Network Working Group Sean Turner
Internet Draft IECA
Intended Status: Standard Track Santosh Chokhani
CygnaCom Solutions
Expires: September 4, 2009 March 4, 2009
Clearance Attribute and Authority Clearance Constraints
Certificate Extension
draft-ietf-pkix-authorityclearanceconstraints-01.txt
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Abstract
This document defines the syntax and semantics for the Clearance
attribute and the Authority Clearance Constraints extension in X.509
certificates. The Clearance attribute is used to indicate the
clearance held by the subject. The Clearance attribute may appear in
the subject directory attributes extension of a public key
certificate or in the attributes field of an attribute certificate.
The Authority Clearance Constraints certificate extension values in a
Trust Anchor (TA), CA public key certificates, and an Attribute
Authority (AA) public key certificate in a public key certification
path constrain the effective Clearance of the subject.
Table of Contents
1. Introduction...................................................3
1.1. Terminology...............................................4
1.2. ASN.1 Syntax Notation.....................................4
2. Clearance Attribute............................................4
3. Authority Clearance Constraints Certificate Extension..........5
4. Clearance and Authority Clearance Constraints Processing in
PKC............................................................6
4.1. Collecting Constraints....................................7
4.1.1. Certification Path Processing........................7
4.1.1.1. Inputs..........................................8
4.1.1.2. Initialization..................................8
4.1.1.3. Basic Certificate Processing....................8
4.1.1.4. Preparation for Certificate i+1.................9
4.1.1.5. Wrap-up Procedure...............................9
4.1.1.5.1. Wrap Up Clearance..........................9
4.1.1.6. Outputs........................................10
5. Clearance and Authority Clearance Constraints Processing in
AC............................................................10
5.1. Collecting Constraints...................................11
5.1.1. Certification Path Processing.......................11
5.1.1.1. Inputs.........................................11
5.1.1.2. Initialization.................................11
5.1.1.3. Basic PKC Processing...........................12
5.1.1.4. Preparation for Certificate i+1................12
5.1.1.5. Wrap-up Procedure..............................12
5.1.1.5.1. Wrap Up Clearance.........................12
5.1.1.6. Outputs........................................12
6. Computing Intersection of permitted-clearances and
AuthorityClearanceConstraints extension.......................12
7. Computing Intersection of securityCategories..................14
8. Recommended securityCategories................................15
9. Security Considerations.......................................15
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10. IANA Considerations..........................................15
11. References...................................................15
11.1. Normative References....................................15
11.2. Informative References..................................16
Appendix A. ASN.1 Module.........................................17
Author's Addresses...............................................19
1. Introduction
Organizations that have implemented a security policy can issue
certificates that include an indication of the clearance values held
by the subject. The Clearance attribute indicates the security
policy, the clearance levels held by the subject, and additional
authorization information held by the subject. This specification
makes use of the ASN.1 syntax for clearance from [3281bis].
Clearance attribute may be placed in the subject directory attributes
extension of a PKC or may be placed in a separate attribute
certificate (AC).
The placement of Clearance attribute in PKCs is desirable when the
credentials such as PKCs need to be revoked when the clearance
information changes or when clearance information is relatively
static, and clearance information can be verified as part of PKC
issuance process (e.g., using local databases). The placement of
Clearance attribute in PKCs may also be made to simplify the
infrastructure, to reduce the infrastructure design cost, or to
reduce the infrastructure operations cost. An example of placement
of Clearance attribute in PKCs in operational PKI is the Defense
Messaging Service. An example of placement of attributes in PKCs is
Qualified Certificates [RFC3739].
The placement of Clearance attribute in ACs is desirable when the
clearance information is relatively dynamic and changes in the
clearance information does not require revocation of credentials such
as PKCs, or the clearance information can not be verified as part of
PKC issuance process.
Since [3281bis] does not permit chain of ACs, the Authority
Clearance Constraints extension may only appear in the PKCs of CA or
AA. The Authority Clearance Constraints extension may also appear
in a TA or may be associated with a TA.
Some organizations have multiple TAs, CAs, and/or AAs and these
organizations may wish to indicate to relying parties which clearance
values from a particular TA, CA, or AA should be accepted. For
example, consider the security policies described in [RFC3114], where
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a security policy has been defined for Amoco with three security
classification values (HIGHLY CONFIDENTIAL, CONFIDENTIAL, and
GENERAL). To constrain a CA for just one security classification, the
Authority Clearance Constraints certificate extension would be
included in the CA's PKC.
