Draft N. Sakimura NRI J. Bradley Ping Identity M. Jones Microsoft May 3, 2013 OpenID Connect Dynamic Client Registration 1.0 - draft 17 Abstract OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol. It allows Clients to verify the identity of the End-User based on the authentication performed by an Authorization Server, as well as to obtain basic profile information about the End-User in an interoperable and REST-like manner. This specification describes how an OpenID Client can obtain the necessary Client Credentials required by the OpenID Connect protocol suite. Sakimura, et al. [Page 1] OpenID Connect Registration 1.0 May 2013 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Notation and Conventions . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Client Metadata . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Metadata Languages and Scripts . . . . . . . . . . . . . . 9 3. Client Registration . . . . . . . . . . . . . . . . . . . . . 10 3.1. Client Registration Request . . . . . . . . . . . . . . . 10 3.2. Client Registration Response . . . . . . . . . . . . . . . 11 3.3. Client Registration Error Response . . . . . . . . . . . . 13 4. Client Read . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.1. Client Read Request . . . . . . . . . . . . . . . . . . . 15 4.2. Client Read Response . . . . . . . . . . . . . . . . . . . 15 4.3. Client Read Error Response . . . . . . . . . . . . . . . . 16 5. "sector_identifier_uri" Validation . . . . . . . . . . . . . . 18 6. String Operations . . . . . . . . . . . . . . . . . . . . . . 19 7. Validation . . . . . . . . . . . . . . . . . . . . . . . . . . 20 8. Implementation Considerations . . . . . . . . . . . . . . . . 21 9. Security Considerations . . . . . . . . . . . . . . . . . . . 22 9.1. TLS Requirements . . . . . . . . . . . . . . . . . . . . . 22 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24 11.1. Normative References . . . . . . . . . . . . . . . . . . . 24 11.2. Informative References . . . . . . . . . . . . . . . . . . 25 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 26 Appendix B. Notices . . . . . . . . . . . . . . . . . . . . . . . 27 Appendix C. Document History . . . . . . . . . . . . . . . . . . 28 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 36 Sakimura, et al. [Page 2] OpenID Connect Registration 1.0 May 2013 1. Introduction In order for an OpenID Connect Client to utilize OpenID services for a user, the Client needs to register with the OpenID Provider to acquire a Client ID and shared secret. This document describes how a new Client can register with the provider, and how a Client already in possession of a "client_id" can retrieve updated registration information. The Client Registration Endpoint may be co-resident with the Token Endpoint as an optimization in some deployments. Note: This specification will likely be modified to use the OAuth Dynamic Client Registration Protocol [I-D.ietf-oauth-dyn-reg] once the OAuth registration draft is stable. While currently self- contained, this specification intentionally uses the same syntax and identifiers as the current version of the OAuth registration draft as of the time that this specification was last updated. 1.1. Requirements Notation and 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 RFC 2119 [RFC2119]. Throughout this document, values are quoted to indicate that they are to be taken literally. When using these values in protocol messages, the quotes MUST NOT be used as part of the value. 1.2. Terminology 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 OAuth 2.0 [RFC6749], and the terms defined by OpenID Connect Messages 1.0 [OpenID.Messages]. This specification defines the following additional terms: Client Registration Endpoint OAuth 2.0 Protected Resource through which a Client can request a new registration. Client Configuration Endpoint The OAuth 2.0 Endpoint through which a specific Client can manage its registration information, provided by the Authorization Server to the Client. This URL for this endpoint is communicated to the Client by the Authorization Server in the Client Registration Response. Sakimura, et al. [Page 3] OpenID Connect Registration 1.0 May 2013 Registration Access Token OAuth 2.0 Bearer Token issued by the Authorization Server through the Client Registration Endpoint that is used by the Client to authenticate itself during update operations. This token is associated with a particular Client. Sakimura, et al. [Page 4] OpenID Connect Registration 1.0 May 2013 2. Client Metadata Clients have 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. Client Metadata values used by OpenID Connect are: redirect_uris REQUIRED. Array of redirect URIs values used in the Authorization Code and Implicit grant types. One of the these registered redirect URI values MUST match the Scheme, Host, and Path segments of the "redirect_uri" parameter value used in each Authorization Request. response_types OPTIONAL. JSON array containing a list of the OAuth 2.0 "response_type" values that the Client is declaring that it will restrict itself to using. If omitted, the default is that the Client will use only the "code" response type. grant_types OPTIONAL. JSON array containing a list of the OAuth 2.0 grant types that the Client is declaring that it will restrict itself to using. The grant type values used by OpenID Connect are: * "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. * "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 type defined in OAuth JWT Bearer Token Profiles [OAuth.JWT]. The following table lists the correspondence between "response_type" values that the Client will use and "grant_type" values that MUST be included in the registered "grant_types" list: * "code": "authorization_code" * "id_token": "implicit" * "token id_token": "implicit" Sakimura, et al. [Page 5] OpenID Connect Registration 1.0 May 2013 * "code id_token": "authorization_code", "implicit" * "code token": "authorization_code", "implicit" * "code token id_token": "authorization_code", "implicit" If omitted, the default is that the Client will use only the "authorization_code" grant type. application_type OPTIONAL. Kind of the application. The default if not specified is "web". The defined values are "native" or "web". Web Clients using the OAuth implicit grant type MUST only register URLs using the "https" scheme as "redirect_uris"; they MAY NOT use "localhost" as the hostname. Native Clients MUST only register "redirect_uris" using custom URI schemes or URLs using the "http:" scheme with "localhost" as the hostname. Authorization Servers may place additional constraints on Native Clients. The Authorization Server MUST verify that all the registered "redirect_uris" conform to these constraints. This prevents sharing a Client ID across different types of Clients. contacts OPTIONAL. Array of e-mail addresses of people responsible for this Client. This may be used by some providers to enable a Web user interface to modify the Client information. client_name OPTIONAL. Name of the Client to be presented to the user. If desired, representation of this Claim in different languages and scripts is represented as described in Section 2.1. logo_uri OPTIONAL. URL that references a logo for the Client application. token_endpoint_auth_method OPTIONAL. Requested authentication method for the Token Endpoint. The options are "client_secret_post", "client_secret_basic", "client_secret_jwt", and "private_key_jwt", as described in Section 2.2.1 of OpenID Connect Messages 1.0 [OpenID.Messages]. Other Authentication methods may be defined by extension. If unspecified or omitted, the default is "client_secret_basic" HTTP Basic Authentication Scheme as specified in Section 2.3.1 of OAuth 2.0 [RFC6749]. policy_uri OPTIONAL. URL that the Relying Party Client provides to the End-User to read about the how the profile data will be used. The OpenID Provider SHOULD display this URL to the End-User if it is given. Sakimura, et al. [Page 6] OpenID Connect Registration 1.0 May 2013 tos_uri OPTIONAL. URL that the Relying Party Client provides to the End-User to read about the Relying Party's terms of service. The OpenID Provider SHOULD display this URL to the End-User if it is given. jwks_uri OPTIONAL. URL for the Client's JSON Web Key Set [JWK] document. If the Client signs requests to the Server, it contains the signing key(s) the Server uses to validate signatures from the Client. The JWK Set MAY also contain the Client's encryption keys(s), which are used by the Server to encrypt responses to the Client. When both signing and encryption keys are made available, a "use" (Key Use) parameter value is REQUIRED for all keys in the document to indicate each key's intended usage. OPTIONAL. sector_identifier_uri OPTIONAL. URL using the "https" scheme to be used in calculating Pseudonymous Identifiers by the OP. The URL references a file with a single JSON array of "redirect_uri" values. Please see Section 5. Providers that use pairwise "sub" (subject) values SHOULD provide a "sector_identifier_uri". subject_type OPTIONAL. "subject_type" requested for responses to this "client_id". The "subject_types_supported" element of discovery contains a list of the supported "subject_type" values for this server. Valid types include "pairwise" and "public". request_object_signing_alg OPTIONAL. JWS [JWS] "alg" algorithm [JWA] that MUST be required by the Authorization Server. The valid values are listed in Section 3.1 of JWA [JWA]. All Request Objects from this "client_id" MUST be rejected if not signed by this algorithm. Servers SHOULD support "RS256". userinfo_signed_response_alg OPTIONAL. JWS "alg" algorithm [JWA] required for UserInfo Responses. The valid values are listed in Section 3.1 of JWA [JWA]. If this is specified the response will be JWT [JWT] serialized, and signed using JWS. userinfo_encrypted_response_alg OPTIONAL. JWE [JWE] "alg" algorithm [JWA] required for encrypting UserInfo Responses. The valid values are listed in Section 4.1 of JWA [JWA]. If this is requested in combination with signing the response will be signed then encrypted. If this is specified the response will be JWT [JWT] serialized, and encrypted using JWE. userinfo_encrypted_response_enc OPTIONAL. JWE "enc" algorithm [JWA] required for symmetric encryption of UserInfo Responses. The valid values are listed in Section 4.2 JWA [JWA]. If "userinfo_encrypted_response_alg" is specified the default for this value is "A128CBC+HS256". If this is requested in Sakimura, et al. [Page 7] OpenID Connect Registration 1.0 May 2013 combination with signing the response will be signed then encrypted. If this is specified the response will be JWT [JWT] serialized, and encrypted using JWE. id_token_signed_response_alg OPTIONAL. JWS "alg" algorithm [JWA] required for the ID Token issued to this "client_id". The valid values are listed in Section 3.1 of JWA [JWA], with the exception of "none", which MAY NOT be used as the ID Token "alg" value. The default if not specified is "RS256". The public key for validating the signature is provided by retrieving the JWK Set referenced by the "jwks_uri" element from Discovery. id_token_encrypted_response_alg OPTIONAL. JWE "alg" algorithm [JWA] required for encrypting the ID Token issued to this "client_id". The valid values are listed in Section 4.1 of JWA [JWA]. If this is requested, the response will be signed then encrypted. The default, if not specified, is no encryption. id_token_encrypted_response_enc OPTIONAL. JWE "enc" algorithm [JWA] required for symmetric encryption of the ID Token issued to this "client_id". The valid values are listed in Section 4.2 of JWA [JWA]. If "id_token_encrypted_response_alg" is specified, the default for this parameter is "A128CBC+HS256". If this is requested in combination with signing, the response will be signed then encrypted. If this is specified, the response will be JWT [JWT] serialized, and encrypted using JWE. default_max_age OPTIONAL. Default Maximum Authentication Age. Specifies that the End-User must be actively authenticated if the End-User was authenticated longer ago than the specified number of seconds. The "max_age" request parameter overrides this default value. require_auth_time OPTIONAL. Boolean value specifying whether the "auth_time" Claim in the "id_token" is REQUIRED. It is REQUIRED when the value is "true". The "auth_time" Claim request in the Request Object overrides this setting. default_acr_values OPTIONAL. Default requested Authentication Context Class Reference values. Array of strings that specifies the default "acr" values that the Authorization Server MUST use for processing requests from this Client. The "acr_values_supported" discovery element contains a list of the supported "acr" values supported by this server. Values specified in the "acr_values" request parameter or an "acr" Claim request override these default values. Sakimura, et al. [Page 8] OpenID Connect Registration 1.0 May 2013 initiate_login_uri OPTIONAL. URI using the "https" scheme that the Authorization Server can call to initiate a login at the Client. The URI MUST accept requests via both "GET" and "POST". The Client MUST understand the "login_hint" and "iss" parameters and SHOULD support the "target_link_uri" parameter. post_logout_redirect_uri OPTIONAL. URL supplied by the RP to request that the user be redirected to this location after a logout has been performed, as specified in OpenID Connect Session Management 1.0 [OpenID.Session]. request_uris OPTIONAL. Array of "request_uri" values that are pre- registered by the Client for use at the Authorization Server. Servers MAY cache the contents of the files referenced by these URIs and not retrieve them at the time they are used in a request. OPs can require that "request_uri" values used be pre-registered with the "require_request_uri_registration" discovery parameter. If the contents of the request file could ever change, these URI values SHOULD include the base64url encoded SHA-256 hash value of the file contents referenced by the URI as the value of the URI fragment. If the fragment value used for a URI changes, that signals the server that its cached value for that URI with the old fragment value is no longer valid. 2.1. Metadata Languages and Scripts Human-readable Client Metadata values and Client Metadata values that reference human-readable values MAY be represented in multiple languages and scripts. For example, values such as "client_name", "tos_uri", "policy_uri", "logo_uri", and "client_uri" might have multiple locale-specific values in some Client registrations. To specify the languages and scripts, BCP47 [RFC5646] language tags are added to Client Metadata member names, delimited by a "#" character. The same syntax is used for representing languages and scripts for Client Metadata as is used for Claims, as described in Section 2.5.2 (Claims Languages and Scripts) of OpenID Connect Messages 1.0 [OpenID.Messages]. If such a 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 any human- readable fields sent without language tags contain values suitable for display on a wide variety of systems. Sakimura, et al. [Page 9] OpenID Connect Registration 1.0 May 2013 3. Client Registration The Client Registration Endpoint is an OAuth 2.0 Protected Resource through which a Client can request a new registration and manage the Metadata associated with it. The OpenID Provider may require an Access Token that is provisioned out-of-band (in a manner that is out of scope for this specification) in order to restrict registration requests to only authorized Clients. In order to support open registration, the Client Registration Endpoint SHOULD accept registration requests without OAuth 2.0 Access Tokens. These requests MAY be rate-limited or otherwise limited to prevent a denial-of-service attack on the Client Registration Endpoint. If an Access Token is required for Client registration, the Client Registration Endpoint MUST be able to accept Access Tokens in the manner described in the OAuth 2.0 Bearer Token Usage [RFC6750] specification. 3.1. Client Registration Request To register a new Client to the Authorization Server, the Client sends an HTTP "POST" message to the Client Registration Endpoint with any Client Metadata parameters, as defined in Section 2, that the Client wishes to specify for itself during the registration. 