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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Possible downref: Non-RFC (?) normative reference: ref. 'OIDCC' ** Downref: Normative reference to an Informational RFC: RFC 6973 ** Obsolete normative reference: RFC 7230 (Obsoleted by RFC 9110, RFC 9112) ** Downref: Normative reference to an Informational RFC: RFC 8605 == Outdated reference: A later version (-27) exists of draft-ietf-regext-rdap-openid-08 Summary: 4 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Registration Protocols Extensions M. Loffredo 3 Internet-Draft M. Martinelli 4 Intended status: Standards Track IIT-CNR/Registro.it 5 Expires: 31 May 2022 27 November 2021 7 Registration Data Access Protocol (RDAP) Reverse search capabilities 8 draft-ietf-regext-rdap-reverse-search-08 10 Abstract 12 The Registration Data Access Protocol (RDAP) does not include query 13 capabilities to find the list of domains related to a set of entities 14 matching a given search pattern. In the RDAP context, an entity can 15 be associated to any defined object class. Therefore, a reverse 16 search can be applied to other use cases than the classic domain- 17 entity scenario. This document describes RDAP query extensions that 18 allow servers to provide a reverse search feature based on the 19 relationship between any searchable object and the related entities. 21 Status of This Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at https://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on 31 May 2022. 38 Copyright Notice 40 Copyright (c) 2021 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents (https://trustee.ietf.org/ 45 license-info) in effect on the date of publication of this document. 46 Please review these documents carefully, as they describe your rights 47 and restrictions with respect to this document. Code Components 48 extracted from this document must include Revised BSD License text as 49 described in Section 4.e of the Trust Legal Provisions and are 50 provided without warranty as described in the Revised BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 55 1.1. Conventions Used in This Document . . . . . . . . . . . . 4 56 2. RDAP Path Segment Specification . . . . . . . . . . . . . . . 4 57 3. RDAP Conformance . . . . . . . . . . . . . . . . . . . . . . 5 58 4. Implementation Considerations . . . . . . . . . . . . . . . . 6 59 5. Implementation Status . . . . . . . . . . . . . . . . . . . . 6 60 5.1. IIT-CNR/Registro.it RDAP Server . . . . . . . . . . . . . 6 61 5.2. IIT-CNR/Registro.it RDAP Client . . . . . . . . . . . . . 7 62 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 63 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 7 64 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 65 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 66 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 67 10.1. Normative References . . . . . . . . . . . . . . . . . . 8 68 10.2. Informative References . . . . . . . . . . . . . . . . . 10 69 Appendix A. Paradigms to Enforce Access Control on Reverse Search 70 in RDAP . . . . . . . . . . . . . . . . . . . . . . . . . 11 71 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 11 72 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 74 1. Introduction 76 Reverse Whois is a service provided by many web applications that 77 allow users to find domain names owned by an individual or a company 78 starting from the owner's details, such as name and email. Even if 79 it has been considered useful for some legal purposes (e.g. 80 uncovering trademark infringements, detecting cybercrime cases), its 81 availability as a standardized Whois capability has been objected for 82 two main reasons, which now don't seem to conflict with an RDAP 83 implementation. 85 The first objection has been caused by the potential risks of privacy 86 violation. However, TLDs community is considering a new generation 87 of Registration Directory Services [ICANN-RDS1] [ICANN-RDS2] 88 [ICANN-RA], which provide access to sensitive data under some 89 permissible purposes and according to adequate policies to enforce 90 the requestor accreditation, authentication, authorization, and terms 91 and conditions of data use. It is well known that such security 92 policies are not implemented in Whois [RFC3912], while they are in 93 RDAP [RFC7481]. Therefore, RDAP permits a reverse search 94 implementation complying with privacy protection principles. 