Internet Engineering Task Force                         C. Martinez, Ed.
Internet-Draft                                            A. Servin, Ed.                                                    LACNIC
Intended status: Informational                                    LACNIC
Expires: January 16, 2014                              L. Zhou, Ed.
Expires: August 18, 2014                                           CNNIC
                                                                D. Gomez
                                                                 G. Rada
                                                                  LACNIC
                                                           July 15, 2013
                                                       February 14, 2014

       Redirection Service for Registration Data Access Protocol
                     draft-ietf-weirds-redirects-02
                     draft-ietf-weirds-redirects-03

Abstract

   The traditional WHOIS protocol has several important shortcomings,
   and over the past few years several approaches to a better
   Registration Data Access Protocol (RDAP) have been discussed and
   proposed.

   It is worth noting that the term WHOIS is sometimes used
   interchangeably to mean either (a) the registration data itself or
   (b) the protocol used to access registration data

   Among these shortcomings, different registries operate different
   WHOIS services.  For users this means that several WHOIS queries to
   different registries may be necessary in order to obtain data for a
   given resource.

   This document describes a redirection service for RDAP queries.  This
   service allows clients to query a single RDAP service and expect
   either an authoritative answer or a redirection hint pointing to
   another, possibly authoritative, RDAP server.

   The solution implemented proposed here applies to Regional Internet
   Registries(RIRs) and Domain Name Registries(DNRs).

Status of this Memo

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   This Internet-Draft will expire on January 16, August 18, 2014.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 4
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . . . 4
   2.  Proposed Approach . . . . . . . . . . . . . . . . . . . . . . . 4
     2.1.  The REST Approach to Web Services . . . . . . . . . . . . . 4
     2.2.  Query Redirection for RDAP Queries  . . . . . . . . . . . . 4
     2.3.  A Joint RDAP Tree through HTTP Redirection  . . . . . . . . 5
     2.4.  The Redirection Table. The Bootstrap Problem. . . . . . . . 7
     2.5.  Loops in Redirection  . . . . . . . . . . . . . . . . . . . 8
   3.
     2.6.  Service Discovery . . . . . . . . . . . . . . . . . . . . . . . 8
   4.
     2.7.  Security Considerations . . . . . . . . . . . . . . . . . . . . 8
   5.
   3.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 8
     5.1.
     3.1.  Normative References  . . . . . . . . . . . . . . . . . . . 8
     5.2.
     3.2.  Informative References  . . . . . . . . . . . . . . . . . . 8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 9

1.  Introduction

   A user interested in obtaining registration information for a given
   number or domain resource normally uses the WHOIS service provided by
   the RIRs and DNRs.

   In order to avoid having to query several databases until obtaining
   an answer, some approaches have been discussed and implemented in the
   past, most notably the Joint WHOIS [lacnic-joint-whois] initiative.
   However, among other shortcomings, Joint WHOIS is implemented using
   proxies and server-side referrals.

   The RDAP protocol (draft-ietf-weirds-using-http
   [I-D.ietf-weirds-using-http]) [I-D.ietf-weirds-
   using-http]) makes it comparatively easy to implement client-side
   redirects based on normal HTTP 1.1 semantics and behavior.

   The goal of this I-D is to describe an implementation of an RDAP
   redirection service and to encourage discussion on the topic of
   redirects in this problem domain.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.  Proposed Approach

2.1.  The REST Approach to Web Services

   While a full introduction to REST and RESTful <http://www.rest.org> interfaces is out of
   the scope of this document it is important to note that these
   interfaces employ the verbs defined in HTTP (GET, POST, HEAD, DELETE)
   and HTTP response codes to signal the semantics and outcomes of an
   operation.

   As WHOIS is a read-only service only the GET and HEAD verbS verbs are
   usually implemented.

   HTTP status codes provide signaling for errors and other conditions,
   including the concept of "client-side redirection" as outlined below.

2.2.  Query Redirection for RDAP Queries

   Each RDAP server should answer directly only those queries for which
   it is authoritative.  In this case, being authoritative equals
   "having direct access to a given registry database".

   For all other queries, a RDAP server could provide a 301 MOVED
   PERMANENTLY redirect answer pointing to an URL hosted on a different
   RDAP server.

   As all requests are to be performed employing HTTP GETs, a user agent
   can transparently follow the HTTP 30x redirection hints ([RFC2616])
   until obtaining a non-error answer (HTTP 20x) or an unrecoverable
   error condition (HTTP 40x or 50x).

2.3.  A Joint RDAP Tree through HTTP Redirection

   When a registry does not have the authoritative answers to the user
   agent's query, user agent's query can be redirected to a redirection-
   only RDAP server which could provide the authoritative RDAP server
   address.

   The redirect server is responsible for tracking and returning the
   authoritative sources for IP, AS, domain name, name server or entity
   queries.  All the query format are described in the
   draft-ietf-weirds-rdap-query [I-D.ietf-weirds-rdap-query].  We will
   call this redirect server "the redirector".

   The redirect server needs access to data sources that, given a
   queried resource, provide a pointer to the authoritative RDAP server.
   For lack of a better name, we will call this data source the
   "redirection table".

   Assuming the redirector has access to a redirection table, the
   following pseudo code describes its expected behaviour:

              while(true) {
                  query = read_query_from_network()
                  auth_rdap_svr = redirect_table_lookup (query.resource)
                  if (auth_rdap_svr != null) {
                       write_http_301(auth_rdap_svr)
                  } else {
                      write_http_404("resource not in redirect table")
                  }
              }

                         Redirector state machine

                                 Figure 1

   Figure 2 shows the general scheme of a single RDAP Redirection
   Service serving three different RIRs standalone RDAPs while providing
   a seamless query interface to clients.

