RFC 7906
NSA's Cryptographic Message Syntax (CMS) Key Management Attributes
Independent Submission P. Timmel Request for Comments: 7906 National Security Agency Category: Informational R. Housley ISSN: 2070-1721 Vigil Security S. Turner IECA June 2016 NSA's Cryptographic Message Syntax (CMS) Key Management AttributesAbstract
This document defines key management attributes used by the National Security Agency (NSA). The attributes can appear in asymmetric and/or symmetric key packages as well as the Cryptographic Message Syntax (CMS) content types that subsequently envelope the key packages. Key packages described in RFCs 5958 and 6031 are examples of where these attributes can be used. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor has chosen to publish this document at its discretion and makes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor are not a candidate for any level of Internet Standard; see Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7906. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document.
Table of Contents
1. Introduction ....................................................3 1.1. Attribute Locations ........................................3 1.2. ASN.1 Notation .............................................4 1.3. Terminology ................................................5 2. CMS-Defined Attributes ..........................................6 3. Community Identifiers ...........................................7 4. Key Province Attribute ..........................................8 5. Binary Signing Time .............................................8 6. Manifest ........................................................9 7. Key Algorithm ...................................................9 8. User Certificate ...............................................11 9. Key Package Receivers ..........................................11 10. TSEC Nomenclature .............................................13 11. Key Purpose ...................................................16 12. Key Use .......................................................17 13. Transport Key .................................................20 14. Key Distribution Period .......................................20 15. Key Validity Period ...........................................22 16. Key Duration ..................................................23 17. Classification ................................................24 17.1. Security Label ...........................................25 18. Split Key Identifier ..........................................29 19. Key Package Type ..............................................30 20. Signature Usage ...............................................30 21. Other Certificate Format ......................................33 22. PKI Path ......................................................34 23. Useful Certificates ...........................................35 24. Key Wrap Algorithm ............................................35 25. Content Decryption Key Identifier .............................36 25.1. Content Decryption Key Identifier: Symmetric Key and Symmetric ............................................36 25.2. Content Decryption Key Identifier: Unprotected ...........37 26. Certificate Pointers ..........................................37 27. CRL Pointers ..................................................38 28. Key Package Identifier and Receipt Request ....................38 29. Additional Error Codes ........................................39 30. Processing Key Package Attribute Values and CMS Content Constraints ...........................................39 31. Attribute Scope ...............................................41 32. Security Considerations .......................................48 33. References ....................................................48 33.1. Normative References .....................................48 33.2. Informative References ...................................51 Appendix A. ASN.1 Module ..........................................52 Authors' Addresses ................................................68
1. Introduction
This document defines key management attributes used by the National Security Agency (NSA). The attributes can appear in asymmetric and/or symmetric key packages as well as the Cryptographic Message Syntax (CMS) content types that subsequently envelope the key packages. This document contains definitions for new attributes as well as previously defined attributes. References are provided to the previously defined attributes; however, their definitions are included herein for convenience. CMS allows for arbitrary nesting of content types. Attributes are also supported in various locations in content types and key packages, which are themselves content types (see Section 1.1). An implementation that supports all of the possibilities would be extremely complex. Instead of implementing the full flexibility supported by this document, some devices may choose to support one or more templates, which is a profile for a combination of CMS content type(s), key package, and attribute(s); see Section 19.1.1. Attribute Locations
There are a number of CMS content types that support attributes SignedData [RFC5652], EnvelopedData [RFC5652], EncryptedData [RFC5652], AuthenticatedData [RFC5652], and AuthEnvelopedData [RFC5083] as well as ContentWithAttributes [RFC4073]. There are also a number of other content types defined with CONTENT-TYPE [RFC6268] that support attributes including AsymmetricKeyPackage [RFC5958] and SymmetricKeyPackage [RFC6031]. CMS defines a number of "protecting content types" -- SignedData [RFC5652], EnvelopedData [RFC5652], EncryptedData [RFC5652], AuthenticatedData [RFC5652], and AuthEnvelopedData [RFC5083] -- that provide some type of security service. There are also other CMS content types -- Data [RFC5652], ContentWithAttributes [RFC4073], and ContentCollection [RFC4073] -- that provide no security service. There are also different kinds of attributes in these content types: o SignedData supports two kinds of attributes: signed and unsigned attributes in the signedAttrs and unsignedAttrs fields, respectively. o EnvelopedData and EncryptedData each support one kind of attribute: unprotected attributes in the unprotectedAttrs field.
