rfc9536.original   rfc9536.txt 
Registration Protocols Extensions M. Loffredo Internet Engineering Task Force (IETF) M. Loffredo
Internet-Draft M. Martinelli Request for Comments: 9536 M. Martinelli
Intended status: Standards Track IIT-CNR/Registro.it Category: Standards Track IIT-CNR/Registro.it
Expires: 2 March 2024 30 August 2023 ISSN: 2070-1721 March 2024
Registration Data Access Protocol (RDAP) Reverse Search Registration Data Access Protocol (RDAP) Reverse Search
draft-ietf-regext-rdap-reverse-search-25
Abstract Abstract
The Registration Data Access Protocol (RDAP) does not include query The Registration Data Access Protocol (RDAP) does not include query
capabilities for finding the list of domains related to a set of capabilities for finding the list of domains related to a set of
entities matching a given search pattern. Considering that an RDAP entities matching a given search pattern. Considering that an RDAP
entity can be associated with any defined object class and other entity can be associated with any defined object class and other
relationships between RDAP object classes exist, a reverse search can relationships between RDAP object classes exist, a reverse search can
be applied to other use cases besides the classic domain-entity be applied to other use cases besides the classic domain-entity
scenario. This document describes an RDAP extension that allows scenario. This document describes an RDAP extension that allows
servers to provide a reverse search feature based on the relationship servers to provide a reverse search feature based on the relationship
defined in RDAP between an object class for search and any related defined in RDAP between an object class for search and any related
object class. The reverse search based on the domain-entity object class. The reverse search based on the domain-entity
relationship is treated as a particular case. relationship is treated as a particular case.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
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
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Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on 2 March 2024. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9536.
Copyright Notice Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Please review these documents carefully, as they describe your rights carefully, as they describe your rights and restrictions with respect
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction
1.1. Background . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Background
1.2. Conventions Used in This Document . . . . . . . . . . . . 4 1.2. Conventions Used in This Document
2. Reverse Search Path Segment Specification . . . . . . . . . . 4 2. Reverse Search Path Segment Specification
3. Reverse Search Definition . . . . . . . . . . . . . . . . . . 5 3. Reverse Search Definition
4. Reverse Search Properties Discovery . . . . . . . . . . . . . 5 4. Reverse Search Properties Discovery
5. Reverse Search Properties Mapping . . . . . . . . . . . . . . 6 5. Reverse Search Properties Mapping
6. Reverse Search Response Specification . . . . . . . . . . . . 7 6. Reverse Search Response Specification
7. Reverse Search Query Processing . . . . . . . . . . . . . . . 7 7. Reverse Search Query Processing
8. Reverse Searches Based on Entity Details . . . . . . . . . . 8 8. Reverse Searches Based on Entity Details
9. RDAP Conformance . . . . . . . . . . . . . . . . . . . . . . 10 9. RDAP Conformance
10. Implementation Considerations . . . . . . . . . . . . . . . . 10 10. Implementation Considerations
11. Implementation Status . . . . . . . . . . . . . . . . . . . . 10 11. IANA Considerations
11.1. IIT-CNR/Registro.it RDAP Server . . . . . . . . . . . . 11 11.1. RDAP Extensions Registry
11.2. IIT-CNR/Registro.it RDAP Client . . . . . . . . . . . . 11 11.2. RDAP Reverse Search Registries
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 11.2.1. Creation of the RDAP Reverse Search Registries
12.1. RDAP Extensions Registry . . . . . . . . . . . . . . . . 12 11.2.2. Submit Requests to IANA
12.2. RDAP Reverse Search Registries . . . . . . . . . . . . . 12 11.2.3. RDAP Reverse Search Registry
12.2.1. Creation of the RDAP Reverse Search Registries . . . 12 11.2.3.1. Template
12.2.2. Submit Request to IANA . . . . . . . . . . . . . . . 12 11.2.3.2. Initial Content
12.2.3. RDAP Reverse Search Registry . . . . . . . . . . . . 13 11.2.4. RDAP Reverse Search Mapping Registry
12.2.3.1. Template . . . . . . . . . . . . . . . . . . . . 13 11.2.4.1. Template
12.2.3.2. Initial Content . . . . . . . . . . . . . . . . 13 11.2.4.2. Initial Content
12.2.4. RDAP Reverse Search Mapping Registry . . . . . . . . 14 12. Privacy Considerations
12.2.4.1. Template . . . . . . . . . . . . . . . . . . . . 14 13. Security Considerations
12.2.4.2. Initial Content . . . . . . . . . . . . . . . . 15 14. References
13. Privacy Considerations . . . . . . . . . . . . . . . . . . . 16 14.1. Normative References
14. Security Considerations . . . . . . . . . . . . . . . . . . . 16 14.2. Informative References
15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
16. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
16.1. Normative References . . . . . . . . . . . . . . . . . . 17
16.2. Informative References . . . . . . . . . . . . . . . . . 18
Appendix A. Paradigms to Enforce Access Control on Reverse Search Appendix A. Paradigms to Enforce Access Control on Reverse Search
in RDAP . . . . . . . . . . . . . . . . . . . . . . . . . 19 in RDAP
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 21 Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses
1. Introduction 1. Introduction
The protocol described in this specification aims to extend the RDAP The protocol described in this specification aims to extend the RDAP
query capabilities and response to enable reverse search based on the query capabilities and response to enable reverse search based on the
relationships defined in RDAP between an object class for search and relationships defined in RDAP between an object class for search and
a related object class. The reverse search based on the domain- a related object class. The reverse search based on the domain-
entity relationship is treated as a particular case of such a generic entity relationship is treated as a particular case of such a generic
model. model.
RDAP providers willing to implement this specification should RDAP providers willing to implement this specification should
carefully consider its implications on the efficiency (see carefully consider its implications on the efficiency (see
Section 10), the security (see Section 14) and the compliance with Section 10), the security (see Section 13), and the compliance with
privacy regulations (see Section 13) of their RDAP service. privacy regulations (see Section 12) of their RDAP service.
1.1. Background 1.1. Background
Reverse Whois is a service provided by many web applications that Reverse WHOIS is a service provided by many web applications that
allows users to find domain names owned by an individual or a company 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 starting from the owner's details, such as name and email. Even if
it has been considered useful for some legal purposes (e.g. it has been considered useful for some legal purposes (e.g.,
uncovering trademark infringements, detecting cybercrimes), its uncovering trademark infringements and detecting cybercrimes), its
availability as a standardized Whois [RFC3912] capability has been availability as a standardized WHOIS [RFC3912] capability has been
objected to for two main reasons, which now don't seem to conflict objected to for two main reasons, which now don't seem to conflict
with an RDAP implementation. with an RDAP implementation.
