rfc3280.txt

PKIX的RFC英文文档

Network Working Group                                         R. Housley
Request for Comments: 3280                              RSA Laboratories
Obsoletes: 2459                                                  W. Polk
Category: Standards Track                                           NIST
                                                                 W. Ford
                                                                VeriSign
                                                                 D. Solo
                                                               Citigroup
                                                              April 2002

                Internet X.509 Public Key Infrastructure
       Certificate and Certificate Revocation List (CRL) Profile

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This memo profiles the X.509 v3 certificate and X.509 v2 Certificate
   Revocation List (CRL) for use in the Internet.  An overview of this
   approach and model are provided as an introduction.  The X.509 v3
   certificate format is described in detail, with additional
   information regarding the format and semantics of Internet name
   forms.  Standard certificate extensions are described and two
   Internet-specific extensions are defined.  A set of required
   certificate extensions is specified.  The X.509 v2 CRL format is
   described in detail, and required extensions are defined.  An
   algorithm for X.509 certification path validation is described.  An
   ASN.1 module and examples are provided in the appendices.

Table of Contents

   1  Introduction  . . . . . . . . . . . . . . . . . . . . . .   4
   2  Requirements and Assumptions  . . . . . . . . . . . . . .   5
   2.1  Communication and Topology  . . . . . . . . . . . . . .   6
   2.2  Acceptability Criteria  . . . . . . . . . . . . . . . .   6
   2.3  User Expectations . . . . . . . . . . . . . . . . . . .   7
   2.4  Administrator Expectations  . . . . . . . . . . . . . .   7
   3  Overview of Approach  . . . . . . . . . . . . . . . . . .   7



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RFC 3280        Internet X.509 Public Key Infrastructure      April 2002


   3.1  X.509 Version 3 Certificate . . . . . . . . . . . . . .   8
   3.2  Certification Paths and Trust . . . . . . . . . . . . .   9
   3.3  Revocation  . . . . . . . . . . . . . . . . . . . . . .  11
   3.4  Operational Protocols . . . . . . . . . . . . . . . . .  13
   3.5  Management Protocols  . . . . . . . . . . . . . . . . .  13
   4  Certificate and Certificate Extensions Profile  . . . . .  14
   4.1  Basic Certificate Fields  . . . . . . . . . . . . . . .  15
   4.1.1  Certificate Fields  . . . . . . . . . . . . . . . . .  16
   4.1.1.1  tbsCertificate  . . . . . . . . . . . . . . . . . .  16
   4.1.1.2  signatureAlgorithm  . . . . . . . . . . . . . . . .  16
   4.1.1.3  signatureValue  . . . . . . . . . . . . . . . . . .  16
   4.1.2  TBSCertificate  . . . . . . . . . . . . . . . . . . .  17
   4.1.2.1  Version . . . . . . . . . . . . . . . . . . . . . .  17
   4.1.2.2  Serial number . . . . . . . . . . . . . . . . . . .  17
   4.1.2.3  Signature . . . . . . . . . . . . . . . . . . . . .  18
   4.1.2.4  Issuer  . . . . . . . . . . . . . . . . . . . . . .  18
   4.1.2.5  Validity  . . . . . . . . . . . . . . . . . . . . .  22
   4.1.2.5.1  UTCTime . . . . . . . . . . . . . . . . . . . . .  22
   4.1.2.5.2  GeneralizedTime . . . . . . . . . . . . . . . . .  22
   4.1.2.6  Subject . . . . . . . . . . . . . . . . . . . . . .  23
   4.1.2.7  Subject Public Key Info . . . . . . . . . . . . . .  24
   4.1.2.8  Unique Identifiers  . . . . . . . . . . . . . . . .  24
   4.1.2.9 Extensions . . . . . . . . . . . . . . . . . . . . .  24
   4.2  Certificate Extensions  . . . . . . . . . . . . . . . .  24
   4.2.1  Standard Extensions . . . . . . . . . . . . . . . . .  25
   4.2.1.1  Authority Key Identifier  . . . . . . . . . . . . .  26
   4.2.1.2  Subject Key Identifier  . . . . . . . . . . . . . .  27
   4.2.1.3  Key Usage . . . . . . . . . . . . . . . . . . . . .  28
   4.2.1.4  Private Key Usage Period  . . . . . . . . . . . . .  29
   4.2.1.5  Certificate Policies  . . . . . . . . . . . . . . .  30
   4.2.1.6  Policy Mappings . . . . . . . . . . . . . . . . . .  33
   4.2.1.7  Subject Alternative Name  . . . . . . . . . . . . .  33
   4.2.1.8  Issuer Alternative Name . . . . . . . . . . . . . .  36
   4.2.1.9  Subject Directory Attributes  . . . . . . . . . . .  36
   4.2.1.10  Basic Constraints  . . . . . . . . . . . . . . . .  36
   4.2.1.11  Name Constraints . . . . . . . . . . . . . . . . .  37
   4.2.1.12  Policy Constraints . . . . . . . . . . . . . . . .  40
   4.2.1.13  Extended Key Usage . . . . . . . . . . . . . . . .  40
   4.2.1.14  CRL Distribution Points  . . . . . . . . . . . . .  42
   4.2.1.15  Inhibit Any-Policy . . . . . . . . . . . . . . . .  44
   4.2.1.16  Freshest CRL . . . . . . . . . . . . . . . . . . .  44
   4.2.2  Internet Certificate Extensions . . . . . . . . . . .  45
   4.2.2.1  Authority Information Access  . . . . . . . . . . .  45
   4.2.2.2  Subject Information Access  . . . . . . . . . . . .  46
   5  CRL and CRL Extensions Profile  . . . . . . . . . . . . .  48
   5.1  CRL Fields  . . . . . . . . . . . . . . . . . . . . . .  49
   5.1.1  CertificateList Fields  . . . . . . . . . . . . . . .  50
   5.1.1.1  tbsCertList . . . . . . . . . . . . . . . . . . . .  50



