HTTP/1.1 200 OK Date: Tue, 09 Apr 2002 06:22:16 GMT Server: Apache/1.3.20 (Unix) Last-Modified: Mon, 06 Apr 1998 23:36:00 GMT ETag: "2e7b6a-3e473-352966e0" Accept-Ranges: bytes Content-Length: 255091 Connection: close Content-Type: text/plain PKIX Working Group R. Housley (SPYRUS) Internet Draft W. Ford (Verisign) W. Polk (NIST) D. Solo (Citicorp) expires in six months March 25, 1998 Internet Public Key Infrastructure X.509 Certificate and CRL Profile Status of this Memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." To view the entire list of current Internet-Drafts, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). Abstract This is the seventh draft of the Internet Public Key Infrastructure X.509 Certificate and CRL Profile. This draft is a complete specification. This text includes minor modifications over the previous draft. This draft introduces UTF8 support, updates the path validation process to conform with the current X.509 specification, forbids wildcarding in subject alternative names, and clarifies conformance requirements. Please send comments on this document to the ietf-pkix@tandem.com mail list. Housley, Ford, Polk, & Solo [Page 1] INTERNET DRAFT March 25, 1998 Table of Contents 1 Executive Summary ........................................... 5 2 Requirements and Assumptions ................................ 6 2.1 Communication and Topology ................................ 6 2.2 Acceptability Criteria .................................... 7 2.3 User Expectations ......................................... 7 2.4 Administrator Expectations ................................ 7 3 Overview of Approach ........................................ 7 3.1 X.509 Version 3 Certificate ............................... 9 3.2 Certification Paths and Trust ............................. 10 3.3 Revocation ................................................ 12 3.4 Operational Protocols ..................................... 13 3.5 Management Protocols ...................................... 14 4 Certificate and Certificate Extensions Profile .............. 15 4.1 Basic Certificate Fields .................................. 15 4.1.1 Certificate Fields ...................................... 16 4.1.1.1 tbsCertificate ........................................ 16 4.1.1.2 signatureAlgorithm .................................... 17 4.1.1.3 signature ............................................. 17 4.1.2 TBSCertificate .......................................... 17 4.1.2.1 Version ............................................... 18 4.1.2.2 Serial number ......................................... 18 4.1.2.3 Signature ............................................. 18 4.1.2.4 Issuer Name ........................................... 18 4.1.2.5 Validity .............................................. 20 4.1.2.5.1 UTCTime ............................................. 20 4.1.2.5.2 GeneralizedTime ..................................... 20 4.1.2.6 Subject Name .......................................... 21 4.1.2.7 Subject Public Key Info ............................... 21 4.1.2.8 Unique Identifiers .................................... 21 4.1.2.9 Extensions ............................................. 22 4.2 Certificate Extensions .................................... 22 4.2.1 Standard Extensions ..................................... 23 4.2.1.1 Authority Key Identifier .............................. 23 4.2.1.2 Subject Key Identifier ................................ 24 4.2.1.3 Key Usage ............................................. 24 4.2.1.4 Private Key Usage Period .............................. 26 4.2.1.5 Certificate Policies .................................. 26 4.2.1.6 Policy Mappings ....................................... 28 4.2.1.7 Subject Alternative Name .............................. 29 4.2.1.8 Issuer Alternative Name ............................... 31 4.2.1.9 Subject Directory Attributes .......................... 31 Housley, Ford, Polk, & Solo [Page 2] INTERNET DRAFT March 25, 1998 4.2.1.10 Basic Constraints .................................... 31 4.2.1.11 Name Constraints ..................................... 32 4.2.1.12 Policy Constraints ................................... 33 4.2.1.13 CRL Distribution Points .............................. 34 4.2.1.14 Extended key usage field ............................. 35 4.2.2 Private Internet Extensions ............................. 36 4.2.2.1 Authority Information Access .......................... 37 5 CRL and CRL Extensions Profile .............................. 39 5.1 CRL Fields ................................................ 39 5.1.1 CertificateList Fields .................................. 40 5.1.1.1 tbsCertList ........................................... 40 5.1.1.2 signatureAlgorithm .................................... 41 5.1.1.3 signature ............................................. 41 5.1.2 Certificate List "To Be Signed" ......................... 41 5.1.2.1 Version ............................................... 41 5.1.2.2 Signature ............................................. 42 5.1.2.3 Issuer Name ........................................... 42 5.1.2.4 This Update ........................................... 42 5.1.2.5 Next Update ........................................... 42 5.1.2.6 Revoked Certificates .................................. 43 5.1.2.7 Extensions ............................................ 43 5.2 CRL Extensions ............................................ 43 5.2.1 Authority Key Identifier ................................ 44 5.2.2 Issuer Alternative Name ................................. 44 5.2.3 CRL Number .............................................. 44 5.2.4 Issuing Distribution Point .............................. 45 5.2.5 Delta CRL Indicator ..................................... 45 5.2.6 Certificate Issuer ....................................... 46 5.3 CRL Entry Extensions ...................................... 46 5.3.1 Reason Code ............................................. 47 5.3.2 Hold Instruction Code ................................... 47 5.3.3 Invalidity Date ......................................... 48 6 Certificate Path Validation ................................. 48 7 Algorithm Support ........................................... 53 7.1 One-way Hash Functions .................................... 53 7.1.1 MD2 One-way Hash Function ............................... 53 7.1.2 MD5 One-way Hash Function ............................... 54 7.1.3 SHA-1 One-way Hash Function ............................. 54 7.2 Signature Algorithms ...................................... 54 7.2.1 RSA Signature Algorithm ................................. 55 7.2.2 DSA Signature Algorithm ................................. 56 7.3 Subject Public Key Algorithms ............................. 57 7.3.1 RSA Keys ................................................ 57 7.3.2 Diffie-Hellman Key Exchange Key .......................... 58 7.3.3 DSA Signature Keys ....................................... 59 References ..................................................... 60 Patent Statements .............................................. 62 Appendix A. ASN.1 Structures and OIDs .......................... 66 Housley, Ford, Polk, & Solo [Page 3] INTERNET DRAFT March 25, 1998 Appendix B. 1993 ASN.1 Structures and OIDs ..................... 83 Appendix C. ASN.1 Notes ........................................ 100 Appendix D. Examples ........................................... 101 D.1 Certificate ................................................ 102 D.1.1 ASN.1 Dump of "Self-Signed" Certificate .................. 102 D.1.2 Pretty Print of "Self-Signed" Certificate ................ 104 D.2 Certificate ................................................ 106 D.2.1 Basic ASN.1 Dump of "End Entity" Certificate ............. 106 D.2.2 Pretty Print of "End Entity" Certificate ................. 108 D.3 End-Entity Certificate Using RSA ........................... 110 D.4 Certificate Revocation List ................................ 114 Security Considerations ........................................ 111 Author Addresses ............................................... 116 Housley, Ford, Polk, & Solo [Page 4] INTERNET DRAFT March 25, 1998 1 Executive Summary This specification is one part of a multipart standard for the Public Key Infrastructure (PKI) for the Internet. This specification is a standalone document; implementations of this standard may proceed independent from the other parts. This specification profiles the format and semantics of certificates and certificate revocation lists for the Internet PKI. Procedures are described for processing of certification paths in the Internet environment. Encoding rules are provided for popular cryptographic algorithms. Finally, ASN.1 modules are provided in the appendices for all data structure defined or referenced. The specification describes the requirements which inspire the crea- tion of this document and the assumptions which affect its scope in Section 2. Section 3 presents an architectural model and describes its relationship to previous IETF and ISO standards. In particular, this document's relationship with the IETF PEM specifications and the ISO X.509 documents are described. The specification profiles the X.509 version 3 certificate in Section 4, and the X.509 version 2 certificate revocation list (CRL) in Sec- tion 5. The profiles include the identification of ISO and ANSI extensions which may be useful in the Internet PKI and definition of new extensions to meet the Internet's requirements. The profiles are presented in the 1988 Abstract Syntax Notation One (ASN.1) rather than the 1993 syntax used in the ISO standards. The ASN.1 notation assumes implict tagging throughout. This specification also includes path validation procedures in Sec- tion 6. These procedures are based upon the ISO definition, but the presentation assumes a self-signed root certificate. Implementations are required to derive the same results but are not required to use the specified procedures. Finally, Section 7 of the specification describes procedures for identification and encoding of public key materials and digital sig- natures. Implementations are not required to use any particular cryptographic algorithms. However, conforming implementations which use the identified algorithms are required to identify and encode the public key materials and digital signatures as described. Appendix A contains all ASN.1 structures defined or referenced within this specification. As above, the material is presented in the 1988 Abstract Syntax Notation One (ASN.1) rather than the 1993 syntax. Appendix B contains the same information in the 1993 ASN.1 notation. Appendix C contains notes on less familiar features of the ASN.1 Housley, Ford, Polk, & Solo [Page 5] INTERNET DRAFT March 25, 1998 notation used within this specification. Appendix D contains exam- ples of a conforming certificate and a conforming CRL. 2 Requirements and Assumptions Goal is to develop a profile and associated management structure to facilitate the adoption/use of X.509 certificates within Internet applications for those communities wishing to make use of X.509 tech- nology. Such applications may include WWW, electronic mail, user authentication, and IPSEC, as well as others. In order to relieve some of the obstacles to using X.509 certificates, this document defines a profile to promote the development of certificate manage- ment systems; development of application tools; and interoperability determined by policy, as opposed to syntax. Some communities will need to supplement, or possibly replace, this profile in order to meet the requirements of specialized application domains or environments with additional authorization, assurance, or operational requirements. However, for basic applications, common representations of frequently used attributes are defined so that application developers can obtain necessary information without regard to the issuer of a particular certificate or certificate revo- cation list (CRL). A certificate user should review the certification practice Statement (CPS) generated by the CA before relying on the authentication or non-repudiation services associated with the public key in a particu- lar certificate. To this end, this standard does not prescribe legally binding rules or duties. As supplemental authorization and attribute management tools emerge, such as attribute certificates, it may be appropriate to limit the authenticated attributes that are included in a certificate. These other management tools may be more appropriate method of conveying many authenticated attributes. 2.1 Communication and Topology The users of certificates will operate in a wide range of environ- ments with respect to their communication topology, especially users of secure electronic mail. This profile supports users without high bandwidth, real-time IP connectivity, or high connection availablity. In addition, the profile allows for the presence of firewall or other filtered communication. This profile does not assume the deployment of an X.500 Directory system. The profile does not prohibit the use of an X.500 Directory, but other means of distributing certificates and certificate Housley, Ford, Polk, & Solo [Page 6] INTERNET DRAFT March 25, 1998 revocation lists (CRLs) are supported. 2.2 Acceptability Criteria The goal of the Internet Public Key Infrastructure (PKI) is to meet the needs of deterministic, automated identification, authentication, access control, and authorization functions. Support for these ser- vices determines the attributes contained in the certificate as well as the ancillary control information in the certificate such as pol- icy data and certification path constraints. 2.3 User Expectations Users of the Internet PKI are people and processes who use client software and are the subjects named in certificates. These uses include readers and writers of electronic mail, the clients for WWW browsers, WWW servers, and the key manager for IPSEC within a router. This profile recognizes the limitations of the platforms these users employ and the sophistication/attentiveness of the users themselves. This manifests itself in minimal user configuration responsibility (e.g., root keys, rules), explicit platform usage constraints within the certificate, certification path constraints which shield the user from many malicious actions, and applications which sensibly automate validation functions. 2.4 Administrator Expectations As with users, the Internet PKI profile is structured to support the individuals who generally operate Certification Authorities (CAs). Providing administrators with unbounded choices increases the chances that a subtle CA administrator mistake will result in broad comprom- ise. Also, unbounded choices greatly complicates the software that must process and validate the certificates created by the CA. 3 Overview of Approach Following is a simplified view of the architectural model assumed by the PKIX specifications. Housley, Ford, Polk, & Solo [Page 7] INTERNET DRAFT March 25, 1998 +---+ | C | +------------+ | e | <-------------------->| End entity | | r | Operational +------------+ | t | transactions ^ | | and management | Management | / | transactions | transactions | | | | C | PKI users v | R | -------+-------+--------+------ | L | PKI management ^ ^ | | entities | | | | v | | R | +------+ | | e | <-------------- | RA | <-----+ | | p | certificate | | | | | o | publish +------+ | | | s | | | | I | v v | t | +------------+ | o | <--------------------------| CA | | r | certificate publish +------------+ | y | CRL publish ^ | | | +---+ | Management | transactions v +------+ | CA | +------+ Figure 1 - PKI Entities The components in this model are: end entity: user of PKI certificates and/or end user system that is the subject of a certificate; CA: certification authority; RA: registration authority, i.e., an optional system to which a CA delegates certain management functions; repository: a system or collection of distributed systems that store certificates and CRLs and serves as a means of distributing these certificates and CRLs to end entities. Housley, Ford, Polk, & Solo [Page 8] INTERNET DRAFT March 25, 1998 3.1 X.509 Version 3 Certificate Application of public key technology requires the user of a public key to be confident that the public key belongs to the correct remote subject (person or system) with which an encryption or digital signa- ture mechanism will be used. This confidence is obtained through the use of public key certificates, which are data structures that bind public key values to subjects. The binding is achieved by having a trusted certification authority (CA) digitally sign each certificate. A certificate has a limited valid lifetime which is indicated in its signed contents. Because a certificate's signature and timeliness can be independently checked by a certificate-using client, certifi- cates can be distributed via untrusted communications and server sys- tems, and can be cached in unsecured storage in certificate-using systems. The standard known as ITU-T X.509 (formerly CCITT X.509) or ISO/IEC 9594-8, which was first published in 1988 as part of the X.500 Direc- tory recommendations, defines a standard certificate format. The cer- tificate format in the 1988 standard is called the version 1 (v1) format. When X.500 was revised in 1993, two more fields were added, resulting in the version 2 (v2) format. These two fields are used to support directory access control. The Internet Privacy Enhanced Mail (PEM) proposals, published in 1993, include specifications for a public key infrastructure based on X.509 v1 certificates [RFC 1422]. The experience gained in attempts to deploy RFC 1422 made it clear that the v1 and v2 certificate for- mats are deficient in several respects. Most importantly, more fields were needed to carry information which PEM design and imple- mentation experience has proven necessary. In response to these new requirements, ISO/IEC and ANSI X9 developed the X.509 version 3 (v3) certificate format. The v3 format extends the v2 format by adding provision for additional extension fields. Particular extension field types may be specified in standards or may be defined and registered by any organization or community. In June 1996, standardi- zation of the basic v3 format was completed [X.509]. ISO/IEC and ANSI X9 have also developed standard extensions for use in the v3 extensions field [X.509][X9.55]. These extensions can con- vey such data as additional subject identification information, key attribute information, policy information, and certification path constraints. However, the ISO/IEC and ANSI standard extensions are very broad in their applicability. In order to develop interoperable implementa- tions of X.509 v3 systems for Internet use, it is necessary to specify a profile for use of the X.509 v3 extensions tailored for the Housley, Ford, Polk, & Solo [Page 9] INTERNET DRAFT March 25, 1998 Internet. It is one goal of this document to specify a profile for Internet WWW, electronic mail, and IPSEC applications. Environments with additional requirements may build on this profile or may replace it. 3.2 Certification Paths and Trust A user of a security service requiring knowledge of a public key gen- erally needs to obtain and validate a certificate containing the required public key. If the public-key user does not already hold an assured copy of the public key of the CA that signed the certificate, then it might need an additional certificate to obtain that public key. In general, a chain of multiple certificates may be needed, comprising a certificate of the public key owner (the end entity) signed by one CA, and zero or more additional certificates of CAs signed by other CAs. Such chains, called certification paths, are required because a public key user is only initialized with a limited number of assured CA public keys. There are different ways in which CAs might be configured in order for public key users to be able to find certification paths. For PEM, RFC 1422 defined a rigid hierarchical structure of CAs. There are three types of PEM certification authority: (a) Internet Policy Registration Authority (IPRA): This author- ity, operated under the auspices of the Internet Society, acts as the root of the PEM certification hierarchy at level 1. It issues certificates only for the next level of authorities, PCAs. All certification paths start with the IPRA. (b) Policy Certification Authorities (PCAs): PCAs are at level 2 of the hierarchy, each PCA being certified by the IPRA. A PCA must establish and publish a statement of its policy with respect to certifying users or subordinate certification authorities. Distinct PCAs aim to satisfy different user needs. For example, one PCA (an organizational PCA) might support the general elec- tronic mail needs of commercial organizations, and another PCA (a high-assurance PCA) might have a more stringent policy designed for satisfying legally binding signature requirements. (c) Certification Authorities (CAs): CAs are at level 3 of the hierarchy and can also be at lower levels. Those at level 3 are certified by PCAs. CAs represent, for example, particular organi- zations, particular organizational units (e.g., departments, groups, sections), or particular geographical areas. RFC 1422 furthermore has a name subordination rule which requires that a CA can only issue certificates for entities whose names are Housley, Ford, Polk, & Solo [Page 10] INTERNET DRAFT March 25, 1998 subordinate (in the X.500 naming tree) to the name of the CA itself. The trust associated with a PEM certification path is implied by the PCA name. The name subordination rule ensures that CAs below the PCA are sensibly constrained as to the set of subordinate entities they can certify (e.g., a CA for an organization can only certify entities in that organization's name tree). Certificate user systems are able to mechanically check that the name subordination rule has been fol- lowed. The RFC 1422 was based upon the X.509 v1 certificate formats. The limitations of X.509 v1 required imposition of several structural restrictions to clearly associate policy information or restrict the utility of certificates. These restrictions included: (a) a pure top-down hierarchy, with all certification paths start- ing from the root; (b) a naming subordination rule restricting the names of a CA's subjects; and (c) use of the PCA concept, which requires knowledge of individual PCAs to be built into certificate chain verification logic. Knowledge of individual PCAs was required to determine if a chain could be accepted. With X.509 v3, most of the requirements addressed by RFC 1422 can be addressed using certificate extensions, without a need to restrict the CA structures used. In particular, the certificate extensions relating to certificate policies obviate the need for PCAs and the constraint extensions obviate the need for the name subordination rule. As a result, this document supports a more flexible architec- ture, including: (a) Certification paths may start with a public key of a CA in a user's own domain, or with the public key of the top of a hierar- chy. Starting with the public key of a CA in a user's own domain has certain advantages. In many environments, the local domain is often the most trusted. Initialization and key-pair-update opera- tions can often be more effectively conducted between an end entity and a local management system. (b) Name constraints may be imposed through explicit inclusion of a name constraints extension in a certificate, but are not required. (c) Policy extensions and policy mappings replace the PCA con- cept, which permits a greater degree of automation. The applica- tion can determine if the certification path is acceptable based Housley, Ford, Polk, & Solo [Page 11] INTERNET DRAFT March 25, 1998 on the contents of the certificates instead of a priori knowledge of PCAs. This permits the full process of certificate chain pro- cessing to be implemented in software. 