REGEXT Working Group                                       S. Hollenbeck
Internet-Draft                                             Verisign Labs
Intended status: Standards Track                         8 February 2022
Expires: 12 August 2022


   Federated Authentication for the Registration Data Access Protocol
                      (RDAP) using OpenID Connect
                    draft-ietf-regext-rdap-openid-10

Abstract

   The Registration Data Access Protocol (RDAP) provides "RESTful" web
   services to retrieve registration metadata from domain name and
   regional internet registries.  RDAP allows a server to make access
   control decisions based on client identity, and as such it includes
   support for client identification features provided by the Hypertext
   Transfer Protocol (HTTP).  Identification methods that require
   clients to obtain and manage credentials from every RDAP server
   operator present management challenges for both clients and servers,
   whereas a federated authentication system would make it easier to
   operate and use RDAP without the need to maintain server-specific
   client credentials.  This document describes a federated
   authentication system for RDAP based on OpenID Connect.

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 https://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 12 August 2022.

Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





Hollenbeck               Expires 12 August 2022                 [Page 1]


Internet-Draft           OpenID Connect for RDAP           February 2022


   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Problem Statement . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Proposal  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   4
   3.  Federated Authentication for RDAP . . . . . . . . . . . . . .   4
     3.1.  RDAP and OpenID Connect . . . . . . . . . . . . . . . . .   5
       3.1.1.  Terminology . . . . . . . . . . . . . . . . . . . . .   5
       3.1.2.  Overview  . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.3.  RDAP Authentication and Authorization Steps . . . . .   6
         3.1.3.1.  Provider Discovery  . . . . . . . . . . . . . . .   6
         3.1.3.2.  Authentication Request  . . . . . . . . . . . . .   7
         3.1.3.3.  End-User Authorization  . . . . . . . . . . . . .   7
         3.1.3.4.  Authorization Response and Validation . . . . . .   8
         3.1.3.5.  Token Processing  . . . . . . . . . . . . . . . .   8
         3.1.3.6.  Delivery of User Information  . . . . . . . . . .   8
       3.1.4.  Specialized Claims for RDAP . . . . . . . . . . . . .   8
         3.1.4.1.  Stated Purpose  . . . . . . . . . . . . . . . . .   8
         3.1.4.2.  Do Not Track  . . . . . . . . . . . . . . . . . .   9
   4.  Protocol Parameters . . . . . . . . . . . . . . . . . . . . .  10
     4.1.  Client Login  . . . . . . . . . . . . . . . . . . . . . .  10
       4.1.1.  Clients with Limited User Interfaces  . . . . . . . .  13
         4.1.1.1.  OAuth 2.0 Device Authorization Grant  . . . . . .  13
         4.1.1.2.  UI-limited Client Login . . . . . . . . . . . . .  13
         4.1.1.3.  UI-limited Client Login Polling . . . . . . . . .  15
     4.2.  Session Status  . . . . . . . . . . . . . . . . . . . . .  15
     4.3.  Client Logout . . . . . . . . . . . . . . . . . . . . . .  18
     4.4.  Token Exchange  . . . . . . . . . . . . . . . . . . . . .  18
     4.5.  Parameter Processing  . . . . . . . . . . . . . . . . . .  19
   5.  RDAP Query Processing . . . . . . . . . . . . . . . . . . . .  19
   6.  RDAP Conformance  . . . . . . . . . . . . . . . . . . . . . .  19
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  20
     7.1.  RDAP Extensions Registry  . . . . . . . . . . . . . . . .  20
     7.2.  JSON Web Token Claims Registry  . . . . . . . . . . . . .  20
     7.3.  RDAP Query Purpose Registry . . . . . . . . . . . . . . .  21
   8.  Implementation Status . . . . . . . . . . . . . . . . . . . .  23
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  24
     9.1.  Authentication and Access Control . . . . . . . . . . . .  24



Hollenbeck               Expires 12 August 2022                 [Page 2]


Internet-Draft           OpenID Connect for RDAP           February 2022


   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  24
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  24
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  24
     11.2.  Informative References . . . . . . . . . . . . . . . . .  26
   Appendix A.  Change Log . . . . . . . . . . . . . . . . . . . . .  27
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   The Registration Data Access Protocol (RDAP) provides "RESTful" web
   services to retrieve registration metadata from domain name and
   regional internet registries.  RDAP allows a server to make access
   control decisions based on client identity, and as such it includes
   support for client identification features provided by the Hypertext
   Transfer Protocol (HTTP) [RFC7230].

   RDAP is specified in multiple documents, including "HTTP Usage in the
   Registration Data Access Protocol (RDAP)" [RFC7480], "Security
   Services for the Registration Data Access Protocol (RDAP)" [RFC7481],
   "Registration Data Access Protocol Query Format" [RFC9082], and "JSON
   Responses for the Registration Data Access Protocol (RDAP)"
   [RFC9083].  RFC 7481 describes client identification and
   authentication services that can be used with RDAP, but it does not
   specify how any of these services can (or should) be used with RDAP.

1.1.  Problem Statement

   The traditional "user name and password" authentication method does
   not scale well in the RDAP ecosystem.  Assuming that all domain name
   and address registries will eventually provide RDAP service, it is
   impractical and inefficient for users to secure login credentials
   from the hundreds of different server operators.  Authentication
   methods based on user names and passwords do not provide information
   that describes the user in sufficient detail (while protecting the
   personal privacy of the user) for server operators to make fine-
   grained access control decisions based on the user's identity.  The
   authentication system used for RDAP needs to address all of these
   needs.

1.2.  Proposal

   A basic level of RDAP service can be provided to users who possess an
   identifier issued by a recognized provider who is able to
   authenticate and validate the user.  The identifiers issued by social
   media services, for example, can be used.  Users who require higher
   levels of service (and who are willing to share more information
   about them self to gain access to that service) can secure
   identifiers from specialized providers who are or will be able to



Hollenbeck               Expires 12 August 2022                 [Page 3]


Internet-Draft           OpenID Connect for RDAP           February 2022


   provide more detailed information about the user.  Server operators
   can then make access control decisions based on the identification
   information provided by the user.

