Network Working Group R. Housley
Internet-Draft Vigil Security, LLC
Intended status: Standards Track S. Ashmore
Expires: April 18, 2010 National Security Agency
C. Wallace
Cygnacom Solutions
October 15, 2009
Trust Anchor Format
draft-ietf-pkix-ta-format-04
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. This document may contain material
from IETF Documents or IETF Contributions published or made publicly
available before November 10, 2008. The person(s) controlling the
copyright in some of this material may not have granted the IETF
Trust the right to allow modifications of such material outside the
IETF Standards Process. Without obtaining an adequate license from
the person(s) controlling the copyright in such materials, this
document may not be modified outside the IETF Standards Process, and
derivative works of it may not be created outside the IETF Standards
Process, except to format it for publication as an RFC or to
translate it into languages other than English.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 18, 2010.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
Housley, et al. Expires April 18, 2010 [Page 1]
Internet-Draft TAF October 2009
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Housley, et al. Expires April 18, 2010 [Page 2]
Internet-Draft TAF October 2009
Abstract
This document describes a structure for representing trust anchor
information. A trust anchor is an authoritative entity represented
by a public key and associated data. The public key is used to
verify digital signatures and the associated data is used to
constrain the types of information or actions for which the trust
anchor is authoritative. The structures defined in this document are
intended to satisfy the format-related requirements defined in Trust
Anchor Management Requirements.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. Trust Anchor Information Syntax . . . . . . . . . . . . . . . 5
2.1. Version . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2. Public Key . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Key Identifier . . . . . . . . . . . . . . . . . . . . . . 5
2.4. Trust Anchor Title . . . . . . . . . . . . . . . . . . . . 5
2.5. Certification Path Controls . . . . . . . . . . . . . . . 6
2.6. Extensions . . . . . . . . . . . . . . . . . . . . . . . . 10
3. Trust Anchor List . . . . . . . . . . . . . . . . . . . . . . 11
4. Security Considerations . . . . . . . . . . . . . . . . . . . 12
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1. Normative References . . . . . . . . . . . . . . . . . . . 14
6.2. Informative References . . . . . . . . . . . . . . . . . . 14
Appendix A. ASN.1 Modules . . . . . . . . . . . . . . . . . . . . 15
A.1. ASN.1 Module Using 1993 Syntax . . . . . . . . . . . . . . 15
A.2. ASN.1 Module Using 1988 Syntax . . . . . . . . . . . . . . 16
A.2.1. ASN.1 Module . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
Housley, et al. Expires April 18, 2010 [Page 3]
Internet-Draft TAF October 2009
1. Introduction
Trust anchors are widely used to verify digital signatures and
validate certification paths [RFC5280][X.509]. They are required
when validating certification paths. Though widely used, there is no
standard format for representing trust anchor information. This
document describes the TrustAnchorInfo structure. This structure is
intended to satisfy the format-related requirements expressed in
Trust Anchor Management Requirements
[I-D.draft-ietf-pkix-ta-mgmt-reqs] and is expressed using ASN.1
[X.680]. It can provide a more compact alternative to X.509
certificates for exchanging trust anchor information and provides a
means of associating additional or alternative constraints with
certificates without breaking the signature on the certificate.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Housley, et al. Expires April 18, 2010 [Page 4]
Internet-Draft TAF October 2009
2. Trust Anchor Information Syntax
This section describes the TrustAnchorInfo structure.
TrustAnchorInfo ::= SEQUENCE {
version TrustAnchorInfoVersion DEFAULT v1,
pubKey SubjectPublicKeyInfo,
keyId KeyIdentifier,
taTitle TrustAnchorTitle OPTIONAL,
certPath CertPathControls OPTIONAL,
exts [1] EXPLICIT Extensions OPTIONAL,
taTitleLangTag [2] UTF8String OPTIONAL }
TrustAnchorInfoVersion ::= INTEGER { v1(1) }
2.1. Version
version identifies the version of TrustAnchorInfo. Future updates to
this document may include changes to the TrustAnchorInfo structure,
in which case the version number should be incremented. However, the
default value, v1, cannot be changed.
