Registration Protocols Extensions S. Hollenbeck
Internet-Draft Verisign Labs
Updates: 7484 (if approved) A. Newton
Intended status: Best Current Practice ARIN
Expires: February 4, 2019 August 3, 2018

Registration Data Access Protocol (RDAP) Object Tagging
draft-ietf-regext-rdap-object-tag-05

Abstract

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 updates RFC 7484 by describing 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.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on February 4, 2019.

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Table of Contents

1. Introduction

The Registration Data Access Protocol (RDAP) includes a method ([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.

As noted in Section 9 of RFC 7484 [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.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2. Object Naming Practice

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 [RFC7484]. A service provider tag is constructed by prepending the Unicode HYPHEN-MINUS character "-" (U+002D, described as an "unreserved" character in RFC 3986 [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".

In combination with the rdapConformance attribute described in Section 4, 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 [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":

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 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 RDAP query URL is formed using the base RDAP URL and entity path segment described in Section 3.1.5 of RFC 7482 [RFC7482], using "XXXX-YYY" as the value of the handle identifier. The complete RDAP query URL becomes "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 ("..." is used to note elided response objects) from Section 5.3 of RFC 7483 [RFC7483] in which the handle identifiers have been tagged with service provider tags "RIR", "DNR", and "ABC" respectively:

{
  "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" ]
  }
}
        

Figure 1

{
  "objectClassName" : "domain",
  "handle" : "XXXX-YYY-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" :
       [
         ...
       ]
     }
   ]
}
        

Figure 2

As described in Section 5 of RFC 7483 [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.

There is a risk of unpredictable processing behavior if the HYPHEN-MINUS character is used for naturally occurring, non-separator purposes in an entity handle. This could lead to a client mistakenly assuming that a HYPHEN-MINUS character represents a separator and the text that follows HYPHEN-MINUS 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, use of the HYPHEN-MINUS character as a service provider tag separator MUST be noted by adding an rdapConformance value to query responses as described in Section 4.

The HYPHEN-MINUS character was chosen as a separator for two reasons: 1) it is a familiar separator character in operational use, and 2) it avoids collision with URI-reserved characters. The list of unreserved characters specified in Section 2.3 of RFC 3986 [RFC3986] provided multiple options for consideration:

unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"

ALPHA and DIGIT characters were excluded because they are commonly used in entity handles for non-separator purposes. HYPHEN-MINUS is commonly used as a separator and recognition of this practice will reduce implementation requirements and operational risk. The remaining characters were excluded because they are not broadly used as separators in entity handles.

3. Bootstrap Service Registry for Provider Object Tags

The bootstrap service registry for the RDAP service provider space is represented using the structure specified in Section 3 of RFC 7484 [RFC7484]. The JSON output of this registry contains contact information for the registered service provider identifiers, alphanumeric identifiers that identify RDAP service providers, and base RDAP service URLs as shown in this example.

{
  "version": "1.0",
  "publication": "YYYY-MM-DDTHH:MM:SSZ",
  "description": "RDAP bootstrap file for service provider object tags",
  "services": [
    [
      ["contact@example.com"],
      ["YYYY"],
      [
        "https://example.com/rdap/"
      ]
    ],
    [
      ["contact@example.org"],
      ["ZZ54"],
      [
        "http://rdap.example.org/"
      ]
    ],
    [
      ["contact@example.net"],
      ["1754"],
      [
        "https://example.net/rdap/",
        "http://example.net/rdap/"
      ]
    ]
  ]
 }
          

Figure 3

Alphanumeric service provider identifiers conform to the suffix portion ("\w{1,8}") of the "roidType" syntax specified in Section 4.2 of RFC 5730 [RFC5730].

3.1. Registration Procedure

The service provider registry is populated using the "First Come First Served" policy defined in RFC 8126 [RFC8126]. Provider identifier values can be derived and assigned by IANA on request. Registration requests include an email address to be associated with the registered service provider identifier, 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.