Cross-certified domains can also make use of the Authority Clearance
Constraints certificate extension to indicate which clearance values
should be acceptable to relying parties.
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 [RFC2119].
1.2. ASN.1 Syntax Notation
All X.509 PKC [RFC5280] extensions are defined using ASN.1 [X.680].
All X.509 AC [3281bis] extensions are defined using ASN.1 [X.680].
2. Clearance Attribute
The Clearance attribute in a certificate indicates the clearances
held by the subject. It uses the clearance attribute syntax from
Section 4.4.6 of [3281bis], which is included below for convenience,
in the Attributes field. A certificate MUST include either zero or
one instance of the Clearance attribute. If the Clearance attribute
is present, it must contain a single value.
The following object identifier identifies the Clearance attribute
(either in the subject directory attributes extension of a PKC or in
the Attributes field of an AC):
id-at-clearance OBJECT IDENTIFIER ::= { joint-iso-ccitt(2)
ds(5) attributeTypes(5) clearance(55) }
The ASN.1 syntax for the Clearance attribute is as follows [PKI-ASN]:
Clearance ::= SEQUENCE {
policyId OBJECT IDENTIFIER,
classList ClassList DEFAULT {unclassified},
securityCategories SET OF SecurityCategory OPTIONAL
}
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ClassList ::= BIT STRING {
unmarked (0),
unclassified (1),
restricted (2),
confidential (3),
secret (4),
topSecret (5)
}
SECURITY-CATEGORY ::= TYPE-IDENTIFIER
SecurityCategory ::= SEQUENCE {
type [0]
TYPE-IDENTIFIER.&id({SupportedSecurityCategories}),
value [1]
EXPLICIT TYPE-IDENTIFIER.&Type
({SupportedSecurityCategories}{@type})
}
The Clearance attribute takes its meaning from Section 4.4.6 of
[3281bis], which is repeated here for convenience:
- policyId identifies the security policy to which the clearance
relates. The policyId indicates the semantics of the classList
and securityCategory fields.
- classlist identifies the security classifications. Six basic
values are defined in bit positions 0 through 5 and more may be
defined by an organizational security policy.
- securityCategories provides additional authorization information.
If a trust anchor's public key is used directly, then the Clearance
associated with the trust anchor, if any, should be used as the
effective clearance (also defined as effective-clearance for a
certification path).
3. Authority Clearance Constraints Certificate Extension
The Authority Clearance Constraints certificate extension indicates
to the relying party what clearances should be acceptable for the
subject of the AC or the subject of the last certificate in a PKC
certification path. It is only meaningful in trust anchor, CA PKCs,
or AA PKCs. A trust anchor, CA PKC, or AA PKC MUST include either
zero or one instance of the Authority Clearance Constraints
certificate extension. The Authority Clearance Constraints
certificate extension MAY be critical or non-critical.
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Absence of this certificate extension in a TA, in a CA PKC, or in an
AA PKC indicates that clearance of the subject of the AC or the
subject of the last certificate in a PKC certification path
containing the TA, the CA or the AA is not constrained by the
respective TA, CA or AA.
The following object identifier identifies the Authority Clearance
Constraints certificate extension:
id-pe-authorityClearanceConstraints OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) pe(1) 21 }
The ASN.1 syntax for the Authority Clearance Constraints certificate
extension is as follows:
AuthorityClearanceConstraints ::= SEQUENCE SIZE (1..MAX) OF
Clearance
The syntax for Authority Clearance Constraints certificate extension
contains Clearance values that the CA or the AA asserts. The
sequence MUST NOT include more than one entry with the same policyId.
This constraint is enforced during Clearance and Authority Clearance
Constraints Processing described below. If more than one entry with
the same policyId is present in AuthorityClearanceConstraints
certificate extension, the certification path is rejected. In
addition, each Clearance attribute in the SEQUENCE must not contain
more than one value.
4. Clearance and Authority Clearance Constraints Processing in PKC
This section describes the processing of certification path when
Clearance is asserted in PKC.
