Network Working Group                                      M. Richardson
Internet-Draft                                                       SSW
Intended status: Informational                              May 22, 2014
Expires: November 23, 2014


  X509.v3 certificate extension for authorization of device ownership
                 draft-richardson-6tisch-idevid-cert-00

Abstract

   This document details an X.509 extension to provide authorization and
   indication of ownership of a constrained device containing 802.1AR
   IDevID.

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Table of Contents

   1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.   Terminology  . . . . . . . . . . . . . . . . . . . . . .   3
   2.   Autonomous System Identifier Delegation Extension  . . . . .   4
     2.1.   Context  . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.   Specification  . . . . . . . . . . . . . . . . . . . . .   4
       2.2.1.   Criticality  . . . . . . . . . . . . . . . . . . . .   5
       2.2.2.   Syntax . . . . . . . . . . . . . . . . . . . . . . .   5
       2.2.3.   Type IDevID  . . . . . . . . . . . . . . . . . . . .   5
       2.2.4.   Elements asnum, rdi, and Type ASIdentifierChoice . .   5
       2.2.5.   Element inherit  . . . . . . . . . . . . . . . . . .   6
       2.2.6.   Element asIdsOrRanges  . . . . . . . . . . . . . . .   6
       2.2.7.   Type ASIdOrRange . . . . . . . . . . . . . . . . . .   6
       2.2.8.   Element id . . . . . . . . . . . . . . . . . . . . .   6
       2.2.9.   Element range  . . . . . . . . . . . . . . . . . . .   6
       2.2.10.  Type IDevIDRange . . . . . . . . . . . . . . . . . .   6
       2.2.11.  Elements min and max . . . . . . . . . . . . . . . .   6
       2.2.12.  Type IDevId  . . . . . . . . . . . . . . . . . . . .   6
     2.3.   Autonomous System Identifier Delegation Extension
           Certification . . . . . . . . . . . . . . . . . . . . . .   7
   3.   Security Considerations  . . . . . . . . . . . . . . . . . .   7
   4.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   7
   5.  Appendix A -- ASN.1 Module  . . . . . . . . . . . . . . . . .   7
   6.  Appendix C -- Example of an AS Identifier Delegation
       Extension . . . . . . . . . . . . . . . . . . . . . . . . . .   8
   7.  Normative References  . . . . . . . . . . . . . . . . . . . .   8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   This document defines two X.509 v3 certificate extensions that
   authorize the transfer of the right-to-use for a set of devices
   identified by 802.1AR IDevID from a production Factory through
   national and regional distributors (VARs) to Plant Owners/Operators.
   This extension binds a list of IDevID identifiers to the subject
   (private key holder) of a certificate.  The issuer of the certificate
   is an entity (e.g., a Factory) that has produced the device to to
   transfer ownership set of IDevID to the subject of the certificate.
   These certificates provide a scalable, no-touch means of verifying
   the ownership of a constrainted device.  The constrained is
   initialized with the trusted certificate of the Factory at the
   Factory.  This process may be used by enrollment protocols such as
   1x, PANA, EAP-TLS and RPL to validate that the network infrastructure
   being presented is the legitimate infrastructure for the constrainted
   device.





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   Sections 2 specify several rules about the encoding of the extensions
   defined in this specification that MUST be followed.  These encoding
   rules serve the following purposes.  First, they result in a unique
   encoding of the extension's value; two instances of an extension can
   be compared for equality octet-by-octet.  Second, they achieve the
   minimal size encoding of the information.  Third, they allow relying
   parties to use one-pass algorithms when performing certification path
   validation; in particular, the relying parties do not need to sort
   the information, or to implement extra code in the subset checking
   algorithms to handle several boundary cases (adjacent, overlapping,
   or subsumed ranges).

1.1.  Terminology

   It is assumed that the reader is familiar with the terms and concepts
   described in "Internet X.509 Public Key Infrastructure Certificate
   and Certificate Revocation List (CRL) Profile" [RFC3280], "INTERNET
   PROTOCOL" [RFC791], "Internet Protocol Version 6 (IPv6) Addressing
   Architecture" [RFC3513], "INTERNET REGISTRY IP ALLOCATION GUIDELINES"
   [RFC2050], and related regional Internet registry address management
   policy documents.  Some relevant terms include:

   allocate - the transfer of custodianship of a resource to an
   intermediate organization (see [RFC2050]).

   assign - the transfer of custodianship of a resource to an end
   organization (see [RFC2050]).

