Internet DRAFT - draft-dseomn-sidr-slurm

draft-dseomn-sidr-slurm







Secure Inter-Domain Routing                                D. Mandelberg
Internet-Draft                                          BBN Technologies
Intended status: Best Current Practice                      May 13, 2015
Expires: November 14, 2015


   Simplified Local internet nUmber Resource Management with the RPKI
                       draft-dseomn-sidr-slurm-02

Abstract

   The Resource Public Key Infrastructure (RPKI) is a global
   authorization infrastructure that allows the holder of Internet
   Number Resources (INRs) to make verifiable statements about those
   resources.  Network operators, e.g., Internet Service Providers
   (ISPs), can use the RPKI to validate BGP route origination
   assertions.  In the future, ISPs also will be able to use the RPKI to
   validate the path of a BGP route.  Some ISPs locally use BGP with
   private address space or private AS numbers (see RFC6890).  These
   local BGP routes cannot be verified by the global RPKI, and SHOULD be
   considered invalid based on the global RPKI (see RFC6491).  The
   mechanisms described below provide ISPs with a way to make local
   assertions about private (reserved) INRs while using the RPKI's
   assertions about all other INRs.

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 http://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 14, 2015.

Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





Mandelberg              Expires November 14, 2015               [Page 1]

Internet-Draft                    SLURM                         May 2015


   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://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.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Validation Output Filtering . . . . . . . . . . . . . . . . .   4
   3.  Locally Adding Assertions . . . . . . . . . . . . . . . . . .   4
   4.  Configuring SLURM . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Combining Mechanisms  . . . . . . . . . . . . . . . . . . . .   7
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     9.1.  Informative References  . . . . . . . . . . . . . . . . .   8
     9.2.  Normative References  . . . . . . . . . . . . . . . . . .   9
   Appendix A.  Example SLURM File . . . . . . . . . . . . . . . . .  10
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   The Resource Public Key Infrastructure (RPKI) is a global
   authorization infrastructure that allows the holder of Internet
   Number Resources (INRs) to make verifiable statements about those
   resources.  For example, the holder of a block of IP(v4 or v6)
   addresses can issue a Route Origination Authorization (ROA) [RFC6482]
   to authorize an Autonomous System (AS) to originate routes for that
   block.

   Internet Service Providers (ISPs) can then use the RPKI to validate
   BGP routes.  (Validation of the origin of a route is described in
   [RFC6483], and validation of the path of a route is described in
   [I-D.ietf-sidr-bgpsec-overview].)  However, some ISPs locally use BGP
   with private address space ([RFC1918], [RFC4193], [RFC6598]) or
   private AS numbers ([RFC1930], [RFC6996]).  These local BGP routes
   cannot be verified by the global RPKI, and SHOULD be considered
   invalid when using the RPKI.  For example, [RFC6491] recommends the
   creation of ROAs that would invalidate routes for reserved and
   unallocated address space.




Mandelberg              Expires November 14, 2015               [Page 2]

Internet-Draft                    SLURM                         May 2015


   This document specifies two new mechanisms to enable ISPs to make
   local assertions about some INRs while using the RPKI's assertions
   about all other INRs.  These mechanisms support the second and third
   use cases in [I-D.ietf-sidr-lta-use-cases].  The second use case
   describes use of [RFC1918] addresses or use of public address space
   not allocated to the ISP that is using it.  The third use case
   describes a situation in which an ISP publishes a variant of the RPKI
   hierarchy (for its customers).  In this variant some prefixes and/or
   AS numbers are different from what the RPKI repository system
   presents to the general ISP population.  The result is that routes
   for consumers of this variant hierarchy will be re-directed (via
   routing).

