< draft-ietf-pkix-new-part1-00.txt   draft-ietf-pkix-new-part1-01.txt >
PKIX Working Group R. Housley (SPYRUS) PKIX Working Group R. Housley (SPYRUS)
Internet Draft W. Ford (VeriSign) Internet Draft W. Ford (VeriSign)
W. Polk (NIST) W. Polk (NIST)
D. Solo (Citicorp) D. Solo (Citigroup)
expires in six months October 22, 1999 expires in six months March 10, 2000
Internet X.509 Public Key Infrastructure Internet X.509 Public Key Infrastructure
Certificate and CRL Profile Certificate and CRL Profile
<draft-ietf-pkix-new-part1-00.txt> <draft-ietf-pkix-new-part1-01.txt>
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. Internet-Drafts are working all provisions of Section 10 of RFC2026. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, documents of the Internet Engineering Task Force (IETF), its areas,
and its working groups. Note that other groups may also distribute and its working groups. Note that other groups may also distribute
working documents as Internet-Drafts. working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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4.1.2.7 Subject Public Key Info ............................... 24 4.1.2.7 Subject Public Key Info ............................... 24
4.1.2.8 Unique Identifiers .................................... 24 4.1.2.8 Unique Identifiers .................................... 24
4.1.2.9 Extensions ............................................. 25 4.1.2.9 Extensions ............................................. 25
4.2 Certificate Extensions .................................... 25 4.2 Certificate Extensions .................................... 25
4.2.1 Standard Extensions ..................................... 26 4.2.1 Standard Extensions ..................................... 26
4.2.1.1 Authority Key Identifier .............................. 26 4.2.1.1 Authority Key Identifier .............................. 26
4.2.1.2 Subject Key Identifier ................................ 27 4.2.1.2 Subject Key Identifier ................................ 27
4.2.1.3 Key Usage ............................................. 28 4.2.1.3 Key Usage ............................................. 28
4.2.1.4 Private Key Usage Period .............................. 30 4.2.1.4 Private Key Usage Period .............................. 30
4.2.1.5 Certificate Policies .................................. 30 4.2.1.5 Certificate Policies .................................. 30
4.2.1.6 Policy Mappings ....................................... 32 4.2.1.6 Policy Mappings ....................................... 33
4.2.1.7 Subject Alternative Name .............................. 33 4.2.1.7 Subject Alternative Name .............................. 33
4.2.1.8 Issuer Alternative Name ............................... 35 4.2.1.8 Issuer Alternative Name ............................... 36
4.2.1.9 Subject Directory Attributes .......................... 36 4.2.1.9 Subject Directory Attributes .......................... 36
4.2.1.10 Basic Constraints .................................... 36 4.2.1.10 Basic Constraints .................................... 36
4.2.1.11 Name Constraints ..................................... 36 4.2.1.11 Name Constraints ..................................... 37
4.2.1.12 Policy Constraints ................................... 39 4.2.1.12 Policy Constraints ................................... 39
4.2.1.13 Extended key usage field ............................. 39 4.2.1.13 Extended key usage field ............................. 40
4.2.1.14 CRL Distribution Points .............................. 41 4.2.1.14 CRL Distribution Points .............................. 42
4.2.2 Internet Certificate Extensions ......................... 42 4.2.1.15 Inhibit Any-Policy ................................... 42
4.2.2.1 Authority Information Access .......................... 42 4.2.2 Internet Certificate Extensions ......................... 43
5 CRL and CRL Extensions Profile .............................. 43 4.2.2.1 Authority Information Access .......................... 43
5.1 CRL Fields ................................................ 44 5 CRL and CRL Extensions Profile .............................. 44
5.1.1 CertificateList Fields .................................. 45 5.1 CRL Fields ................................................ 45
5.1.1.1 tbsCertList ........................................... 45 5.1.1 CertificateList Fields .................................. 46
5.1.1.2 signatureAlgorithm .................................... 45 5.1.1.1 tbsCertList ........................................... 46
5.1.1.3 signatureValue ........................................ 45 5.1.1.2 signatureAlgorithm .................................... 46
5.1.2 Certificate List "To Be Signed" ......................... 45 5.1.1.3 signatureValue ........................................ 46
5.1.2.1 Version ............................................... 46 5.1.2 Certificate List "To Be Signed" ......................... 46
5.1.2.2 Signature ............................................. 46 5.1.2.1 Version ............................................... 47
5.1.2.3 Issuer Name ........................................... 46 5.1.2.2 Signature ............................................. 47
5.1.2.4 This Update ........................................... 46 5.1.2.3 Issuer Name ........................................... 47
5.1.2.5 Next Update ........................................... 46 5.1.2.4 This Update ........................................... 47
5.1.2.6 Revoked Certificates .................................. 47 5.1.2.5 Next Update ........................................... 48
5.1.2.7 Extensions ............................................ 47 5.1.2.6 Revoked Certificates .................................. 48
5.2 CRL Extensions ............................................ 47 5.1.2.7 Extensions ............................................ 48
5.2.1 Authority Key Identifier ................................ 48 5.2 CRL Extensions ............................................ 48
5.2.2 Issuer Alternative Name ................................. 48 5.2.1 Authority Key Identifier ................................ 49
5.2.3 CRL Number .............................................. 48 5.2.2 Issuer Alternative Name ................................. 49
5.2.4 Delta CRL Indicator ..................................... 49 5.2.3 CRL Number .............................................. 49
5.2.5 Issuing Distribution Point .............................. 49 5.2.4 Delta CRL Indicator ..................................... 50
5.3 CRL Entry Extensions ...................................... 50 5.2.5 Issuing Distribution Point .............................. 51
5.3.1 Reason Code ............................................. 51 5.3 CRL Entry Extensions ...................................... 52
5.3.2 Hold Instruction Code ................................... 51 5.3.1 Reason Code ............................................. 53
5.3.3 Invalidity Date ......................................... 52 5.3.2 Hold Instruction Code ................................... 53
5.3.4 Certificate Issuer ...................................... 52 5.3.3 Invalidity Date ......................................... 54
6 Certificate Path Validation ................................. 52 5.3.4 Certificate Issuer ...................................... 54
6.1 Basic Path Validation ..................................... 53 6 Certificate Path Validation ................................. 55
6.1.1 Inputs ................................................... 55 6.1 Basic Path Validation ..................................... 55
6.1.2 Initialization ........................................... 56 6.1.1 Inputs ................................................... 57
6.1.3 Basic Certificate Processing ............................. 59 6.1.2 Initialization ........................................... 58
6.1.4 Preparation for Certificate i+1 .......................... 64 6.1.3 Basic Certificate Processing ............................. 61
6.1.5 Wrap-up procedure ........................................ 67 6.1.4 Preparation for Certificate i+1 .......................... 66
6.1.6 Outputs .................................................. 68 6.1.5 Wrap-up procedure ........................................ 69
6.2 Extending Path Validation ................................. 68 6.1.6 Outputs .................................................. 70
6.3 CRL Validation ............................................ 69 6.2 Extending Path Validation ................................. 70
6.3.1 Revocation Inputs ....................................... 69 6.3 CRL Validation ............................................ 71
6.3.2 Initialization and Revocation State Variables ........... 69 6.3.1 Revocation Inputs ....................................... 71
6.3.3 Basic Certificate Processing ............................ 70 6.3.2 Initialization and Revocation State Variables ........... 71
6.3.4 Preparation for Next Certificate ......................... 72 6.3.3 CRL Processing .......................................... 72
7 Algorithm Support ........................................... 72 7 Algorithm Support ........................................... 72
7.1 One-way Hash Functions .................................... 73 7.1 One-way Hash Functions .................................... 74
7.1.1 MD2 One-way Hash Function ............................... 73 7.1.1 MD2 One-way Hash Function ............................... 75
7.1.2 MD5 One-way Hash Function ............................... 73 7.1.2 MD5 One-way Hash Function ............................... 75
7.1.3 SHA-1 One-way Hash Function ............................. 74 7.1.3 SHA-1 One-way Hash Function ............................. 75
7.2 Signature Algorithms ...................................... 74 7.2 Signature Algorithms ...................................... 76
7.2.1 RSA Signature Algorithm ................................. 74 7.2.1 RSA Signature Algorithm ................................. 76
7.2.2 DSA Signature Algorithm ................................. 75 7.2.2 DSA Signature Algorithm ................................. 77
7.3 Subject Public Key Algorithms ............................. 76 7.3 Subject Public Key Algorithms ............................. 78
7.3.1 RSA Keys ................................................ 76 7.3.1 RSA Keys ................................................ 78
7.3.2 Diffie-Hellman Key Exchange Key ......................... 77 7.3.2 Diffie-Hellman Key Exchange Key ......................... 79
7.3.3 DSA Signature Keys ...................................... 78 7.3.3 DSA Signature Keys ...................................... 80
8 References .................................................. 80 8 References .................................................. 81
9 Intellectual Property Rights ................................ 82 9 Intellectual Property Rights ................................ 83
10 Security Considerations .................................... 82 10 Security Considerations .................................... 84
Appendix A. ASN.1 Structures and OIDs ......................... 85 Appendix A. ASN.1 Structures and OIDs ......................... 87
A.1 Explicitly Tagged Module, 1988 Syntax ...................... 85 A.1 Explicitly Tagged Module, 1988 Syntax ...................... 87
A.2 Implicitly Tagged Module, 1988 Syntax ...................... 99 A.2 Implicitly Tagged Module, 1988 Syntax ...................... 101
Appendix B. 1993 ASN.1 Structures and OIDs .................... 106 Appendix B. 1993 ASN.1 Structures and OIDs .................... 108
B.1 Explicitly Tagged Module, 1993 Syntax ...................... 106 B.1 Explicitly Tagged Module, 1993 Syntax ...................... 108
B.2 Implicitly Tagged Module, 1993 Syntax ...................... 122 B.2 Implicitly Tagged Module, 1993 Syntax ...................... 125
Appendix C. ASN.1 Notes ....................................... 130 Appendix C. ASN.1 Notes ....................................... 132
Appendix D. Examples .......................................... 131 Appendix D. Examples .......................................... 134
D.1 Certificate ............................................... 131 D.1 Certificate ............................................... 134
D.2 Certificate ............................................... 134 D.2 Certificate ............................................... 137
D.3 End-Entity Certificate Using RSA .......................... 137 D.3 End-Entity Certificate Using RSA .......................... 140
D.4 Certificate Revocation List ............................... 140 D.4 Certificate Revocation List ............................... 143
Appendix E. Author Addresses .................................. 142 Appendix E. Author Addresses .................................. 145
Appendix F. Full Copyright Statement .......................... 142 Appendix F. Full Copyright Statement .......................... 145
1 Introduction 1 Introduction
This specification is one part of a family of standards for the X.509 This specification is one part of a family of standards for the X.509
Public Key Infrastructure (PKI) for the Internet. This specification Public Key Infrastructure (PKI) for the Internet. This specification
is a standalone document; implementations of this standard may is a standalone document; implementations of this standard may
proceed independent from the other parts. proceed independent from the other parts.
This specification profiles the format and semantics of certificates This specification profiles the format and semantics of certificates
and certificate revocation lists for the Internet PKI. Procedures and certificate revocation lists for the Internet PKI. Procedures
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Implementations SHOULD be prepared to accept any version certificate. Implementations SHOULD be prepared to accept any version certificate.
At a minimum, conforming implementations MUST recognize version 3 At a minimum, conforming implementations MUST recognize version 3
certificates. certificates.
Generation of version 2 certificates is not expected by implementa- Generation of version 2 certificates is not expected by implementa-
tions based on this profile. tions based on this profile.
4.1.2.2 Serial number 4.1.2.2 Serial number
The serial number is an integer assigned by the CA to each certifi- The serial number is a positive integer assigned by the CA to each
cate. It MUST be unique for each certificate issued by a given CA certificate. It MUST be unique for each certificate issued by a
(i.e., the issuer name and serial number identify a unique given CA (i.e., the issuer name and serial number identify a unique
certificate). certificate).
4.1.2.3 Signature 4.1.2.3 Signature
This field contains the algorithm identifier for the algorithm used This field contains the algorithm identifier for the algorithm used
by the CA to sign the certificate. by the CA to sign the certificate.
