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'I-D.ietf-weirds-rdap-sec' ** Obsolete normative reference: RFC 7230 (Obsoleted by RFC 9110, RFC 9112) ** Obsolete normative reference: RFC 7231 (Obsoleted by RFC 9110) -- Obsolete informational reference (is this intentional?): RFC 7159 (Obsoleted by RFC 8259) Summary: 2 errors (**), 0 flaws (~~), 4 warnings (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Newton 3 Internet-Draft ARIN 4 Intended status: Standards Track B. Ellacott 5 Expires: March 8, 2015 APNIC 6 N. Kong 7 CNNIC 8 September 4, 2014 10 HTTP usage in the Registration Data Access Protocol (RDAP) 11 draft-ietf-weirds-using-http-11 13 Abstract 15 This document is one of a collection that together describe the 16 Registration Data Access Protocol (RDAP). It describes how RDAP is 17 transported using the Hypertext Transfer Protocol (HTTP). RDAP is a 18 successor protocol to the very old WHOIS protocol. 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at http://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on March 8, 2015. 37 Copyright Notice 39 Copyright (c) 2014 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (http://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 55 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 56 3. Design Intents . . . . . . . . . . . . . . . . . . . . . . . 4 57 4. Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 58 4.1. HTTP Methods . . . . . . . . . . . . . . . . . . . . . . 5 59 4.2. Accept Header . . . . . . . . . . . . . . . . . . . . . . 5 60 4.3. Query Parameters . . . . . . . . . . . . . . . . . . . . 5 61 5. Types of HTTP Response . . . . . . . . . . . . . . . . . . . 5 62 5.1. Positive Answers . . . . . . . . . . . . . . . . . . . . 5 63 5.2. Redirects . . . . . . . . . . . . . . . . . . . . . . . . 6 64 5.3. Negative Answers . . . . . . . . . . . . . . . . . . . . 6 65 5.4. Malformed Queries . . . . . . . . . . . . . . . . . . . . 6 66 5.5. Rate Limits . . . . . . . . . . . . . . . . . . . . . . . 7 67 5.6. Cross-Origin Resource Sharing . . . . . . . . . . . . . . 7 68 6. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 7 69 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 70 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 71 8.1. RDAP Extensions Registry . . . . . . . . . . . . . . . . 8 72 9. Internationalization Considerations . . . . . . . . . . . . . 9 73 9.1. URIs and IRIs . . . . . . . . . . . . . . . . . . . . . . 9 74 9.2. Language Identifiers in Queries and Responses . . . . . . 9 75 9.3. Language Identifiers in HTTP Headers . . . . . . . . . . 9 76 10. Contributing Authors and Acknowledgements . . . . . . . . . . 10 77 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 78 11.1. Normative References . . . . . . . . . . . . . . . . . . 10 79 11.2. Informative References . . . . . . . . . . . . . . . . . 11 80 Appendix A. Protocol Example . . . . . . . . . . . . . . . . . . 11 81 Appendix B. Cache Busting . . . . . . . . . . . . . . . . . . . 12 82 Appendix C. Changelog . . . . . . . . . . . . . . . . . . . . . 13 83 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 85 1. Introduction 87 This document describes the usage of HTTP[RFC7230] for Registration 88 Data Directory Services. The goal of this document is to tie 89 together usage patterns of HTTP into a common profile applicable to 90 the various types of Directory Services serving Registration Data 91 using RESTful practices. By giving the various Directory Services 92 common behavior, a single client is better able to retrieve data from 93 Directory Services adhering to this behavior. 95 The registration data expected to be presented by this service is 96 Internet resource registration data - registration of domain names 97 and Internet number resources. This data is typically provided by 98 WHOIS [RFC3912] services, but the WHOIS protocol is insufficient to 99 modern registration data service requirements. A replacement 100 protocol is expected to retain the simple transactional nature of 101 WHOIS, while providing a specification for queries and responses, 102 redirection to authoritative sources, support for Internationalized 103 Domain Names (IDNs, [RFC5890]), and support for localized 104 registration data such as addresses and organisation or person names. 106 In designing these common usage patterns, this document introduces 107 considerations for a simple use of HTTP. Where complexity may 108 reside, it is the goal of this document to place it upon the server 109 and to keep the client as simple as possible. A client 110 implementation should be possible using common operating system 111 scripting tools (e.g. bash and wget). 