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Table of Contents

[Note that this file is a concatenation of more than one RFC.]

Internet Engineering Task Force (IETF) A. Newton Request for Comments: 7480 ARIN Category: Standards Track B. Ellacott ISSN: 2070-1721 APNIC

                                                               N. Kong
                                                                 CNNIC
                                                            March 2015
     HTTP Usage in the Registration Data Access Protocol (RDAP)

Abstract

 This document is one of a collection that together describes the
 Registration Data Access Protocol (RDAP).  It describes how RDAP is
 transported using the Hypertext Transfer Protocol (HTTP).  RDAP is a
 successor protocol to the very old WHOIS protocol.  The purpose of
 this document is to clarify the use of standard HTTP mechanisms for
 this application.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc7480.

Copyright Notice

 Copyright (c) 2015 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Newton, et al. Standards Track [Page 1] RFC 7480 RDAP over HTTP March 2015

Table of Contents

 1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
 2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
 3.  Design Intents  . . . . . . . . . . . . . . . . . . . . . . .   5
 4.  Queries . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.1.  HTTP Methods  . . . . . . . . . . . . . . . . . . . . . .   5
   4.2.  Accept Header . . . . . . . . . . . . . . . . . . . . . .   5
   4.3.  Query Parameters  . . . . . . . . . . . . . . . . . . . .   6
 5.  Types of HTTP Response  . . . . . . . . . . . . . . . . . . .   6
   5.1.  Positive Answers  . . . . . . . . . . . . . . . . . . . .   6
   5.2.  Redirects . . . . . . . . . . . . . . . . . . . . . . . .   6
   5.3.  Negative Answers  . . . . . . . . . . . . . . . . . . . .   7
   5.4.  Malformed Queries . . . . . . . . . . . . . . . . . . . .   7
   5.5.  Rate Limits . . . . . . . . . . . . . . . . . . . . . . .   7
   5.6.  Cross-Origin Resource Sharing (CORS)  . . . . . . . . . .   8
 6.  Extensibility . . . . . . . . . . . . . . . . . . . . . . . .   8
 7.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
 8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   8.1.  RDAP Extensions Registry  . . . . . . . . . . . . . . . .   9
 9.  Internationalization Considerations . . . . . . . . . . . . .  10
   9.1.  URIs and IRIs . . . . . . . . . . . . . . . . . . . . . .  10
   9.2.  Language Identifiers in Queries and Responses . . . . . .  10
   9.3.  Language Identifiers in HTTP Headers  . . . . . . . . . .  10
 10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
   10.1.  Normative References . . . . . . . . . . . . . . . . . .  11
   10.2.  Informative References . . . . . . . . . . . . . . . . .  12
 Appendix A.  Protocol Example . . . . . . . . . . . . . . . . . .  13
 Appendix B.  Cache Busting  . . . . . . . . . . . . . . . . . . .  13
 Appendix C.  Bootstrapping and Redirection  . . . . . . . . . . .  14
 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . 15
 Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  16

Newton, et al. Standards Track [Page 2] RFC 7480 RDAP over HTTP March 2015

1. Introduction

 This document describes the usage of the Hypertext Transfer Protocol
 (HTTP) [RFC7230] for the Registration Data Access Protocol (RDAP).
 The goal of this document is to tie together usage patterns of HTTP
 into a common profile applicable to the various types of directory
 services serving registration data using practices informed by the
 Representational State Transfer (REST) [REST] architectural style.
 By giving the various directory services common behavior, a single
 client is better able to retrieve data from directory services
 adhering to this behavior.
 Registration data expected to be presented by this service is
 Internet resource registration data -- registration of domain names
 and Internet number resources.  This data is typically provided by
 WHOIS [RFC3912] services, but the WHOIS protocol is insufficient to
 modern registration data service requirements.  A replacement
 protocol is expected to retain the simple transactional nature of
 WHOIS, while providing a specification for queries and responses,
 redirection to authoritative sources, support for Internationalized
 Domain Names (IDNs) [RFC5890], and support for localized registration
 data such as addresses and organization or person names.
 In designing these common usage patterns, this document introduces
 considerations for a simple use of HTTP.  Where complexity may
 reside, it is the goal of this document to place it upon the server
 and to keep the client as simple as possible.  A client
 implementation should be possible using common operating system
 scripting tools (e.g., bash and wget).
 This is the basic usage pattern for this protocol:
 1.  A client determines an appropriate server to query along with the
     appropriate base Uniform Resource Locator (URL) to use in such
     queries.  [RFC7484] describes one method to determine the server
     and the base URL.  See Appendix C for more information.
 2.  A client issues an HTTP (or HTTPS) query using GET [RFC7231].  As
     an example, a query URL for the network registration 192.0.2.0
     might be
        http://example.com/rdap/ip/192.0.2.0
     [RFC7482] details the various queries used in RDAP.

Newton, et al. Standards Track [Page 3] RFC 7480 RDAP over HTTP March 2015

 3.  If the receiving server has the information for the query, it
     examines the Accept header field of the query and returns a 200
     response with a response entity appropriate for the requested
     format.  [RFC7483] details a response in JavaScript Object
     Notation (JSON).
 4.  If the receiving server does not have the information for the
     query but does have knowledge of where the information can be
     found, it will return a redirection response (3xx) with the
     Location header field containing an HTTP(S) URL pointing to the
     information or another server known to have knowledge of the
     location of the information.  The client is expected to requery
     using that HTTP URL.
 5.  If the receiving server does not have the information being
     requested and does not have knowledge of where the information
     can be found, it returns a 404 response.
 6.  If the receiving server will not answer a request for policy
     reasons, it will return an error response (4xx) indicating the
     reason for giving no answer.
 It is not the intent of this document to redefine the meaning and
 semantics of HTTP.  The purpose of this document is to clarify the
 use of standard HTTP mechanisms for this application.

2. Terminology

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].
 As is noted in "Security and Stability Advisory Committee (SSAC)
 Report on WHOIS Terminology and Structure" [SAC-051], the term
 "WHOIS" is overloaded, often referring to a protocol, a service, and
 data.  In accordance with [SAC-051], this document describes the base
 behavior for an RDAP.  [SAC-051] describes a protocol profile of RDAP
 for Domain Name Registries (DNRs), the Domain Name Registration Data
 Access Protocol (DNRD-AP).
 In this document, an RDAP client is an HTTP user agent performing an
 RDAP query, and an RDAP server is an HTTP server providing an RDAP
 response.  RDAP query and response formats are described in [RFC7482]
 and [RFC7483], while this document describes how RDAP clients and
 servers use HTTP to exchange queries and responses.  [RFC7481]
 describes security considerations for RDAP.

Newton, et al. Standards Track [Page 4] RFC 7480 RDAP over HTTP March 2015

3. Design Intents

 There are a few design criteria this document attempts to meet.
 First, each query is meant to require only one path of execution to
 obtain an answer.  A response may contain an answer, no answer, or a
 redirect, and clients are not expected to fork multiple paths of
 execution to make a query.
 Second, the semantics of the request/response allow for future and/or
 non-standard response formats.  In this document, only a JSON
 [RFC7159] response media type is noted, with the response contents to
 be described separately (see [RFC7483]).  This document only
 describes how RDAP is transported using HTTP with this format.
 Third, this protocol is intended to be able to make use of the range
 of mechanisms available for use with HTTP.  HTTP offers a number of
 mechanisms not described further in this document.  Operators are
 able to make use of these mechanisms according to their local policy,
 including cache control, authorization, compression, and redirection.
 HTTP also benefits from widespread investment in scalability,
 reliability, and performance, as well as widespread programmer
 understanding of client behaviors for web services styled after REST
 [REST], reducing the cost to deploy Registration Data Directory
 Services and clients.  This protocol is forward compatible with HTTP
 2.0.

4. Queries

4.1. HTTP Methods

 Clients use the GET method to retrieve a response body and use the
 HEAD method to determine existence of data on the server.  Clients
 SHOULD use either the HTTP GET or HEAD methods (see [RFC7231]).
 Servers are under no obligation to support other HTTP methods;
 therefore, clients using other methods will likely not interoperate
 properly.
 Clients and servers MUST support HTTPS to support security services.

4.2. Accept Header

 To indicate to servers that an RDAP response is desired, clients
 include an Accept header field with an RDAP-specific JSON media type,
 the generic JSON media type, or both.  Servers receiving an RDAP
 request return an entity with a Content-Type header containing the
 RDAP-specific JSON media type.

Newton, et al. Standards Track [Page 5] RFC 7480 RDAP over HTTP March 2015

 This specification does not define the responses a server returns to
 a request with any other media types in the Accept header field, or
 with no Accept header field.  One possibility would be to return a
 response in a media type suitable for rendering in a web browser.

4.3. Query Parameters

 Servers MUST ignore unknown query parameters.  Use of unknown query
 parameters for cache busting is described in Appendix B.

5. Types of HTTP Response

 This section describes the various types of responses a server may
 send to a client.  While no standard HTTP response code is forbidden
 in usage, this section defines the minimal set of response codes in
 common use by servers that a client will need to understand.  While
 some clients may be constructed with simple tooling that does not
 account for all of these response codes, a more robust client
 accounting for these codes will likely provide a better user
 experience.  It is expected that usage of response codes and types
 for this application not defined here will be described in subsequent
 documents.

5.1. Positive Answers

 If a server has the information requested by the client and wishes to
 respond to the client with the information according to its policies,
 it returns that answer in the body of a 200 (OK) response (see
 [RFC7231]).

5.2. Redirects

 If a server wishes to inform a client that the answer to a given
 query can be found elsewhere, it returns either a 301 (Moved
 Permanently) response code to indicate a permanent move or a 302
 (Found), 303 (See Other), or 307 (Temporary Redirect) response code
 to indicate a non-permanent redirection, and it includes an HTTP(S)
 URL in the Location header field (see [RFC7231]).  The client is
 expected to issue a subsequent request to satisfy the original query
 using the given URL without any processing of the URL.  In other
 words, the server is to hand back a complete URL, and the client
 should not have to transform the URL to follow it.  Servers are under
 no obligation to return a URL conformant to [RFC7482].
 For this application, such an example of a permanent move might be a
 Top-Level Domain (TLD) operator informing a client the information

Newton, et al. Standards Track [Page 6] RFC 7480 RDAP over HTTP March 2015

 being sought can be found with another TLD operator (i.e., a query
 for the domain bar in foo.example is found at
 http://foo.example/domain/bar).
 For example, if the client uses
    http://serv1.example.com/weirds/domain/example.com
 the server redirecting to
    https://serv2.example.net/weirds2/
 would set the Location: field to the value
    https://serv2.example.net/weirds2/domain/example.com

5.3. Negative Answers

 If a server wishes to respond that it has an empty result set (that
 is, no data appropriately satisfying the query), it returns a 404
 (Not Found) response code.  Optionally, it MAY include additional
 information regarding the negative answer in the HTTP entity body.
 If a server wishes to inform the client that information about the
 query is available, but cannot include the information in the
 response to the client for policy reasons, the server MUST respond
 with an appropriate response code out of HTTP's 4xx range.  A client
 MAY retry the query if that is appropriate for the respective
 response code.

5.4. Malformed Queries

 If a server receives a query that it cannot interpret as an RDAP
 query, it returns a 400 (Bad Request) response code.  Optionally, it
 MAY include additional information regarding this negative answer in
 the HTTP entity body.

5.5. Rate Limits

 Some servers apply rate limits to deter address scraping and other
 abuses.  When a server declines to answer a query due to rate limits,
 it returns a 429 (Too Many Requests) response code as described in
 [RFC6585].  A client that receives a 429 response SHOULD decrease its
 query rate and honor the Retry-After header field if one is present.
 Servers may place stricter limits upon clients that do not honor the
 Retry-After header.  Optionally, the server MAY include additional
 information regarding the rate limiting in the HTTP entity body.

Newton, et al. Standards Track [Page 7] RFC 7480 RDAP over HTTP March 2015

 Note that this is not a defense against denial-of-service (DoS)
 attacks, since a malicious client could ignore the code and continue
 to send queries at a high rate.  A server might use another response
 code if it did not wish to reveal to a client that rate limiting is
 the reason for the denial of a reply.

5.6. Cross-Origin Resource Sharing (CORS)

 When responding to queries, it is RECOMMENDED that servers use the
 Access-Control-Allow-Origin header field, as specified by
 [W3C.REC-cors-20140116].  A value of "*" is suitable when RDAP is
 used for public resources.
 This header (often called the CORS header) helps in-browser web
 applications by lifting the "same-origin" restriction (i.e., a
 browser may load RDAP client code from one web server but query
 others for RDAP data).
 By default, browsers do not send cookies when cross origin requests
 are allowed.  Setting the Access-Control-Allow-Credentials header
 field to "true" will send cookies.  Use of the
 Access-Control-Allow-Credentials header field is NOT RECOMMENDED.

6. Extensibility

 For extensibility purposes, this document defines an IANA registry
 for prefixes used in JSON [RFC7159] data serialization and URI path
 segments (see Section 8).
 Prefixes and identifiers SHOULD only consist of the alphabetic US-
 ASCII characters A through Z in both uppercase and lowercase, the
 numerical digits 0 through 9, and the underscore character, and they
 SHOULD NOT begin with an underscore character, numerical digit, or
 the characters "xml".  The following describes the production of JSON
 names in ABNF [RFC5234].
   name = ALPHA *( ALPHA / DIGIT / "_" )
                     Figure 1: ABNF for JSON Names
 This restriction is a union of the Ruby programming language
 identifier syntax and the XML element name syntax and has two
 purposes.  First, client implementers using modern programming
 languages such as Ruby or Java can use libraries that automatically
 promote JSON names to first-order object attributes or members.
 Second, a clean mapping between JSON and XML is easy to accomplish
 using these rules.

Newton, et al. Standards Track [Page 8] RFC 7480 RDAP over HTTP March 2015

7. Security Considerations

 This document does not pose strong security requirements to the RDAP
 protocol.  However, it does not restrict against the use of security
 mechanisms offered by the HTTP protocol.  It does require that RDAP
 clients and servers MUST support HTTPS.
 This document makes recommendations for server implementations
 against DoS (Section 5.5) and interoperability with existing security
 mechanisms in HTTP clients (Section 5.6).
 Additional security considerations to the RDAP protocol are covered
 in [RFC7481].

8. IANA Considerations

8.1. RDAP Extensions Registry

 IANA has created a new category in the protocol registries labeled
 "Registration Data Access Protocol (RDAP)", and within that category,
 has established a URL-referenceable, stand-alone registry labeled
 "RDAP Extensions".  The purpose of this registry is to ensure
 uniqueness of extension identifiers.  The extension identifier is
 used as a prefix in JSON names and as a prefix of path segments in
 RDAP URLs.
 The production rule for these identifiers is specified in Section 6.
 In accordance with [RFC5226], the IANA policy for assigning new
 values, shall be Specification Required: values and their meanings
 must be documented in an RFC or in some other permanent and readily
 available reference, in sufficient detail that interoperability
 between independent implementations is possible.
 The following is a template for an RDAP extension registration:
    Extension identifier: the identifier of the extension
    Registry operator: the name of the registry operator
    Published specification: RFC number, bibliographical reference, or
    URL to a permanent and readily available specification
    Person & email address to contact for further information: The
    names and email addresses of individuals to contact regarding this
    registry entry

Newton, et al. Standards Track [Page 9] RFC 7480 RDAP over HTTP March 2015

    Intended usage: brief reasons for this registry entry (as defined
    by [RFC5226]).
 The following is an example of a registration in the RDAP extension
 registry:
    Extension identifier: lunarNic
    Registry operator: The Registry of the Moon, LLC
    Published specification: http://www.example/moon_apis/rdap
    Person & email address to contact for further information:
    Professor Bernardo de la Paz <berny@moon.example>
    Intended usage: COMMON

9. Internationalization Considerations

9.1. URIs and IRIs

 Clients can use Internationalized Resource Identifiers (IRIs)
 [RFC3987] for internal use as they see fit but MUST transform them to
 URIs [RFC3986] for interaction with RDAP servers.  RDAP servers MUST
 use URIs in all responses, and again clients can transform these URIs
 to IRIs for internal use as they see fit.

9.2. Language Identifiers in Queries and Responses

 Under most scenarios, clients requesting data will not signal that
 the data be returned in a particular language or script.  On the
 other hand, when servers return data and have knowledge that the data
 is in a language or script, the data SHOULD be annotated with
 language identifiers whenever they are available, thus allowing
 clients to process and display the data accordingly.
 [RFC7483] provides such a mechanism.

9.3. Language Identifiers in HTTP Headers

 Given the description of the use of language identifiers in
 Section 9.2, unless otherwise specified, servers SHOULD ignore the
 HTTP [RFC7231] Accept-Language header field when formulating HTTP
 entity responses, so that clients do not conflate the Accept-Language
 header with the 'lang' values in the entity body.

Newton, et al. Standards Track [Page 10] RFC 7480 RDAP over HTTP March 2015

 However, servers MAY return language identifiers in the Content-
 Language header field so as to inform clients of the intended
 language of HTTP layer messages.

10. References

10.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997,
            <http://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, January 2005,
            <http://www.rfc-editor.org/info/rfc3986>.
 [RFC3987]  Duerst, M. and M. Suignard, "Internationalized Resource
            Identifiers (IRIs)", RFC 3987, January 2005,
            <http://www.rfc-editor.org/info/rfc3987>.
 [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
            IANA Considerations Section in RFCs", BCP 26, RFC 5226,
            May 2008, <http://www.rfc-editor.org/info/rfc5226>.
 [RFC6585]  Nottingham, M. and R. Fielding, "Additional HTTP Status
            Codes", RFC 6585, April 2012,
            <http://www.rfc-editor.org/info/rfc6585>.
 [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
            Protocol (HTTP/1.1): Message Syntax and Routing", RFC
            7230, June 2014, <http://www.rfc-editor.org/info/rfc7230>.
 [RFC7231]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
            Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
            June 2014, <http://www.rfc-editor.org/info/rfc7231>.
 [RFC7481]  Hollenbeck, S. and N. Kong, "Security Services for the
            Registration Data Access Protocol (RDAP)", RFC 7481,
            February 2015, <http://www.rfc-editor.org/info/rfc7481>.
 [RFC7482]  Newton, A. and S. Hollenbeck, "Registration Data Access
            Protocol (RDAP) Query Format", RFC 7482, February 2015,
            <http://www.rfc-editor.org/info/rfc7482>.
 [RFC7483]  Newton, A. and S. Hollenbeck, "JSON Responses for the
            Registration Data Access Protocol (RDAP)", RFC 7483,
            February 2015, <http://www.rfc-editor.org/info/rfc7483>.

Newton, et al. Standards Track [Page 11] RFC 7480 RDAP over HTTP March 2015

 [RFC7484]  Blanchet, M., "Finding the Authoritative Registration Data
            (RDAP) Service", RFC 7484, February 2015,
            <http://www.rfc-editor.org/info/rfc7484>.
 [W3C.REC-cors-20140116]
            Kesteren, A., "Cross-Origin Resource Sharing", W3C
            Recommendation, REC-cors-20140116, January 2014,
            <http://www.w3.org/TR/2014/REC-cors-20140116/>.

10.2. Informative References

 [REST]     Fielding, R. and R. Taylor, "Principled Design of the
            Modern Web Architecture", ACM Transactions on Internet
            Technology, Vol. 2, No. 2, May 2002.
 [RFC3912]  Daigle, L., "WHOIS Protocol Specification", RFC 3912,
            September 2004, <http://www.rfc-editor.org/info/rfc3912>.
 [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
            Specifications: ABNF", STD 68, RFC 5234, January 2008,
            <http://www.rfc-editor.org/info/rfc5234>.
 [RFC5890]  Klensin, J., "Internationalized Domain Names for
            Applications (IDNA): Definitions and Document Framework",
            RFC 5890, August 2010,
            <http://www.rfc-editor.org/info/rfc5890>.
 [RFC7159]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
            Interchange Format", RFC 7159, March 2014,
            <http://www.rfc-editor.org/info/rfc7159>.
 [SAC-051]  Piscitello, D., Ed., "SSAC Report on Domain Name WHOIS
            Terminology and Structure", A report from the ICANN
            Security and Stability Advisory Committee (SSAC),
            September 2011.
 [lacnic-joint-whois]
            LACNIC, "Joint Whois", December 2005,
            <ftp://anonymous@ftp.registro.br/pub/gter/
            gter20/02-jwhois-lacnic.pdf>.

Newton, et al. Standards Track [Page 12] RFC 7480 RDAP over HTTP March 2015

Appendix A. Protocol Example

 To demonstrate typical behavior of an RDAP client and server, the
 following is an example of an exchange, including a redirect.  The
 data in the response has been elided for brevity, as the data format
 is not described in this document.  The media type used here is
 described in [RFC7483].
 An example of an RDAP client and server exchange:
   Client:
       <TCP connect to rdap.example.com port 80>
       GET /rdap/ip/203.0.113.0/24 HTTP/1.1
       Host: rdap.example.com
       Accept: application/rdap+json
   rdap.example.com:
       HTTP/1.1 301 Moved Permanently
       Location: http://rdap-ip.example.com/rdap/ip/203.0.113.0/24
       Content-Length: 0
       Content-Type: application/rdap+json
       <TCP disconnect>
   Client:
       <TCP connect to rdap-ip.example.com port 80>
       GET /rdap/ip/203.0.113.0/24 HTTP/1.1
       Host:  rdap-ip.example.com
       Accept: application/rdap+json
   rdap-ip.example.com:
       HTTP/1.1 200 OK
       Content-Type: application/rdap+json
       Content-Length: 9001
       { ... }
       <TCP disconnect>

Appendix B. Cache Busting

 Some HTTP [RFC7230] cache infrastructures do not adhere to caching
 standards adequately and could cache responses longer than is
 intended by the server.  To overcome these issues, clients can use an
 ad hoc and improbably used query parameter with a random value of
 their choosing.  As Section 4.3 instructs servers to ignore unknown
 parameters, this is compatible with the RDAP definition.

Newton, et al. Standards Track [Page 13] RFC 7480 RDAP over HTTP March 2015

 An example of using an unknown query parameter to bust caches:
   http://example.com/ip/192.0.2.0?__fuhgetaboutit=xyz123
 Use of an unknown parameter to overcome misbehaving caches is not
 part of any specification and is offered here for informational
 purposes.

Appendix C. Bootstrapping and Redirection

 The traditional deployment model of WHOIS [RFC3912] does not provide
 a mechanism for determining the authoritative source for information.
 Some approaches have been implemented in the past, most notably the
 Joint WHOIS [lacnic-joint-whois] initiative.  However, among other
 shortcomings, Joint WHOIS is implemented using proxies and server-
 side referrals.
 These issues are solved in RDAP using HTTP redirects and
 bootstrapping.  Bootstrapping is discussed in [RFC7484].  In
 constrained environments, the processes outlined in [RFC7484] may not
 be viable, and there may be the need for servers acting as a
 "redirector".
 Redirector servers issue HTTP redirects to clients using a
 redirection table informed by [RFC7484].  Figure 2 diagrams a client
 using a redirector for bootstrapping.
                                    REDIRECTOR       ARIN
                                    RDAP             RDAP
                                      .               .
                                      |               |
      Q: 23.1.1.1? -----------------> |               |
                                      |               |
         <---------- HTTP 301 --------|               |
                ('Try ARIN RDAP')     |               |
                                      |               |
                                                      |
        Q: 23.1.1.1? -------------------------------> |
                                                      |
           <---------- HTTP 200 --------------------- |
                  (JSON response is returned)         |
                                                      |
                                                      |
                                                      .
               Figure 2: Querying RDAP Data for 23.1.1.1

Newton, et al. Standards Track [Page 14] RFC 7480 RDAP over HTTP March 2015

 In some cases, particularly sub-delegations made between Regional
 Internet Registries (RIRs) known as "ERX space" and transfers of
 networks, multiple HTTP redirects will be issued.  Figure 3 shows
 such a scenario.
                        REDIRECTOR  LACNIC           ARIN
                        RDAP        RDAP             RDAP
                          .           .               .
      Q: 23.1.1.1? ---->  |           |               |
                          |           |               |
        <-- HTTP 301 ---  |           |               |
       ('Try LACNIC')     |           |               |
                          |           |               |
                          |           |               |
      Q: 23.1.1.1? -----------------> |               |
                                      |               |
         <---------- HTTP 301 --------|               |
                ('Try ARIN RDAP')     |               |
                                      |               |
                                                      |
        Q: 23.1.1.1? -------------------------------> |
                                                      |
           <---------- HTTP 200 --------------------- |
                  (JSON response is returned)         |
                                                      |
                                                      |
                                                      .
    Figure 3: Querying RDAP Data for Data That Has Been Transferred

Acknowledgements

 John Levine provided text to tighten up the Accept header field usage
 and the text for the section on 429 responses.
 Marc Blanchet provided some clarifying text regarding the use of URLs
 with redirects, as well as very useful feedback during Working Group
 Last Call (WGLC).
 Normative language reviews were provided by Murray S. Kucherawy,
 Andrew Sullivan, Tom Harrison, Ed Lewis, and Alexander Mayrhofer.
 Jean-Phillipe Dionne provided text for the Security Considerations
 section.
 The concept of the redirector server informatively discussed in
 Appendix C was documented by Carlos M.  Martinez and Gerardo Rada of

Newton, et al. Standards Track [Page 15] RFC 7480 RDAP over HTTP March 2015

 LACNIC and Linlin Zhou of CNNIC and subsequently incorporated into
 this document.
 This document is the work product of the IETF's WEIRDS working group,
 of which Olaf Kolkman and Murray Kucherawy were chairs.

