<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE rfcSYSTEM "http://xml.resource.org/authoring/rfc2629.dtd"[ <!ENTITYRFC2119 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'>nbsp " "> <!ENTITYRFC3912 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3912.xml'>zwsp "​"> <!ENTITYRFC5730 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.5730.xml'>nbhy "‑"> <!ENTITYRFC6350 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.6350.xml'> <!ENTITY RFC6973 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.6973.xml'> <!ENTITY RFC7095 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.7095.xml'> <!ENTITY RFC7481 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.7481.xml'> <!ENTITY RFC7942 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.7942.xml'> <!ENTITY RFC8126 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.8126.xml'> <!ENTITY RFC8174 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.8174.xml'> <!ENTITY RFC8977 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.8977.xml'> <!ENTITY RFC8982 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.8982.xml'> <!ENTITY RFC9082 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.9082.xml'> <!ENTITY RFC9083 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.9083.xml'> <!ENTITY RFC9110 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.9110.xml'> <!ENTITY I-D.ietf-jsonpath-base PUBLIC '' 'https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-jsonpath-base.xml'>wj "⁠"> ]><?xml-stylesheet type="text/xsl" href="rfc2629.xslt"?> <?rfc toc="yes"?> <?rfc tocompact="yes"?> <?rfc tocdepth="4"?> <?rfc compact="yes"?> <?rfc subcompact="yes"?> <?rfc sortrefs="yes"?> <?rfc symrefs="yes"?> <?rfc iprnotified="no"?><rfc xmlns:xi="http://www.w3.org/2001/XInclude" submissionType="IETF" category="std" consensus="true" docName="draft-ietf-regext-rdap-reverse-search-25" number="9536" ipr="trust200902"submissionType="IETF" consensus="true">tocInclude="true" tocDepth="4" sortRefs="true" symRefs="true" updates="" obsoletes="" xml:lang="en" version="3"> <!-- xml2rfc v2v3 conversion 3.18.0 --> <front> <title abbrev="RDAP Reversesearch">RegistrationSearch">Registration Data Access Protocol (RDAP) Reverse Search</title> <seriesInfo name="RFC" value="9536"/> <author fullname="Mario Loffredo" initials="M." surname="Loffredo"> <organization>IIT-CNR/Registro.it</organization> <address> <postal> <street>Via Moruzzi,1</street> <city>Pisa</city><country>IT</country><country>Italy</country> <code>56124</code> </postal> <email>mario.loffredo@iit.cnr.it</email> <uri>http://www.iit.cnr.it</uri> </address> </author> <author fullname="Maurizio Martinelli" initials="M." surname="Martinelli"> <organization>IIT-CNR/Registro.it</organization> <address> <postal> <street>Via Moruzzi,1</street> <city>Pisa</city><country>IT</country><country>Italy</country> <code>56124</code> </postal> <email>maurizio.martinelli@iit.cnr.it</email> <uri>http://www.iit.cnr.it</uri> </address> </author><date/> <area>Applications and Real-Time</area> <workgroup>Registration Protocols Extensions</workgroup><date year="2024" month="April"/> <area>art</area> <workgroup>regext</workgroup> <keyword>RDAP</keyword> <keyword>Reverse search</keyword> <abstract> <t>The Registration Data Access Protocol (RDAP) does not include query capabilities for finding the list of domains related to a set of entities matching a given search pattern. Considering that an RDAP entity can be associated with any defined object class and other relationships between RDAP object classes exist, a reverse search can be applied to other use cases besides the classic domain-entity scenario. This document describes an RDAP extension that allows 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.</t> </abstract> </front> <middle> <sectionanchor="introduction" title="Introduction">anchor="introduction"> <name>Introduction</name> <t>The protocol described in this specification aims to extend the RDAP query capabilities and response to enable reverse search based on the relationships defined in RDAP between an object class for search and a related object class. The reverse search based on the domain-entity relationship is treated as a particular case of such a generic model.</t> <t>RDAP providers willing to implement this specification should carefully consider its implications on the efficiency (see <xref target="impl-considerations"/>), the security (see <xreftarget="security-considerations"/>)target="security-considerations"/>), and the compliance with privacy regulations (see <xref target="privacy-considerations"/>) of their RDAP service.</t> <sectionanchor="background" title="Background">anchor="background"> <name>Background</name> <t>ReverseWhoisWHOIS is a service provided by many web applications that allows 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.(e.g., uncovering trademarkinfringements,infringements and detecting cybercrimes), its availability as a standardizedWhoisWHOIS <xref target="RFC3912"/> capability has been objected to for two main reasons, which now don't seem to conflict with an RDAP implementation.</t> <t>The first objection concerns the potential risks of privacy violation. However, the domain name community is considering a new generation of Registration Directory Services <xreftarget="ICANN-RDS1"/>target="ICANN-RDS"/> <xreftarget="ICANN-RDS2"/> <xref target="ICANN-RA"/>, whichtarget="ICANN-RA"/> that provide access to sensitive data under some permissible purposes and in accordance with appropriate policies for requestor accreditation,authenticationauthentication, and authorization. RDAP's reliance on HTTP means that it can make use of common HTTP-based approaches to authentication and authorization, making it more useful thanWhoisWHOIS in the context of such directory services. Since RDAP consequently permits a reverse search implementation complying with privacy protection principles, this first objection is not well-founded.</t> <t>The second objection to the implementation of a reverse search capability has been connected with its impact on server processing. However, the core RDAP specifications already define search queries, with similar processing requirements, so the basis of this objection is not clear.</t> <t>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:</t><t><list style="symbols"> <t>the<ul spacing="normal"> <li>the loss of synchronization between the registrar database and the registrydatabase;<vspace blankLines='1' /></t> <t>thedatabase and </li> <li>the need for such data to perform bulk Extensible Provisioning Protocol (EPP) <xref target="RFC5730"/> updates(e.g.(e.g., changing the contacts of a set of domains,etc.).</t> </list></t>etc.).</li> </ul> <t>Currently, RDAP does not provide any means for a client to search for the collection of domains associated with an entity <xref target="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 <xref target="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 objectsin relationship withthat relates to another query matching a given search pattern.</t> </section><section title="Conventions<section> <name>Conventions Used in ThisDocument">Document</name> <t>The key words"MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY","<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>", and"OPTIONAL""<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as described inBCP 14BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they appear in all capitals, as shown here.