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'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: May 1, 2015 APNIC 6 N. Kong 7 CNNIC 8 October 28, 2014 10 HTTP usage in the Registration Data Access Protocol (RDAP) 11 draft-ietf-weirds-using-http-14 13 Abstract 15 This document is one of a collection that together describes 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 May 1, 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 . . . . . . . . . . . . . . . . . . . . . 9 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 the Registration Data Access Protocol (RDAP). 92 The goal of this document is to tie together usage patterns of HTTP 93 into a common profile applicable to the various types of directory 94 services 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 Registration data expected to be presented by this service is 101 Internet resource registration data - registration of domain names 102 and Internet number resources. This 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 require 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 to support security 222 services. 224 4.2. Accept Header 226 To indicate to servers that an RDAP response is desired, clients 227 include an Accept: header field with an RDAP specific JSON media 228 type, the generic JSON media type, or both. Servers receiving an 229 RDAP request return an entity with a Content-Type: header containing 230 the RDAP specific JSON media type. 232 This specification does not define the responses a server returns to 233 a request with any other media types in the Accept: header field, or 234 with no Accept: header field. One possibility would be to return a 235 response in a media type suitable for rendering in a web browser. 237 4.3. Query Parameters 239 Servers MUST ignore unknown query parameters. Use of unknown query 240 parameters for cache-busting is described in Appendix B. 242 5. Types of HTTP Response 244 This section describes the various types of responses a server may 245 send to a client. While no standard HTTP response code is forbidden 246 in usage, this section defines the minimal set of response codes in 247 common use by servers that a client will need to understand. While 248 some clients may be constructed with simple tooling that does not 249 account for all of these response codes, a more robust client 250 accounting for these codes will likely provide a better user 251 experience. It is expected that usage of response codes and types 252 for this application not defined here will be described in subsequent 253 documents. 255 5.1. Positive Answers 257 If a server has the information requested by the client and wishes to 258 respond to the client with the information according to its policies, 259 it returns that answer in the body of a 200 (OK) response (see 260 [RFC7231]). 262 5.2. Redirects 264 If a server wishes to inform a client that the answer to a given 265 query can be found elsewhere, it returns either a 301 (Moved 266 Permanently) response code to indicate a permanent move, or a 302 267 (Found), 303 (See Other) or 307 (Temporary Redirect) response code to 268 indicate a non-permanent redirection, and it includes an HTTP(s) URL 269 in the Location: header field (see [RFC7231]). The client is 270 expected to issue a subsequent request to satisfy the original query 271 using the given URL without any processing of the URL. In other 272 words, the server is to hand back a complete URL and the client 273 should not have to transform the URL to follow it. Servers are under 274 no obligation to return a URL conformant to 275 [I-D.ietf-weirds-rdap-query]. 277 For this application, such an example of a permanent move might be a 278 Top Level Domain (TLD) operator informing a client the information 279 being sought can be found with another TLD operator (i.e. a query for 280 the domain bar in foo.example is found at http://foo.example/domain/ 281 bar). 