2.2. Public Key
pubKey identifies the public key and algorithm associated with the
trust anchor using the SubjectPublicKeyInfo structure [RFC5280]. The
SubjectPublicKeyInfo structure contains the algorithm identifier
followed by the public key itself. The algorithm field is an
AlgorithmIdentifier, which contains an object identifier and OPTIONAL
parameters. The object identifier names the public key algorithm and
indicates the syntax of the parameters, if present, as well as the
format of the public key. The public key is encoded as a BIT STRING.
2.3. Key Identifier
keyId contains the public key identifier of the trust anchor public
key. See section 4.2.1.2 of [RFC5280] for a description of common
key identifier calculation methods.
2.4. Trust Anchor Title
TrustAnchorTitle ::= UTF8String (SIZE (1..64))
Housley, et al. Expires April 18, 2010 [Page 5]
Internet-Draft TAF October 2009
taTitle is OPTIONAL. When it is present, it provides a human
readable name for the trust anchor. The text is encoded in UTF-8
[RFC3629], which accommodates most of the world's writing systems.
The taTitleLangTag field identifies the language used to express the
taTitle. When taTitleLangTag is absent, English is used. The value
of the taTitleLangTag should be a language tag as described in
[RFC5646]
2.5. Certification Path Controls
CertPathControls ::= SEQUENCE {
taName Name,
certificate [0] Certificate OPTIONAL,
policySet [1] CertificatePolicies OPTIONAL,
policyFlags [2] CertPolicyFlags OPTIONAL,
nameConstr [3] NameConstraints OPTIONAL,
pathLenConstraint[4] INTEGER (0..MAX) OPTIONAL}
certPath is OPTIONAL. When it is present, it provides the controls
needed to initialize an X.509 certification path validation algorithm
implementation (see Section 6 in [RFC5280]). When absent, the trust
anchor cannot be used to validate the signature on an X.509
certificate.
taName provides the X.500 distinguished name associated with the
trust anchor, and this distinguished name is used to construct and
validate an X.509 certification path. The name MUST NOT be an empty
sequence.
certificate provides an OPTIONAL X.509 certificate, which can be used
in some environments to represent the trust anchor in certification
path development and validation. If the certificate is present, the
subject name in the certificate MUST exactly match the X.500
distinguished name provided in the taName field, the public key MUST
exactly match the public key in the pubKey field and the
subjectKeyIdentifier extension, if present, MUST exactly match the
key identifier in the keyId field. The complete description of the
syntax and semantics of the Certificate are provided in [RFC5280].
Constraints defined in the policySet, policyFlags, nameConstr,
pathLenConstraint and exts fields within TrustAnchorInfo replace
values contained in a certificate or provide values for extensions
not present in the certificate. Values defined in these
TrustAnchorInfo fields are always enforced. Extensions included in a
certificate are enforced only if there is no corresponding value in
the TrustAnchorInfo. Correspondence between extensions within a
certificate and TrustAnchorInfo fields is defined as follows:
Housley, et al. Expires April 18, 2010 [Page 6]
Internet-Draft TAF October 2009
o an id-ce-certificatePolicies certificate extension corresponds to
the CertPathControls.policySet field.
o an id-ce-policyConstraints certificate extension corresponds to
the CertPolicyFlags.inhibitPolicyMapping and
CertPolicyFlags.requireExplicitPolicy fields.
o an id-ce-inhibitAnyPolicy certificate extension corresponds to the
CertPolicyFlags.inhibitAnyPolicy field.
o an id-ce-nameConstraints certificate extension corresponds to the
CertPathControls.nameConstr field.
o the pathLenConstraint field of an id-ce-basicConstraints
certificate extension corresponds to the
CertPathControls.pathLenConstraint field (the presence of a
CertPathControls structure corresponds to a TRUE value in the cA
field of a BasicConstraints extension).
o any other certificate extension corresponds to the same type of
extension in the TrustAnchorInfo.exts field.
CertificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
PolicyInformation ::= SEQUENCE {
policyIdentifier CertPolicyId,
policyQualifiers SEQUENCE SIZE (1..MAX) OF
PolicyQualifierInfo OPTIONAL }
CertPolicyId ::= OBJECT IDENTIFIER
policySet is OPTIONAL. When present, it contains sequence of
certificate policy identifiers to be provided as inputs to the
certification path validation algorithm. When absent, the special
value any-policy is provided as the input to the certification path
validation algorithm. The complete description of the syntax and
semantics of the CertificatePolicies are provided in [RFC5280],
including the syntax for PolicyInformation. In this context, the
OPTIONAL policyQualifiers structure MUST NOT be included.
CertPolicyFlags ::= BIT STRING {
inhibitPolicyMapping (0),
requireExplicitPolicy (1),
inhibitAnyPolicy (2) }
Housley, et al. Expires April 18, 2010 [Page 7]
Internet-Draft TAF October 2009
policyFlags is OPTIONAL. When present, three Boolean values for
input to the certification path validation algorithm are provided in
a BIT STRING. When absent, the input to the certification path
validation algorithm is { FALSE, FALSE, FALSE }, which represents the
most liberal setting for these flags. The three bits are used as
follows:
inhibitPolicyMapping indicates if policy mapping is allowed in the
certification path. When set to TRUE, policy mapping is not
permitted. This value represents the initial-policy-mapping-
inhibit input value to the certification path validation algorithm
described in section 6.1.1 of [RFC5280].
requireExplicitPolicy indicates if the certification path MUST be
valid for at least one of the certificate policies in the
policySet. When set to TRUE, all certificates in the
certification path MUST contain an acceptable policy identifier in
the certificate policies extension. This value represents the
initial-explicit-policy input value to the certification path
validation algorithm described in section 6.1.1 of [RFC5280]. An
acceptable policy identifier is a member of the policySet or the
identifier of a policy that is declared to be equivalent through
policy mapping. This bit MUST be set to FALSE if policySet is
absent.
inhibitAnyPolicy indicates whether the special anyPolicy policy
identifier, with the value { 2 5 29 32 0 }, is considered an
explicit match for other certificate policies. This value
represents the initial-any-policy-inhibit input value to the
certification path validation algorithm described in section 6.1.1
of [RFC5280].
NameConstraints ::= SEQUENCE {
permittedSubtrees [0] GeneralSubtrees OPTIONAL,
excludedSubtrees [1] GeneralSubtrees OPTIONAL }
GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
GeneralSubtree ::= SEQUENCE {
base GeneralName,
minimum [0] BaseDistance DEFAULT 0,
maximum [1] BaseDistance OPTIONAL }
BaseDistance ::= INTEGER (0..MAX)
Housley, et al. Expires April 18, 2010 [Page 8]
Internet-Draft TAF October 2009
nameConstr is OPTIONAL. It has the same syntax and semantics as the
Name Constraints certificate extension [RFC5280], which includes a
list of permitted names and a list of excluded names. The definition
of GeneralName can be found in [RFC5280]. When it is present,
constraints are provided on names (including alternative names) that
might appear in subsequent X.509 certificates in a certification
path. This field is used to set the initial-permitted-subtrees and
initial-excluded-subtrees input values to the certification path
validation algorithm described in section 6.1.1 of [RFC5280]. When
this field is absent, the initial-permitted-subtrees variable is
unbounded and the initial-excluded-subtrees variable is empty.