o AuthEnvelopedData supports two kinds of attributes:
authenticated and unauthenticated attributes in the authAttrs
and unauthAttrs fields, respectively. Both of these attributes
are also unprotected (i.e., they are not encrypted); therefore,
when referring to AuthEnvelopedData attributes, they are
authenticated&unprotected and unauthenticated&unprotected. For
this specification, unauthenticated attributes MUST NOT be
included.
o AuthenticatedData supports two kinds of attributes:
authenticated and unauthenticated attributes in the authAttrs
and unauthAttrs fields, respectively. For this specification,
unauthenticated attributes MUST NOT be included.
o ContentWithAttributes supports one kind of attribute: content
attributes in the attrs field.
o AsymmetricKeyPackage supports one kind of attribute: asymmetric
key attributes in the attributes field. If an attribute
appears as part of an asymmetric key package, it SHOULD appear
in the attributes field of the AsymmetricKeyPackage.
o SymmetricKeyPackage supports two kinds of attributes: symmetric
key and symmetric key package attributes in the sKeyAttrs and
sKeyPkgAttrs fields, respectively. Note that [RFC6031]
prohibits the same attribute from appearing in both locations
in the same SymmetricKeyPackage.
Note that this specification updates the following information object
sets SignedAttributesSet, UnsignedAttributes,
UnprotectedEnvAttributes, UnprotectedEncAttributes, AuthAttributeSet,
UnauthAttributeSet, AuthEnvDataAttributeSet,
UnauthEnvDataAttributeSet, and ContentAttributeSet from [RFC6268] as
well as OneAsymmetricKeyAttributes from [RFC5958], SKeyPkgAttributes
from [RFC6031], and SKeyAttributes from [RFC6031] to constrain the
permissible locations for attributes. See Appendix A for the ASN.1
for the information object sets.
1.2. ASN.1 Notation
The attributes defined in this document use 2002 ASN.1 [X.680]
[X.681] [X.682] [X.683]. The attributes MUST be DER [X.690] encoded.
Each of the attributes has a single attribute value instance in the
values set. Even though the syntax is defined as a set, there MUST
be exactly one instance of AttributeValue present. Further, the
SignedAttributes, UnsignedAttributes, UnprotectedAttributes,
AuthAttributes, and UnauthAttributes are also defined as a set, and
this set MUST include only one instance of any particular type of attribute. That is, any object identifier appearing in AttributeType MUST only appear one time in the set of attributes. SignedData, EnvelopedData, EncryptedData, AuthenticatedData, AuthEnvelopedData, and ContentWithAttributes were originally defined using the 1988 version of ASN.1. These definitions were updated to the 2008 version of ASN.1 by [RFC6268]. None of the new 2008 ASN.1 tokens are used; this allows 2002 compilers to compile 2008 ASN.1. AsymmetricKeyPackage and SymmetricKeyPackage are defined using the 2002 ASN.1. [RFC5652] and [RFC2634] define generally useful attributes for CMS using the 1988 version of ASN.1. These definitions were updated to the 2008 version of ASN.1 by [RFC6268] and the 2002 version of ASN.1 by [RFC5911], respectively. [RFC4108] and [RFC6019] also defined attributes using the 1988 version of ASN.1, which this document uses. Both were updated by [RFC5911] to the 2002 ASN.1. Refer to [RFC2634], [RFC4108], [RFC5652], and [RFC6019] for the attribute's semantics, but refer to [RFC5911] or [RFC6268] for the attribute's ASN.1 syntax.1.3. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Attribute Scope: The scope of an attribute is the compilation of keying material to which the attribute value is assigned. The scope of each attribute is determined by its placement within the key package or content collection. See Section 31. SIR: Source Intermediary Receiver is a model with three entities: o A source initiates the delivery of a key to one or more receivers. It may wrap or encrypt the key for delivery. This is expected to be the common case, since a cleartext key is vulnerable to exposure and compromise. If the sender is to encrypt the key for delivery, it must know how to encrypt the key so that the receiver(s) can decrypt it. A sender may also carry out any of the functions of an intermediary. * The original key package creators are sometimes referred to as key source authorities. These entities create the symmetric and/or asymmetric key package and apply the initial CMS protecting layer, which is normally a SignedData
but sometimes an AuthenticatedData. This initial CMS
protecting layer is maintained through any intermediary for
the receivers of the key package to ensure that receivers
can validate the key source authority.
o An intermediary does not have access to the cleartext key. An
intermediary may perform source authentication on key packages
and may append or remove management information related to the
package. It may encapsulate the encrypted key packages in
larger packages that contain other user data destined for later
intermediaries or receivers.
o A receiver has access to the cleartext key. If the received key
package is encrypted, it can unwrap or decrypt the encrypted
key to obtain the cleartext key. A receiver may be the final
destination of the cryptographic product. An element that acts
as a receiver and is not the final destination of the key
package may also act as a sender or as an intermediary. After
receiving a key, a receiver may encrypt the received key for
local storage.