283 For example, if the client sends 285 http://serv1.example.com/weirds/domain/example.com 287 the server redirecting to 289 https://serv2.example.net/weirds2/ 291 would set the Location: field to the value 293 https://serv2.example.net/weirds2/domain/example.com 295 5.3. Negative Answers 297 If a server wishes to respond that it has an empty result set (that 298 is, no data appropriately satisfying the query), it returns a 404 299 (Not Found) response code. Optionally, it MAY include additional 300 information regarding the negative answer in the HTTP entity body. 302 If a server wishes to inform the client that information about the 303 query is available, but cannot include the information in the 304 response to the client for policy reasons, the server MUST respond 305 with an appropriate response code out of HTTP's 4xx range. Clients 306 MAY retry the query based on the respective response code. 308 5.4. Malformed Queries 310 If a server receives a query which it cannot interpret as an RDAP 311 query, it returns a 400 (Bad Request) response code. Optionally, it 312 MAY include additional information regarding this negative answer in 313 the HTTP entity body. 315 5.5. Rate Limits 317 Some servers apply rate limits to deter address scraping and other 318 abuses. When a server declines to answer a query due to rate limits, 319 it returns a 429 (Too Many Requests) response code as described in 320 [RFC6585]. A client that receives a 429 response SHOULD decrease its 321 query rate, and honor the Retry-After header field if one is present. 322 Servers may place stricter limits upon clients that do not honor the 323 Retry-After header. 325 Note that this is not a defense against denial-of-service attacks, 326 since a malicious client could ignore the code and continue to send 327 queries at a high rate. A server might use another response code if 328 it did not wish to reveal to a client that rate limiting is the 329 reason for the denial of a reply. 331 5.6. Cross-Origin Resource Sharing 333 When responding to queries, it is RECOMMENDED that servers use the 334 Access-Control-Allow-Origin header field, as specified by 335 [W3C.CR-cors-20130129]. A value of "*" is suitable when RDAP is used 336 for public resources. 338 This header (often called the CORS header) helps in-browser web 339 applications by lifting the "same-origin" restriction. 341 6. Extensibility 343 For extensibility purposes, this document defines an IANA registry 344 for prefixes used in JSON [RFC7159] data serialization and URI path 345 segments (see Section 8). 347 Prefixes and identifiers SHOULD only consist of the alphabetic ASCII 348 characters A through Z in both uppercase and lowercase, the numerical 349 digits 0 through 9, underscore characters, and SHOULD NOT begin with 350 an underscore character, numerical digit or the characters "xml". 351 The following describes the production of JSON names in ABNF 352 [RFC5234]. 354 ABNF for JSON names 356 name = ALPHA *( ALPHA / DIGIT / "_" ) 358 Figure 1 360 This restriction is a union of the Ruby programming language 361 identifier syntax and the XML element name syntax and has two 362 purposes. First, client implementers using modern programming 363 languages such as Ruby or Java can use libraries that automatically 364 promote JSON names to first order object attributes or members. 365 Second, a clean mapping between JSON and XML is easy to accomplish 366 using these rules. 368 7. Security Considerations 370 This document does not pose strong security requirements to the RDAP 371 protocol. However, it does not restrict against the use of security 372 mechanisms offered by the HTTP protocol. It does require that RDAP 373 clients MUST support HTTPS. 375 This document makes recommendations for server implementations 376 against denial-of-service (Section 5.5) and interoperability with 377 existing security mechanism in HTTP clients (Section 5.6). 379 Additional security considerations to the RDAP protocol are covered 380 in [I-D.ietf-weirds-rdap-sec]. 382 8. IANA Considerations 384 8.1. RDAP Extensions Registry 386 This section requests that the IANA create a new category in the 387 protocol registries labeled "Registration Data Access Protocol 388 (RDAP)" (if it does not already exist), and within that category 389 establish a URL referenceable, stand-alone registry labeled "RDAP 390 Extensions". The purpose of this registry is to ensure uniqueness of 391 extension identifiers. The extension identifier is used as a prefix 392 in JSON names and as a prefix of path segments in RDAP URLs. 394 The production rule for these identifiers is specified in Section 6. 396 In accordance with [RFC5226], the IANA policy for assigning new 397 values shall be Specification Required: values and their meanings 398 must be documented in an RFC or in some other permanent and readily 399 available reference, in sufficient detail that interoperability 400 between independent implementations is possible. 