--- 1/draft-ietf-regext-rdap-reverse-search-08.txt 2022-02-10 02:13:03.838907247 -0800 +++ 2/draft-ietf-regext-rdap-reverse-search-09.txt 2022-02-10 02:13:03.858907502 -0800 @@ -1,236 +1,269 @@ Registration Protocols Extensions M. Loffredo Internet-Draft M. Martinelli Intended status: Standards Track IIT-CNR/Registro.it -Expires: 31 May 2022 27 November 2021 +Expires: 14 August 2022 10 February 2022 Registration Data Access Protocol (RDAP) Reverse search capabilities - draft-ietf-regext-rdap-reverse-search-08 + draft-ietf-regext-rdap-reverse-search-09 Abstract The Registration Data Access Protocol (RDAP) does not include query capabilities to find the list of domains related to a set of entities matching a given search pattern. In the RDAP context, an entity can - be associated to any defined object class. Therefore, a reverse - search can be applied to other use cases than the classic domain- - entity scenario. This document describes RDAP query extensions that - allow servers to provide a reverse search feature based on the - relationship between any searchable object and the related entities. + be associated with any defined object class. Moreover, other + relationships between object classes exist and might be used for + providing a reverse search capability. Therefore, a reverse search + can be applied to other use cases than the classic domain-entity + scenario. This document describes RDAP query extensions that allow + servers to provide a reverse search feature based on the relationship + defined in RDAP between an object class for search and any related + object class. The reverse search based on the domain-entity + relationship is treated as a particular case but with a special focus + on its privacy implications. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on 31 May 2022. + This Internet-Draft will expire on 14 August 2022. Copyright Notice - Copyright (c) 2021 IETF Trust and the persons identified as the + Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Conventions Used in This Document . . . . . . . . . . . . 4 2. RDAP Path Segment Specification . . . . . . . . . . . . . . . 4 - 3. RDAP Conformance . . . . . . . . . . . . . . . . . . . . . . 5 + 2.1. Reverse Searches Based on Entity Details . . . . . . . . 4 + 3. RDAP Conformance . . . . . . . . . . . . . . . . . . . . . . 6 4. Implementation Considerations . . . . . . . . . . . . . . . . 6 5. Implementation Status . . . . . . . . . . . . . . . . . . . . 6 - 5.1. IIT-CNR/Registro.it RDAP Server . . . . . . . . . . . . . 6 + 5.1. IIT-CNR/Registro.it RDAP Server . . . . . . . . . . . . . 7 5.2. IIT-CNR/Registro.it RDAP Client . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 - 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 7 + 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 8 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 10.1. Normative References . . . . . . . . . . . . . . . . . . 8 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 9 10.2. Informative References . . . . . . . . . . . . . . . . . 10 Appendix A. Paradigms to Enforce Access Control on Reverse Search in RDAP . . . . . . . . . . . . . . . . . . . . . . . . . 11 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction Reverse Whois is a service provided by many web applications that allow users to find domain names owned by an individual or a company starting from the owner's details, such as name and email. Even if it has been considered useful for some legal purposes (e.g. - uncovering trademark infringements, detecting cybercrime cases), its - availability as a standardized Whois capability has been objected for - two main reasons, which now don't seem to conflict with an RDAP + uncovering trademark infringements, detecting cybercrimes), its + availability as a standardized Whois capability has been objected to + for two main reasons, which now don't seem to conflict with an RDAP implementation. The first objection has been caused by the potential risks of privacy violation. However, TLDs community is considering a new generation of Registration Directory Services [ICANN-RDS1] [ICANN-RDS2] [ICANN-RA], which provide access to sensitive data under some permissible purposes and according to adequate policies to enforce the requestor accreditation, authentication, authorization, and terms and conditions of data use. It is well known that such security policies are not implemented in Whois [RFC3912], while they are in RDAP [RFC7481]. Therefore, RDAP permits a reverse search implementation complying with privacy protection principles. - Another objection to the implementation of a reverse search + The other objection to the implementation of a reverse search capability has been connected with its impact on server processing. Since RDAP supports search queries, the impact of both standard and reverse searches is equivalent and can be mitigated by servers adopting ad hoc strategies. Furthermore, the reverse search is almost always performed by specifying an entity role (e.g. registrant, technical contact) and this can contribute to restricting the result set. Reverse searches, such as finding the list of domain names associated with contacts or nameservers may be useful to registrars as well. Usually, registries adopt out-of-band solutions to provide results to registrars asking for reverse searches on their domains. Possible reasons for such requests are: * the loss of synchronization between the registrar database and the registry database; * the need for such data to perform massive EPP [RFC5730] updates (e.g. changing the contacts of a set of domains, etc.). - Currently, RDAP does not provide any way for a client to search for + Currently, RDAP does not provide any means for a client to search for the collection of domains associated with an entity [RFC9082]. A query (lookup or search) on domains can return the array of entities related to a domain with different roles (registrant, registrar, administrative, technical, reseller, etc.), but the reverse operation is not allowed. Only reverse searches to find the collection of domains related to a nameserver (ldhName or ip) can be requested. Since an entity can be in relationship with any RDAP object - [RFC9083], the availability of a reverse search can be common to all - resource type path segments defined for search. + [RFC9083], the availability of a reverse search as largely intended + can be common to all the object classes allowed for search. Through + a further step of generalization, the meaning of reverse search in + the RDAP context can be extended to include any query for retrieving + all the objects in relationship with another matching a given search + pattern. The protocol described in this specification aims to extend the RDAP query capabilities to enable the reverse search based on the - relationship between any object and the associated entities. The - extension is implemented by adding new path segments (i.e. search + relationships defined in RDAP between an object class for search and + any related object class. The reverse search based on the domain- + entity relationship is treated as a particular case of such a generic + query model but with a special focus on its privacy implications. + The extension is implemented by adding new path segments (i.e. search paths) and using a RESTful web service [REST]. The service is implemented using the Hypertext Transfer Protocol (HTTP) [RFC7230] and the conventions described in [RFC7480]. 1.1. Conventions Used in This Document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 2. RDAP Path Segment Specification The new search paths are OPTIONAL extensions of those defined in [RFC9082]. A generic reverse search path is described by the syntax: - {resource-type}/reverse/{role}?{property}= + {searchable-resource-type}/reverse/{related-resource-type}? The path segments are defined as in the following: - * resource-type: it MUST be one of resource type path segments - defined in Section 3.2 of [RFC9082]: "domains", "nameservers" or - "entities"; - * role: it MUST be one of the roles described in Section 10.2.4 of - [RFC9083]. For role independent reverse searches, the value - "entity" MUST be used; - * property: it identifies the entity property to be used in matching - the search pattern. A pre-defined list of properties includes: - fn, handle, email, city, country, cc. The mapping between such - properties and the RDAP properties is shown in Table 1. Some of - the properties are related to jCard elements [RFC7095] but, being - jCard the JSON format for vCard [RFC6350], the corresponding - definitions are included in vCard specification. Servers MAY - implement other properties than those defined in this document. + * searchable-resource-type: it MUST be one of resource types for + search defined in Section 3.2 of [RFC9082], i.e. "domains", + "nameservers" and "entities"; + * related-resource-type: it MUST be one of the resource types for + lookup defined in Section 3.1 of [RFC9082], i.e. "domain", + "nameserver", "entity", "ip" and "autnum"; + * search-condition: a sequence of "property=search pattern" + predicates separated by the ampersand character ('&', US-ASCII + value 0x0026). Each "property" represents a JSON object property + of the RDAP object class corresponding to "related-resource-type". + All the predicates are joined by the AND logical operator. Based + on their policy, servers MAY restrict the usage of predicates to + make a valid search condition. - Partial string matching is allowed as defined in section 4.1 of - [RFC9082]. + Partial string matching in search patterns is allowed as defined in + section 4.1 of [RFC9082]. - +=========================+===============+==========+=======+======+ - | Reverse search property | RDAP property | RFC | RFC | RFC | - | | | 9083 | 6350 | 8605 | - +=========================+===============+==========+=======+======+ - | handle | handle | 5.1. | | | - +-------------------------+---------------+----------+-------+------+ - | fn | jCard fn | | 6.2.1 | | - +-------------------------+---------------+----------+-------+------+ - | email | jCard email | | 6.4.2 | | - +-------------------------+---------------+----------+-------+------+ - | city | locality in | | 6.3.1 | | - | | jCard adr | | | | - +-------------------------+---------------+----------+-------+------+ - | country | country name | | 6.3.1 | | - | | in jCard adr | | | | - +-------------------------+---------------+----------+-------+------+ - | cc | country code | | | 3.1 | - | | in jCard adr | | | | - +-------------------------+---------------+----------+-------+------+ +2.1. Reverse Searches Based on Entity Details - Table 1: Mapping between the reverse search properties and the - RDAP properties + Since in RDAP, an entity can be associated with any other object + class, the most common kind of reverse searches are based on the + entity details. Such reverse searches arise from the above query + model by setting the related resource type to "entity". - https://example.com/rdap/domains/reverse/technical?handle=CID-40* + By