The first objection concerns the potential risks of privacy The first objection concerns the potential risks of privacy
violation. However, the domain name community is considering a new violation. However, the domain name community is considering a new
generation of Registration Directory Services [ICANN-RDS1] generation of Registration Directory Services [ICANN-RDS] [ICANN-RA]
[ICANN-RDS2] [ICANN-RA], which provide access to sensitive data under that provide access to sensitive data under some permissible purposes
some permissible purposes and in accordance with appropriate policies and in accordance with appropriate policies for requestor
for requestor accreditation, authentication and authorization. accreditation, authentication, and authorization. RDAP's reliance on
RDAP's reliance on HTTP means that it can make use of common HTTP- HTTP means that it can make use of common HTTP-based approaches to
based approaches to authentication and authorization, making it more authentication and authorization, making it more useful than WHOIS in
useful than Whois in the context of such directory services. Since the context of such directory services. Since RDAP consequently
RDAP consequently permits a reverse search implementation complying permits a reverse search implementation complying with privacy
with privacy protection principles, this first objection is not well- protection principles, this first objection is not well-founded.
founded.
The second objection to the implementation of a reverse search The second objection to the implementation of a reverse search
capability has been connected with its impact on server processing. capability has been connected with its impact on server processing.
However, the core RDAP specifications already define search queries, However, the core RDAP specifications already define search queries,
with similar processing requirements, so the basis of this objection with similar processing requirements, so the basis of this objection
is not clear. is not clear.
Reverse searches, such as finding the list of domain names associated Reverse searches, such as finding the list of domain names associated
with contacts or nameservers, may be useful to registrars as well. with contacts or nameservers, may be useful to registrars as well.
Usually, registries adopt out-of-band solutions to provide results to Usually, registries adopt out-of-band solutions to provide results to
registrars asking for reverse searches on their domains. Possible registrars asking for reverse searches on their domains. Possible
reasons for such requests are: reasons for such requests are:
* the loss of synchronization between the registrar database and the * the loss of synchronization between the registrar database and the
registry database; registry database and
* the need for such data to perform bulk Extensible Provisioning * the need for such data to perform bulk Extensible Provisioning
Protocol (EPP) [RFC5730] updates (e.g. changing the contacts of a Protocol (EPP) [RFC5730] updates (e.g., changing the contacts of a
set of domains, etc.). set of domains, etc.).
Currently, RDAP does not provide any means 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 the collection of domains associated with an entity [RFC9082]. A
query (lookup or search) on domains can return the array of entities query (lookup or search) on domains can return the array of entities
related to a domain with different roles (registrant, registrar, related to a domain with different roles (registrant, registrar,
administrative, technical, reseller, etc.), but the reverse operation administrative, technical, reseller, etc.), but the reverse operation
is not allowed. Only reverse searches to find the collection of is not allowed. Only reverse searches to find the collection of
domains related to a nameserver (ldhName or ip) can be requested. domains related to a nameserver (ldhName or ip) can be requested.
Since an entity can be in relationship with any RDAP object Since an entity can be in relationship with any RDAP object
[RFC9083], the availability of a reverse search as largely intended [RFC9083], the availability of a reverse search as largely intended
can be common to all the object classes allowed for search. Through can be common to all the object classes allowed for search. Through
a further step of generalization, the meaning of reverse search in a further step of generalization, the meaning of reverse search in
the RDAP context can be extended to include any query for retrieving the RDAP context can be extended to include any query for retrieving
all the objects in relationship with another matching a given search all the objects that relates to another query matching a given search
pattern. pattern.
1.2. Conventions Used in This Document 1.2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
2. Reverse Search Path Segment Specification 2. Reverse Search Path Segment Specification
A generic reverse search path is described by the syntax: A generic reverse search path is described by the syntax:
{searchable-resource-type}/reverse_search/{related-resource- {searchable-resource-type}/reverse_search/{related-resource-
type}?<search-condition> type}?<search-condition>
The path segments are defined as in the following: The path segments are defined as follows:
"searchable-resource-type": it MUST be one of the resource types for "searchable-resource-type": It MUST be one of the resource types for
search defined in Section 3.2 of [RFC9082] (i.e. "domains", search defined in Section 3.2 of [RFC9082] (i.e., "domains",
"nameservers" and "entities") or a resource type extension; "nameservers", and "entities") or a resource type extension.
"related-resource-type": it MUST be one of the resource types for "related-resource-type": It MUST be one of the resource types for
lookup defined in Section 3.1 of [RFC9082] (i.e. "domain", lookup defined in Section 3.1 of [RFC9082] (i.e., "domain",
"nameserver", "entity", "ip" and "autnum") or a resource type "nameserver", "entity", "ip", and "autnum") or a resource type
extension; extension.
"search-condition": a sequence of "property=search pattern" "search-condition": A sequence of "property=search pattern"
predicates separated by the ampersand character ('&', US-ASCII predicates separated by the ampersand character ('&', US-ASCII
value 0x0026). value 0x0026).
While related-resource-type is defined as having one of a number of While related-resource-type is defined as having one of a number of
different values, the only reverse searches defined in this document different values, the only reverse searches defined in this document
are for a related-resource-type of "entity". Reverse searches for are for a related-resource-type of "entity". Reverse searches for
the other resource types specified in [RFC9082] and resource type the other resource types specified in [RFC9082] and resource type
extensions may be defined by future documents. extensions may be defined by future documents.
3. Reverse Search Definition 3. Reverse Search Definition
Based on the content of Section 2, defining a reverse search means to Based on the content of Section 2, defining a reverse search means to
define the triple <searchable resource type, related resource type, define the triple <searchable resource type, related resource type,
property> and the mapping with the corresponding RDAP object member. property> and the mapping with the corresponding RDAP object member.
The mapping is done through the use of a JSONPath expression The mapping is done through the use of a JSONPath expression
[I-D.ietf-jsonpath-base]. Reverse searches are registered in the [RFC9535]. Reverse searches are registered in the "RDAP Reverse
Reverse Search registry (see Section 12.2.3), whereas reverse search Search" registry (see Section 11.2.3), whereas reverse search
mappings are registered in the Reverse Search Mapping registry (see mappings are registered in the "RDAP Reverse Search Mapping" registry
Section 12.2.4). The reason for having two registries is that it may (see Section 11.2.4). The reason for having two registries is that
be possible for a single type of reverse search to rely on different it may be possible for a single type of reverse search to rely on
members, depending on the server's configuration (see Section 5). different members, depending on the server's configuration (see
Section 5).
All of the reverse searches defined by this document (see Section 8) All of the reverse searches defined by this document (see Section 8)
have property names that are the same as the name of the RDAP object 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 member that is the subject of the search. For example, the reverse
search with the property name "fn" relies on the value of the "fn" search with the property name "fn" relies on the value of the "fn"
member inside the jCard of an entity object. However, it is not member inside the jCard of an entity object. However, it is not
necessary that these two names be the same. In particular, remapping necessary that these two names be the same. In particular, remapping
of searches as part of the deprecation of an existing member (see of searches as part of the deprecation of an existing member (see
Section 5) will typically lead to a member with a different name Section 5) will typically lead to a member with a different name
being used for the search. being used for the search.