   A federated authentication system would make it easier to operate and
   use RDAP by re-using existing identifiers to provide a basic level of
   access.  It can also provide the ability to collect additional user
   identification information, and that information can be shared with
   the consent of the user.  This document describes a federated
   authentication system for RDAP based on OpenID Connect [OIDC] that
   meets all of these needs.

2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  Federated Authentication for RDAP

   RDAP itself does not include native security services.  Instead, RDAP
   relies on features that are available in other protocol layers to
   provide needed security services including access control,
   authentication, authorization, availability, data confidentiality,
   data integrity, and identification.  A description of each of these
   security services can be found in "Internet Security Glossary,
   Version 2" [RFC4949].  This document focuses on a federated
   authentication system for RDAP that provides services for
   authentication, authorization, and identification, allowing a server
   operator to make access control decisions.  Section 3 of RFC 7481
   [RFC7481] describes general considerations for RDAP access control,
   authentication, and authorization.

   The traditional client-server authentication model requires clients
   to maintain distinct credentials for every RDAP server.  This
   situation can become unwieldy as the number of RDAP servers
   increases.  Federated authentication mechanisms allow clients to use
   one credential to access multiple RDAP servers and reduce client
   credential management complexity.










Hollenbeck               Expires 12 August 2022                 [Page 4]


Internet-Draft           OpenID Connect for RDAP           February 2022


3.1.  RDAP and OpenID Connect

   OpenID Connect 1.0 [OIDCC] is a decentralized, single sign-on (SSO)
   federated authentication system that allows users to access multiple
   web resources with one identifier instead of having to create
   multiple server-specific identifiers.  Users acquire identifiers from
   OpenID Providers, or OPs.  Relying Parties, or RPs, are applications
   (such as RDAP) that outsource their user authentication function to
   an OP.  OpenID Connect is built on top of the authorization framework
   provided by the OAuth 2.0 [RFC6749] protocol.

   The OAuth authorization framework describes a method for users to
   access protected web resources without having to hand out their
   credentials.  Instead, clients are issued Access Tokens by
   authorization servers with the permission of the resource owners.
   Using OpenID Connect and OAuth, multiple RDAP servers can form a
   federation and clients can access any server in the federation by
   providing one credential registered with any OP in that federation.
   The OAuth authorization framework is designed for use with HTTP and
   thus can be used with RDAP.

3.1.1.  Terminology

   This document uses the terms "client" and "server" defined by RDAP
   [RFC7480].  An RDAP client performs the role of an OpenID Connect
   Core [OIDCC] Entity or End-User.  An RDAP server performs the role of
   an OpenID Connect Core Relying Party (RP).  Additional terms from
   Section 1.2 of the OpenID Connect Core specification are incorporated
   by reference.

3.1.2.  Overview

   At a high level, RDAP authentication of a browser-like client using
   OpenID Connect requires completion of the following steps:

   1.   An RDAP client sends an RDAP "help" query to an RDAP server to
        determine the type of OpenID Authorization Server that's used by
        the RDAP server.  This information is returned in the
        rdapConformance section of the response.  A value of
        "rdap_openidc_local_level_0" indicates that the server uses a
        local Authorization Server.  A value of
        "rdap_openidc_remote_level_0" indicates that the server uses a
        remote Authorization Server.
   2.   An RDAP client (acting as an OpenID End-User) sends a "login"
        request (see Section 4.1) to an RDAP server.  The request MUST
        include an "id" query parameter if the server uses only a remote
        Authorization Server.  The "id" query parameter is OPTIONAL if
        the server uses a local Authorization Server.



Hollenbeck               Expires 12 August 2022                 [Page 5]


Internet-Draft           OpenID Connect for RDAP           February 2022


   3.   The RDAP server (acting as an OpenID Relying Party (RP))
        prepares an Authentication Request containing the desired
        request parameters.
   4.   The RDAP server sends the RDAP client and Authentication Request
        to an Authorization Server operated by an OpenID Provider (OP)
        using an HTTP redirect.
   5.   The Authorization Server authenticates the End-User.
   6.   The Authorization Server obtains End-User consent/authorization.
   7.   The Authorization Server sends the RDAP Client back to the RDAP
        server with an Authorization Code using an HTTP redirect.
   8.   The RDAP server requests a response using the Authorization Code
        at the Token Endpoint.
   9.   The RDAP server receives a response that contains an ID Token
        and Access Token in the response body.
   10.  The RDAP server validates the ID Token and retrieves the claims
        associated with the end-user's identity.

   The RDAP server can then make identification, authorization, and
   access control decisions based on end-user identity information and
   local policies.  Note that OpenID Connect describes different process
   flows for other types of clients, such as script-based or command
   line clients.

3.1.3.  RDAP Authentication and Authorization Steps

   End-Users MUST possess an identifier (an OpenID) issued by an OP to
   use OpenID Connect with RDAP.  An OP SHOULD include support for the
   claims described in Section 3.1.4 to provide additional information
   needed for RDAP End-User authorization.  OpenID Connect requires RPs
   to register with OPs to use OpenID Connect services for an End-User.
   That process is described by the "OpenID Connect Dynamic Client
   Registration" protocol [OIDCR].

3.1.3.1.  Provider Discovery

   An RDAP server/RP needs to be able to map an End-User's identifier to
   an OP.  This can be accomplished using the OPTIONAL "OpenID Connect
   Discovery" protocol [OIDCD], but that protocol is not widely
   implemented and can be unreliable.  Out-of-band methods are also
   possible and can be more dependable.  For example, an RP can support
   a limited number of OPs and maintain internal associations of those
   identifiers with the OPs that issued them.  An RP can also ask an
   end-user to identify the OP that issued their identifier as part of
   an RDAP query workflow.  In this case, the RP will need to maintain
   state for the association between the user's identifier and the OP in
   order to process later queries that rely on passing the access token
   and user identifier as authorization parameters.  An RP MAY use any
   provider discovery approach that is suitable for its operating



Hollenbeck               Expires 12 August 2022                 [Page 6]


Internet-Draft           OpenID Connect for RDAP           February 2022


   environment.