This field MUST contain the same algorithm identifier as the signa- This field MUST contain the same algorithm identifier as the signa-
tureAlgorithm field in the sequence Certificate (see sec. 4.1.1.2). tureAlgorithm field in the sequence Certificate (see sec. 4.1.1.2).
The contents of the optional parameters field will vary according to The contents of the optional parameters field will vary according to
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Standard sets of attributes have been defined in the X.500 series of Standard sets of attributes have been defined in the X.500 series of
specifications.[X.520] Implementations of this specification MUST be specifications.[X.520] Implementations of this specification MUST be
prepared to receive the following standard attribute types in issuer prepared to receive the following standard attribute types in issuer
and subject (see 4.1.2.6) names: and subject (see 4.1.2.6) names:
* country, * country,
* organization, * organization,
* organizational-unit, * organizational-unit,
* distinguished name qualifier, * distinguished name qualifier,
* state or province name, and * state or province name,
* common name (e.g., "Susan Housley"). * common name (e.g., "Susan Housley"), and
* serial number.
In addition, implementations of this specification SHOULD be prepared In addition, implementations of this specification SHOULD be prepared
to receive the following standard attribute types in issuer and sub- to receive the following standard attribute types in issuer and sub-
ject names: ject names:
* locality, * locality,
* title, * title,
* surname, * surname,
* given name, * given name,
* initials, and * initials, and
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certificate. The field is represented as a SEQUENCE of two dates: certificate. The field is represented as a SEQUENCE of two dates:
the date on which the certificate validity period begins (notBefore) the date on which the certificate validity period begins (notBefore)
and the date on which the certificate validity period ends and the date on which the certificate validity period ends
(notAfter). Both notBefore and notAfter may be encoded as UTCTime or (notAfter). Both notBefore and notAfter may be encoded as UTCTime or
GeneralizedTime. GeneralizedTime.
CAs conforming to this profile MUST always encode certificate vali- CAs conforming to this profile MUST always encode certificate vali-
dity dates through the year 2049 as UTCTime; certificate validity dity dates through the year 2049 as UTCTime; certificate validity
dates in 2050 or later MUST be encoded as GeneralizedTime. dates in 2050 or later MUST be encoded as GeneralizedTime.
The validity period for a certificate is the period of time from
notBefore through notAfter, inclusive.
4.1.2.5.1 UTCTime 4.1.2.5.1 UTCTime
The universal time type, UTCTime, is a standard ASN.1 type intended The universal time type, UTCTime, is a standard ASN.1 type intended
for representation of dates and time. UTCTime specifies the year for representation of dates and time. UTCTime specifies the year
through the two low order digits and time is specified to the preci- through the two low order digits and time is specified to the preci-
sion of one minute or one second. UTCTime includes either Z (for sion of one minute or one second. UTCTime includes either Z (for
Zulu, or Greenwich Mean Time) or a time differential. Zulu, or Greenwich Mean Time) or a time differential.
For the purposes of this profile, UTCTime values MUST be expressed For the purposes of this profile, UTCTime values MUST be expressed
Greenwich Mean Time (Zulu) and MUST include seconds (i.e., times are Greenwich Mean Time (Zulu) and MUST include seconds (i.e., times are
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extnID and the corresponding ASN.1 encoded structure is the value of extnID and the corresponding ASN.1 encoded structure is the value of
the octet string extnValue. Only one instance of a particular exten- the octet string extnValue. Only one instance of a particular exten-
sion may appear in a particular certificate. For example, a certifi- sion may appear in a particular certificate. For example, a certifi-
cate may contain only one authority key identifier extension (see cate may contain only one authority key identifier extension (see
sec. 4.2.1.1). An extension includes the boolean critical, with a sec. 4.2.1.1). An extension includes the boolean critical, with a
default value of FALSE. The text for each extension specifies the default value of FALSE. The text for each extension specifies the
acceptable values for the critical field. acceptable values for the critical field.
Conforming CAs MUST support key identifiers (see sec. 4.2.1.1 and Conforming CAs MUST support key identifiers (see sec. 4.2.1.1 and
4.2.1.2), basic constraints (see sec. 4.2.1.10), key usage (see sec. 4.2.1.2), basic constraints (see sec. 4.2.1.10), key usage (see sec.
4.2.1.3), and certificate policies (see sec. 4.2.1.5) extensions. If 4.2.1.3), and certificate policies (see sec. 4.2.1.5) extensions. If
the CA issues certificates with an empty sequence for the subject the CA issues certificates with an empty sequence for the subject
field, the CA MUST support the subject alternative name extension field, the CA MUST support the subject alternative name extension
(see sec. 4.2.1.7). Support for the remaining extensions is (see sec. 4.2.1.7). Support for the remaining extensions is
OPTIONAL. Conforming CAs may support extensions that are not identi- OPTIONAL. Conforming CAs may support extensions that are not identi-
fied within this specification; certificate issuers are cautioned fied within this specification; certificate issuers are cautioned
that marking such extensions as critical may inhibit that marking such extensions as critical may inhibit interoperabil-
interoperability. ity.
At a minimum, applications conforming to this profile MUST recognize At a minimum, applications conforming to this profile MUST recognize
the extensions which must or may be critical in this specification. the following extensions: key usage (see sec. 4.2.1.3), certificate
These extensions are: key usage (see sec. 4.2.1.3), certificate pol- policies (see sec. 4.2.1.5), the subject alternative name (see sec.
icies (see sec. 4.2.1.5), the subject alternative name (see sec.
4.2.1.7), basic constraints (see sec. 4.2.1.10), name constraints 4.2.1.7), basic constraints (see sec. 4.2.1.10), name constraints
(see sec. 4.2.1.11), policy constraints (see sec. 4.2.1.12), and (see sec. 4.2.1.11), policy constraints (see sec. 4.2.1.12), and
extended key usage (see sec. 4.2.1.13). extended key usage (see sec. 4.2.1.13).
In addition, this profile RECOMMENDS application support for the In addition, this profile RECOMMENDS application support for the
authority and subject key identifier (see sec. 4.2.1.1 and 4.2.1.2) authority and subject key identifier (see sec. 4.2.1.1 and 4.2.1.2),
extensions. and inhibit any-policy (see sec. 4.2.1.15) extensions.
4.2.1 Standard Extensions 4.2.1 Standard Extensions
This section identifies standard certificate extensions defined in This section identifies standard certificate extensions defined in
[X.509] for use in the Internet PKI. Each extension is associated [X.509] for use in the Internet PKI. Each extension is associated
with an OID defined in [X.509]. These OIDs are members of the id-ce with an OID defined in [X.509]. These OIDs are members of the id-ce
arc, which is defined by the following: arc, which is defined by the following:
id-ce OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29} id-ce OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29}
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SHA-1 hash of the value of the BIT STRING subjectPublicKey. SHA-1 hash of the value of the BIT STRING subjectPublicKey.
One common method for generating unique values is a monotomically One common method for generating unique values is a monotomically
increasing sequence of integers. increasing sequence of integers.
For end entity certificates, the subject key identifier extension For end entity certificates, the subject key identifier extension
provides a means for identifying certificates containing the particu- provides a means for identifying certificates containing the particu-
lar public key used in an application. Where an end entity has lar public key used in an application. Where an end entity has
obtained multiple certificates, especially from multiple CAs, the obtained multiple certificates, especially from multiple CAs, the
subject key identifier provides a means to quickly identify the set subject key identifier provides a means to quickly identify the set
of certificates containing a particular public key. To assist of certificates containing a particular public key. To assist appli-
applications in identificiation the appropriate end entity certifi- cations in identificiation the appropriate end entity certificate,
cate, this extension SHOULD be included in all end entity certifi- this extension SHOULD be included in all end entity certificates.
cates.
For end entity certificates, subject key identifiers SHOULD be For end entity certificates, subject key identifiers SHOULD be
derived from the public key. Two common methods for generating key derived from the public key. Two common methods for generating key
identifiers from the public key are identifed above. identifiers from the public key are identifed above.
Where a key identifier has not been previously established, this Where a key identifier has not been previously established, this
specification recommends use of one of these methods for generating specification recommends use of one of these methods for generating
keyIdentifiers. keyIdentifiers.
This extension MUST NOT be marked critical. This extension MUST NOT be marked critical.
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is used with a digital signature mechanism to support security is used with a digital signature mechanism to support security
services other than non-repudiation (bit 1), certificate signing services other than non-repudiation (bit 1), certificate signing
(bit 5), or revocation information signing (bit 6). Digital signa- (bit 5), or revocation information signing (bit 6). Digital signa-
ture mechanisms are often used for entity authentication and data ture mechanisms are often used for entity authentication and data
origin authentication with integrity. origin authentication with integrity.
The nonRepudiation bit is asserted when the subject public key is The nonRepudiation bit is asserted when the subject public key is
used to verify digital signatures used to provide a non- used to verify digital signatures used to provide a non-
repudiation service which protects against the signing entity repudiation service which protects against the signing entity
falsely denying some action, excluding certificate or CRL signing. falsely denying some action, excluding certificate or CRL signing.
In the case of later conflict, a reliable third party may deter-
mine the authenticity of the signed data.
Further distinctions between the digitalSignature and nonRepudia-
tion bits may be provided in specific certificate policies.
The keyEncipherment bit is asserted when the subject public key is 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 for key transport. For example, when an RSA key is to be
used for key management, then this bit shall asserted. used for key management, then this bit shall asserted.
The dataEncipherment bit is asserted when the subject public key The dataEncipherment bit is asserted when the subject public key
is used for enciphering user data, other than cryptographic keys. is used for enciphering user data, other than cryptographic keys.
The keyAgreement bit is asserted when the subject public key is The keyAgreement bit is asserted when the subject public key is
used for key agreement. For example, when a Diffie-Hellman key is used for key agreement. For example, when a Diffie-Hellman key is
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id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= { id-ce 16 } id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= { id-ce 16 }
PrivateKeyUsagePeriod ::= SEQUENCE { PrivateKeyUsagePeriod ::= SEQUENCE {
notBefore [0] GeneralizedTime OPTIONAL, notBefore [0] GeneralizedTime OPTIONAL,
notAfter [1] GeneralizedTime OPTIONAL } notAfter [1] GeneralizedTime OPTIONAL }
4.2.1.5 Certificate Policies 4.2.1.5 Certificate Policies
The certificate policies extension contains a sequence of one or more The certificate policies extension contains a sequence of one or more
policy information terms, each of which consists of an object iden- policy information terms, each of which consists of an object iden-
tifier (OID) and optional qualifiers. In an end entity certificate, tifier (OID) and optional qualifiers. Optional qualifiers, which may
these policy information terms indicate the policy under which the be present, are not expected to change the definition of the policy.
certificate has been issued and the purposes for which the certifi-
cate may be used. In a CA certificate, these policy information In an end-entity certificate, these policy information terms indicate
terms limit the set of policies for certification paths which include the policy under which the certificate has been issued and the pur-
When a CA does not wish to limit the set of policies for certifica- poses for which the certificate may be used. In a CA certificate,
tion paths which include this certificate, they may assert the spe- these policy information terms limit the set of policies for certifi-
cial policy anyPolicy. Optional qualifiers, which may be present, cation paths which include this certificate. When a CA does not wish
are not expected to change the definition of the policy. to limit the set of policies for certification paths which include
this certificate, they may assert the special policy anyPolicy, with
a value of {2 5 29 32 0}.
Applications with specific policy requirements are expected to have a Applications with specific policy requirements are expected to have a
list of those policies which they will accept and to compare the pol- 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- icy OIDs in the certificate to that list. If this extension is crit-
ical, the path validation software MUST be able to interpret this ical, the path validation software MUST be able to interpret this
extension (including the optional qualifier), or MUST reject the cer- extension (including the optional qualifier), or MUST reject the cer-
tificate. tificate.
To promote interoperability, this profile RECOMMENDS that policy To promote interoperability, this profile RECOMMENDS that policy
information terms consist of only an OID. Where an OID alone is information terms consist of only an OID. Where an OID alone is
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ia5String IA5String (SIZE (1..200)), ia5String IA5String (SIZE (1..200)),
visibleString VisibleString (SIZE (1..200)), visibleString VisibleString (SIZE (1..200)),
bmpString BMPString (SIZE (1..200)), bmpString BMPString (SIZE (1..200)),
utf8String UTF8String (SIZE (1..200)) } utf8String UTF8String (SIZE (1..200)) }
4.2.1.6 Policy Mappings 4.2.1.6 Policy Mappings
This extension is used in CA certificates. It lists one or more This extension is used in CA certificates. It lists one or more
pairs of OIDs; each pair includes an issuerDomainPolicy and a sub- pairs of OIDs; each pair includes an issuerDomainPolicy and a sub-
jectDomainPolicy. The pairing indicates the issuing CA considers its jectDomainPolicy. The pairing indicates the issuing CA considers its
issuerDomainPolicy equivalent to the subject CA's issuerDomainPolicy equivalent to the subject CA's subjectDomainPol-
subjectDomainPolicy. icy.