   Both mechanisms are specified in terms of abstract sets of
   assertions.  For Origin Validation [RFC6483], an assertion is a tuple
   of {IP prefix, prefix length, maximum length, AS number} as used by
   rpki-rtr version 0 [RFC6810] and version 1
   [I-D.ietf-sidr-rpki-rtr-rfc6810-bis].  For BGPsec
   [I-D.ietf-sidr-bgpsec-overview], an assertion is a tuple of {AS
   number, subject key identifier, router public key} as used by rpki-
   rtr version 1.  Output Filtering, described in Section 2, filters out
   any assertions by the RPKI about locally reserved INRs.  Locally
   Adding Assertions, described in Section 3, adds local assertions
   about locally reserved INRs.  The combination of both mechanisms is
   described in Section 5.

   To ensure local consistency, the effect of SLURM MUST be atomic.
   That is, the output of the relying party must be either the same as
   if SLURM were not used, or it must reflect the entire SLURM
   configuration.  For an example of why this is required, consider the
   case of two local routes for the same prefix but different origin AS
   numbers.  Both routes are configured with Locally Adding Assertions.
   If neither addition occurs, then both routes could be in the unknown
   state [RFC6483].  If both additions occur then both routes would be
   in the valid state.  However, if one addition occurs and the other
   does not, then one could be invalid while the other is valid.

   In general, the primary output of an RPKI relying party is the data
   it sends to routers over the rpki-rtr protocol.  The rpki-rtr
   protocol enables routers to query a relying party for all assertions
   it knows about (Reset Query) or for an update of only the changes in
   assertions (Serial Query).  The mechanisms specified in this document
   are to be applied to the result set for a Reset Query, and to both
   the old and new sets that are compared for a Serial Query.  Relying
   party software MAY modify other forms of output in comparable ways,
   but that is outside the scope of this document.





Mandelberg              Expires November 14, 2015               [Page 3]

Internet-Draft                    SLURM                         May 2015


   This document is intended to supersede [I-D.ietf-sidr-ltamgmt] while
   focusing only on local management of private INRs.  Another draft
   [I-D.kent-sidr-suspenders] focuses on the other aspects of local
   management.

1.1.  Terminology

   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 [RFC2119].

2.  Validation Output Filtering

   To prevent the global RPKI from affecting routes with locally
   reserved INRs, a relying party may be locally configured with a list
   of IP prefixes and/or AS numbers that are used locally, and taken
   from reserved INR spaces.  Any Origin Validation assertions where the
   IP prefix is equal to or subsumed by a locally reserved IP prefix,
   are removed from the relying party's output.  Any Origin Validation
   assertions where the IP prefix contains a locally reserved IP prefix
   are removed; the relying party software SHOULD issue a warning when
   this action is taken.  (Note that an Origin Validation assertion is
   not removed due to its AS number matching a locally reserved AS
   number.)  Any BGPsec assertion where the AS number is equal to a
   locally reserved AS number is removed from the relying party's
   output.

3.  Locally Adding Assertions

   Each relying party is locally configured with a (possibly empty) list
   of assertions.  This list is added to the relying party's output.

4.  Configuring SLURM

   Relying party software SHOULD support the following configuration
   format for Validation Output Filtering and Locally Adding Assertions.
   The format is defined using the Augmented Backus-Naur Form (ABNF)
   notation and core rules from [RFC5234] and the rules <IPv4address>
   and <IPv6address> from Appendix A of [RFC3986].  See Appendix A for
   an example SLURM file.

   A SLURM configuration file, <SLURMFile>, consists of a head and a
   body.  The head identifies the file as a SLURM configuration file,
   specifies the version of SLURM for which the file was written, and
   optionally contains other information described below.  The body
   contains the configuration for Validation Output Filtering and
   Locally Adding Assertions.




Mandelberg              Expires November 14, 2015               [Page 4]

Internet-Draft                    SLURM                         May 2015


      SLURMFile = head body

      head = firstLine *(commentLine / headLine)

      body = *(commentLine / bodyLine)

      firstLine = %x53.4c.55.52.4d SP "1.0" EOL ; "SLURM 1.0"

      commentLine = *WSP [comment] EOL

      headLine = *WSP headCommand [ 1*WSP [comment] ] EOL

      bodyLine = *WSP bodyCommand [ 1*WSP [comment] ] EOL

      comment = "#" *(VCHAR / WSP)