3.1.3.2.  Authentication Request

   Once the OP is known, an RP MUST form an Authentication Request and
   send it to the OP as described in Section 3 of the OpenID Connect
   Core protocol [OIDCC].  The authentication path followed
   (authorization, implicit, or hybrid) will depend on the
   Authentication Request response_type set by the RP.  The remainder of
   the processing steps described here assume that the Authorization
   Code Flow is being used by setting "response_type=code" in the
   Authentication Request.

   The benefits of using the Authorization Code Flow for authenticating
   a human user are described in Section 3.1 of the OpenID Connect Core
   protocol.  The Implicit Flow is more commonly used by clients
   implemented in a web browser using a scripting language; it is
   described in Section 3.2 of the OpenID Connect Core protocol.  The
   Hybrid Flow (described in Section 3.3 of the OpenID Connect Core
   protocol) combines elements of the Authorization and Implicit Flows
   by returning some tokens from the Authorization Endpoint and others
   from the Token Endpoint.

   An Authentication Request can contain several parameters.  REQUIRED
   parameters are specified in Section 3.1.2.1 of the OpenID Connect
   Core protocol [OIDCC].  Apart from these parameters, it is
   RECOMMENDED that the RP include the optional "login_hint" parameter
   in the request, with the value being that of the "id" query parameter
   of the End-User's RDAP "login" request.  Passing the "login_hint"
   parameter allows a client to pre-fill login form information, so
   logging in can be more convenient for users.  Other parameters MAY be
   included.

   The OP receives the Authentication Request and attempts to validate
   it as described in Section 3.1.2.2 of the OpenID Connect Core
   protocol [OIDCC].  If the request is valid, the OP attempts to
   authenticate the End-User as described in Section 3.1.2.3 of the
   OpenID Connect Core protocol [OIDCC].  The OP returns an error
   response if the request is not valid or if any error is encountered.

3.1.3.3.  End-User Authorization

   After the End-User is authenticated, the OP MUST obtain authorization
   information from the End-User before releasing information to the
   RDAP Server/RP.  This process is described in Section 3.1.2.4 of the
   OpenID Connect Core protocol [OIDCC].





Hollenbeck               Expires 12 August 2022                 [Page 7]


Internet-Draft           OpenID Connect for RDAP           February 2022


3.1.3.4.  Authorization Response and Validation

   After the End-User is authenticated, the OP will send a response to
   the RP that describes the result of the authorization process in the
   form of an Authorization Grant.  The RP MUST validate the response.
   This process is described in Sections 3.1.2.5 - 3.1.2.7 of the OpenID
   Connect Core protocol [OIDCC].

3.1.3.5.  Token Processing

   The RP sends a Token Request using the Authorization Grant to a Token
   Endpoint to obtain a Token Response containing an Access Token, ID
   Token, and an OPTIONAL Refresh Token.  The RP MUST validate the Token
   Response.  This process is described in Section 3.1.3 of the OpenID
   Connect Core protocol [OIDCC].

3.1.3.6.  Delivery of User Information

   The set of Claims can be retrieved by sending a request to a UserInfo
   Endpoint using the Access Token.  The Claims MAY be returned in the
   ID Token.  The process of retrieving Claims from a UserInfo Endpoint
   is described in Section 5.3 of the OpenID Connect Core protocol
   [OIDCC].

   OpenID Connect specified a set of standard Claims in Section 5.1.
   Additional Claims for RDAP are described in Section 3.1.4.

3.1.4.  Specialized Claims for RDAP

   OpenID Connect claims are pieces of information used to make
   assertions about an entity.  Section 5 of the OpenID Connect Core
   protocol [OIDCC] describes a set of standard claims that can be used
   to identify a person.  Section 5.1.2 notes that additional claims MAY
   be used, and it describes a method to create them.

3.1.4.1.  Stated Purpose

   There are communities of RDAP users and operators who wish to make
   and validate claims about a user's "need to know" when it comes to
   requesting access to a resource.  For example, a law enforcement
   agent or a trademark attorney may wish to be able to assert that they
   have a legal right to access a protected resource, and a server
   operator will need to be able to receive and validate that claim.
   These needs can be met by defining and using an additional "purpose"
   claim.






Hollenbeck               Expires 12 August 2022                 [Page 8]


Internet-Draft           OpenID Connect for RDAP           February 2022


   The "purpose" claim identifies the purpose for which access to a
   protected resource is being requested.  Use of the "purpose" claim is
   OPTIONAL; processing of this claim is subject to server acceptance of
   the purpose and successful authentication of the End-User.
   Unrecognized purpose values MUST be ignored and the associated query
   MUST be processed as if the unrecognized purpose value was not
   present at all.

   The "purpose" value is a case-sensitive string containing a
   StringOrURI value as specified in Section 2 of the JSON Web Token
   (JWT) specification ([RFC7519]).  An example:

   {"purpose" : "domainNameControl"}

   Purpose values are themselves registered with IANA.  Each entry in
   the registry contains the following fields:

   Value: the purpose string value being registered.  Value strings can
   contain upper case characters from "A" to "Z", lower case ASCII
   characters from "a" to "z", and the underscore ("_") character.
   Value strings contain at least one character and no more than 64
   characters.

   Description: a one- or two-sentence description of the meaning of the
   purpose value, how it might be used, and/or how it should be
   interpreted by clients and servers.

   This registry is operated under the "Specification Required" policy
   defined in RFC 5226 ([RFC5226]).  The set of initial values used to
   populate the registry as described in Section 7.3 are taken from the
   final report (https://www.icann.org/en/system/files/files/final-
   report-06jun14-en.pdf) produced by the Expert Working Group on gTLD
   Directory Services chartered by the Internet Corporation for Assigned
   Names and Numbers (ICANN).

3.1.4.2.  Do Not Track

   There are also communities of RDAP users and operators who wish to
   make and validate claims about a user's wish to not have their
   queries logged, tracked, or recorded.  For example, a law enforcement
   agent may wish to be able to assert that their queries are part of a
   criminal investigation and should not be tracked due to a risk of
   query exposure compromising the investigation, and a server operator
   will need to be able to receive and validate that claim.  These needs
   can be met by defining and using an additional "do not track" claim.






