Internet Engineering Task Force                         C. Martinez, Ed.
Internet-Draft                                            A. Servin, Ed.
Intended status: Informational                                    LACNIC
Expires: August 5, 2013 January 16, 2014                                   L. Zhou, Ed.
                                                                   CNNIC
                                                                D. Gomez
                                                                 G. Rada
                                                                  LACNIC
                                                                Feb
                                                           July 15, 2013

       Redirection Service for Registration Data Access Protocol
                     draft-ietf-weirds-redirects-01
                     draft-ietf-weirds-redirects-02

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 implies 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 RESTful WHOIS RDAP queries.  This
   service allows users clients to query a single WHOIS RDAP service and be redirected to the expect
   either an authoritative registry. 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 August 5, 2013. January 16, 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 RESTful WHOIS RDAP Queries  . . . . . . . . . . . . 4
     2.3.  A Single RESTful WHOIS trough Joint RDAP Tree through HTTP Redirection  . . . . . . . . 5
     2.4.  The Redirection Table. The Bootstrap Problem. . . . . . . . 7
     2.5.  Loops in Redirection  . . . . . . . . . . . . . . . . . . .  6 8
   3.  Service Discovery . . . . . . . . . . . . . . . . . . . . . .  9 . 8
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  9 . 8
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8
     5.1.  Normative References  . . . . . . . . . . . . . . . . . . . 10 8
     5.2.  Informative References  . . . . . . . . . . . . . . . . . . 10 8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 10 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 RESTful approach to WHOIS services RDAP protocol (draft-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 a RESTful WHOIS 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 verb is and HEAD 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 RESTful WHOIS RDAP Queries

   Each RESTful WHOIS 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 RESTful WHOIS RDAP server could provide a 301 MOVED
   PERMANENTLY redirect answer pointing to an URL hosted on a different RESTful WHOIS
   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 Single RESTful WHOIS trough 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 will can be redirected to a
   redirection-only RESTful WHOIS redirection-
   only RDAP server which could provide the authoritative WHOIS 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] Until now,
   there are some alternative solutions for the bootstrapping problem of
   redirect server, such as using DNS SRV or NAPTR records.  But [I-D.ietf-weirds-rdap-query].  We will
   call this
   problem is out of scope 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 this document and a better name, we will be discussed
   further in call this data source the
   "redirection table".

   Assuming the redirector has access to a redirection table, the
   following drafts 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 WEIRDS working group. redirect table")
                 }
             }

                         Redirector state machine

                                 Figure 1

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

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

                         RESTful

                          RDAP Joint WHOIS Tree.

                                 Figure 1

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

                     Querying WHOIS data for 23.1.1.1

                                 Figure 2 3

2.4.  Loops in  The Redirection

   When Table. The Bootstrap Problem.

   For the redirection is used there is always table lookup function, the risk that bogus user-
   agents and applications or malicious user redirector can create loops that in
   turn may become Denial either
   have pre-populated local table or have access to a service provided
   by some form of Service attacks.

   To minimize directory service.  How either this local table or
   directory service is fed is known as the risk "bootstrapping problem".

   The bootstrapping problem was initially declared out of scope of loops created by bogus applications and user-
   agents operators MAY use the mechanism shown in Section 3.1.
   WEIRDS WG.  However, this mechanism could be forged the problem has been discussed and bypassed by malicious
   users possibly creating a Denial several
   proposals have been presented (**insert references to Marc's docs**).
   Some of Service attack against the
   operator.  To avoid completely these solutions contemplate using the risk of DoS operators should use
   other methods such DNS tree as rate-limit and authentication that are outside directory
   service while others, for the scope specific case of this document.

   One of the challenges by number resources,
   contemplate using redirection is loop avoidance.  Even
   though recommendation from REFERENCE** indicates that user-agents
   should have IANA's XML registry files as seed files for a mechanism to break loops, due local
   redirection table.

   The bootstrapping problem needs to sometimes not
   carefully coded user-agents be addressed differently for names
   and other applications or due to
   malicious users' activities loops that could end up in a Denial numbers.  Not only the coount of
   Service potential authoritative RDAP
   servers for the RESTful WHOIS operator.

   A simple scenario that creates a loop names (huge) is shown in Figure 3.  A user
   request (1) an object vastly different from Operator 1; Operator 1 do not have the
   object but it has a pointer that Operator 2 has it, so it redirects
   (2) the user to Operator 2; user request Object X to Operator 2 (3);
   Operator 2 does not have the object either object count for
   numbers (currently 5), but it has a
   pointer that Operator 1 has it, so it redirects (4) the user to
   Operator 1; it creates a loop (5).