                           ......................
                           |                    |
                           |  RDAP REDIRECTOR   |
                           |                    |
                           `....................'
                                 _,  |   ._
                              ,,'    |     `.
                           ,-'       |       `-.
                        ,-'          |          `._
                    _,-'             |             `.
                  .'                 |               `-.
             +-----------Y    +-------------.    ,------------b
             |   LACNIC  |    |  RIPE-NCC   |    |   ARIN     |
             |           |    |             |    |            |
             '`'''''''''''    '`''''''''''''     '`''''''''''''

                          RDAP Joint WHOIS Tree.

                                 Figure 2

   Figure 3 shows how HTTP 301 redirection hints guide a client looking
   for registration data for the IPv4 address 23.1.1.1 (administered by
   ARIN) from LACNIC's WHOIS, the redirector and finally ARIN's WHOIS.

                          LACNIC      REDIRECTOR       ARIN
                          RDAP        RDAP             RDAP
                            .           .               .
        Q: 23.1.1.1? ---->  |           |               |
                            |           |               |
          <-- HTTP 301 ---  |           |               |
         ('Try Redirector') |           |               |
                            |           |               |
                            |           |               |
        Q: 23.1.1.1? -----------------> |               |
                                        |               |
           <---------- HTTP 301 --------|               |
                  ('Try ARIN RDAP')     |               |
                                        |               |
                                                        |
          Q: 23.1.1.1? -------------------------------> |
                                                        |
             <---------- HTTP 200 --------------------- |
                    (WHOIS response is returned)        |
                                                        |
                                                        |
                                                        .

                     Querying WHOIS data for 23.1.1.1

                                 Figure 3

2.4.  The Redirection Table. The Bootstrap Problem.

   For the redirection table lookup function, the redirector can either
   have pre-populated local table or have access to a service provided
   by some form of directory service.  How either this local table or
   directory service is fed is known as the "bootstrapping problem".

   The bootstrapping problem was initially declared out of scope of the
   WEIRDS WG.  However, the problem has been discussed and several
   proposals have been presented (**insert references to Marc's docs**).
   Some of these solutions contemplate using the DNS tree as directory
   service while others, for the specific case of number resources,
   contemplate using IANA's XML registry files as seed files for a local
   redirection table.

   The bootstrapping problem needs to be addressed differently for names
   and numbers.  Not only numbers as the coount of potential authoritative RDAP servers for
   names (huge) is vastly different from the count for numbers
   (currently 5), but also the relationships between the RIRs
   and name registries and registrars are very different.

   For the number resources case, parsing IANA's XML registries for
   IPv4, IPv6 and Autonomous System Numbers (**insert refs**) allows a
   simple way for building a redirection table. 5).

2.5.  Loops in Redirection

   When redirection is used there is always the risk that bogus user-
   agents and applications or malicious user can create loops that in
   turn may become Denial of Service attacks.

   Commonly used user agents (including HTTP libraries) have loop
   detection features that are deemed sufficient for breaking loops in
   RDAP.

3.

2.6.  Service Discovery

   TBD

4.

2.7.  Security Considerations

   HTTP 30x-based redirection could offer an attack vector for a Man-in-
   the-Middle type of attack, where the adversary modifies the
   redirection URL offered by the server to the client.

   For example, an attacker able to modify HTTP traffic could modify the
   redirect URL from
   http://www.labs.lacnic.net/restwhois/rwhois_redir/ip/23.1.1.1 and
   change it into
   http://www.labs.somenic.net/restwhois/rwhois_redir/ip/23.1.1.1, where
   bogus information can be offered to the client.

   This particular type of attack can be prevented by usint HTTPS for
   the RDAP connection.  However, this certainly places a load burden
   upon the servers.

   While security practices are outside the scope of this document, the
   authors believe it is important to identify such problematic use
   cases to any DNR or RIR that may implement the redirection WHOIS
   service.

5.

3.  References

5.1.

3.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

5.2.

3.2.  Informative References

   [I-D.ietf-weirds-rdap-query]
              Newton, A. and S. Hollenbeck, "Registration Data Access
              Protocol Query Format", draft-ietf-weirds-rdap-query-02
              (work in progress), December 2012.

   [I-D.ietf-weirds-using-http]
              Newton, A., Ellacott, B., and N. Kong, "Using the
              Registration Data Access Protocol (RDAP) with HTTP",
              draft-ietf-weirds-using-http-01 (work in progress),
              December 2012.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.

   [lacnic-joint-whois]
              LACNIC, "Joint WHOIS", 2005, <ftp://
              anonymous@ftp.registro.br/pub/gter/gter20/
              02-jwhois-lacnic.pdf>.

Authors' Addresses

   Carlos M. Martinez (editor)
   LACNIC
   Rambla Mexico 6125
   Montevideo,   11400
   Uruguay

   Phone: +598-2604-2222
   Email: carlos@lacnic.net

   Arturo L. Servin (editor)
   LACNIC
   Rambla Mexico 6125
   Montevideo,   11400
   Uruguay

   Phone: +598-2604-2222
   Email: aservin@lacnic.net

   Linlin Zhou (editor)
   CNNIC
   No. 4, South 4th Steet, Zhongguancun
   Beijing,   100190
   China

   Phone: +8610-5881-2677
   Email: zhoulinlin@cnnic.cn
   Dario Gomez
   LACNIC
   Rambla Mexico 6125
   Montevideo,   11400
   Uruguay

   Phone: +598-2604-2222
   Email: dario@lacnic.net
   Gerardo Rada
   LACNIC
   Rambla Mexico 6125
   Montevideo,   11400
   Uruguay

   Phone: +598-2604-2222
   Email: gerardo@lacnic.net