</t> </section> </section> <sectionanchor="reverse-search-path-segment-specification" title="Reverseanchor="reverse-search-path-segment-specification"> <name>Reverse Search Path SegmentSpecification">Specification</name> <t>A generic reverse search path is described by the syntax:</t> <t>{searchable-resource-type}/reverse_search/{related-resource-type}?<search-condition></t> <t>The path segments are defined asin the following:</t> <t> <list style="hanging"> <t hangText=""searchable-resource-type":">it MUSTfollows:</t> <dl newline="false" spacing="normal"> <dt>"searchable-resource-type":</dt> <dd>It <bcp14>MUST</bcp14> be one of the resource types for search defined inSection 3.2 of<xreftarget="RFC9082"/> (i.e. "domains", "nameservers"target="RFC9082" section="3.2" sectionFormat="of" /> (i.e., "domains", "nameservers", and"entities")"entities") or a resource typeextension;<vspace blankLines='1'/></t> </list> </t> <t> <list style="hanging"> <t hangText=""related-resource-type":">it MUSTextension. </dd> <dt>"related-resource-type":</dt> <dd>It <bcp14>MUST</bcp14> be one of the resource types for lookup defined inSection 3.1 of<xreftarget="RFC9082"/> (i.e. "domain", "nameserver", "entity", "ip"target="RFC9082" section="3.1" sectionFormat="of" /> (i.e., "domain", "nameserver", "entity", "ip", and"autnum")"autnum") or a resource typeextension;<vspace blankLines='1'/></t> </list> </t> <t> <list style="hanging"> <t hangText=""search-condition":">aextension. </dd> <dt>"search-condition":</dt> <dd>A sequence of"property=search pattern""property=search pattern" predicates separated by the ampersand character ('&', US-ASCII value0x0026).</t> </list> </t>0x0026).</dd> </dl> <t>While related-resource-type is defined as having one of a number of different values, the only reverse searches defined in this document are for a related-resource-type of"entity"."entity". Reverse searches for the other resource types specified in <xref target="RFC9082"/> and resource type extensions may be defined by future documents.</t> </section> <sectionanchor="reverse-search-definition" title="Reverseanchor="reverse-search-definition"> <name>Reverse SearchDefinition">Definition</name> <t>Based on the content of <xref target="reverse-search-path-segment-specification"/>, defining a reverse search means to define the triple <searchable resource type, related resource type, property> and the mapping with the corresponding RDAP object member. The mapping is done through the use of a JSONPath expression <xreftarget="I-D.ietf-jsonpath-base"/>.target="RFC9535"/>. Reverse searches are registered in the "RDAP ReverseSearchSearch" registry (see <xreftarget="rdap-reverse-search-registry" />),target="rdap-reverse-search-registry"/>), whereas reverse search mappings are registered in the "RDAP Reverse SearchMappingMapping" registry (see <xref target="rdap-reverse-search-mapping-registry"/>). The reason for having two registries is that it may be possible for a single type of reverse search to rely on different members, depending on the server's configuration (see <xreftarget="reverse-search-properties-mapping" />).</t>target="reverse-search-properties-mapping"/>).</t> <t>All of the reverse searches defined by this document (see <xref target="reverse-search-on-entities"/>) have property names that are the same as the name of the RDAP object member that is the subject of the search. For example, the reverse search with the property name"fn""fn" relies on the value of the"fn""fn" member inside the jCard of an entity object. However, it is not necessary that these two names be the same. In particular, remapping of searches as part of the deprecation of an existing member (see <xref target="reverse-search-properties-mapping"/>) will typically lead to a member with a different name being used for the search.</t> <t>ServersMUST NOT<bcp14>MUST NOT</bcp14> provide or implement reverse searches or reverse search mappings that are not registered with IANA.</t> </section> <sectionanchor="reverse-search-properties-discovery" title="Reverseanchor="reverse-search-properties-discovery"> <name>Reverse Search PropertiesDiscovery">Discovery</name> <t>Servers complying with this specificationMUST<bcp14>MUST</bcp14> extend the help response <xref target="RFC9083"/> with the"reverse_search_properties""reverse_search_properties" memberwhichthat contains an array of objects with the following mandatory child members:</t><t> <list style="hanging"> <t hangText=""searchableResourceType":">the<dl newline="false" spacing="normal"> <dt>"searchableResourceType":</dt> <dd>the searchable resource type of the reverse searchqueryquery, as defined in <xreftarget="reverse-search-path-segment-specification"/>;</t> </list> </t> <t> <list style="hanging"> <t hangText=""relatedResourceType":">thetarget="reverse-search-path-segment-specification"/></dd> <dt>"relatedResourceType":</dt> <dd>the related resource type of the reverse searchqueryquery, as defined in <xreftarget="reverse-search-path-segment-specification"/>;</t> </list> </t> <t> <list style="hanging"> <t hangText=""property":">thetarget="reverse-search-path-segment-specification"/></dd> <dt>"property":</dt> <dd>the reverse search property used in the predicate of the reverse searchqueryquery, as defined in <xreftarget="reverse-search-path-segment-specification"/>;</t> </list> </t>target="reverse-search-path-segment-specification"/></dd> </dl> <t>An example of the help response including the"reverse_search_properties""reverse_search_properties" member is shown in <xreftarget="reverse-search-properties-example"/>.</t>target="reverse-search-properties-example"/></t> </section> <sectionanchor="reverse-search-properties-mapping" title="Reverseanchor="reverse-search-properties-mapping"> <name>Reverse Search PropertiesMapping">Mapping</name> <t>To permit clients to determine the member used by the server for a reverse search, serversMUST<bcp14>MUST</bcp14> detail the mapping that is occurring by adding the"reverse_search_properties_mapping""reverse_search_properties_mapping" member to the topmost object of a reverse search response. This data structure is included in the search response, rather than in the help response, because it may differ depending on the query that is sent to the server.</t> <t>Documents that deprecate or restructure RDAP responses such that a registered reverse search is no longer able to be usedMUST<bcp14>MUST</bcp14> either note that the relevant reverse search is no longer available (in the case of deprecation) or describe how to continue supporting the relevant search by adding another mapping for the reverse search property (in the case of restructuring).</t> <t>The "reverse_search_properties_mapping" member contains an array of objects with the following mandatory child members:</t><t> <list style="hanging"> <t hangText=""property":">the<dl newline="false" spacing="normal"> <dt>"property":</dt> <dd>the reverse search property used in the predicate of the currentqueryquery, as defined in <xreftarget="reverse-search-path-segment-specification"/>;</t> </list> </t> <t> <list style="hanging"> <t hangText=""propertyPath":">thetarget="reverse-search-path-segment-specification"/></dd> <dt>"propertyPath":</dt> <dd>the JSONPath expression of the object member (or members) corresponding to the reverse searchproperty.