wdiff rfc7480.original rfc7480.txt

Network Working Group
Internet Engineering Task Force (IETF) A. Newton
Internet-Draft
Request for Comments: 7480 ARIN
Intended status:
Category: Standards Track B. Ellacott
Expires: May 23, 2015
ISSN: 2070-1721 APNIC
N. Kong
CNNIC
November 19, 2014
March 2015

HTTP usage Usage in the Registration Data Access Protocol (RDAP)
draft-ietf-weirds-using-http-15

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 Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents an Internet Standards Track document.

This document is a product of the Internet Engineering Task Force
(IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list It represents the consensus of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid the IETF community. It has
received public review and has been approved for a maximum 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 six months this document, any errata,
and how to provide feedback on it may be updated, replaced, or obsoleted by other documents obtained at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."

This Internet-Draft will expire on May 23, 2015.
http://www.rfc-editor.org/info/rfc7480.

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publication of this document. Please review these documents
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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Design Intents . . . . . . . . . . . . . . . . . . . . . . . 4
4. Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. HTTP Methods . . . . . . . . . . . . . . . . . . . . . . 5
4.2. Accept Header . . . . . . . . . . . . . . . . . . . . . . 5
4.3. Query Parameters . . . . . . . . . . . . . . . . . . . . 6 5
5. Types of HTTP Response . . . . . . . . . . . . . . . . . . . 6 5
5.1. Positive Answers . . . . . . . . . . . . . . . . . . . . 6
5.2. Redirects . . . . . . . . . . . . . . . . . . . . . . . . 6
5.3. Negative Answers . . . . . . . . . . . . . . . . . . . . 7 6
5.4. Malformed Queries . . . . . . . . . . . . . . . . . . . . 7
5.5. Rate Limits . . . . . . . . . . . . . . . . . . . . . . . 7
5.6. Cross-Origin Resource Sharing (CORS) . . . . . . . . . . . . . . 8 7
6. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9 8
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. Contributing Authors and Acknowledgements . . . . . . . . . . 11
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
11.1. 10
10.1. Normative References . . . . . . . . . . . . . . . . . . 11
11.2. 10
10.2. Informative References . . . . . . . . . . . . . . . . . 12 11
Appendix A. Protocol Example . . . . . . . . . . . . . . . . . . 13
Appendix B. Cache Busting . . . . . . . . . . . . . . . . . . . 14 13
Appendix C. Bootstrapping and Redirection . . . . . . . . . . . 15 14
Appendix D. Changelog . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . 20 15

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) [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]), (IDNs) [RFC5890], and support for localized registration
data such as addresses and organisation 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. (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. [I-D.ietf-weirds-bootstrap] [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

[I-D.ietf-weirds-rdap-query]

[RFC7482] details the various queries used in RDAP.

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. [I-D.ietf-weirds-json-response] [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:
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 re-query 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 RFC 2119 [RFC2119].

As is noted in Security "Security and Stability Advisory Committee (SSAC)
Report on WHOIS Terminology and Structure Structure" [SAC-051], the term
"WHOIS" is overloaded, often referring to a protocol, a service service, and
data. In accordance with [SAC-051], this document describes the base
behavior for a Registration Data Access Protocol (RDAP). 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
[I-D.ietf-weirds-rdap-query] [RFC7482]
and [I-D.ietf-weirds-json-response], [RFC7483], while this document describes how RDAP clients and
servers use HTTP to exchange queries and responses. [I-D.ietf-weirds-rdap-sec] [RFC7481]
describes security considerations for RDAP.

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 [I-D.ietf-weirds-json-response]). [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, and as well as widespread programmer
understanding of client behaviours 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 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: Accept header field with an RDAP specific RDAP-specific JSON media type,
the generic JSON media type, or both. Servers receiving an RDAP
request return an entity with a Content-Type: Content-Type header containing the RDAP specific
RDAP-specific JSON media type.

This specification does not define the responses a server returns to
a request with any other media types in the Accept: Accept header field, or
with no Accept: 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 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, move or a 302
(Found), 303 (See Other) Other), or 307 (Temporary Redirect) response code
to indicate a non-permanent redirection, and it includes an HTTP(s) HTTP(S)
URL in the Location: 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 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
[I-D.ietf-weirds-rdap-query]. [RFC7482].

For this application, such an example of a permanent move might be a
Top Level
Top-Level Domain (TLD) operator informing a client the information
being sought can be found with another TLD operator (i.e. (i.e., a query
for the domain bar in foo.example is found at http://foo.example/domain/
bar).
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 which 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, 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.

