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- Committer: Bazaar Package Importer
- Author(s): W. Borgert
- Date: 2005-05-28 12:36:42 UTC
- Revision ID: james.westby@ubuntu.com-20050528123642-3h6kstws5u0xcovl
Tags: upstream-0.9.14
Import upstream version 0.9.14
- files added:
- asn1c
- asn1c/tests
- asn1c/tests/data-*
- asn1c/tests/data-62
- asn1c/tests/data-70
- asn1c/webcgi
- doc
- libasn1compiler
- libasn1fix
- libasn1parser
- libasn1print
- samples
- samples/sample.source.PKIX1
- samples/sample.source.TAP3
- skeletons
- skeletons/tests
- tests
added
removed
samples/rfc3280.txt
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Network Working Group R. Housley
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Request for Comments: 3280 RSA Laboratories
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Obsoletes: 2459 W. Polk
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Category: Standards Track NIST
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W. Ford
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VeriSign
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D. Solo
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Citigroup
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April 2002
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Internet X.509 Public Key Infrastructure
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Certificate and Certificate Revocation List (CRL) Profile
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Status of this Memo
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This document specifies an Internet standards track protocol for the
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Internet community, and requests discussion and suggestions for
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improvements. Please refer to the current edition of the "Internet
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Official Protocol Standards" (STD 1) for the standardization state
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and status of this protocol. Distribution of this memo is unlimited.
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Copyright Notice
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Copyright (C) The Internet Society (2002). All Rights Reserved.
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Abstract
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This memo profiles the X.509 v3 certificate and X.509 v2 Certificate
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Revocation List (CRL) for use in the Internet. An overview of this
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approach and model are provided as an introduction. The X.509 v3
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certificate format is described in detail, with additional
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information regarding the format and semantics of Internet name
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forms. Standard certificate extensions are described and two
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Internet-specific extensions are defined. A set of required
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certificate extensions is specified. The X.509 v2 CRL format is
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described in detail, and required extensions are defined. An
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algorithm for X.509 certification path validation is described. An
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ASN.1 module and examples are provided in the appendices.
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Table of Contents
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1 Introduction . . . . . . . . . . . . . . . . . . . . . . 4
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2 Requirements and Assumptions . . . . . . . . . . . . . . 5
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2.1 Communication and Topology . . . . . . . . . . . . . . 6
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2.2 Acceptability Criteria . . . . . . . . . . . . . . . . 6
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2.3 User Expectations . . . . . . . . . . . . . . . . . . . 7
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2.4 Administrator Expectations . . . . . . . . . . . . . . 7
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3 Overview of Approach . . . . . . . . . . . . . . . . . . 7
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Housley, et. al. Standards Track [Page 1]
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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3.1 X.509 Version 3 Certificate . . . . . . . . . . . . . . 8
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3.2 Certification Paths and Trust . . . . . . . . . . . . . 9
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3.3 Revocation . . . . . . . . . . . . . . . . . . . . . . 11
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3.4 Operational Protocols . . . . . . . . . . . . . . . . . 13
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3.5 Management Protocols . . . . . . . . . . . . . . . . . 13
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4 Certificate and Certificate Extensions Profile . . . . . 14
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4.1 Basic Certificate Fields . . . . . . . . . . . . . . . 15
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4.1.1 Certificate Fields . . . . . . . . . . . . . . . . . 16
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4.1.1.1 tbsCertificate . . . . . . . . . . . . . . . . . . 16
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4.1.1.2 signatureAlgorithm . . . . . . . . . . . . . . . . 16
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4.1.1.3 signatureValue . . . . . . . . . . . . . . . . . . 16
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4.1.2 TBSCertificate . . . . . . . . . . . . . . . . . . . 17
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4.1.2.1 Version . . . . . . . . . . . . . . . . . . . . . . 17
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4.1.2.2 Serial number . . . . . . . . . . . . . . . . . . . 17
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4.1.2.3 Signature . . . . . . . . . . . . . . . . . . . . . 18
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4.1.2.4 Issuer . . . . . . . . . . . . . . . . . . . . . . 18
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4.1.2.5 Validity . . . . . . . . . . . . . . . . . . . . . 22
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4.1.2.5.1 UTCTime . . . . . . . . . . . . . . . . . . . . . 22
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4.1.2.5.2 GeneralizedTime . . . . . . . . . . . . . . . . . 22
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4.1.2.6 Subject . . . . . . . . . . . . . . . . . . . . . . 23
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4.1.2.7 Subject Public Key Info . . . . . . . . . . . . . . 24
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4.1.2.8 Unique Identifiers . . . . . . . . . . . . . . . . 24
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4.1.2.9 Extensions . . . . . . . . . . . . . . . . . . . . . 24
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4.2 Certificate Extensions . . . . . . . . . . . . . . . . 24
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4.2.1 Standard Extensions . . . . . . . . . . . . . . . . . 25
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4.2.1.1 Authority Key Identifier . . . . . . . . . . . . . 26
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4.2.1.2 Subject Key Identifier . . . . . . . . . . . . . . 27
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4.2.1.3 Key Usage . . . . . . . . . . . . . . . . . . . . . 28
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4.2.1.4 Private Key Usage Period . . . . . . . . . . . . . 29
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4.2.1.5 Certificate Policies . . . . . . . . . . . . . . . 30
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4.2.1.6 Policy Mappings . . . . . . . . . . . . . . . . . . 33
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4.2.1.7 Subject Alternative Name . . . . . . . . . . . . . 33
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4.2.1.8 Issuer Alternative Name . . . . . . . . . . . . . . 36
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4.2.1.9 Subject Directory Attributes . . . . . . . . . . . 36
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4.2.1.10 Basic Constraints . . . . . . . . . . . . . . . . 36
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4.2.1.11 Name Constraints . . . . . . . . . . . . . . . . . 37
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4.2.1.12 Policy Constraints . . . . . . . . . . . . . . . . 40
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4.2.1.13 Extended Key Usage . . . . . . . . . . . . . . . . 40
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4.2.1.14 CRL Distribution Points . . . . . . . . . . . . . 42
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4.2.1.15 Inhibit Any-Policy . . . . . . . . . . . . . . . . 44
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4.2.1.16 Freshest CRL . . . . . . . . . . . . . . . . . . . 44
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4.2.2 Internet Certificate Extensions . . . . . . . . . . . 45
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4.2.2.1 Authority Information Access . . . . . . . . . . . 45
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4.2.2.2 Subject Information Access . . . . . . . . . . . . 46
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5 CRL and CRL Extensions Profile . . . . . . . . . . . . . 48
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5.1 CRL Fields . . . . . . . . . . . . . . . . . . . . . . 49
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5.1.1 CertificateList Fields . . . . . . . . . . . . . . . 50
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5.1.1.1 tbsCertList . . . . . . . . . . . . . . . . . . . . 50
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Housley, et. al. Standards Track [Page 2]
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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5.1.1.2 signatureAlgorithm . . . . . . . . . . . . . . . . 50
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5.1.1.3 signatureValue . . . . . . . . . . . . . . . . . . 51
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5.1.2 Certificate List "To Be Signed" . . . . . . . . . . . 51
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5.1.2.1 Version . . . . . . . . . . . . . . . . . . . . . . 52
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5.1.2.2 Signature . . . . . . . . . . . . . . . . . . . . . 52
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5.1.2.3 Issuer Name . . . . . . . . . . . . . . . . . . . . 52
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5.1.2.4 This Update . . . . . . . . . . . . . . . . . . . . 52
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5.1.2.5 Next Update . . . . . . . . . . . . . . . . . . . . 53
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5.1.2.6 Revoked Certificates . . . . . . . . . . . . . . . 53
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5.1.2.7 Extensions . . . . . . . . . . . . . . . . . . . . 53
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5.2 CRL Extensions . . . . . . . . . . . . . . . . . . . . 53
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5.2.1 Authority Key Identifier . . . . . . . . . . . . . . 54
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5.2.2 Issuer Alternative Name . . . . . . . . . . . . . . . 54
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5.2.3 CRL Number . . . . . . . . . . . . . . . . . . . . . 55
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5.2.4 Delta CRL Indicator . . . . . . . . . . . . . . . . . 55
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5.2.5 Issuing Distribution Point . . . . . . . . . . . . . 58
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5.2.6 Freshest CRL . . . . . . . . . . . . . . . . . . . . 59
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5.3 CRL Entry Extensions . . . . . . . . . . . . . . . . . 60
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5.3.1 Reason Code . . . . . . . . . . . . . . . . . . . . . 60
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5.3.2 Hold Instruction Code . . . . . . . . . . . . . . . . 61
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5.3.3 Invalidity Date . . . . . . . . . . . . . . . . . . . 62
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5.3.4 Certificate Issuer . . . . . . . . . . . . . . . . . 62
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6 Certificate Path Validation . . . . . . . . . . . . . . . 62
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6.1 Basic Path Validation . . . . . . . . . . . . . . . . . 63
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6.1.1 Inputs . . . . . . . . . . . . . . . . . . . . . . . 66
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6.1.2 Initialization . . . . . . . . . . . . . . . . . . . 67
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6.1.3 Basic Certificate Processing . . . . . . . . . . . . 70
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6.1.4 Preparation for Certificate i+1 . . . . . . . . . . . 75
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6.1.5 Wrap-up procedure . . . . . . . . . . . . . . . . . . 78
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6.1.6 Outputs . . . . . . . . . . . . . . . . . . . . . . . 80
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6.2 Extending Path Validation . . . . . . . . . . . . . . . 80
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6.3 CRL Validation . . . . . . . . . . . . . . . . . . . . 81
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6.3.1 Revocation Inputs . . . . . . . . . . . . . . . . . . 82
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6.3.2 Initialization and Revocation State Variables . . . . 82
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6.3.3 CRL Processing . . . . . . . . . . . . . . . . . . . 83
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7 References . . . . . . . . . . . . . . . . . . . . . . . 86
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8 Intellectual Property Rights . . . . . . . . . . . . . . 88
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9 Security Considerations . . . . . . . . . . . . . . . . . 89
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Appendix A. ASN.1 Structures and OIDs . . . . . . . . . . . 92
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A.1 Explicitly Tagged Module, 1988 Syntax . . . . . . . . . 92
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A.2 Implicitly Tagged Module, 1988 Syntax . . . . . . . . . 105
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Appendix B. ASN.1 Notes . . . . . . . . . . . . . . . . . . 112
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Appendix C. Examples . . . . . . . . . . . . . . . . . . . 115
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C.1 DSA Self-Signed Certificate . . . . . . . . . . . . . . 115
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C.2 End Entity Certificate Using DSA . . . . . . . . . . . 119
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C.3 End Entity Certificate Using RSA . . . . . . . . . . . 122
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C.4 Certificate Revocation List . . . . . . . . . . . . . . 126
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Author Addresses . . . . . . . . . . . . . . . . . . . . . . 128
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Housley, et. al. Standards Track [Page 3]
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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Full Copyright Statement . . . . . . . . . . . . . . . . . . 129
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1 Introduction
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This specification is one part of a family of standards for the X.509
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Public Key Infrastructure (PKI) for the Internet.
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This specification profiles the format and semantics of certificates
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and certificate revocation lists (CRLs) for the Internet PKI.
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Procedures are described for processing of certification paths in the
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Internet environment. Finally, ASN.1 modules are provided in the
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appendices for all data structures defined or referenced.
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Section 2 describes Internet PKI requirements, and the assumptions
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which affect the scope of this document. Section 3 presents an
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architectural model and describes its relationship to previous IETF
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and ISO/IEC/ITU-T standards. In particular, this document's
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relationship with the IETF PEM specifications and the ISO/IEC/ITU-T
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X.509 documents are described.
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Section 4 profiles the X.509 version 3 certificate, and section 5
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profiles the X.509 version 2 CRL. The profiles include the
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identification of ISO/IEC/ITU-T and ANSI extensions which may be
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useful in the Internet PKI. The profiles are presented in the 1988
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Abstract Syntax Notation One (ASN.1) rather than the 1997 ASN.1
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syntax used in the most recent ISO/IEC/ITU-T standards.
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Section 6 includes certification path validation procedures. These
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procedures are based upon the ISO/IEC/ITU-T definition.
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Implementations are REQUIRED to derive the same results but are not
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required to use the specified procedures.
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Procedures for identification and encoding of public key materials
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and digital signatures are defined in [PKIXALGS]. Implementations of
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this specification are not required to use any particular
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cryptographic algorithms. However, conforming implementations which
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use the algorithms identified in [PKIXALGS] MUST identify and encode
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the public key materials and digital signatures as described in that
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specification.
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Finally, three appendices are provided to aid implementers. Appendix
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A contains all ASN.1 structures defined or referenced within this
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specification. As above, the material is presented in the 1988
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ASN.1. Appendix B contains notes on less familiar features of the
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ASN.1 notation used within this specification. Appendix C contains
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examples of a conforming certificate and a conforming CRL.
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Housley, et. al. Standards Track [Page 4]
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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This specification obsoletes RFC 2459. This specification differs
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from RFC 2459 in five basic areas:
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* To promote interoperable implementations, a detailed algorithm
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for certification path validation is included in section 6.1 of
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this specification; RFC 2459 provided only a high-level
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description of path validation.
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* An algorithm for determining the status of a certificate using
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CRLs is provided in section 6.3 of this specification. This
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material was not present in RFC 2459.
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* To accommodate new usage models, detailed information describing
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the use of delta CRLs is provided in Section 5 of this
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specification.
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* Identification and encoding of public key materials and digital
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signatures are not included in this specification, but are now
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described in a companion specification [PKIXALGS].
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* Four additional extensions are specified: three certificate
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extensions and one CRL extension. The certificate extensions are
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subject info access, inhibit any-policy, and freshest CRL. The
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freshest CRL extension is also defined as a CRL extension.
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* Throughout the specification, clarifications have been
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introduced to enhance consistency with the ITU-T X.509
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specification. X.509 defines the certificate and CRL format as
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well as many of the extensions that appear in this specification.
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These changes were introduced to improve the likelihood of
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interoperability between implementations based on this
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specification with implementations based on the ITU-T
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specification.
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
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"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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document are to be interpreted as described in RFC 2119.
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2 Requirements and Assumptions
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The goal of this specification is to develop a profile to facilitate
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the use of X.509 certificates within Internet applications for those
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communities wishing to make use of X.509 technology. Such
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applications may include WWW, electronic mail, user authentication,
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and IPsec. In order to relieve some of the obstacles to using X.509
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Housley, et. al. Standards Track [Page 5]
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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certificates, this document defines a profile to promote the
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development of certificate management systems; development of
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application tools; and interoperability determined by policy.
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Some communities will need to supplement, or possibly replace, this
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profile in order to meet the requirements of specialized application
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domains or environments with additional authorization, assurance, or
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operational requirements. However, for basic applications, common
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representations of frequently used attributes are defined so that
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application developers can obtain necessary information without
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regard to the issuer of a particular certificate or certificate
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revocation list (CRL).
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A certificate user should review the certificate policy generated by
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the certification authority (CA) before relying on the authentication
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or non-repudiation services associated with the public key in a
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particular certificate. To this end, this standard does not
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prescribe legally binding rules or duties.
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As supplemental authorization and attribute management tools emerge,
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such as attribute certificates, it may be appropriate to limit the
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authenticated attributes that are included in a certificate. These
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other management tools may provide more appropriate methods of
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conveying many authenticated attributes.
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2.1 Communication and Topology
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The users of certificates will operate in a wide range of
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environments with respect to their communication topology, especially
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users of secure electronic mail. This profile supports users without
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high bandwidth, real-time IP connectivity, or high connection
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availability. In addition, the profile allows for the presence of
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firewall or other filtered communication.
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This profile does not assume the deployment of an X.500 Directory
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system or a LDAP directory system. The profile does not prohibit the
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use of an X.500 Directory or a LDAP directory; however, any means of
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distributing certificates and certificate revocation lists (CRLs) may
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be used.
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2.2 Acceptability Criteria
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The goal of the Internet Public Key Infrastructure (PKI) is to meet
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the needs of deterministic, automated identification, authentication,
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access control, and authorization functions. Support for these
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services determines the attributes contained in the certificate as
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well as the ancillary control information in the certificate such as
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policy data and certification path constraints.
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2.3 User Expectations
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Users of the Internet PKI are people and processes who use client
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software and are the subjects named in certificates. These uses
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include readers and writers of electronic mail, the clients for WWW
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browsers, WWW servers, and the key manager for IPsec within a router.
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This profile recognizes the limitations of the platforms these users
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employ and the limitations in sophistication and attentiveness of the
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users themselves. This manifests itself in minimal user
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configuration responsibility (e.g., trusted CA keys, rules), explicit
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platform usage constraints within the certificate, certification path
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constraints which shield the user from many malicious actions, and
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applications which sensibly automate validation functions.
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2.4 Administrator Expectations
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As with user expectations, the Internet PKI profile is structured to
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support the individuals who generally operate CAs. Providing
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administrators with unbounded choices increases the chances that a
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subtle CA administrator mistake will result in broad compromise.
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Also, unbounded choices greatly complicate the software that process
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and validate the certificates created by the CA.
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3 Overview of Approach
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Following is a simplified view of the architectural model assumed by
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the PKIX specifications.
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The components in this model are:
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end entity: user of PKI certificates and/or end user system that is
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the subject of a certificate;
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CA: certification authority;
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RA: registration authority, i.e., an optional system to which
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a CA delegates certain management functions;
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CRL issuer: an optional system to which a CA delegates the
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publication of certificate revocation lists;
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repository: a system or collection of distributed systems that stores
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certificates and CRLs and serves as a means of
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distributing these certificates and CRLs to end entities.
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Note that an Attribute Authority (AA) might also choose to delegate
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the publication of CRLs to a CRL issuer.
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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+---+
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| C | +------------+
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| e | <-------------------->| End entity |
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| r | Operational +------------+
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| t | transactions ^
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| i | and management | Management
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| f | transactions | transactions PKI
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| i | | users
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| c | v
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| a | ======================= +--+------------+ ==============
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| t | ^ ^
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| e | | | PKI
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| | v | management
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| & | +------+ | entities
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| | <---------------------| RA |<----+ |
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| C | Publish certificate +------+ | |
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| R | | |
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| L | | |
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| | v v
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| R | +------------+
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| e | <------------------------------| CA |
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| p | Publish certificate +------------+
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| o | Publish CRL ^ ^
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| s | | | Management
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| i | +------------+ | | transactions
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| t | <--------------| CRL Issuer |<----+ |
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| o | Publish CRL +------------+ v
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| r | +------+
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| y | | CA |
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+---+ +------+
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Figure 1 - PKI Entities
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3.1 X.509 Version 3 Certificate
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Users of a public key require confidence that the associated private
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key is owned by the correct remote subject (person or system) with
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which an encryption or digital signature mechanism will be used.
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This confidence is obtained through the use of public key
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certificates, which are data structures that bind public key values
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to subjects. The binding is asserted by having a trusted CA
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digitally sign each certificate. The CA may base this assertion upon
441
technical means (a.k.a., proof of possession through a challenge-
442
response protocol), presentation of the private key, or on an
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assertion by the subject. A certificate has a limited valid lifetime
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which is indicated in its signed contents. Because a certificate's
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signature and timeliness can be independently checked by a
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certificate-using client, certificates can be distributed via
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RFC 3280 Internet X.509 Public Key Infrastructure April 2002
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untrusted communications and server systems, and can be cached in
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unsecured storage in certificate-using systems.
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ITU-T X.509 (formerly CCITT X.509) or ISO/IEC 9594-8, which was first
459
published in 1988 as part of the X.500 Directory recommendations,
460
defines a standard certificate format [X.509]. The certificate
461
format in the 1988 standard is called the version 1 (v1) format.
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When X.500 was revised in 1993, two more fields were added, resulting
463
in the version 2 (v2) format.
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The Internet Privacy Enhanced Mail (PEM) RFCs, published in 1993,
466
include specifications for a public key infrastructure based on X.509
467
v1 certificates [RFC 1422]. The experience gained in attempts to
468
deploy RFC 1422 made it clear that the v1 and v2 certificate formats
469
are deficient in several respects. Most importantly, more fields
470
were needed to carry information which PEM design and implementation
471
experience had proven necessary. In response to these new
472
requirements, ISO/IEC, ITU-T and ANSI X9 developed the X.509 version
473
3 (v3) certificate format. The v3 format extends the v2 format by
474
adding provision for additional extension fields. Particular
475
extension field types may be specified in standards or may be defined
476
and registered by any organization or community. In June 1996,
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standardization of the basic v3 format was completed [X.509].
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ISO/IEC, ITU-T, and ANSI X9 have also developed standard extensions
480
for use in the v3 extensions field [X.509][X9.55]. These extensions
481
can convey such data as additional subject identification
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information, key attribute information, policy information, and
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certification path constraints.
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However, the ISO/IEC, ITU-T, and ANSI X9 standard extensions are very
486
broad in their applicability. In order to develop interoperable
487
implementations of X.509 v3 systems for Internet use, it is necessary
488
to specify a profile for use of the X.509 v3 extensions tailored for
489
the Internet. It is one goal of this document to specify a profile
490
for Internet WWW, electronic mail, and IPsec applications.
491
Environments with additional requirements may build on this profile
492
or may replace it.
493
494
3.2 Certification Paths and Trust
495
496
A user of a security service requiring knowledge of a public key
497
generally needs to obtain and validate a certificate containing the
498
required public key. If the public key user does not already hold an
499
assured copy of the public key of the CA that signed the certificate,
500
the CA's name, and related information (such as the validity period
501
or name constraints), then it might need an additional certificate to
502
obtain that public key. In general, a chain of multiple certificates
503
504
505
506
Housley, et. al. Standards Track [Page 9]
507
508
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
509
510
511
may be needed, comprising a certificate of the public key owner (the
512
end entity) signed by one CA, and zero or more additional
513
certificates of CAs signed by other CAs. Such chains, called
514
certification paths, are required because a public key user is only
515
initialized with a limited number of assured CA public keys.
516
517
There are different ways in which CAs might be configured in order
518
for public key users to be able to find certification paths. For
519
PEM, RFC 1422 defined a rigid hierarchical structure of CAs. There
520
are three types of PEM certification authority:
521
522
(a) Internet Policy Registration Authority (IPRA): This
523
authority, operated under the auspices of the Internet Society,
524
acts as the root of the PEM certification hierarchy at level 1.
525
It issues certificates only for the next level of authorities,
526
PCAs. All certification paths start with the IPRA.
527
528
(b) Policy Certification Authorities (PCAs): PCAs are at level 2
529
of the hierarchy, each PCA being certified by the IPRA. A PCA
530
shall establish and publish a statement of its policy with respect
531
to certifying users or subordinate certification authorities.
532
Distinct PCAs aim to satisfy different user needs. For example,
533
one PCA (an organizational PCA) might support the general
534
electronic mail needs of commercial organizations, and another PCA
535
(a high-assurance PCA) might have a more stringent policy designed
536
for satisfying legally binding digital signature requirements.
537
538
(c) Certification Authorities (CAs): CAs are at level 3 of the
539
hierarchy and can also be at lower levels. Those at level 3 are
540
certified by PCAs. CAs represent, for example, particular
541
organizations, particular organizational units (e.g., departments,
542
groups, sections), or particular geographical areas.
543
544
RFC 1422 furthermore has a name subordination rule which requires
545
that a CA can only issue certificates for entities whose names are
546
subordinate (in the X.500 naming tree) to the name of the CA itself.
547
The trust associated with a PEM certification path is implied by the
548
PCA name. The name subordination rule ensures that CAs below the PCA
549
are sensibly constrained as to the set of subordinate entities they
550
can certify (e.g., a CA for an organization can only certify entities
551
in that organization's name tree). Certificate user systems are able
552
to mechanically check that the name subordination rule has been
553
followed.
554
555
The RFC 1422 uses the X.509 v1 certificate formats. The limitations
556
of X.509 v1 required imposition of several structural restrictions to
557
clearly associate policy information or restrict the utility of
558
certificates. These restrictions included:
559
560
561
562
Housley, et. al. Standards Track [Page 10]
563
564
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
565
566
567
(a) a pure top-down hierarchy, with all certification paths
568
starting from IPRA;
569
570
(b) a naming subordination rule restricting the names of a CA's
571
subjects; and
572
573
(c) use of the PCA concept, which requires knowledge of
574
individual PCAs to be built into certificate chain verification
575
logic. Knowledge of individual PCAs was required to determine if
576
a chain could be accepted.
577
578
With X.509 v3, most of the requirements addressed by RFC 1422 can be
579
addressed using certificate extensions, without a need to restrict
580
the CA structures used. In particular, the certificate extensions
581
relating to certificate policies obviate the need for PCAs and the
582
constraint extensions obviate the need for the name subordination
583
rule. As a result, this document supports a more flexible
584
architecture, including:
585
586
(a) Certification paths start with a public key of a CA in a
587
user's own domain, or with the public key of the top of a
588
hierarchy. Starting with the public key of a CA in a user's own
589
domain has certain advantages. In some environments, the local
590
domain is the most trusted.
591
592
(b) Name constraints may be imposed through explicit inclusion of
593
a name constraints extension in a certificate, but are not
594
required.
595
596
(c) Policy extensions and policy mappings replace the PCA
597
concept, which permits a greater degree of automation. The
598
application can determine if the certification path is acceptable
599
based on the contents of the certificates instead of a priori
600
knowledge of PCAs. This permits automation of certification path
601
processing.
602
603
3.3 Revocation
604
605
When a certificate is issued, it is expected to be in use for its
606
entire validity period. However, various circumstances may cause a
607
certificate to become invalid prior to the expiration of the validity
608
period. Such circumstances include change of name, change of
609
association between subject and CA (e.g., an employee terminates
610
employment with an organization), and compromise or suspected
611
compromise of the corresponding private key. Under such
612
circumstances, the CA needs to revoke the certificate.
613
614
615
616
617
618
Housley, et. al. Standards Track [Page 11]
619
620
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
621
622
623
X.509 defines one method of certificate revocation. This method
624
involves each CA periodically issuing a signed data structure called
625
a certificate revocation list (CRL). A CRL is a time stamped list
626
identifying revoked certificates which is signed by a CA or CRL
627
issuer and made freely available in a public repository. Each
628
revoked certificate is identified in a CRL by its certificate serial
629
number. When a certificate-using system uses a certificate (e.g.,
630
for verifying a remote user's digital signature), that system not
631
only checks the certificate signature and validity but also acquires
632
a suitably-recent CRL and checks that the certificate serial number
633
is not on that CRL. The meaning of "suitably-recent" may vary with
634
local policy, but it usually means the most recently-issued CRL. A
635
new CRL is issued on a regular periodic basis (e.g., hourly, daily,
636
or weekly). An entry is added to the CRL as part of the next update
637
following notification of revocation. An entry MUST NOT be removed
638
from the CRL until it appears on one regularly scheduled CRL issued
639
beyond the revoked certificate's validity period.
640
641
An advantage of this revocation method is that CRLs may be
642
distributed by exactly the same means as certificates themselves,
643
namely, via untrusted servers and untrusted communications.
644
645
One limitation of the CRL revocation method, using untrusted
646
communications and servers, is that the time granularity of
647
revocation is limited to the CRL issue period. For example, if a
648
revocation is reported now, that revocation will not be reliably
649
notified to certificate-using systems until all currently issued CRLs
650
are updated -- this may be up to one hour, one day, or one week
651
depending on the frequency that CRLs are issued.
652
653
As with the X.509 v3 certificate format, in order to facilitate
654
interoperable implementations from multiple vendors, the X.509 v2 CRL
655
format needs to be profiled for Internet use. It is one goal of this
656
document to specify that profile. However, this profile does not
657
require the issuance of CRLs. Message formats and protocols
658
supporting on-line revocation notification are defined in other PKIX
659
specifications. On-line methods of revocation notification may be
660
applicable in some environments as an alternative to the X.509 CRL.
661
On-line revocation checking may significantly reduce the latency
662
between a revocation report and the distribution of the information
663
to relying parties. Once the CA accepts a revocation report as
664
authentic and valid, any query to the on-line service will correctly
665
reflect the certificate validation impacts of the revocation.
666
However, these methods impose new security requirements: the
667
certificate validator needs to trust the on-line validation service
668
while the repository does not need to be trusted.
669
670
671
672
673
674
Housley, et. al. Standards Track [Page 12]
675
676
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
677
678
679
3.4 Operational Protocols
680
681
Operational protocols are required to deliver certificates and CRLs
682
(or status information) to certificate using client systems.
683
Provisions are needed for a variety of different means of certificate
684
and CRL delivery, including distribution procedures based on LDAP,
685
HTTP, FTP, and X.500. Operational protocols supporting these
686
functions are defined in other PKIX specifications. These
687
specifications may include definitions of message formats and
688
procedures for supporting all of the above operational environments,
689
including definitions of or references to appropriate MIME content
690
types.
691
692
3.5 Management Protocols
693
694
Management protocols are required to support on-line interactions
695
between PKI user and management entities. For example, a management
696
protocol might be used between a CA and a client system with which a
697
key pair is associated, or between two CAs which cross-certify each
698
other. The set of functions which potentially need to be supported
699
by management protocols include:
700
701
(a) registration: This is the process whereby a user first makes
702
itself known to a CA (directly, or through an RA), prior to that
703
CA issuing a certificate or certificates for that user.
704
705
(b) initialization: Before a client system can operate securely
706
it is necessary to install key materials which have the
707
appropriate relationship with keys stored elsewhere in the
708
infrastructure. For example, the client needs to be securely
709
initialized with the public key and other assured information of
710
the trusted CA(s), to be used in validating certificate paths.
711
712
Furthermore, a client typically needs to be initialized with its
713
own key pair(s).
714
715
(c) certification: This is the process in which a CA issues a
716
certificate for a user's public key, and returns that certificate
717
to the user's client system and/or posts that certificate in a
718
repository.
719
720
(d) key pair recovery: As an option, user client key materials
721
(e.g., a user's private key used for encryption purposes) may be
722
backed up by a CA or a key backup system. If a user needs to
723
recover these backed up key materials (e.g., as a result of a
724
forgotten password or a lost key chain file), an on-line protocol
725
exchange may be needed to support such recovery.
726
727
728
729
730
Housley, et. al. Standards Track [Page 13]
731
732
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
733
734
735
(e) key pair update: All key pairs need to be updated regularly,
736
i.e., replaced with a new key pair, and new certificates issued.
737
738
(f) revocation request: An authorized person advises a CA of an
739
abnormal situation requiring certificate revocation.
740
741
(g) cross-certification: Two CAs exchange information used in
742
establishing a cross-certificate. A cross-certificate is a
743
certificate issued by one CA to another CA which contains a CA
744
signature key used for issuing certificates.
745
746
Note that on-line protocols are not the only way of implementing the
747
above functions. For all functions there are off-line methods of
748
achieving the same result, and this specification does not mandate
749
use of on-line protocols. For example, when hardware tokens are
750
used, many of the functions may be achieved as part of the physical
751
token delivery. Furthermore, some of the above functions may be
752
combined into one protocol exchange. In particular, two or more of
753
the registration, initialization, and certification functions can be
754
combined into one protocol exchange.
755
756
The PKIX series of specifications defines a set of standard message
757
formats supporting the above functions. The protocols for conveying
758
these messages in different environments (e.g., e-mail, file
759
transfer, and WWW) are described in those specifications.
760
761
4 Certificate and Certificate Extensions Profile
762
763
This section presents a profile for public key certificates that will
764
foster interoperability and a reusable PKI. This section is based
765
upon the X.509 v3 certificate format and the standard certificate
766
extensions defined in [X.509]. The ISO/IEC and ITU-T documents use
767
the 1997 version of ASN.1; while this document uses the 1988 ASN.1
768
syntax, the encoded certificate and standard extensions are
769
equivalent. This section also defines private extensions required to
770
support a PKI for the Internet community.
771
772
Certificates may be used in a wide range of applications and
773
environments covering a broad spectrum of interoperability goals and
774
a broader spectrum of operational and assurance requirements. The
775
goal of this document is to establish a common baseline for generic
776
applications requiring broad interoperability and limited special
777
purpose requirements. In particular, the emphasis will be on
778
supporting the use of X.509 v3 certificates for informal Internet
779
electronic mail, IPsec, and WWW applications.
780
781
782
783
784
785
786
Housley, et. al. Standards Track [Page 14]
787
788
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
789
790
791
4.1 Basic Certificate Fields
792
793
The X.509 v3 certificate basic syntax is as follows. For signature
794
calculation, the data that is to be signed is encoded using the ASN.1
795
distinguished encoding rules (DER) [X.690]. ASN.1 DER encoding is a
796
tag, length, value encoding system for each element.
797
798
Certificate ::= SEQUENCE {
799
tbsCertificate TBSCertificate,
800
signatureAlgorithm AlgorithmIdentifier,
801
signatureValue BIT STRING }
802
803
TBSCertificate ::= SEQUENCE {
804
version [0] EXPLICIT Version DEFAULT v1,
805
serialNumber CertificateSerialNumber,
806
signature AlgorithmIdentifier,
807
issuer Name,
808
validity Validity,
809
subject Name,
810
subjectPublicKeyInfo SubjectPublicKeyInfo,
811
issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
812
-- If present, version MUST be v2 or v3
813
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
814
-- If present, version MUST be v2 or v3
815
extensions [3] EXPLICIT Extensions OPTIONAL
816
-- If present, version MUST be v3
817
}
818
819
Version ::= INTEGER { v1(0), v2(1), v3(2) }
820
821
CertificateSerialNumber ::= INTEGER
822
823
Validity ::= SEQUENCE {
824
notBefore Time,
825
notAfter Time }
826
827
Time ::= CHOICE {
828
utcTime UTCTime,
829
generalTime GeneralizedTime }
830
831
UniqueIdentifier ::= BIT STRING
832
833
SubjectPublicKeyInfo ::= SEQUENCE {
834
algorithm AlgorithmIdentifier,
835
subjectPublicKey BIT STRING }
836
837
Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
838
839
840
841
842
Housley, et. al. Standards Track [Page 15]
843
844
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
845
846
847
Extension ::= SEQUENCE {
848
extnID OBJECT IDENTIFIER,
849
critical BOOLEAN DEFAULT FALSE,
850
extnValue OCTET STRING }
851
852
The following items describe the X.509 v3 certificate for use in the
853
Internet.
854
855
4.1.1 Certificate Fields
856
857
The Certificate is a SEQUENCE of three required fields. The fields
858
are described in detail in the following subsections.
859
860
4.1.1.1 tbsCertificate
861
862
The field contains the names of the subject and issuer, a public key
863
associated with the subject, a validity period, and other associated
864
information. The fields are described in detail in section 4.1.2;
865
the tbsCertificate usually includes extensions which are described in
866
section 4.2.