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 Authorization Server MAY provision default values for any items omitted in the Client Metadata. The Client sends an HTTP "POST" to the Client Registration Endpoint with a content type of "application/json" and all parameters as top- level members of a JSON object. For example, a Client could send the following registration request to the Client Registration Endpoint: Sakimura, et al. [Page 10] OpenID Connect Registration 1.0 May 2013 The following is a non-normative example request (with line breaks within values for display purposes only): POST /connect/register HTTP/1.1 Content-Type: application/json Accept: application/json Host: server.example.com Authorization: Bearer eyJhbGciOiJSUzI1NiJ9.eyJ ... { "application_type": "web", "redirect_uris": ["https://client.example.org/callback", "https://client.example.org/callback2"], "client_name": "My Example", "client_name#ja-Jpan-JP": "クライアント名", "logo_uri": "https://client.example.org/logo.png", "subject_type": "pairwise", "sector_identifier_uri": "https://other.example.net/file_of_redirect_uris.json", "token_endpoint_auth_method": "client_secret_basic", "jwks_uri": "https://client.example.org/my_public_keys.jwks", "userinfo_encrypted_response_alg": "RSA1_5", "userinfo_encrypted_response_enc": "A128CBC+HS256", "contacts": ["ve7jtb@example.org", "mary@example.org"], "request_uris": ["https://client.example.org/rf.txt #qpXaRLh_n93TTR9F252ValdatUQvQiJi5BDub2BeznA"] } 3.2. Client Registration Response Upon successful registration, the Client Registration Endpoint returns the newly-created Client Identifier and, if applicable, a Client Secret, along with 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 field values and substitute them with suitable values. If this happens, the Authorization Server MUST include these fields in the response to the Client. The response also contains a Registration Access Token that is used by the Client to perform subsequent operations upon the resulting Client registration. All of the response items are returned as a JSON document [RFC4627] with the following fields as top-level members of the root JSON Sakimura, et al. [Page 11] OpenID Connect Registration 1.0 May 2013 object. client_id REQUIRED. Unique Client identifier. It MUST NOT be currently valid for any other registered Client. client_secret OPTIONAL. Client secret. This MUST be unique for each "client_id". This value is used by Confidential Clients to authenticate to the Token Endpoint as described in OAuth 2.0 Section 2.3.1. It is not required for Clients selecting a "token_endpoint_auth_method" of "private_key_jwt". registration_access_token REQUIRED. Access Token that is used by the Client to perform subsequent operations upon the resulting Client registration. registration_client_uri REQUIRED. Location where the Access Token can be used to perform subsequent operations upon the resulting Client registration. issued_at 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. expires_at OPTIONAL. 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 1970-01-01T0:0:0Z as measured in UTC until the date/ time. Sakimura, et al. [Page 12] OpenID Connect Registration 1.0 May 2013 The following is a non-normative example response (with line breaks within values for display purposes only): HTTP/1.1 200 OK Content-Type: application/json Cache-Control: no-store Pragma: no-cache { "client_id": "s6BhdRkqt3", "client_secret": "ZJYCqe3GGRvdrudKyZS0XhGv_Z45DuKhCUk0gBR1vZk", "expires_at": 1577858400, "registration_access_token": "this.is.an.access.token.value.ffx83", "registration_client_uri": "https://server.example.com/connect/register?client_id=s6BhdRkqt3", "token_endpoint_auth_method": "client_secret_basic", "application_type": "web", "redirect_uris": ["https://client.example.org/callback" "https://client.example.org/callback2"], "client_name": "My Example", "client_name#ja-Jpan-JP": "クライアント名", "logo_uri": "https://client.example.org/logo.png", "subject_type": "pairwise", "sector_identifier_uri": "https://other.example.net/file_of_redirect_uris.json", "jwks_uri": "https://client.example.org/my_public_keys.jwks", "userinfo_encrypted_response_alg": "RSA1_5", "userinfo_encrypted_response_enc": "A128CBC+HS256", "contacts": ["ve7jtb@example.org", "mary@example.org"], "request_uris": ["https://client.example.org/rf.txt #qpXaRLh_n93TTR9F252ValdatUQvQiJi5BDub2BeznA"] } 3.3. Client Registration Error Response When an OAuth error condition occurs, the Client Registration Endpoint returns an Error Response as defined in Section 3 of the OAuth 2.0 Bearer Token Usage [RFC6750] specification. When a registration error condition occurs, the Client Registration Endpoint returns a HTTP 400 status code including a JSON object describing the error in the response body. Sakimura, et al. [Page 13] OpenID Connect Registration 1.0 May 2013 The JSON object contains two members: error_code Error code. error_description Additional text description of the error for debugging. This specification defines the following error codes: invalid_redirect_uri The value of one or more "redirect_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. The following is a non-normative example error response: HTTP/1.1 400 Bad Request Content-Type: application/json Cache-Control: no-store Pragma: no-cache { "error_code": "invalid_redirect_uri", "error_description": "The value of one or more redirect_uris are invalid." } Sakimura, et al. [Page 14] OpenID Connect Registration 1.0 May 2013 4. Client Read This operation retrieves the Client Metadata for a previously registered Client. 