      EOL = CRLF / LF

   The head may specify a target.  If present, the target string
   identifies the environment in which the SLURM file is intended to be
   used.  The meaning of the target string, if any, is determined by the
   user.  If a target is present, a relying party SHOULD verify that
   that the target is an acceptable value, and reject the SLURM file if
   the target is not acceptable.  For example, the relying party could
   be configured to accept SLURM files only if they do not specify a
   target, have a target value of "hostname=rpki.example.com", or have a
   target value of "as=65536".  If more than one target line is present,
   all targets must be acceptable to the RP.

      headCommand = target

      target =
         %x74.61.72.67.65.74 1*WSP ; "target"
         1*VCHAR

   The body contains zero or more configuration lines for Validation
   Output Filtering and Locally Adding Assertions.  Each <del> command
   specifies an INR to use for Validation Output Filtering.  Each <add>
   command specifies an assertion to use for Locally Adding Assertions.

      bodyCommand = add / del

      add =
         %x61.64.64 1*WSP ; "add"
         addItem

      del =
         %x64.65.6c 1*WSP ; "del"



Mandelberg              Expires November 14, 2015               [Page 5]

Internet-Draft                    SLURM                         May 2015


         delItem

      addItem = addItemPrefixAS / addItemASKey

      ; Add a mapping from a prefix and max length to an AS number.
      addItemPrefixAS =
         %x6f.72.69.67.69.6e.61.74.69.6f.6e 1*WSP ; "origination"
         IPprefixMaxLen 1*WSP
         ASnum

      ; Add a mapping from an AS number to a router public key.
      addItemASKey =
         %x62.67.70.73.65.63 1*WSP ; "bgpsec"
         ASnum 1*WSP
         RouterSKI 1*WSP
         RouterPubKey

      delItem = delItemPrefix / delItemAS

      ; Filter prefix-AS mappings, using the given prefix
      delItemPrefix =
         %x6f.72.69.67.69.6e.61.74.69.6f.6e 1*WSP ; "origination"
         IPprefix

      ; Filter AS-key mappings for the given AS
      delItemAS =
         %x62.67.70.73.65.63 1*WSP ; "bgpsec"
         ASnum

      IPprefix = IPv4prefix / IPv6prefix

      IPprefixMaxLen = IPv4prefixMaxLen / IPv6prefixMaxLen

      IPv4prefix = IPv4address "/" 1*2DIGIT
      IPv6prefix = IPv6address "/" 1*3DIGIT

      ; In the following two rules, if the maximum length component is
      ; missing, it is treated as equal to the prefix length.
      IPv4prefixMaxLen = IPv4prefix ["-" 1*2DIGIT]
      IPv6prefixMaxLen = IPv6prefix ["-" 1*3DIGIT]

      ASnum = 1*DIGIT

      ; This is the Base64 [RFC4648] encoding of a router certificate's
      ; Subject Key Identifer, as described in
      ; [I-D.ietf-sidr-bgpsec-pki-profiles] and [RFC6487]. This is the
      ; value of the ASN.1 OCTET STRING without the ASN.1 tag or length
      ; fields.



Mandelberg              Expires November 14, 2015               [Page 6]

Internet-Draft                    SLURM                         May 2015


      RouterSKI = Base64

      ; This is the Base64 [RFC4648] encoding of a router public key's
      ; subjectPublicKeyInfo value, as described in
      ; [I-D.ietf-sidr-bgpsec-algs]. This is the full ASN.1 DER encoding
      ; of the subjectPublicKeyInfo, including the ASN.1 tag and length
      ; values of the subjectPublicKeyInfo SEQUENCE.
      RouterPubKey = Base64

      Base64 = 1*(ALPHA / DIGIT / "+" / "/") 0*2"="

   An implementation MAY support the concurrent use of multiple SLURM
   files.  In this case, the resulting inputs to Validation Output
   Filtering and Locally Adding Assertions are the respective unions of
   the inputs from each file.  The typical use case for multiple files
   is when the files have distinct scopes.  For example, an organization
   may belong to two separate networks that use different private-use IP
   prefixes and AS numbers.  To detect conflict between multiple SLURM
   files, a relying party SHOULD issue a warning in the following cases:

   1.  There may be conflicting changes to Origin Validation assertions
       if there exists an IP address X and distinct SLURM files Y,Z such
       that X is contained by any prefix in any <addItemPrefixAS> or
       <delItemPrefix> in file Y and X is contained by any prefix in any
       <addItemPrefixAS> or <delItemPrefix> in file Z.