The issuing CA's users may accept an issuerDomainPolicy for certain The issuing CA's users may accept an issuerDomainPolicy for certain
applications. The policy mapping tells the issuing CA's users which applications. The policy mapping tells the issuing CA's users which
policies associated with the subject CA are comparable to the policy policies associated with the subject CA are comparable to the policy
they accept. they accept.
Policies should not be mapped either to or from the special value Policies should not be mapped either to or from the special value
anyPolicy. (see 4.2.1.5 certificate policies). anyPolicy. (see 4.2.1.5 certificate policies).
This extension may be supported by CAs and/or applications, and it This extension may be supported by CAs and/or applications, and it
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The subject alternative names extension allows additional identities The subject alternative names extension allows additional identities
to be bound to the subject of the certificate. Defined options to be bound to the subject of the certificate. Defined options
include an Internet electronic mail address, a DNS name, an IP include an Internet electronic mail address, a DNS name, an IP
address, and a uniform resource identifier (URI). Other options address, and a uniform resource identifier (URI). Other options
exist, including completely local definitions. Multiple name forms, exist, including completely local definitions. Multiple name forms,
and multiple instances of each name form, may be included. Whenever and multiple instances of each name form, may be included. Whenever
such identities are to be bound into a certificate, the subject such identities are to be bound into a certificate, the subject
alternative name (or issuer alternative name) extension MUST be used. alternative name (or issuer alternative name) extension MUST be used.
Because the subject alternative name is considered to be defini- Because the subject alternative name is considered to be definitively
tiviely bound to the public key, all parts of the subject alternative bound to the public key, all parts of the subject alternative name
name MUST be verified by the CA. MUST be verified by the CA.
Further, if the only subject identity included in the certificate is Further, if the only subject identity included in the certificate is
an alternative name form (e.g., an electronic mail address), then the an alternative name form (e.g., an electronic mail address), then the
subject distinguished name MUST be empty (an empty sequence), and the subject distinguished name MUST be empty (an empty sequence), and the
subjectAltName extension MUST be present. If the subject field con- subjectAltName extension MUST be present. If the subject field con-
tains an empty sequence, the subjectAltName extension MUST be marked tains an empty sequence, the subjectAltName extension MUST be marked
critical. critical.
When the subjectAltName extension contains an Internet mail address, When the subjectAltName extension contains an Internet mail address,
the address MUST be included as an rfc822Name. The format of an the address MUST be included as an rfc822Name. The format of an
skipping to change at page 34, line 41 skipping to change at page 34, line 50
specific-part must include a fully qualified domain name or IP specific-part must include a fully qualified domain name or IP
address as the host. address as the host.
As specified in [RFC 1738], the scheme name is not case-sensitive As specified in [RFC 1738], the scheme name is not case-sensitive
(e.g., "http" is equivalent to "HTTP"). The host part is also not (e.g., "http" is equivalent to "HTTP"). The host part is also not
case-sensitive, but other components of the scheme-specific-part may case-sensitive, but other components of the scheme-specific-part may
be case-sensitive. When comparing URIs, conforming implementations be case-sensitive. When comparing URIs, conforming implementations
MUST compare the scheme and host without regard to case, but assume MUST compare the scheme and host without regard to case, but assume
the remainder of the scheme-specific-part is case sensitive. the remainder of the scheme-specific-part is case sensitive.
The subjectAltName may carry additional name types through the use of
the otherName field. For example, Kerberos [KRB] format names can be
encoded into the otherName, using the krb5PrincipalName OID and the
KerberosName syntax as defined in [PKINIT].
Subject alternative names may be constrained in the same manner as Subject alternative names may be constrained in the same manner as
subject distinguished names using the name constraints extension as subject distinguished names using the name constraints extension as
described in section 4.2.1.11. described in section 4.2.1.11.
If the subjectAltName extension is present, the sequence MUST contain If the subjectAltName extension is present, the sequence MUST contain
at least one entry. Unlike the subject field, conforming CAs MUST at least one entry. Unlike the subject field, conforming CAs MUST
NOT issue certificates with subjectAltNames containing empty General- NOT issue certificates with subjectAltNames containing empty General-
Name fields. For example, an rfc822Name is represented as an Name fields. For example, an rfc822Name is represented as an
IA5String. While an empty string is a valid IA5String, such an IA5String. While an empty string is a valid IA5String, such an
rfc822Name is not permitted by this profile. The behavior of clients rfc822Name is not permitted by this profile. The behavior of clients
skipping to change at page 41, line 21 skipping to change at page 41, line 30
-- source. Key usage bits that may be consistent: digitalSignature, -- source. Key usage bits that may be consistent: digitalSignature,
-- nonRepudiation -- nonRepudiation
4.2.1.14 CRL Distribution Points 4.2.1.14 CRL Distribution Points
The CRL distribution points extension identifies how CRL information The CRL distribution points extension identifies how CRL information
is obtained. The extension SHOULD be non-critical, but this profile is obtained. The extension SHOULD be non-critical, but this profile
recommends support for this extension by CAs and applications. recommends support for this extension by CAs and applications.
Further discussion of CRL management is contained in section 5. Further discussion of CRL management is contained in section 5.
The cRLDistributionPoints extension is a SEQUENCE of Distribution-
Point. A DistributionPoint consists of three fields, each of which
is optional: the name of the DistributionPoint, ReasonsFlags, and the
cRLIssuer. While each component is optional, a DistributionPoint
MUST NOT consist of only the ReasonsFlags field. If the distribution-
Point omits cRLIssuer, the CRL MUST be issued by the CA that issued
the certificate. If the distributionPointName is absent, cRLIssuer
MUST be present and include a Name corresponding to an X.500 or LDAP
directory entry where the CRL is located.
If the cRLDistributionPoints extension contains a Distribution- If the cRLDistributionPoints extension contains a Distribution-
PointName of type URI, the following semantics MUST be assumed: the PointName of type URI, the following semantics MUST be assumed: the
URI is a pointer to the current CRL for the associated reasons and URI is a pointer to the current CRL for the associated reasons and
will be issued by the associated cRLIssuer. The expected values for 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 the URI are those defined in 4.2.1.7. Processing rules for other
values are not defined by this specification. If the distribution- values are not defined by this specification. If the distribution-
Point omits reasons, the CRL MUST include revocations for all rea- Point omits reasons, the CRL MUST include revocations for all rea-
sons. If the distributionPoint omits cRLIssuer, the CRL MUST be sons.
issued by the CA that issued the certificate.
id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= { id-ce 31 } id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= { id-ce 31 }
cRLDistributionPoints ::= { CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint
CRLDistPointsSyntax }
CRLDistPointsSyntax ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint
DistributionPoint ::= SEQUENCE { DistributionPoint ::= SEQUENCE {
distributionPoint [0] DistributionPointName OPTIONAL, distributionPoint [0] DistributionPointName OPTIONAL,
reasons [1] ReasonFlags OPTIONAL, reasons [1] ReasonFlags OPTIONAL,
cRLIssuer [2] GeneralNames OPTIONAL } cRLIssuer [2] GeneralNames OPTIONAL }
DistributionPointName ::= CHOICE { DistributionPointName ::= CHOICE {
fullName [0] GeneralNames, fullName [0] GeneralNames,
nameRelativeToCRLIssuer [1] RelativeDistinguishedName } nameRelativeToCRLIssuer [1] RelativeDistinguishedName }
ReasonFlags ::= BIT STRING { ReasonFlags ::= BIT STRING {
unused (0), unused (0),
keyCompromise (1), keyCompromise (1),
cACompromise (2), cACompromise (2),
affiliationChanged (3), affiliationChanged (3),
superseded (4), superseded (4),
cessationOfOperation (5), cessationOfOperation (5),
certificateHold (6) } certificateHold (6) }
4.2.1.15 Inhibit Any-Policy
The inhibit any-policy extension can be used in certificates issued
to CAs. The inhibit any-policy indicates that the special any-policy
OID, with the value {2 5 29 32 0}, is not considered an explicit
match for other certificate policies. The value indicates the number
of additional certificates that may appear in the path before any-
policy is no longer permitted. For example, a value of one indicates
that any-policy may be processed in certificates issued by the sub-
ject of this certificate, but not in additional certificates in the
path.
This extension MUST be critical.
id-ce-inhibitAnyPolicy OBJECT IDENTIFIER ::= { id-ce 54 }
InhibitAnyPolicy ::= SkipCerts
SkipCerts ::= INTEGER (0..MAX)
4.2.1.16 Freshest CRL (a.k.a. Delta CRL Distribution Point)
The freshest CRL extension identifies how delta-CRL information is
obtained. The extension MUST 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.
The same syntax is used for this extension and the
cRLDistributionPoints extension, and is described in section
4.2.1.14. The same conventions apply to both extensions.
id-ce-freshestCRL OBJECT IDENTIFIER ::= { id-ce 46 }
FreshestCRL ::= CRLDistributionPoints
4.2.2 Private Internet Extensions 4.2.2 Private Internet Extensions
This section defines one new extension for use in the Internet Public This section defines one new extension for use in the Internet Public
Key Infrastructure. This extension may be used to direct applica- Key Infrastructure. This extension may be used to direct applica-
tions to identify an on-line validation service supporting the issu- tions to identify an on-line validation service supporting the issu-
ing CA. As the information may be available in multiple forms, each ing CA. As the information may be available in multiple forms, each
extension is a sequence of IA5String values, each of which represents extension is a sequence of IA5String values, each of which represents
a URI. The URI implicitly specifies the location and format of the a URI. The URI implicitly specifies the location and format of the
information and the method for obtaining the information. information and the method for obtaining the information.
skipping to change at page 43, line 4 skipping to change at page 44, line 8
AuthorityInfoAccessSyntax ::= AuthorityInfoAccessSyntax ::=
SEQUENCE SIZE (1..MAX) OF AccessDescription SEQUENCE SIZE (1..MAX) OF AccessDescription
AccessDescription ::= SEQUENCE { AccessDescription ::= SEQUENCE {
accessMethod OBJECT IDENTIFIER, accessMethod OBJECT IDENTIFIER,
accessLocation GeneralName } accessLocation GeneralName }
id-ad OBJECT IDENTIFIER ::= { id-pkix 48 } id-ad OBJECT IDENTIFIER ::= { id-pkix 48 }
id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 } id-ad-caIssuers OBJECT IDENTIFIER ::= { id-ad 2 }
Each entry in the sequence AuthorityInfoAccessSyntax describes the Each entry in the sequence AuthorityInfoAccessSyntax describes the
format and location of additional information provided by the CA who format and location of additional information provided by the CA who
issued the certificate in which this extension appears. The type and issued the certificate in which this extension appears. The type and
format of the information is specified by the accessMethod field; the format of the information is specified by the accessMethod field; the
accessLocation field specifies the location of the information. The accessLocation field specifies the location of the information. The
retrieval mechanism may be implied by the accessMethod or specified retrieval mechanism may be implied by the accessMethod or specified
by accessLocation. by accessLocation.
This profile defines one OID for accessMethod. The id-ad-caIssuers <<add pointer to OCSP>> This profile defines one OID for
OID is used when the additional information lists CAs that have accessMethod. The id-ad-caIssuers OID is used when the additional
issued certificates superior to the CA that issued the certificate information lists CAs that have issued certificates superior to the
containing this extension. The referenced CA Issuers description is CA that issued the certificate containing this extension. The refer-
intended to aid certificate users in the selection of a certification enced CA Issuers description is intended to aid certificate users in
path that terminates at a point trusted by the certificate user. the selection of a certification path that terminates at a point
trusted by the certificate user.
