ISO/IEC 9594-8:2017

Information technology — Open Systems Interconnection — The Directory — Part 8: Public-key and attribute certificate frameworks

ISO/IEC 9594-8:2017 addresses some of the security requirements in the areas of authentication and other security services through the provision of a set of frameworks upon which full services can be based. Specifically, this Recommendation | International Standard defines frameworks for: - public-key certificates; and - attribute certificates. The public-key certificate framework defined in this Recommendation | International Standard specifies the information objects and data types for a public-key infrastructure (PKI), including public-key certificates, certificate revocation lists (CRLs), trust broker and authorization and validation lists (AVLs). The attribute certificate framework specifies the information objects and data types for a privilege management infrastructure (PMI), including attribute certificates, and attribute certificate revocation lists (ACRLs). This Recommendation | International Standard also provides the framework for issuing, managing, using and revoking certificates. An extensibility mechanism is included in the defined formats for both certificate types and for all revocation list schemes. This Recommendation | International Standard also includes a set of extensions, which is expected to be generally useful across a number of applications of PKI and PMI. The schema components (including object classes, attribute types and matching rules) for storing PKI and PMI information in a directory, are included in this Recommendation | International Standard. ISO/IEC 9594-8:2017 specifies the framework for strong authentication, involving credentials formed using cryptographic techniques. It is not intended to establish this as a general framework for authentication, but it can be of general use for applications which consider these techniques adequate. Authentication (and other security services) can only be provided within the context of a defined security policy. It is a matter for users of an application to define their own security policy.

Technologies de l'information — Interconnexion de systèmes ouverts (OSI) — L'annuaire — Partie 8: Cadre général des certificats de clé publique et d'attribut

General Information

• Status: Withdrawn
• Publication Date: 04-May-2017
• Withdrawal Date: 04-May-2017
• ICS: 35.100.70 - Application layer
• Technical Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Drafting Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 01-Dec-2020

Relations

• Revised: ISO/IEC 9594-8:2020 - Information technology — Open systems interconnection — Part 8: The Directory: Public-key and attribute certificate frameworks
• Effective Date: 23-Apr-2020
• Revises: ISO/IEC 9594-8:2014 - Information technology — Open Systems Interconnection — The Directory — Part 8: Public-key and attribute certificate frameworks
• Effective Date: 10-Dec-2016

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 9594-8
Eighth edition
2017-05
Information technology — Open
Systems Interconnection — The
Directory —
Part 8:
Public-key and attribute certificate
frameworks
Technologies de l’information — Interconnexion de systèmes ouverts
(OSI) — L’annuaire —
Partie 8: Cadre général des certificats de clé publique et d’attribut
Reference number
ISO/IEC 9594-8:2017(E)
©
ISO/IEC 2017

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ISO/IEC 9594-8:2017(E)

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ii © ISO/IEC 2017 – All rights reserved

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ISO/IEC 9594-8:2017(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non‐governmental, in liaison with ISO and IEC, also
take part in the work. In the field of information technology, ISO and IEC have established a joint
technical committee, ISO/IEC JTC 1.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does
not constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the World Trade Organization (WTO)
principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html.
This eighth edition cancels and replaces the seventh edition (ISO/IEC 9594‐8:2014), which
has been technically revised.te
This document was prepared by ISO/IEC JTC 1, Information technology, SC 6, Telecommunications
and information exchange between systems, in collaboration with ITU‐T. The identical text is
published as ITU‐T X.509 (10/2016).
A list of all parts in the ISO/IEC 9594 series, published under the general title Information technology
— Open Systems Interconnection — The Directory, can be found on the ISO website.
© ISO/IEC 2017 – All rights reserved ii-1

