idnits 2.17.1 draft-ietf-weirds-using-http-13.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- == There are 6 instances of lines with non-RFC6890-compliant IPv4 addresses in the document. If these are example addresses, they should be changed. -- The document has examples using IPv4 documentation addresses according to RFC6890, but does not use any IPv6 documentation addresses. Maybe there should be IPv6 examples, too? Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (October 7, 2014) is 3486 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-11) exists of draft-ietf-weirds-bootstrap-07 == Outdated reference: A later version (-14) exists of draft-ietf-weirds-json-response-09 == Outdated reference: A later version (-18) exists of draft-ietf-weirds-rdap-query-14 == Outdated reference: A later version (-12) exists of draft-ietf-weirds-rdap-sec-09 -- Possible downref: Normative reference to a draft: ref. 'I-D.ietf-weirds-rdap-sec' ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) ** 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: 3 errors (**), 0 flaws (~~), 6 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: April 10, 2015 APNIC 6 N. Kong 7 CNNIC 8 October 7, 2014 10 HTTP usage in the Registration Data Access Protocol (RDAP) 11 draft-ietf-weirds-using-http-13 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. The purpose of 19 this document is to clarify the use of standard HTTP mechanisms for 20 this application. 22 Status of This Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at http://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 This Internet-Draft will expire on April 10, 2015. 39 Copyright Notice 41 Copyright (c) 2014 IETF Trust and the persons identified as the 42 document authors. All rights reserved. 44 This document is subject to BCP 78 and the IETF Trust's Legal 45 Provisions Relating to IETF Documents 46 (http://trustee.ietf.org/license-info) in effect on the date of 47 publication of this document. Please review these documents 48 carefully, as they describe your rights and restrictions with respect 49 to this document. Code Components extracted from this document must 50 include Simplified BSD License text as described in Section 4.e of 51 the Trust Legal Provisions and are provided without warranty as 52 described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 57 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 58 3. Design Intents . . . . . . . . . . . . . . . . . . . . . . . 4 59 4. Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 60 4.1. HTTP Methods . . . . . . . . . . . . . . . . . . . . . . 5 61 4.2. Accept Header . . . . . . . . . . . . . . . . . . . . . . 5 62 4.3. Query Parameters . . . . . . . . . . . . . . . . . . . . 5 63 5. Types of HTTP Response . . . . . . . . . . . . . . . . . . . 6 64 5.1. Positive Answers . . . . . . . . . . . . . . . . . . . . 6 65 5.2. Redirects . . . . . . . . . . . . . . . . . . . . . . . . 6 66 5.3. Negative Answers . . . . . . . . . . . . . . . . . . . . 7 67 5.4. Malformed Queries . . . . . . . . . . . . . . . . . . . . 7 68 5.5. Rate Limits . . . . . . . . . . . . . . . . . . . . . . . 7 69 5.6. Cross-Origin Resource Sharing . . . . . . . . . . . . . . 7 70 6. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 8 71 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 72 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 73 8.1. RDAP Extensions Registry . . . . . . . . . . . . . . . . 9 74 9. Internationalization Considerations . . . . . . . . . . . . . 10 75 9.1. URIs and IRIs . . . . . . . . . . . . . . . . . . . . . . 10 76 9.2. Language Identifiers in Queries and Responses . . . . . . 10 77 9.3. Language Identifiers in HTTP Headers . . . . . . . . . . 10 78 10. Contributing Authors and Acknowledgements . . . . . . . . . . 10 79 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 80 11.1. Normative References . . . . . . . . . . . . . . . . . . 11 81 11.2. Informative References . . . . . . . . . . . . . . . . . 12 82 Appendix A. Protocol Example . . . . . . . . . . . . . . . . . . 12 83 Appendix B. Cache Busting . . . . . . . . . . . . . . . . . . . 13 84 Appendix C. Bootstrapping and Redirection . . . . . . . . . . . 14 85 Appendix D. Changelog . . . . . . . . . . . . . . . . . . . . . 