Servers MUST NOT provide or implement reverse searches or reverse Servers MUST NOT provide or implement reverse searches or reverse
search mappings that are not registered with IANA. search mappings that are not registered with IANA.
4. Reverse Search Properties Discovery 4. Reverse Search Properties Discovery
Servers complying with this specification MUST extend the help Servers complying with this specification MUST extend the help
response [RFC9083] with the "reverse_search_properties" member which response [RFC9083] with the "reverse_search_properties" member that
contains an array of objects with the following mandatory child contains an array of objects with the following mandatory child
members: members:
"searchableResourceType": the searchable resource type of the "searchableResourceType": the searchable resource type of the
reverse search query as defined in Section 2; reverse search query, as defined in Section 2
"relatedResourceType": the related resource type of the reverse "relatedResourceType": the related resource type of the reverse
search query as defined in Section 2; search query, as defined in Section 2
"property": the reverse search property used in the predicate of the "property": the reverse search property used in the predicate of the
reverse search query as defined in Section 2; reverse search query, as defined in Section 2
An example of the help response including the An example of the help response including the
"reverse_search_properties" member is shown in Figure 2. "reverse_search_properties" member is shown in Figure 2
5. Reverse Search Properties Mapping 5. Reverse Search Properties Mapping
To permit clients to determine the member used by the server for a To permit clients to determine the member used by the server for a
reverse search, servers MUST detail the mapping that is occurring by reverse search, servers MUST detail the mapping that is occurring by
adding the "reverse_search_properties_mapping" member to the topmost adding the "reverse_search_properties_mapping" member to the topmost
object of a reverse search response. This data is included in the object of a reverse search response. This data structure is included
search response, rather than in the help response, because it may in the search response, rather than in the help response, because it
differ depending on the query that is sent to the server. may differ depending on the query that is sent to the server.
Documents that deprecate or restructure RDAP responses such that a Documents that deprecate or restructure RDAP responses such that a
registered reverse search is no longer able to be used MUST either registered reverse search is no longer able to be used MUST either
note that the relevant reverse search is no longer available (in the note that the relevant reverse search is no longer available (in the
case of deprecation) or describe how to continue supporting the case of deprecation) or describe how to continue supporting the
relevant search by adding another mapping for the reverse search relevant search by adding another mapping for the reverse search
property (in the case of restructuring). property (in the case of restructuring).
The "reverse_search_properties_mapping" member contains an array of The "reverse_search_properties_mapping" member contains an array of
objects with the following mandatory child members: objects with the following mandatory child members:
"property": the reverse search property used in the predicate of the "property": the reverse search property used in the predicate of the
current query as defined in Section 2; current query, as defined in Section 2
"propertyPath": the JSONPath expression of the object member (or "propertyPath": the JSONPath expression of the object member (or
members) corresponding to the reverse search property. members) corresponding to the reverse search property
The searchable and the related resource types are derived from the The searchable and the related resource types are derived from the
query, so there is no need to include them in addition to the query, so there is no need to include them in addition to the
property in this member. property in this member.
This member MUST be included for all properties used in the search, This member MUST be included for all properties used in the search,
regardless of whether that property has multiple registered mappings regardless of whether that property has multiple registered mappings
as at the time of the search, because new mappings may be registered as at the time of the search, because new mappings may be registered
at any time. at any time.
When applied to an object, the JSONPath expression MUST produce a When applied to an object, the JSONPath expression MUST produce a
list of values, each of which is a JSON number or string. list of values, each of which is a JSON number or string.
An example of a reverse search response including the An example of a reverse search response including the
"reverse_search_properties_mapping" member is shown in Figure 3. "reverse_search_properties_mapping" member is shown in Figure 3.
6. Reverse Search Response Specification 6. Reverse Search Response Specification
Reverse search responses use the formats defined in section 8 of Reverse search responses use the formats defined in Section 8 of
[RFC9083], which correspond to the searchable resource types defined [RFC9083], which correspond to the searchable resource types defined
in Section 2. in Section 2.
7. Reverse Search Query Processing 7. Reverse Search Query Processing
To process a reverse search, the server returns the objects from its To process a reverse search, the server returns the objects from its
data store that are of type searchable-resource-type and that match data store that are of type searchable-resource-type and that match
each of the predicates from the search conditions. To determine each of the predicates from the search conditions. To determine
whether an object matches a predicate, the server: whether an object matches a predicate, the server:
* applies the mapping it uses for the reverse search property to the * applies the mapping it uses for the reverse search property to the
object in order to generate a list of values, each of which MUST object in order to generate a list of values, each of which MUST
be a JSON number or string; and be a JSON number or string and
* checks whether the search pattern matches one or more of those * checks whether the search pattern matches one or more of those
values. values.
A search pattern matches a value where it equals the string A search pattern matches a value where it equals the string
representation of the value, or where it is a match for the value in representation of the value or where it is a match for the value in
accordance with the partial string matching behaviour defined in accordance with the partial string matching behavior defined in
section 4.1 of [RFC9082]. Section 4.1 of [RFC9082].
Objects are only included in the search results if they satisfy all Objects are only included in the search results if they satisfy all
included predicates. This includes predicates that are for the same included predicates. This includes predicates that are for the same
property: it is necessary in such a case for the related object to property; in such a case, it is necessary for the related object to
match against each of those predicates. match against each of those predicates.
Servers MUST return an HTTP 501 (Not Implemented) [RFC9110] response Servers MUST return an HTTP 501 (Not Implemented) [RFC9110] response
to inform clients of unsupported reverse searches. to inform clients of unsupported reverse searches.
Based on their policy, servers MAY restrict how predicates are used Based on their policy, servers MAY restrict how predicates are used
to make a valid search condition, by returning a 400 (Bad Request) to make a valid search condition by returning a 400 (Bad Request)
response when a problematic request is received. response when a problematic request is received.
A given reverse search or reverse search mapping MAY define A given reverse search or reverse search mapping MAY define
additional or alternative search behaviour past that set out in this additional or alternative search behavior past that set out in this
section. section.
8. Reverse Searches Based on Entity Details 8. Reverse Searches Based on Entity Details
Since in RDAP, an entity can be associated with any other object Since an entity can be associated with any other object class in
class, the most common kind of reverse search is one based on an RDAP, the most common kind of reverse search is one based on an
entity's details. Such reverse searches arise from the query model entity's details. Such reverse searches arise from the query model
by setting the related resource type to "entity". by setting the related resource type to "entity".
By selecting a specific searchable resource type, the resulting By selecting a specific searchable resource type, the resulting
reverse search aims at retrieving all the objects (e.g. all the reverse search aims at retrieving all the objects (e.g., all the
domains) that are related to any entity object matching the search domains) that are related to any entity object matching the search
conditions. conditions.