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CONTENTS
Page
1 Scope . 1
2 Normative references. 1
2.1 Identical Recommendations | International Standards . 1
2.2 Paired Recommendations | International Standards equivalent in technical content . 2
2.3 Recommendations . 2
2.4 Other references . 2
3 Definitions . 2
3.1 OSI Reference Model security architecture definitions. 2
3.2 Baseline identity management terms and definitions . 3
3.3 Directory model definitions . 3
3.4 Access control framework definitions . 3
3.5 Public-key and attribute certificate definitions . 3
4 Abbreviations . 7
5 Conventions . 8
6 Frameworks overview . 8
6.1 Digital signatures . 9
6.2 Public-key cryptography and cryptographic algorithms. 10
6.3 Distinguished encoding of basic encoding rules . 11
6.4 Applying distinguished encoding . 12
6.5 Using repositories . 12
7 Public keys and public-key certificates . 13
7.1 Introduction . 13
7.2 Public-key certificate. 13
7.3 Public-key certificate extensions . 15
7.4 Types of public-key certificates . 16
7.5 Trust anchor . 16
7.6 Entity relationship . 17
7.7 Certification path . 18
7.8 Generation of key pairs . 19
7.9 Public-key certificate creation . 19
7.10 Certificate revocation list . 20
7.11 Uniqueness of names . 22
7.12 Indirect CRLs . 22
7.13 Repudiation of a digital signing . 24
8 Trust models . 24
8.1 Three-cornered trust model . 24
8.2 Four cornered trust model . 25
9 Public-key certificate and CRL extensions . 26
9.1 Policy handling . 26
9.2 Key and policy information extensions . 29
9.3 Subject and issuer information extensions . 35
9.4 Certification path constraint extensions . 37
9.5 Basic CRL extensions . 41
9.6 CRL distribution points and delta CRL extensions . 49
10 Delta CRL relationship to base . 53
11 Authorization and validation lists . 55
11.1 Authorization and validation list concept . 55
11.2 The authorizer . 55
11.3 Authorization and validation list syntax . 55
11.4 Authorization and validation restrictions . 57
 Rec. ITU-T X.509 (10/2016) iii

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Page
12 Certification path processing procedure . 57
12.1 Path processing inputs . 57
12.2 Path processing outputs . 58
12.3 Path processing variables . 59
12.4 Initialization step . 59
12.5 Public-key certificate processing . 59
13 PKI directory schema . 62
13.1 PKI directory object classes and name forms . 62
13.2 PKI directory attributes . 63
13.3 PKI directory matching rules . 66
13.4 PKI directory syntax definitions. 71
14 Attribute certificates . 73
14.1 Attribute certificate structure. 73
14.2 Delegation paths . 76
14.3 Attribute certificate revocation lists . 76
15 Attribute authority, source of authority and certification authority relationship . 77
15.1 Privilege in attribute certificates . 79
15.2 Privilege in public-key certificates . 79
16 PMI models . 79
16.1 General model . 79
16.2 Control model. 81
16.3 Delegation model . 81
16.4 Group assignment model . 82
16.5 Roles model . 83
16.6 Recognition of Authority Model . 84
16.7 XML privilege information attribute . 88
16.8 Permission attribute and matching rule . 89
17 Attribute certificate and attribute certificate revocation list extensions . 89
17.1 Basic privilege management extensions . 90
17.2 Privilege revocation extensions . 93
17.3 Source of authority extensions . 95
17.4 Role extensions . 97
17.5 Delegation extensions . 98
17.6 Recognition of authority extensions . 103
17.7 Use of basic CRL extension for ACRLs . 105
18 Delegation path processing procedure . 109
18.1 Basic processing procedure . 109
18.2 Role processing procedure . 110
18.3 Delegation processing procedure . 110
19 PMI directory schema. 112
19.1 PMI directory object classes . 113
19.2 PMI directory attributes . 114
19.3 PMI general directory matching rules . 116
20 Protocol support for public-key and privilege management infrastructures . 118
20.1 General syntax . 118
20.2 Wrapping of non-encrypted protocol data units . 118
20.3 Wrapping of encrypted protocol data unit . 119
20.4 Check of PKI-PMI-Wrapper protocol elements . 121
20.5 PKI-PMI-Wrapper error codes . 122
21 Authorization and validation list management . 123
21.1 General . 123
21.2 Defined protocol data unit (PDU) types . 123
21.3 Checking of received PDU . 123
iv Rec. ITU-T X.509 (10/2016)