867
868
4.1.1.2 signatureAlgorithm
869
870
The signatureAlgorithm field contains the identifier for the
871
cryptographic algorithm used by the CA to sign this certificate.
872
[PKIXALGS] lists supported signature algorithms, but other signature
873
algorithms MAY also be supported.
874
875
An algorithm identifier is defined by the following ASN.1 structure:
876
877
AlgorithmIdentifier ::= SEQUENCE {
878
algorithm OBJECT IDENTIFIER,
879
parameters ANY DEFINED BY algorithm OPTIONAL }
880
881
The algorithm identifier is used to identify a cryptographic
882
algorithm. The OBJECT IDENTIFIER component identifies the algorithm
883
(such as DSA with SHA-1). The contents of the optional parameters
884
field will vary according to the algorithm identified.
885
886
This field MUST contain the same algorithm identifier as the
887
signature field in the sequence tbsCertificate (section 4.1.2.3).
888
889
4.1.1.3 signatureValue
890
891
The signatureValue field contains a digital signature computed upon
892
the ASN.1 DER encoded tbsCertificate. The ASN.1 DER encoded
893
tbsCertificate is used as the input to the signature function. This
894
895
896
897
898
Housley, et. al. Standards Track [Page 16]
899
900
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
901
902
903
signature value is encoded as a BIT STRING and included in the
904
signature field. The details of this process are specified for each
905
of algorithms listed in [PKIXALGS].
906
907
By generating this signature, a CA certifies the validity of the
908
information in the tbsCertificate field. In particular, the CA
909
certifies the binding between the public key material and the subject
910
of the certificate.
911
912
4.1.2 TBSCertificate
913
914
The sequence TBSCertificate contains information associated with the
915
subject of the certificate and the CA who issued it. Every
916
TBSCertificate contains the names of the subject and issuer, a public
917
key associated with the subject, a validity period, a version number,
918
and a serial number; some MAY contain optional unique identifier
919
fields. The remainder of this section describes the syntax and
920
semantics of these fields. A TBSCertificate usually includes
921
extensions. Extensions for the Internet PKI are described in Section
922
4.2.
923
924
4.1.2.1 Version
925
926
This field describes the version of the encoded certificate. When
927
extensions are used, as expected in this profile, version MUST be 3
928
(value is 2). If no extensions are present, but a UniqueIdentifier
929
is present, the version SHOULD be 2 (value is 1); however version MAY
930
be 3. If only basic fields are present, the version SHOULD be 1 (the
931
value is omitted from the certificate as the default value); however
932
the version MAY be 2 or 3.
933
934
Implementations SHOULD be prepared to accept any version certificate.
935
At a minimum, conforming implementations MUST recognize version 3
936
certificates.
937
938
Generation of version 2 certificates is not expected by
939
implementations based on this profile.
940
941
4.1.2.2 Serial number
942
943
The serial number MUST be a positive integer assigned by the CA to
944
each certificate. It MUST be unique for each certificate issued by a
945
given CA (i.e., the issuer name and serial number identify a unique
946
certificate). CAs MUST force the serialNumber to be a non-negative
947
integer.
948
949
950
951
952
953
954
Housley, et. al. Standards Track [Page 17]
955
956
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
957
958
959
Given the uniqueness requirements above, serial numbers can be
960
expected to contain long integers. Certificate users MUST be able to
961
handle serialNumber values up to 20 octets. Conformant CAs MUST NOT
962
use serialNumber values longer than 20 octets.
963
964
Note: Non-conforming CAs may issue certificates with serial numbers
965
that are negative, or zero. Certificate users SHOULD be prepared to
966
gracefully handle such certificates.
967
968
4.1.2.3 Signature
969
970
This field contains the algorithm identifier for the algorithm used
971
by the CA to sign the certificate.
972
973
This field MUST contain the same algorithm identifier as the
974
signatureAlgorithm field in the sequence Certificate (section
975
4.1.1.2). The contents of the optional parameters field will vary
976
according to the algorithm identified. [PKIXALGS] lists the
977
supported signature algorithms, but other signature algorithms MAY
978
also be supported.
979
980
4.1.2.4 Issuer
981
982
The issuer field identifies the entity who has signed and issued the
983
certificate. The issuer field MUST contain a non-empty distinguished
984
name (DN). The issuer field is defined as the X.501 type Name
985
[X.501]. Name is defined by the following ASN.1 structures:
986
987
Name ::= CHOICE {
988
RDNSequence }
989
990
RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
991
992
RelativeDistinguishedName ::=
993
SET OF AttributeTypeAndValue
994
995
AttributeTypeAndValue ::= SEQUENCE {
996
type AttributeType,
997
value AttributeValue }
998
999
AttributeType ::= OBJECT IDENTIFIER
1000
1001
AttributeValue ::= ANY DEFINED BY AttributeType
1002
1003
1004
1005
1006
1007
1008
1009
1010
Housley, et. al. Standards Track [Page 18]
1011
1012
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1013
1014
1015
DirectoryString ::= CHOICE {
1016
teletexString TeletexString (SIZE (1..MAX)),
1017
printableString PrintableString (SIZE (1..MAX)),
1018
universalString UniversalString (SIZE (1..MAX)),
1019
utf8String UTF8String (SIZE (1..MAX)),
1020
bmpString BMPString (SIZE (1..MAX)) }
1021
1022
The Name describes a hierarchical name composed of attributes, such
1023
as country name, and corresponding values, such as US. The type of
1024
the component AttributeValue is determined by the AttributeType; in
1025
general it will be a DirectoryString.
1026
1027
The DirectoryString type is defined as a choice of PrintableString,
1028
TeletexString, BMPString, UTF8String, and UniversalString. The
1029
UTF8String encoding [RFC 2279] is the preferred encoding, and all
1030
certificates issued after December 31, 2003 MUST use the UTF8String
1031
encoding of DirectoryString (except as noted below). Until that
1032
date, conforming CAs MUST choose from the following options when
1033
creating a distinguished name, including their own:
1034
1035
(a) if the character set is sufficient, the string MAY be
1036
represented as a PrintableString;
1037
1038
(b) failing (a), if the BMPString character set is sufficient the
1039
string MAY be represented as a BMPString; and
1040
1041
(c) failing (a) and (b), the string MUST be represented as a
1042
UTF8String. If (a) or (b) is satisfied, the CA MAY still choose
1043
to represent the string as a UTF8String.
1044
1045
Exceptions to the December 31, 2003 UTF8 encoding requirements are as
1046
follows:
1047
1048
(a) CAs MAY issue "name rollover" certificates to support an
1049
orderly migration to UTF8String encoding. Such certificates would
1050
include the CA's UTF8String encoded name as issuer and and the old
1051
name encoding as subject, or vice-versa.
1052
1053
(b) As stated in section 4.1.2.6, the subject field MUST be
1054
populated with a non-empty distinguished name matching the
1055
contents of the issuer field in all certificates issued by the
1056
subject CA regardless of encoding.
1057
1058
The TeletexString and UniversalString are included for backward
1059
compatibility, and SHOULD NOT be used for certificates for new
1060
subjects. However, these types MAY be used in certificates where the
1061
name was previously established. Certificate users SHOULD be
1062
prepared to receive certificates with these types.
1063
1064
1065
1066
Housley, et. al. Standards Track [Page 19]
1067
1068
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1069
1070
1071
In addition, many legacy implementations support names encoded in the
1072
ISO 8859-1 character set (Latin1String) [ISO 8859-1] but tag them as
1073
TeletexString. TeletexString encodes a larger character set than ISO
1074
8859-1, but it encodes some characters differently. Implementations
1075
SHOULD be prepared to handle both encodings.
1076
1077
As noted above, distinguished names are composed of attributes. This
1078
specification does not restrict the set of attribute types that may
1079
appear in names. However, conforming implementations MUST be
1080
prepared to receive certificates with issuer names containing the set
1081
of attribute types defined below. This specification RECOMMENDS
1082
support for additional attribute types.
1083
1084
Standard sets of attributes have been defined in the X.500 series of
1085
specifications [X.520]. Implementations of this specification MUST
1086
be prepared to receive the following standard attribute types in
1087
issuer and subject (section 4.1.2.6) names:
1088
1089
* country,
1090
* organization,
1091
* organizational-unit,
1092
* distinguished name qualifier,
1093
* state or province name,
1094
* common name (e.g., "Susan Housley"), and
1095
* serial number.
1096
1097
In addition, implementations of this specification SHOULD be prepared
1098
to receive the following standard attribute types in issuer and
1099
subject names:
1100
1101
* locality,
1102
* title,
1103
* surname,
1104
* given name,
1105
* initials,
1106
* pseudonym, and
1107
* generation qualifier (e.g., "Jr.", "3rd", or "IV").
1108
1109
The syntax and associated object identifiers (OIDs) for these
1110
attribute types are provided in the ASN.1 modules in Appendix A.
1111
1112
In addition, implementations of this specification MUST be prepared
1113
to receive the domainComponent attribute, as defined in [RFC 2247].
1114
The Domain Name System (DNS) provides a hierarchical resource
1115
labeling system. This attribute provides a convenient mechanism for
1116
organizations that wish to use DNs that parallel their DNS names.
1117
This is not a replacement for the dNSName component of the
1118
1119
1120
1121
1122
Housley, et. al. Standards Track [Page 20]
1123
1124
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1125
1126
1127
alternative name field. Implementations are not required to convert
1128
such names into DNS names. The syntax and associated OID for this
1129
attribute type is provided in the ASN.1 modules in Appendix A.
1130
1131
Certificate users MUST be prepared to process the issuer
1132
distinguished name and subject distinguished name (section 4.1.2.6)
1133
fields to perform name chaining for certification path validation
1134
(section 6). Name chaining is performed by matching the issuer
1135
distinguished name in one certificate with the subject name in a CA
1136
certificate.
1137
1138
This specification requires only a subset of the name comparison
1139
functionality specified in the X.500 series of specifications.
1140
Conforming implementations are REQUIRED to implement the following
1141
name comparison rules:
1142
1143
(a) attribute values encoded in different types (e.g.,
1144
PrintableString and BMPString) MAY be assumed to represent
1145
different strings;
1146
1147
(b) attribute values in types other than PrintableString are case
1148
sensitive (this permits matching of attribute values as binary
1149
objects);
1150
1151
(c) attribute values in PrintableString are not case sensitive
1152
(e.g., "Marianne Swanson" is the same as "MARIANNE SWANSON"); and
1153
1154
(d) attribute values in PrintableString are compared after
1155
removing leading and trailing white space and converting internal
1156
substrings of one or more consecutive white space characters to a
1157
single space.
1158
1159
These name comparison rules permit a certificate user to validate
1160
certificates issued using languages or encodings unfamiliar to the
1161
certificate user.
1162
1163
In addition, implementations of this specification MAY use these
1164
comparison rules to process unfamiliar attribute types for name
1165
chaining. This allows implementations to process certificates with
1166
unfamiliar attributes in the issuer name.
1167
1168
Note that the comparison rules defined in the X.500 series of
1169
specifications indicate that the character sets used to encode data
1170
in distinguished names are irrelevant. The characters themselves are
1171
compared without regard to encoding. Implementations of this profile
1172
are permitted to use the comparison algorithm defined in the X.500
1173
series. Such an implementation will recognize a superset of name
1174
matches recognized by the algorithm specified above.
1175
1176
1177
1178
Housley, et. al. Standards Track [Page 21]
1179
1180
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1181
1182
1183
4.1.2.5 Validity
1184
1185
The certificate validity period is the time interval during which the
1186
CA warrants that it will maintain information about the status of the
1187
certificate. The field is represented as a SEQUENCE of two dates:
1188
the date on which the certificate validity period begins (notBefore)
1189
and the date on which the certificate validity period ends
1190
(notAfter). Both notBefore and notAfter may be encoded as UTCTime or
1191
GeneralizedTime.
1192
1193
CAs conforming to this profile MUST always encode certificate
1194
validity dates through the year 2049 as UTCTime; certificate validity
1195
dates in 2050 or later MUST be encoded as GeneralizedTime.
1196
1197
The validity period for a certificate is the period of time from
1198
notBefore through notAfter, inclusive.
1199
1200
4.1.2.5.1 UTCTime
1201
1202
The universal time type, UTCTime, is a standard ASN.1 type intended
1203
for representation of dates and time. UTCTime specifies the year
1204
through the two low order digits and time is specified to the
1205
precision of one minute or one second. UTCTime includes either Z
1206
(for Zulu, or Greenwich Mean Time) or a time differential.
1207
1208
For the purposes of this profile, UTCTime values MUST be expressed
1209
Greenwich Mean Time (Zulu) and MUST include seconds (i.e., times are
1210
YYMMDDHHMMSSZ), even where the number of seconds is zero. Conforming
1211
systems MUST interpret the year field (YY) as follows:
1212
1213
Where YY is greater than or equal to 50, the year SHALL be
1214
interpreted as 19YY; and
1215
1216
Where YY is less than 50, the year SHALL be interpreted as 20YY.
1217
1218
4.1.2.5.2 GeneralizedTime
1219
1220
The generalized time type, GeneralizedTime, is a standard ASN.1 type
1221
for variable precision representation of time. Optionally, the
1222
GeneralizedTime field can include a representation of the time
1223
differential between local and Greenwich Mean Time.
1224
1225
For the purposes of this profile, GeneralizedTime values MUST be
1226
expressed Greenwich Mean Time (Zulu) and MUST include seconds (i.e.,
1227
times are YYYYMMDDHHMMSSZ), even where the number of seconds is zero.
1228
GeneralizedTime values MUST NOT include fractional seconds.
1229
1230
1231
1232
1233
1234
Housley, et. al. Standards Track [Page 22]
1235
1236
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1237
1238
1239
4.1.2.6 Subject
1240
1241
The subject field identifies the entity associated with the public
1242
key stored in the subject public key field. The subject name MAY be
1243
carried in the subject field and/or the subjectAltName extension. If
1244
the subject is a CA (e.g., the basic constraints extension, as
1245
discussed in 4.2.1.10, is present and the value of cA is TRUE), then
1246
the subject field MUST be populated with a non-empty distinguished
1247
name matching the contents of the issuer field (section 4.1.2.4) in
1248
all certificates issued by the subject CA. If the subject is a CRL
1249
issuer (e.g., the key usage extension, as discussed in 4.2.1.3, is
1250
present and the value of cRLSign is TRUE) then the subject field MUST
1251
be populated with a non-empty distinguished name matching the
1252
contents of the issuer field (section 4.1.2.4) in all CRLs issued by
1253
the subject CRL issuer. If subject naming information is present
1254
only in the subjectAltName extension (e.g., a key bound only to an
1255
email address or URI), then the subject name MUST be an empty
1256
sequence and the subjectAltName extension MUST be critical.
1257
1258
Where it is non-empty, the subject field MUST contain an X.500
1259
distinguished name (DN). The DN MUST be unique for each subject
1260
entity certified by the one CA as defined by the issuer name field.
1261
A CA MAY issue more than one certificate with the same DN to the same
1262
subject entity.
1263
1264
The subject name field is defined as the X.501 type Name.
1265
Implementation requirements for this field are those defined for the
1266
issuer field (section 4.1.2.4). When encoding attribute values of
1267
type DirectoryString, the encoding rules for the issuer field MUST be
1268
implemented. Implementations of this specification MUST be prepared
1269
to receive subject names containing the attribute types required for
1270
the issuer field. Implementations of this specification SHOULD be
1271
prepared to receive subject names containing the recommended
1272
attribute types for the issuer field. The syntax and associated
1273
object identifiers (OIDs) for these attribute types are provided in
1274
the ASN.1 modules in Appendix A. Implementations of this
1275
specification MAY use these comparison rules to process unfamiliar
1276
attribute types (i.e., for name chaining). This allows
1277
implementations to process certificates with unfamiliar attributes in
1278
the subject name.
1279
1280
In addition, legacy implementations exist where an RFC 822 name is
1281
embedded in the subject distinguished name as an EmailAddress
1282
attribute. The attribute value for EmailAddress is of type IA5String
1283
to permit inclusion of the character '@', which is not part of the
1284
PrintableString character set. EmailAddress attribute values are not
1285
case sensitive (e.g., "fanfeedback@redsox.com" is the same as
1286
"FANFEEDBACK@REDSOX.COM").
1287
1288
1289
1290
Housley, et. al. Standards Track [Page 23]
1291
1292
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1293
1294
1295
Conforming implementations generating new certificates with
1296
electronic mail addresses MUST use the rfc822Name in the subject
1297
alternative name field (section 4.2.1.7) to describe such identities.
1298
Simultaneous inclusion of the EmailAddress attribute in the subject
1299
distinguished name to support legacy implementations is deprecated
1300
but permitted.
1301
1302
4.1.2.7 Subject Public Key Info
1303
1304
This field is used to carry the public key and identify the algorithm
1305
with which the key is used (e.g., RSA, DSA, or Diffie-Hellman). The
1306
algorithm is identified using the AlgorithmIdentifier structure
1307
specified in section 4.1.1.2. The object identifiers for the
1308
supported algorithms and the methods for encoding the public key
1309
materials (public key and parameters) are specified in [PKIXALGS].
1310
1311
4.1.2.8 Unique Identifiers
1312
1313
These fields MUST only appear if the version is 2 or 3 (section
1314
4.1.2.1). These fields MUST NOT appear if the version is 1. The
1315
subject and issuer unique identifiers are present in the certificate
1316
to handle the possibility of reuse of subject and/or issuer names
1317
over time. This profile RECOMMENDS that names not be reused for
1318
different entities and that Internet certificates not make use of
1319
unique identifiers. CAs conforming to this profile SHOULD NOT
1320
generate certificates with unique identifiers. Applications
1321
conforming to this profile SHOULD be capable of parsing unique
1322
identifiers.
1323
1324
4.1.2.9 Extensions
1325
1326
This field MUST only appear if the version is 3 (section 4.1.2.1).
1327
If present, this field is a SEQUENCE of one or more certificate
1328
extensions. The format and content of certificate extensions in the
1329
Internet PKI is defined in section 4.2.
1330
1331
4.2 Certificate Extensions
1332
1333
The extensions defined for X.509 v3 certificates provide methods for
1334
associating additional attributes with users or public keys and for
1335
managing a certification hierarchy. The X.509 v3 certificate format
1336
also allows communities to define private extensions to carry
1337
information unique to those communities. Each extension in a
1338
certificate is designated as either critical or non-critical. A
1339
certificate using system MUST reject the certificate if it encounters
1340
a critical extension it does not recognize; however, a non-critical
1341
extension MAY be ignored if it is not recognized. The following
1342
sections present recommended extensions used within Internet
1343
1344
1345
1346
Housley, et. al. Standards Track [Page 24]
1347
1348
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1349
1350
1351
certificates and standard locations for information. Communities may
1352
elect to use additional extensions; however, caution ought to be
1353
exercised in adopting any critical extensions in certificates which
1354
might prevent use in a general context.
1355
1356
Each extension includes an OID and an ASN.1 structure. When an
1357
extension appears in a certificate, the OID appears as the field
1358
extnID and the corresponding ASN.1 encoded structure is the value of
1359
the octet string extnValue. A certificate MUST NOT include more than
1360
one instance of a particular extension. For example, a certificate
1361
may contain only one authority key identifier extension (section
1362
4.2.1.1). An extension includes the boolean critical, with a default
1363
value of FALSE. The text for each extension specifies the acceptable
1364
values for the critical field.
1365
1366
Conforming CAs MUST support key identifiers (sections 4.2.1.1 and
1367
4.2.1.2), basic constraints (section 4.2.1.10), key usage (section
1368
4.2.1.3), and certificate policies (section 4.2.1.5) extensions. If
1369
the CA issues certificates with an empty sequence for the subject
1370
field, the CA MUST support the subject alternative name extension
1371
(section 4.2.1.7). Support for the remaining extensions is OPTIONAL.
1372
Conforming CAs MAY support extensions that are not identified within
1373
this specification; certificate issuers are cautioned that marking
1374
such extensions as critical may inhibit interoperability.
1375
1376
At a minimum, applications conforming to this profile MUST recognize
1377
the following extensions: key usage (section 4.2.1.3), certificate
1378
policies (section 4.2.1.5), the subject alternative name (section
1379
4.2.1.7), basic constraints (section 4.2.1.10), name constraints
1380
(section 4.2.1.11), policy constraints (section 4.2.1.12), extended
1381
key usage (section 4.2.1.13), and inhibit any-policy (section
1382
4.2.1.15).
1383
1384
In addition, applications conforming to this profile SHOULD recognize
1385
the authority and subject key identifier (sections 4.2.1.1 and
1386
4.2.1.2), and policy mapping (section 4.2.1.6) extensions.
1387
1388
4.2.1 Standard Extensions
1389
1390
This section identifies standard certificate extensions defined in
1391
[X.509] for use in the Internet PKI. Each extension is associated
1392
with an OID defined in [X.509]. These OIDs are members of the id-ce
1393
arc, which is defined by the following:
1394
1395
id-ce OBJECT IDENTIFIER ::= { joint-iso-ccitt(2) ds(5) 29 }
1396
1397
1398
1399
1400
1401
1402
Housley, et. al. Standards Track [Page 25]
1403
1404
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1405
1406
1407
4.2.1.1 Authority Key Identifier
1408
1409
The authority key identifier extension provides a means of
1410
identifying the public key corresponding to the private key used to
1411
sign a certificate. This extension is used where an issuer has
1412
multiple signing keys (either due to multiple concurrent key pairs or
1413
due to changeover). The identification MAY be based on either the
1414
key identifier (the subject key identifier in the issuer's
1415
certificate) or on the issuer name and serial number.
1416
1417
The keyIdentifier field of the authorityKeyIdentifier extension MUST
1418
be included in all certificates generated by conforming CAs to
1419
facilitate certification path construction. There is one exception;
1420
where a CA distributes its public key in the form of a "self-signed"
1421
certificate, the authority key identifier MAY be omitted. The
1422
signature on a self-signed certificate is generated with the private
1423
key associated with the certificate's subject public key. (This
1424
proves that the issuer possesses both the public and private keys.)
1425
In this case, the subject and authority key identifiers would be
1426
identical, but only the subject key identifier is needed for
1427
certification path building.
1428
1429
The value of the keyIdentifier field SHOULD be derived from the
1430
public key used to verify the certificate's signature or a method
1431
that generates unique values. Two common methods for generating key
1432
identifiers from the public key, and one common method for generating
1433
unique values, are described in section 4.2.1.2. Where a key
1434
identifier has not been previously established, this specification
1435
RECOMMENDS use of one of these methods for generating keyIdentifiers.
1436
Where a key identifier has been previously established, the CA SHOULD
1437
use the previously established identifier.
1438
1439
This profile RECOMMENDS support for the key identifier method by all
1440
certificate users.
1441
1442
This extension MUST NOT be marked critical.
1443
1444
id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 }
1445
1446
AuthorityKeyIdentifier ::= SEQUENCE {
1447
keyIdentifier [0] KeyIdentifier OPTIONAL,
1448
authorityCertIssuer [1] GeneralNames OPTIONAL,
1449
authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
1450
1451
KeyIdentifier ::= OCTET STRING
1452
1453
1454
1455
1456
1457
1458
Housley, et. al. Standards Track [Page 26]
1459
1460
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1461
1462
1463
4.2.1.2 Subject Key Identifier
1464
1465
The subject key identifier extension provides a means of identifying
1466
certificates that contain a particular public key.
1467
1468
To facilitate certification path construction, this extension MUST
1469
appear in all conforming CA certificates, that is, all certificates
1470
including the basic constraints extension (section 4.2.1.10) where
1471
the value of cA is TRUE. The value of the subject key identifier
1472
MUST be the value placed in the key identifier field of the Authority
1473
Key Identifier extension (section 4.2.1.1) of certificates issued by
1474
the subject of this certificate.
1475
1476
For CA certificates, subject key identifiers SHOULD be derived from
1477
the public key or a method that generates unique values. Two common
1478
methods for generating key identifiers from the public key are:
1479
1480
(1) The keyIdentifier is composed of the 160-bit SHA-1 hash of the
1481
value of the BIT STRING subjectPublicKey (excluding the tag,
1482
length, and number of unused bits).
1483
1484
(2) The keyIdentifier is composed of a four bit type field with
1485
the value 0100 followed by the least significant 60 bits of the
1486
SHA-1 hash of the value of the BIT STRING subjectPublicKey
1487
(excluding the tag, length, and number of unused bit string bits).
1488
1489
One common method for generating unique values is a monotonically
1490
increasing sequence of integers.
1491
1492
For end entity certificates, the subject key identifier extension
1493
provides a means for identifying certificates containing the
1494
particular public key used in an application. Where an end entity
1495
has obtained multiple certificates, especially from multiple CAs, the
1496
subject key identifier provides a means to quickly identify the set
1497
of certificates containing a particular public key. To assist
1498
applications in identifying the appropriate end entity certificate,
1499
this extension SHOULD be included in all end entity certificates.
1500
1501
For end entity certificates, subject key identifiers SHOULD be
1502
derived from the public key. Two common methods for generating key
1503
identifiers from the public key are identified above.
1504
1505
Where a key identifier has not been previously established, this
1506
specification RECOMMENDS use of one of these methods for generating
1507
keyIdentifiers. Where a key identifier has been previously
1508
established, the CA SHOULD use the previously established identifier.
1509
1510
This extension MUST NOT be marked critical.
1511
1512
1513
1514
Housley, et. al. Standards Track [Page 27]
1515
1516
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1517
1518
1519
id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 14 }
1520
1521
SubjectKeyIdentifier ::= KeyIdentifier
1522
1523
4.2.1.3 Key Usage
1524
1525
The key usage extension defines the purpose (e.g., encipherment,
1526
signature, certificate signing) of the key contained in the
1527
certificate. The usage restriction might be employed when a key that
1528
could be used for more than one operation is to be restricted. For
1529
example, when an RSA key should be used only to verify signatures on
1530
objects other than public key certificates and CRLs, the
1531
digitalSignature and/or nonRepudiation bits would be asserted.
1532
Likewise, when an RSA key should be used only for key management, the
1533
keyEncipherment bit would be asserted.
1534
1535
This extension MUST appear in certificates that contain public keys
1536
that are used to validate digital signatures on other public key
1537
certificates or CRLs. When this extension appears, it SHOULD be
1538
marked critical.
1539
1540
id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 }
1541
1542
KeyUsage ::= BIT STRING {
1543
digitalSignature (0),
1544
nonRepudiation (1),
1545
keyEncipherment (2),
1546
dataEncipherment (3),
1547
keyAgreement (4),
1548
keyCertSign (5),
1549
cRLSign (6),
1550
encipherOnly (7),
1551
decipherOnly (8) }
1552
1553
Bits in the KeyUsage type are used as follows:
1554
1555
The digitalSignature bit is asserted when the subject public key
1556
is used with a digital signature mechanism to support security
1557
services other than certificate signing (bit 5), or CRL signing
1558
(bit 6). Digital signature mechanisms are often used for entity
1559
authentication and data origin authentication with integrity.
1560
1561
The nonRepudiation bit is asserted when the subject public key is
1562
used to verify digital signatures used to provide a non-
1563
repudiation service which protects against the signing entity
1564
falsely denying some action, excluding certificate or CRL signing.
1565
In the case of later conflict, a reliable third party may
1566
determine the authenticity of the signed data.
1567
1568
1569
1570
Housley, et. al. Standards Track [Page 28]
1571
1572
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1573
1574
1575
Further distinctions between the digitalSignature and
1576
nonRepudiation bits may be provided in specific certificate
1577
policies.
1578
1579
The keyEncipherment bit is asserted when the subject public key is
1580
used for key transport. For example, when an RSA key is to be
1581
used for key management, then this bit is set.
1582
1583
The dataEncipherment bit is asserted when the subject public key
1584
is used for enciphering user data, other than cryptographic keys.
1585
1586
The keyAgreement bit is asserted when the subject public key is
1587
used for key agreement. For example, when a Diffie-Hellman key is
1588
to be used for key management, then this bit is set.
1589
1590
The keyCertSign bit is asserted when the subject public key is
1591
used for verifying a signature on public key certificates. If the
1592
keyCertSign bit is asserted, then the cA bit in the basic
1593
constraints extension (section 4.2.1.10) MUST also be asserted.
1594
1595
The cRLSign bit is asserted when the subject public key is used
1596
for verifying a signature on certificate revocation list (e.g., a
1597
CRL, delta CRL, or an ARL). This bit MUST be asserted in
1598
certificates that are used to verify signatures on CRLs.
1599
1600
The meaning of the encipherOnly bit is undefined in the absence of
1601
the keyAgreement bit. When the encipherOnly bit is asserted and
1602
the keyAgreement bit is also set, the subject public key may be
1603
used only for enciphering data while performing key agreement.
1604
1605
The meaning of the decipherOnly bit is undefined in the absence of
1606
the keyAgreement bit. When the decipherOnly bit is asserted and
1607
the keyAgreement bit is also set, the subject public key may be
1608
used only for deciphering data while performing key agreement.
1609
1610
This profile does not restrict the combinations of bits that may be
1611
set in an instantiation of the keyUsage extension. However,
1612
appropriate values for keyUsage extensions for particular algorithms
1613
are specified in [PKIXALGS].
1614
1615
4.2.1.4 Private Key Usage Period
1616
1617
This extension SHOULD NOT be used within the Internet PKI. CAs
1618
conforming to this profile MUST NOT generate certificates that
1619
include a critical private key usage period extension.
1620
1621
1622
1623
1624
1625
1626
Housley, et. al. Standards Track [Page 29]
1627
1628
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1629
1630
1631
The private key usage period extension allows the certificate issuer
1632
to specify a different validity period for the private key than the
1633
certificate. This extension is intended for use with digital
1634
signature keys. This extension consists of two optional components,
1635
notBefore and notAfter. The private key associated with the
1636
certificate SHOULD NOT be used to sign objects before or after the
1637
times specified by the two components, respectively. CAs conforming
1638
to this profile MUST NOT generate certificates with private key usage
1639
period extensions unless at least one of the two components is
1640
present and the extension is non-critical.
1641
1642
Where used, notBefore and notAfter are represented as GeneralizedTime
1643
and MUST be specified and interpreted as defined in section
1644
4.1.2.5.2.
1645
1646
id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= { id-ce 16 }
1647
1648
PrivateKeyUsagePeriod ::= SEQUENCE {
1649
notBefore [0] GeneralizedTime OPTIONAL,
1650
notAfter [1] GeneralizedTime OPTIONAL }
1651
1652
4.2.1.5 Certificate Policies
1653
1654
The certificate policies extension contains a sequence of one or more
1655
policy information terms, each of which consists of an object
1656
identifier (OID) and optional qualifiers. Optional qualifiers, which
1657
MAY be present, are not expected to change the definition of the
1658
policy.
1659
1660
In an end entity certificate, these policy information terms indicate
1661
the policy under which the certificate has been issued and the
1662
purposes for which the certificate may be used. In a CA certificate,
1663
these policy information terms limit the set of policies for
1664
certification paths which include this certificate. When a CA does
1665
not wish to limit the set of policies for certification paths which
1666
include this certificate, it MAY assert the special policy anyPolicy,
1667
with a value of { 2 5 29 32 0 }.
1668
1669
Applications with specific policy requirements are expected to have a
1670
list of those policies which they will accept and to compare the
1671
policy OIDs in the certificate to that list. If this extension is
1672
critical, the path validation software MUST be able to interpret this
1673
extension (including the optional qualifier), or MUST reject the
1674
certificate.
1675
1676
To promote interoperability, this profile RECOMMENDS that policy
1677
information terms consist of only an OID. Where an OID alone is
1678
insufficient, this profile strongly recommends that use of qualifiers
1679
1680
1681
1682
Housley, et. al. Standards Track [Page 30]
1683
1684
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1685
1686
1687
be limited to those identified in this section. When qualifiers are
1688
used with the special policy anyPolicy, they MUST be limited to the
1689
qualifiers identified in this section.
1690
1691
This specification defines two policy qualifier types for use by
1692
certificate policy writers and certificate issuers. The qualifier
1693
types are the CPS Pointer and User Notice qualifiers.
1694
1695
The CPS Pointer qualifier contains a pointer to a Certification
1696
Practice Statement (CPS) published by the CA. The pointer is in the
1697
form of a URI. Processing requirements for this qualifier are a
1698
local matter. No action is mandated by this specification regardless
1699
of the criticality value asserted for the extension.
1700
1701
User notice is intended for display to a relying party when a
1702
certificate is used. The application software SHOULD display all
1703
user notices in all certificates of the certification path used,
1704
except that if a notice is duplicated only one copy need be
1705
displayed. To prevent such duplication, this qualifier SHOULD only
1706
be present in end entity certificates and CA certificates issued to
1707
other organizations.
1708
1709
The user notice has two optional fields: the noticeRef field and the
1710
explicitText field.
1711
1712
The noticeRef field, if used, names an organization and
1713
identifies, by number, a particular textual statement prepared by
1714
that organization. For example, it might identify the
1715
organization "CertsRUs" and notice number 1. In a typical
1716
implementation, the application software will have a notice file
1717
containing the current set of notices for CertsRUs; the
1718
application will extract the notice text from the file and display
1719
it. Messages MAY be multilingual, allowing the software to select
1720
the particular language message for its own environment.
1721
1722
An explicitText field includes the textual statement directly in
1723
the certificate. The explicitText field is a string with a
1724
maximum size of 200 characters.
1725
1726
If both the noticeRef and explicitText options are included in the
1727
one qualifier and if the application software can locate the notice
1728
text indicated by the noticeRef option, then that text SHOULD be
1729
displayed; otherwise, the explicitText string SHOULD be displayed.
1730
1731
Note: While the explicitText has a maximum size of 200 characters,
1732
some non-conforming CAs exceed this limit. Therefore, certificate
1733
users SHOULD gracefully handle explicitText with more than 200
1734
characters.