This section defines the reverse search properties servers SHOULD This section defines the reverse search properties servers SHOULD
support for the domain, nameserver, and entity searchable resource support for the domain, nameserver, entity-searchable resource types,
types and the entity related resource type: and entity-related resource type:
Reverse search property: role Reverse search property: role
RDAP member path: $.entities[*].roles RDAP member path: $.entities[*].roles
Reference: Section 10.2.4 of [RFC9083] Reference: Section 10.2.4 of [RFC9083]
Reverse search property: handle Reverse search property: handle
RDAP member path: $.entities[*].handle RDAP member path: $.entities[*].handle
Reference: Section 5.1 of [RFC9083] Reference: Section 5.1 of [RFC9083]
Reverse search property: fn Reverse search property: fn
skipping to change at page 9, line 4 skipping to change at line 369
format for vCard. format for vCard.
Examples of reverse search paths based on the domain-entity Examples of reverse search paths based on the domain-entity
relationship are presented in Figure 1. relationship are presented in Figure 1.
/domains/reverse_search/entity?handle=CID-40*&role=technical /domains/reverse_search/entity?handle=CID-40*&role=technical
/domains/reverse_search/entity?fn=Bobby*&role=registrant /domains/reverse_search/entity?fn=Bobby*&role=registrant
/domains/reverse_search/entity?handle=RegistrarX&role=registrar /domains/reverse_search/entity?handle=RegistrarX&role=registrar
Figure 1: Examples of reverse search queries
An example of the help response including the reverse search Figure 1: Examples of Reverse Search Queries
properties supported is shown below.
An example of the help response including the supported reverse
search properties is shown in Figure 2.
{ {
"rdapConformance": [ "rdapConformance": [
"rdap_level_0", "rdap_level_0",
"reverse_search" "reverse_search"
], ],
... ...
"reverse_search_properties": [ "reverse_search_properties": [
{ {
"searchableResourceType": "domains", "searchableResourceType": "domains",
skipping to change at page 9, line 40 skipping to change at line 406
}, },
{ {
"searchableResourceType": "domains", "searchableResourceType": "domains",
"relatedResourceType": "entity", "relatedResourceType": "entity",
"property": "role" "property": "role"
} }
], ],
... ...
} }
Figure 2: An example of help response including the Figure 2: An Example of the Help Response including the
"reverse_search_properties_mapping" member "reverse_search_properties" Member
An example of a response including the mapping that is occurring for An example of a response including the mapping that is occurring for
the first reverse search in Figure 1 is shown below. the first reverse search in Figure 1 is shown below.
{ {
"rdapConformance": [ "rdapConformance": [
"rdap_level_0", "rdap_level_0",
"reverse_search" "reverse_search"
], ],
... ...
skipping to change at page 10, line 24 skipping to change at line 431
"propertyPath": "$.entities[*].handle" "propertyPath": "$.entities[*].handle"
}, },
{ {
"property": "role", "property": "role",
"propertyPath": "$.entities[*].roles" "propertyPath": "$.entities[*].roles"
} }
], ],
... ...
} }
Figure 3: An example of an RDAP response including the Figure 3: An Example of an RDAP Response including the
"reverse_search_properties" member "reverse_search_properties_mapping" Member
9. RDAP Conformance 9. RDAP Conformance
Servers complying with this specification MUST include the value Servers complying with this specification MUST include the value
"reverse_search" in the rdapConformance property of the help response "reverse_search" in the rdapConformance property of the help response
[RFC9083] and any other response including the [RFC9083] and any other response including the
"reverse_search_properties_mapping" member. The information needed "reverse_search_properties_mapping" member. The information needed
to register this value in the "RDAP Extensions" registry is described to register this value in the "RDAP Extensions" registry is described
in Section 12.1. in Section 11.1.
10. Implementation Considerations 10. Implementation Considerations
To limit the impact of processing the search predicates, servers are To limit the impact of processing the search predicates, servers are
RECOMMENDED to make use of techniques to speed up the data retrieval RECOMMENDED to make use of techniques to speed up the data retrieval
in their underlying data store such as indexes or similar. In in their underlying data store, such as indexes or similar. In
addition, risks with respect to performance degradation or result set addition, risks with respect to performance degradation or result set
generation can be mitigated by adopting practices used for standard generation can be mitigated by adopting practices used for standard
searches, e.g. restricting the search functionality, limiting the searches, e.g., restricting the search functionality, limiting the
rate of search requests according to the user's authorization, rate of search requests according to the user's authorization,
truncating and paging the results [RFC8977], and returning partial truncating and paging the results [RFC8977], and returning partial
responses [RFC8982]. responses [RFC8982].
11. Implementation Status 11. IANA Considerations
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
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.
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".
11.1. IIT-CNR/Registro.it RDAP Server
* Responsible Organization: Institute of Informatics and Telematics
of National Research Council (IIT-CNR)/Registro.it
* Location: https://rdap.pubtest.nic.it/
* 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.
* Level of Maturity: This is an "alpha" test implementation.
* Coverage: This implementation includes all of the features
described in this specification.
* Contact Information: Mario Loffredo, mario.loffredo@iit.cnr.it
11.2. IIT-CNR/Registro.it RDAP Client 11.1. RDAP Extensions Registry
* Responsible Organization: Institute of Informatics and Telematics IANA has registered the following value in the "RDAP Extensions"
of National Research Council (IIT-CNR)/Registro.it registry:
* Location: https://web-rdap.pubtest.nic.it/
* 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.
* Level of Maturity: This is an "alpha" test implementation.
* Coverage: This implementation includes all of the features Extension Identifier: reverse_search
described in this specification.
* Contact Information: Francesco Donini, francesco.donini@iit.cnr.it
12. IANA Considerations Registry Operator: Any
12.1. RDAP Extensions Registry Specification: RFC 9536
IANA is requested to register the following value in the "RDAP Contact: IETF <iesg@ietf.org>
Extensions" registry:
* Extension identifier: reverse_search Intended Usage: This extension identifier is used for both URI path
* Registry operator: Any segments and response extensions related to the reverse search in
* Published specification: This document. RDAP.
* Contact: IETF <iesg@ietf.org>
* Intended usage: This extension identifier is used for both URI
path segments and response extensions related to the reverse
search in RDAP.
12.2. RDAP Reverse Search Registries 11.2. RDAP Reverse Search Registries
12.2.1. Creation of the RDAP Reverse Search Registries 11.2.1. Creation of the RDAP Reverse Search Registries
IANA is requested to create the "RDAP Reverse Search" and "RDAP IANA has created the "RDAP Reverse Search" and "RDAP Reverse Search
Reverse Search Mapping" registries within the group "Registration Mapping" registries within the "Registration Data Access Protocol
Data Access Protocol (RDAP)". (RDAP)" category in the protocol registries.