User input, Authority Clearance Constraints certificate extension,
and Clearance attribute processing determines the effective clearance
(henceforth called effective-clearance) for the end PKC. User input,
Authority Clearance Constraints certificate extension in the TA and
in each PKC up to but not including the end PKC in a PKC
certification path impact the effective-clearance. If there is more
than one path to the end-entity PKC, each path is processed
independently. The process involves two steps:
1) collecting the Authority Clearance Constraints; and
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2) using Authority Clearance Constraints in the certification path
and the Clearance in the end PKC to determine the effective-
clearance for the subject of the end PKC.
Assuming a certification path consisting of n PKCs, the effective-
clearance for the subject of the end PKC is the intersection of
Clearance attribute in the subject PKC, Authority Clearance
Constraints, if present, in trust anchor, user input, and all
Authority Clearance Constraints present in intermediate PKCs. Any
effective-clearance calculation algorithm that performs this
calculation and provides the same outcome as the one from the
algorithm described herein is considered compliant with the
requirements of this RFC.
When processing a certification path, Authority Clearance Constraints
are maintained in one state variable: permitted-clearances. When
processing begins, permitted-clearances is initialized to the user
input value or special value all-clearances if Authority Clearance
Constraints user input is not provided. The permitted-clearances
state variable is updated by first processing Authority Clearance
Constraints associated with the trust anchor, and then each time an
intermediate PKC that contains an Authority Clearance Constraints
certificate extension in the path is processed.
When processing the end PKC, the value in the Clearance attribute in
the end PKC is intersected with the permitted-clearances state
variable.
The output of Clearance attribute and Authority Clearance Constraint
certificate extensions processing is the effective-clearance, which
could also be an empty list; and success or failure with reason code
for failure.
4.1. Collecting Constraints
Authority Clearance Constraints are collected from the user input,
the trust anchor and the intermediate PKCs in a certification path.
4.1.1. Certification Path Processing
When processing Authority Clearance Constraints certificate extension
for the purposes of validating Clearance attribute in the end PKC,
the processing described in this section or an equivalent algorithm
MUST be included in the certification path validation. The
processing is presented as additions to the certification path
validation algorithm described in section 6 of [RFC5280]. Note that
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this RFC is fully consistent with [RFC5280]; however, it augments
[RFC5280] with the following steps:
. Ability to provide and process Authority Clearance Constraints
as an additional input to the certification path processing
engine
. Requirement to process Authority Clearance Constraints present
with Trust anchor information.
4.1.1.1. Inputs
User input may include AuthorityClearanceConstraints structure or
omit it.
Trust anchor information may include the
AuthorityClearanceConstraints structure to specify Authority
Clearance Constraints for the trust anchor. The trust anchor may be
constrained or unconstrained.
4.1.1.2. Initialization
If user input includes AuthorityClearanceConstraints, set the
permitted-clearances to the input value, otherwise,, set the
permitted-clearances to special value all-clearances.
If any of the Clearance attributes in the permitted-clearances
contains more than one value, set effective-clearance to an empty
list, set error code to "multiple values in input", and exit with
failure.
Examine the permitted-clearances for the same Policy ID appearing
more then once. If a policyID appears more than once in the
permitted-clearances state variable, set effective-clearance to an
empty list, set error code to "multiple instances of same clearance",
and exit with failure.
If the trust anchor does not contain an AuthorityClearanceConstraints
extension, continue at Section 4.1.1.3. Otherwise, execute the
procedure described in Section 6 as an in-line macro by treating the
trust anchor as a PKC.
4.1.1.3. Basic Certificate Processing
If the PKC is the last PKC (i.e., certificate n), skip the steps
listed in this section. Otherwise, execute the procedure described
in Section 6. as an in-line macro.
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4.1.1.4. Preparation for Certificate i+1
No additional action associated with the Clearance attribute or
AuthorityClearanceConstraints certificate extensions is taken during
this phase of certification path validation as described in section 6
of [RFC5280].
4.1.1.5. Wrap-up Procedure
To complete the processing, perform the following steps for the last
PKC (i.e., certificate n).
Examine the PKC and verify that it does not contain more than one
instance of Clearance attribute. If the PKC contains more than one
instance of Clearance attribute, set effective-clearance to an empty
list, set error code to "multiple instances of an attribute", and
exit with failure.
If the Clearance attribute is not present in the end PKC, set
effective-clearance to an empty list and exit with success.
Set effective-clearance to the Clearance attribute in the end PKC.