NOTE: As noted in Section 1, a receiver can be tailored to support a
particular combination of CMS content type(s), key package, and
attribute(s) resulting in less-complex implementations. All of these
tailored receivers can be supported by a common key management
infrastructure that uses this specification; this also can yield
efficiencies in generation and provisioning. Senders and
intermediaries that have to understand multiple tailored receivers
get the efficiency of a common specification language and modular
implementation, as opposed to needing stove-piped processing for each
different receiver.
2. CMS-Defined Attributes
The following attributes are defined for [RFC5652]:
o content-type [RFC5652] [RFC5911] [RFC6268] uniquely specifies
the CMS content type. This attribute MUST be included as a
signed, authenticated, or authenticated&unprotected attribute.
o message-digest [RFC5652] [RFC5911] [RFC6268] is the message
digest of the encapsulated content calculated using the
signer's message digest algorithm. As specified in [RFC5652],
it must be included as a signed attribute and an authenticated
attribute; as specified in [RFC5652], it must not be an
unsigned attribute, unauthenticated attribute, or unprotected
attribute; as specified in [RFC5083], it should not be included
as an authenticated&unprotected attribute in AuthEnvelopedData.
This attribute MUST NOT be included elsewhere.
o content-hints [RFC2634] [RFC5911] [RFC6268] identifies the
innermost content when multiple layers of encapsulation have
been applied. Every instance of SignedData, AuthenticatedData,
and AuthEnvelopedData that does not directly encapsulate a
SymmetricKeyPackage, an AsymmetricKeyPackage, or an
EncryptedKeyPackage [RFC6032] MUST include this attribute.
3. Community Identifiers
The community-identifiers attribute, defined in [RFC4108] and
[RFC5911], lists the communities that are authorized recipients of
the signed content. It can appear as a signed, authenticated,
authenticated&unprotected, or content attribute. This attribute MUST
be supported.
The 2002 ASN.1 syntax for the community-identifiers attribute is
included for convenience:
aa-communityIdentifiers ATTRIBUTE ::= {
TYPE CommunityIdentifiers
IDENTIFIED BY id-aa-communityIdentifiers }
id-aa-communityIdentifiers OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
smime(16) aa(2) 40 }
CommunityIdentifiers ::= SEQUENCE OF CommunityIdentifier
CommunityIdentifier ::= CHOICE {
communityOID OBJECT IDENTIFIER,
hwModuleList HardwareModules }
HardwareModules ::= SEQUENCE {
hwType OBJECT IDENTIFIER,
hwSerialEntries SEQUENCE OF HardwareSerialEntry }
HardwareSerialEntry ::= CHOICE {
all NULL,
single OCTET STRING,
block SEQUENCE {
low OCTET STRING,
high OCTET STRING } }
Consult [RFC4108] for the attribute's semantics.
4. Key Province Attribute
The key-province-v2 attribute identifies the scope, range, or jurisdiction in which the key is to be used. The key-province-v2 attribute MUST be present as a signed attribute or an authenticated attribute in the innermost CMS protection content type that provides authentication (i.e., SignedData, AuthEnvelopedData, or AuthenticatedData) and encapsulates a symmetric key package or an asymmetric key package. The key-province attribute has the following syntax: aa-keyProvince-v2 ATTRIBUTE ::= { TYPE KeyProvinceV2 IDENTIFIED BY id-aa-KP-keyProvinceV2 } id-aa-KP-keyProvinceV2 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) dod(2) infosec(1) attributes(5) 71 } KeyProvinceV2 ::= OBJECT IDENTIFIER5. Binary Signing Time
The binary-signing-time attribute, defined in [RFC6019] and [RFC6268], specifies the time at which the signature or the Message Authentication Code (MAC) was applied to the encapsulated content. It can appear as a signed, authenticated, or authenticated&unprotected attribute. The 2002 ASN.1 syntax is included for convenience: aa-binarySigningTime ATTRIBUTE ::= { TYPE BinarySigningTime IDENTIFIED BY id-aa-binarySigningTime } id-aa-binarySigningTime OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9) smime(16) aa(2) 46 } BinarySigningTime ::= BinaryTime BinaryTime ::= INTEGER (0..MAX) Consult [RFC6019] for the binary-signing-time attribute's semantics.