</t> </list> </t>property</dd> </dl> <t>The searchable and the related resource types are derived from the query, so there is no need to include them in addition to the property in this member.</t> <t>This memberMUST<bcp14>MUST</bcp14> be included for all properties used in the search, regardless of whether that property has multiple registered mappings as at the time of the search, because new mappings may be registered at any time.</t> <t>When applied to an object, the JSONPath expressionMUST<bcp14>MUST</bcp14> produce a list of values, each of which is a JSON number or string.</t> <t>An example of a reverse search response including the"reverse_search_properties_mapping""reverse_search_properties_mapping" member is shown in <xref target="reverse-search-properties-mapping-example"/>.</t> </section> <sectionanchor="reverse-search-response-specification" title="Reverseanchor="reverse-search-response-specification"> <name>Reverse Search ResponseSpecification">Specification</name> <t>Reverse search responses use the formats defined insection 8 of<xreftarget="RFC9083"/>,target="RFC9083" section="8" sectionFormat="of" />, which correspond to the searchable resource types defined in <xref target="reverse-search-path-segment-specification"/>.</t> </section> <sectionanchor="reverse-search-query-processing" title="Reverseanchor="reverse-search-query-processing"> <name>Reverse Search QueryProcessing">Processing</name> <t>To process a reverse search, the server returns the objects from its data store that are of type searchable-resource-type and that match each of the predicates from the search conditions. To determine whether an object matches a predicate, the server:</t><list style="symbols"> <t>applies<ul spacing="normal"> <li>applies the mapping it uses for the reverse search property to the object in order to generate a list of values, each of whichMUST<bcp14>MUST</bcp14> be a JSON number orstring; and</t> <t>checksstring and</li> <li>checks whether the search pattern matches one or more of thosevalues.</t> </list>values.</li> </ul> <t>A search pattern matches a value where it equals the string representation of thevalue,value or where it is a match for the value in accordance with the partial string matchingbehaviourbehavior defined insection 4.1 of<xref target="RFC9082" section="4.1" sectionFormat="of" />.</t> <t>Objects are only included in the search results if they satisfy all included predicates. This includes predicates that are for the sameproperty: it is necessaryproperty; in such acasecase, it is necessary for the related object to match against each of those predicates.</t> <t>ServersMUST<bcp14>MUST</bcp14> return an HTTP 501 (Not Implemented) <xref target="RFC9110"/> response to inform clients of unsupported reverse searches.</t> <t>Based on their policy, serversMAY<bcp14>MAY</bcp14> restrict how predicates are used to make a valid searchcondition,condition by returning a 400 (Bad Request) response when a problematic request is received.</t> <t>A given reverse search or reverse search mappingMAY<bcp14>MAY</bcp14> define additional or alternative searchbehaviourbehavior past that set out in this section.</t> </section> <sectionanchor="reverse-search-on-entities" title="Reverseanchor="reverse-search-on-entities"> <name>Reverse Searches Based on EntityDetails">Details</name> <t>Sincein RDAP,an entity can be associated with any other objectclass,class in RDAP, the most common kind of reverse search is one based on an entity's details. Such reverse searches arise from the query model by setting the related resource type to"entity".</t>"entity".</t> <t>By selecting a specific searchable resource type, the resulting reverse search aims at retrieving all the objects(e.g.(e.g., all the domains) that are related to any entity object matching the search conditions.</t> <t>This section defines the reverse search properties serversSHOULD<bcp14>SHOULD</bcp14> support for the domain, nameserver,and entity searchableentity-searchable resourcetypestypes, andthe entity relatedentity-related resource type:</t><t> <list style="hanging"> <t hangText="Reverse search property:">role</t> <t hangText="RDAP<dl newline="false" spacing="compact"> <dt>Reverse search property:</dt> <dd>role</dd> <dt>RDAP memberpath:">$.entities[*].roles</t> <t hangText="Reference:">Section 10.2.4 of <xref target="RFC9083"/></t> </list> </t> <t> <list style="hanging"> <t hangText="Reverse search property:">handle</t> <t hangText="RDAPpath:</dt> <dd>$.entities[*].roles</dd> <dt>Reference:</dt> <dd><xref target="RFC9083" section="10.2.4" sectionFormat="of" /></dd> </dl> <dl newline="false" spacing="compact"> <dt>Reverse search property:</dt> <dd>handle</dd> <dt>RDAP memberpath:">$.entities[*].handle</t> <t hangText="Reference:">Section 5.1 of <xref target="RFC9083"/></t> </list> </t> <t> <list style="hanging"> <t hangText="Reverse search property:">fn</t> <t hangText="RDAPpath:</dt> <dd>$.entities[*].handle</dd> <dt>Reference:</dt> <dd><xref target="RFC9083" section="5.1" sectionFormat="of" /></dd> </dl> <dl newline="false" spacing="compact"> <dt>Reverse search property:</dt> <dd>fn</dd> <dt>RDAP memberpath:">$.entities[*].vcardArray[1][?(@[0]=='fn')][3]</t> <t hangText="Reference:">Section 6.2.1 of <xref target="RFC6350"/></t> </list> </t> <t> <list style="hanging"> <t hangText="Reverse search property:">email</t> <t hangText="RDAPpath:</dt> <dd>$.entities[*].vcardArray[1][?(@[0]=='fn')][3]</dd> <dt>Reference:</dt> <dd><xref target="RFC6350" section="6.2.1" sectionFormat="of" /></dd> </dl> <dl newline="false" spacing="compact"> <dt>Reverse search property:</dt> <dd>email</dd> <dt>RDAP memberpath:">$.entities[*].vcardArray[1][?(@[0]=='email')][3]</t> <t hangText="Reference:">Section 6.4.2 of <xref target="RFC6350"/></t> </list> </t>path:</dt> <dd>$.entities[*].vcardArray[1][?(@[0]=='email')][3]</dd> <dt>Reference:</dt> <dd><xref target="RFC6350" section="6.4.2" sectionFormat="of" /></dd> </dl> <t>The presence of a predicate on the reverse search property"role""role" means that the RDAP response property"roles" MUST"roles" <bcp14>MUST</bcp14> contain at least the specified role.</t> <t>The last two properties are related to jCard elements <xref target="RFC7095"/>, but the field references are to vCard <xref target="RFC6350"/>, since jCard is the JSON format for vCard.</t> <t>Examples of reverse search paths based on the domain-entity relationship are presented in <xref target="reverse-search-request"/>.</t> <figureanchor="reverse-search-request" title="Examplesanchor="reverse-search-request"> <name>Examples ofreverse search queries"> <artwork xml:space="preserve"><![CDATA[Reverse Search Queries</name> <artwork><![CDATA[ /domains/reverse_search/entity?handle=CID-40*&role=technical /domains/reverse_search/entity?fn=Bobby*&role=registrant /domains/reverse_search/entity?handle=RegistrarX&role=registrar ]]></artwork> </figure> <t>An example of the help response including the supported reverse search propertiessupportedis shownbelow.</t>in <xref target="reverse-search-properties-example"/>.