The pathLenConstraint field gives the maximum number of non-self-
issued intermediate certificates that may follow this certificate in
a valid certification path. (Note: The last certificate in the
certification path is not an intermediate certificate, and is not
included in this limit. Usually, the last certificate is an end
entity certificate, but it can be a CA certificate.) A
pathLenConstraint of zero indicates that no non- self-issued
intermediate certification authority (CA) certificates may follow in
a valid certification path. Where it appears, the pathLenConstraint
field MUST be greater than or equal to zero. Where pathLenConstraint
does not appear, no limit is imposed.
When the trust anchor is used to validate a certification path,
CertPathControls provides limitations on certification paths that
will successfully validate. An application that is validating a
certification path SHOULD NOT ignore these limitations, but the
application can impose additional limitations to ensure that the
validated certification path is appropriate for the intended
application context. As input to the certification path validation
algorithm, an application MAY:
o Provide a subset of the certification policies provided in the
policySet;
o Provide a TRUE value, if appropriate, for any of the flags in the
policyFlags;
o Provide a subset of the permitted names provided in the
nameConstr;
o Provide additional excluded names to the ones that are provided in
the nameConstr;
o Provide a smaller value for pathLenConstraint
Housley, et al. Expires April 18, 2010 [Page 9]
Internet-Draft TAF October 2009
2.6. Extensions
exts is OPTIONAL. When it is present, it can be used to associate
additional information with the trust anchor using the standard
Extensions structure. Extensions that are anticipated to be widely
used have been included in the CertPathControls structure to avoid
overhead associated with use of the Extensions structure. To avoid
duplication with the CertPathControls field, the following types of
extensions MUST NOT appear in the exts field and are ignored if they
do appear: id-ce-certificatePolicies, id-ce-policyConstraints, id-ce-
inhibitAnyPolicy or id-ce-nameConstraints.
Housley, et al. Expires April 18, 2010 [Page 10]
Internet-Draft TAF October 2009
3. Trust Anchor List
TrustAnchorInfo allows for the representation of a single trust
anchor. In many cases, it is convenient to represent a collection of
trust anchors. The TrustAnchorList structure is defined for this
purpose. TrustAnchorList is defined as a sequence of one or more
TrustAnchorChoice objects. TrustAnchorChoice provides three options
for representing a trust anchor. The certificate option allows for
the use of a certificate with no additional associated constraints.
The tbsCert option allows for associating constraints by removing a
signature on a certificate and changing the extensions field. The
taInfo option allows for use of the TrustAnchorInfo structure defined
in this document.
TrustAnchorList ::= SEQUENCE SIZE (1..MAX) OF TrustAnchorChoice
TrustAnchorChoice ::= CHOICE {
certificate Certificate,
tbsCert [1] EXPLICIT TBSCertificate,
taInfo [2] EXPLICIT TrustAnchorInfo }
trust-anchor-list PKCS7-CONTENT-TYPE ::=
{ TrustAnchorList IDENTIFIED BY id-ct-trustAnchorList }
The TrustAnchorList structure can be protected using the SignedData
structured defined in the Cryptographic Message Syntax(CMS)
[RFC3852]. The id-ct-trustAnchorList object identifier has been
defined to represent TrustAnchorList payloads with CMS structures.
Housley, et al. Expires April 18, 2010 [Page 11]
Internet-Draft TAF October 2009
4. Security Considerations
Compromise of a trust anchor private key permits unauthorized parties
to masquerade as the trust anchor, with potentially severe
consequences. Where TA-based constraints are enforced, the
unauthorized holder of the trust anchor private key will be limited
by the certification path controls associated with the trust anchor,
as expressed in the certPath and exts fields. For example, name
constraints in the trust anchor will determine the name space that
will be accepted in certificates that are validated using the
compromised trust anchor. Reliance on an inappropriate or incorrrect
trust anchor public key has similar potentially severe consequences.
The compromise of a CA's private key leads to the same type of
problems as the compromise of a trust anchor private key. The
unauthorized holder of the CA private key will be limited by the
certification path controls associated with the trust anchor, as
expressed in the certPath field or as an extension.