113 This is the basic usage pattern for this protocol: 115 1. A client issues an HTTP query using GET[RFC7231]. As an example, 116 a query for the network registration 192.0.2.0 might be 117 http://example.com/ip/192.0.2.0. [I-D.ietf-weirds-rdap-query] 118 details the various queries used in RDAP. 120 2. If the receiving server has the information for the query, it 121 examines the Accept header field of the query and returns a 200 122 response with a response entity appropriate for the requested 123 format. [I-D.ietf-weirds-json-response] details a response in 124 JSON standardized by the IETF. Other formats may be used as 125 well. 127 3. If the receiving server does not have the information for the 128 query but does have knowledge of where the information can be 129 found, it will return a redirection response (3xx) with the 130 Location: header field containing an HTTP(S) URL (Uniform 131 Resource Locator) pointing to the information or another server 132 known to have knowledge of the location of the information. The 133 client is expected to re-query using that HTTP URL. 135 4. If the receiving server does not have the information being 136 requested and does not have knowledge of where the information 137 can be found, it returns a 404 response. 139 5. If the receiving server will not answer a request for policy 140 reasons, it will return an error response (4xx) indicating the 141 reason for giving no answer. 143 It is important to note that it is not the intent of this document to 144 redefine the meaning and semantics of HTTP. The purpose of this 145 document is to clarify the use of standard HTTP mechanisms for this 146 application. 148 2. Terminology 150 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 151 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 152 document are to be interpreted as described in RFC 2119 [RFC2119]. 154 As is noted in Security and Stability Advisory Committee (SSAC) 155 Report on WHOIS Terminology and Structure [SAC-051], the term "WHOIS" 156 is overloaded, often referring to a protocol, a service and data. In 157 accordance with [SAC-051], this document describes the base behavior 158 for a Registration Data Access Protocol (RDAP). [SAC-051] describes 159 a protocol profile of RDAP for Domain Name Registries (DNRs), the 160 Domain Name Registration Data Access Protocol (DNRD-AP). 162 In this document, an RDAP client is an HTTP User Agent performing an 163 RDAP query, and an RDAP server is an HTTP server providing an RDAP 164 response. RDAP query and response formats are described in 165 [I-D.ietf-weirds-rdap-query] and [I-D.ietf-weirds-json-response], 166 while this document describes how RDAP clients and servers use HTTP 167 to exchange queries and responses. [I-D.ietf-weirds-rdap-sec] 168 describes security consideration for RDAP. 170 3. Design Intents 172 There are a few design criteria this document attempts to meet. 174 First, each query is meant to return either zero or one result. With 175 the maximum upper bound being set to one, the issuance of redirects 176 is simplified to the traditional query/response model used by HTTP 177 [RFC7230]. Should an entity contain more than one result, some of 178 which are better served by other servers, the redirection model 179 becomes much more complicated. 181 Second, the semantics of the request/response allow for future and/or 182 non-standard response formats. In this document, only a JSON 183 [RFC7159] response media type is noted, with the response contents to 184 be described separately (see [I-D.ietf-weirds-json-response]). This 185 document only describes how RDAP is transported using HTTP with this 186 format. 188 Third, this protocol is intended to be able to make use of the range 189 of mechanisms available for use with HTTP. HTTP offers a number of 190 mechanisms not described further in this document. Operators are 191 able to make use of these mechanisms according to their local policy, 192 including cache control, authorization, compression, and redirection. 194 HTTP also benefits from widespread investment in scalability, 195 reliability, and performance, and widespread programmer understanding 196 of client behaviours for RESTful web services, reducing the cost to 197 deploy Registration Data Directory Services and clients. 