15 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 88 1. Introduction 90 This document describes the usage of the Hypertext Transfer Protocol 91 (HTTP) [RFC7230] for registration data directory services. The goal 92 of this document is to tie together usage patterns of HTTP into a 93 common profile applicable to the various types of directory services 94 serving registration data using practices informed by the 95 Representational State Transfer REST [REST] architectural style. By 96 giving the various directory services common behavior, a single 97 client is better able to retrieve data from directory services 98 adhering to this behavior. 100 The registration data expected to be presented by this service is 101 Internet resource registration data - registration of domain names 102 and Internet number resources. These data is typically provided by 103 WHOIS [RFC3912] services, but the WHOIS protocol is insufficient to 104 modern registration data service requirements. A replacement 105 protocol is expected to retain the simple transactional nature of 106 WHOIS, while providing a specification for queries and responses, 107 redirection to authoritative sources, support for Internationalized 108 Domain Names (IDNs, [RFC5890]), and support for localized 109 registration data such as addresses and organisation or person names. 111 In designing these common usage patterns, this document introduces 112 considerations for a simple use of HTTP. Where complexity may 113 reside, it is the goal of this document to place it upon the server 114 and to keep the client as simple as possible. A client 115 implementation should be possible using common operating system 116 scripting tools (e.g. bash and wget). 118 This is the basic usage pattern for this protocol: 120 1. A client determines an appropriate server to query along with the 121 appropriate base URL to use in such queries. 122 [I-D.ietf-weirds-bootstrap] describes one method to determine the 123 server and the base URL. See Appendix C for more information. 125 2. A client issues an HTTP (or HTTPS) query using GET [RFC7231]. As 126 an example, a query for the network registration 192.0.2.0 might 127 be 129 http://example.com/rdap/ip/192.0.2.0 131 [I-D.ietf-weirds-rdap-query] details the various queries used in 132 RDAP. 134 3. If the receiving server has the information for the query, it 135 examines the Accept header field of the query and returns a 200 136 response with a response entity appropriate for the requested 137 format. [I-D.ietf-weirds-json-response] details a response in 138 JavaScript Object Notation (JSON). 140 4. If the receiving server does not have the information for the 141 query but does have knowledge of where the information can be 142 found, it will return a redirection response (3xx) with the 143 Location: header field containing an HTTP(S) URL (Uniform 144 Resource Locator) pointing to the information or another server 145 known to have knowledge of the location of the information. The 146 client is expected to re-query using that HTTP URL. 148 5. If the receiving server does not have the information being 149 requested and does not have knowledge of where the information 150 can be found, it returns a 404 response. 152 6. If the receiving server will not answer a request for policy 153 reasons, it will return an error response (4xx) indicating the 154 reason for giving no answer. 156 It is not the intent of this document to redefine the meaning and 157 semantics of HTTP. The purpose of this document is to clarify the 158 use of standard HTTP mechanisms for this application. 160 2. Terminology 162 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 163 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 164 document are to be interpreted as described in RFC 2119 [RFC2119]. 166 As is noted in Security and Stability Advisory Committee (SSAC) 167 Report on WHOIS Terminology and Structure [SAC-051], the term "WHOIS" 168 is overloaded, often referring to a protocol, a service and data. In 169 accordance with [SAC-051], this document describes the base behavior 170 for a Registration Data Access Protocol (RDAP). [SAC-051] describes 171 a protocol profile of RDAP for Domain Name Registries (DNRs), the 172 Domain Name Registration Data Access Protocol (DNRD-AP). 174 In this document, an RDAP client is an HTTP user agent performing an 175 RDAP query, and an RDAP server is an HTTP server providing an RDAP 176 response. RDAP query and response formats are described in 177 [I-D.ietf-weirds-rdap-query] and [I-D.ietf-weirds-json-response], 178 while this document describes how RDAP clients and servers use HTTP 179 to exchange queries and responses. [I-D.ietf-weirds-rdap-sec] 180 describes security considerations for RDAP. 182 3. Design Intents 184 There are a few design criteria this document attempts to meet. 186 First, each query is meant to return only one path of execution to 187 obtain an answer. A response may contain an answer, no answer, or a 188 redirect, and clients are not expected to fork multiple paths of 189 execution to satisfy a query. 