4.1. Client Read Request To read the current configuration of the Client on the Authorization Server, the Client makes an HTTP "GET" request to the Client Configuration Endpoint with the Registration Access Token. The following is a non-normative example request: GET /connect/register?client_id=s6BhdRkqt3 HTTP/1.1 Accept: application/json Host: server.example.com Authorization: Bearer this.is.an.access.token.value.ffx83 4.2. Client Read Response Upon a successful read operation, the Authorization Server SHOULD return all registered Metadata about this Client, including any fields provisioned by the Authorization Server itself. Some values, including the "client_secret" value, may have been updated since the initial registration. The Authorization Server need not include the "registration_access_token" or "registration_client_uri" value in this response unless they have been updated. The response is a JSON Document [RFC4627] with the Client Metadata as top-level members of a JSON object. Sakimura, et al. [Page 15] OpenID Connect Registration 1.0 May 2013 The following is a non-normative example response (with line breaks within values for display purposes only): HTTP/1.1 200 OK Content-Type: application/json Cache-Control: no-store Pragma: no-cache { "client_id": "s6BhdRkqt3", "client_secret": "OylyaC56ijpAQ7G5ZZGL7MMQ6Ap6mEeuhSTFVps2N4Q", "expires_at": 17514165600, "registration_client_uri": "https://server.example.com/connect/register?client_id=s6BhdRkqt3", "token_endpoint_auth_method": "client_secret_basic", "application_type": "web", "redirect_uris": ["https://client.example.org/callback" "https://client.example.org/callback2"], "client_name": "My Example", "client_name#ja-Jpan-JP": "クライアント名", "logo_uri": "https://client.example.org/logo.png", "subject_type": "pairwise", "sector_identifier_uri": "https://other.example.net/file_of_redirect_uris.json", "jwks_uri": "https://client.example.org/my_public_keys.jwks", "userinfo_encrypted_response_alg": "RSA1_5", "userinfo_encrypted_response_enc": "A128CBC+HS256", "contacts": ["ve7jtb@example.org", "mary@example.org"], "request_uris": ["https://client.example.org/rf.txt #qpXaRLh_n93TTR9F252ValdatUQvQiJi5BDub2BeznA"] } 4.3. Client Read Error Response When a read error condition occurs, the Client Configuration Endpoint returns a HTTP 403 Forbidden status code. This indicates that the Access Token is invalid or the Client record requested is invalid or non-existent. Note that for security reasons, to inhibit brute force attacks, endpoints MUST NOT return 404 Not Found error codes. Sakimura, et al. [Page 16] OpenID Connect Registration 1.0 May 2013 The following is a non-normative example error response: HTTP/1.1 403 Forbidden Content-Type: application/json Cache-Control: no-store Pragma: no-cache Sakimura, et al. [Page 17] OpenID Connect Registration 1.0 May 2013 5. "sector_identifier_uri" Validation The sector identifier list provides a way for a group of Web sites under single administrative control to have consistent pairwise "sub" values, independent of their domain names, as described in Section 2.8.1 of OpenID Connect Messages 1.0 [OpenID.Messages]. It also provides a way for Clients to change "redirect_uri" domains without having to re-register all of their users. The value of the "sector_identifier_uri" must be a URL using the "https" scheme that references a JSON file containing an array of "redirect_uri" values. The values registered in "redirect_uris" MUST be included in the elements of the array, or registration MUST fail. The following is a non-normative example request to and reply from a "sector_identifier_uri". GET https://other.example.net/file_of_redirect_uris.json HTTP/1.1 Accept: application/json Host: client.example.org HTTP/1.1 200 OK Content-Type: application/json Cache-Control: no-store Pragma: no-cache [ "https://client.example.org/callback", "https://client.example.org/callback2", "https://client.other_company.example.net/callback" ] Sakimura, et al. [Page 18] OpenID Connect Registration 1.0 May 2013 6. String Operations Processing some OpenID Connect messages requires comparing values in the messages to known values. For example, the member names in the Client registration response might be compared to specific member names such as "client_id". Comparing Unicode strings, however, has significant security implications. Therefore, comparisons between JSON strings and other Unicode strings MUST be performed as specified below: 1. Remove any JSON applied escaping to produce an array of Unicode code points. 2. Unicode Normalization [USA15] MUST NOT be applied at any point to either the JSON string or to the string it is to be compared against. 3. Comparisons between the two strings MUST be performed as a Unicode code point to code point equality comparison. In several places, this specification uses space delimited lists of strings. In all such cases, only the ASCII space character (0x20) MAY be used for this purpose. Sakimura, et al. [Page 19] OpenID Connect Registration 1.0 May 2013 7. Validation If any of the validation procedures defined in this specification fail, any operations requiring the information that failed to correctly validate MUST be aborted and the information that failed to validate MUST NOT be used. Sakimura, et al. [Page 20] OpenID Connect Registration 1.0 May 2013 8. Implementation Considerations This specification defines features used by both Relying Parties and OpenID Providers that choose to implement Dynamic Client Registration. All of these Relying Parties and OpenID Providers MUST implement the features that are listed in this specification as being "REQUIRED" or are described with a "MUST". No other implementation considerations for implementations of Dynamic Client Registration are defined by this specification. Sakimura, et al. [Page 21] OpenID Connect Registration 1.0 May 2013 9. Security Considerations Since requests to the Client Registration Endpoint result in the transmission of clear-text credentials (in the HTTP request and response), all communication with the Registration Endpoint MUST utilize TLS. See Section 9.1 for more information on using TLS. A rogue RP might use the logo for the legitimate RP, which it is trying to impersonate. An OP needs to take steps to mitigate this phishing risk, since the logo could confuse users into thinking they're logging in to the legitimate RP. An OP could also warn if the domain/site of the logo doesn't match the domain/site of redirect URIs. An OP can also make warnings against untrusted RPs in all cases, especially if they're dynamically registered, have not been trusted by any users at the OP before, and want to use the logo feature. 