When id-ad-caIssuers appears as accessInfoType, the accessLocation When id-ad-caIssuers appears as accessInfoType, the accessLocation
field describes the referenced description server and the access pro- field describes the referenced description server and the access pro-
tocol to obtain the referenced description. The accessLocation field tocol to obtain the referenced description. The accessLocation field
is defined as a GeneralName, which can take several forms. Where the is defined as a GeneralName, which can take several forms. Where the
information is available via http, ftp, or ldap, accessLocation MUST information is available via http, ftp, or ldap, accessLocation MUST
be a uniformResourceIdentifier. Where the information is available be a uniformResourceIdentifier. Where the information is available
via the directory access protocol (dap), accessLocation MUST be a via the directory access protocol (dap), accessLocation MUST be a
directoryName. When the information is available via electronic mail, directoryName. When the information is available via electronic mail,
accessLocation MUST be an rfc822Name. The semantics of other name accessLocation MUST be an rfc822Name. The semantics of other name
skipping to change at page 44, line 47 skipping to change at page 46, line 4
revocationDate Time, revocationDate Time,
crlEntryExtensions Extensions OPTIONAL crlEntryExtensions Extensions OPTIONAL
-- if present, shall be v2 -- if present, shall be v2
} OPTIONAL, } OPTIONAL,
crlExtensions [0] EXPLICIT Extensions OPTIONAL crlExtensions [0] EXPLICIT Extensions OPTIONAL
-- if present, shall be v2 -- if present, shall be v2
} }
-- Version, Time, CertificateSerialNumber, and Extensions -- Version, Time, CertificateSerialNumber, and Extensions
-- are all defined in the ASN.1 in section 4.1 -- are all defined in the ASN.1 in section 4.1
-- AlgorithmIdentifier is defined in section 4.1.1.2 -- AlgorithmIdentifier is defined in section 4.1.1.2
The following items describe the use of the X.509 v2 CRL in the The following items describe the use of the X.509 v2 CRL in the
Internet PKI. Internet PKI.
5.1.1 CertificateList Fields 5.1.1 CertificateList Fields
The CertificateList is a SEQUENCE of three required fields. The The CertificateList is a SEQUENCE of three required fields. The
fields are described in detail in the following subsections. fields are described in detail in the following subsections.
5.1.1.1 tbsCertList 5.1.1.1 tbsCertList
The first field in the sequence is the tbsCertList. This field is The first field in the sequence is the tbsCertList. This field is
itself a sequence containing the name of the issuer, issue date, itself a sequence containing the name of the issuer, issue date,
issue date of the next list, the list of revoked certificates, and issue date of the next list, the optional list of revoked certifi-
optional CRL extensions. Further, each entry on the revoked certifi- cates, and optional CRL extensions. When there are no revoked certi-
cate list is defined by a sequence of user certificate serial number, ficates, the revoked certificates list is absent. When one or more
revocation date, and optional CRL entry extensions. certificates are revoked, each entry on the revoked certificate list
is defined by a sequence of user certificate serial number, revoca-
tion date, and optional CRL entry extensions.
5.1.1.2 signatureAlgorithm 5.1.1.2 signatureAlgorithm
The signatureAlgorithm field contains the algorithm identifier for The signatureAlgorithm field contains the algorithm identifier for
the algorithm used by the CA to sign the CertificateList. The field the algorithm used by the CA to sign the CertificateList. The field
is of type AlgorithmIdentifier, which is defined in section 4.1.1.2. is of type AlgorithmIdentifier, which is defined in section 4.1.1.2.
Section 7.2 lists the supported algorithms for this specification. Section 7.2 lists the supported algorithms for this specification.
Conforming CAs MUST use the algorithm identifiers presented in sec- Conforming CAs MUST use the algorithm identifiers presented in sec-
tion 7.2 when signing with a supported signature algorithm. tion 7.2 when signing with a supported signature algorithm.
skipping to change at page 47, line 23 skipping to change at page 48, line 31
profile that issue CRLs MUST encode nextUpdate as GeneralizedTime for profile that issue CRLs MUST encode nextUpdate as GeneralizedTime for
dates in the year 2050 or later. dates in the year 2050 or later.
Where encoded as UTCTime, nextUpdate MUST be specified and inter- Where encoded as UTCTime, nextUpdate MUST be specified and inter-
preted as defined in section 4.1.2.5.1. Where encoded as General- preted as defined in section 4.1.2.5.1. Where encoded as General-
izedTime, nextUpdate MUST be specified and interpreted as defined in izedTime, nextUpdate MUST be specified and interpreted as defined in
section 4.1.2.5.2. section 4.1.2.5.2.
5.1.2.6 Revoked Certificates 5.1.2.6 Revoked Certificates
Revoked certificates are listed. The revoked certificates are named When there are no revoked certificates, the revoked certificates list
by their serial numbers. Certificates revoked by the CA are uniquely is absent. Otherwise, revoked certificates are listed by their
identified by the certificate serial number. The date on which the serial numbers. Certificates revoked by the CA are uniquely identi-
revocation occurred is specified. The time for revocationDate MUST fied by the certificate serial number. The date on which the revoca-
be expressed as described in section 5.1.2.4. Additional information tion occurred is specified. The time for revocationDate MUST be
may be supplied in CRL entry extensions; CRL entry extensions are expressed as described in section 5.1.2.4. Additional information may
discussed in section 5.3. be supplied in CRL entry extensions; CRL entry extensions are dis-
cussed in section 5.3.
5.1.2.7 Extensions 5.1.2.7 Extensions
This field may only appear if the version is 2 (see sec. 5.1.2.1). This field may only appear if the version is 2 (see sec. 5.1.2.1).
If present, this field is a SEQUENCE of one or more CRL extensions. If present, this field is a SEQUENCE of one or more CRL extensions.
CRL extensions are discussed in section 5.2. CRL extensions are discussed in section 5.2.
5.2 CRL Extensions 5.2 CRL Extensions
The extensions defined by ANSI X9 and ISO/IEC/ITU for X.509 v2 CRLs The extensions defined by ANSI X9 and ISO/IEC/ITU for X.509 v2 CRLs
skipping to change at page 49, line 8 skipping to change at page 50, line 13
supersedes another CRL. CAs conforming to this profile MUST include supersedes another CRL. CAs conforming to this profile MUST include
this extension in all CRLs. this extension in all CRLs.
id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 } id-ce-cRLNumber OBJECT IDENTIFIER ::= { id-ce 20 }
cRLNumber ::= INTEGER (0..MAX) cRLNumber ::= INTEGER (0..MAX)
5.2.4 Delta CRL Indicator 5.2.4 Delta CRL Indicator
The delta CRL indicator is a critical CRL extension that identifies a The delta CRL indicator is a critical CRL extension that identifies a
delta-CRL. The use of delta-CRLs can significantly improve process- CRL as being a delta CRL. Delta CRLs contain updates to revocation
ing time for applications which store revocation information in a information previously distributed, rather than all the information
format other than the CRL structure. This allows changes to be added that would appear in a complete CRL. The use of delta CRLs can sig-
to the local database while ignoring unchanged information that is nificantly reduce network load and processing time in some environ-
already in the local database. ments. Delta CRLs are generally smaller than the CRLs they update,
so applications that obtain delta CRLs consume less network bandwidth
than applications that obtain the corresponding complete CRLs.
Applications which store revocation information in a format other
than the CRL structure can add new revocation information to the
local database without reprocessing information.
When a delta-CRL is issued, the CAs MUST also issue a complete CRL. The delta CRL indicator extension contains a single value of type
BaseCRLNumber. This value identifies the CRL number of the base CRL
that was used as the foundation in the generation of this delta CRL.
The referenced base CRL is a CRL that was explicitly issued as a CRL
that is complete for a given scope (e.g., a set of revocation reasons
or a particular distribution point.) The CRL containing the delta CRL
indicator extension contains all updates to the certificate revoca-
tion status for that same scope. The combination of a CRL containing
the delta CRL indicator extension plus the CRL referenced in the
BaseCRLNumber component of this extension is equivalent to a full
CRL, for the applicable scope, at the time of publication of the
delta CRL.
The value of BaseCRLNumber identifies the CRL number of the base CRL When a conforming CA issues a delta CRL, the CA MUST also issue a CRL
that was used as the starting point in the generation of this delta- that is complete for the given scope. The CRL number extension in
CRL. The delta-CRL contains the changes between the base CRL and the the delta CRL and the complete CRL MUST contain the same value. When
current CRL issued along with the delta-CRL. It is the decision of a a delta CRL is issued, it MUST cover the same set of reasons and same
CA as to whether to provide delta-CRLs. Again, a delta-CRL MUST NOT set of certificates that were covered by the base CRL it references.
be issued without a corresponding complete CRL. The value of
CRLNumber for both the delta-CRL and the corresponding complete CRL
MUST be identical.
A CRL user constructing a locally held CRL from delta-CRLs MUST con- An application can construct a CRL that is complete for a given
sider the constructed CRL incomplete and unusable if the CRLNumber of scope, at the current time, in either of the following ways:
the received delta-CRL is more than one greater than the CRLnumber of (a) by retrieving the current delta CRL for that scope, and com-
the delta-CRL last processed. bining it with an issued CRL that is complete for that scope and
that has a cRLNumber greater than or equal to the cRLNumber of the
base CRL referenced in the delta CRL; or
(b) by retrieving the current delta CRL for that scope and combin-
ing it with a locally constructed CRL whose cRLNumber is greater
than or equal to the cRLNumber of the base CRL referenced in the
current delta CRL.
The constructed CRL has the CRL number specified in the CRL number
extension found in the delta CRL used in its construction.
CAs must ensure that application of a delta CRL to the referenced
base revocation information accurately reflects the current status of
revocation. If a CA supports the certificateHold revocation reason
the following rules must be applied when generating delta CRLs:
(a) If a certificate was listed as revoked with revocation reason
certificateHold on a CRL (either a delta CRL or a CRL that is com-
plete for a given scope), whose cRLNumber is n, and the hold is
subsequently released, the certificate must be included in all
delta CRLs issued after the hold is released where the cRLNumber
of the referenced base CRL is less than or equal to n. The certi-
ficate must be listed with revocation reason removeFromCRL unless
the certificate is subsequently revoked again for one of the revo-
cation reasons covered by the delta CRL, in which case the certi-
ficate must be listed with the revocation reason appropriate for
the subsequent revocation.
(b) If the certificate was not removed from hold, but was per-
manently revoked, then it must be listed on all subsequent delta
CRLs where the cRLNumber of the referenced base CRL is less than
the cRLNumber of the CRL (either a delta CRL or a CRL that is com-
plete for the given scope) on which the permanent revocation
notice first appeared.
id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= { id-ce 27 } id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= { id-ce 27 }
deltaCRLIndicator ::= BaseCRLNumber deltaCRLIndicator EXTENSION ::= {
SYNTAX BaseCRLNumber
IDENTIFIED BY id-ce-deltaCRLIndicator }
BaseCRLNumber ::= CRLNumber BaseCRLNumber ::= CRLNumber
5.2.5 Issuing Distribution Point 5.2.5 Issuing Distribution Point
The issuing distribution point is a critical CRL extension that iden- The issuing distribution point is a critical CRL extension that iden-
tifies the CRL distribution point for a particular CRL, and it indi- tifies the CRL distribution point for a particular CRL, and it indi-
cates whether the CRL covers revocation for end entity certificates cates whether the CRL covers revocation for end entity certificates
only, CA certificates only, or a limitied set of reason codes. only, CA certificates only, or a limited set of reason codes.
Although the extension is critical, conforming implementations are Although the extension is critical, conforming implementations are
not required to support this extension. not required to support this extension.
The CRL is signed using the CA's private key. CRL Distribution 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 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 X.500 Directory, it is stored in the Directory entry corresponding to
the CRL distribution point, which may be different than the Directory the CRL distribution point, which may be different than the Directory
entry of the CA. entry of the CA.
The reason codes associated with a distribution point shall be speci- The reason codes associated with a distribution point shall be speci-
fied in onlySomeReasons. If onlySomeReasons does not appear, the fied in onlySomeReasons. If onlySomeReasons does not appear, the dis-
distribution point shall contain revocations for all reason codes. tribution point shall contain revocations for all reason codes. CAs
CAs may use CRL distribution points to partition the CRL on the basis may use CRL distribution points to partition the CRL on the basis of
of compromise and routine revocation. In this case, the revocations compromise and routine revocation. In this case, the revocations
with reason code keyCompromise (1) and cACompromise (2) appear in one with reason code keyCompromise (1) and cACompromise (2) appear in one
distribution point, and the revocations with other reason codes distribution point, and the revocations with other reason codes
appear in another distribution point. appear in another distribution point.