Authors' Addresses

 Andrew Lee Newton
 American Registry for Internet Numbers
 3635 Concorde Parkway
 Chantilly, VA  20151
 United States
 EMail: andy@arin.net
 URI:   http://www.arin.net
 Byron J. Ellacott
 Asia Pacific Network Information Centre
 6 Cordelia Street
 South Brisbane  QLD 4101
 Australia
 EMail: bje@apnic.net
 URI:   http://www.apnic.net
 Ning Kong
 China Internet Network Information Center
 4 South 4th Street, Zhongguancun, Haidian District
 Beijing  100190
 China
 Phone: +86 10 5881 3147
 EMail: nkong@cnnic.cn

Newton, et al. Standards Track [Page 16]

Internet Engineering Task Force (IETF) S. Hollenbeck Request for Comments: 7481 Verisign Labs Category: Standards Track N. Kong ISSN: 2070-1721 CNNIC

                                                            March 2015
 Security Services for the Registration Data Access Protocol (RDAP)

Abstract

 The Registration Data Access Protocol (RDAP) provides "RESTful" web
 services to retrieve registration metadata from Domain Name and
 Regional Internet Registries.  This document describes information
 security services, including access control, authentication,
 authorization, availability, data confidentiality, and data integrity
 for RDAP.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc7481.

Copyright Notice

 Copyright (c) 2015 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Hollenbeck & Kong Standards Track [Page 1] RFC 7481 RDAP Security Services March 2015

Table of Contents

 1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
 2.  Conventions Used in This Document . . . . . . . . . . . . . .   2
   2.1.  Acronyms and Abbreviations  . . . . . . . . . . . . . . .   3
 3.  Information Security Services and RDAP  . . . . . . . . . . .   3
   3.1.  Access Control  . . . . . . . . . . . . . . . . . . . . .   3
   3.2.  Authentication  . . . . . . . . . . . . . . . . . . . . .   3
     3.2.1.  Federated Authentication  . . . . . . . . . . . . . .   4
   3.3.  Authorization . . . . . . . . . . . . . . . . . . . . . .   6
   3.4.  Availability  . . . . . . . . . . . . . . . . . . . . . .   6
   3.5.  Data Confidentiality  . . . . . . . . . . . . . . . . . .   7
   3.6.  Data Integrity  . . . . . . . . . . . . . . . . . . . . .   7
 4.  Privacy Threats Associated with Registration Data . . . . . .   8
 5.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
 6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
   6.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
   6.2.  Informative References  . . . . . . . . . . . . . . . . .  11
 Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  13
 Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1. Introduction

 The Registration Data Access Protocol (RDAP) is specified in multiple
 documents, including "Registration Data Access Protocol (RDAP) Query
 Format" [RFC7482], "JSON Responses for the Registration Data Access
 Protocol (RDAP)" [RFC7483], and "HTTP Usage in the Registration Data
 Access Protocol (RDAP)" [RFC7480].
 One goal of RDAP is to provide security services that do not exist in
 the WHOIS [RFC3912] protocol, including access control,
 authentication, authorization, availability, data confidentiality,
 and data integrity.  This document describes how each of these
 services is achieved by RDAP using features that are available in
 other protocol layers.  Additional or alternative mechanisms can be
 added in the future.  Where applicable, informative references to
 requirements for a WHOIS replacement service [RFC3707] are noted.

2. Conventions Used in This Document

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].

Hollenbeck & Kong Standards Track [Page 2] RFC 7481 RDAP Security Services March 2015

2.1. Acronyms and Abbreviations

    DNR: Domain Name Registry
    HTTP: Hypertext Transfer Protocol
    JSON: JavaScript Object Notation
    RDAP: Registration Data Access Protocol
    RIR: Regional Internet Registry
    TLS: Transport Layer Security

3. Information Security Services and 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,
 and data integrity.  A description of each of these security services
 can be found in "Internet Security Glossary, Version 2" [RFC4949].
 No requirements have been identified for other security services.

3.1. Access Control

 WHOIS does not include specific features to control access to
 registration information.  As described in the following sections,
 RDAP includes features to identify, authenticate, and authorize
 clients, allowing server operators to control access to information
 based on a client's identity and associated authorizations.
 Information returned to a client can be clearly marked with a status
 value (see Section 10.2.2 of [RFC7483]) that identifies the access
 granted to the client.

3.2. Authentication

 This section describes security authentication mechanisms and the
 need for authorization policies to include them.  It describes
 requirements for the implementations of clients and servers but does
 not dictate the policies of server operators.  For example, a server
 operator with no policy regarding differentiated or tiered access to
 data will have no authorization mechanisms and will have no need for
 any type of authentication.  A server operator with policies on
 differentiated access will have to construct an authorization scheme
 and will need to follow the specified authentication requirements.

Hollenbeck & Kong Standards Track [Page 3] RFC 7481 RDAP Security Services March 2015

 WHOIS does not provide features to identify and authenticate clients.
 As noted in Section 3.1.4.2 of "Cross Registry Internet Service
 Protocol (CRISP) Requirements" [RFC3707], there is utility in
 allowing server operators to offer "varying degrees of access
 depending on policy and need."  Clients have to be identified and
 authenticated to provide that utility.
 RDAP's authentication framework needs to accommodate anonymous access
 as well as verification of identities using a range of authentication
 methods and credential services.  To that end, RDAP clients and
 servers MUST implement the authentication framework specified in
 "Hypertext Transfer Protocol (HTTP/1.1): Authentication" [RFC7235].
 The "basic" scheme can be used to send a client's user name and
 password to a server in plaintext, base64-encoded form.  The "digest"
 scheme can be used to authenticate a client without exposing the
 client's plaintext password.  If the "basic" scheme is used, HTTP
 over TLS [RFC2818] MUST be used to protect the client's credentials
 from disclosure while in transit (see Section 3.5).
 Servers MUST support either Basic or Digest authentication; they are
 not required to support both.  Clients MUST support both to
 interoperate with servers that support one or the other.  Servers may
 provide a login page that triggers HTTP authentication.  Clients
 should continue sending the HTTP authentication header once they
 receive an initial 401 (Unauthorized) response from the HTTP server
 as long as the scheme portion of the URL doesn't change.
 The Transport Layer Security protocol [RFC5246] includes an optional
 feature to identify and authenticate clients who possess and present
 a valid X.509 digital certificate [RFC5280].  Support for this
 feature is OPTIONAL.
 RDAP does not impose any unique server authentication requirements.
 The server authentication provided by TLS fully addresses the needs
 of RDAP.  In general, transports for RDAP must either provide a
 TLS-protected transport (e.g., HTTPS) or a mechanism that provides an
 equivalent level of server authentication.
 Work on HTTP authentication methods continues.  RDAP is designed to
 be agile enough to support additional methods as they are defined.

3.2.1. Federated Authentication

 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

Hollenbeck & Kong Standards Track [Page 4] RFC 7481 RDAP Security Services March 2015

 credential management complexity.  RDAP MAY include a federated
 authentication mechanism that permits a client to access multiple
 RDAP servers in the same federation with one credential.
 Federated authentication mechanisms used by RDAP MUST be fully
 supported by HTTP.  OAuth, OpenID, Security Assertion Markup Language
 (SAML), and mechanisms based on Certification Authority (CA) are all
 possible approaches to provide federated authentication.  At the time
 of this document's publication, negotiation or advertisement of
 federated authentication services is still an undefined mechanism by
 the noted federated authentication protocols.  Developing this
 mechanism is beyond the scope of this document.
 The OAuth authorization framework [RFC6749] 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 OAuth, multiple RDAP servers can form a federation, and the
 clients can access any server in the same federation by providing one
 credential registered in any server in that federation.  The OAuth
 authorization framework is designed for use with HTTP and thus can be
 used with RDAP.
 OpenID [OpenID] is a decentralized single sign-on authentication
 system that allows users to log in at multiple web sites with one ID
 instead of having to create multiple unique accounts.  An end user
 can freely choose which OpenID provider to use and can preserve their
 Identifier if they switch OpenID providers.
 Note that OAuth and OpenID do not consistently require data
 confidentiality services to protect interactions between providers
 and consumers.  HTTP over TLS [RFC2818] can be used as needed to
 provide protection against man-in-the-middle attacks.
 SAML 2.0 [SAML] is an XML-based protocol that can be used to
 implement web-based authentication and authorization services,
 including single sign on.  It uses security tokens containing
 assertions to exchange information about an end user between an
 identity provider and a service provider.
 The Transport Layer Security protocol describes the specification of
 a client certificate in Section 7.4.6 of [RFC5246].  Clients who
 possess and present a valid X.509 digital certificate, issued by a
 CA, could be identified and authenticated by a server who trusts the
 corresponding CA.  A certificate authentication method can be used to
 achieve federated authentication in which multiple RDAP servers all
 trust the same CAs, and then any client with a certificate issued by
 a trusted CA can access any RDAP server in the federation.  This

Hollenbeck & Kong Standards Track [Page 5] RFC 7481 RDAP Security Services March 2015

 certificate-based mechanism is supported by HTTPS and can be used
 with RDAP.

3.3. Authorization

 WHOIS does not provide services to grant different levels of access
 to clients based on a client's authenticated identity.  As noted in
 Section 3.1.4.2 of "Cross Registry Internet Service Protocol (CRISP)
 Requirements" [RFC3707], there is utility in allowing server
 operators to offer "varying degrees of access depending on policy and
 need."  Access control decisions can be made once a client's identity
 has been established and authenticated (see Section 3.2).
 Server operators MAY offer varying degrees of access depending on
 policy and need in conjunction with the authentication methods
 described in Section 3.2.  If such varying degrees of access are
 supported, an RDAP server MUST provide granular access controls (that
 is, per registration data object) in order to implement authorization
 policies.  Some examples:
  1. Clients will be allowed access only to data for which they have a

relationship.

  1. Unauthenticated or anonymous access status may not yield any

contact information.

  1. Full access may be granted to a special group of authenticated

clients.

 The type of access allowed by a server will most likely vary from one
 operator to the next.  A description of the response privacy
 considerations associated with different levels of authorization can
 be found in Section 13 of [RFC7483].

3.4. Availability

 An RDAP service has to be available to be useful.  There are no RDAP-
 unique requirements to provide availability, but as a general
 security consideration, a service operator needs to be aware of the
 issues associated with denial of service.  A thorough reading of
 "Internet Denial-of-Service Considerations" [RFC4732] is advised.
 An RDAP service MAY use an HTTP throttling mechanism to limit the
 number of queries that a single client can send in a given period of
 time.  If used, the server SHOULD return an HTTP 429 (Too Many
 Requests) response code as described in "Additional HTTP Status
 Codes" [RFC6585].  A client that receives a 429 response SHOULD
 decrease its query rate and honor the Retry-After header field if one

Hollenbeck & Kong Standards Track [Page 6] RFC 7481 RDAP Security Services March 2015

 is present.  Note that this is not a defense against
 denial-of-service attacks, since a malicious client could ignore the
 code and continue to send queries at a high rate.  A server might use
 another response code if it did not wish to reveal to a client that
 rate limiting is the reason for the denial of a reply.

3.5. Data Confidentiality

 WHOIS does not provide the ability to protect data from inadvertent
 disclosure while in transit.  RDAP uses HTTP over TLS [RFC2818] to
 provide that protection by encrypting all traffic sent on the
 connection between client and server.  HTTP over TLS MUST be used to
 protect all client-server exchanges unless operational constraints
 make it impossible to meet this requirement.  It is also possible to
 encrypt discrete objects (such as command path segments and JSON-
 encoded response objects) at one endpoint, send them to the other
 endpoint via an unprotected transport protocol, and decrypt the
 object on receipt.  Encryption algorithms as described in "Internet
 Security Glossary, Version 2" [RFC4949] are commonly used to provide
 data confidentiality at the object level.
 There are no current requirements for object-level data
 confidentiality using encryption.  Support for this feature could be
 added to RDAP in the future.
 As noted in Section 3.2, the HTTP "basic" authentication scheme can
 be used to authenticate a client.  When this scheme is used, HTTP
 over TLS MUST be used to protect the client's credentials from
 disclosure while in transit.  If the policy of the server operator
 requires encryption to protect client-server data exchanges (such as
 to protect non-public data that cannot be accessed without client
 identification and authentication), HTTP over TLS MUST be used to
 protect those exchanges.
 A description of privacy threats that can be addressed with
 confidentiality services can be found in Section 4.  Section 10.2.2
 of [RFC7483] describes status values that can be used to describe
 operator actions used to protect response data from disclosure to
 unauthorized clients.

3.6. Data Integrity

 WHOIS does not provide the ability to protect data from modification
 while in transit.  Web services such as RDAP commonly use HTTP over
 TLS [RFC2818] to provide that protection by using a keyed Message
 Authentication Code (MAC) to detect modifications.  It is also
 possible to sign discrete objects (such as command path segments and
 JSON-encoded response objects) at one endpoint, send them to the

Hollenbeck & Kong Standards Track [Page 7] RFC 7481 RDAP Security Services March 2015

 other endpoint via a transport protocol, and validate the signature
 of the object on receipt.  Digital signature algorithms as described
 in "Internet Security Glossary, Version 2" [RFC4949] are commonly
 used to provide data integrity at the object level.
 There are no current requirements for object-level data integrity
 using digital signatures.  Support for this feature could be added to
 RDAP in the future.
 The most specific need for this service is to provide assurance that
 HTTP 30x redirection hints [RFC7231] and response elements returned
 from the server are not modified while in transit.  If the policy of
 the server operator requires message integrity for client-server data
 exchanges, HTTP over TLS MUST be used to protect those exchanges.

4. Privacy Threats Associated with Registration Data

 Registration data has historically included personal data about
 registrants.  WHOIS services have historically made this information
 available to the public, creating a privacy risk by revealing the
 personal details of registrants.  WHOIS services have not had the
 benefit of authentication or access control mechanisms to gate access
 to registration data.  As a result of this, proxy and privacy
 services have arisen to shield the identities of registrants.
 The standardization of RDAP does not change or impact the data that
 operators may require to be collected from registrants, but it
 provides support for a number of mechanisms that may be used to
 mitigate privacy threats to registrants should operators choose to
 use them.
 RDAP includes mechanisms that can be used to authenticate clients,
 allowing servers to support tiered access based on local policy.
 This means that all registration data need no longer be public, and
 personal data or data that may be considered more sensitive can have
 its access restricted to specifically privileged clients.
 RDAP data structures allow servers to indicate via status values when
 data returned to clients has been made private, redacted, obscured,
 or registered by a proxy.  "Private" means that the data is not
 designated for public consumption.  "Redacted" means that some
 registration data fields are not being made available.  "Obscured"
 means that data has been altered for the purposes of not readily
 revealing the actual registration information.  One option that
 operators have available to them to reduce privacy risks to
 registrants is to adopt policies that make use of these status values
 to restrict the registrant data shared with any or all clients

Hollenbeck & Kong Standards Track [Page 8] RFC 7481 RDAP Security Services March 2015

 according to the sensitivity of the data, the privileges of the
 clients, or some other heuristics.
 RDAP uses the jCard [RFC7095] standard format for entity
 representation.  Operators may find that many of the jCard fields are
 irrelevant for registry operation purposes or that they have no
 reason to collect information from registrants that would correspond
 to certain fields.  Operators wishing to reduce privacy risks for
 registrants may restrict which information they collect and/or which
 fields they populate in responses.
 In addition to privacy risks to registrants, there are also potential
 privacy risks for those who query registration data.  For example,
 the fact that a registry employee performs a particular query may
 reveal information about the employee's activities that he or she
 would have preferred to keep private.  RDAP supports the use of HTTP
 over TLS to provide privacy protection for those querying registrant
 data as well as registrants, unless operational constraints make it
 impossible to meet this requirement.

5. Security Considerations

 One of the goals of RDAP is to provide security services that do not
 exist in the WHOIS protocol.  This document describes the security
 services provided by RDAP and associated protocol layers, including
 authentication, authorization, availability, data confidentiality,
 and data integrity.  Non-repudiation services were also considered
 and ultimately rejected due to a lack of requirements.  There are,
 however, currently deployed WHOIS servers that can return signed
 responses that provide non-repudiation with proof of origin.  RDAP
 might need to be extended to provide this service in the future.
 As an HTTP-based protocol, RDAP is susceptible to code injection
 attacks.  Code injection refers to adding code into a computer system
 or program to alter the course of execution.  There are many types of
 code injection, including SQL injection, dynamic variable or function
 injection, include-file injection, shell injection, and HTML-script
 injection, among others.  Data confidentiality and integrity services
 provide a measure of defense against man-in-the-middle injection
 attacks, but vulnerabilities in both client- and server-side software
 make it possible for injection attacks to succeed.  Consistently
 checking and validating server credentials can help detect
 man-in-the-middle attacks.
 As noted in Section 3.2.1, digital certificates can be used to
 implement federated authentication.  There is a risk of too
 promiscuous, or even rogue, CAs being included in the list of
 acceptable CAs that the TLS server sends the client as part of the

Hollenbeck & Kong Standards Track [Page 9] RFC 7481 RDAP Security Services March 2015

 TLS client-authentication handshake and lending the appearance of
 trust to certificates signed by those CAs.  Periodic monitoring of
 the list of CAs that RDAP servers trust for client authentication can
 help reduce this risk.
 The Transport Layer Security protocol [RFC5246] includes a null
 cipher suite that does not encrypt data and thus does not provide
 data confidentiality.  This option MUST NOT be used when data
 confidentiality services are needed.  Additional considerations for
 secure use of TLS are described in [SECURE-TLS-DTLS].
 Data integrity services are sometimes mistakenly associated with
 directory service operational policy requirements focused on data
 accuracy.  "Accuracy" refers to the truthful association of data
 elements (such as names, addresses, and telephone numbers) in the
 context of a particular directory object (such as a domain name).
 Accuracy requirements are out of scope for this protocol.
 Additional security considerations are described in the
 specifications for HTTP [RFC7231], HTTP Basic and Digest access
 authentication [RFC7235], HTTP over TLS [RFC2818], and additional
 HTTP status codes [RFC6585].  Security considerations for federated
 authentication systems can be found in the OAuth [RFC6749] and OpenID
 [OpenID] specifications.

6. References

6.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997,
            <http://www.rfc-editor.org/info/rfc2119>.
 [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000,
            <http://www.rfc-editor.org/info/rfc2818>.
 [RFC6585]  Nottingham, M. and R. Fielding, "Additional HTTP Status
            Codes", RFC 6585, April 2012,
            <http://www.rfc-editor.org/info/rfc6585>.
 [RFC7231]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
            Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
            June 2014, <http://www.rfc-editor.org/info/rfc7231>.
 [RFC7235]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
            Protocol (HTTP/1.1): Authentication", RFC 7235, June 2014,
            <http://www.rfc-editor.org/info/rfc7235>.

Hollenbeck & Kong Standards Track [Page 10] RFC 7481 RDAP Security Services March 2015

 [RFC7480]  Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
            Registration Data Access Protocol (RDAP)", RFC 7480, March
            2015, <http://www.rfc-editor.org/info/rfc7480>.
 [RFC7482]  Newton, A. and S. Hollenbeck, "Registration Data Access
            Protocol (RDAP) Query Format", RFC 7482, March 2015,
            <http://www.rfc-editor.org/info/rfc7482>.
 [RFC7483]  Newton, A. and S. Hollenbeck, "JSON Responses for the
            Registration Data Access Protocol (RDAP)", RFC 7483, March
            2015, <http://www.rfc-editor.org/info/rfc7483>.

6.2. Informative References

 [OpenID]   OpenID Foundation, "OpenID Authentication 2.0 - Final",
            December 2007, <http://specs.openid.net/auth/2.0>.
 [RFC3707]  Newton, A., "Cross Registry Internet Service Protocol
            (CRISP) Requirements", RFC 3707, February 2004,
            <http://www.rfc-editor.org/info/rfc3707>.
 [RFC3912]  Daigle, L., "WHOIS Protocol Specification", RFC 3912,
            September 2004, <http://www.rfc-editor.org/info/rfc3912>.
 [RFC4732]  Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
            Denial-of-Service Considerations", RFC 4732, December
            2006, <http://www.rfc-editor.org/info/rfc4732>.
 [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2", FYI
            36, RFC 4949, August 2007,
            <http://www.rfc-editor.org/info/rfc4949>.
 [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
            (TLS) Protocol Version 1.2", RFC 5246, August 2008,
            <http://www.rfc-editor.org/info/rfc5246>.
 [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
            Housley, R., and W. Polk, "Internet X.509 Public Key
            Infrastructure Certificate and Certificate Revocation List
            (CRL) Profile", RFC 5280, May 2008,
            <http://www.rfc-editor.org/info/rfc5280>.
 [RFC6749]  Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
            RFC 6749, October 2012,
            <http://www.rfc-editor.org/info/rfc6749>.
 [RFC7095]  Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095,
            January 2014, <http://www.rfc-editor.org/info/rfc7095>.

Hollenbeck & Kong Standards Track [Page 11] RFC 7481 RDAP Security Services March 2015

 [SAML]     OASIS, "Security Assertion Markup Language (SAML) v2.0",
            March 2005, <https://www.oasis-open.org/
            standards#samlv2.0>.
 [SECURE-TLS-DTLS]
            Sheffer, Y., Holz, R., and P. Saint-Andre,
            "Recommendations for Secure Use of TLS and DTLS", Work in
            Progress, draft-ietf-uta-tls-bcp-09, February 2015.

Hollenbeck & Kong Standards Track [Page 12] RFC 7481 RDAP Security Services March 2015

Acknowledgements

 The authors would like to acknowledge the following individuals for
 their contributions to this document: Richard Barnes, Marc Blanchet,
 Alissa Cooper, Ernie Dainow, Spencer Dawkins, Jean-Philippe Dionne,
 Byron Ellacott, Stephen Farrell, Tony Hansen, Peter Koch, Murray
 Kucherawy, Barry Leiba, Andrew Newton, and Linlin Zhou.

Authors' Addresses

 Scott Hollenbeck
 Verisign Labs
 12061 Bluemont Way
 Reston, VA  20190
 United States
 EMail: shollenbeck@verisign.com
 URI:   http://www.verisignlabs.com/
 Ning Kong
 China Internet Network Information Center
 4 South 4th Street, Zhongguancun, Haidian District
 Beijing  100190
 China
 Phone: +86 10 5881 3147
 EMail: nkong@cnnic.cn

Hollenbeck & Kong Standards Track [Page 13]

Internet Engineering Task Force (IETF) S. Hollenbeck Request for Comments: 9082 Verisign Labs STD: 95 A. Newton Obsoletes: 7482 AWS Category: Standards Track June 2021 ISSN: 2070-1721

       Registration Data Access Protocol (RDAP) Query Format

Abstract

 This document describes uniform patterns to construct HTTP URLs that
 may be used to retrieve registration information from registries
 (including both Regional Internet Registries (RIRs) and Domain Name
 Registries (DNRs)) using "RESTful" web access patterns.  These
 uniform patterns define the query syntax for the Registration Data
 Access Protocol (RDAP).  This document obsoletes RFC 7482.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 https://www.rfc-editor.org/info/rfc9082.