402 The following is a preliminary template for an RDAP extension 403 registration: 405 Extension identifier: the identifier of the extension 407 Registry operator: the name of the registry operator 409 Published specification: RFC number, bibliographical reference or 410 URL to a permanent and readily available specification 412 Person & email address to contact for further information: The 413 names and email addresses of individuals for contact regarding 414 this registry entry 416 Intended usage: brief reasons for this registry entry (as defined 417 by [RFC5226]. 419 The following is an example of a registration in the RDAP extension 420 registry: 422 Extension identifier: lunarNic 424 Registry operator: The Registry of the Moon, LLC 426 Published specification: http://www.example/moon_apis/rdap 428 Person & email address to contact for further information: 429 Professor Bernardo de la Paz 430 Intended usage: COMMON 432 9. Internationalization Considerations 434 9.1. URIs and IRIs 436 Clients can use IRIs [RFC3987] for internal use as they see fit, but 437 MUST transform them to URIs [RFC3986] for interaction with RDAP 438 servers. RDAP servers MUST use URIs in all responses, and again 439 clients can transform these URIs to IRIs for internal use as they see 440 fit. 442 9.2. Language Identifiers in Queries and Responses 444 Under most scenarios, clients requesting data will not signal that 445 the data be returned in a particular language or script. On the 446 other hand, when servers return data and have knowledge that the data 447 is in a language or script, the data SHOULD be annotated with 448 language identifiers whenever they are available, thus allowing 449 clients to process and display the data accordingly. 451 [I-D.ietf-weirds-json-response] provides such a mechanism. 453 9.3. Language Identifiers in HTTP Headers 455 Given the description of the use of language identifiers in 456 Section 9.2, unless otherwise specified, servers SHOULD ignore the 457 HTTP [RFC7231] Accept-Language header field when formulating HTTP 458 entity responses, so that clients do not conflate the Accept-Language 459 header with the 'lang' values in the entity body. 461 However, servers MAY return language identifiers in the Content- 462 Language header field so as to inform clients of the intended 463 language of HTTP layer messages. 465 10. Contributing Authors and Acknowledgements 467 John Levine provided text to tighten up the Accept header field usage 468 and the text for the section on 429 responses. 470 Marc Blanchet provided some clarifying text regarding the use of URLs 471 with redirects, as well as very useful feedback during WGLC. 473 Normative language reviews were provided by Murray S. Kucherawy, 474 Andrew Sullivan, Tom Harrison, Ed Lewis, and Alexander Mayrhofer. 476 Jean-Phillipe Dionne provided text for the Security Considerations 477 section. 479 The concept of the redirector server informatively discussed in 480 Appendix C was documented by Carlos M. Martinez and Gerardo Rada of 481 LACNIC and Linlin Zhou of CNNIC and subsequently incorporated into 482 this document. 484 This document is the work product of the IETF's WEIRDS working group, 485 of which Olaf Kolkman and Murray Kucherawy were chairs. 487 11. References 489 11.1. Normative References 491 [I-D.ietf-weirds-bootstrap] 492 Blanchet, M., "Finding the Authoritative Registration Data 493 (RDAP) Service", draft-ietf-weirds-bootstrap-09 (work in 494 progress), October 2014. 496 [I-D.ietf-weirds-json-response] 497 Newton, A. and S. Hollenbeck, "JSON Responses for the 498 Registration Data Access Protocol (RDAP)", draft-ietf- 499 weirds-json-response-10 (work in progress), October 2014. 501 [I-D.ietf-weirds-rdap-query] 502 Newton, A. and S. Hollenbeck, "Registration Data Access 503 Protocol Query Format", draft-ietf-weirds-rdap-query-15 504 (work in progress), October 2014. 506 [I-D.ietf-weirds-rdap-sec] 507 Hollenbeck, S. and N. Kong, "Security Services for the 508 Registration Data Access Protocol", draft-ietf-weirds- 509 rdap-sec-09 (work in progress), September 2014. 511 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 512 Requirement Levels", BCP 14, RFC 2119, March 1997. 514 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 515 Resource Identifier (URI): Generic Syntax", STD 66, RFC 516 3986, January 2005. 518 [RFC3987] Duerst, M. and M. Suignard, "Internationalized Resource 519 Identifiers (IRIs)", RFC 3987, January 2005. 521 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 522 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 523 May 2008. 525 [RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status 526 Codes", RFC 6585, April 2012. 528 [RFC7230] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol 529 (HTTP/1.1): Message Syntax and Routing", RFC 7230, June 530 2014. 