Where the issuingDistributionPoint extension contains a URL, the fol- Where the issuingDistributionPoint extension contains a URL, the fol-
lowing semantics MUST be assumed: the object is a pointer to the most lowing semantics MUST be assumed: the object is a pointer to the most
current CRL issued by this CA. The URI schemes ftp, http, mailto current CRL issued by this CA. The URI schemes ftp, http, mailto
[RFC1738] and ldap [RFC1778] are defined for this purpose. The URI [RFC1738] and ldap [RFC1778] are defined for this purpose. The URI
MUST be an absolute, not relative, pathname and MUST specify the MUST be an absolute, not relative, pathname and MUST specify the
host. host.
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must satisfy each of the following: must satisfy each of the following:
(1) The certificate was signed with the (1) The certificate was signed with the
working_public_key_algorithm using the working_public_key and working_public_key_algorithm using the working_public_key and
the working_public_key_parameters. the working_public_key_parameters.
(2) The certificate validity period includes time T. (2) The certificate validity period includes time T.
(3) At time T, the certificate is not revoked and is not on (3) At time T, the certificate is not revoked and is not on
hold status. This may be determined by obtaining the appropri- hold status. This may be determined by obtaining the appropri-
ate CRL (see section 6.4), status information, or by out-of- ate CRL (see section 6.3), status information, or by out-of-
band mechanisms. band mechanisms.
(4) The certificate issuer name is the working_issuer_name. (4) The certificate issuer name is the working_issuer_name.
(5) The certificate issuer unique identifier is the (5) The certificate issuer unique identifier is the
working_issuer_UID, meaning: working_issuer_UID, meaning:
(i) working_issuer_UID is non-null and matches the value in (i) working_issuer_UID is non-null and matches the value in
the issuerUID field, or the issuerUID field, or
(ii) working_issuer_UID is null and the issuerUID field is (ii) working_issuer_UID is null and the issuerUID field is
not present. not present.
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(c) Assign the certificate subject name to working_issuer_name. (c) Assign the certificate subject name to working_issuer_name.
(d) Assign the certificate subjectPublicKey to working_public_key. (d) Assign the certificate subjectPublicKey to working_public_key.
(e) If the subjectPublicKeyInfo field of the certificate contains (e) If the subjectPublicKeyInfo field of the certificate contains
an algorithm field with non-null parameters, assign the parameters an algorithm field with non-null parameters, assign the parameters
to the working_public_key_parameters variable. to the working_public_key_parameters variable.
If the subjectPublicKeyInfo field of the certificate contains an If the subjectPublicKeyInfo field of the certificate contains an
algorithm field with null parameters, compare the certificate sub- algorithm field with null parameters or parameters are omitted,
jectPublicKey algorithm to the working_public_key_algorithm. If compare the certificate subjectPublicKey algorithm to the
the certificate subjectPublicKey algorithm and the working_public_key_algorithm. If the certificate subjectPublicKey
working_public_key_algorithm are different, set the algorithm and the working_public_key_algorithm are different, set
working_public_key_parameters to null. the working_public_key_parameters to null.
(f) Assign the certificate subjectPublicKey algorithm to the (f) Assign the certificate subjectPublicKey algorithm to the
working_public_key_algorithm variable. working_public_key_algorithm variable.
(g) If a name constraints extension is included in the certifi- (g) If a name constraints extension is included in the certifi-
cate, modify the permitted_subtrees and excluded_subtrees state cate, modify the permitted_subtrees and excluded_subtrees state
variables as follows: variables as follows:
(1) If permittedSubtrees is present in the certificate, set the (1) If permittedSubtrees is present in the certificate, set the
permitted_subtrees state variable to the intersection of its permitted_subtrees state variable to the intersection of its
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(b) If a policy constraints extension is included in the certifi- (b) If a policy constraints extension is included in the certifi-
cate and requireExplicitPolicy is present and has a value of 0, cate and requireExplicitPolicy is present and has a value of 0,
set the explicit_policy state variable to 0. set the explicit_policy state variable to 0.
(c) Assign the certificate subjectPublicKey to working_public_key. (c) Assign the certificate subjectPublicKey to working_public_key.
(d) If the subjectPublicKeyInfo field of the certificate contains (d) If the subjectPublicKeyInfo field of the certificate contains
an algorithm field with non-null parameters, assign the parameters an algorithm field with non-null parameters, assign the parameters
to the working_public_key_parameters variable. to the working_public_key_parameters variable.
If the subjectPublicKeyInfo field of the certificate contains an
algorithm field with null parameters or parameters are omitted,
compare the certificate subjectPublicKey algorithm to the
working_public_key_algorithm. If the certificate subjectPublicKey
algorithm and the working_public_key_algorithm are different, set
the working_public_key_parameters to null.
(e) Assign the certificate subjectPublicKey algorithm to the (e) Assign the certificate subjectPublicKey algorithm to the
working_public_key_algorithm variable. working_public_key_algorithm variable.
(f) Recognize and process any other critical extension present in (f) Recognize and process any other critical extension present in
the certificate n. the certificate n.
(g) Calculate the intersection of the valid_policy_tree and the (g) Calculate the intersection of the valid_policy_tree and the
user_initial_policy_set, as follows: user_initial_policy_set, as follows:
(i) If the valid_policy_tree is NULL, the intersection is NULL. (i) If the valid_policy_tree is NULL, the intersection is NULL.
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position in the certification path where the PCA is expected. At the position in the certification path where the PCA is expected. At the
nominated PCA position, the CA name is compared against this list. nominated PCA position, the CA name is compared against this list.
If a recognized PCA name is found, then a constraint of Subordina- If a recognized PCA name is found, then a constraint of Subordina-
teToCA is implicitly assumed for the remainder of the certification teToCA is implicitly assumed for the remainder of the certification
path and processing continues. If no valid PCA name is found, and if path and processing continues. If no valid PCA name is found, and if
the certification path cannot be validated on the basis of identified the certification path cannot be validated on the basis of identified
policies, then the certification path is considered invalid. policies, then the certification path is considered invalid.
6.3 CRL Validation 6.3 CRL Validation
This section augments section 6.1, Basic Path Validation. In that This section describes the steps necessary to determine if a certifi-
section 6.1.3, Basic Certificate Processing, each certificate i must cate is revoked or on hold status when CRLs are the revocation
satisfy the condition (a), (3): "At time T, the certificate is not mechanism used by the certificate issuer. Conforming implementations
revoked and is not on hold status." Section 6.1 is independent of of this specification are not required to implement this algorithm,
the mechanism(s) used to verify certificate status. This section but MUST be functionally equivalent to the external behavior result-
describes the inputs, state variables, and processing steps required ing from this procedure. Any algorithm may be used by a particular
to perform 6.1 using CRLs. implementation so long as it derives the correct result.
The section is organized in parallel with section 6.1. Section 6.3.1 This algorithm defines a set of inputs, a set of state variables, and
supplements section 6.1.1, and so on. There are no sections 6.3.5 or processing steps that are performed for each certificate in the path.
6.3.6; this section does not modify the wrap-up procedure or output
procedure of path validation.
6.3.1 Revocation Inputs 6.3.1 Revocation Inputs
To support revocation processing, the algorithm requires the intro- To support revocation processing, the algorithm requires two inputs:
duction of three additional state variables:
(h) which-reasons: This input contains the set of reasons for (a) certificate: the algorithm requires the certificate serial
revocation that are of interest, or the special value "any- number and issuer name to determine if a certificate is on a par-
reason." The legal members of the set are the possible values for ticular CRL. The basicConstraints extension is used to determine
reasonflags: keyCompromise; caCompromise; affiliationChanged; whether the supplied certificate is associated with a CA or an
superseded; cessationOfOperation; and certificateHold. end-entity. If present, the algorithm may use the cRLDistribu-
tionsPoint and freshestCRL extensions to determine revocation
status.
(i) required-freshness: This input defines the oldest acceptable (b) use-deltas: This boolean input determines if the delta needs
revocation data. This input is a relative time, or the special to be checked if the CRL is still valid
value "best available".
(j) current-time: This input specifies the current date and time. Note that implementations supporting legacy PKIs, such as RFC 1422
and X.509 version 1, will need an additional input indicating
whether the supplied certificate is associated with a CA or an
end-entity.
6.3.2 Initialization and Revocation State Variables 6.3.2 Initialization and Revocation State Variables
To support CRL processing, the algorithm requires five new state To support CRL processing, the algorithm requires the following state
variables: variables:
(m) CRL_sign_flag: This flag indicates that the previous certifi- (a) reasons_mask: This variable contains the set of revocation
cate in the path can be used to validate the signature on a CRL. reasons supported by the CRLs and delta CRLs processed so far. The
(This is true if the certificate was a CA certificate and either legal members of the set are the possible values for reasonflags:
(a) the keyUsage extension did not appear or (b) the key usage unspecified; keyCompromise; caCompromise; affiliationChanged;
extension asserted the cRLSign bit.) The initial value of this superseded; cessationOfOperation; and certificateHold. The spe-
variable is TRUE. cial value "all-reasons" is used to denote the set of all legal
members. This variable is initialized to the empty set.
(n) possible_CRLs: This variable contains the set of prospective (b) cert_status: This variable contains the status of the certifi-
CRLs that may be useful for verifying the status of this certifi- cate. Legal values are unspecified; keyCompromise; caCompromise;
cate. affiliationChanged; superseded; cessationOfOperation; and certifi-
cateHold, the special value "UNREVOKED", or the special value
"UNDETERMINED". This variable is initialized to the special value
"UNREVOKED".
(o) approved_CRLs: This variable contains the set of CRLs that may (c) interim_reasons_mask: This contains the set of revocation rea-
be used to verify the status of this certificate. The initial sons supported by the CRL or delta CRL currently being processed.
value for this variable is "empty."
(p) oldest_CRL: This constant specifies the earliest acceptable Note: In some environments, it is not necessary to check all reason
issue date for a CRL. It is set to the value current-time minus codes. For example, some envornments only are concerned with
required-freshness. If required_freshness is "best_available", caCompromise and keyCompromise for CA certificates. This algorithnm
oldest_CRL is set to the issue date of certificate i. checks all reason codes. Additional processing and state variables
may be necessary to limit the checking to a subset of the reason
codes.
(q) approved_reasons: This variable contains the set of revocation 6.3.3 CRL Processing
reasons supported by the approved_CRLs. This variable is initial-
ized to the empty set.
6.3.3 Basic Certificate Processing This algorithm begins by assuming the certificate is not revoked.
The algorithm checks one or more CRLs until either the certificate
status is determined to be revoked or sufficent CRLs have been
checked to cover all reason codes.
This algorithm attempts to satisfy the requirements using CRLs that For each distribution point (DP) in the crl distribution points
can be validated using certificate i-1. Such CRLs are most efficient extension while ((reasons_mask is not "all-reasons") and (cert_status
to process, since no additional certification paths need be pro- is UNREVOKED))
cessed. If this cannot be achieved, other CRLs issued by the
working_issuer_name and indirect CRLs are added. In both cases,
additional certification paths must be constructed and validated.
In the second step, this algorithm determines if the certificate (1) locate the corresponding CRL in CRL cache, and perform the
should be accepted or rejected. following verifications:
Step 1. (a) compute the interim_reasons_mask for this CRL as follows:
(a) For each CRL in possible_CRLs, verify that the issuer name is 1. if the CRL includes reasons and the DP includes reasons,
the working_issuer_name or that certificate i contains a distribu- then set interim_reasons_mask to the intersection of of rea-
tion points extension and the issuer name is specified a cRLIssuer sons in the DP and reasons in CRL reasons extension.
field.
(b) For each CRL X in possible_CRLs, perform the following steps: 2. if the CRL includes reasons but the DP omits reasons,
then set interim_reasons_mask to the value of CRL reasons.
(1) Verify that the value of the thisUpdate field is equal to 3. if the CRL omits reasons but the DP includes reasons,
or after oldest_CRL. (2) If the required_freshness is "best then set interim_reasons_mask to the value of DP reasons.
available", verify that the value of the nextUpdate field is
after current-time.