3.3 Revocation When a certificate is issued, it is expected to be in use for its entire validity period. However, various circumstances may cause a certificate to become invalid prior to the expiration of the validity period. Such circumstances might include change of name, change of association between subject and CA (e.g., an employee terminates employment with an organization), and compromise or suspected compromise of the corresponding private key. Under such cir- cumstances, the CA needs to revoke the certificate. X.509 defines one method of certificate revocation. This method involves each CA periodically issuing a signed data structure called a certificate revocation list (CRL). A CRL is a time stamped list identifying revoked certificates which is signed by a CA and made freely available in a public repository. Each revoked certificate is identified in a CRL by its certificate serial number. When a certificate-using system uses a certificate (e.g., for verifying a remote user's digital signature), that system not only checks the certificate signature and validity but also acquires a suitably- recent CRL and checks that the certificate serial number is not on that CRL. The meaning of "suitably-recent" may vary with local pol- icy, but it usually means the most recently-issued CRL. A CA issues a new CRL on a regular periodic basis (e.g., hourly, daily, or weekly). Entries are added to CRLs as revocations occur, and an entry may be removed when the certificate expiration date is reached. An advantage of this revocation method is that CRLs may be distri- buted by exactly the same means as certificates themselves, namely, via untrusted communications and server systems. One limitation of the CRL revocation method, using untrusted communi- cations and servers, is that the time granularity of revocation is limited to the CRL issue period. For example, if a revocation is reported now, that revocation will not be reliably notified to certificate-using systems until the next periodic CRL is issued -- this may be up to one hour, one day, or one week depending on the frequency that the CA issues CRLs. Another potential problem with CRLs is the risk of a CRL growing to an entirely unacceptable size. In the 1988 and 1993 versions of X.509, the CRL for the end-user certificates needed to cover the entire population of end-users for one CA. It is desirable to allow such populations to be in the range of thousands, tens of thousands, Housley, Ford, Polk, & Solo [Page 12] INTERNET DRAFT March 25, 1998 or possibly even hundreds of thousands of users. The end-user CRL is therefore at risk of growing to such sizes, which present major com- munication and storage overhead problems. With the version 2 CRL format, introduced along with the v3 certificate format, it becomes possible to arbitrarily divide the population of certificates for one CA into a number of partitions, each partition being associated with one CRL distribution point (e.g., directory entry or URL) from which CRLs are distributed. Therefore, the maximum CRL size can be con- trolled by a CA. Separate CRL distribution points can also exist for different revocation reasons. For example, routine revocations (e.g., name change) may be placed on a different CRL to revocations resulting from suspected key compromises, and policy may specify that the latter CRL be updated and issued more frequently than the former. As with the X.509 v3 certificate format, in order to facilitate interoperable implementations from multiple vendors, the X.509 v2 CRL format needs to be profiled for Internet use. It is one goal of this document to specify that profile. Furthermore, it is recognized that on-line methods of revocation notification may be applicable in some environments as an alternative to the X.509 CRL. On-line revocation checking significantly reduces the latency between a revocation report and the next issue of a CRL. Once the CA accepts the report as authentic and valid, any query to the on-line service will correctly reflect the certificate validation impacts of the revocation. However, these methods impose new secu- rity requirements; the certificate validator must trust the on-line validation service while the repository did not need to be trusted. Therefore, this profile also considers standard approaches to on-line revocation notification. The PKIX series of specifications defines a set of standard message formats supporting these functions in [PKIX- OCSP]. The protocols for conveying these messages in different environments are also specified. 3.4 Operational Protocols Operational protocols are required to deliver certificates and CRLs (or status information) to certificate using client systems. Provi- sion is needed for a variety of different means of certificate and CRL delivery, including request/delivery procedures based on E-mail, http, X.500, and WHOIS++. These specifications include definitions of, and/or references to, message formats and procedures for support- ing all of the above operational environments, including definitions of or references to appropriate MIME content types. Operational protocols supporting these functions are defined in the PKIX specifications [PKIXLDAP], [PKIXFTP] and [PKIXOCSP]. Housley, Ford, Polk, & Solo [Page 13] INTERNET DRAFT March 25, 1998 3.5 Management Protocols Management protocols are required to support on-line interactions between Public Key Infrastructure (PKI) components. For example, management protocol might be used between a CA and a client system with which a key pair is associated, or between two CAs which cross- certify each other. The set of functions which potentially need to be supported by management protocols include: (a) registration: This is the process whereby a user first makes itself known to a CA (directly, or through an RA), prior to that CA issuing a certificate or certificates for that user. (b) initialization: Before a client system can operate securely it is necessary to install in it necessary key materials which have the appropriate relationship with keys stored elsewhere in the infras- tructure. For example, the client needs to be securely initialized with the public key of a CA, to be used in validating certificate paths. Furthermore, a client typically needs to be initialized with its own key pair(s). (c) certification: This is the process in which a CA issues a cer- tificate for a user's public key, and returns that certificate to the user's client system and/or posts that certificate in a repository. (d) key pair recovery: As an option, user client key materials (e.g., a user's private key used for encryption purposes) may be backed up by a CA or a key backup system. If a user needs to recover these backed up key materials (e.g., as a result of a forgotten pass- word or a lost key chain file), an on-line protocol exchange may be needed to support such recovery. (e) key pair update: All key pairs need to be updated regularly, i.e., replaced with a new key pair, and new certificates issued. (f) revocation request: An authorized person advises a CA of an abnormal situation requiring certificate revocation. (g) cross-certification: Two CAs exchange the information necessary to establish cross-certificates between those CAs. Note that on-line protocols are not the only way of implementing the above functions. For all functions there are off-line methods of achieving the same result, and this specification does not mandate use of on-line protocols. For example, when hardware tokens are used, many of the functions may be achieved as part of the physical token delivery. Furthermore, some of the above functions may be com- bined into one protocol exchange. In particular, two or more of the Housley, Ford, Polk, & Solo [Page 14] INTERNET DRAFT March 25, 1998 registration, initialization, and certification functions can be com- bined into one protocol exchange. The PKIX series of specifications defines a set of standard message formats supporting the above functions in [PKIXMGMT]. The protocols for conveying these messages in different environments (on-line, e- mail, and WWW) are also specified in [PKIXMGMT]. 4 Certificate and Certificate Extensions Profile This section presents a profile for public key certificates that will foster interoperability and a reusable public key infrastructure. This section is based upon the X.509 V3 certificate format and the standard certificate extensions defined in [X.509]. The ISO docu- ments use the 1993 version of ASN.1; while this document uses the 1988 ASN.1 syntax, the encoded certificate and standard extensions are equivalent. This section also defines private extensions required to support a public key infrastructure for the Internet com- munity. Certificates may be used in a wide range of applications and environ- ments covering a broad spectrum of interoperability goals and a broader spectrum of operational and assurance requirements. The goal of this document is to establish a common baseline for generic appli- cations requiring broad interoperability and limited special purpose requirements. In particular, the emphasis will be on supporting the use of X.509 v3 certificates for informal internet electronic mail, IPSEC, and WWW applications. Other efforts are looking at certifi- cate profiles for payment systems. 4.1 Basic Certificate Fields The X.509 v3 certificate basic syntax is as follows. For signature calculation, the certificate is encoded using the ASN.1 distinguished encoding rules (DER) [X.208]. ASN.1 DER encoding is a tag, length, value encoding system for each element. Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= SEQUENCE { version [0] EXPLICIT Version DEFAULT v1, serialNumber CertificateSerialNumber, signature AlgorithmIdentifier, issuer Name, validity Validity, Housley, Ford, Polk, & Solo [Page 15] INTERNET DRAFT March 25, 1998 subject Name, subjectPublicKeyInfo SubjectPublicKeyInfo, issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, -- If present, version must be v2 or v3 subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL, -- If present, version must be v2 or v3 extensions [3] EXPLICIT Extensions OPTIONAL -- If present, version must be v3 } Version ::= INTEGER { v1(0), v2(1), v3(2) } CertificateSerialNumber ::= INTEGER Validity ::= SEQUENCE { notBefore Time, notAfter Time } Time ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime } UniqueIdentifier ::= BIT STRING SubjectPublicKeyInfo ::= SEQUENCE { algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING } Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension Extension ::= SEQUENCE { extnID OBJECT IDENTIFIER, critical BOOLEAN DEFAULT FALSE, extnValue OCTET STRING } The following items describe a proposed use of the X.509 v3 certifi- cate for the Internet. 4.1.1 Certificate Fields The Certificate is a SEQUENCE of three required fields. The fields are are described in detail in the following subsections 4.1.1.1 tbsCertificate The first field in the sequence is the tbsCertificate. This is a itself a sequence, and contains the names of the subject and issuer, a public key associated with the subject an expiration date, and Housley, Ford, Polk, & Solo [Page 16] INTERNET DRAFT March 25, 1998 other associated information. The fields of the basic tbsCertificate are described in detail in section 4.1.2; the tbscertificate may also include extensions which are described in section 4.2. 4.1.1.2 signatureAlgorithm The signatureAlgorithm field contains the algorithm identifier for the algorithm used by the CA to sign this certificate. Section 7.2 lists the supported signature algorithms. An algorithm identifier is defined by the following ASN.1 structure: AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } and it is used to identify a cryptographic algorithm. The OBJECT IDENTIFIER algorithm identifies the algorithm (such as RSA with SHA- 1). In the sigantureAlgorithm field, the contents of the optional parameters field shall be the value NULL. Section 7.2 lists the sup- ported algorithms for this specification. This field must contain the same algorithm identifier as the signa- ture field in the sequence tbsCertificate (see section 4.1.2.3) 4.1.1.3 signature The signature field contains a digital signature computed upon the ASN.1 DER encoded TBSCertificate. The ASN.1 DER encoded TBSCertifi- cate is used as the input to a one-way hash function. The one-way hash function output value is encrypted (e.g., using RSA Encryption) to form the signed quantity. This signature value is then ASN.1 encoded as a BIT STRING and included in the Certificate's signature field. The details of this process are specified for each of the sup- ported algorithms in Section 7.2. By generating this signature, a CA certifies the validity of the information in tbscertificate. In particular, the CA certifies the binding between the public key material and the subject of the certi- ficate. 4.1.2 TBSCertificate The sequence TBSCertificate is a sequence which contains information associated with the subject of the certificate and the CA who issued it. Every TBSCertificate contains the names of the subject and issuer, a public key associated with the subject, an expiration date, a version number and a serial number; some may contain optional Housley, Ford, Polk, & Solo [Page 17] INTERNET DRAFT March 25, 1998 unique identifier fields. The remainder of this section describes the syntax and semantics of these fields. A TBSCertificate may also include extensions. Extensions for the Internet PKI are described in Section 4.2. 4.1.2.1 Version This field describes the version of the encoded certificate. When extensions are used, as expected in this profile, use X.509 version 3 (value is 2). If no extensions are present, but a UniqueIdentifier is present, use version 2 (value is 1). If only basic fields are present, use version 1 (the value is omitted from the certificate as the default value). Implementations should be prepared to accept any version certificate. At a minimum, conforming implementations shall recognize version 3 certificates. Generation of version 2 certificates is not expected by implementa- tions based on this profile. 4.1.2.2 Serial number The serial number is an integer assigned by the certification author- ity to each certificate. It must be unique for each certificate issued by a given CA (i.e., the issuer name and serial number iden- tify a unique certificate). 4.1.2.3 Signature This field contains the algorithm identifier for the algorithm used by the CA to sign the certificate. Section 7.2 lists the supported signature algorithms. This field must contain the same algorithm identifier as the signa- tureAlgorithm field in the sequence Certificate (see section 4.1.1.2). As with signatureAlgorithm, the parameters component shall contain the value NULL. 4.1.2.4 Issuer Name The issuer name identifies the entity who has signed (and issued the certificate). The issuer identity may be carried in the issuer name field and/or the issuerAltName extension. If identity information is present only in the issuerAltName extension, then the issuer name may be an empty sequence and the issuerAltName extension must be criti- cal. Housley, Ford, Polk, & Solo [Page 18] INTERNET DRAFT March 25, 1998 Where it is non-null, the issuer name field shall contain an X.500 distinguished name (DN). The issuer field is defined as the X.501 type Name. Name is defined by the following ASN.1 structures: Name ::= CHOICE { RDNSequence } RDNSequence ::= SEQUENCE OF RelativeDistinguishedName RelativeDistinguishedName ::= SET OF AttributeTypeAndValue AttributeTypeAndValue ::= SEQUENCE { type AttributeType, value AttributeValue } AttributeType ::= OBJECT IDENTIFIER AttributeValue ::= ANY -- Directory string type -- DirectoryString ::= CHOICE { teletexString TeletexString (SIZE (1..MAX), printableString PrintableString (SIZE (1..MAX)), universalString UniversalString (SIZE (1..MAX)), utf8String UTF8String (SIZE (1.. MAX)), bmpString BMPString (SIZE (1..MAX)) } The Name describes a hierarchical name composed of attributes, such as country name, and corresponding values, such as US. The type of the component AttributeValue is determined by the AttributeType; in general it will be a directoryString. The directoryString is defined as a choice of PrintableString, TeletexString, BMPString UTF8String and UniversalString. Conforming CAs shall choose from these options as follows: (a) if the character set is sufficient, the string will be represented as a PrintableString; (b) failing (a), if the bMPString character set is sufficient the string shall be represented as a BMPString; (c) failing (a) and (b), if the UTF8 character set is sufficient, Housley, Ford, Polk, & Solo [Page 19] INTERNET DRAFT March 25, 1998 the string shall be represented as a UTF8String; and (d) failing (a), (b) and (c), the string shall be represented as a UniversalString. Standard sets of attributes have been defined in the X.500 series of specifications. Where CAs issue certificates with X.501 type names, it is recommended that these attributes types be used. 4.1.2.5 Validity This field indicates the period of validity of the certificate, and consists of two dates, the first and last on which the certificate is valid. The certificate validity period is the time interval during which the CA warrants that it will maintain information about the status of the certificate, i.e. publish revocation data. The field is represented as a SEQUENCE of two dates: the date on which the certi- ficate validity period begins (notBefore) and the date on which the certificate validity period ends (notAfter). Both notBefore and notAfter may be encoded as UTCTime or GeneralizedTime. CAs conforming to this profile shall always encode certificate vali- dity dates through the year 2049 as UTCTime; certificate validity dates in 2050 or later shall be encoded as GeneralizedTime. 4.1.2.5.1 UTCTime The universal time type, UTCTime, is a standard ASN.1 type intended for international applications where local time alone is not ade- quate. UTCTime specifies the year through the two low order digits and time is specified to the precision of one minute or one second. UTCTime includes either Z (for Zulu, or Greenwich Mean Time) or a time differential. For the purposes of this profile, UTCTime values shall be expressed Greenwich Mean Time (Zulu) and shall include seconds (i.e., times are YYMMDDHHMMSSZ), even where the number of seconds is zero. Conforming systems shall interpret the year field (YY) as follows: Where YY is greater than or equal to 50, the year shall be inter- preted as 19YY; and Where YY is less than 50, the year shall be interpreted as 20YY. 4.1.2.5.2 GeneralizedTime The generalized time type, GeneralizedTime, is a standard ASN.1 type for variable precision representation of time. Optionally, the Housley, Ford, Polk, & Solo [Page 20] INTERNET DRAFT March 25, 1998 GeneralizedTime field can include a representation of the time dif- ferential between local and Greenwich Mean Time. For the purposes of this profile, GeneralizedTime values shall be expressed Greenwich Mean Time (Zulu) and shall include seconds (i.e., times are YYYYMMDDHHMMSSZ), even where the number of seconds is zero. GeneralizedTime values shall not include fractional seconds. 4.1.2.6 Subject Name The subject name identifies the entity associated with the public key stored in the subject public key field. The subject identity may be carried in the subject field and/or the subjectAltName extension. If identity information is present only in the subjectAltName extension (e.g., a key bound only to an email address or URI), then the subject name may be an empty sequence and the subjectAltName extension must be critical. Where it is non-null, the subject name field shall contain an X.500 distinguished name (DN). The DN must be unique for each subject entity certified by the one CA as defined by the issuer name field. (A CA may issue more than one certificate with the same DN to the same subject entity.) The subject name field is defined as the X.501 type Name, and shall follow the encoding rules for the issuer name field (see 4.1.2.4). 4.1.2.7 Subject Public Key Info This field is used to carry the public key and identify the algorithm with which the key is used. The algorithm is identified using the algorithmIdentifier structure specified in Section 4.1.1.2. The object identifiers for the supported algorithms and the methods for encoding the public key materials (public key and parameters) are specified in Section 7.3. 4.1.2.8 Unique Identifiers The subject and issuer unique identifier are present in the certifi- cate to handle the possibility of reuse of subject and/or issuer names over time. This profile recommends that names not be reused and that Internet certificates not make use of unique identifiers. CAs conforming to this profile should not generate certificates with unique identifiers. Applications conforming to this profile should be capable of parsing unique identifiers and making comparisons. Housley, Ford, Polk, & Solo [Page 21] INTERNET DRAFT March 25, 1998 4.1.2.9 Extensions This field may only appear if the version number is 3 (see 4.1.2.x). If present, this field is a SEQUENCE of one or more certificate extensions. The format and content of certificate extensions in the Internet PKI is defined in Section 4.2. 4.2 Certificate Extensions The extensions defined for X.509 v3 certificates provide methods for associating additional attributes with users or public keys, for managing the certification hierarchy, and for managing CRL distribu- tion. The X.509 v3 certificate format also allows communities to define private extensions to carry information unique to those com- munities. Each extension in a certificate may be designated as crit- ical or non-critical. A certificate using system (an application validating a certificate) must reject the certificate if it encounters a critical extension it does not recognize. A non- critical extension may be ignored if it is not recognized. The fol- lowing presents recommended extensions used within Internet certifi- cates and standard locations for information. Communities may elect to use additional extensions; however, caution should be exercised in adopting any critical extensions in certificates which might be used in a general context. Each extension includes an object identifier and an ASN.1 structure. When an extension appears in a certificate, the object identifier appears as the field extnID and the corresponding ASN.1 encoded structure is the value of the octet string extnValue. Only one instance of a particular extension may appear in a particular certi- ficate. For example, a certificate may contain only one authority key identifier extension (4.2.1.1). An extension may also include the optional boolean critical; critical's default value is FALSE. The text for each extension specifies the acceptable values for the crit- ical field. Conforming CAs are required to support the basic Constraints exten- sion (Section 4.2.1.10), the key usage extension (4.2.1.3) and certi- ficate policies extension (4.2.1.5). If the CA issues certificates with an empty sequence for the subject field, the CA must support the subjectAltName extension. If the CA issues certificates with an empty sequence for the issuer field, the CA must support the issuerAltName extension. Support for the remaining extensions is optional. Conforming CAs may support extensions that are not identi- fied within this specification; certificate issuers are cautioned that marking such extensions as critical may inhibit interoperabil- ity. Housley, Ford, Polk, & Solo [Page 22] INTERNET DRAFT March 25, 1998 At a minimum, applications conforming to this profile shall recognize extensions which shall or may be critical. These extensions are: key usage (4.2.1.3), certificate policies (4.2.1.5), the alternative sub- ject name (4.2.1.7), issuer alternative name (4.2.1.8), basic con- straints (4.2.1.10), name constraints (4.2.1.11), policy constraints (4.2.1.12), and extended key usage (4.2.1.14). In addition, this profile recommends support for key identifiers (4.2.1.1 and 4.2.1.2), CRL distribution points (4.2.1.13), and authority information access (4.2.2.1). 4.2.1 Standard Extensions This section identifies standard certificate extensions defined in [X.509] for use in the Internet Public Key Infrastructure. Each extension is associated with an object identifier defined in [X.509]. These object identifiers are members of the certificateExtension arc, which is defined by the following: certificateExtension OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29} id-ce OBJECT IDENTIFIER ::= certificateExtension 4.2.1.1 Authority Key Identifier The authority key identifier extension provides a means of identify- ing the public key corresponding to the particular private key used to sign a certificate. This extension would be used where an issuer has multiple signing keys (either due to multiple concurrent key pairs or due to changeover). In general, this extension should be included in certificates. The identification can be based on either the key identifier (the subject key identifier in the issuer's certificate) or on the issuer name and serial number. The key identifier method is recommended in this profile. Conforming CAs that generate this extension shall include or omit both authorityCertIssuer and authorityCertSerial- Number. If authorityCertIssuer and authorityCertSerialNumber are omitted, the keyIdentifier field shall be present. This extension shall not be marked critical. id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 } AuthorityKeyIdentifier ::= SEQUENCE { keyIdentifier [0] KeyIdentifier OPTIONAL, authorityCertIssuer [1] GeneralNames OPTIONAL, authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL Housley, Ford, Polk, & Solo [Page 23] INTERNET DRAFT March 25, 1998 } KeyIdentifier ::= OCTET STRING 4.2.1.2 Subject Key Identifier The subject key identifier extension provides a means of identifying the particular public key used in an application. Where a reference to a public key identifier is needed (as with an Authority Key Iden- tifier) and one is not included in the associated certificate, a SHA-1 hash of the subject public key shall be used. The hash shall be calculated over the value (excluding tag and length) of the BIT STRING subjectPublicKey in the certificate. This extension should be marked non-critical. id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 14 } SubjectKeyIdentifier ::= KeyIdentifier 4.2.1.3 Key Usage The key usage extension defines the purpose (e.g., encipherment, sig- nature, certificate signing) of the key contained in the certificate. The usage restriction might be employed when a key that could be used for more than one operation is to be restricted. For example, when an RSA key should be used only for signing, the digitalSignature and nonRepudiation bits would be asserted. Likewise, when an RSA key should be used only for key management, the keyEncipherment bit would be asserted. The profile recommends that when used, this be marked as a critical extension. id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 } KeyUsage ::= BIT STRING { digitalSignature (0), nonRepudiation (1), keyEncipherment (2), dataEncipherment (3), keyAgreement (4), keyCertSign (5), cRLSign (6), encipherOnly (7), decipherOnly (8) } Bits in the KeyUsage type are used as follows: The digitalSignature bit is asserted when the subject public key Housley, Ford, Polk, & Solo [Page 24] INTERNET DRAFT March 25, 1998 is used to verifying digital signatures that have purposes other than non-repudiation, certificate signature, and CRL signature. For example, The digitalSignature bit is asserted when the subject public key is used to provide authentication. The nonRepudiation bit is asserted when the subject public key is used to verifying digital signatures used to provide a non- repudiation service which protects against the signing entity falsely denying some action, excluding certificate or CRL signing. The keyEncipherment bit is asserted when the subject public key is used for key transport. For example, when an RSA key is to be used exclusively for key management, then this bit must asserted. The dataEncipherment bit is asserted when the subject public key is used for enciphering user data, other than cryptographic keys. The keyAgreement bit is asserted when the subject public key is used for key agreement. For example, when a Diffie-Hellman key is to be used exclusively for key management, then this bit must