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Versions: (draft-loffredo-regext-rdap-reverse-search) 00 01 02 03 04

Registration Protocols Extensions                            M. Loffredo
Internet-Draft                                             M. Martinelli
Intended status: Standards Track                     IIT-CNR/Registro.it
Expires: November 19, 2020                                  May 18, 2020

  Registration Data Access Protocol (RDAP) Reverse search capabilities


   The Registration Data Access Protocol (RDAP) does not include query
   capabilities to find the list of domains related to a set of entities
   matching a given search pattern.  Even if such capabilities, commonly
   referred as reverse search, respond to some needs not yet readily
   fulfilled by the current Whois protocol, they have raised concerns
   from two perspectives: server processing impact and data privacy.
   Anyway, the impact of the reverse queries on RDAP servers processing
   is the same as the standard searches and it can be reduced by
   implementing policies to deal with large result sets, while data
   privacy risks can be prevented by RDAP access control functionality.
   In the RDAP context, an entity can be associated to any defined
   object class.  Therefore, a reverse search can be applied to other
   use cases than the classic domain-entity scenario.  This document
   describes an RDAP search query extension that allows clients to
   request a reverse search based on the relationship between an object
   and the associated entities.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   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
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 19, 2020.

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Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Conventions Used in This Document . . . . . . . . . . . .   4
   2.  RDAP Path Segment Specification . . . . . . . . . . . . . . .   4
   3.  Implementation Considerations . . . . . . . . . . . . . . . .   5
   4.  Implementation Status . . . . . . . . . . . . . . . . . . . .   6
     4.1.  IIT-CNR/Registro.it . . . . . . . . . . . . . . . . . . .   6
   5.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Appendix A.  Change Log . . . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   Reverse Whois is a service provided by many web applications that
   allow users to find domain names owned by an individual or a company
   starting from the owner's details, such as name and email.  Even if
   it has been considered useful for some legal purposes (e.g.
   uncovering trademark infringements, detecting cybercrime cases), its
   availability as a standardized Whois capability has been objected for
   two main reasons, which now don't seem to conflict with an RDAP

   The first objection has been caused by the potential risks of privacy
   violation.  However, TLDs community is considering a new generation
   of Registration Directory Services
   ([ICANN-RDS1],[ICANN-RDS2],[ICANN-RA]), which provide access to

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   sensitive data under some permissible purposes and according to
   adequate policies to enforce the requestor accreditation,
   authentication, authorization, and terms and conditions of data use.
   It is well known that such security policies are not implemented in
   Whois ([RFC3912]), while they are in RDAP ([RFC7481]).  Therefore,
   RDAP permits a reverse search implementation complying with privacy
   protection principles.

   Another objection to the implementation of a reverse search
   capability has been connected with its impact on server processing.
   Since RDAP supports search queries, the impact of both standard and
   reverse searches is equivalent and can be mitigated by servers
   adopting ad hoc strategies.  Furthermore, the reverse search is
   almost always performed by specifying an entity role (e.g.
   registrant, technical contact) and this can contribute to restricting
   the result set.

   Reverse searches, such as finding the list of domain names associated
   with contacts or nameservers may be useful to registrars as well.
   Usually, registries adopt out-of-band solutions to provide results to
   registrars asking for reverse searches on their domains.  Possible
   reasons for such requests are:

   o  the loss of synchronization between the registrar database and the
      registry database;

   o  the need for such data to perform massive EPP ([RFC5730]) updates
      (e.g. changing the contacts of a set of domains, etc.).

   Currently, RDAP does not provide any way for a client to search for
   the collection of domains associated with an entity ([RFC7482]).  A
   query (lookup or search) on domains can return the array of entities
   related to a domain with different roles (registrant, registrar,
   administrative, technical, reseller, etc.), but the reverse operation
   is not allowed.  Only reverse searches to find the collection of
   domains related to a nameserver (ldhName or ip) can be requested.
   Since an entity can be in relationship with any RDAP object
   ([RFC7483]), the availability of a reverse search can be common to
   all resource type path segments defined for search.

   The protocol described in this specification aims to extend the RDAP
   query capabilities to enable the reverse search based on the
   relationship between any object and the associated entities.  The
   extension is implemented by adding new path segments (i.e. search
   paths) and using a RESTful web service ([REST]).  The service is
   implemented using the Hypertext Transfer Protocol (HTTP) ([RFC7230])
   and the conventions described in RFC 7480 ([RFC7480]).

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1.1.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119].

2.  RDAP Path Segment Specification

   The new search paths are OPTIONAL extensions of those defined in RFC
   7482 ([RFC7482]).  A generic reverse search path is described by the

   {resource-type}/reverse/{role}?{property}=<search pattern>

   The path segments are defined as in the following:

   o  resource-type: it MUST be one of resource type path segments
      defined in Section 3.2 of RFC 7482 ([RFC7482]): "domains",
      "nameservers" or "entities";

   o  role: it MUST be one of the roles described in Section 10.2.4 of
      RFC 7483 ([RFC7483]).  For role independent reverse searches, the
      value "entity" MUST be used;

   o  property: it identifies the entity property to be used in matching
      the search pattern.  A pre-defined list of properties includes:
      fn, handle, email, city, country, cc.  The mapping between such
      properties and the RDAP fields is shown in Table 1.  Servers MAY
      implement additional properties to those defined in this document.