Hollenbeck               Expires 12 August 2022                 [Page 9]


Internet-Draft           OpenID Connect for RDAP           February 2022


   The "do not track" ("dnt") claim can be used to identify an End-User
   that is authorized to perform queries without the End-User's
   association with those queries being logged, tracked, or recorded by
   the server.  Client use of the "dnt" claim is OPTIONAL.  Server
   operators MUST NOT log, track, or record any association of the query
   and the End-User's identity if the End-User is successfully
   identified and authorized, the "dnt" claim is present, the value of
   the claim is "true", and accepting the claim complies with local
   regulations regarding logging and tracking.

   The "dnt" value is represented as a JSON boolean literal.  An
   example:

   {"dnt" : true}

   No special query tracking processing is required if this claim is not
   present or if the value of the claim is "false".  Use of this claim
   MUST be limited to End-Users who are granted "do not track"
   privileges in accordance with service policies and regulations.
   Specification of these policies and regulations is beyond the scope
   of this document.

4.  Protocol Parameters

   This specification adds the following protocol parameters to RDAP:

   1.  A query parameter to request authentication for a specific end-
       user identity.
   2.  Path segments to start, stop, and determine the status of an
       authenticated session for a specific end-user identity.

4.1.  Client Login

   Client authentication is requested by sending a "login" query to an
   RDAP server.  If the RDAP server supports only remote Authorization
   Servers, the "login" query MUST include an End-User identifier that's
   delivered using one of two methods: by adding a query component to an
   RDAP request URI using the syntax described in Section 3.4 of RFC
   3986 [RFC3986], or by including an HTTP authorization header for the
   Basic authentication scheme as described in RFC 7617 [RFC7617].  If
   the RDAP server supports a local Authorization Servers, the End-User
   identifier MAY be omitted.  Clients can use either of these methods.
   Servers MUST support both methods.

   The query used to request client authentication is represented as an
   OPTIONAL "key=value" pair using a key value of "id" and a value
   component that contains the client identifier issued by an OP.  An
   example for client identifier "user.idp.example":



Hollenbeck               Expires 12 August 2022                [Page 10]


Internet-Draft           OpenID Connect for RDAP           February 2022


   https://example.com/rdap/login?id=user.idp.example

   The authorization header for the Basic authentication scheme contains
   a Base64-encoded representation of the client identifier issued by an
   OP.  No password is provided.  An example for client identifier
   "user.idp.example":

   https://example.com/rdap/login

   Authorization: Basic dXNlci5pZHAuZXhhbXBsZQ==

   An example for use with a local Authorization Server:

   https://example.com/rdap/login

   The response to this query MUST use the response structures specified
   in RFC 9083 [RFC9083].  In addition, the response MUST include an
   indication of the requested operation's success or failure, and, if
   successful, the client identifier associated with the request, the
   claims received from the Authorization Server, and the duration of
   the authorized session.

   An example of a successful "login" response:




























Hollenbeck               Expires 12 August 2022                [Page 11]


Internet-Draft           OpenID Connect for RDAP           February 2022


     {
       "notices": {
         "title": "Login Result",
         "description": [
           "Login succeeded",
           [
             "Client ID",
             "user.idp.example"
           ],
           [
             "Claims",
             {
               "iss": "https://accounts.someprovider.com",
               "azp": "729559086898-onapsvnhf2og.apps.someprovider.com",
               "aud": "729559086898-onapsvnhf2og.apps.someprovider.com",
               "sub": "103892603076825016132",
               "email": "user@someprovider.com",
               "email_verified": true,
               "at_hash": "es5maY5y9jBAWCBMhLokAQ",
               "nonce": "dcb29f97c836726ddc074f76fbc21bfd",
               "name": "User Person",
               "picture": "https://lh3.someprovider.com/a-/AOh14=s96-c",
               "given_name": "User",
               "family_name": "Person",
               "locale": "en",
               "iat": 1644239971,
               "exp": 1644243571,
               "purpose": "domainNameControl",
               "dnt": false
             }
           ],
           [
             "Expires in (seconds)",
             3599
           ]
         ]
       },
       "lang": "en-US"
     }

                                  Figure 1

   An example of a failed "login" response:








Hollenbeck               Expires 12 August 2022                [Page 12]


Internet-Draft           OpenID Connect for RDAP           February 2022


     {
       "notices": {
         "title": "Login Result",
         "description": [
           "Login failed",
           [
             "Client ID",
             "user.idp.example"
           ]
       },
       "lang": "en-US"
     }

                                  Figure 2

4.1.1.  Clients with Limited User Interfaces

   The flow described in Section 3.1.3 requires an end-user to interact
   with a server using a user interface that can process HTTP.  This
   will not work well in situations where the client is automated or an
   end-user is using a command line user interface such as curl
   (http://curl.haxx.se/) or wget (https://www.gnu.org/software/wget/).
   This limitation can be addressed using a web browser on a second
   device.

4.1.1.1.  OAuth 2.0 Device Authorization Grant

   The "OAuth 2.0 Device Authorization Grant" [RFC8628] provides an
   OPTIONAL method to request user authorization from devices that have
   an Internet connection, but lack a suitable browser for a more
   traditional OAuth flow.  This method requires a client to use a
   second device (such as a smart telephone) that has access to a web
   browser for entry of a code sequence that is presented on the
   constrained device.

4.1.1.2.  UI-limited Client Login

   Client authentication is requested by sending a "login/device" query
   to an RDAP server.  If the RDAP server supports only remote
   Authorization Servers, the "login/device" query MUST include an End-
   User identifier that's delivered using one of two methods: by adding
   a query component to an RDAP request URI using the syntax described
   in Section 3.4 of RFC 3986 [RFC3986], or by including an HTTP
   authorization header for the Basic authentication scheme as described
   in RFC 7617 [RFC7617].  If the RDAP server supports a local
   Authorization Servers, the End-User identifier MAY be omitted.
   Clients can use either of these methods.  Servers MUST support both
   methods.