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Page
21.4 Authorization and validation management protocol . 124
21.5 Certification authority subscription protocol . 130
22 Trust broker protocol . 137
Annex A – Public-key and attribute certificate frameworks . 140
Annex B – Reference definition of cryptographic algorithms . 176
Annex C – Certificate extension attribute types . 182
C.1 Certificate extension attribute concept . 182
C.2 Formal specification for certificate extension attribute types . 182
Annex D – External ASN.1 modules . 190
Annex E – CRL generation and processing rules . 199
E.1 Introduction . 199
E.2 Determine parameters for CRLs . 200
E.3 Determine CRLs required . 201
E.4 Obtain CRLs. 202
E.5 Process CRLs . 202
Annex F – Examples of delta CRL issuance. 206
Annex G – Privilege policy and privilege attribute definition examples . 208
G.1 Introduction . 208
G.2 Sample syntaxes . 208
G.3 Privilege attribute example . 212
2)
Annex H – An introduction to public key cryptography . 213
Annex I – Examples of use of certification path constraints . 215
I.1 Example 1: Use of basic constraints . 215
I.2 Example 2: Use of policy mapping and policy constraints . 215
I.3 Use of name constraints extension . 215
Annex J – Guidance on determining for which policies a certification path is valid . 224
J.1 Certification path valid for a user-specified policy required . 224
J.2 Certification path valid for any policy required . 225
J.3 Certification path valid regardless of policy . 225
J.4 Certification path valid for a user-specific policy desired, but not required . 225
Annex K – Key usage certificate extension issues . 226
Annex L – Deprecated extensions . 227
L.1 CRL scope extension . 227
Annex M – Directory concepts . 230
M.1 Scope . 230
M.2 Basic directory concepts . 230
M.3 Directory schema . 230
M.4 Directory distinguished names . 231
M.5 Subtrees . 231
Annex N – Considerations on strong authentication . 232
N.1 Introduction . 232
N.2 One-way authentication . 233
N.3 Two-way authentication . 233
N.4 Three-way authentication . 234
N.5 Five-way authentication (initiated by A) . 235
N.6 Five-way authentication (initiated by B) . 236
Annex O – Alphabetical list of information item definitions . 238
Annex P – Amendments and corrigenda . 241
Bibliography . 242

 Rec. ITU-T X.509 (10/2016) v

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Introduction
Many applications have requirements for security to protect against threats to the communication of information. Virtually
all security services are dependent upon the identities of the communicating parties being reliably known, i.e.,
authenticated.
This Recommendation | International Standard defines a framework for public-key certificates. This framework includes
the specification of data objects used to represent the public-key certificates themselves, as well as revocation notices for
issued public-key certificates that should no longer be trusted. It defines some critical components of a public-key
infrastructure (PKI), but it does not define a PKI in its entirety. However, this Recommendation | International Standard
provides the foundation upon which full PKIs and their specifications can be built.
Similarly, this Recommendation | International Standard defines a framework for attribute certificates. This framework
includes the specification of data objects used to represent the attribute certificates themselves, as well as revocation
notices for issued attribute certificates that should no longer be trusted. It defines some critical components of a privilege
management infrastructure (PMI), but it does not define a PMI in its entirety. However, this Recommendation |
International Standard provides the foundation upon which full PMIs and their specifications can be built.
Schema definitions are defined for holding PKI and PMI information in a directory according to the specification found
in the ITU-T X.500 series of Recommendations | ISO/IEC 9594 (all parts) or according to the lightweight directory access
protocol (LDAP) specification.
This Recommendation | International Standard provides the foundation frameworks upon which industry profiles can be
defined by other standards groups and industry forums. Many of the features defined as optional in these frameworks may
be mandated for use in certain environments through profiles. This eighth edition technically revises and enhances the
seventh edition of this Recommendation | International Standard.
This eighth edition specifies versions 1, 2 and 3 of public-key certificates, versions 1 and 2 of certificate revocation lists
and version 2 of attribute certificates.
The extensibility function was added in an earlier edition with version 3 of the public-key certificate and with version 2
of the certificate revocation list and was incorporated into the attribute certificate from its initial inception.
Annex A, which is an integral part of this Recommendation | International Standard, provides the ASN.1 modules which
contain all of the definitions associated with the frameworks.
Annex B, which is not an integral part of this Recommendation | International Standard, lists object identifiers assigned
t
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