   Partial string matching is allowed as defined in section 4.1 of RFC
   7482 ([RFC7482]).

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   | Reverse search    | RDAP property      | RFC    | RFC    | RFC    |
   | property          |                    | 7483   | 6350   | 8605   |
   | handle            | handle             | 5.1.   |        |        |
   | fn                | vcard fn           |        | 6.2.1  |        |
   | email             | vcard email        |        | 6.4.2  |        |
   | city              | locality in vcard  |        | 6.3.1  |        |
   |                   | adr                |        |        |        |
   | country           | country name in    |        | 6.3.1  |        |
   |                   | vcard adr          |        |        |        |
   | cc                | country code in    |        |        | 3.1    |
   |                   | vcard adr          |        |        |        |

    Table 1: Mapping between the reverse search properties and the RDAP





               Figure 1: Examples of reverse search queries

   The "country" property can be used as an alternative to "cc" when
   RDAP servers don't include the vCard "cc" parameter ([RFC8605]) in
   their response.

3.  Implementation Considerations

   The implementation of the proposed extension is technically feasible.
   Both handle and fn are used as standard path segments to search for
   entities ([RFC7482]).  With regards to the other reverse search
   properties, namely email, city and country code, the impact of their
   usage on server processing is evaluated to be the same as other
   existing query capabilities (e.g. wildcard prefixed search pattern)
   so the risks to degrade the performance or to generate huge result
   sets can be mitigated by adopting the same policies (e.g. restricting
   the search functionality, limiting the rate of search requests
   according to the user profile, truncating and paging the results,
   returning partial responses).

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4.  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".

4.1.  IIT-CNR/Registro.it

      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.
      Level of Maturity: This is a "proof of concept" research
      Coverage: This implementation includes all of the features
      described in this specification.
      Contact Information: Mario Loffredo, mario.loffredo@iit.cnr.it

5.  Privacy Considerations

   The use of the capability described in this document MUST be
   compliant with the rules about privacy protection each RDAP provider
   is subject to.  Sensitive registration data MUST be protected and
   accessible for permissible purposes only.  Therefore, RDAP servers
   MUST provide reverse search only to those requestors who are
   authorized according to a lawful basis.  Some potential users of this
   capability include registrars searching for their own domains and
   operators in the exercise of an official authority or performing a

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   specific task in the public interest that is set out in a law.
   Another scenario consists of permitting reverse searches, which take
   into account only those entities that have previously given the
   explicit consent for publishing and processing their personal data.

6.  Security Considerations

   Security services required to provide controlled access to the
   operations specified in this document are described in RFC 7481

   The specification of the entity role within the reverse search path
   allows the RDAP servers to implement different authorization policies
   on a per-role basis.

7.  IANA Considerations

   This document has no actions for IANA.

8.  Acknowledgements

   The authors would like to acknowledge Tom Harrison, Scott Hollenbeck,
   Francisco Arias, Gustavo Lozano and Eduardo Alvarez for their
   contribution to 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,

   [RFC3912]  Daigle, L., "WHOIS Protocol Specification", RFC 3912,
              DOI 10.17487/RFC3912, September 2004,

   [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
              STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,

   [RFC6350]  Perreault, S., "vCard Format Specification", RFC 6350,
              DOI 10.17487/RFC6350, August 2011,

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   [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Message Syntax and Routing",
              RFC 7230, DOI 10.17487/RFC7230, June 2014,

   [RFC7480]  Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
              Registration Data Access Protocol (RDAP)", RFC 7480,
              DOI 10.17487/RFC7480, March 2015,

   [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,

   [RFC8605]  Hollenbeck, S. and R. Carney, "vCard Format Extensions:
              ICANN Extensions for the Registration Data Access Protocol
              (RDAP)", RFC 8605, DOI 10.17487/RFC8605, May 2019,

9.2.  Informative References

              Internet Corporation For Assigned Names and Numbers,
              "Registry Agreement", July 2017,

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              Internet Corporation For Assigned Names and Numbers,
              "Final Report from the Expert Working Group on gTLD
              Directory Services: A Next-Generation Registration
              Directory Service (RDS)", June 2014,

              Internet Corporation For Assigned Names and Numbers,
              "Final Issue Report on a Next-Generation gTLD RDS to
              Replace WHOIS", October 2015,

   [REST]     Fielding, R., "Architectural Styles and the Design of
              Network-based Software Architectures", 2000,

Appendix A.  Change Log

   00:  Initial working group version ported from draft-loffredo-regext-
   01:  Updated "Privacy Considerations" section.
   02:  Revised the text.
   03:  Refactored the query model.
   04:  Keepalive refresh.

Authors' Addresses

   Mario Loffredo
   Via Moruzzi,1
   Pisa  56124

   Email: mario.loffredo@iit.cnr.it
   URI:   http://www.iit.cnr.it

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   Maurizio Martinelli
   Via Moruzzi,1
   Pisa  56124

   Email: maurizio.martinelli@iit.cnr.it
   URI:   http://www.iit.cnr.it

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