191 Second, the semantics of the request/response allow for future and/or 192 non-standard response formats. In this document, only a JSON 194 [RFC7159] response media type is noted, with the response contents to 195 be described separately (see [I-D.ietf-weirds-json-response]). This 196 document only describes how RDAP is transported using HTTP with this 197 format. 199 Third, this protocol is intended to be able to make use of the range 200 of mechanisms available for use with HTTP. HTTP offers a number of 201 mechanisms not described further in this document. Operators are 202 able to make use of these mechanisms according to their local policy, 203 including cache control, authorization, compression, and redirection. 204 HTTP also benefits from widespread investment in scalability, 205 reliability, and performance, and widespread programmer understanding 206 of client behaviours for web services styled after REST [REST], 207 reducing the cost to deploy Registration Data Directory Services and 208 clients. 210 4. Queries 212 4.1. HTTP Methods 214 Clients use the GET method to retrieve a response body and use the 215 HEAD method to determine existence of data on the server. Clients 216 SHOULD use either the HTTP GET or HEAD methods (see [RFC7231]). 217 Servers are under no obligation to support other HTTP methods, 218 therefore clients using other methods will likely not interoperate 219 properly. 221 Clients MUST support HTTPS as well as HTTP. 223 4.2. Accept Header 225 To indicate to servers that an RDAP response is desired, clients 226 include an Accept: header field with an RDAP specific JSON media 227 type, the generic JSON media type, or both. Servers receiving an 228 RDAP request return an entity with a Content-Type: header containing 229 the RDAP specific JSON media type. 231 This specification does not define the responses a server returns to 232 a request with any other media types in the Accept: header field, or 233 with no Accept: header field. One possibility would be to return a 234 response in a media type suitable for rendering in a web browser. 236 4.3. Query Parameters 238 Servers MUST ignore unknown query parameters. Use of unknown query 239 parameters for cache-busting is described in Appendix B. 241 5. Types of HTTP Response 243 This section describes the various types of responses a server may 244 send to a client. While no standard HTTP response code is forbidden 245 in usage, this section defines the minimal set of response codes in 246 common use by servers that a client will need to understand. While 247 some clients may be constructed with simple tooling that does not 248 account for all of these response codes, a more robust client 249 accounting for these codes will likely provide a better user 250 experience. It is expected that usage of response codes and types 251 for this application not defined here will be described in subsequent 252 documents. 254 5.1. Positive Answers 256 If a server has the information requested by the client and wishes to 257 respond to the client with the information according to its policies, 258 it returns that answer in the body of a 200 response. 260 5.2. Redirects 262 If a server wishes to inform a client that the answer to a given 263 query can be found elsewhere, it returns either a 301 response code 264 to indicate a permanent move, or a 302, 303 or 307 response code to 265 indicate a non-permanent redirection, and it includes an HTTP(s) URL 266 in the Location: header field. The client is expected to issue a 267 subsequent request to satisfy the original query using the given URL 268 without any processing of the URL. In other words, the server is to 269 hand back a complete URL and the client should not have to transform 270 the URL to follow it. Servers are under no obligation to return a 271 URL conformant to [I-D.ietf-weirds-rdap-query]. 273 For this application, such an example of a permanent move might be a 274 Top Level Domain (TLD) operator informing a client the information 275 being sought can be found with another TLD operator (i.e. a query for 276 the domain bar in foo.example is found at http://foo.example/domain/ 277 bar). 