Copyright Notice

 Copyright (c) 2021 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (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 Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1.  Introduction
 2.  Conventions Used in This Document
   2.1.  Acronyms and Abbreviations
 3.  Path Segment Specification
   3.1.  Lookup Path Segment Specification
     3.1.1.  IP Network Path Segment Specification
     3.1.2.  Autonomous System Path Segment Specification
     3.1.3.  Domain Path Segment Specification
     3.1.4.  Nameserver Path Segment Specification
     3.1.5.  Entity Path Segment Specification
     3.1.6.  Help Path Segment Specification
   3.2.  Search Path Segment Specification
     3.2.1.  Domain Search
     3.2.2.  Nameserver Search
     3.2.3.  Entity Search
 4.  Query Processing
   4.1.  Partial String Searching
   4.2.  Associated Records
 5.  Extensibility
 6.  Internationalization Considerations
   6.1.  Character Encoding Considerations
 7.  IANA Considerations
 8.  Security Considerations
 9.  References
   9.1.  Normative References
   9.2.  Informative References
 Appendix A.  Changes from RFC 7482
 Acknowledgments
 Authors' Addresses

1. Introduction

 This document describes a specification for querying registration
 data using a RESTful web service and uniform query patterns.  The
 service is implemented using the Hypertext Transfer Protocol (HTTP)
 [RFC7230] and the conventions described in [RFC7480].  These uniform
 patterns define the query syntax for the Registration Data Access
 Protocol (RDAP).  This document obsoletes RFC 7482.
 The protocol described in this specification is intended to address
 deficiencies with the WHOIS protocol [RFC3912] that have been
 identified over time, including:
  • lack of standardized command structures;
  • lack of standardized output and error structures;
  • lack of support for internationalization and localization; and
  • lack of support for user identification, authentication, and

access control.

 The patterns described in this document purposefully do not encompass
 all of the methods employed in the WHOIS and other RESTful web
 services used by the RIRs and DNRs.  The intent of the patterns
 described here is to enable queries of:
  • networks by IP address;
  • Autonomous System (AS) numbers by number;
  • reverse DNS metadata by domain;
  • nameservers by name; and
  • entities (such as registrars and contacts) by identifier.
 Server implementations are free to support only a subset of these
 features depending on local requirements.  Servers MUST return an
 HTTP 501 (Not Implemented) [RFC7231] response to inform clients of
 unsupported query types.  It is also envisioned that each registry
 will continue to maintain WHOIS and/or other RESTful web services
 specific to their needs and those of their constituencies, and the
 information retrieved through the patterns described here may
 reference such services.
 Likewise, future IETF specifications may add additional patterns for
 additional query types.  A simple pattern namespacing scheme is
 described in Section 5 to accommodate custom extensions that will not
 interfere with the patterns defined in this document or patterns
 defined in future IETF specifications.
 WHOIS services, in general, are read-only services.  Accordingly, URL
 [RFC3986] patterns specified in this document are only applicable to
 the HTTP [RFC7231] GET and HEAD methods.
 This document does not describe the results or entities returned from
 issuing the described URLs with an HTTP GET.  The specification of
 these entities is described in [RFC9083].
 Additionally, resource management, provisioning, and update functions
 are out of scope for this document.  Registries have various and
 divergent methods covering these functions, and it is unlikely a
 uniform approach is needed for interoperability.
 HTTP contains mechanisms for servers to authenticate clients and for
 clients to authenticate servers (from which authorization schemes may
 be built), so such mechanisms are not described in this document.
 Policy, provisioning, and processing of authentication and
 authorization are out of scope for this document as deployments will
 have to make choices based on local criteria.  Supported
 authentication mechanisms are described in [RFC7481].

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.

2.1. Acronyms and Abbreviations

 IDN:  Internationalized Domain Name, a fully-qualified domain name
    containing one or more labels that are intended to include one or
    more Unicode code points outside the ASCII range (cf. "domain
    name", "fully-qualified domain name", and "internationalized
    domain name" in RFC 8499 [RFC8499]).
 IDNA:  Internationalized Domain Names in Applications, a protocol for
    the handling of IDNs.  In this document, "IDNA" refers
    specifically to the version of those specifications known as
    "IDNA2008" [RFC5890].
 DNR:  Domain Name Registry or Domain Name Registrar
 NFC:  Unicode Normalization Form C [Unicode-UAX15]
 NFKC:  Unicode Normalization Form KC [Unicode-UAX15]
 RDAP:  Registration Data Access Protocol
 REST:  Representational State Transfer.  The term was first described
    in a doctoral dissertation [REST].
 RESTful:  An adjective that describes a service using HTTP and the
    principles of REST.
 RIR:  Regional Internet Registry

3. Path Segment Specification

 The base URLs used to construct RDAP queries are maintained in an
 IANA registry (the "bootstrap registry") described in [RFC7484].
 Queries are formed by retrieving an appropriate base URL from the
 registry and appending a path segment specified in either Sections
 3.1 or 3.2.  Generally, a registry or other service provider will
 provide a base URL that identifies the protocol, host, and port, and
 this will be used as a base URL that the complete URL is resolved
 against, as per Section 5 of RFC 3986 [RFC3986].  For example, if the
 base URL is "https://example.com/rdap/", all RDAP query URLs will
 begin with "https://example.com/rdap/".
 The bootstrap registry does not contain information for query objects
 that are not part of a global namespace, including entities and help.
 A base URL for an associated object is required to construct a
 complete query.  This limitation can be overcome for entities by
 using the practice described in RFC 8521 [RFC8521].
 For entities, a base URL is retrieved for the service (domain,
 address, etc.) associated with a given entity.  The query URL is
 constructed by concatenating the base URL with the entity path
 segment specified in either Sections 3.1.5 or 3.2.3.
 For help, a base URL is retrieved for any service (domain, address,
 etc.) for which additional information is required.  The query URL is
 constructed by concatenating the base URL with the help path segment
 specified in Section 3.1.6.

3.1. Lookup Path Segment Specification

 A simple lookup to determine if an object exists (or not) without
 returning RDAP-encoded results can be performed using the HTTP HEAD
 method as described in Section 4.1 of [RFC7480].
 The resource type path segments for exact match lookup are:
 'ip':  Used to identify IP networks and associated data referenced
    using either an IPv4 or IPv6 address.
 'autnum':  Used to identify Autonomous System number registrations
    and associated data referenced using an asplain Autonomous System
    number.
 'domain':  Used to identify reverse DNS (RIR) or domain name (DNR)
    information and associated data referenced using a fully qualified
    domain name.
 'nameserver':  Used to identify a nameserver information query using
    a host name.
 'entity':  Used to identify an entity information query using a
    string identifier.

3.1.1. IP Network Path Segment Specification

 Syntax:  ip/<IP address> or ip/<CIDR prefix>/<CIDR length>
 Queries for information about IP networks are of the form /ip/XXX or
 /ip/XXX/YY where the path segment following 'ip' is either an IPv4
 dotted decimal or IPv6 [RFC5952] address (i.e., XXX) or an IPv4 or
 IPv6 Classless Inter-domain Routing (CIDR) [RFC4632] notation address
 block (i.e., XXX/YY).  Semantically, the simpler form using the
 address can be thought of as a CIDR block with a prefix length of 32
 for IPv4 and a prefix length of 128 for IPv6.  A given specific
 address or CIDR may fall within multiple IP networks in a hierarchy
 of networks; therefore, this query targets the "most-specific" or
 smallest IP network that completely encompasses it in a hierarchy of
 IP networks.
 The IPv4 and IPv6 address formats supported in this query are
 described in Section 3.2.2 of RFC 3986 [RFC3986] as IPv4address and
 IPv6address ABNF definitions.  Any valid IPv6 text address format
 [RFC4291] can be used.  This includes IPv6 addresses written using
 with or without compressed zeros and IPv6 addresses containing
 embedded IPv4 addresses.  The rules to write a text representation of
 an IPv6 address [RFC5952] are RECOMMENDED.  However, the zone_id
 [RFC4007] is not appropriate in this context; therefore, the
 corresponding syntax extension in RFC 6874 [RFC6874] MUST NOT be
 used, and servers SHOULD ignore it.
 For example, the following URL would be used to find information for
 the most specific network containing 192.0.2.0:
 https://example.com/rdap/ip/192.0.2.0
 The following URL would be used to find information for the most
 specific network containing 192.0.2.0/24:
 https://example.com/rdap/ip/192.0.2.0/24
 The following URL would be used to find information for the most
 specific network containing 2001:db8::
 https://example.com/rdap/ip/2001:db8::

3.1.2. Autonomous System Path Segment Specification

 Syntax:  autnum/<autonomous system number>
 Queries for information regarding Autonomous System number
 registrations are of the form /autnum/XXX where XXX is an asplain
 Autonomous System number [RFC5396].  In some registries, registration
 of Autonomous System numbers is done on an individual number basis,
 while other registries may register blocks of Autonomous System
 numbers.  The semantics of this query are such that if a number falls
 within a range of registered blocks, the target of the query is the
 block registration and that individual number registrations are
 considered a block of numbers with a size of 1.
 For example, the following URL would be used to find information
 describing Autonomous System number 12 (a number within a range of
 registered blocks):
 https://example.com/rdap/autnum/12
 The following URL would be used to find information describing 4-byte
 Autonomous System number 65538:
 https://example.com/rdap/autnum/65538

3.1.3. Domain Path Segment Specification

 Syntax:  domain/<domain name>
 Queries for domain information are of the form /domain/XXXX, where
 XXXX is a fully qualified (relative to the root) domain name (as
 specified in [RFC0952] and [RFC1123]) in either the in-addr.arpa or
 ip6.arpa zones (for RIRs) or a fully qualified domain name in a zone
 administered by the server operator (for DNRs).  Internationalized
 Domain Names (IDNs) represented in either A-label or U-label format
 [RFC5890] are also valid domain names.  See Section 6.1 for
 information on character encoding for the U-label format.
 IDNs SHOULD NOT be represented as a mixture of A-labels and U-labels;
 that is, internationalized labels in an IDN SHOULD be either all
 A-labels or all U-labels.  It is possible for an RDAP client to
 assemble a query string from multiple independent data sources.  Such
 a client might not be able to perform conversions between A-labels
 and U-labels.  An RDAP server that receives a query string with a
 mixture of A-labels and U-labels MAY convert all the U-labels to
 A-labels, perform IDNA processing, and proceed with exact-match
 lookup.  In such cases, the response to be returned to the query
 source may not match the input from the query source.  Alternatively,
 the server MAY refuse to process the query.
 The server MAY perform the match using either the A-label or U-label
 form.  Using one consistent form for matching every label is likely
 to be more reliable.
 The following URL would be used to find information describing the
 zone serving the network 192.0.2/24:
 https://example.com/rdap/domain/2.0.192.in-addr.arpa
 The following URL would be used to find information describing the
 zone serving the network 2001:db8:1::/48:
 https://example.com/rdap/domain/1.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa
 The following URL would be used to find information for the
 blah.example.com domain name:
 https://example.com/rdap/domain/blah.example.com
 The following URL would be used to find information for the
 xn--fo-5ja.example IDN:
 https://example.com/rdap/domain/xn--fo-5ja.example

3.1.4. Nameserver Path Segment Specification

 Syntax:  nameserver/<nameserver name>
 The <nameserver name> parameter represents a fully qualified host
 name as specified in [RFC0952] and [RFC1123].  Internationalized
 names represented in either A-label or U-label format [RFC5890] are
 also valid nameserver names.  IDN processing for nameserver names
 uses the domain name processing instructions specified in
 Section 3.1.3.  See Section 6.1 for information on character encoding
 for the U-label format.
 The following URL would be used to find information for the
 ns1.example.com nameserver:
 https://example.com/rdap/nameserver/ns1.example.com
 The following URL would be used to find information for the
 ns1.xn--fo-5ja.example nameserver:
 https://example.com/rdap/nameserver/ns1.xn--fo-5ja.example

3.1.5. Entity Path Segment Specification

 Syntax:  entity/<handle>
 The <handle> parameter represents an entity (such as a contact,
 registrant, or registrar) identifier whose syntax is specific to the
 registration provider.  For example, for some DNRs, contact
 identifiers are specified in [RFC5730] and [RFC5733].
 The following URL would be used to find information for the entity
 associated with handle XXXX:
 https://example.com/rdap/entity/XXXX

3.1.6. Help Path Segment Specification

 Syntax:  help
 The help path segment can be used to request helpful information
 (command syntax, terms of service, privacy policy, rate-limiting
 policy, supported authentication methods, supported extensions,
 technical support contact, etc.) from an RDAP server.  The response
 to "help" should provide basic information that a client needs to
 successfully use the service.  The following URL would be used to
 return "help" information:
 https://example.com/rdap/help

3.2. Search Path Segment Specification

 Pattern matching semantics are described in Section 4.1.  The
 resource type path segments for search are:
 'domains':  Used to identify a domain name information search using a
    pattern to match a fully qualified domain name.
 'nameservers':  Used to identify a nameserver information search
    using a pattern to match a host name.
 'entities':  Used to identify an entity information search using a
    pattern to match a string identifier.
 RDAP search path segments are formed using a concatenation of the
 plural form of the object being searched for and an HTTP query
 string.  The HTTP query string is formed using a concatenation of the
 question mark character ('?', US-ASCII value 0x003F), a noun
 representing the JSON object property associated with the object
 being searched for, the equal sign character ('=', US-ASCII value
 0x003D), and the search pattern (this is in contrast to the more
 generic HTTP query string that allows multiple simultaneous
 parameters).  Search pattern query processing is described more fully
 in Section 4.  For the domain, nameserver, and entity objects
 described in this document, the plural object forms are "domains",
 "nameservers", and "entities".
 Detailed results can be retrieved using the HTTP GET method and the
 path segments specified here.

3.2.1. Domain Search

 Syntax:  domains?name=<domain search pattern>
 Syntax:  domains?nsLdhName=<nameserver search pattern>
 Syntax:  domains?nsIp=<nameserver IP address>
 Searches for domain information by name are specified using this
 form:
 domains?name=XXXX
 XXXX is a search pattern representing a domain name in "letters,
 digits, hyphen" (LDH) format [RFC5890].  The following URL would be
 used to find DNR information for domain names matching the
 "example*.com" pattern:
 https://example.com/rdap/domains?name=example*.com
 IDNs in U-label format [RFC5890] can also be used as search patterns
 (see Section 4).  Searches for these names are of the form
 /domains?name=XXXX, where XXXX is a search pattern representing a
 domain name in U-label format [RFC5890].  See Section 6.1 for
 information on character encoding for the U-label format.
 Searches for domain information by nameserver name are specified
 using this form:
 domains?nsLdhName=YYYY
 YYYY is a search pattern representing a host name in "letters,
 digits, hyphen" format [RFC5890].  The following URL would be used to
 search for domains delegated to nameservers matching the
 "ns1.example*.com" pattern:
 https://example.com/rdap/domains?nsLdhName=ns1.example*.com
 Searches for domain information by nameserver IP address are
 specified using this form:
 domains?nsIp=ZZZZ
 ZZZZ is an IPv4 [RFC1166] or IPv6 [RFC5952] address.  The following
 URL would be used to search for domains that have been delegated to
 nameservers that resolve to the "192.0.2.0" address:
 https://example.com/rdap/domains?nsIp=192.0.2.0

3.2.2. Nameserver Search

 Syntax:  nameservers?name=<nameserver search pattern>
 Syntax:  nameservers?ip=<nameserver IP address>
 Searches for nameserver information by nameserver name are specified
 using this form:
 nameservers?name=XXXX
 XXXX is a search pattern representing a host name in "letters,
 digits, hyphen" format [RFC5890].  The following URL would be used to
 find information for nameserver names matching the "ns1.example*.com"
 pattern:
 https://example.com/rdap/nameservers?name=ns1.example*.com
 Internationalized nameserver names in U-label format [RFC5890] can
 also be used as search patterns (see Section 4).  Searches for these
 names are of the form /nameservers?name=XXXX, where XXXX is a search
 pattern representing a nameserver name in U-label format [RFC5890].
 See Section 6.1 for information on character encoding for the U-label
 format.
 Searches for nameserver information by nameserver IP address are
 specified using this form:
 nameservers?ip=YYYY
 YYYY is an IPv4 [RFC1166] or IPv6 [RFC5952] address.  The following
 URL would be used to search for nameserver names that resolve to the
 "192.0.2.0" address:
 https://example.com/rdap/nameservers?ip=192.0.2.0

3.2.3. Entity Search

 Syntax:  entities?fn=<entity name search pattern>
 Syntax:  entities?handle=<entity handle search pattern>
 Searches for entity information by name are specified using this
 form:
 entities?fn=XXXX
 XXXX is a search pattern representing the "fn" property of an entity
 (such as a contact, registrant, or registrar) name as described in
 Section 5.1 of [RFC9083].  The following URL would be used to find
 information for entity names matching the "Bobby Joe*" pattern:
 https://example.com/rdap/entities?fn=Bobby%20Joe*
 Searches for entity information by handle are specified using this
 form:
 entities?handle=XXXX
 XXXX is a search pattern representing an entity (such as a contact,
 registrant, or registrar) identifier whose syntax is specific to the
 registration provider.  The following URL would be used to find
 information for entity handles matching the "CID-40*" pattern:
 https://example.com/rdap/entities?handle=CID-40*
 URLs MUST be properly encoded according to the rules of [RFC3986].
 In the example above, "Bobby Joe*" is encoded to "Bobby%20Joe*".

4. Query Processing

 Servers indicate the success or failure of query processing by
 returning an appropriate HTTP response code to the client.  Response
 codes not specifically identified in this document are described in
 [RFC7480].

4.1. Partial String Searching

 Partial string searching uses the asterisk ('*', US-ASCII value 0x2A)
 character to match zero or more trailing characters.  A character
 string representing a domain label suffix MAY be concatenated to the
 end of the search pattern to limit the scope of the search.  For
 example, the search pattern "exam*" will match "example.com" and
 "example.net".  The search pattern "exam*.com" will match
 "example.com".  If an asterisk appears in a search string, any label
 that contains the non-asterisk characters in sequence plus zero or
 more characters in sequence in place of the asterisk would match.  A
 partial string search MUST NOT include more than one asterisk.
 Additional pattern matching processing is beyond the scope of this
 specification.
 If a server receives a search request but cannot process the request
 because it does not support a particular style of partial match
 searching, it SHOULD return an HTTP 422 (Unprocessable Entity)
 [RFC4918] response (unless another response code is more appropriate
 based on a server's policy settings) to note that search
 functionality is supported, but this particular query cannot be
 processed.  When returning a 422 error, the server MAY also return an
 error response body as specified in Section 6 of [RFC9083] if the
 requested media type is one that is specified in [RFC7480].
 Partial matching is not feasible across combinations of Unicode
 characters because Unicode characters can be combined with each
 other.  Servers SHOULD NOT partially match combinations of Unicode
 characters where a legal combination is possible.  It should be
 noted, though, that it may not always be possible to detect cases
 where a character could have been combined with another character,
 but was not, because characters can be combined in many different
 ways.
 Clients SHOULD NOT submit a partial match search of Unicode
 characters where a Unicode character may be legally combined with
 another Unicode character or characters.  Partial match searches with
 incomplete combinations of characters where a character must be
 combined with another character or characters are invalid.  Partial
 match searches with characters that may be combined with another
 character or characters are to be considered non-combined characters
 (that is, if character x may be combined with character y but
 character y is not submitted in the search string, then character x
 is a complete character and no combinations of character x are to be
 searched).

4.2. Associated Records

 Conceptually, any query-matching record in a server's database might
 be a member of a set of related records, related in some fashion as
 defined by the server -- for example, variants of an IDN.  The entire
 set ought to be considered as candidates for inclusion when
 constructing the response.  However, the construction of the final
 response needs to be mindful of privacy and other data-releasing
 policies when assembling the RDAP response set.
 Note too that due to the nature of searching, there may be a list of
 query-matching records.  Each one of those is subject to being a
 member of a set as described in the previous paragraph.  What is
 ultimately returned in a response will be the union of all the sets
 that has been filtered by whatever policies are in place.
 Note that this model includes arrangements for associated names,
 including those that are linked by policy mechanisms and names bound
 together for some other purposes.  Note also that returning
 information that was not explicitly selected by an exact-match
 lookup, including additional names that match a relatively fuzzy
 search as well as lists of names that are linked together, may cause
 privacy issues.
 Note that there might not be a single, static information return
 policy that applies to all clients equally.  Client identity and
 associated authorizations can be a relevant factor in determining how
 broad the response set will be for any particular query.

5. Extensibility

 This document describes path segment specifications for a limited
 number of objects commonly registered in both RIRs and DNRs.  It does
 not attempt to describe path segments for all of the objects
 registered in all registries.  Custom path segments can be created
 for objects not specified here using the process described in
 Section 6 of "HTTP Usage in the Registration Data Access Protocol
 (RDAP)" [RFC7480].
 Custom path segments can be created by prefixing the segment with a
 unique identifier followed by an underscore character (0x5F).  For
 example, a custom entity path segment could be created by prefixing
 "entity" with "custom_", producing "custom_entity".  Servers MUST
 return an appropriate failure status code for a request with an
 unrecognized path segment.

6. Internationalization Considerations

 There is value in supporting the ability to submit either a U-label
 (Unicode form of an IDN label) or an A-label (US-ASCII form of an IDN
 label) as a query argument to an RDAP service.  Clients capable of
 processing non-US-ASCII characters may prefer a U-label since this is
 more visually recognizable and familiar than A-label strings, but
 clients using programmatic interfaces might find it easier to submit
 and display A-labels if they are unable to input U-labels with their
 keyboard configuration.  Both query forms are acceptable.
 Internationalized domain and nameserver names can contain character
 variants and variant labels as described in [RFC4290].  Clients that
 support queries for internationalized domain and nameserver names
 MUST accept service provider responses that describe variants as
 specified in "JSON Responses for the Registration Data Access
 Protocol (RDAP)" [RFC9083].

6.1. Character Encoding Considerations

 Servers can expect to receive search patterns from clients that
 contain character strings encoded in different forms supported by
 HTTP.  It is entirely possible to apply filters and normalization
 rules to search patterns prior to making character comparisons, but
 this type of processing is more typically needed to determine the
 validity of registered strings than to match patterns.
 An RDAP client submitting a query string containing non-US-ASCII
 characters converts such strings into Unicode in UTF-8 encoding.  It
 then performs any local case mapping deemed necessary.  Strings are
 normalized using Normalization Form C (NFC) [Unicode-UAX15]; note
 that clients might not be able to do this reliably.  UTF-8 encoded
 strings are then appropriately percent-encoded [RFC3986] in the query
 URL.
 After parsing any percent-encoding, an RDAP server treats each query
 string as Unicode in UTF-8 encoding.  If a string is not valid UTF-8,
 the server can immediately stop processing the query and return an
 HTTP 400 (Bad Request) response.
 When processing queries, there is a difference in handling DNS names,
 including those with putative U-labels, and everything else.  DNS
 names are treated according to the DNS matching rules as described in
 Section 3.1 of RFC 1035 [RFC1035] for Non-Reserved LDH (NR-LDH)
 labels and the matching rules described in Section 5.4 of RFC 5891
 [RFC5891] for U-labels.  Matching of DNS names proceeds one label at
 a time because it is possible for a combination of U-labels and NR-
 LDH labels to be found in a single domain or host name.  The
 determination of whether a label is a U-label or an NR-LDH label is
 based on whether the label contains any characters outside of the US-
 ASCII letters, digits, or hyphen (the so-called LDH rule).
 For everything else, servers map fullwidth and halfwidth characters
 to their decomposition equivalents.  Servers convert strings to the
 same coded character set of the target data that is to be looked up
 or searched, and each string is normalized using the same
 normalization that was used on the target data.  In general, storage
 of strings as Unicode is RECOMMENDED.  For the purposes of
 comparison, Normalization Form KC (NFKC) [Unicode-UAX15] with case
 folding is used to maximize predictability and the number of matches.
 Note the use of case-folded NFKC as opposed to NFC in this case.

7. IANA Considerations

 This document has no IANA actions.

8. Security Considerations

 Security services for the operations specified in this document are
 described in "Security Services for the Registration Data Access
 Protocol (RDAP)" [RFC7481].
 Search functionality typically requires more server resources (such
 as memory, CPU cycles, and network bandwidth) when compared to basic
 lookup functionality.  This increases the risk of server resource
 exhaustion and subsequent denial of service due to abuse.  This risk
 can be mitigated by developing and implementing controls to restrict
 search functionality to identified and authorized clients.  If those
 clients behave badly, their search privileges can be suspended or
 revoked.  Rate limiting as described in Section 5.5 of "HTTP Usage in
 the Registration Data Access Protocol (RDAP)" [RFC7480] can also be
 used to control the rate of received search requests.  Server
 operators can also reduce their risk by restricting the amount of
 information returned in response to a search request.
 Search functionality also increases the privacy risk of disclosing
 object relationships that might not otherwise be obvious.  For
 example, a search that returns IDN variants [RFC6927] that do not
 explicitly match a client-provided search pattern can disclose
 information about registered domain names that might not be otherwise
 available.  Implementers need to consider the policy and privacy
 implications of returning information that was not explicitly
 requested.
 Note that there might not be a single, static information return
 policy that applies to all clients equally.  Client identity and
 associated authorizations can be a relevant factor in determining how
 broad the response set will be for any particular query.