</t> <figureanchor="reverse-search-properties-example" title="An exampleanchor="reverse-search-properties-example"> <name>An Example ofhelp responsethe Help Response including the"reverse_search_properties_mapping" member"> <artwork xml:space="preserve"><![CDATA["reverse_search_properties" Member</name> <sourcecode type="json"><![CDATA[ { "rdapConformance": [ "rdap_level_0", "reverse_search" ], ... "reverse_search_properties": [ { "searchableResourceType": "domains", "relatedResourceType": "entity", "property": "fn" }, { "searchableResourceType": "domains", "relatedResourceType": "entity", "property": "handle" }, { "searchableResourceType": "domains", "relatedResourceType": "entity", "property": "email" }, { "searchableResourceType": "domains", "relatedResourceType": "entity", "property": "role" } ], ... }]]></artwork>]]></sourcecode> </figure> <t>An example of a response including the mapping that is occurring for the first reverse search in <xref target="reverse-search-request"/> is shown below.</t> <figureanchor="reverse-search-properties-mapping-example" title="An exampleanchor="reverse-search-properties-mapping-example"> <name>An Example of an RDAPresponseResponse including the"reverse_search_properties" member"> <artwork xml:space="preserve"><![CDATA["reverse_search_properties_mapping" Member</name> <sourcecode type="json"><![CDATA[ { "rdapConformance": [ "rdap_level_0", "reverse_search" ], ... "reverse_search_properties_mapping": [ { "property": "handle", "propertyPath": "$.entities[*].handle" }, { "property": "role", "propertyPath": "$.entities[*].roles" } ], ... }]]></artwork>]]></sourcecode> </figure> </section> <sectionanchor="rdap-conformance" title="RDAP Conformance">anchor="rdap-conformance"> <name>RDAP Conformance</name> <t>Servers complying with this specificationMUST<bcp14>MUST</bcp14> include the value"reverse_search""reverse_search" in the rdapConformance property of the help response <xref target="RFC9083"/> and any other response including the"reverse_search_properties_mapping""reverse_search_properties_mapping" member. The information needed to register this value in the"RDAP Extensions""RDAP Extensions" registry is described in <xref target="rdap-extensions-registry"/>.</t> </section> <sectionanchor="impl-considerations" title="Implementation Considerations">anchor="impl-considerations"> <name>Implementation Considerations</name> <t>To limit the impact of processing the search predicates, servers areRECOMMENDED<bcp14>RECOMMENDED</bcp14> to make use of techniques to speed up the data retrieval in their underlying datastorestore, such as indexes or similar. In addition, risks with respect to performance degradation or result set generation can be mitigated by adopting practices used for standard searches,e.g.e.g., restricting the search functionality, limiting the rate of search requests according to the user's authorization, truncating and paging the results <xref target="RFC8977"/>, and returning partial responses <xref target="RFC8982"/>.</t> </section> <section> <name>IANA Considerations</name> <sectionanchor="impl-status" title="Implementation Status"> <t>NOTE: Please remove this section and the reference to RFC 7942 prior to publication as an RFC.</t> <t>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 <xref target="RFC7942"/>. The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs. Please note that the listing of any individual implementation here does not imply endorsement by the IETF. Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors. This is not intended as, and must not be construed to be, a catalog of available implementations or their features. Readers are advised to note that other implementations may exist.</t> <t>According to RFC 7942, "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit".</t> <section anchor="iit-cnr-registro-it-rdap-server" title="IIT-CNR/Registro.it RDAP Server"> <t><list style="none"> <t>Responsible Organization: Institute of Informatics and Telematics of National Research Council (IIT-CNR)/Registro.it<vspace blankLines='1' /></t> <t>Location: https://rdap.pubtest.nic.it/<vspace blankLines='1' /></t> <t>Description: This implementation includes support for RDAP queries using data from the public test environment of .it ccTLD. Reverse search is allowed to authenticated users. Registrar users are allowed to perform reverse searches on their own domains and contacts. This is achieved by adding an implicit predicate to the search condition.<vspace blankLines='1' /></t> <t>Level of Maturity: This is an "alpha" test implementation.<vspace blankLines='1' /></t> <t>Coverage: This implementation includes all of the features described in this specification.<vspace blankLines='1' /></t> <t>Contact Information: Mario Loffredo, mario.loffredo@iit.cnr.it</t> </list></t> </section> <section anchor="registro-it-rdap-client" title="IIT-CNR/Registro.it RDAP Client"> <t><list style="none"> <t>Responsible Organization: Institute of Informatics and Telematics of National Research Council (IIT-CNR)/Registro.it<vspace blankLines='1' /></t> <t>Location: https://web-rdap.pubtest.nic.it/<vspace blankLines='1' /></t> <t>Description: This is a Javascript web-based RDAP client. RDAP responses are retrieved from RDAP servers by the browser, parsed into an HTML representation, and displayed in a format improving the user experience. Reverse search is allowed to authenticated users.<vspace blankLines='1' /></t> <t>Level of Maturity: This is an "alpha" test implementation.<vspace blankLines='1' /></t> <t>Coverage: This implementation includes all of the features described in this specification.<vspace blankLines='1' /></t> <t>Contact Information: Francesco Donini, francesco.donini@iit.cnr.it</t> </list></t> </section> </section> <section title="IANA Considerations"> <section anchor="rdap-extensions-registry" title="RDAPanchor="rdap-extensions-registry"> <name>RDAP ExtensionsRegistry">Registry</name> <t>IANAis requested to registerhas registered the following value in the"RDAP Extensions""RDAP Extensions" registry:</t><t><list style="none"> <t>Extension identifier: reverse_search<vspace blankLines='1' /></t> <t>Registry operator: Any<vspace blankLines='1' /></t> <t>Published specification: This document.<vspace blankLines='1' /></t> <t>Contact: IETF <iesg@ietf.org><vspace blankLines='1' /></t> <t>Intended usage: This<dl spacing="normal"> <dt>Extension Identifier:</dt> <dd>reverse_search</dd> <dt>Registry Operator:</dt> <dd>Any</dd> <dt>Specification:</dt> <dd>RFC 9536</dd> <dt>Contact:</dt> <dd>IETF <iesg@ietf.org></dd> <dt>Intended Usage:</dt> <dd>This extension identifier is used for both URI path segments and response extensions related to the reverse search inRDAP.</t> </list></t>RDAP.</dd> </dl> </section> <sectionanchor="rdap-reverse-search-registries" title="RDAPanchor="rdap-reverse-search-registries"> <name>RDAP Reverse SearchRegistries">Registries</name> <sectionanchor="rdap-reverse-search-registries-creation" title="Creationanchor="rdap-reverse-search-registries-creation"> <name>Creation of the RDAP Reverse SearchRegistries">Registries</name> <t>IANAis requested to createhas created the"RDAP"RDAP ReverseSearch"Search" and"RDAP"RDAP Reverse SearchMapping"Mapping" registries within thegroup "Registration"Registration Data Access Protocol(RDAP)".</t>(RDAP)" category in the protocol registries. </t> <t>These registries follow the Specification Requiredprocessregistration policy, as defined inSection 4.5 of<xreftarget="RFC8126"/>.</t>target="RFC8126" section="4.6" sectionFormat="of" />.</t> <t>The designated expert should prevent collisions and confirm that suitable documentation, as described inSection 4.6 of<xreftarget="RFC8126"/>,target="RFC8126" section="4.5" sectionFormat="of" />, is available to ensure interoperability.