(3) If the CRL includes an issuing distribution point exten- 4. if the CRL omits reasons and the DP omits reasons, then
sion, and the onlySomeReasons field is present, verify that the set interim_reasons_mask to the special value "all-reasons".
intersection of onlySomeReasons and which-reasons is not empty.
(4) If the CRL includes an issuing distribution point Verify that interim_reasons_mask includes one or more reasons
extension, and the onlyContainsUserCerts is asserted, verify that is not included in the reasons_mask.
that certificate i is not a CA certificate.
(5) If the CRL includes an issuing distribution point exten- (b) Verify the issuer of the CRL as follows:
sion, and the onlyContainsCACerts is asserted, verify that cer-
tificate i is a CA certificate.
If any of the checks (1), (2), (3), (4) or (5) fail, delete CRL X if the DP includes cRLIssuer, then verify that the CRL
from possible_CRLs. issuer matches cRLIssuer else verify that the CRL issuer
matches the certificate issuer.
(b) If CRL_sign_flag is TRUE, repeat the following steps until (c) obtain and validate the certification path for the CRL
approved the approved_reasons = "all reasons" or approved_reasons issuer.
is a superset of which_reasons or possible_CRLs is exhausted:
(1) For each CRL X in possible_CRLs that was issued by the (d) validate the signature on the CRL.
working_issuer_name and signed with the
working_public_key_algorithm using the working_public_key and
working_public_key_parameters:
(i) Delete CRL X from possible_CRLs and add it to (2) If each of the verifications (a) through (d) succeeds, then
approved_CRLs. perform the following steps:
(ii) If CRL X did not include an issuing distribution point (a) If the value of next update field is before the current-
extension, or the onlySomeReasons field was not present in time, otain an appropriate delta CRL or discard the CRL.
that extension, set approved_reasons to "all_reasons." If
CRL X includes an issuing distribution point extension, and
the onlySomeReasons field is present, assign
approved_reasons the intersection of approved reasons and
the onlySomeReasons field.
If approved_reasons is "all reasons", or is a superset of (b) If the user wants freshest available info AND the freshest
which-reasons, go to step 2. CRL extension is present, check for a corresponding delta for
this base.
(c) For each CRL X in possible_CRLs: (c) If a delta was obtained in (a) or (b), verify that the
delta CRL addresses the same set of certificates and the same
set of reasons as the CRL.
(1) If CRL X is valid for all reasons, or the intersection of (d) Perform the checks in step 1 (b) and (c):
onlySomeReasons and which-reasons is not a subset of
approved_reasons and you can construct and validate a certifi-
cation path where cRLSigning is assserted in certificate n-1 or
the key usage extension is omitted from certificate n-1. These
paths may use certificate i-1 to specify the trust anchor.
(The path from the normal trust anchor through certificate i-1
has already been validated at this stage in the algorithm in
Section 6.1)
(i) Add CRL X to approved_CRLs. 1. obtain and validate the certification path for the delta
issuer
(ii) If CRL X did not include an issuing distribution point 2. validate the signature on the delta CRL
extension, or the onlySomeReasons field was not present in
that extension, set approved_reasons to "all_reasons." If
CRL X includes an issuing distribution point extension, and
the onlySomeReasons field is present, assign
approved_reasons the intersection of approved reasons and
the onlySomeReasons field.
If approved_reasons is "all reasons", or is a superset of (e) If a delta CRL was obtained in (a) or (b), and the
which-reasons, go to step 2. verifications (c) and (d) suceeded, combine the base and
delta to form a complete CRL.
(2) If such a path cannot be constructed or it doesn't add (3) If steps and (1) and (2) succeed, then set reasons_mask to the
value, delete it from the possible_CRLs. union of reasons_mask and interim_reasons_mask
(4) Search for the certificate on the CRL
(d) If approved_reasons is still not a superset of which-reasons, (a) search for the serial number on the CRL
reject the certificate due to insufficient information.
Step 2. (b) if (a) succeeds, verify that (1) the CRL entry extension
Certificate issuer is not present or (2) the issuer identified
in the CRL entry extension Certificate issuer is the issuer of
the certificate.
Determine if certificate i is on any of the CRLs. If the certifi- (c) if (a) and (b) succeeded, set the cert_status variable as
cate is listed as certificatehold on one CRL and revoked on appropriate:
another, ignore the certificatehold. If the reasonCode is in
which-reasons, the certificate must be rejected. If the certifi-
cate is not on any of the CRLs, or the reasonCode is not in
which-reasons, the certificate is accepted.
6.3.4 Preparation for Certificate i+1 1. if the reasons extension is present, set the cert_status
variable to the value of the reasons extension
Add the following four steps to the steps in section 6.1.X: 2. if the reasons extension is not present, set the
cert_status variable to the special value "not specified"
(p) If certificate i does not include the key usage extenion, or if ((reasons_mask is "all-reasons") OR (if cert_status is not
the key usage extension asserts the value cRLSigning, set UNREVOKED) return cert_status
CRL_sign_flag to TRUE, otherwise set CRL_sign_flag to FALSE.
(q) Set possible_CRLs to the empty set. If all CRLs named in the crl distribution points extension have
been exhausted, and the reasons_mask is not "all-reasons" and the
cert_status is still UNREVOKED, the verifier must obtain addi-
tional CRLs. If the
(r) Set approved_CRLs to the empty set. The verifier must repeat the process above with the additional
CRLs not specified in a distribution point.
(s) Set approved_reasons to the empty set. If all CRLs are exhausted and the reasons_mask is not "all rea-
sons" return the cert_status UNDETERMINED.
7 Algorithm Support 7 Algorithm Support
This section describes cryptographic algorithms which may be used This section describes cryptographic algorithms which may be used
with this profile. The section describes one-way hash functions and with this profile. The section describes one-way hash functions and
digital signature algorithms which may be used to sign certificates digital signature algorithms which may be used to sign certificates
and CRLs, and identifies OIDs for public keys contained in a certifi- and CRLs, and identifies OIDs for public keys contained in a certifi-
cate. cate.
Conforming CAs and applications are not required to support the Conforming CAs and applications are not required to support the algo-
algorithms or algorithm identifiers described in this section. How- rithms or algorithm identifiers described in this section. However,
ever, conforming CAs and applications that use the algorithms identi- conforming CAs and applications that use the algorithms identified
fied here MUST support them as specified. here MUST support them as specified.
7.1 One-way Hash Functions 7.1 One-way Hash Functions
This section identifies one-way hash functions for use in the Inter- This section identifies one-way hash functions for use in the Inter-
net PKI. One-way hash functions are also called message digest algo- 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 rithms. SHA-1 is the preferred one-way hash function for the Internet
PKI. However, PEM uses MD2 for certificates [RFC 1422] [RFC 1423] 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 is used in other legacy applications. For this reason, MD2
and MD5 are included in this profile. and MD5 are included in this profile.
skipping to change at page 76, line 10 skipping to change at page 77, line 51
id-dsa-with-sha1 ID ::= { id-dsa-with-sha1 ID ::= {
iso(1) member-body(2) us(840) x9-57 (10040) iso(1) member-body(2) us(840) x9-57 (10040)
x9cm(4) 3 } x9cm(4) 3 }
Where the id-dsa-with-sha1 algorithm identifier appears as the algo- Where the id-dsa-with-sha1 algorithm identifier appears as the algo-
rithm field in an AlgorithmIdentifier, the encoding shall omit the rithm field in an AlgorithmIdentifier, the encoding shall omit the
parameters field. That is, the AlgorithmIdentifier shall be a parameters field. That is, the AlgorithmIdentifier shall be a
SEQUENCE of one component - the OBJECT IDENTIFIER id-dsa-with-sha1. SEQUENCE of one component - the OBJECT IDENTIFIER id-dsa-with-sha1.
The DSA parameters in the subjectPublicKeyInfo field of the certifi- The DSA parameters in the subjectPublicKeyInfo field of the
cate of the issuer shall apply to the verification of the signature. certificate of the issuer shall apply to the verification of the sig-
nature.
When signing, the DSA algorithm generates two values. These values When signing, the DSA algorithm generates two values. These values
are commonly referred to as r and s. To easily transfer these two 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- values as one signature, they shall be ASN.1 encoded using the fol-
lowing ASN.1 structure: lowing ASN.1 structure:
Dss-Sig-Value ::= SEQUENCE { Dss-Sig-Value ::= SEQUENCE {
r INTEGER, r INTEGER,
s INTEGER } s INTEGER }
skipping to change at page 78, line 52 skipping to change at page 80, line 46
id-dsa ID ::= { iso(1) member-body(2) us(840) x9-57(10040) id-dsa ID ::= { iso(1) member-body(2) us(840) x9-57(10040)
x9cm(4) 1 } x9cm(4) 1 }
The id-dsa algorithm syntax includes optional parameters. These The id-dsa algorithm syntax includes optional parameters. These
parameters are commonly referred to as p, q, and g. When omitted, parameters are commonly referred to as p, q, and g. When omitted,
the parameters component shall be omitted entirely. That is, the the parameters component shall be omitted entirely. That is, the
AlgorithmIdentifier shall be a SEQUENCE of one component - the OBJECT AlgorithmIdentifier shall be a SEQUENCE of one component - the OBJECT
IDENTIFIER id-dsa. IDENTIFIER id-dsa.
If the DSA algorithm parameters are present in the If the DSA algorithm parameters are present in the subjectPublicKey-
subjectPublicKeyInfo AlgorithmIdentifier, the parameters are included Info AlgorithmIdentifier, the parameters are included using the fol-
using the following ASN.1 structure: lowing ASN.1 structure:
Dss-Parms ::= SEQUENCE { Dss-Parms ::= SEQUENCE {
p INTEGER, p INTEGER,
q INTEGER, q INTEGER,
g INTEGER } g INTEGER }
If the DSA algorithm parameters are absent from the subjectPublicKey- If the DSA algorithm parameters are absent from the subjectPublicKey-
Info AlgorithmIdentifier and the CA signed the subject certificate Info AlgorithmIdentifier and the CA signed the subject certificate
using DSA, then the certificate issuer's DSA parameters apply to the using DSA, then the certificate issuer's DSA parameters apply to the
subject's DSA key. If the DSA algorithm parameters are absent from subject's DSA key. If the DSA algorithm parameters are absent from
skipping to change at page 84, line 10 skipping to change at page 85, line 51
In addition, where a key compromise or CA failure occurs for a In addition, where a key compromise or CA failure occurs for a
trusted CA, the user will need to modify the information provided to trusted CA, the user will need to modify the information provided to
the path validation routine. Selection of too many trusted CAs will the path validation routine. Selection of too many trusted CAs will
make the trusted CA information difficult to maintain. On the other make the trusted CA information difficult to maintain. On the other
hand, selection of only one trusted CA may limit users to a closed hand, selection of only one trusted CA may limit users to a closed
community of users until a global PKI emerges. community of users until a global PKI emerges.
The quality of implementations that process certificates may also The quality of implementations that process certificates may also
affect the degree of assurance provided. The path validation algo- affect the degree of assurance provided. The path validation algo-
rithm described in section 6 relies upon the integrity of the trusted rithm described in section 6 relies upon the integrity of the trusted
CA information, and especially the integrity of the public keys asso- CA information, and especially the integrity of the public keys
ciated with the trusted CAs. By substituting public keys for which associated with the trusted CAs. By substituting public keys for
an attacker has the private key, an attacker could trick the user which an attacker has the private key, an attacker could trick the
into accepting false certificates. user into accepting false certificates.
The binding between a key and certificate subject cannot be stronger The binding between a key and certificate subject cannot be stronger
than the cryptographic module implementation and algorithms used to than the cryptographic module implementation and algorithms used to
generate the signature. Short key lengths or weak hash algorithms generate the signature. Short key lengths or weak hash algorithms
will limit the utility of a certificate. CAs are encouraged to note will limit the utility of a certificate. CAs are encouraged to note
advances in cryptology so they can employ strong cryptographic tech- advances in cryptology so they can employ strong cryptographic tech-
niques. In addition, CAs should decline to issue certificates to CAs niques. In addition, CAs should decline to issue certificates to CAs
or end entities that generate weak signatures. or end entities that generate weak signatures.