9. References

9.1. Normative References

 [RFC0952]  Harrenstien, K., Stahl, M., and E. Feinler, "DoD Internet
            host table specification", RFC 952, DOI 10.17487/RFC0952,
            October 1985, <https://www.rfc-editor.org/info/rfc952>.
 [RFC1035]  Mockapetris, P., "Domain names - implementation and
            specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
            November 1987, <https://www.rfc-editor.org/info/rfc1035>.
 [RFC1123]  Braden, R., Ed., "Requirements for Internet Hosts -
            Application and Support", STD 3, RFC 1123,
            DOI 10.17487/RFC1123, October 1989,
            <https://www.rfc-editor.org/info/rfc1123>.
 [RFC1166]  Kirkpatrick, S., Stahl, M., and M. Recker, "Internet
            numbers", RFC 1166, DOI 10.17487/RFC1166, July 1990,
            <https://www.rfc-editor.org/info/rfc1166>.
 [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>.
 [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
            Architecture", RFC 4291, DOI 10.17487/RFC4291, February
            2006, <https://www.rfc-editor.org/info/rfc4291>.
 [RFC4632]  Fuller, V. and T. Li, "Classless Inter-domain Routing
            (CIDR): The Internet Address Assignment and Aggregation
            Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
            2006, <https://www.rfc-editor.org/info/rfc4632>.
 [RFC4918]  Dusseault, L., Ed., "HTTP Extensions for Web Distributed
            Authoring and Versioning (WebDAV)", RFC 4918,
            DOI 10.17487/RFC4918, June 2007,
            <https://www.rfc-editor.org/info/rfc4918>.
 [RFC5396]  Huston, G. and G. Michaelson, "Textual Representation of
            Autonomous System (AS) Numbers", RFC 5396,
            DOI 10.17487/RFC5396, December 2008,
            <https://www.rfc-editor.org/info/rfc5396>.
 [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
            STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
            <https://www.rfc-editor.org/info/rfc5730>.
 [RFC5733]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
            Contact Mapping", STD 69, RFC 5733, DOI 10.17487/RFC5733,
            August 2009, <https://www.rfc-editor.org/info/rfc5733>.
 [RFC5890]  Klensin, J., "Internationalized Domain Names for
            Applications (IDNA): Definitions and Document Framework",
            RFC 5890, DOI 10.17487/RFC5890, August 2010,
            <https://www.rfc-editor.org/info/rfc5890>.
 [RFC5891]  Klensin, J., "Internationalized Domain Names in
            Applications (IDNA): Protocol", RFC 5891,
            DOI 10.17487/RFC5891, August 2010,
            <https://www.rfc-editor.org/info/rfc5891>.
 [RFC5952]  Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
            Address Text Representation", RFC 5952,
            DOI 10.17487/RFC5952, August 2010,
            <https://www.rfc-editor.org/info/rfc5952>.
 [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>.
 [RFC7231]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
            Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
            DOI 10.17487/RFC7231, June 2014,
            <https://www.rfc-editor.org/info/rfc7231>.
 [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>.
 [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>.
 [RFC7484]  Blanchet, M., "Finding the Authoritative Registration Data
            (RDAP) Service", RFC 7484, DOI 10.17487/RFC7484, March
            2015, <https://www.rfc-editor.org/info/rfc7484>.
 [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>.
 [RFC8499]  Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
            Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
            January 2019, <https://www.rfc-editor.org/info/rfc8499>.
 [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>.
 [Unicode-UAX15]
            The Unicode Consortium, "Unicode Standard Annex #15:
            Unicode Normalization Forms", September 2013,
            <https://www.unicode.org/reports/tr15/>.

9.2. Informative References

 [REST]     Fielding, R., "Architectural Styles and the Design of
            Network-based Software Architectures", Ph.D.
            Dissertation, University of California, Irvine, 2000,
            <https://www.ics.uci.edu/~fielding/pubs/dissertation/
            fielding_dissertation.pdf>.
 [RFC3912]  Daigle, L., "WHOIS Protocol Specification", RFC 3912,
            DOI 10.17487/RFC3912, September 2004,
            <https://www.rfc-editor.org/info/rfc3912>.
 [RFC4007]  Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and
            B. Zill, "IPv6 Scoped Address Architecture", RFC 4007,
            DOI 10.17487/RFC4007, March 2005,
            <https://www.rfc-editor.org/info/rfc4007>.
 [RFC4290]  Klensin, J., "Suggested Practices for Registration of
            Internationalized Domain Names (IDN)", RFC 4290,
            DOI 10.17487/RFC4290, December 2005,
            <https://www.rfc-editor.org/info/rfc4290>.
 [RFC6874]  Carpenter, B., Cheshire, S., and R. Hinden, "Representing
            IPv6 Zone Identifiers in Address Literals and Uniform
            Resource Identifiers", RFC 6874, DOI 10.17487/RFC6874,
            February 2013, <https://www.rfc-editor.org/info/rfc6874>.
 [RFC6927]  Levine, J. and P. Hoffman, "Variants in Second-Level Names
            Registered in Top-Level Domains", RFC 6927,
            DOI 10.17487/RFC6927, May 2013,
            <https://www.rfc-editor.org/info/rfc6927>.
 [RFC8521]  Hollenbeck, S. and A. Newton, "Registration Data Access
            Protocol (RDAP) Object Tagging", BCP 221, RFC 8521,
            DOI 10.17487/RFC8521, November 2018,
            <https://www.rfc-editor.org/info/rfc8521>.

Appendix A. Changes from RFC 7482

  • Addressed known errata.
  • Addressed other reported clarifications and corrections: IDN,

IDNA, and DNR definitions. Noted that registrars are entities.

    Added a reference to RFC 8521 to address the bootstrap registry
    limitation.  Removed extraneous "...".  Clarified HTTP query
    string, search pattern, name server search, domain label suffix,
    and asterisk search.
  • Addressed "The HTTP query string" clarification.
  • Modified coauthor address.
  • Updated references to RFC 7483 to RFC 9083.
  • Added an IANA Considerations section. Changed references to use

HTTPS for targets.

  • Changed "XXXX is a search pattern representing the "FN" property

of an entity (such as a contact, registrant, or registrar) name as

    specified in Section 5.1" to "Changed "XXXX is a search pattern
    representing the "fn" property of an entity (such as a contact,
    registrant, or registrar) name as described in Section 5.1".
  • Added acknowledgments.
  • Changed "The intent of the patterns described here are to enable

queries" to "The intent of the patterns described here is to

    enable queries".
  • Changed "the corresponding syntax extension in RFC 6874 [RFC6874]

MUST NOT be used, and servers are to ignore it if possible" to

    "the corresponding syntax extension in RFC 6874 [RFC6874] MUST NOT
    be used, and servers SHOULD ignore it".
  • Changed "Only a single asterisk is allowed for a partial string

search" to "A partial string search MUST NOT include more than one

    asterisk".
  • Changed "Clients should avoid submitting a partial match search of

Unicode characters where a Unicode character may be legally

    combined with another Unicode character or characters" to "Clients
    SHOULD NOT submit a partial match search of Unicode characters
    where a Unicode character may be legally combined with another
    Unicode character or characters".
  • Changed description of nameserver IP address "search pattern" in

Sections 3.2.1 and 3.2.2.

  • IESG review feedback: Added "obsoletes 7482" to the headers,

Abstract, and Introduction. Changed "IETF standards" to "IETF

    specifications" and "Therefore" to "Accordingly" in Section 1.
    Updated the BCP 14 boilerplate.  Added definition of "bootstrap
    registry" and changed "concatenating ... to" to "concatenating ...
    with" in Section 3.  Changed "bitmask length" to "prefix length"
    and "2001:db8::0" to "2001:db8::" in Section 3.1.1.  Added "in
    contrast to the more generic HTTP query string that admits
    multiple simultaneous parameters" in Section 3.2.  Changed
    "0x002A" to "0x2A" in Section 4.1.  Clarified use of HTTP 422
    SHOULD in Section 4.1.

Acknowledgments

 This document is derived from original work on RIR query formats
 developed by Byron J. Ellacott of APNIC, Arturo L. Servin of LACNIC,
 Kaveh Ranjbar of the RIPE NCC, and Andrew L. Newton of ARIN.
 Additionally, this document incorporates DNR query formats originally
 described by Francisco Arias and Steve Sheng of ICANN and Scott
 Hollenbeck of Verisign Labs.
 The authors would like to acknowledge the following individuals for
 their contributions to this document: Francisco Arias, Marc Blanchet,
 Ernie Dainow, Jean-Philippe Dionne, Byron J. Ellacott, Behnam
 Esfahbod, John Klensin, John Levine, Edward Lewis, Mario Loffredo,
 Patrick Mevzek, Mark Nottingham, Kaveh Ranjbar, Arturo L. Servin,
 Steve Sheng, Jasdip Singh, and Andrew Sullivan.

Authors' Addresses

 Scott Hollenbeck
 Verisign Labs
 12061 Bluemont Way
 Reston, VA 20190
 United States of America
 Email: shollenbeck@verisign.com
 URI:   https://www.verisignlabs.com/
 Andy Newton
 Amazon Web Services, Inc.
 13200 Woodland Park Road
 Herndon, VA 20171
 United States of America
 Email: andy@hxr.us

Internet Engineering Task Force (IETF) S. Hollenbeck Request for Comments: 9083 Verisign Labs STD: 95 A. Newton Obsoletes: 7483 AWS Category: Standards Track June 2021 ISSN: 2070-1721

  JSON Responses for the Registration Data Access Protocol (RDAP)

Abstract

 This document describes JSON data structures representing
 registration information maintained by Regional Internet Registries
 (RIRs) and Domain Name Registries (DNRs).  These data structures are
 used to form Registration Data Access Protocol (RDAP) query
 responses.  This document obsoletes RFC 7483.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 https://www.rfc-editor.org/info/rfc9083.

Copyright Notice

 Copyright (c) 2021 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (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 Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1.  Introduction
   1.1.  Terminology and Definitions
   1.2.  Data Model
 2.  Use of JSON
   2.1.  Naming
 3.  Common Data Types
 4.  Common Data Structures
   4.1.  RDAP Conformance
   4.2.  Links
   4.3.  Notices and Remarks
   4.4.  Language Identifier
   4.5.  Events
   4.6.  Status
   4.7.  Port 43 WHOIS Server
   4.8.  Public IDs
   4.9.  Object Class Name
   4.10. An Example
 5.  Object Classes
   5.1.  The Entity Object Class
   5.2.  The Nameserver Object Class
   5.3.  The Domain Object Class
   5.4.  The IP Network Object Class
   5.5.  The Autonomous System Number Object Class
 6.  Error Response Body
 7.  Responding to Help Queries
 8.  Responding To Searches
 9.  Indicating Truncated Responses
 10. IANA Considerations
   10.1.  RDAP JSON Media Type Registration
   10.2.  JSON Values Registry
     10.2.1.  Notice and Remark Types
     10.2.2.  Status
     10.2.3.  Event Actions
     10.2.4.  Roles
     10.2.5.  Variant Relations
 11. Security Considerations
 12. Internationalization Considerations
   12.1.  Character Encoding
   12.2.  URIs and IRIs
   12.3.  Language Tags
   12.4.  Internationalized Domain Names
 13. Privacy Considerations
 14. References
   14.1.  Normative References
   14.2.  Informative References
 Appendix A.  Suggested Data Modeling with the Entity Object Class
   A.1.  Registrants and Contacts
   A.2.  Registrars
 Appendix B.  Modeling Events
 Appendix C.  Structured vs. Unstructured Addresses
 Appendix D.  Secure DNS
 Appendix E.  Motivations for Using JSON
 Appendix F.  Changes from RFC 7483
 Acknowledgments
 Authors' Addresses

1. Introduction

 This document describes responses in the JSON [RFC8259] format for
 the queries as defined by the Registration Data Access Protocol Query
 Format [RFC9082].  A communication protocol for exchanging queries
 and responses is described in [RFC7480].  This document obsoletes RFC
 7483.

1.1. Terminology and Definitions

 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.
 The following list describes terminology and definitions used
 throughout this document:
 DNR:  Domain Name Registry or Domain Name Registrar
 LDH:  letters, digits, hyphen
 member:  data found within an object as defined by JSON [RFC8259]
 object:  a data structure as defined by JSON [RFC8259]
 object class:  the definition of members that may be found in JSON
  objects described in this document
 object instance:  an instantiation or specific instance of an object
  class
 RDAP:  Registration Data Access Protocol
 RIR:  Regional Internet Registry

1.2. Data Model

 The data model for JSON responses is specified in five sections:
 1.  simple data types conveyed in JSON primitive types (strings,
     numbers, booleans, and null)
 2.  data structures specified as JSON arrays or objects that are used
     repeatedly when building up larger objects
 3.  object classes representing structured data corresponding to a
     lookup of a single object
 4.  arrays of objects representing structured data corresponding to a
     search for multiple objects
 5.  the response to an error
 The object classes represent responses for two major categories of
 data: responses returned by RIRs for registration data related to IP
 addresses, reverse DNS names, and Autonomous System numbers and
 responses returned by DNRs for registration data related to forward
 DNS names.  The following object classes are returned by both RIRs
 and DNRs:
 1.  domains
 2.  nameservers
 3.  entities
 The information served by both RIRs and DNRs for these object classes
 overlap extensively and are given in this document as a unified model
 for both classes of service.
 In addition to the object classes listed above, RIRs also serve the
 following object classes:
 1.  IP networks
 2.  Autonomous System numbers
 Object classes defined in this document represent a minimal set of
 what a compliant client/server needs to understand to function
 correctly; however, some deployments may want to include additional
 object classes to suit individual needs.  Anticipating this need for
 extension, Section 2.1 of this document defines a mechanism for
 extending the JSON objects that are described in this document.
 Positive responses take two forms.  A response to a lookup of a
 single object in the registration system yields a JSON object, which
 is the subject of the lookup.  A response to a search for multiple
 objects yields a JSON object that contains an array of JSON objects
 that are the subject of the search.  In each type of response, other
 data structures are present within the topmost JSON object.

2. Use of JSON

2.1. Naming

 Clients of these JSON responses SHOULD ignore unrecognized JSON
 members in responses.  Servers can insert members into the JSON
 responses, which are not specified in this document, but that does
 not constitute an error in the response.  Servers that insert such
 unspecified members into JSON responses SHOULD have member names
 prefixed with a short identifier followed by an underscore followed
 by a meaningful name.  It has been observed that these short
 identifiers aid software implementers with identifying the
 specification of the JSON member, and failure to use one could cause
 an implementer to assume the server is erroneously using a name from
 this specification.  This allowance does not apply to jCard [RFC7095]
 objects.  The full JSON name (the prefix plus the underscore plus the
 meaningful name) SHOULD adhere to the character and name limitations
 of the prefix registry described in [RFC7480].  Failure to use these
 limitations could result in slower adoption as these limitations have
 been observed to aid some client programming models.
 Consider the following JSON response with JSON members, all of which
 are specified in this document.
 {
   "handle" : "ABC123",
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ]
 }
                                Figure 1
 If The Registry of the Moon desires to express information not found
 in this specification, it might select "lunarNIC" as its identifying
 prefix and insert, as an example, the member named
 "lunarNIC_beforeOneSmallStep" to signify registrations occurring
 before the first moon landing and the member named
 "lunarNIC_harshMistressNotes" that contains other descriptive text.
 Consider the following JSON response with JSON names, some of which
 should be ignored by clients without knowledge of their meaning.
 {
   "handle" : "ABC123",
   "lunarNIC_beforeOneSmallStep" : "TRUE THAT!",
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "lunarNIC_harshMistressNotes" :
   [
     "In space,",
     "nobody can hear you scream."
   ]
 }
                                Figure 2
 Insertion of unrecognized members ignored by clients may also be used
 for future revisions to this specification.
 Clients processing JSON responses need to be prepared for members
 representing registration data specified in this document to be
 absent from a response.  In other words, servers are free to omit
 unrequired/optional JSON members containing registration data based
 on their own policies.
 Finally, all JSON names specified in this document are case
 sensitive.  Both servers and clients MUST transmit and process them
 using the specified character case.

3. Common Data Types

 JSON [RFC8259] defines the data types of a number, character string,
 boolean, array, object, and null.  This section describes the
 semantics and/or syntax reference for common, JSON character strings
 used in this document.
 handle:           DNRs and RIRs have registry-unique identifiers that
                   may be used to specifically reference an object
                   instance.  The semantics of this data type as found
                   in this document are to be a registry-unique
                   reference to the closest enclosing object where the
                   value is found.  The data type names "registryId",
                   "roid", "nic-handle", "registrationNo", etc., are
                   terms often synonymous with this data type.  In
                   this document, the term "handle" is used.  The term
                   exposed to users by clients is a presentation issue
                   beyond the scope of this document.  This value is a
                   simple character string.
 IPv4 addresses:   The representation of IPv4 addresses in this
                   document uses the dotted-decimal notation.  An
                   example of this textual representation is
                   "192.0.2.0".
 IPv6 addresses:   The representation of IPv6 addresses in this
                   document follow the forms outlined in [RFC5952].
                   An example of this textual representation is
                   "2001:db8::1:0:0:1".
 country codes:    Where the identity of a geopolitical nation or
                   country is needed, these identities are represented
                   with the alpha-2 or two-character country code
                   designation as defined in [ISO.3166.2020].  The
                   alpha-2 representation is used because it is freely
                   available, whereas the alpha-3 and numeric-3
                   standards are not.
 LDH names:        Textual representations of DNS names where the
                   labels of the domain are all "letters, digits,
                   hyphen" labels as described by [RFC5890].  Trailing
                   periods are optional.
 Unicode names:    Textual representations of DNS names where one or
                   more of the labels are U-labels as described by
                   [RFC5890].  Trailing periods are optional.
 dates and times:  The syntax for values denoting dates and times is
                   defined in [RFC3339].
 URIs:             The syntax for values denoting a Uniform Resource
                   Identifier (URI) is defined by [RFC3986].
 Contact information is defined using jCards as described in
 [RFC7095].  The "fn" member is required and MUST NOT be null
 according to [RFC6350].  An empty "fn" member MAY be used when the
 contact name does not exist or is redacted.

4. Common Data Structures

 This section defines common data structures used in responses and
 object classes.

4.1. RDAP Conformance

 The data structure named "rdapConformance" is an array of strings,
 each providing a hint as to the specifications used in the
 construction of the response.  This data structure MUST appear in the
 topmost JSON object of a response and MUST NOT appear anywhere else.
 A response to a "help" request will include identifiers for all of
 the specifications supported by the server.  A response to any other
 request will include only identifiers for the specifications used in
 the construction of the response.  The set of returned identifiers
 MAY vary depending on the authorization level of the client.
 An example rdapConformance data structure:
 "rdapConformance" :
 [
   "rdap_level_0"
 ]
                                Figure 3
 The string literal "rdap_level_0" signifies conformance with this
 specification.  When custom JSON values are inserted into responses,
 conformance to those custom specifications MUST be indicated by
 including a unique string literal value registered in the IANA RDAP
 Extensions registry specified in [RFC7480].  For example, if the
 fictional Registry of the Moon wants to signify that their JSON
 responses are conformant with their registered extensions, the string
 used might be "lunarNIC_level_0".  These registered values aid the
 identification of specifications for software implementers, and
 failure to use them could result in slower adoption of extensions.
 Example rdapConformance structure with custom extensions noted:
 "rdapConformance" :
 [
   "rdap_level_0",
   "lunarNIC_level_0"
 ]
                                Figure 4

4.2. Links

 The "links" array is found in data structures to signify links to
 other resources on the Internet.  The relationship of these links is
 defined by the IANA registry described by [RFC8288].
 The following is an example of the link structure:
     {
       "value" : "https://example.com/context_uri",
       "rel" : "self",
       "href" : "https://example.com/target_uri",
       "hreflang" : [ "en", "ch" ],
       "title" : "title",
       "media" : "screen",
       "type" : "application/json"
     }
                                Figure 5
 The JSON name/values of "rel", "href", "hreflang", "title", "media",
 and "type" correspond to values found in Section 3 of [RFC8288].  The
 "value" JSON value is the context URI as described by [RFC8288].  The
 "value", "rel", and "href" JSON values MUST be specified.  All other
 JSON values are OPTIONAL.  A "related" link relation MUST NOT include
 an "href" URI that is the same as the "self" link relation "href" URI
 to reduce the risk of infinite client processing loops.
 Internationalized Domain Names (IDNs) returned in URIs SHOULD be
 consistently returned in LDH name format to allow clients to process
 these IDNs according to their capabilities.
 This is an example of the "links" array as it might be found in an
 object class:
     "links" :
     [
         {
           "value" : "https://example.com/ip/2001:db8::123",
           "rel" : "self",
           "href" : "https://example.com/ip/2001:db8::123",
           "type" : "application/rdap+json"
         },
         {
           "value" : "https://example.com/ip/2001:db8::123",
           "rel" : "up",
           "href" : "https://example.com/ip/2001:db8::/48",
           "type" : "application/rdap+json"
         }
     ]
                                Figure 6

4.3. Notices and Remarks

 The "notices" and "remarks" data structures take the same form.  The
 notices structure denotes information about the service providing
 RDAP information and/or information about the entire response,
 whereas the remarks structure denotes information about the object
 class that contains it (see Section 5 regarding object classes).
 Both are arrays of objects.  Each object contains a "title" string
 representing the title of the object, a "type" string denoting a
 registered type of remark or notice (see Section 10.2.1), an array of
 strings named "description" for the purposes of conveying any
 descriptive text, and a "links" array as described in Section 4.2.
 The "description" array MUST be included.  All other JSON values are
 OPTIONAL.
 An example of the notices data structure:
 "notices" :
 [
   {
     "title" : "Terms of Use",
     "description" :
     [
       "Service subject to The Registry of the Moon's TOS.",
       "Copyright (c) 2020 LunarNIC"
     ],
     "links" :
     [
       {
         "value" : "https://example.net/entity/XXXX",
         "rel" : "alternate",
         "type" : "text/html",
         "href" : "https://www.example.com/terms_of_use.html"
       }
     ]
   }
 ]
                                Figure 7
 It is the job of the clients to determine line breaks, spacing, and
 display issues for sentences within the character strings of the
 "description" array.  Each string in the "description" array contains
 a single complete division of human-readable text indicating to
 clients where there are semantic breaks.
 An example of the remarks data structure:
 "remarks" :
 [
   {
     "description" :
     [
       "She sells sea shells down by the sea shore.",
       "Originally written by Terry Sullivan."
     ]
   }
 ]
                                Figure 8
 Note that objects in the "remarks" array may also have a "links"
 array.
 While the "title" and "description" fields are intended primarily for
 human consumption, the "type" string contains a well-known value to
 be registered with IANA (see Section 10.2.1) for programmatic use.
 An example of the remarks data structure:
 "remarks" :
 [
   {
     "type" : "object truncated due to authorization",
     "description" :
     [
       "Some registration data may not have been given.",
       "Use proper authorization credentials to see all of it."
     ]
   }
 ]
                                Figure 9
 While the "remarks" array will appear in many object classes in a
 response, the "notices" array appears only in the topmost object of a
 response.

4.4. Language Identifier

 This data structure consists solely of a name/value pair, where the
 name is "lang" and the value is a string containing a language
 identifier as described in [RFC5646].
 "lang" : "mn-Cyrl-MN"
                               Figure 10
 The "lang" attribute as defined in this section MAY appear anywhere
 in an object class or data structure, except for in jCard objects.
 vCard supports similar functionality by way of the LANGUAGE property
 parameter (see Section 5.1 of RFC 6350 [RFC6350]).

4.5. Events

 This data structure represents events that have occurred on an
 instance of an object class (see Section 5 regarding object classes).
 This is an example of an "events" array.
 "events" :
 [
   {
     "eventAction" : "registration",
     "eventActor" : "SOMEID-LUNARNIC",
     "eventDate" : "1990-12-31T23:59:59Z"
   },
   {
     "eventAction" : "last changed",
     "eventActor" : "OTHERID-LUNARNIC",
     "eventDate" : "1991-12-31T23:59:59Z"
   }
 ]
                               Figure 11
 The "events" array consists of objects, each with the following
 members:
  • "eventAction" – a REQUIRED string denoting the reason for the

event

  • "eventActor" – an OPTIONAL identifier denoting the actor

responsible for the event

  • "eventDate" – a REQUIRED string containing the time and date the

event occurred

  • "links" – OPTIONAL; see Section 4.2
 Events can be future dated.  One use case for future dating of events
 is to denote when an object expires from a registry.
 The "links" array in this data structure is provided for references
 to the event actor.  In order to reference an RDAP entity, a "rel" of
 "related" and a "type" of "application/rdap+json" is used in the link
 reference.
 See Section 10.2.3 for a list of values for the "eventAction" string.
 See Appendix B regarding the various ways events can be modeled.