6. Manifest
The manifest attribute lists the short titles of all the Transmission Security Nomenclature (TSEC-Nomenclature) attributes from inner key packages. It MUST only appear as an outermost signed, authenticated, or authenticated&unprotected attribute. If a short title is repeated in inner packages, it need only appear once in the manifest attribute. The manifest attribute MUST NOT appear in the same level as the TSEC-Nomenclature from Section 10. The manifest attribute has the following syntax: aa-manifest ATTRIBUTE ::= { TYPE Manifest IDENTIFIED BY id-aa-KP-manifest } id-aa-KP-manifest OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) dod(2) infosec(1) attributes(5) 72 } Manifest ::= SEQUENCE SIZE (1..MAX) OF ShortTitle7. Key Algorithm
The key-algorithm attribute indirectly specifies the size and format of the keying material in the skey field of a symmetric key package, which is defined in [RFC6031]. It can appear as a symmetric key, symmetric key package, signed, authenticated, authenticated&unprotected, or content attribute. If this attribute appears as a signed attribute, then all of the keying material within the SignedData content MUST be associated with the same algorithm. If this attribute appears as an authenticated or authenticated&unprotected attribute, then all of the keying material within the AuthenticatedData or AuthEnvelopedData content type MUST be associated with the same algorithm. If this attribute appears as a content attribute, then all of the keying material within the collection MUST be associated with the same algorithm. If both the key-wrap-algorithm (Section 24) and key-algorithm attributes apply to an sKey, then the key-algorithm attribute refers to the decrypted value of sKey rather than to the content of sKey itself. This attribute MUST be supported. The key-algorithm attribute has the following syntax: aa-keyAlgorithm ATTRIBUTE ::= { TYPE KeyAlgorithm IDENTIFIED BY id-kma-keyAlgorithm }
id-kma-keyAlgorithm OBJECT IDENTIFIER ::= {
joint-iso-itu-t(2) country(16) us(840) organization(1)
gov(101) dod(2) infosec(1) keying-material-attributes(13) 1 }
KeyAlgorithm ::= SEQUENCE {
keyAlg OBJECT IDENTIFIER,
checkWordAlg [1] OBJECT IDENTIFIER OPTIONAL,
crcAlg [2] OBJECT IDENTIFIER OPTIONAL }
The fields in the key-algorithm attribute have the following
semantics:
o keyAlg specifies the size and format of the keying material.
o If the particular key format supports more than one check-word
algorithm, then the OPTIONAL checkWordAlg identifier indicates
which check-word algorithm was used to generate the check word
that is present. If the check-word algorithm is implied by the
key algorithm, then the checkWordAlg field SHOULD be omitted.
o If the particular key format supports more than one Cyclic
Redundancy Check (CRC) algorithm, then the OPTIONAL crcAlg
identifier indicates which CRC algorithm was used to generate
the value that is present. If the CRC algorithm is implied by
the key algorithm, then the crcAlg field SHOULD be omitted.
The keyAlg identifier, the checkWordAlg identifier, and the crcAlg
identifier are object identifiers. The use of an object identifier
accommodates any algorithm from any registry.
The format of the keying material in the skey field of a symmetric
key package will not match this attribute if the keying material is
split (see Section 18 for a discussion of the split-identifier
attribute). In this situation, this attribute identifies the format
of the keying material once the two splits are combined.
Due to multiple layers of encapsulation or the use of content
collections, the key-algorithm attribute can appear in more than one
location in the overall key package. When there are multiple
occurrences of the key-algorithm attribute within the same scope, the
keyAlg field MUST match in all instances. The OPTIONAL checkWordAlg
and crcAlg fields can be omitted in the key-algorithm attribute when
it appears as a signed, authenticated, authenticated&unprotected, or
content attribute. However, if these optional fields are present,
they MUST also match the other occurrences within the same scope.
Receivers MUST reject any key package that fails these consistency
checks.
