Network Working Group                                          A. Azimov
Internet-Draft                                                    Yandex
Intended status: Standards Track                                E. Uskov
Expires: 30 January 2023                                         JetLend
                                                                 R. Bush
                                               Internet Initiative Japan
                                                             J. Snijders
                                                                  Fastly
                                                              R. Housley
                                                          Vigil Security
                                                             B. Maddison
                                                              Workonline
                                                            29 July 2022


         A Profile for Autonomous System Provider Authorization
                   draft-ietf-sidrops-aspa-profile-09

Abstract

   This document defines a standard profile for Autonomous System
   Provider Authorization in the Resource Public Key Infrastructure.  An
   Autonomous System Provider Authorization is a digitally signed object
   that provides a means of validating that a Customer Autonomous System
   holder has authorized members of Provider set to be its upstream
   providers or provide route server service at internet exchange point.
   For the Providers it means that they are legal to send prefixes
   received from the Customer Autonomous System in all directions
   including providers and peers.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

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/.




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   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 30 January 2023.

Copyright Notice

   Copyright (c) 2022 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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The ASPA Content Type . . . . . . . . . . . . . . . . . . . .   3
   3.  The ASPA eContent . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  version . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  customerASID  . . . . . . . . . . . . . . . . . . . . . .   6
     3.3.  providers . . . . . . . . . . . . . . . . . . . . . . . .   6
       3.3.1.  ProviderAS  . . . . . . . . . . . . . . . . . . . . .   6
         3.3.1.1.  providerASID  . . . . . . . . . . . . . . . . . .   6
         3.3.1.2.  afiLimit  . . . . . . . . . . . . . . . . . . . .   6
   4.  ASPA Validation . . . . . . . . . . . . . . . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   7.  Implementation status . . . . . . . . . . . . . . . . . . . .   8
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   9
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10










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1.  Introduction

   The primary purpose of the Resource Public Key Infrastructure (RPKI)
   is to improve routing security.  (See [RFC6480] for more
   information.)  As part of this infrastructure, a mechanism is needed
   to validate that a AS has permission from a Customer AS (CAS) holder
   to send routes in all directions.  The digitally signed Autonomous
   System Provider Authorization (ASPA) object provides this validation
   mechanism.

   The ASPA uses the template for RPKI digitally signed objects
   [RFC6488], which defines a Cryptographic Message Syntax (CMS)
   [RFC5652] wrapper for the ASPA content as well as a generic
   validation procedure for RPKI signed objects.  As ASPAs need to be
   validated with RPKI certificates issued by the current
   infrastructure, we assume the mandatory-to-implement algorithms in
   [RFC6485], or its successor.

   To complete the specification of the ASPA (see Section 4 of
   [RFC6488]), this document defines:

   1.  The object identifier (OID) that identifies the ASPA signed
       object.  This OID appears in the eContentType field of the
       encapContentInfo object as well as the content-type signed
       attribute within the signerInfo structure).

   2.  The ASN.1 syntax for the ASPA content, which is the payload
       signed by the CAS.  The ASPA content is encoded using the ASN.1
       [X680] Distinguished Encoding Rules (DER) [X690].

   3.  The steps required to validate an ASPA beyond the validation
       steps specified in [RFC6488]).

2.  The ASPA Content Type

   The content-type for an ASPA is defined as id-ct-ASPA, which has the
   numerical value of 1.2.840.113549.1.9.16.1.49.  This OID MUST appear
   both within the eContentType in the encapContentInfo structure as
   well as the content-type signed attribute within the signerInfo
   structure (see [RFC6488]).

3.  The ASPA eContent

   The content of an ASPA identifies the Customer AS (CAS) as well as
   the Set of Provider ASes (SPAS) that are authorized to further
   propagate announcements received from the customer.





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   Not all route servers at internet exchange points are transparent,
   e.g. in some cases they are present in the ASPATH.  In this case
   route server AS is acting as a provider AS, which propagates routes
   between its customers.  Thus, a customer MUST add both upstream
   providers and non-transparent route sever AS it is connected to its
   SPAS.

   If customer is connected to multiple transit providers/non-
   transparent route servers they MUST be registered in a single ASPA
   object.  This rule is important to avoid possible race conditions
   during updates.