4.6. Status

 This data structure, named "status", is an array of strings
 indicating the state of a registered object (see Section 10.2.2 for a
 list of values).

4.7. Port 43 WHOIS Server

 This data structure, a member named "port43", is a simple character
 string containing the fully qualified host name or IP address of the
 WHOIS [RFC3912] server where the containing object instance may be
 found.  Note that this is not a URI, as there is no WHOIS URI scheme.

4.8. Public IDs

 This data structure maps a public identifier to an object class.  It
 is named "publicIds" and is an array of objects, with each object
 containing the following REQUIRED members:
  • type – a string denoting the type of public identifier
  • identifier – a string denoting a public identifier of the type

related to "type"

 The following is an example of a publicIds structure.
 "publicIds":
 [
   {
     "type":"IANA Registrar ID",
     "identifier":"1"
   }
 ]
                               Figure 12

4.9. Object Class Name

 This data structure, a member named "objectClassName", gives the
 object class name of a particular object as a string.  This
 identifies the type of object being processed.  An objectClassName is
 REQUIRED in all RDAP response objects so that the type of the object
 can be interpreted.

4.10. An Example

 This is an example response with both rdapConformance and notices
 embedded:
 {
   "rdapConformance" :
   [
     "rdap_level_0"
   ],
   "notices" :
   [
     {
       "title" : "Content Removed",
       "description" :
       [
         "Without full authorization, content has been removed.",
         "Sorry, dude!"
       ],
       "links" :
       [
         {
           "value" : "https://example.net/ip/192.0.2.0/24",
           "rel" : "alternate",
           "type" : "text/html",
           "href" : "https://www.example.com/redaction_policy.html"
         }
       ]
     }
   ],
   "lang" : "en",
   "objectClassName" : "ip network",
   "startAddress" : "192.0.2.0",
   "endAddress" : "192.0.2.255",
   "handle" : "XXXX-RIR",
   "ipVersion" : "v4",
   "name": "NET-RTR-1",
   "parentHandle" : "YYYY-RIR",
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ]
 }
                               Figure 13

5. Object Classes

 Object classes represent structures appropriate for a response from
 the queries specified in [RFC9082].
 Each object class contains a "links" array as specified in
 Section 4.2.  For every object class instance in a response, whether
 the object class instance is directly representing the response to a
 query or is embedded in other object class instances or is an item in
 a search result set, servers SHOULD provide a link representing a URI
 for that object class instance using the "self" relationship as
 described in the IANA registry specified by [RFC8288].  As explained
 in Section 5.2, this may be not always be possible for nameserver
 data.  Clients MUST be able to process object instances without a
 self link.  When present, clients can use the self link for caching
 data.  Servers MAY provide more than one self link for any given
 object instance.  Failure to provide any self link by a server may
 result in clients being unable to cache object class instances.
 Clients using self links for caching SHOULD NOT cache any object
 class instances where the authority of the self link is different
 than the authority of the server returning the data.  Failing to do
 so might result in cache poisoning.
 Self links MUST contain a "type" element containing the "application/
 rdap+json" media type when referencing RDAP object instances as
 defined by this document.
 This is an example of the "links" array with a self link to an object
 class:
     "links" :
     [
         {
           "value" : "https://example.com/ip/2001:db8::123",
           "rel" : "self",
           "href" : "https://example.com/ip/2001:db8::123",
           "type" : "application/rdap+json"
         }
     ]
                               Figure 14

5.1. The Entity Object Class

 The entity object class appears throughout this document and is an
 appropriate response for the /entity/XXXX query defined in
 "Registration Data Access Protocol (RDAP) Query Format" [RFC9082].
 This object class represents the information of organizations,
 corporations, governments, non-profits, clubs, individual persons,
 and informal groups of people.  All of these representations are so
 similar that it is best to represent them in JSON [RFC8259] with one
 construct, the entity object class, to aid in the reuse of code by
 implementers.
 The entity object class uses jCard [RFC7095] to represent contact
 information, such as postal addresses, email addresses, phone numbers
 and names of organizations and individuals.  Many of the types of
 information that can be represented with jCard have little or no use
 in RDAP, such as birthdays, anniversaries, and gender.
 The entity object is served by both RIRs and DNRs.  The following is
 an example of an entity that might be served by an RIR.
 {
   "objectClassName" : "entity",
   "handle":"XXXX",
   "vcardArray":[
     "vcard",
     [
       ["version", {}, "text", "4.0"],
       ["fn", {}, "text", "Joe User"],
       ["n", {}, "text",
         ["User", "Joe", "", "", ["ing. jr", "M.Sc."]]
       ],
       ["kind", {}, "text", "individual"],
       ["lang", {
         "pref":"1"
       }, "language-tag", "fr"],
       ["lang", {
         "pref":"2"
       }, "language-tag", "en"],
       ["org", {
         "type":"work"
       }, "text", "Example"],
       ["title", {}, "text", "Research Scientist"],
       ["role", {}, "text", "Project Lead"],
       ["adr",
         { "type":"work" },
         "text",
         [
           "",
           "Suite 1234",
           "4321 Rue Somewhere",
           "Quebec",
           "QC",
           "G1V 2M2",
           "Canada"
         ]
       ],
       ["adr",
         {
           "type":"home",
           "label":"123 Maple Ave\nSuite 90001\nVancouver\nBC\n1239\n"
         },
         "text",
         [
           "", "", "", "", "", "", ""
         ]
       ],
       ["tel",
         {
           "type":["work", "voice"],
           "pref":"1"
         },
         "uri",
         "tel:+1-555-555-1234;ext=102"
       ],
       ["tel",
         { "type":["work", "cell", "voice", "video", "text"] },
         "uri",
         "tel:+1-555-555-4321"
       ],
       ["email",
         { "type":"work" },
         "text",
         "joe.user@example.com"
       ],
       ["geo", {
         "type":"work"
       }, "uri", "geo:46.772673,-71.282945"],
       ["key",
         { "type":"work" },
         "uri",
         "https://www.example.com/joe.user/joe.asc"
       ],
       ["tz", {},
         "utc-offset", "-05:00"],
       ["url", { "type":"home" },
         "uri", "https://example.org"]
     ]
   ],
   "roles":[ "registrar" ],
   "publicIds":[
     {
       "type":"IANA Registrar ID",
       "identifier":"1"
     }
   ],
   "remarks":[
     {
       "description":[
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "links":[
     {
       "value":"https://example.com/entity/XXXX",
       "rel":"self",
       "href":"https://example.com/entity/XXXX",
       "type" : "application/rdap+json"
     }
   ],
   "events":[
     {
       "eventAction":"registration",
       "eventDate":"1990-12-31T23:59:59Z"
     }
   ],
   "asEventActor":[
     {
       "eventAction":"last changed",
       "eventDate":"1991-12-31T23:59:59Z"
     }
   ]
 }
                               Figure 15
 The entity object class can contain the following members:
  • objectClassName – the string "entity"
  • handle – a string representing a registry-unique identifier of

the entity

  • vcardArray – a jCard with the entity's contact information
  • roles – an array of strings, each signifying the relationship an

object would have with its closest containing object (see

    Section 10.2.4 for a list of values)
  • publicIds – see Section 4.8
  • entities – an array of entity objects as defined by this section
  • remarks – see Section 4.3
  • links – see Section 4.2
  • events – see Section 4.5
  • asEventActor – this data structure takes the same form as the

events data structure (see Section 4.5), but each object in the

    array MUST NOT have an "eventActor" member.  These objects denote
    that the entity is an event actor for the given events.  See
    Appendix B regarding the various ways events can be modeled.
  • status – see Section 4.6
  • port43 – see Section 4.7
  • networks – an array of IP network objects as defined in

Section 5.4

  • autnums – an array of autnum objects as defined in Section 5.5
 Entities may also have other entities embedded with them in an array.
 This can be used to model an organization with specific individuals
 fulfilling designated roles of responsibility.
 The following is an elided example of an entity with embedded
 entities.
 {
   "objectClassName" : "entity",
   "handle" : "ANENTITY",
   "roles" : [ "registrar" ],
   ...
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle": "ANEMBEDDEDENTITY",
       "roles" : [ "technical" ],
       ...
     },
     ...
   ],
   ...
 }
                               Figure 16
 The following is an example of an entity that might be served by a
 DNR.
 {
   "objectClassName" : "entity",
   "handle":"XXXX",
   "vcardArray":[
     "vcard",
     [
       ["version", {}, "text", "4.0"],
       ["fn", {}, "text", "Joe User"],
       ["kind", {}, "text", "individual"],
       ["lang", {
         "pref":"1"
       }, "language-tag", "fr"],
       ["lang", {
         "pref":"2"
       }, "language-tag", "en"],
       ["org", {
         "type":"work"
       }, "text", "Example"],
       ["title", {}, "text", "Research Scientist"],
       ["role", {}, "text", "Project Lead"],
       ["adr",
         { "type":"work" },
         "text",
         [
           "",
           "Suite 1234",
           "4321 Rue Somewhere",
           "Quebec",
           "QC",
           "G1V 2M2",
           "Canada"
         ]
       ],
       ["tel",
         { "type":["work", "voice"], "pref":"1" },
         "uri", "tel:+1-555-555-1234;ext=102"
       ],
       ["email",
         { "type":"work" },
         "text", "joe.user@example.com"
       ]
     ]
   ],
   "status":[ "validated", "locked" ],
   "remarks":[
     {
       "description":[
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "links":[
     {
       "value":"https://example.com/entity/XXXX",
       "rel":"self",
       "href":"https://example.com/entity/XXXX",
       "type":"application/rdap+json"
     }
   ],
   "port43":"whois.example.net",
   "events":[
     {
       "eventAction":"registration",
       "eventDate":"1990-12-31T23:59:59Z"
     },
     {
       "eventAction":"last changed",
       "eventDate":"1991-12-31T23:59:59Z",
       "eventActor":"joe@example.com"
     }
   ]
 }
                               Figure 17
 See Appendix A for use of the entity object class to model various
 types of entities found in both RIRs and DNRs.  See Appendix C
 regarding structured vs.  unstructured postal addresses in entities.

5.2. The Nameserver Object Class

 The nameserver object class represents information regarding DNS
 nameservers used in both forward and reverse DNS.  RIRs and some DNRs
 register or expose nameserver information as an attribute of a domain
 name, while other DNRs model nameservers as "first class objects".
 Please note that some of the examples in this section include lines
 that have been wrapped for reading clarity.
 The nameserver object class accommodates both models and degrees of
 variation in between.
 The following is an example of a nameserver object.
   {
     "objectClassName" : "nameserver",
     "handle" : "XXXX",
     "ldhName" : "ns1.xn--fo-5ja.example",
     "unicodeName" : "ns.fóo.example",
     "status" : [ "active" ],
     "ipAddresses" :
     {
       "v4": [ "192.0.2.1", "192.0.2.2" ],
       "v6": [ "2001:db8::123" ]
     },
     "remarks" :
     [
       {
         "description" :
         [
           "She sells sea shells down by the sea shore.",
           "Originally written by Terry Sullivan."
         ]
       }
     ],
     "links" :
     [
       {
         "value" : "https://example.net/nameserver/
                    ns1.xn--fo-5ja.example",
         "rel" : "self",
         "href" : "https://example.net/nameserver/
                   ns1.xn--fo-5ja.example",
         "type" : "application/rdap+json"
       }
     ],
     "port43" : "whois.example.net",
     "events" :
     [
       {
         "eventAction" : "registration",
         "eventDate" : "1990-12-31T23:59:59Z"
       },
       {
         "eventAction" : "last changed",
         "eventDate" : "1991-12-31T23:59:59Z",
         "eventActor" : "joe@example.com"
       }
     ]
   }
                               Figure 18
 Figure 18 is an example of a nameserver object with all appropriate
 values given.  Registries using a first-class nameserver data model
 would embed this in domain objects as well as allowing references to
 it with the "/nameserver" query type (all depending on the registry
 operators policy).  Other registries may pare back the information as
 needed.  Figure 19 is an example of a nameserver object as would be
 found in RIRs and some DNRs, while Figure 20 is an example of a
 nameserver object as would be found in other DNRs.
 The following is an example of the simplest nameserver object:
   {
     "objectClassName" : "nameserver",
     "ldhName" : "ns1.example.com"
   }
                               Figure 19
 The following is an example of a simple nameserver object that might
 be commonly used by DNRs:
   {
     "objectClassName" : "nameserver",
     "ldhName" : "ns1.example.com",
     "ipAddresses" : { "v6" : [ "2001:db8::123", "2001:db8::124" ] }
   }
                               Figure 20
 As nameservers can be modeled by some registries to be first-class
 objects, they may also have an array of entities (Section 5.1)
 embedded to signify parties responsible for the maintenance,
 registrations, etc., of the nameservers.
 The following is an elided example of a nameserver with embedded
 entities.
 {
   "objectClassName" : "nameserver",
   "handle" : "XXXX",
   "ldhName" : "ns.xn--fo-5ja.example",
   ...
   "entities" :
   [
     ...
   ],
   ...
 }
                               Figure 21
 The nameserver object class can contain the following members:
  • objectClassName – the string "nameserver"
  • handle – a string representing a registry-unique identifier of

the nameserver

  • ldhName – a string containing the LDH name of the nameserver (see

Section 3)

  • unicodeName – a string containing a DNS Unicode name of the

nameserver (see Section 3)

  • ipAddresses – an object containing the following members:
  1. v6 – an array of strings containing IPv6 addresses of the

nameserver

  1. v4 – an array of strings containing IPv4 addresses of the

nameserver

  • entities – an array of entity objects as defined by Section 5.1
  • status – see Section 4.6
  • remarks – see Section 4.3
  • links – see Section 4.2
  • port43 – see Section 4.7
  • events – see Section 4.5

5.3. The Domain Object Class

 The domain object class represents a DNS name and point of
 delegation.  For RIRs, these delegation points are in the reverse DNS
 tree, whereas for DNRs, these delegation points are in the forward
 DNS tree.
 In both cases, the high-level structure of the domain object class
 consists of information about the domain registration, nameserver
 information related to the domain name, and entities related to the
 domain name (e.g., registrant information, contacts, etc.).
 The following is an elided example of the domain object showing the
 high-level structure:
 {
   "objectClassName" : "domain",
   "handle" : "XXX",
   "ldhName" : "blah.example.com",
   ...
   "nameservers" :
   [
     ...
   ],
   ...
   "entities" :
   [
     ...
   ]
 }
                               Figure 22
 The domain object class can contain the following members:
  • objectClassName – the string "domain"
  • handle – a string representing a registry-unique identifier of

the domain object instance

  • ldhName – a string describing a domain name in LDH form as

described in Section 3

  • unicodeName – a string containing a domain name with U-labels as

described in Section 3

  • variants – an array of objects, each containing the following

values:

  1. relation – an array of strings, with each string denoting the

relationship between the variants and the containing domain

       object (see Section 10.2.5 for a list of suggested variant
       relations).
  1. idnTable – the character string literal that represents the

Internationalized Domain Name (IDN) table that has been

       registered in the IANA Repository of IDN Practices
       [IANA_IDNTABLES].
  1. variantNames – an array of objects, with each object

containing an "ldhName" member and a "unicodeName" member (see

       Section 3).
  • nameservers – an array of nameserver objects as defined by

Section 5.2

  • secureDNS – an object with the following members:
  1. zoneSigned – boolean true if the zone has been signed, false

otherwise.

  1. delegationSigned – boolean true if there are DS records in the

parent, false otherwise.

  1. maxSigLife – an integer representing the signature lifetime in

seconds to be used when creating the RRSIG DS record in the

       parent zone [RFC5910].
  1. dsData – an array of objects, each with the following members:
       o  keyTag -- an integer as specified by the key tag field of a
          DNS DS record as specified by [RFC4034] in presentation
          format
       o  algorithm -- an integer as specified by the algorithm field
          of a DNS DS record as described by RFC 4034 in presentation
          format
       o  digest -- a string as specified by the digest field of a DNS
          DS record as specified by RFC 4034 in presentation format
       o  digestType -- an integer as specified by the digest type
          field of a DNS DS record as specified by RFC 4034 in
          presentation format
       o  events -- see Section 4.5
       o  links -- see Section 4.2
  1. keyData – an array of objects, each with the following

members:

       o  flags -- an integer representing the flags field value in
          the DNSKEY record [RFC4034] in presentation format
       o  protocol -- an integer representation of the protocol field
          value of the DNSKEY record [RFC4034] in presentation format
       o  publicKey -- a string representation of the public key in
          the DNSKEY record [RFC4034] in presentation format
       o  algorithm -- an integer as specified by the algorithm field
          of a DNSKEY record as specified by [RFC4034] in presentation
          format
       o  events -- see Section 4.5
       o  links -- see Section 4.2
          See Appendix D for background information on these objects.
  • entities – an array of entity objects as defined by Section 5.1
  • status – see Section 4.6
  • publicIds – see Section 4.8
  • remarks – see Section 4.3
  • links – see Section 4.2
  • port43 – see Section 4.7
  • events – see Section 4.5
  • network – represents the IP network for which a reverse DNS

domain is referenced; see Section 5.4

 The following is an example of a JSON domain object representing a
 reverse DNS delegation point that might be served by an RIR (note
 that the dsData digest value has been modified to fit on one line).
 {
   "objectClassName" : "domain",
   "handle" : "XXXX",
   "ldhName" : "0.2.192.in-addr.arpa",
   "nameservers" :
   [
     {
       "objectClassName" : "nameserver",
       "ldhName" : "ns1.rir.example"
     },
     {
       "objectClassName" : "nameserver",
       "ldhName" : "ns2.rir.example"
     }
   ],
   "secureDNS":
   {
     "delegationSigned": true,
     "dsData":
     [
       {
         "keyTag": 25345,
         "algorithm": 8,
         "digestType": 2,
         "digest": "2788970E18EA14...C890C85B8205B94"
       }
     ]
   },
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "links" :
   [
     {
       "value": "https://example.net/domain/0.2.192.in-addr.arpa",
       "rel" : "self",
       "href" : "https://example.net/domain/0.2.192.in-addr.arpa",
       "type" : "application/rdap+json"
     }
   ],
   "events" :
   [
     {
       "eventAction" : "registration",
       "eventDate" : "1990-12-31T23:59:59Z"
     },
     {
       "eventAction" : "last changed",
       "eventDate" : "1991-12-31T23:59:59Z",
       "eventActor" : "joe@example.com"
     }
   ],
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle" : "XXXX",
       "vcardArray":[
         "vcard",
         [
           ["version", {}, "text", "4.0"],
           ["fn", {}, "text", "Joe User"],
           ["kind", {}, "text", "individual"],
           ["lang", {
             "pref":"1"
           }, "language-tag", "fr"],
           ["lang", {
             "pref":"2"
           }, "language-tag", "en"],
           ["org", {
             "type":"work"
           }, "text", "Example"],
           ["title", {}, "text", "Research Scientist"],
           ["role", {}, "text", "Project Lead"],
           ["adr",
             { "type":"work" },
             "text",
             [
               "",
               "Suite 1234",
               "4321 Rue Somewhere",
               "Quebec",
               "QC",
               "G1V 2M2",
               "Canada"
             ]
           ],
           ["tel",
             { "type":["work", "voice"], "pref":"1" },
             "uri", "tel:+1-555-555-1234;ext=102"
           ],
           ["email",
             { "type":"work" },
             "text", "joe.user@example.com"
           ]
         ]
       ],
       "roles" : [ "registrant" ],
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links" :
       [
         {
           "value": "https://example.net/entity/XXXX",
           "rel" : "self",
           "href" : "https://example.net/entity/XXXX",
           "type" : "application/rdap+json"
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z",
           "eventActor" : "joe@example.com"
         }
       ]
     }
   ],
   "network" :
   {
     "objectClassName" : "ip network",
     "handle" : "XXXX-RIR",
     "startAddress" : "192.0.2.0",
     "endAddress" : "192.0.2.255",
     "ipVersion" : "v4",
     "name": "NET-RTR-1",
     "type" : "DIRECT ALLOCATION",
     "country" : "AU",
     "parentHandle" : "YYYY-RIR",
     "status" : [ "active" ]
   }
 }
                               Figure 23
 The following is an example of a JSON domain object representing a
 forward DNS delegation point that might be served by a DNR.  Note
 that the secureDNS keyData publicKey value has been modified to fit
 on a single line.
 {
   "objectClassName" : "domain",
   "handle" : "XXXX",
   "ldhName" : "xn--fo-5ja.example",
   "unicodeName" : "fóo.example",
   "variants" :
   [
     {
       "relation" : [ "registered", "conjoined" ],
       "variantNames" :
       [
         {
           "ldhName" : "xn--fo-cka.example",
           "unicodeName" : "fõo.example"
         },
         {
           "ldhName" : "xn--fo-fka.example",
           "unicodeName" : "föo.example"
         }
       ]
     },
     {
       "relation" : [ "unregistered", "registration restricted" ],
       "idnTable": ".EXAMPLE Swedish",
       "variantNames" :
       [
         {
           "ldhName": "xn--fo-8ja.example",
           "unicodeName" : "fôo.example"
         }
       ]
     }
   ],
   "status" : [ "locked", "transfer prohibited" ],
   "publicIds":[
     {
       "type":"ENS_Auth ID",
       "identifier":"1234567890"
     }
   ],
   "nameservers" :
   [
     {
       "objectClassName" : "nameserver",
       "handle" : "XXXX",
       "ldhName" : "ns1.example.com",
       "status" : [ "active" ],
       "ipAddresses" :
       {
         "v6": [ "2001:db8::123", "2001:db8::124" ],
         "v4": [ "192.0.2.1", "192.0.2.2" ]
       },
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links" :
       [
         {
           "value" : "https://example.net/nameserver/ns1.example.com",
           "rel" : "self",
           "href" : "https://example.net/nameserver/ns1.example.com",
           "type" : "application/rdap+json"
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z"
         }
       ]
     },
     {
       "objectClassName" : "nameserver",
       "handle" : "XXXX",
       "ldhName" : "ns2.example.com",
       "status" : [ "active" ],
       "ipAddresses" :
       {
         "v6" : [ "2001:db8::125", "2001:db8::126" ],
         "v4" : [ "192.0.2.3", "192.0.2.4" ]
       },
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links" :
       [
         {
           "value" : "https://example.net/nameserver/ns2.example.com",
           "rel" : "self",
           "href" : "https://example.net/nameserver/ns2.example.com",
           "type" : "application/rdap+json"
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z"
         }
       ]
     }
   ],
   "secureDNS":
   {
      "zoneSigned": true,
      "delegationSigned": true,
      "maxSigLife": 604800,
      "keyData":
      [
        {
          "flags": 257,
          "protocol": 3,
          "algorithm": 8,
          "publicKey": "AwEAAa6eDzronzjEDbT...Jg1M5N rBSPkuXpdFE=",
          "events":
          [
            {
              "eventAction": "last changed",
              "eventDate": "2012-07-23T05:15:47Z"
            }
          ]
        }
      ]
   },
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "links" :
   [
     {
       "value": "https://example.net/domain/xn--fo-5ja.example",
       "rel" : "self",
       "href" : "https://example.net/domain/xn--fo-5ja.example",
       "type" : "application/rdap+json"
     }
   ],
   "port43" : "whois.example.net",
   "events" :
   [
     {
       "eventAction" : "registration",
       "eventDate" : "1990-12-31T23:59:59Z"
     },
     {
       "eventAction" : "last changed",
       "eventDate" : "1991-12-31T23:59:59Z",
       "eventActor" : "joe@example.com"
     },
     {
       "eventAction" : "transfer",
       "eventDate" : "1991-12-31T23:59:59Z",
       "eventActor" : "joe@example.com"
     },
     {
       "eventAction" : "expiration",
       "eventDate" : "2016-12-31T23:59:59Z",
       "eventActor" : "joe@example.com"
     }
   ],
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle" : "XXXX",
       "vcardArray":[
         "vcard",
         [
           ["version", {}, "text", "4.0"],
           ["fn", {}, "text", "Joe User"],
           ["kind", {}, "text", "individual"],
           ["lang", {
             "pref":"1"
           }, "language-tag", "fr"],
           ["lang", {
             "pref":"2"
           }, "language-tag", "en"],
           ["org", {
             "type":"work"
           }, "text", "Example"],
           ["title", {}, "text", "Research Scientist"],
           ["role", {}, "text", "Project Lead"],
           ["adr",
             { "type":"work" },
             "text",
             [
               "",
               "Suite 1234",
               "4321 Rue Somewhere",
               "Quebec",
               "QC",
               "G1V 2M2",
               "Canada"
             ]
           ],
           ["tel",
             { "type":["work", "voice"], "pref":"1" },
             "uri", "tel:+1-555-555-1234;ext=102"
           ],
           ["email",
             { "type":"work" },
             "text", "joe.user@example.com"
           ]
         ]
       ],
       "status" : [ "validated", "locked" ],
       "roles" : [ "registrant" ],
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links" :
       [
         {
           "value" : "https://example.net/entity/XXXX",
           "rel" : "self",
           "href" : "https://example.net/entity/XXXX",
           "type" : "application/rdap+json"
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z"
         }
       ]
     }
   ]
 }
                               Figure 24