Inconsistent application of name comparison rules may result in Inconsistent application of name comparison rules may result in
skipping to change at page 88, line 45 skipping to change at page 90, line 48
bmpString BMPString (SIZE(1..ub-title)) } bmpString BMPString (SIZE(1..ub-title)) }
-- --
id-at-dnQualifier AttributeType ::= {id-at 46} id-at-dnQualifier AttributeType ::= {id-at 46}
X520dnQualifier ::= PrintableString X520dnQualifier ::= PrintableString
id-at-countryName AttributeType ::= {id-at 6} id-at-countryName AttributeType ::= {id-at 6}
X520countryName ::= PrintableString (SIZE (2)) -- IS 3166 codes X520countryName ::= PrintableString (SIZE (2)) -- IS 3166 codes
id-at-serialNumber AttributeType ::= { id-at 5 }
X520SerialNumber PrintableString (SIZE (1..ub-serial-number))
-- domaincomponent and identifier from RFC 2247
id-domainComponent OBJECT IDENTIFIER :=
{ 0 9 2342 19200300 100 1 25 }
id-domainComponent AttributeType ::= id-domainComponent
domainComponent ::= IA5String
-- Legacy attributes -- Legacy attributes
pkcs-9 OBJECT IDENTIFIER ::= pkcs-9 OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 9 } { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 9 }
emailAddress AttributeType ::= { pkcs-9 1 } emailAddress AttributeType ::= { pkcs-9 1 }
Pkcs9email ::= IA5String (SIZE (1..ub-emailaddress-length)) Pkcs9email ::= IA5String (SIZE (1..ub-emailaddress-length))
-- naming data types -- -- naming data types --
Name ::= CHOICE { -- only one possibility for now -- Name ::= CHOICE { -- only one possibility for now --
rdnSequence RDNSequence } rdnSequence RDNSequence }
RDNSequence ::= SEQUENCE OF RelativeDistinguishedName RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
DistinguishedName ::= RDNSequence DistinguishedName ::= RDNSequence
skipping to change at page 97, line 18 skipping to change at page 99, line 32
-- Upper Bounds -- Upper Bounds
-- Upper Bounds -- Upper Bounds
ub-name INTEGER ::= 32768 ub-name INTEGER ::= 32768
ub-common-name INTEGER ::= 64 ub-common-name INTEGER ::= 64
ub-locality-name INTEGER ::= 128 ub-locality-name INTEGER ::= 128
ub-state-name INTEGER ::= 128 ub-state-name INTEGER ::= 128
ub-organization-name INTEGER ::= 64 ub-organization-name INTEGER ::= 64
ub-organizational-unit-name INTEGER ::= 64 ub-organizational-unit-name INTEGER ::= 64
ub-title INTEGER ::= 64 ub-title INTEGER ::= 64
ub-serialNumber INTEGER ::= 64
ub-match INTEGER ::= 128 ub-match INTEGER ::= 128
ub-emailaddress-length INTEGER ::= 128 ub-emailaddress-length INTEGER ::= 128
ub-common-name-length INTEGER ::= 64 ub-common-name-length INTEGER ::= 64
ub-country-name-alpha-length INTEGER ::= 2 ub-country-name-alpha-length INTEGER ::= 2
ub-country-name-numeric-length INTEGER ::= 3 ub-country-name-numeric-length INTEGER ::= 3
ub-domain-defined-attributes INTEGER ::= 4 ub-domain-defined-attributes INTEGER ::= 4
ub-domain-defined-attribute-type-length INTEGER ::= 8 ub-domain-defined-attribute-type-length INTEGER ::= 8
ub-domain-defined-attribute-value-length INTEGER ::= 128 ub-domain-defined-attribute-value-length INTEGER ::= 128
skipping to change at page 103, line 14 skipping to change at page 105, line 14
PolicyConstraints ::= SEQUENCE { PolicyConstraints ::= SEQUENCE {
requireExplicitPolicy [0] SkipCerts OPTIONAL, requireExplicitPolicy [0] SkipCerts OPTIONAL,
inhibitPolicyMapping [1] SkipCerts OPTIONAL } inhibitPolicyMapping [1] SkipCerts OPTIONAL }
SkipCerts ::= INTEGER (0..MAX) SkipCerts ::= INTEGER (0..MAX)
-- CRL distribution points extension OID and syntax -- CRL distribution points extension OID and syntax
id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= {id-ce 31} id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= {id-ce 31}
CRLDistPointsSyntax ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint
DistributionPoint ::= SEQUENCE { DistributionPoint ::= SEQUENCE {
distributionPoint [0] DistributionPointName OPTIONAL, distributionPoint [0] DistributionPointName OPTIONAL,
reasons [1] ReasonFlags OPTIONAL, reasons [1] ReasonFlags OPTIONAL,
cRLIssuer [2] GeneralNames OPTIONAL } cRLIssuer [2] GeneralNames OPTIONAL }
DistributionPointName ::= CHOICE { DistributionPointName ::= CHOICE {
fullName [0] GeneralNames, fullName [0] GeneralNames,
nameRelativeToCRLIssuer [1] RelativeDistinguishedName } nameRelativeToCRLIssuer [1] RelativeDistinguishedName }
skipping to change at page 104, line 4 skipping to change at page 106, line 4
-- extended key purpose OIDs -- extended key purpose OIDs
id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 } id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 }
id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 } id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 }
id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 } id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 }
id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 } id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 }
id-kp-ipsecEndSystem OBJECT IDENTIFIER ::= { id-kp 5 } id-kp-ipsecEndSystem OBJECT IDENTIFIER ::= { id-kp 5 }
id-kp-ipsecTunnel OBJECT IDENTIFIER ::= { id-kp 6 } id-kp-ipsecTunnel OBJECT IDENTIFIER ::= { id-kp 6 }
id-kp-ipsecUser OBJECT IDENTIFIER ::= { id-kp 7 } id-kp-ipsecUser OBJECT IDENTIFIER ::= { id-kp 7 }
id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 } id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 }
-- inhibit any policy OID and syntax
id-ce-inhibitAnyPolicy OBJECT IDENTIFIER ::= { id-ce 54 }
InhibitAnyPolicy ::= SkipCerts
-- freshest (delta-)CRL extension OID and syntax
id-ce-freshestCRL OBJECT IDENTIFIER ::= { id-ce 46 }
FreshestCRL ::= CRLDistributionPoints
-- authority info access -- authority info access
id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 } id-pe-authorityInfoAccess OBJECT IDENTIFIER ::= { id-pe 1 }
AuthorityInfoAccessSyntax ::= AuthorityInfoAccessSyntax ::=
SEQUENCE SIZE (1..MAX) OF AccessDescription SEQUENCE SIZE (1..MAX) OF AccessDescription
AccessDescription ::= SEQUENCE { AccessDescription ::= SEQUENCE {
accessMethod OBJECT IDENTIFIER, accessMethod OBJECT IDENTIFIER,
accessLocation GeneralName } accessLocation GeneralName }
skipping to change at page 114, line 9 skipping to change at page 116, line 9
ID id-at-organizationName } ID id-at-organizationName }
organizationalUnitName ATTRIBUTE ::= { organizationalUnitName ATTRIBUTE ::= {
WITH SYNTAX DirectoryString {ub-organizational-unit-name} WITH SYNTAX DirectoryString {ub-organizational-unit-name}
ID id-at-organizationalUnitName } ID id-at-organizationalUnitName }
title ATTRIBUTE ::= { title ATTRIBUTE ::= {
WITH SYNTAX DirectoryString {ub-title} WITH SYNTAX DirectoryString {ub-title}
ID id-at-title } ID id-at-title }
-- domainComponent from RFC 2247
domainComponent ATTRIBUTE ::= {
WITH SYNTAX IA5String
ID id-domaincomponent }
-- Legacy attributes -- Legacy attributes
pkcs9email ATTRIBUTE ::= { pkcs9email ATTRIBUTE ::= {
WITH SYNTAX PHGString, WITH SYNTAX PHGString,
ID emailAddress } ID emailAddress }
PHGString ::= IA5String (SIZE(1..ub-emailaddress-length)) PHGString ::= IA5String (SIZE(1..ub-emailaddress-length))
pkcs-9 OBJECT IDENTIFIER ::= pkcs-9 OBJECT IDENTIFIER ::=
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 9 } { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 9 }
skipping to change at page 114, line 43 skipping to change at page 116, line 48
id-at-localityName OBJECT IDENTIFIER ::= {id-at 7} id-at-localityName OBJECT IDENTIFIER ::= {id-at 7}
id-at-stateOrProvinceName OBJECT IDENTIFIER ::= {id-at 8} id-at-stateOrProvinceName OBJECT IDENTIFIER ::= {id-at 8}
id-at-organizationName OBJECT IDENTIFIER ::= {id-at 10} id-at-organizationName OBJECT IDENTIFIER ::= {id-at 10}
id-at-organizationalUnitName OBJECT IDENTIFIER ::= {id-at 11} id-at-organizationalUnitName OBJECT IDENTIFIER ::= {id-at 11}
id-at-title OBJECT IDENTIFIER ::= {id-at 12} id-at-title OBJECT IDENTIFIER ::= {id-at 12}
id-at-name OBJECT IDENTIFIER ::= {id-at 41} id-at-name OBJECT IDENTIFIER ::= {id-at 41}
id-at-givenName OBJECT IDENTIFIER ::= {id-at 42} id-at-givenName OBJECT IDENTIFIER ::= {id-at 42}
id-at-initials OBJECT IDENTIFIER ::= {id-at 43} id-at-initials OBJECT IDENTIFIER ::= {id-at 43}
id-at-generationQualifier OBJECT IDENTIFIER ::= {id-at 44} id-at-generationQualifier OBJECT IDENTIFIER ::= {id-at 44}
id-at-dnQualifier OBJECT IDENTIFIER ::= {id-at 46} id-at-dnQualifier OBJECT IDENTIFIER ::= {id-at 46}
id-at-serialNumber OBJECT IDENTIFIER ::= { id-at 5 }
id-domainComponent OBJECT IDENTIFIER :=
{ 0 9 2342 19200300 100 1 25 }
-- Directory string type, used extensively in Name types -- -- Directory string type, used extensively in Name types --
DirectoryString { INTEGER:maxSize } ::= CHOICE { DirectoryString { INTEGER:maxSize } ::= CHOICE {
teletexString TeletexString (SIZE (1..maxSize)), teletexString TeletexString (SIZE (1..maxSize)),
printableString PrintableString (SIZE (1..maxSize)), printableString PrintableString (SIZE (1..maxSize)),
universalString UniversalString (SIZE (1..maxSize)), universalString UniversalString (SIZE (1..maxSize)),
bmpString BMPString (SIZE(1..maxSize)), bmpString BMPString (SIZE(1..maxSize)),
utf8String UTF8String (SIZE(1..maxSize)) utf8String UTF8String (SIZE(1..maxSize))
} }
-- End of ASN.1 for Name type and directory attribute support -- -- End of ASN.1 for Name type and directory attribute support --
skipping to change at page 125, line 24 skipping to change at page 127, line 24
SupportedPolicyQualifiers CERT-POLICY-QUALIFIER ::= { noticeToUser | SupportedPolicyQualifiers CERT-POLICY-QUALIFIER ::= { noticeToUser |
pointerToCPS } pointerToCPS }
CERT-POLICY-QUALIFIER ::= CLASS { CERT-POLICY-QUALIFIER ::= CLASS {
&id OBJECT IDENTIFIER UNIQUE, &id OBJECT IDENTIFIER UNIQUE,
&Qualifier OPTIONAL } &Qualifier OPTIONAL }
WITH SYNTAX { WITH SYNTAX {
POLICY-QUALIFIER-ID &id POLICY-QUALIFIER-ID &id
[QUALIFIER-TYPE &Qualifier] } [QUALIFIER-TYPE &Qualifier] }
-- the following OID describes the special policy "any-policy"
anyPolicy OBJECT IDENTIFIER ::= {id-ce-certificate-policies 0}
policyMappings EXTENSION ::= { policyMappings EXTENSION ::= {
SYNTAX PolicyMappingsSyntax SYNTAX PolicyMappingsSyntax
IDENTIFIED BY id-ce-policyMappings } IDENTIFIED BY id-ce-policyMappings }
PolicyMappingsSyntax ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE { PolicyMappingsSyntax ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE {
issuerDomainPolicy CertPolicyId, issuerDomainPolicy CertPolicyId,
subjectDomainPolicy CertPolicyId } subjectDomainPolicy CertPolicyId }
-- Certificate subject and certificate issuer attributes extensions -- -- Certificate subject and certificate issuer attributes extensions --
skipping to change at page 127, line 7 skipping to change at page 129, line 11
policyConstraints EXTENSION ::= { policyConstraints EXTENSION ::= {
SYNTAX PolicyConstraintsSyntax SYNTAX PolicyConstraintsSyntax
IDENTIFIED BY id-ce-policyConstraints } IDENTIFIED BY id-ce-policyConstraints }
PolicyConstraintsSyntax ::= SEQUENCE { PolicyConstraintsSyntax ::= SEQUENCE {
requireExplicitPolicy [0] SkipCerts OPTIONAL, requireExplicitPolicy [0] SkipCerts OPTIONAL,