199 4. Queries 201 4.1. HTTP Methods 203 Clients SHOULD use either the HTTP GET or HEAD methods (see 204 [RFC7231]). The GET method should be used to retreive a response 205 body. The HEAD method can be used to determine existence of data on 206 the server. Servers are under no obligation to support other HTTP 207 methods. 209 4.2. Accept Header 211 To indicate to servers that an RDAP response is desired, clients 212 include an Accept: header field with an RDAP specific JSON media 213 type, the generic JSON media type, or both. Servers receiving an 214 RDAP request return an entity with a Content-Type: header containing 215 the RDAP specific JSON media type. 217 This specification does not define the responses a server returns to 218 a request with any other media types in the Accept: header field, or 219 with no Accept: header field. One possibility would be to return a 220 response in a media type suitable for rendering in a web browser. 222 4.3. Query Parameters 224 Servers MUST ignore unknown query parameters. Use of unknown query 225 parameters for cache-busting is described in Appendix B. 227 5. Types of HTTP Response 229 This section describes the various types of responses a server may 230 send to a client. While no standard HTTP response code is forbidden 231 in usage, at a minimum clients SHOULD understand the response codes 232 described in this section as they will be in common use by servers. 233 It is expected that usage of response codes and types for this 234 application not defined here will be described in subsequent 235 documents. 237 5.1. Positive Answers 239 If a server has the information requested by the client and wishes to 240 respond to the client with the information according to its policies, 241 it returns that answer in the body of a 200 response. 243 5.2. Redirects 245 If a server wishes to inform a client that the answer to a given 246 query can be found elsewhere, it returns either a 301 response code 247 to indicate a permanent move, or a 302, 303 or 307 response code to 248 indicate a non-permanent redirection, and it includes an HTTP(s) URL 249 in the Location: header field. The client is expected to issue a 250 subsequent request to satisfy the original query using the given URL 251 without any processing of the URL. In other words, the server is to 252 hand back a complete URL and the client should not have to transform 253 the URL to follow it. Servers are under no obligation to return a 254 URL conformant to [I-D.ietf-weirds-rdap-query]. 256 For this application, such an example of a permanent move might be a 257 Top Level Domain (TLD) operator informing a client the information 258 being sought can be found with another TLD operator (i.e. a query for 259 the domain bar in foo.example is found at http://foo.example/domain/ 260 bar). 262 For example, if the client sends 263 http://serv1.example.com/weirds/domain/example.com, the server 264 redirecting to https://serv2.example.net/weirds2/ would set the 265 Location: field to the value: 266 https://serv2.example.net/weirds2/domain/example.com. 268 5.3. Negative Answers 270 If a server wishes to respond that it has an empty result set, it 271 returns a 404 response code. Optionally, it MAY include additional 272 information regarding the negative answer in the HTTP entity body. 274 If a server wishes to inform the client that information about the 275 query is available, but cannot include the information in the 276 response to the client for policy reasons, the server MUST respond 277 with an appropriate response code out of HTTP's 4xx range. Clients 278 MAY retry the query based on the respective response code. 280 5.4. Malformed Queries 282 If a server receives a query which it cannot interpret as an RDAP 283 query, it returns a 400 response code. Optionally, it MAY include 284 additional information regarding this negative answer in the HTTP 285 entity body. 287 5.5. Rate Limits 289 Some servers apply rate limits to deter address scraping and other 290 abuses. When a server declines to answer a query due to rate limits, 291 it returns a 429 response code as described in [RFC6585]. A client 292 that receives a 429 response SHOULD decrease its query rate, and 293 honor the Retry-After header field if one is present. 295 Note that this is not a defense against denial-of-service attacks, 296 since a malicious client could ignore the code and continue to send 297 queries at a high rate. A server might use another response code if 298 it did not wish to reveal to a client that rate limiting is the 299 reason for the denial of a reply. 