1735
1736
1737
1738
Housley, et. al. Standards Track [Page 31]
1739
1740
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1741
1742
1743
id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 }
1744
1745
anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificate-policies 0 }
1746
1747
certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
1748
1749
PolicyInformation ::= SEQUENCE {
1750
policyIdentifier CertPolicyId,
1751
policyQualifiers SEQUENCE SIZE (1..MAX) OF
1752
PolicyQualifierInfo OPTIONAL }
1753
1754
CertPolicyId ::= OBJECT IDENTIFIER
1755
1756
PolicyQualifierInfo ::= SEQUENCE {
1757
policyQualifierId PolicyQualifierId,
1758
qualifier ANY DEFINED BY policyQualifierId }
1759
1760
-- policyQualifierIds for Internet policy qualifiers
1761
1762
id-qt OBJECT IDENTIFIER ::= { id-pkix 2 }
1763
id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 }
1764
id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 }
1765
1766
PolicyQualifierId ::=
1767
OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice )
1768
1769
Qualifier ::= CHOICE {
1770
cPSuri CPSuri,
1771
userNotice UserNotice }
1772
1773
CPSuri ::= IA5String
1774
1775
UserNotice ::= SEQUENCE {
1776
noticeRef NoticeReference OPTIONAL,
1777
explicitText DisplayText OPTIONAL}
1778
1779
NoticeReference ::= SEQUENCE {
1780
organization DisplayText,
1781
noticeNumbers SEQUENCE OF INTEGER }
1782
1783
DisplayText ::= CHOICE {
1784
ia5String IA5String (SIZE (1..200)),
1785
visibleString VisibleString (SIZE (1..200)),
1786
bmpString BMPString (SIZE (1..200)),
1787
utf8String UTF8String (SIZE (1..200)) }
1788
1789
1790
1791
1792
1793
1794
Housley, et. al. Standards Track [Page 32]
1795
1796
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1797
1798
1799
4.2.1.6 Policy Mappings
1800
1801
This extension is used in CA certificates. It lists one or more
1802
pairs of OIDs; each pair includes an issuerDomainPolicy and a
1803
subjectDomainPolicy. The pairing indicates the issuing CA considers
1804
its issuerDomainPolicy equivalent to the subject CA's
1805
subjectDomainPolicy.
1806
1807
The issuing CA's users might accept an issuerDomainPolicy for certain
1808
applications. The policy mapping defines the list of policies
1809
associated with the subject CA that may be accepted as comparable to
1810
the issuerDomainPolicy.
1811
1812
Each issuerDomainPolicy named in the policy mapping extension SHOULD
1813
also be asserted in a certificate policies extension in the same
1814
certificate. Policies SHOULD NOT be mapped either to or from the
1815
special value anyPolicy (section 4.2.1.5).
1816
1817
This extension MAY be supported by CAs and/or applications, and it
1818
MUST be non-critical.
1819
1820
id-ce-policyMappings OBJECT IDENTIFIER ::= { id-ce 33 }
1821
1822
PolicyMappings ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE {
1823
issuerDomainPolicy CertPolicyId,
1824
subjectDomainPolicy CertPolicyId }
1825
1826
4.2.1.7 Subject Alternative Name
1827
1828
The subject alternative names extension allows additional identities
1829
to be bound to the subject of the certificate. Defined options
1830
include an Internet electronic mail address, a DNS name, an IP
1831
address, and a uniform resource identifier (URI). Other options
1832
exist, including completely local definitions. Multiple name forms,
1833
and multiple instances of each name form, MAY be included. Whenever
1834
such identities are to be bound into a certificate, the subject
1835
alternative name (or issuer alternative name) extension MUST be used;
1836
however, a DNS name MAY be represented in the subject field using the
1837
domainComponent attribute as described in section 4.1.2.4.
1838
1839
Because the subject alternative name is considered to be definitively
1840
bound to the public key, all parts of the subject alternative name
1841
MUST be verified by the CA.
1842
1843
Further, if the only subject identity included in the certificate is
1844
an alternative name form (e.g., an electronic mail address), then the
1845
subject distinguished name MUST be empty (an empty sequence), and the
1846
1847
1848
1849
1850
Housley, et. al. Standards Track [Page 33]
1851
1852
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1853
1854
1855
subjectAltName extension MUST be present. If the subject field
1856
contains an empty sequence, the subjectAltName extension MUST be
1857
marked critical.
1858
1859
When the subjectAltName extension contains an Internet mail address,
1860
the address MUST be included as an rfc822Name. The format of an
1861
rfc822Name is an "addr-spec" as defined in RFC 822 [RFC 822]. An
1862
addr-spec has the form "local-part@domain". Note that an addr-spec
1863
has no phrase (such as a common name) before it, has no comment (text
1864
surrounded in parentheses) after it, and is not surrounded by "<" and
1865
">". Note that while upper and lower case letters are allowed in an
1866
RFC 822 addr-spec, no significance is attached to the case.
1867
1868
When the subjectAltName extension contains a iPAddress, the address
1869
MUST be stored in the octet string in "network byte order," as
1870
specified in RFC 791 [RFC 791]. The least significant bit (LSB) of
1871
each octet is the LSB of the corresponding byte in the network
1872
address. For IP Version 4, as specified in RFC 791, the octet string
1873
MUST contain exactly four octets. For IP Version 6, as specified in
1874
RFC 1883, the octet string MUST contain exactly sixteen octets [RFC
1875
1883].
1876
1877
When the subjectAltName extension contains a domain name system
1878
label, the domain name MUST be stored in the dNSName (an IA5String).
1879
The name MUST be in the "preferred name syntax," as specified by RFC
1880
1034 [RFC 1034]. Note that while upper and lower case letters are
1881
allowed in domain names, no signifigance is attached to the case. In
1882
addition, while the string " " is a legal domain name, subjectAltName
1883
extensions with a dNSName of " " MUST NOT be used. Finally, the use
1884
of the DNS representation for Internet mail addresses (wpolk.nist.gov
1885
instead of wpolk@nist.gov) MUST NOT be used; such identities are to
1886
be encoded as rfc822Name.
1887
1888
Note: work is currently underway to specify domain names in
1889
international character sets. Such names will likely not be
1890
accommodated by IA5String. Once this work is complete, this profile
1891
will be revisited and the appropriate functionality will be added.
1892
1893
When the subjectAltName extension contains a URI, the name MUST be
1894
stored in the uniformResourceIdentifier (an IA5String). The name
1895
MUST NOT be a relative URL, and it MUST follow the URL syntax and
1896
encoding rules specified in [RFC 1738]. The name MUST include both a
1897
scheme (e.g., "http" or "ftp") and a scheme-specific-part. The
1898
scheme-specific-part MUST include a fully qualified domain name or IP
1899
address as the host.
1900
1901
1902
1903
1904
1905
1906
Housley, et. al. Standards Track [Page 34]
1907
1908
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1909
1910
1911
As specified in [RFC 1738], the scheme name is not case-sensitive
1912
(e.g., "http" is equivalent to "HTTP"). The host part is also not
1913
case-sensitive, but other components of the scheme-specific-part may
1914
be case-sensitive. When comparing URIs, conforming implementations
1915
MUST compare the scheme and host without regard to case, but assume
1916
the remainder of the scheme-specific-part is case sensitive.
1917
1918
When the subjectAltName extension contains a DN in the directoryName,
1919
the DN MUST be unique for each subject entity certified by the one CA
1920
as defined by the issuer name field. A CA MAY issue more than one
1921
certificate with the same DN to the same subject entity.
1922
1923
The subjectAltName MAY carry additional name types through the use of
1924
the otherName field. The format and semantics of the name are
1925
indicated through the OBJECT IDENTIFIER in the type-id field. The
1926
name itself is conveyed as value field in otherName. For example,
1927
Kerberos [RFC 1510] format names can be encoded into the otherName,
1928
using using a Kerberos 5 principal name OID and a SEQUENCE of the
1929
Realm and the PrincipalName.
1930
1931
Subject alternative names MAY be constrained in the same manner as
1932
subject distinguished names using the name constraints extension as
1933
described in section 4.2.1.11.
1934
1935
If the subjectAltName extension is present, the sequence MUST contain
1936
at least one entry. Unlike the subject field, conforming CAs MUST
1937
NOT issue certificates with subjectAltNames containing empty
1938
GeneralName fields. For example, an rfc822Name is represented as an
1939
IA5String. While an empty string is a valid IA5String, such an
1940
rfc822Name is not permitted by this profile. The behavior of clients
1941
that encounter such a certificate when processing a certificication
1942
path is not defined by this profile.
1943
1944
Finally, the semantics of subject alternative names that include
1945
wildcard characters (e.g., as a placeholder for a set of names) are
1946
not addressed by this specification. Applications with specific
1947
requirements MAY use such names, but they must define the semantics.
1948
1949
id-ce-subjectAltName OBJECT IDENTIFIER ::= { id-ce 17 }
1950
1951
SubjectAltName ::= GeneralNames
1952
1953
GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
1954
1955
1956
1957
1958
1959
1960
1961
1962
Housley, et. al. Standards Track [Page 35]
1963
1964
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
1965
1966
1967
GeneralName ::= CHOICE {
1968
otherName [0] OtherName,
1969
rfc822Name [1] IA5String,
1970
dNSName [2] IA5String,
1971
x400Address [3] ORAddress,
1972
directoryName [4] Name,
1973
ediPartyName [5] EDIPartyName,
1974
uniformResourceIdentifier [6] IA5String,
1975
iPAddress [7] OCTET STRING,
1976
registeredID [8] OBJECT IDENTIFIER }
1977
1978
OtherName ::= SEQUENCE {
1979
type-id OBJECT IDENTIFIER,
1980
value [0] EXPLICIT ANY DEFINED BY type-id }
1981
1982
EDIPartyName ::= SEQUENCE {
1983
nameAssigner [0] DirectoryString OPTIONAL,
1984
partyName [1] DirectoryString }
1985
1986
4.2.1.8 Issuer Alternative Names
1987
1988
As with 4.2.1.7, this extension is used to associate Internet style
1989
identities with the certificate issuer. Issuer alternative names
1990
MUST be encoded as in 4.2.1.7.
1991
1992
Where present, this extension SHOULD NOT be marked critical.
1993
1994
id-ce-issuerAltName OBJECT IDENTIFIER ::= { id-ce 18 }
1995
1996
IssuerAltName ::= GeneralNames
1997
1998
4.2.1.9 Subject Directory Attributes
1999
2000
The subject directory attributes extension is used to convey
2001
identification attributes (e.g., nationality) of the subject. The
2002
extension is defined as a sequence of one or more attributes. This
2003
extension MUST be non-critical.
2004
2005
id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= { id-ce 9 }
2006
2007
SubjectDirectoryAttributes ::= SEQUENCE SIZE (1..MAX) OF Attribute
2008
2009
4.2.1.10 Basic Constraints
2010
2011
The basic constraints extension identifies whether the subject of the
2012
certificate is a CA and the maximum depth of valid certification
2013
paths that include this certificate.
2014
2015
2016
2017
2018
Housley, et. al. Standards Track [Page 36]
2019
2020
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2021
2022
2023
The cA boolean indicates whether the certified public key belongs to
2024
a CA. If the cA boolean is not asserted, then the keyCertSign bit in
2025
the key usage extension MUST NOT be asserted.
2026
2027
The pathLenConstraint field is meaningful only if the cA boolean is
2028
asserted and the key usage extension asserts the keyCertSign bit
2029
(section 4.2.1.3). In this case, it gives the maximum number of non-
2030
self-issued intermediate certificates that may follow this
2031
certificate in a valid certification path. A certificate is self-
2032
issued if the DNs that appear in the subject and issuer fields are
2033
identical and are not empty. (Note: The last certificate in the
2034
certification path is not an intermediate certificate, and is not
2035
included in this limit. Usually, the last certificate is an end
2036
entity certificate, but it can be a CA certificate.) A
2037
pathLenConstraint of zero indicates that only one more certificate
2038
may follow in a valid certification path. Where it appears, the
2039
pathLenConstraint field MUST be greater than or equal to zero. Where
2040
pathLenConstraint does not appear, no limit is imposed.
2041
2042
This extension MUST appear as a critical extension in all CA
2043
certificates that contain public keys used to validate digital
2044
signatures on certificates. This extension MAY appear as a critical
2045
or non-critical extension in CA certificates that contain public keys
2046
used exclusively for purposes other than validating digital
2047
signatures on certificates. Such CA certificates include ones that
2048
contain public keys used exclusively for validating digital
2049
signatures on CRLs and ones that contain key management public keys
2050
used with certificate enrollment protocols. This extension MAY
2051
appear as a critical or non-critical extension in end entity
2052
certificates.
2053
2054
CAs MUST NOT include the pathLenConstraint field unless the cA
2055
boolean is asserted and the key usage extension asserts the
2056
keyCertSign bit.
2057
2058
id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 }
2059
2060
BasicConstraints ::= SEQUENCE {
2061
cA BOOLEAN DEFAULT FALSE,
2062
pathLenConstraint INTEGER (0..MAX) OPTIONAL }
2063
2064
4.2.1.11 Name Constraints
2065
2066
The name constraints extension, which MUST be used only in a CA
2067
certificate, indicates a name space within which all subject names in
2068
subsequent certificates in a certification path MUST be located.
2069
Restrictions apply to the subject distinguished name and apply to
2070
subject alternative names. Restrictions apply only when the
2071
2072
2073
2074
Housley, et. al. Standards Track [Page 37]
2075
2076
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2077
2078
2079
specified name form is present. If no name of the type is in the
2080
certificate, the certificate is acceptable.
2081
2082
Name constraints are not applied to certificates whose issuer and
2083
subject are identical (unless the certificate is the final
2084
certificate in the path). (This could prevent CAs that use name
2085
constraints from employing self-issued certificates to implement key
2086
rollover.)
2087
2088
Restrictions are defined in terms of permitted or excluded name
2089
subtrees. Any name matching a restriction in the excludedSubtrees
2090
field is invalid regardless of information appearing in the
2091
permittedSubtrees. This extension MUST be critical.
2092
2093
Within this profile, the minimum and maximum fields are not used with
2094
any name forms, thus minimum MUST be zero, and maximum MUST be
2095
absent.
2096
2097
For URIs, the constraint applies to the host part of the name. The
2098
constraint MAY specify a host or a domain. Examples would be
2099
"foo.bar.com"; and ".xyz.com". When the the constraint begins with
2100
a period, it MAY be expanded with one or more subdomains. That is,
2101
the constraint ".xyz.com" is satisfied by both abc.xyz.com and
2102
abc.def.xyz.com. However, the constraint ".xyz.com" is not satisfied
2103
by "xyz.com". When the constraint does not begin with a period, it
2104
specifies a host.
2105
2106
A name constraint for Internet mail addresses MAY specify a
2107
particular mailbox, all addresses at a particular host, or all
2108
mailboxes in a domain. To indicate a particular mailbox, the
2109
constraint is the complete mail address. For example, "root@xyz.com"
2110
indicates the root mailbox on the host "xyz.com". To indicate all
2111
Internet mail addresses on a particular host, the constraint is
2112
specified as the host name. For example, the constraint "xyz.com" is
2113
satisfied by any mail address at the host "xyz.com". To specify any
2114
address within a domain, the constraint is specified with a leading
2115
period (as with URIs). For example, ".xyz.com" indicates all the
2116
Internet mail addresses in the domain "xyz.com", but not Internet
2117
mail addresses on the host "xyz.com".
2118
2119
DNS name restrictions are expressed as foo.bar.com. Any DNS name
2120
that can be constructed by simply adding to the left hand side of the
2121
name satisfies the name constraint. For example, www.foo.bar.com
2122
would satisfy the constraint but foo1.bar.com would not.
2123
2124
Legacy implementations exist where an RFC 822 name is embedded in the
2125
subject distinguished name in an attribute of type EmailAddress
2126
(section 4.1.2.6). When rfc822 names are constrained, but the
2127
2128
2129
2130
Housley, et. al. Standards Track [Page 38]
2131
2132
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2133
2134
2135
certificate does not include a subject alternative name, the rfc822
2136
name constraint MUST be applied to the attribute of type EmailAddress
2137
in the subject distinguished name. The ASN.1 syntax for EmailAddress
2138
and the corresponding OID are supplied in Appendix A.
2139
2140
Restrictions of the form directoryName MUST be applied to the subject
2141
field in the certificate and to the subjectAltName extensions of type
2142
directoryName. Restrictions of the form x400Address MUST be applied
2143
to subjectAltName extensions of type x400Address.
2144
2145
When applying restrictions of the form directoryName, an
2146
implementation MUST compare DN attributes. At a minimum,
2147
implementations MUST perform the DN comparison rules specified in
2148
Section 4.1.2.4. CAs issuing certificates with a restriction of the
2149
form directoryName SHOULD NOT rely on implementation of the full ISO
2150
DN name comparison algorithm. This implies name restrictions MUST be
2151
stated identically to the encoding used in the subject field or
2152
subjectAltName extension.
2153
2154
The syntax of iPAddress MUST be as described in section 4.2.1.7 with
2155
the following additions specifically for Name Constraints. For IPv4
2156
addresses, the ipAddress field of generalName MUST contain eight (8)
2157
octets, encoded in the style of RFC 1519 (CIDR) to represent an
2158
address range [RFC 1519]. For IPv6 addresses, the ipAddress field
2159
MUST contain 32 octets similarly encoded. For example, a name
2160
constraint for "class C" subnet 10.9.8.0 is represented as the octets
2161
0A 09 08 00 FF FF FF 00, representing the CIDR notation
2162
10.9.8.0/255.255.255.0.
2163
2164
The syntax and semantics for name constraints for otherName,
2165
ediPartyName, and registeredID are not defined by this specification.
2166
2167
id-ce-nameConstraints OBJECT IDENTIFIER ::= { id-ce 30 }
2168
2169
NameConstraints ::= SEQUENCE {
2170
permittedSubtrees [0] GeneralSubtrees OPTIONAL,
2171
excludedSubtrees [1] GeneralSubtrees OPTIONAL }
2172
2173
GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
2174
2175
GeneralSubtree ::= SEQUENCE {
2176
base GeneralName,
2177
minimum [0] BaseDistance DEFAULT 0,
2178
maximum [1] BaseDistance OPTIONAL }
2179
2180
BaseDistance ::= INTEGER (0..MAX)
2181
2182
2183
2184
2185
2186
Housley, et. al. Standards Track [Page 39]
2187
2188
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2189
2190
2191
4.2.1.12 Policy Constraints
2192
2193
The policy constraints extension can be used in certificates issued
2194
to CAs. The policy constraints extension constrains path validation
2195
in two ways. It can be used to prohibit policy mapping or require
2196
that each certificate in a path contain an acceptable policy
2197
identifier.
2198
2199
If the inhibitPolicyMapping field is present, the value indicates the
2200
number of additional certificates that may appear in the path before
2201
policy mapping is no longer permitted. For example, a value of one
2202
indicates that policy mapping may be processed in certificates issued
2203
by the subject of this certificate, but not in additional
2204
certificates in the path.
2205
2206
If the requireExplicitPolicy field is present, the value of
2207
requireExplicitPolicy indicates the number of additional certificates
2208
that may appear in the path before an explicit policy is required for
2209
the entire path. When an explicit policy is required, it is
2210
necessary for all certificates in the path to contain an acceptable
2211
policy identifier in the certificate policies extension. An
2212
acceptable policy identifier is the identifier of a policy required
2213
by the user of the certification path or the identifier of a policy
2214
which has been declared equivalent through policy mapping.
2215
2216
Conforming CAs MUST NOT issue certificates where policy constraints
2217
is a empty sequence. That is, at least one of the
2218
inhibitPolicyMapping field or the requireExplicitPolicy field MUST be
2219
present. The behavior of clients that encounter a empty policy
2220
constraints field is not addressed in this profile.
2221
2222
This extension MAY be critical or non-critical.
2223
2224
id-ce-policyConstraints OBJECT IDENTIFIER ::= { id-ce 36 }
2225
2226
PolicyConstraints ::= SEQUENCE {
2227
requireExplicitPolicy [0] SkipCerts OPTIONAL,
2228
inhibitPolicyMapping [1] SkipCerts OPTIONAL }
2229
2230
SkipCerts ::= INTEGER (0..MAX)
2231
2232
4.2.1.13 Extended Key Usage
2233
2234
This extension indicates one or more purposes for which the certified
2235
public key may be used, in addition to or in place of the basic
2236
purposes indicated in the key usage extension. In general, this
2237
extension will appear only in end entity certificates. This
2238
extension is defined as follows:
2239
2240
2241
2242
Housley, et. al. Standards Track [Page 40]
2243
2244
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2245
2246
2247
id-ce-extKeyUsage OBJECT IDENTIFIER ::= { id-ce 37 }
2248
2249
ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
2250
2251
KeyPurposeId ::= OBJECT IDENTIFIER
2252
2253
Key purposes may be defined by any organization with a need. Object
2254
identifiers used to identify key purposes MUST be assigned in
2255
accordance with IANA or ITU-T Recommendation X.660 [X.660].
2256
2257
This extension MAY, at the option of the certificate issuer, be
2258
either critical or non-critical.
2259
2260
If the extension is present, then the certificate MUST only be used
2261
for one of the purposes indicated. If multiple purposes are
2262
indicated the application need not recognize all purposes indicated,
2263
as long as the intended purpose is present. Certificate using
2264
applications MAY require that a particular purpose be indicated in
2265
order for the certificate to be acceptable to that application.
2266
2267
If a CA includes extended key usages to satisfy such applications,
2268
but does not wish to restrict usages of the key, the CA can include
2269
the special keyPurposeID anyExtendedKeyUsage. If the
2270
anyExtendedKeyUsage keyPurposeID is present, the extension SHOULD NOT
2271
be critical.
2272
2273
If a certificate contains both a key usage extension and an extended
2274
key usage extension, then both extensions MUST be processed
2275
independently and the certificate MUST only be used for a purpose
2276
consistent with both extensions. If there is no purpose consistent
2277
with both extensions, then the certificate MUST NOT be used for any
2278
purpose.
2279
2280
The following key usage purposes are defined:
2281
2282
anyExtendedKeyUsage OBJECT IDENTIFIER ::= { id-ce-extKeyUsage 0 }
2283
2284
id-kp OBJECT IDENTIFIER ::= { id-pkix 3 }
2285
2286
id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 }
2287
-- TLS WWW server authentication
2288
-- Key usage bits that may be consistent: digitalSignature,
2289
-- keyEncipherment or keyAgreement
2290
2291
id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 }
2292
-- TLS WWW client authentication
2293
-- Key usage bits that may be consistent: digitalSignature
2294
-- and/or keyAgreement
2295
2296
2297
2298
Housley, et. al. Standards Track [Page 41]
2299
2300
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2301
2302
2303
id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 }
2304
-- Signing of downloadable executable code
2305
-- Key usage bits that may be consistent: digitalSignature
2306
2307
id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 }
2308
-- E-mail protection
2309
-- Key usage bits that may be consistent: digitalSignature,
2310
-- nonRepudiation, and/or (keyEncipherment or keyAgreement)
2311
2312
id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 }
2313
-- Binding the hash of an object to a time
2314
-- Key usage bits that may be consistent: digitalSignature
2315
-- and/or nonRepudiation
2316
2317
id-kp-OCSPSigning OBJECT IDENTIFIER ::= { id-kp 9 }
2318
-- Signing OCSP responses
2319
-- Key usage bits that may be consistent: digitalSignature
2320
-- and/or nonRepudiation
2321
2322
4.2.1.14 CRL Distribution Points
2323
2324
The CRL distribution points extension identifies how CRL information
2325
is obtained. The extension SHOULD be non-critical, but this profile
2326
RECOMMENDS support for this extension by CAs and applications.
2327
Further discussion of CRL management is contained in section 5.
2328
2329
The cRLDistributionPoints extension is a SEQUENCE of
2330
DistributionPoint. A DistributionPoint consists of three fields,
2331
each of which is optional: distributionPoint, reasons, and cRLIssuer.
2332
While each of these fields is optional, a DistributionPoint MUST NOT
2333
consist of only the reasons field; either distributionPoint or
2334
cRLIssuer MUST be present. If the certificate issuer is not the CRL
2335
issuer, then the cRLIssuer field MUST be present and contain the Name
2336
of the CRL issuer. If the certificate issuer is also the CRL issuer,
2337
then the cRLIssuer field MUST be omitted and the distributionPoint
2338
field MUST be present. If the distributionPoint field is omitted,
2339
cRLIssuer MUST be present and include a Name corresponding to an
2340
X.500 or LDAP directory entry where the CRL is located.
2341
2342
When the distributionPoint field is present, it contains either a
2343
SEQUENCE of general names or a single value, nameRelativeToCRLIssuer.
2344
If the cRLDistributionPoints extension contains a general name of
2345
type URI, the following semantics MUST be assumed: the URI is a
2346
pointer to the current CRL for the associated reasons and will be
2347
issued by the associated cRLIssuer. The expected values for the URI
2348
are those defined in 4.2.1.7. Processing rules for other values are
2349
not defined by this specification.
2350
2351
2352
2353
2354
Housley, et. al. Standards Track [Page 42]
2355
2356
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2357
2358
2359
If the DistributionPointName contains multiple values, each name
2360
describes a different mechanism to obtain the same CRL. For example,
2361
the same CRL could be available for retrieval through both LDAP and
2362
HTTP.
2363
2364
If the DistributionPointName contains the single value
2365
nameRelativeToCRLIssuer, the value provides a distinguished name
2366
fragment. The fragment is appended to the X.500 distinguished name
2367
of the CRL issuer to obtain the distribution point name. If the
2368
cRLIssuer field in the DistributionPoint is present, then the name
2369
fragment is appended to the distinguished name that it contains;
2370
otherwise, the name fragment is appended to the certificate issuer
2371
distinguished name. The DistributionPointName MUST NOT use the
2372
nameRealtiveToCRLIssuer alternative when cRLIssuer contains more than
2373
one distinguished name.
2374
2375
If the DistributionPoint omits the reasons field, the CRL MUST
2376
include revocation information for all reasons.
2377
2378
The cRLIssuer identifies the entity who signs and issues the CRL. If
2379
present, the cRLIssuer MUST contain at least one an X.500
2380
distinguished name (DN), and MAY also contain other name forms.
2381
Since the cRLIssuer is compared to the CRL issuer name, the X.501
2382
type Name MUST follow the encoding rules for the issuer name field in
2383
the certificate (section 4.1.2.4).
2384
2385
id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= { id-ce 31 }
2386
2387
CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint
2388
2389
DistributionPoint ::= SEQUENCE {
2390
distributionPoint [0] DistributionPointName OPTIONAL,
2391
reasons [1] ReasonFlags OPTIONAL,
2392
cRLIssuer [2] GeneralNames OPTIONAL }
2393
2394
DistributionPointName ::= CHOICE {
2395
fullName [0] GeneralNames,
2396
nameRelativeToCRLIssuer [1] RelativeDistinguishedName }
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
Housley, et. al. Standards Track [Page 43]
2411
2412
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2413
2414
2415
ReasonFlags ::= BIT STRING {
2416
unused (0),
2417
keyCompromise (1),
2418
cACompromise (2),
2419
affiliationChanged (3),
2420
superseded (4),
2421
cessationOfOperation (5),
2422
certificateHold (6),
2423
privilegeWithdrawn (7),
2424
aACompromise (8) }
2425
2426
4.2.1.15 Inhibit Any-Policy
2427
2428
The inhibit any-policy extension can be used in certificates issued
2429
to CAs. The inhibit any-policy indicates that the special anyPolicy
2430
OID, with the value { 2 5 29 32 0 }, is not considered an explicit
2431
match for other certificate policies. The value indicates the number
2432
of additional certificates that may appear in the path before
2433
anyPolicy is no longer permitted. For example, a value of one
2434
indicates that anyPolicy may be processed in certificates issued by
2435
the subject of this certificate, but not in additional certificates
2436
in the path.
2437
2438
This extension MUST be critical.
2439
2440
id-ce-inhibitAnyPolicy OBJECT IDENTIFIER ::= { id-ce 54 }
2441
2442
InhibitAnyPolicy ::= SkipCerts
2443
2444
SkipCerts ::= INTEGER (0..MAX)
2445
2446
4.2.1.16 Freshest CRL (a.k.a. Delta CRL Distribution Point)
2447
2448
The freshest CRL extension identifies how delta CRL information is
2449
obtained. The extension MUST be non-critical. Further discussion of
2450
CRL management is contained in section 5.
2451
2452
The same syntax is used for this extension and the
2453
cRLDistributionPoints extension, and is described in section
2454
4.2.1.14. The same conventions apply to both extensions.
2455
2456
id-ce-freshestCRL OBJECT IDENTIFIER ::= { id-ce 46 }
2457
2458
FreshestCRL ::= CRLDistributionPoints
2459
2460
2461
2462
2463
2464
2465
2466
Housley, et. al. Standards Track [Page 44]
2467
2468
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2469
2470
2471
4.2.2 Private Internet Extensions
2472
2473
This section defines two extensions for use in the Internet Public
2474
Key Infrastructure. These extensions may be used to direct
2475
applications to on-line information about the issuing CA or the
2476
subject. As the information may be available in multiple forms, each
2477
extension is a sequence of IA5String values, each of which represents
2478
a URI. The URI implicitly specifies the location and format of the
2479
information and the method for obtaining the information.
2480
2481
An object identifier is defined for the private extension. The
2482
object identifier associated with the private extension is defined
2483
under the arc id-pe within the arc id-pkix. Any future extensions
2484
defined for the Internet PKI are also expected to be defined under
2485
the arc id-pe.
2486
2487
id-pkix OBJECT IDENTIFIER ::=
2488
{ iso(1) identified-organization(3) dod(6) internet(1)
2489
security(5) mechanisms(5) pkix(7) }
2490
2491
id-pe OBJECT IDENTIFIER ::= { id-pkix 1 }
2492
2493
4.2.2.1 Authority Information Access
2494
2495
The authority information access extension indicates how to access CA
2496
information and services for the issuer of the certificate in which
2497
the extension appears. Information and services may include on-line
2498
validation services and CA policy data. (The location of CRLs is not
2499
specified in this extension; that information is provided by the
2500
cRLDistributionPoints extension.) This extension may be included in
2501
end entity or CA certificates, and it MUST be non-critical.
2502
2503
id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 }
2504
2505
AuthorityInfoAccessSyntax ::=
2506
SEQUENCE SIZE (1..MAX) OF AccessDescription
2507
2508
AccessDescription ::= SEQUENCE {
2509
accessMethod OBJECT IDENTIFIER,
2510
accessLocation GeneralName }
2511
2512
id-ad OBJECT IDENTIFIER ::= { id-pkix 48 }
2513
2514
id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 }
2515
2516
id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 }
2517
2518
2519
2520
2521
2522
Housley, et. al. Standards Track [Page 45]
2523
2524
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2525
2526
2527
Each entry in the sequence AuthorityInfoAccessSyntax describes the
2528
format and location of additional information provided by the CA that
2529
issued the certificate in which this extension appears. The type and
2530
format of the information is specified by the accessMethod field; the
2531
accessLocation field specifies the location of the information. The
2532
retrieval mechanism may be implied by the accessMethod or specified
2533
by accessLocation.
2534
2535
This profile defines two accessMethod OIDs: id-ad-caIssuers and
2536
id-ad-ocsp.
2537
2538
The id-ad-caIssuers OID is used when the additional information lists
2539
CAs that have issued certificates superior to the CA that issued the
2540
certificate containing this extension. The referenced CA issuers
2541
description is intended to aid certificate users in the selection of
2542
a certification path that terminates at a point trusted by the
2543
certificate user.
2544
2545
When id-ad-caIssuers appears as accessMethod, the accessLocation
2546
field describes the referenced description server and the access
2547
protocol to obtain the referenced description. The accessLocation
2548
field is defined as a GeneralName, which can take several forms.
2549
Where the information is available via http, ftp, or ldap,
2550
accessLocation MUST be a uniformResourceIdentifier. Where the
2551
information is available via the Directory Access Protocol (DAP),
2552
accessLocation MUST be a directoryName. The entry for that
2553
directoryName contains CA certificates in the crossCertificatePair
2554
attribute. When the information is available via electronic mail,
2555
accessLocation MUST be an rfc822Name. The semantics of other
2556
id-ad-caIssuers accessLocation name forms are not defined.
2557
2558
The id-ad-ocsp OID is used when revocation information for the
2559
certificate containing this extension is available using the Online
2560
Certificate Status Protocol (OCSP) [RFC 2560].
2561
2562
When id-ad-ocsp appears as accessMethod, the accessLocation field is
2563
the location of the OCSP responder, using the conventions defined in
2564
[RFC 2560].
2565
2566
Additional access descriptors may be defined in other PKIX
2567
specifications.
2568
2569
4.2.2.2 Subject Information Access
2570
2571
The subject information access extension indicates how to access
2572
information and services for the subject of the certificate in which
2573
the extension appears. When the subject is a CA, information and
2574
services may include certificate validation services and CA policy
2575
2576
2577
2578
Housley, et. al. Standards Track [Page 46]
2579
2580
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2581
2582
2583
data. When the subject is an end entity, the information describes
2584
the type of services offered and how to access them. In this case,
2585
the contents of this extension are defined in the protocol
2586
specifications for the suported services. This extension may be
2587
included in subject or CA certificates, and it MUST be non-critical.
2588
2589
id-pe-subjectInfoAccess OBJECT IDENTIFIER ::= { id-pe 11 }
2590
2591
SubjectInfoAccessSyntax ::=
2592
SEQUENCE SIZE (1..MAX) OF AccessDescription
2593
2594
AccessDescription ::= SEQUENCE {
2595
accessMethod OBJECT IDENTIFIER,
2596
accessLocation GeneralName }
2597
2598
Each entry in the sequence SubjectInfoAccessSyntax describes the
2599
format and location of additional information provided by the subject
2600
of the certificate in which this extension appears. The type and
2601
format of the information is specified by the accessMethod field; the
2602
accessLocation field specifies the location of the information. The
2603
retrieval mechanism may be implied by the accessMethod or specified
2604
by accessLocation.
2605
2606
This profile defines one access method to be used when the subject is
2607
a CA, and one access method to be used when the subject is an end
2608
entity. Additional access methods may be defined in the future in
2609
the protocol specifications for other services.
2610
2611
The id-ad-caRepository OID is used when the subject is a CA, and
2612
publishes its certificates and CRLs (if issued) in a repository. The
2613
accessLocation field is defined as a GeneralName, which can take
2614
several forms. Where the information is available via http, ftp, or
2615
ldap, accessLocation MUST be a uniformResourceIdentifier. Where the
2616
information is available via the directory access protocol (dap),
2617
accessLocation MUST be a directoryName. When the information is
2618
available via electronic mail, accessLocation MUST be an rfc822Name.
2619
The semantics of other name forms of of accessLocation (when
2620
accessMethod is id-ad-caRepository) are not defined by this
2621
specification.