</t> <t>Creators of either new RDAP reverse searches or new mappings for registered reverse searchesSHOULD NOT<bcp14>SHOULD NOT</bcp14> replicate functionality already available by way of other documents referenced in these registries. CreatorsMAY<bcp14>MAY</bcp14> register additional reverse search mappings for existing properties, but theySHOULD NOT<bcp14>SHOULD NOT</bcp14> map a registered reverse search property to a response field with a meaning other than that of the response fields referenced by the mappings already registered for that property. In other words, all the mappings for a reverse search propertyMUST<bcp14>MUST</bcp14> point to response fields with the same meaning.</t> </section><section title="Submit Request<section> <name>Submit Requests toIANA">IANA</name> <t>Registration requests can be sent to <iana@iana.org>.</t> </section> <sectionanchor="rdap-reverse-search-registry" title="RDAPanchor="rdap-reverse-search-registry"> <name>RDAP Reverse SearchRegistry">Registry</name> <sectionanchor="rdap-reverse-search-registry-template" title="Template"> <t> <list style="hanging"> <t hangText=""Searchableanchor="rdap-reverse-search-registry-template"> <name>Template</name> <dl newline="false" spacing="normal"> <dt>Property:</dt> <dd>The name of the reverse search property.</dd> <dt>Description:</dt> <dd>A brief human-readable text describing the reverse search property.</dd> <dt>Searchable ResourceType":">TheType:</dt> <dd>The searchable resource type of the reverse search query (<xref target="reverse-search-path-segment-specification"/>) including the reverse search property. Multiple reverse search properties differing only by this field can be grouped together by listing all the searchable resource types separated by comma (see <xreftarget="rdap-reverse-search-registry-initial-content"/>).</t> </list> </t> <t> <list style="hanging"> <t hangText=""Relatedtarget="rdap-reverse-search-registry-initial-content"/>).</dd> <dt>Related ResourceType":">TheType:</dt> <dd>The related resource type of the reverse search query (<xref target="reverse-search-path-segment-specification"/>) including the reverse searchproperty.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Property":">The name of the reverse search property.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Description":">A brief human-readable text describing the reverse search property.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Registrant Name":">Theproperty.</dd> <dt>Registrant:</dt> <dd>The name of the person registering the reverse searchproperty.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Registrant Contact Information":">Anproperty.</dd> <dt>Contact Information:</dt> <dd>An email address, postal address, or some other information to be used to contact theregistrant.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Reference":">Document (e.g.registrant.</dd> <dt>Reference:</dt> <dd>Document (e.g., the RFC number) and section reference where the reverse search property isspecified.</t> </list> </t>specified.</dd> </dl> <t>The combination of"SearchableSearchable ResourceType", "RelatedType, Related ResourceType"Type, and"Property" MUSTProperty <bcp14>MUST</bcp14> be unique across the registry entries.</t> </section> <sectionanchor="rdap-reverse-search-registry-initial-content" title="Initial Content">anchor="rdap-reverse-search-registry-initial-content"> <name>Initial Content</name> <t>IANAis requested to registerhas registered the following entries in the"RDAP"RDAP ReverseSearch" registry.</t> <t>ForSearch" registry. For all entries, the common values are shown in <xreftarget="table1"/>target="table1"/>, whereas the specific values are shown in <xref target="table2"/>.</t><texttable anchor="table1" title="Common values<table anchor="table1"> <name>Common Values forall entriesAll Entries in the"RDAPRDAP ReverseSearch" registry"> <ttcolSearch Registry</name> <thead> <tr> <th align="left">RegistryProperty</ttcol> <ttcol align="left">Value</ttcol> <c>SearchableProperty</th> <th align="left">Value</th> </tr> </thead> <tbody> <tr> <td align="left">Searchable ResourceType</c><c>domains,Type</td> <td align="left">domains, nameservers,entities</c> <c>Relatedentities</td> </tr> <tr> <td align="left">Related ResourceType</c><c>entity</c> <c>Registrant Name</c><c>IETF</c> <c>Registrant Contact Information</c><c>iesg@ietf.org</c> <c>Reference</c><c>This document, <xref target="reverse-search-on-entities"/></c> </texttable> <texttable anchor="table2" title="Specific valuesType</td> <td align="left">entity</td> </tr> <tr> <td align="left">Registrant</td> <td align="left">IETF</td> </tr> <tr> <td align="left">Contact Information</td> <td align="left">iesg@ietf.org</td> </tr> <tr> <td align="left">Reference</td> <td align="left">RFC 9536</td> </tr> </tbody> </table> <table anchor="table2"> <name>Specific Values forall entriesEntries in the"RDAPRDAP ReverseSearch" registry"> <ttcol align="left">Property</ttcol> <ttcol align="left">Description</ttcol> <c>fn</c><c>TheSearch Registry</name> <thead> <tr> <th align="left">Property</th> <th align="left">Description</th> </tr> </thead> <tbody> <tr> <td align="left">fn</td> <td align="left">The server supports the domain/nameserver/entity search based on the full name (a.k.a. formatted name) of an associatedentity</c> <c>handle</c><c>Theentity</td> </tr> <tr> <td align="left">handle</td> <td align="left">The server supports the domain/nameserver/entity search based on the handle of an associatedentity</c> <c>email</c><c>Theentity</td> </tr> <tr> <td align="left">email</td> <td align="left">The server supports the domain/nameserver/entity search based on the email address of an associatedentity</c> <c>role</c><c>Theentity</td> </tr> <tr> <td align="left">role</td> <td align="left">The server supports the domain/nameserver/entity search based on the role of an associatedentity</c> </texttable>entity</td> </tr> </tbody> </table> </section> </section> <sectionanchor="rdap-reverse-search-mapping-registry" title="RDAPanchor="rdap-reverse-search-mapping-registry"> <name>RDAP Reverse Search MappingRegistry">Registry</name> <sectionanchor="rdap-reverse-search-mapping-registry-template" title="Template"> <t> <list style="hanging"> <t hangText=""Searchable Resource Type":">Theanchor="rdap-reverse-search-mapping-registry-template"> <name>Template</name> <dl newline="false" spacing="normal"> <dt>Property:</dt> <dd>The same as defined in the"Reverse Search Registry".</t> </list> </t> <t> <list style="hanging"> <t hangText=""Related"RDAP Reverse Search" registry.</dd> <dt>Property Path:</dt> <dd>The JSONPath of the RDAP property this reverse search property maps to.</dd> <dt>Searchable ResourceType":">TheType:</dt> <dd>The same as defined in the"Reverse Search Registry".</t> </list> </t> <t> <list style="hanging"> <t hangText=""Property":">The"RDAP Reverse Search" registry.</dd> <dt>Related Resource Type:</dt> <dd>The same as defined in the"Reverse Search Registry".</t> </list> </t> <t> <list style="hanging"> <t hangText=""Property Path":">The JSONPath of the RDAP property this reverse search property maps to.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Description":">A brief human-readable text describing this reverse search property mapping.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Registrant Name":">The"RDAP Reverse Search" registry.