asserted. The keyCertSign bit is asserted when the subject public key is used for verifying a signature on certificates. This bit may only be asserted in CA certificates. The cRLSign bit is asserted when the subject public key is used for verifying a signature on CRLs. This bit may only be asserted in CA certificates. When the encipherOnly bit is asserted and the keyAgreement bit is also set, the subject public key may be used only for enciphering data while performing key agreement. The meaning of the enci- pherOnly bit is undefined in the absence of the keyAgreement bit. When the decipherOnly bit is asserted and the keyAgreement bit is also set, the subject public key may be used only for deciphering data while performing key agreement. The meaning of the deci- pherOnly bit is undefined in the absence of the keyAgreement bit. This profile does not restrict the combinations the bits that may be set in an instantiation of the keyUsage extension. However, appropriate values for keyUsage extensions for particular algo- rithms are specifed in section 7.3. Housley, Ford, Polk, & Solo [Page 25] INTERNET DRAFT March 25, 1998 4.2.1.4 Private Key Usage Period The private key usage period extension allows the certificate issuer to specify a different validity period for the private key than the certificate. This extension is intended for use with digital signa- ture keys. This extension consists of two optional components notBe- fore and notAfter. The private key associated with the certificate should not be used to sign objects before or after the times speci- fied by the two components, respectively. CAs conforming to this pro- file shall not generate certificates with private key usage period extensions unless at least one of the two components is present. This profile recommends against the use of this extension. CAs con- forming to this profile shall not generate certificates with critical private key usage period extensions. Where used, notBefore and notAfter are represented as GeneralizedTime and shall be specified and interpreted as defined in Section 4.1.2.5.2. id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= { id-ce 16 } PrivateKeyUsagePeriod ::= SEQUENCE { notBefore [0] GeneralizedTime OPTIONAL, notAfter [1] GeneralizedTime OPTIONAL } 4.2.1.5 Certificate Policies The certificate policies extension contains a sequence of one or more policy information terms, each of which consists of an object iden- tifier (OID) and optional qualifiers. These policy information terms indicate the policy under which the certificate has been issued and the purposes for which the certificate may be used. This profile strongly recommends that a simple OID be present in this field. Optional qualifiers which may be present are expected to provide information about obtaining CA rules, not change the definition of the policy. Applications with specific policy requirements are expected to have a list of those policies which they will accept and to compare the pol- icy OIDs in the certificate to that list. If this extension is crit- ical, the path validation software must be able to interpret this extension, or must reject the certificate. (Applications without specific policy requirements are not required to list acceptable pol- icies, and may accept any valid certificate regardless of policy even if the extension is marked critical.) This specification defines two policy qualifiers types for use by certificate policy writers and certificate issuers at their own dis- cretion. The qualifier types are the CPS Pointer qualifier, and the Housley, Ford, Polk, & Solo [Page 26] INTERNET DRAFT March 25, 1998 User Notice qualifier. The CPS Pointer qualifier contains a pointer to a Certification Prac- tice Statement (CPS) published by the CA. The pointer is in the form of a URI. User notice is intended for display to a relying party when a certi- ficate is used. The application software should display all user notices in all certificates of the certification path used, except that if a notice is duplicated only one copy need be displayed. It is recommended that only the lowest-level certificate issued by one organization in a certification path contain a user notice. The user notice has two optional fields: the noticeRef field and the explicitText field. The noticeRef field, if used, names an organization and identi- fies, by number, a particular textual statement prepared by that organization. For example, it might identify the organization "CertsRUs" and notice number 1. In a typical implementation, the application software will have a notice file containing the current set of notices for CertsRUs; the application will extract the notice text from the file and display it. Messages may be multilingual, allowing the software to select the particular language message for its own environment. An explicitText field includes the textual statement directly in the certificate. The explicitText field is a string with a max- imum size of 200 characters. If both the noticeRef and explicitText options are included in the one qualifier and if the application software can locate the notice text indicated by the noticeRef option then that text should be displayed; otherwise, the explicitText string should be displayed. id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 } certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyInformation ::= SEQUENCE { policyIdentifier CertPolicyId, policyQualifiers SEQUENCE SIZE (1..MAX) OF PolicyQualifierInfo OPTIONAL } CertPolicyId ::= OBJECT IDENTIFIER PolicyQualifierInfo ::= SEQUENCE { policyQualifierId PolicyQualifierId, Housley, Ford, Polk, & Solo [Page 27] INTERNET DRAFT March 25, 1998 qualifier ANY DEFINED BY policyQualifierId } -- policyQualifierIds for Internet policy qualifiers id-qt ::= { id-pkix 2 } -- pkix arc for qualifier types id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 } id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 } PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice ) Qualifier ::= CHOICE { cPSuri CPSuri, userNotice UserNotice } CPSuri ::= IA5String UserNotice ::= SEQUENCE { noticeRef NoticeReference OPTIONAL, explicitText DisplayText OPTIONAL} NoticeReference ::= SEQUENCE { organization IA5String, noticeNumbers SEQUENCE OF INTEGER } DisplayText ::= CHOICE { visibleString VisibleString, bmpString BMPString, utf8String UTF8String } 4.2.1.6 Policy Mappings This extension is used in CA certificates. It lists one or more pairs of object identifiers; each pair includes an issuerDomainPolicy and a subjectDomainPolicy. The pairing indicates the issuing CA con- siders its issuerDomainPolicy equivalent to the subject CA's sub- jectDomainPolicy. The issuing CA's users may accept an issuerDomainPolicy for certain applications. The policy mapping tells the issuing CA's users which policies associated with the subject CA are comparable to the policy they accept. This extension may be supported by CAs and/or applications, and it is always non-critical. id-ce-policyMappings OBJECT IDENTIFIER ::= { id-ce 33 } Housley, Ford, Polk, & Solo [Page 28] INTERNET DRAFT March 25, 1998 PolicyMappings ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE { issuerDomainPolicy CertPolicyId, subjectDomainPolicy CertPolicyId } 4.2.1.7 Subject Alternative Name The subject alternative names extension allows additional identities to be bound to the subject of the certificate. Defined options include an rfc822 name (electronic mail address), a DNS name, an IP address, and a URI. Other options exist, including completely local definitions. Multiple instances of a name and multiple name forms may be included. Whenever such identities are to be bound into a certificate, the subject alternative name (or issuer alternative name) extension shall be used. (Note: a form of such an identifier may also be present in the subject distinguished name; however, the alternative name extension is the preferred location for finding such information.) Because the subject alternative name is considered to be defini- tiviely bound to the public key, all parts of the subject alternative name must be verified by the CA. In addition, subject alternative names shall not include wildcard characters as a placeholder for a set of names. Further, if the only subject identity included in the certificate is an alternative name form (e.g., an electronic mail address), then the subject distinguished name shall be empty (an empty sequence), and the subjectAltName extension shall be present. If the subject field contains an empty sequence, the subjectAltName extension shall be marked critical. Where the subjectAltName extension contains a uniformResourceIdentif- ier, the URI is a pointer to a sequence of certificates issued by this CA (and optionally other CAs) to this subject. The URI must be an absolute, not relative, pathname and must specify the host. This specification recognizes the following values for the URI scheme: ftp, http, ldap, and mailto. The mailto scheme indi- cates that mail sent to the specified address will generate an elec- tronic mail response (to the sender) containing the subject's certi- ficates. No message is required. If the URI scheme is ftp, then the information is available through anonymous ftp. If the URI scheme is http or ldap, then the information may be retrieved using that proto- col. (If the URI specifies any other scheme, contains a relative pathname, or omits the host, the semantics are not defined by this specifica- tion.) Housley, Ford, Polk, & Solo [Page 29] INTERNET DRAFT March 25, 1998 When the subjectAltName extension contains a iPAddress, the address shall be stored in the octet string in "network byte order," as specified in RFC791. The least significant bit (LSB) of each octet is the LSB of the corresponding byte in the network address. For IP Ver- sion 4, as specified in RFC 791, the octet string must contain exactly four octets. For IP Version 6, as specified in RFC 1883, the octet string must contain exactly sixteen octets. Alternative names may be constrained in the same manner as subject distinguished names using the name constraints extension as described in section 4.2.1.11. If the subjectAltName extension is present, the sequence must contain at least one entry. Unlike the subject field, conforming CAs shall not issue certificates with subjectAltNames containing empty General- Name fields. For example, an rfc822Name is represented as an IA5String. While an empty string is a valid IA5String, such an rfc822Name is not permitted by this profile. The behavior of clients that encounter such a certificate when processing a certificication path is not defined by this profile. id-ce-subjectAltName OBJECT IDENTIFIER ::= { id-ce 17 } SubjectAltName ::= GeneralNames GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName GeneralName ::= CHOICE { otherName [0] OtherName, rfc822Name [1] IA5String, dNSName [2] IA5String, x400Address [3] ORAddress, directoryName [4] Name, ediPartyName [5] EDIPartyName, uniformResourceIdentifier [6] IA5String, iPAddress [7] OCTET STRING, registeredID [8] OBJECT IDENTIFIER} OtherName ::= SEQUENCE { type-id OBJECT IDENTIFIER, value [0] EXPLICIT ANY DEFINED BY type-id } EDIPartyName ::= SEQUENCE { nameAssigner [0] DirectoryString OPTIONAL, partyName [1] DirectoryString } Housley, Ford, Polk, & Solo [Page 30] INTERNET DRAFT March 25, 1998 4.2.1.8 Issuer Alternative Name As with 4.2.1.7, this extension is used to associate Internet style identities with the certificate issuer. If the only issuer identity included in the certificate is an alternative name form (e.g., an electronic mail address), then the issuer distinguished name shall be empty (an empty sequence), and the issuerAltName extension shall be present. If the subject field contains an empty sequence, the issuerAltName extension shall be marked critical. Where the issuerAltName extension contains a URI, the following semantics shall be assumed: the URI is a pointer to an ASN.1 sequence of certificates issued to this CA (and optionally other CAs). The expected values for the URI are those defined in 4.2.1.7. Processing rules for other values are not defined by this specification. Where the issuerAltName extension contains a dNSName, rfc822Name, or a URI, wildcard characters are not permitted. id-ce-issuerAltName OBJECT IDENTIFIER ::= { id-ce 18 } IssuerAltName ::= GeneralNames 4.2.1.9 Subject Directory Attributes The subject directory attributes extension is not recommended as an essential part of this profile, but it may be used in local environ- ments. This extension is always non-critical. id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= { id-ce 9 } SubjectDirectoryAttributes ::= SEQUENCE SIZE (1..MAX) OF Attribute 4.2.1.10 Basic Constraints The basic constraints extension identifies whether the subject of the certificate is a CA and how deep a certification path may exist through that CA. The pathLenConstraint field is meaningful only if cA is set to TRUE. In this case, it gives the maximum number of CA certificates that may follow this certificate in a certification path. A value of zero indicates that only an end-entity certificate may follow in the path. Where it appears, the pathLenConstraint field must be greater than or equal to zero. Where pathLenConstraint does not appear, there is no limit to the allowed length of the certification path. This profile requires the use of this extension, and it shall always Housley, Ford, Polk, & Solo [Page 31] INTERNET DRAFT March 25, 1998 be critical for CA certificates. id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 } BasicConstraints ::= SEQUENCE { cA BOOLEAN DEFAULT FALSE, pathLenConstraint INTEGER (0..MAX) OPTIONAL } 4.2.1.11 Name Constraints The name constraints extension, which shall be used only in a CA cer- tificate, indicates a name space within which all subject names in subsequent certificates in a certification path must be located. Restrictions may apply to the subject distinguished name or subject alternative names. Restrictions are defined in terms of permitted or excluded name subtrees. Any name matching a restriction in the excludedSubtrees field is invalid regardless of information appearing in the permittedSubtrees. This extension must be critical. Within this profile, the minimum and maximum fields are not used with any name forms, thus minimum is always zero, and maximum is always absent. Restrictions for the rfc822, dNSName, and uri name forms are all expressed in terms of strings with wild card matching. An "*" is the wildcard character. For uris and rfc822 names, the restriction applies to the host part of the name. Examples would be foo.bar.com; www*.bar.com; *.xyz.com. Legacy implementations exist where an RFC 822 name is embeded in the subject distinguished name as a PKCS #9 e-mail attribute, which has the ASN.1 type EmailAddress. When rfc822 names are constrained, but the certificate does not include a subject alternative name, the rfc822 name constraint must be applied to PKCS #9 e-mail attributes in the subject distinguished name. The ASN.1 syntax for EmailAddress and the corresponding OID are supplied below. EmailAddress ::= IA5String pkcs-9 OBJECT IDENTIFIER ::= { iso(1) member-body(2) US(840) rsadsi(113549) pkcs(1) 9 } emailAddress OBJECT IDENTIFIER ::= { pkcs-9 1 } Restrictions of the form directoryName shall be applied to the sub- ject field in the certificate and to the subjectAltName extensions of type directoryName. Restrictions of the form x400Address shall be applied to subjectAltName extensions of type x400Address. Housley, Ford, Polk, & Solo [Page 32] INTERNET DRAFT March 25, 1998 The syntax and semantics for name constraints for otherName, ediPar- tyName, iPAddress, and registeredID are not defined by this specifi- cation. id-ce-nameConstraints OBJECT IDENTIFIER ::= { id-ce 30 } NameConstraints ::= SEQUENCE { permittedSubtrees [0] GeneralSubtrees OPTIONAL, excludedSubtrees [1] GeneralSubtrees OPTIONAL } GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree GeneralSubtree ::= SEQUENCE { base GeneralName, minimum [0] BaseDistance DEFAULT 0, maximum [1] BaseDistance OPTIONAL } BaseDistance ::= INTEGER (0..MAX) 4.2.1.12 Policy Constraints The policy constraints extension can be used in certificates issued to CAs. The policy constraints extension constrains path validation in two ways. It can be used to prohibit policy mapping or require that each certificate in a path contain an acceptable policy identif- ier. If the inhibitPolicyMapping field is present, the value indicates the number of additional certificates that may appear in the path before policy mapping is no longer permitted. For example, a value of one indicates that policy mapping may be processed in certificates issued by the subject of this certificate, but not in additional certifi- cates in the path. If the requireExplicitPolicy field is present, subsequent certifi- cates must include an acceptable policy identifier. The value of requireExplicitPolicy indicates the number of additional certificates that may appear in the path before an explicit policy is required. An acceptable policy identifier is the identifier of a policy required by the user of the certification path or the identifier of a policy which has been declared equivalent through policy mapping. Conforming CAs shall not issue certificates where policy constraints is a null sequence. That is, at least one of the inhibitPolicyMapping field or the requireExplicitPolicy field must be present. The behavior of clients that encounter a null policy constraints field is not addressed in this profile. Housley, Ford, Polk, & Solo [Page 33] INTERNET DRAFT March 25, 1998 This extension may be critical or non-critical. id-ce-policyConstraints OBJECT IDENTIFIER ::= { id-ce 36 } CertificatePoliciesSyntax ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyConstraints ::= SEQUENCE { requireExplicitPolicy [0] SkipCerts OPTIONAL, inhibitPolicyMapping [1] SkipCerts OPTIONAL } SkipCerts ::= INTEGER (0..MAX) 4.2.1.13 CRL Distribution Points The CRL distribution points extension identifies how CRL information is obtained. The extension should be non-critical, but this profile recommends support for this extension by CAs and applications. Further discussion of CRL management is contained in section 5. If the cRLDistributionPoints extension contains a Distribution- PointName of type URI, the following semantics shall be assumed: the URI is a pointer to the current CRL for the associated reasons and will be issued by the associated cRLIssuer. The expected values for the URI are those defined in 4.2.1.7. Processing rules for other values are not defined by this specification. If the distribution- Point omits reasons, the CRL shall include revocations for all rea- sons. If the distributionPoint omits cRLIssuer, the CRL shall be issued by the CA that issued the certificate. id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= { id-ce 31 } cRLDistributionPoints ::= { CRLDistPointsSyntax } CRLDistPointsSyntax ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer [2] GeneralNames OPTIONAL } DistributionPointName ::= CHOICE { fullName [0] GeneralNames, nameRelativeToCRLIssuer [1] RelativeDistinguishedName } ReasonFlags ::= BIT STRING { unused (0), Housley, Ford, Polk, & Solo [Page 34] INTERNET DRAFT March 25, 1998 keyCompromise (1), cACompromise (2), affiliationChanged (3), superseded (4), cessationOfOperation (5), certificateHold (6) } 4.2.1.14 Extended key usage field This field indicates one or more purposes for which the certified public key may be used, in addition to or in place of the basic pur- poses indicated in the key usage extension field. This field is defined as follows: id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37} ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId KeyPurposeId ::= OBJECT IDENTIFIER Key purposes may be defined by any organization with a need. Object identifiers used to identify key purposes shall be assigned in accor- dance with ITU-T Rec. X.660 | ISO/IEC 9834-1. This extension may, at the option of the certificate issuer, be either critical or non-critical. If the extension is flagged critical, then the certificate shall be used only for one of the purposes indicated. If the extension is flagged non-critical, then it indicates the intended purpose or purposes of the key, and may be used in finding the correct key/certificate of an entity that has multiple keys/certificates. It is an advisory field and does not imply that usage of the key is restricted by the certification authority to the purpose indicated. (Using applications may nevertheless require that a particular purpose be indicated in order for the certificate to be acceptable to that application.) If a certificate contains both a critical key usage field and a crit- ical extended key usage field, then both fields shall be processed independently and the certificate shall only be used for a purpose consistent with both fields. If there is no purpose consistent with both fields, then the certificate shall not be used for any purpose. The following key usage purposes are defined by this profile: id-kp OBJECT IDENTIFIER ::= { id-pkix 3 } Housley, Ford, Polk, & Solo [Page 35] INTERNET DRAFT March 25, 1998 id-kp-serverAuth OBJECT IDENTIFIER ::= {id-kp 1} -- TLS Web server authentication -- Key usage bits that may be consistent: digitalSignature, -- keyEncipherment or keyAgreement -- id-kp-clientAuth OBJECT IDENTIFIER ::= {id-kp 2} -- TLS Web client authentication -- Key usage bits that may be consistent: digitalSignature and/or -- keyAgreement -- id-kp-codeSigning OBJECT IDENTIFIER ::= {id-kp 3} -- Signing of downloadable executable code -- Key usage bits that may be consistent: digitalSignature -- id-kp-emailProtection OBJECT IDENTIFIER ::= {id-kp 4} -- E-mail protection -- Key usage bits that may be consistent: digitalSignature, -- nonRepudiation, and/or (keyEncipherment -- or keyAgreement) -- id-kp-ipsecEndSystem OBJECT IDENTIFIER ::= {id-kp 5} -- IP security end system (host or router) -- Key usage bits that may be consistent: digitalSignature and/or -- (keyEncipherment or keyAgreement) -- id-kp-ipsecTunnel OBJECT IDENTIFIER ::= {id-kp 6} -- IP security tunnel termination -- Key usage bits that may be consistent: digitalSignature and/or -- (keyEncipherment or keyAgreement) -- id-kp-ipsecUser OBJECT IDENTIFIER ::= {id-kp 7} -- IP security user -- Key usage bits that may be consistent: digitalSignature and/or -- (keyEncipherment or keyAgreement) id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 } -- Binding the hash of an object to a time from an agreed-upon time -- source. Key usage bits that may be consistent: digitalSignature, -- nonRepudiation 4.2.2 Private Internet Extensions This section defines one new extension for use in the Internet Public Key Infrastructure. This extension may be used to direct applica- tions to identify an on-line validation service supporting the issu- ing CA. As the information may be available in multiple forms, each extension is a sequence of IA5String values, each of which represents a URI. The URI implicitly specifies the location and format of the information and the method for obtaining the information. Housley, Ford, Polk, & Solo [Page 36] INTERNET DRAFT March 25, 1998 An object identifier is defined for the private extension. The object identifier associated with the private extension is defined under the arc id-pe within the id-pkix name space. Any future exten- sions defined for the Internet PKI will also be defined uder the arc id-pe. id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) } id-pe OBJECT IDENTIFIER ::= { id-pkix 1 } 4.2.2.1 Authority Information Access The authority information access extension indicates how to access CA information and services for the issuer of the certificate in which the extension appears. Information and services may include on-line validation services and CA policy data. (The location of CRLs is not specified in this extension; that information is provided by the cRLDistributionPoints extension.) This extension may be included in subject or CA certificates, and it is always non-critical. id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 } AuthorityInfoAccessSyntax ::= SEQUENCE SIZE (1..MAX) OF AccessDescription AccessDescription ::= SEQUENCE { accessMethod OBJECT IDENTIFIER, accessLocation GeneralName } id-ad OBJECT IDENTIFIER ::= { id-pkix 48 } id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 } id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 } Each entry in the sequence AuthorityInfoAccessSyntax describes the format and location of additional information about the CA who issued the certificate in which this extension appears. This profile defines an object identifier for the On-line Certificate Status Protocol (OCSP) that will be defined in [PKIXOCSP]. When id- ad-ocsp appears as accessMethod, the accessLocation field describes the on-line status server and the access protocol to obtain current certificate status information for the certificate containing this extension. Housley, Ford, Polk, & Solo [Page 37] INTERNET DRAFT March 25, 1998 This profile defines an object identifier to obtain a description of the CAs that have issued certificates superior to the CA that issued the certificate containing this extension. The referenced CA Issuers description is intended to aid certificate users in the selection of a certification path that terminates at a point trusted by the certi- ficate user. When id-ad-caIssuers appears as accessMethod, the accessLocation field describes the referenced description server and the access protocol to obtain referenced description. Additional access descriptors will likely be defined in the future. The authorityInfoAccess extension may be included in a PKCS 7 encap- sulation as an X.501 ATTRIBUTE. This attribute can then be used to locate certificates automatically rather than include the certifi- cates directly. The intended effect is to reduce the size of the encapsulated message or object. PKCS 9 identifies attributes for inclusion in PKCS 7, referencing X.520 standard attributes and defining additional attributes unique to PKCS 9. The attributes defined in X.520 are based on the defini- tion of ATTRIBUTE in ITU-T X.501 | ISO/IEC 9594-2. The following syntax defines authorityInfoAccess as an ATTRIBUTE suitable for inclusion in a PKCS #7 message: authorityInfoAccess ATTRIBUTE ::= { WITH SYNTAX authorityInfoAccessSyntax, ID id-pe-authorityInfoAccess } Other parts of the PKIX specifications [PKIXOCSP] [PKIXLDAP] estab- lish requirements on certificate retrieval mechanisms. It is expected that applications using the URI form of the authorityInfo field for such a purpose will: 1. Prepend a suitable HTTP retrieval primitive to the URL (e.g. "GET"). 