5.4. The IP Network Object Class

 The IP network object class models IP network registrations found in
 RIRs and is the expected response for the "/ip" query as defined by
 [RFC9082].  There is no equivalent object class for DNRs.  The high-
 level structure of the IP network object class consists of
 information about the network registration and entities related to
 the IP network (e.g., registrant information, contacts, etc.).
 The following is an elided example of the IP network object type
 showing the high-level structure:
 {
   "objectClassName" : "ip network",
   "handle" : "XXX",
   ...
   "entities" :
   [
     ...
   ]
 }
                               Figure 25
 The following is an example of the JSON object for the network
 registration information.
 {
   "objectClassName" : "ip network",
   "handle" : "XXXX-RIR",
   "startAddress" : "2001:db8::",
   "endAddress" : "2001:db8:0:ffff:ffff:ffff:ffff:ffff",
   "ipVersion" : "v6",
   "name": "NET-RTR-1",
   "type" : "DIRECT ALLOCATION",
   "country" : "AU",
   "parentHandle" : "YYYY-RIR",
   "status" : [ "active" ],
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "links" :
   [
     {
       "value" : "https://example.net/ip/2001:db8::/48",
       "rel" : "self",
       "href" : "https://example.net/ip/2001:db8::/48",
       "type" : "application/rdap+json"
     },
     {
       "value" : "https://example.net/ip/2001:db8::/48",
       "rel" : "up",
       "href" : "https://example.net/ip/2001:db8::/32",
       "type" : "application/rdap+json"
     }
   ],
   "events" :
   [
     {
       "eventAction" : "registration",
       "eventDate" : "1990-12-31T23:59:59Z"
     },
     {
       "eventAction" : "last changed",
       "eventDate" : "1991-12-31T23:59:59Z"
     }
   ],
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle" : "XXXX",
       "vcardArray":[
         "vcard",
         [
           ["version", {}, "text", "4.0"],
           ["fn", {}, "text", "Joe User"],
           ["kind", {}, "text", "individual"],
           ["lang", {
             "pref":"1"
           }, "language-tag", "fr"],
           ["lang", {
             "pref":"2"
           }, "language-tag", "en"],
           ["org", {
             "type":"work"
           }, "text", "Example"],
           ["title", {}, "text", "Research Scientist"],
           ["role", {}, "text", "Project Lead"],
           ["adr",
             { "type":"work" },
             "text",
             [
               "",
               "Suite 1234",
               "4321 Rue Somewhere",
               "Quebec",
               "QC",
               "G1V 2M2",
               "Canada"
             ]
           ],
           ["tel",
             { "type":["work", "voice"], "pref":"1" },
             "uri", "tel:+1-555-555-1234;ext=102"
           ],
           ["email",
             { "type":"work" },
             "text", "joe.user@example.com"
           ]
         ]
       ],
       "roles" : [ "registrant" ],
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links" :
       [
         {
           "value" : "https://example.net/entity/xxxx",
           "rel" : "self",
           "href" : "https://example.net/entity/xxxx",
           "type" : "application/rdap+json"
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z"
         }
       ]
     }
   ]
 }
                               Figure 26
 The IP network object class can contain the following members:
  • objectClassName – the string "ip network"
  • handle – a string representing the RIR-unique identifier of the

network registration

  • startAddress – a string representing the starting IP address of

the network, either IPv4 or IPv6

  • endAddress – a string representing the ending IP address of the

network, either IPv4 or IPv6

  • ipVersion – a string signifying the IP protocol version of the

network: "v4" signifies an IPv4 network, and "v6" signifies an

    IPv6 network
  • name – a string representing an identifier assigned to the

network registration by the registration holder

  • type – a string containing an RIR-specific classification of the

network per that RIR's registration model

  • country – a string containing the two-character country code of

the network

  • parentHandle – a string containing an RIR-unique identifier of

the parent network of this network registration

  • status – an array of strings indicating the state of the IP

network as defined by Section 4.6

  • entities – an array of entity objects as defined by Section 5.1
  • remarks – see Section 4.3
  • links – see Section 4.2
  • port43 – see Section 4.7
  • events – see Section 4.5

5.5. The Autonomous System Number Object Class

 The Autonomous System number (autnum) object class models Autonomous
 System number registrations found in RIRs and represents the expected
 response to an "/autnum" query as defined by [RFC9082].  There is no
 equivalent object class for DNRs.  The high-level structure of the
 autnum object class consists of information about the Autonomous
 System number registration and entities related to the autnum
 registration (e.g., registrant information, contacts, etc.) and is
 similar to the IP network object class.
 The following is an example of a JSON object representing an autnum.
 {
   "objectClassName" : "autnum",
   "handle" : "XXXX-RIR",
   "startAutnum" : 65536,
   "endAutnum" : 65541,
   "name": "AS-RTR-1",
   "type" : "DIRECT ALLOCATION",
   "status" : [ "active" ],
   "country": "AU",
   "remarks" :
   [
     {
       "description" :
       [
         "She sells sea shells down by the sea shore.",
         "Originally written by Terry Sullivan."
       ]
     }
   ],
   "links" :
   [
     {
       "value" : "https://example.net/autnum/65537",
       "rel" : "self",
       "href" : "https://example.net/autnum/65537",
       "type" : "application/rdap+json"
     }
   ],
   "events" :
   [
     {
       "eventAction" : "registration",
       "eventDate" : "1990-12-31T23:59:59Z"
     },
     {
       "eventAction" : "last changed",
       "eventDate" : "1991-12-31T23:59:59Z"
     }
   ],
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle" : "XXXX",
       "vcardArray":[
         "vcard",
         [
           ["version", {}, "text", "4.0"],
           ["fn", {}, "text", "Joe User"],
           ["kind", {}, "text", "individual"],
           ["lang", {
             "pref":"1"
           }, "language-tag", "fr"],
           ["lang", {
             "pref":"2"
           }, "language-tag", "en"],
           ["org", {
             "type":"work"
           }, "text", "Example"],
           ["title", {}, "text", "Research Scientist"],
           ["role", {}, "text", "Project Lead"],
           ["adr",
             { "type":"work" },
             "text",
             [
               "",
               "Suite 1234",
               "4321 Rue Somewhere",
               "Quebec",
               "QC",
               "G1V 2M2",
               "Canada"
             ]
           ],
           ["tel",
             { "type":["work", "voice"], "pref":"1" },
             "uri", "tel:+1-555-555-1234;ext=102"
           ],
           ["email",
             { "type":"work" },
             "text", "joe.user@example.com"
           ]
         ]
       ],
       "roles" : [ "registrant" ],
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links" :
       [
         {
           "value" : "https://example.net/entity/XXXX",
           "rel" : "self",
           "href" : "https://example.net/entity/XXXX",
           "type" : "application/rdap+json"
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z"
         }
       ]
     }
   ]
 }
                               Figure 27
 The Autonomous System number object class can contain the following
 members:
  • objectClassName – the string "autnum"
  • handle – a string representing the RIR-unique identifier of the

autnum registration

  • startAutnum – an unsigned 32-bit integer representing the

starting number [RFC5396] in the block of Autonomous System

    numbers
  • endAutnum – an unsigned 32-bit integer representing the ending

number [RFC5396] in the block of Autonomous System numbers

  • name – a string representing an identifier assigned to the autnum

registration by the registration holder

  • type – a string containing an RIR-specific classification of the

autnum per that RIR's registration model

  • status – an array of strings indicating the state of the autnum

as defined by Section 4.6

  • country – a string containing the two-character country code of

the autnum

  • entities – an array of entity objects as defined by Section 5.1
  • remarks – see Section 4.3
  • links – see Section 4.2
  • port43 – see Section 4.7
  • events – see Section 4.5

6. Error Response Body

 Some non-answer responses MAY return entity bodies with information
 that could be more descriptive.
 The basic structure of that response is an object class containing a
 REQUIRED error code number (corresponding to the HTTP response code)
 followed by an OPTIONAL string named "title" and an OPTIONAL array of
 strings named "description".
 This is an example of the common response body.
 {
   "errorCode": 418,
   "title": "Your Beverage Choice is Not Available",
   "description":
   [
     "I know coffee has more ummppphhh.",
     "Sorry, dude!"
   ]
 }
                               Figure 28
 This is an example of the common response body with an
 rdapConformance and notices data structures:
 {
   "rdapConformance" :
   [
     "rdap_level_0"
   ],
   "notices" :
   [
     {
       "title" : "Beverage Policy",
       "description" :
       [
         "Beverages with caffeine for keeping horses awake."
       ],
       "links" :
       [
         {
           "value" : "https://example.net/ip/192.0.2.0/24",
           "rel" : "alternate",
           "type" : "text/html",
           "href" : "https://www.example.com/redaction_policy.html"
         }
       ]
     }
   ],
   "lang" : "en",
   "errorCode": 418,
   "title": "Your beverage choice is not available",
   "description":
   [
     "I know coffee has more ummppphhh.",
     "Sorry, dude!"
   ]
 }
                               Figure 29

7. Responding to Help Queries

 The appropriate response to /help queries as defined by [RFC9082] is
 to use the notices structure as defined in Section 4.3.
 This is an example of a response to a /help query including the
 rdapConformance data structure.
 {
   "rdapConformance" :
   [
     "rdap_level_0"
   ],
   "notices" :
   [
     {
       "title" : "Authentication Policy",
       "description" :
       [
         "Access to sensitive data for users with proper credentials."
       ],
       "links" :
       [
         {
           "value" : "https://example.net/help",
           "rel" : "alternate",
           "type" : "text/html",
           "href" : "https://www.example.com/auth_policy.html"
         }
       ]
     }
   ]
 }
                               Figure 30

8. Responding To Searches

 [RFC9082] specifies three types of searches: domains, nameservers,
 and entities.  Responses to these searches take the form of an array
 of object instances where each instance is an appropriate object
 class for the search (i.e., a search for /domains yields an array of
 domain object instances).  These arrays are contained within the
 response object.
 The names of the arrays are as follows:
  • for /domains searches, the array is "domainSearchResults"
  • for /nameservers searches, the array is "nameserverSearchResults"
  • for /entities searches, the array is "entitySearchResults"
 The following is an elided example of a response to a /domains
 search.
 {
   "rdapConformance" :
   [
     "rdap_level_0"
   ],
   ...
   "domainSearchResults" :
   [
     {
       "objectClassName" : "domain",
       "handle" : "1-XXXX",
       "ldhName" : "1.example.com",
       ...
     },
     {
       "objectClassName" : "domain",
       "handle" : "2-XXXX",
       "ldhName" : "2.example.com",
       ...
     }
   ]
 }
                               Figure 31

9. Indicating Truncated Responses

 In cases where the data of a response needs to be limited or parts of
 the data need to be omitted, the response is considered "truncated".
 A truncated response is still valid JSON, but some of the results in
 a search set or some of the data in an object are not provided by the
 server.  A server may indicate this by including a typed notice in
 the response object.
 The following is an elided example of a search response that has been
 truncated.
 {
   "rdapConformance" :
   [
     "rdap_level_0"
   ],
   "notices" :
   [
     {
       "title" : "Search Policy",
       "type" : "result set truncated due to authorization",
       "description" :
       [
         "Search results are limited to 25 per day per querying IP."
       ],
       "links" :
       [
         {
           "value" : "https://example.net/help",
           "rel" : "alternate",
           "type" : "text/html",
           "href" : "https://www.example.com/search_policy.html"
         }
       ]
     }
   ],
   "domainSearchResults" :
   [
     ...
   ]
 }
                               Figure 32
 A similar technique can be used with a typed remark where a single
 object has been returned and data in that object has been truncated.
 Such an example might be an entity object with only a partial set of
 the IP networks associated with it.
 The following is an elided example of an entity truncated data.
 {
   "objectClassName" : "entity",
   "handle" : "ANENTITY",
   "roles" : [ "registrant" ],
   ...
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle": "ANEMBEDDEDENTITY",
       "roles" : [ "technical" ],
       ...
     },
     ...
   ],
   "networks" :
   [
     ...
   ],
   ...
   "remarks" :
   [
     {
       "title" : "Data Policy",
       "type" : "object truncated due to unexplainable reason",
       "description" :
       [
         "Some of the data in this object has been removed."
       ],
       "links" :
       [
         {
           "value" : "https://example.net/help",
           "rel" : "alternate",
           "type" : "text/html",
           "href" : "https://www.example.com/data_policy.html"
         }
       ]
     }
   ]
 }
                               Figure 33

10. IANA Considerations

 IANA has updated the description of the "transfer" event action as
 described in Section 10.2.3.

10.1. RDAP JSON Media Type Registration

 IANA has updated the media type registration as described below.
 This specification registers the "application/rdap+json" media type.
 Type name:  application
 Subtype name:  rdap+json
 Required parameters:  n/a
 Encoding considerations:  See Section 3.1 of [RFC6839].
 Security considerations:  The media represented by this identifier
    does not have security considerations beyond that found in
    Section 12 of [RFC8259].
 Interoperability considerations:  There are no known interoperability
    problems regarding this media format.
 Published specification:  RFC 9083
 Applications that use this media type:  Implementations of the
    Registration Data Access Protocol (RDAP).
 Additional information:  This media type is a product of the IETF
    REGEXT Working Group.  The REGEXT charter, information on the
    REGEXT mailing list, and other documents produced by the REGEXT
    Working Group can be found at https://datatracker.ietf.org/wg/
    regext/.
 Person & email address to contact for further information:
    IESG <iesg@ietf.org>
 Intended usage:  COMMON
 Restrictions on usage:  none
 Author:  Andy Newton
 Change controller:  IETF
 Provisional Registration:  No

10.2. JSON Values Registry

 IANA has created a category in the protocol registries labeled
 "Registration Data Access Protocol (RDAP)", and within that category,
 IANA has established a URL-referenceable, stand-alone registry
 labeled "RDAP JSON Values".  This new registry is for use in the
 notices and remarks (Section 4.3), status (Section 4.6), role
 (Section 5.1), event action (Section 4.5), and domain variant
 relation (Section 5.3) fields specified in RDAP.
 Each entry in the registry contains the following fields:
 1.  Value -- the string value being registered.
 2.  Type -- the type of value being registered.  It should be one of
     the following:
  • "notice or remark type" – denotes a type of notice or remark.
  • "status" – denotes a value for the "status" object member as

defined by Section 4.6.

  • "role" – denotes a value for the "role" array as defined in

Section 5.1.

  • "event action" – denotes a value for an event action as

defined in Section 4.5.

  • "domain variant relation" – denotes a relationship between a

domain and a domain variant as defined in Section 5.3.

 3.  Description -- a one- or two-sentence description regarding the
     meaning of the value, how it might be used, and/or how it should
     be interpreted by clients.
 4.  Registrant Name -- the name of the person registering the value.
 5.  Registrant Contact Information -- an email address, postal
     address, or some other information to be used to contact the
     registrant.
 This registry is operated under the "Expert Review" policy defined in
 [RFC8126].
 Review of registrations into this registry by the designated
 expert(s) should be narrowly judged on the following criteria:
 1.  Values in need of being placed into multiple types must be
     assigned a separate registration for each type.
 2.  Values must be strings.  They should be multiple words separated
     by single space characters.  Every character should be
     lowercased.  If possible, every word should be given in English
     and each character should be US-ASCII.
 3.  Registrations should not duplicate the meaning of any existing
     registration.  That is, if a request for a registration is
     significantly similar in nature to an existing registration, the
     request should be denied.  For example, the terms "maintainer"
     and "registrant" are significantly similar in nature as they both
     denote a holder of a domain name or Internet number resource.  In
     cases where it may be reasonably argued that machine
     interpretation of two similar values may alter the operation of
     client software, designated experts should not judge the values
     to be of significant similarity.
 4.  Registrations should be relevant to the common usages of RDAP.
     Designated experts may rely upon the serving of the value by a
     DNR or RIR to make this determination.
 The following sections provide initial registrations into this
 registry.

10.2.1. Notice and Remark Types

 The following values have been registered in the "RDAP JSON Values"
 registry:
 Value:  result set truncated due to authorization
 Type:  notice and remark type
 Description:  The list of results does not contain all results due to
    lack of authorization.  This may indicate to some clients that
    proper authorization will yield a longer result set.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  result set truncated due to excessive load
 Type:  notice and remark type
 Description:  The list of results does not contain all results due to
    an excessively heavy load on the server.  This may indicate to
    some clients that requerying at a later time will yield a longer
    result set.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  result set truncated due to unexplainable reasons
 Type:  notice and remark type
 Description:  The list of results does not contain all results for an
    unexplainable reason.  This may indicate to some clients that
    requerying for any reason will not yield a longer result set.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  object truncated due to authorization
 Type:  notice and remark type
 Description:  The object does not contain all data due to lack of
    authorization.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  object truncated due to excessive load
 Type:  notice and remark type
 Description:  The object does not contain all data due to an
    excessively heavy load on the server.  This may indicate to some
    clients that requerying at a later time will yield all data of the
    object.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  object truncated due to unexplainable reasons
 Type:  notice and remark type
 Description:  The object does not contain all data for an
    unexplainable reason.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org

10.2.2. Status

 The following values have been registered in the "RDAP JSON Values"
 registry:
 Value:  validated
 Type:  status
 Description:  Signifies that the data of the object instance has been
    found to be accurate.  This type of status is usually found on
    entity object instances to note the validity of identifying
    contact information.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  renew prohibited
 Type:  status
 Description:  Renewal or reregistration of the object instance is
    forbidden.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  update prohibited
 Type:  status
 Description:  Updates to the object instance are forbidden.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  transfer prohibited
 Type:  status
 Description:  Transfers of the registration from one registrar to
    another are forbidden.  This type of status normally applies to
    DNR domain names.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  delete prohibited
 Type:  status
 Description:  Deletion of the registration of the object instance is
    forbidden.  This type of status normally applies to DNR domain
    names.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  proxy
 Type:  status
 Description:  The registration of the object instance has been
    performed by a third party.  This is most commonly applied to
    entities.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  private
 Type:  status
 Description:  The information of the object instance is not
    designated for public consumption.  This is most commonly applied
    to entities.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  removed
 Type:  status
 Description:  Some of the information of the object instance has not
    been made available and has been removed.  This is most commonly
    applied to entities.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  obscured
 Type:  status
 Description:  Some of the information of the object instance has been
    altered for the purposes of not readily revealing the actual
    information of the object instance.  This is most commonly applied
    to entities.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  associated
 Type:  status
 Description:  The object instance is associated with other object
    instances in the registry.  This is most commonly used to signify
    that a nameserver is associated with a domain or that an entity is
    associated with a network resource or domain.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  active
 Type:  status
 Description:  The object instance is in use.  For domain names, it
    signifies that the domain name is published in DNS.  For network
    and autnum registrations, it signifies that they are allocated or
    assigned for use in operational networks.  This maps to the "OK"
    status of the Extensible Provisioning Protocol (EPP) [RFC5730].
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  inactive
 Type:  status
 Description:  The object instance is not in use.  See "active".
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  locked
 Type:  status
 Description:  Changes to the object instance cannot be made,
    including the association of other object instances.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  pending create
 Type:  status
 Description:  A request has been received for the creation of the
    object instance, but this action is not yet complete.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  pending renew
 Type:  status
 Description:  A request has been received for the renewal of the
    object instance, but this action is not yet complete.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  pending transfer
 Type:  status
 Description:  A request has been received for the transfer of the
    object instance, but this action is not yet complete.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  pending update
 Type:  status
 Description:  A request has been received for the update or
    modification of the object instance, but this action is not yet
    complete.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  pending delete
 Type:  status
 Description:  A request has been received for the deletion or removal
    of the object instance, but this action is not yet complete.  For
    domains, this might mean that the name is no longer published in
    DNS but has not yet been purged from the registry database.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org

10.2.3. Event Actions

 The following values have been registered in the "RDAP JSON Values"
 registry:
 Value:  registration
 Type:  event action
 Description:  The object instance was initially registered.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  reregistration
 Type:  event action
 Description:  The object instance was registered subsequently to
    initial registration.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  last changed
 Type:  event action
 Description:  An action noting when the information in the object
    instance was last changed.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  expiration
 Type:  event action
 Description:  The object instance has been removed or will be removed
    at a predetermined date and time from the registry.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  deletion
 Type:  event action
 Description:  The object instance was removed from the registry at a
    point in time that was not predetermined.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  reinstantiation
 Type:  event action
 Description:  The object instance was reregistered after having been
    removed from the registry.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  transfer
 Type:  event action
 Description:  The object instance was transferred from one registrar
    to another.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  locked
 Type:  event action
 Description:  The object instance was locked (see the "locked"
    status).
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  unlocked
 Type:  event action
 Description:  The object instance was unlocked (see the "locked"
    status).
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org

10.2.4. Roles

 The following values have been registered in the "RDAP JSON Values"
 registry:
 Value:  registrant
 Type:  role
 Description:  The entity object instance is the registrant of the
    registration.  In some registries, this is known as a maintainer.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  technical
 Type:  role
 Description:  The entity object instance is a technical contact for
    the registration.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  administrative
 Type:  role
 Description:  The entity object instance is an administrative contact
    for the registration.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  abuse
 Type:  role
 Description:  The entity object instance handles network abuse issues
    on behalf of the registrant of the registration.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  billing
 Type:  role
 Description:  The entity object instance handles payment and billing
    issues on behalf of the registrant of the registration.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  registrar
 Type:  role
 Description:  The entity object instance represents the authority
    responsible for the registration in the registry.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  reseller
 Type:  role
 Description:  The entity object instance represents a third party
    through which the registration was conducted (i.e., not the
    registry or registrar).
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  sponsor
 Type:  role
 Description:  The entity object instance represents a domain policy
    sponsor, such as an ICANN-approved sponsor.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  proxy
 Type:  role
 Description:  The entity object instance represents a proxy for
    another entity object, such as a registrant.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  notifications
 Type:  role
 Description:  An entity object instance designated to receive
    notifications about association object instances.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  noc
 Type:  role
 Description:  The entity object instance handles communications
    related to a network operations center (NOC).
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org

10.2.5. Variant Relations

 The following values have been registered in the "RDAP JSON Values"
 registry:
 Value:  registered
 Type:  domain variant relation
 Description:  The variant names are registered in the registry.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  unregistered
 Type:  domain variant relation
 Description:  The variant names are not found in the registry.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  registration restricted
 Type:  domain variant relation
 Description:  Registration of the variant names is restricted to
    certain parties or within certain rules.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  open registration
 Type:  domain variant relation
 Description:  Registration of the variant names is available to
    generally qualified registrants.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org
 Value:  conjoined
 Type:  domain variant relation
 Description:  Registration of the variant names occurs automatically
    with the registration of the containing domain registration.
 Registrant Name:  IESG
 Registrant Contact Information:  iesg@ietf.org

11. Security Considerations

 This specification models information serialized in JSON format.  As
 JSON is a subset of JavaScript, implementations are advised to follow
 the security considerations outlined in Section 12 of [RFC8259] to
 prevent code injection.
 Though not specific to JSON, RDAP implementers should be aware of the
 security considerations specified in [RFC7480] and the security
 requirements and considerations in [RFC7481].
 RDAP responses allow for retrieval of DNSSEC (key) related
 information, but the RRSIG DS from the parent zone is not conveyed
 alongside it.  This means that the DNSSEC keys retrieved by RDAP are
 disconnected from their containing PKI, and as such are not generally
 expected to be trusted without additional information.  In
 particular, the HTTPS channel protecting the RDAP connection is not
 expected to be authorized to certify the validity of the DNSSEC keys.
 Clients caching data, especially clients using RDAP-specific caches
 (instead of HTTP-layer caches), should have safeguards to prevent
 cache poisoning.  See Section 5 for advice on using the self links
 for caching.
 Finally, service operators should be aware of the privacy mechanisms
 noted in Section 13.

12. Internationalization Considerations

12.1. Character Encoding

 The default text encoding for JSON responses in RDAP is UTF-8
 [RFC3629], and all servers and clients MUST support UTF-8.