Hollenbeck               Expires 12 August 2022                [Page 13]


Internet-Draft           OpenID Connect for RDAP           February 2022


   The query used to request client authentication is represented as an
   OPTIONAL "key=value" pair using a key value of "id" and a value
   component that contains the client identifier issued by an OP.  An
   example using wget for client identifier "user.idp.example":

   wget -qO- --keep-session-cookies --save-
   cookies\https://example.com/rdap/login/device?id=user.idp.example

   The authorization header for the Basic authentication scheme contains
   a Base64-encoded representation of the client identifier issued by an
   OP.  No password is provided.  An example using curl and an
   authorization header:

   curl -H "Authorization: Bearer dXNlci5pZHAuZXhhbXBsZQ=="\-c
   cookies.txt https://example.com/rdap/domain/login/device

   The response to this query MUST use the response structures specified
   in RFC 9083 [RFC9083].  In addition, the response MUST include an
   indication of the requested operation's success or failure, and, if
   successful, the name-value pairs described in Section 3.2 of RFC 8628
   [RFC8628].

   An example of a device "login" response (the device_code has been
   abbreviated):

     {
       "notices": {
         "title": "Device Login Result",
         "description": [
           "Login succeeded",
           {
             "device_code": "AH-1N...iy7yg",
             "user_code": "CVYP-SYRC",
             "expires_in": 1800,
             "interval": 5,
             "verification_url": "https:\/\/www.example.net\/device"
           }
         ]
       },
       "lang": "en-US"
     }

                                  Figure 3








Hollenbeck               Expires 12 August 2022                [Page 14]


Internet-Draft           OpenID Connect for RDAP           February 2022


4.1.1.3.  UI-limited Client Login Polling

   After successful processing of the "login/device" query, the client
   MUST send a "login/devicepoll" query to the RDAP server to continue
   the login process.  This query performs the polling function
   described in RFC 8628 [RFC8628], allowing the RDAP server to wait for
   the End-User to enter the information returned from the "login/
   device" query using the interface on their second device.  After the
   End-User has completed that process, or if the process fails or times
   out, the OP will respond to the polling requests with an indication
   of success or failure.  Both should be noted using the response
   structures described in Section 4.1.  An example using wget:

   wget -qO- --load-cookies cookies.txt\https://example.com/rdap/login/
   devicepoll

   An example using curl:

   curl -b cookies.txt https://example.com/rdap/domain/login/devicepoll

   The response to this query MUST use the response structures described
   in Section 4.1.  RDAP query processing can continue normally on the
   UI-limited device once the "login" process has been completed.

4.2.  Session Status

   Clients MAY send a request to an RDAP server to determine the status
   of an existing login session using a "session" path segment.  This
   request MAY include an OPTIONAL "refresh" path segment to refresh the
   access token associated with the current session and to extend the
   session for a period of time determined by the OP.  As described in
   RFC 6749 [RFC6749], support for refresh tokens is OPTIONAL.  An RDAP
   server MUST determine if the OP supports token refresh and process
   the refresh request by either requesting refresh of the access token
   or by returning a response that indicates that token refresh is not
   supported by the OP.  An example "session" request:

   https://example.com/rdap/session

   An example "session" request with token refresh included:

   https://example.com/rdap/session/refresh

   In addition to any core RDAP response elements, the response MUST
   include an indication of the requested operation's success or
   failure, and, if successful, the client identifier associated with
   the session, the claims received from the Authorization Server, and
   the duration of the authorized session.



Hollenbeck               Expires 12 August 2022                [Page 15]


Internet-Draft           OpenID Connect for RDAP           February 2022


   An example without token refresh:

     {
       "notices": {
         "title": "Session Status Result",
         "description": [
           "Session status succeeded",
           [
             "Client ID",
             "user.idp.example"
           ],
           [
             "Token Refresh Status",
             "Token refresh not requested."
           ]
           [
             "Expires in (seconds)",
             1873
           ]
           [
             "Claims",
             {
               "iss": "https://accounts.someprovider.com",
               "azp": "729559086898-onapsvnhf2og.apps.someprovider.com",
               "aud": "729559086898-onapsvnhf2og.apps.someprovider.com",
               "sub": "103892603076825016132",
               "email": "user@someprovider.com",
               "email_verified": true,
               "at_hash": "es5maY5y9jBAWCBMhLokAQ",
               "nonce": "dcb29f97c836726ddc074f76fbc21bfd",
               "name": "User Person",
               "picture": "https://lh3.someprovider.com/a-/AOh14=s96-c",
               "given_name": "User",
               "family_name": "Person",
               "locale": "en",
               "iat": 1644239971,
               "exp": 1644243571,
               "purpose": "domainNameControl",
               "dnt": false
             }
           ],
         ]
       },
       "lang": "en-US"
     }

                                  Figure 4




Hollenbeck               Expires 12 August 2022                [Page 16]


Internet-Draft           OpenID Connect for RDAP           February 2022


   An example with token refresh:

     {
       "notices": {
         "title": "Session Status Result",
         "description": [
           "Session status succeeded",
           [
             "Client ID",
             "user.idp.example"
           ],
           [
             "Token Refresh Status",
             "Token refresh successful."
           ]
           [
             "Expires in (seconds)",
             3599
           ]
           [
             "Claims",
             {
               "iss": "https://accounts.someprovider.com",
               "azp": "729559086898-onapsvnhf2og.apps.someprovider.com",
               "aud": "729559086898-onapsvnhf2og.apps.someprovider.com",
               "sub": "103892603076825016132",
               "email": "user@someprovider.com",
               "email_verified": true,
               "at_hash": "es5maY5y9jBAWCBMhLokAQ",
               "nonce": "dcb29f97c836726ddc074f76fbc21bfd",
               "name": "User Person",
               "picture": "https://lh3.someprovider.com/a-/AOh14=s96-c",
               "given_name": "User",
               "family_name": "Person",
               "locale": "en",
               "iat": 1644239971,
               "exp": 1644243571,
               "purpose": "domainNameControl",
               "dnt": false
             }
           ],
         ]
       },
       "lang": "en-US"
     }

                                  Figure 5




Hollenbeck               Expires 12 August 2022                [Page 17]


Internet-Draft           OpenID Connect for RDAP           February 2022


4.3.  Client Logout

   Clients MAY send a request to an RDAP server to terminate an existing
   login session.  Termination of a session is requested using a
   "logout" path segment.  An example:

   https://example.com/rdap/logout

   In addition to any core RDAP response elements, the response MUST
   include an indication of the requested operation's success or
   failure, and, if successful, the client identifier associated with
   the session.