8. User Certificate
The user-certificate attribute specifies the type, format, and value of an X.509 certificate and is used in asymmetric key package's attributes field. This attribute can appear as an asymmetric key attribute. This attribute MUST NOT appear in an asymmetric key package attributes field that includes the other-certificate-formats attribute. Symmetric key packages do not contain any certificates, so the user-certificate attribute MUST NOT appear in a symmetric key package. The user-certificate attribute MUST NOT appear as a signed, authenticated, authenticated&unprotected, or content attribute. This attribute MUST be supported. The syntax is taken from [X.509] but redefined using the ATTRIBUTE CLASS from [RFC5912]. The user-certificate attribute has the following syntax: aa-userCertificate ATTRIBUTE ::= { TYPE Certificate EQUALITY MATCHING RULE certificateExactMatch IDENTIFIED BY id-at-userCertificate } id-at-userCertificate OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) ds(5) attributes(4) 36 } Since the user-certificate attribute MUST NOT appear as a signed, authenticated, authenticated&unprotected, or content attribute, an asymmetric key package cannot include multiple occurrences of the user-certificate attribute within the same scope. Receivers MUST reject any asymmetric key package in which the user-certificate attribute appears as a signed, authenticated, authenticated&unprotected, or content attribute.9. Key Package Receivers
The key-package-receivers-v2 attribute indicates the intended audience for the key package. The key-package-receivers-v2 attribute is not intended for access control decisions; rather, intermediate systems may use this attribute to make routing and relaying decisions. If the receiver is not listed, it will not be able to decrypt the package; therefore, the receiver SHOULD reject the key package if the key-package-receivers-v2 attribute is present and they are not listed as an intended receiver. The key-package-receivers-v2 attribute can be used as a signed, authenticated, authenticated&unprotected, or content attribute. If the key-package- receivers-v2 attribute is associated with a collection, then the named receivers MUST be able to receive all of the key packages within the collection. This attribute MUST be supported.
The key-package-receivers-v2 attribute has the following syntax:
aa-keyPackageReceivers-v2 ATTRIBUTE ::= {
TYPE KeyPkgReceiversV2
IDENTIFIED BY id-kma-keyPkgReceiversV2 }
id-kma-keyPkgReceiversV2 OBJECT IDENTIFIER ::= {
joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101)
dod(2) infosec(1) keying-material-attributes(13) 16 }
KeyPkgReceiversV2 ::= SEQUENCE SIZE (1..MAX) OF KeyPkgReceiver
KeyPkgReceiver ::= CHOICE {
sirEntity [0] SIREntityName,
community [1] CommunityIdentifier }
The key-package-receivers-v2 attribute contains a list of receiver
identifiers. The receiver identifier is either a SIREntityName
[RFC7191] or a CommunityIdentifier (see Section 3). The
SIREntityName syntax does not impose any particular structure on the
receiver identifier, but it does require registration of receiver
identifier types. The nameType ensures that two receiver identifiers
of different types that contain the same values are not interpreted
as equivalent. Name types are expected to be defined that represent
several different granularities. For example, one name type will
represent the receiver organization. At a finer granularity, the
name type will identify a specific cryptographic device, perhaps
using a manufacturer identifier and serial number.
If a receiver does not recognize a particular nameType or a community
identifier, then keying material within the scope of the unrecognized
nameType or community identifier MUST NOT be used in any manner.
However, the receiver need not discard the associated key package.
Since many cryptographic devices are programmable, a different
firmware load may recognize the nameType. Likewise, a change in the
configuration may lead to the recognition of a previously
unrecognized community identifier. Therefore, the receiver may
retain the key package, but refuse to use it for anything with a
firmware load that does not recognize the nameType or a configuration
that does not recognize the community identifier.
Whenever a key package is saved for later processing due to an
unrecognized nameType or community identifier, subsequent processing
MUST NOT rely on any checks that were made the first time the key
package processing was attempted. That is, the subsequent processing
MUST include the full complement of checks. Further, a receipt for
the packages MUST NOT be generated unless all of these checks are
successfully completed.
