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<rfc category="bcp" docName="draft-hollenbeck-regext-rdap-object-tag-03" ipr="trust200902" updates="7484">
  <front>
    <title abbrev="RDAP Object Tagging">Registration Data Access Protocol (RDAP) Object Tagging</title>
    
    <author initials="S." surname="Hollenbeck" fullname="Scott Hollenbeck">
      <organization>Verisign Labs</organization>
      <address>
        <postal>
          <street>12061 Bluemont Way</street>
          <city>Reston</city>
          <region>VA</region>
          <code>20190</code>
          <country>USA</country>
        </postal>
        <email>shollenbeck@verisign.com</email>
        <uri>http://www.verisignlabs.com/</uri>
      </address>
    </author>
    
    <author fullname="Andrew Lee Newton" initials="A.L." surname="Newton">
      <organization abbrev="ARIN">American Registry for Internet Numbers</organization>
      <address>
        <postal>
          <street>PO Box 232290</street>
          <city>Centreville</city>
          <region>VA</region>
          <country>US</country>
          <code>20120</code>
        </postal>
        <email>andy@arin.net</email>
        <uri>http://www.arin.net</uri>
      </address>
    </author>

    <date/>
    <area>Applications and Real-Time</area>
    <workgroup>Registration Protocols Extensions</workgroup>
    <keyword>RDAP</keyword>
    <keyword>Entity</keyword>
    <keyword>Bootstrap</keyword>
    
    <abstract>
      <t>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 queries. The  method does not describe how to identify the authoritative server for processing other RDAP query types, such as entity queries. This limitation exists because the identifiers associated with these query types are typically unstructured. 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.</t>
    </abstract>
  </front>

  <middle>
    <section title="Introduction">
      <t>The Registration Data Access Protocol (RDAP) includes a method (<xref target="RFC7484"/>) 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.</t>
      
      <t>As noted in Section 9 of RFC 7484 <xref target="RFC7484"/>, 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.</t>
    </section>
      
    <section anchor="practice" title="Object Naming Practice">
      <t>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 <xref target="RFC7484"/>. A service provider tag is constructed by prepending the Unicode TILDE character "~" (U+007E, described as an "unreserved" character in RFC 3986 <xref target="RFC3986"/>) 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".</t>
      
      <t>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 <xref target="RFC7482"/>, 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":</t>
      
      <t>XXXX~ARIN</t>
      
      <t>Clients that wish to bootstrap an entity query can parse this identifier into distinct handle and service provider identifier elements. Handles can themselves contain TILDE characters; the service provider identifier is found following the last TILDE 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".</t>
      
      <t>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 <xref target="RFC7483"/> in which the handle identifiers have been tagged with a service provider tag:</t>
      
      <figure anchor="dom-rir-7483-example">
        <artwork xml:space="preserve">
{
  "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" : "v4",
    "name": "NET-RTR-1",
    "type" : "DIRECT ALLOCATION",
    "country" : "AU",
    "parentHandle" : "YYYY~RIR",
    "status" : [ "active" ]
  }
}
        </artwork>
      </figure>
      
      <figure anchor="dom-dnr-7483-example">
        <artwork xml:space="preserve">
{
  "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~ABC",
       "vcardArray":
       [
         ...
       ],
       "status" : [ "validated", "locked" ],
       "roles" : [ "registrant" ],
       "remarks" :
       [
         ...
       ],
       "links" :
       [
         ...
       ],
       "events" :
       [
         ...
       ]
     }
   ]
}
        </artwork>
      </figure>
      
      <t>As described in Section 5 of RFC 7483 <xref target="RFC7483"/>, RDAP responses can contain "self" links. Service provider tags and self references SHOULD be consistent. If they are inconsistent, the service provider tag is processed with higher priority when using these values to identify a service provider.</t>
      
      <t>There is a risk of unpredictable processing behavior if the TILDE character is used for naturally occurring, non-separator purposes in an entity handle. This could lead to a client mistakenly assuming that a TILDE character represents a separator and the text that follows TILDE is a service provider identifier. A client that queries the IANA registry for what they assume is a valid service provider will likely receive an unexpected invalid result. As a consequence, the TILDE character MUST NOT be used in an entity handle for any purpose other than to separate an object identifier from a service provider tag.</t>
    </section>
    