   Autonomous System (AS) - a set of routers under a single technical
   administration with a uniform policy, using one or more interior
   gateway protocols and metrics to determine how to route packets
   within the autonomous system, and using an exterior gateway protocol
   to determine how to route packets to other autonomous systems.

   Autonomous System number - a 32-bit number that identifies an
   autonomous system.

   delegate - transfer of custodianship (that is, the right-to-use) of
   an IP address block or AS identifier through issuance of a
   certificate to an entity.

   initial octet - the first octet in the value of a DER encoded BIT
   STRING [X.690].

   IDevID - a variable octet identifier written as in hexadecimal.
   While there is no length limit to the IDevID, a Factory is expected
   to pick a particularly length and stick to that length so that the
   IDevID can be aggregated by simple integer enumeration.



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   subsequent octets - the second through last octets in the value of a
   DER encoded BIT STRING [X.690].

   trust anchor - a certificate that is to be trusted when performing
   certification path validation (see [RFC3280]).

   The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
   SHOULD NOT, RECOMMENDED, and MAY, and OPTIONAL, when they appear in
   this document, are to be interpreted as described in [RFC2119].

2.  Autonomous System Identifier Delegation Extension

   This extension conveys the delegation of ownership of a device
   identified by an 802.1AR Device ID to an entity by binding those
   IDevID to a public key belonging to the entity.

2.1.  Context

   802.1AR defines a mechanism by which a manufacturer may place a
   certificate that attests to the a device's identity into the device
   at manufacturer time.  This mechanism permits a device to
   cryptographically identify itself to a network.  The device, however
   is unable to know to which network it belongs.  This extension
   permits the manufacturer, using the same trusted anchor to delegate
   ownership of the device to the end user (possibly via a series of
   intermediaries, such as a supplier chain).  The use of such a
   certificate chain can be easily verified by the device, and
   therefore, combined with 802.1AR, permits mutual authentication of
   devices and network entities.

2.2.  Specification

   The OID for this extension is id-pe-iDevID.

       id-pe-iDevID OBJECT IDENTIFIER ::= { id-pe IANA-TBD }
       where [RFC3280] defines:

       id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3)
           dod(6) internet(1) security(5) mechanisms(5) pkix(7) }

       id-pe OBJECT IDENTIFIER ::= { id-pkix 1 }

                               Figure 1: OID








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2.2.1.  Criticality

   This extension SHOULD be CRITICAL.  The intended use of this
   extension is to connote an ownership of the device specified in the
   extension.  A CA marks the extension as CRITICAL to convey the notion
   that a relying party must understand the semantics of the extension
   to make use of the certificate for the purpose it was issued.  Newly
   created applications that use certificates containing this extension
   are expected to recognize the extension.

2.2.2.  Syntax

       id-pe-iDevID OBJECT IDENTIFIER ::= { id-pe IANA_TBD }

       IDevID ::= SEQUENCE { idevnum [0] EXPLICIT
                   IDevIDChoice OPTIONAL,
                   rdi [1] EXPLICIT ASIdentifierChoice OPTIONAL
               }

       IDevIDChoice ::= CHOICE { inherit NULL, -- inherit from issuer --
                   iDevIdsOrRanges SEQUENCE OF iDevIdOrRange
               }

       IDevIdOrRange ::= CHOICE { id IDevId, range IDevRange }
       IDevRange ::= SEQUENCE { min IDevId, max IDevId }
       IDevId ::= INTEGER

                               Figure 2: OID

2.2.3.  Type IDevID

   The IDevID type is a SEQUENCE containing one or more forms of Device
   Identifiers-- IDevID numbers (in the idevnum element) or routing
   domain identifiers (in the rdi element).  When the IDevID type
   contains multiple forms of identifiers, the idevnum entry MUST
   precede the rdi entry.  IDevID numbers are used by 802.1AR and are
   specified there.