96 Another objection to the implementation of a reverse search 97 capability has been connected with its impact on server processing. 98 Since RDAP supports search queries, the impact of both standard and 99 reverse searches is equivalent and can be mitigated by servers 100 adopting ad hoc strategies. Furthermore, the reverse search is 101 almost always performed by specifying an entity role (e.g. 102 registrant, technical contact) and this can contribute to restricting 103 the result set. 105 Reverse searches, such as finding the list of domain names associated 106 with contacts or nameservers may be useful to registrars as well. 107 Usually, registries adopt out-of-band solutions to provide results to 108 registrars asking for reverse searches on their domains. Possible 109 reasons for such requests are: 111 * the loss of synchronization between the registrar database and the 112 registry database; 113 * the need for such data to perform massive EPP [RFC5730] updates 114 (e.g. changing the contacts of a set of domains, etc.). 116 Currently, RDAP does not provide any way for a client to search for 117 the collection of domains associated with an entity [RFC9082]. A 118 query (lookup or search) on domains can return the array of entities 119 related to a domain with different roles (registrant, registrar, 120 administrative, technical, reseller, etc.), but the reverse operation 121 is not allowed. Only reverse searches to find the collection of 122 domains related to a nameserver (ldhName or ip) can be requested. 123 Since an entity can be in relationship with any RDAP object 124 [RFC9083], the availability of a reverse search can be common to all 125 resource type path segments defined for search. 127 The protocol described in this specification aims to extend the RDAP 128 query capabilities to enable the reverse search based on the 129 relationship between any object and the associated entities. The 130 extension is implemented by adding new path segments (i.e. search 131 paths) and using a RESTful web service [REST]. The service is 132 implemented using the Hypertext Transfer Protocol (HTTP) [RFC7230] 133 and the conventions described in [RFC7480]. 135 1.1. Conventions Used in This Document 137 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 138 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 139 "OPTIONAL" in this document are to be interpreted as described in BCP 140 14 [RFC2119] [RFC8174] when, and only when, they appear in all 141 capitals, as shown here. 143 2. RDAP Path Segment Specification 145 The new search paths are OPTIONAL extensions of those defined in 146 [RFC9082]. A generic reverse search path is described by the syntax: 148 {resource-type}/reverse/{role}?{property}= 150 The path segments are defined as in the following: 152 * resource-type: it MUST be one of resource type path segments 153 defined in Section 3.2 of [RFC9082]: "domains", "nameservers" or 154 "entities"; 155 * role: it MUST be one of the roles described in Section 10.2.4 of 156 [RFC9083]. For role independent reverse searches, the value 157 "entity" MUST be used; 158 * property: it identifies the entity property to be used in matching 159 the search pattern. A pre-defined list of properties includes: 160 fn, handle, email, city, country, cc. The mapping between such 161 properties and the RDAP properties is shown in Table 1. Some of 162 the properties are related to jCard elements [RFC7095] but, being 163 jCard the JSON format for vCard [RFC6350], the corresponding 164 definitions are included in vCard specification. Servers MAY 165 implement other properties than those defined in this document. 167 Partial string matching is allowed as defined in section 4.1 of 168 [RFC9082]. 