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   5.1.1.2  signatureAlgorithm  . . . . . . . . . . . . . . . .  50
   5.1.1.3  signatureValue  . . . . . . . . . . . . . . . . . .  51
   5.1.2  Certificate List "To Be Signed" . . . . . . . . . . .  51
   5.1.2.1  Version . . . . . . . . . . . . . . . . . . . . . .  52
   5.1.2.2  Signature . . . . . . . . . . . . . . . . . . . . .  52
   5.1.2.3  Issuer Name . . . . . . . . . . . . . . . . . . . .  52
   5.1.2.4  This Update . . . . . . . . . . . . . . . . . . . .  52
   5.1.2.5  Next Update . . . . . . . . . . . . . . . . . . . .  53
   5.1.2.6  Revoked Certificates  . . . . . . . . . . . . . . .  53
   5.1.2.7  Extensions  . . . . . . . . . . . . . . . . . . . .  53
   5.2  CRL Extensions  . . . . . . . . . . . . . . . . . . . .  53
   5.2.1  Authority Key Identifier  . . . . . . . . . . . . . .  54
   5.2.2  Issuer Alternative Name . . . . . . . . . . . . . . .  54
   5.2.3  CRL Number  . . . . . . . . . . . . . . . . . . . . .  55
   5.2.4  Delta CRL Indicator . . . . . . . . . . . . . . . . .  55
   5.2.5  Issuing Distribution Point  . . . . . . . . . . . . .  58
   5.2.6  Freshest CRL  . . . . . . . . . . . . . . . . . . . .  59
   5.3  CRL Entry Extensions  . . . . . . . . . . . . . . . . .  60
   5.3.1  Reason Code . . . . . . . . . . . . . . . . . . . . .  60
   5.3.2  Hold Instruction Code . . . . . . . . . . . . . . . .  61
   5.3.3  Invalidity Date . . . . . . . . . . . . . . . . . . .  62
   5.3.4  Certificate Issuer  . . . . . . . . . . . . . . . . .  62
   6  Certificate Path Validation . . . . . . . . . . . . . . .  62
   6.1  Basic Path Validation . . . . . . . . . . . . . . . . .  63
   6.1.1  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  66
   6.1.2  Initialization  . . . . . . . . . . . . . . . . . . .  67
   6.1.3  Basic Certificate Processing  . . . . . . . . . . . .  70
   6.1.4  Preparation for Certificate i+1 . . . . . . . . . . .  75
   6.1.5  Wrap-up procedure . . . . . . . . . . . . . . . . . .  78
   6.1.6  Outputs . . . . . . . . . . . . . . . . . . . . . . .  80
   6.2  Extending Path Validation . . . . . . . . . . . . . . .  80
   6.3  CRL Validation  . . . . . . . . . . . . . . . . . . . .  81
   6.3.1  Revocation Inputs . . . . . . . . . . . . . . . . . .  82
   6.3.2  Initialization and Revocation State Variables . . . .  82
   6.3.3  CRL Processing  . . . . . . . . . . . . . . . . . . .  83
   7  References  . . . . . . . . . . . . . . . . . . . . . . .  86
   8  Intellectual Property Rights  . . . . . . . . . . . . . .  88
   9  Security Considerations . . . . . . . . . . . . . . . . .  89
   Appendix A.  ASN.1 Structures and OIDs . . . . . . . . . . .  92
   A.1 Explicitly Tagged Module, 1988 Syntax  . . . . . . . . .  92
   A.2 Implicitly Tagged Module, 1988 Syntax  . . . . . . . . . 105
   Appendix B.  ASN.1 Notes . . . . . . . . . . . . . . . . . . 112
   Appendix C.  Examples  . . . . . . . . . . . . . . . . . . . 115
   C.1  DSA Self-Signed Certificate . . . . . . . . . . . . . . 115
   C.2  End Entity Certificate Using DSA  . . . . . . . . . . . 119
   C.3  End Entity Certificate Using RSA  . . . . . . . . . . . 122
   C.4  Certificate Revocation List . . . . . . . . . . . . . . 126
   Author Addresses . . . . . . . . . . . . . . . . . . . . . . 128