Due to multiple layers of encapsulation or the use of content collections, the key-package-receivers-v2 attribute can appear in more than one location in the overall key package. When that happens, each occurrence is evaluated independently. In a content collection, each member of the collection might contain its own signed, authenticated, authenticated&unprotected, or content attribute that includes a key-package-receivers-v2 attribute. In this situation, each member of the collection is evaluated separately, and any member that includes an acceptable receiver SHOULD be retained. Other members can be rejected or retained for later processing with a different firmware load.10. TSEC Nomenclature
The Telecommunications Security Nomenclature (TSEC-Nomenclature) attribute provides the name for a piece of keying material, which always includes a printable string called a "short title" (see below). The TSEC-Nomenclature attribute also contains other identifiers when the shortTitle is insufficient to uniquely name a particular piece of keying material. This attribute can appear as a symmetric key, symmetric key package, asymmetric key, signed, authenticated, authenticated&unprotected, or content attribute. If this attribute appears in the sKeyAttrs field, the editionID, registerID, and segmentID attribute fields MUST NOT be ranges. If this attribute appears as a signed, authenticated, authenticated&unprotected, or content attribute, all of the keying material within the associated content MUST have the same shortTitle, and the attribute value MUST contain only a shortTitle. That is, when this attribute appears as a signed, authenticated, authenticated&unprotected, or content attribute, all of the optional fields MUST be absent. If this attribute is associated with a collection, all of the keying material within the collection MUST have the same shortTitle; however, the editionID, registerID, and segmentID will be different for each key package in the collection. This attribute MUST be supported. The TSEC-Nomenclature attribute has the following syntax: aa-tsecNomenclature ATTRIBUTE ::= { TYPE TSECNomenclature IDENTIFIED BY id-kma-TSECNomenclature } id-kma-TSECNomenclature OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) dod(2) infosec(1) keying-material-attributes(13) 3 }
TSECNomenclature ::= SEQUENCE {
shortTitle ShortTitle,
editionID EditionID OPTIONAL,
registerID RegisterID OPTIONAL,
segmentID SegmentID OPTIONAL }
ShortTitle ::= PrintableString
EditionID ::= CHOICE {
char CHOICE {
charEdition [1] CharEdition,
charEditionRange [2] CharEditionRange }
num CHOICE {
numEdition [3] NumEdition,
numEditionRange [4] NumEditionRange } }
CharEdition ::= PrintableString
CharEditionRange ::= SEQUENCE {
firstCharEdition CharEdition,
lastCharEdition CharEdition }
NumEdition ::= INTEGER (0..308915776)
NumEditionRange ::= SEQUENCE {
firstNumEdition NumEdition,
lastNumEdition NumEdition }
RegisterID ::= CHOICE {
register [5] Register,
registerRange [6] RegisterRange }
Register ::= INTEGER (0..2147483647)
RegisterRange ::= SEQUENCE {
firstRegister Register,
lastRegister Register }
SegmentID ::= CHOICE {
segmentNumber [7] SegmentNumber,
segmentRange [8] SegmentRange }
SegmentNumber ::= INTEGER (1..127)
SegmentRange ::= SEQUENCE {
firstSegment SegmentNumber,
lastSegment SegmentNumber }
The fields in the TSEC-Nomenclature attribute have the following
semantics:
o The shortTitle consists of up to 32 alphanumeric characters.
shortTitle processing always uses the value in its entirety.
o The editionID is OPTIONAL, and the editionIdentifier is used to
distinguish accountable items. The editionID consists of
either six alphanumeric characters or an integer. When
present, the editionID is either a single value or a range.
The integer encoding should be used when it is important to
keep key package size to a minimum.
o The registerID is OPTIONAL. For electronic keying material,
the registerID is usually omitted. The registerID is an
accounting number assigned to identify Communications Security
(COMSEC) material. The registerID is either a single value or
a range.
o The segmentID is OPTIONAL, and it distinguishes the individual
symmetric keys delivered in one edition. A unique
segmentNumber is assigned to each key in an edition. The
segmentNumber is set to one for the first item in each edition,
and it is incremented by one for each additional item within
that edition. The segmentID is either a single value or a
range.
The order that the keying material will appear in the key package is
illustrated by the following example: a cryptographic device may
require fresh keying material every day, an edition represents the
keying material for a single month, and the segments represent the
keying material for a day within that month. Consider a key package
that contains the keying material for July and August; it will
contain keying material for 62 days. The keying material will appear
in the following order: Edition 1, Segment 1; Edition 1, Segment 2;
Edition 1, Segment 3; ...; Edition 1, Segment 31; Edition 2,
Segment 1; Edition 2, Segment 2; Edition 2, Segment 3; ...;
Edition 2, Segment 31.
Due to multiple layers of encapsulation or the use of content
collections, the TSEC-Nomenclature attribute can appear in more than
one location in the overall key package. When there are multiple
occurrences of the TSEC-Nomenclature attribute within the same scope,
the shortTitle field MUST match in all instances. Receivers MUST
reject any key package that fails these consistency checks.
When the manifest attribute from Section 6 is included in an outer layer, the ShortTitle field values present in TSEC-Nomenclature attributes MUST be one of the values in the manifest attribute. Receivers MUST reject any key package that fails this consistency check.11. Key Purpose
The key-purpose attribute specifies the intended purpose of the key material. It can appear as a symmetric key, symmetric key package, asymmetric key, signed, authenticated, authenticated&unprotected, or content attribute. If the key-purpose attribute appears as a signed, authenticated, authenticated&unprotected, or content attribute, then all of the keying material within the associated content MUST have the same key purpose value. The key-purpose attribute has the following syntax: aa-keyPurpose ATTRIBUTE ::= { TYPE KeyPurpose IDENTIFIED BY id-kma-keyPurpose } id-kma-keyPurpose OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) dod(2) infosec(1) keying-material-attributes(13) 13 } KeyPurpose ::= ENUMERATED { n-a (0), -- Not Applicable A (65), -- Operational B (66), -- Compatible Multiple Key L (76), -- Logistics Combinations M (77), -- Maintenance R (82), -- Reference S (83), -- Sample T (84), -- Training V (86), -- Developmental X (88), -- Exercise Z (90), -- "On the Air" Testing ... -- Expect additional key purpose values -- } Due to multiple layers of encapsulation or the use of content collections, the key-purpose attribute can appear in more than one location in the overall key package. When there are multiple occurrences of the key-purpose attribute within the same scope, all fields within the attribute MUST contain exactly the same values. Receivers MUST reject any key package that fails these consistency checks.