2. Append a filename to the URL. 3. Use the result to retrieve a file containing the requested certi- ficate. 4. Use the authorityInfoAccess extension in that and subsequent cer- tificates to complete a certificate path. The filename will be formed as the IA5string representation of SHA1(Issuer DN | certificate serial number) concatenated with ".cer." The IA5String representation will display the SHA1 result as a Housley, Ford, Polk, & Solo [Page 38] INTERNET DRAFT March 25, 1998 hexidecimal number using digits and the lowercase letters 'a' through 'f.' The SignerInfo syntax of PKCS 7 provides the necessary informa- tion as issuerAndSerialNumber. The specified file will contain a single DER encoded certficate. 5 CRL and CRL Extensions Profile As described above, one goal of this X.509 v2 CRL profile is to foster the creation of an interoperable and reusable Internet PKI. To achieve this goal, guidelines for the use of extensions are speci- fied, and some assumptions are made about the nature of information included in the CRL. CRLs may be used in a wide range of applications and environments covering a broad spectrum of interoperability goals and an even broader spectrum of operational and assurance requirements. This profile establishes a common baseline for generic applications requiring broad interoperability. Emphasis is placed on support for X.509 v2 CRLs. The profile defines a baseline set of information that can be expected in every CRL. Also, the profile defines common locations within the CRL for frequently used attributes, and common representations for these attributes. This profile does not define any private Internet CRL extensions or CRL entry extensions. Environments with additional or special purpose requirements may build on this profile or may replace it. Conforming CAs are not required to issue CRLs if other revocation or status mechanisms are provided. Conforming CAs that issue CRLs are required to issue version 2 CRLs, and must include the date by which the next CRL will be issued in the nextUpdate field (Section 5.1.2.5). Conforming applications are required to process version 1 and 2 CRLs. 5.1 CRL Fields The X.509 v2 CRL syntax is as follows. For signature calculation, the data that is to be signed is ASN.1 DER encoded. ASN.1 DER encod- ing is a tag, length, value encoding system for each element. CertificateList ::= SEQUENCE { tbsCertList TBSCertList, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } Housley, Ford, Polk, & Solo [Page 39] INTERNET DRAFT March 25, 1998 TBSCertList ::= SEQUENCE { version Version OPTIONAL, -- if present, must be v2 signature AlgorithmIdentifier, issuer Name, thisUpdate Time, nextUpdate Time OPTIONAL, revokedCertificates SEQUENCE OF SEQUENCE { userCertificate CertificateSerialNumber, revocationDate Time, crlEntryExtensions Extensions OPTIONAL -- if present, must be v2 } OPTIONAL, crlExtensions [0] EXPLICIT Extensions OPTIONAL -- if present, must be v2 } -- Version, Time, CertificateSerialNumber and Extensions -- are all defined in the ASN.1 in section 4.1 AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } -- contains a value of the type -- registered for use with the -- algorithm object identifier value The following items describe the proposed use of the X.509 v2 CRL in the Internet PKI. 5.1.1 CertificateList Fields The CertificateList is a SEQUENCE of three required fields. The fields are are described in detail in the following subsections 5.1.1.1 tbsCertList The first field in the sequence is the tbsCertList. This field is itself a sequence containing the name of the issuer, issue date, issue date of the next list, the list of revoked certificates, and optional CRL extensions. Further, each entry on the revoked certifi- cate list is defined by a sequence of user certificate serial number, revocation date, and optional CRL entry extensions. Housley, Ford, Polk, & Solo [Page 40] INTERNET DRAFT March 25, 1998 5.1.1.2 signatureAlgorithm The signatureAlgorithm field contains the algorithm identifier for the algorithm used by the CA to sign the CertificateList. In the sigantureAlgorithm field, the contents of the optional parameters field shall be the value NULL. Section 7.2 lists the supported algo- rithms for this specification. Conforming CAs shall use the algo- rithm identifiers presented in Section 7.2 when signing with a sup- ported signature algorithm. 5.1.1.3 signature The signature field contains a digital signature computed upon the ASN.1 DER encoded TBSCertList. The ASN.1 DER encoded TBSCertList is used as the input to a one-way hash function. The one-way hash func- tion output value is encrypted (e.g., using RSA Encryption) to form the signed quantity. This signature value is then ASN.1 encoded as a BIT STRING and included in the CRL's signature field. The details of this process are specified for each of the supported algorithms in Section 7.2. 5.1.2 Certificate List "To Be Signed" The certificate list to be signed, or tBSCertList, is a SEQUENCE of required and optional fields. The required fields identify the CRL issuer, the algorithm used to sign the CRL, the date and time the CRL was issued, and the date and time by which the CA will issue the next CRL. Optional fields include lists of revoked certificates and CRL exten- sions. The revoked certificate list is optional to support the spe- cial case where a CA has not revoked any unexpired certificates it has issued. It is expected that nearly all CRLs issued in the Inter- net PKI will contain one or more lists of revoked certificates. Similarly, the profile requires conforming CAs to use the CRL exten- sion cRLNumber in all CRLs issued. 5.1.2.1 Version This optional field describes the version of the encoded CRL. When extensions are used, as expected in this profile, this field shall be present and shall specify version 2 (the integer value is 1). If neither CRL extensions nor CRL entry extensions are present, version 1 CRLs are recommended. In this case, the field shall be ommitted. Housley, Ford, Polk, & Solo [Page 41] INTERNET DRAFT March 25, 1998 5.1.2.2 Signature This field contains the algorithm identifier for the algorithm used to sign the CRL. Section 7.2 lists OIDs for the most popular signa- ture algorithms used in the Internet PKI. This field must contain the same algorithm identifier as the signa- tureAlgorithm field in the sequence CertificateList (see section 5.1.1.2). As with signatureAlgorithm, the parameters component shall contain the value NULL. 5.1.2.3 Issuer Name The issuer name identifies the entity who has signed (and issued the CRL). The issuer identity may be carried in the issuer name field and/or the issuerAltName extension. If identity information is present only in the issuerAltName extension, then the issuer name may be an empty sequence and the issuerAltName extension must be criti- cal. Where it is non-null, the issuer name field shall contain an X.500 distinguished name (DN). The issuer name field is defined as the X.501 type Name, and shall follow the encoding rules for the issuer name field in the certificate (see 4.1.2.4). 5.1.2.4 This Update This field indicates the issue date of this CRL. ThisUpdate may be encoded as UTCTime or GeneralizedTime. CAs conforming to this profile that issue CRLs shall encode thisUp- date as UTCTime for dates through the year 2049. CAs conforming to this profile that issue CRLs shall encode thisUpdate as Generalized- Time for dates in the year 2050 or later. Where encoded as UTCTime, thisUpdate shall be specified and inter- preted as defined in Section 4.1.2.5.1. Where encoded as General- izedTime, thisUpdate shall be specified and interpreted as defined in Section 4.1.2.5.2. 5.1.2.5 Next Update This field indicates the date by which the next CRL will be issued. The next CRL could be issued before the indicated date, but it will not be issued any later than the indicated date. nextUpdate may be encoded as UTCTime or GeneralizedTime. This profile requires inclusion of nextUpdate in all CRLs issued by Housley, Ford, Polk, & Solo [Page 42] INTERNET DRAFT March 25, 1998 conforming CAs. Note that the ASN.1 syntax of TBSCertList describes this field as OPTIONAL, which is consistent with the ASN.1 structure defined in [X.509]. The behavior of clients processing CRLs which omit nextUpdate is not specified by this profile. CAs conforming to this profile that issue CRLs shall encode nextUp- date as UTCTime for dates through the year 2049. CAs conforming to this profile that issue CRLs shall encode nextUpdate as Generalized- Time for dates in the year 2050 or later. Where encoded as UTCTime, nextUpdate shall be specified and inter- preted as defined in Section 4.1.2.5.1. Where encoded as General- izedTime, nextUpdate shall be specified and interpreted as defined in Section 4.1.2.5.2. 5.1.2.6 Revoked Certificates Revoked certificates are listed. The revoked certificates are named by their serial numbers. Certificates are uniquely identified by the combination of the issuer name or issuer alternative name along with the user certificate serial number. The date on which the revocation occurred is specified. The time for revocationDate shall be expressed as described in section 5.1.2.4. Additional information may be supplied in CRL entry extensions; CRL entry extensions are dis- cussed in section 5.3. 5.1.2.7 Extensions This field may only appear if the version number is 2 (see 5.1.2.1). If present, this field is a SEQUENCE of one or more CRL extensions. CRL extensions are discussed in section 5.2. 5.2 CRL Extensions The extensions defined by ANSI X9 and ISO for X.509 v2 CRLs [X.509] [X9.55] provide methods for associating additional attributes with CRLs. The X.509 v2 CRL format also allows communities to define private extensions to carry information unique to those communities. Each extension in a CRL may be designated as critical or non- critical. A CRL validation must fail if it encounters an critical extension which it does not know how to process. However, an unrecognized non-critical extension may be ignored. The following presents those extensions used within Internet CRLs. Communities may elect to include extensions in CRLs which are not defined in this specification. However, caution should be exercised in adopting any critical extensions in CRLs which might be used in a general context. Conforming CAs that issue CRLs are required to support the CRL number Housley, Ford, Polk, & Solo [Page 43] INTERNET DRAFT March 25, 1998 extension (5.2.3), and include it in all CRLs issued. Conforming applications are required to support the critical and optionally critical CRL extensions issuer alternative name (5.2.2), issuing dis- tribution point (5.2.4) and delta CRL indicator (5.2.5). 5.2.1 Authority Key Identifier The authority key identifier extension provides a means of identify- ing the particular public key used to sign a CRL. The identification can be based on either the key identifier (the subject key identifier in the CRL signer's certificate) or on the issuer name and serial number. The key identifier method is recommended in this profile. This extension would be used where an issuer has multiple signing keys, either due to multiple concurrent key pairs or due to change- over. In general, this non-critical extension should be included in certificates. The syntax for this CRL extension is defined in Section 4.2.1.1. 5.2.2 Issuer Alternative Name The issuer alternative names extension allows additional identities to be associated with the issuer of the CRL. Defined options include an rfc822 name (electronic mail address), a DNS name, an IP address, and a URI. Multiple instances of a name and multiple name forms may be included. Whenever such identities are used, the issuer alterna- tive name extension shall be used. Further, if the only issuer identity included in the CRL is an alter- native name form (e.g., an electronic mail address), then the issuer distinguished name should be empty (an empty sequence), the issuerAltName extension should be used, and the issuerAltName exten- sion must be marked critical. The object identifier and syntax for this CRL extension are defined in Section 4.2.1.8. 5.2.3 CRL Number The CRL number is a non-critical CRL extension which conveys a mono- tonically increasing sequence number for each CRL issued by a given CA through a specific CA X.500 Directory entry or CRL distribution point. This extension allows users to easily determine when a par- ticular CRL supersedes another CRL. CAs conforming to this profile shall include this extension in all CRLs. id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 } Housley, Ford, Polk, & Solo [Page 44] INTERNET DRAFT March 25, 1998 cRLNumber ::= INTEGER (0..MAX) 5.2.4 Issuing Distribution Point The issuing distribution point is a critical CRL extension that iden- tifies the CRL distribution point for a particular CRL, and it indi- cates whether the CRL covers revocation for end entity certificates only, CA certificates only, or a limitied set of reason codes. Since this extension is critical, all certificate users must be prepared to receive CRLs with this extension. The CRL is signed using the CA's private key. CRL Distribution Points do not have their own key pairs. If the CRL is stored in the X.500 Directory, it is stored in the Directory entry corresponding to the CRL distribution point, which may be different than the Directory entry of the CA. CAs may use CRL distribution points to partition the CRL on the basis of compromise and routine revocation. In this case, the revocations with reason code keyCompromise (1) shall appear in one distribution point, and the revocations with other reason codes shall appear in another distribution point. The reason codes associated with a dis- tribution point must be specified in onlySomeReasons. If onlySomeRea- sons does not appear, the distribution point must contain revocations for all reason codes. Where the issuingDistributionPoint extension contains a URL, the fol- lowing semantics shall be assumed: the object is a pointer to the most current CRL issued by this CA. The URI schemes ftp, http, mailto [RFC1738] and ldap [RFC1778] are defined for this purpose. The URI must be an absolute, not relative, pathname and must specify the host. id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= { id-ce 28 } issuingDistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, onlyContainsUserCerts [1] BOOLEAN DEFAULT FALSE, onlyContainsCACerts [2] BOOLEAN DEFAULT FALSE, onlySomeReasons [3] ReasonFlags OPTIONAL, indirectCRL [4] BOOLEAN DEFAULT FALSE } 5.2.5 Delta CRL Indicator The delta CRL indicator is a critical CRL extension that identifies a delta-CRL. The use of delta-CRLs can significantly improve process- ing time for applications which store revocation information in a format other than the CRL structure. This allows changes to be added Housley, Ford, Polk, & Solo [Page 45] INTERNET DRAFT March 25, 1998 to the local database while ignoring unchanged information that is already in the local database. When a delta-CRL is issued, the CAs shall also issue a complete CRL. The value of BaseCRLNumber identifies the CRL number of the base CRL that was used as the starting point in the generation of this delta- CRL. The delta-CRL contains the changes between the base CRL and the current CRL issued along with the delta-CRL. It is the decision of a CA as to whether to provide delta-CRLs. Again, a delta-CRL shall not be issued without a corresponding CRL. The value of CRLNumber for both the delta-CRL and the corresponding CRL shall be identical. A CRL user constructing a locally held CRL from delta-CRLs shall con- sider the constructed CRL incomplete and unusable if the CRLNumber of the received delta-CRL is more that one greater that the CRLnumber of the delta-CRL last processed. id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= { id-ce 27 } deltaCRLIndicator ::= BaseCRLNumber BaseCRLNumber ::= CRLNumber 5.2.6 Certificate Issuer This CRL entry extension identifies the certificate issuer associated with an entry in an indirect CRL, i.e. a CRL that has the indirectCRL indicator set in its issuing distribution point extension. If this extension is not present on the first entry in an indirect CRL, the certificate issuer defaults to the CRL issuer. On subsequent entries in an indirect CRL, if this extension is not present, the certificate issuer for the entry is the same as that for the preceding entry. This field is defined as follows: id-ce-certificateIssuer OBJECT IDENTIFIER ::= { id-ce 29 } certificateIssuer ::= GeneralNames If used by conforming CAs that issue CRLs, this extension is always critical. Conforming applications if an implementation ignored this extension it could not correctly attribute CRL entries to certifi- cates. 5.3 CRL Entry Extensions The CRL entry extensions already defined by ANSI X9 and ISO for X.509 v2 CRLs [X.509] [X9.55] provide methods for associating additional Housley, Ford, Polk, & Solo [Page 46] INTERNET DRAFT March 25, 1998 attributes with CRL entries. The X.509 v2 CRL format also allows communities to define private CRL entry extensions to carry informa- tion unique to those communities. Each extension in a CRL entry may be designated as critical or non-critical. A CRL validation must fail if it encounters a critical CRL entry extension which it does not know how to process. However, an unrecognized non-critical CRL entry extension may be ignored. The following presents recommended extensions used within Internet CRL entries and standard locations for information. Communities may elect to use additional CRL entry extensions; however, caution should be exercised in adopting any critical extensions in CRL entries which might be used in a general context. All CRL entry extensions are non-critical; support for these exten- sions is optional for conforming CAs and applications. However, CAs that issue CRLs are strongly encouraged to include reason codes (5.3.1) whenever this information is available. 5.3.1 Reason Code The reasonCode is a non-critical CRL entry extension that identifies the reason for the certificate revocation. CAs are strongly encouraged to include reason codes in CRL entries; however, the rea- son code CRL entry extension should be absent instead of using the unspecified (0) reasonCode value. id-ce-cRLReason OBJECT IDENTIFIER ::= { id-ce 21 } -- reasonCode ::= { CRLReason } CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), superseded (4), cessationOfOperation (5), certificateHold (6), removeFromCRL (8) } 5.3.2 Hold Instruction Code The hold instruction code is a non-critical CRL entry extension that provides a registered instruction identifier which indicates the action to be taken after encountering a certificate that has been placed on hold. id-ce-holdInstructionCode OBJECT IDENTIFIER ::= { id-ce 23 } Housley, Ford, Polk, & Solo [Page 47] INTERNET DRAFT March 25, 1998 holdInstructionCode ::= OBJECT IDENTIFIER The following instruction codes have been defined. Conforming appli- cations that process this extension shall recognize the following instruction codes. holdInstruction OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) x9-57(10040) 2 } id-holdinstruction-none OBJECT IDENTIFIER ::= {holdInstruction 1} id-holdinstruction-callissuer OBJECT IDENTIFIER ::= {holdInstruction 2} id-holdinstruction-reject OBJECT IDENTIFIER ::= {holdInstruction 3} Conforming applications which encounter a id-holdinstruction- callissuer must call the certificate issuer or reject the certifi- cate. Conforming applications which encounter a id-holdinstruction- reject ID shall reject the transaction. id-holdinstruction-none is semantically equivalent to the absence of a holdInstructionCode. Its use is strongly deprecated for the Internet PKI. 5.3.3 Invalidity Date The invalidity date is a non-critical CRL entry extension that pro- vides the date on which it is known or suspected that the private key was compromised or that the certificate otherwise became invalid. This date may be earlier than the revocation date in the CRL entry, but it must be later than the issue date of the previously issued CRL. Remember that the revocation date in the CRL entry specifies the date that the CA revoked the certificate. Whenever this informa- tion is available, CAs are strongly encouraged to share it with CRL users. The GeneralizedTime values included in this field shall be expressed in Greenwich Mean Time (Zulu), and shall be specified and interpreted as defined in Section 4.1.2.5.2. id-ce-invalidityDate OBJECT IDENTIFIER ::= { id-ce 24 } invalidityDate ::= GeneralizedTime 6 Certificate Path Validation Certification path validation procedures for the Internet PKI are based on Section 12.4.3 of [X.509]. Certification path processing verifies the binding between the subject distinguished name and sub- ject public key. The binding is limited by constraints which are specified in the certificates which comprise the path. The basic Housley, Ford, Polk, & Solo [Page 48] INTERNET DRAFT March 25, 1998 constraints and policy constraints extensions allow the certification path processing logic to automate the decision making process. This section describes an algorithm for validating certification paths. Conforming implementations of this specification are not required to implement this algorithm, but shall be functionally equivalent to the external behaviour resulting from this procedure. Any algorithm may be used by a particular implementation so long as it derives the correct result. The following text assumes that all valid paths begin with the public key of a single "most-trusted CA". The "most-trusted CA" is a matter of policy: it could be a root CA in a hierarchical PKI; the CA that issued the verifier's own certificate(s); or any other CA in a net- work PKI. The path validation procedure is the same regardless of the choice of "most-trusted CA." The text assumes that this public key is contained in a "self-signed" certificate. This simplifies the description of the path processing procedure. Note that the signature on the self-signed certificate does not provide any security services. The public key it contains is trusted because of other procedures used to obtain and protect it. The goal of path validation is to verify the binding between a sub- ject distinguished name and subject public key, as represented in the "end entity" certificate, based on the public key of the "most- trusted CA". This requires obtaining a sequence of certificates that support that binding. The procedures performed to obtain this sequence is outside the scope of this section. The following text also assumes that certificates do not use subject or unique identifier fields or private critical extensions, as recom- mended within this profile. However, if these components appear in certificates, they must be processed. Finally, policy qualifiers are also neglected for the sake of clarity. A certification path is a sequence of n certificates where: * for all x in {1,(n-1)}, the subject of certificate x is the issuer of certificate x+1. * certificate x=1 is the the self-signed certificate, and * certificate x=n is the end entity certificate. This section assumes the following inputs are provided to the path processing logic: (a) a certification path of length n; Housley, Ford, Polk, & Solo [Page 49] INTERNET DRAFT March 25, 1998 (b) a set of initial policy identifiers (each comprising a sequence of policy element identifiers), which identifies one or more certificate policies, any one of which would be acceptable for the purposes of certification path processing, or the special value "any-policy"; and (c) the current date/time (if not available internally to the certification path processing module). From the inputs, the procedure intializes five state variables: (a) acceptable policy set: A set of certificate policy identif- iers comprising the policy or policies recognized by the public key user together with policies deemed equivalent through policy mapping. The initial value of the acceptable policy set is the special value "any-policy". (b) constrained subtrees: A set of root names defining a set of subtrees within which all subject names in subsequent certificates in the certification path shall fall. The initial value is "unbounded". (c) excluded subtrees: A set of root names defining a set of subtrees within which no subject name in subsequent certificates in the certification path may fall. The initial value is "empty". (d) explicit policy: an integer which indicates if an explicit policy identifier is required. The integer indicates the first certificate in the path where this requirement is imposed. Once set, this variable may be decreased, but may not be increased. (That is, if a certificate in the path requires explicit policy identifiers, a later certificate can not remove this requirement.) The initial value is n+1. (e) policy mapping: an integer which indicates if policy mapping is permitted. The integer indicates the last certificate on which policy mapping may be applied. Once set, this variable may be decreased, but may not be increased. (That is, if a certificate in the path specifies policy mapping is not permitted, it can not be overriden by a later certificate.) The initial value is n+1. The actions performed by the path processing software for each certi- ficate i=1 through n are described below. The self-signed certifi- cate is certificate i=1, the end entity certificate is i=n. The pro- cessing is performed sequentially, so that processing certificate i affects the state variables for processing certificate (i+1). Note that actions (h) through (l) are not applied to the end entity certi- ficate (certificate n). Housley, Ford, Polk, & Solo [Page 50] INTERNET DRAFT March 25, 1998 The path processing actions to be performed are: (a) Verify the basic certificate information, including: (1) the