532 [RFC7231] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol 533 (HTTP/1.1): Semantics and Content", RFC 7231, June 2014. 535 [W3C.CR-cors-20130129] 536 Kesteren, A., "Cross-Origin Resource Sharing", World Wide 537 Web Consortium Candidate Recommendation CR-cors-20130129, 538 January 2013, 539 . 541 11.2. Informative References 543 [REST] Fielding, R. and R. Taylor, "Principled Design of the 544 Modern Web Architecture", ACM Transactions on Internet 545 Technology Vol. 2, No. 2, May 2002. 547 [RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, 548 September 2004. 550 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 551 Specifications: ABNF", STD 68, RFC 5234, January 2008. 553 [RFC5890] Klensin, J., "Internationalized Domain Names for 554 Applications (IDNA): Definitions and Document Framework", 555 RFC 5890, August 2010. 557 [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data 558 Interchange Format", RFC 7159, March 2014. 560 [SAC-051] Piscitello, D., Ed., "SSAC Report on Domain Name WHOIS 561 Terminology and Structure", September 2011. 563 [lacnic-joint-whois] 564 LACNIC, "LACNIC Joint WHOIS Implementation", 2005, 565 . 568 Appendix A. Protocol Example 570 To demonstrate typical behaviour of an RDAP client and server, the 571 following is an example of an exchange, including a redirect. The 572 data in the response has been elided for brevity, as the data format 573 is not described in this document. The media type used here is 574 described in [I-D.ietf-weirds-json-response]. 576 An example of an RDAP client and server exchange: 578 Client: 579 580 GET /rdap/ip/203.0.113.0/24 HTTP/1.1 581 Host: rdap.example.com 582 Accept: application/rdap+json 584 rdap.example.com: 585 HTTP/1.1 301 Moved Permanently 586 Location: http://rdap-ip.example.com/rdap/ip/203.0.113.0/24 587 Content-Length: 0 588 Content-Type: application/rdap+json 589 591 Client: 592 593 GET /rdap/ip/203.0.113.0/24 HTTP/1.1 594 Host: rdap-ip.example.com 595 Accept: application/rdap+json 597 rdap-ip.example.com: 598 HTTP/1.1 200 OK 599 Content-Type: application/rdap+json 600 Content-Length: 9001 602 { ... } 603 605 Appendix B. Cache Busting 607 Some HTTP [RFC7230] cache infrastructure does not adhere to caching 608 standards adequately, and could cache responses longer than is 609 intended by the server. To overcome these issues, clients can use an 610 adhoc and improbably used query parameter with a random value of 611 their choosing. As Section 4.3 instructs servers to ignore unknown 612 parameters, this is compatible with the RDAP definition. 614 An example of using an unknown query parameter to bust caches: 616 http://example.com/ip/192.0.2.0?__fuhgetaboutit=xyz123 618 Use of an unknown parameter to overcome misbehaving caches is not 619 part of any specification and is offered here for informational 620 purposes. 622 Appendix C. Bootstrapping and Redirection 624 The traditional deployment model of WHOIS [RFC3912] does not provide 625 a mechanism for determining the authoritative source for information. 627 Some approaches have been implemented in the past, most notably the 628 Joint WHOIS [lacnic-joint-whois] initiative. However, among other 629 shortcomings, Joint WHOIS is implemented using proxies and server- 630 side referrals. 632 These issues are solved in RDAP using HTTP redirects and 633 bootstrapping. Bootstrapping is discussed in 634 [I-D.ietf-weirds-bootstrap]. In constrained environments, the 635 processes outlined in [I-D.ietf-weirds-bootstrap] may not be viable 636 and there may be need for servers acting as a "redirector". 638 Redirector servers issue HTTP redirects to clients using a 639 redirection table informed by [I-D.ietf-weirds-bootstrap]. Figure 2 640 diagrams a client using a redirector for bootstrapping. 642 REDIRECTOR ARIN 643 RDAP RDAP 644 . . 645 | | 646 Q: 23.1.1.1? -----------------> | | 647 | | 648 <---------- HTTP 301 --------| | 649 ('Try ARIN RDAP') | | 650 | | 651 | 652 Q: 23.1.1.1? -------------------------------> | 653 | 654 <---------- HTTP 200 --------------------- | 655 (JSON response is returned) | 656 | 657 | 658 . 660 Querying RDAP data for 23.1.1.1 662 Figure 2 664 In some cases, particularly sub-delegations made between RIRs known 665 as "ERX space" and transfers of networks, multiple HTTP redirects 666 will be issued. Figure 3 shows such a scenario. 668 REDIRECTOR LACNIC ARIN 669 RDAP RDAP RDAP 670 . . . 