inhibitPolicyMapping [1] SkipCerts OPTIONAL } inhibitPolicyMapping [1] SkipCerts OPTIONAL }
SkipCerts ::= INTEGER (0..MAX) SkipCerts ::= INTEGER (0..MAX)
inhibitAnyPolicy EXTENSION ::= {
SYNTAX SkipCerts
IDENTIFIED BY id-ce-inhibitAnyPolicy}
-- Basic CRL extensions -- -- Basic CRL extensions --
cRLNumber EXTENSION ::= { cRLNumber EXTENSION ::= {
SYNTAX CRLNumber SYNTAX CRLNumber
IDENTIFIED BY id-ce-cRLNumber } IDENTIFIED BY id-ce-cRLNumber }
CRLNumber ::= INTEGER (0..MAX) CRLNumber ::= INTEGER (0..MAX)
reasonCode EXTENSION ::= { reasonCode EXTENSION ::= {
SYNTAX CRLReason SYNTAX CRLReason
skipping to change at page 128, line 48 skipping to change at page 131, line 7
certificateIssuer EXTENSION ::= { certificateIssuer EXTENSION ::= {
SYNTAX GeneralNames SYNTAX GeneralNames
IDENTIFIED BY id-ce-certificateIssuer } IDENTIFIED BY id-ce-certificateIssuer }
deltaCRLIndicator EXTENSION ::= { deltaCRLIndicator EXTENSION ::= {
SYNTAX BaseCRLNumber SYNTAX BaseCRLNumber
IDENTIFIED BY id-ce-deltaCRLIndicator } IDENTIFIED BY id-ce-deltaCRLIndicator }
BaseCRLNumber ::= CRLNumber BaseCRLNumber ::= CRLNumber
freshestCRL EXTENSION ::= {
SYNTAX CRLDistPointsSyntax
IDENTIFIED BY id-ce-freshestCRL }
-- Object identifier assignments for ISO certificate extensions -- -- Object identifier assignments for ISO certificate extensions --
id-ce OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29} id-ce OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29}
id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= {id-ce 9} id-ce-subjectDirectoryAttributes OBJECT IDENTIFIER ::= {id-ce 9}
id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= {id-ce 14} id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= {id-ce 14}
id-ce-keyUsage OBJECT IDENTIFIER ::= {id-ce 15} id-ce-keyUsage OBJECT IDENTIFIER ::= {id-ce 15}
id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= {id-ce 16} id-ce-privateKeyUsagePeriod OBJECT IDENTIFIER ::= {id-ce 16}
id-ce-subjectAltName OBJECT IDENTIFIER ::= {id-ce 17} id-ce-subjectAltName OBJECT IDENTIFIER ::= {id-ce 17}
id-ce-issuerAltName OBJECT IDENTIFIER ::= {id-ce 18} id-ce-issuerAltName OBJECT IDENTIFIER ::= {id-ce 18}
id-ce-basicConstraints OBJECT IDENTIFIER ::= {id-ce 19} id-ce-basicConstraints OBJECT IDENTIFIER ::= {id-ce 19}
skipping to change at page 129, line 24 skipping to change at page 131, line 35
id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= {id-ce 27} id-ce-deltaCRLIndicator OBJECT IDENTIFIER ::= {id-ce 27}
id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= {id-ce 28} id-ce-issuingDistributionPoint OBJECT IDENTIFIER ::= {id-ce 28}
id-ce-certificateIssuer OBJECT IDENTIFIER ::= {id-ce 29} id-ce-certificateIssuer OBJECT IDENTIFIER ::= {id-ce 29}
id-ce-nameConstraints OBJECT IDENTIFIER ::= {id-ce 30} id-ce-nameConstraints OBJECT IDENTIFIER ::= {id-ce 30}
id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= {id-ce 31} id-ce-cRLDistributionPoints OBJECT IDENTIFIER ::= {id-ce 31}
id-ce-certificatePolicies OBJECT IDENTIFIER ::= {id-ce 32} id-ce-certificatePolicies OBJECT IDENTIFIER ::= {id-ce 32}
id-ce-policyMappings OBJECT IDENTIFIER ::= {id-ce 33} id-ce-policyMappings OBJECT IDENTIFIER ::= {id-ce 33}
id-ce-policyConstraints OBJECT IDENTIFIER ::= {id-ce 36} id-ce-policyConstraints OBJECT IDENTIFIER ::= {id-ce 36}
id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= {id-ce 35} id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= {id-ce 35}
id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37} id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37}
anyPolicy OBJECT IDENTIFIER ::= {id-ce-certificate-policies 0} id-ce-freshestCRL OBJECT IDENTIFIER ::= {id-ce 46}
id-ce-inhibitAnyPolicy OBJECT IDENTIFIER ::= {id-ce 54}
-- PKIX 1 extensions -- PKIX 1 extensions
authorityInfoAccess EXTENSION ::= { authorityInfoAccess EXTENSION ::= {
SYNTAX AuthorityInfoAccessSyntax SYNTAX AuthorityInfoAccessSyntax
IDENTIFIED BY id-pe-authorityInfoAccess } IDENTIFIED BY id-pe-authorityInfoAccess }
AuthorityInfoAccessSyntax ::= AuthorityInfoAccessSyntax ::=
SEQUENCE SIZE (1..MAX) OF AccessDescription SEQUENCE SIZE (1..MAX) OF AccessDescription
skipping to change at page 130, line 28 skipping to change at page 132, line 38
DisplayText ::= CHOICE { DisplayText ::= CHOICE {
ia5String IA5String (SIZE (1..200)), ia5String IA5String (SIZE (1..200)),
visibleString VisibleString (SIZE (1..200)), visibleString VisibleString (SIZE (1..200)),
bmpString BMPString (SIZE (1..200)), bmpString BMPString (SIZE (1..200)),
utf8String UTF8String (SIZE (1..200)) } utf8String UTF8String (SIZE (1..200)) }
END END
Appendix C. ASN.1 Notes Appendix C. ASN.1 Notes
CAs MUST force the serialNumber to be a positive integer, that is,
the sign bit in the DER encoding of the INTEGER value MUST be zero -
this can be done by adding a leading (leftmost) `00'H octet if neces-
sary. This removes a potential ambiguity in mapping between a string
of octets and an integer value.
Given the uniqueness requirements above serial numbers can be
expected to contain long integers. Certificate users MUST be able to
handle serialNumber values longer than 32 bits. Conformant CAs MUST
NOT use serialNumber values longer than 20 octets.
The construct "SEQUENCE SIZE (1..MAX) OF" appears in several ASN.1 The construct "SEQUENCE SIZE (1..MAX) OF" appears in several ASN.1
constructs. A valid ASN.1 sequence will have zero or more entries. constructs. A valid ASN.1 sequence will have zero or more entries.
The SIZE (1..MAX) construct constrains the sequence to have at least The SIZE (1..MAX) construct constrains the sequence to have at least
one entry. MAX indicates the upper bound is unspecified. Implementa- one entry. MAX indicates the upper bound is unspecified. Implementa-
tions are free to choose an upper bound that suits their environment. tions are free to choose an upper bound that suits their environment.
The construct "positiveInt ::= INTEGER (0..MAX)" defines positiveInt The construct "positiveInt ::= INTEGER (0..MAX)" defines positiveInt
as a subtype of INTEGER containing integers greater than or equal to as a subtype of INTEGER containing integers greater than or equal to
zero. The upper bound is unspecified. Implementations are free to zero. The upper bound is unspecified. Implementations are free to
select an upper bound that suits their environment. select an upper bound that suits their environment.
skipping to change at page 130, line 49 skipping to change at page 133, line 24
The character string type PrintableString supports a very basic Latin The character string type PrintableString supports a very basic Latin
character set: the lower case letters 'a' through 'z', upper case character set: the lower case letters 'a' through 'z', upper case
letters 'A' through 'Z', the digits '0' through '9', eleven special letters 'A' through 'Z', the digits '0' through '9', eleven special
characters ' " ( ) + , - . / : ? and space. characters ' " ( ) + , - . / : ? and space.
The character string type TeletexString is a superset of Printable- The character string type TeletexString is a superset of Printable-
String. TeletexString supports a fairly standard (ascii-like) Latin String. TeletexString supports a fairly standard (ascii-like) Latin
character set, Latin characters with non-spacing accents and Japanese character set, Latin characters with non-spacing accents and Japanese
characters. characters.
The character string type UniversalString supports any of the The character string type UniversalString supports any of the charac-
characters allowed by ISO 10646-1. ISO 10646 is the Universal ters allowed by ISO 10646-1. ISO 10646 is the Universal multiple-
multiple-octet coded Character Set (UCS). ISO 10646-1 specifes the octet coded Character Set (UCS). ISO 10646-1 specifes the architec-
architecture and the "basic multilingual plane" - a large standard ture and the "basic multilingual plane" - a large standard character
character set which includes all major world character standards. set which includes all major world character standards.
The character string type UTF8String will be introduced in the 1998 The character string type UTF8String will be introduced in the 1998
version of ASN.1. UTF8String is a universal type and has been version of ASN.1. UTF8String is a universal type and has been
assigned tag number 12. The content of UTF8String was defined by RFC assigned tag number 12. The content of UTF8String was defined by RFC
2044 and updated in RFC 2279, "UTF-8, a transformation Format of ISO 2044 and updated in RFC 2279, "UTF-8, a transformation Format of ISO
10646." ISO is expected to formally add UTF8String to the list of 10646." ISO is expected to formally add UTF8String to the list of
choices for DirectoryString in 1998 as well. choices for DirectoryString in 1998 as well.
In anticipation of these changes, and in conformance with IETF Best In anticipation of these changes, and in conformance with IETF Best
Practices codified in RFC 2277, IETF Policy on Character Sets and Practices codified in RFC 2277, IETF Policy on Character Sets and
Languages, this document includes UTF8String as a choice in Directo- Languages, this document includes UTF8String as a choice in Directo-
ryString and the CPS qualifier extensions. ryString and the CPS qualifier extensions.
Implementers should note that the DER encoding of the SET OF values
requires ordering of the encodings of the values. In particular, this
issue arises with respect to distinguished names.
Object Identifiers (OIDs) are used throught this specification to
identify certificate policies, public key and signature algorithms,
certificate extensions, etc. There is no maximum size for OIDs.
This specification mandates support for OIDs which have arc elements
with values that are less than 2^28, i.e. they MUST be between 0 and
268,435,455 inclusive. This allows each arc element to be represented
within a single 32 bit word. Implementations MUST also support OIDs
where the length of the dotted decimal (see [LDAP], section 4.1.2)
string representation can be up to 100 bytes (inclusive). Implementa-
tions MUST be able to handle OIDs with up to 20 elements (inclusive).
CAs SHOULD NOT issue certificates which contain OIDs that breach
these requirements.
Appendix D. Examples Appendix D. Examples
This section contains four examples: three certificates and a CRL. This section contains four examples: three certificates and a CRL.
The first two certificates and the CRL comprise a minimal certifica- The first two certificates and the CRL comprise a minimal certifica-
tion path. tion path.
Section D.1 contains an annotated hex dump of a "self-signed" certi- Section D.1 contains an annotated hex dump of a "self-signed" certi-
ficate issued by a CA whose distinguished name is ficate issued by a CA whose distinguished name is
cn=us,o=gov,ou=nist. The certificate contains a DSA public key with cn=us,o=gov,ou=nist. The certificate contains a DSA public key with
parameters, and is signed by the corresponding DSA private key. parameters, and is signed by the corresponding DSA private key.
 End of changes. 102 change blocks. 
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