certificate was signed using the subject public key from certificate i-1 (in the special case i=1, this step may be omitted; if not, use the subject public key from the same cer- tificate), (2) the certificate is not expired, and (if present) the private key usage period is satisfied, (3) the certificate has not been revoked (this may be deter- mined by obtaining current CRL, current status information, or by out-of-band mechanisms), and (4) the subject and issuer names chain correctly. (If the cer- tificate has an empty sequence in the name field, name chaining will use the critical subjectAltNames and issuerAltNames fields.) (b) Verify that the subject name or critical subjectAltName extension is consistent with the constrained subtrees state vari- ables; and (c) Verify that the subject name or critical subjectAltName extension is consistent with the excluded subtrees state vari- ables. (d) Verify that policy information is consistent with the initial policy set: (1) if the explicit policy state variable is less than or equal to i, a policy identifier in the certificate must be in the initial policy set; and (2) if the policy mapping variable is less than or equal to i, the policy identifier may not be mapped. (e) Verify that policy information is consistent with the accept- able policy set: (1) if the certificate policies extension is marked critical, the intersection of the policies extension and the acceptable policy set must be non-null; (2) the acceptable policy set is assigned the resulting inter- section as its new value. (g) Verify that the intersection of the acceptable policy set and Housley, Ford, Polk, & Solo [Page 51] INTERNET DRAFT March 25, 1998 the intial policy set is non-null. (h) Recognize and process any other critical extension present in the certificate. (i) Verify that the certificate is a CA certificate (as specified in a basicConstraints extension or as verified out-of-band). (j) If permittedSubtrees is present in the certificate, set the constrained subtrees state variable to the intersection of its previous value and the value indicated in the extension field. (k) If excludedSubtrees is present in the certificate, set the excluded subtrees state variable to the union of its previous value and the value indicated in the extension field. (l) If a policy constraints extension is included in the certifi- cate, modify the explicit policy and policy mapping state vari- ables as follows: (1) If requireExplicitPolicy is present and has value r, the explicit policy state variable is set to the minimum of (a) its current value and (b) the sum of r and i (the current certifi- cate in the sequence). (2) If inhibitPolicyMapping is present and has value q, the policy mapping state variable is set to the minimum of (a) its current value and (b) the sum of q and i (the current certifi- cate in the sequence). If any one of the above checks fail, the procedure terminates, returning a failure indication and an appropriate reason. If none of the above checks fail on the end-entity certificate, the procedure terminates, returning a success indication together with the set of all policy qualifier values encountered in the set of certificates. Notes: It is possible to specify an extended version of the above certification path processing procedure which results in default behaviour identical to the rules of Privacy Enhanced Mail [RFC 1422]. In this extended version, additional inputs to the procedure are a list of one or more Policy Certification Authoritys (PCAs) names and an indicator of the position in the certification path where the PCA is expected. At the nominated PCA position, the CA name is compared against this list. If a recognized PCA name is found, then a con- straint of SubordinateToCA is implicitly assumed for the remainder of the certification path and processing continues. If no valid PCA name is found, and if the certification path cannot be validated on the basis of identified policies, then the certification path is Housley, Ford, Polk, & Solo [Page 52] INTERNET DRAFT March 25, 1998 considered invalid. This procedure may also be extended by providing a set of self-signed certificates to the validation module. In this case, a valid path could begin with any one of the self-signed certificates. These self-signed certificates permit the path validation module to automatically incorporate local security policy and requirements. 7 Algorithm Support This section describes cryptographic algorithms which may be used with this standard. The section describes one-way hash functions and digital signature algorithms which may be used to sign certificates and CRLs, and identifies object identifiers for public keys contained in a certificate. Conforming CAs and applications are not required to support the algo- rithms or algorithm identifiers described in this section. However, this profile requires conforming CAs and applications to conform when they use the algorithms identified here. 7.1 One-way Hash Functions This section identifies one-way hash functions for use in the Inter- net PKI. One-way hash functions are also called message digest algo- rithms. SHA-1 is the preferred one-way hash function for the Internet PKI. However, PEM uses MD2 for certificates [RFC 1422] [RFC 1423] and MD5 is used in other legacy applications. For this reason, MD2 and MD5 are included in this profile. 7.1.1 MD2 One-way Hash Function MD2 was developed by Ron Rivest, but RSA Data Security has not placed the MD2 algorithm in the public domain. Rather, RSA Data Security has granted license to use MD2 for non-commercial Internet Privacy- Enhanced Mail. For this reason, MD2 may continue to be used with PEM certificates, but SHA-1 is preferred. MD2 is fully described in RFC 1319 [RFC 1319]. At the Selected Areas in Cryptography '95 conference in May 1995, Rogier and Chauvaud presented an attack on MD2 that can nearly find collisions [RC95]. Collisions occur when one can find two different messages that generate the same message digest. A checksum operation in MD2 is the only remaining obstacle to the success of the attack. For this reason, the use of MD2 for new applications is discouraged. It is still reasonable to use MD2 to verify existing signatures, as the ability to find collisions in MD2 does not enable an attacker to find new messages having a previously computed hash value. Housley, Ford, Polk, & Solo [Page 53] INTERNET DRAFT March 25, 1998 << More information on the attack and its implications can be obtained from a RSA Laboratories security bulletin. These bulletins are available from . >> 7.1.2 MD5 One-way Hash Function MD5 was developed by Ron Rivest in 1991. The algorithm takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input. The MD5 message dig- est algorithm is specified by RFC 1321, "The MD5 Message-Digest Algorithm"[RFC1321]. Den Boer and Bosselaers [DB94] have found pseudo-collisions for MD5, but there are no other known cryptanalytic results. The use of MD5 for new applications is discouraged. It is still reasonable to use MD5 to verify existing signatures. 7.1.3 SHA-1 One-way Hash Function SHA-1 was developed by the U.S. Government. The algorithm takes as input a message of arbitrary length and produces as output a 160-bit "hash" of the input. SHA-1 is fully described in FIPS 180-1 [FIPS 180-1]. SHA-1 is the one-way hash function of choice for use with both the RSA and DSA signature algorithms (see Section 7.2). 7.2 Signature Algorithms Certificates and CRLs described by this standard may be signed with any public key signature algorithm. The certificate or CRL indicates the algorithm through an algorithmidentifier which appears in the signatureAlgorithm field in a Certificate or CertificateList. This algorithmidentifier is an OID and has optionally associated parame- ters. This section identifies algorithm identifiers that shall be used in the signatureAlgorithm field in a Certificate or Certifi- cateList. RSA and DSA are the most popular signature algorithms used in the Internet. Signature algorithms are always used in conjunction with a one-way hash function identified in Section 7.1. The signature algorithm (and one-way hash function) used to sign a certificate or CRL is indicated by use of an algorithm identifier. An algorithm identifier is an object identifier, and may include associated parameters. This section identifies OIDS for RSA and DSA. The parameters component in signatureAlgorithm field of a Certificate or CertificateList shall always be present with a value of NULL. Housley, Ford, Polk, & Solo [Page 54] INTERNET DRAFT March 25, 1998 The data to be signed (e.g., the one-way hash function output value) is formatted for the signature algorithm to be used. Then, a private key operation (e.g., RSA encryption) is performed to generate the signature value. This signature value is then ASN.1 encoded as a BIT STRING and included in the Certificate or CertificateList (in the signature field). 7.2.1 RSA Signature Algorithm A patent statement regarding the RSA algorithm can be found at the end of this profile. The RSA algorithm is named for its inventors: Rivest, Shamir, and Adleman. This profile includes three signature algorithms based on the RSA asymmetric encryption algorithm. The signature algorithms combine RSA with either the MD2, MD5, or the SHA-1 one-way hash func- tions. The signature algorithm with MD2 and the RSA encryption algorithm is defined in PKCS #1 [PKCS#1]. As defined in PKCS #1, the ASN.1 object identifier used to identify this signature algorithm is: md2WithRSAEncryption OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 2 } The signature algorithm with MD5 and the RSA encryption algorithm is defined in PKCS #1 [PKCS#1]. As defined in PKCS #1, the ASN.1 object identifier used to identify this signature algorithm is: md5WithRSAEncryption OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 4 } The signature algorithm with SHA-1 and the RSA encryption algorithm is defined in by the OSI Interoperability Workshop in [OIW]. Padding conventions described in PKCS #1, section 8.1, must be used. As defined in [OIW], the ASN.1 object identifier used to identify this signature algorithm is: sha1WithRSASignature OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) oiw(14) secsig(3) algorithm(2) 29 } When any of these three object identifiers appears within the ASN.1 type AlgorithmIdentifier, the parameters component of that type shall be the ASN.1 type NULL. Housley, Ford, Polk, & Solo [Page 55] INTERNET DRAFT March 25, 1998 The data to be signed (e.g., the one-way hash function output value) is first ASN.1 encoded as an OCTET STRING and the result is encrypted (e.g., using RSA Encryption) to form the signed quantity. When sign- ing, the RSA algorithm generates an integer y. This signature value is then ASN.1 encoded as a BIT STRING, such that the most significant bit in y is the first bit in the bit string and the least significant bit in y is the last bit in the bit string, and included in the Cer- tificate or CertificateList (in the signature field). (In general the conversion to a bit string occurs in two steps. The integer y is converted to an octet string such that the first octet has the most significance and the last octet has the least signifi- cance. The octet string is converted into a bit string such that the most significant bit of the first octet shall become the first bit in the bit string, and the least significant bit of the last octet is the last bit in the BIT STRING.) 7.2.2 DSA Signature Algorithm A patent statement regarding the DSA can be found at the end of this profile. The Digital Signature Algorithm (DSA) is also called the Digital Sig- nature Standard (DSS). DSA was developed by the U.S. Government, and DSA is used in conjunction with the the SHA-1 one-way hash function. DSA is fully described in FIPS 186 [FIPS 186]. The ASN.1 object identifiers used to identify this signature algorithm are: id-dsa-with-sha1 ID ::= { iso(1) member-body(2) us(840) x9-57 (10040) x9cm(4) 3 } The id-dsa-with-sha1 algorithm syntax has NULL parameters. The DSA parameters in the subjectPublicKeyInfo field of the certificate of the issuer shall apply to the verification of the signature. If the subjectPublicKeyInfo AlgorithmIdentifier field has NULL param- eters and the CA signed the subject certificate using DSA, then the certificate issuer's parameters apply to the subject's DSA key. If the subjectPublicKeyInfo AlgorithmIdentifier field has NULL parame- ters and the CA signed the subject with a signature algorithm other than DSA, then clients shall not validate the certificate. When signing, the DSA algorithm generates two values. These values are commonly referred to as r and s. To easily transfer these two values as one signature, they shall be ASN.1 encoded using the fol- lowing ASN.1 structure: Housley, Ford, Polk, & Solo [Page 56] INTERNET DRAFT March 25, 1998 Dss-Sig-Value ::= SEQUENCE { r INTEGER, s INTEGER } 7.3 Subject Public Key Algorithms Certificates described by this standard may convey a public key for any public key algorithm. The certificate indicates the algorithm through an algorithmidentifier. This algorithm identfieier is an OID and optionally associated parameters. This section identifies preferred OIDs and parameters for the RSA, DSA, and Diffie-Hellman algorithms. Conforming CAs shall use the identified OIDs when issuing certificates containing public keys for these algorithms. Conforming applications supporting any of these algorithms shall, at a minimum, recognize the OID identified in this section. 7.3.1 RSA Keys The object identifier rsaEncryption identifies RSA public keys. pkcs-1 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 1 } rsaEncryption OBJECT IDENTIFIER ::= { pkcs-1 1} The rsaEncryption object identifier is intended to be used in the algorithm field of a value of type AlgorithmIdentifier. The parame- ters field shall have ASN.1 type NULL for this algorithm identifier. The rsa public key shall be encoded using the ASN.1 type RSAPub- licKey: RSAPublicKey ::= SEQUENCE { modulus INTEGER, -- n publicExponent INTEGER -- e } where modulus is the modulus n, and publicExponent is the public exponent e. The DER encoded RSAPublicKey is the value of the BIT STRING subjectPubliKey. This object identifier is used in public key certificates for both RSA signature keys and RSA encryption keys. The intended application for the key may be indicated in the key usage field (see Section 4.2.1.3). The use of a single key for both signature and encryption purposes is not recommended, but is not forbidden. Housley, Ford, Polk, & Solo [Page 57] INTERNET DRAFT March 25, 1998 If the keyUsage extension is present in an end entity certificate which conveys an RSA public key, any combination of the following values may be present: digitalSignature; nonRepudiation; keyEncipherment; and dataEncipherment. If the keyUsage extension is present in a CA certificate which con- veys an RSA public key, any combination of the following values may be present: digitalSignature; nonRepudiation; keyEncipherment; dataEncipherment; keyCertSign; and cRLSign. However, this specification recommends that if keyCertSign or cRLSign is present, both keyEncipherment and dataEncipherment should not be present. 7.3.2 Diffie-Hellman Key Exchange Key This diffie-hellman object identifier supported by this standard is defined by ANSI X9.42. dhpublicnumber OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-x942(10046) number-type(2) 1 } The dhpublicnumber object identifier is intended to be used in the algorithm field of a value of type AlgorithmIdentifier. The parame- ters field of that type, which has the algorithm-specific syntax ANY DEFINED BY algorithm, would have ASN.1 type DHParameter for this algorithm. DHParameter ::= SEQUENCE { prime INTEGER, -- p base INTEGER, -- g } The fields of type DHParameter have the following meanings: prime is the prime p. base is the base g. The Diffie-Hellman public key shall be ASN.1 encoded as an INTEGER; Housley, Ford, Polk, & Solo [Page 58] INTERNET DRAFT March 25, 1998 this encoding shall be used as the contents (i.e., the value) of the subjectPublicKey component (a BIT STRING) of the subjectPublicKeyInfo data element. DHPublicKey ::= INTEGER -- public key y = g^x mod p If the keyUsage extension is present in a certificate which conveys a DH public key, the following values may be present: keyAgreement; encipherOnly; and decipherOnly. At most one of encipherOnly and decipherOnly shall be asserted in keyUsage extension. 7.3.3 DSA Signature Keys The object identifier supported by this standard is id-dsa ID ::= { iso(1) member-body(2) us(840) x9-57(10040) x9cm(4) 1 } The id-dsa algorithm syntax includes optional parameters. These parameters are commonly referred to as p, q, and g. When omitted, the parameters component shall be present and have the value NULL. If the DSA algorithm parameters are absent from the subjectPublicKey- Info AlgorithmIdentifier and the CA signed the subject certificate using DSA, then the certificate issuer's DSA parameters apply to the subject's DSA key. If the DSA algorithm parameters are absent from the subjectPublicKeyInfo AlgorithmIdentifier and the CA signed the subject certificate using a signature algorithm other than DSA, then the subject's DSA parameters are distributed by other means. The parameters are included using the following ASN.1 structure: Dss-Parms ::= SEQUENCE { p INTEGER, q INTEGER, g INTEGER } If the subjectPublicKeyInfo AlgorithmIdentifier field has NULL param- eters and the CA signed the subject certificate using DSA, then the certificate issuer's parameters apply to the subject's DSA key. If the subjectPublicKeyInfo AlgorithmIdentifier field has NULL parame- ters and the CA signed the subject with a signature algorithm other than DSA, then clients shall not validate the certificate. Housley, Ford, Polk, & Solo [Page 59] INTERNET DRAFT March 25, 1998 When signing, DSA algorithm generates two values. These values are commonly referred to as r and s. To easily transfer these two values as one signature, they are ASN.1 encoded using the following ASN.1 structure: Dss-Sig-Value ::= SEQUENCE { r INTEGER, s INTEGER } The encoded signature is conveyed as the value of the BIT STRING sig- nature in a Certificate or CertificateList. The DSA public key shall be ASN.1 encoded as an INTEGER; this encod- ing shall be used as the contents (i.e., the value) of the sub- jectPublicKey component (a BIT STRING) of the SubjectPublicKeyInfo data element. DSAPublicKey ::= INTEGER -- public key Y If the keyUsage extension is present in an end entity certificate which conveys a DSA public key, any combination of the following values may be present: digitalSignature; and nonRepudiation. If the keyUsage extension is present in an CA certificate which con- veys a DSA public key, any combination of the following values may be present: digitalSignature; nonRepudiation; keyCertSign; and cRLSign. References [FIPS 180-1] Federal Information Processing Standards Publication (FIPS PUB) 180-1, Secure Hash Standard, 17 April 1995. [Supersedes FIPS PUB 180 dated 11 May 1993.] [FIPS 186] Federal Information Processing Standards Publication (FIPS PUB) 186, Digital Signature Standard, 18 May 1994. [OIW] Stable Implementation Agreements for Open Systems Interconnection Protocols: Part 12 - OS Security, Output from the June 1995 Open Systems Environment Housley, Ford, Polk, & Solo [Page 60] INTERNET DRAFT March 25, 1998 Implementors' Workshop (OIW). [PKCS#1] PKCS #1: RSA Encryption Standard, Version 1.4, RSA Data Security, Inc., 3 June 1991. [RC95] Rogier, N. and Chauvaud, P., "The compression function of MD2 is not collision free," Presented at Selected Areas in Cryptography '95, Carleton University, Ottawa, Canada, 18-19 May 1995. [RFC 791] J. Postel, "Internet Protocol", September 1981. [RFC 1319] Kaliski, B., "The MD2 Message-Digest Algorithm," RFC 1319, RSA Laboratories, April 1992. [RFC 1422] Kent, S., "Privacy Enhancement for Internet Electronic Mail: Part II: Certificate-Based Key Management," RFC 1422, BBN Communications, February 1993. [RFC 1423] Balenson, D., "Privacy Enhancement for Internet Electronic Mail: Part III: Algorithms, Modes, and Identifiers," RFC 1423, Trusted Information Systems, February 1993. [RFC 1738] T. Berners-Lee, L. Masinter & M. McCahill, "Uniform Resource Locators (URL)," December 1994. [RFC 1777] W. Yeong, T. Howes & S. Kille, "Lightweight Directory Access Protocol," March 1995. [RFC 1778] T. Howes, S. Kille, W. Yeong, C. Robbins, "The String Representation of Standard Attribute Syntaxes", March 1995. [RFC 1883] S. Deering, R. Hinden, "Internet Protocol, Version 6 (IPv6)," December 1995. [RFC 1959] T. Howes, M. Smith, "An LDAP URL Format", RFC 1959, June 1996. [RFC 2044] F. Yergeau, "UTF-8, a transformation format of Unicode and ISO 10646", October 1996. [RFC 2277] H. Alvestrand, "IETF Policy on Character Sets and Languages", January 1998. [RFC 2279] F. Yergeau, "UTF-8, a transformation format of ISO 10646", January 1998. [PKIXMGMT] C. Adams, S. Farrell, "Internet Public Key Infrastructure Housley, Ford, Polk, & Solo [Page 61] INTERNET DRAFT March 25, 1998 Certificate Management Protocols", draft-ietf-pkix-ipki3cmp-07.txt, February 1998. [PKIXLDAP] S. Boyeun, T. Howes and P. Richard "Internet Public Key Infrastructure Operational Protocols - LDAP", draft-ietf-pkix-ipki2opp-07.txt, March 1998. [PKIXOCSP] M. Myers, in "Internet Public Key Infrastructure Part 2: Operational Protocols", draft-ietf-pkix-ocsp-02.txt, February 1998. [PKIXFTP] R. Housley, "Internet Public Key Infrastructure Operational Protocols: FTP and HTTP", draft-ietf-pkix-opp-ftp-http-02.txt, November 1997. [SDN.701R] SDN.701, "Message Security Protocol", Revision 4.0 1996-06-07 with "Corrections to Message Security Protocol, SDN.701, Rev 4.0, 96-06-07." August 30, 1996. [X.208] CCITT Recommendation X.208: Specification of Abstract Syntax Notation One (ASN.1), 1988. [X.509] ITU-T Recommendation X.509 (1197 E): Information Technology - Open Systems Interconnection - The Directory: Authentication Framework, June 1997. [X9.55] ANSI X9.55-1995, Public Key Cryptography For The Financial Services Industry: Extensions To Public Key Certificates And Certificate Revocation Lists, 8 December, 1995. [X9.57] ANSI X9.57-199x, Public Key Cryptography For The Financial Services Industry: Certificate Management (Working Draft), 21 June, 1996. Patent Statements The Internet PKI relies on the use of patented public key technology and secure hash technology for digital signature services. This specification references public key encryption technology for provi- sioning key exchange services. This specification also permits the use of the cRLDistributionPoints extension to assist in the manage- ment of certificate revocation lists. The Internet Standards Process as defined in RFC 1310 requires a written statement from the Patent holder that a license will be made available to applicants under reasonable terms and conditions prior to approving a specification as a Proposed, Draft or Internet Stan- dard. Housley, Ford, Polk, & Solo [Page 62] INTERNET DRAFT March 25, 1998 Patent statements for DSA, RSA, Diffie-Hellman and one method for managing CRLs follow. These statements have been supplied by the patent holders, not the authors of this profile. The Internet Society, Internet Architecture Board, Internet Engineer- ing Steering Group and the Corporation for National Research Initia- tives take no position on the validity or scope of the following patents and patent applications, nor on the appropriateness of the terms of the assurance. The Internet Society and other groups men- tioned above have not made any determination as to any other intel- lectual property rights which may apply to the practice of this stan- dard. Any further consideration of these matters is the user's own responsibility. Digital Signature Algorithm (DSA) The U.S. Government holds patent 5,231,668 on the Digital Signa- ture Algorithm (DSA), which has been incorporated into Federal Information Processing Standard (FIPS) 186. The patent was issued on July 27, 1993. The National Institute of Standards and Technology (NIST) has a long tradition of supplying U.S. Government-developed techniques to committees and working groups for inclusion into standards on a royalty-free basis. NIST has made the DSA patent available royalty-free to users worldwide. Regarding patent infringement, FIPS 186 summarizes our position; the Department of Commerce is not aware of any patents that would be infringed by the DSA. Questions regarding this matter may be directed to the Deputy Chief Counsel for NIST. RSA Signature and Encryption The Massachusetts Institute of Technology has granted RSA Data Security, Inc., exclusive sub-licensing rights to the following patent issued in the United States: Cryptographic Communications System and Method ("RSA"), No. 4,405,829 RSA Data Security, Inc. has provided the following statement with regard to this patent: It is our understanding that the proposed PKIX Certificate Pro- file (PKIX-1) standard currently under review contemplates the use of U.S Patent 4,405,829 entitled "Cryptographic Communica- tion System and Method" (the "RSA patent") which patent is Housley, Ford, Polk, & Solo [Page 63] INTERNET DRAFT March 25, 1998 controlled by RSA. It is RSA's business practice to make licenses to its patents available on reasonable and nondiscriminatory terms. Accord- ingly, if the foregoing identified IETF standard is adopted, RSA is willing, upon request, to grant non-exclusive licenses to such patent on reasonable and non-discriminatory terms and conditions to those who respect RSA's intellectual property rights and subject to RSA's then current royalty rate for the patent licensed. The royalty rate for the RSA patent is presently set at 2% of the licensee's selling price for each product covered by the patent. Any requests for license infor- mation may be directed to: Director of Licensing RSA Data Security, Inc. 100 Marine Parkway, Suite 500 Redwood City, CA 94065 A license under RSA's patent(s) does not include any rights to know-how or other technical information or license under other intellectual property rights. Such license does not extend to any activities which constitute infringement or inducement