301 5.6. Cross-Origin Resource Sharing 303 When responding to queries, it is RECOMMENDED that servers use the 304 Access-Control-Allow-Origin header field, as specified by 305 [W3C.CR-cors-20130129]. As the use of RDAP is for public resources, 306 a value of "*" is suitable for most cases. 308 This header (often called the CORS header), helps in-browser web 309 applications by lifting the "same-origin" restriction. 311 6. Extensibility 313 For extensibility purposes, this document defines an IANA registry 314 for prefixes used in JSON [RFC7159] data serialization and URI path 315 segments (see Section 8). 317 Prefixes and identifiers SHOULD only consist of the alphabetic ASCII 318 characters A through Z in both uppercase and lowercase, the numerical 319 digits 0 through 9, underscore characters, and SHOULD NOT begin with 320 an underscore character, numerical digit or the characters "xml". 321 The following describes the production of JSON names in ABNF 322 [RFC5234]. 324 ABNF for JSON names 326 name = ALPHA *( ALPHA / DIGIT / "_" ) 328 Figure 1 330 This restriction is a union of the Ruby programming language 331 identifier syntax and the XML element name syntax and has two 332 purposes. First, client implementers using modern programming 333 languages such as Ruby or Java can use libraries that automatically 334 promote JSON names to first order object attributes or members. 335 Second, a clean mapping between JSON and XML is easy to accomplish 336 using these rules. 338 7. Security Considerations 340 This document does not pose strong security requirements to the RDAP 341 protocol. However, it does not restrict against the use of security 342 mechanisms offered by the HTTP protocol. It does require the RDAP 343 clients MUST support HTTPS. 345 This document made recommendations for server implementations against 346 denial-of-service (Section 5.5) and interoperability with existing 347 security mechanism in HTTP clients (Section 5.6). 349 Additional security considerations to the RDAP protocol are covered 350 in [I-D.ietf-weirds-rdap-sec]. 352 8. IANA Considerations 354 8.1. RDAP Extensions Registry 356 This specification proposes an IANA registry for RDAP extensions. 357 The purpose of this registry is to ensure uniqueness of extension 358 identifiers. The extension identifier is used as a prefix in JSON 359 names and as a prefix of path segments in RDAP URLs. 361 The production rule for these identifiers is specified in Section 6. 363 In accordance with RFC5226, the IANA policy for assigning new values 364 shall be Specification Required: values and their meanings must be 365 documented in an RFC or in some other permanent and readily available 366 reference, in sufficient detail that interoperability between 367 independent implementations is possible. 369 The following is a preliminary template for an RDAP extension 370 registration: 372 Extension identifier: the identifier of the extension 374 Registry operator: the name of the registry operator 376 Published specification: RFC number, bibliographical reference or 377 URL to a permanent and readily available specification 378 Person & email address to contact for further information: The 379 names and email addresses of individuals for contact regarding 380 this registry entry 382 Intended usage: brief reasons for this registry entry 384 The following is an example of a registration in the RDAP extension 385 registry: 387 Extension identifier: lunarNic 389 Registry operator: The Registry of the Moon, LLC 391 Published specification: http://www.example/moon_apis/rdap 393 Person & email address to contact for further information: 394 Professor Bernardo de la Paz 396 Intended usage: COMMON 398 9. Internationalization Considerations 400 9.1. URIs and IRIs 402 Clients can use IRIs [RFC3987] for internal use as they see fit, but 403 MUST transform them to URIs [RFC3986] for interaction with RDAP 404 servers. RDAP servers MUST use URIs in all responses, and again 405 clients can transform these URIs to IRIs for internal use as they see 406 fit. 408 9.2. Language Identifiers in Queries and Responses 410 Under most scenarios, clients requesting data will not signal that 411 the data be returned in a particular language or script. On the 412 other hand, when servers return data and have knowledge that the data 413 is in a language or script, the data SHOULD be annotated with 414 language identifiers whenever they are available, thus allowing 415 clients to process and display the data accordingly. 