Usage of a certificate independent of the TrustAnchorInfo structure
that envelopes it must be carefully managed to avoid violating
constraints expressed in the TrustAnchorInfo. When enveloping a
certificate in a TrustAnchorInfo structure, values included in the
certificate should be evaluated to ensure there is no confusion or
conflict with values in the TrustAnchorInfo structure.
Housley, et al. Expires April 18, 2010 [Page 12]
Internet-Draft TAF October 2009
5. IANA Considerations
There are no IANA considerations. Please delete this section prior
to RFC publication.
Housley, et al. Expires April 18, 2010 [Page 13]
Internet-Draft TAF October 2009
6. References
6.1. Normative References
[I-D.ietf-pkix-new-asn1]
Hoffman, P. and J. Schaad, "New ASN.1 Modules for PKIX",
draft-ietf-pkix-new-asn1-05 (work in progress),
April 2009.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC3852] Housley, R., "Cryptographic Message Syntax (CMS)",
RFC 3852, July 2004.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC5646] Phillips, A. and M. Davis, "Tags for Identifying
Languages", BCP 47, RFC 5646, September 2009.
[X.680] "ITU-T Recommendation X.680: Information Technology -
Abstract Syntax Notation One", 1997.
6.2. Informative References
[I-D.draft-ietf-pkix-ta-mgmt-reqs]
Reddy, R. and C. Wallace, "Trust Anchor Management
Requirements", draft-ietf-pkix-ta-mgmt-reqs-04 (work in
progress).
[X.509] "ITU-T Recommendation X.509 - The Directory -
Authentication Framework", 2000.
Housley, et al. Expires April 18, 2010 [Page 14]
Internet-Draft TAF October 2009
Appendix A. ASN.1 Modules
Appendix A.1 provides the normative ASN.1 definitions for the
structures described in this specification using ASN.1 as defined in
[X.680]. It includes definitions imported from [RFC5280] and
[I-D.ietf-pkix-new-asn1].
A.1. ASN.1 Module Using 1993 Syntax
TrustAnchorInfoModule
{ joint-iso-ccitt(2) country(16) us(840) organization(1)
gov(101) dod(2) infosec(1) modules(0) 33 }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
IMPORTS
Certificate, Name, SubjectPublicKeyInfo, TBSCertificate
FROM PKIX1Explicit-2009 -- from [I-D.ietf-pkix-new-asn1]
{iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-explicit-02(51)}
CertificatePolicies, KeyIdentifier, NameConstraints
FROM PKIX1Implicit-2009 -- from [I-D.ietf-pkix-new-asn1]
{iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-implicit-02(59)}
Extensions
FROM PKIX-CommonTypes-2009 -- from [I-D.ietf-pkix-new-asn1]
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkixCommon-02(57) } ;
TrustAnchorInfo ::= SEQUENCE {
version TrustAnchorInfoVersion DEFAULT v1,
pubKey SubjectPublicKeyInfo,
keyId KeyIdentifier,
taTitle TrustAnchorTitle OPTIONAL,
certPath CertPathControls OPTIONAL,
exts [1] EXPLICIT Extensions OPTIONAL,
taTitleLangTag [2] UTF8String OPTIONAL }
TrustAnchorInfoVersion ::= INTEGER { v1(1) }
TrustAnchorTitle ::= UTF8String (SIZE (1..64))
CertPathControls ::= SEQUENCE {
taName Name,
certificate [0] Certificate OPTIONAL,
Housley, et al. Expires April 18, 2010 [Page 15]
Internet-Draft TAF October 2009
policySet [1] CertificatePolicies OPTIONAL,
policyFlags [2] CertPolicyFlags OPTIONAL,
nameConstr [3] NameConstraints OPTIONAL,
pathLenConstraint[4] INTEGER (0..MAX) OPTIONAL}
CertPolicyFlags ::= BIT STRING {
inhibitPolicyMapping (0),
requireExplicitPolicy (1),
inhibitAnyPolicy (2) }
TrustAnchorList ::= SEQUENCE SIZE (1..MAX) OF TrustAnchorChoice
TrustAnchorChoice ::= CHOICE {
certificate Certificate,
tbsCert [1] EXPLICIT TBSCertificate,
taInfo [2] EXPLICIT TrustAnchorInfo }
id-ct-trustAnchorList OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
id-smime(16) id-ct(1) 34 }
PKCS7-CONTENT-TYPE ::= TYPE-IDENTIFIER
trust-anchor-list PKCS7-CONTENT-TYPE ::=
{ TrustAnchorList IDENTIFIED BY id-ct-trustAnchorList }
END
A.2. ASN.1 Module Using 1988 Syntax
Appendix A.1 provides the normative ASN.1 definitions for the
structures described in this specification using ASN.1 as defined in
[X.680].