170 +=========================+===============+==========+=======+======+ 171 | Reverse search property | RDAP property | RFC | RFC | RFC | 172 | | | 9083 | 6350 | 8605 | 173 +=========================+===============+==========+=======+======+ 174 | handle | handle | 5.1. | | | 175 +-------------------------+---------------+----------+-------+------+ 176 | fn | jCard fn | | 6.2.1 | | 177 +-------------------------+---------------+----------+-------+------+ 178 | email | jCard email | | 6.4.2 | | 179 +-------------------------+---------------+----------+-------+------+ 180 | city | locality in | | 6.3.1 | | 181 | | jCard adr | | | | 182 +-------------------------+---------------+----------+-------+------+ 183 | country | country name | | 6.3.1 | | 184 | | in jCard adr | | | | 185 +-------------------------+---------------+----------+-------+------+ 186 | cc | country code | | | 3.1 | 187 | | in jCard adr | | | | 188 +-------------------------+---------------+----------+-------+------+ 190 Table 1: Mapping between the reverse search properties and the 191 RDAP properties 193 https://example.com/rdap/domains/reverse/technical?handle=CID-40* 195 https://example.com/rdap/domains/reverse/registrant?fn=Bobby* 197 https://example.com/rdap/domains/reverse/registrant?cc=US 199 https://example.com/rdap/entites/reverse/registrar?handle=RegistrarX 201 Figure 1: Examples of reverse search queries 203 The "country" property can be used as an alternative to "cc" when 204 RDAP servers don't include the jCard "cc" parameter [RFC8605] in 205 their response. 207 3. RDAP Conformance 209 Servers complying with this specification MUST include the value 210 "reverse_search" in the rdapConformance property of the help response 211 [RFC9083]. The information needed to register this value in the 212 "RDAP Extensions" registry is described in Section 6. 214 4. Implementation Considerations 216 The implementation of the proposed extension is technically feasible. 217 Both handle and fn are used as standard path segments to search for 218 entities [RFC9082]. With regards to the other reverse search 219 properties, namely email, city and country code, the impact of their 220 usage on server processing is evaluated to be the same as other 221 existing query capabilities (e.g. wildcard prefixed search pattern) 222 so the risks to degrade the performance or to generate huge result 223 sets can be mitigated by adopting the same policies (e.g. restricting 224 the search functionality, limiting the rate of search requests 225 according to the user profile, truncating and paging the results, 226 returning partial responses). 228 5. Implementation Status 230 NOTE: Please remove this section and the reference to RFC 7942 prior 231 to publication as an RFC. 233 This section records the status of known implementations of the 234 protocol defined by this specification at the time of posting of this 235 Internet-Draft, and is based on a proposal described in [RFC7942]. 236 The description of implementations in this section is intended to 237 assist the IETF in its decision processes in progressing drafts to 238 RFCs. Please note that the listing of any individual implementation 239 here does not imply endorsement by the IETF. Furthermore, no effort 240 has been spent to verify the information presented here that was 241 supplied by IETF contributors. This is not intended as, and must not 242 be construed to be, a catalog of available implementations or their 243 features. Readers are advised to note that other implementations may 244 exist. 246 According to RFC 7942, "this will allow reviewers and working groups 247 to assign due consideration to documents that have the benefit of 248 running code, which may serve as evidence of valuable experimentation 249 and feedback that have made the implemented protocols more mature. 250 It is up to the individual working groups to use this information as 251 they see fit". 253 5.1. IIT-CNR/Registro.it RDAP Server 255 * Responsible Organization: Institute of Informatics and Telematics 256 of National Research Council (IIT-CNR)/Registro.it 257 * Location: https://rdap.pubtest.nic.it/ 258 * Description: This implementation includes support for RDAP queries 259 using data from the public test environment of .it ccTLD. Reverse 260 search is allowed to authenticated users. Registrar users are 261 allowed to perform reverse searches on their own domains and 262 contacts. This is achieved by adding an implicit condition to the 263 search pattern. 264 * Level of Maturity: This is an "alpha" test implementation. 265 * Coverage: This implementation includes all of the features 266 described in this specification. 