279 For example, if the client sends 281 http://serv1.example.com/weirds/domain/example.com 283 the server redirecting to 285 https://serv2.example.net/weirds2/ 287 would set the Location: field to the value 288 https://serv2.example.net/weirds2/domain/example.com 290 5.3. Negative Answers 292 If a server wishes to respond that it has an empty result set (that 293 is, no data appropriately satisfying the query), it returns a 404 294 response code. Optionally, it MAY include additional information 295 regarding the negative answer in the HTTP entity body. 297 If a server wishes to inform the client that information about the 298 query is available, but cannot include the information in the 299 response to the client for policy reasons, the server MUST respond 300 with an appropriate response code out of HTTP's 4xx range. Clients 301 MAY retry the query based on the respective response code. 303 5.4. Malformed Queries 305 If a server receives a query which it cannot interpret as an RDAP 306 query, it returns a 400 response code. Optionally, it MAY include 307 additional information regarding this negative answer in the HTTP 308 entity body. 310 5.5. Rate Limits 312 Some servers apply rate limits to deter address scraping and other 313 abuses. When a server declines to answer a query due to rate limits, 314 it returns a 429 response code as described in [RFC6585]. A client 315 that receives a 429 response SHOULD decrease its query rate, and 316 honor the Retry-After header field if one is present. Servers may 317 place stricter limits upon clients that do not honor the Retry-After 318 header. 320 Note that this is not a defense against denial-of-service attacks, 321 since a malicious client could ignore the code and continue to send 322 queries at a high rate. A server might use another response code if 323 it did not wish to reveal to a client that rate limiting is the 324 reason for the denial of a reply. 326 5.6. Cross-Origin Resource Sharing 328 When responding to queries, it is RECOMMENDED that servers use the 329 Access-Control-Allow-Origin header field, as specified by 330 [W3C.CR-cors-20130129]. As the use of RDAP is for public resources, 331 a value of "*" is suitable for most cases. 333 This header (often called the CORS header) helps in-browser web 334 applications by lifting the "same-origin" restriction. 336 6. Extensibility 338 For extensibility purposes, this document defines an IANA registry 339 for prefixes used in JSON [RFC7159] data serialization and URI path 340 segments (see Section 8). 342 Prefixes and identifiers SHOULD only consist of the alphabetic ASCII 343 characters A through Z in both uppercase and lowercase, the numerical 344 digits 0 through 9, underscore characters, and SHOULD NOT begin with 345 an underscore character, numerical digit or the characters "xml". 346 The following describes the production of JSON names in ABNF 347 [RFC5234]. 349 ABNF for JSON names 351 name = ALPHA *( ALPHA / DIGIT / "_" ) 353 Figure 1 355 This restriction is a union of the Ruby programming language 356 identifier syntax and the XML element name syntax and has two 357 purposes. First, client implementers using modern programming 358 languages such as Ruby or Java can use libraries that automatically 359 promote JSON names to first order object attributes or members. 360 Second, a clean mapping between JSON and XML is easy to accomplish 361 using these rules. 363 7. Security Considerations 365 This document does not pose strong security requirements to the RDAP 366 protocol. However, it does not restrict against the use of security 367 mechanisms offered by the HTTP protocol. It does require the RDAP 368 clients MUST support HTTPS. 370 This document made recommendations for server implementations against 371 denial-of-service (Section 5.5) and interoperability with existing 372 security mechanism in HTTP clients (Section 5.6). 374 Additional security considerations to the RDAP protocol are covered 375 in [I-D.ietf-weirds-rdap-sec]. 377 8. IANA Considerations 378 8.1. RDAP Extensions Registry 380 This specification proposes an IANA registry for RDAP extensions. 381 The purpose of this registry is to ensure uniqueness of extension 382 identifiers. The extension identifier is used as a prefix in JSON 383 names and as a prefix of path segments in RDAP URLs. 385 The production rule for these identifiers is specified in Section 6. 387 In accordance with [RFC5226], the IANA policy for assigning new 388 values shall be Specification Required: values and their meanings 389 must be documented in an RFC or in some other permanent and readily 390 available reference, in sufficient detail that interoperability 391 between independent implementations is possible. 