Internet Draft C. Francis PKIX Working Group Raytheon April 2003 D. Pinkas Expires: October 2003 Bull Attribute Certificate Policy extension Status of this memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document describes one certificate extension to explicitly state the Attribute Certificate (AC) policies that apply to a given Attribute Certificate. Conventions Used In This Document 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]. 1. Introduction When issuing a PKC, a Certificate Authority (CA) can perform various levels of verification with regard to the subject identity. A CA makes its verification procedures, as well as other operational rules it abides by, "visible" through a certificate policy, which may be referenced by a certificate policies extension in the PKC. The purpose of this document is to define such an extension, but not the AC policies themselves. Francis, Pinkas Page 1 Internet-Draft AC Policy extension April 2003 2. AC Policy Extension Semantics Attribute Certificates are defined in [RFC3281]. An Attribute Certificate Policy (ACP) is a set of rules that indicates generic rules for registering, verifying, delivering and revoking the attributes contained in a particular Attribute Certificate. It should thus be noticed that an AA does not necessarily support one single policy. However, for each AC that is delivered it SHALL make sure that the policy applies to all the attributes that are contained in it. An Attribute Certificate Policy may be used by a certificate user to decide whether or not to trust the attributes contained in a certificate for a particular purpose. When a certificate contains an AC policies extension, the extension MAY, at the option of the certificate issuer, be either critical or non-critical. The AC Policies extension MAY be included in an attribute certificate. Like all X.509 certificate extensions [X.509], the AC policies extension is defined using ASN.1 [ASN1]. The AC policies extension is identified by id-pe-ac-policies. id-pe-ac-policies OBJECT IDENTIFIER ::= { id-pe 15 } The AC policies extension includes a list of AC policies recognized by the issuing authority that apply to the attributes included in the certificate. AC Policies may be defined by any organization with a need. Object identifiers used to identify AC Policies are assigned in accordance with [ITU-T Rec. X660 | ISO/IEC 9834-1]. The presence of this extension in an attribute certificate indicates the AC policies for which the attribute certificate is valid. An application that recognizes this extension and its content SHALL process the extension regardless of the value of the criticality flag. If the extension is both flagged non-critical and is not recognized, then the application MAY ignore it. If the extension is flagged critical or is recognized, it indicates that the attributes contained in the certificate SHALL only be used for the purpose, and in accordance with the rules implied by one of the indicated AC policies. Francis, Pinkas Page 2 Internet-Draft AC Policy extension April 2003 If the extension is marked critical or is recognized, certificate users MUST use the list of AC policies to determine whether it is appropriate to use the attributes contained in that certificate for a particular transaction. 2.1 AC Policy Extension Syntax The syntax for the AC Policy extension is: ac-policies EXTENSION ::= { SYNTAX ac-policiesSyntax IDENTIFIED BY id-pe-ac-policies} ac-policiesSyntax ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyInformation ::= SEQUENCE { policyIdentifier AcPolicyId, policyQualifiers SEQUENCE SIZE (1..MAX) OF PolicyQualifierInfo OPTIONAL} AcPolicyId ::= OBJECT IDENTIFIER PolicyQualifierInfo ::= SEQUENCE { policyQualifierId PolicyQualifierId, qualifier ANY DEFINED BY policyQualifierId } To promote interoperability, this document RECOMMENDS that policy information terms consist of only an OID. When more than one policy is used, the policy requirements have to be non conflicting, e.g. one policy may refine the general requirements mandated by another policy. 2.2 Attribute Certificate Policies The scope of this document is not the definition of the detailed content of Attribute Certificate policies themselves, therefore specific policies are not defined in this document. 2.3. Generic Policy Qualifiers This specification defines two generic policy qualifier types for use by certificate policy writers and certificate issuers, which are similar to those used for Certificate Policies in Public Key Certificates. The qualifier types are the CPS Pointer and User Notice qualifiers. The CPS Pointer qualifier contains a pointer to a Certification Practice Statement (CPS) published by the AA. The pointer is in the form of a URI. User notice is intended for display to a relying party when a certificate is used. The application software SHOULD display all user notices in all certificates of the certification path used, except that if a notice is duplicated only one copy need be Francis, Pinkas Page 3 Internet-Draft AC Policy extension April 2003 displayed. To prevent such duplication, this qualifier SHOULD only be present in end-entity certificates. These policies Qualifiers are defined in [RFC3280]. -- policyQualifierIds for Internet policy qualifiers id-qt OBJECT IDENTIFIER ::= { id-pkix 2 } id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 } id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 } 3. Security Considerations The Attribute Certification Policy defined in this document applies for all the attributes that are included in one AC. AAs shall make sure that the policy applies to all the attributes which are included in the certificates they issue. Attributes may be dynamically grouped in several ACs. It should be observed that since the management of some attributes may be different, different policies may be used by the same AA. 4. Normative references [ITU-T Rec. X660 | ITU-T Recommendation Rec X.660 (1992) ISO/IEC 9834-1] | ISO/IEC 9834-1: 1993, Information technology - Open Systems Interconnection Procedures for the operation of OSI Registration Authorities: General procedures. [RFC3280] Certificate and Certificate Revocation List (CRL) Profile. R. Housley, W.Polk, W.Ford, and D. Solo. April 2002. [RFC3281] An Internet Attribute Certificate Profile for Authorization. S. Farrell S. and R. Housley. April 2002. [ASN1] X.680 - X.693 | ISO/IEC 8824: 1-4 Abstract Syntax Notation One (ASN.1). See: http://www.itu.int/ITU-T/studygroups/com17/languages/ and http://asn1.elibel.tm.fr/en/standards/index.htm [X.509] ITU-T Recommendation X.509 (2000): Information Technology û Open Systems Interconnections - The Directory: Public-key and Attribute Frameworks, March 2000 Francis, Pinkas Page 4 Internet-Draft AC Policy extension April 2003 Author's Addresses Christopher S. Francis Raytheon 1501 72nd Street North, MS 25 St. Petersburg, Florida 33764 Email: Chris_S_Francis@Raytheon.com Denis Pinkas Bull Rue Jean Jaures 78340 Les Clayes-sous-Bois FRANCE Email: Denis.Pinkas@bull.net Full Copyright Statement Copyright (C) The Internet Society 2002. All Rights Reserved. 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Francis, Pinkas Page 5 Internet-Draft AC Policy extension April 2003 Annex A (normative): ASN.1 Definitions ASN.1 Module PKIXac-policies { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-ac-policies(26) } DEFINITIONS IMPLICIT TAGS ::= BEGIN -- EXPORTS ALL -- -- IMPORTS -- -- Imports from RFC 3280 [PROFILE], Appendix A.1 PolicyQualifierId FROM PKIX1Explicit88 { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) mod(0) pkix1-explicit(18) } -- Arc for private certificate extensions id-pe OBJECT IDENTIFIER ::= { id-pkix 1} -- Locally defined OIDs -- Attributes id-pe-ac-policies OBJECT IDENTIFIER ::= { id-pe 15 } ac-policies EXTENSION ::= { SYNTAX ac-policiesSyntax IDENTIFIED BY id-pe-ac-policies} ac-policiesSyntax ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyInformation ::= SEQUENCE { policyIdentifier acPolicyId, policyQualifiers SEQUENCE SIZE (1..MAX) OF PolicyQualifierInfo OPTIONAL} acPolicyId ::= OBJECT IDENTIFIER PolicyQualifierInfo ::= SEQUENCE { policyQualifierId PolicyQualifierId, qualifier ANY DEFINED BY policyQualifierId } END Francis, Pinkas Page 6