These registries follow the Specification Required process as defined These registries follow the Specification Required registration
in Section 4.5 of [RFC8126]. policy, as defined in Section 4.6 of [RFC8126].
The designated expert should prevent collisions and confirm that The designated expert should prevent collisions and confirm that
suitable documentation, as described in Section 4.6 of [RFC8126], is suitable documentation, as described in Section 4.5 of [RFC8126], is
available to ensure interoperability. available to ensure interoperability.
Creators of either new RDAP reverse searches or new mappings for Creators of either new RDAP reverse searches or new mappings for
registered reverse searches SHOULD NOT replicate functionality registered reverse searches SHOULD NOT replicate functionality
already available by way of other documents referenced in these already available by way of other documents referenced in these
registries. Creators MAY register additional reverse search mappings registries. Creators MAY register additional reverse search mappings
for existing properties, but they SHOULD NOT map a registered reverse for existing properties, but they SHOULD NOT map a registered reverse
search property to a response field with a meaning other than that of search property to a response field with a meaning other than that of
the response fields referenced by the mappings already registered for the response fields referenced by the mappings already registered for
that property. In other words, all the mappings for a reverse search that property. In other words, all the mappings for a reverse search
property MUST point to response fields with the same meaning. property MUST point to response fields with the same meaning.
12.2.2. Submit Request to IANA 11.2.2. Submit Requests to IANA
Registration requests can be sent to <iana@iana.org>. Registration requests can be sent to <iana@iana.org>.
12.2.3. RDAP Reverse Search Registry 11.2.3. RDAP Reverse Search Registry
12.2.3.1. Template 11.2.3.1. Template
"Searchable Resource Type": The searchable resource type of the Property: The name of the reverse search property.
Description: A brief human-readable text describing the reverse
search property.
Searchable Resource Type: The searchable resource type of the
reverse search query (Section 2) including the reverse search reverse search query (Section 2) including the reverse search
property. Multiple reverse search properties differing only by property. Multiple reverse search properties differing only by
this field can be grouped together by listing all the searchable this field can be grouped together by listing all the searchable
resource types separated by comma (see Section 12.2.3.2). resource types separated by comma (see Section 11.2.3.2).
"Related Resource Type": The related resource type of the reverse Related Resource Type: The related resource type of the reverse
search query (Section 2) including the reverse search property. search query (Section 2) including the reverse search property.
"Property": The name of the reverse search property. Registrant: The name of the person registering the reverse search
property.
"Description": A brief human-readable text describing the reverse
search property.
"Registrant Name": The name of the person registering the reverse
search property.
"Registrant Contact Information": An email address, postal address, Contact Information: An email address, postal address, or some other
or some other information to be used to contact the registrant. information to be used to contact the registrant.
"Reference": Document (e.g. the RFC number) and section reference Reference: Document (e.g., the RFC number) and section reference
where the reverse search property is specified. where the reverse search property is specified.
The combination of "Searchable Resource Type", "Related Resource The combination of Searchable Resource Type, Related Resource Type,
Type" and "Property" MUST be unique across the registry entries. and Property MUST be unique across the registry entries.
12.2.3.2. Initial Content
IANA is requested to register the following entries in the "RDAP 11.2.3.2. Initial Content
Reverse Search" registry.
For all entries, the common values are shown in Table 1 whereas the IANA has registered the following entries in the "RDAP Reverse
specific values are shown in Table 2. Search" registry. For all entries, the common values are shown in
Table 1, whereas the specific values are shown in Table 2.
+================================+================================+ +==========================+================================+
| Registry Property | Value | | Registry Property | Value |
+================================+================================+ +==========================+================================+
| Searchable Resource Type | domains, nameservers, entities | | Searchable Resource Type | domains, nameservers, entities |
+--------------------------------+--------------------------------+ +--------------------------+--------------------------------+
| Related Resource Type | entity | | Related Resource Type | entity |
+--------------------------------+--------------------------------+ +--------------------------+--------------------------------+
| Registrant Name | IETF | | Registrant | IETF |
+--------------------------------+--------------------------------+ +--------------------------+--------------------------------+
| Registrant Contact Information | iesg@ietf.org | | Contact Information | iesg@ietf.org |
+--------------------------------+--------------------------------+ +--------------------------+--------------------------------+
| Reference | This document, Section 8 | | Reference | RFC 9536 |
+--------------------------------+--------------------------------+ +--------------------------+--------------------------------+
Table 1: Common values for all entries in the "RDAP Reverse Table 1: Common Values for All Entries in the RDAP
Search" registry Reverse Search Registry
+==========+==============================================+ +==========+==============================================+
| Property | Description | | Property | Description |
+==========+==============================================+ +==========+==============================================+
| fn | The server supports the domain/nameserver/ | | fn | The server supports the domain/nameserver/ |
| | entity search based on the full name (a.k.a. | | | entity search based on the full name (a.k.a. |
| | formatted name) of an associated entity | | | formatted name) of an associated entity |
+----------+----------------------------------------------+ +----------+----------------------------------------------+
| handle | The server supports the domain/nameserver/ | | handle | The server supports the domain/nameserver/ |
| | entity search based on the handle of an | | | entity search based on the handle of an |
skipping to change at page 14, line 42 skipping to change at line 576
+----------+----------------------------------------------+ +----------+----------------------------------------------+
| email | The server supports the domain/nameserver/ | | email | The server supports the domain/nameserver/ |
| | entity search based on the email address of | | | entity search based on the email address of |
| | an associated entity | | | an associated entity |
+----------+----------------------------------------------+ +----------+----------------------------------------------+
| role | The server supports the domain/nameserver/ | | role | The server supports the domain/nameserver/ |
| | entity search based on the role of an | | | entity search based on the role of an |
| | associated entity | | | associated entity |
+----------+----------------------------------------------+ +----------+----------------------------------------------+
Table 2: Specific values for all entries in the "RDAP Table 2: Specific Values for Entries in the RDAP
Reverse Search" registry Reverse Search Registry
12.2.4. RDAP Reverse Search Mapping Registry
12.2.4.1. Template 11.2.4. RDAP Reverse Search Mapping Registry
"Searchable Resource Type": The same as defined in the "Reverse 11.2.4.1. Template
Search Registry".
"Related Resource Type": The same as defined in the "Reverse Search Property: The same as defined in the "RDAP Reverse Search" registry.
Registry".
"Property": The same as defined in the "Reverse Search Registry". Property Path: The JSONPath of the RDAP property this reverse search
property maps to.
"Property Path": The JSONPath of the RDAP property this reverse Searchable Resource Type: The same as defined in the "RDAP Reverse
search property maps to. Search" registry.
"Description": A brief human-readable text describing this reverse Related Resource Type: The same as defined in the "RDAP Reverse
search property mapping. Search" registry.
