o Updated author information.
 -22
 o Reorganized registration response sections.
 o Addressed shepherd comments.
 o Added concrete JWK set to example.
 -21
 o Applied minor editorial fixes.
 o Added software statement examples.
 o Moved software statement request details to sub-section.
 o Clarified that a server MAY ignore the software statement (just as
 it MAY ignore other metadata values).
 o Removed TLS 1.0.
 o Added privacy considerations around "contacts" field.
 o Marked software_id as RECOMMENDED inside of a software statement.
 -20
 o Applied minor editorial fixes from working group comments.
 -19
 o Added informative references to the OpenID Connect Dynamic Client
 Registration and UMA specifications in the introduction.
 o Clarified the "jwks" and "jwks_uri" descriptions and included an
 example situation in which they might be used.
 o Removed "application_type".
 o Added redirection URI usage restrictions to the Security
 Considerations section, based on the client type.
 o Expanded the "tos_uri" and "policy_uri" descriptions.
Richer, et al. Expires November 29, 2015 [Page 37]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 -18
 o Corrected an example HTTP response status code to be 201 Created.
 o Said more about who issues and uses initial access tokens and
 software statements.
 o Stated that the use of an initial access token is required when
 the authorization server limits the parties that can register a
 client.
 o Stated that the implementation and use of all client metadata
 fields is OPTIONAL, other than "redirect_uris", which MUST be used
 for redirect-based flows and implemented to fulfill the
 requirement in Section 2 of OAuth 2.0.
 o Added the "application_type" metadata value, which had somehow
 been omitted.
 o Added missing default metadata values, which had somehow been
 omitted.
 o Clarified that the "software_id" is ultimately asserted by the
 client developer.
 o Clarified that the "error" member is required in error responses,
 "error_description" member is optional, and other members may be
 present.
 o Added security consideration about registrations with duplicate
 "software_id" and "software_version" values.
 -17
 o Merged draft-ietf-oauth-dyn-reg-metadata back into this document.
 o Removed "Core" from the document title.
 o Explicitly state that all metadata members are optional.
 o Clarified language around software statements for use in
 registration context.
 o Clarified that software statements need to be digitally signed or
 MACed.
 o Added a "jwks" metadata parameter to parallel the "jwks_uri"
 parameter.
 o Removed normative language from terminology.
 o Expanded abstract and introduction.
 o Addressed review comments from several working group members.
 -16
 o Replaced references to draft-jones-oauth-dyn-reg-metadata and
 draft-jones-oauth-dyn-reg-management with draft-ietf-oauth-dyn-
 reg-metadata and draft-ietf-oauth-dyn-reg-management.
 o Addressed review comments by Phil Hunt and Tony Nadalin.
 -15
Richer, et al. Expires November 29, 2015 [Page 38]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o Partitioned the Dynamic Client Registration specification into
 core, metadata, and management specifications. This built on work
 first published as draft-richer-oauth-dyn-reg-core-00 and draft-
 richer-oauth-dyn-reg-management-00.
 o Added the ability to use Software Statements. This built on work
 first published as draft-hunt-oauth-software-statement-00 and
 draft-hunt-oauth-client-association-00.
 o Created the IANA OAuth Registration Client Metadata registry for
 registering Client Metadata values.
 o Defined Client Instance term and stated that multiple instances
 can use the same client identifier value under certain
 circumstances.
 o Rewrote the introduction.
 o Rewrote the Use Cases appendix.
 -14
 o Added software_id and software_version metadata fields
 o Added direct references to RFC6750 errors in read/update/delete
 methods
 -13
 o Fixed broken example text in registration request and in delete
 request
 o Added security discussion of separating clients of different grant
 types
 o Fixed error reference to point to RFC6750 instead of RFC6749
 o Clarified that servers must respond to all requests to
 configuration endpoint, even if it's just an error code
 o Lowercased all Terms to conform to style used in RFC6750
 -12
 o Improved definition of Initial Access Token
 o Changed developer registration scenario to have the Initial Access
 Token gotten through a normal OAuth 2.0 flow
 o Moved non-normative client lifecycle examples to appendix
 o Marked differentiating between auth servers as out of scope
 o Added protocol flow diagram
 o Added credential rotation discussion
 o Called out Client Registration Endpoint as an OAuth 2.0 Protected
 Resource
 o Cleaned up several pieces of text
 -11
Richer, et al. Expires November 29, 2015 [Page 39]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o Added localized text to registration request and response
 examples.
 o Removed "client_secret_jwt" and "private_key_jwt".
 o Clarified "tos_uri" and "policy_uri" definitions.
 o Added the OAuth Token Endpoint Authentication Methods registry for
 registering "token_endpoint_auth_method" metadata values.
 o Removed uses of non-ASCII characters, per RFC formatting rules.
 o Changed "expires_at" to "client_secret_expires_at" and "issued_at"
 to "client_id_issued_at" for greater clarity.
 o Added explanatory text for different credentials (Initial Access
 Token, Registration Access Token, Client Credentials) and what
 they're used for.
 o Added Client Lifecycle discussion and examples.
 o Defined Initial Access Token in Terminology section.