   Example "logout" response:

     {
       "notices": {
         "title": "Logout Result",
         "description": [
           "Logout succeeded",
           [
             "Client ID",
             "user.idp.example"
           ],
           "Token revocation successful."
         ]
       },
       "lang": "en-US"
     }

                                  Figure 6

   Access and refresh tokens can be revoked during the "logout" process
   as described in RFC 7009 [RFC7009] if supported by the OP (token
   revocation endpoint support is OPTIONAL per RFC 8414 [RFC8414]).  If
   supported, this feature SHOULD be used to ensure that the tokens are
   not mistakenly associated with a future RDAP session.  In the absence
   of a "logout" query, an RDAP session MUST be terminated by the RDAP
   server after a server-defined period of time.

4.4.  Token Exchange

   ID tokens include an audience parameter that contains the OAuth 2.0
   client_id of the RP as an audience value.  In some operational
   scenarios (such as a client that is providing a proxy service), an RP
   can receive tokens with an audience value that does not include the
   RP's client_id.  These tokens might not be trusted by the RP, and the
   RP might refuse to accept the tokens.  This situation can be remedied



Hollenbeck               Expires 12 August 2022                [Page 18]


Internet-Draft           OpenID Connect for RDAP           February 2022


   by having the RP exchange these tokens with the OP for a set of
   trusted tokens that reset the audience parameter.  This token
   exchange protocol is described in RFC 8693 [RFC8693].  This issue is
   not visible to the RDAP client and should be managed by the OpenID
   implementation used by the RDAP server.

4.5.  Parameter Processing

   Unrecognized query parameters MUST be ignored.  An RDAP server that
   processes an authenticated query MUST determine if the end-user
   identification information is associated with an OP that is
   recognized and supported by the server.  Servers MUST reject queries
   that include identification information that is not associated with a
   supported OP by returning an HTTP 501 (Not Implemented) response.  An
   RDAP server that receives a query containing identification
   information associated with a recognized OP MUST perform the steps
   required to authenticate the user with the OP, process the query, and
   return an RDAP response that is appropriate for the End-User's level
   of authorization and access.

5.  RDAP Query Processing

   Once an RDAP "login" session is active, an RDAP server MUST determine
   if the End-User is authorized to perform any queries that are
   received during the duration of the session.  This MAY include
   rejecting queries outright, and it MAY include omitting or otherwise
   redacting information that the End-User is not authorized to receive.
   Specific processing requirements are beyond the scope of this
   document.  A client can end a session explicitly by sending a
   "logout" query to the RDAP server.  A session can also be ended
   implicitly by the server after a server-defined period of time.  The
   status of a session can be determined at any time by sending a
   "session" query to the RDAP server.

   An RDAP server MUST maintain session state information for the
   duration of an active session.  This is commonly done using HTTP
   cookies as described in RFC 6265 [RFC6265]>.  Doing so allows End-
   User to submit queries without having to explicitly identify and
   authenticate themselves for each and every query.

6.  RDAP Conformance

   RDAP responses that contain values described in this document MUST
   indicate conformance with this specification by including an
   rdapConformance ([RFC9083]) value of "rdap_openidc_remote_level_0" or
   "rdap_openidc_local_level_0".  Both values MAY be present if a server
   supports both local and remote OpenID Authorization Servers.  The
   information needed to register this value in the RDAP Extensions



Hollenbeck               Expires 12 August 2022                [Page 19]


Internet-Draft           OpenID Connect for RDAP           February 2022


   Registry is described in Section 7.1.

   Example rdapConformance structure with extension specified:

      "rdapConformance" :
        [
          "rdap_level_0",
          "rdap_openidc_remote_level_0"
        ]

                                  Figure 7

7.  IANA Considerations

7.1.  RDAP Extensions Registry

   IANA is requested to register the following values in the RDAP
   Extensions Registry:

   *  Extension identifier: rdap_openidc_remote_level_0
   *  Registry operator: Any
   *  Published specification: This document.
   *  Contact: IESG <iesg@ietf.org>
   *  Intended usage: This extension describes a federated
      authentication method for RDAP using OAuth 2.0, OpenID Connect,
      and a remote Authorization Server.

   *  Extension identifier: rdap_openidc_local_level_0
   *  Registry operator: Any
   *  Published specification: This document.
   *  Contact: IESG <iesg@ietf.org>
   *  Intended usage: This extension describes a federated
      authentication method for RDAP using OAuth 2.0, OpenID Connect,
      and a local Authorization Server.

7.2.  JSON Web Token Claims Registry

   IANA is requested to register the following values in the JSON Web
   Token Claims Registry:

   *  Claim Name: "purpose"
   *  Claim Description: This claim describes the stated purpose for
      submitting a request to access a protected RDAP resource.
   *  Change Controller: IESG
   *  Specification Document(s): Section 3.1.4.1 of this document.

   *  Claim Name: "dnt"




Hollenbeck               Expires 12 August 2022                [Page 20]


Internet-Draft           OpenID Connect for RDAP           February 2022


   *  Claim Description: This claim contains a JSON boolean literal that
      describes an End-User's "do not track" preference for identity
      tracking, logging, or recording when accessing a protected RDAP
      resource.
   *  Change Controller: IESG
   *  Specification Document(s): Section 3.1.4.2 of this document.

7.3.  RDAP Query Purpose Registry

   IANA is requested to create a new protocol registry to manage RDAP
   query purpose values.  This registry should appear under its own
   heading on IANA's protocol listings, using the same title as the name
   of the registry.  The information to be registered and the procedures
   to be followed in populating the registry are described in
   Section 3.1.4.1.

   Name of registry: Registration Data Access Protocol (RDAP) Query
   Purpose Values

   Section at http://www.iana.org/protocols:

   Registry Title: Registration Data Access Protocol (RDAP) Query
   Purpose Values

   Registry Name: Registration Data Access Protocol (RDAP) Query Purpose
   Values

   Registration Procedure: Specification Required

   Reference: This draft

   Required information: See Section 3.1.4.1.