2622
2623
The id-ad-timeStamping OID is used when the subject offers
2624
timestamping services using the Time Stamp Protocol defined in
2625
[PKIXTSA]. Where the timestamping services are available via http or
2626
ftp, accessLocation MUST be a uniformResourceIdentifier. Where the
2627
timestamping services are available via electronic mail,
2628
accessLocation MUST be an rfc822Name. Where timestamping services
2629
2630
2631
2632
2633
2634
Housley, et. al. Standards Track [Page 47]
2635
2636
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2637
2638
2639
are available using TCP/IP, the dNSName or ipAddress name forms may
2640
be used. The semantics of other name forms of accessLocation (when
2641
accessMethod is id-ad-timeStamping) are not defined by this
2642
specification.
2643
2644
Additional access descriptors may be defined in other PKIX
2645
specifications.
2646
2647
id-ad OBJECT IDENTIFIER ::= { id-pkix 48 }
2648
2649
id-ad-caRepository OBJECT IDENTIFIER ::= { id-ad 5 }
2650
2651
id-ad-timeStamping OBJECT IDENTIFIER ::= { id-ad 3 }
2652
2653
5 CRL and CRL Extensions Profile
2654
2655
As discussed above, one goal of this X.509 v2 CRL profile is to
2656
foster the creation of an interoperable and reusable Internet PKI.
2657
To achieve this goal, guidelines for the use of extensions are
2658
specified, and some assumptions are made about the nature of
2659
information included in the CRL.
2660
2661
CRLs may be used in a wide range of applications and environments
2662
covering a broad spectrum of interoperability goals and an even
2663
broader spectrum of operational and assurance requirements. This
2664
profile establishes a common baseline for generic applications
2665
requiring broad interoperability. The profile defines a set of
2666
information that can be expected in every CRL. Also, the profile
2667
defines common locations within the CRL for frequently used
2668
attributes as well as common representations for these attributes.
2669
2670
CRL issuers issue CRLs. In general, the CRL issuer is the CA. CAs
2671
publish CRLs to provide status information about the certificates
2672
they issued. However, a CA may delegate this responsibility to
2673
another trusted authority. Whenever the CRL issuer is not the CA
2674
that issued the certificates, the CRL is referred to as an indirect
2675
CRL.
2676
2677
Each CRL has a particular scope. The CRL scope is the set of
2678
certificates that could appear on a given CRL. For example, the
2679
scope could be "all certificates issued by CA X", "all CA
2680
certificates issued by CA X", "all certificates issued by CA X that
2681
have been revoked for reasons of key compromise and CA compromise",
2682
or could be a set of certificates based on arbitrary local
2683
information, such as "all certificates issued to the NIST employees
2684
located in Boulder".
2685
2686
2687
2688
2689
2690
Housley, et. al. Standards Track [Page 48]
2691
2692
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2693
2694
2695
A complete CRL lists all unexpired certificates, within its scope,
2696
that have been revoked for one of the revocation reasons covered by
2697
the CRL scope. The CRL issuer MAY also generate delta CRLs. A delta
2698
CRL only lists those certificates, within its scope, whose revocation
2699
status has changed since the issuance of a referenced complete CRL.
2700
The referenced complete CRL is referred to as a base CRL. The scope
2701
of a delta CRL MUST be the same as the base CRL that it references.
2702
2703
This profile does not define any private Internet CRL extensions or
2704
CRL entry extensions.
2705
2706
Environments with additional or special purpose requirements may
2707
build on this profile or may replace it.
2708
2709
Conforming CAs are not required to issue CRLs if other revocation or
2710
certificate status mechanisms are provided. When CRLs are issued,
2711
the CRLs MUST be version 2 CRLs, include the date by which the next
2712
CRL will be issued in the nextUpdate field (section 5.1.2.5), include
2713
the CRL number extension (section 5.2.3), and include the authority
2714
key identifier extension (section 5.2.1). Conforming applications
2715
that support CRLs are REQUIRED to process both version 1 and version
2716
2 complete CRLs that provide revocation information for all
2717
certificates issued by one CA. Conforming applications are NOT
2718
REQUIRED to support processing of delta CRLs, indirect CRLs, or CRLs
2719
with a scope other than all certificates issued by one CA.
2720
2721
5.1 CRL Fields
2722
2723
The X.509 v2 CRL syntax is as follows. For signature calculation,
2724
the data that is to be signed is ASN.1 DER encoded. ASN.1 DER
2725
encoding is a tag, length, value encoding system for each element.
2726
2727
CertificateList ::= SEQUENCE {
2728
tbsCertList TBSCertList,
2729
signatureAlgorithm AlgorithmIdentifier,
2730
signatureValue BIT STRING }
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
Housley, et. al. Standards Track [Page 49]
2747
2748
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2749
2750
2751
TBSCertList ::= SEQUENCE {
2752
version Version OPTIONAL,
2753
-- if present, MUST be v2
2754
signature AlgorithmIdentifier,
2755
issuer Name,
2756
thisUpdate Time,
2757
nextUpdate Time OPTIONAL,
2758
revokedCertificates SEQUENCE OF SEQUENCE {
2759
userCertificate CertificateSerialNumber,
2760
revocationDate Time,
2761
crlEntryExtensions Extensions OPTIONAL
2762
-- if present, MUST be v2
2763
} OPTIONAL,
2764
crlExtensions [0] EXPLICIT Extensions OPTIONAL
2765
-- if present, MUST be v2
2766
}
2767
2768
-- Version, Time, CertificateSerialNumber, and Extensions
2769
-- are all defined in the ASN.1 in section 4.1
2770
2771
-- AlgorithmIdentifier is defined in section 4.1.1.2
2772
2773
The following items describe the use of the X.509 v2 CRL in the
2774
Internet PKI.
2775
2776
5.1.1 CertificateList Fields
2777
2778
The CertificateList is a SEQUENCE of three required fields. The
2779
fields are described in detail in the following subsections.
2780
2781
5.1.1.1 tbsCertList
2782
2783
The first field in the sequence is the tbsCertList. This field is
2784
itself a sequence containing the name of the issuer, issue date,
2785
issue date of the next list, the optional list of revoked
2786
certificates, and optional CRL extensions. When there are no revoked
2787
certificates, the revoked certificates list is absent. When one or
2788
more certificates are revoked, each entry on the revoked certificate
2789
list is defined by a sequence of user certificate serial number,
2790
revocation date, and optional CRL entry extensions.
2791
2792
5.1.1.2 signatureAlgorithm
2793
2794
The signatureAlgorithm field contains the algorithm identifier for
2795
the algorithm used by the CRL issuer to sign the CertificateList.
2796
The field is of type AlgorithmIdentifier, which is defined in section
2797
4.1.1.2. [PKIXALGS] lists the supported algorithms for this
2798
specification, but other signature algorithms MAY also be supported.
2799
2800
2801
2802
Housley, et. al. Standards Track [Page 50]
2803
2804
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2805
2806
2807
This field MUST contain the same algorithm identifier as the
2808
signature field in the sequence tbsCertList (section 5.1.2.2).
2809
2810
5.1.1.3 signatureValue
2811
2812
The signatureValue field contains a digital signature computed upon
2813
the ASN.1 DER encoded tbsCertList. The ASN.1 DER encoded tbsCertList
2814
is used as the input to the signature function. This signature value
2815
is encoded as a BIT STRING and included in the CRL signatureValue
2816
field. The details of this process are specified for each of the
2817
supported algorithms in [PKIXALGS].
2818
2819
CAs that are also CRL issuers MAY use one private key to digitally
2820
sign certificates and CRLs, or MAY use separate private keys to
2821
digitally sign certificates and CRLs. When separate private keys are
2822
employed, each of the public keys associated with these private keys
2823
is placed in a separate certificate, one with the keyCertSign bit set
2824
in the key usage extension, and one with the cRLSign bit set in the
2825
key usage extension (section 4.2.1.3). When separate private keys
2826
are employed, certificates issued by the CA contain one authority key
2827
identifier, and the corresponding CRLs contain a different authority
2828
key identifier. The use of separate CA certificates for validation
2829
of certificate signatures and CRL signatures can offer improved
2830
security characteristics; however, it imposes a burden on
2831
applications, and it might limit interoperability. Many applications
2832
construct a certification path, and then validate the certification
2833
path (section 6). CRL checking in turn requires a separate
2834
certification path to be constructed and validated for the CA's CRL
2835
signature validation certificate. Applications that perform CRL
2836
checking MUST support certification path validation when certificates
2837
and CRLs are digitally signed with the same CA private key. These
2838
applications SHOULD support certification path validation when
2839
certificates and CRLs are digitally signed with different CA private
2840
keys.
2841
2842
5.1.2 Certificate List "To Be Signed"
2843
2844
The certificate list to be signed, or TBSCertList, is a sequence of
2845
required and optional fields. The required fields identify the CRL
2846
issuer, the algorithm used to sign the CRL, the date and time the CRL
2847
was issued, and the date and time by which the CRL issuer will issue
2848
the next CRL.
2849
2850
Optional fields include lists of revoked certificates and CRL
2851
extensions. The revoked certificate list is optional to support the
2852
case where a CA has not revoked any unexpired certificates that it
2853
2854
2855
2856
2857
2858
Housley, et. al. Standards Track [Page 51]
2859
2860
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2861
2862
2863
has issued. The profile requires conforming CRL issuers to use the
2864
CRL number and authority key identifier CRL extensions in all CRLs
2865
issued.
2866
2867
5.1.2.1 Version
2868
2869
This optional field describes the version of the encoded CRL. When
2870
extensions are used, as required by this profile, this field MUST be
2871
present and MUST specify version 2 (the integer value is 1).
2872
2873
5.1.2.2 Signature
2874
2875
This field contains the algorithm identifier for the algorithm used
2876
to sign the CRL. [PKIXALGS] lists OIDs for the most popular
2877
signature algorithms used in the Internet PKI.
2878
2879
This field MUST contain the same algorithm identifier as the
2880
signatureAlgorithm field in the sequence CertificateList (section
2881
5.1.1.2).
2882
2883
5.1.2.3 Issuer Name
2884
2885
The issuer name identifies the entity who has signed and issued the
2886
CRL. The issuer identity is carried in the issuer name field.
2887
Alternative name forms may also appear in the issuerAltName extension
2888
(section 5.2.2). The issuer name field MUST contain an X.500
2889
distinguished name (DN). The issuer name field is defined as the
2890
X.501 type Name, and MUST follow the encoding rules for the issuer
2891
name field in the certificate (section 4.1.2.4).
2892
2893
5.1.2.4 This Update
2894
2895
This field indicates the issue date of this CRL. ThisUpdate may be
2896
encoded as UTCTime or GeneralizedTime.
2897
2898
CRL issuers conforming to this profile MUST encode thisUpdate as
2899
UTCTime for dates through the year 2049. CRL issuers conforming to
2900
this profile MUST encode thisUpdate as GeneralizedTime for dates in
2901
the year 2050 or later.
2902
2903
Where encoded as UTCTime, thisUpdate MUST be specified and
2904
interpreted as defined in section 4.1.2.5.1. Where encoded as
2905
GeneralizedTime, thisUpdate MUST be specified and interpreted as
2906
defined in section 4.1.2.5.2.
2907
2908
2909
2910
2911
2912
2913
2914
Housley, et. al. Standards Track [Page 52]
2915
2916
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2917
2918
2919
5.1.2.5 Next Update
2920
2921
This field indicates the date by which the next CRL will be issued.
2922
The next CRL could be issued before the indicated date, but it will
2923
not be issued any later than the indicated date. CRL issuers SHOULD
2924
issue CRLs with a nextUpdate time equal to or later than all previous
2925
CRLs. nextUpdate may be encoded as UTCTime or GeneralizedTime.
2926
2927
This profile requires inclusion of nextUpdate in all CRLs issued by
2928
conforming CRL issuers. Note that the ASN.1 syntax of TBSCertList
2929
describes this field as OPTIONAL, which is consistent with the ASN.1
2930
structure defined in [X.509]. The behavior of clients processing
2931
CRLs which omit nextUpdate is not specified by this profile.
2932
2933
CRL issuers conforming to this profile MUST encode nextUpdate as
2934
UTCTime for dates through the year 2049. CRL issuers conforming to
2935
this profile MUST encode nextUpdate as GeneralizedTime for dates in
2936
the year 2050 or later.
2937
2938
Where encoded as UTCTime, nextUpdate MUST be specified and
2939
interpreted as defined in section 4.1.2.5.1. Where encoded as
2940
GeneralizedTime, nextUpdate MUST be specified and interpreted as
2941
defined in section 4.1.2.5.2.
2942
2943
5.1.2.6 Revoked Certificates
2944
2945
When there are no revoked certificates, the revoked certificates list
2946
MUST be absent. Otherwise, revoked certificates are listed by their
2947
serial numbers. Certificates revoked by the CA are uniquely
2948
identified by the certificate serial number. The date on which the
2949
revocation occurred is specified. The time for revocationDate MUST
2950
be expressed as described in section 5.1.2.4. Additional information
2951
may be supplied in CRL entry extensions; CRL entry extensions are
2952
discussed in section 5.3.
2953
2954
5.1.2.7 Extensions
2955
2956
This field may only appear if the version is 2 (section 5.1.2.1). If
2957
present, this field is a sequence of one or more CRL extensions. CRL
2958
extensions are discussed in section 5.2.
2959
2960
5.2 CRL Extensions
2961
2962
The extensions defined by ANSI X9, ISO/IEC, and ITU-T for X.509 v2
2963
CRLs [X.509] [X9.55] provide methods for associating additional
2964
attributes with CRLs. The X.509 v2 CRL format also allows
2965
communities to define private extensions to carry information unique
2966
to those communities. Each extension in a CRL may be designated as
2967
2968
2969
2970
Housley, et. al. Standards Track [Page 53]
2971
2972
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
2973
2974
2975
critical or non-critical. A CRL validation MUST fail if it
2976
encounters a critical extension which it does not know how to
2977
process. However, an unrecognized non-critical extension may be
2978
ignored. The following subsections present those extensions used
2979
within Internet CRLs. Communities may elect to include extensions in
2980
CRLs which are not defined in this specification. However, caution
2981
should be exercised in adopting any critical extensions in CRLs which
2982
might be used in a general context.
2983
2984
Conforming CRL issuers are REQUIRED to include the authority key
2985
identifier (section 5.2.1) and the CRL number (section 5.2.3)
2986
extensions in all CRLs issued.
2987
2988
5.2.1 Authority Key Identifier
2989
2990
The authority key identifier extension provides a means of
2991
identifying the public key corresponding to the private key used to
2992
sign a CRL. The identification can be based on either the key
2993
identifier (the subject key identifier in the CRL signer's
2994
certificate) or on the issuer name and serial number. This extension
2995
is especially useful where an issuer has more than one signing key,
2996
either due to multiple concurrent key pairs or due to changeover.
2997
2998
Conforming CRL issuers MUST use the key identifier method, and MUST
2999
include this extension in all CRLs issued.
3000
3001
The syntax for this CRL extension is defined in section 4.2.1.1.
3002
3003
5.2.2 Issuer Alternative Name
3004
3005
The issuer alternative names extension allows additional identities
3006
to be associated with the issuer of the CRL. Defined options include
3007
an rfc822 name (electronic mail address), a DNS name, an IP address,
3008
and a URI. Multiple instances of a name and multiple name forms may
3009
be included. Whenever such identities are used, the issuer
3010
alternative name extension MUST be used; however, a DNS name MAY be
3011
represented in the issuer field using the domainComponent attribute
3012
as described in section 4.1.2.4.
3013
3014
The issuerAltName extension SHOULD NOT be marked critical.
3015
3016
The OID and syntax for this CRL extension are defined in section
3017
4.2.1.8.
3018
3019
3020
3021
3022
3023
3024
3025
3026
Housley, et. al. Standards Track [Page 54]
3027
3028
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3029
3030
3031
5.2.3 CRL Number
3032
3033
The CRL number is a non-critical CRL extension which conveys a
3034
monotonically increasing sequence number for a given CRL scope and
3035
CRL issuer. This extension allows users to easily determine when a
3036
particular CRL supersedes another CRL. CRL numbers also support the
3037
identification of complementary complete CRLs and delta CRLs. CRL
3038
issuers conforming to this profile MUST include this extension in all
3039
CRLs.
3040
3041
If a CRL issuer generates delta CRLs in addition to complete CRLs for
3042
a given scope, the complete CRLs and delta CRLs MUST share one
3043
numbering sequence. If a delta CRL and a complete CRL that cover the
3044
same scope are issued at the same time, they MUST have the same CRL
3045
number and provide the same revocation information. That is, the
3046
combination of the delta CRL and an acceptable complete CRL MUST
3047
provide the same revocation information as the simultaneously issued
3048
complete CRL.
3049
3050
If a CRL issuer generates two CRLs (two complete CRLs, two delta
3051
CRLs, or a complete CRL and a delta CRL) for the same scope at
3052
different times, the two CRLs MUST NOT have the same CRL number.
3053
That is, if the this update field (section 5.1.2.4) in the two CRLs
3054
are not identical, the CRL numbers MUST be different.
3055
3056
Given the requirements above, CRL numbers can be expected to contain
3057
long integers. CRL verifiers MUST be able to handle CRLNumber values
3058
up to 20 octets. Conformant CRL issuers MUST NOT use CRLNumber
3059
values longer than 20 octets.
3060
3061
id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 }
3062
3063
CRLNumber ::= INTEGER (0..MAX)
3064
3065
5.2.4 Delta CRL Indicator
3066
3067
The delta CRL indicator is a critical CRL extension that identifies a
3068
CRL as being a delta CRL. Delta CRLs contain updates to revocation
3069
information previously distributed, rather than all the information
3070
that would appear in a complete CRL. The use of delta CRLs can
3071
significantly reduce network load and processing time in some
3072
environments. Delta CRLs are generally smaller than the CRLs they
3073
update, so applications that obtain delta CRLs consume less network
3074
bandwidth than applications that obtain the corresponding complete
3075
CRLs. Applications which store revocation information in a format
3076
other than the CRL structure can add new revocation information to
3077
the local database without reprocessing information.
3078
3079
3080
3081
3082
Housley, et. al. Standards Track [Page 55]
3083
3084
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3085
3086
3087
The delta CRL indicator extension contains the single value of type
3088
BaseCRLNumber. The CRL number identifies the CRL, complete for a
3089
given scope, that was used as the starting point in the generation of
3090
this delta CRL. A conforming CRL issuer MUST publish the referenced
3091
base CRL as a complete CRL. The delta CRL contains all updates to
3092
the revocation status for that same scope. The combination of a
3093
delta CRL plus the referenced base CRL is equivalent to a complete
3094
CRL, for the applicable scope, at the time of publication of the
3095
delta CRL.
3096
3097
When a conforming CRL issuer generates a delta CRL, the delta CRL
3098
MUST include a critical delta CRL indicator extension.
3099
3100
When a delta CRL is issued, it MUST cover the same set of reasons and
3101
the same set of certificates that were covered by the base CRL it
3102
references. That is, the scope of the delta CRL MUST be the same as
3103
the scope of the complete CRL referenced as the base. The referenced
3104
base CRL and the delta CRL MUST omit the issuing distribution point
3105
extension or contain identical issuing distribution point extensions.
3106
Further, the CRL issuer MUST use the same private key to sign the
3107
delta CRL and any complete CRL that it can be used to update.
3108
3109
An application that supports delta CRLs can construct a CRL that is
3110
complete for a given scope by combining a delta CRL for that scope
3111
with either an issued CRL that is complete for that scope or a
3112
locally constructed CRL that is complete for that scope.
3113
3114
When a delta CRL is combined with a complete CRL or a locally
3115
constructed CRL, the resulting locally constructed CRL has the CRL
3116
number specified in the CRL number extension found in the delta CRL
3117
used in its construction. In addition, the resulting locally
3118
constructed CRL has the thisUpdate and nextUpdate times specified in
3119
the corresponding fields of the delta CRL used in its construction.
3120
In addition, the locally constructed CRL inherits the issuing
3121
distribution point from the delta CRL.
3122
3123
A complete CRL and a delta CRL MAY be combined if the following four
3124
conditions are satisfied:
3125
3126
(a) The complete CRL and delta CRL have the same issuer.
3127
3128
(b) The complete CRL and delta CRL have the same scope. The two
3129
CRLs have the same scope if either of the following conditions are
3130
met:
3131
3132
(1) The issuingDistributionPoint extension is omitted from
3133
both the complete CRL and the delta CRL.
3134
3135
3136
3137
3138
Housley, et. al. Standards Track [Page 56]
3139
3140
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3141
3142
3143
(2) The issuingDistributionPoint extension is present in both
3144
the complete CRL and the delta CRL, and the values for each of
3145
the fields in the extensions are the same in both CRLs.
3146
3147
(c) The CRL number of the complete CRL is equal to or greater
3148
than the BaseCRLNumber specified in the delta CRL. That is, the
3149
complete CRL contains (at a minimum) all the revocation
3150
information held by the referenced base CRL.
3151
3152
(d) The CRL number of the complete CRL is less than the CRL
3153
number of the delta CRL. That is, the delta CRL follows the
3154
complete CRL in the numbering sequence.
3155
3156
CRL issuers MUST ensure that the combination of a delta CRL and any
3157
appropriate complete CRL accurately reflects the current revocation
3158
status. The CRL issuer MUST include an entry in the delta CRL for
3159
each certificate within the scope of the delta CRL whose status has
3160
changed since the generation of the referenced base CRL:
3161
3162
(a) If the certificate is revoked for a reason included in the
3163
scope of the CRL, list the certificate as revoked.
3164
3165
(b) If the certificate is valid and was listed on the referenced
3166
base CRL or any subsequent CRL with reason code certificateHold,
3167
and the reason code certificateHold is included in the scope of
3168
the CRL, list the certificate with the reason code removeFromCRL.
3169
3170
(c) If the certificate is revoked for a reason outside the scope
3171
of the CRL, but the certificate was listed on the referenced base
3172
CRL or any subsequent CRL with a reason code included in the scope
3173
of this CRL, list the certificate as revoked but omit the reason
3174
code.
3175
3176
(d) If the certificate is revoked for a reason outside the scope
3177
of the CRL and the certificate was neither listed on the
3178
referenced base CRL nor any subsequent CRL with a reason code
3179
included in the scope of this CRL, do not list the certificate on
3180
this CRL.
3181
3182
The status of a certificate is considered to have changed if it is
3183
revoked, placed on hold, released from hold, or if its revocation
3184
reason changes.
3185
3186
It is appropriate to list a certificate with reason code
3187
removeFromCRL on a delta CRL even if the certificate was not on hold
3188
in the referenced base CRL. If the certificate was placed on hold in
3189
3190
3191
3192
3193
3194
Housley, et. al. Standards Track [Page 57]
3195
3196
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3197
3198
3199
any CRL issued after the base but before this delta CRL and then
3200
released from hold, it MUST be listed on the delta CRL with
3201
revocation reason removeFromCRL.
3202
3203
A CRL issuer MAY optionally list a certificate on a delta CRL with
3204
reason code removeFromCRL if the notAfter time specified in the
3205
certificate precedes the thisUpdate time specified in the delta CRL
3206
and the certificate was listed on the referenced base CRL or in any
3207
CRL issued after the base but before this delta CRL.
3208
3209
If a certificate revocation notice first appears on a delta CRL, then
3210
it is possible for the certificate validity period to expire before
3211
the next complete CRL for the same scope is issued. In this case,
3212
the revocation notice MUST be included in all subsequent delta CRLs
3213
until the revocation notice is included on at least one explicitly
3214
issued complete CRL for this scope.
3215
3216
An application that supports delta CRLs MUST be able to construct a
3217
current complete CRL by combining a previously issued complete CRL
3218
and the most current delta CRL. An application that supports delta
3219
CRLs MAY also be able to construct a current complete CRL by
3220
combining a previously locally constructed complete CRL and the
3221
current delta CRL. A delta CRL is considered to be the current one
3222
if the current time is between the times contained in the thisUpdate
3223
and nextUpdate fields. Under some circumstances, the CRL issuer may
3224
publish one or more delta CRLs before indicated by the nextUpdate
3225
field. If more than one current delta CRL for a given scope is
3226
encountered, the application SHOULD consider the one with the latest
3227
value in thisUpdate to be the most current one.
3228
3229
id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= { id-ce 27 }
3230
3231
BaseCRLNumber ::= CRLNumber
3232
3233
5.2.5 Issuing Distribution Point
3234
3235
The issuing distribution point is a critical CRL extension that
3236
identifies the CRL distribution point and scope for a particular CRL,
3237
and it indicates whether the CRL covers revocation for end entity
3238
certificates only, CA certificates only, attribute certificates only,
3239
3240
or a limited set of reason codes. Although the extension is
3241
critical, conforming implementations are not required to support this
3242
extension.
3243
3244
3245
3246
3247
3248
3249
3250
Housley, et. al. Standards Track [Page 58]
3251
3252
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3253
3254
3255
The CRL is signed using the CRL issuer's private key. CRL
3256
Distribution Points do not have their own key pairs. If the CRL is
3257
stored in the X.500 Directory, it is stored in the Directory entry
3258
corresponding to the CRL distribution point, which may be different
3259
than the Directory entry of the CRL issuer.
3260
3261
The reason codes associated with a distribution point MUST be
3262
specified in onlySomeReasons. If onlySomeReasons does not appear,
3263
the distribution point MUST contain revocations for all reason codes.
3264
CAs may use CRL distribution points to partition the CRL on the basis
3265
of compromise and routine revocation. In this case, the revocations
3266
with reason code keyCompromise (1), cACompromise (2), and
3267
aACompromise (8) appear in one distribution point, and the
3268
revocations with other reason codes appear in another distribution
3269
point.
3270
3271
If the distributionPoint field is present and contains a URI, the
3272
following semantics MUST be assumed: the object is a pointer to the
3273
most current CRL issued by this CRL issuer. The URI schemes ftp,
3274
http, mailto [RFC1738] and ldap [RFC1778] are defined for this
3275
purpose. The URI MUST be an absolute pathname, not a relative
3276
pathname, and MUST specify the host.
3277
3278
If the distributionPoint field is absent, the CRL MUST contain
3279
entries for all revoked unexpired certificates issued by the CRL
3280
issuer, if any, within the scope of the CRL.
3281
3282
The CRL issuer MUST assert the indirectCRL boolean, if the scope of
3283
the CRL includes certificates issued by authorities other than the
3284
CRL issuer. The authority responsible for each entry is indicated by
3285
the certificate issuer CRL entry extension (section 5.3.4).
3286
3287
id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= { id-ce 28 }
3288
3289
issuingDistributionPoint ::= SEQUENCE {
3290
distributionPoint [0] DistributionPointName OPTIONAL,
3291
onlyContainsUserCerts [1] BOOLEAN DEFAULT FALSE,
3292
onlyContainsCACerts [2] BOOLEAN DEFAULT FALSE,
3293
onlySomeReasons [3] ReasonFlags OPTIONAL,
3294
indirectCRL [4] BOOLEAN DEFAULT FALSE,
3295
onlyContainsAttributeCerts [5] BOOLEAN DEFAULT FALSE }
3296
3297
5.2.6 Freshest CRL (a.k.a. Delta CRL Distribution Point)
3298
3299
The freshest CRL extension identifies how delta CRL information for
3300
this complete CRL is obtained. The extension MUST be non-critical.
3301
This extension MUST NOT appear in delta CRLs.
3302
3303
3304
3305
3306
Housley, et. al. Standards Track [Page 59]
3307
3308
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3309
3310
3311
The same syntax is used for this extension as the
3312
cRLDistributionPoints certificate extension, and is described in
3313
section 4.2.1.14. However, only the distribution point field is
3314
meaningful in this context. The reasons and CRLIssuer fields MUST be
3315
omitted from this CRL extension.
3316
3317
Each distribution point name provides the location at which a delta
3318
CRL for this complete CRL can be found. The scope of these delta
3319
CRLs MUST be the same as the scope of this complete CRL. The
3320
contents of this CRL extension are only used to locate delta CRLs;
3321
the contents are not used to validate the CRL or the referenced delta
3322
CRLs. The encoding conventions defined for distribution points in
3323
section 4.2.1.14 apply to this extension.
3324
3325
id-ce-freshestCRL OBJECT IDENTIFIER ::= { id-ce 46 }
3326
3327
FreshestCRL ::= CRLDistributionPoints
3328
3329
5.3 CRL Entry Extensions
3330
3331
The CRL entry extensions defined by ISO/IEC, ITU-T, and ANSI X9 for
3332
X.509 v2 CRLs provide methods for associating additional attributes
3333
with CRL entries [X.509] [X9.55]. The X.509 v2 CRL format also
3334
allows communities to define private CRL entry extensions to carry
3335
information unique to those communities. Each extension in a CRL
3336
entry may be designated as critical or non-critical. A CRL
3337
validation MUST fail if it encounters a critical CRL entry extension
3338
which it does not know how to process. However, an unrecognized non-
3339
critical CRL entry extension may be ignored. The following
3340
subsections present recommended extensions used within Internet CRL
3341
entries and standard locations for information. Communities may
3342
elect to use additional CRL entry extensions; however, caution should
3343
be exercised in adopting any critical extensions in CRL entries which
3344
might be used in a general context.
3345
3346
All CRL entry extensions used in this specification are non-critical.
3347
Support for these extensions is optional for conforming CRL issuers
3348
and applications. However, CRL issuers SHOULD include reason codes
3349
(section 5.3.1) and invalidity dates (section 5.3.3) whenever this
3350
information is available.
3351
3352
5.3.1 Reason Code
3353
3354
The reasonCode is a non-critical CRL entry extension that identifies
3355
the reason for the certificate revocation. CRL issuers are strongly
3356
encouraged to include meaningful reason codes in CRL entries;
3357
however, the reason code CRL entry extension SHOULD be absent instead
3358
of using the unspecified (0) reasonCode value.
3359
3360
3361
3362
Housley, et. al. Standards Track [Page 60]
3363
3364
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3365
3366
3367
id-ce-cRLReason OBJECT IDENTIFIER ::= { id-ce 21 }
3368
3369
-- reasonCode ::= { CRLReason }
3370
3371
CRLReason ::= ENUMERATED {
3372
unspecified (0),
3373
keyCompromise (1),
3374
cACompromise (2),
3375
affiliationChanged (3),
3376
superseded (4),
3377
cessationOfOperation (5),
3378
certificateHold (6),
3379
removeFromCRL (8),
3380
privilegeWithdrawn (9),
3381
aACompromise (10) }
3382
3383
5.3.2 Hold Instruction Code
3384
3385
The hold instruction code is a non-critical CRL entry extension that
3386
provides a registered instruction identifier which indicates the
3387
action to be taken after encountering a certificate that has been
3388
placed on hold.
3389
3390
id-ce-holdInstructionCode OBJECT IDENTIFIER ::= { id-ce 23 }
3391
3392
holdInstructionCode ::= OBJECT IDENTIFIER
3393
3394
The following instruction codes have been defined. Conforming
3395
applications that process this extension MUST recognize the following
3396
instruction codes.
3397
3398
holdInstruction OBJECT IDENTIFIER ::=
3399
{ iso(1) member-body(2) us(840) x9-57(10040) 2 }
3400
3401
id-holdinstruction-none OBJECT IDENTIFIER ::= {holdInstruction 1}
3402
id-holdinstruction-callissuer
3403
OBJECT IDENTIFIER ::= {holdInstruction 2}
3404
id-holdinstruction-reject OBJECT IDENTIFIER ::= {holdInstruction 3}
3405
3406
Conforming applications which encounter an id-holdinstruction-
3407
callissuer MUST call the certificate issuer or reject the
3408
certificate. Conforming applications which encounter an id-
3409
holdinstruction-reject MUST reject the certificate. The hold
3410
instruction id-holdinstruction-none is semantically equivalent to the
3411
absence of a holdInstructionCode, and its use is strongly deprecated
3412
for the Internet PKI.
3413
3414
3415
3416
3417
3418
Housley, et. al. Standards Track [Page 61]
3419
3420
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3421
3422
3423
5.3.3 Invalidity Date
3424
3425
The invalidity date is a non-critical CRL entry extension that
3426
provides the date on which it is known or suspected that the private
3427
key was compromised or that the certificate otherwise became invalid.
3428
This date may be earlier than the revocation date in the CRL entry,
3429
which is the date at which the CA processed the revocation. When a
3430
revocation is first posted by a CRL issuer in a CRL, the invalidity
3431
date may precede the date of issue of earlier CRLs, but the
3432
revocation date SHOULD NOT precede the date of issue of earlier CRLs.
3433
Whenever this information is available, CRL issuers are strongly
3434
encouraged to share it with CRL users.
3435
3436
The GeneralizedTime values included in this field MUST be expressed
3437
in Greenwich Mean Time (Zulu), and MUST be specified and interpreted
3438
as defined in section 4.1.2.5.2.
3439
3440
id-ce-invalidityDate OBJECT IDENTIFIER ::= { id-ce 24 }
3441
3442
invalidityDate ::= GeneralizedTime
3443
3444
5.3.4 Certificate Issuer
3445
3446
This CRL entry extension identifies the certificate issuer associated
3447
with an entry in an indirect CRL, that is, a CRL that has the
3448
indirectCRL indicator set in its issuing distribution point
3449
extension. If this extension is not present on the first entry in an
3450
indirect CRL, the certificate issuer defaults to the CRL issuer. On
3451
subsequent entries in an indirect CRL, if this extension is not
3452
present, the certificate issuer for the entry is the same as that for
3453
the preceding entry. This field is defined as follows:
3454
3455
id-ce-certificateIssuer OBJECT IDENTIFIER ::= { id-ce 29 }
3456
3457
certificateIssuer ::= GeneralNames
3458
3459
If used by conforming CRL issuers, this extension MUST always be
3460
critical. If an implementation ignored this extension it could not
3461
correctly attribute CRL entries to certificates. This specification
3462
RECOMMENDS that implementations recognize this extension.
3463
3464
6 Certification Path Validation
3465
3466
Certification path validation procedures for the Internet PKI are
3467
based on the algorithm supplied in [X.509]. Certification path
3468
processing verifies the binding between the subject distinguished
3469
name and/or subject alternative name and subject public key. The
3470
binding is limited by constraints which are specified in the
3471
3472
3473
3474
Housley, et. al. Standards Track [Page 62]
3475
3476
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3477
3478
3479
certificates which comprise the path and inputs which are specified
3480
by the relying party. The basic constraints and policy constraints
3481
extensions allow the certification path processing logic to automate
3482
the decision making process.
3483
3484
This section describes an algorithm for validating certification
3485
paths. Conforming implementations of this specification are not
3486
required to implement this algorithm, but MUST provide functionality
3487
equivalent to the external behavior resulting from this procedure.
3488
Any algorithm may be used by a particular implementation so long as
3489
it derives the correct result.