 -10
 o Added language to point out that scope values are service-specific
 o Clarified normative language around client metadata
 o Added extensibility to token_endpoint_auth_method using absolute
 URIs
 o Added security consideration about registering redirect URIs
 o Changed erroneous 403 responses to 401's with notes about token
 handling
 o Added example for initial registration credential
 -09
 o Added method of internationalization for Client Metadata values
 o Fixed SAML reference
 -08
 o Collapsed jwk_uri, jwk_encryption_uri, x509_uri, and
 x509_encryption_uri into a single jwks_uri parameter
 o Renamed grant_type to grant_types since it's a plural value
 o Formalized name of "OAuth 2.0" throughout document
 o Added JWT Bearer Assertion and SAML 2 Bearer Assertion to example
 grant types
 o Added response_types parameter and explanatory text on its use
 with and relationship to grant_types
 -07
 o Changed registration_access_url to registration_client_uri
 o Fixed missing text in 5.1
 o Added Pragma: no-cache to examples
 o Changed "no such client" error to 403
Richer, et al. Expires November 29, 2015 [Page 40]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o Renamed Client Registration Access Endpoint to Client
 Configuration Endpoint
 o Changed all the parameter names containing "_url" to instead use
 "_uri"
 o Updated example text for forming Client Configuration Endpoint URL
 -06
 o Removed secret_rotation as a client-initiated action, including
 removing client secret rotation endpoint and parameters.
 o Changed _links structure to single value registration_access_url.
 o Collapsed create/update/read responses into client info response.
 o Changed return code of create action to 201.
 o Added section to describe suggested generation and composition of
 Client Registration Access URL.
 o Added clarifying text to PUT and POST requests to specify JSON in
 the body.
 o Added Editor's Note to DELETE operation about its inclusion.
 o Added Editor's Note to registration_access_url about alternate
 syntax proposals.
 -05
 o changed redirect_uri and contact to lists instead of space
 delimited strings
 o removed operation parameter
 o added _links structure
 o made client update management more RESTful
 o split endpoint into three parts
 o changed input to JSON from form-encoded
 o added READ and DELETE operations
 o removed Requirements section
 o changed token_endpoint_auth_type back to
 token_endpoint_auth_method to match OIDC who changed to match us
 -04
 o removed default_acr, too undefined in the general OAuth2 case
 o removed default_max_auth_age, since there's no mechanism for
 supplying a non-default max_auth_age in OAuth2
 o clarified signing and encryption URLs
 o changed token_endpoint_auth_method to token_endpoint_auth_type to
 match OIDC
 -03
 o added scope and grant_type claims
 o fixed various typos and changed wording for better clarity
Richer, et al. Expires November 29, 2015 [Page 41]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 o endpoint now returns the full set of client information
 o operations on client_update allow for three actions on metadata:
 leave existing value, clear existing value, replace existing value
 with new value
 -02
 o Reorganized contributors and references
 o Moved OAuth references to RFC
 o Reorganized model/protocol sections for clarity
 o Changed terminology to "client register" instead of "client
 associate"
 o Specified that client_id must match across all subsequent requests
 o Fixed RFC2XML formatting, especially on lists
 -01
 o Merged UMA and OpenID Connect registrations into a single document
 o Changed to form-parameter inputs to endpoint
 o Removed pull-based registration
 -00
 o Imported original UMA draft specification
Authors' Addresses
 Justin Richer (editor)
 Email: ietf@justin.richer.org
 Michael B. Jones
 Microsoft
 Email: mbj@microsoft.com
 URI: http://self-issued.info/
 John Bradley
 Ping Identity
 Email: ve7jtb@ve7jtb.com
Richer, et al. Expires November 29, 2015 [Page 42]

Internet-Draft OAuth 2.0 Dynamic Registration May 2015
 Maciej Machulak
 Newcastle University
 Email: maciej.machulak@gmail.com
 Phil Hunt
 Oracle Corporation
 Email: phil.hunt@yahoo.com
Richer, et al. Expires November 29, 2015 [Page 43]

AltStyle によって変換されたページ (->オリジナル) /