"Registrant Name": The name of the person registering this reverse Registrant: The name of the person registering this reverse search
search property mapping. property mapping.
"Registrant Contact Information": The same as defined in the Contact Information: The same as defined in the "RDAP Reverse
"Reverse Search Registry". Search" registry.
"Reference": Document (e.g. the RFC number) and section reference Reference: Document (e.g., the RFC number) and section reference
where this reverse search property mapping is specified. where this reverse search property mapping is specified.
The combination of "Searchable Resource Type", "Related Resource The combination of Searchable Resource Type, Related Resource Type,
Type", "Property" and "Property Path" MUST be unique across the Property, and Property Path MUST be unique across the registry
registry entries. entries.
12.2.4.2. Initial Content
IANA is requested to register the following entries in the "RDAP 11.2.4.2. Initial Content
Reverse Search Mapping" registry.
For all entries, the common values are the same as defined in the IANA has registered the following entries in the "RDAP Reverse Search
"RDAP Reverse Search" registry (see Table 1) whereas the specific Mapping" registry. For all entries, the common values are the same
values are shown in Table 3. as defined in the "RDAP Reverse Search" registry (see Table 1),
whereas the specific values are shown below (see Table 3).
+==========+==================================================+ +==========+==================================================+
| Property | Property Path | | Property | Property Path |
+==========+==================================================+ +==========+==================================================+
| fn | $.entities[*].vcardArray[1][?(@[0]=='fn')][3] | | fn | $.entities[*].vcardArray[1][?(@[0]=='fn')][3] |
+----------+--------------------------------------------------+ +----------+--------------------------------------------------+
| handle | $.entities[*].handle | | handle | $.entities[*].handle |
+----------+--------------------------------------------------+ +----------+--------------------------------------------------+
| email | $.entities[*].vcardArray[1][?(@[0]=='email')][3] | | email | $.entities[*].vcardArray[1][?(@[0]=='email')][3] |
+----------+--------------------------------------------------+ +----------+--------------------------------------------------+
| role | $.entities[*].roles | | role | $.entities[*].roles |
+----------+--------------------------------------------------+ +----------+--------------------------------------------------+
Table 3: Specific values for all entries in the "RDAP Table 3: Specific Values for Entries in the RDAP Reverse
Reverse Search Mapping" registry Search Mapping Registry
13. Privacy Considerations 12. Privacy Considerations
The search functionality defined in this document may affect the The search functionality defined in this document may affect the
privacy of entities in the registry (and elsewhere) in various ways: privacy of entities in the registry (and elsewhere) in various ways;
see [RFC6973] for a general treatment of privacy in protocol see [RFC6973] for a general treatment of privacy in protocol
specifications. Registry operators should be aware of the tradeoffs specifications. Registry operators should be aware of the trade-offs
that result from implementation of this functionality. that result from implementing this functionality.
Many jurisdictions have laws or regulations that restrict the use of Many jurisdictions have laws or regulations that restrict the use of
"Personal Data", per the definition in [RFC6973]. Given that, "personal data", per the definition in [RFC6973]. Given that,
registry operators should ascertain whether the regulatory registry operators should ascertain whether the regulatory
environment in which they operate permits implementation of the environment in which they operate permits implementation of the
functionality defined in this document. functionality defined in this document.
In those cases where this functionality makes use of sensitive In those cases where this functionality makes use of sensitive
information, it MUST only be accessible to authorized users supported information, the information MUST only be accessible to authorized
by lawful basis. users under a lawful basis.
Since reverse search requests and responses could contain Personally Since reverse search requests and responses could contain Personally
Identifiable Information (PII), reverse search functionality MUST be Identifiable Information (PII), reverse search functionality MUST be
available over HTTPS only. available over HTTPS only.
Providing reverse search in RDAP carries the following threats as Providing reverse search in RDAP carries the following threats as
described in [RFC6973]: described in [RFC6973]:
* Correlation * Correlation
* Disclosure * Disclosure
* Misuse of information
* Misuse of data
Therefore, RDAP providers need to mitigate the risk of those threats Therefore, RDAP providers need to mitigate the risk of those threats
by implementing appropriate measures supported by security services by implementing appropriate measures supported by security services
(see Section 14). (see Section 13).
14. Security Considerations 13. Security Considerations
Security services required to provide controlled access to the Security services that are required to provide controlled access to
operations specified in this document are described in [RFC7481]. A the operations specified in this document are described in [RFC7481].
non-exhaustive list of access control paradigms an RDAP provider can A non-exhaustive list of access control paradigms an RDAP provider
implement is presented in Appendix A. can implement is presented in Appendix A.
As an additional measure to enforce security by preventing reverse As an additional measure to enforce security by preventing reverse
searches to be accessed from unauthorized users, the RDAP providers searches to be accessed from unauthorized users, the RDAP providers
may consider to physically separate the reverse search endpoints from may consider physically separating the reverse search endpoints from
the other ones by configuring a proxy routing the reverse searches to the other ones by configuring a proxy routing the reverse searches to
a dedicated backend server and leveraging further security services a dedicated backend server and leveraging further security services
offered by other protocol layers such as digital certificates and IP offered by other protocol layers, such as digital certificates and IP
whitelisting. allow-listing.
Finally, the specification of the relationship within the reverse Finally, the specification of the relationship within the reverse
search path allows the RDAP servers to implement different search path allows the RDAP servers to implement different
authorization policies on a per-relationship basis. authorization policies on a per-relationship basis.
15. Acknowledgements 14. References
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.
Tom Harrison and Jasdip Singh provided relevant feedback and constant
support to the implementation of this proposal. Their contributions
have been greatly appreciated.
16. References
16.1. Normative References
[I-D.ietf-jsonpath-base] 14.1. Normative References
Gössner, S., Normington, G., and C. Bormann, "JSONPath:
Query expressions for JSON", Work in Progress, Internet-
Draft, draft-ietf-jsonpath-base-20, 25 August 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-
jsonpath-base-20>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC6350] Perreault, S., "vCard Format Specification", RFC 6350, [RFC6350] Perreault, S., "vCard Format Specification", RFC 6350,
DOI 10.17487/RFC6350, August 2011, DOI 10.17487/RFC6350, August 2011,
<https://www.rfc-editor.org/info/rfc6350>. <https://www.rfc-editor.org/info/rfc6350>.
[RFC7095] Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095, [RFC7095] Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095,
DOI 10.17487/RFC7095, January 2014, DOI 10.17487/RFC7095, January 2014,
<https://www.rfc-editor.org/info/rfc7095>. <https://www.rfc-editor.org/info/rfc7095>.
[RFC7481] Hollenbeck, S. and N. Kong, "Security Services for the [RFC7481] Hollenbeck, S. and N. Kong, "Security Services for the
Registration Data Access Protocol (RDAP)", STD 95, Registration Data Access Protocol (RDAP)", STD 95,
RFC 7481, DOI 10.17487/RFC7481, March 2015, RFC 7481, DOI 10.17487/RFC7481, March 2015,
<https://www.rfc-editor.org/info/rfc7481>. <https://www.rfc-editor.org/info/rfc7481>.