        +--------------+                     +--------------+
        |              |                     |              |
        |  Operator A  |                     |  Operator B  |
        |              |                     |              |
        +---^-----+----+                     +----^----.----+
   1)       |     |  2)                3)         |    | 4) Redirect
   Request  |     |  Redirect          Request    |    |    to
   Object X |     |  to                Object X   |    |  Operator A
            |     |  Operator B                   |    |
            |     |____________    _______________|    |
            |_______________  |    |  _________________|
                           |  |    |  |
                         +--------------+
                         |              |      5) Loop
                         |     User     |
                         |              |
                         +--------------+

                               A simple loop

                                 Figure 3

   The loop described could be avoided by simple forbidding redirecting
   a response when the query has been originated by a redirect.  However
   this solution only allows one redirection.  A less restrictive
   approach forbidding redirection to only when also the destination is relationships between the
   same than RIRs
   and name registries and registrars are very different.

   For the originator number resources case, parsing IANA's XML registries for the redirection does not work either as
   shown in Figure 4.

            +--------------+                   +--------------+
            |              |                   |              |
            |  Operator A  |                   |  Operator B  |
            |              |                   |              |
            +---^-----+----+                   +----^----+----+
       1)       |     |  2)                3)       |    | 4)Redirect
       Request  |     |  Redirect          Request  |    |   to
       Object X |     |  to                Object X |    |  Operator C
                |     |  Operator B                 |    |
                |     |____________    _____________|    |
                |_______________  |    |  _______________|
                               |  |    |  |
                             +---\/------\/-+
          7) Loop            |              |
                             |     User     |
                             |              |
                             +---^-----+----+
             6) Redirect         |     |    5)
                to Operator A    |     |     Request
                                 |     |     Object X
                             +--------\/----+
                             |              |
                             |  Operator C  |
                             |              |
                             +--------------+

                           A more complex loop.

                                 Figure 4

   In the scenario depicted in Figure 4 the user request object X from
   Operator A which redirects him/her to Operator B which in turn
   redirects the user to Operator C. Operator C then redirects the user
   back to Operator A again creating a loop.

   To avoid loops created by not well-programmed user-agents or
   applications when redirecting operators MAY append or modify a
   special URI indicating that a redirection
   IPv4, IPv6 and how many times it has
   been done.  The format of the URI is described as follows.

   When Autonomous System Numbers (**insert refs**) allows a RESTful WHOIS operator redirects
   simple way for building a user to retrieve an object
   from another operator, the operator making the redirection operator
   MAY append or modify a special URI.

   When using an URI to indicate redirection, the URI MUST have the
   following structure:

   /redirect/[step]
   Where [step] is a consecutive counter that MUST be increased by every
   operator when the URI is encountered table.

2.5.  Loops in a query object. Redirection

   When an operator is redirecting a query for the first time it MAY
   append the redirection URI to the original URL.  If the redirection
   URI is used, it MUST use the format previously described and it MUST
   set "step" equal to 1.  For example, the URL
   "http://whois.lacnic.net/restfulwhois/ip/200.7.84.0/24" would be
   replaced by

   "http://whois.example.com/restfulwhois/ip/200.7.84.0/24/redirect/1"

   If an operator receives a request with the redirect URI it first
   SHOULD check if "step" used there is shorter that the defined threshold.  If it
   does the operator SHOULD strip it and process the query.  If the
   query requires further redirection the operator MAY use always the
   redirection URI and it MUST increase "step" in one.

   Operators risk that support the redirect URI MUST never bogus user-
   agents and applications or malicious user can create a new
   redirect loops that contain a step value greater in
   turn may become Denial of Service attacks.

   Commonly used user agents (including HTTP libraries) have loop
   detection features that their locally set
   threshold.  However if the operator has an authoritative response to
   the agent it MUST respond regardless to the threshold value. are deemed sufficient for breaking loops in
   RDAP.

3.  Service Discovery

   TBD

4.  Security Considerations

   Firstly, redirect server settings cannot be modified by someone other
   than the user validated by the redirection server.

   Secondly, insure the redirection URL data must not be able to modify
   URL in data transmission process.  Such as
   http://www.labs.lacnic.net/restwhois/rwhois_redir/ip/23.1.1.1 cannot
   be modified to
   http://www.labs.somenic.net/restwhois/rwhois_redir/ip/23.1.1.1.

   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.  References

5.1.  Normative References

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

5.2.  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