393 The following is a preliminary template for an RDAP extension 394 registration: 396 Extension identifier: the identifier of the extension 398 Registry operator: the name of the registry operator 400 Published specification: RFC number, bibliographical reference or 401 URL to a permanent and readily available specification 403 Person & email address to contact for further information: The 404 names and email addresses of individuals for contact regarding 405 this registry entry 407 Intended usage: brief reasons for this registry entry (as defined 408 by [RFC5226]. 410 The following is an example of a registration in the RDAP extension 411 registry: 413 Extension identifier: lunarNic 415 Registry operator: The Registry of the Moon, LLC 417 Published specification: http://www.example/moon_apis/rdap 419 Person & email address to contact for further information: 420 Professor Bernardo de la Paz 422 Intended usage: COMMON 424 9. Internationalization Considerations 426 9.1. URIs and IRIs 428 Clients can use IRIs [RFC3987] for internal use as they see fit, but 429 MUST transform them to URIs [RFC3986] for interaction with RDAP 430 servers. RDAP servers MUST use URIs in all responses, and again 431 clients can transform these URIs to IRIs for internal use as they see 432 fit. 434 9.2. Language Identifiers in Queries and Responses 436 Under most scenarios, clients requesting data will not signal that 437 the data be returned in a particular language or script. On the 438 other hand, when servers return data and have knowledge that the data 439 is in a language or script, the data SHOULD be annotated with 440 language identifiers whenever they are available, thus allowing 441 clients to process and display the data accordingly. 443 [I-D.ietf-weirds-json-response] provides such a mechanism. 445 9.3. Language Identifiers in HTTP Headers 447 Given the description of the use of language identifiers in 448 Section 9.2, unless otherwise specified, servers SHOULD ignore the 449 HTTP [RFC7231] Accept-Language header field when formulating HTTP 450 entity responses, so that clients do not conflate the Accept-Language 451 header with the 'lang' values in the entity body. 453 However, servers MAY return language identifiers in the Content- 454 Language header field so as to inform clients of the intended 455 language of HTTP layer messages. 457 10. Contributing Authors and Acknowledgements 459 John Levine provided text to tighten up the Accept header field usage 460 and the text for the section on 429 responses. 462 Marc Blanchet provided some clarifying text regarding the use of URLs 463 with redirects, as well as very useful feedback during WGLC. 465 Normative language reviews were provided by Murray S. Kucherawy, 466 Andrew Sullivan, Tom Harrison, Ed Lewis, and Alexander Mayrhofer. 468 Jean-Phillipe Dionne provided text for the Security Considerations 469 section. 471 The concept of the redirector server informatively discussed in 472 Appendix C was documented by Carlos M. Martinez and Gerardo Rada of 473 LACNIC and Linlin Zhou of CNNIC and subsequently incorporated into 474 this document. 476 This document is the work product of the IETF's WEIRDS working group, 477 of which Olaf Kolkman and Murray Kucherawy were chairs. 479 11. References 481 11.1. Normative References 483 [I-D.ietf-weirds-bootstrap] 484 Blanchet, M. and G. Leclanche, "Finding the Authoritative 485 Registration Data (RDAP) Service", draft-ietf-weirds- 486 bootstrap-07 (work in progress), September 2014. 488 [I-D.ietf-weirds-json-response] 489 Newton, A. and S. Hollenbeck, "JSON Responses for the 490 Registration Data Access Protocol (RDAP)", draft-ietf- 491 weirds-json-response-09 (work in progress), September 492 2014. 494 [I-D.ietf-weirds-rdap-query] 495 Newton, A. and S. Hollenbeck, "Registration Data Access 496 Protocol Query Format", draft-ietf-weirds-rdap-query-14 497 (work in progress), September 2014. 499 [I-D.ietf-weirds-rdap-sec] 500 Hollenbeck, S. and N. Kong, "Security Services for the 501 Registration Data Access Protocol", draft-ietf-weirds- 502 rdap-sec-09 (work in progress), September 2014. 504 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 505 Requirement Levels", BCP 14, RFC 2119, March 1997. 507 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 508 Resource Identifier (URI): Generic Syntax", STD 66, RFC 509 3986, January 2005. 511 [RFC3987] Duerst, M. and M. Suignard, "Internationalized Resource 512 Identifiers (IRIs)", RFC 3987, January 2005. 514 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 515 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 516 May 2008. 518 [RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status 519 Codes", RFC 6585, April 2012. 