Internet Engineering Task Force                           A. Newton, Ed.
Internet-Draft                                                      ARIN
Intended status: Informational                 C. Martinez-Cagnazzo, Ed.
Expires: January 21, 2017                                         LACNIC
                                                                 D. Shaw
                                                          T. Bruijnzeels
                                                                RIPE NCC
                                                             B. Ellacott
                                                           July 20, 2016

  RPKI Multiple "All Resources" Trust Anchors Applicability Statement


   This document provides an applicability statement for the use of
   multiple, over-claiming 'all resources' (0/0) RPKI certificate
   authorities (CA) certificates used as trust anchors (TAs) operated by
   the Regional Internet Registry community to help mitigate the risk of
   massive downstream invalidation in the case of transient registry

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 January 21, 2017.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   ( in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Requirements Language . . . . . . . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Applicability to reduce overclaiming possibilities  . . . . .   3
   4.  Normative References  . . . . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.  Introduction

   The RPKI is a hierarchical cryptologic system that uses X.509
   certificates to match and validate holdership of Internet number
   resources.  This validation follows the allocation change from IANA
   to an RIR, to an NIR or LIR, and ending with end users who make use
   of the address block.  Since these allocations can be
   cryptographically validated, this can then be tied to assertions made
   by the holder of those number resources.  As an improvement of this
   system, the RPKI was updated to add validation of origin routing
   announcements via ROAs.  These ROAs can then be independently and
   cryptographically validated by third parties to assure themselves
   that the origin of the announcement as seen in the actual routing
   system is valid.

   Since this system is envisioned to be used by network operators and
   ISPs to determine their routing decisions, there is a goal to be 100%
   correct 100% of the time.  This goal could be achieved if the system
   was contained in a static environment where there is little or no
   movement of holdership changes from one organization to another of
   number resources.  Unfortunately, this state cannot be achieved
   today, as movement of number resouces from from organization to
   organization is becoming common largely due to IPv4 scarcity.

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   Unfortunately, this state of 100% correctness at all times is
   infeasible in a model where separate entities are operating
   independently, yet rely critically on each others' perfect
   synchronisation at all times.

   Because the current validation mechanism is all-or-nothing, any
   inconsistency at all at a high apex CA has the potential to
   invalidate a large number of additional Internet Number Resources.
   The higher the apex, and the larger the total set of INRs maintained
   by the CA, the greater the impact of even a small inconsistency.

   As resources do change at high apex CAs for a variety of reasons, the
   likelihood of a small inconsistency is non-zero.  And the likelihood
   of a transitional inconsistency is moderate.  Due to the distributed
   nature of the RPKI repository mechanism, even if all CAs were able to
   operate in perfect synchronicity at all times, there is a reasonable
   likelihood that a given validating client may witness a temporarily
   inconsistent state of the system as a whole.  A risk of wide-spread
   invalidity therefore exists as a very high impact and moderate
   likelihood event.

   This brittleness in the RPKI validation rules has been identified and
   presented by the current RPKI TA operators to the IETF.  A solution
   has also been proposed
   ([I-D.ietf-sidr-rpki-validation-reconsidered]), a solution that would
   allow for accidental over-claiming only to invalidate the resource
   that is incorrectly listed and allow the remaining to continue to be
   valid.  As the implementation and deployment of solutions to this
   problem will occur according to timelines outside the control of the
   current TA operators, the workaround proposed in the present draft
   provides an acceptable trade-off.

3.  Applicability to reduce overclaiming possibilities

   The consequences of an RIR over-claiming are grave given that every
   ISP within their certificate would be invalidated.  If routing was to
   be reliant on RPKI at this point, all routes announced by those ISPs
   below the affected RIR certificate would cease to work.

   To mitigate risk and alleviate this threat, each RIR will move from a
   Trust Anchor that reflects their current holdings only, to one that
   reflects all holdings (e.g. 0/0).  This will then ensure that over-
   claiming can not occur at a RIR level when dealing with transfers
   from one RIR to another.  RPKI validators will not see the five Trust
   anchors from the RIRs as over-claiming and validation can proceed

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   For those who may want to audit the RIRs to ensure that RIRs are not
   allocating the same IP addresses in separate regions, this can be
   done by matching the inventory of each RIR ([NROSTATS]) that is
   provided by the RIRs with the certificates issued by the RIRs within
   the RPKI.

   Note that there will be minor changes from time to time to account
   for movements from IP address holdings that are in flight from one
   RIR to another and that transient overlaps can, and probably will,
   occur as inter-RIR transfers become more and more common.

4.  Normative References

              Huston, G., Michaelson, G., Martinez, C., Bruijnzeels, T.,
              Newton, A., and D. Shaw, "RPKI Validation Reconsidered",
              draft-ietf-sidr-rpki-validation-reconsidered-06 (work in
              progress), July 2016.

              "NRO Extended Stats File", July 2016,

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,

Authors' Addresses

   Andrew Newton (editor)
   Chantilly  VA
   United States


   Carlos Martinez-Cagnazzo (editor)


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   Daniel Shaw
   Cybercity Ebene
   Republic of Mauritius


   Tim Bruijnzeels


   Byron Ellacott


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