3490
3491
In section 6.1, the text describes basic path validation. Valid
3492
paths begin with certificates issued by a trust anchor. The
3493
algorithm requires the public key of the CA, the CA's name, and any
3494
constraints upon the set of paths which may be validated using this
3495
key.
3496
3497
The selection of a trust anchor is a matter of policy: it could be
3498
the top CA in a hierarchical PKI; the CA that issued the verifier's
3499
own certificate(s); or any other CA in a network PKI. The path
3500
validation procedure is the same regardless of the choice of trust
3501
anchor. In addition, different applications may rely on different
3502
trust anchor, or may accept paths that begin with any of a set of
3503
trust anchor.
3504
3505
Section 6.2 describes methods for using the path validation algorithm
3506
in specific implementations. Two specific cases are discussed: the
3507
case where paths may begin with one of several trusted CAs; and where
3508
compatibility with the PEM architecture is required.
3509
3510
Section 6.3 describes the steps necessary to determine if a
3511
certificate is revoked or on hold status when CRLs are the revocation
3512
mechanism used by the certificate issuer.
3513
3514
6.1 Basic Path Validation
3515
3516
This text describes an algorithm for X.509 path processing. A
3517
conformant implementation MUST include an X.509 path processing
3518
procedure that is functionally equivalent to the external behavior of
3519
this algorithm. However, support for some of the certificate
3520
extensions processed in this algorithm are OPTIONAL for compliant
3521
implementations. Clients that do not support these extensions MAY
3522
omit the corresponding steps in the path validation algorithm.
3523
3524
3525
3526
3527
3528
3529
3530
Housley, et. al. Standards Track [Page 63]
3531
3532
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3533
3534
3535
For example, clients are NOT REQUIRED to support the policy mapping
3536
extension. Clients that do not support this extension MAY omit the
3537
path validation steps where policy mappings are processed. Note that
3538
clients MUST reject the certificate if it contains an unsupported
3539
critical extension.
3540
3541
The algorithm presented in this section validates the certificate
3542
with respect to the current date and time. A conformant
3543
implementation MAY also support validation with respect to some point
3544
in the past. Note that mechanisms are not available for validating a
3545
certificate with respect to a time outside the certificate validity
3546
period.
3547
3548
The trust anchor is an input to the algorithm. There is no
3549
requirement that the same trust anchor be used to validate all
3550
certification paths. Different trust anchors MAY be used to validate
3551
different paths, as discussed further in Section 6.2.
3552
3553
The primary goal of path validation is to verify the binding between
3554
a subject distinguished name or a subject alternative name and
3555
subject public key, as represented in the end entity certificate,
3556
based on the public key of the trust anchor. This requires obtaining
3557
a sequence of certificates that support that binding. The procedure
3558
performed to obtain this sequence of certificates is outside the
3559
scope of this specification.
3560
3561
To meet this goal, the path validation process verifies, among other
3562
things, that a prospective certification path (a sequence of n
3563
certificates) satisfies the following conditions:
3564
3565
(a) for all x in {1, ..., n-1}, the subject of certificate x is
3566
the issuer of certificate x+1;
3567
3568
(b) certificate 1 is issued by the trust anchor;
3569
3570
(c) certificate n is the certificate to be validated; and
3571
3572
(d) for all x in {1, ..., n}, the certificate was valid at the
3573
time in question.
3574
3575
When the trust anchor is provided in the form of a self-signed
3576
certificate, this self-signed certificate is not included as part of
3577
the prospective certification path. Information about trust anchors
3578
are provided as inputs to the certification path validation algorithm
3579
(section 6.1.1).
3580
3581
3582
3583
3584
3585
3586
Housley, et. al. Standards Track [Page 64]
3587
3588
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3589
3590
3591
A particular certification path may not, however, be appropriate for
3592
all applications. Therefore, an application MAY augment this
3593
algorithm to further limit the set of valid paths. The path
3594
validation process also determines the set of certificate policies
3595
that are valid for this path, based on the certificate policies
3596
extension, policy mapping extension, policy constraints extension,
3597
and inhibit any-policy extension. To achieve this, the path
3598
validation algorithm constructs a valid policy tree. If the set of
3599
certificate policies that are valid for this path is not empty, then
3600
the result will be a valid policy tree of depth n, otherwise the
3601
result will be a null valid policy tree.
3602
3603
A certificate is self-issued if the DNs that appear in the subject
3604
and issuer fields are identical and are not empty. In general, the
3605
issuer and subject of the certificates that make up a path are
3606
different for each certificate. However, a CA may issue a
3607
certificate to itself to support key rollover or changes in
3608
certificate policies. These self-issued certificates are not counted
3609
when evaluating path length or name constraints.
3610
3611
This section presents the algorithm in four basic steps: (1)
3612
initialization, (2) basic certificate processing, (3) preparation for
3613
the next certificate, and (4) wrap-up. Steps (1) and (4) are
3614
performed exactly once. Step (2) is performed for all certificates
3615
in the path. Step (3) is performed for all certificates in the path
3616
except the final certificate. Figure 2 provides a high-level
3617
flowchart of this algorithm.
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
Housley, et. al. Standards Track [Page 65]
3643
3644
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3645
3646
3647
+-------+
3648
| START |
3649
+-------+
3650
|
3651
V
3652
+----------------+
3653
| Initialization |
3654
+----------------+
3655
|
3656
+<--------------------+
3657
| |
3658
V |
3659
+----------------+ |
3660
| Process Cert | |
3661
+----------------+ |
3662
| |
3663
V |
3664
+================+ |
3665
| IF Last Cert | |
3666
| in Path | |
3667
+================+ |
3668
| | |
3669
THEN | | ELSE |
3670
V V |
3671
+----------------+ +----------------+ |
3672
| Wrap up | | Prepare for | |
3673
+----------------+ | Next Cert | |
3674
| +----------------+ |
3675
V | |
3676
+-------+ +--------------+
3677
| STOP |
3678
+-------+
3679
3680
3681
Figure 2. Certification Path Processing Flowchart
3682
3683
6.1.1 Inputs
3684
3685
This algorithm assumes the following seven inputs are provided to the
3686
path processing logic:
3687
3688
(a) a prospective certification path of length n.
3689
3690
(b) the current date/time.
3691
3692
3693
3694
3695
3696
3697
3698
Housley, et. al. Standards Track [Page 66]
3699
3700
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3701
3702
3703
(c) user-initial-policy-set: A set of certificate policy
3704
identifiers naming the policies that are acceptable to the
3705
certificate user. The user-initial-policy-set contains the
3706
special value any-policy if the user is not concerned about
3707
certificate policy.
3708
3709
(d) trust anchor information, describing a CA that serves as a
3710
trust anchor for the certification path. The trust anchor
3711
information includes:
3712
3713
(1) the trusted issuer name,
3714
3715
(2) the trusted public key algorithm,
3716
3717
(3) the trusted public key, and
3718
3719
(4) optionally, the trusted public key parameters associated
3720
with the public key.
3721
3722
The trust anchor information may be provided to the path
3723
processing procedure in the form of a self-signed certificate.
3724
The trusted anchor information is trusted because it was delivered
3725
to the path processing procedure by some trustworthy out-of-band
3726
procedure. If the trusted public key algorithm requires
3727
parameters, then the parameters are provided along with the
3728
trusted public key.
3729
3730
(e) initial-policy-mapping-inhibit, which indicates if policy
3731
mapping is allowed in the certification path.
3732
3733
(f) initial-explicit-policy, which indicates if the path must be
3734
valid for at least one of the certificate policies in the user-
3735
initial-policy-set.
3736
3737
(g) initial-any-policy-inhibit, which indicates whether the
3738
anyPolicy OID should be processed if it is included in a
3739
certificate.
3740
3741
6.1.2 Initialization
3742
3743
This initialization phase establishes eleven state variables based
3744
upon the seven inputs:
3745
3746
(a) valid_policy_tree: A tree of certificate policies with their
3747
optional qualifiers; each of the leaves of the tree represents a
3748
valid policy at this stage in the certification path validation.
3749
If valid policies exist at this stage in the certification path
3750
validation, the depth of the tree is equal to the number of
3751
3752
3753
3754
Housley, et. al. Standards Track [Page 67]
3755
3756
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3757
3758
3759
certificates in the chain that have been processed. If valid
3760
policies do not exist at this stage in the certification path
3761
validation, the tree is set to NULL. Once the tree is set to
3762
NULL, policy processing ceases.
3763
3764
Each node in the valid_policy_tree includes four data objects: the
3765
valid policy, a set of associated policy qualifiers, a set of one
3766
or more expected policy values, and a criticality indicator. If
3767
the node is at depth x, the components of the node have the
3768
following semantics:
3769
3770
(1) The valid_policy is a single policy OID representing a
3771
valid policy for the path of length x.
3772
3773
(2) The qualifier_set is a set of policy qualifiers associated
3774
with the valid policy in certificate x.
3775
3776
(3) The criticality_indicator indicates whether the
3777
certificate policy extension in certificate x was marked as
3778
critical.
3779
3780
(4) The expected_policy_set contains one or more policy OIDs
3781
that would satisfy this policy in the certificate x+1.
3782
3783
The initial value of the valid_policy_tree is a single node with
3784
valid_policy anyPolicy, an empty qualifier_set, an
3785
expected_policy_set with the single value anyPolicy, and a
3786
criticality_indicator of FALSE. This node is considered to be at
3787
depth zero.
3788
3789
Figure 3 is a graphic representation of the initial state of the
3790
valid_policy_tree. Additional figures will use this format to
3791
describe changes in the valid_policy_tree during path processing.
3792
3793
+----------------+
3794
| anyPolicy | <---- valid_policy
3795
+----------------+
3796
| {} | <---- qualifier_set
3797
+----------------+
3798
| FALSE | <---- criticality_indicator
3799
+----------------+
3800
| {anyPolicy} | <---- expected_policy_set
3801
+----------------+
3802
3803
Figure 3. Initial value of the valid_policy_tree state variable
3804
3805
3806
3807
3808
3809
3810
Housley, et. al. Standards Track [Page 68]
3811
3812
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3813
3814
3815
(b) permitted_subtrees: A set of root names for each name type
3816
(e.g., X.500 distinguished names, email addresses, or ip
3817
addresses) defining a set of subtrees within which all subject
3818
names in subsequent certificates in the certification path MUST
3819
fall. This variable includes a set for each name type: the
3820
initial value for the set for Distinguished Names is the set of
3821
all Distinguished names; the initial value for the set of RFC822
3822
names is the set of all RFC822 names, etc.
3823
3824
(c) excluded_subtrees: A set of root names for each name type
3825
(e.g., X.500 distinguished names, email addresses, or ip
3826
addresses) defining a set of subtrees within which no subject name
3827
in subsequent certificates in the certification path may fall.
3828
This variable includes a set for each name type, and the initial
3829
value for each set is empty.
3830
3831
(d) explicit_policy: an integer which indicates if a non-NULL
3832
valid_policy_tree is required. The integer indicates the number of
3833
non-self-issued certificates to be processed before this
3834
requirement is imposed. Once set, this variable may be decreased,
3835
but may not be increased. That is, if a certificate in the path
3836
requires a non-NULL valid_policy_tree, a later certificate can not
3837
remove this requirement. If initial-explicit-policy is set, then
3838
the initial value is 0, otherwise the initial value is n+1.
3839
3840
(e) inhibit_any-policy: an integer which indicates whether the
3841
anyPolicy policy identifier is considered a match. The integer
3842
indicates the number of non-self-issued certificates to be
3843
processed before the anyPolicy OID, if asserted in a certificate,
3844
is ignored. Once set, this variable may be decreased, but may not
3845
be increased. That is, if a certificate in the path inhibits
3846
processing of anyPolicy, a later certificate can not permit it.
3847
If initial-any-policy-inhibit is set, then the initial value is 0,
3848
otherwise the initial value is n+1.
3849
3850
(f) policy_mapping: an integer which indicates if policy mapping
3851
is permitted. The integer indicates the number of non-self-issued
3852
certificates to be processed before policy mapping is inhibited.
3853
Once set, this variable may be decreased, but may not be
3854
increased. That is, if a certificate in the path specifies policy
3855
mapping is not permitted, it can not be overridden by a later
3856
certificate. If initial-policy-mapping-inhibit is set, then the
3857
initial value is 0, otherwise the initial value is n+1.
3858
3859
(g) working_public_key_algorithm: the digital signature algorithm
3860
used to verify the signature of a certificate. The
3861
working_public_key_algorithm is initialized from the trusted
3862
public key algorithm provided in the trust anchor information.
3863
3864
3865
3866
Housley, et. al. Standards Track [Page 69]
3867
3868
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3869
3870
3871
(h) working_public_key: the public key used to verify the
3872
signature of a certificate. The working_public_key is initialized
3873
from the trusted public key provided in the trust anchor
3874
information.
3875
3876
(i) working_public_key_parameters: parameters associated with the
3877
current public key, that may be required to verify a signature
3878
(depending upon the algorithm). The working_public_key_parameters
3879
variable is initialized from the trusted public key parameters
3880
provided in the trust anchor information.
3881
3882
(j) working_issuer_name: the issuer distinguished name expected
3883
in the next certificate in the chain. The working_issuer_name is
3884
initialized to the trusted issuer provided in the trust anchor
3885
information.
3886
3887
(k) max_path_length: this integer is initialized to n, is
3888
decremented for each non-self-issued certificate in the path, and
3889
may be reduced to the value in the path length constraint field
3890
within the basic constraints extension of a CA certificate.
3891
3892
Upon completion of the initialization steps, perform the basic
3893
certificate processing steps specified in 6.1.3.
3894
3895
6.1.3 Basic Certificate Processing
3896
3897
The basic path processing actions to be performed for certificate i
3898
(for all i in [1..n]) are listed below.
3899
3900
(a) Verify the basic certificate information. The certificate
3901
MUST satisfy each of the following:
3902
3903
(1) The certificate was signed with the
3904
working_public_key_algorithm using the working_public_key and
3905
the working_public_key_parameters.
3906
3907
(2) The certificate validity period includes the current time.
3908
3909
(3) At the current time, the certificate is not revoked and is
3910
not on hold status. This may be determined by obtaining the
3911
appropriate CRL (section 6.3), status information, or by out-
3912
of-band mechanisms.
3913
3914
(4) The certificate issuer name is the working_issuer_name.
3915
3916
3917
3918
3919
3920
3921
3922
Housley, et. al. Standards Track [Page 70]
3923
3924
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3925
3926
3927
(b) If certificate i is self-issued and it is not the final
3928
certificate in the path, skip this step for certificate i.
3929
Otherwise, verify that the subject name is within one of the
3930
permitted_subtrees for X.500 distinguished names, and verify that
3931
each of the alternative names in the subjectAltName extension
3932
(critical or non-critical) is within one of the permitted_subtrees
3933
for that name type.
3934
3935
(c) If certificate i is self-issued and it is not the final
3936
certificate in the path, skip this step for certificate i.
3937
Otherwise, verify that the subject name is not within one of the
3938
excluded_subtrees for X.500 distinguished names, and verify that
3939
each of the alternative names in the subjectAltName extension
3940
(critical or non-critical) is not within one of the
3941
excluded_subtrees for that name type.
3942
3943
(d) If the certificate policies extension is present in the
3944
certificate and the valid_policy_tree is not NULL, process the
3945
policy information by performing the following steps in order:
3946
3947
(1) For each policy P not equal to anyPolicy in the
3948
certificate policies extension, let P-OID denote the OID in
3949
policy P and P-Q denote the qualifier set for policy P.
3950
Perform the following steps in order:
3951
3952
(i) If the valid_policy_tree includes a node of depth i-1
3953
where P-OID is in the expected_policy_set, create a child
3954
node as follows: set the valid_policy to OID-P; set the
3955
qualifier_set to P-Q, and set the expected_policy_set to
3956
{P-OID}.
3957
3958
For example, consider a valid_policy_tree with a node of
3959
depth i-1 where the expected_policy_set is {Gold, White}.
3960
Assume the certificate policies Gold and Silver appear in
3961
the certificate policies extension of certificate i. The
3962
Gold policy is matched but the Silver policy is not. This
3963
rule will generate a child node of depth i for the Gold
3964
policy. The result is shown as Figure 4.
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
Housley, et. al. Standards Track [Page 71]
3979
3980
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
3981
3982
3983
+-----------------+
3984
| Red |
3985
+-----------------+
3986
| {} |
3987
+-----------------+ node of depth i-1
3988
| FALSE |
3989
+-----------------+
3990
| {Gold, White} |
3991
+-----------------+
3992
|
3993
|
3994
|
3995
V
3996
+-----------------+
3997
| Gold |
3998
+-----------------+
3999
| {} |
4000
+-----------------+ node of depth i
4001
| uninitialized |
4002
+-----------------+
4003
| {Gold} |
4004
+-----------------+
4005
4006
Figure 4. Processing an exact match
4007
4008
(ii) If there was no match in step (i) and the
4009
valid_policy_tree includes a node of depth i-1 with the
4010
valid policy anyPolicy, generate a child node with the
4011
following values: set the valid_policy to P-OID; set the
4012
qualifier_set to P-Q, and set the expected_policy_set to
4013
{P-OID}.
4014
4015
For example, consider a valid_policy_tree with a node of
4016
depth i-1 where the valid_policy is anyPolicy. Assume the
4017
certificate policies Gold and Silver appear in the
4018
certificate policies extension of certificate i. The Gold
4019
policy does not have a qualifier, but the Silver policy has
4020
the qualifier Q-Silver. If Gold and Silver were not matched
4021
in (i) above, this rule will generate two child nodes of
4022
depth i, one for each policy. The result is shown as Figure
4023
5.
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
Housley, et. al. Standards Track [Page 72]
4035
4036
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4037
4038
4039
+-----------------+
4040
| anyPolicy |
4041
+-----------------+
4042
| {} |
4043
+-----------------+ node of depth i-1
4044
| FALSE |
4045
+-----------------+
4046
| {anyPolicy} |
4047
+-----------------+
4048
/ \
4049
/ \
4050
/ \
4051
/ \
4052
+-----------------+ +-----------------+
4053
| Gold | | Silver |
4054
+-----------------+ +-----------------+
4055
| {} | | {Q-Silver} |
4056
+-----------------+ nodes of +-----------------+
4057
| uninitialized | depth i | uninitialized |
4058
+-----------------+ +-----------------+
4059
| {Gold} | | {Silver} |
4060
+-----------------+ +-----------------+
4061
4062
Figure 5. Processing unmatched policies when a leaf node
4063
specifies anyPolicy
4064
4065
(2) If the certificate policies extension includes the policy
4066
anyPolicy with the qualifier set AP-Q and either (a)
4067
inhibit_any-policy is greater than 0 or (b) i<n and the
4068
certificate is self-issued, then:
4069
4070
For each node in the valid_policy_tree of depth i-1, for each
4071
value in the expected_policy_set (including anyPolicy) that
4072
does not appear in a child node, create a child node with the
4073
following values: set the valid_policy to the value from the
4074
expected_policy_set in the parent node; set the qualifier_set
4075
to AP-Q, and set the expected_policy_set to the value in the
4076
valid_policy from this node.
4077
4078
For example, consider a valid_policy_tree with a node of depth
4079
i-1 where the expected_policy_set is {Gold, Silver}. Assume
4080
anyPolicy appears in the certificate policies extension of
4081
certificate i, but Gold and Silver do not. This rule will
4082
generate two child nodes of depth i, one for each policy. The
4083
result is shown below as Figure 6.
4084
4085
4086
4087
4088
4089
4090
Housley, et. al. Standards Track [Page 73]
4091
4092
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4093
4094
4095
+-----------------+
4096
| Red |
4097
+-----------------+
4098
| {} |
4099
+-----------------+ node of depth i-1
4100
| FALSE |
4101
+-----------------+
4102
| {Gold, Silver} |
4103
+-----------------+
4104
/ \
4105
/ \
4106
/ \
4107
/ \
4108
+-----------------+ +-----------------+
4109
| Gold | | Silver |
4110
+-----------------+ +-----------------+
4111
| {} | | {} |
4112
+-----------------+ nodes of +-----------------+
4113
| uninitialized | depth i | uninitialized |
4114
+-----------------+ +-----------------+
4115
| {Gold} | | {Silver} |
4116
+-----------------+ +-----------------+
4117
4118
Figure 6. Processing unmatched policies when the certificate
4119
policies extension specifies anyPolicy
4120
4121
(3) If there is a node in the valid_policy_tree of depth i-1
4122
or less without any child nodes, delete that node. Repeat this
4123
step until there are no nodes of depth i-1 or less without
4124
children.
4125
4126
For example, consider the valid_policy_tree shown in Figure 7
4127
below. The two nodes at depth i-1 that are marked with an 'X'
4128
have no children, and are deleted. Applying this rule to the
4129
resulting tree will cause the node at depth i-2 that is marked
4130
with an 'Y' to be deleted. The following application of the
4131
rule does not cause any nodes to be deleted, and this step is
4132
complete.
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
Housley, et. al. Standards Track [Page 74]
4147
4148
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4149
4150
4151
+-----------+
4152
| | node of depth i-3
4153
+-----------+
4154
/ | \
4155
/ | \
4156
/ | \
4157
+-----------+ +-----------+ +-----------+
4158
| | | | | Y | nodes of
4159
+-----------+ +-----------+ +-----------+ depth i-2
4160
/ \ | |
4161
/ \ | |
4162
/ \ | |
4163
+-----------+ +-----------+ +-----------+ +-----------+ nodes of
4164
| | | X | | | | X | depth
4165
+-----------+ +-----------+ +-----------+ +-----------+ i-1
4166
| / | \
4167
| / | \
4168
| / | \
4169
+-----------+ +-----------+ +-----------+ +-----------+ nodes of
4170
| | | | | | | | depth
4171
+-----------+ +-----------+ +-----------+ +-----------+ i
4172
4173
Figure 7. Pruning the valid_policy_tree
4174
4175
(4) If the certificate policies extension was marked as
4176
critical, set the criticality_indicator in all nodes of depth i
4177
to TRUE. If the certificate policies extension was not marked
4178
critical, set the criticality_indicator in all nodes of depth i
4179
to FALSE.
4180
4181
(e) If the certificate policies extension is not present, set the
4182
valid_policy_tree to NULL.
4183
4184
(f) Verify that either explicit_policy is greater than 0 or the
4185
valid_policy_tree is not equal to NULL;
4186
4187
If any of steps (a), (b), (c), or (f) fails, the procedure
4188
terminates, returning a failure indication and an appropriate reason.
4189
4190
If i is not equal to n, continue by performing the preparatory steps
4191
listed in 6.1.4. If i is equal to n, perform the wrap-up steps
4192
listed in 6.1.5.
4193
4194
6.1.4 Preparation for Certificate i+1
4195
4196
To prepare for processing of certificate i+1, perform the following
4197
steps for certificate i:
4198
4199
4200
4201
4202
Housley, et. al. Standards Track [Page 75]
4203
4204
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4205
4206
4207
(a) If a policy mapping extension is present, verify that the
4208
special value anyPolicy does not appear as an issuerDomainPolicy
4209
or a subjectDomainPolicy.
4210
4211
(b) If a policy mapping extension is present, then for each
4212
issuerDomainPolicy ID-P in the policy mapping extension:
4213
4214
(1) If the policy_mapping variable is greater than 0, for each
4215
node in the valid_policy_tree of depth i where ID-P is the
4216
valid_policy, set expected_policy_set to the set of
4217
subjectDomainPolicy values that are specified as equivalent to
4218
ID-P by the policy mapping extension.
4219
4220
If no node of depth i in the valid_policy_tree has a
4221
valid_policy of ID-P but there is a node of depth i with a
4222
valid_policy of anyPolicy, then generate a child node of the
4223
node of depth i-1 that has a valid_policy of anyPolicy as
4224
follows:
4225
4226
(i) set the valid_policy to ID-P;
4227
4228
(ii) set the qualifier_set to the qualifier set of the
4229
policy anyPolicy in the certificate policies extension of
4230
certificate i;
4231
4232
(iii) set the criticality_indicator to the criticality of
4233
the certificate policies extension of certificate i;
4234
4235
(iv) and set the expected_policy_set to the set of
4236
subjectDomainPolicy values that are specified as equivalent
4237
to ID-P by the policy mappings extension.
4238
4239
(2) If the policy_mapping variable is equal to 0:
4240
4241
(i) delete each node of depth i in the valid_policy_tree
4242
where ID-P is the valid_policy.
4243
4244
(ii) If there is a node in the valid_policy_tree of depth
4245
i-1 or less without any child nodes, delete that node.
4246
Repeat this step until there are no nodes of depth i-1 or
4247
less without children.
4248
4249
(c) Assign the certificate subject name to working_issuer_name.
4250
4251
(d) Assign the certificate subjectPublicKey to
4252
working_public_key.
4253
4254
4255
4256
4257
4258
Housley, et. al. Standards Track [Page 76]
4259
4260
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4261
4262
4263
(e) If the subjectPublicKeyInfo field of the certificate contains
4264
an algorithm field with non-null parameters, assign the parameters
4265
to the working_public_key_parameters variable.
4266
4267
If the subjectPublicKeyInfo field of the certificate contains an
4268
algorithm field with null parameters or parameters are omitted,
4269
compare the certificate subjectPublicKey algorithm to the
4270
working_public_key_algorithm. If the certificate subjectPublicKey
4271
algorithm and the working_public_key_algorithm are different, set
4272
the working_public_key_parameters to null.
4273
4274
(f) Assign the certificate subjectPublicKey algorithm to the
4275
working_public_key_algorithm variable.
4276
4277
(g) If a name constraints extension is included in the
4278
certificate, modify the permitted_subtrees and excluded_subtrees
4279
state variables as follows:
4280
4281
(1) If permittedSubtrees is present in the certificate, set
4282
the permitted_subtrees state variable to the intersection of
4283
its previous value and the value indicated in the extension
4284
field. If permittedSubtrees does not include a particular name
4285
type, the permitted_subtrees state variable is unchanged for
4286
that name type. For example, the intersection of nist.gov and
4287
csrc.nist.gov is csrc.nist.gov. And, the intersection of
4288
nist.gov and rsasecurity.com is the empty set.
4289
4290
(2) If excludedSubtrees is present in the certificate, set the
4291
excluded_subtrees state variable to the union of its previous
4292
value and the value indicated in the extension field. If
4293
excludedSubtrees does not include a particular name type, the
4294
excluded_subtrees state variable is unchanged for that name
4295
type. For example, the union of the name spaces nist.gov and
4296
csrc.nist.gov is nist.gov. And, the union of nist.gov and
4297
rsasecurity.com is both name spaces.
4298
4299
(h) If the issuer and subject names are not identical:
4300
4301
(1) If explicit_policy is not 0, decrement explicit_policy by
4302
1.
4303
4304
(2) If policy_mapping is not 0, decrement policy_mapping by 1.
4305
4306
(3) If inhibit_any-policy is not 0, decrement inhibit_any-
4307
policy by 1.
4308
4309
4310
4311
4312
4313
4314
Housley, et. al. Standards Track [Page 77]
4315
4316
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4317
4318
4319
(i) If a policy constraints extension is included in the
4320
certificate, modify the explicit_policy and policy_mapping state
4321
variables as follows:
4322
4323
(1) If requireExplicitPolicy is present and is less than
4324
explicit_policy, set explicit_policy to the value of
4325
requireExplicitPolicy.
4326
4327
(2) If inhibitPolicyMapping is present and is less than
4328
policy_mapping, set policy_mapping to the value of
4329
inhibitPolicyMapping.
4330
4331
(j) If the inhibitAnyPolicy extension is included in the
4332
certificate and is less than inhibit_any-policy, set inhibit_any-
4333
policy to the value of inhibitAnyPolicy.
4334
4335
(k) Verify that the certificate is a CA certificate (as specified
4336
in a basicConstraints extension or as verified out-of-band).
4337
4338
(l) If the certificate was not self-issued, verify that
4339
max_path_length is greater than zero and decrement max_path_length
4340
by 1.
4341
4342
(m) If pathLengthConstraint is present in the certificate and is
4343
less than max_path_length, set max_path_length to the value of
4344
pathLengthConstraint.
4345
4346
(n) If a key usage extension is present, verify that the
4347
keyCertSign bit is set.
4348
4349
(o) Recognize and process any other critical extension present in
4350
the certificate. Process any other recognized non-critical
4351
extension present in the certificate.
4352
4353
If check (a), (k), (l), (n) or (o) fails, the procedure terminates,
4354
returning a failure indication and an appropriate reason.
4355
4356
If (a), (k), (l), (n) and (o) have completed successfully, increment
4357
i and perform the basic certificate processing specified in 6.1.3.
4358
4359
6.1.5 Wrap-up procedure
4360
4361
To complete the processing of the end entity certificate, perform the
4362
following steps for certificate n:
4363
4364
(a) If certificate n was not self-issued and explicit_policy is
4365
not 0, decrement explicit_policy by 1.
4366
4367
4368
4369
4370
Housley, et. al. Standards Track [Page 78]
4371
4372
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4373
4374
4375
(b) If a policy constraints extension is included in the
4376
certificate and requireExplicitPolicy is present and has a value
4377
of 0, set the explicit_policy state variable to 0.
4378
4379
(c) Assign the certificate subjectPublicKey to
4380
working_public_key.
4381
4382
(d) If the subjectPublicKeyInfo field of the certificate contains
4383
an algorithm field with non-null parameters, assign the parameters
4384
to the working_public_key_parameters variable.
4385
4386
If the subjectPublicKeyInfo field of the certificate contains an
4387
algorithm field with null parameters or parameters are omitted,
4388
compare the certificate subjectPublicKey algorithm to the
4389
working_public_key_algorithm. If the certificate subjectPublicKey
4390
algorithm and the working_public_key_algorithm are different, set
4391
the working_public_key_parameters to null.
4392
4393
(e) Assign the certificate subjectPublicKey algorithm to the
4394
working_public_key_algorithm variable.
4395
4396
(f) Recognize and process any other critical extension present in
4397
the certificate n. Process any other recognized non-critical
4398
extension present in certificate n.
4399
4400
(g) Calculate the intersection of the valid_policy_tree and the
4401
user-initial-policy-set, as follows:
4402
4403
(i) If the valid_policy_tree is NULL, the intersection is
4404
NULL.
4405
4406
(ii) If the valid_policy_tree is not NULL and the user-
4407
initial-policy-set is any-policy, the intersection is the
4408
entire valid_policy_tree.
4409
4410
(iii) If the valid_policy_tree is not NULL and the user-
4411
initial-policy-set is not any-policy, calculate the
4412
intersection of the valid_policy_tree and the user-initial-
4413
policy-set as follows:
4414
4415
1. Determine the set of policy nodes whose parent nodes
4416
have a valid_policy of anyPolicy. This is the
4417
valid_policy_node_set.
4418
4419
2. If the valid_policy of any node in the
4420
valid_policy_node_set is not in the user-initial-policy-set
4421
and is not anyPolicy, delete this node and all its children.
4422
4423
4424
4425
4426
Housley, et. al. Standards Track [Page 79]
4427
4428
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4429
4430
4431
3. If the valid_policy_tree includes a node of depth n with
4432
the valid_policy anyPolicy and the user-initial-policy-set
4433
is not any-policy perform the following steps:
4434
4435
a. Set P-Q to the qualifier_set in the node of depth n
4436
with valid_policy anyPolicy.
4437
4438
b. For each P-OID in the user-initial-policy-set that is
4439
not the valid_policy of a node in the
4440
valid_policy_node_set, create a child node whose parent
4441
is the node of depth n-1 with the valid_policy anyPolicy.
4442
Set the values in the child node as follows: set the
4443
valid_policy to P-OID; set the qualifier_set to P-Q; copy
4444
the criticality_indicator from the node of depth n with
4445
the valid_policy anyPolicy; and set the
4446
expected_policy_set to {P-OID}.
4447
4448
c. Delete the node of depth n with the valid_policy
4449
anyPolicy.
4450
4451
4. If there is a node in the valid_policy_tree of depth n-1
4452
or less without any child nodes, delete that node. Repeat
4453
this step until there are no nodes of depth n-1 or less
4454
without children.
4455
4456
If either (1) the value of explicit_policy variable is greater than
4457
zero, or (2) the valid_policy_tree is not NULL, then path processing
4458
has succeeded.
4459
4460
6.1.6 Outputs
4461
4462
If path processing succeeds, the procedure terminates, returning a
4463
success indication together with final value of the
4464
valid_policy_tree, the working_public_key, the
4465
working_public_key_algorithm, and the working_public_key_parameters.
4466
4467
6.2 Using the Path Validation Algorithm
4468
4469
The path validation algorithm describes the process of validating a
4470
single certification path. While each certification path begins with
4471
a specific trust anchor, there is no requirement that all
4472
certification paths validated by a particular system share a single
4473
trust anchor. An implementation that supports multiple trust anchors
4474
MAY augment the algorithm presented in section 6.1 to further limit
4475
the set of valid certification paths which begin with a particular
4476
trust anchor. For example, an implementation MAY modify the
4477
algorithm to apply name constraints to a specific trust anchor during
4478
the initialization phase, or the application MAY require the presence
4479
4480
4481
4482
Housley, et. al. Standards Track [Page 80]
4483
4484
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4485
4486
4487
of a particular alternative name form in the end entity certificate,
4488
or the application MAY impose requirements on application-specific
4489
extensions. Thus, the path validation algorithm presented in section
4490
6.1 defines the minimum conditions for a path to be considered valid.
4491
4492
The selection of one or more trusted CAs is a local decision. A
4493
system may provide any one of its trusted CAs as the trust anchor for
4494
a particular path. The inputs to the path validation algorithm may
4495
be different for each path. The inputs used to process a path may
4496
reflect application-specific requirements or limitations in the trust
4497
accorded a particular trust anchor. For example, a trusted CA may
4498
only be trusted for a particular certificate policy. This
4499
restriction can be expressed through the inputs to the path
4500
validation procedure.
4501
4502
It is also possible to specify an extended version of the above
4503
certification path processing procedure which results in default
4504
behavior identical to the rules of PEM [RFC 1422]. In this extended
4505
version, additional inputs to the procedure are a list of one or more
4506
Policy Certification Authority (PCA) names and an indicator of the
4507
position in the certification path where the PCA is expected. At the
4508
nominated PCA position, the CA name is compared against this list.
4509
If a recognized PCA name is found, then a constraint of
4510
SubordinateToCA is implicitly assumed for the remainder of the
4511
certification path and processing continues. If no valid PCA name is
4512
found, and if the certification path cannot be validated on the basis
4513
of identified policies, then the certification path is considered
4514
invalid.