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" and "policy_uri"). A rogue Client could specify a registration request with a reference to a drive-by download in the "policy_uri". The Authorization Server should check to see if the "logo_uri" and "policy_uri" have the same host as the hosts defined in the array of "redirect_uris". 9.1. TLS Requirements Implementations MUST support TLS. Which version(s) ought to be implemented will vary over time, and depend on the widespread deployment and known security vulnerabilities at the time of implementation. At the time of this writing, TLS version 1.2 [RFC5246] is the most recent version, but has very limited actual deployment, and might not be readily available in implementation toolkits. TLS version 1.0 [RFC2246] is the most widely deployed version, and will give the broadest interoperability. To protect against information disclosure and tampering, confidentiality protection MUST be applied using TLS with a ciphersuite that provides confidentiality and integrity protection. Whenever TLS is used, a TLS server certificate check MUST be performed, per RFC 6125 [RFC6125]. Sakimura, et al. [Page 22] OpenID Connect Registration 1.0 May 2013 10. IANA Considerations This document makes no requests of IANA. Sakimura, et al. [Page 23] OpenID Connect Registration 1.0 May 2013 11. References 11.1. Normative References [JWA] Jones, M., "JSON Web Algorithms (JWA)", draft-ietf-jose-json-web-algorithms (work in progress), April 2013. [JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web Encryption (JWE)", draft-ietf-jose-json-web-encryption (work in progress), April 2013. [JWK] Jones, M., "JSON Web Key (JWK)", draft-ietf-jose-json-web-key (work in progress), April 2013. [JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)", draft-ietf-jose-json-web-signature (work in progress), April 2013. [JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token (JWT)", draft-ietf-oauth-json-web-token (work in progress), April 2013. [OAuth.JWT] Jones, M., Campbell, B., and C. Mortimore, "JSON Web Token (JWT) Bearer Token Profiles for OAuth 2.0", draft-ietf-oauth-jwt-bearer (work in progress), March 2013. [OpenID.Messages] Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., Mortimore, C., and E. Jay, "OpenID Connect Messages 1.0", May 2013. [OpenID.Session] Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and N. Agarwal, "OpenID Connect Session Management 1.0", March 2013. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC 2246, January 1999. [RFC4627] Crockford, D., "The application/json Media Type for JavaScript Object Notation (JSON)", RFC 4627, July 2006. Sakimura, et al. [Page 24] OpenID Connect Registration 1.0 May 2013 [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. [USA15] Davis, M., Whistler, K., and M. Duerst, "Unicode Normalization Forms", Unicode Standard Annex 15, 09 2009. 11.2. Informative References [I-D.ietf-oauth-dyn-reg] Richer, J., Bradley, J., Jones, M., and M. Machulak, "OAuth 2.0 Dynamic Client Registration Protocol", draft-ietf-oauth-dyn-reg-09 (work in progress), March 2013. Sakimura, et al. [Page 25] OpenID Connect Registration 1.0 May 2013 Appendix A. Acknowledgements The OpenID Community would like to thank the following people for the work they have done in the drafting and editing of this specification. Amanda Anganes (aanganes@mitre.org), Mitre John Bradley (ve7jtb@ve7jtb.com), Ping Identity Brian Campbell (bcampbell@pingidentity.com), Ping Identity Vladimir Dzhuvinov (vladimir@nimbusds.com), NimbusDS Roland Hedberg (roland.hedberg@adm.umu.se), Independent Edmund Jay (ejay@mgi1.com), Illumila Michael B. Jones (mbj@microsoft.com), Microsoft Justin Richer (jricher@mitre.org), Mitre Nat Sakimura (n-sakimura@nri.co.jp), Nomura Research Institute, Ltd. Sakimura, et al. [Page 26] OpenID Connect Registration 1.0 May 2013 Appendix B. Notices Copyright (c) 2013 The OpenID Foundation. The OpenID Foundation (OIDF) grants to any Contributor, developer, implementer, or other interested party a non-exclusive, royalty free, worldwide copyright license to reproduce, prepare derivative works from, distribute, perform and display, this Implementers Draft or Final Specification solely for the purposes of (i) developing specifications, and (ii) implementing Implementers Drafts and Final Specifications based on such documents, provided that attribution be made to the OIDF as the source of the material, but that such attribution does not indicate an endorsement by the OIDF. The technology described in this specification was made available from contributions from various sources, including members of the OpenID Foundation and others. Although the OpenID Foundation has taken steps to help ensure that the technology is available for distribution, it takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this specification or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any independent effort to identify any such rights. The OpenID Foundation and the contributors to this