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.CR-cors-20130129].
[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. (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
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 characters, character, and they
SHOULD NOT begin with an underscore character, numerical digit digit, or
the characters "xml". The following describes the production of JSON
names in ABNF [RFC5234].

ABNF for JSON names

name = ALPHA *( ALPHA / DIGIT / "_" )

Figure 1 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 first-order object attributes or members.
Second, a clean mapping between JSON and XML is easy to accomplish
using these rules.

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 server servers MUST support HTTPS.

This document makes recommendations for server implementations
against denial-of-service DoS (Section 5.5) and interoperability with existing security mechanism
mechanisms in HTTP clients (Section 5.6).

Additional security considerations to the RDAP protocol are covered
in [I-D.ietf-weirds-rdap-sec]. [RFC7481].

8. IANA Considerations

8.1. RDAP Extensions Registry

This section requests that the

IANA create has created a new category in the protocol registries labeled
"Registration Data Access Protocol
(RDAP)" (if it does not already exist), (RDAP)", and within that category
establish category,
has established a URL referenceable, 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
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 preliminary 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 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 for to contact regarding this
registry entry

Intended usage: brief reasons for this registry entry (as defined
by [RFC5226]. [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 IRIs [RFC3987] Internationalized Resource Identifiers (IRIs)
[RFC3987] for internal use as they see fit, 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.

[I-D.ietf-weirds-json-response]

[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.

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. Contributing Authors and 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 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
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.

11. References

11.1.

10.1. Normative References

[I-D.ietf-weirds-bootstrap]
Blanchet, M., "Finding the Authoritative Registration Data
(RDAP) Service", draft-ietf-weirds-bootstrap-10 (work in
progress), October 2014.

[I-D.ietf-weirds-json-response]
Newton, A. and S. Hollenbeck, "JSON Responses for the
Registration Data Access Protocol (RDAP)", draft-ietf-
weirds-json-response-11 (work in progress), October 2014.

[I-D.ietf-weirds-rdap-query]
Newton, A. and S. Hollenbeck, "Registration Data Access
Protocol Query Format", draft-ietf-weirds-rdap-query-16
(work in progress), October 2014.

[I-D.ietf-weirds-rdap-sec]
Hollenbeck, S. and N. Kong, "Security Services for the
Registration Data Access Protocol", draft-ietf-weirds-
rdap-sec-10 (work in progress), October 2014.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. 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. 2005,
<http://www.rfc-editor.org/info/rfc3986>.

[RFC3987] Duerst, M. and M. Suignard, "Internationalized Resource
Identifiers (IRIs)", RFC 3987, January 2005. 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. 2008, <http://www.rfc-editor.org/info/rfc5226>.

[RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status
Codes", RFC 6585, April 2012. 2012,
<http://www.rfc-editor.org/info/rfc6585>.

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

[RFC7231] Fielding, R. R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
June 2014.

[W3C.CR-cors-20130129] 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>.

[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", World Wide
Web Consortium Candidate Recommendation CR-cors-20130129, W3C
Recommendation, REC-cors-20140116, January 2013,
<http://www.w3.org/TR/2013/CR-cors-20130129>.

11.2. 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
Technology, Vol. 2, No. 2, May 2002.

[RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912,
September 2004. 2004, <http://www.rfc-editor.org/info/rfc3912>.

[RFC5234] Crocker, D. D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. 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. 2010,
<http://www.rfc-editor.org/info/rfc5890>.

[RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7159, March 2014. 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, "LACNIC Joint WHOIS Implementation", "Joint Whois", December 2005,
<ftp://anonymous@ftp.registro.br/pub/gter/gter20/02-
jwhois-lacnic.pdf>.
<ftp://anonymous@ftp.registro.br/pub/gter/
gter20/02-jwhois-lacnic.pdf>.

Appendix A. Protocol Example

To demonstrate typical behaviour 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 [I-D.ietf-weirds-json-response]. [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 infrastructure does infrastructures do not adhere to caching
standards adequately, adequately and could cache responses longer than is
intended by the server. To overcome these issues, clients can use an
adhoc
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.