4.1.1.5.1. Wrap Up Clearance
Examine effective-clearance and verify that it does not contain more
than one value. If effective-clearance contains more than one value,
set effective-clearance to an empty list, set error code to "multiple
values", and exit with failure.
Let us say policyID in effective-clearance is X.
If permitted-clearances is an empty list, set effective-clearance to
an empty list and exit with success.
If the permitted-clearances has special value of all-clearances, exit
with success.
If the policyID X in effective-clearance is absent from the
permitted-clearances, set effective-clearance to an empty list and
exit with success.
Assign those classList bits in effective-clearance a value of one (1)
that have a value of one (1) both in effective-clearance and in the
clearance structure in permitted-clearances associated with policyID
X. Assign all other classList bits in effective-clearance a value of
zero (0).
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If none of the classList bits have a value of one (1) in effective-
clearance, set effective-clearance to an empty list and exit with
success.
Set the securityCategories in effective-clearance to the intersection
of securityCategories in effective-clearance and in permitted-
clearances using the algorithm described in Section 6. Note that
empty an SET is represented by simply omitting the SET.
Exit with Success
4.1.1.6. Outputs
If certification path validation processing succeeds, effective-
clearance contains the effective clearance for the subject of the
certification path. Processing also returns success or failure
indication and reason for failure, if applicable.
5. Clearance and Authority Clearance Constraints Processing in AC
This section describes the processing of certification path when
Clearance is asserted in an AC. Relevant to processing are: one TA;
0 or more CA PKCs; 0 or 1 AA PKC; and 1 AC.
User input, Authority Clearance Constraints certificate extension and
Clearance attribute processing determines the effective clearance
(henceforth called effective-clearance) for the AC. User input,
Authority Clearance Constraints certificate extension in the TA and
in each PKC up to and including the AA PKC in a certification path
impact the effective-clearance. If there is more than one path to
the AA PKC, each path is processed independently. The process
involves two steps:
1) collecting the Authority Clearance Constraints; and
2) using Authority Clearance Constraints in the PKC certification
path and the Clearance in the AC to determine the effective-
clearance for the subject of the AC.
The effective-clearance for the subject of the AC is the intersection
of Clearance in the subject AC, Authority Clearance Constraints, if
present, in trust anchor, user input, and all Authority Clearance
Constraints present in PKC certification path from the TA to the AA.
Any effective-clearance calculation algorithm that performs this
calculation and provides the same outcome as the one from the
algorithm described herein is considered compliant with the
requirements of this RFC.
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Authority Clearance Constraints is maintained in one state variable:
permitted-clearances. When processing begins, permitted-clearances
is initialized to user input or special value all-clearances if
Authority Clearance Constraints user input is not provided. The
permitted-clearances state variable is updated by first processing
Authority Clearance Constraints associated with the trust anchor, and
then each time a PKC (other than AC holder PKC) that contains an
Authority Clearance Constraints certificate extension in the path is
processed.
When processing the AC, the value in the Clearance attribute in the
AC is intersected with the permitted-clearances state variable.
The output of Clearance and Authority Clearance Constraint
certificate extensions processing is the effective-clearance, which
could also be an empty list; and success or failure with reason code
for failure.
5.1. Collecting Constraints
Authority Clearance Constraints are collected from the user input,
the trust anchor and all the PKCs in a PKC certification path.
5.1.1. Certification Path Processing
When processing Authority Clearance Constraints certificate extension
for the purposes of validating Clearance in the AC, the processing
described in this section or an equivalent algorithm MUST be included
in the certification path validation. The processing is presented as
additions to the PKC certification path validation algorithm
described in section 6 of [RFC5280] for the AA PKC certification path
and the algorithm described in section 5 of [3281bis] for the AC
validation. Also see note related to [RFC5280 augmentation in
Section 4.1.1.
5.1.1.1. Inputs
Same as Section 4.1.1.1.
In addition, let us assume that the PKC certification path for the AA
consists of n certificates.
5.1.1.2. Initialization
Same as Section 4.1.1.2.
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5.1.1.3. Basic PKC Processing
Same as Section 4.1.1.3. except that the logic is applied to all n
PKCs.
5.1.1.4. Preparation for Certificate i+1
Same as Section 4.1.1.4.
5.1.1.5. Wrap-up Procedure
To complete the processing, perform the following steps for the AC.
Examine the AC and verify that it does not contain more than one
instance of Clearance attribute. If the AC contains more than one
instance of Clearance attribute, set effective-clearance to an empty
list, set error code to "multiple instances of an attribute", and
exit with failure.