</dd> <dt>Registrant:</dt> <dd>The name of the person registering this reverse search propertymapping.</t> </list> </t> <t> <list style="hanging"> <t hangText=""Registrant Contact Information":">Themapping.</dd> <dt>Contact Information:</dt> <dd>The same as defined in the"Reverse Search Registry".</t> </list> </t> <t> <list style="hanging"> <t hangText=""Reference":">Document (e.g."RDAP Reverse Search" registry.</dd> <dt>Reference:</dt> <dd>Document (e.g., the RFC number) and section reference where this reverse search property mapping isspecified.</t> </list> </t>specified.</dd> </dl> <t>The combination of"SearchableSearchable ResourceType", "RelatedType, Related ResourceType", "Property"Type, Property, and"Property Path" MUSTProperty Path <bcp14>MUST</bcp14> be unique across the registry entries.</t> </section> <sectionanchor="rdap-reverse-search-mapping-registry-initial-content" title="Initial Content">anchor="rdap-reverse-search-mapping-registry-initial-content"> <name>Initial Content</name> <t>IANAis requested to registerhas registered the following entries in the"RDAP"RDAP Reverse SearchMapping" registry.</t> <t>ForMapping" registry. For all entries, the common values are the same as defined in the"RDAP"RDAP ReverseSearch"Search" registry (see <xreftarget="table1"/>)target="table1"/>), whereas the specific values are showninbelow (see <xreftarget="table3"/>.</t> <texttable anchor="table3" title="Specific valuestarget="table3"/>).</t> <table anchor="table3"> <name>Specific Values forall entriesEntries in the"RDAPRDAP Reverse SearchMapping" registry"> <ttcol align="left">Property</ttcol> <ttcolMapping Registry</name> <thead> <tr> <th align="left">Property</th> <th align="left">PropertyPath</ttcol> <c>fn</c><c>$.entities[*].vcardArray[1][?(@[0]=='fn')][3]</c> <c>handle</c><c>$.entities[*].handle</c> <c>email</c><c>$.entities[*].vcardArray[1][?(@[0]=='email')][3]</c> <c>role</c><c>$.entities[*].roles</c> </texttable>Path</th> </tr> </thead> <tbody> <tr> <td align="left">fn</td> <td align="left">$.entities[*].vcardArray[1][?(@[0]=='fn')][3]</td> </tr> <tr> <td align="left">handle</td> <td align="left">$.entities[*].handle</td> </tr> <tr> <td align="left">email</td> <td align="left">$.entities[*].vcardArray[1][?(@[0]=='email')][3]</td> </tr> <tr> <td align="left">role</td> <td align="left">$.entities[*].roles</td> </tr> </tbody> </table> </section> </section> </section> </section> <sectionanchor="privacy-considerations" title="Privacy Considerations">anchor="privacy-considerations"> <name>Privacy Considerations</name> <t>The search functionality defined in this document may affect the privacy of entities in the registry (and elsewhere) in variousways:ways; see <xref target="RFC6973"/> for a general treatment of privacy in protocol specifications. Registry operators should be aware of thetradeoffstrade-offs that result fromimplementation ofimplementing this functionality.</t> <t>Many jurisdictions have laws or regulations that restrict the use of"Personal Data","personal data", per the definition in <xreftarget="RFC6973" />.target="RFC6973"/>. Given that, registry operators should ascertain whether the regulatory environment in which they operate permits implementation of the functionality defined in this document.</t> <t>In those cases where this functionality makes use of sensitive information,it MUSTthe information <bcp14>MUST</bcp14> only be accessible to authorized userssupported byunder a lawful basis.</t> <t>Since reverse search requests and responses could contain Personally Identifiable Information (PII), reverse search functionalityMUST<bcp14>MUST</bcp14> be available over HTTPS only.</t> <t>Providing reverse search in RDAP carries the following threats as described in <xref target="RFC6973"/>:</t><t><list style="symbols"> <t>Correlation</t> <t>Disclosure</t> <t>Misuse<ul spacing="normal"> <li>Correlation</li> <li>Disclosure</li> <li>Misuse ofinformation</t> </list></t>data</li> </ul> <t>Therefore, RDAP providers need to mitigate the risk of those threats by implementing appropriate measures supported by security services (see <xref target="security-considerations"/>).</t> </section> <sectionanchor="security-considerations" title="Security Considerations">anchor="security-considerations"> <name>Security Considerations</name> <t>Security services that are required to provide controlled access to the operations specified in this document are described in <xref target="RFC7481"/>. A non-exhaustive list of access control paradigms an RDAP provider can implement is presented in <xref target="access-control-paradigms"/>.</t> <t>As an additional measure to enforce security by preventing reverse searches to be accessed from unauthorized users, the RDAP providers may considertophysicallyseparateseparating the reverse search endpoints from the other ones by configuring a proxy routing the reverse searches to a dedicated backend server and leveraging further security services offered by other protocollayerslayers, such as digital certificates and IPwhitelisting.</t>allow-listing.</t> <t>Finally, the specification of the relationship within the reverse search path allows the RDAP servers to implement different authorization policies on a per-relationship basis.</t> </section><section title="Acknowledgements"> <t>The authors would like to acknowledge the following individuals for their contributions to this document: Francesco Donini, Scott Hollenbeck, Francisco Arias, Gustavo Lozano, Eduardo Alvarez, Ulrich Wisser, James Gould and Pawel Kowalik.</t> <t>Tom Harrison and Jasdip Singh provided relevant feedback and constant support to the implementation of this proposal. Their contributions have been greatly appreciated.</t> </section></middle> <back><references title="Normative References"> &I-D.ietf-jsonpath-base; &RFC2119; &RFC6350; &RFC7095; &RFC7481; &RFC7942; &RFC8126; &RFC8174; &RFC9082; &RFC9083; &RFC9110;<references> <name>References</name> <references> <name>Normative References</name> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6350.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7095.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7481.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9082.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9083.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9110.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9535.xml"/> </references><references title="Informative References"> &RFC3912; &RFC5730; &RFC6973; &RFC8977; &RFC8982;<references> <name>Informative References</name> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3912.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5730.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6973.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8977.