[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,
<https://www.rfc-editor.org/info/rfc7942>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC9082] Hollenbeck, S. and A. Newton, "Registration Data Access [RFC9082] Hollenbeck, S. and A. Newton, "Registration Data Access
skipping to change at page 18, line 29 skipping to change at line 729
[RFC9083] Hollenbeck, S. and A. Newton, "JSON Responses for the [RFC9083] Hollenbeck, S. and A. Newton, "JSON Responses for the
Registration Data Access Protocol (RDAP)", STD 95, Registration Data Access Protocol (RDAP)", STD 95,
RFC 9083, DOI 10.17487/RFC9083, June 2021, RFC 9083, DOI 10.17487/RFC9083, June 2021,
<https://www.rfc-editor.org/info/rfc9083>. <https://www.rfc-editor.org/info/rfc9083>.
[RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, [RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP Semantics", STD 97, RFC 9110, Ed., "HTTP Semantics", STD 97, RFC 9110,
DOI 10.17487/RFC9110, June 2022, DOI 10.17487/RFC9110, June 2022,
<https://www.rfc-editor.org/info/rfc9110>. <https://www.rfc-editor.org/info/rfc9110>.
16.2. Informative References [RFC9535] Gössner, S., Ed., Normington, G., Ed., and C. Bormann,
Ed., "JSONPath: Query Expressions for JSON", RFC 9535,
DOI 10.17487/RFC9535, February 2024,
<https://www.rfc-editor.org/info/rfc9535>.
[ICANN-RA] Internet Corporation For Assigned Names and Numbers, 14.2. Informative References
"Registry Agreement", July 2017,
<https://newgtlds.icann.org/sites/default/files/
agreements/agreement-approved-31jul17-en.pdf>.
[ICANN-RDS1] [ICANN-RA] ICANN, "Base Registry Agreement", January 2024,
Internet Corporation For Assigned Names and Numbers, <https://www.icann.org/en/registry-agreements/base-
"Final Report from the Expert Working Group on gTLD agreement>.
[ICANN-RDS]
ICANN, "Final Report from the Expert Working Group on gTLD
Directory Services: A Next-Generation Registration Directory Services: A Next-Generation Registration
Directory Service (RDS)", June 2014, Directory Service (RDS)", June 2014,
<https://www.icann.org/en/system/files/files/final-report- <https://www.icann.org/en/system/files/files/final-report-
06jun14-en.pdf>. 06jun14-en.pdf>.
[ICANN-RDS2] [OIDCC] Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and
Internet Corporation For Assigned Names and Numbers, C. Mortimore, "OpenID Connect Core 1.0 incorporating
"Final Issue Report on a Next-Generation gTLD RDS to errata set 2", December 2023,
Replace WHOIS", October 2015,
<http://whois.icann.org/sites/default/files/files/final-
issue-report-next-generation-rds-07oct15-en.pdf>.
[OIDCC] OpenID Foundation, "OpenID Connect Core incorporating
errata set 1", November 2014,
<http://openid.net/specs/openid-connect-core-1_0.html>. <http://openid.net/specs/openid-connect-core-1_0.html>.
[RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, [RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912,
DOI 10.17487/RFC3912, September 2004, DOI 10.17487/RFC3912, September 2004,
<https://www.rfc-editor.org/info/rfc3912>. <https://www.rfc-editor.org/info/rfc3912>.
[RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)", [RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009, STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
<https://www.rfc-editor.org/info/rfc5730>. <https://www.rfc-editor.org/info/rfc5730>.
skipping to change at page 19, line 38 skipping to change at line 781
[RFC8982] Loffredo, M. and M. Martinelli, "Registration Data Access [RFC8982] Loffredo, M. and M. Martinelli, "Registration Data Access
Protocol (RDAP) Partial Response", RFC 8982, Protocol (RDAP) Partial Response", RFC 8982,
DOI 10.17487/RFC8982, February 2021, DOI 10.17487/RFC8982, February 2021,
<https://www.rfc-editor.org/info/rfc8982>. <https://www.rfc-editor.org/info/rfc8982>.
Appendix A. Paradigms to Enforce Access Control on Reverse Search in Appendix A. Paradigms to Enforce Access Control on Reverse Search in
RDAP RDAP
Access control can be implemented according to different paradigms Access control can be implemented according to different paradigms
introducing increasingly stringent rules. The paradigms reported introducing increasingly stringent rules. The paradigms listed below
here in the following leverage the capabilities either built-in or leverage the capabilities that are either built in or provided as
provided as extensions by the OpenID Connect [OIDCC]: extensions by the OpenID Connect [OIDCC]:
* Role-Based Access Control (RBAC): access rights are granted Role-Based Access Control (RBAC): Access rights are granted
depending on roles. Generally, this is done by grouping users depending on roles. Generally, this is done by grouping users
into fixed categories and assigning static grants to each into fixed categories and assigning static grants to each
category. A more dynamic approach can be implemented by using the category. A more dynamic approach can be implemented by using the
OpenID Connect "scope" claim; OpenID Connect "scope" claim.
* Purpose-Based Access Control (PBAC): access rules are based on the
Purpose-Based Access Control (PBAC): Access rules are based on the
notion of purpose, being the intended use of some data by a user. 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 It can be implemented by tagging a request with the usage purpose
and making the RDAP server check the compliance between the given and making the RDAP server check the compliance between the given
purpose and the control rules applied to the data to be returned; purpose and the control rules applied to the data to be returned.
* Attribute-Based Access Control (ABAC): rules to manage access Attribute-Based Access Control (ABAC): Rules to manage access rights
rights are evaluated and applied according to specific attributes are evaluated and applied according to specific attributes
describing the context within which data are requested. It can be describing the context within which data are requested. It can be
implemented by setting within an out-of-band process additional implemented within an out-of-band process by setting additional
OpenID Connect claims describing the request context and making OpenID Connect claims that describe the request context and make
the RDAP server check the compliance between the given context and the RDAP server check for compliance between the given context and
the control rules applied to the data to be returned; the control rules that are applied to the data to be returned.
* Time-Based Access Control (TBAC): 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.
With regard to the privacy threats reported in Section 13, Time-Based Access Control (TBAC): Data access is allowed for a
limited time only. It can be implemented by assigning users
temporary credentials linked to access grants with limited scopes.