If the Clearance attribute is not present in the AC, set effective-
clearance to an empty list and exit with success.
Set effective-clearance to the Clearance attribute in the AC.
5.1.1.5.1. Wrap Up Clearance
Same as Section 4.1.1.5.1.
5.1.1.6. Outputs
Same as Section 4.1.1.6.
In addition, apply AC processing rules described in Section 5 of
[3281bis].
6. Computing Intersection of permitted-clearances and
AuthorityClearanceConstraints extension
Examine the PKC and verify that it does not contain more than one
instance of AuthorityClearanceConstraints extension. If the PKC
contains more than one instance of AuthorityClearanceConstraints
extension, set effective-clearance to an empty list, set error code
to "multiple extension instances", and exit with failure.
If any of the Clearance attributes in the
AuthorityClearanceConstraints extension contains more than one value,
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set effective-clearance to an empty list, set error code to "multiple
values", and exit with failure.
If the AuthorityClearanceConstraints certificate extension is not
present in the PKC, no action is taken, and the permitted-clearances
value is unchanged.
If the AuthorityClearanceConstraints certificate extension is present
in the PKC, set the variable temp-clearances to
AuthorityClearanceConstraints certificate extension. Examine the
temp-clearances for the same Policy ID appearing more then once. If
a policyID appears more than once in the temp-clearances state
variable, set effective-clearance to an empty list, set error code to
"multiple instances of same clearance", and exit with failure.
If the AuthorityClearanceConstraints certificate extension is present
in the PKC and permitted-clearances contains the all-clearances
special value, then assign permitted-clearances the value of the
temp-clearances.
If the AuthorityClearanceConstraints certificate extension is present
in the PKC and permitted-clearances does not contain the all-
clearances special value, take the intersection of temp-clearances
and permitted-clearances by repeating the following steps for each
clearance in the permitted-clearances state variable:
- If the policyID associated with the clearance is absent in the
temp-clearances, delete the clearance structure associated with
the policyID from the permitted-clearances state variable.
- If the policyID is present in the temp-clearances:
-- For every classList bit, assign the classList bit a value of
one (1) for the policyID in permitted-clearances state
variable if the bit is one (1) in both the permitted-
clearances state variable and the temp-clearances for that
policyID; otherwise assign the bit a value of zero (0).
-- If no bits are one (1) for the classList, delete the clearance
structure associated with the policyID from the permitted-
clearances state variable and skip the next step of processing
securityCategories.
-- For the policyID in permitted-clearances, set the
securityCategories to the intersection of securityCategories
for the policyID in permitted-clearances and in temp-
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clearances using the algorithm described in Section 7. Note
that an empty SET is represented by simply omitting the SET.
7. Computing Intersection of securityCategories
This section describes how to compute the intersection of
securityCategories A and B. It uses the state variable temp-set.
Set the SET temp-set to empty.
If SET A is empty (i.e., securityCategories is absent), return temp-
set.
If SET B is empty (i.e., securityCategories is absent), return temp-
set.
For every element (i.e., securityCategory) in the SET A carry out the
following steps:
1. If there is no element in SET B with the same Type OID as the
type OID in the element from SET A, go to step 6.
2. If there is an element in SET B with the same Type OID and value
as in the element in SET A, carry out the following steps:
a) Add an element containing the Type OID and the value to the
SET temp-set.
b) Delete all elements with the same Type OID and the same
value from the SET B.
c) Go to step 6.
3. If the processing semantics of Type OID in the element in SET A
is not known, go to step 6.
4. Perform Type OID specific intersection of the value in the
element in SET A with the values in the applicable elements in
SET B with the same Type OID.
5. If the intersection is not empty, add and element containing the
Type OID and intersection result as value to temp-set.
6. If more elements remain in SET A, process the next element
starting with step 1.
Return temp-set.
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8. Recommended securityCategories
This RFC also include a recommended securityCategories as follows:
SecurityCategory ::= SEQUENCE {
type [0] OID id-TBSL,
value [1] BIT STRING
}
Note that Type specific intersection of two values for this Type will
be simply setting the bits that are set in both values. If the
resulting intersection has none of the bits set, the intersection is
considered empty.
9. Security Considerations
Certificate issuers must recognize that absence of the
AuthorityClearanceConstraints in a CA or AA certificate means that in
terms of the clearance, the subject Authority is not constrained.