12.2. URIs and IRIs

 [RFC7480] defines the use of URIs and IRIs in RDAP.

12.3. Language Tags

 Section 4.4 defines the use of language tags in the JSON responses
 defined in this document.

12.4. Internationalized Domain Names

 IDNs are denoted in this specification by the separation of DNS names
 in LDH form and Unicode form (see Section 3).  Representation of IDNs
 in registries is described by the "variants" object in Section 5.3
 and the suggested values listed in Section 10.2.5.

13. Privacy Considerations

 This specification suggests status values to denote contact and
 registrant information that has been marked as private and/or has
 been removed or obscured.  See Section 10.2.2 for the complete list
 of status values.  A few of the status values indicate that there are
 privacy concerns associated with the object instance.  The following
 status codes SHOULD be used to describe data elements of a response
 when appropriate:
  • private – The object is not be shared in query responses, unless

the user is authorized to view this information.

  • removed – Data elements within the object have been collected but

have been omitted from the response. This option can be used to

    prevent unauthorized access to associated object instances without
    the need to mark them as private.
  • obscured – Data elements within the object have been collected,

but the response value has been altered so that values are not

    easily discernible.  A value changed from "1212" to "XXXX" is an
    example of obscured data.  This option may reveal privacy
    sensitive information and should only be used when data
    sensitivity does not require a more protective option like
    "private" or "removed".
 See Appendix A.1 for an example of applying those values to contacts
 and registrants.

14. References

14.1. Normative References

 [ISO.3166.2020]
            International Organization for Standardization, "Codes for
            the representation of names of countries and their
            subdivisions", Fourth edition, ISO Standard 3166, August
            2020.
 [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>.
 [RFC3339]  Klyne, G. and C. Newman, "Date and Time on the Internet:
            Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
            <https://www.rfc-editor.org/info/rfc3339>.
 [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
            10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
            2003, <https://www.rfc-editor.org/info/rfc3629>.
 [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>.
 [RFC4034]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
            Rose, "Resource Records for the DNS Security Extensions",
            RFC 4034, DOI 10.17487/RFC4034, March 2005,
            <https://www.rfc-editor.org/info/rfc4034>.
 [RFC5396]  Huston, G. and G. Michaelson, "Textual Representation of
            Autonomous System (AS) Numbers", RFC 5396,
            DOI 10.17487/RFC5396, December 2008,
            <https://www.rfc-editor.org/info/rfc5396>.
 [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
            Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
            September 2009, <https://www.rfc-editor.org/info/rfc5646>.
 [RFC5890]  Klensin, J., "Internationalized Domain Names for
            Applications (IDNA): Definitions and Document Framework",
            RFC 5890, DOI 10.17487/RFC5890, August 2010,
            <https://www.rfc-editor.org/info/rfc5890>.
 [RFC5952]  Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
            Address Text Representation", RFC 5952,
            DOI 10.17487/RFC5952, August 2010,
            <https://www.rfc-editor.org/info/rfc5952>.
 [RFC7095]  Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095,
            DOI 10.17487/RFC7095, January 2014,
            <https://www.rfc-editor.org/info/rfc7095>.
 [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>.
 [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>.
 [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
            Writing an IANA Considerations Section in RFCs", BCP 26,
            RFC 8126, DOI 10.17487/RFC8126, June 2017,
            <https://www.rfc-editor.org/info/rfc8126>.
 [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>.
 [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
            Interchange Format", STD 90, RFC 8259,
            DOI 10.17487/RFC8259, December 2017,
            <https://www.rfc-editor.org/info/rfc8259>.
 [RFC8288]  Nottingham, M., "Web Linking", RFC 8288,
            DOI 10.17487/RFC8288, October 2017,
            <https://www.rfc-editor.org/info/rfc8288>.
 [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>.

14.2. Informative References

 [IANA_IDNTABLES]
            IANA, "Repository of IDN Practices",
            <https://www.iana.org/domains/idn-tables>.
 [JSON_ascendancy]
            MacVittie, L., "The Stealthy Ascendancy of JSON", April
            2011, <https://devcentral.f5.com/s/articles/the-stealthy-
            ascendancy-of-json>.
 [JSON_performance_study]
            Nurseitov, N., Paulson, M., Reynolds, R., and C. Izurieta,
            "Comparison of JSON and XML Data Interchange Formats: A
            Case Study", 2009,
            <https://www.cs.montana.edu/izurieta/pubs/caine2009.pdf>.
 [RFC3912]  Daigle, L., "WHOIS Protocol Specification", RFC 3912,
            DOI 10.17487/RFC3912, September 2004,
            <https://www.rfc-editor.org/info/rfc3912>.
 [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
            STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
            <https://www.rfc-editor.org/info/rfc5730>.
 [RFC5910]  Gould, J. and S. Hollenbeck, "Domain Name System (DNS)
            Security Extensions Mapping for the Extensible
            Provisioning Protocol (EPP)", RFC 5910,
            DOI 10.17487/RFC5910, May 2010,
            <https://www.rfc-editor.org/info/rfc5910>.
 [RFC6350]  Perreault, S., "vCard Format Specification", RFC 6350,
            DOI 10.17487/RFC6350, August 2011,
            <https://www.rfc-editor.org/info/rfc6350>.
 [RFC6839]  Hansen, T. and A. Melnikov, "Additional Media Type
            Structured Syntax Suffixes", RFC 6839,
            DOI 10.17487/RFC6839, January 2013,
            <https://www.rfc-editor.org/info/rfc6839>.

Appendix A. Suggested Data Modeling with the Entity Object Class

A.1. Registrants and Contacts

 This document does not provide specific object classes for
 registrants and contacts.  Instead, the entity object class may be
 used to represent a registrant or contact.  When the entity object is
 embedded inside a containing object such as a domain name or IP
 network, the "roles" string array can be used to signify the
 relationship.  It is recommended that the values from Section 10.2.4
 be used.
 The following is an example of an elided containing object with an
 embedded entity that is both a registrant and administrative contact:
 {
   ...
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle" : "XXXX",
       "vcardArray":[
         "vcard",
         [
           ["version", {}, "text", "4.0"],
           ["fn", {}, "text", "Joe User"],
           ["kind", {}, "text", "individual"],
           ["lang", {
             "pref":"1"
           }, "language-tag", "fr"],
           ["lang", {
             "pref":"2"
           }, "language-tag", "en"],
           ["org", {
             "type":"work"
           }, "text", "Example"],
           ["title", {}, "text", "Research Scientist"],
           ["role", {}, "text", "Project Lead"],
           ["adr",
             { "type":"work" },
             "text",
             [
               "",
               "Suite 1234",
               "4321 Rue Somewhere",
               "Quebec",
               "QC",
               "G1V 2M2",
               "Canada"
             ]
           ],
           ["tel",
             { "type":["work", "voice"], "pref":"1" },
             "uri", "tel:+1-555-555-1234;ext=102"
           ],
           ["email",
             { "type":"work" },
             "text", "joe.user@example.com"
           ]
         ]
       ],
       "roles" : [ "registrant", "administrative" ],
       "remarks" :
       [
         {
           "description" :
           [
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "events" :
       [
         {
           "eventAction" : "registration",
           "eventDate" : "1990-12-31T23:59:59Z"
         },
         {
           "eventAction" : "last changed",
           "eventDate" : "1991-12-31T23:59:59Z"
         }
       ]
     }
   ]
 }
                               Figure 34
 In many use cases, it is necessary to hide or obscure the information
 of a registrant or contact due to policy or other operational
 matters.  Registries can denote these situations with "status" values
 (see Section 10.2.2).
 The following is an elided example of a registrant with information
 changed to reflect that of a third party.
 {
   ...
   "entities" :
   [
     {
       "objectClassName" : "entity",
       "handle" : "XXXX",
       ...
       "roles" : [ "registrant", "administrative" ],
       "status" : [ "proxy", "private", "obscured" ]
     }
   ]
 }
                               Figure 35

A.2. Registrars

 This document does not provide a specific object class for
 registrars, but like registrants and contacts (see Appendix A.1), the
 "roles" string array maybe used.  Additionally, many registrars have
 publicly assigned identifiers.  The publicIds structure (Section 4.8)
 represents that information.
 The following is an example of an elided containing object with an
 embedded entity that is a registrar:
 {
   ...
   "entities":[
     {
       "objectClassName" : "entity",
       "handle":"XXXX",
       "vcardArray":[
         "vcard",
         [
           ["version", {}, "text", "4.0"],
           ["fn", {}, "text", "Joe's Fish, Chips, and Domains"],
           ["kind", {}, "text", "org"],
           ["lang", {
             "pref":"1"
           }, "language-tag", "fr"],
           ["lang", {
             "pref":"2"
           }, "language-tag", "en"],
           ["org", {
             "type":"work"
           }, "text", "Example"],
           ["adr",
             { "type":"work" },
             "text",
             [
               "",
               "Suite 1234",
               "4321 Rue Somewhere",
               "Quebec",
               "QC",
               "G1V 2M2",
               "Canada"
             ]
           ],
           ["tel",
             {
               "type":["work", "voice"],
               "pref":"1"
             },
             "uri", "tel:+1-555-555-1234;ext=102"
           ],
           ["email",
             { "type":"work" },
             "text", "joes_fish_chips_and_domains@example.com"
           ]
         ]
       ],
       "roles":[ "registrar" ],
       "publicIds":[
         {
           "type":"IANA Registrar ID",
           "identifier":"1"
         }
       ],
       "remarks":[
         {
           "description":[
             "She sells sea shells down by the sea shore.",
             "Originally written by Terry Sullivan."
           ]
         }
       ],
       "links":[
         {
           "value":"https://example.net/entity/XXXX",
           "rel":"alternate",
           "type":"text/html",
           "href":"https://www.example.com"
         }
       ]
     }
   ]
 }
                               Figure 36

Appendix B. Modeling Events

 Events represent actions that have taken place against a registered
 object at a certain date and time.  Events have three properties: the
 action, the actor, and the date and time of the event (which is
 sometimes in the future).  In some cases, the identity of the actor
 is not captured.
 Events can be modeled in three ways:
 1.  events with no designated actor
 2.  events where the actor is only designated by an identifier
 3.  events where the actor can be modeled as an entity
 For the first use case, the events data structure (Section 4.5) is
 used without the "eventActor" object member.
 This is an example of an "events" array without the "eventActor".
 "events" :
 [
   {
     "eventAction" : "registration",
     "eventDate" : "1990-12-31T23:59:59Z"
   }
 ]
                               Figure 37
 For the second use case, the events data structure (Section 4.5) is
 used with the "eventActor" object member.
 This is an example of an "events" array with the "eventActor".
 "events" :
 [
   {
     "eventAction" : "registration",
     "eventActor" : "XYZ-NIC",
     "eventDate" : "1990-12-31T23:59:59Z"
   }
 ]
                               Figure 38
 For the third use case, the "asEventActor" array is used when an
 entity (Section 5.1) is embedded into another object class.  The
 "asEventActor" array follows the same structure as the "events" array
 but does not have "eventActor" attributes.
 The following is an elided example of a domain object with an entity
 as an event actor.
 {
   "objectClassName" : "domain",
   "handle" : "XXXX",
   "ldhName" : "foo.example",
   "status" : [ "locked", "transfer prohibited" ],
   ...
   "entities" :
   [
     {
       "handle" : "XXXX",
       ...
       "asEventActor" :
       [
         {
           "eventAction" : "last changed",
           "eventDate" : "1990-12-31T23:59:59Z"
         }
       ]
     }
   ]
 }
                               Figure 39

Appendix C. Structured vs. Unstructured Addresses

 The entity (Section 5.1) object class uses jCard [RFC7095] to
 represent contact information, including postal addresses. jCard has
 the ability to represent multiple language preferences, multiple
 email address and phone numbers, and multiple postal addresses in
 both a structured and unstructured format.  This section describes
 the use of jCard for representing structured and unstructured
 addresses.
 The following is an example of a jCard.
 {
   "vcardArray":[
     "vcard",
     [
       ["version", {}, "text", "4.0"],
       ["fn", {}, "text", "Joe User"],
       ["n", {}, "text",
         ["User", "Joe", "", "", ["ing. jr", "M.Sc."]]
       ],
       ["kind", {}, "text", "individual"],
       ["lang", {
         "pref":"1"
       }, "language-tag", "fr"],
       ["lang", {
         "pref":"2"
       }, "language-tag", "en"],
       ["org", {
         "type":"work"
       }, "text", "Example"],
       ["title", {}, "text", "Research Scientist"],
       ["role", {}, "text", "Project Lead"],
       ["adr",
         { "type":"work" },
         "text",
         [
           "",
           "Suite 1234",
           "4321 Rue Somewhere",
           "Quebec",
           "QC",
           "G1V 2M2",
           "Canada"
         ]
       ],
       ["adr",
         {
           "type":"home",
           "label":"123 Maple Ave\nSuite 90001\nVancouver\nBC\n1239\n"
         },
         "text",
         [
           "", "", "", "", "", "", ""
         ]
       ],
       ["tel",
         { "type":["work", "voice"], "pref":"1" },
         "uri", "tel:+1-555-555-1234;ext=102"
       ],
       ["tel",
         {
           "type":["work", "cell", "voice", "video", "text"]
         },
         "uri",
         "tel:+1-555-555-1234"
       ],
       ["email",
         { "type":"work" },
         "text", "joe.user@example.com"
       ],
       ["geo", {
         "type":"work"
       }, "uri", "geo:46.772673,-71.282945"],
       ["key",
         { "type":"work" },
         "uri", "https://www.example.com/joe.user/joe.asc"
       ],
       ["tz", {},
         "utc-offset", "-05:00"],
       ["url", { "type":"home" },
         "uri", "https://example.org"]
     ]
   ]
 }
                               Figure 40
 The arrays in Figure 40 with the first member of "adr" represent
 postal addresses.  In the first example, the postal address is given
 as an array of strings and constitutes a structured address.  For
 components of the structured address that are not applicable, an
 empty string is given.  Each member of that array aligns with the
 positions of a vCard as given in [RFC6350].  In this example, the
 following data corresponds to the following positional meanings:
 1.  post office box -- not applicable; empty string
 2.  extended address (e.g., apartment or suite number) -- Suite 1234
 3.  street address -- 4321 Rue Somewhere
 4.  locality (e.g., city) -- Quebec
 5.  region (e.g., state or province) -- QC
 6.  postal code -- G1V 2M2
 7.  country name (full name) -- Canada
 The second example is an unstructured address.  It uses the "label"
 attribute, which is a string containing a newline (\n) character to
 separate address components in an unordered, unspecified manner.
 Note that in this example, the structured address array is still
 given but that each string is an empty string.

Appendix D. Secure DNS

 Section 5.3 defines the "secureDNS" member to represent secure DNS
 information about domain names.
 DNSSEC provides data integrity for DNS through the digital signing of
 resource records.  To enable DNSSEC, the zone is signed by one or
 more private keys and the signatures are stored as RRSIG records.  To
 complete the chain of trust in the DNS zone hierarchy, a digest of
 each DNSKEY record (which contains the public key) must be loaded
 into the parent zone, stored as DS records, and signed by the
 parent's private key (RRSIG DS record), as indicated in "Resource
 Records for the DNS Security Extensions" [RFC4034].  Creating the DS
 records in the parent zone can be done by the registration authority
 "Domain Name System (DNS) Security Extensions Mapping for the
 Extensible Provisioning Protocol (EPP)" [RFC5910].
 Only DS-related information is provided by RDAP, since other
 information is not generally stored in the registration database.
 Other DNSSEC-related information can be retrieved with other DNS
 tools such as dig.
 The domain object class (Section 5.3) can represent this information
 using either the "dsData" or "keyData" object arrays.  Client
 implementers should be aware that some registries do not collect or
 do not publish all of the secure DNS meta-information.

Appendix E. Motivations for Using JSON

 This section addresses a common question regarding the use of JSON
 over other data formats, most notably XML.
 It is often pointed out that many DNRs and one RIR support the EPP
 [RFC5730] standard, which is an XML serialized protocol.  The logic
 is that since EPP is a common protocol in the industry, it follows
 that XML would be a more natural choice.  While EPP does influence
 this specification quite a bit, EPP serves a different purpose, which
 is the provisioning of Internet resources between registries and
 accredited registrars and serving a much narrower audience than that
 envisioned for RDAP.
 By contrast, RDAP has a broader audience and is designed for public
 consumption of data.  Experience from RIRs with first generation
 RESTful web services for WHOIS indicate that a large percentage of
 clients operate within browsers and other platforms where full-blown
 XML stacks are not readily available and where JSON is a better fit.
 Additionally, while EPP is used in much of the DNR community it is
 not a universal constant in that industry.  And finally, EPP's use of
 XML predates the specification of JSON.  If EPP had been defined
 today, it may very well have used JSON instead of XML.
 Beyond the specific DNR and RIR communities, the trend in the broader
 Internet industry is also switching to JSON over XML, especially in
 the area of RESTful web services (see [JSON_ascendancy]).  Studies
 have also found that JSON is generally less bulky and consequently
 faster to parse (see [JSON_performance_study]).

Appendix F. Changes from RFC 7483

  • Addressed known errata.
  • Updated references to 7482 to RFC 9082. Adjusted case of "xxxx"

used in examples where "XXXX" was previously used, and removed an

    "X" from "XXXXX".  Changed IPv6 address example using "C00" to
    "c00".  Added "a string representing" to the definitions of
    startAddress and endAddress.  Removed "entity" from "Autonomous
    System Number Entity Object Class".  Added "an unsigned 32-bit
    integer" to the definition of startAutnum and endAutnum.  Added "a
    string representing" to the definition of name in the IP network
    and ASN object classes.  Clarified rdapConformance identifier
    registration expectations in Section 4.1.  Changed
    "lunarNic_level_0" to "lunarNIC_level_0".
  • Clarified that the "value", "rel" and "href" JSON values MUST be

specified in the "links" array.

  • Clarified that the "description" array is required in the Notices

and Remarks data structures and other values are OPTIONAL.

  • Noted that all members of the "events" and "Public IDs" arrays are

REQUIRED.

  • Fix "self" link values in examples. Changed "http" to "https"

link values in examples. Noted that Figure 18 is an example of a

    nameserver object with all "appropriate" values given.  In
    Appendix C, quoted the word "label" in "label attribute".  Added
    reference to "status" definition in the descriptions for IP
    networks and autnums.  Fixed a 404 for the informative reference
    to "The Stealthy Ascendancy of JSON".  Added "boolean" to the
    definition of zoneSigned.
  • Clarified REQUIRED and OPTIONAL members of the "events" array.
  • Changed "SHOULD not" to "SHOULD NOT" in Section 5.
  • Updated normative references (RFC 5226 to RFC 8126, RFC 5988 to

RFC 8288, RFC 7159 to RFC 8259). Changed examples using "ns1.xn–

    fo-5ja.example" to split URLs to avoid long lines.
  • Added acknowledgments.
  • Changed "The "lang" attribute may appear anywhere in an object

class or data structure except for in jCard objects" to "The

    "lang" attribute as defined in this section MAY appear anywhere in
    an object class or data structure, except for in jCard objects.
    jCard supports similar functionality by way of the LANGUAGE
    property parameter (see Section 5.1 of RFC 6350 [RFC6350]".
  • Changed "simple data types conveyed in JSON strings" to "simple

data types conveyed in JSON primitive types (strings, numbers,

    booleans, and null)".  Changed "In other words, servers are free
    to not include JSON members containing registration data based on
    their own policies" to "In other words, servers are free to omit
    unrequired/optional JSON members containing registration data
    based on their own policies".
  • Changed "This data structure appears only in the topmost JSON

object of a response" to "This data structure MUST appear in the

    topmost JSON object of a response".
  • Changed "Some non-answer responses may return entity bodies with

information that could be more descriptive" to "Some non-answer

    responses MAY return entity bodies with information that could be
    more descriptive".
  • Changed "The basic structure of that response is an object class

containing an error code number (corresponding to the HTTP

    response code) followed by a string named "title" and an array of
    strings named "description"" to "The basic structure of that
    response is an object class containing a REQUIRED error code
    number (corresponding to the HTTP response code) followed by an
    OPTIONAL string named "title" and an OPTIONAL array of strings
    named "description"".
  • Changed the "Autonomous System Number Object Class" section title

to "The Autonomous System Number Object Class" for consistency

    with other section titles.  Removed trailing periods in the
    "Terminology and Definitions" section for consistency.  Changed
    instances of "lunarNic" to "lunarNIC" for consistency.  Removed an
    extraneous trailing period after the eventDate description.
    Changed a "." to ";" in the description of the "network" member of
    the domain object class.  Changed "The high-level structure of the
    autnum object class consists of information about the network
    registration" to "The high-level structure of the autnum object
    class consists of information about the Autonomous System number
    registration".  Changed "registry unique" to "registry-unique".
  • Changed "registrant" to "registrar" in the description of the

"transfer" event action to address erratum 6158. Added IANA

    instructions to correct the description of the value in the
    registry.
  • Added text to Section 4.2 to note that "self" and "related" "href"

URIs MUST NOT be the same.

  • Added text to Section 4.2 to describe return of IDNs in LDH name

format.

  • Added text to note that the "fn" member of a contact object MAY be

empty in Section 3.

  • Added text to clarify rdapConformance requirements in Section 4.1.
  • Added "obsoletes 7483" to the headers, Abstract, and Introduction.

Updated BCP 14 boilerplate. Updated IANA Considerations to note

    that this RFC (a product of the REGEXT Working Group) replaces RFC
    7483.  Changed "simple string" to "simple character string" in
    Sections 3 and 4.7.  Clarified requirement for the "fn" member in
    Section 3.  Modified the requirement for rdapConformance placement
    in Section 4.1.  Changed "jCard" to "vCard" LANGUAGE property
    reference in Section 4.4.  Changed "no use" to "little or no use"
    in Section 5.1.  Added example line wrap note in Section 5.2.
    Modified the definition of "idnTable" in Section 5.3.  Modified
    the dsData and keyData examples in Section 5.3.  Changed
    "2001:c00::/23" to "2001:db8::/32" in Section 5.4.  Expanded the
    definition of "type" in Sections 5.4 and 5.5.  Modified example
    autnums in Section 5.5.  Added text to the Security Considerations
    section to note that DNSSEC information returned in a response
    cannot be trusted directly.

Acknowledgments

 This document is derived from original work on RIR responses in JSON
 by Byron J. Ellacott, Arturo L. Servin, Kaveh Ranjbar, and Andrew L. 
 Newton.  Additionally, this document incorporates work on DNR
 responses in JSON by Ning Kong, Linlin Zhou, Jiagui Xie, and Sean
 Shen.
 The components of the DNR object classes are derived from a
 categorization of WHOIS response formats created by Ning Kong, Linlin
 Zhou, Guangqing Deng, Steve Sheng, Francisco Arias, Ray Bellis, and
 Frederico Neves.
 Tom Harrison, Murray Kucherawy, Ed Lewis, Audric Schiltknecht, Naoki
 Kambe, Maarten Bosteels, Mario Loffredo, and Jasdip Singh contributed
 significant review comments and provided clarifying text.  James
 Mitchell provided text regarding the processing of unknown JSON
 attributes and identified issues leading to the remodeling of events.
 Ernie Dainow and Francisco Obispo provided concrete suggestions that
 led to a better variant model for domain names.
 Ernie Dainow provided the background information on the secure DNS
 attributes and objects for domains, informative text on DNSSEC, and
 many other attributes that appear throughout the object classes of
 this document.
 The switch to and incorporation of jCard was performed by Simon
 Perreault.
 Olaf Kolkman and Murray Kucherawy chaired the IETF's WEIRDS Working
 Group from which this document was originally created.  James Galvin
 and Antoin Verschuren chaired the REGEXT Working Group that worked on
 this document.

Authors' Addresses

 Scott Hollenbeck
 Verisign Labs
 12061 Bluemont Way
 Reston, VA 20190
 United States of America
 Email: shollenbeck@verisign.com
 URI:   https://www.verisignlabs.com/
 Andy Newton
 Amazon Web Services, Inc.
 13200 Woodland Park Road
 Herndon, VA 20171
 United States of America
 Email: andy@hxr.us

Internet Engineering Task Force (IETF) M. Blanchet Request for Comments: 9224 Viagenie STD: 95 March 2022 Obsoletes: 7484 Category: Standards Track ISSN: 2070-1721

 Finding the Authoritative Registration Data Access Protocol (RDAP)
                              Service

Abstract

 This document specifies a method to find which Registration Data
 Access Protocol (RDAP) server is authoritative to answer queries for
 a requested scope, such as domain names, IP addresses, or Autonomous
 System numbers.  This document obsoletes RFC 7484.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 https://www.rfc-editor.org/info/rfc9224.