   2.  There may be conflicting changes to BGPsec assertions if there
       exists an AS number X and distinct SLURM files Y,Z such that X is
       used in any <addItemASKey> or <delItemAS> in file Y and X is used
       in any <addItemASKey> or <delItemAS> in file Z.

5.  Combining Mechanisms

   In the typical use case, a relying party uses both output filtering
   and locally added assertions.  In this case, the resulting assertions
   MUST be the same as if output filtering were performed before locally
   adding assertions.  I.e., locally added assertions MUST NOT be
   removed by output filtering.

   If a relying party chooses to use both SLURM and Suspenders
   [I-D.kent-sidr-suspenders], the SLURM mechanisms MUST be performed on
   the output of Suspenders.

6.  IANA Considerations

   TBD





Mandelberg              Expires November 14, 2015               [Page 7]

Internet-Draft                    SLURM                         May 2015


7.  Security Considerations

   The mechanisms described in this document provide a network operator
   with additional ways to control its own network while making use of
   RPKI data.  These mechanisms are applied only locally; they do not
   influence how other network operators interpret RPKI data.
   Nonetheless, care should be taken in how these mechanisms are
   employed.

8.  Acknowledgements

   The author would like to thank Stephen Kent for his guidance and
   detailed reviews of this document.  Thanks go to Wesley Wang for the
   idea behind the target command, to Declan Ma for the idea behind use
   of multiple SLURM files, and to Richard Hansen for his careful
   reviews.

9.  References

9.1.  Informative References

   [I-D.ietf-sidr-bgpsec-overview]
              Lepinski, M. and S. Turner, "An Overview of BGPsec",
              draft-ietf-sidr-bgpsec-overview-06 (work in progress),
              January 2015.

   [I-D.ietf-sidr-lta-use-cases]
              Bush, R., "RPKI Local Trust Anchor Use Cases", draft-ietf-
              sidr-lta-use-cases-02 (work in progress), December 2014.

   [I-D.ietf-sidr-ltamgmt]
              Reynolds, M., Kent, S., and M. Lepinski, "Local Trust
              Anchor Management for the Resource Public Key
              Infrastructure", draft-ietf-sidr-ltamgmt-08 (work in
              progress), April 2013.

   [I-D.ietf-sidr-rpki-rtr-rfc6810-bis]
              Bush, R. and R. Austein, "The Resource Public Key
              Infrastructure (RPKI) to Router Protocol", draft-ietf-
              sidr-rpki-rtr-rfc6810-bis-03 (work in progress), March
              2015.

   [I-D.kent-sidr-suspenders]
              Kent, S. and D. Mandelberg, "Suspenders: A Fail-safe
              Mechanism for the RPKI", draft-kent-sidr-suspenders-03
              (work in progress), April 2015.





Mandelberg              Expires November 14, 2015               [Page 8]

Internet-Draft                    SLURM                         May 2015


   [RFC1918]  Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
              E. Lear, "Address Allocation for Private Internets", BCP
              5, RFC 1918, February 1996.

   [RFC1930]  Hawkinson, J. and T. Bates, "Guidelines for creation,
              selection, and registration of an Autonomous System (AS)",
              BCP 6, RFC 1930, March 1996.

   [RFC4193]  Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
              Addresses", RFC 4193, October 2005.

   [RFC6482]  Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
              Origin Authorizations (ROAs)", RFC 6482, February 2012.

   [RFC6483]  Huston, G. and G. Michaelson, "Validation of Route
              Origination Using the Resource Certificate Public Key
              Infrastructure (PKI) and Route Origin Authorizations
              (ROAs)", RFC 6483, February 2012.