Absence of Clearance attribute in a certificate means that the
subject has not been assigned any clearance.
If there is no Clearance associated with a TA, it means that the TA
has not been assigned any clearance.
If the local security policy considers the clearance held by a
subject or those supported by a CA or AA to be sensitive, then the
Clearance attribute or Authority Clearance Constraints should only be
included if the subject's and Authority's certificate can be privacy
protected. Also in this case, distribution of trust anchors and
associated Authority Clearance Constraints extension or Clearance
must also be privacy protected.
10. IANA Considerations
None. Please remove this section prior to publication as an RFC.
11. References
11.1. Normative References
[PKI-ASN] Hoffman, P., and J. Schaad, "New ASN.1 Modules for PKIX",
draft-ietf-pkix-new-asn1, work-in-progress.
/*** RFC EDITOR: Please replace PKI-ASN with RFCXYZA when draft-ietf-
pkix-new-asn1 is published.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[3281bis] Farrell, S., Housely, R., and S. Turner, "An Internet
Attribute Certificate Profile for Authorization: Update",
draft-ietf-pkix-3281update-04, work-in-progress.
/*** RFC EDITOR: Please replace 3281bis with RFCXYZA when draft-ietf-
pkix-3281update is published.
[RFC5280] Cooper, D. et. al., "Internet X.509 Public Key
Infrastructure Certificate and Certification Revocation
List (CRL) Profile", RFC 5280, May 2008.
[X.680] ITU-T Recommendation X.680 (2004) | ISO/IEC 8824-1:2004.
Information Technology - Abstract Syntax Notation One.
11.2. Informative References
[RFC3114] Nicolls, W., "Implementing Company Classification Policy
with S/MIME Security Label", RFC3114, May 2002.
[RFC3739] Santesson, S. et. al., "Internet X.509 Public Key
Infrastructure: Qualified Certificate Profile", RFC 3739,
March 2004.
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Appendix A. ASN.1 Module
This appendix provides the normative ASN.1 definitions for
the structures described in this specification using ASN.1 as defined
in X.680.
ClearanceConstraints { iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7) mod(0) 46 }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
-- EXPORTS ALL --
IMPORTS
-- IMPORTS from [PKI-ASN]
id-at-clearance, Clearance
FROM PKIXAttributeCertificate
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-attribute-cert(12)
}
-- IMPORTS from [PKI-ASN]
EXTENSION
FROM PKIX-CommonTypes
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkixCommon(43)
}
;
-- Clearance attribute OID and syntax
-- The following is a '93 version for clearance.
-- It is included for convenience.
-- id-at-clearance OBJECT IDENTIFIER ::=
-- { joint-iso-ccitt(2) ds(5) attributeTypes(5) clearance (55) }
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-- Clearance ::= SEQUENCE {
-- policyId OBJECT IDENTIFIER,
-- classList ClassList DEFAULT {unclassified},
-- securityCategories SET OF SecurityCategory OPTIONAL
-- }
-- ClassList ::= BIT STRING {
-- unmarked (0),
-- unclassified (1),
-- restricted (2),
-- confidential (3),
-- secret (4),
-- topSecret (5)
-- }
-- SECURITY-CATEGORY ::= TYPE-IDENTIFIER
-- SecurityCategory ::= SEQUENCE {
-- type [0]
-- TYPE-IDENTIFIER.&id({SupportedSecurityCategories}),
-- value [1]
-- EXPLICIT TYPE-IDENTIFIER.&Type
-- ({SupportedSecurityCategories}{@type})
-- }
-- Authority Clearance Constraints certificate extension OID
-- and syntax
id-pe-clearanceConstraints OBJECT IDENTIFIER ::=
{ iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) pe(1) 21 }
authorityClearanceConstraints EXTENSION ::= {
SYNTAX AuthorityClearanceConstraints
IDENTIFIED BY id-pe-clearanceConstraints
}
AuthorityClearanceConstraints ::= SEQUENCE SIZE (1..MAX) OF Clearance
END
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Author's Addresses
Sean Turner
IECA, Inc.
3057 Nutley Street, Suite 106
Fairfax, VA 22031
USA
EMail: turners@ieca.com
Santosh Chokhani
CygnaCom Solutions, Inc.
Email: SChokhani@cygnacom.com
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