12. Key Use
The key-use attribute specifies the intended use of the key material. It can appear as a symmetric key, symmetric key package, asymmetric, signed, authenticated, authenticated&unprotected, or content attribute. If the key-use attribute appears as a signed, authenticated, authenticated&unprotected, or content attribute, then all of the keying material within the associated content MUST have the same key use value. The key-use attribute has the following syntax: aa-key-Use ATTRIBUTE ::= { TYPE KeyUse IDENTIFIED BY id-kma-keyUse } id-kma-keyUse OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) dod(2) infosec(1) keying-material-attributes(13) 14 } KeyUse ::= ENUMERATED { n-a (0), -- Not applicable ffk (1), -- FIREFLY/CROSSTALK Key (Basic Format) kek (2), -- Key Encryption Key kpk (3), -- Key Production Key msk (4), -- Message Signature Key qkek (5), -- QUADRANT Key Encryption Key tek (6), -- Traffic Encryption Key tsk (7), -- Transmission Security Key trkek (8), -- Transfer Key Encryption Key nfk (9), -- Netted FIREFLY Key effk (10), -- FIREFLY Key (Enhanced Format) ebfk (11), -- FIREFLY Key (Enhanceable Basic Format) aek (12), -- Algorithm Encryption Key wod (13), -- Word of Day kesk (246), -- Key Establishment Key eik (247), -- Entity Identification Key ask (248), -- Authority Signature Key kmk (249), -- Key Modifier Key rsk (250), -- Revocation Signature Key csk (251), -- Certificate Signature Key sak (252), -- Symmetric Authentication Key rgk (253), -- Random Generation Key cek (254), -- Certificate Encryption Key exk (255), -- Exclusion Key ... -- Expect additional key use values -- }
The values for the key-use attribute have the following semantics:
o ffk: A FIREFLY/CROSSTALK key is used to establish a Key
Establishment Key (KEK) or a Transmission Encryption Key (TEK)
between two parties. The KEK or TEK generated from the
exchange is used with a symmetric encryption algorithm. This
key use value is associated with keys in the basic format.
o kek: A Key Encryption Key is used to encrypt or decrypt other
keys for transmission or storage.
o kpk: A Key Production Key is used to initialize a keystream
generator for the production of other electronically generated
keys.
o msk: A Message Signature Key is used in a digital signature
process that operates on a message to assure message source
authentication, message integrity, and non-repudiation.
o qkek: QUADRANT Key Encryption Key is one part of a tamper-
resistance solution.
o tek: A Traffic Encryption Key is used to encrypt plaintext, to
superencrypt previously encrypted data, and/or to decrypt
ciphertext.
o tsk: A Transmission Security Key is used to protect
transmissions from interception and exploitation by means other
than cryptanalysis.
o trkek: Transfer Key Encryption Key. The keys used to protect
communications with an intermediary.
o nfk: A Netted FIREFLY Key is a FIREFLY key that has an edition
number associated with it. When rekeyed, it is incremented,
preventing communications with FIREFLY key of previous
editions. This edition number is maintained within a universal
edition.
o effk: Enhanced FIREFLY Key is used to establish a KEK or a TEK
between two parties. The KEK or TEK generated from an exchange
is used with a symmetric encryption algorithm. This key use
value is associated with keys in the enhanced format.
o ebfk: Enhanceable Basic FIREFLY Key is used to establish a KEK
or a TEK between two parties. The KEK or TEK generated from an
exchange is used with a symmetric encryption algorithm. This
key use value is associated with keys in the enhanceable basic
format.
o aek: An Algorithm Encryption Key is used to encrypt or decrypt
an algorithm implementation as well as other functionality in
the implementation.
o wod: A key used to generate the Word of the Day (WOD).
o kesk: A Key Establishment Key is an asymmetric key set (e.g.,
public/private/parameters) used to enable the establishment of
symmetric key(s) between entities.
o eik: An Entity Identification Key is an asymmetric key set
(e.g., public/private/parameters) used to identify one entity
to another for access control and other similar purposes.