2.2.4.  Elements asnum, rdi, and Type ASIdentifierChoice

   The idevnum and rdi elements are both of type IDevIDChoice.  The
   IDevIDChoice type is a CHOICE of either the inherit or asIdsOrRanges
   element.

   XXX - But I don't think we need this CHOICE






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2.2.5.  Element inherit

   If the IDevIDChoice choice contains the inherit element, then the set
   of authorized IDevIDs is taken from the issuer's certificate, or from
   the issuer's issuer's certificate, recursively, until a certificate
   containing an IDevIDChoice containing an iDevIdsOrRanges element is
   located.  If no authorization is being granted for a particular form
   of IDevID, then there MUST NOT be a corresponding idevnum/rdi member
   in the IDevID sequence.

2.2.6.  Element asIdsOrRanges

   The asIdsOrRanges element is a SEQUENCE of ASIdOrRange types.  Any
   pair of items in the asIdsOrRanges SEQUENCE MUST NOT overlap.  Any
   contiguous series of AS identifiers MUST be combined into a single
   range whenever possible.  The AS identifiers in the asIdsOrRanges
   element MUST be sorted by increasing numeric value.

2.2.7.  Type ASIdOrRange

   The ASIdOrRange type is a CHOICE of either a single integer (IDevId)
   or a single sequence (IdevIDRange).

2.2.8.  Element id

   The id element has type ASId.

2.2.9.  Element range

   The range element has type ASRange.

2.2.10.  Type IDevIDRange

   The IDevIDRange type is a SEQUENCE consisting of a min and a max
   element, and is used to specify a range of IDevID identifier values.

2.2.11.  Elements min and max

   The min and max elements have type IDevID.  The min element is used
   to specify the value of the minimum IDevID identifier in the range,
   and the max element specifies the value of the maximum IDevID
   identifier in the range.

2.2.12.  Type IDevId

   The IDevId type is an INTEGER.  XXX - this will need work





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2.3.  Autonomous System Identifier Delegation Extension Certification

   Path Validation

   Certification path validation of a certificate containing the
   autonomous system identifier delegation extension requires additional
   processing.  As each certificate in a path is validated, the AS
   identifiers in the autonomous system identifier delegation extension
   of that certificate MUST be subsumed by the AS identifiers in the
   autonomous system identifier delegation extension in the issuer's
   certificate.  Validation MUST fail when this is not the case.  A
   certificate that is a trust anchor for certification path validation
   of certificates containing the autonomous system identifier
   delegation extension, as well as all certificates along the path,
   MUST each contain the autonomous system identifier delegation
   extension.  The initial set of allowed AS identifiers is taken from
   the trust anchor certificate.

3.  Security Considerations

   This specification describes an X.509 extension.  Since X.509
   certificates are digitally signed, no additional integrity service is
   necessary.  Certificates with these extensions need not be kept
   secret, and unrestricted and anonymous access to these certificates
   has no security implications.

   However, security factors outside the scope of this specification
   will affect the assurance provided to certificate users.  This
   section highlights critical issues that should be considered by
   implementors, administrators, and users.

   This extensions represent authorization information, i.e., a right-
   to-use/ownership statement for a device.  They were developed to
   support zero-touch autonomic configuration of constrained devices in
   a sensor network.  As a result of this capability model, the Subject
   field is largely irrelevant for security purposes, contrary to common
   PKI conventions.

4.  Acknowledgments

   This document was cribbed extensively from RFC3779, however, errors
   were introduced here.

5.  Appendix A -- ASN.1 Module

   This normative appendix will describes the IDevID extensions used by
   conforming PKI components in ASN.1 syntax.




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6.  Appendix C -- Example of an AS Identifier Delegation Extension

   A critical X.509 v3 certificate extension that specifies:

7.  Normative References

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

Author's Address

   Michael C. Richardson
   Sandelman Software Works
   470 Dawson Avenue
   Ottawa, ON  K1Z 5V7
   CA

   Email: mcr+ietf@sandelman.ca
   URI:   http://www.sandelman.ca/
































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