With regard to the privacy threats reported in Section 12,
correlation and disclosure can be mitigated by minimizing both the correlation and disclosure can be mitigated by minimizing both the
request features and the response data based on user roles (i.e. request features and the response data based on user roles (i.e.,
RBAC). Misuse can be mitigated by checking for the purpose of the RBAC). Misuse can be mitigated by checking for the purpose of the
request (i.e. PBAC). It can be accomplished according to the request (i.e., PBAC). It can be accomplished according to the
following approaches: following approaches:
* Full Trust: the registry trusts the fairness of an accredited Full Trust: The registry trusts the fairness of an accredited user.
user. The requestor is always legitimized to submit his requests The requestor is always legitimized to submit their requests under
under a lawful basis. Additionally, he can be required to specify a lawful basis. Additionally, they can be required to specify the
the purpose as either a claim of his account or a query parameter. purpose as either a claim of their account or a query parameter.
In the former case, the purpose is assumed to be the same for 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 every request. In the latter case, the purpose must be one of
those associated to the user; those associated to the user.
* Zero Trust: the registry requires documents assessing that the
Zero Trust: The registry requires documents that assess whether the
requestor is legitimized to submit a given request. It can be requestor is legitimized to submit a given request. It can be
implemented by assigning the requestor with temporary OpenID implemented by assigning the requestor a temporary OpenID account
account linked to the given request (i.e. TBAC) and describing linked to the given request (i.e., TBAC) and describing the
the request through a set of claims (i.e. ABAC). The association request through a set of claims (i.e., ABAC). The association
between the temporary account and the claims about the request is between the temporary account and the claims about the request is
made by an out-of-band application. In so doing, the RDAP server 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 is able to check that the incoming request is consistent with the
request claims linked to the temporary account. request claims linked to the temporary account.
The two approaches can be used together: The two approaches can be used together:
* The former is suitable for users carrying out a task in the public * The former is suitable for users carrying out a task in the public
interest, or exercising their official authority (e.g. an officer interest or exercising their official authority (e.g., an officer
of a cybercrime agency). Similarly, registrars can submit reverse of a cybercrime agency). Similarly, registrars can submit reverse
searches on their domains and contacts based on their contractual searches on their domains and contacts based on their contractual
relationship with the domain holders. In this case, the query relationship with the domain holders. In this case, the query
results can be restricted to those pertaining a registrar by results can be restricted to those pertaining to a registrar by
adding an implicit predicate to the search condition. adding an implicit predicate to the search condition.
* The latter can be taken to allow domain name dispute resolution * The latter can be taken to allow domain name dispute resolution
service providers to request information in defense of the service providers to request information in defense of the
legitimate interests of complainants. legitimate interests of complainants.
Appendix B. Change Log Acknowledgements
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 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.
10: Updated "Reverse Searches Based on Entity Details" section to
consider the use of JSContact format instead of jCard. Added
references to JSContact documents.
11: Updated the document based on Tom Harrison and James Gould
feedback:
* Updated section "RDAP Path Segment Specification":
- Clarified how servers must evaluate a reverse search
including predicates that are for the same property.
- Specified the error response servers must return when
receiving a wrong reverse search request according to their
policy.
- Clarified that searchs for the related-resource-type values
other than "entity" may be defined in future documents.
* Reviewed text in section "Reverse Searches Based on Entity
Details" about reverse searches based on custom response
extensions.
* 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.
* Added section "RDAP Response Specification".
* Changed the text to present reverse search as a single
extension with multiple features.
* Changed the definition of searchable-resource-type and related-
resource-type to consider also the resource type extensions.
* Replaced "reverse" with "reverse_search_0" in the generic
reverse search path. Updated Figure 1 accordingly.
* 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.
* Reviewed the text of "Privacy Considerations" section.
* Text cleaning.
12: Replaced "reverse_search_0" with "reverse_search" as both URI
path segment, extension identifier and rdapConformance tag to
match the working group consensus.
13: Done some minor text changes.
14: Revised text of first sentence and added references to RFC8977
and RFC8982 in the "Implementation Considerations" section.
15: Moved RFC6973 from Normative References to Informative
References. Remnoved informative reference to draft-ietf-regext-
rdap-openid. Rephrased text in Appendix A accordingly.
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.
17: Revised the "Reverse Search Properties Discovery" section.
Replaced "RDAP JSON Values Registry" section with the "RDAP
Reverse Search Properties Registry" section.
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 document
to separate the implementation of a generic reverse search from
that based on domain-entity relationship.
19: Added the "Reverse Search Query Processing" section. Changed
the definition of search-condition in Section 2. Moved the
"Reverse Search Response Specification" section. Corrected
Figure 3.
20:
* Changed document title.
* 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
Section 3.
* Changed "...that the RDAP response property "roles" must The authors would like to acknowledge the following individuals for
contain at least the specified role" to "...that the RDAP their contributions to this document: Francesco Donini, Scott
response property "roles" MUST contain at least the specified Hollenbeck, Francisco Arias, Gustavo Lozano, Eduardo Alvarez, Ulrich
role" in Section 8. Wisser, James Gould, and Pawel Kowalik.
* Changed the value of the "Intended usage" property of the "RDAP
Extensions Registry" entry in Section 12.1.
* Changed "..., reverse search functionality SHOULD be available
over HTTPS only." to "..., reverse search functionality MUST be
available over HTTPS only." in Section 13.
21:
* Added a sentence about servers signaling the unsupported
reverse searches to Section 7.
* Replaced "$.." with "$." in JSONPath expressions.
* Clarified that the registry group the new registries must be
added to is "Registration Data Access Protocol (RDAP)".
* Removed unused normative reference to RFC7480.
22:
* Expanded EPP acronym in Section 1.
* Moved RFC3912 and RFC5730 from normative to informative
references.
23:
* Replaced IESG with IETF as the Registrant Name for each entry
in the IANA registries.
* Rearranged the layout of the initial content for the IANA
registries.
* Added titles to figures.
* Repalced "RDAP providers are REQUIRED to" with "RDAP providers
need to" in Section 14.
* Text cleaning.
24:
* Added text to Section 12.2.1 to make the term "collisions"
clear enough for future DEs.
* Added titles to tables.
25:
* Added text to Section 1 to reference the implications of this
specification on efficiency, security and compliance with
privacy regulations.
* 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.
* Added text to Section 14 to describe additional measures to
enforce the security.
* Added text to Appendix A to clarify how the proposed access
control paradigms can contribute to mitigate the threats listed
in Section 13.
* Moved the reference to RFC3912.
* Moved reference to draft-ietf-jsonpath-based to Normative
References.
* Text cleaning. Tom Harrison and Jasdip Singh provided relevant feedback and constant
support to the implementation of this proposal. Their contributions
have been greatly appreciated.
Authors' Addresses Authors' Addresses
Mario Loffredo Mario Loffredo
IIT-CNR/Registro.it IIT-CNR/Registro.it
Via Moruzzi,1 Via Moruzzi,1
56124 Pisa 56124 Pisa
Italy Italy
Email: mario.loffredo@iit.cnr.it Email: mario.loffredo@iit.cnr.it
URI: http://www.iit.cnr.it URI: http://www.iit.cnr.it
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