o ask: An Authority Signature Key is an asymmetric key set (e.g.,
public/private/parameters) used by designated authorities to
sign objects such as Trust Anchor Management Protocol (TAMP)
messages and firmware packages.
o kmk: A Key Modifier Key is a symmetric key used to modify the
results of the process that forms a symmetric key from a public
key exchange process.
o rsk: A Revocation Signature Key is an asymmetric key set (e.g.,
public/private/parameters) used to sign and authenticate
revocation lists and compromised key lists.
o csk: A Certificate Signature Key is an asymmetric key set
(e.g., public/private/parameters) used to sign and authenticate
public key certificates.
o sak: A Symmetric Authentication Key is used in a MAC algorithm
to provide message integrity. Differs from a Message Signature
Key in that it is symmetric key material and it does not
provide source authentication or non-repudiation.
o rgk: Random Generation Key is a key used to seed a
deterministic pseudorandom number generator.
o cek: A Certificate Encryption Key is used to encrypt public key
certificates to support privacy.
o exk: An Exclusion Key is a symmetric key used to
cryptographically subdivide a single large security domain into
smaller segregated domains.
Due to multiple layers of encapsulation or the use of content
collections, the key-use attribute can appear in more than one
location in the overall key package. When there are multiple
occurrences of the key-use attribute within the same scope, all
fields within the attribute MUST contain exactly the same values.
Receivers MUST reject any key package that fails these consistency
checks.
13. Transport Key
The transport-key attribute identifies whether an asymmetric key is a
transport key or an operational key (i.e., whether or not the key can
be used as is). It can appear as an asymmetric key, signed,
authenticated, authenticated&unprotected, or content attribute. If
the transport-key attribute appears as a signed, authenticated,
authenticated&unprotected, or content attribute, then all of the
keying material within the associated content MUST have the same
operational/transport key material.
aa-transportKey ATTRIBUTE ::= {
TYPE TransOp
IDENTIFIED BY id-kma-transportKey }
id-kma-transportKey OBJECT IDENTIFIER ::= {
joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101)
dod(2) infosec(1) keying-material-attributes(13) 15 }
TransOp ::= ENUMERATED {
transport (1),
operational (2) }
Due to multiple layers of encapsulation or the use of content
collections, the transport-key attribute can appear in more than one
location in the overall key package. When there are multiple
occurrences of the transport-key attribute within the same scope, all
fields within the attribute MUST contain exactly the same values.
Receivers MUST reject any key package that fails these consistency
checks.
14. Key Distribution Period
The key-distribution-period attribute indicates the period of time
that the keying material is intended for distribution. Keying
material is often distributed before it is intended to be used. Time
of day must be represented in Coordinated Universal Time (UTC). It
can appear as a symmetric key, symmetric key package, asymmetric key,
signed, authenticated, authenticated&unprotected, or content
attribute. If the key-distribution-period attribute appears as a
signed, authenticated, authenticated&unprotected, or content
attribute, then all of the keying material within the content MUST
have the same key distribution period.
The key-distribution-period attribute has the following syntax:
aa-keyDistributionPeriod ATTRIBUTE ::= {
TYPE KeyDistPeriod
IDENTIFIED BY id-kma-keyDistPeriod }
id-kma-keyDistPeriod OBJECT IDENTIFIER ::= {
joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101)
dod(2) infosec(1) keying-material-attributes(13) 5 }
KeyDistPeriod ::= SEQUENCE {
doNotDistBefore [0] BinaryTime OPTIONAL,
doNotDistAfter BinaryTime }
BinaryTime ::= INTEGER
The fields in the key-distribution-period attribute have the
following semantics:
o The doNotDistBefore field is OPTIONAL, and when it is present,
the keying material SHOULD NOT be distributed before the date
and time provided.
o The doNotDistAfter field is REQUIRED, and the keying material
SHOULD NOT be distributed after the date and time provided.
When the key-distribution-period attribute is associated with a
collection of keying material, the distribution period applies to all
of the keys in the collection. None of the keying material in the
collection SHOULD be distributed outside the indicated period.
Due to multiple layers of encapsulation or the use of content
collections, the key-distribution-period attribute can appear in more
than one location in the overall key package. When there are
multiple occurrences of the key-distribution-period attribute within
the same scope, all of the included attribute fields MUST contain
exactly the same value. However, if the doNotDistBefore field is
absent in an inner layer, a value MAY appear in an outer layer
because the outer layer constrains the inner layer. Receivers MUST
reject any key package that fails these consistency checks.
(next page on part 2)