thereto. A licensee must make his own determination as to whether a license is necessary under patents of others. Diffie-Hellman Key Agreement and Hellman-Merkle Public Key Cryptogra- phy Patent No. 4,200,770: Cryptographic Apparatus and Method ("Diffie- Hellman") expired on August 19, 1997. Patent No. 4,218,582: Public Key Cryptographic Apparatus and Method ("Hellman-Merkle") expired on April 29, 1997. Method for Efficient Management of Certificate Revocation Lists Entrust Technologies Limited advises the IETF that it holds the Patent (as defined herein) which may relate to the IETF. In accor- dance with the Intellectual Property rights procedures of the IETF standards process, Entrust Technologies Limited, for itself and its subsidiaries (hereinafter called Entrust) will offer licenses under its Patent on a non-exclusive basis and on non- discriminatory, fair and reasonable terms to all parties solely for their use in complying with the Standard, but on condition that any such party offers to Entrust and its corporate affiliates similar licenses under such partys patents, if any, for use in complying with the Standard and related IETF standards. Any application for a license under Entrusts Patent pursuant to this Patent Disclosure Statement should be made to: Housley, Ford, Polk, & Solo [Page 64] INTERNET DRAFT March 25, 1998 Stephen Samson Entrust Technologies Limited 8th Floor, 750 Heron Road, Ottawa, Ontario, Canada, K1V 1A7 As used herein: "Patent" means US Patent 5,699,431 issued on 16 December, 1997 for an invention known as a "Method for Efficient Management of Certi- ficate Revocation Lists and Update Information", which invention is owned or controlled by Entrust and the use of which may be required in conjunction with the Standard. "Standard" means a specification progressing through the Standard Track of the IETF and relating to the Public Key Infrastructure (X.509) specifications. GRANT OF RIGHTS FOR US PATENT 5,699,431 Purpose This grant is made to help facilitate inclusion of certain patented technology covered under US Patent 5,699,431 (herein called the Technology) in the Public Key Infrastructure (X.509) Standard (herein called the Standard). Entrust Technologies Lim- ited (herein called Entrust) offers the Technology to the IETF as a method for efficient management of Certificate Revocation Lists and Update Information. It should be noted that the confirmatory license mentioned is optional, since the grant of rights is automatic. Grant of Rights to Entrust Technologies US Patent 5,699,431 Entrust hereby covenants that it will not assert any claims in US Patent 5,699,431 any continuations, divisions, or continuations- in-part of either, or any non-US counterparts of any of the fore- going against any party that makes, uses, or offers a non- commercial implementation of an IETF specification that includes the Technology, or any continuation, division or continuation-in- part of that contribution, provided that contribution is employed to implement the Public Key Infrastructure (X.509) Standard. Such grant of rights is limited in that it does not include rights for commercialization of the Technology, including incorporating such Technology into commercial products. A license for commercial uses of the Technology must be applied for at the address written below. This grant of rights will permanently terminate with respect to Housley, Ford, Polk, & Solo [Page 65] INTERNET DRAFT March 25, 1998 any party (and to any affiliate of the party) that asserts a patent it owns or controls, either directly or indirectly, against Entrust or any of its affiliates for implementation of, or opera- tion of any system utilizing the Technology. The termination of rights will occur as of the date the patent is asserted against Entrust. Confirmatory License A written confirmation of this grant, and/or a license under any other patent under Entrust's then-current terms, conditions, and royalty rates, can be obtained by sending a request to: Stephen Samson Entrust Technologies Limited 8th Floor, 750 Heron Road, Ottawa, Ontario, Canada, K1V 1A7 Appendix A. Psuedo-ASN.1 Structures and OIDs This section describes data objects used by conforming PKI components in an "ASN.1-like" syntax. This syntax is a hybrid of the 1988 and 1993 ASN.1 syntaxes. The 1988 ASN.1 syntax is augmented with 1993 UNIVERSAL Types UniversalString, BMPString and UTF8String. The ASN.1 syntax does not permit the inclusion of type statements in the ASN.1 module, and the 1993 ASN.1 standard does not permit use of the new UNIVERSAL types in modules using the 1988 syntax. As a result, this module does not conform to either version of the ASN.1 standard. This appendix may be converted into 1988 ASN.1 by replacing the defintions for the UNIVERSAL Types with the 1988 catch-all "ANY". PKIX1 DEFINITIONS IMPLICIT TAGS::= BEGIN -- UNIVERSAL Types defined in '93 ASN.1 -- but required by this specification UniversalString ::= [UNIVERSAL 28] IMPLICIT OCTET STRING -- UniversalString is defined in ASN.1:1993 BMPString ::= [UNIVERSAL 30] IMPLICIT OCTET STRING -- BMPString is the subtype of -- UniversalString and models the Basic Multilingual Plane -- of ISO/IEC 10646-1 Housley, Ford, Polk, & Solo [Page 66] INTERNET DRAFT March 25, 1998 -- UNIVERSAL Type defined in draft '98 ASN.1 -- but required by this specification UTF8String ::= [UNIVERSAL 12] IMPLICIT OCTET STRING -- The content of this type conforms to RFC 2044. -- -- PKIX OIDs id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) } -- PKIX arcs -- arc for private certificate extensions id-pe OBJECT IDENTIFIER ::= { id-pkix 1 } -- arc for policy qualifier types id-qt OBJECT IDENTIFIER ::= { id-pkix 2 } -- arc for extended key purpose OIDS id-kp OBJECT IDENTIFIER ::= { id-pkix 3 } -- arc for access descriptors id-ad OBJECT IDENTIFIER ::= { id-pkix 48 } -- pkix private extensions id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 } -- policyQualifierIds for Internet policy qualifiers id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 } id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 } -- extended key purpose OIDs id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 } id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 } id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 } id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 } id-kp-ipsecEndSystem OBJECT IDENTIFIER ::= { id-kp 5 } id-kp-ipsecTunnel OBJECT IDENTIFIER ::= { id-kp 6 } id-kp-ipsecUser OBJECT IDENTIFIER ::= { id-kp 7 } id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 } -- access descriptors for authority info access extension id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 } id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 } -- attribute data types -- Attribute ::= SEQUENCE { type AttributeValue, Housley, Ford, Polk, & Solo [Page 67] INTERNET DRAFT March 25, 1998 values SET OF AttributeValue -- at least one value is required -- } AttributeType ::= OBJECT IDENTIFIER AttributeValue ::= ANY AttributeTypeAndValue ::= SEQUENCE { type AttributeType, value AttributeValue } -- naming data types -- Name ::= CHOICE { -- only one possibility for now -- rdnSequence RDNSequence } RDNSequence ::= SEQUENCE OF RelativeDistinguishedName DistinguishedName ::= RDNSequence RelativeDistinguishedName ::= SET SIZE (1 .. MAX) OF AttributeTypeAndValue -- Directory string type -- DirectoryString ::= CHOICE { teletexString TeletexString (SIZE (1..MAX)), printableString PrintableString (SIZE (1..MAX)), universalString UniversalString (SIZE (1..MAX)), utf8String UTF8String (SIZE (1..MAX)) bmpString BMPString (SIZE(1..MAX)) } -- certificate and CRL specific structures begin here Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= SEQUENCE { version [0] EXPLICIT Version DEFAULT v1, serialNumber CertificateSerialNumber, signature AlgorithmIdentifier, issuer Name, validity Validity, subject Name, subjectPublicKeyInfo SubjectPublicKeyInfo, Housley, Ford, Polk, & Solo [Page 68] INTERNET DRAFT March 25, 1998 issuerUniqueID [1] UniqueIdentifier OPTIONAL, -- If present, version must be v2 or v3 subjectUniqueID [2] UniqueIdentifier OPTIONAL, -- If present, version must be v2 or v3 extensions [3] EXPLICIT Extensions OPTIONAL -- If present, version must be v3 } Version ::= INTEGER { v1(0), v2(1), v3(2) } CertificateSerialNumber ::= INTEGER Validity ::= SEQUENCE { notBefore Time, notAfter Time } Time ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime } UniqueIdentifier ::= BIT STRING SubjectPublicKeyInfo ::= SEQUENCE { algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING } Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension Extension ::= SEQUENCE { extnID OBJECT IDENTIFIER, critical BOOLEAN DEFAULT FALSE, extnValue OCTET STRING } -- Extension ::= { {id-ce 15}, ... , keyUsage } ID ::= OBJECT IDENTIFIER joint-iso-ccitt ID ::= { 2 } ds ID ::= {joint-iso-ccitt 5} id-ce ID ::= {ds 29} AuthorityKeyIdentifier ::= SEQUENCE { keyIdentifier [0] KeyIdentifier OPTIONAL, authorityCertIssuer [1] GeneralNames OPTIONAL, authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL } ( WITH COMPONENTS {..., authorityCertIssuer PRESENT, authorityCertSerialNumber PRESENT} | WITH COMPONENTS {..., authorityCertIssuer ABSENT, Housley, Ford, Polk, & Solo [Page 69] INTERNET DRAFT March 25, 1998 authorityCertSerialNumber ABSENT} ) KeyIdentifier ::= OCTET STRING -- subjectKeyIdentifier ::= KeyIdentifier KeyUsage ::= BIT STRING { digitalSignature (0), nonRepudiation (1), keyEncipherment (2), dataEncipherment (3), keyAgreement (4), keyCertSign (5), cRLSign (6) } id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= { id-ce 16 } PrivateKeyUsagePeriod ::= SEQUENCE { notBefore [0] GeneralizedTime OPTIONAL, notAfter [1] GeneralizedTime OPTIONAL } ( WITH COMPONENTS {..., notBefore PRESENT} | WITH COMPONENTS {..., notAfter PRESENT} ) id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 } CertificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyInformation ::= SEQUENCE { policyIdentifier CertPolicyId, policyQualifiers SEQUENCE SIZE (1..MAX) OF PolicyQualifierInfo OPTIONAL } CertPolicyId ::= OBJECT IDENTIFIER PolicyQualifierInfo ::= SEQUENCE { policyQualifierId PolicyQualifierId, qualifier ANY DEFINED BY policyQualifierId } PolicyQualifierId ::= OBJECT IDENTIFIER id-ce-policyMappings OBJECT IDENTIFIER ::= { id-ce 33 } PolicyMappings ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE { issuerDomainPolicy CertPolicyId, subjectDomainPolicy CertPolicyId } id-ce-subjectAltName OBJECT IDENTIFIER ::= { id-ce 17 } Housley, Ford, Polk, & Solo [Page 70] INTERNET DRAFT March 25, 1998 SubjectAltName ::= GeneralNames GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName GeneralName ::= CHOICE { -- OTHER-NAME ::= TYPE-IDENTIFIER note: not supported in '88 ASN.1 otherName [0] AnotherName, rfc822Name [1] IA5String, dNSName [2] IA5String, x400Address [3] ORAddress, directoryName [4] Name, ediPartyName [5] EDIPartyName, uniformResourceIdentifier [6] IA5String, iPAddress [7] OCTET STRING, registeredID [8] OBJECT IDENTIFIER } AnotherName ::= SEQUENCE { type-id OBJECT IDENTIFIER, value [0] EXPLICIT ANY DEFINED BY type-id } EDIPartyName ::= SEQUENCE { nameAssigner [0] DirectoryString OPTIONAL, partyName [1] DirectoryString } id-ce-issuerAltName OBJECT IDENTIFIER ::= { id-ce 18 } IssuerAltName ::= GeneralNames id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= { id-ce 9 } SubjectDirectoryAttributes ::= SEQUENCE SIZE (1..MAX) OF Attribute id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 } BasicConstraints ::= SEQUENCE { cA BOOLEAN DEFAULT FALSE, pathLenConstraint INTEGER (0..MAX) OPTIONAL } id-ce-nameConstraints OBJECT IDENTIFIER ::= { id-ce 30 } NameConstraints ::= SEQUENCE { permittedSubtrees [0] GeneralSubtrees OPTIONAL, excludedSubtrees [1] GeneralSubtrees OPTIONAL } GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree GeneralSubtree ::= SEQUENCE { Housley, Ford, Polk, & Solo [Page 71] INTERNET DRAFT March 25, 1998 base GeneralName, minimum [0] BaseDistance DEFAULT 0, maximum [1] BaseDistance OPTIONAL } BaseDistance ::= INTEGER (0..MAX) id-ce-policyConstraints OBJECT IDENTIFIER ::= { id-ce 36 } PolicyConstraints ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE { requireExplicitPolicy [0] SkipCerts OPTIONAL, inhibitPolicyMapping [1] SkipCerts OPTIONAL } SkipCerts ::= INTEGER (0..MAX) -- cRLDistributionPoints CRLDistPointsSyntax ::= -- SEQUENCE SIZE (1..MAX) OF DistributionPoint CRLDistPointsSyntax ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer [2] GeneralNames OPTIONAL } DistributionPointName ::= CHOICE { fullName [0] GeneralNames, nameRelativeToCRLIssuer [1] RelativeDistinguishedName } ReasonFlags ::= BIT STRING { unused (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), superseded (4), cessationOfOperation (5), certificateHold (6) } id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37} ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId KeyPurposeId ::= OBJECT IDENTIFIER AuthorityInfoAccessSyntax ::= SEQUENCE SIZE (1..MAX) OF AccessDescription AccessDescription ::= SEQUENCE { accessMethod OBJECT IDENTIFIER, Housley, Ford, Polk, & Solo [Page 72] INTERNET DRAFT March 25, 1998 accessLocation GeneralName } -- CRL structures CertificateList ::= SEQUENCE { tbsCertList TBSCertList, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertList ::= SEQUENCE { version Version OPTIONAL, -- if present, must be v2 signature AlgorithmIdentifier, issuer Name, thisUpdate Time, nextUpdate Time OPTIONAL, revokedCertificates SEQUENCE OF SEQUENCE { userCertificate CertificateSerialNumber, revocationDate Time, crlEntryExtensions Extensions OPTIONAL -- if present, must be v2 } OPTIONAL, crlExtensions [0] EXPLICIT Extensions OPTIONAL -- if present, must be v2 } -- Version, Time, CertificateSerialNumber, and Extensions were -- defined earlier for use in the certificate structure AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } -- contains a value of the type -- registered for use with the -- algorithm object identifier value id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 } CRLNumber ::= INTEGER (0..MAX) id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= { id-ce 28 } IssuingDistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, onlyContainsUserCerts [1] BOOLEAN DEFAULT FALSE, onlyContainsCACerts [2] BOOLEAN DEFAULT FALSE, onlySomeReasons [3] ReasonFlags OPTIONAL, Housley, Ford, Polk, & Solo [Page 73] INTERNET DRAFT March 25, 1998 indirectCRL [4] BOOLEAN DEFAULT FALSE } id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= { id-ce 27 } -- deltaCRLIndicator ::= BaseCRLNumber id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 } BaseCRLNumber ::= CRLNumber id-ce-cRLReasons OBJECT IDENTIFIER ::= { id-ce 21 } CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), superseded (4), cessationOfOperation (5), certificateHold (6), removeFromCRL (8) } id-ce-certificateIssuer OBJECT IDENTIFIER ::= { id-ce 29 } CertificateIssuer ::= GeneralNames id-ce-holdInstructionCode OBJECT IDENTIFIER ::= { id-ce 23 } HoldInstructionCode ::= OBJECT IDENTIFIER -- ANSI x9 arc holdinstruction arc member-body ID ::= { iso 2 } us ID ::= { member-body 840 } x9cm ID ::= { us 10040 } holdInstruction ID ::= {x9cm 2} -- ANSI X9 holdinstructions referenced by this standard id-holdinstruction-none ID ::= {holdInstruction 1} id-holdinstruction-callissuer ID ::= {holdInstruction 2} id-holdinstruction-reject ID ::= {holdInstruction 3} id-ce-invalidityDate OBJECT IDENTIFIER ::= { id-ce 24 } InvalidityDate ::= GeneralizedTime Housley, Ford, Polk, & Solo [Page 74] INTERNET DRAFT March 25, 1998 -- Algorithm structures md2WithRSAEncryption OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 2 } md5WithRSAEncryption OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 4 } sha1WithRSASignature OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) oiw(14) secsig(3) algorithm(2) 29 } id-dsa-with-sha1 ID ::= { iso(1) member-body(2) us(840) x9-57 (10040) x9algorithm(4) 3 } Dss-Sig-Value ::= SEQUENCE { r INTEGER, s INTEGER } pkcs-1 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 1 } rsaEncryption OBJECT IDENTIFIER ::= { pkcs-1 1} dhpublicnumber OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-x942(10046) number-type(2) 1 } DHParameter ::= SEQUENCE { prime INTEGER, -- p base INTEGER -- g } id-dsa ID ::= { iso(1) member-body(2) us(840) x9-57(10040) x9algorithm(4) 1 } Dss-Parms ::= SEQUENCE { p INTEGER, q INTEGER, g INTEGER } id-keyEncryptionAlgorithm OBJECT IDENTIFIER ::= { 2 16 840 1 101 2 1 1 22 } KEA-Parms-Id ::= OCTET STRING Housley, Ford, Polk, & Solo [Page 75] INTERNET DRAFT March 25, 1998 id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 14 } id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 } id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 } CPSuri ::= IA5String UserNotice ::= CHOICE { visibleString VisibleString, bmpString BMPString } PresentationAddress ::= SEQUENCE { pSelector [0] EXPLICIT OCTET STRING OPTIONAL, sSelector [1] EXPLICIT OCTET STRING OPTIONAL, tSelector [2] EXPLICIT OCTET STRING OPTIONAL, nAddresses [3] EXPLICIT SET SIZE (1..MAX) OF OCTET STRING} -- x400 address syntax starts here -- OR Names ORAddressAndOrDirectoryName ::= ORName ORAddressAndOptionalDirectoryName ::= ORName ORName ::= [APPLICATION 0] SEQUENCE { -- address -- COMPONENTS OF ORAddress, directory-name [0] Name OPTIONAL } ORAddress ::= SEQUENCE { built-in-standard-attributes BuiltInStandardAttributes, built-in-domain-defined-attributes BuiltInDomainDefinedAttributes OPTIONAL, -- see also teletex-domain-defined-attributes extension-attributes ExtensionAttributes OPTIONAL } -- The OR-address is semantically absent from the OR-name if the -- built-in-standard-attribute sequence is empty and the -- built-in-domain-defined-attributes and extension-attributes are -- both omitted. -- Built-in Standard Attributes BuiltInStandardAttributes ::= SEQUENCE { country-name CountryName OPTIONAL, administration-domain-name AdministrationDomainName OPTIONAL, network-address [0] NetworkAddress OPTIONAL, -- see also extended-network-address terminal-identifier [1] TerminalIdentifier OPTIONAL, private-domain-name [2] PrivateDomainName OPTIONAL, organization-name [3] OrganizationName OPTIONAL, Housley, Ford, Polk, & Solo [Page 76] INTERNET DRAFT March 25, 1998 -- see also teletex-organization-name numeric-user-identifier [4] NumericUserIdentifier OPTIONAL, personal-name [5] PersonalName OPTIONAL, -- see also teletex-personal-name organizational-unit-names [6] OrganizationalUnitNames OPTIONAL -- see also teletex-organizational-unit-names -- } CountryName ::= [APPLICATION 1] CHOICE { x121-dcc-code NumericString (SIZE (ub-country-name-numeric-length)), iso-3166-alpha2-code PrintableString (SIZE (ub-country-name-alpha-length)) } AdministrationDomainName ::= [APPLICATION 2] CHOICE { numeric NumericString (SIZE (0..ub-domain-name-length)), printable PrintableString (SIZE (0..ub-domain-name-length)) } NetworkAddress ::= X121Address -- see also extended-network-address X121Address ::= NumericString (SIZE (1..ub-x121-address-length)) TerminalIdentifier ::= PrintableString (SIZE (1..ub-terminal-id-length)) PrivateDomainName ::= CHOICE { numeric NumericString (SIZE (1..ub-domain-name-length)), printable PrintableString (SIZE (1..ub-domain-name-length)) } OrganizationName ::= PrintableString (SIZE (1..ub-organization-name-length)) -- see also teletex-organization-name NumericUserIdentifier ::= NumericString (SIZE (1..ub-numeric-user-id-length)) PersonalName ::= SET { surname [0] PrintableString (SIZE (1..ub-surname-length)), given-name [1] PrintableString (SIZE (1..ub-given-name-length)) OPTIONAL, initials [2] PrintableString (SIZE (1..ub-initials-length)) OPTIONAL, generation-qualifier [3] PrintableString (SIZE (1..ub-generation-qualifier-length)) OPTIONAL} -- see also teletex-personal-name OrganizationalUnitNames ::= SEQUENCE SIZE (1..ub-organizational-units) OF OrganizationalUnitName -- see also teletex-organizational-unit-names Housley, Ford, Polk, & Solo [Page 77] INTERNET DRAFT March 25, 1998 OrganizationalUnitName ::= PrintableString (SIZE (1..ub-organizational-unit-name-length)) -- Built-in Domain-defined Attributes BuiltInDomainDefinedAttributes ::= SEQUENCE SIZE (1..ub-domain-defined-attributes) OF BuiltInDomainDefinedAttribute BuiltInDomainDefinedAttribute ::= SEQUENCE { type PrintableString (SIZE (1..ub-domain-defined-attribute-type-length)), value PrintableString (SIZE (1..ub-domain-defined-attribute-value-length))} -- Extension Attributes ExtensionAttributes ::= SET SIZE (1..ub-extension-attributes) OF ExtensionAttribute ExtensionAttribute ::= EXTENSION-ATTRIBUTE EXTENSION-ATTRIBUTE ::= SEQUENCE { extension-attribute-type [0] INTEGER (0..ub-extension-attributes), extension-attribute-value [1] ANY DEFINED BY extension-attribute-type } extensionAttributeTable EXTENSION-ATTRIBUTE ::= { common-name | teletex-common-name | teletex-organization-name | teletex-personal-name | teletex-organizational-unit-names | teletex-domain-defined-attributes | pds-name | physical-delivery-country-name | postal-code | physical-delivery-office-name | physical-delivery-office-number | extension-OR-address-components | physical-delivery-personal-name | physical-delivery-organization-name | extension-physical-delivery-address-components | unformatted-postal-address | street-address | post-office-box-address | poste-restante-address | unique-postal-name | local-postal-attributes | extended-network-address | terminal-type } Housley, Ford, Polk, & Solo [Page 78] INTERNET DRAFT March 25, 1998 -- Extension Standard Attributes common-name EXTENSION-ATTRIBUTE ::= {CommonName IDENTIFIED BY 1} CommonName ::= PrintableString (SIZE (1..ub-common-name-length)) teletex-common-name EXTENSION-ATTRIBUTE ::= {TeletexCommonName IDENTIFIED BY 2} TeletexCommonName ::= TeletexString (SIZE (1..ub-common-name-length)) teletex-organization-name EXTENSION-ATTRIBUTE ::= {TeletexOrganizationName IDENTIFIED BY 3} TeletexOrganizationName ::= TeletexString (SIZE (1..ub-organization-name-length)) teletex-personal-name EXTENSION-ATTRIBUTE ::= {TeletexPersonalName IDENTIFIED BY 4} TeletexPersonalName ::= SET { surname [0] TeletexString (SIZE (1..ub-surname-length)), given-name [1] TeletexString (SIZE (1..ub-given-name-length)) OPTIONAL, initials [2] TeletexString (SIZE (1..ub-initials-length)) OPTIONAL, generation-qualifier [3] TeletexString (SIZE (1..ub-generation-qualifier-length)) OPTIONAL } teletex-organizational-unit-names EXTENSION-ATTRIBUTE ::= {TeletexOrganizationalUnitNames IDENTIFIED BY 5} TeletexOrganizationalUnitNames ::= SEQUENCE SIZE (1..ub-organizational-units) OF TeletexOrganizationalUnitName TeletexOrganizationalUnitName ::= TeletexString (SIZE (1..ub-organizational-unit-name-length)) pds-name EXTENSION-ATTRIBUTE ::= {PDSName IDENTIFIED BY 7} PDSName ::= PrintableString (SIZE (1..ub-pds-name-length)) physical-delivery-country-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryCountryName IDENTIFIED BY 8} PhysicalDeliveryCountryName ::= CHOICE { x121-dcc-code NumericString (SIZE (ub-country-name-numeric-length)), iso-3166-alpha2-code PrintableString (SIZE (ub-country-name-alpha-length)) } Housley, Ford, Polk, & Solo [Page 79] INTERNET DRAFT March 25, 1998 postal-code EXTENSION-ATTRIBUTE ::= {PostalCode IDENTIFIED BY 9} PostalCode ::= CHOICE { numeric-code NumericString (SIZE (1..ub-postal-code-length)), printable-code PrintableString (SIZE (1..ub-postal-code-length)) } physical-delivery-office-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryOfficeName IDENTIFIED BY 10} PhysicalDeliveryOfficeName ::= PDSParameter physical-delivery-office-number EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryOfficeNumber IDENTIFIED BY 11} PhysicalDeliveryOfficeNumber ::= PDSParameter extension-OR-address-components EXTENSION-ATTRIBUTE ::= {ExtensionORAddressComponents IDENTIFIED BY 12} ExtensionORAddressComponents ::= PDSParameter physical-delivery-personal-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryPersonalName IDENTIFIED BY 13} PhysicalDeliveryPersonalName ::= PDSParameter physical-delivery-organization-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryOrganizationName IDENTIFIED BY 14} PhysicalDeliveryOrganizationName ::= PDSParameter extension-physical-delivery-address-components EXTENSION-ATTRIBUTE ::= {ExtensionPhysicalDeliveryAddressComponents IDENTIFIED BY 15} ExtensionPhysicalDeliveryAddressComponents ::= PDSParameter unformatted-postal-address EXTENSION-ATTRIBUTE ::= {UnformattedPostalAddress IDENTIFIED BY 16} UnformattedPostalAddress ::= SET { printable-address SEQUENCE SIZE (1..ub-pds-physical-address-lines) OF PrintableString (SIZE (1..ub-pds-parameter-length)) OPTIONAL, teletex-string TeletexString (SIZE (1..ub-unformatted-address-length)) OPTIONAL } street-address EXTENSION-ATTRIBUTE ::= {StreetAddress IDENTIFIED BY 17} Housley, Ford, Polk, & Solo [Page 80] INTERNET DRAFT March 25, 1998 StreetAddress ::= PDSParameter post-office-box-address EXTENSION-ATTRIBUTE ::= {PostOfficeBoxAddress IDENTIFIED BY 18} PostOfficeBoxAddress ::= PDSParameter poste-restante-address EXTENSION-ATTRIBUTE ::= {PosteRestanteAddress IDENTIFIED BY 19} PosteRestanteAddress ::= PDSParameter unique-postal-name EXTENSION-ATTRIBUTE ::= {UniquePostalName IDENTIFIED BY 20} UniquePostalName ::= PDSParameter local-postal-attributes EXTENSION-ATTRIBUTE ::= {LocalPostalAttributes IDENTIFIED BY 21} LocalPostalAttributes ::= PDSParameter PDSParameter ::= SET { printable-string PrintableString (SIZE(1..ub-pds-parameter-length)) OPTIONAL, teletex-string TeletexString (SIZE(1..ub-pds-parameter-length)) OPTIONAL } extended-network-address EXTENSION-ATTRIBUTE ::= {ExtendedNetworkAddress IDENTIFIED BY 22} ExtendedNetworkAddress ::= CHOICE { e163-4-address SEQUENCE { number [0] NumericString (SIZE (1..ub-e163-4-number-length)), sub-address [1] NumericString (SIZE (1..ub-e163-4-sub-address-length)) OPTIONAL }, psap-address [0] PresentationAddress } terminal-type EXTENSION-ATTRIBUTE ::= {TerminalType IDENTIFIED BY 23} TerminalType ::= INTEGER { telex (3), teletex (4), g3-facsimile (5), g4-facsimile (6), ia5-terminal (7), videotex (8) } (0..ub-integer-options) Housley, Ford, Polk, & Solo [Page 81] INTERNET DRAFT March 25, 1998 -- Extension Domain-defined Attributes teletex-domain-defined-attributes EXTENSION-ATTRIBUTE ::= {TeletexDomainDefinedAttributes