specification make no (and hereby expressly disclaim any) warranties (express, implied, or otherwise), including implied warranties of merchantability, non- infringement, fitness for a particular purpose, or title, related to this specification, and the entire risk as to implementing this specification is assumed by the implementer. The OpenID Intellectual Property Rights policy requires contributors to offer a patent promise not to assert certain patent claims against other contributors and against implementers. The OpenID Foundation invites any interested party to bring to its attention any copyrights, patents, patent applications, or other proprietary rights that may cover technology that may be required to practice this specification. Sakimura, et al. [Page 27] OpenID Connect Registration 1.0 May 2013 Appendix C. Document History [[ To be removed from the final specification ]] -17 o Fixed #820 - Removed assumption that Clients that want encrypted responses also sign requests. -16 o Fixed #803 - No longer use "client_id" query parameter. o Fixed #804 - Removed "access_token" from client metadata. -15 o Fixed #708 - Registration access token requirement. o Fixed #734 - Invalid JSON in examples. o Fixed #736 - Client Update Operation Response: expires_at should be removed from example. o Fixed #735 - Require expires_at value in Client Register response. o Added Security Considerations section about TLS version requirements and usage. o State that when any validations fail, any operations requiring the information that failed to correctly validate MUST be aborted and the information that failed to validate MUST NOT be used. o Fixed #746 - Deleted the "operation" parameter. o Fixed #745 - Deleted the "rotate_secret" operation. o Changed the Japanese client name to make it sound more natural. o Added optional "issued_at" response value. o Added client update example. o Fixed #727 - Deleted invalid_client_secret error. o Fixed #744 - Promoted "max_age" to being a top-level parameter. Sakimura, et al. [Page 28] OpenID Connect Registration 1.0 May 2013 o Fixed #765 - Created "acr_values" top-level request parameter and changed "default_acr" registration parameter to "default_acr_values". o Fixed #747 - Changed requests from being form-urlencoded to JSON. o Fixed #755 - Removed client update operation. o Fixed #751 - Added client read operation. o Fixed #749 - Added "registration_access_url". o Fixed #756 - State that an updated "client_secret" value can be returned by a read operation. o Fixed #774 - Moved invalid client_id from 3.3 to 4.3 and fixed example. o Fixed #774 - Removed invalid client_id and made GET return 403 Forbidden. o Fixed missing registration_access_url in GET example response. o Fixed #776 - Removed client adding client_id query parameter but make the examples include it as part of the registration_access_url. o Fixed #775 - Made redirects_uri, contacts, and default_acr_values arrays to match the examples. o Changed "invalid_configuration_parameter" error to "invalid_client_metadata" to match the OAuth Registration spec. o Fixed #777 - Added "Pragma: no-cache" to the example responses that were missing it. o Fixed #773 - Added "request_uris" registration parameter to pre- register "request_uri" values. Also clarified that Request File contents may be cached. o Fixed #758 - State the registration requests can be rate-limited to prevent a DoS attack. o Fixed #782 - Changed uses of "_url" in identifiers to "_uri". o Fixed #783 - Changed "registration_access_url" to "registered_client_uri". Sakimura, et al. [Page 29] OpenID Connect Registration 1.0 May 2013 o Fixed #703 - Added the PKIX JWK key type for X.509 certificates and consolidated the "x509_uri", "x509_encryption_uri", and "jwk_encryption_uri" parameters into a combined "jwk_uri" parameter. o Fixed #786 - Changed the name of "jwk_uri" to "jwks_uri". o Added the "response_types" registration parameter. o Added the "grant_types" registration parameter. o Added table documenting correspondence between "response_type" values used and "grant_type" values used. o Fixed #788 - Renamed "OpenID Request Object" to "Request Object". -14 o Changed the syntax of some elements to match the syntax used in the OAuth Dynamic Client Registration draft. Specifically, changed "type" to "operation", changed "associate" to "register", and changed "application_name" to "client_name". Also changed the responses of "client_register" and "client_update" to include full client information instead of just the Client ID. o Added Implementation Considerations section. o Fixed #656 - Changed "token_endpoint_auth_type" to "token_endpoint_auth_method" and "token_endpoint_auth_types_supported" to "token_endpoint_auth_methods_supported". o Fixed #698 - Inconsistent use of articles. o Deleted "javascript_origin_uris", which is no longer present in Session. o Reference and provide note to implementers about OAuth Dynamic Client Registration Protocol [I-D.ietf-oauth-dyn-reg]. o Changed token_endpoint_auth_method example result value from "client_secret_basic client_secret_post" to "client_secret_basic" since the definition requires the value to be a single method. -13 o Fixed #687 - Inconsistency between "user_id" and "prn" claims. The fix changed these names: user_id -> sub, Sakimura, et al. [Page 30] OpenID Connect Registration 1.0 May 2013 user_id_types_supported -> subject_types_supported, user_id_type -> subject_type, and prn -> sub. o Renamed "acrs_supported" to "acr_values_supported" for naming consistency. o Fixed #685 - The policy URL should be different from the terms-of- service URL. A new "tos_url" registration parameter was added. o Clarified that "jwk_url" and "jwk_encryption_url" refer to documents containing JWK Sets - not single JWK keys. o Re #601 add initiate_login_uri for unsolicited request -12 o Made application_type REQUIRED and added an explanation about redirect_uris registration o Section 2.1 clarification that updates replace all parameters previously set. o Section 2.3 add rotate_secret to invalid client_id error o Added registration_access_token for updating and made client secret optional o added registration_access_token to example response o removed client_id from request as the client_id is implicit in the access token for updates o Changed redirect_uris from RECOMMENDED for code and REQUIRED for implicit to REQUIRED o Changed 2.1 to only allow access_token as a parameter if type is rotate_secret o Fixed reference in application_name and added example of ja-Hani-JP encoded name. o Made application_type OPTIONAL with web as the default o Fixes #642 - Registration separates application errors from bearer. o Updated references to OAuth and Bearer to reflect current drafts Sakimura, et al. [Page 31] OpenID Connect Registration 1.0 May 2013 o Fix typo error_description o Re #642 change error to error_code in 2.3 example o Fixed #614 - Discovery - 3.2 Distinguishing between signature and integrity parameters for HMAC algorithms. This fix tracks the parameter changes made to the JWE spec in draft-ietf-jose-json-web-encryption-06. It deletes the parameters {userinfo,id_token}_encrypted_response_int. It replaces the parameters {userinfo,id_token,request_object,token_endpoint}_algs_supported with {userinfo,id_token,request_object,token_endpoint}_signing_alg _values_supported and {userinfo,id_token,request_object,token_endp oint}_encryption_{alg,enc}_values_supported. o Fixed #673 - Registration 2.1: Rename require_signed_request_object to request_object_alg. The actual change was to rename require_signed_request_object to request_object_signing_alg, following the naming convention used in the resolution to issue #614. o Fixed #666 - JWS signature validation vs. verification. o Referenced OAuth 2.0 RFCs -- RFC 6749 and RFC 6750. o Fixed #674 - Description of require_auth_time. -11 o Made "rotate_secret" a separate registration request type and stop client secret changing with every response, per issue #363 o Changed default ID Token signing algorithm to RS256, per issue #571 o Changed client.example.com to client.example.org, per issue #251 o Added text for authz to the registration endpoint, per issue #587 o Use standards track version of JSON Web Token spec (draft-ietf-oauth-json-web-token) -10 o Split encrypted response configurations into separate parameters for alg, enc, int Sakimura, et al. [Page 32] OpenID Connect Registration 1.0 May 2013 o Removed extra "s" from signed response parameter names o Add reference to JWA o Updated Notices o Updated References -09 o Removed erroneous spanx declarations from example o Fixed example in Sec 2.2 to show expires_at o Fixed Sec 2.1.1 to clarify it is the registration server doing the certificate check o Fixed Sec 2.1.1 example to include http portion of response o Fixed #542 Sec 2.1 userinfo_signed_response_algs fixed to say signature. Clarify response is signed. o Fixed Sec 2.1 userinfo_encrypted_response_algs Clarify response is JWE containing JWT o Fixes #529 Sec 2.3 Clarify error response is Bearer and fix example o Add default_max_age registration parameter o Add default_acr registration parameter o Add require_auth_time registration parameter -08 o Replaced token_endpoint with a defined term Token Endpoint [OAuth 2.0] o Added policy_url parameter o Renamed expires_in but expires_at o Registration Endpoint can be OAuth Protected o Added parameters for requiring encryption and/or signing of OpenID Request Object, UserInfo and ID Token Sakimura, et al. [Page 33] OpenID Connect Registration 1.0 May 2013 o Added token_endpoint_auth_type and list of valid authentication types o Added JWK and X509 URLs for signature and encryption o Added user_id_type o Changed sector_identifier to sector_identifier_url and added URL verification o Use RFC 6125 to verify TLS endpoints o Changed 'contact' to 'contacts', 'redirect_uri' to 'redirect_uris' o Changed redirect_uris to RECOMMENDED for code flow and REQUIRED for implicit flow Clients o Removed js_origin_uri o Added section about string comparison rules needed o Clarified redirect_uris matching o Update John Bradley email and affiliation for Implementer's Draft -07 o Changed request from posting a JSON object to being HTTP Form encoded. o Added x509_url to support optional encryption. -06 o Changes associated with renaming "Lite" to "Basic Client" and replacing "Core" and "Framework" with "Messages" and "Standard". o Numerous cleanups, including updating references. -05 o Changed "redirect_url" to "redirect_uri" and "js_origin_url" to "js_origin_uri". -04 o Correct issues raised by Johnny Bufu and discussed on the 7-Jul-11 working group call. Sakimura, et al. [Page 34] OpenID Connect Registration 1.0 May 2013 -03 o Incorporate working group decisions from 5-Jul-11 spec call. o Consistency and cleanup pass, including removing unused references. -02 o Incorporate working group decisions from 23-Jun-11 spec call. -01 o Initial version. Sakimura, et al. [Page 35] OpenID Connect Registration 1.0 May 2013 Authors' Addresses Nat Sakimura Nomura Research Institute, Ltd. Email: n-sakimura@nri.co.jp John Bradley Ping Identity Email: ve7jtb@ve7jtb.com Michael B. Jones Microsoft Email: mbj@microsoft.com Sakimura, et al. [Page 36]