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8982.xml"/> <referenceanchor='ICANN-RA' target='https://newgtlds.icann.org/sites/default/files/agreements/agreement-approved-31jul17-en.pdf'>anchor="ICANN-RA" target="https://www.icann.org/en/registry-agreements/base-agreement"> <front><title>Registry<title>Base Registry Agreement</title> <author><organization>Internet Corporation For Assigned Names and Numbers</organization><organization>ICANN</organization> </author> <dateyear='2017' month='July' />month="January" year="2024"/> </front> </reference> <referenceanchor='ICANN-RDS1' target='https://www.icann.org/en/system/files/files/final-report-06jun14-en.pdf'>anchor="ICANN-RDS" target="https://www.icann.org/en/system/files/files/final-report-06jun14-en.pdf"> <front> <title>Final Report from the Expert Working Group on gTLD Directory Services: A Next-Generation Registration Directory Service (RDS)</title> <author><organization>Internet Corporation For Assigned Names and Numbers</organization> </author> <date year='2014' month='June' /> </front> </reference> <reference anchor='ICANN-RDS2' target='http://whois.icann.org/sites/default/files/files/final-issue-report-next-generation-rds-07oct15-en.pdf'> <front> <title>Final Issue Report on a Next-Generation gTLD RDS to Replace WHOIS</title> <author> <organization>Internet Corporation For Assigned Names and Numbers</organization><organization>ICANN</organization> </author> <dateyear='2015' month='October' />year="2014" month="June"/> </front> </reference> <reference anchor="OIDCC" target="http://openid.net/specs/openid-connect-core-1_0.html"> <front> <title>OpenID Connect Core 1.0 incorporating errata set1</title>2</title> <author initials="N" surname="Sakimura"> </author> <author initials="J" surname="Bradley"> </author> <author initials="M" surname="Jones"> </author> <author initials="B" surname="de Medeiros"> </author> <authorinitials="" surname=""> <organization>OpenID Foundation</organization>initials="C" surname="Mortimore"> </author> <datemonth="November" year="2014" />month="December" year="2023"/> </front> </reference> </references> </references> <sectionanchor="access-control-paradigms" title="Paradigmsanchor="access-control-paradigms"> <name>Paradigms to Enforce Access Control on Reverse Search inRDAP">RDAP</name> <t>Access control can be implemented according to different paradigms introducing increasingly stringent rules. The paradigmsreported here in the followinglisted below leverage the capabilities that are eitherbuilt-inbuilt in or provided as extensions by the OpenID Connect <xref target="OIDCC"/>:</t><t><list style="symbols"> <t>Role-Based<dl spacing="normal"> <dt>Role-Based Access Control(RBAC): access(RBAC):</dt> <dd>Access rights are granted depending on roles. Generally, this is done by grouping users into fixed categories and assigning static grants to each category. A more dynamic approach can be implemented by using the OpenID Connect"scope" claim;<vspace blankLines='1' /></t> <t>Purpose-Based"scope" claim.</dd> <dt>Purpose-Based Access Control(PBAC): access(PBAC):</dt> <dd>Access rules are based on the notion of purpose, being the intended use of some data by a user. It can be implemented by tagging a request with the usage purpose and making the RDAP server check the compliance between the given purpose and the control rules applied to the data to bereturned;<vspace blankLines='1' /></t> <t>Attribute-Basedreturned.</dd> <dt>Attribute-Based Access Control(ABAC): rules(ABAC):</dt> <dd>Rules to manage access rights are evaluated and applied according to specific attributes describing the context within which data are requested. It can be implementedby settingwithin an out-of-band process by setting additional OpenID Connect claimsdescribingthat describe the request context andmakingmake the RDAP server checkthefor compliance between the given context and the control rules that are applied to the data to bereturned;<vspace blankLines='1' /></t> <t>Time-Basedreturned.</dd> <dt>Time-Based Access Control(TBAC): data(TBAC):</dt> <dd>Data access is allowed for a limited time only. It can be implemented by assigningtheuserswithtemporary credentials linked to access grantswhose scope is limited.</t> </list></t>with limited scopes.</dd> </dl> <t>With regard to the privacy threats reported in <xref target="privacy-considerations"/>, correlation and disclosure can be mitigated by minimizing both the request features and the response data based on user roles(i.e.(i.e., RBAC). Misuse can be mitigated by checking for the purpose of the request(i.e.(i.e., PBAC). It can be accomplished according to the following approaches:</t><t><list style="symbols"> <t>Full Trust: the<dl spacing="normal"> <dt>Full Trust:</dt> <dd>The registry trusts the fairness of an accredited user. The requestor is always legitimized to submithistheir requests under a lawful basis. Additionally,hethey can be required to specify the purpose as either a claim ofhistheir account or a query parameter. In the former case, the purpose is assumed to be the same for every request. In the latter case, the purpose must be one of those associated to theuser;<vspace blankLines='1' /></t> <t>Zero Trust: theuser.</dd> <dt>Zero Trust:</dt> <dd>The registry requires documentsassessingthat assess whether the requestor is legitimized to submit a given request. It can be implemented by assigning the requestorwitha temporary OpenID account linked to the given request(i.e.(i.e., TBAC) and describing the request through a set of claims(i.e.(i.e., ABAC). The association between the temporary account and the claims about the request is made by an out-of-band application. In so doing, the RDAP server is able to check that the incoming request is consistent with the request claims linked to the temporaryaccount.</t> </list></t>account.</dd> </dl> <t>The two approaches can be used together:</t><t><list style="symbols"> <t>The<ul spacing="normal"> <li>The former is suitable for users carrying out a task in the publicinterest,interest or exercising their official authority(e.g.(e.g., an officer of a cybercrime agency). Similarly, registrars can submit reverse searches on their domains and contacts based on their contractual relationship with the domain holders. In this case, the query results can be restricted to those pertaining to a registrar by adding an implicit predicate to the searchcondition.<vspace blankLines='1' /></t> <t>Thecondition. </li> <li>The latter can be taken to allow domain name dispute resolution service providers to request information in defense of the legitimate interests ofcomplainants.</t> </list></t>complainants.</li> </ul> </section> <sectiontitle="Change Log"> <t> <list style="hanging"> <t hangText="00:">Initial working group version ported from draft-loffredo-regext-rdap-reverse-search-04</t> <t hangText="01:">Updated "Privacy Considerations" section.</t> <t hangText="02:">Revised the text.</t> <t hangText="03:">Refactored the query model.</t> <t hangText="04:">Keepalive refresh.</t> <t hangText="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.</t> <t hangText="06:">Updated "Privacy Considerations", "Security Considerations" and "Acknowledgements" sections. Added some normative and informative references. Added <xref target="access-control-paradigms"/>.</t> <t hangText="07:">Updated normative references.</t> <t hangText="08:">Changed "Implementation Status" section. Updated informative references.</t> <t hangText="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.</t> <t hangText="10:">Updated "Reverse Searches Based on Entity Details" section to consider the use of JSContact format instead of jCard. Added referencesnumbered="false"> <name>Acknowledgements</name> <t>The authors would like toJSContact documents.</t> <t hangText="11:">Updatedacknowledge thedocument based on Tom Harrison and James Gould feedback: <list style="symbols"> <t>Updated section "RDAP Path Segment Specification": <list style="symbols"> <t>Clarified how servers must evaluate a reverse search including predicates that arefollowing individuals forthe same property.