671 Q: 23.1.1.1? ----> | | | 672 | | | 673 <-- HTTP 301 --- | | | 674 ('Try LACNIC') | | | 675 | | | 676 | | | 677 Q: 23.1.1.1? -----------------> | | 678 | | 679 <---------- HTTP 301 --------| | 680 ('Try ARIN RDAP') | | 681 | | 682 | 683 Q: 23.1.1.1? -------------------------------> | 684 | 685 <---------- HTTP 200 --------------------- | 686 (JSON response is returned) | 687 | 688 | 689 . 691 Querying RDAP data for data that has been transfered 693 Figure 3 695 Appendix D. Changelog 697 RFC Editor: Please remove this section. 699 Initial WG -00: Updated to working group document 2012-September-20 701 -01 703 * Updated for the sections moved to the JSON responses draft. 705 * Simplified media type, removed "level" parameter. 707 * Updated 2119 language and added boilerplate. 709 * In section 1, noted that redirects can go to redirect servers 710 as well. 712 * Added Section 9.2 and Section 9.3. 714 -02 716 * Added a section on 429 response codes. 718 * Changed Accept header language in section 4.1 720 * Removed reference to the now dead requirements draft. 722 * Added contributing authors and acknowledgements section. 724 * Added some clarifying text regarding complete URLs in the 725 redirect section. 727 * Changed media type to application/rdap+json 729 * Added media type registration 731 -03 733 * Removed forward reference to draft-ietf-weirds-json-response. 735 * Added reference and recommended usage of CORS 737 -04 739 * Revised introduction and abstract. 741 * Added negative responses other than 404. 743 * Added security considerations. 745 * Added and corrected references: CORS, RFC3912, RFC3987, 746 RFC5890. 748 * Expanded on first use several acronyms. 750 * Updated 2119 language. 752 -05 754 * Update the media type registration. 756 * Further explained the SHOULD in section 5. 758 * Split the references into normative and informative. 760 * Other minor fixes. 762 -06 764 * Rewritten the third paragraph in Section 3 to avoid 765 contradictions 767 * Simplified the wording in Seciton 5.1. 769 * Removed some RFC 2119 words in Section 5.2, 5.3, 5.4 and 5.5. 771 * Corrected RFC 6839 as an informative reference. 773 * Replaced MAYs with cans in Seciton 9.1. 775 * Replaced MAY with can in Appendix B. 777 * Added a note in in Appendix C for the RFC Editor to remove this 778 section. 780 -07 782 * Dropped reference to MUST with application/rdap+json 784 * Dropped IANA registration of application/rdap+json 786 -08 788 * Keep alive version. 790 -09 792 * Changed status lines in example to include http version number. 794 * Removed charset from media types in examples. 796 * Changed wording of 404 negative response to specifically say 797 "empty result set". 799 * Changed references to HTTP. 801 -10 803 * Corrected references to HTTP. 805 * Added a reference to draft-ietf-weirds-json-response (discuss 806 item from Barry Leiba) 808 * Added a reference to draft-ietf-weirds-rdap-query (discuss item 809 from Barry Leiba) 811 * Noted that redirect URLs do not have to conform to draft-ietf- 812 weirds-rdap-query (comment by Richard Barnes) 814 * Noted that CORS header is most likely to be "*" (comment by 815 Richard Barnes) 817 * Added reference to draft-ietf-weirds-rdap-sec (comment by 818 Richard Barnes) 820 * Added a sentence to the abstract explaining the purpose of RDAP 821 (comment by Stephen Farrell) 823 * Added further references to draft-ietf-weirds-rdap-query and 824 draft-ietf-weirds-json-response (comment by Stephen Farrell) 826 * Added comment regarding the use of the CORS header (comment by 827 Stephen Farrell) 829 * Explanded SSAC (comment by Sean Turner) 831 * Added text about HEAD and GET. 833 -11 835 * Changed JSON reference to RFC 7159. 837 * Noted that clients MUST support HTTPS. 839 -12 841 * Added reference to REST. 843 * Numerous textual clarifications. 845 * Added an actual reference to RFC 5226 instead of just talking 846 about it. 848 * A reference to draft-ietf-weirds-bootstrap was added. 850 * Included a section on redirectors. 852 -13 854 * Addressed AD feedback. 856 -15 858 * Addressed Last Call comments. 860 Authors' Addresses 862 Andrew Lee Newton 863 American Registry for Internet Numbers 864 3635 Concorde Parkway 865 Chantilly, VA 20151 866 US 868 Email: andy@arin.net 869 URI: http://www.arin.net 871 Byron J. Ellacott 872 Asia Pacific Network Information Center 873 6 Cordelia Street 874 South Brisbane QLD 4101 875 Australia 877 Email: bje@apnic.net 878 URI: http://www.apnic.net 880 Ning Kong 881 China Internet Network Information Center 882 4 South 4th Street, Zhongguancun, Haidian District 883 Beijing 100190 884 China 886 Phone: +86 10 5881 3147 887 Email: nkong@cnnic.cn