   Review process: "Specification Required" as described in RFC 5226
   [RFC5226].

   Size, format, and syntax of registry entries: See Section 3.1.4.1.

   Initial assignments and reservations:

   -----BEGIN FORM----- Value: domainNameControl Description: Tasks
   within the scope of this purpose include creating and managing and
   monitoring a registrant's own domain name, including creating the
   domain name, updating information about the domain name, transferring
   the domain name, renewing the domain name, deleting the domain name,
   maintaining a domain name portfolio, and detecting fraudulent use of
   the Registrant's own contact information.  -----END FORM-----




Hollenbeck               Expires 12 August 2022                [Page 21]


Internet-Draft           OpenID Connect for RDAP           February 2022


   -----BEGIN FORM----- Value: personalDataProtection Description: Tasks
   within the scope of this purpose include identifying the accredited
   privacy/proxy provider associated with a domain name and reporting
   abuse, requesting reveal, or otherwise contacting the provider.
   -----END FORM-----

   -----BEGIN FORM----- Value: technicalIssueResolution Description:
   Tasks within the scope of this purpose include (but are not limited
   to) working to resolve technical issues, including email delivery
   issues, DNS resolution failures, and web site functional issues.
   -----END FORM-----

   -----BEGIN FORM----- Value: domainNameCertification Description:
   Tasks within the scope of this purpose include a Certification
   Authority (CA) issuing an X.509 certificate to a subject identified
   by a domain name.  -----END FORM-----

   -----BEGIN FORM----- Value: individualInternetUse Description: Tasks
   within the scope of this purpose include identifying the organization
   using a domain name to instill consumer trust, or contacting that
   organization to raise a customer complaint to them or file a
   complaint about them.  -----END FORM-----

   -----BEGIN FORM----- Value: businessDomainNamePurchaseOrSale
   Description: Tasks within the scope of this purpose include making
   purchase queries about a domain name, acquiring a domain name from a
   registrant, and enabling due diligence research.  -----END FORM-----

   -----BEGIN FORM----- Value: academicPublicInterestDNSRResearch
   Description: Tasks within the scope of this purpose include academic
   public interest research studies about domain names published in the
   registration data service, including public information about the
   registrant and designated contacts, the domain name's history and
   status, and domain names registered by a given registrant (reverse
   query).  -----END FORM-----

   -----BEGIN FORM----- Value: legalActions Description: Tasks within
   the scope of this purpose include investigating possible fraudulent
   use of a registrant's name or address by other domain names,
   investigating possible trademark infringement, contacting a
   registrant/licensee's legal representative prior to taking legal
   action and then taking a legal action if the concern is not
   satisfactorily addressed.  -----END FORM-----








Hollenbeck               Expires 12 August 2022                [Page 22]


Internet-Draft           OpenID Connect for RDAP           February 2022


   -----BEGIN FORM----- Value: regulatoryAndContractEnforcement
   Description: Tasks within the scope of this purpose include tax
   authority investigation of businesses with online presence, Uniform
   Dispute Resolution Policy (UDRP) investigation, contractual
   compliance investigation, and registration data escrow audits.
   -----END FORM-----

   -----BEGIN FORM----- Value:
   criminalInvestigationAndDNSAbuseMitigation Description: Tasks within
   the scope of this purpose include reporting abuse to someone who can
   investigate and address that abuse, or contacting entities associated
   with a domain name during an offline criminal investigation.
   -----END FORM-----

   -----BEGIN FORM----- Value: dnsTransparency Description: Tasks within
   the scope of this purpose involve querying the registration data made
   public by registrants to satisfy a wide variety of use cases around
   informing the general public.  -----END FORM-----

8.  Implementation Status

   NOTE: Please remove this section and the reference to RFC 7942 prior
   to publication as an RFC.

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in RFC 7942
   [RFC7942].  The description of implementations in this section is
   intended to assist the IETF in its decision processes in progressing
   drafts to RFCs.  Please note that the listing of any individual
   implementation here does not imply endorsement by the IETF.
   Furthermore, no effort has been spent to verify the information
   presented here that was supplied by IETF contributors.  This is not
   intended as, and must not be construed to be, a catalog of available
   implementations or their features.  Readers are advised to note that
   other implementations may exist.

   According to RFC 7942, "this will allow reviewers and working groups
   to assign due consideration to documents that have the benefit of
   running code, which may serve as evidence of valuable experimentation
   and feedback that have made the implemented protocols more mature.
   It is up to the individual working groups to use this information as
   they see fit".

   Version -09 of this specification introduced changes that are
   incompatible with earlier implementations.  Implementations that are
   consistent with this specification will be added as they are
   identified.



Hollenbeck               Expires 12 August 2022                [Page 23]


Internet-Draft           OpenID Connect for RDAP           February 2022


9.  Security Considerations

   Security considerations for RDAP can be found in RFC 7481 [RFC7481].
   Security considerations for OpenID Connect Core [OIDCC] and OAuth 2.0
   [RFC6749] can be found in their reference specifications.  OpenID
   Connect defines optional mechanisms for robust signing and encryption
   that can be used to provide data integrity and data confidentiality
   services as needed.

9.1.  Authentication and Access Control

   Having completed the client identification, authorization, and
   validation process, an RDAP server can make access control decisions
   based on a comparison of client-provided information and local
   policy.  For example, a client who provides an email address (and
   nothing more) might be entitled to receive a subset of the
   information that would be available to a client who provides an email
   address, a full name, and a stated purpose.  Development of these
   access control policies is beyond the scope of this document.

10.  Acknowledgments

   The author would like to acknowledge the following individuals for
   their contributions to the development of this document: Tom
   Harrison, Russ Housley, Rhys Smith, Jaromir Talir, and Alessandro
   Vesely.  In addition, the Verisign Registry Services Lab development
   team of Joseph Harvey, Andrew Kaizer, Sai Mogali, Anurag Saxena,
   Swapneel Sheth, Nitin Singh, and Zhao Zhao provided critical "proof
   of concept" implementation experience that helped demonstrate the
   validity of the concepts described in this document.