417 The mechanism for including a language identifier in a response will 418 be defined in subsequent documents describing specific response 419 formats. 421 9.3. Language Identifiers in HTTP Headers 423 Given the description of the use of language identifiers in 424 Section 9.2, unless otherwise specified servers SHOULD ignore the 425 HTTP [RFC7231] Accept-Language header field when formulating HTTP 426 entity responses, so that clients do not conflate the Accept-Language 427 header with the 'lang' values in the entity body. 429 However, servers MAY return language identifiers in the Content- 430 Language header field so as to inform clients of the intended 431 language of HTTP layer messages. 433 10. Contributing Authors and Acknowledgements 435 John Levine provided text to tighten up the Accept header field usage 436 and the text for the section on 429 responses. 438 Marc Blanchet provided some clarifying text regarding the use of URLs 439 with redirects, as well as very useful feedback during WGLC. 441 Normative language reviews were provided by Murray S. Kucherawy and 442 Andrew Sullivan. 444 Jean-Phillipe Dionne provided text for the Security Considerations 445 section. 447 11. References 449 11.1. Normative References 451 [I-D.ietf-weirds-json-response] 452 Newton, A. and S. Hollenbeck, "JSON Responses for the 453 Registration Data Access Protocol (RDAP)", draft-ietf- 454 weirds-json-response-08 (work in progress), August 2014. 456 [I-D.ietf-weirds-rdap-query] 457 Newton, A. and S. Hollenbeck, "Registration Data Access 458 Protocol Query Format", draft-ietf-weirds-rdap-query-13 459 (work in progress), August 2014. 461 [I-D.ietf-weirds-rdap-sec] 462 Hollenbeck, S. and N. Kong, "Security Services for the 463 Registration Data Access Protocol", draft-ietf-weirds- 464 rdap-sec-08 (work in progress), August 2014. 466 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 467 Requirement Levels", BCP 14, RFC 2119, March 1997. 469 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 470 Resource Identifier (URI): Generic Syntax", STD 66, RFC 471 3986, January 2005. 473 [RFC3987] Duerst, M. and M. Suignard, "Internationalized Resource 474 Identifiers (IRIs)", RFC 3987, January 2005. 476 [RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status 477 Codes", RFC 6585, April 2012. 479 [RFC7230] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol 480 (HTTP/1.1): Message Syntax and Routing", RFC 7230, June 481 2014. 483 [RFC7231] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol 484 (HTTP/1.1): Semantics and Content", RFC 7231, June 2014. 486 [W3C.CR-cors-20130129] 487 Kesteren, A., "Cross-Origin Resource Sharing", World Wide 488 Web Consortium Candidate Recommendation CR-cors-20130129, 489 January 2013, 490 . 492 11.2. Informative References 494 [RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, 495 September 2004. 497 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 498 Specifications: ABNF", STD 68, RFC 5234, January 2008. 500 [RFC5890] Klensin, J., "Internationalized Domain Names for 501 Applications (IDNA): Definitions and Document Framework", 502 RFC 5890, August 2010. 504 [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data 505 Interchange Format", RFC 7159, March 2014. 507 [SAC-051] Piscitello, D., Ed., "SSAC Report on Domain Name WHOIS 508 Terminology and Structure", September 2011. 510 Appendix A. Protocol Example 512 To demonstrate typical behaviour of an RDAP client and server, the 513 following is an example of an exchange, including a redirect. The 514 data in the response has been elided for brevity, as the data format 515 is not described in this document. The media type used here is 516 described in [I-D.ietf-weirds-json-response]. 518 An example of an RDAP client and server exchange: 520 Client: 521 522 GET /ip/203.0.113.0/24 HTTP/1.1 523 Host: rdap.example.com 524 Accept: application/rdap+json 526 rdap.example.com: 527 HTTP/1.1 301 Moved Permanently 528 Location: http://rdap-ip.example.com/ip/203.0.113.0/24 529 Content-Length: 0 530 Content-Type: application/rdap+json 531 533 Client: 534 535 GET /ip/203.0.113.0/24 HTTP/1.1 536 Host: rdap-ip.example.com 537 Accept: application/rdap+json 539 rdap-ip.example.com: 540 HTTP/1.1 200 OK 541 Content-Type: application/rdap+json 542 Content-Length: 9001 544 { ... } 545 547 Appendix B. Cache Busting 549 Some HTTP [RFC7230] cache infrastructure does not adhere to caching 550 standards adequately, and could cache responses longer than is 551 intended by the server. To overcome these issues, clients can use an 552 adhoc and improbably used query parameter with a random value of 553 their choosing. As Section 4.3 instructs servers to ignore unknown 554 parameters, this is unlikely to have any known side effects. 