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   Full Copyright Statement . . . . . . . . . . . . . . . . . . 129

1  Introduction

   This specification is one part of a family of standards for the X.509
   Public Key Infrastructure (PKI) for the Internet.

   This specification profiles the format and semantics of certificates
   and certificate revocation lists (CRLs) for the Internet PKI.
   Procedures are described for processing of certification paths in the
   Internet environment.  Finally, ASN.1 modules are provided in the
   appendices for all data structures defined or referenced.

   Section 2 describes Internet PKI requirements, and the assumptions
   which affect the scope of this document.  Section 3 presents an
   architectural model and describes its relationship to previous IETF
   and ISO/IEC/ITU-T standards.  In particular, this document's
   relationship with the IETF PEM specifications and the ISO/IEC/ITU-T
   X.509 documents are described.

   Section 4 profiles the X.509 version 3 certificate, and section 5
   profiles the X.509 version 2 CRL.  The profiles include the
   identification of ISO/IEC/ITU-T and ANSI extensions which may be
   useful in the Internet PKI.  The profiles are presented in the 1988
   Abstract Syntax Notation One (ASN.1) rather than the 1997 ASN.1
   syntax used in the most recent ISO/IEC/ITU-T standards.

   Section 6 includes certification path validation procedures.  These
   procedures are based upon the ISO/IEC/ITU-T definition.
   Implementations are REQUIRED to derive the same results but are not
   required to use the specified procedures.

   Procedures for identification and encoding of public key materials
   and digital signatures are defined in [PKIXALGS].  Implementations of
   this specification are not required to use any particular
   cryptographic algorithms.  However, conforming implementations which
   use the algorithms identified in [PKIXALGS] MUST identify and encode
   the public key materials and digital signatures as described in that
   specification.

   Finally, three appendices are provided to aid implementers.  Appendix
   A contains all ASN.1 structures defined or referenced within this
   specification.  As above, the material is presented in the 1988
   ASN.1.  Appendix B contains notes on less familiar features of the
   ASN.1 notation used within this specification.  Appendix C contains
   examples of a conforming certificate and a conforming CRL.





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RFC 3280        Internet X.509 Public Key Infrastructure      April 2002


   This specification obsoletes RFC 2459.  This specification differs
   from RFC 2459 in five basic areas:

      * To promote interoperable implementations, a detailed algorithm
      for certification path validation is included in section 6.1 of
      this specification; RFC 2459 provided only a high-level
      description of path validation.

      * An algorithm for determining the status of a certificate using
      CRLs is provided in section 6.3 of this specification.  This
      material was not present in RFC 2459.

      * To accommodate new usage models, detailed information describing
      the use of delta CRLs is provided in Section 5 of this
      specification.

      * Identification and encoding of public key materials and digital
      signatures are not included in this specification, but are now
      described in a companion specification [PKIXALGS].

      * Four additional extensions are specified: three certificate
      extensions and one CRL extension.  The certificate extensions are
      subject info access, inhibit any-policy, and freshest CRL.  The
      freshest CRL extension is also defined as a CRL extension.

      * Throughout the specification, clarifications have been
      introduced to enhance consistency with the ITU-T X.509
      specification.  X.509 defines the certificate and CRL format as
      well as many of the extensions that appear in this specification.
      These changes were introduced to improve the likelihood of
      interoperability between implementations based on this
      specification with implementations based on the ITU-T
      specification.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119.

2  Requirements and Assumptions

   The goal of this specification is to develop a profile to facilitate
   the use of X.509 certificates within Internet applications for those
   communities wishing to make use of X.509 technology.  Such
   applications may include WWW, electronic mail, user authentication,
   and IPsec.  In order to relieve some of the obstacles to using X.509






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