4515
4516
6.3 CRL Validation
4517
4518
This section describes the steps necessary to determine if a
4519
certificate is revoked or on hold status when CRLs are the revocation
4520
mechanism used by the certificate issuer. Conforming implementations
4521
that support CRLs are not required to implement this algorithm, but
4522
they MUST be functionally equivalent to the external behavior
4523
resulting from this procedure. Any algorithm may be used by a
4524
particular implementation so long as it derives the correct result.
4525
4526
This algorithm assumes that all of the needed CRLs are available in a
4527
local cache. Further, if the next update time of a CRL has passed,
4528
the algorithm assumes a mechanism to fetch a current CRL and place it
4529
in the local CRL cache.
4530
4531
This algorithm defines a set of inputs, a set of state variables, and
4532
processing steps that are performed for each certificate in the path.
4533
The algorithm output is the revocation status of the certificate.
4534
4535
4536
4537
4538
Housley, et. al. Standards Track [Page 81]
4539
4540
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4541
4542
4543
6.3.1 Revocation Inputs
4544
4545
To support revocation processing, the algorithm requires two inputs:
4546
4547
(a) certificate: The algorithm requires the certificate serial
4548
number and issuer name to determine whether a certificate is on a
4549
particular CRL. The basicConstraints extension is used to
4550
determine whether the supplied certificate is associated with a CA
4551
or an end entity. If present, the algorithm uses the
4552
cRLDistributionsPoint and freshestCRL extensions to determine
4553
revocation status.
4554
4555
(b) use-deltas: This boolean input determines whether delta CRLs
4556
are applied to CRLs.
4557
4558
Note that implementations supporting legacy PKIs, such as RFC 1422
4559
and X.509 version 1, will need an additional input indicating
4560
whether the supplied certificate is associated with a CA or an end
4561
entity.
4562
4563
6.3.2 Initialization and Revocation State Variables
4564
4565
To support CRL processing, the algorithm requires the following state
4566
variables:
4567
4568
(a) reasons_mask: This variable contains the set of revocation
4569
reasons supported by the CRLs and delta CRLs processed so far.
4570
The legal members of the set are the possible revocation reason
4571
values: unspecified, keyCompromise, caCompromise,
4572
affiliationChanged, superseded, cessationOfOperation,
4573
certificateHold, privilegeWithdrawn, and aACompromise. The
4574
special value all-reasons is used to denote the set of all legal
4575
members. This variable is initialized to the empty set.
4576
4577
(b) cert_status: This variable contains the status of the
4578
certificate. This variable may be assigned one of the following
4579
values: unspecified, keyCompromise, caCompromise,
4580
affiliationChanged, superseded, cessationOfOperation,
4581
certificateHold, removeFromCRL, privilegeWithdrawn, aACompromise,
4582
the special value UNREVOKED, or the special value UNDETERMINED.
4583
This variable is initialized to the special value UNREVOKED.
4584
4585
(c) interim_reasons_mask: This contains the set of revocation
4586
reasons supported by the CRL or delta CRL currently being
4587
processed.
4588
4589
4590
4591
4592
4593
4594
Housley, et. al. Standards Track [Page 82]
4595
4596
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4597
4598
4599
Note: In some environments, it is not necessary to check all reason
4600
codes. For example, some environments are only concerned with
4601
caCompromise and keyCompromise for CA certificates. This algorithm
4602
checks all reason codes. Additional processing and state variables
4603
may be necessary to limit the checking to a subset of the reason
4604
codes.
4605
4606
6.3.3 CRL Processing
4607
4608
This algorithm begins by assuming the certificate is not revoked.
4609
The algorithm checks one or more CRLs until either the certificate
4610
status is determined to be revoked or sufficient CRLs have been
4611
checked to cover all reason codes.
4612
4613
For each distribution point (DP) in the certificate CRL distribution
4614
points extension, for each corresponding CRL in the local CRL cache,
4615
while ((reasons_mask is not all-reasons) and (cert_status is
4616
UNREVOKED)) perform the following:
4617
4618
(a) Update the local CRL cache by obtaining a complete CRL, a
4619
delta CRL, or both, as required:
4620
4621
(1) If the current time is after the value of the CRL next
4622
update field, then do one of the following:
4623
4624
(i) If use-deltas is set and either the certificate or the
4625
CRL contains the freshest CRL extension, obtain a delta CRL
4626
with the a next update value that is after the current time
4627
and can be used to update the locally cached CRL as
4628
specified in section 5.2.4.
4629
4630
(ii) Update the local CRL cache with a current complete
4631
CRL, verify that the current time is before the next update
4632
value in the new CRL, and continue processing with the new
4633
CRL. If use-deltas is set, then obtain the current delta
4634
CRL that can be used to update the new locally cached
4635
complete CRL as specified in section 5.2.4.
4636
4637
(2) If the current time is before the value of the next update
4638
field and use-deltas is set, then obtain the current delta CRL
4639
that can be used to update the locally cached complete CRL as
4640
specified in section 5.2.4.
4641
4642
(b) Verify the issuer and scope of the complete CRL as follows:
4643
4644
4645
4646
4647
4648
4649
4650
Housley, et. al. Standards Track [Page 83]
4651
4652
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4653
4654
4655
(1) If the DP includes cRLIssuer, then verify that the issuer
4656
field in the complete CRL matches cRLIssuer in the DP and that
4657
the complete CRL contains an issuing distribution point
4658
extension with the indrectCRL boolean asserted. Otherwise,
4659
verify that the CRL issuer matches the certificate issuer.
4660
4661
(2) If the complete CRL includes an issuing distribution point
4662
(IDP) CRL extension check the following:
4663
4664
(i) If the distribution point name is present in the IDP
4665
CRL extension and the distribution field is present in the
4666
DP, then verify that one of the names in the IDP matches one
4667
of the names in the DP. If the distribution point name is
4668
present in the IDP CRL extension and the distribution field
4669
is omitted from the DP, then verify that one of the names in
4670
the IDP matches one of the names in the cRLIssuer field of
4671
the DP.
4672
4673
(ii) If the onlyContainsUserCerts boolean is asserted in
4674
the IDP CRL extension, verify that the certificate does not
4675
include the basic constraints extension with the cA boolean
4676
asserted.
4677
4678
(iii) If the onlyContainsCACerts boolean is asserted in the
4679
IDP CRL extension, verify that the certificate includes the
4680
basic constraints extension with the cA boolean asserted.
4681
4682
(iv) Verify that the onlyContainsAttributeCerts boolean is
4683
not asserted.
4684
4685
(c) If use-deltas is set, verify the issuer and scope of the
4686
delta CRL as follows:
4687
4688
(1) Verify that the delta CRL issuer matches complete CRL
4689
issuer.
4690
4691
(2) If the complete CRL includes an issuing distribution point
4692
(IDP) CRL extension, verify that the delta CRL contains a
4693
matching IDP CRL extension. If the complete CRL omits an IDP
4694
CRL extension, verify that the delta CRL also omits an IDP CRL
4695
extension.
4696
4697
(3) Verify that the delta CRL authority key identifier
4698
extension matches complete CRL authority key identifier
4699
extension.
4700
4701
4702
4703
4704
4705
4706
Housley, et. al. Standards Track [Page 84]
4707
4708
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4709
4710
4711
(d) Compute the interim_reasons_mask for this CRL as follows:
4712
4713
(1) If the issuing distribution point (IDP) CRL extension is
4714
present and includes onlySomeReasons and the DP includes
4715
reasons, then set interim_reasons_mask to the intersection of
4716
reasons in the DP and onlySomeReasons in IDP CRL extension.
4717
4718
(2) If the IDP CRL extension includes onlySomeReasons but the
4719
DP omits reasons, then set interim_reasons_mask to the value of
4720
onlySomeReasons in IDP CRL extension.
4721
4722
(3) If the IDP CRL extension is not present or omits
4723
onlySomeReasons but the DP includes reasons, then set
4724
interim_reasons_mask to the value of DP reasons.
4725
4726
(4) If the IDP CRL extension is not present or omits
4727
onlySomeReasons and the DP omits reasons, then set
4728
interim_reasons_mask to the special value all-reasons.
4729
4730
(e) Verify that interim_reasons_mask includes one or more reasons
4731
that is not included in the reasons_mask.
4732
4733
(f) Obtain and validate the certification path for the complete CRL
4734
issuer. If a key usage extension is present in the CRL issuer's
4735
certificate, verify that the cRLSign bit is set.
4736
4737
(g) Validate the signature on the complete CRL using the public key
4738
validated in step (f).
4739
4740
(h) If use-deltas is set, then validate the signature on the delta
4741
CRL using the public key validated in step (f).
4742
4743
(i) If use-deltas is set, then search for the certificate on the
4744
delta CRL. If an entry is found that matches the certificate issuer
4745
and serial number as described in section 5.3.4, then set the
4746
cert_status variable to the indicated reason as follows:
4747
4748
(1) If the reason code CRL entry extension is present, set the
4749
cert_status variable to the value of the reason code CRL entry
4750
extension.
4751
4752
(2) If the reason code CRL entry extension is not present, set
4753
the cert_status variable to the value unspecified.
4754
4755
4756
4757
4758
4759
4760
4761
4762
Housley, et. al. Standards Track [Page 85]
4763
4764
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4765
4766
4767
(j) If (cert_status is UNREVOKED), then search for the
4768
certificate on the complete CRL. If an entry is found that
4769
matches the certificate issuer and serial number as described in
4770
section 5.3.4, then set the cert_status variable to the indicated
4771
reason as described in step (i).
4772
4773
(k) If (cert_status is removeFromCRL), then set cert_status to
4774
UNREVOKED.
4775
4776
If ((reasons_mask is all-reasons) OR (cert_status is not UNREVOKED)),
4777
then the revocation status has been determined, so return
4778
cert_status.
4779
4780
If the revocation status has not been determined, repeat the process
4781
above with any available CRLs not specified in a distribution point
4782
but issued by the certificate issuer. For the processing of such a
4783
CRL, assume a DP with both the reasons and the cRLIssuer fields
4784
omitted and a distribution point name of the certificate issuer.
4785
That is, the sequence of names in fullName is generated from the
4786
certificate issuer field as well as the certificate issuerAltName
4787
extension. If the revocation status remains undetermined, then
4788
return the cert_status UNDETERMINED.
4789
4790
7 References
4791
4792
[ISO 10646] ISO/IEC 10646-1:1993. International Standard --
4793
Information technology -- Universal Multiple-Octet Coded
4794
Character Set (UCS) -- Part 1: Architecture and Basic
4795
Multilingual Plane.
4796
4797
[RFC 791] Postel, J., "Internet Protocol", STD 5, RFC 791,
4798
September 1981.
4799
4800
[RFC 822] Crocker, D., "Standard for the format of ARPA Internet
4801
text messages", STD 11, RFC 822, August 1982.
4802
4803
[RFC 1034] Mockapetris, P., "Domain Names - Concepts and
4804
Facilities", STD 13, RFC 1034, November 1987.
4805
4806
[RFC 1422] Kent, S., "Privacy Enhancement for Internet Electronic
4807
Mail: Part II: Certificate-Based Key Management," RFC
4808
1422, February 1993.
4809
4810
[RFC 1423] Balenson, D., "Privacy Enhancement for Internet
4811
Electronic Mail: Part III: Algorithms, Modes, and
4812
Identifiers," RFC 1423, February 1993.
4813
4814
4815
4816
4817
4818
Housley, et. al. Standards Track [Page 86]
4819
4820
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4821
4822
4823
[RFC 1510] Kohl, J. and C. Neuman, "The Kerberos Network
4824
Authentication Service (V5)," RFC 1510, September 1993.
4825
4826
[RFC 1519] Fuller, V., T. Li, J. Yu and K. Varadhan, "Classless
4827
Inter-Domain Routing (CIDR): An Address Assignment and
4828
Aggregation Strategy", RFC 1519, September 1993.
4829
4830
[RFC 1738] Berners-Lee, T., L. Masinter and M. McCahill, "Uniform
4831
Resource Locators (URL)", RFC 1738, December 1994.
4832
4833
[RFC 1778] Howes, T., S. Kille, W. Yeong and C. Robbins, "The String
4834
Representation of Standard Attribute Syntaxes," RFC 1778,
4835
March 1995.
4836
4837
[RFC 1883] Deering, S. and R. Hinden. "Internet Protocol, Version 6
4838
(IPv6) Specification", RFC 1883, December 1995.
4839
4840
[RFC 2044] F. Yergeau, F., "UTF-8, a transformation format of
4841
Unicode and ISO 10646", RFC 2044, October 1996.
4842
4843
[RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate
4844
Requirement Levels", BCP 14, RFC 2119, March 1997.
4845
4846
[RFC 2247] Kille, S., M. Wahl, A. Grimstad, R. Huber and S.
4847
Sataluri, "Using Domains in LDAP/X.500 Distinguished
4848
Names", RFC 2247, January 1998.
4849
4850
[RFC 2252] Wahl, M., A. Coulbeck, T. Howes and S. Kille,
4851
"Lightweight Directory Access Protocol (v3): Attribute
4852
Syntax Definitions", RFC 2252, December 1997.
4853
4854
[RFC 2277] Alvestrand, H., "IETF Policy on Character Sets and
4855
Languages", BCP 18, RFC 2277, January 1998.
4856
4857
[RFC 2279] Yergeau, F., "UTF-8, a transformation format of ISO
4858
10646", RFC 2279, January 1998.
4859
4860
[RFC 2459] Housley, R., W. Ford, W. Polk and D. Solo, "Internet
4861
X.509 Public Key Infrastructure: Certificate and CRL
4862
Profile", RFC 2459, January 1999.
4863
4864
[RFC 2560] Myers, M., R. Ankney, A. Malpani, S. Galperin and C.
4865
Adams, "Online Certificate Status Protocal - OCSP", June
4866
1999.
4867
4868
[SDN.701] SDN.701, "Message Security Protocol 4.0", Revision A,
4869
1997-02-06.
4870
4871
4872
4873
4874
Housley, et. al. Standards Track [Page 87]
4875
4876
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4877
4878
4879
[X.501] ITU-T Recommendation X.501: Information Technology - Open
4880
Systems Interconnection - The Directory: Models, 1993.
4881
4882
[X.509] ITU-T Recommendation X.509 (1997 E): Information
4883
Technology - Open Systems Interconnection - The
4884
Directory: Authentication Framework, June 1997.
4885
4886
[X.520] ITU-T Recommendation X.520: Information Technology - Open
4887
Systems Interconnection - The Directory: Selected
4888
Attribute Types, 1993.
4889
4890
[X.660] ITU-T Recommendation X.660 Information Technology - ASN.1
4891
encoding rules: Specification of Basic Encoding Rules
4892
(BER), Canonical Encoding Rules (CER) and Distinguished
4893
Encoding Rules (DER), 1997.
4894
4895
[X.690] ITU-T Recommendation X.690 Information Technology - Open
4896
Systems Interconnection - Procedures for the operation of
4897
OSI Registration Authorities: General procedures, 1992.
4898
4899
[X9.55] ANSI X9.55-1995, Public Key Cryptography For The
4900
Financial Services Industry: Extensions To Public Key
4901
Certificates And Certificate Revocation Lists, 8
4902
December, 1995.
4903
4904
[PKIXALGS] Bassham, L., Polk, W. and R. Housley, "Algorithms and
4905
Identifiers for the Internet X.509 Public Key
4906
Infrastructure Certificate and Certificate Revocation
4907
Lists (CRL) Profile", RFC 3279, April 2002.
4908
4909
[PKIXTSA] Adams, C., Cain, P., Pinkas, D. and R. Zuccherato,
4910
"Internet X.509 Public Key Infrastructure Time-Stamp
4911
Protocol (TSP)", RFC 3161, August 2001.
4912
4913
8 Intellectual Property Rights
4914
4915
The IETF has been notified of intellectual property rights claimed in
4916
regard to some or all of the specification contained in this
4917
document. For more information consult the online list of claimed
4918
rights (see http://www.ietf.org/ipr.html).
4919
4920
The IETF takes no position regarding the validity or scope of any
4921
intellectual property or other rights that might be claimed to
4922
pertain to the implementation or use of the technology described in
4923
this document or the extent to which any license under such rights
4924
might or might not be available; neither does it represent that it
4925
has made any effort to identify any such rights. Information on the
4926
IETF's procedures with respect to rights in standards-track and
4927
4928
4929
4930
Housley, et. al. Standards Track [Page 88]
4931
4932
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4933
4934
4935
standards-related documentation can be found in BCP 11. Copies of
4936
claims of rights made available for publication and any assurances of
4937
licenses to be made available, or the result of an attempt made to
4938
obtain a general license or permission for the use of such
4939
proprietary rights by implementors or users of this specification can
4940
be obtained from the IETF Secretariat.
4941
4942
9 Security Considerations
4943
4944
The majority of this specification is devoted to the format and
4945
content of certificates and CRLs. Since certificates and CRLs are
4946
digitally signed, no additional integrity service is necessary.
4947
Neither certificates nor CRLs need be kept secret, and unrestricted
4948
and anonymous access to certificates and CRLs has no security
4949
implications.
4950
4951
However, security factors outside the scope of this specification
4952
will affect the assurance provided to certificate users. This
4953
section highlights critical issues to be considered by implementers,
4954
administrators, and users.
4955
4956
The procedures performed by CAs and RAs to validate the binding of
4957
the subject's identity to their public key greatly affect the
4958
assurance that ought to be placed in the certificate. Relying
4959
parties might wish to review the CA's certificate practice statement.
4960
This is particularly important when issuing certificates to other
4961
CAs.
4962
4963
The use of a single key pair for both signature and other purposes is
4964
strongly discouraged. Use of separate key pairs for signature and
4965
key management provides several benefits to the users. The
4966
ramifications associated with loss or disclosure of a signature key
4967
are different from loss or disclosure of a key management key. Using
4968
separate key pairs permits a balanced and flexible response.
4969
Similarly, different validity periods or key lengths for each key
4970
pair may be appropriate in some application environments.
4971
Unfortunately, some legacy applications (e.g., SSL) use a single key
4972
pair for signature and key management.
4973
4974
The protection afforded private keys is a critical security factor.
4975
On a small scale, failure of users to protect their private keys will
4976
permit an attacker to masquerade as them, or decrypt their personal
4977
information. On a larger scale, compromise of a CA's private signing
4978
key may have a catastrophic effect. If an attacker obtains the
4979
private key unnoticed, the attacker may issue bogus certificates and
4980
CRLs. Existence of bogus certificates and CRLs will undermine
4981
confidence in the system. If such a compromise is detected, all
4982
certificates issued to the compromised CA MUST be revoked, preventing
4983
4984
4985
4986
Housley, et. al. Standards Track [Page 89]
4987
4988
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
4989
4990
4991
services between its users and users of other CAs. Rebuilding after
4992
such a compromise will be problematic, so CAs are advised to
4993
implement a combination of strong technical measures (e.g., tamper-
4994
resistant cryptographic modules) and appropriate management
4995
procedures (e.g., separation of duties) to avoid such an incident.
4996
4997
Loss of a CA's private signing key may also be problematic. The CA
4998
would not be able to produce CRLs or perform normal key rollover.
4999
CAs SHOULD maintain secure backup for signing keys. The security of
5000
the key backup procedures is a critical factor in avoiding key
5001
compromise.
5002
5003
The availability and freshness of revocation information affects the
5004
degree of assurance that ought to be placed in a certificate. While
5005
certificates expire naturally, events may occur during its natural
5006
lifetime which negate the binding between the subject and public key.
5007
If revocation information is untimely or unavailable, the assurance
5008
associated with the binding is clearly reduced. Relying parties
5009
might not be able to process every critical extension that can appear
5010
in a CRL. CAs SHOULD take extra care when making revocation
5011
information available only through CRLs that contain critical
5012
extensions, particularly if support for those extensions is not
5013
mandated by this profile. For example, if revocation information is
5014
supplied using a combination of delta CRLs and full CRLs, and the
5015
delta CRLs are issued more frequently than the full CRLs, then
5016
relying parties that cannot handle the critical extensions related to
5017
delta CRL processing will not be able to obtain the most recent
5018
revocation information. Alternatively, if a full CRL is issued
5019
whenever a delta CRL is issued, then timely revocation information
5020
will be available to all relying parties. Similarly, implementations
5021
of the certification path validation mechanism described in section 6
5022
that omit revocation checking provide less assurance than those that
5023
support it.
5024
5025
The certification path validation algorithm depends on the certain
5026
knowledge of the public keys (and other information) about one or
5027
more trusted CAs. The decision to trust a CA is an important
5028
decision as it ultimately determines the trust afforded a
5029
certificate. The authenticated distribution of trusted CA public
5030
keys (usually in the form of a "self-signed" certificate) is a
5031
security critical out-of-band process that is beyond the scope of
5032
this specification.
5033
5034
In addition, where a key compromise or CA failure occurs for a
5035
trusted CA, the user will need to modify the information provided to
5036
the path validation routine. Selection of too many trusted CAs makes
5037
5038
5039
5040
5041
5042
Housley, et. al. Standards Track [Page 90]
5043
5044
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5045
5046
5047
the trusted CA information difficult to maintain. On the other hand,
5048
selection of only one trusted CA could limit users to a closed
5049
community of users.
5050
5051
The quality of implementations that process certificates also affects
5052
the degree of assurance provided. The path validation algorithm
5053
described in section 6 relies upon the integrity of the trusted CA
5054
information, and especially the integrity of the public keys
5055
associated with the trusted CAs. By substituting public keys for
5056
which an attacker has the private key, an attacker could trick the
5057
user into accepting false certificates.
5058
5059
The binding between a key and certificate subject cannot be stronger
5060
than the cryptographic module implementation and algorithms used to
5061
generate the signature. Short key lengths or weak hash algorithms
5062
will limit the utility of a certificate. CAs are encouraged to note
5063
advances in cryptology so they can employ strong cryptographic
5064
techniques. In addition, CAs SHOULD decline to issue certificates to
5065
CAs or end entities that generate weak signatures.
5066
5067
Inconsistent application of name comparison rules can result in
5068
acceptance of invalid X.509 certification paths, or rejection of
5069
valid ones. The X.500 series of specifications defines rules for
5070
comparing distinguished names that require comparison of strings
5071
without regard to case, character set, multi-character white space
5072
substring, or leading and trailing white space. This specification
5073
relaxes these requirements, requiring support for binary comparison
5074
at a minimum.
5075
5076
CAs MUST encode the distinguished name in the subject field of a CA
5077
certificate identically to the distinguished name in the issuer field
5078
in certificates issued by that CA. If CAs use different encodings,
5079
implementations might fail to recognize name chains for paths that
5080
include this certificate. As a consequence, valid paths could be
5081
rejected.
5082
5083
In addition, name constraints for distinguished names MUST be stated
5084
identically to the encoding used in the subject field or
5085
subjectAltName extension. If not, then name constraints stated as
5086
excludedSubTrees will not match and invalid paths will be accepted
5087
and name constraints expressed as permittedSubtrees will not match
5088
and valid paths will be rejected. To avoid acceptance of invalid
5089
paths, CAs SHOULD state name constraints for distinguished names as
5090
permittedSubtrees wherever possible.
5091
5092
5093
5094
5095
5096
5097
5098
Housley, et. al. Standards Track [Page 91]
5099
5100
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5101
5102
5103
Appendix A. Psuedo-ASN.1 Structures and OIDs
5104
5105
This section describes data objects used by conforming PKI components
5106
in an "ASN.1-like" syntax. This syntax is a hybrid of the 1988 and
5107
1993 ASN.1 syntaxes. The 1988 ASN.1 syntax is augmented with 1993
5108
UNIVERSAL Types UniversalString, BMPString and UTF8String.
5109
5110
The ASN.1 syntax does not permit the inclusion of type statements in
5111
the ASN.1 module, and the 1993 ASN.1 standard does not permit use of
5112
the new UNIVERSAL types in modules using the 1988 syntax. As a
5113
result, this module does not conform to either version of the ASN.1
5114
standard.
5115
5116
This appendix may be converted into 1988 ASN.1 by replacing the
5117
definitions for the UNIVERSAL Types with the 1988 catch-all "ANY".
5118
5119
A.1 Explicitly Tagged Module, 1988 Syntax
5120
5121
PKIX1Explicit88 { iso(1) identified-organization(3) dod(6) internet(1)
5122
security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-explicit(18) }
5123
5124
DEFINITIONS EXPLICIT TAGS ::=
5125
5126
BEGIN
5127
5128
-- EXPORTS ALL --
5129
5130
-- IMPORTS NONE --
5131
5132
-- UNIVERSAL Types defined in 1993 and 1998 ASN.1
5133
-- and required by this specification
5134
5135
UniversalString ::= [UNIVERSAL 28] IMPLICIT OCTET STRING
5136
-- UniversalString is defined in ASN.1:1993
5137
5138
BMPString ::= [UNIVERSAL 30] IMPLICIT OCTET STRING
5139
-- BMPString is the subtype of UniversalString and models
5140
-- the Basic Multilingual Plane of ISO/IEC/ITU 10646-1
5141
5142
UTF8String ::= [UNIVERSAL 12] IMPLICIT OCTET STRING
5143
-- The content of this type conforms to RFC 2279.
5144
5145
-- PKIX specific OIDs
5146
5147
id-pkix OBJECT IDENTIFIER ::=
5148
{ iso(1) identified-organization(3) dod(6) internet(1)
5149
security(5) mechanisms(5) pkix(7) }
5150
5151
5152
5153
5154
Housley, et. al. Standards Track [Page 92]
5155
5156
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5157
5158
5159
-- PKIX arcs
5160
5161
id-pe OBJECT IDENTIFIER ::= { id-pkix 1 }
5162
-- arc for private certificate extensions
5163
id-qt OBJECT IDENTIFIER ::= { id-pkix 2 }
5164
-- arc for policy qualifier types
5165
id-kp OBJECT IDENTIFIER ::= { id-pkix 3 }
5166
-- arc for extended key purpose OIDS
5167
id-ad OBJECT IDENTIFIER ::= { id-pkix 48 }
5168
-- arc for access descriptors
5169
5170
-- policyQualifierIds for Internet policy qualifiers
5171
5172
id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 }
5173
-- OID for CPS qualifier
5174
id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 }
5175
-- OID for user notice qualifier
5176
5177
-- access descriptor definitions
5178
5179
id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 }
5180
id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 }
5181
id-ad-timeStamping OBJECT IDENTIFIER ::= { id-ad 3 }
5182
id-ad-caRepository OBJECT IDENTIFIER ::= { id-ad 5 }
5183
5184
-- attribute data types
5185
5186
Attribute ::= SEQUENCE {
5187
type AttributeType,
5188
values SET OF AttributeValue }
5189
-- at least one value is required
5190
5191
AttributeType ::= OBJECT IDENTIFIER
5192
5193
AttributeValue ::= ANY
5194
5195
AttributeTypeAndValue ::= SEQUENCE {
5196
type AttributeType,
5197
value AttributeValue }
5198
5199
-- suggested naming attributes: Definition of the following
5200
-- information object set may be augmented to meet local
5201
-- requirements. Note that deleting members of the set may
5202
-- prevent interoperability with conforming implementations.