4. RDAP Conformance

RDAP responses that contain values described in this document MUST indicate conformance with this specification by including an rdapConformance ([RFC7483]) value of "rdap_objectTag_level_0". The information needed to register this value in the RDAP Extensions Registry is described in Section 5.2.

Example rdapConformance structure with extension specified:

          "rdapConformance" : 
          [
            "rdap_level_0",
            "rdap_objectTag_level_0"
          ]
          

Figure 4

5. IANA Considerations

IANA is requested to create the RDAP "Bootstrap Service Registry for Provider Object Tags" listed below and make it available as JSON objects. The contents of this registry is described in Section 3, with the formal syntax specified in Section 10 of RFC 7484 [RFC7484].

5.1. Bootstrap Service Registry Structure

Entries in this registry contain the following information:

5.2. RDAP Extensions Registry

IANA is requested to register the following value in the RDAP Extensions Registry:

6. Implementation Status

NOTE: Please remove this section and the reference to RFC 7942 prior to publication as an RFC.

This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in RFC 7942 [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".

6.1. Verisign Labs

6.2. OpenRDAP

7. Security Considerations

This practice uses IANA as a well-known, central trusted authority to allow users to get RDAP data from an authoritative source, reducing the risk of sending queries to non-authoritative sources and divulging query information to unintended parties. Using TLS [RFC5246] to protect the connection to IANA allows the server to authenticate itself as being operated by IANA and provides integrity protection for the resulting referral information, as well as providing privacy protection via data confidentiality. The subsequent RDAP connection is performed as usual, and retains the same security properties of the RDAP protocols themselves.

8. Acknowledgements

The author would like to acknowledge the following individuals for their contributions to the development of this document: Tom Harrison, Patrick Mevzek, 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.

9. References

9.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)", STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009.
[RFC7484] Blanchet, M., "Finding the Authoritative Registration Data (RDAP) Service", RFC 7484, DOI 10.17487/RFC7484, March 2015.
[RFC8126] Cotton, M., Leiba, B. and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.

9.2. Informative References

[RFC3986] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008.
[RFC7481] Hollenbeck, S. and N. Kong, "Security Services for the Registration Data Access Protocol (RDAP)", RFC 7481, DOI 10.17487/RFC7481, March 2015.
[RFC7482] Newton, A. and S. Hollenbeck, "Registration Data Access Protocol (RDAP) Query Format", RFC 7482, DOI 10.17487/RFC7482, March 2015.
[RFC7483] Newton, A. and S. Hollenbeck, "JSON Responses for the Registration Data Access Protocol (RDAP)", RFC 7483, DOI 10.17487/RFC7483, March 2015.
[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.

Appendix A. Change Log

00:
Initial version.
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 Section 2 (editorial erratum reported for RFC 7483 by Marcos Sanz). Added acknowledgements.
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.
03:
Added Implementation Status section (Section 6).
04:
Keepalive refresh.
05:
Added OpenRDAP implementation information to Section 6.
00:
Initial working group version.
01:
Added text to describe why the TILDE character was chosen as the separator character.
02:
Nit fixes. Added rdapConformance text, switched back to HYPHEN MINUS, and added IANA registration instructions per working group last call discussion. Updated suffix syntax reference from the IANA EPP ROID registry to RFC 5730 (which is what the IANA registry references).
03:
Shepherd writeup review updates to explain examples in Section 2.
04:
AD review update to clarify query path construction.
05:
IESG review update: object naming practice, revised an example to include multiple separator HYPHEN-MINUS characters, revised security considerations, revised IANA considerations, revised IANA registry description and registration procedure to add email address contact information.

Authors' Addresses

Scott Hollenbeck Verisign Labs 12061 Bluemont Way Reston, VA 20190 USA EMail: shollenbeck@verisign.com URI: http://www.verisignlabs.com/
Andrew Lee Newton American Registry for Internet Numbers PO Box 232290 Centreville, VA 20120 US EMail: andy@arin.net URI: http://www.arin.net