267 * Contact Information: Mario Loffredo, mario.loffredo@iit.cnr.it 269 5.2. IIT-CNR/Registro.it RDAP Client 271 * Responsible Organization: Institute of Informatics and Telematics 272 of National Research Council (IIT-CNR)/Registro.it 273 * Location: https://web-rdap.pubtest.nic.it/ 274 * Description: This is a Javascript web-based RDAP client. RDAP 275 responses are retrieved from RDAP servers by the browser, parsed 276 into an HTML representation, and displayed in a format improving 277 the user experience. Reverse search is allowed to authenticated 278 users. 279 * Level of Maturity: This is an "alpha" test implementation. 280 * Coverage: This implementation includes all of the features 281 described in this specification. 282 * Contact Information: Francesco Donini, francesco.donini@iit.cnr.it 284 6. IANA Considerations 286 IANA is requested to register the following value in the RDAP 287 Extensions Registry: 289 * Extension identifier: reverse_search 290 * Registry operator: Any 291 * Published specification: This document. 292 * Contact: IETF 293 * Intended usage: This extension describes reverse search query 294 patterns for RDAP. 296 7. Privacy Considerations 298 The use of the capability described in this document MUST be 299 compliant with the rules about privacy protection each RDAP provider 300 is subject to. Sensitive registration data MUST be protected and 301 accessible for permissible purposes only. This functionality SHOULD 302 be only accessible to authorized users and only for a specified use 303 case. 305 Already the request for this functionality could contain Personal 306 Identifiable Information and SHOULD therefore only be available over 307 HTTPS. 309 Providing reverse search in RDAP carries the following threats as 310 described in [RFC6973]: 312 * Correlation 313 * Disclosure 314 * Misuse of information 316 Therefore, RDAP providers are REQUIRED to mitigate the risk of those 317 threats by implementing appropriate measures supported by security 318 services (see Section 8). 320 8. Security Considerations 322 Security services required to provide controlled access to the 323 operations specified in this document are described in [RFC7481]. A 324 non exhaustive list of access control paradigms an RDAP provider can 325 implement is presented in Appendix A. 327 The specification of the entity role within the reverse search path 328 allows the RDAP servers to implement different authorization policies 329 on a per-role basis. 331 9. Acknowledgements 333 The authors would like to acknowledge the following individuals for 334 their contributions to this document: Tom Harrison, Jasdip Singh, 335 Scott Hollenbeck, Francisco Arias, Gustavo Lozano, Eduardo Alvarez 336 and Ulrich Wisser. 338 10. References 340 10.1. Normative References 342 [OIDCC] OpenID Foundation, "OpenID Connect Core incorporating 343 errata set 1", November 2014, 344 . 346 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 347 Requirement Levels", BCP 14, RFC 2119, 348 DOI 10.17487/RFC2119, March 1997, 349 . 351 [RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, 352 DOI 10.17487/RFC3912, September 2004, 353 . 355 [RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)", 356 STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009, 357 . 359 [RFC6350] Perreault, S., "vCard Format Specification", RFC 6350, 360 DOI 10.17487/RFC6350, August 2011, 361 . 363 [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., 364 Morris, J., Hansen, M., and R. Smith, "Privacy 365 Considerations for Internet Protocols", RFC 6973, 366 DOI 10.17487/RFC6973, July 2013, 367 . 369 [RFC7095] Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095, 370 DOI 10.17487/RFC7095, January 2014, 371 . 373 [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 374 Protocol (HTTP/1.1): Message Syntax and Routing", 375 RFC 7230, DOI 10.17487/RFC7230, June 2014, 376 . 378 [RFC7480] Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the 379 Registration Data Access Protocol (RDAP)", STD 95, 380 RFC 7480, DOI 10.17487/RFC7480, March 2015, 381 . 383 [RFC7481] Hollenbeck, S. and N. Kong, "Security Services for the 384 Registration Data Access Protocol (RDAP)", STD 95, 385 RFC 7481, DOI 10.17487/RFC7481, March 2015, 386 . 388 [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running 389 Code: The Implementation Status Section", BCP 205, 390 RFC 7942, DOI 10.17487/RFC7942, July 2016, 391 . 393 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 394 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 395 May 2017, . 