5203
-- presented in pairs: the AttributeType followed by the
5204
-- type definition for the corresponding AttributeValue
5205
--Arc for standard naming attributes
5206
id-at OBJECT IDENTIFIER ::= { joint-iso-ccitt(2) ds(5) 4 }
5207
5208
5209
5210
Housley, et. al. Standards Track [Page 93]
5211
5212
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5213
5214
5215
-- Naming attributes of type X520name
5216
5217
id-at-name AttributeType ::= { id-at 41 }
5218
id-at-surname AttributeType ::= { id-at 4 }
5219
id-at-givenName AttributeType ::= { id-at 42 }
5220
id-at-initials AttributeType ::= { id-at 43 }
5221
id-at-generationQualifier AttributeType ::= { id-at 44 }
5222
5223
X520name ::= CHOICE {
5224
teletexString TeletexString (SIZE (1..ub-name)),
5225
printableString PrintableString (SIZE (1..ub-name)),
5226
universalString UniversalString (SIZE (1..ub-name)),
5227
utf8String UTF8String (SIZE (1..ub-name)),
5228
bmpString BMPString (SIZE (1..ub-name)) }
5229
5230
-- Naming attributes of type X520CommonName
5231
5232
id-at-commonName AttributeType ::= { id-at 3 }
5233
5234
X520CommonName ::= CHOICE {
5235
teletexString TeletexString (SIZE (1..ub-common-name)),
5236
printableString PrintableString (SIZE (1..ub-common-name)),
5237
universalString UniversalString (SIZE (1..ub-common-name)),
5238
utf8String UTF8String (SIZE (1..ub-common-name)),
5239
bmpString BMPString (SIZE (1..ub-common-name)) }
5240
5241
-- Naming attributes of type X520LocalityName
5242
5243
id-at-localityName AttributeType ::= { id-at 7 }
5244
5245
X520LocalityName ::= CHOICE {
5246
teletexString TeletexString (SIZE (1..ub-locality-name)),
5247
printableString PrintableString (SIZE (1..ub-locality-name)),
5248
universalString UniversalString (SIZE (1..ub-locality-name)),
5249
utf8String UTF8String (SIZE (1..ub-locality-name)),
5250
bmpString BMPString (SIZE (1..ub-locality-name)) }
5251
5252
-- Naming attributes of type X520StateOrProvinceName
5253
5254
id-at-stateOrProvinceName AttributeType ::= { id-at 8 }
5255
5256
X520StateOrProvinceName ::= CHOICE {
5257
teletexString TeletexString (SIZE (1..ub-state-name)),
5258
printableString PrintableString (SIZE (1..ub-state-name)),
5259
universalString UniversalString (SIZE (1..ub-state-name)),
5260
utf8String UTF8String (SIZE (1..ub-state-name)),
5261
bmpString BMPString (SIZE(1..ub-state-name)) }
5262
5263
5264
5265
5266
Housley, et. al. Standards Track [Page 94]
5267
5268
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5269
5270
5271
-- Naming attributes of type X520OrganizationName
5272
5273
id-at-organizationName AttributeType ::= { id-at 10 }
5274
5275
X520OrganizationName ::= CHOICE {
5276
teletexString TeletexString
5277
(SIZE (1..ub-organization-name)),
5278
printableString PrintableString
5279
(SIZE (1..ub-organization-name)),
5280
universalString UniversalString
5281
(SIZE (1..ub-organization-name)),
5282
utf8String UTF8String
5283
(SIZE (1..ub-organization-name)),
5284
bmpString BMPString
5285
(SIZE (1..ub-organization-name)) }
5286
5287
-- Naming attributes of type X520OrganizationalUnitName
5288
5289
id-at-organizationalUnitName AttributeType ::= { id-at 11 }
5290
5291
X520OrganizationalUnitName ::= CHOICE {
5292
teletexString TeletexString
5293
(SIZE (1..ub-organizational-unit-name)),
5294
printableString PrintableString
5295
(SIZE (1..ub-organizational-unit-name)),
5296
universalString UniversalString
5297
(SIZE (1..ub-organizational-unit-name)),
5298
utf8String UTF8String
5299
(SIZE (1..ub-organizational-unit-name)),
5300
bmpString BMPString
5301
(SIZE (1..ub-organizational-unit-name)) }
5302
5303
-- Naming attributes of type X520Title
5304
5305
id-at-title AttributeType ::= { id-at 12 }
5306
5307
X520Title ::= CHOICE {
5308
teletexString TeletexString (SIZE (1..ub-title)),
5309
printableString PrintableString (SIZE (1..ub-title)),
5310
universalString UniversalString (SIZE (1..ub-title)),
5311
utf8String UTF8String (SIZE (1..ub-title)),
5312
bmpString BMPString (SIZE (1..ub-title)) }
5313
5314
-- Naming attributes of type X520dnQualifier
5315
5316
id-at-dnQualifier AttributeType ::= { id-at 46 }
5317
5318
X520dnQualifier ::= PrintableString
5319
5320
5321
5322
Housley, et. al. Standards Track [Page 95]
5323
5324
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5325
5326
5327
-- Naming attributes of type X520countryName (digraph from IS 3166)
5328
5329
id-at-countryName AttributeType ::= { id-at 6 }
5330
5331
X520countryName ::= PrintableString (SIZE (2))
5332
5333
-- Naming attributes of type X520SerialNumber
5334
5335
id-at-serialNumber AttributeType ::= { id-at 5 }
5336
5337
X520SerialNumber ::= PrintableString (SIZE (1..ub-serial-number))
5338
5339
-- Naming attributes of type X520Pseudonym
5340
5341
id-at-pseudonym AttributeType ::= { id-at 65 }
5342
5343
X520Pseudonym ::= CHOICE {
5344
teletexString TeletexString (SIZE (1..ub-pseudonym)),
5345
printableString PrintableString (SIZE (1..ub-pseudonym)),
5346
universalString UniversalString (SIZE (1..ub-pseudonym)),
5347
utf8String UTF8String (SIZE (1..ub-pseudonym)),
5348
bmpString BMPString (SIZE (1..ub-pseudonym)) }
5349
5350
-- Naming attributes of type DomainComponent (from RFC 2247)
5351
5352
id-domainComponent AttributeType ::=
5353
{ 0 9 2342 19200300 100 1 25 }
5354
5355
DomainComponent ::= IA5String
5356
5357
-- Legacy attributes
5358
5359
pkcs-9 OBJECT IDENTIFIER ::=
5360
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 9 }
5361
5362
id-emailAddress AttributeType ::= { pkcs-9 1 }
5363
5364
EmailAddress ::= IA5String (SIZE (1..ub-emailaddress-length))
5365
5366
-- naming data types --
5367
5368
Name ::= CHOICE { -- only one possibility for now --
5369
rdnSequence RDNSequence }
5370
5371
RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
5372
5373
DistinguishedName ::= RDNSequence
5374
5375
5376
5377
5378
Housley, et. al. Standards Track [Page 96]
5379
5380
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5381
5382
5383
RelativeDistinguishedName ::=
5384
SET SIZE (1 .. MAX) OF AttributeTypeAndValue
5385
5386
-- Directory string type --
5387
5388
DirectoryString ::= CHOICE {
5389
teletexString TeletexString (SIZE (1..MAX)),
5390
printableString PrintableString (SIZE (1..MAX)),
5391
universalString UniversalString (SIZE (1..MAX)),
5392
utf8String UTF8String (SIZE (1..MAX)),
5393
bmpString BMPString (SIZE (1..MAX)) }
5394
5395
-- certificate and CRL specific structures begin here
5396
5397
Certificate ::= SEQUENCE {
5398
tbsCertificate TBSCertificate,
5399
signatureAlgorithm AlgorithmIdentifier,
5400
signature BIT STRING }
5401
5402
TBSCertificate ::= SEQUENCE {
5403
version [0] Version DEFAULT v1,
5404
serialNumber CertificateSerialNumber,
5405
signature AlgorithmIdentifier,
5406
issuer Name,
5407
validity Validity,
5408
subject Name,
5409
subjectPublicKeyInfo SubjectPublicKeyInfo,
5410
issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
5411
-- If present, version MUST be v2 or v3
5412
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
5413
-- If present, version MUST be v2 or v3
5414
extensions [3] Extensions OPTIONAL
5415
-- If present, version MUST be v3 -- }
5416
5417
Version ::= INTEGER { v1(0), v2(1), v3(2) }
5418
5419
CertificateSerialNumber ::= INTEGER
5420
5421
Validity ::= SEQUENCE {
5422
notBefore Time,
5423
notAfter Time }
5424
5425
Time ::= CHOICE {
5426
utcTime UTCTime,
5427
generalTime GeneralizedTime }
5428
5429
UniqueIdentifier ::= BIT STRING
5430
5431
5432
5433
5434
Housley, et. al. Standards Track [Page 97]
5435
5436
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5437
5438
5439
SubjectPublicKeyInfo ::= SEQUENCE {
5440
algorithm AlgorithmIdentifier,
5441
subjectPublicKey BIT STRING }
5442
5443
Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
5444
5445
Extension ::= SEQUENCE {
5446
extnID OBJECT IDENTIFIER,
5447
critical BOOLEAN DEFAULT FALSE,
5448
extnValue OCTET STRING }
5449
5450
-- CRL structures
5451
5452
CertificateList ::= SEQUENCE {
5453
tbsCertList TBSCertList,
5454
signatureAlgorithm AlgorithmIdentifier,
5455
signature BIT STRING }
5456
5457
TBSCertList ::= SEQUENCE {
5458
version Version OPTIONAL,
5459
-- if present, MUST be v2
5460
signature AlgorithmIdentifier,
5461
issuer Name,
5462
thisUpdate Time,
5463
nextUpdate Time OPTIONAL,
5464
revokedCertificates SEQUENCE OF SEQUENCE {
5465
userCertificate CertificateSerialNumber,
5466
revocationDate Time,
5467
crlEntryExtensions Extensions OPTIONAL
5468
-- if present, MUST be v2
5469
} OPTIONAL,
5470
crlExtensions [0] Extensions OPTIONAL }
5471
-- if present, MUST be v2
5472
5473
-- Version, Time, CertificateSerialNumber, and Extensions were
5474
-- defined earlier for use in the certificate structure
5475
5476
AlgorithmIdentifier ::= SEQUENCE {
5477
algorithm OBJECT IDENTIFIER,
5478
parameters ANY DEFINED BY algorithm OPTIONAL }
5479
-- contains a value of the type
5480
-- registered for use with the
5481
-- algorithm object identifier value
5482
5483
-- X.400 address syntax starts here
5484
5485
5486
5487
5488
5489
5490
Housley, et. al. Standards Track [Page 98]
5491
5492
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5493
5494
5495
ORAddress ::= SEQUENCE {
5496
built-in-standard-attributes BuiltInStandardAttributes,
5497
built-in-domain-defined-attributes
5498
BuiltInDomainDefinedAttributes OPTIONAL,
5499
-- see also teletex-domain-defined-attributes
5500
extension-attributes ExtensionAttributes OPTIONAL }
5501
5502
-- Built-in Standard Attributes
5503
5504
BuiltInStandardAttributes ::= SEQUENCE {
5505
country-name CountryName OPTIONAL,
5506
administration-domain-name AdministrationDomainName OPTIONAL,
5507
network-address [0] IMPLICIT NetworkAddress OPTIONAL,
5508
-- see also extended-network-address
5509
terminal-identifier [1] IMPLICIT TerminalIdentifier OPTIONAL,
5510
private-domain-name [2] PrivateDomainName OPTIONAL,
5511
organization-name [3] IMPLICIT OrganizationName OPTIONAL,
5512
-- see also teletex-organization-name
5513
numeric-user-identifier [4] IMPLICIT NumericUserIdentifier
5514
OPTIONAL,
5515
personal-name [5] IMPLICIT PersonalName OPTIONAL,
5516
-- see also teletex-personal-name
5517
organizational-unit-names [6] IMPLICIT OrganizationalUnitNames
5518
OPTIONAL }
5519
-- see also teletex-organizational-unit-names
5520
5521
CountryName ::= [APPLICATION 1] CHOICE {
5522
x121-dcc-code NumericString
5523
(SIZE (ub-country-name-numeric-length)),
5524
iso-3166-alpha2-code PrintableString
5525
(SIZE (ub-country-name-alpha-length)) }
5526
5527
AdministrationDomainName ::= [APPLICATION 2] CHOICE {
5528
numeric NumericString (SIZE (0..ub-domain-name-length)),
5529
printable PrintableString (SIZE (0..ub-domain-name-length)) }
5530
5531
NetworkAddress ::= X121Address -- see also extended-network-address
5532
5533
X121Address ::= NumericString (SIZE (1..ub-x121-address-length))
5534
5535
TerminalIdentifier ::= PrintableString (SIZE
5536
(1..ub-terminal-id-length))
5537
5538
PrivateDomainName ::= CHOICE {
5539
numeric NumericString (SIZE (1..ub-domain-name-length)),
5540
printable PrintableString (SIZE (1..ub-domain-name-length)) }
5541
5542
5543
5544
5545
5546
Housley, et. al. Standards Track [Page 99]
5547
5548
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5549
5550
5551
OrganizationName ::= PrintableString
5552
(SIZE (1..ub-organization-name-length))
5553
-- see also teletex-organization-name
5554
5555
NumericUserIdentifier ::= NumericString
5556
(SIZE (1..ub-numeric-user-id-length))
5557
5558
PersonalName ::= SET {
5559
surname [0] IMPLICIT PrintableString
5560
(SIZE (1..ub-surname-length)),
5561
given-name [1] IMPLICIT PrintableString
5562
(SIZE (1..ub-given-name-length)) OPTIONAL,
5563
initials [2] IMPLICIT PrintableString
5564
(SIZE (1..ub-initials-length)) OPTIONAL,
5565
generation-qualifier [3] IMPLICIT PrintableString
5566
(SIZE (1..ub-generation-qualifier-length))
5567
OPTIONAL }
5568
-- see also teletex-personal-name
5569
5570
OrganizationalUnitNames ::= SEQUENCE SIZE (1..ub-organizational-units)
5571
OF OrganizationalUnitName
5572
-- see also teletex-organizational-unit-names
5573
5574
OrganizationalUnitName ::= PrintableString (SIZE
5575
(1..ub-organizational-unit-name-length))
5576
5577
-- Built-in Domain-defined Attributes
5578
5579
BuiltInDomainDefinedAttributes ::= SEQUENCE SIZE
5580
(1..ub-domain-defined-attributes) OF
5581
BuiltInDomainDefinedAttribute
5582
5583
BuiltInDomainDefinedAttribute ::= SEQUENCE {
5584
type PrintableString (SIZE
5585
(1..ub-domain-defined-attribute-type-length)),
5586
value PrintableString (SIZE
5587
(1..ub-domain-defined-attribute-value-length)) }
5588
5589
-- Extension Attributes
5590
5591
ExtensionAttributes ::= SET SIZE (1..ub-extension-attributes) OF
5592
ExtensionAttribute
5593
5594
ExtensionAttribute ::= SEQUENCE {
5595
extension-attribute-type [0] IMPLICIT INTEGER
5596
(0..ub-extension-attributes),
5597
extension-attribute-value [1]
5598
ANY DEFINED BY extension-attribute-type }
5599
5600
5601
5602
Housley, et. al. Standards Track [Page 100]
5603
5604
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5605
5606
5607
-- Extension types and attribute values
5608
5609
common-name INTEGER ::= 1
5610
5611
CommonName ::= PrintableString (SIZE (1..ub-common-name-length))
5612
5613
teletex-common-name INTEGER ::= 2
5614
5615
TeletexCommonName ::= TeletexString (SIZE (1..ub-common-name-length))
5616
5617
teletex-organization-name INTEGER ::= 3
5618
5619
TeletexOrganizationName ::=
5620
TeletexString (SIZE (1..ub-organization-name-length))
5621
5622
teletex-personal-name INTEGER ::= 4
5623
5624
TeletexPersonalName ::= SET {
5625
surname [0] IMPLICIT TeletexString
5626
(SIZE (1..ub-surname-length)),
5627
given-name [1] IMPLICIT TeletexString
5628
(SIZE (1..ub-given-name-length)) OPTIONAL,
5629
initials [2] IMPLICIT TeletexString
5630
(SIZE (1..ub-initials-length)) OPTIONAL,
5631
generation-qualifier [3] IMPLICIT TeletexString
5632
(SIZE (1..ub-generation-qualifier-length))
5633
OPTIONAL }
5634
5635
teletex-organizational-unit-names INTEGER ::= 5
5636
5637
TeletexOrganizationalUnitNames ::= SEQUENCE SIZE
5638
(1..ub-organizational-units) OF TeletexOrganizationalUnitName
5639
5640
TeletexOrganizationalUnitName ::= TeletexString
5641
(SIZE (1..ub-organizational-unit-name-length))
5642
5643
pds-name INTEGER ::= 7
5644
5645
PDSName ::= PrintableString (SIZE (1..ub-pds-name-length))
5646
5647
physical-delivery-country-name INTEGER ::= 8
5648
5649
PhysicalDeliveryCountryName ::= CHOICE {
5650
x121-dcc-code NumericString (SIZE
5651
(ub-country-name-numeric-length)),
5652
iso-3166-alpha2-code PrintableString
5653
(SIZE (ub-country-name-alpha-length)) }
5654
5655
5656
5657
5658
Housley, et. al. Standards Track [Page 101]
5659
5660
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5661
5662
5663
postal-code INTEGER ::= 9
5664
5665
PostalCode ::= CHOICE {
5666
numeric-code NumericString (SIZE (1..ub-postal-code-length)),
5667
printable-code PrintableString (SIZE (1..ub-postal-code-length)) }
5668
5669
physical-delivery-office-name INTEGER ::= 10
5670
5671
PhysicalDeliveryOfficeName ::= PDSParameter
5672
5673
physical-delivery-office-number INTEGER ::= 11
5674
5675
PhysicalDeliveryOfficeNumber ::= PDSParameter
5676
5677
extension-OR-address-components INTEGER ::= 12
5678
5679
ExtensionORAddressComponents ::= PDSParameter
5680
5681
physical-delivery-personal-name INTEGER ::= 13
5682
5683
PhysicalDeliveryPersonalName ::= PDSParameter
5684
5685
physical-delivery-organization-name INTEGER ::= 14
5686
5687
PhysicalDeliveryOrganizationName ::= PDSParameter
5688
5689
extension-physical-delivery-address-components INTEGER ::= 15
5690
5691
ExtensionPhysicalDeliveryAddressComponents ::= PDSParameter
5692
5693
unformatted-postal-address INTEGER ::= 16
5694
5695
UnformattedPostalAddress ::= SET {
5696
printable-address SEQUENCE SIZE (1..ub-pds-physical-address-lines)
5697
OF PrintableString (SIZE (1..ub-pds-parameter-length))
5698
OPTIONAL,
5699
teletex-string TeletexString
5700
(SIZE (1..ub-unformatted-address-length)) OPTIONAL }
5701
5702
street-address INTEGER ::= 17
5703
5704
StreetAddress ::= PDSParameter
5705
5706
post-office-box-address INTEGER ::= 18
5707
5708
PostOfficeBoxAddress ::= PDSParameter
5709
5710
poste-restante-address INTEGER ::= 19
5711
5712
5713
5714
Housley, et. al. Standards Track [Page 102]
5715
5716
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5717
5718
5719
PosteRestanteAddress ::= PDSParameter
5720
5721
unique-postal-name INTEGER ::= 20
5722
5723
UniquePostalName ::= PDSParameter
5724
5725
local-postal-attributes INTEGER ::= 21
5726
5727
LocalPostalAttributes ::= PDSParameter
5728
5729
PDSParameter ::= SET {
5730
printable-string PrintableString
5731
(SIZE(1..ub-pds-parameter-length)) OPTIONAL,
5732
teletex-string TeletexString
5733
(SIZE(1..ub-pds-parameter-length)) OPTIONAL }
5734
5735
extended-network-address INTEGER ::= 22
5736
5737
ExtendedNetworkAddress ::= CHOICE {
5738
e163-4-address SEQUENCE {
5739
number [0] IMPLICIT NumericString
5740
(SIZE (1..ub-e163-4-number-length)),
5741
sub-address [1] IMPLICIT NumericString
5742
(SIZE (1..ub-e163-4-sub-address-length))
5743
OPTIONAL },
5744
psap-address [0] IMPLICIT PresentationAddress }
5745
5746
PresentationAddress ::= SEQUENCE {
5747
pSelector [0] EXPLICIT OCTET STRING OPTIONAL,
5748
sSelector [1] EXPLICIT OCTET STRING OPTIONAL,
5749
tSelector [2] EXPLICIT OCTET STRING OPTIONAL,
5750
nAddresses [3] EXPLICIT SET SIZE (1..MAX) OF OCTET STRING }
5751
5752
terminal-type INTEGER ::= 23
5753
5754
TerminalType ::= INTEGER {
5755
telex (3),
5756
teletex (4),
5757
g3-facsimile (5),
5758
g4-facsimile (6),
5759
ia5-terminal (7),
5760
videotex (8) } (0..ub-integer-options)
5761
5762
-- Extension Domain-defined Attributes
5763
5764
teletex-domain-defined-attributes INTEGER ::= 6
5765
5766
5767
5768
5769
5770
Housley, et. al. Standards Track [Page 103]
5771
5772
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5773
5774
5775
TeletexDomainDefinedAttributes ::= SEQUENCE SIZE
5776
(1..ub-domain-defined-attributes) OF TeletexDomainDefinedAttribute
5777
5778
TeletexDomainDefinedAttribute ::= SEQUENCE {
5779
type TeletexString
5780
(SIZE (1..ub-domain-defined-attribute-type-length)),
5781
value TeletexString
5782
(SIZE (1..ub-domain-defined-attribute-value-length)) }
5783
5784
-- specifications of Upper Bounds MUST be regarded as mandatory
5785
-- from Annex B of ITU-T X.411 Reference Definition of MTS Parameter
5786
-- Upper Bounds
5787
5788
-- Upper Bounds
5789
ub-name INTEGER ::= 32768
5790
ub-common-name INTEGER ::= 64
5791
ub-locality-name INTEGER ::= 128
5792
ub-state-name INTEGER ::= 128
5793
ub-organization-name INTEGER ::= 64
5794
ub-organizational-unit-name INTEGER ::= 64
5795
ub-title INTEGER ::= 64
5796
ub-serial-number INTEGER ::= 64
5797
ub-match INTEGER ::= 128
5798
ub-emailaddress-length INTEGER ::= 128
5799
ub-common-name-length INTEGER ::= 64
5800
ub-country-name-alpha-length INTEGER ::= 2
5801
ub-country-name-numeric-length INTEGER ::= 3
5802
ub-domain-defined-attributes INTEGER ::= 4
5803
ub-domain-defined-attribute-type-length INTEGER ::= 8
5804
ub-domain-defined-attribute-value-length INTEGER ::= 128
5805
ub-domain-name-length INTEGER ::= 16
5806
ub-extension-attributes INTEGER ::= 256
5807
ub-e163-4-number-length INTEGER ::= 15
5808
ub-e163-4-sub-address-length INTEGER ::= 40
5809
ub-generation-qualifier-length INTEGER ::= 3
5810
ub-given-name-length INTEGER ::= 16
5811
ub-initials-length INTEGER ::= 5
5812
ub-integer-options INTEGER ::= 256
5813
ub-numeric-user-id-length INTEGER ::= 32
5814
ub-organization-name-length INTEGER ::= 64
5815
ub-organizational-unit-name-length INTEGER ::= 32
5816
ub-organizational-units INTEGER ::= 4
5817
ub-pds-name-length INTEGER ::= 16
5818
ub-pds-parameter-length INTEGER ::= 30
5819
ub-pds-physical-address-lines INTEGER ::= 6
5820
ub-postal-code-length INTEGER ::= 16
5821
ub-pseudonym INTEGER ::= 128
5822
ub-surname-length INTEGER ::= 40
5823
5824
5825
5826
Housley, et. al. Standards Track [Page 104]
5827
5828
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5829
5830
5831
ub-terminal-id-length INTEGER ::= 24
5832
ub-unformatted-address-length INTEGER ::= 180
5833
ub-x121-address-length INTEGER ::= 16
5834
5835
-- Note - upper bounds on string types, such as TeletexString, are
5836
-- measured in characters. Excepting PrintableString or IA5String, a
5837
-- significantly greater number of octets will be required to hold
5838
-- such a value. As a minimum, 16 octets, or twice the specified
5839
-- upper bound, whichever is the larger, should be allowed for
5840
-- TeletexString. For UTF8String or UniversalString at least four
5841
-- times the upper bound should be allowed.
5842
5843
END
5844
5845
A.2 Implicitly Tagged Module, 1988 Syntax
5846
5847
PKIX1Implicit88 { iso(1) identified-organization(3) dod(6) internet(1)
5848
security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-implicit(19) }
5849
5850
DEFINITIONS IMPLICIT TAGS ::=
5851
5852
BEGIN
5853
5854
-- EXPORTS ALL --
5855
5856
IMPORTS
5857
id-pe, id-kp, id-qt-unotice, id-qt-cps,
5858
-- delete following line if "new" types are supported --
5859
BMPString, UTF8String, -- end "new" types --
5860
ORAddress, Name, RelativeDistinguishedName,
5861
CertificateSerialNumber, Attribute, DirectoryString
5862
FROM PKIX1Explicit88 { iso(1) identified-organization(3)
5863
dod(6) internet(1) security(5) mechanisms(5) pkix(7)
5864
id-mod(0) id-pkix1-explicit(18) };
5865
5866
5867
-- ISO arc for standard certificate and CRL extensions
5868
5869
id-ce OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29}
5870
5871
-- authority key identifier OID and syntax
5872
5873
id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 }
5874
5875
5876
5877
5878
5879
5880
5881
5882
Housley, et. al. Standards Track [Page 105]
5883
5884
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5885
5886
5887
AuthorityKeyIdentifier ::= SEQUENCE {
5888
keyIdentifier [0] KeyIdentifier OPTIONAL,
5889
authorityCertIssuer [1] GeneralNames OPTIONAL,
5890
authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
5891
-- authorityCertIssuer and authorityCertSerialNumber MUST both
5892
-- be present or both be absent
5893
5894
KeyIdentifier ::= OCTET STRING
5895
5896
-- subject key identifier OID and syntax
5897
5898
id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 14 }
5899
5900
SubjectKeyIdentifier ::= KeyIdentifier
5901
5902
-- key usage extension OID and syntax
5903
5904
id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 }
5905
5906
KeyUsage ::= BIT STRING {
5907
digitalSignature (0),
5908
nonRepudiation (1),
5909
keyEncipherment (2),
5910
dataEncipherment (3),
5911
keyAgreement (4),
5912
keyCertSign (5),
5913
cRLSign (6),
5914
encipherOnly (7),
5915
decipherOnly (8) }
5916
5917
-- private key usage period extension OID and syntax
5918
5919
id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= { id-ce 16 }
5920
5921
PrivateKeyUsagePeriod ::= SEQUENCE {
5922
notBefore [0] GeneralizedTime OPTIONAL,
5923
notAfter [1] GeneralizedTime OPTIONAL }
5924
-- either notBefore or notAfter MUST be present
5925
5926
-- certificate policies extension OID and syntax
5927
5928
id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 }
5929
5930
anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 }
5931
5932
CertificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
5933
5934
PolicyInformation ::= SEQUENCE {
5935
5936
5937
5938
Housley, et. al. Standards Track [Page 106]
5939
5940
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5941
5942
5943
policyIdentifier CertPolicyId,
5944
policyQualifiers SEQUENCE SIZE (1..MAX) OF
5945
PolicyQualifierInfo OPTIONAL }
5946
5947
CertPolicyId ::= OBJECT IDENTIFIER
5948
5949
PolicyQualifierInfo ::= SEQUENCE {
5950
policyQualifierId PolicyQualifierId,
5951
qualifier ANY DEFINED BY policyQualifierId }
5952
5953
-- Implementations that recognize additional policy qualifiers MUST
5954
-- augment the following definition for PolicyQualifierId
5955
5956
PolicyQualifierId ::=
5957
OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice )
5958
5959
-- CPS pointer qualifier
5960
5961
CPSuri ::= IA5String
5962
5963
-- user notice qualifier
5964
5965
UserNotice ::= SEQUENCE {
5966
noticeRef NoticeReference OPTIONAL,
5967
explicitText DisplayText OPTIONAL}
5968
5969
NoticeReference ::= SEQUENCE {
5970
organization DisplayText,
5971
noticeNumbers SEQUENCE OF INTEGER }
5972
5973
DisplayText ::= CHOICE {
5974
ia5String IA5String (SIZE (1..200)),
5975
visibleString VisibleString (SIZE (1..200)),
5976
bmpString BMPString (SIZE (1..200)),
5977
utf8String UTF8String (SIZE (1..200)) }
5978
5979
-- policy mapping extension OID and syntax
5980
5981
id-ce-policyMappings OBJECT IDENTIFIER ::= { id-ce 33 }
5982
5983
PolicyMappings ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE {
5984
issuerDomainPolicy CertPolicyId,
5985
subjectDomainPolicy CertPolicyId }
5986
5987
-- subject alternative name extension OID and syntax
5988
5989
id-ce-subjectAltName OBJECT IDENTIFIER ::= { id-ce 17 }
5990
5991
5992
5993
5994
Housley, et. al. Standards Track [Page 107]
5995
5996
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
5997
5998
5999
SubjectAltName ::= GeneralNames
6000
6001
GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
6002
6003
GeneralName ::= CHOICE {
6004
otherName [0] AnotherName,
6005
rfc822Name [1] IA5String,
6006
dNSName [2] IA5String,
6007
x400Address [3] ORAddress,
6008
directoryName [4] Name,
6009
ediPartyName [5] EDIPartyName,
6010
uniformResourceIdentifier [6] IA5String,
6011
iPAddress [7] OCTET STRING,
6012
registeredID [8] OBJECT IDENTIFIER }
6013
6014
-- AnotherName replaces OTHER-NAME ::= TYPE-IDENTIFIER, as
6015
-- TYPE-IDENTIFIER is not supported in the '88 ASN.1 syntax
6016
6017
AnotherName ::= SEQUENCE {
6018
type-id OBJECT IDENTIFIER,
6019
value [0] EXPLICIT ANY DEFINED BY type-id }
6020
6021
EDIPartyName ::= SEQUENCE {
6022
nameAssigner [0] DirectoryString OPTIONAL,
6023
partyName [1] DirectoryString }
6024
6025
-- issuer alternative name extension OID and syntax
6026
6027
id-ce-issuerAltName OBJECT IDENTIFIER ::= { id-ce 18 }
6028
6029
IssuerAltName ::= GeneralNames
6030
6031
id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= { id-ce 9 }
6032
6033
SubjectDirectoryAttributes ::= SEQUENCE SIZE (1..MAX) OF Attribute
6034
6035
-- basic constraints extension OID and syntax
6036
6037
id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 }
6038
6039
BasicConstraints ::= SEQUENCE {
6040
cA BOOLEAN DEFAULT FALSE,
6041
pathLenConstraint INTEGER (0..MAX) OPTIONAL }
6042
6043
-- name constraints extension OID and syntax
6044
6045
id-ce-nameConstraints OBJECT IDENTIFIER ::= { id-ce 30 }
6046
6047
6048
6049
6050
Housley, et. al. Standards Track [Page 108]
6051
6052
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6053
6054
6055
NameConstraints ::= SEQUENCE {
6056
permittedSubtrees [0] GeneralSubtrees OPTIONAL,
6057
excludedSubtrees [1] GeneralSubtrees OPTIONAL }
6058
6059
GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
6060
6061
GeneralSubtree ::= SEQUENCE {
6062
base GeneralName,
6063
minimum [0] BaseDistance DEFAULT 0,
6064
maximum [1] BaseDistance OPTIONAL }
6065
6066
BaseDistance ::= INTEGER (0..MAX)
6067
6068
-- policy constraints extension OID and syntax
6069
6070
id-ce-policyConstraints OBJECT IDENTIFIER ::= { id-ce 36 }
6071
6072
PolicyConstraints ::= SEQUENCE {
6073
requireExplicitPolicy [0] SkipCerts OPTIONAL,
6074
inhibitPolicyMapping [1] SkipCerts OPTIONAL }
6075
6076
SkipCerts ::= INTEGER (0..MAX)
6077
6078
-- CRL distribution points extension OID and syntax
6079
6080
id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= {id-ce 31}
6081
6082
CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint
6083
6084
DistributionPoint ::= SEQUENCE {
6085
distributionPoint [0] DistributionPointName OPTIONAL,
6086
reasons [1] ReasonFlags OPTIONAL,
6087
cRLIssuer [2] GeneralNames OPTIONAL }
6088
6089
DistributionPointName ::= CHOICE {
6090
fullName [0] GeneralNames,
6091
nameRelativeToCRLIssuer [1] RelativeDistinguishedName }
6092
6093
ReasonFlags ::= BIT STRING {
6094
unused (0),
6095
keyCompromise (1),
6096
cACompromise (2),
6097
affiliationChanged (3),
6098
superseded (4),
6099
cessationOfOperation (5),
6100
certificateHold (6),
6101
privilegeWithdrawn (7),
6102
aACompromise (8) }
6103
6104
6105
6106
Housley, et. al. Standards Track [Page 109]
6107
6108
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6109
6110
6111
-- extended key usage extension OID and syntax
6112
6113
id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37}
6114
6115
ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
6116
6117
6118
KeyPurposeId ::= OBJECT IDENTIFIER
6119
6120
-- permit unspecified key uses
6121
6122
anyExtendedKeyUsage OBJECT IDENTIFIER ::= { id-ce-extKeyUsage 0 }
6123
6124
-- extended key purpose OIDs
6125
6126
id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 }
6127
id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 }
6128
id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 }
6129
id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 }
6130
id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 }
6131
id-kp-OCSPSigning OBJECT IDENTIFIER ::= { id-kp 9 }
6132
6133
-- inhibit any policy OID and syntax
6134
6135
id-ce-inhibitAnyPolicy OBJECT IDENTIFIER ::= { id-ce 54 }
6136
6137
InhibitAnyPolicy ::= SkipCerts
6138
6139
-- freshest (delta)CRL extension OID and syntax
6140
6141
id-ce-freshestCRL OBJECT IDENTIFIER ::= { id-ce 46 }
6142
6143
FreshestCRL ::= CRLDistributionPoints
6144
6145
-- authority info access
6146
6147
id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 }
6148
6149
AuthorityInfoAccessSyntax ::=
6150
SEQUENCE SIZE (1..MAX) OF AccessDescription
6151
6152
AccessDescription ::= SEQUENCE {
6153
accessMethod OBJECT IDENTIFIER,
6154
accessLocation GeneralName }
6155
6156
-- subject info access
6157
6158
id-pe-subjectInfoAccess OBJECT IDENTIFIER ::= { id-pe 11 }
6159
6160
6161
6162
Housley, et. al. Standards Track [Page 110]
6163
6164
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6165
6166
6167
SubjectInfoAccessSyntax ::=
6168
SEQUENCE SIZE (1..MAX) OF AccessDescription
6169
6170
-- CRL number extension OID and syntax
6171
6172
id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 }
6173
6174
CRLNumber ::= INTEGER (0..MAX)
6175
6176
-- issuing distribution point extension OID and syntax
6177
6178
id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= { id-ce 28 }
6179
6180
IssuingDistributionPoint ::= SEQUENCE {
6181
distributionPoint [0] DistributionPointName OPTIONAL,
6182
onlyContainsUserCerts [1] BOOLEAN DEFAULT FALSE,
6183
onlyContainsCACerts [2] BOOLEAN DEFAULT FALSE,
6184
onlySomeReasons [3] ReasonFlags OPTIONAL,
6185
indirectCRL [4] BOOLEAN DEFAULT FALSE,
6186
onlyContainsAttributeCerts [5] BOOLEAN DEFAULT FALSE }
6187
6188
id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= { id-ce 27 }
6189
6190
BaseCRLNumber ::= CRLNumber
6191
6192
-- CRL reasons extension OID and syntax
6193
6194
id-ce-cRLReasons OBJECT IDENTIFIER ::= { id-ce 21 }
6195
6196
CRLReason ::= ENUMERATED {
6197
unspecified (0),
6198
keyCompromise (1),
6199
cACompromise (2),
6200
affiliationChanged (3),
6201
superseded (4),
6202
cessationOfOperation (5),
6203
certificateHold (6),
6204
removeFromCRL (8),
6205
privilegeWithdrawn (9),
6206
aACompromise (10) }
6207
6208
-- certificate issuer CRL entry extension OID and syntax
6209
6210
id-ce-certificateIssuer OBJECT IDENTIFIER ::= { id-ce 29 }
6211
6212
CertificateIssuer ::= GeneralNames
6213
6214
-- hold instruction extension OID and syntax
6215
6216
6217
6218
Housley, et. al. Standards Track [Page 111]
6219
6220
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6221
6222
6223
id-ce-holdInstructionCode OBJECT IDENTIFIER ::= { id-ce 23 }
6224
6225
HoldInstructionCode ::= OBJECT IDENTIFIER
6226
6227
-- ANSI x9 holdinstructions
6228
6229
-- ANSI x9 arc holdinstruction arc
6230
6231
holdInstruction OBJECT IDENTIFIER ::=
6232
{joint-iso-itu-t(2) member-body(2) us(840) x9cm(10040) 2}
6233
6234
-- ANSI X9 holdinstructions referenced by this standard
6235
6236
id-holdinstruction-none OBJECT IDENTIFIER ::=
6237
{holdInstruction 1} -- deprecated
6238
6239
id-holdinstruction-callissuer OBJECT IDENTIFIER ::=
6240
{holdInstruction 2}
6241
6242
id-holdinstruction-reject OBJECT IDENTIFIER ::=
6243
{holdInstruction 3}
6244
6245
-- invalidity date CRL entry extension OID and syntax
6246
6247
id-ce-invalidityDate OBJECT IDENTIFIER ::= { id-ce 24 }
6248
6249
InvalidityDate ::= GeneralizedTime
6250
6251
END
6252
6253
Appendix B. ASN.1 Notes
6254
6255
CAs MUST force the serialNumber to be a non-negative integer, that
6256
is, the sign bit in the DER encoding of the INTEGER value MUST be
6257
zero - this can be done by adding a leading (leftmost) `00'H octet if
6258
necessary. This removes a potential ambiguity in mapping between a
6259
string of octets and an integer value.
6260
6261
As noted in section 4.1.2.2, serial numbers can be expected to
6262
contain long integers. Certificate users MUST be able to handle
6263
serialNumber values up to 20 octets in length. Conformant CAs MUST
6264
NOT use serialNumber values longer than 20 octets.
6265
6266
As noted in section 5.2.3, CRL numbers can be expected to contain
6267
long integers. CRL validators MUST be able to handle cRLNumber
6268
values up to 20 octets in length. Conformant CRL issuers MUST NOT
6269
use cRLNumber values longer than 20 octets.
6270
6271
6272
6273
6274
Housley, et. al. Standards Track [Page 112]
6275
6276
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6277
6278
6279
The construct "SEQUENCE SIZE (1..MAX) OF" appears in several ASN.1
6280
constructs. A valid ASN.1 sequence will have zero or more entries.
6281
The SIZE (1..MAX) construct constrains the sequence to have at least
6282
one entry. MAX indicates the upper bound is unspecified.
6283
Implementations are free to choose an upper bound that suits their
6284
environment.
6285
6286
The construct "positiveInt ::= INTEGER (0..MAX)" defines positiveInt
6287
as a subtype of INTEGER containing integers greater than or equal to
6288
zero. The upper bound is unspecified. Implementations are free to
6289
select an upper bound that suits their environment.
6290
6291
The character string type PrintableString supports a very basic Latin
6292
character set: the lower case letters 'a' through 'z', upper case
6293
letters 'A' through 'Z', the digits '0' through '9', eleven special
6294
characters ' = ( ) + , - . / : ? and space.
6295
6296
Implementers should note that the at sign ('@') and underscore ('_')
6297
characters are not supported by the ASN.1 type PrintableString.
6298
These characters often appear in internet addresses. Such addresses
6299
MUST be encoded using an ASN.1 type that supports them. They are
6300
usually encoded as IA5String in either the emailAddress attribute
6301
within a distinguished name or the rfc822Name field of GeneralName.
6302
Conforming implementations MUST NOT encode strings which include
6303
either the at sign or underscore character as PrintableString.
6304
6305
The character string type TeletexString is a superset of
6306
PrintableString. TeletexString supports a fairly standard (ASCII-
6307
like) Latin character set, Latin characters with non-spacing accents
6308
and Japanese characters.
6309
6310
Named bit lists are BIT STRINGs where the values have been assigned
6311
names. This specification makes use of named bit lists in the
6312
definitions for the key usage, CRL distribution points and freshest
6313
CRL certificate extensions, as well as the freshest CRL and issuing
6314
distribution point CRL extensions. When DER encoding a named bit
6315
list, trailing zeroes MUST be omitted. That is, the encoded value
6316
ends with the last named bit that is set to one.
6317
6318
The character string type UniversalString supports any of the
6319
characters allowed by ISO 10646-1 [ISO 10646]. ISO 10646-1 is the
6320
Universal multiple-octet coded Character Set (UCS). ISO 10646-1
6321
specifies the architecture and the "basic multilingual plane" -- a
6322
large standard character set which includes all major world character
6323
standards.
6324
6325
6326
6327
6328
6329
6330
Housley, et. al. Standards Track [Page 113]
6331
6332
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6333
6334
6335
The character string type UTF8String was introduced in the 1997
6336
version of ASN.1, and UTF8String was added to the list of choices for
6337
DirectoryString in the 2001 version of X.520 [X.520]. UTF8String is
6338
a universal type and has been assigned tag number 12. The content of
6339
UTF8String was defined by RFC 2044 [RFC 2044] and updated in RFC 2279
6340
[RFC 2279].
6341
6342
In anticipation of these changes, and in conformance with IETF Best
6343
Practices codified in RFC 2277 [RFC 2277], IETF Policy on Character
6344
Sets and Languages, this document includes UTF8String as a choice in
6345
DirectoryString and the CPS qualifier extensions.