Copyright Notice

 Copyright (c) 2022 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (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
 2.  Conventions Used in This Document
 3.  Structure of the RDAP Bootstrap Service Registries
 4.  Bootstrap Service Registry for Domain Name Space
 5.  Bootstrap Service Registries for Internet Numbers
   5.1.  Bootstrap Service Registry for IPv4 Address Space
   5.2.  Bootstrap Service Registry for IPv6 Address Space
   5.3.  Bootstrap Service Registry for AS Number Space
 6.  Entity
 7.  Non-existent Entries or RDAP URL Values
 8.  Deployment and Implementation Considerations
 9.  Limitations
 10. Formal Definition
   10.1.  Imported JSON Terms
   10.2.  Registry Syntax
 11. Security Considerations
 12. IANA Considerations
   12.1.  Bootstrap Service Registry for IPv4 Address Space
   12.2.  Bootstrap Service Registry for IPv6 Address Space
   12.3.  Bootstrap Service Registry for AS Number Space
   12.4.  Bootstrap Service Registry for Domain Name Space
 13. References
   13.1.  Normative References
   13.2.  Informative References
 Appendix A.  Changes since RFC 7484
 Acknowledgements
 Author's Address

1. Introduction

 Querying and retrieving registration data from registries are defined
 in the Registration Data Access Protocol (RDAP) [RFC7480] [RFC7481]
 [RFC9082] [RFC9083].  These documents do not specify where to send
 the queries.  This document specifies a method to find which server
 is authoritative to answer queries for the requested scope.
 Top-Level Domains (TLDs), Autonomous System (AS) numbers, and network
 blocks are delegated by IANA to Internet registries such as TLD
 registries and Regional Internet Registries (RIRs) that then issue
 further delegations and maintain information about them.  Thus, the
 bootstrap information needed by RDAP clients is best generated from
 data and processes already maintained by IANA; the relevant
 registries already exist at [ipv4reg], [ipv6reg], [asreg], and
 [domainreg].  This document obsoletes [RFC7484].
 Per this document, IANA has created new registries based on a JSON
 format specified in this document, herein named RDAP Bootstrap
 Service Registries.  These new registries are based on the existing
 entries of the above-mentioned registries.  An RDAP client fetches
 the RDAP Bootstrap Service Registries, extracts the data, and then
 performs a match with the query data to find the authoritative
 registration data server and appropriate query base URL.

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. Structure of the RDAP Bootstrap Service Registries

 The RDAP Bootstrap Service Registries, as specified in Section 12
 below, have been made available as JSON [RFC8259] objects, which can
 be retrieved via HTTP from locations specified by IANA.  The JSON
 object for each registry contains a series of members containing
 metadata about the registry such as a version identifier, a timestamp
 of the publication date of the registry, and a description.
 Additionally, a "services" member contains the registry items
 themselves, as an array.  Each item of the array contains a second-
 level array, with two elements, each of them being a third-level
 array.
 Each element of the Services Array is a second-level array with two
 elements: in order, an Entry Array and a Service URL Array.
 The Entry Array contains all entries that have the same set of base
 RDAP URLs.  The Service URL Array contains the list of base RDAP URLs
 usable for the entries found in the Entry Array.  Elements within
 these two arrays are not ordered in any way.
 An example structure of the JSON output of an RDAP Bootstrap Service
 Registry is illustrated:
 {
     "version": "1.0",
     "publication": "YYYY-MM-DDTHH:MM:SSZ",
     "description": "Some text",
     "services": [
       [
         ["entry1", "entry2", "entry3"],
         [
           "https://registry.example.com/myrdap/",
           "http://registry.example.com/myrdap/"
         ]
       ],
       [
         ["entry4"],
         [
           "https://example.org/"
         ]
       ]
     ]
 }
 The formal syntax is described in Section 10.
 The "version" corresponds to the format version of the registry.
 This specification defines version "1.0".
 The syntax of the "publication" value conforms to the Internet date/
 time format [RFC3339].  The value is the latest update date of the
 registry by IANA.
 The optional "description" string can contain a comment regarding the
 content of the bootstrap object.
 Per [RFC7258], in each array of base RDAP URLs, the secure versions
 of the transport protocol SHOULD be preferred and tried first.  For
 example, if the base RDAP URLs array contains both HTTPS and HTTP
 URLs, the bootstrap client SHOULD try the HTTPS version first.
 Base RDAP URLs MUST have a trailing "/" character because they are
 concatenated to the various segments defined in [RFC9082].
 JSON names MUST follow the format recommendations of Section 6 of
 [RFC7480].  Any unrecognized JSON object properties or values MUST be
 ignored by implementations.
 Internationalized Domain Name labels used as entries or base RDAP
 URLs in the registries defined in this document MUST be only
 represented using their A-label form as defined in [RFC5890].
 All Domain Name labels used as entries or base RDAP URLs in the
 registries defined in this document MUST be only represented in
 lowercase.

4. Bootstrap Service Registry for Domain Name Space

 The JSON output of this registry contains domain label entries
 attached to the root, grouped by base RDAP URLs, as shown in this
 example.
 {
     "version": "1.0",
     "publication": "2024-01-07T10:11:12Z",
     "description": "Some text",
     "services": [
       [
         ["net", "com"],
         [
           "https://registry.example.com/myrdap/"
         ]
       ],
       [
         ["org", "mytld"],
         [
           "https://example.org/"
         ]
       ],
       [
         ["xn--zckzah"],
         [
           "https://example.net/rdap/xn--zckzah/",
           "http://example.net/rdap/xn--zckzah/"
         ]
       ]
     ]
 }
 The domain name's authoritative registration data service is found by
 doing the label-wise longest match of the target domain name with the
 domain values in the Entry Arrays in the IANA "Bootstrap Service
 Registry for Domain Name Space".  The match is done per label, from
 right to left.  If the longest match results in multiple entries,
 then those entries are considered equivalent.  The values contained
 in the Service URL Array of the matching second-level array are the
 valid base RDAP URLs as described in [RFC9082].
 For example, a domain RDAP query for a.b.example.com matches the com
 entry in one of the arrays of the registry.  The base RDAP URL for
 this query is then taken from the second element of the array, which
 is an array of base RDAP URLs valid for this entry.  The client
 chooses one of the base URLs from this array; in this example, it
 chooses the only one available, "https://registry.example.com/
 myrdap/".  The segment specified in [RFC9082] is then appended to the
 base URL to complete the query.  The complete query is then
 "https://registry.example.com/myrdap/domain/a.b.example.com".
 If a domain RDAP query for a.b.example.com matches both com and
 example.com entries in the registry, then the longest match applies
 and the example.com entry is used by the client.
 If the registry contains entries such as com and goodexample.com,
 then a domain RDAP query for example.com only matches the com entry
 because matching is done on a per-label basis.
 The entry for the root of the domain name space is specified as "".

5. Bootstrap Service Registries for Internet Numbers

 This section discusses IPv4 and IPv6 address space and Autonomous
 System numbers.
 For IP address space, the authoritative registration data service is
 found by doing a longest match of the target address with the values
 of the arrays in the corresponding RDAP Bootstrap Service Registry
 for Address Space.  The longest match is done the same way as in
 packet forwarding: the addresses are converted in binary form and
 then the binary strings are compared to find the longest match up to
 the specified prefix length.  The values contained in the second
 element of the array are the base RDAP URLs as described in
 [RFC9082].  The longest match method enables covering prefixes of a
 larger address space pointing to one base RDAP URL while more
 specific prefixes within the covering prefix are being served by
 another base RDAP URL.

5.1. Bootstrap Service Registry for IPv4 Address Space

 The JSON output of this registry contains IPv4 prefix entries,
 specified in Classless Inter-domain Routing (CIDR) format [RFC4632]
 and grouped by RDAP URLs, as shown in this example.
 {
     "version": "1.0",
     "publication": "2024-01-07T10:11:12Z",
     "description": "RDAP Bootstrap file for example registries.",
     "services": [
       [
         ["198.51.100.0/24", "192.0.0.0/8"],
         [
           "https://rir1.example.com/myrdap/"
         ]
       ],
       [
         ["203.0.113.0/24", "192.0.2.0/24"],
         [
           "https://example.org/"
         ]
       ],
       [
         ["203.0.113.0/28"],
         [
           "https://example.net/rdaprir2/",
           "http://example.net/rdaprir2/"
         ]
       ]
     ]
 }
 For example, a query for "192.0.2.1/25" matches the "192.0.0.0/8"
 entry and the "192.0.2.0/24" entry in the example registry above.
 The latter is chosen by the client because it is the longest match.
 The base RDAP URL for this query is then taken from the second
 element of the array, which is an array of base RDAP URLs valid for
 this entry.  The client chooses one of the base URLs from this array;
 in this example, it chooses the only one available,
 "https://example.org/".  The {resource} specified in [RFC9082] is
 then appended to the base URL to complete the query.  The complete
 query is then "https://example.org/ip/192.0.2.1/25".

5.2. Bootstrap Service Registry for IPv6 Address Space

 The JSON output of this registry contains IPv6 prefix entries, using
 [RFC5952] text representation of the address prefixes format, grouped
 by base RDAP URLs, as shown in this example.
 {
     "version": "1.0",
     "publication": "2024-01-07T10:11:12Z",
     "description": "RDAP Bootstrap file for example registries.",
     "services": [
       [
         ["2001:db8::/34"],
         [
           "https://rir2.example.com/myrdap/"
         ]
       ],
       [
         ["2001:db8:4000::/36", "2001:db8:ffff::/48"],
         [
           "https://example.org/"
         ]
       ],
       [
         ["2001:db8:1000::/36"],
         [
           "https://example.net/rdaprir2/",
           "http://example.net/rdaprir2/"
         ]
       ]
     ]
 }
 For example, a query for "2001:db8:1000::/48" matches the
 "2001:db8::/34" entry and the "2001:db8:1000::/36" entry in the
 example registry above.  The latter is chosen by the client because
 it is the longest match.  The base RDAP URL for this query is then
 taken from the second element of the array, which is an array of base
 RDAP URLs valid for this entry.  The client chooses one of the base
 URLs from this array; in this example, it chooses
 "https://example.net/rdaprir2/" because it's the secure version of
 the protocol.  The segment specified in [RFC9082] is then appended to
 the base URL to complete the query.  The complete query is therefore
 "https://example.net/rdaprir2/ip/2001:db8:1000::/48".  If the target
 RDAP server does not answer, the client can then use another URL
 prefix from the array.

5.3. Bootstrap Service Registry for AS Number Space

 The JSON output of this registry contains entries for AS number
 ranges, grouped by base RDAP URLs, as shown in this example.  The
 Entry Array is an array containing the list of AS number ranges
 served by the base RDAP URLs found in the second element.  Each
 element of the array contains two AS numbers represented in decimal
 format, separated by a hyphen, that represents the range of AS
 numbers between the two AS numbers (inclusive), where values are in
 increasing order (e.g., 100-200, not 200-100).  A single AS number is
 represented as a range of two identical AS numbers.  AS numbers are
 represented as 'asplain' as defined in [RFC5396].  Ranges MUST NOT
 overlap.
 {
     "version": "1.0",
     "publication": "2024-01-07T10:11:12Z",
     "description": "RDAP Bootstrap file for example registries.",
     "services": [
       [
         ["64496-64496"],
         [
           "https://rir3.example.com/myrdap/"
         ]
       ],
       [
         ["64497-64510", "65536-65551"],
         [
           "https://example.org/"
         ]
       ],
       [
         ["64512-65534"],
         [
           "http://example.net/rdaprir2/",
           "https://example.net/rdaprir2/"
         ]
       ]
     ]
 }
 For example, a query for AS 65411 matches the 64512-65534 entry in
 the example registry above.  The base RDAP URL for this query is then
 taken from the second element of the array, which is an array of base
 RDAP URLs valid for this entry.  The client chooses one of the base
 URLs from this array; in this example, it chooses
 "https://example.net/rdaprir2/".  The segment specified in [RFC9082]
 is then appended to the base URL to complete the query.  The complete
 query is, therefore, "https://example.net/rdaprir2/autnum/65411".  If
 the server does not answer, the client can then use another URL
 prefix from the array.

6. Entity

 Entities (such as contacts, registrants, or registrars) can be
 queried by handle as described in [RFC9082].  Since there is no
 global name space for entities, this document does not describe how
 to find the authoritative RDAP server for entities.  However, it is
 possible that, if the entity identifier was received from a previous
 query, the same RDAP server could be queried for that entity, or the
 entity identifier itself is a fully qualified URL that can be
 queried.  The mechanism described in [RFC8521] MAY also be used.

7. Non-existent Entries or RDAP URL Values

 The registries may not contain the requested value.  In these cases,
 there is no known RDAP server for that requested value, and the
 client SHOULD provide an appropriate error message to the user.

8. Deployment and Implementation Considerations

 This method relies on the fact that RDAP clients are fetching the
 IANA registries to then find the servers locally.  Clients SHOULD NOT
 fetch the registry on every RDAP request.  Clients SHOULD cache the
 registry, but use underlying protocol signaling, such as the HTTP
 Expires header field [RFC7234], to identify when it is time to
 refresh the cached registry.
 Some authorities of registration data may work together on sharing
 their information for a common service, including mutual redirection
 [REDIRECT-RDAP].
 When a new object is allocated, such as a new AS range, a new TLD, or
 a new IP address range, there is no guarantee that this new object
 will have an entry in the corresponding bootstrap RDAP registry,
 since the setup of the RDAP server for this new entry may become live
 and registered later.  Therefore, the clients should expect that even
 if an object, such as TLD, IP address range, or AS range is
 allocated, the existence of the entry in the corresponding bootstrap
 registry is not guaranteed.

9. Limitations

 This method does not provide a direct way to find authoritative RDAP
 servers for any other objects than the ones described in this
 document.  In particular, the following objects are not bootstrapped
 with the method described in this document:
  • entities
  • queries using search patterns that do not contain a terminating

string that matches some entries in the registries

  • nameservers
  • help

10. Formal Definition

 This section is the formal definition of the registries.  The
 structure of JSON objects and arrays using a set of primitive
 elements is defined in [RFC8259].  Those elements are used to
 describe the JSON structure of the registries.

10.1. Imported JSON Terms

 OBJECT:  a JSON object, defined in Section 4 of [RFC8259]
 MEMBER:  a member of a JSON object, defined in Section 4 of [RFC8259]
 MEMBER-NAME:  the name of a MEMBER, defined as a "string" in
    Section 4 of [RFC8259]
 MEMBER-VALUE:  the value of a MEMBER, defined as a "value" in
    Section 4 of [RFC8259]
 ARRAY:  an array, defined in Section 5 of [RFC8259]
 ARRAY-VALUE:  an element of an ARRAY, defined in Section 5 of
    [RFC8259]
 STRING:  a "string", as defined in Section 7 of [RFC8259]

10.2. Registry Syntax

 Using the above terms for the JSON structures, the syntax of a
 registry is defined as follows:
 rdap-bootstrap-registry:  an OBJECT containing a MEMBER version and a
    MEMBER publication, an optional MEMBER description, and a MEMBER
    services-list
 version:  a MEMBER with MEMBER-NAME "version" and MEMBER-VALUE a
    STRING
 publication:  a MEMBER with MEMBER-NAME "publication" and MEMBER-
    VALUE a STRING
 description:  a MEMBER with MEMBER-NAME "description" and MEMBER-
    VALUE a STRING
 services-list:  a MEMBER with MEMBER-NAME "services" and MEMBER-VALUE
    a services-array
 services-array:  an ARRAY, where each ARRAY-VALUE is a service
 service:  an ARRAY of 2 elements, where the first ARRAY-VALUE is an
    entry-list and the second ARRAY-VALUE is a service-uri-list
 entry-list:  an ARRAY, where each ARRAY-VALUE is an entry
 entry:  a STRING
 service-uri-list:  an ARRAY, where each ARRAY-VALUE is a service-uri
 service-uri:  a STRING

11. Security Considerations

 By providing a bootstrap method to find RDAP servers, this document
 helps to ensure that the end users will get the RDAP data from an
 authoritative source instead of from rogue sources.  The method has
 the same security properties as the RDAP protocols themselves.  The
 transport used to access the registries uses TLS [RFC8446].
 Additional considerations on using RDAP are described in [RFC7481].

12. IANA Considerations

 IANA has created the RDAP Bootstrap Services Registries listed below
 and made them available as JSON objects.  The contents of these
 registries are described in Sections 3, 4, and 5, with the formal
 syntax specified in Section 10.  The registries MUST be accessible
 only through HTTPS (TLS [RFC8446]) transport.
 The process for adding or updating entries in these registries
 differs from the normal IANA registry processes: these registries are
 generated from the data, processes, and policies maintained by IANA
 in their allocation registries ([ipv4reg], [ipv6reg], [asreg], and
 [domainreg]), with the addition of new RDAP server information.
 IANA updates RDAP Bootstrap Services Registries entries from the
 allocation registries as those registries are updated.
 This document does not change any policies related to the allocation
 registries; IANA has provided a mechanism for collecting the RDAP
 server information.
 IANA has created a new top-level category on the Protocol Registries
 page: <https://www.iana.org/protocols>.  The group is called
 "Registration Data Access Protocol (RDAP)".  Each of the RDAP
 Bootstrap Services Registries has been made available for on-demand
 download in the JSON format by the general public, and that
 registry's URI is listed directly on the Protocol Registries page.
 Other normal registries will be added to this group by other
 documents, but the reason the URIs for these registries are clearly
 listed on the main page is to make those URIs obvious to implementers
 -- these are registries that will be accessed by software, as well as
 by humans using them for reference information.
 Because these registries will be accessed by software, the download
 demand for the RDAP Bootstrap Services Registries may be unusually
 high compared to normal IANA registries.  The technical
 infrastructure by which registries are published has been put in
 place by IANA to support the load.  Since the publication of
 [RFC7484], no issues have been reported regarding the load or the
 service.
 As discussed in Section 8, software that accesses these registries
 will depend on the HTTP Expires header field to limit their query
 rate.  It is, therefore, important for that header field to be
 properly set to provide timely information as the registries change,
 while maintaining a reasonable load on the IANA servers.
 The HTTP Content-Type returned to clients accessing these JSON-
 formatted registries MUST be "application/json", as defined in
 [RFC8259].
 Because of how information in the RDAP Bootstrap Services Registries
 is grouped and formatted, the registry entries may not be sortable.
 It is, therefore, not required or expected that the entries be
 ordered in any way.

12.1. Bootstrap Service Registry for IPv4 Address Space

 Entries in this registry contain at least the following:
  • a CIDR [RFC4632] specification of the network block being

registered

  • one or more URLs that provide the RDAP service regarding this

registration

12.2. Bootstrap Service Registry for IPv6 Address Space

 Entries in this registry contain at least the following:
  • an IPv6 prefix [RFC5952] specification of the network block being

registered

  • one or more URLs that provide the RDAP service regarding this

registration

12.3. Bootstrap Service Registry for AS Number Space

 Entries in this registry contain at least the following:
  • a range of Autonomous System numbers being registered
  • one or more URLs that provide the RDAP service regarding this

registration

12.4. Bootstrap Service Registry for Domain Name Space

 Entries in this registry contain at least the following:
  • a domain name attached to the root being registered
  • one or more URLs that provide the RDAP service regarding this

registration

13. References

13.1. Normative References

 [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>.
 [RFC3339]  Klyne, G. and C. Newman, "Date and Time on the Internet:
            Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
            <https://www.rfc-editor.org/info/rfc3339>.
 [RFC4632]  Fuller, V. and T. Li, "Classless Inter-domain Routing
            (CIDR): The Internet Address Assignment and Aggregation
            Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
            2006, <https://www.rfc-editor.org/info/rfc4632>.
 [RFC5396]  Huston, G. and G. Michaelson, "Textual Representation of
            Autonomous System (AS) Numbers", RFC 5396,
            DOI 10.17487/RFC5396, December 2008,
            <https://www.rfc-editor.org/info/rfc5396>.
 [RFC5890]  Klensin, J., "Internationalized Domain Names for
            Applications (IDNA): Definitions and Document Framework",
            RFC 5890, DOI 10.17487/RFC5890, August 2010,
            <https://www.rfc-editor.org/info/rfc5890>.
 [RFC5952]  Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
            Address Text Representation", RFC 5952,
            DOI 10.17487/RFC5952, August 2010,
            <https://www.rfc-editor.org/info/rfc5952>.
 [RFC7258]  Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
            Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
            2014, <https://www.rfc-editor.org/info/rfc7258>.
 [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>.
 [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>.
 [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
            Interchange Format", STD 90, RFC 8259,
            DOI 10.17487/RFC8259, December 2017,
            <https://www.rfc-editor.org/info/rfc8259>.

13.2. Informative References

 [asreg]    IANA, "Autonomous System (AS) Numbers",
            <https://www.iana.org/assignments/as-numbers>.
 [domainreg]
            IANA, "Root Zone Database",
            <https://www.iana.org/domains/root/db>.
 [ipv4reg]  IANA, "IANA IPv4 Address Space Registry",
            <https://www.iana.org/assignments/ipv4-address-space>.
 [ipv6reg]  IANA, "IPv6 Global Unicast Address Assignments",
            <https://www.iana.org/assignments/ipv6-unicast-address-
            assignments>.
 [REDIRECT-RDAP]
            Martinez, C.M., Ed., Zhou, L., Ed., and G. Rada,
            "Redirection Service for Registration Data Access
            Protocol", Work in Progress, Internet-Draft, draft-ietf-
            weirds-redirects-04, July 2014,
            <https://datatracker.ietf.org/doc/html/draft-ietf-weirds-
            redirects-04>.
 [RFC7071]  Borenstein, N. and M. Kucherawy, "A Media Type for
            Reputation Interchange", RFC 7071, DOI 10.17487/RFC7071,
            November 2013, <https://www.rfc-editor.org/info/rfc7071>.
 [RFC7234]  Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
            Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
            RFC 7234, DOI 10.17487/RFC7234, June 2014,
            <https://www.rfc-editor.org/info/rfc7234>.
 [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>.
 [RFC7484]  Blanchet, M., "Finding the Authoritative Registration Data
            (RDAP) Service", RFC 7484, DOI 10.17487/RFC7484, March
            2015, <https://www.rfc-editor.org/info/rfc7484>.
 [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
            Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
            <https://www.rfc-editor.org/info/rfc8446>.
 [RFC8521]  Hollenbeck, S. and A. Newton, "Registration Data Access
            Protocol (RDAP) Object Tagging", BCP 221, RFC 8521,
            DOI 10.17487/RFC8521, November 2018,
            <https://www.rfc-editor.org/info/rfc8521>.
 [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>.

Appendix A. Changes since RFC 7484

 There are no substantive changes except for minor clarifications.
 This update is primarily to meet the requirements for moving to an
 Internet Standard.

Acknowledgements

 The WEIRDS Working Group had multiple discussions on this topic,
 including a session during IETF 84, where various methods such as in-
 DNS and others were debated.  The idea of using IANA registries was
 discovered by the author during discussions with his colleagues as
 well as by a comment from Andy Newton.  All the people involved in
 these discussions are herein acknowledged.  Linlin Zhou, Jean-
 Philippe Dionne, John Levine, Kim Davies, Ernie Dainow, Scott
 Hollenbeck, Arturo Servin, Andy Newton, Murray Kucherawy, Tom
 Harrison, Naoki Kambe, Alexander Mayrhofer, Edward Lewis, Pete
 Resnick, Alessandro Vesely, Bert Greevenbosch, Barry Leiba, Jari
 Arkko, Kathleen Moriaty, Stephen Farrell, Richard Barnes, and Jean-
 Francois Tremblay provided input and suggestions to the first version
 of this document.
 Guillaume Leclanche was a coauthor of this document for some
 revisions; his support is therein acknowledged and greatly
 appreciated.  The section on formal definition was inspired by
 Section 6.2 of [RFC7071].  This new version [This document] received
 comments and suggestions from Gavin Brown, Patrick Mevzek, John
 Levine, Jasdip Singh, George Michaelson, Scott Hollenbeck, Russ
 Housley, Joel Halpern, Lars Eggert, Benjamin Kaduk, Scott Kelly, Éric
 Vyncke, John Scudder, Erik Kline, and Robert Wilton.  Errata for RFC
 7484 were submitted by Pieter Vandepitte and were applied to this
 document.

Author's Address

 Marc Blanchet
 Viagenie
 246 Aberdeen
 Quebec QC G1R 2E1
 Canada
 Email: Marc.Blanchet@viagenie.ca
 URI:   https://viagenie.ca
/home/gen.uk/domains/wiki.gen.uk/public_html/data/pages/rfc/std/std95.txt · Last modified: 2022/03/31 22:48 by 127.0.0.1

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