<vspace blankLines='1' /></t> <t>Specified the error response servers must return when receiving a wrong reverse search request according totheirpolicy.<vspace blankLines='1' /></t> <t>Clarified that searchs for the related-resource-type values other than "entity" may be defined in future documents.<vspace blankLines='1' /></t> </list> </t> <t>Reviewed text in section "Reverse Searches Based on Entity Details" about reverse searches based on custom response extensions.<vspace blankLines='1' /></t> <t>Removed references to JSContact documents in section "Reverse Searches Based on Entity Details". Moved the mapping between jCard properties used in the RDAP response and JSContact counterparts to draft-ietf-regext-rdap-jscontact.<vspace blankLines='1' /></t> <t>Added section "RDAP Response Specification".<vspace blankLines='1' /></t> <t>Changed the text to present reverse search as a single extension with multiple features.<vspace blankLines='1' /></t> <t>Changed the definition of searchable-resource-type and related-resource-type to consider also the resource type extensions.<vspace blankLines='1' /></t> <t>Replaced "reverse" with "reverse_search_0" in the generic reverse search path. Updated <xref target="reverse-search-request"/> accordingly.<vspace blankLines='1' /></t> <t>Removed the phrase "but with a special focus on its privacy implications" from both the "Abstract" and the "Introduction". Moved the mapping between jCard properties used in the RDAP response and JSContact counterparts to draft-ietf-regext-rdap-jscontact.<vspace blankLines='1' /></t> <t>Reviewed the text of "Privacy Considerations" section.<vspace blankLines='1' /></t> <t>Text cleaning.<vspace blankLines='1' /></t> </list> </t> <t hangText="12:">Replaced "reverse_search_0" with "reverse_search" as both URI path segment, extension identifier and rdapConformance tag to match the working group consensus.</t> <t hangText="13:">Done some minor text changes.</t> <t hangText="14:">Revised text of first sentence and added referencescontributions toRFC8977this document: <contact fullname="Francesco Donini"/>, <contact fullname="Scott Hollenbeck"/>, <contact fullname="Francisco Arias"/>, <contact fullname="Gustavo Lozano"/>, <contact fullname="Eduardo Alvarez"/>, <contact fullname="Ulrich Wisser"/>, <contact fullname="James Gould"/>, and <contact fullname="Pawel Kowalik"/>.</t> <t><contact fullname="Tom Harrison"/> and <contact fullname="Jasdip Singh"/> provided relevant feedback andRFC8982 in the "Implementation Considerations" section.</t> <t hangText="15:">Moved RFC6973 from Normative References to Informative References. Remnoved informative reference to draft-ietf-regext-rdap-openid. Rephrased text in Appendix A accordingly.</t> <t hangText="16:">Moved OIDC from Normative References to Informative References. Added the "Reverse Search Properties Discovery" section. Added "RDAP JSON Values Registry" as a subsection of the "IANA Considerations" section. Rephrased the "Reverse Searches Based on Entity Details" section to refer to the "Reverse Search Properties Discovery" section. Updated the "Acknowledgements" section. Minor text edits.</t> <t hangText="17:">Revised the "Reverse Search Properties Discovery" section. Replaced "RDAP JSON Values Registry" section with the "RDAP Reverse Search Properties Registry" section.</t> <t hangText="18:">Changed "Expert Review" with "Specification Required" in the "Creation of the RDAP Reverse Search Properties Registry" section. Renamed the "RDAP Reverse Search Properties Registry" into "RDAP Reverse Search Registry". Aligned the RDAP Reverse Search Registry template with the initial content. Introduced the "reverse_search_properties_mapping" response extension. Added the "RDAP Reverse Search Mapping Registry". Reorganized the documentconstant support toseparatethe implementation ofa generic reverse search from that based on domain-entity relationship.</t> <t hangText="19:">Added the "Reverse Search Query Processing" section. Changed the definition of search-condition in <xref target="reverse-search-path-segment-specification"/>. Moved the "Reverse Search Response Specification" section. Corrected <xref target="reverse-search-properties-mapping-example"/>.</t> <t hangText="20:"> <list style="symbols"> <t>Changed document title.</t> <t>Changed "Servers MUST NOT provide or implement unregistered reverse searches or unregistered reverse search mappings." to "Servers MUST NOT provide or implement reverse searches or reverse search mappings that are not registered with IANA." in <xref target="reverse-search-definition"/>.</t> <t>Changed "...that the RDAP response property "roles" must contain at least the specified role" to "...that the RDAP response property "roles" MUST contain at least the specified role" in <xref target="reverse-search-on-entities"/>.</t> <t>Changed the value of the "Intended usage" property of the "RDAP Extensions Registry" entry in <xref target="rdap-extensions-registry"/>.</t> <t>Changed "..., reverse search functionality SHOULD be available over HTTPS only." to "..., reverse search functionality MUST be available over HTTPS only." in <xref target="privacy-considerations"/>.</t> </list> </t> <t hangText="21:"> <list style="symbols"> <t>Added a sentence about servers signaling the unsupported reverse searches to <xref target="reverse-search-query-processing"/>.</t> <t>Replaced "$.." with "$." in JSONPath expressions.</t> <t>Clarified that the registry group the new registries must be added to is "Registration Data Access Protocol (RDAP)".</t> <t>Removed unused normative reference to RFC7480.</t> </list> </t> <t hangText="22:"> <list style="symbols"> <t>Expanded EPP acronym in <xref target="introduction"/>.</t> <t>Moved RFC3912 and RFC5730 from normative to informative references.</t> </list> </t> <t hangText="23:"> <list style="symbols"> <t>Replaced IESG with IETF as the Registrant Name for each entry in the IANA registries.</t> <t>Rearranged the layout of the initial content for the IANA registries.</t> <t>Added titles to figures.</t> <t>Repalced "RDAP providers are REQUIRED to" with "RDAP providers need to" in <xref target="security-considerations"/>.</t> <t>Text cleaning.</t> </list> </t> <t hangText="24:"> <list style="symbols"> <t>Added text to <xref target="rdap-reverse-search-registries-creation"/> to make the term "collisions" clear enough for future DEs.</t> <t>Added titles to tables.</t> </list> </t> <t hangText="25:"> <list style="symbols"> <t>Added text to <xref target="introduction"/> to reference the implications ofthisspecification on efficiency, security and compliance with privacy regulations.</t> <t>Changed text in Privacy Considerations to clarify that in those cases where sensitive information are used, this feature MUST be accessble to authorized users only.</t> <t>Added text to <xref target="security-considerations"/> to describe additional measures to enforce the security.</t> <t>Added text to <xref target="access-control-paradigms"/> to clarify how the proposed access control paradigms can contribute to mitigate the threats listed in <xref target="privacy-considerations"/>.</t> <t>Moved the reference to RFC3912.</t> <t>Moved reference to draft-ietf-jsonpath-based to Normative References.</t> <t>Text cleaning.</t> </list> </t> </list> </t>proposal. Their contributions have been greatly appreciated.</t> </section> </back> </rfc>