Network Working Group D. Cooper
Request for Comments: 5280 NIST
Obsoletes: 3280, 4325, 4630 S. Santesson
Category: Standards Track Microsoft
S. Farrell
Trinity College Dublin
S. Boeyen
Entrust
R. Housley
Vigil Security
W. Polk
NIST
May 2008
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.
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 is 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 along with standard and Internet-specific
extensions. An algorithm for X.509 certification path validation is
described. An ASN.1 module and examples are provided in the
appendices.
Cooper, et al. Standards Track [Page 1]RFC 5280 PKIX Certificate and CRL Profile May 2008Table of Contents
1. Introduction ....................................................4
2. Requirements and Assumptions ....................................6
2.1. Communication and Topology .................................7
2.2. Acceptability Criteria .....................................7
2.3. User Expectations ..........................................7
2.4. Administrator Expectations .................................8
3. Overview of Approach ............................................8
3.1. X.509 Version 3 Certificate ................................9
3.2. Certification Paths and Trust .............................10
3.3. Revocation ................................................13
3.4. Operational Protocols .....................................14
3.5. Management Protocols ......................................14
4. Certificate and Certificate Extensions Profile .................16
4.1. Basic Certificate Fields ..................................16
4.1.1. Certificate Fields .................................17
4.1.1.1. tbsCertificate ............................18
4.1.1.2. signatureAlgorithm ........................18
4.1.1.3. signatureValue ............................18
4.1.2. TBSCertificate .....................................18
4.1.2.1. Version ...................................19
4.1.2.2. Serial Number .............................19
4.1.2.3. Signature .................................19
4.1.2.4. Issuer ....................................20
4.1.2.5. Validity ..................................22
4.1.2.5.1. UTCTime ........................23
4.1.2.5.2. GeneralizedTime ................23
4.1.2.6. Subject ...................................23
4.1.2.7. Subject Public Key Info ...................25
4.1.2.8. Unique Identifiers ........................25
4.1.2.9. Extensions ................................26
4.2. Certificate Extensions ....................................26
4.2.1. Standard Extensions ................................27
4.2.1.1. Authority Key Identifier ..................27
4.2.1.2. Subject Key Identifier ....................28
4.2.1.3. Key Usage .................................29
datatracker.ietf.org