A.2.1. ASN.1 Module
TrustAnchorInfoModule-88
{ joint-iso-ccitt(2) country(16) us(840) organization(1)
gov(101) dod(2) infosec(1) modules(0) 37 }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
IMPORTS
Certificate, Name, Extensions,
Housley, et al. Expires April 18, 2010 [Page 16]
Internet-Draft TAF October 2009
SubjectPublicKeyInfo, TBSCertificate
FROM PKIX1Explicit88 -- from [RFC5280]
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-pkix1-explicit(18) }
CertificatePolicies, KeyIdentifier, NameConstraints
FROM PKIX1Implicit88 -- [RFC5280]
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-pkix1-implicit(19) }
;
TrustAnchorInfo ::= SEQUENCE {
version TrustAnchorInfoVersion DEFAULT v1,
pubKey SubjectPublicKeyInfo,
keyId KeyIdentifier,
taTitle TrustAnchorTitle OPTIONAL,
certPath CertPathControls OPTIONAL,
exts [1] EXPLICIT Extensions OPTIONAL,
taTitleLangTag [2] UTF8String OPTIONAL }
TrustAnchorInfoVersion ::= INTEGER { v1(1) }
TrustAnchorTitle ::= UTF8String (SIZE (1..64))
CertPathControls ::= SEQUENCE {
taName Name,
certificate [0] Certificate OPTIONAL,
policySet [1] CertificatePolicies OPTIONAL,
policyFlags [2] CertPolicyFlags OPTIONAL,
nameConstr [3] NameConstraints OPTIONAL,
pathLenConstraint[4] INTEGER (0..MAX) OPTIONAL}
CertPolicyFlags ::= BIT STRING {
inhibitPolicyMapping (0),
requireExplicitPolicy (1),
inhibitAnyPolicy (2) }
TrustAnchorList ::= SEQUENCE SIZE (1..MAX) OF TrustAnchorChoice
TrustAnchorChoice ::= CHOICE {
certificate Certificate,
tbsCert [1] EXPLICIT TBSCertificate,
taInfo [2] EXPLICIT TrustAnchorInfo }
id-ct-trustAnchorList OBJECT IDENTIFIER ::= { iso(1)
member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
id-smime(16) id-ct(1) 34 }
Housley, et al. Expires April 18, 2010 [Page 17]
Internet-Draft TAF October 2009
END
Housley, et al. Expires April 18, 2010 [Page 18]
Internet-Draft TAF October 2009
Authors' Addresses
Russ Housley
Vigil Security, LLC
918 Spring Knoll Drive
Herndon, VA 20170
Email: housley@vigilsec.com
Sam Ashmore
National Security Agency
Suite 6751
9800 Savage Road
Fort Meade, MD 20755
Email: srashmo@radium.ncsc.mil
Carl Wallace
Cygnacom Solutions
Suite 5200
7925 Jones Branch Drive
McLean, VA 22102
Email: cwallace@cygnacom.com
Housley, et al. Expires April 18, 2010 [Page 19]