   Mario Loffredo provided significant feedback based on implementation
   experience that led to welcome improvements in several sections of
   this document.  His contributions are greatly appreciated.

11.  References

11.1.  Normative References

   [OIDC]     OpenID Foundation, "OpenID Connect",
              <http://openid.net/connect/>.

   [OIDCC]    OpenID Foundation, "OpenID Connect Core incorporating
              errata set 1", November 2014,
              <http://openid.net/specs/openid-connect-core-1_0.html>.






Hollenbeck               Expires 12 August 2022                [Page 24]


Internet-Draft           OpenID Connect for RDAP           February 2022


   [OIDCD]    OpenID Foundation, "OpenID Connect Discovery 1.0
              incorporating errata set 1", November 2014,
              <http://openid.net/specs/openid-connect-discovery-
              1_0.html>.

   [OIDCR]    OpenID Foundation, "OpenID Connect Dynamic Client
              Registration 1.0 incorporating errata set 1", November
              2014, <http://openid.net/specs/openid-connect-
              registration-1_0.html>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <https://www.rfc-editor.org/info/rfc5226>.

   [RFC6265]  Barth, A., "HTTP State Management Mechanism", RFC 6265,
              DOI 10.17487/RFC6265, April 2011,
              <https://www.rfc-editor.org/info/rfc6265>.

   [RFC6749]  Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
              RFC 6749, DOI 10.17487/RFC6749, October 2012,
              <https://www.rfc-editor.org/info/rfc6749>.

   [RFC7009]  Lodderstedt, T., Ed., Dronia, S., and M. Scurtescu, "OAuth
              2.0 Token Revocation", RFC 7009, DOI 10.17487/RFC7009,
              August 2013, <https://www.rfc-editor.org/info/rfc7009>.

   [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Message Syntax and Routing",
              RFC 7230, DOI 10.17487/RFC7230, June 2014,
              <https://www.rfc-editor.org/info/rfc7230>.

   [RFC7480]  Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
              Registration Data Access Protocol (RDAP)", STD 95,
              RFC 7480, DOI 10.17487/RFC7480, March 2015,
              <https://www.rfc-editor.org/info/rfc7480>.





Hollenbeck               Expires 12 August 2022                [Page 25]


Internet-Draft           OpenID Connect for RDAP           February 2022


   [RFC7481]  Hollenbeck, S. and N. Kong, "Security Services for the
              Registration Data Access Protocol (RDAP)", STD 95,
              RFC 7481, DOI 10.17487/RFC7481, March 2015,
              <https://www.rfc-editor.org/info/rfc7481>.

   [RFC7519]  Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
              (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
              <https://www.rfc-editor.org/info/rfc7519>.

   [RFC7617]  Reschke, J., "The 'Basic' HTTP Authentication Scheme",
              RFC 7617, DOI 10.17487/RFC7617, September 2015,
              <https://www.rfc-editor.org/info/rfc7617>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8628]  Denniss, W., Bradley, J., Jones, M., and H. Tschofenig,
              "OAuth 2.0 Device Authorization Grant", RFC 8628,
              DOI 10.17487/RFC8628, August 2019,
              <https://www.rfc-editor.org/info/rfc8628>.

   [RFC8693]  Jones, M., Nadalin, A., Campbell, B., Ed., Bradley, J.,
              and C. Mortimore, "OAuth 2.0 Token Exchange", RFC 8693,
              DOI 10.17487/RFC8693, January 2020,
              <https://www.rfc-editor.org/info/rfc8693>.

   [RFC9082]  Hollenbeck, S. and A. Newton, "Registration Data Access
              Protocol (RDAP) Query Format", STD 95, RFC 9082,
              DOI 10.17487/RFC9082, June 2021,
              <https://www.rfc-editor.org/info/rfc9082>.

   [RFC9083]  Hollenbeck, S. and A. Newton, "JSON Responses for the
              Registration Data Access Protocol (RDAP)", STD 95,
              RFC 9083, DOI 10.17487/RFC9083, June 2021,
              <https://www.rfc-editor.org/info/rfc9083>.

11.2.  Informative References

   [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2",
              FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
              <https://www.rfc-editor.org/info/rfc4949>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/info/rfc7942>.




Hollenbeck               Expires 12 August 2022                [Page 26]


Internet-Draft           OpenID Connect for RDAP           February 2022


   [RFC8414]  Jones, M., Sakimura, N., and J. Bradley, "OAuth 2.0
              Authorization Server Metadata", RFC 8414,
              DOI 10.17487/RFC8414, June 2018,
              <https://www.rfc-editor.org/info/rfc8414>.

Appendix A.  Change Log

   00:  Initial working group version ported from draft-hollenbeck-
      regext-rdap-openid-10.
   01:  Modified ID Token delivery approach to note proper use of an
      HTTP bearer authorization header.
   02:  Modified token delivery approach (Access Token is the bearer
      token) to note proper use of an HTTP bearer authorization header,
      fixing the change made in -01.
   03:  Updated OAuth 2.0 Device Authorization Grant description and
      reference due to publication of RFC 8628.
   04:  Updated OAuth 2.0 token exchange description and reference due
      to publication of RFC 8693.  Corrected the RDAP conformance
      identifier to be registered with IANA.
   05:  Keepalive refresh.
   06:  Keepalive refresh.
   07:  Added "login_hint" description to Section 3.1.3.2.  Added some
      text to Section 3.1.4.2 to note that "do not track" requires
      compliance with local regulations.
   08:  Rework of token management processing in Sections 4 and 5.
   09:  Updated RDAP specification references.  Added text to describe
      both local and remote Authorization Server processing.  Removed
      text that described passing of ID Tokens as query parameters.
   10:  Updated Section 3.1.3.1.  Replaced token processing queries with
      "login", "session", and "logout" queries.

Author's Address

   Scott Hollenbeck
   Verisign Labs
   12061 Bluemont Way
   Reston, VA 20190
   United States of America

   Email: shollenbeck@verisign.com
   URI:   http://www.verisignlabs.com/










Hollenbeck               Expires 12 August 2022                [Page 27]