   The eContent of an ASPA is an instance of ASProviderAttestation,
   formally defined by the following ASN.1 [X680] module:





































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   RPKI-ASPA-2022
     { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
        pkcs-9(9) smime(16) modules(0) id-mod-rpki-aspa-2020(TBD) }

   DEFINITIONS IMPLICIT TAGS ::=
   BEGIN

   IMPORTS
     CONTENT-TYPE
     FROM CryptographicMessageSyntax-2010  -- RFC 6268
       { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
          pkcs-9(9) smime(16) modules(0) id-mod-cms-2009(58) } ;

   id-ct-ASPA OBJECT IDENTIFIER ::=
     { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
       pkcs-9(9) id-smime(16) id-ct(1) 49 }

   ct-ASPA CONTENT-TYPE ::=
     { TYPE ASProviderAttestation IDENTIFIED BY id-ct-ASPA }

   ASProviderAttestation ::= SEQUENCE {
     version [0]   ASPAVersion DEFAULT v0,
     customerASID  ASID,
     providers     ProviderASSet }

   ASPAVersion ::= INTEGER  { v0(0) }

   ProviderASSet ::= SEQUENCE (SIZE(1..MAX)) OF ProviderAS

   ProviderAS ::= SEQUENCE {
     providerASID  ASID,
     afiLimit      AddressFamilyIdentifier OPTIONAL }

   ASID ::= INTEGER

   AddressFamilyIdentifier ::= OCTET STRING (SIZE (2))

   END

   Note that this content appears as the eContent within the
   encapContentInfo as specified in [RFC6488].

3.1.  version

   The version number of the ASProviderAttestation MUST be v0.






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3.2.  customerASID

   The customerASID field contains the AS number of the Autonomous
   System (AS) that authorizes a collection of provider ASes (as listed
   in the providerASSet) to propagate prefixes in the specified address
   family to other ASes.

3.3.  providers

   The providers field contains the listing of ASes that are authorized
   to further propagate announcements in the specified address family
   received from the customer.

   Each element contained in the providers field is an instance of
   ProviderAS.

   In addition to the constraints described by the formal ASN.1
   definition, the contents of the providers field MUST satisfy the
   following constraints:

   *  The elements of providers MUST be ordered in ascending numerical
      order by the value of the providerASID field.

   *  Each value of providerASID MUST be unique (with respect to the
      other elements of providers).

3.3.1.  ProviderAS

3.3.1.1.  providerASID

   The providerASID field contains the AS number of an AS that has been
   authorized by the customer AS to propagate prefixes in the specified
   address family to other ASes.

3.3.1.2.  afiLimit

   The afiLimit field optionally constrains the authorization given to
   the provider AS to a single address family.

   If present, it contains the two-octet Address Family Identifier (AFI)
   for which the relation between the customer and provider is
   authorized.  Only permitted AFI values are the IPv4 and IPv6 AFI
   values as specified in [IANA-AF].

   If omitted, the authorization is valid for both IPv4 and IPv6
   announcements.





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4.  ASPA Validation

   Before a relying party can use an ASPA to validate a routing
   announcement, the relying party MUST first validate the ASPA object
   itself.  To validate an ASPA, the relying party MUST perform all the
   validation checks specified in [RFC6488] as well as the following
   additional ASPA-specific validation step.

   *  The autonomous system identifier delegation extension [RFC3779] is
      present in the end-entity (EE) certificate (contained within the
      ASPA), and the customer AS number in the ASPA is contained within
      the set of AS numbers specified by the EE certificate's autonomous
      system identifier delegation extension.

5.  IANA Considerations

   Please add the id-mod-rpki-aspa-2022 to the SMI Security for S/MIME
   Module Identifier (1.2.840.113549.1.9.16.0) registry
   (https://www.iana.org/assignments/smi-numbers/smi-
   numbers.xml#security-smime-0) as follows:

       Decimal   | Description                   | Specification
       -----------------------------------------------------------
       TBD2      | id-mod-rpki-aspa-2022         | [ThisRFC]

   Please add the ASPA to the SMI Security for S/MIME CMS Content Type
   (1.2.840.113549.1.9.16.1) registry (https://www.iana.org/assignments/
   smi-numbers/smi-numbers.xml#security-smime-1) as follows:

       Decimal   | Description                   | Specification
       -----------------------------------------------------------
       49        | id-ct-ASPA                    | [ThisRFC]

   Please add Autonomous System Provider Authorization to the RPKI
   Signed Object registry (https://www.iana.org/assignments/rpki/
   rpki.xhtml#signed-objects) as follows:

    Name                                     | OID                         | Specification
    --------------------------------------------------------------------------------------
    Autonomous System Provider Authorization | 1.2.840.113549.1.9.16.1.49  | [ThisRFC]

   Please add an item for the Autonomous System Provider Authorization
   file extension to the "RPKI Repository Name Scheme" registry created
   by [RFC6481] as follows:







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   Filename
   Extension  RPKI Object                               Reference
   --------------------------------------------------------------------------------------
      .asa    Autonomous System Provider Authorization  [draft-ietf-sidrops-aspa-profile]


6.  Security Considerations

   While it's not restricted, but it's highly recommended maintaining
   for selected Customer AS a single ASPA object that covers all
   connected providers/route servers.  Such policy should prevent race
   conditions during ASPA updates that might affect prefix propagation.
   The software that provides hosting for ASPA records SHOULD support
   enforcement of this rule.  In the case of the transition process
   between different CA registries, the ASPA records SHOULD be kept
   identical in all registries.