    <section anchor="bootstrap-entity-1" title="Bootstrap Service Registry for RDAP Service Providers">
      <t>The bootstrap service registry for the RDAP service provider space is represented using the structure specified in Section 3 of RFC 7484 <xref target="RFC7484"/>. The JSON output of this registry contains alphanumeric identifiers that identify RDAP service providers, grouped by base RDAP URLs, as shown in this example.</t>

      <figure anchor="reg-example">
        <artwork xml:space="preserve">
{
  "version": "1.0",
  "publication": "YYYY-MM-DDTHH:MM:SSZ",
  "description": "RDAP service provider bootstrap values",
  "services": [
    [
      ["YYYY"],
      [
        "https://example.com/rdap/"
      ]
    ],
    [
      ["ZZ54"],
      [
        "http://rdap.example.org/"
      ]
    ],
    [
      ["1754"],
      [
        "https://example.net/rdap/",
        "http://example.net/rdap/"
      ]
    ]
  ]
 }
          </artwork>
        </figure>
        
        <t>Alphanumeric service provider identifiers conform to the syntax specified in the IANA registry of <eref target="http://www.iana.org/assignments/epp-repository-ids/epp-repository-ids.xhtml#epp-repository-ids-1">Extensible Provisioning Protocol (EPP) Repository Identifiers</eref>.</t>
      
      <section anchor="reg-proc" title="Registration Procedure">
        <t>The service provider registry is populated using the "First Come First Served" policy defined in RFC 5226 <xref target="RFC5226"/>. 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 one or more base RDAP URLs to be associated with the service provider identifier.</t>
      </section>
    </section>

    <section anchor="IANA" title="IANA Considerations">
      <t>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 <xref target="bootstrap-entity-1"/>, with the formal syntax specified in Section 10 of RFC 7484 <xref target="RFC7484"/>.</t>
      
      <section anchor="bootstrap-entity-2" title="Bootstrap Service Registry for RDAP Service Providers">
        <t>Entries in this registry contain at least the following:</t>
        
        <t><list style="symbols">
	  <t>An alphanumeric value that identifies the RDAP service provider being registered.</t>
	  <t>One or more URLs that provide the RDAP service regarding this registration.</t>
	</list></t>
      </section>
    </section>

    <section anchor="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 RFC 7942 <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="vlabs" title="Verisign Labs">
        <t><list style="none">
	  <t>Responsible Organization: Verisign Labs</t>
	  <t>Location: https://rdap.verisignlabs.com/</t>
	  <t>Description: This implementation includes support for domain registry RDAP queries using live data from the .cc and .tv country code top-level domains. Client authentication is required to receive entity information in query responses.</t>
	  <t>Level of Maturity: This is a "proof of concept" research implementation.</t>
	  <t>Coverage: This implementation includes all of the features described in this specification.</t>
	  <t>Contact Information: Scott Hollenbeck, shollenbeck@verisign.com</t>
	</list></t>
      </section>
    </section>

    <section anchor="Security" title="Security Considerations">
      <t>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 <xref target="RFC5246"/>, which IANA supports. Additional considerations associated with RDAP are described in RFC 7481 <xref target="RFC7481"/>.</t>
    </section>

    <section title="Acknowledgements">
      <t>The author would like to acknowledge the following individuals for their contributions to the development of this document: Tom Harrison, and Marcos Sanz. 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.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      &RFC5226;
      &RFC7484;
    </references>
    
    <references title="Informative References">
      &RFC3986;
      &RFC5246;
      &RFC7481;
      &RFC7482;
      &RFC7483;
      &RFC7942;
    </references>

    <section title="Change Log">
      <t>
        <list style="hanging">
          <t hangText="00:">Initial version.</t>
          <t hangText="01:">Changed separator character from HYPHEN MINUS to COMMERCIAL AT. Added a recommendation to maintain consistency between service provider tags and "self" links (suggestion received from Tom Harrison). Fixed a spelling error, and corrected the network example in <xref target="practice"/> (editorial erratum reported for RFC 7483 by Marcos Sanz). Added acknowledgements.</t>
          <t hangText="02:">Changed separator character from COMMERCIAL AT to TILDE. Clarity updates and fixed an example handle. Added text to describe the risk of separator characters appearing naturally in entity handles and being misinterpreted as separator characters.</t>
          <t hangText="03:">Added Implementation Status section (<xref target="impl-status"/>).</t>
        </list>
      </t>
    </section>
  </back>
</rfc>