selecting a specific searchable resource type, the resulting + reverse search aims at retrieving all the objects (e.g. all the + domains) that are related to any entity object matching the search + condition. - https://example.com/rdap/domains/reverse/registrant?fn=Bobby* + This section defines the following reverse search properties to be + used regardless of the searchable resource type being selected: - https://example.com/rdap/domains/reverse/registrant?cc=US + Reverse search property: role + RDAP property: $..entities[*].roles + RFC reference: Section 10.2.4 of [RFC9083] - https://example.com/rdap/entites/reverse/registrar?handle=RegistrarX + Reverse search property: handle + RDAP property: $..entities[*].handle + RFC reference: Section 5.1 of [RFC9083] - Figure 1: Examples of reverse search queries + Reverse search property: fn + RDAP property: $..entities[*].vcardArray[1][?(@[0]=='fn')][3] + RFC reference: Section 6.2.1 of [RFC6350] - The "country" property can be used as an alternative to "cc" when - RDAP servers don't include the jCard "cc" parameter [RFC8605] in - their response. + Reverse search property: email + RDAP property: $..entities[*].vcardArray[1][?(@[0]=='email')][3] + RFC reference: Section 6.4.2 of [RFC6350] + + Regarding the definitions above, it must be noted that: + + * The mapping between the reverse search property and the + corresponding RDAP response property is done through the use of a + JSONPath expression [I-D.ietf-jsonpath-base]. + * The presence of a predicate on the reverse search property "role" + means that the RDAP response property "roles" must contain at + least the specified role. + * Some of the properties are related to jCard elements [RFC7095] + but, being jCard the JSON format for vCard [RFC6350], the + corresponding RFC reference is to the vCard specification + [RFC6350]. + + Servers MAY implement other properties than those defined in this + section. + + Examples of reverse search paths based on the domain-entity + relationship are presented below: + + /domains/reverse/entity?handle=CID-40*&role=technical + + /domains/reverse/entity?fn=Bobby*&role=registrant + + /domains/reverse/entity?handle=RegistrarX&role=registrar + Figure 1 3. RDAP Conformance Servers complying with this specification MUST include the value - "reverse_search" in the rdapConformance property of the help response - [RFC9083]. The information needed to register this value in the - "RDAP Extensions" registry is described in Section 6. + "reverse_search_0" in the rdapConformance property of the help + response [RFC9083]. The information needed to register this value in + the "RDAP Extensions" registry is described in Section 6. 4. Implementation Considerations The implementation of the proposed extension is technically feasible. - Both handle and fn are used as standard path segments to search for - entities [RFC9082]. With regards to the other reverse search - properties, namely email, city and country code, the impact of their - usage on server processing is evaluated to be the same as other - existing query capabilities (e.g. wildcard prefixed search pattern) - so the risks to degrade the performance or to generate huge result - sets can be mitigated by adopting the same policies (e.g. restricting - the search functionality, limiting the rate of search requests - according to the user profile, truncating and paging the results, - returning partial responses). + To limit the impact of processing the search predicates, servers are + RECOMMENDED to mandate the use of at least one property among those + mapped to indexed fields of the registry database. Other properties, + such as "role", MAY be allowed to further restrict the set of + possible results. In addition, the risks to degrade the performance + or to generate huge result sets can be mitigated by adopting the same + policies valid for handling searches (e.g. restricting the search + functionality, limiting the rate of search requests according to the + user profile, truncating and paging the results, returning partial + responses). 5. Implementation Status NOTE: Please remove this section and the reference to RFC 7942 prior to publication as an RFC. This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in [RFC7942]. The description of implementations in this section is intended to @@ -279,71 +312,74 @@ * Level of Maturity: This is an "alpha" test implementation. * Coverage: This implementation includes all of the features described in this specification. * Contact Information: Francesco Donini, francesco.donini@iit.cnr.it 6. IANA Considerations IANA is requested to register the following value in the RDAP Extensions Registry: - * Extension identifier: reverse_search + * Extension identifier: reverse_search_0 * Registry operator: Any * Published specification: This document. * Contact: IETF * Intended usage: This extension describes reverse search query patterns for RDAP. 7. Privacy Considerations - The use of the capability described in this document MUST be - compliant with the rules about privacy protection each RDAP provider - is subject to. Sensitive registration data MUST be protected and - accessible for permissible purposes only. This functionality SHOULD - be only accessible to authorized users and only for a specified use - case. + The use of the capability described in this document whenever a + contact detail is taken MUST be compliant with the rules about + privacy protection each RDAP provider is subject to. Sensitive + registration data MUST be protected and accessible for permissible + purposes only. This feature SHOULD be only accessible to authorized + users and only for a specified use case. - Already the request for this functionality could contain Personal - Identifiable Information and SHOULD therefore only be available over - HTTPS. + Since the request for this feature could contain Personal + Identifiable Information, it SHOULD only be accessible to authorized + users and available over HTTPS. Providing reverse search in RDAP carries the following threats as described in [RFC6973]: * Correlation * Disclosure * Misuse of information Therefore, RDAP providers are REQUIRED to mitigate the risk of those threats by implementing appropriate measures supported by security services (see Section 8). 