IDENTIFIED BY 6} TeletexDomainDefinedAttributes ::= SEQUENCE SIZE (1..ub-domain-defined-attributes) OF TeletexDomainDefinedAttribute TeletexDomainDefinedAttribute ::= SEQUENCE { type TeletexString (SIZE (1..ub-domain-defined-attribute-type-length)), value TeletexString (SIZE (1..ub-domain-defined-attribute-value-length)) } -- specifications of Upper Bounds -- must be regarded as mandatory -- from Annex B of ITU-T X.411 -- Reference Definition of MTS Parameter Upper Bounds -- Upper Bounds ub-common-name-length INTEGER ::= 64 ub-country-name-alpha-length INTEGER ::= 2 ub-country-name-numeric-length INTEGER ::= 3 ub-domain-defined-attributes INTEGER ::= 4 ub-domain-defined-attribute-type-length INTEGER ::= 8 ub-domain-defined-attribute-value-length INTEGER ::= 128 ub-domain-name-length INTEGER ::= 16 ub-extension-attributes INTEGER ::= 256 ub-e163-4-number-length INTEGER ::= 15 ub-e163-4-sub-address-length INTEGER ::= 40 ub-generation-qualifier-length INTEGER ::= 3 ub-given-name-length INTEGER ::= 16 ub-initials-length INTEGER ::= 5 ub-integer-options INTEGER ::= 256 ub-numeric-user-id-length INTEGER ::= 32 ub-organization-name-length INTEGER ::= 64 ub-organizational-unit-name-length INTEGER ::= 32 ub-organizational-units INTEGER ::= 4 ub-pds-name-length INTEGER ::= 16 ub-pds-parameter-length INTEGER ::= 30 ub-pds-physical-address-lines INTEGER ::= 6 ub-postal-code-length INTEGER ::= 16 ub-surname-length INTEGER ::= 40 ub-terminal-id-length INTEGER ::= 24 ub-unformatted-address-length INTEGER ::= 180 ub-x121-address-length INTEGER ::= 16 -- Note - upper bounds on TeletexString are measured in characters. Housley, Ford, Polk, & Solo [Page 82] INTERNET DRAFT March 25, 1998 -- A significantly greater number of octets will be required to hold -- such a value. As a minimum, 16 octets, or twice the specified upper -- bound, whichever is the larger, should be allowed. END Appendix B. 1993 ASN.1 Structures and OIDs PKIX1 DEFINITIONS IMPLICIT TAGS::= BEGIN -- -- Proposed PKIX OIDs id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) } -- PKIX arcs -- arc for private certificate extensions id-pe OBJECT IDENTIFIER ::= { id-pkix 1 } -- arc for policy qualifier types id-qt OBJECT IDENTIFIER ::= { id-pkix 2 } -- arc for extended key purpose OIDS id-kp OBJECT IDENTIFIER ::= { id-pkix 3 } -- arc for access descriptors id-ad OBJECT IDENTIFIER ::= { id-pkix 48 } -- pkix private extensions id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 } -- policyQualifierIds for Internet policy qualifiers id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 } id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 } -- extended key purpose OIDs id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 } id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 } id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 } id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 } id-kp-ipsecEndSystem OBJECT IDENTIFIER ::= { id-kp 5 } id-kp-ipsecTunnel OBJECT IDENTIFIER ::= { id-kp 6 } id-kp-ipsecUser OBJECT IDENTIFIER ::= { id-kp 7 } id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 } -- access descriptors for authority info access extension id-ad-ocsp OBJECT IDENTIFIER ::= { id-ad 1 } Housley, Ford, Polk, & Solo [Page 83] INTERNET DRAFT March 25, 1998 id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 } -- attribute data types -- Attribute ::= SEQUENCE { type AttributeValue, values SET OF AttributeValue -- at least one value is required -- } AttributeType ::= OBJECT IDENTIFIER AttributeValue ::= ANY AttributeTypeAndValue ::= SEQUENCE { type AttributeType, value AttributeValue } AttributeValueAssertion ::= SEQUENCE {AttributeType, AttributeValue} -- naming data types -- Name ::= CHOICE { -- only one possibility for now -- rdnSequence RDNSequence } RDNSequence ::= SEQUENCE OF RelativeDistinguishedName DistinguishedName ::= RDNSequence RelativeDistinguishedName ::= SET SIZE (1 .. MAX) OF AttributeTypeAndValue -- Directory string type -- DirectoryString ::= CHOICE { teletexString TeletexString (SIZE (1..maxSize)), printableString PrintableString (SIZE (1..maxSize)), universalString UniversalString (SIZE (1..maxSize)), bmpString BMPString (SIZE(1..maxSIZE)) } -- from AuthenticationFramework -- {joint-iso-ccitt ds(5) modules(1) authenticationFramework(7) 2} -- note this module was defined with EXPLICIT TAGS -- types -- Certificate ::= EXPLICIT SIGNED {SEQUENCE{ version [0] Version DEFAULT v1, Housley, Ford, Polk, & Solo [Page 84] INTERNET DRAFT March 25, 1998 serialNumber CertificateSerialNumber, signature AlgorithmIdentifier, issuer Name, validity Validity, subject Name, subjectPublicKeyInfo SubjectPublicKeyInfo} issuerUniqueIdentifier [1] IMPLICIT UniqueIdentifier OPTIONAL, ---if present, version must be v1 or v2-- subjectUniqueIdentifier [2] IMPLICIT UniqueIdentifier OPTIONAL, ---if present, version must be v1 or v2-- extensions [3] Extensions Optional --if present, version must be v3--} } Version ::= INTEGER {v1(0), v2(1), v3(2) } CertificateSerialNumber ::= INTEGER Algorithmidentifier ::= SEQUENCE{ algorithm ALGORITHM.&id({SupportedAlgorithms}), parameters ALGORITHM.&Type({SupportedAlgorithms} { @algorithm}) OPTIONAL } -- Definition of the following information object is deferred. -- SupportedAlgorithms ALGORITHM ::= { ...|... } Validity ::= SEQUENCE{ notBefore Time, notAfter Time } Time ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime } SubjectPublicKeyInfo ::= SEQUENCE{ algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING} Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension Extension ::= SEQUENCE { extnId EXTENSION.&id ({ExtensionSet}), critical BOOLEAN DEFAULT FALSE, extnValue OCTET STRING -- contains a DER encoding of a value of type -- &ExtnType for the -- extension object identified by extnId -- -- Definition of the following information object set is deferred, Housley, Ford, Polk, & Solo [Page 85] INTERNET DRAFT March 25, 1998 -- The set is required to specify a table constraint on the critical -- component of Extension. -- ExtensionSet EXTENSION ::= { ... | ... } EXTENSION ::= CLASS { &id OBJECT IDENTIFIER UNIQUE, &ExtnType } WITH SYNTAX { SYNTAX &ExtnType IDENTIFIED BY &id } CertificateList ::= EXPLICIT SIGNED { SEQUENCE { version Version OPTIONAL, -- if present, must be v2 signature AlgorithmIdentifier, issuer Name, thisUpdate Time, nextUpdate Time OPTIONAL, revokedCertificates SEQUENCE OF SEQUENCE { userCertificate CertificateSerialNumber, revocationDate Time, crlEntryExtensions Extensions OPTIONAL } OPTIONAL, crlExtensions [0] Extensions OPTIONAL }} -- information object classes -- ALGORITHM ::= TYPE-IDENTIFIER -- Parameterized Types -- HASHED {ToBeHashed} ::= OCTET STRING ( CONSTRAINED-BY { --must be the result of applying a hashing procedure to the -- --DER-encoded octets of a value of -- ToBeHashed }) ENCRYPTED { ToBeEnciphered} := BIT STRING ( CONSTRAINED BY { --must be the result of applying an encipherment procedure to the -- --BER-encoded octets of a value of -- ToBeEnciphered }) SIGNED { ToBeSigned } ::= SEQUENCE{ ToBeSigned, COMPONENTS OF SIGNATURE { ToBeSigned }), SIGNATURE { OfSignature } ::= SEQUENCE { AlgorithmIdentifier, Housley, Ford, Polk, & Solo [Page 86] INTERNET DRAFT March 25, 1998 ENCRYPTED { HASHED { OfSignature }}} -- Key and policy information extensions -- authorityKeyIdentifier EXTENSION ::= { SYNTAX AuthorityKeyIdentifier IDENTIFIED BY { id-ce 35 } } AuthorityKeyIdentifier ::= SEQUENCE { keyIdentifier [0] KeyIdentifier OPTIONAL, authorityCertIssuer [1] GeneralNames OPTIONAL, authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL } ( WITH COMPONENTS {..., authorityCertIssuer PRESENT, authorityCertSerialNumber PRESENT} | WITH COMPONENTS {..., authorityCertIssuer ABSENT, authorityCertSerialNumber ABSENT} ) KeyIdentifier ::= OCTET STRING subjectKeyIdentifier EXTENSION ::= { SYNTAX SubjectKeyIdentifier IDENTIFIED BY { id-ce 14 } } SubjectKeyIdentifier ::= KeyIdentifier keyUsage EXTENSION ::= { SYNTAX KeyUsage IDENTIFIED BY { id-ce 15 } } KeyUsage ::= BIT STRING { digitalSignature (0), nonRepudiation (1), keyEncipherment (2), dataEncipherment (3), keyAgreement (4), keyCertSign (5), cRLSign (6) } privateKeyUsagePeriod EXTENSION ::= { SYNTAX PrivateKeyUsagePeriod IDENTIFIED BY { id-ce 16 } } PrivateKeyUsagePeriod ::= SEQUENCE { notBefore [0] GeneralizedTime OPTIONAL, notAfter [1] GeneralizedTime OPTIONAL } ( WITH COMPONENTS {..., notBefore PRESENT} | WITH COMPONENTS {..., notAfter PRESENT} ) Housley, Ford, Polk, & Solo [Page 87] INTERNET DRAFT March 25, 1998 certificatePolicies EXTENSION ::= { SYNTAX CertificatePoliciesSyntax IDENTIFIED BY { id-ce 32 } } CertificatePoliciesSyntax ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation PolicyInformation ::= SEQUENCE { policyIdentifier CertPolicyId, policyQualifiers SEQUENCE SIZE (1..MAX) OF PolicyQualifierInfo OPTIONAL } CertPolicyId ::= OBJECT IDENTIFIER PolicyQualifierInfo ::= SEQUENCE { policyQualifierId CERT-POLICY-QUALIFIER.&id ({SupportedPolicyQualifiers}), qualifier CERT-POLICY-QUALIFIER.&Qualifier ({SupportedPolicyQualifiers} {@policyQualifierId})OPTIONAL } SupportedPolicyQualifiers CERT-POLICY-QUALIFIER ::= { ... } CERT-POLICY-QUALIFIER ::= CLASS { &id OBJECT IDENTIFIER UNIQUE, &Qualifier OPTIONAL } WITH SYNTAX { POLICY-QUALIFIER-ID &id [QUALIFIER-TYPE &Qualifier] } policyMappings EXTENSION ::= { SYNTAX PolicyMappingsSyntax IDENTIFIED BY { id-ce 33 } } PolicyMappingsSyntax ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE { issuerDomainPolicy CertPolicyId, subjectDomainPolicy CertPolicyId } supportedAlgorithms ATTRIBUTE ::= { WITH SYNTAX SupportedAlgorithm EQUALITY MATCHING RULE algorithmIdentifierMatch ID { id-at 52 } } SupportedAlgorithm ::= SEQUENCE { algorithmIdentifier AlgorithmIdentifier, intendedUsage [0] KeyUsage OPTIONAL, intendedCertificatePolicies [1] CertificatePoliciesSyntax OPTIONAL } Housley, Ford, Polk, & Solo [Page 88] INTERNET DRAFT March 25, 1998 -- Certificate subject and certificate issuer attributes extensions -- subjectAltName EXTENSION ::= { SYNTAX GeneralNames IDENTIFIED BY { id-ce 17 } } GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName GeneralName ::= CHOICE { otherName [0] INSTANCE OF OTHER-NAME, rfc822Name [1] IA5String, dNSName [2] IA5String, x400Address [3] ORAddress, directoryName [4] Name, ediPartyName [5] EDIPartyName, uniformResourceIdentifier [6] IA5String, iPAddress [7] OCTET STRING, registeredID [8] OBJECT IDENTIFIER } OTHER-NAME ::= TYPE-IDENTIFIER EDIPartyName ::= SEQUENCE { nameAssigner [0] DirectoryString {ub-name} OPTIONAL, partyName [1] DirectoryString {ub-name} } issuerAltName EXTENSION ::= { SYNTAX GeneralNames IDENTIFIED BY { id-ce 18 } } subjectDirectoryAttributes EXTENSION ::= { SYNTAX AttributesSyntax IDENTIFIED BY { id-ce 9 } } AttributesSyntax ::= SEQUENCE SIZE (1..MAX) OF Attribute -- Certification path constraints extensions -- basicConstraints EXTENSION ::= { SYNTAX BasicConstraintsSyntax IDENTIFIED BY { id-ce 19 } } BasicConstraintsSyntax ::= SEQUENCE { cA BOOLEAN DEFAULT FALSE, pathLenConstraint INTEGER (0..MAX) OPTIONAL } nameConstraints EXTENSION ::= { SYNTAX NameConstraintsSyntax Housley, Ford, Polk, & Solo [Page 89] INTERNET DRAFT March 25, 1998 IDENTIFIED BY { id-ce 30 } } NameConstraintsSyntax ::= SEQUENCE { permittedSubtrees [0] GeneralSubtrees OPTIONAL, excludedSubtrees [1] GeneralSubtrees OPTIONAL } GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree GeneralSubtree ::= SEQUENCE { base GeneralName, minimum [0] BaseDistance DEFAULT 0, maximum [1] BaseDistance OPTIONAL } BaseDistance ::= INTEGER (0..MAX) policyConstraints EXTENSION ::= { SYNTAX PolicyConstraintsSyntax IDENTIFIED BY { id-ce 36 } } PolicyConstraints Syntax ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE { requireExplicitPolicy [0] SkipCerts OPTIONAL, inhibitPolicyMapping [1] SkipCerts OPTIONAL } SkipCerts ::= INTEGER (0..MAX) -- Basic CRL extensions -- cRLNumber EXTENSION ::= { SYNTAX CRLNumber IDENTIFIED BY { id-ce 20 } } CRLNumber ::= INTEGER (0..MAX) reasonCode EXTENSION ::= { SYNTAX CRLReason IDENTIFIED BY { id-ce 21 } } CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), superseded (4), cessationOfOperation (5), certificateHold (6), removeFromCRL (8) } instructionCode EXTENSION ::= { Housley, Ford, Polk, & Solo [Page 90] INTERNET DRAFT March 25, 1998 SYNTAX HoldInstruction IDENTIFIED BY { id-ce 23 } } HoldInstruction ::= OBJECT IDENTIFIER invalidityDate EXTENSION ::= { SYNTAX GeneralizedTime IDENTIFIED BY { id-ce 24 } } -- CRL distribution points and delta-CRL extensions -- cRLDistributionPoints EXTENSION ::= { SYNTAX CRLDistPointsSyntax IDENTIFIED BY { id-ce 31 } } CRLDistPointsSyntax ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer [2] GeneralNames OPTIONAL } DistributionPointName ::= CHOICE { fullName [0] GeneralNames, nameRelativeToCRLIssuer [1] RelativeDistinguishedName } ReasonFlags ::= BIT STRING { unused (0), keyCompromise (1), caCompromise (2), affiliationChanged (3), superseded (4), cessationOfOperation (5), certificateHold (6) } issuingDistributionPoint EXTENSION ::= { SYNTAX IssuingDistPointSyntax IDENTIFIED BY { id-ce 28 } } IssuingDistPointSyntax ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, onlyContainsUserCerts [1] BOOLEAN DEFAULT FALSE, onlyContainsCACerts [2] BOOLEAN DEFAULT FALSE, onlySomeReasons [3] ReasonFlags OPTIONAL, indirectCRL [4] BOOLEAN DEFAULT FALSE } certificateIssuer EXTENSION ::= { Housley, Ford, Polk, & Solo [Page 91] INTERNET DRAFT March 25, 1998 SYNTAX GeneralNames IDENTIFIED BY { id-ce 29 } } deltaCRLIndicator EXTENSION ::= { SYNTAX BaseCRLNumber IDENTIFIED BY { id-ce 27 } } BaseCRLNumber ::= CRLNumber deltaRevocationList ATTRIBUTE ::= { WITH SYNTAX CertificateList EQUALITY MATCHING RULE certificateListExactMatch ID {id-at 53 } } -- Object identifier assignments -- id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= {id-ce 9} id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= {id-ce 14} id-ce-keyUsage OBJECT IDENTIFIER ::= {id-ce 15} id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= {id-ce 16} id-ce-subjectAltName OBJECT IDENTIFIER ::= {id-ce 17} id-ce-issuerAltName OBJECT IDENTIFIER ::= {id-ce 18} id-ce-basicConstraints OBJECT IDENTIFIER ::= {id-ce 19} id-ce-cRLNumber OBJECT IDENTIFIER ::= {id-ce 20} id-ce-reasonCode OBJECT IDENTIFIER ::= {id-ce 21} id-ce-instructionCode OBJECT IDENTIFIER ::= {id-ce 23} id-ce-invalidityDate OBJECT IDENTIFIER ::= {id-ce 24} id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= {id-ce 27} id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= {id-ce 28} id-ce-certificateIssuer OBJECT IDENTIFIER ::= {id-ce 29} id-ce-nameConstraints OBJECT IDENTIFIER ::= {id-ce 30} id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= {id-ce 31} id-ce-certificatePolicies OBJECT IDENTIFIER ::= {id-ce 32} id-ce-policyMappings OBJECT IDENTIFIER ::= {id-ce 33} id-ce-policyConstraints OBJECT IDENTIFIER ::= {id-ce 36} id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= {id-ce 35} -- PKIX 1 extensions id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 } AuthorityInfoAccessSyntax ::= SEQUENCE SIZE (1..MAX) OF AccessDescription AccessDescription ::= SEQUENCE { accessMethod OBJECT IDENTIFIER, accessLocation GeneralName } Housley, Ford, Polk, & Solo [Page 92] INTERNET DRAFT March 25, 1998 CPSuri ::= IA5String UserNotice ::= CHOICE { visibleString VisibleString, bmpString BMPString } -- misc missing ASN.1 PresentationAddress ::= SEQUENCE { pSelector [0] EXPLICIT OCTET STRING OPTIONAL, sSelector [1] EXPLICIT OCTET STRING OPTIONAL, tSelector [2] EXPLICIT OCTET STRING OPTIONAL, nAddresses [3] EXPLICIT SET SIZE (1..MAX) OF OCTET STRING} -- The following OBJECT IDENTIFIERS are not used by this specification: -- {id-ce 2}, {id-ce 3}, {id-ce 4}, {id-ce 5}, {id-ce 6}, {id-ce 7}, -- {id-ce 8}, {id-ce 10}, {id-ce 11}, {id-ce 12}, {id-ce 13}, -- {id-ce 22}, {id-ce 25}, {id-ce 26} -- X.400, Algorithm Identifier, and maximum values Module ORAddressAndOrDirectoryName ::= ORName ORAddressAndOptionalDirectoryName ::= ORName ORName ::= [APPLICATION 0] SEQUENCE { -- address -- COMPONENTS OF ORAddress, directory-name [0] Name OPTIONAL } ORAddress ::= SEQUENCE { built-in-standard-attributes BuiltInStandardAttributes, built-in-domain-defined-attributes BuiltInDomainDefinedAttributes OPTIONAL, -- see also teletex-domain-defined-attributes extension-attributes ExtensionAttributes OPTIONAL } -- The OR-address is semantically absent from the OR-name if the -- built-in-standard-attribute sequence is empty and the -- built-in-domain-defined-attributes and extension-attributes are -- both omitted. -- Built-in Standard Attributes BuiltInStandardAttributes ::= SEQUENCE { country-name CountryName OPTIONAL, administration-domain-name AdministrationDomainName OPTIONAL, Housley, Ford, Polk, & Solo [Page 93] INTERNET DRAFT March 25, 1998 network-address [0] NetworkAddress OPTIONAL, -- see also extended-network-address terminal-identifier [1] TerminalIdentifier OPTIONAL, private-domain-name [2] PrivateDomainName OPTIONAL, organization-name [3] OrganizationName OPTIONAL, -- see also teletex-organization-name numeric-user-identifier [4] NumericUserIdentifier OPTIONAL, personal-name [5] PersonalName OPTIONAL, -- see also teletex-personal-name organizational-unit-names [6] OrganizationalUnitNames OPTIONAL -- see also teletex-organizational-unit-names -- } CountryName ::= [APPLICATION 1] CHOICE { x121-dcc-code NumericString (SIZE (ub-country-name-numeric-length)), iso-3166-alpha2-code PrintableString (SIZE (ub-country-name-alpha-length)) } AdministrationDomainName ::= [APPLICATION 2] CHOICE { numeric NumericString (SIZE (0..ub-domain-name-length)), printable PrintableString (SIZE (0..ub-domain-name-length)) } NetworkAddress ::= X121Address -- see also extended-network-address X121Address ::= NumericString (SIZE (1..ub-x121-address-length)) TerminalIdentifier ::= PrintableString (SIZE (1..ub-terminal-id-length)) PrivateDomainName ::= CHOICE { numeric NumericString (SIZE (1..ub-domain-name-length)), printable PrintableString (SIZE (1..ub-domain-name-length)) } OrganizationName ::= PrintableString (SIZE (1..ub-organization-name-length)) -- see also teletex-organization-name NumericUserIdentifier ::= NumericString (SIZE (1..ub-numeric-user-id-length)) PersonalName ::= SET { surname [0] PrintableString (SIZE (1..ub-surname-length)), given-name [1] PrintableString (SIZE (1..ub-given-name-length)) OPTIONAL, initials [2] PrintableString (SIZE (1..ub-initials-length)) OPTIONAL, generation-qualifier [3] PrintableString (SIZE (1..ub-generation-qualifier-length)) OPTIONAL} Housley, Ford, Polk, & Solo [Page 94] INTERNET DRAFT March 25, 1998 -- see also teletex-personal-name OrganizationalUnitNames ::= SEQUENCE SIZE (1..ub-organizational-units) OF OrganizationalUnitName -- see also teletex-organizational-unit-names OrganizationalUnitName ::= PrintableString (SIZE (1..ub-organizational-unit-name-length)) -- Built-in Domain-defined Attributes BuiltInDomainDefinedAttributes ::= SEQUENCE SIZE (1..ub-domain-defined-attributes) OF BuiltInDomainDefinedAttribute BuiltInDomainDefinedAttribute ::= SEQUENCE { type PrintableString (SIZE (1..ub-domain-defined-attribute-type-length)), value PrintableString (SIZE (1..ub-domain-defined-attribute-value-length)) } -- Extension Attributes ExtensionAttributes ::= SET SIZE (1..ub-extension-attributes) OF ExtensionAttribute ExtensionAttribute ::= SEQUENCE { extension-attribute-type [0] EXTENSION-ATTRIBUTE.&id ({ExtensionAttributeTable}), extension-attribute-value [1] EXTENSION-ATTRIBUTE.&Type ({ExtensionAttributeTable} {@extension-attribute-type}) } EXTENSION-ATTRIBUTE ::= CLASS { &id INTEGER (0..ub-extension-attributes) UNIQUE, &Type } WITH SYNTAX {&Type IDENTIFIED BY &id} ExtensionAttributeTable EXTENSION-ATTRIBUTE ::= { common-name | teletex-common-name | teletex-organization-name | teletex-personal-name | teletex-organizational-unit-names | teletex-domain-defined-attributes | pds-name | physical-delivery-country-name | postal-code | physical-delivery-office-name | physical-delivery-office-number | extension-OR-address-components | Housley, Ford, Polk, & Solo [Page 95] INTERNET DRAFT March 25, 1998 physical-delivery-personal-name | physical-delivery-organization-name | extension-physical-delivery-address-components | unformatted-postal-address | street-address | post-office-box-address | poste-restante-address | unique-postal-name | local-postal-attributes | extended-network-address | terminal-type } -- Extension Standard Attributes common-name EXTENSION-ATTRIBUTE ::= {CommonName IDENTIFIED BY 1} CommonName ::= PrintableString (SIZE (1..ub-common-name-length)) teletex-common-name EXTENSION-ATTRIBUTE ::= {TeletexCommonName IDENTIFIED BY 2} TeletexCommonName ::= TeletexString (SIZE (1..ub-common-name-length)) teletex-organization-name EXTENSION-ATTRIBUTE ::= {TeletexOrganizationName IDENTIFIED BY 3} TeletexOrganizationName ::= TeletexString (SIZE (1..ub-organization-name-length)) teletex-personal-name EXTENSION-ATTRIBUTE ::= {TeletexPersonalName IDENTIFIED BY 4} TeletexPersonalName ::= SET { surname [0] TeletexString (SIZE (1..ub-surname-length)), given-name [1] TeletexString (SIZE (1..ub-given-name-length)) OPTIONAL, initials [2] TeletexString (SIZE (1..ub-initials-length)) OPTIONAL, generation-qualifier [3] TeletexString (SIZE (1..ub-generation-qualifier-length)) OPTIONAL } teletex-organizational-unit-names EXTENSION-ATTRIBUTE ::= {TeletexOrganizationalUnitNames IDENTIFIED BY 5} TeletexOrganizationalUnitNames ::= SEQUENCE SIZE (1..ub-organizational-units) OF TeletexOrganizationalUnitName TeletexOrganizationalUnitName ::= TeletexString (SIZE (1..ub-organizational-unit-name-length)) Housley, Ford, Polk, & Solo [Page 96] INTERNET DRAFT March 25, 1998 pds-name EXTENSION-ATTRIBUTE ::= {PDSName IDENTIFIED BY 7} PDSName ::= PrintableString (SIZE (1..ub-pds-name-length)) physical-delivery-country-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryCountryName IDENTIFIED BY 8} PhysicalDeliveryCountryName ::= CHOICE { x121-dcc-code NumericString (SIZE (ub-country-name-numeric-length)), iso-3166-alpha2-code PrintableString (SIZE (ub-country-name-alpha-length)) } postal-code EXTENSION-ATTRIBUTE ::= {PostalCode IDENTIFIED BY 9} PostalCode ::= CHOICE { numeric-code NumericString (SIZE (1..ub-postal-code-length)), printable-code PrintableString (SIZE (1..ub-postal-code-length)) } physical-delivery-office-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryOfficeName IDENTIFIED BY 10} PhysicalDeliveryOfficeName ::= PDSParameter physical-delivery-office-number EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryOfficeNumber IDENTIFIED BY 11} PhysicalDeliveryOfficeNumber ::= PDSParameter extension-OR-address-components EXTENSION-ATTRIBUTE ::= {ExtensionORAddressComponents IDENTIFIED BY 12} ExtensionORAddressComponents ::= PDSParameter physical-delivery-personal-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryPersonalName IDENTIFIED BY 13} PhysicalDeliveryPersonalName ::= PDSParameter physical-delivery-organization-name EXTENSION-ATTRIBUTE ::= {PhysicalDeliveryOrganizationName IDENTIFIED BY 14} PhysicalDeliveryOrganizationName ::= PDSParameter extension-physical-delivery-address-components EXTENSION-ATTRIBUTE ::= {ExtensionPhysicalDeliveryAddressComponents IDENTIFIED BY 15} ExtensionPhysicalDeliveryAddressComponents ::= PDSParameter Housley, Ford, Polk, & Solo [Page 97] INTERNET DRAFT March 25, 1998 unformatted-postal-address EXTENSION-ATTRIBUTE ::= {UnformattedPostalAddress IDENTIFIED BY 16} UnformattedPostalAddress ::= SET { printable-address SEQUENCE SIZE (1..ub-pds-physical-address-lines) OF PrintableString (SIZE (1..ub-pds-parameter-length)) OPTIONAL, teletex-string TeletexString (SIZE (1..ub-unformatted-address-length)) OPTIONAL } street-address EXTENSION-ATTRIBUTE ::= {StreetAddress IDENTIFIED BY 17} StreetAddress ::= PDSParameter post-office-box-address EXTENSION-ATTRIBUTE ::= {PostOfficeBoxAddress IDENTIFIED BY 18} PostOfficeBoxAddress ::= PDSParameter poste-restante-address EXTENSION-ATTRIBUTE ::= {PosteRestanteAddress IDENTIFIED BY 19} PosteRestanteAddress ::= PDSParameter unique-postal-name EXTENSION-ATTRIBUTE ::= {UniquePostalName IDENTIFIED BY 20} UniquePostalName ::= PDSParameter local-postal-attributes EXTENSION-ATTRIBUTE ::= {LocalPostalAttributes IDENTIFIED BY 21} LocalPostalAttributes ::= PDSParameter PDSParameter ::= SET { printable-string PrintableString (SIZE(1..ub-pds-parameter-length)) OPTIONAL, teletex-string TeletexString (SIZE(1..ub-pds-parameter-length)) OPTIONAL } extended-network-address EXTENSION-ATTRIBUTE ::= {ExtendedNetworkAddress IDENTIFIED BY 22} ExtendedNetworkAddress ::= CHOICE { e163-4-address SEQUENCE { number [0] NumericString (SIZE (1..ub-e163-4-number-length)), sub-address [1] NumericString Housley, Ford, Polk, & Solo [Page 98] INTERNET DRAFT March 25, 1998 (SIZE (1..ub-e163-4-sub-address-length)) OPTIONAL}, psap-address [0] PresentationAddress } terminal-type EXTENSION-ATTRIBUTE ::= {TerminalType IDENTIFIED BY 23} TerminalType ::= INTEGER { telex (3), teletex (4), g3-facsimile (5), g4-facsimile (6), ia5-terminal (7), videotex (8) } (0..ub-integer-options) -- Extension Domain-defined Attributes teletex-domain-defined-attributes EXTENSION-ATTRIBUTE ::= {TeletexDomainDefinedAttributes IDENTIFIED BY 6} TeletexDomainDefinedAttributes ::= SEQUENCE SIZE (1..ub-domain-defined-attributes) OF TeletexDomainDefinedAttribute TeletexDomainDefinedAttribute ::= SEQUENCE { type TeletexString (SIZE (1..ub-domain-defined-attribute-type-length)), value TeletexString (SIZE (1..ub-domain-defined-attribute-value-length)) } -- specifications of Upper Bounds -- must be regarded as mandatory -- from Annex B of ITU-T X.411 -- Reference Definition of MTS Parameter Upper Bounds -- Upper Bounds ub-common-name-length INTEGER ::= 64 ub-country-name-alpha-length INTEGER ::= 2 ub-country-name-numeric-length INTEGER ::= 3 ub-domain-defined-attributes INTEGER ::= 4 ub-domain-defined-attribute-type-length INTEGER ::= 8 ub-domain-defined-attribute-value-length INTEGER ::= 128 ub-domain-name-length INTEGER ::= 16 ub-extension-attributes INTEGER ::= 256 ub-e163-4-number-length INTEGER ::= 15 ub-e163-4-sub-address-length INTEGER ::= 40 ub-generation-qualifier-length INTEGER ::= 3 ub-given-name-length INTEGER ::= 16 ub-initials-length INTEGER ::= 5 ub-integer-options INTEGER ::= 256 ub-numeric-user-id-length INTEGER ::= 