521 [RFC7230] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol 522 (HTTP/1.1): Message Syntax and Routing", RFC 7230, June 523 2014. 525 [RFC7231] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol 526 (HTTP/1.1): Semantics and Content", RFC 7231, June 2014. 528 [W3C.CR-cors-20130129] 529 Kesteren, A., "Cross-Origin Resource Sharing", World Wide 530 Web Consortium Candidate Recommendation CR-cors-20130129, 531 January 2013, 532 . 534 11.2. Informative References 536 [REST] Fielding, R. and R. Taylor, "Principled Design of the 537 Modern Web Architecture", ACM Transactions on Internet 538 Technology Vol. 2, No. 2, May 2002. 540 [RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, 541 September 2004. 543 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 544 Specifications: ABNF", STD 68, RFC 5234, January 2008. 546 [RFC5890] Klensin, J., "Internationalized Domain Names for 547 Applications (IDNA): Definitions and Document Framework", 548 RFC 5890, August 2010. 550 [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data 551 Interchange Format", RFC 7159, March 2014. 553 [SAC-051] Piscitello, D., Ed., "SSAC Report on Domain Name WHOIS 554 Terminology and Structure", September 2011. 556 [lacnic-joint-whois] 557 LACNIC, "LACNIC Joint WHOIS Implementation", 2005, 558 . 561 Appendix A. Protocol Example 563 To demonstrate typical behaviour of an RDAP client and server, the 564 following is an example of an exchange, including a redirect. The 565 data in the response has been elided for brevity, as the data format 566 is not described in this document. The media type used here is 567 described in [I-D.ietf-weirds-json-response]. 569 An example of an RDAP client and server exchange: 571 Client: 572 573 GET /rdap/ip/203.0.113.0/24 HTTP/1.1 574 Host: rdap.example.com 575 Accept: application/rdap+json 577 rdap.example.com: 578 HTTP/1.1 301 Moved Permanently 579 Location: http://rdap-ip.example.com/rdap/ip/203.0.113.0/24 580 Content-Length: 0 581 Content-Type: application/rdap+json 582 584 Client: 585 586 GET /rdap/ip/203.0.113.0/24 HTTP/1.1 587 Host: rdap-ip.example.com 588 Accept: application/rdap+json 590 rdap-ip.example.com: 591 HTTP/1.1 200 OK 592 Content-Type: application/rdap+json 593 Content-Length: 9001 595 { ... } 596 598 Appendix B. Cache Busting 600 Some HTTP [RFC7230] cache infrastructure does not adhere to caching 601 standards adequately, and could cache responses longer than is 602 intended by the server. To overcome these issues, clients can use an 603 adhoc and improbably used query parameter with a random value of 604 their choosing. As Section 4.3 instructs servers to ignore unknown 605 parameters, this is unlikely to have any known side effects. 607 An example of using an unknown query parameter to bust caches: 609 http://example.com/ip/192.0.2.0?__fuhgetaboutit=xyz123 611 Use of an unknown parameter to overcome misbehaving caches is not 612 part of any specification and is offered here for informational 613 purposes. 615 Appendix C. Bootstrapping and Redirection 617 The traditional deployment model of WHOIS [RFC3912] does not provide 618 a mechanism for determining the authoritative source for information. 620 Some approaches have been implemented in the past, most notably the 621 Joint WHOIS [lacnic-joint-whois] initiative. However, among other 622 shortcomings, Joint WHOIS is implemented using proxies and server- 623 side referrals. 625 These issues are solved in RDAP using HTTP redirects and 626 bootstrapping. Bootstrapping is discussed in 627 [I-D.ietf-weirds-bootstrap]. In constrained environments, the 628 processes outlined in [I-D.ietf-weirds-bootstrap] may not be viable 629 and there may be need for servers acting as a "redirector". 631 Redirector servers issue HTTP redirects to clients using a 632 redirection table informed by [I-D.ietf-weirds-bootstrap]. Figure 2 633 diagrams a client using a redirector for bootstrapping. 635 REDIRECTOR ARIN 636 RDAP RDAP 637 . . 638 | | 639 Q: 23.1.1.1? -----------------> | | 640 | | 641 <---------- HTTP 301 --------| | 642 ('Try ARIN RDAP') | | 643 | | 644 | 645 Q: 23.1.1.1? -------------------------------> | 646 | 647 <---------- HTTP 200 --------------------- | 648 (JSON response is returned) | 649 | 650 | 651 . 653 Querying RDAP data for 23.1.1.1 655 Figure 2 657 In some cases, particularly sub-delegations made between RIRs known 658 as "ERX space" and transfers of networks, multiple HTTP redirects 659 will be issued. Figure 3 shows such a scenario. 661 REDIRECTOR LACNIC ARIN 662 RDAP RDAP RDAP 663 . . . 