Registration Data Access Protocol (RDAP) Object Tagging

The Registration Data Access Protocol (RDAP) includes a method () that can be used to identify the authoritative server for processing domain name, IP address, and autonomous system number (ASN) queries. This method works because each of these data elements is structured in a way that facilitates automated parsing of the element and association of the data element with a particular RDAP service provider. For example, domain names include labels (such as "com", "net", and "org") that are associated with specific service providers. As noted in Section 9 of RFC 7484 , the method does not describe how to identify the authoritative server for processing entity queries, name server queries, help queries, or queries using certain search patterns. This limitation exists because the identifiers bound to these queries are typically not structured in a way that makes it easy to associate an identifier with a specific service provider. This document describes an operational practice that can be used to add structure to RDAP identifiers that makes it possible to identify the authoritative server for additional RDAP queries.

Tagging object identifiers with a service provider tag makes it possible to identify the authoritative server for processing an RDAP query using the method described in RFC 7484 . A service provider tag is constructed by concatenating the Unicode HYPHEN-MINUS character '-' (U+002D) to an IANA-registered value that represents the service provider. For example, a tag for a service provider identified by the string value "ARIN" is represented as "-ARIN". Service provider tags are concatenated to the end of RDAP query object identifiers to unambiguously identify the authoritative server for processing an RDAP query. Building on the example from Section 3.1.5 of RFC 7482 , an RDAP entity handle can be constructed that allows an RDAP client to bootstrap an entity query. The following identifier is used to find information for the entity associated with handle "XXXX" at service provider "ARIN": XXXX-ARIN Clients that wish to bootstrap an entity query can parse this identifier into distinct handle and service provider identifier elements. Handles can themselves contain HYPHEN-MINUS characters; the service provider identifier is found following the last (reading from left to right) HYPHEN-MINUS character in the tagged identifier. The service provider identifier is used to retrieve a base RDAP URL from an IANA registry. The base URL and entity handle are then used to form a complete RDAP query path segment. For example, if the base RDAP URL "https://example.com/rdap/" is associated with service provider "YYYY" in an IANA registry, an RDAP client will parse a tagged entity identifier "XXXX-YYYY" into distinct handle ("XXXX") and service provider ("YYYY") identifiers. The service provider identifier "YYYY" is used to query an IANA registry to retrieve the base RDAP URL "https://example.com/rdap/". The base RDAP URL is concatenated to the entity handle to create a complete RDAP query path segment of "https://example.com/rdap/entity/XXXX-YYYY". Implementation of this practice requires tagging of unstructured potential query identifiers in RDAP responses. Consider these elided examples from Section 5.3 of RFC 7483 in which the handle identifiers have been tagged with a service provider tag:

{ "objectClassName" : "domain", "handle" : "XXXX-RIR", "ldhName" : "0.2.192.in-addr.arpa", "nameservers" : [ ... ], "secureDNS": { ... }, "remarks" : [ ... ], "links" : [ ... ], "events" : [ ... ], "entities" : [ { "objectClassName" : "entity", "handle" : "XXXX-RIR", "vcardArray": [ ... ], "roles" : [ "registrant" ], "remarks" : [ ... ], "links" : [ ... ], "events" : [ ... ] } ], "network" : { "objectClassName" : "ip network", "handle" : "XXXX-RIR", "startAddress" : "192.0.2.0", "endAddress" : "192.0.2.255", "ipVersion" : "v6", "name": "NET-RTR-1", "type" : "DIRECT ALLOCATION", "country" : "AU", "parentHandle" : "YYYY-RIR", "status" : [ "active" ] } }

{ "objectClassName" : "domain", "handle" : "XXXX-DNR", "ldhName" : "xn--fo-5ja.example", "unicodeName" : "foo.example", "variants" : [ ... ], "status" : [ "locked", "transfer prohibited" ], "publicIds": [ ... ], "nameservers" : [ { "objectClassName" : "nameserver", "handle" : "XXXX-DNR", "ldhName" : "ns1.example.com", "status" : [ "active" ], "ipAddresses" : { ... }, "remarks" : [ ... ], "links" : [ ... ], "events" : [ ... ] }, { "objectClassName" : "nameserver", "handle" : "XXXX-DNR", "ldhName" : "ns2.example.com", "status" : [ "active" ], "ipAddresses" : { ... }, "remarks" : [ ... ], "links" : [ ... ], "events" : [ ... ] } ], "secureDNS": { ... }, "remarks" : [ ... ], "links" : [ ... ], "port43" : "whois.example.net", "events" : [ ... ], "entities" : [ { "objectClassName" : "entity", "handle" : "XXXX-8", "vcardArray": [ ... ], "status" : [ "validated", "locked" ], "roles" : [ "registrant" ], "remarks" : [ ... ], "links" : [ ... ], "events" : [ ... ] } ] }

The bootstrap service registry for the RDAP service provider space is represented using the structure specified in Section 3 of RFC 7484 . The JSON output of this registry contains alphanumeric identifiers that identify RDAP service providers, grouped by base RDAP URLs, as shown in this example.

{ "version": "1.0", "publication": "YYYY-MM-DDTHH:MM:SSZ", "description": "RDAP bootstrap file for service provider allocations", "services": [ [ ["YYYY"], [ "https://example.com/rdap/" ] ], [ ["ZZ54"], [ "http://rdap.example.org/" ] ], [ ["1754"], [ "https://example.net/rdap/", "http://example.net/rdap/" ] ] ] } Alphanumeric service provider identifiers conform to the syntax specified in the IANA registry of Extensible Provisioning Protocol (EPP) Repository Identifiers, with one exception: identifiers always start with a letter to avoid confusion with network handles of the form "NET-192-0-0-0-1" that always end with a HYPHEN-MINUS character followed by a number.

The service provider registry is populated using the "First Come First Served" policy defined in RFC 5226 . Provider identifier values can be derived and assigned by IANA on request. Registration requests include the requested service provider identifier (or an indication that IANA should assign an identifier) and the base RDAP URL to be associated with the service provider identifier.

IANA is requested to create the RDAP Bootstrap Services Registry listed below and make it available as JSON objects. The contents of this registry is described in , with the formal syntax specified in Section 10 of RFC 7484 .

Entries in this registry contain at least the following: An alpanumeric value that identifies the RDAP service provider being registered. One or more URLs that provide the RDAP service regarding this registration.

This practice helps to ensure that end users will get RDAP data from an authoritative source using a bootstrap method to find authoritative RDAP servers, reducing the risk of sending queries to non-authoritative sources. The method has the same security properties as the RDAP protocols themselves. The transport used to access the IANA registries can be more secure by using TLS , which IANA supports. Additional considerations associated with RDAP are described in RFC 7481 .

The author would like to acknowledge the following individuals for their contributions to the development of this document: TBD. In addition, the authors would like to recognize the Regional Internet Registry (RIR) operators (AFRINIC, APNIC, ARIN, LACNIC, and RIPE) that have been implementing and using the practice of tagging handle identifiers for several years. Their experience provided significant inspiration for the development of this document.