6346
6347
Implementers should note that the DER encoding of the SET OF values
6348
requires ordering of the encodings of the values. In particular,
6349
this issue arises with respect to distinguished names.
6350
6351
Implementers should note that the DER encoding of SET or SEQUENCE
6352
components whose value is the DEFAULT omit the component from the
6353
encoded certificate or CRL. For example, a BasicConstraints
6354
extension whose cA value is FALSE would omit the cA boolean from the
6355
encoded certificate.
6356
6357
Object Identifiers (OIDs) are used throughout this specification to
6358
identify certificate policies, public key and signature algorithms,
6359
certificate extensions, etc. There is no maximum size for OIDs.
6360
This specification mandates support for OIDs which have arc elements
6361
with values that are less than 2^28, that is, they MUST be between 0
6362
and 268,435,455, inclusive. This allows each arc element to be
6363
represented within a single 32 bit word. Implementations MUST also
6364
support OIDs where the length of the dotted decimal (see [RFC 2252],
6365
section 4.1) string representation can be up to 100 bytes
6366
(inclusive). Implementations MUST be able to handle OIDs with up to
6367
20 elements (inclusive). CAs SHOULD NOT issue certificates which
6368
contain OIDs that exceed these requirements. Likewise, CRL issuers
6369
SHOULD NOT issue CRLs which contain OIDs that exceed these
6370
requirements.
6371
6372
Implementors are warned that the X.500 standards community has
6373
developed a series of extensibility rules. These rules determine
6374
when an ASN.1 definition can be changed without assigning a new
6375
object identifier (OID). For example, at least two extension
6376
definitions included in RFC 2459 [RFC 2459], the predecessor to this
6377
profile document, have different ASN.1 definitions in this
6378
specification, but the same OID is used. If unknown elements appear
6379
within an extension, and the extension is not marked critical, those
6380
unknown elements ought to be ignored, as follows:
6381
6382
(a) ignore all unknown bit name assignments within a bit string;
6383
6384
6385
6386
Housley, et. al. Standards Track [Page 114]
6387
6388
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6389
6390
6391
(b) ignore all unknown named numbers in an ENUMERATED type or
6392
INTEGER type that is being used in the enumerated style, provided
6393
the number occurs as an optional element of a SET or SEQUENCE; and
6394
6395
(c) ignore all unknown elements in SETs, at the end of SEQUENCEs,
6396
or in CHOICEs where the CHOICE is itself an optional element of a
6397
SET or SEQUENCE.
6398
6399
If an extension containing unexpected values is marked critical, the
6400
implementation MUST reject the certificate or CRL containing the
6401
unrecognized extension.
6402
6403
Appendix C. Examples
6404
6405
This section contains four examples: three certificates and a CRL.
6406
The first two certificates and the CRL comprise a minimal
6407
certification path.
6408
6409
Section C.1 contains an annotated hex dump of a "self-signed"
6410
certificate issued by a CA whose distinguished name is
6411
cn=us,o=gov,ou=nist. The certificate contains a DSA public key with
6412
parameters, and is signed by the corresponding DSA private key.
6413
6414
Section C.2 contains an annotated hex dump of an end entity
6415
certificate. The end entity certificate contains a DSA public key,
6416
and is signed by the private key corresponding to the "self-signed"
6417
certificate in section C.1.
6418
6419
Section C.3 contains a dump of an end entity certificate which
6420
contains an RSA public key and is signed with RSA and MD5. This
6421
certificate is not part of the minimal certification path.
6422
6423
Section C.4 contains an annotated hex dump of a CRL. The CRL is
6424
issued by the CA whose distinguished name is cn=us,o=gov,ou=nist and
6425
the list of revoked certificates includes the end entity certificate
6426
presented in C.2.
6427
6428
The certificates were processed using Peter Gutman's dumpasn1 utility
6429
to generate the output. The source for the dumpasn1 utility is
6430
available at <http://www.cs.auckland.ac.nz/~pgut001/dumpasn1.c>. The
6431
binaries for the certificates and CRLs are available at
6432
<http://csrc.nist.gov/pki/pkixtools>.
6433
6434
C.1 Certificate
6435
6436
This section contains an annotated hex dump of a 699 byte version 3
6437
certificate. The certificate contains the following information:
6438
(a) the serial number is 23 (17 hex);
6439
6440
6441
6442
Housley, et. al. Standards Track [Page 115]
6443
6444
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6445
6446
6447
(b) the certificate is signed with DSA and the SHA-1 hash algorithm;
6448
(c) the issuer's distinguished name is OU=NIST; O=gov; C=US
6449
(d) and the subject's distinguished name is OU=NIST; O=gov; C=US
6450
(e) the certificate was issued on June 30, 1997 and will expire on
6451
December 31, 1997;
6452
(f) the certificate contains a 1024 bit DSA public key with
6453
parameters;
6454
(g) the certificate contains a subject key identifier extension
6455
generated using method (1) of section 4.2.1.2; and
6456
(h) the certificate is a CA certificate (as indicated through the
6457
basic constraints extension.)
6458
6459
0 30 699: SEQUENCE {
6460
4 30 635: SEQUENCE {
6461
8 A0 3: [0] {
6462
10 02 1: INTEGER 2
6463
: }
6464
13 02 1: INTEGER 17
6465
16 30 9: SEQUENCE {
6466
18 06 7: OBJECT IDENTIFIER dsaWithSha1 (1 2 840 10040 4 3)
6467
: }
6468
27 30 42: SEQUENCE {
6469
29 31 11: SET {
6470
31 30 9: SEQUENCE {
6471
33 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
6472
38 13 2: PrintableString 'US'
6473
: }
6474
: }
6475
42 31 12: SET {
6476
44 30 10: SEQUENCE {
6477
46 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
6478
51 13 3: PrintableString 'gov'
6479
: }
6480
: }
6481
56 31 13: SET {
6482
58 30 11: SEQUENCE {
6483
60 06 3: OBJECT IDENTIFIER
6484
: organizationalUnitName (2 5 4 11)
6485
65 13 4: PrintableString 'NIST'
6486
: }
6487
: }
6488
: }
6489
71 30 30: SEQUENCE {
6490
73 17 13: UTCTime '970630000000Z'
6491
88 17 13: UTCTime '971231000000Z'
6492
: }
6493
103 30 42: SEQUENCE {
6494
105 31 11: SET {
6495
6496
6497
6498
Housley, et. al. Standards Track [Page 116]
6499
6500
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6501
6502
6503
107 30 9: SEQUENCE {
6504
109 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
6505
114 13 2: PrintableString 'US'
6506
: }
6507
: }
6508
118 31 12: SET {
6509
120 30 10: SEQUENCE {
6510
122 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
6511
127 13 3: PrintableString 'gov'
6512
: }
6513
: }
6514
132 31 13: SET {
6515
134 30 11: SEQUENCE {
6516
136 06 3: OBJECT IDENTIFIER
6517
: organizationalUnitName (2 5 4 11)
6518
141 13 4: PrintableString 'NIST'
6519
: }
6520
: }
6521
: }
6522
147 30 440: SEQUENCE {
6523
151 30 300: SEQUENCE {
6524
155 06 7: OBJECT IDENTIFIER dsa (1 2 840 10040 4 1)
6525
164 30 287: SEQUENCE {
6526
168 02 129: INTEGER
6527
: 00 B6 8B 0F 94 2B 9A CE A5 25 C6 F2 ED FC
6528
: FB 95 32 AC 01 12 33 B9 E0 1C AD 90 9B BC
6529
: 48 54 9E F3 94 77 3C 2C 71 35 55 E6 FE 4F
6530
: 22 CB D5 D8 3E 89 93 33 4D FC BD 4F 41 64
6531
: 3E A2 98 70 EC 31 B4 50 DE EB F1 98 28 0A
6532
: C9 3E 44 B3 FD 22 97 96 83 D0 18 A3 E3 BD
6533
: 35 5B FF EE A3 21 72 6A 7B 96 DA B9 3F 1E
6534
: 5A 90 AF 24 D6 20 F0 0D 21 A7 D4 02 B9 1A
6535
: FC AC 21 FB 9E 94 9E 4B 42 45 9E 6A B2 48
6536
: 63 FE 43
6537
300 02 21: INTEGER
6538
: 00 B2 0D B0 B1 01 DF 0C 66 24 FC 13 92 BA
6539
: 55 F7 7D 57 74 81 E5
6540
323 02 129: INTEGER
6541
: 00 9A BF 46 B1 F5 3F 44 3D C9 A5 65 FB 91
6542
: C0 8E 47 F1 0A C3 01 47 C2 44 42 36 A9 92
6543
: 81 DE 57 C5 E0 68 86 58 00 7B 1F F9 9B 77
6544
: A1 C5 10 A5 80 91 78 51 51 3C F6 FC FC CC
6545
: 46 C6 81 78 92 84 3D F4 93 3D 0C 38 7E 1A
6546
: 5B 99 4E AB 14 64 F6 0C 21 22 4E 28 08 9C
6547
: 92 B9 66 9F 40 E8 95 F6 D5 31 2A EF 39 A2
6548
: 62 C7 B2 6D 9E 58 C4 3A A8 11 81 84 6D AF
6549
: F8 B4 19 B4 C2 11 AE D0 22 3B AA 20 7F EE
6550
: 1E 57 18
6551
6552
6553
6554
Housley, et. al. Standards Track [Page 117]
6555
6556
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6557
6558
6559
: }
6560
: }
6561
455 03 133: BIT STRING 0 unused bits, encapsulates {
6562
459 02 129: INTEGER
6563
: 00 B5 9E 1F 49 04 47 D1 DB F5 3A DD CA 04
6564
: 75 E8 DD 75 F6 9B 8A B1 97 D6 59 69 82 D3
6565
: 03 4D FD 3B 36 5F 4A F2 D1 4E C1 07 F5 D1
6566
: 2A D3 78 77 63 56 EA 96 61 4D 42 0B 7A 1D
6567
: FB AB 91 A4 CE DE EF 77 C8 E5 EF 20 AE A6
6568
: 28 48 AF BE 69 C3 6A A5 30 F2 C2 B9 D9 82
6569
: 2B 7D D9 C4 84 1F DE 0D E8 54 D7 1B 99 2E
6570
: B3 D0 88 F6 D6 63 9B A7 E2 0E 82 D4 3B 8A
6571
: 68 1B 06 56 31 59 0B 49 EB 99 A5 D5 81 41
6572
: 7B C9 55
6573
: }
6574
: }
6575
591 A3 50: [3] {
6576
593 30 48: SEQUENCE {
6577
595 30 29: SEQUENCE {
6578
597 06 3: OBJECT IDENTIFIER
6579
: subjectKeyIdentifier (2 5 29 14)
6580
602 04 22: OCTET STRING, encapsulates {
6581
604 04 20: OCTET STRING
6582
: 86 CA A5 22 81 62 EF AD 0A 89 BC AD 72 41
6583
: 2C 29 49 F4 86 56
6584
: }
6585
: }
6586
626 30 15: SEQUENCE {
6587
628 06 3: OBJECT IDENTIFIER basicConstraints (2 5 29 19)
6588
633 01 1: BOOLEAN TRUE
6589
636 04 5: OCTET STRING, encapsulates {
6590
638 30 3: SEQUENCE {
6591
640 01 1: BOOLEAN TRUE
6592
: }
6593
: }
6594
: }
6595
: }
6596
: }
6597
: }
6598
643 30 9: SEQUENCE {
6599
645 06 7: OBJECT IDENTIFIER dsaWithSha1 (1 2 840 10040 4 3)
6600
: }
6601
654 03 47: BIT STRING 0 unused bits, encapsulates {
6602
657 30 44: SEQUENCE {
6603
659 02 20: INTEGER
6604
: 43 1B CF 29 25 45 C0 4E 52 E7 7D D6 FC B1
6605
: 66 4C 83 CF 2D 77
6606
681 02 20: INTEGER
6607
6608
6609
6610
Housley, et. al. Standards Track [Page 118]
6611
6612
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6613
6614
6615
: 0B 5B 9A 24 11 98 E8 F3 86 90 04 F6 08 A9
6616
: E1 8D A5 CC 3A D4
6617
: }
6618
: }
6619
: }
6620
6621
C.2 Certificate
6622
6623
This section contains an annotated hex dump of a 730 byte version 3
6624
certificate. The certificate contains the following information:
6625
(a) the serial number is 18 (12 hex);
6626
(b) the certificate is signed with DSA and the SHA-1 hash algorithm;
6627
(c) the issuer's distinguished name is OU=nist; O=gov; C=US
6628
(d) and the subject's distinguished name is CN=Tim Polk; OU=nist;
6629
O=gov; C=US
6630
(e) the certificate was valid from July 30, 1997 through December 1,
6631
1997;
6632
(f) the certificate contains a 1024 bit DSA public key;
6633
(g) the certificate is an end entity certificate, as the basic
6634
constraints extension is not present;
6635
(h) the certificate contains an authority key identifier extension
6636
matching the subject key identifier of the certificate in Appendix
6637
C.1; and
6638
(i) the certificate includes one alternative name - an RFC 822
6639
address of "wpolk@nist.gov".
6640
6641
0 30 730: SEQUENCE {
6642
4 30 665: SEQUENCE {
6643
8 A0 3: [0] {
6644
10 02 1: INTEGER 2
6645
: }
6646
13 02 1: INTEGER 18
6647
16 30 9: SEQUENCE {
6648
18 06 7: OBJECT IDENTIFIER dsaWithSha1 (1 2 840 10040 4 3)
6649
: }
6650
27 30 42: SEQUENCE {
6651
29 31 11: SET {
6652
31 30 9: SEQUENCE {
6653
33 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
6654
38 13 2: PrintableString 'US'
6655
: }
6656
: }
6657
42 31 12: SET {
6658
44 30 10: SEQUENCE {
6659
46 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
6660
51 13 3: PrintableString 'gov'
6661
: }
6662
: }
6663
6664
6665
6666
Housley, et. al. Standards Track [Page 119]
6667
6668
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6669
6670
6671
56 31 13: SET {
6672
58 30 11: SEQUENCE {
6673
60 06 3: OBJECT IDENTIFIER
6674
: organizationalUnitName (2 5 4 11)
6675
65 13 4: PrintableString 'NIST'
6676
: }
6677
: }
6678
: }
6679
71 30 30: SEQUENCE {
6680
73 17 13: UTCTime '970730000000Z'
6681
88 17 13: UTCTime '971201000000Z'
6682
: }
6683
103 30 61: SEQUENCE {
6684
105 31 11: SET {
6685
107 30 9: SEQUENCE {
6686
109 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
6687
114 13 2: PrintableString 'US'
6688
: }
6689
: }
6690
118 31 12: SET {
6691
120 30 10: SEQUENCE {
6692
122 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
6693
127 13 3: PrintableString 'gov'
6694
: }
6695
: }
6696
132 31 13: SET {
6697
134 30 11: SEQUENCE {
6698
136 06 3: OBJECT IDENTIFIER
6699
: organizationalUnitName (2 5 4 11)
6700
141 13 4: PrintableString 'NIST'
6701
: }
6702
: }
6703
147 31 17: SET {
6704
149 30 15: SEQUENCE {
6705
151 06 3: OBJECT IDENTIFIER commonName (2 5 4 3)
6706
156 13 8: PrintableString 'Tim Polk'
6707
: }
6708
: }
6709
: }
6710
166 30 439: SEQUENCE {
6711
170 30 300: SEQUENCE {
6712
174 06 7: OBJECT IDENTIFIER dsa (1 2 840 10040 4 1)
6713
183 30 287: SEQUENCE {
6714
187 02 129: INTEGER
6715
: 00 B6 8B 0F 94 2B 9A CE A5 25 C6 F2 ED FC
6716
: FB 95 32 AC 01 12 33 B9 E0 1C AD 90 9B BC
6717
: 48 54 9E F3 94 77 3C 2C 71 35 55 E6 FE 4F
6718
: 22 CB D5 D8 3E 89 93 33 4D FC BD 4F 41 64
6719
6720
6721
6722
Housley, et. al. Standards Track [Page 120]
6723
6724
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6725
6726
6727
: 3E A2 98 70 EC 31 B4 50 DE EB F1 98 28 0A
6728
: C9 3E 44 B3 FD 22 97 96 83 D0 18 A3 E3 BD
6729
: 35 5B FF EE A3 21 72 6A 7B 96 DA B9 3F 1E
6730
: 5A 90 AF 24 D6 20 F0 0D 21 A7 D4 02 B9 1A
6731
: FC AC 21 FB 9E 94 9E 4B 42 45 9E 6A B2 48
6732
: 63 FE 43
6733
319 02 21: INTEGER
6734
: 00 B2 0D B0 B1 01 DF 0C 66 24 FC 13 92 BA
6735
: 55 F7 7D 57 74 81 E5
6736
342 02 129: INTEGER
6737
: 00 9A BF 46 B1 F5 3F 44 3D C9 A5 65 FB 91
6738
: C0 8E 47 F1 0A C3 01 47 C2 44 42 36 A9 92
6739
: 81 DE 57 C5 E0 68 86 58 00 7B 1F F9 9B 77
6740
: A1 C5 10 A5 80 91 78 51 51 3C F6 FC FC CC
6741
: 46 C6 81 78 92 84 3D F4 93 3D 0C 38 7E 1A
6742
: 5B 99 4E AB 14 64 F6 0C 21 22 4E 28 08 9C
6743
: 92 B9 66 9F 40 E8 95 F6 D5 31 2A EF 39 A2
6744
: 62 C7 B2 6D 9E 58 C4 3A A8 11 81 84 6D AF
6745
: F8 B4 19 B4 C2 11 AE D0 22 3B AA 20 7F EE
6746
: 1E 57 18
6747
: }
6748
: }
6749
474 03 132: BIT STRING 0 unused bits, encapsulates {
6750
478 02 128: INTEGER
6751
: 30 B6 75 F7 7C 20 31 AE 38 BB 7E 0D 2B AB
6752
: A0 9C 4B DF 20 D5 24 13 3C CD 98 E5 5F 6C
6753
: B7 C1 BA 4A BA A9 95 80 53 F0 0D 72 DC 33
6754
: 37 F4 01 0B F5 04 1F 9D 2E 1F 62 D8 84 3A
6755
: 9B 25 09 5A 2D C8 46 8E 2B D4 F5 0D 3B C7
6756
: 2D C6 6C B9 98 C1 25 3A 44 4E 8E CA 95 61
6757
: 35 7C CE 15 31 5C 23 13 1E A2 05 D1 7A 24
6758
: 1C CB D3 72 09 90 FF 9B 9D 28 C0 A1 0A EC
6759
: 46 9F 0D B8 D0 DC D0 18 A6 2B 5E F9 8F B5
6760
: 95 BE
6761
: }
6762
: }
6763
609 A3 62: [3] {
6764
611 30 60: SEQUENCE {
6765
613 30 25: SEQUENCE {
6766
615 06 3: OBJECT IDENTIFIER subjectAltName (2 5 29 17)
6767
620 04 18: OCTET STRING, encapsulates {
6768
622 30 16: SEQUENCE {
6769
624 81 14: [1] 'wpolk@nist.gov'
6770
: }
6771
: }
6772
: }
6773
640 30 31: SEQUENCE {
6774
642 06 3: OBJECT IDENTIFIER
6775
6776
6777
6778
Housley, et. al. Standards Track [Page 121]
6779
6780
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6781
6782
6783
: authorityKeyIdentifier (2 5 29 35)
6784
647 04 24: OCTET STRING, encapsulates {
6785
649 30 22: SEQUENCE {
6786
651 80 20: [0]
6787
: 86 CA A5 22 81 62 EF AD 0A 89 BC AD 72
6788
: 41 2C 29 49 F4 86 56
6789
: }
6790
: }
6791
: }
6792
: }
6793
: }
6794
: }
6795
673 30 9: SEQUENCE {
6796
675 06 7: OBJECT IDENTIFIER dsaWithSha1 (1 2 840 10040 4 3)
6797
: }
6798
684 03 48: BIT STRING 0 unused bits, encapsulates {
6799
687 30 45: SEQUENCE {
6800
689 02 20: INTEGER
6801
: 36 97 CB E3 B4 2C E1 BB 61 A9 D3 CC 24 CC
6802
: 22 92 9F F4 F5 87
6803
711 02 21: INTEGER
6804
: 00 AB C9 79 AF D2 16 1C A9 E3 68 A9 14 10
6805
: B4 A0 2E FF 22 5A 73
6806
: }
6807
: }
6808
: }
6809
6810
C.3 End Entity Certificate Using RSA
6811
6812
This section contains an annotated hex dump of a 654 byte version 3
6813
certificate. The certificate contains the following information:
6814
(a) the serial number is 256;
6815
(b) the certificate is signed with RSA and the SHA-1 hash algorithm;
6816
(c) the issuer's distinguished name is OU=NIST; O=gov; C=US
6817
(d) and the subject's distinguished name is CN=Tim Polk; OU=NIST;
6818
O=gov; C=US
6819
(e) the certificate was issued on May 21, 1996 at 09:58:26 and
6820
expired on May 21, 1997 at 09:58:26;
6821
(f) the certificate contains a 1024 bit RSA public key;
6822
(g) the certificate is an end entity certificate (not a CA
6823
certificate);
6824
(h) the certificate includes an alternative subject name of
6825
"<http://www.itl.nist.gov/div893/staff/polk/index.html>" and an
6826
alternative issuer name of "<http://www.nist.gov/>" - both are URLs;
6827
(i) the certificate include an authority key identifier extension
6828
and a certificate policies extension specifying the policy OID
6829
2.16.840.1.101.3.2.1.48.9; and
6830
6831
6832
6833
6834
Housley, et. al. Standards Track [Page 122]
6835
6836
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6837
6838
6839
(j) the certificate includes a critical key usage extension
6840
specifying that the public key is intended for verification of
6841
digital signatures.
6842
6843
0 30 654: SEQUENCE {
6844
4 30 503: SEQUENCE {
6845
8 A0 3: [0] {
6846
10 02 1: INTEGER 2
6847
: }
6848
13 02 2: INTEGER 256
6849
17 30 13: SEQUENCE {
6850
19 06 9: OBJECT IDENTIFIER
6851
: sha1withRSAEncryption (1 2 840 113549 1 1 5)
6852
30 05 0: NULL
6853
: }
6854
32 30 42: SEQUENCE {
6855
34 31 11: SET {
6856
36 30 9: SEQUENCE {
6857
38 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
6858
43 13 2: PrintableString 'US'
6859
: }
6860
: }
6861
47 31 12: SET {
6862
49 30 10: SEQUENCE {
6863
51 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
6864
56 13 3: PrintableString 'gov'
6865
: }
6866
: }
6867
61 31 13: SET {
6868
63 30 11: SEQUENCE {
6869
65 06 3: OBJECT IDENTIFIER
6870
: organizationalUnitName (2 5 4 11)
6871
70 13 4: PrintableString 'NIST'
6872
: }
6873
: }
6874
: }
6875
76 30 30: SEQUENCE {
6876
78 17 13: UTCTime '960521095826Z'
6877
93 17 13: UTCTime '970521095826Z'
6878
: }
6879
108 30 61: SEQUENCE {
6880
110 31 11: SET {
6881
112 30 9: SEQUENCE {
6882
114 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
6883
119 13 2: PrintableString 'US'
6884
: }
6885
: }
6886
123 31 12: SET {
6887
6888
6889
6890
Housley, et. al. Standards Track [Page 123]
6891
6892
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6893
6894
6895
125 30 10: SEQUENCE {
6896
127 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
6897
132 13 3: PrintableString 'gov'
6898
: }
6899
: }
6900
137 31 13: SET {
6901
139 30 11: SEQUENCE {
6902
141 06 3: OBJECT IDENTIFIER
6903
: organizationalUnitName (2 5 4 11)
6904
146 13 4: PrintableString 'NIST'
6905
: }
6906
: }
6907
152 31 17: SET {
6908
154 30 15: SEQUENCE {
6909
156 06 3: OBJECT IDENTIFIER commonName (2 5 4 3)
6910
161 13 8: PrintableString 'Tim Polk'
6911
: }
6912
: }
6913
: }
6914
171 30 159: SEQUENCE {
6915
174 30 13: SEQUENCE {
6916
176 06 9: OBJECT IDENTIFIER
6917
: rsaEncryption (1 2 840 113549 1 1 1)
6918
187 05 0: NULL
6919
: }
6920
189 03 141: BIT STRING 0 unused bits, encapsulates {
6921
193 30 137: SEQUENCE {
6922
196 02 129: INTEGER
6923
: 00 E1 6A E4 03 30 97 02 3C F4 10 F3 B5 1E
6924
: 4D 7F 14 7B F6 F5 D0 78 E9 A4 8A F0 A3 75
6925
: EC ED B6 56 96 7F 88 99 85 9A F2 3E 68 77
6926
: 87 EB 9E D1 9F C0 B4 17 DC AB 89 23 A4 1D
6927
: 7E 16 23 4C 4F A8 4D F5 31 B8 7C AA E3 1A
6928
: 49 09 F4 4B 26 DB 27 67 30 82 12 01 4A E9
6929
: 1A B6 C1 0C 53 8B 6C FC 2F 7A 43 EC 33 36
6930
: 7E 32 B2 7B D5 AA CF 01 14 C6 12 EC 13 F2
6931
: 2D 14 7A 8B 21 58 14 13 4C 46 A3 9A F2 16
6932
: 95 FF 23
6933
328 02 3: INTEGER 65537
6934
: }
6935
: }
6936
: }
6937
333 A3 175: [3] {
6938
336 30 172: SEQUENCE {
6939
339 30 63: SEQUENCE {
6940
341 06 3: OBJECT IDENTIFIER subjectAltName (2 5 29 17)
6941
346 04 56: OCTET STRING, encapsulates {
6942
348 30 54: SEQUENCE {
6943
6944
6945
6946
Housley, et. al. Standards Track [Page 124]
6947
6948
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
6949
6950
6951
350 86 52: [6]
6952
: 'http://www.itl.nist.gov/div893/staff/'
6953
: 'polk/index.html'
6954
: }
6955
: }
6956
: }
6957
404 30 31: SEQUENCE {
6958
406 06 3: OBJECT IDENTIFIER issuerAltName (2 5 29 18)
6959
411 04 24: OCTET STRING, encapsulates {
6960
413 30 22: SEQUENCE {
6961
415 86 20: [6] 'http://www.nist.gov/'
6962
: }
6963
: }
6964
: }
6965
437 30 31: SEQUENCE {
6966
439 06 3: OBJECT IDENTIFIER
6967
: authorityKeyIdentifier (2 5 29 35)
6968
444 04 24: OCTET STRING, encapsulates {
6969
446 30 22: SEQUENCE {
6970
448 80 20: [0]
6971
: 08 68 AF 85 33 C8 39 4A 7A F8 82 93 8E
6972
: 70 6A 4A 20 84 2C 32
6973
: }
6974
: }
6975
: }
6976
470 30 23: SEQUENCE {
6977
472 06 3: OBJECT IDENTIFIER
6978
: certificatePolicies (2 5 29 32)
6979
477 04 16: OCTET STRING, encapsulates {
6980
479 30 14: SEQUENCE {
6981
481 30 12: SEQUENCE {
6982
483 06 10: OBJECT IDENTIFIER
6983
: '2 16 840 1 101 3 2 1 48 9'
6984
: }
6985
: }
6986
: }
6987
: }
6988
495 30 14: SEQUENCE {
6989
497 06 3: OBJECT IDENTIFIER keyUsage (2 5 29 15)
6990
502 01 1: BOOLEAN TRUE
6991
505 04 4: OCTET STRING, encapsulates {
6992
507 03 2: BIT STRING 7 unused bits
6993
: '1'B (bit 0)
6994
: }
6995
: }
6996
: }
6997
: }
6998
: }
6999
7000
7001
7002
Housley, et. al. Standards Track [Page 125]
7003
7004
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
7005
7006
7007
511 30 13: SEQUENCE {
7008
513 06 9: OBJECT IDENTIFIER
7009
: sha1withRSAEncryption (1 2 840 113549 1 1 5)
7010
524 05 0: NULL
7011
: }
7012
526 03 129: BIT STRING 0 unused bits
7013
: 1E 07 77 6E 66 B5 B6 B8 57 F0 03 DC 6F 77
7014
: 6D AF 55 1D 74 E5 CE 36 81 FC 4B C5 F4 47
7015
: 82 C4 0A 25 AA 8D D6 7D 3A 89 AB 44 34 39
7016
: F6 BD 61 1A 78 85 7A B8 1E 92 A2 22 2F CE
7017
: 07 1A 08 8E F1 46 03 59 36 4A CB 60 E6 03
7018
: 40 01 5B 2A 44 D6 E4 7F EB 43 5E 74 0A E6
7019
: E4 F9 3E E1 44 BE 1F E7 5F 5B 2C 41 8D 08
7020
: BD 26 FE 6A A6 C3 2F B2 3B 41 12 6B C1 06
7021
: 8A B8 4C 91 59 EB 2F 38 20 2A 67 74 20 0B
7022
: 77 F3
7023
: }
7024
7025
C.4 Certificate Revocation List
7026
7027
This section contains an annotated hex dump of a version 2 CRL with
7028
one extension (cRLNumber). The CRL was issued by OU=NIST; O=gov;
7029
C=US on August 7, 1997; the next scheduled issuance was September 7,
7030
1997. The CRL includes one revoked certificates: serial number 18
7031
(12 hex), which was revoked on July 31, 1997 due to keyCompromise.
7032
The CRL itself is number 18, and it was signed with DSA and SHA-1.
7033
7034
0 30 203: SEQUENCE {
7035
3 30 140: SEQUENCE {
7036
6 02 1: INTEGER 1
7037
9 30 9: SEQUENCE {
7038
11 06 7: OBJECT IDENTIFIER dsaWithSha1 (1 2 840 10040 4 3)
7039
: }
7040
20 30 42: SEQUENCE {
7041
22 31 11: SET {
7042
24 30 9: SEQUENCE {
7043
26 06 3: OBJECT IDENTIFIER countryName (2 5 4 6)
7044
31 13 2: PrintableString 'US'
7045
: }
7046
: }
7047
35 31 12: SET {
7048
37 30 10: SEQUENCE {
7049
39 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10)
7050
44 13 3: PrintableString 'gov'
7051
: }
7052
: }
7053
49 31 13: SET {
7054
51 30 11: SEQUENCE {
7055
7056
7057
7058
Housley, et. al. Standards Track [Page 126]
7059
7060
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
7061
7062
7063
53 06 3: OBJECT IDENTIFIER
7064
: organizationalUnitName (2 5 4 11)
7065
58 13 4: PrintableString 'NIST'
7066
: }
7067
: }
7068
: }
7069
64 17 13: UTCTime '970807000000Z'
7070
79 17 13: UTCTime '970907000000Z'
7071
94 30 34: SEQUENCE {
7072
96 30 32: SEQUENCE {
7073
98 02 1: INTEGER 18
7074
101 17 13: UTCTime '970731000000Z'
7075
116 30 12: SEQUENCE {
7076
118 30 10: SEQUENCE {
7077
120 06 3: OBJECT IDENTIFIER cRLReason (2 5 29 21)
7078
125 04 3: OCTET STRING, encapsulates {
7079
127 0A 1: ENUMERATED 1
7080
: }
7081
: }
7082
: }
7083
: }
7084
: }
7085
130 A0 14: [0] {
7086
132 30 12: SEQUENCE {
7087
134 30 10: SEQUENCE {
7088
136 06 3: OBJECT IDENTIFIER cRLNumber (2 5 29 20)
7089
141 04 3: OCTET STRING, encapsulates {
7090
143 02 1: INTEGER 12
7091
: }
7092
: }
7093
: }
7094
: }
7095
: }
7096
146 30 9: SEQUENCE {
7097
148 06 7: OBJECT IDENTIFIER dsaWithSha1 (1 2 840 10040 4 3)
7098
: }
7099
157 03 47: BIT STRING 0 unused bits, encapsulates {
7100
160 30 44: SEQUENCE {
7101
162 02 20: INTEGER
7102
: 22 4E 9F 43 BA 95 06 34 F2 BB 5E 65 DB A6
7103
: 80 05 C0 3A 29 47
7104
184 02 20: INTEGER
7105
: 59 1A 57 C9 82 D7 02 21 14 C3 D4 0B 32 1B
7106
: 96 16 B1 1F 46 5A
7107
: }
7108
: }
7109
: }
7110
7111
7112
7113
7114
Housley, et. al. Standards Track [Page 127]
7115
7116
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
7117
7118
7119
Author Addresses
7120
7121
Russell Housley
7122
RSA Laboratories
7123
918 Spring Knoll Drive
7124
Herndon, VA 20170
7125
USA
7126
7127
EMail: rhousley@rsasecurity.com
7128
7129
Warwick Ford
7130
VeriSign, Inc.
7131
401 Edgewater Place
7132
Wakefield, MA 01880
7133
USA
7134
7135
EMail: wford@verisign.com
7136
7137
Tim Polk
7138
NIST
7139
Building 820, Room 426
7140
Gaithersburg, MD 20899
7141
USA
7142
7143
EMail: wpolk@nist.gov
7144
7145
David Solo
7146
Citigroup
7147
909 Third Ave, 16th Floor
7148
New York, NY 10043
7149
USA
7150
7151
EMail: dsolo@alum.mit.edu
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
Housley, et. al. Standards Track [Page 128]
7171
7172
RFC 3280 Internet X.509 Public Key Infrastructure April 2002
7173
7174
7175
Full Copyright Statement
7176
7177
Copyright (C) The Internet Society (2002). All Rights Reserved.
7178
7179
This document and translations of it may be copied and furnished to
7180
others, and derivative works that comment on or otherwise explain it
7181
or assist in its implementation may be prepared, copied, published
7182
and distributed, in whole or in part, without restriction of any
7183
kind, provided that the above copyright notice and this paragraph are
7184
included on all such copies and derivative works. However, this
7185
document itself may not be modified in any way, such as by removing
7186
the copyright notice or references to the Internet Society or other
7187
Internet organizations, except as needed for the purpose of
7188
developing Internet standards in which case the procedures for
7189
copyrights defined in the Internet Standards process must be
7190
followed, or as required to translate it into languages other than
7191
English.
7192
7193
The limited permissions granted above are perpetual and will not be
7194
revoked by the Internet Society or its successors or assigns.
7195
7196
This document and the information contained herein is provided on an
7197
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
7198
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
7199
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
7200
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
7201
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
7202
7203
Acknowledgement
7204
7205
Funding for the RFC Editor function is currently provided by the
7206
Internet Society.
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
Housley, et. al. Standards Track [Page 129]
7227
Loggerhead is a web-based interface for Breezy
Version: 2.0.1