7.  Implementation status

   This section is to be removed before publishing 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.
   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".

   *  A validator implementation [rpki-client] written in C based on the
      OpenBSD RPKI Validator was provided by Job Snijders from Fastly.

   *  A signer and decoder implementation [rpkimancer] written in Python
      was provided by Ben Maddison from Workonline.





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   *  A signer implementation [krill] written in Rust was provided by
      Tim Bruijnzeels from NLnetLabs.

   *  At IETF114 Ties de Kock from RIPE NCC shared a signer
      implementation had been developed internally.

   *  Di Ma reported [rpstir2] success in RPSTIR2 validating objects
      produced by Tim Bruijnzeels.

8.  Acknowledgments

   The authors would like to thank Keyur Patel for helping kickstart the
   ASPA profile project; and Ties de Kock & Tim Bruijnzeels for
   suggesting that the ProviderASSet be in a canonical form.

9.  References

9.1.  Normative References

   [IANA-AF]  IANA, "Address Family Numbers",
              <https://www.iana.org/assignments/address-family-numbers/
              address-family-numbers.xhtml>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3779]  Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP
              Addresses and AS Identifiers", RFC 3779,
              DOI 10.17487/RFC3779, June 2004,
              <https://www.rfc-editor.org/info/rfc3779>.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, DOI 10.17487/RFC5652, September 2009,
              <https://www.rfc-editor.org/info/rfc5652>.

   [RFC6481]  Huston, G., Loomans, R., and G. Michaelson, "A Profile for
              Resource Certificate Repository Structure", RFC 6481,
              DOI 10.17487/RFC6481, February 2012,
              <https://www.rfc-editor.org/info/rfc6481>.

   [RFC6485]  Huston, G., "The Profile for Algorithms and Key Sizes for
              Use in the Resource Public Key Infrastructure (RPKI)",
              RFC 6485, DOI 10.17487/RFC6485, February 2012,
              <https://www.rfc-editor.org/info/rfc6485>.





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   [RFC6488]  Lepinski, M., Chi, A., and S. Kent, "Signed Object
              Template for the Resource Public Key Infrastructure
              (RPKI)", RFC 6488, DOI 10.17487/RFC6488, February 2012,
              <https://www.rfc-editor.org/info/rfc6488>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [X680]     ITU-T, "Information technology -- Abstract Syntax Notation
              One (ASN.1): Specification of basic notation",
              ITU-T Recommendation X.680, 2015.

   [X690]     ITU-T, "Information Technology -- ASN.1 encoding rules:
              Specification of Basic Encoding Rules (BER), Canonical
              Encoding Rules (CER) and Distinguished Encoding Rules
              (DER)", ITU-T Recommendation X.690, 2015.

9.2.  Informative References

   [krill]    Bruijnzeels, T., "Krill", 2022,
              <https://github.com/NLnetLabs/krill>.

   [RFC6480]  Lepinski, M. and S. Kent, "An Infrastructure to Support
              Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
              February 2012, <https://www.rfc-editor.org/info/rfc6480>.

   [rpki-client]
              Snijders, J., "rpki-client", 2022,
              <https://mailarchive.ietf.org/arch/msg/sidrops/
              Jdowj_bDhN_T993SN4bbsWeDgGA/>.

   [rpkimancer]
              Maddison, B., "rpkimancer-aspa", 2022,
              <https://github.com/benmaddison/rpkimancer-aspa>.

   [rpstir2]  Ma, D., "RPSTIR2",
              <https://mailarchive.ietf.org/arch/msg/sidrops/
              pxqAGPmR0MA3NMe-NxYyiEZ7RXw>.

Authors' Addresses

   Alexander Azimov
   Yandex
   Email: a.e.azimov@gmail.com






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   Eugene Uskov
   JetLend
   Email: eu@jetlend.ru


   Randy Bush
   Internet Initiative Japan
   Email: randy@psg.com


   Job Snijders
   Fastly
   Amsterdam
   Email: job@fastly.com


   Russ Housley
   Vigil Security, LLC
   918 Spring Knoll Drive
   Herndon, VA 20170
   United States of America
   Email: housley@vigilsec.com


   Ben Maddison
   Workonline
   Cape Town
   South Africa
   Email: benm@workonline.africa






















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