8. Security Considerations Security services required to provide controlled access to the operations specified in this document are described in [RFC7481]. A - non exhaustive list of access control paradigms an RDAP provider can + non-exhaustive list of access control paradigms an RDAP provider can implement is presented in Appendix A. - The specification of the entity role within the reverse search path + The specification of the relationship within the reverse search path allows the RDAP servers to implement different authorization policies - on a per-role basis. + on a per-relationship basis. 9. Acknowledgements The authors would like to acknowledge the following individuals for - their contributions to this document: Tom Harrison, Jasdip Singh, - Scott Hollenbeck, Francisco Arias, Gustavo Lozano, Eduardo Alvarez - and Ulrich Wisser. + their contributions to this document: Francesco Donini, Scott + Hollenbeck, Francisco Arias, Gustavo Lozano, Eduardo Alvarez and + Ulrich Wisser. -10. References + Tom Harrison and Jasdip Singh provided relevant feedback and constant + support to the implementation of this proposal. Their contributions + are greatly appreciated. +10. References 10.1. Normative References [OIDCC] OpenID Foundation, "OpenID Connect Core incorporating errata set 1", November 2014, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . @@ -387,37 +423,39 @@ [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running Code: The Implementation Status Section", BCP 205, RFC 7942, DOI 10.17487/RFC7942, July 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . - [RFC8605] Hollenbeck, S. and R. Carney, "vCard Format Extensions: - ICANN Extensions for the Registration Data Access Protocol - (RDAP)", RFC 8605, DOI 10.17487/RFC8605, May 2019, - . - [RFC9082] Hollenbeck, S. and A. Newton, "Registration Data Access Protocol (RDAP) Query Format", STD 95, RFC 9082, DOI 10.17487/RFC9082, June 2021, . [RFC9083] Hollenbeck, S. and A. Newton, "JSON Responses for the Registration Data Access Protocol (RDAP)", STD 95, RFC 9083, DOI 10.17487/RFC9083, June 2021, . 10.2. Informative References + [I-D.ietf-jsonpath-base] + Gössner, S., Normington, G., and C. Bormann, "JSONPath: + Query expressions for JSON", Work in Progress, Internet- + Draft, draft-ietf-jsonpath-base-03, 16 January 2022, + . + [I-D.ietf-regext-rdap-openid] Hollenbeck, S., "Federated Authentication for the Registration Data Access Protocol (RDAP) using OpenID Connect", Work in Progress, Internet-Draft, draft-ietf- regext-rdap-openid-08, 8 November 2021, . [ICANN-RA] Internet Corporation For Assigned Names and Numbers, "Registry Agreement", July 2017, @@ -465,42 +503,46 @@ purpose can be stated within an out-of-band process by setting the OpenID Connect RDAP specific "purpose" claim as defined in [I-D.ietf-regext-rdap-openid]; * Attribute-Based Access Control: rules to manage access rights are evaluated and applied according to specific attributes describing the context within which data are requested. It can be implemented by setting within an out-of-band process additional OpenID Connect claims describing the request context and making the RDAP server check the compliance between the given context and the control rules applied to data to be returned; - * Time-Based Access Control: data access is allowed for limited time - only. It can be implemented by assigning the users with temporary - credentials linked to access grants whose scope is limited. + * Time-Based Access Control: data access is allowed for a limited + time only. It can be implemented by assigning the users with + temporary credentials linked to access grants whose scope is + limited. Appendix B. Change Log 00: Initial working group version ported from draft-loffredo-regext- rdap-reverse-search-04 01: Updated "Privacy Considerations" section. 02: Revised the text. 03: Refactored the query model. 04: Keepalive refresh. 05: Reorganized "Abstract". Corrected "Conventions Used in This Document" section. Added "RDAP Conformance" section. Changed "IANA Considerations" section. Added references to RFC7095 and RFC8174. Other minor edits. 06: Updated "Privacy Considerations", "Security Considerations" and "Acknowledgements" sections. Added some normative and informative references. Added Appendix A. - 07: Updated normative refernces. - 08: Changed "Implementation Status" secion. Updated informative + 07: Updated normative references. + 08: Changed "Implementation Status" section. Updated informative references. + 09: Extended the query model to represent a reverse search based on + any relationship between the RDAP object classes. Changed the + path segment "role" into a query parameter. Authors' Addresses Mario Loffredo IIT-CNR/Registro.it Via Moruzzi,1 56124 Pisa Italy Email: mario.loffredo@iit.cnr.it