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
[I-D.ietf-weirds-bootstrap]. [RFC7484]. In
constrained environments, the processes outlined in [I-D.ietf-weirds-bootstrap] [RFC7484] may not
be viable 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 [I-D.ietf-weirds-bootstrap]. [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 Data for 23.1.1.1

Figure 2
In some cases, particularly sub-delegations made between RIRs 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 Data for data that has been transfered

Figure 3 Data That Has Been Transferred

Appendix D. Changelog

RFC Editor: Please remove this section.

Initial WG -00: Updated to working group document 2012-September-20

-01

* Updated for the sections moved Acknowledgements

John Levine provided text to tighten up the JSON responses draft.

* Simplified media type, removed "level" parameter.

* Updated 2119 language and added boilerplate.

* In section 1, noted that redirects can go to redirect servers
as well.

* Added Section 9.2 Accept header field usage
and Section 9.3.

-02

* Added a the text for the section on 429 response codes.

* Changed Accept header language in section 4.1

* Removed reference to the now dead requirements draft.

* Added contributing authors and acknowledgements section.

* Added responses.

Marc Blanchet provided some clarifying text regarding complete URLs in the
redirect section.

* Changed media type to application/rdap+json

* Added media type registration

-03

* Removed forward reference to draft-ietf-weirds-json-response.

* Added reference and recommended usage of CORS

-04

* Revised introduction and abstract.

* Added negative responses other than 404.

* Added security considerations.

* Added and corrected references: CORS, RFC3912, RFC3987,
RFC5890.

* Expanded on first use several acronyms.

* Updated 2119 language.

-05

* Update the media type registration.

* Further explained the SHOULD in section 5.

* Split the references into normative 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 informative.

* Other minor fixes.

-06

* Rewritten Alexander Mayrhofer.

Jean-Phillipe Dionne provided text for the third paragraph in Section 3 to avoid
contradictions

* Simplified Security Considerations
section.

The concept of the wording in Seciton 5.1.

* Removed some RFC 2119 words in Section 5.2, 5.3, 5.4 and 5.5.

* Corrected RFC 6839 as an informative reference.

* Replaced MAYs with cans in Seciton 9.1.

* Replaced MAY with can in Appendix B.

* Added a note in redirector server informatively discussed in
Appendix C for the RFC Editor to remove this
section.

-07

* Dropped reference to MUST with application/rdap+json

* Dropped IANA registration was documented by Carlos M. Martinez and Gerardo Rada of application/rdap+json

-08

* Keep alive version.

-09

* Changed status lines in example to include http version number.

* Removed charset from media types in examples.

* Changed wording
LACNIC and Linlin Zhou of 404 negative response to specifically say
"empty result set".

* Changed references to HTTP.

-10

* Corrected references to HTTP.

* Added a reference to draft-ietf-weirds-json-response (discuss
item from Barry Leiba)
* Added a reference to draft-ietf-weirds-rdap-query (discuss item
from Barry Leiba)

* Noted that redirect URLs do not have to conform to draft-ietf-
weirds-rdap-query (comment by Richard Barnes)

* Noted that CORS header CNNIC and subsequently incorporated into
this document.

This document is most likely to be "*" (comment by
Richard Barnes)

* Added reference to draft-ietf-weirds-rdap-sec (comment by
Richard Barnes)

* Added a sentence to the abstract explaining the purpose work product of RDAP
(comment by Stephen Farrell)

* Added further references to draft-ietf-weirds-rdap-query and
draft-ietf-weirds-json-response (comment by Stephen Farrell)

* Added comment regarding the use IETF's WEIRDS working group,
of the CORS header (comment by
Stephen Farrell)

* Explanded SSAC (comment by Sean Turner)

* Added text about HEAD which Olaf Kolkman and GET.

-11

* Changed JSON reference to RFC 7159.

* Noted that clients MUST support HTTPS.

-12

* Added reference to REST.

* Numerous textual clarifications.

* Added an actual reference to RFC 5226 instead of just talking
about it.

* A reference to draft-ietf-weirds-bootstrap was added.

* Included a section on redirectors.

-13

* Addressed AD feedback.

-14

* Addressed Last Call comments.

-15

* Addressed IESG comments. Murray Kucherawy were chairs.

Authors' Addresses

Andrew Lee Newton
American Registry for Internet Numbers
3635 Concorde Parkway
Chantilly, VA 20151
US

Email:
United States

EMail: andy@arin.net
URI: http://www.arin.net

Byron J. Ellacott
Asia Pacific Network Information Center Centre
6 Cordelia Street
South Brisbane QLD 4101
Australia

Email:

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:
EMail: nkong@cnnic.cn