   [RFC6491]  Manderson, T., Vegoda, L., and S. Kent, "Resource Public
              Key Infrastructure (RPKI) Objects Issued by IANA", RFC
              6491, February 2012.

   [RFC6598]  Weil, J., Kuarsingh, V., Donley, C., Liljenstolpe, C., and
              M. Azinger, "IANA-Reserved IPv4 Prefix for Shared Address
              Space", BCP 153, RFC 6598, April 2012.

   [RFC6810]  Bush, R. and R. Austein, "The Resource Public Key
              Infrastructure (RPKI) to Router Protocol", RFC 6810,
              January 2013.

   [RFC6890]  Cotton, M., Vegoda, L., Bonica, R., and B. Haberman,
              "Special-Purpose IP Address Registries", BCP 153, RFC
              6890, April 2013.

   [RFC6996]  Mitchell, J., "Autonomous System (AS) Reservation for
              Private Use", BCP 6, RFC 6996, July 2013.

9.2.  Normative References

   [I-D.ietf-sidr-bgpsec-algs]
              Turner, S., "BGP Algorithms, Key Formats, & Signature
              Formats", draft-ietf-sidr-bgpsec-algs-09 (work in
              progress), January 2015.







Mandelberg              Expires November 14, 2015               [Page 9]

Internet-Draft                    SLURM                         May 2015


   [I-D.ietf-sidr-bgpsec-pki-profiles]
              Reynolds, M., Turner, S., and S. Kent, "A Profile for
              BGPSEC Router Certificates, Certificate Revocation Lists,
              and Certification Requests", draft-ietf-sidr-bgpsec-pki-
              profiles-10 (work in progress), January 2015.

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

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66, RFC
              3986, January 2005.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, October 2006.

   [RFC5234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234, January 2008.

   [RFC6487]  Huston, G., Michaelson, G., and R. Loomans, "A Profile for
              X.509 PKIX Resource Certificates", RFC 6487, February
              2012.

Appendix A.  Example SLURM File



























Mandelberg              Expires November 14, 2015              [Page 10]

Internet-Draft                    SLURM                         May 2015


   SLURM 1.0

   # This file is only intended to be used on a relying party running
   # on rpki.example.com.
   target hostname=rpki.example.com # this is a comment

   # Reserve IP prefixes for local use.
   del origination 10.0.0.0/24
   del origination fd0b:dd1d:2dcc::/48

   # Reserve AS numbers for local use.
   del bgpsec 64512
   del bgpsec 64513

   # Allow either 64512 or 64513 to originate routes to 10.0.0.0/24.
   add origination 10.0.0.0/24 64512
   add origination 10.0.0.0/24 64513

   # 64512 originates fd0b:dd1d:2dcc::/52 and sub-prefixes up to length
   # 56.
   add origination fd0b:dd1d:2dcc::/52-56 64512

   # However, 64513 originates fd0b:dd1d:2dcc:42::/64.
   add origination fd0b:dd1d:2dcc:42::/64 64513

   # 64513 also originates fd0b:dd1d:2dcc:100::/52
   add origination fd0b:dd1d:2dcc:100::/52 64513

   # Authorize router keys to sign BGPsec paths on behalf of the
   # specified ASes. Note that the Base64 strings used in this
   # example are not valid SKIs or router public keys, due to line
   # length restrictions in RFCs.
   add bgpsec 64512 Zm9v VGhpcyBpcyBub3QgYSByb3V0ZXIgcHVibGljIGtleQ==
   add bgpsec 64512 YmFy b3IgYSBmbG9jayBvZiBkdWNrcw==
   add bgpsec 64513 YWJj bWF5YmUgYSBkaWZmZXJlbnQgYXZpYW4gY2Fycmllcj8=

Author's Address

   David Mandelberg
   BBN Technologies
   10 Moulton St.
   Camridge, MA  02138
   US

   Email: david@mandelberg.org






Mandelberg              Expires November 14, 2015              [Page 11]