32 Housley, Ford, Polk, & Solo [Page 99] INTERNET DRAFT March 25, 1998 ub-organization-name-length INTEGER ::= 64 ub-organizational-unit-name-length INTEGER ::= 32 ub-organizational-units INTEGER ::= 4 ub-pds-name-length INTEGER ::= 16 ub-pds-parameter-length INTEGER ::= 30 ub-pds-physical-address-lines INTEGER ::= 6 ub-postal-code-length INTEGER ::= 16 ub-surname-length INTEGER ::= 40 ub-terminal-id-length INTEGER ::= 24 ub-unformatted-address-length INTEGER ::= 180 ub-x121-address-length INTEGER ::= 16 -- Note - upper bounds on TeletexString are measured in characters. -- A significantly greater number of octets will be required to hold -- such a value. As a minimum, 16 octets, or twice the specified upper -- bound, whichever is the larger, should be allowed. END Appendix C. ASN.1 Notes The construct SEQUENCE SIZE (1..MAX) OF appears in several ASN.1 constructs. A valid ASN.1 sequence will have zero or more entries. The SIZE (1..MAX) construct constrains the sequence to have at least one entry. MAX indicates the upper bound is unspecified. Implementations are free to choose an upper bound that suits their environment. The construct positiveInt ::= INTEGER (0..MAX) defines positiveInt as a subtype of INTEGER containing integers greater than or equal to zero. The upper bound is unspecified. Implementations are free to select an upper bound that suits their environment. The character string type PrintableString supports a very basic Latin character set: the lower case letters 'a' through 'z', upper case letters 'A' through 'Z', the digits '0' through '9', eleven special characters ' " ( ) + , - . / : ? and space. The character string type TeletexString is a superset of Printable- String. TeletexString supports a fairly standard (ascii-like) Latin character set, Latin characters with non-spacing accents and Japanese Housley, Ford, Polk, & Solo [Page 100] INTERNET DRAFT March 25, 1998 characters. The character string type UniversalString supports any of the charac- ters allowed by ISO 10646-1. ISO 10646 is the Universal multiple- octet coded Character Set (UCS). ISO 10646-1 specifes the architec- ture and the "basic multilingual plane" - a large standard character set which includes all major world character standards. The character string type UTF8String will be introduced in the 1998 version of ASN.1. UTF8String is a universal type and has been assigned tag number 12. The content of UTF8String was defined by RFC 2044 and updated in RFC 2279, "UTF-8, a transformation Format of ISP 10646." ISO is expected to formally add UTF8String to the list of choices for DirectoryString in 1998 as well. In anticipation of these changes, and in conformance with IETF Best Practices codified in RFC 2277, IETF Policy on Character Sets and Languages, this document includes UTF8String as a choice in Directo- ryString and the CPS qualifier extensions. Appendix D. Examples This section contains four examples; three certificates and a CRL. The first two certificates and the CRL comprise a minimal certifica- tion path. Section D.1 contains two annotated hex dumps of a "self-signed" cer- tificate issued by a CA whose distinguished name is cn=us,o=gov,ou=nist. The certificate contains a DSA public key with parameters, and is signed by the corresponding DSA private key. The first hex dump is a basic dump of the ASN.1 encoding and does not not reflect the fact that the object is a certificate. The second dump identfies the values of the various certificate fields. Section D.2 contains an annotated hex dump of an end-entity certifi- cate. The end entity certificate contains a DSA public key, and is signed by the private key corresponding to the "self-signed" certifi- cate in section D.1. The first hex dump is a basic dump of the ASN.1 encoding and does not not reflect the fact that the object is a certificate. The second dump identfies the values of the various cer- tificate fields. Section D.3 contains a dump of an end entity certificate which con- tains an RSA public key and is signed with RSA and MD5. (This certi- ficate is not part of the minimal certification path.) Section D.4 contains an annotated hex dump of a CRL. The CRL is issued by the CA whose distinguished name is cn=us,o=gov,ou=nist and Housley, Ford, Polk, & Solo [Page 101] INTERNET DRAFT March 25, 1998 the list of revoked certifcates includes the end entity certificate presented in D.2. The hex dump is a basic dump of the ASN.1 encod- ing. D.1 Certificate This section contains an annotated hex dump of a 662 byte version 3 certificate. The certificate contains the following information: (a) the serial number is 17 (11 hex); (b) the certificate is signed with DSA and the SHA-1 hash algorithm; (c) the issuer's distinguished name is OU=nist;O=gov;C=US (d) and the subject's distinguished name is OU=nist;O=gov;C=US (e) the certificate was issued on June 30, 1997 and will expire on December 31, 1997; (f) the certificate contains a 1024 bit DSA public key; and (g) the certificate is a CA certificate (as indicated through the basic constraints extension.) D.1.1 ASN.1 Dump of "Self-Signed" Certificate get 0, len=662 (662 bytes in file) 0000 30 82 02 92 658: SEQUENCE 0004 30 82 02 52 594: . SEQUENCE 0008 a0 03 3: . . [0] 0010 02 01 1: . . . INTEGER 2 0013 02 01 1: . . INTEGER 17 0016 30 09 9: . . SEQUENCE 0018 06 07 7: . . . OID 1.2.840.10040.4.3: dsa-with-sha 0027 30 2a 42: . . SEQUENCE 0029 31 0b 11: . . . SET 0031 30 09 9: . . . . SEQUENCE 0033 06 03 3: . . . . . OID 2.5.4.6: C 0038 13 02 2: . . . . . PrintableString 'US' 0042 31 0c 12: . . . SET 0044 30 0a 10: . . . . SEQUENCE 0046 06 03 3: . . . . . OID 2.5.4.10: O 0051 13 03 3: . . . . . PrintableString 'gov' 0056 31 0d 13: . . . SET 0058 30 0b 11: . . . . SEQUENCE 0060 06 03 3: . . . . . OID 2.5.4.11: OU 0065 13 04 4: . . . . . PrintableString 'nist' 0071 30 1e 30: . . SEQUENCE 0073 17 0d 13: . . . UTCTime '970630000000Z' 0088 17 0d 13: . . . UTCTime '971231000000Z' 0103 30 2a 42: . . SEQUENCE 0105 31 0b 11: . . . SET 0107 30 09 9: . . . . SEQUENCE 0109 06 03 3: . . . . . OID 2.5.4.6: C Housley, Ford, Polk, & Solo [Page 102] INTERNET DRAFT March 25, 1998 0114 13 02 2: . . . . . PrintableString 'US' 0118 31 0c 12: . . . SET 0120 30 0a 10: . . . . SEQUENCE 0122 06 03 3: . . . . . OID 2.5.4.10: O 0127 13 03 3: . . . . . PrintableString 'gov' 0132 31 0d 13: . . . SET 0134 30 0b 11: . . . . SEQUENCE 0136 06 03 3: . . . . . OID 2.5.4.11: OU 0141 13 04 4: . . . . . PrintableString 'nist' 0147 30 82 01 b4 436: . . SEQUENCE 0151 30 82 01 29 297: . . . SEQUENCE 0155 06 07 7: . . . . OID 1.2.840.10040.4.1: dsa 0164 30 82 01 1c 284: . . . . SEQUENCE 0168 02 81 80 128: . . . . . INTEGER : d4 38 02 c5 35 7b d5 0b a1 7e 5d 72 59 63 55 d3 : 45 56 ea e2 25 1a 6b c5 a4 ab aa 0b d4 62 b4 d2 : 21 b1 95 a2 c6 01 c9 c3 fa 01 6f 79 86 83 3d 03 : 61 e1 f1 92 ac bc 03 4e 89 a3 c9 53 4a f7 e2 a6 : 48 cf 42 1e 21 b1 5c 2b 3a 7f ba be 6b 5a f7 0a : 26 d8 8e 1b eb ec bf 1e 5a 3f 45 c0 bd 31 23 be : 69 71 a7 c2 90 fe a5 d6 80 b5 24 dc 44 9c eb 4d : f9 da f0 c8 e8 a2 4c 99 07 5c 8e 35 2b 7d 57 8d 0299 02 14 20: . . . . . INTEGER : a7 83 9b f3 bd 2c 20 07 fc 4c e7 e8 9f f3 39 83 : 51 0d dc dd 0321 02 81 80 128: . . . . . INTEGER : 0e 3b 46 31 8a 0a 58 86 40 84 e3 a1 22 0d 88 ca : 90 88 57 64 9f 01 21 e0 15 05 94 24 82 e2 10 90 : d9 e1 4e 10 5c e7 54 6b d4 0c 2b 1b 59 0a a0 b5 : a1 7d b5 07 e3 65 7c ea 90 d8 8e 30 42 e4 85 bb : ac fa 4e 76 4b 78 0e df 6c e5 a6 e1 bd 59 77 7d : a6 97 59 c5 29 a7 b3 3f 95 3e 9d f1 59 2d f7 42 : 87 62 3f f1 b8 6f c7 3d 4b b8 8d 74 c4 ca 44 90 : cf 67 db de 14 60 97 4a d1 f7 6d 9e 09 94 c4 0d 0452 03 81 84 132: . . . BIT STRING (0 unused bits) : 02 81 80 aa 98 ea 13 94 a2 db f1 5b 7f 98 2f 78 : e7 d8 e3 b9 71 86 f6 80 2f 40 39 c3 da 3b 4b 13 : 46 26 ee 0d 56 c5 a3 3a 39 b7 7d 33 c2 6b 5c 77 : 92 f2 55 65 90 39 cd 1a 3c 86 e1 32 eb 25 bc 91 : c4 ff 80 4f 36 61 bd cc e2 61 04 e0 7e 60 13 ca : c0 9c dd e0 ea 41 de 33 c1 f1 44 a9 bc 71 de cf : 59 d4 6e da 44 99 3c 21 64 e4 78 54 9d d0 7b ba : 4e f5 18 4d 5e 39 30 bf e0 d1 f6 f4 83 25 4f 14 : aa 71 e1 0587 a3 0d 13: . . [3] 0589 30 0b 11: . . . SEQUENCE 0591 30 09 9: . . . . SEQUENCE 0593 06 03 3: . . . . . OID 2.5.29.19: basicConstraints Housley, Ford, Polk, & Solo [Page 103] INTERNET DRAFT March 25, 1998 0598 04 02 2: . . . . . OCTET STRING : 30 00 0602 30 09 9: . SEQUENCE 0604 06 07 7: . . OID 1.2.840.10040.4.3: dsa-with-sha 0613 03 2f 47: . BIT STRING (0 unused bits) : 30 2c 02 14 a0 66 c1 76 33 99 13 51 8d 93 64 2f : ca 13 73 de 79 1a 7d 33 02 14 5d 90 f6 ce 92 4a : bf 29 11 24 80 28 a6 5a 8e 73 b6 76 02 68 ------- extensions ---------- printber -s 456 pkix-ex1.ber get 0, len=131 (662 bytes in file) 0000 02 81 80 128: INTEGER : aa 98 ea 13 94 a2 db f1 5b 7f 98 2f 78 e7 d8 e3 : b9 71 86 f6 80 2f 40 39 c3 da 3b 4b 13 46 26 ee : 0d 56 c5 a3 3a 39 b7 7d 33 c2 6b 5c 77 92 f2 55 : 65 90 39 cd 1a 3c 86 e1 32 eb 25 bc 91 c4 ff 80 : 4f 36 61 bd cc e2 61 04 e0 7e 60 13 ca c0 9c dd : e0 ea 41 de 33 c1 f1 44 a9 bc 71 de cf 59 d4 6e : da 44 99 3c 21 64 e4 78 54 9d d0 7b ba 4e f5 18 : 4d 5e 39 30 bf e0 d1 f6 f4 83 25 4f 14 aa 71 e1 D.1.2 Pretty Print of "Self-Signed" Certificate ---------- decode: 0-OK, len=662 (662 bytes in file) Version: v3 Serial Number: 17 Signature Alg: dsa-with-sha (1.2.840.10040.4.3) Issuer: C=US, O=gov, OU=nist Validity: from 970630000000Z to 971231000000Z Subject: OU=nist, O=gov, C=US SubjectPKInfo: dsa (1.2.840.10040.4.1) params: 02 81 80 d4 38 02 c5 35 7b d5 0b a1 7e 5d 72 59 63 55 d3 45 56 ea e2 25 1a 6b c5 a4 ab aa 0b d4 62 b4 d2 21 b1 95 a2 c6 01 c9 c3 fa 01 6f 79 86 83 3d 03 61 e1 f1 92 ac bc 03 4e 89 a3 c9 53 4a f7 e2 a6 48 cf 42 1e 21 b1 5c 2b 3a 7f ba be 6b 5a f7 0a 26 d8 8e 1b eb ec bf 1e 5a 3f 45 c0 bd 31 23 be 69 71 a7 c2 90 fe a5 d6 80 b5 24 dc 44 9c eb 4d f9 da f0 c8 e8 a2 4c 99 07 5c 8e 35 2b 7d 57 8d 02 14 a7 83 9b f3 bd 2c 20 07 fc 4c e7 Housley, Ford, Polk, & Solo [Page 104] INTERNET DRAFT March 25, 1998 e8 9f f3 39 83 51 0d dc dd 02 81 80 0e 3b 46 31 8a 0a 58 86 40 84 e3 a1 22 0d 88 ca 90 88 57 64 9f 01 21 e0 15 05 94 24 82 e2 10 90 d9 e1 4e 10 5c e7 54 6b d4 0c 2b 1b 59 0a a0 b5 a1 7d b5 07 e3 65 7c ea 90 d8 8e 30 42 e4 85 bb ac fa 4e 76 4b 78 0e df 6c e5 a6 e1 bd 59 77 7d a6 97 59 c5 29 a7 b3 3f 95 3e 9d f1 59 2d f7 42 87 62 3f f1 b8 6f c7 3d 4b b8 8d 74 c4 ca 44 90 cf 67 db de 14 60 97 4a d1 f7 6d 9e 09 94 c4 0d Public Key: 00 02 81 80 aa 98 ea 13 94 a2 db f1 5b 7f 98 2f 78 e7 d8 e3 b9 71 86 f6 80 2f 40 39 c3 da 3b 4b 13 46 26 ee 0d 56 c5 a3 3a 39 b7 7d 33 c2 6b 5c 77 92 f2 55 65 90 39 cd 1a 3c 86 e1 32 eb 25 bc 91 c4 ff 80 4f 36 61 bd cc e2 61 04 e0 7e 60 13 ca c0 9c dd e0 ea 41 de 33 c1 f1 44 a9 bc 71 de cf 59 d4 6e da 44 99 3c 21 64 e4 78 54 9d d0 7b ba 4e f5 18 4d 5e 39 30 bf e0 d1 f6 f4 83 25 4f 14 aa 71 e1 issuerUID: subjectUID: 1 extensions: Exten 1: basicConstraints (2.5.29.19) 30 00 Signature Alg: dsa-with-sha (1.2.840.10040.4.3) Sig Value: 368 bits: 30 2c 02 14 a0 66 c1 76 33 99 13 51 8d 93 64 2f ca 13 73 de 79 1a 7d 33 02 14 5d 90 f6 ce 92 4a bf 29 11 24 80 28 a6 5a 8e 73 b6 76 02 68 ------- extensions ---------- printber -s 616 pkix-ex1.ber get 0, len=46 (662 bytes in file) 0000 30 2c 44: SEQUENCE 0002 02 14 20: . INTEGER : 9d 2d 0c 75 ec ce 01 79 25 4c cd 7b dc fc 17 0e : 0f 2a 22 ef 0024 02 14 20: . INTEGER : 80 61 6f fb dc 71 cf 3f 09 62 b4 aa ad 4b 8c 28 : 68 d7 60 fe Housley, Ford, Polk, & Solo [Page 105] INTERNET DRAFT March 25, 1998 D.2 Certificate This section contains an annotated hex dump of a xxx byte version 3 certificate. The certificate contains the following information: (a) the serial number is 18 (12 hex); (b) the certificate is signed with DSA and the SHA-1 hash algorithm; (c) the issuer's distinguished name is OU=nist;O=gov;C=US (d) and the subject's distinguished name is CN=Tim Polk;OU=nist;O=gov;C=US (e) the certificate was valid from July 30, 1997 and will expire on December 1, 1997; (f) the certificate contains a 1024 bit DSA public key; (g) the certificate is an end entity certificate unless external information is provided, as the basic constraints extension is not present; (h) the certificate includes one alternative name - an RFC 822 address. D.2.1 Basic ASN.1 Dump of "End Entity" Certificate ---------- get 0, len=697 (697 bytes in file) 0000 30 82 02 b5 693: SEQUENCE 0004 30 82 02 75 629: . SEQUENCE 0008 a0 03 3: . . [0] 0010 02 01 1: . . . INTEGER 2 0013 02 01 1: . . INTEGER 18 0016 30 09 9: . . SEQUENCE 0018 06 07 7: . . . OID 1.2.840.10040.4.3: dsa-with-sha 0027 30 2a 42: . . SEQUENCE 0029 31 0b 11: . . . SET 0031 30 09 9: . . . . SEQUENCE 0033 06 03 3: . . . . . OID 2.5.4.6: C 0038 13 02 2: . . . . . PrintableString 'US' 0042 31 0c 12: . . . SET 0044 30 0a 10: . . . . SEQUENCE 0046 06 03 3: . . . . . OID 2.5.4.10: O 0051 13 03 3: . . . . . PrintableString 'gov' 0056 31 0d 13: . . . SET 0058 30 0b 11: . . . . SEQUENCE 0060 06 03 3: . . . . . OID 2.5.4.11: OU 0065 13 04 4: . . . . . PrintableString 'nist' 0071 30 1e 30: . . SEQUENCE 0073 17 0d 13: . . . UTCTime '970730000000Z' 0088 17 0d 13: . . . UTCTime '971201000000Z' 0103 30 3d 61: . . SEQUENCE Housley, Ford, Polk, & Solo [Page 106] INTERNET DRAFT March 25, 1998 0105 31 0b 11: . . . SET 0107 30 09 9: . . . . SEQUENCE 0109 06 03 3: . . . . . OID 2.5.4.6: C 0114 13 02 2: . . . . . PrintableString 'US' 0118 31 0c 12: . . . SET 0120 30 0a 10: . . . . SEQUENCE 0122 06 03 3: . . . . . OID 2.5.4.10: O 0127 13 03 3: . . . . . PrintableString 'gov' 0132 31 0d 13: . . . SET 0134 30 0b 11: . . . . SEQUENCE 0136 06 03 3: . . . . . OID 2.5.4.11: OU 0141 13 04 4: . . . . . PrintableString 'nist' 0147 31 11 17: . . . SET 0149 30 0f 15: . . . . SEQUENCE 0151 06 03 3: . . . . . OID 2.5.4.3: CN 0156 13 08 8: . . . . . PrintableString 'Tim Polk' 0166 30 82 01 b4 436: . . SEQUENCE 0170 30 82 01 29 297: . . . SEQUENCE 0174 06 07 7: . . . . OID 1.2.840.10040.4.1: dsa 0183 30 82 01 1c 284: . . . . SEQUENCE 0187 02 81 80 128: . . . . . INTEGER : d4 38 02 c5 35 7b d5 0b a1 7e 5d 72 59 63 55 d3 : 45 56 ea e2 25 1a 6b c5 a4 ab aa 0b d4 62 b4 d2 : 21 b1 95 a2 c6 01 c9 c3 fa 01 6f 79 86 83 3d 03 : 61 e1 f1 92 ac bc 03 4e 89 a3 c9 53 4a f7 e2 a6 : 48 cf 42 1e 21 b1 5c 2b 3a 7f ba be 6b 5a f7 0a : 26 d8 8e 1b eb ec bf 1e 5a 3f 45 c0 bd 31 23 be : 69 71 a7 c2 90 fe a5 d6 80 b5 24 dc 44 9c eb 4d : f9 da f0 c8 e8 a2 4c 99 07 5c 8e 35 2b 7d 57 8d 0318 02 14 20: . . . . . INTEGER : a7 83 9b f3 bd 2c 20 07 fc 4c e7 e8 9f f3 39 83 : 51 0d dc dd 0340 02 81 80 128: . . . . . INTEGER : 0e 3b 46 31 8a 0a 58 86 40 84 e3 a1 22 0d 88 ca : 90 88 57 64 9f 01 21 e0 15 05 94 24 82 e2 10 90 : d9 e1 4e 10 5c e7 54 6b d4 0c 2b 1b 59 0a a0 b5 : a1 7d b5 07 e3 65 7c ea 90 d8 8e 30 42 e4 85 bb : ac fa 4e 76 4b 78 0e df 6c e5 a6 e1 bd 59 77 7d : a6 97 59 c5 29 a7 b3 3f 95 3e 9d f1 59 2d f7 42 : 87 62 3f f1 b8 6f c7 3d 4b b8 8d 74 c4 ca 44 90 : cf 67 db de 14 60 97 4a d1 f7 6d 9e 09 94 c4 0d 0471 03 81 84 132: . . . BIT STRING (0 unused bits) : 02 81 80 a8 63 b1 60 70 94 7e 0b 86 08 93 0c 0d : 08 12 4a 58 a9 af 9a 09 38 54 3b 46 82 fb 85 0d : 18 8b 2a 77 f7 58 e8 f0 1d d2 18 df fe e7 e9 35 : c8 a6 1a db 8d 3d 3d f8 73 14 a9 0b 39 c7 95 f6 : 52 7d 2d 13 8c ae 03 29 3c 4e 8c b0 26 18 b6 d8 : 11 1f d4 12 0c 13 ce 3f f1 c7 05 4e df e1 fc 44 Housley, Ford, Polk, & Solo [Page 107] INTERNET DRAFT March 25, 1998 : fd 25 34 19 4a 81 0d dd 98 42 ac d3 b6 91 0c 7f : 16 72 a3 a0 8a d7 01 7f fb 9c 93 e8 99 92 c8 42 : 47 c6 43 0606 a3 1d 29: . . [3] 0608 30 1b 27: . . . SEQUENCE 0610 30 19 25: . . . . SEQUENCE 0612 06 03 3: . . . . . OID 2.5.29.17: subjectAltName 0617 04 12 18: . . . . . OCTET STRING : 30 10 81 0e 77 70 6f 6c 6b 40 6e 69 73 74 2e 67 : 6f 76 0637 30 09 9: . SEQUENCE 0639 06 07 7: . . OID 1.2.840.10040.4.3: dsa-with-sha 0648 03 2f 47: . BIT STRING (0 unused bits) : 30 2c 02 14 3c 02 e0 ab d9 5d 05 77 75 15 71 58 : 92 29 48 c4 1c 54 df fc 02 14 5b da 53 98 7f c5 : 33 df c6 09 b2 7a e3 6f 97 70 1e 14 ed 94 -------- extensions ---------- printber -s 475 pkix-ex2.ber get 0, len=131 (697 bytes in file) 0000 02 81 80 128: INTEGER : a8 63 b1 60 70 94 7e 0b 86 08 93 0c 0d 08 12 4a : 58 a9 af 9a 09 38 54 3b 46 82 fb 85 0d 18 8b 2a : 77 f7 58 e8 f0 1d d2 18 df fe e7 e9 35 c8 a6 1a : db 8d 3d 3d f8 73 14 a9 0b 39 c7 95 f6 52 7d 2d : 13 8c ae 03 29 3c 4e 8c b0 26 18 b6 d8 11 1f d4 : 12 0c 13 ce 3f f1 c7 05 4e df e1 fc 44 fd 25 34 : 19 4a 81 0d dd 98 42 ac d3 b6 91 0c 7f 16 72 a3 : a0 8a d7 01 7f fb 9c 93 e8 99 92 c8 42 47 c6 43 D.2.2 Pretty Print of "End Entity" Certificate ---------- decode: 0-OK, len=697 (697 bytes in file) Version: v3 Serial Number: 18 Signature Alg: dsa-with-sha (1.2.840.10040.4.3) Issuer: C=US, O=gov, OU=nist Validity: from 970730000000Z to 971201000000Z Subject: CN=Tim Polk, OU=nist, O=gov, C=US SubjectPKInfo: dsa (1.2.840.10040.4.1) params: 02 81 80 d4 38 02 c5 35 7b d5 0b a1 7e 5d 72 59 63 55 d3 45 56 ea e2 25 1a 6b c5 a4 ab aa 0b d4 Housley, Ford, Polk, & Solo [Page 108] INTERNET DRAFT March 25, 1998 62 b4 d2 21 b1 95 a2 c6 01 c9 c3 fa 01 6f 79 86 83 3d 03 61 e1 f1 92 ac bc 03 4e 89 a3 c9 53 4a f7 e2 a6 48 cf 42 1e 21 b1 5c 2b 3a 7f ba be 6b 5a f7 0a 26 d8 8e 1b eb ec bf 1e 5a 3f 45 c0 bd 31 23 be 69 71 a7 c2 90 fe a5 d6 80 b5 24 dc 44 9c eb 4d f9 da f0 c8 e8 a2 4c 99 07 5c 8e 35 2b 7d 57 8d 02 14 a7 83 9b f3 bd 2c 20 07 fc 4c e7 e8 9f f3 39 83 51 0d dc dd 02 81 80 0e 3b 46 31 8a 0a 58 86 40 84 e3 a1 22 0d 88 ca 90 88 57 64 9f 01 21 e0 15 05 94 24 82 e2 10 90 d9 e1 4e 10 5c e7 54 6b d4 0c 2b 1b 59 0a a0 b5 a1 7d b5 07 e3 65 7c ea 90 d8 8e 30 42 e4 85 bb ac fa 4e 76 4b 78 0e df 6c e5 a6 e1 bd 59 77 7d a6 97 59 c5 29 a7 b3 3f 95 3e 9d f1 59 2d f7 42 87 62 3f f1 b8 6f c7 3d 4b b8 8d 74 c4 ca 44 90 cf 67 db de 14 60 97 4a d1 f7 6d 9e 09 94 c4 0d Public Key: 00 02 81 80 a8 63 b1 60 70 94 7e 0b 86 08 93 0c 0d 08 12 4a 58 a9 af 9a 09 38 54 3b 46 82 fb 85 0d 18 8b 2a 77 f7 58 e8 f0 1d d2 18 df fe e7 e9 35 c8 a6 1a db 8d 3d 3d f8 73 14 a9 0b 39 c7 95 f6 52 7d 2d 13 8c ae 03 29 3c 4e 8c b0 26 18 b6 d8 11 1f d4 12 0c 13 ce 3f f1 c7 05 4e df e1 fc 44 fd 25 34 19 4a 81 0d dd 98 42 ac d3 b6 91 0c 7f 16 72 a3 a0 8a d7 01 7f fb 9c 93 e8 99 92 c8 42 47 c6 43 issuerUID: subjectUID: 1 extensions: Exten 1: subjectAltName (2.5.29.17) 30 10 81 0e 77 70 6f 6c 6b 40 6e 69 73 74 2e 67 6f 76 Signature Alg: dsa-with-sha (1.2.840.10040.4.3) Sig Value: 368 bits: 30 2c 02 14 3c 02 e0 ab d9 5d 05 77 75 15 71 58 92 29 48 c4 1c 54 df fc 02 14 5b da 53 98 7f c5 33 df c6 09 b2 7a e3 6f 97 70 1e 14 ed 94 -------- extensions ---------- printber -s 619 pkix-ex2.ber get 0, len=18 (697 bytes in file) 0000 30 10 16: SEQUENCE 0002 81 0e 14: . [1] : 77 70 6f 6c 6b 40 6e 69 73 74 2e 67 6f 76 printber -s 651 pkix-ex2.ber get 0, len=46 (697 bytes in file) Housley, Ford, Polk, & Solo [Page 109] INTERNET DRAFT March 25, 1998 0000 30 2c 44: SEQUENCE 0002 02 14 20: . INTEGER : 2b 82 c9 2d 79 9c a4 16 97 22 b1 48 16 03 c2 ed : 31 65 99 d5 0024 02 14 20: . INTEGER : 3f 90 79 17 f8 9d 50 fb f3 5d 70 b7 40 31 a3 74 : 31 d7 b1 30 D.3 End-Entity Certificate Using RSA This section contains an annotated hex dump of a 675 byte version 3 certificate. The certificate contains the following information: (a) the serial number is 2; (b) the certificate is signed with RSA and the MD5 hash algorithm; (c) the issuer's distinguished name is OU=esCert- UPC;O=UPC;L=Barcelona;STREET=Catalunya;C=ES (d) and the subject's distinguished name is CN=escert.upc.es;OU=esCert- UPC;O=UPC;L=Barcelona;STREET=Catalunya;C=ES (e) the certificate was issued on May 21, 1996 and will expire on May 21, 1997; (f) the certificate contains a 768 bit RSA public key which is intended for generation of digital signatures; (g) the certificate is an end entity certificate (not a CA certifi- cate); (h) the certificate includes two alternative names - an RFC 822 address, and a URL. sequence length 029f=671 bytes 30 82 02 9f sequence length 0208h=520 bytes 30 82 02 08 explicit tag 00 "Version" a0 03 integer length 1 value 2 [version is 3] 02 01 02 integer length 1 value 2 [serial number 2] 02 01 02 sequence length 13 [signature] 30 0d object identifier length 9 {1 2 840 113549 1 1 4} {iso(1) member-body(2) us(840) etc.} 06 09 2a 86 48 86 f7 0d 01 01 04 null [null parameters] 05 00 sequence length 88 [issuer] 30 58 RDN length 11 Housley, Ford, Polk, & Solo [Page 110] INTERNET DRAFT March 25, 1998 31 0b sequence length 9 30 09 object identifier length 3 { 2 5 4 6 } 06 03 55 04 06 printable string length 2 "ES" 13 02 45 53 RDN length 18 31 12 sequence length 16 30 10 object identifier length 3 { 2 5 4 9 } 06 03 55 04 09 printable string length 9 "Catalunya" 13 09 43 61 74 61 6c 75 6e 79 61 RDN length 18 31 12 sequence length 16 30 10 object identifier length 3 { 2 5 4 7 } 06 03 55 04 07 printable string length 9 "Barcelona" 13 09 42 61 72 63 65 6c 6f 6e 61 RDN length 12 31 0c sequence length 10 30 0a object identifier {2 5 4 10 } 06 03 55 04 0a printable string length 3 "UPC" 13 03 55 50 43 RDN length 19 31 13 sequence length 17 30 11 object identifier {2 5 4 13 } 06 03 55 04 0b printable string length 10 "esCERT-UPC" 13 0a 65 73 43 45 52 54 2d 55 50 43 sequence length 0x1e= 30 30 1e UTCTime "960521095826Z" 17 0d 39 36 30 35 32 31 30 39 35 38 32 36 5a UTCTime "979521095826Z" 17 0d 39 37 30 35 32 31 30 39 35 38 32 36 5a sequence length 30 70 31 0b Housley, Ford, Polk, & Solo [Page 111] INTERNET DRAFT March 25, 1998 30 09 { 2 5 4 6 } 06 03 55 04 06 "ES" 13 02 45 53 RDN 31 12 30 10 { 2 5 4 9 } 06 03 55 04 09 "Catalunya" 13 09 43 61 74 61 6c 75 6e 7961 RDN 31 12 30 10 { 2 5 4 7 } 06 03 55 04 07 "Barcelona" 13 09 42 61 72 63 65 6c 6f 6e 61 RDN 31 0c 30 0a { 2 5 4 10 } 06 03 55 04 0a "UPC" 13 03 55 50 43 RDN 31 13 30 11 { 2 5 4 11 } 06 03 55 04 0b "esCERT-UPC" 13 0a 65 73 43 45 52 54 2d 55 50 43 RDN 31 16 30 14 { 2 5 4 3 } 06 03 55 04 03 "escert.upc.es" 13 0d 65 73 63 65 72 74 2e 75 70 63 2e 65 73 subjectPublicKeyInfo 30 7c algorithmIdentifier 30 0d { 1 2 840 113549 1 1 1} 06 09 2a 86 48 86 f7 0d 01 01 01 null parameters 05 00 Housley, Ford, Polk, & Solo [Page 112] INTERNET DRAFT March 25, 1998 { subject's public key } 03 6b BIT STRING length 107 bytes (856 bits) 0030 6802 6100 beaa 8b77 54a3 afca 779f 2fb0 cf43 88ff a66d 7955 5b61 8c68 ec48 1e8a 8638 a4fe 19b8 6217 1d9d 0f47 2cff 638f 2991 04d1 52bc 7f67 b6b2 8f74 55c1 3321 6c8f ab01 9524 c8b2 7393 9d22 6150 a935 fb9d 5750 32ef 5652 5093 abb1 8894 7856 15c6 1c8b 0203 0100 01 explicit tag 3 "extensions" length 0x84=132 a3 81 84 sequence 129 bytes 30 81 81 sequence 12 bytes 30 0b id-ce-keyUsage = { 2 5 29 15 } 06 03 55 1d 0f by default, critical = FALSE octet string 04 04 03 02 07 80 30 09 id-ce-basicConstraints = { 2 5 29 19 } 06 03 55 1d 13 by default, critical = FALSE octet string 04 02 null sequence - by default, subject is end entity 30 00 30 3d id-ce-subjectAltName = { 2 5 29 17 } 06 03 55 1d 11 by default, critical = FALSE octet string 04 36 30 34 rfc822name a1 1a IA5String "escert-upc@escert.upc.es" 16 18 65 73 63 65 72 74 2d 75 70 63 40 65 73 63 65 72 74 2e 75 70 63 2e 65 73 uniformResourceIdentifier a6 16 IA5String "http://escert.upc.es" 16 14 68 74 74 70 3a 2f 2f 65 73 63 65 72 74 2e 75 70 63 2e 65 73 30 28 id-ce-certificatePolicies = { 2 5 29 32 } 06 03 55 1d 20 Housley, Ford, Polk, & Solo [Page 113] INTERNET DRAFT March 25, 1998 by default, critical = FALSE octet string 04 21 30 1f 30 1d 06 04 2a 84 80 00 { 2 2 32768 } 30 15 30 07 { 2 2 32768 1 } 06 05 2a 84 80 00 01 30 0a { 2 2 32768 2 } 06 05 2a 84 80 00 02 02 01 0a sequence 30 0d { 1 2 840 113549 1 1 4 } 06 09 2a 86 48 86 f7 0d 01 01 04 null parameters 05 00 bit string length 129 (signature) 03 81 81 005b fdc2 a704 d483 4e17 6da6 fa27 e7c6 f8ab b95d 9fd0 a1df d797 9fe0 20a6 c57a 64cd 522f e9ae dabe 9ce4 d597 edf1 84c0 d0fe 9bef 54b1 80e5 bf3c c9ed 9320 2d52 21e9 bcb9 e34f ac11 650e 8fa1 6899 6347 e53d e442 7313 fac5 c834 8cc0 4118 89d5 e6a0 185b 5d86 1c1e c670 d80e 8964 9483 8e3b 407c 59cf 2b2f b7ce 9798 1215 ef13 d4 D.4 Certificate Revocation List This section contains an annotated hex dump of a version 2 CRL with one extension (cRLNumber). The CRL was issued by OU=nist;O=gov;C=us on July 7, 1996; the next scheduled issuance was August 7, 1996. The CRL includes one revoked certificates: serial number 18 (12 hex). The CRL itself is number 18, and it was signed with DSA. printber pkix-crl.ber get 0, len=189 (189 bytes in file) 0000 30 81 ba 186: SEQUENCE 0003 30 7c 124: . SEQUENCE 0005 02 01 1: . . INTEGER 1 0008 30 09 9: . . SEQUENCE 0010 06 07 7: . . . OID 1.2.840.10040.4.3: dsa-with-sha Housley, Ford, Polk, & Solo [Page 114] INTERNET DRAFT March 25, 1998 0019 30 2a 42: . . SEQUENCE 0021 31 0b 11: . . . SET 0023 30 09 9: . . . . SEQUENCE 0025 06 03 3: . . . . . OID 2.5.4.6: C 0030 13 02 2: . . . . . PrintableString 'US' 0034 31 0c 12: . . . SET 0036 30 0a 10: . . . . SEQUENCE 0038 06 03 3: . . . . . OID 2.5.4.10: O 0043 13 03 3: . . . . . PrintableString 'gov' 0048 31 0d 13: . . . SET 0050 30 0b 11: . . . . SEQUENCE 0052 06 03 3: . . . . . OID 2.5.4.11: OU 0057 13 04 4: . . . . . PrintableString 'nist' 0063 17 0d 13: . . UTCTime '970801000000Z' 0078 17 0d 13: . . UTCTime '970808000000Z' 0093 30 22 34: . . SEQUENCE 0095 30 20 32: . . . SEQUENCE 0097 02 01 1: . . . . INTEGER 18 0100 17 0d 13: . . . . UTCTime '970731000000Z' 0115 30 0c 12: . . . . SEQUENCE 0117 30 0a 10: . . . . . SEQUENCE 0119 06 03 3: . . . . . . OID 2.5.29.21: reasonCode 0124 04 03 3: . . . . . . OCTET STRING : 0a 01 01 0129 30 09 9: . SEQUENCE 0131 06 07 7: . . OID 1.2.840.10040.4.3: dsa-with-sha 0140 03 2f 47: . BIT STRING (0 unused bits) : 30 2c 02 14 9e d8 6b c1 7d c2 c4 02 f5 17 84 f9 : 9f 46 7a ca cf b7 05 8a 02 14 9e 43 39 85 dc ea : 14 13 72 93 54 5d 44 44 e5 05 fe 73 9a b2 printber -s 143 pkix-crl.ber get 0, len=46 (189 bytes in file) 0000 30 2c 44: SEQUENCE 0002 02 14 20: . INTEGER : 9e d8 6b c1 7d c2 c4 02 f5 17 84 f9 9f 46 7a ca : cf b7 05 8a 0024 02 14 20: . INTEGER : 9e 43 39 85 dc ea 14 13 72 93 54 5d 44 44 e5 05 : fe 73 9a b2 Security Considerations This entire memo is about security mechanisms. Housley, Ford, Polk, & Solo [Page 115] INTERNET DRAFT March 25, 1998 Author Addresses: Russell Housley SPYRUS PO Box 1198 Herndon, VA 20172 USA housley@spyrus.com Warwick Ford VeriSign, Inc. One Alewife Center Cambridge, MA 02140 USA wford@verisign.com Tim Polk NIST Building 820, Room 426 Gaithersburg, MD 20899 USA wpolk@nist.gov David Solo Citicorp 666 Fifth Ave, 3rd Floor New York, NY 10103 USA david.solo@citicorp.com Housley, Ford, Polk, & Solo [Page 116]