397 [RFC8605] Hollenbeck, S. and R. Carney, "vCard Format Extensions: 398 ICANN Extensions for the Registration Data Access Protocol 399 (RDAP)", RFC 8605, DOI 10.17487/RFC8605, May 2019, 400 . 402 [RFC9082] Hollenbeck, S. and A. Newton, "Registration Data Access 403 Protocol (RDAP) Query Format", STD 95, RFC 9082, 404 DOI 10.17487/RFC9082, June 2021, 405 . 407 [RFC9083] Hollenbeck, S. and A. Newton, "JSON Responses for the 408 Registration Data Access Protocol (RDAP)", STD 95, 409 RFC 9083, DOI 10.17487/RFC9083, June 2021, 410 . 412 10.2. Informative References 414 [I-D.ietf-regext-rdap-openid] 415 Hollenbeck, S., "Federated Authentication for the 416 Registration Data Access Protocol (RDAP) using OpenID 417 Connect", Work in Progress, Internet-Draft, draft-ietf- 418 regext-rdap-openid-08, 8 November 2021, 419 . 422 [ICANN-RA] Internet Corporation For Assigned Names and Numbers, 423 "Registry Agreement", July 2017, 424 . 427 [ICANN-RDS1] 428 Internet Corporation For Assigned Names and Numbers, 429 "Final Report from the Expert Working Group on gTLD 430 Directory Services: A Next-Generation Registration 431 Directory Service (RDS)", June 2014, 432 . 435 [ICANN-RDS2] 436 Internet Corporation For Assigned Names and Numbers, 437 "Final Issue Report on a Next-Generation gTLD RDS to 438 Replace WHOIS", October 2015, 439 . 442 [REST] Fielding, R., "Architectural Styles and the Design of 443 Network-based Software Architectures", 2000, 444 . 447 Appendix A. Paradigms to Enforce Access Control on Reverse Search in 448 RDAP 450 Access control can be implemented according to different paradigms 451 introducing increasingly stringent rules. The paradigms reported 452 here in the following leverage the capabilities either supported 453 natively or provided as extensions by the OpenID Connect [OIDCC]: 455 * Role-Based Access Control: access rights are granted depending on 456 roles. Generally, this is done by grouping users into fixed 457 categories and assigning each category with static grants. A more 458 dynamic approach can be implemented by using the OpenID Connect 459 "scope" claim; 460 * Purpose-Based Access Control: access rules are based on the notion 461 of purpose which means the intended usage of some data by a user. 462 It can be implemented by tagging a request with the usage purpose 463 and making the RDAP server check the compliance between the given 464 purpose and the control rules applied to data to be returned. The 465 purpose can be stated within an out-of-band process by setting the 466 OpenID Connect RDAP specific "purpose" claim as defined in 467 [I-D.ietf-regext-rdap-openid]; 468 * Attribute-Based Access Control: rules to manage access rights are 469 evaluated and applied according to specific attributes describing 470 the context within which data are requested. It can be 471 implemented by setting within an out-of-band process additional 472 OpenID Connect claims describing the request context and making 473 the RDAP server check the compliance between the given context and 474 the control rules applied to data to be returned; 475 * Time-Based Access Control: data access is allowed for limited time 476 only. It can be implemented by assigning the users with temporary 477 credentials linked to access grants whose scope is limited. 479 Appendix B. Change Log 481 00: Initial working group version ported from draft-loffredo-regext- 482 rdap-reverse-search-04 483 01: Updated "Privacy Considerations" section. 484 02: Revised the text. 485 03: Refactored the query model. 486 04: Keepalive refresh. 487 05: Reorganized "Abstract". Corrected "Conventions Used in This 488 Document" section. Added "RDAP Conformance" section. Changed 489 "IANA Considerations" section. Added references to RFC7095 and 490 RFC8174. Other minor edits. 491 06: Updated "Privacy Considerations", "Security Considerations" and 492 "Acknowledgements" sections. Added some normative and informative 493 references. Added Appendix A. 494 07: Updated normative refernces. 495 08: Changed "Implementation Status" secion. Updated informative 496 references. 498 Authors' Addresses 500 Mario Loffredo 501 IIT-CNR/Registro.it 502 Via Moruzzi,1 503 56124 Pisa 504 Italy 506 Email: mario.loffredo@iit.cnr.it 507 URI: http://www.iit.cnr.it 509 Maurizio Martinelli 510 IIT-CNR/Registro.it 511 Via Moruzzi,1 512 56124 Pisa 513 Italy 515 Email: maurizio.martinelli@iit.cnr.it 516 URI: http://www.iit.cnr.it