556 An example of using an unknown query parameter to bust caches: 558 http://example.com/ip/192.0.2.0?__fuhgetaboutit=xyz123 560 Use of an unknown parameter to overcome misbehaving caches is not 561 part of any specification and is offered here for informational 562 purposes. 564 Appendix C. Changelog 566 RFC Editor: Please remove this section. 568 Initial WG -00: Updated to working group document 2012-September-20 570 -01 572 * Updated for the sections moved to the JSON responses draft. 574 * Simplified media type, removed "level" parameter. 576 * Updated 2119 language and added boilerplate. 578 * In section 1, noted that redirects can go to redirect servers 579 as well. 581 * Added Section 9.2 and Section 9.3. 583 -02 585 * Added a section on 429 response codes. 587 * Changed Accept header language in section 4.1 589 * Removed reference to the now dead requirements draft. 591 * Added contributing authors and acknowledgements section. 593 * Added some clarifying text regarding complete URLs in the 594 redirect section. 596 * Changed media type to application/rdap+json 598 * Added media type registration 600 -03 602 * Removed forward reference to draft-ietf-weirds-json-response. 604 * Added reference and recommended usage of CORS 606 -04 607 * Revised introduction and abstract. 609 * Added negative responses other than 404. 611 * Added security considerations. 613 * Added and corrected references: CORS, RFC3912, RFC3987, 614 RFC5890. 616 * Expanded on first use several acronyms. 618 * Updated 2119 language. 620 -05 622 * Update the media type registration. 624 * Further explained the SHOULD in section 5. 626 * Split the references into normative and informative. 628 * Other minor fixes. 630 -06 632 * Rewritten the third paragraph in Section 3 to avoid 633 contradictions 635 * Simplified the wording in Seciton 5.1. 637 * Removed some RFC 2119 words in Section 5.2, 5.3, 5.4 and 5.5. 639 * Corrected RFC 6839 as an informative reference. 641 * Replaced MAYs with cans in Seciton 9.1. 643 * Replaced MAY with can in Appendix B. 645 * Added a note in in Appendix C for the RFC Editor to remove this 646 section. 648 -07 650 * Dropped reference to MUST with application/rdap+json 652 * Dropped IANA registration of application/rdap+json 654 -08 655 * Keep alive version. 657 -09 659 * Changed status lines in example to include http version number. 661 * Removed charset from media types in examples. 663 * Changed wording of 404 negative response to specifically say 664 "empty result set". 666 * Changed references to HTTP. 668 -10 670 * Corrected references to HTTP. 672 * Added a reference to draft-ietf-weirds-json-response (discuss 673 item from Barry Leiba) 675 * Added a reference to draft-ietf-weirds-rdap-query (discuss item 676 from Barry Leiba) 678 * Noted that redirect URLs do not have to conform to draft-ietf- 679 weirds-rdap-query (comment by Richard Barnes) 681 * Noted that CORS header is most likely to be "*" (comment by 682 Richard Barnes) 684 * Added reference to draft-ietf-weirds-rdap-sec (comment by 685 Richard Barnes) 687 * Added a sentence to the abstract explaining the purpose of RDAP 688 (comment by Stephen Farrell) 690 * Added further references to draft-ietf-weirds-rdap-query and 691 draft-ietf-weirds-json-response (comment by Stephen Farrell) 693 * Added comment regarding the use of the CORS header (comment by 694 Stephen Farrell) 696 * Explanded SSAC (comment by Sean Turner) 698 * Added text about HEAD and GET. 700 -11 702 * Changed JSON reference to RFC 7159. 704 * Noted that clients MUST support HTTPS. 706 Authors' Addresses 708 Andrew Lee Newton 709 American Registry for Internet Numbers 710 3635 Concorde Parkway 711 Chantilly, VA 20151 712 US 714 Email: andy@arin.net 715 URI: http://www.arin.net 717 Byron J. Ellacott 718 Asia Pacific Network Information Center 719 6 Cordelia Street 720 South Brisbane QLD 4101 721 Australia 723 Email: bje@apnic.net 724 URI: http://www.apnic.net 726 Ning Kong 727 China Internet Network Information Center 728 4 South 4th Street, Zhongguancun, Haidian District 729 Beijing 100190 730 China 732 Phone: +86 10 5881 3147 733 Email: nkong@cnnic.cn