664 Q: 23.1.1.1? ----> | | | 665 | | | 666 <-- HTTP 301 --- | | | 667 ('Try LACNIC') | | | 668 | | | 669 | | | 670 Q: 23.1.1.1? -----------------> | | 671 | | 672 <---------- HTTP 301 --------| | 673 ('Try ARIN RDAP') | | 674 | | 675 | 676 Q: 23.1.1.1? -------------------------------> | 677 | 678 <---------- HTTP 200 --------------------- | 679 (JSON response is returned) | 680 | 681 | 682 . 684 Querying RDAP data for data that has been transfered 686 Figure 3 688 Appendix D. Changelog 690 RFC Editor: Please remove this section. 692 Initial WG -00: Updated to working group document 2012-September-20 694 -01 696 * Updated for the sections moved to the JSON responses draft. 698 * Simplified media type, removed "level" parameter. 700 * Updated 2119 language and added boilerplate. 702 * In section 1, noted that redirects can go to redirect servers 703 as well. 705 * Added Section 9.2 and Section 9.3. 707 -02 709 * Added a section on 429 response codes. 711 * Changed Accept header language in section 4.1 713 * Removed reference to the now dead requirements draft. 715 * Added contributing authors and acknowledgements section. 717 * Added some clarifying text regarding complete URLs in the 718 redirect section. 720 * Changed media type to application/rdap+json 722 * Added media type registration 724 -03 726 * Removed forward reference to draft-ietf-weirds-json-response. 728 * Added reference and recommended usage of CORS 730 -04 732 * Revised introduction and abstract. 734 * Added negative responses other than 404. 736 * Added security considerations. 738 * Added and corrected references: CORS, RFC3912, RFC3987, 739 RFC5890. 741 * Expanded on first use several acronyms. 743 * Updated 2119 language. 745 -05 747 * Update the media type registration. 749 * Further explained the SHOULD in section 5. 751 * Split the references into normative and informative. 753 * Other minor fixes. 755 -06 757 * Rewritten the third paragraph in Section 3 to avoid 758 contradictions 760 * Simplified the wording in Seciton 5.1. 762 * Removed some RFC 2119 words in Section 5.2, 5.3, 5.4 and 5.5. 764 * Corrected RFC 6839 as an informative reference. 766 * Replaced MAYs with cans in Seciton 9.1. 768 * Replaced MAY with can in Appendix B. 770 * Added a note in in Appendix C for the RFC Editor to remove this 771 section. 773 -07 775 * Dropped reference to MUST with application/rdap+json 777 * Dropped IANA registration of application/rdap+json 779 -08 781 * Keep alive version. 783 -09 785 * Changed status lines in example to include http version number. 787 * Removed charset from media types in examples. 789 * Changed wording of 404 negative response to specifically say 790 "empty result set". 792 * Changed references to HTTP. 794 -10 796 * Corrected references to HTTP. 798 * Added a reference to draft-ietf-weirds-json-response (discuss 799 item from Barry Leiba) 801 * Added a reference to draft-ietf-weirds-rdap-query (discuss item 802 from Barry Leiba) 804 * Noted that redirect URLs do not have to conform to draft-ietf- 805 weirds-rdap-query (comment by Richard Barnes) 807 * Noted that CORS header is most likely to be "*" (comment by 808 Richard Barnes) 810 * Added reference to draft-ietf-weirds-rdap-sec (comment by 811 Richard Barnes) 813 * Added a sentence to the abstract explaining the purpose of RDAP 814 (comment by Stephen Farrell) 816 * Added further references to draft-ietf-weirds-rdap-query and 817 draft-ietf-weirds-json-response (comment by Stephen Farrell) 819 * Added comment regarding the use of the CORS header (comment by 820 Stephen Farrell) 822 * Explanded SSAC (comment by Sean Turner) 824 * Added text about HEAD and GET. 826 -11 828 * Changed JSON reference to RFC 7159. 830 * Noted that clients MUST support HTTPS. 832 -12 834 * Added reference to REST. 836 * Numerous textual clarifications. 838 * Added an actual reference to RFC 5226 instead of just talking 839 about it. 841 * A reference to draft-ietf-weirds-bootstrap was added. 843 * Included a section on redirectors. 845 -13 847 * Addressed AD feedback. 849 Authors' Addresses 851 Andrew Lee Newton 852 American Registry for Internet Numbers 853 3635 Concorde Parkway 854 Chantilly, VA 20151 855 US 857 Email: andy@arin.net 858 URI: http://www.arin.net 860 Byron J. Ellacott 861 Asia Pacific Network Information Center 862 6 Cordelia Street 863 South Brisbane QLD 4101 864 Australia 866 Email: bje@apnic.net 867 URI: http://www.apnic.net 869 Ning Kong 870 China Internet Network Information Center 871 4 South 4th Street, Zhongguancun, Haidian District 872 Beijing 100190 873 China 875 Phone: +86 10 5881 3147 876 Email: nkong@cnnic.cn