SACM Working Group H. Birkholz
Internet-Draft Fraunhofer SIT
Intended status: Standards Track J. Fitzgerald-McKay
Expires: January 5, 2018 Department of Defense
C. Schmidt
The MITRE Corporation
D. Waltermire
NIST
July 04, 2017
Concise Software Identifiers
draft-ietf-sacm-coswid-02
Abstract
This document defines a concise representation of ISO 19770-2:2015
Software Identifiers (SWID tags) that is interoperable with the XML
schema definition of ISO 19770-2:2015 and augmented for application
in Constrained-Node Networks. Next to the inherent capability of
SWID tags to express arbitrary context information, CoSWID support
the definition of additional semantics via well-defined data
definitions incorporated by extension points.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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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."
This Internet-Draft will expire on January 5, 2018.
Copyright Notice
Copyright (c) 2017 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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Concise SWID Extensions . . . . . . . . . . . . . . . . . 4
1.2. Requirements Notation . . . . . . . . . . . . . . . . . . 4
2. Concise SWID Data Definition . . . . . . . . . . . . . . . . 4
3. Description of the SWID Attribute Vocabulary Definition . . . 9
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 9
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
7. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 11
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1. Normative References . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. Explicit file-hash Type Used in Concise SWID Tags
(label 56) . . . . . . . . . . . . . . . . . . . . . 13
Appendix B. CoSWID Attributes for Firmware (label 57) . . . . . 14
Appendix C. Signed Concise SWID Tags using COSE . . . . . . . . 16
Appendix D. CoSWID used as Reference Integrity Measurements
(CoSWID RIM) . . . . . . . . . . . . . . . . . . . . 17
Appendix E. CBOR Web Token for Concise SWID Tags . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
SWID tags have several use-applications including but not limited to:
o Software Inventory Management, a part of the Software Asset
Management [SAM] process, which requires an accurate list of
discernible deployed software components.
o Vulnerability Assessment, which requires a semantic link between
standardized vulnerability descriptions and IT-assets [X.1520].
o Remote Attestation, which requires a link between reference
integrity measurements (RIM) and security logs of measured
software components [I-D.birkholz-tuda].
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SWID tags, as defined in ISO-19770-2:2015 [SWID], provide a
standardized format for a record that identifies and describes a
specific release of a software product. Different software products,
and even different releases of a particular software product, each
have a different SWID tag record associated with them. In addition
to defining the format of these records, ISO-19770-2:2015 defines
requirements concerning the SWID tag life-cycle. Specifically, when
a software product is installed on an endpoint, that product's SWID
tag is also installed. Likewise, when the product is uninstalled or
replaced, the SWID tag is deleted or replaced, as appropriate. As a
result, ISO-19770-2:2015 describes a system wherein there is a
correspondence between the set of installed software products on an
endpoint, and the presence on that endpoint of the SWID tags
corresponding to those products.
SWID tags are meant to be flexible and able to express a broad set of
metadata about a software product. Moreover, there are multiple
types of SWID tags, each providing different types of information.
For example, a "corpus tag" is used to describe an application's
installation image on an installation media, while a "patch tag" is
meant to describe a patch that modifies some other application.
While there are very few required fields in SWID tags, there are many
optional fields that support different uses of these different types
of tags. While a SWID tag that consisted only of required fields
could be a few hundred bytes in size, a tag containing many of the
optional fields could be many orders of magnitude larger.
This document defines a more concise representation of SWID tags in
the Concise Binary Object Representation (CBOR) [RFC7049]. This is
described via the Concise Data Definition Language (CDDL)
[I-D.greevenbosch-appsawg-cbor-cddl]. The resulting Concise SWID
data definition is interoperable with the XML schema definition of
ISO-19770-2:2015 [SWID]. The vocabulary, i.e., the CDDL names of the
types and members used in the CoSWID data definition, is mapped to
more concise labels represented as small integers. The names used in
the CDDL data definition and the mapping to the CBOR representation
using integer labels is based on the vocabulary of the XML attribute
and element names defined in ISO-19770-2:2015.
Real-world instances of SWID tags can be fairly large, and the
communication of SWID tags in use-applications such as those
described earlier can cause a large amount of data to be transported.
This can be larger than acceptable for constrained devices and
networks. CoSWID tags significantly reduce the amount of data
transported as compared to a typical SWID tag. This reduction is
enable through the use of CBOR, which maps human-readable labels of
that content to more concise integer labels (indices). This allows
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SWID tags to be part of an enterprise security solution for a wider
range of endpoints and environments.
1.1. Concise SWID Extensions
This document specifies a standard equivalent to the ISO-19770-2:2015
standard. The corresponding CoSWID data definition includes two
kinds of augmentation.
o the explicit definition of types for attributes that are typically
stored in the "any attribute" of an ISO-19770-2:2015 in XML
representation. These are covered in the main body of this
document.
o the inclusion of extension points in the CoSWID data definition
that allow for additional uses of CoSWID tags that go beyond the
original scope of ISO-19770-2:2015 tags. These are covered in
appendices to this document.
1.2. Requirements Notation
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, BCP 14 [RFC2119].
2. Concise SWID Data Definition
The following is a CDDL representation of the ISO-19770-2:2015 [SWID]
XML schema definition of SWID tags. This representation includes
every SWID tag fields and attribute and thus supports all SWID tag
use cases. The CamelCase notation used in the XML schema definition
is changed to a hyphen-separated notation (e.g. ResourceCollection
is named resource-collection in the CoSWID data definition). This
deviation from the original notation used in the XML representation
reduces ambiguity when referencing certain attributes in
corresponding textual descriptions. An attribute referred by its
name in CamelCase notation explicitly relates to XML SWID tags, an
attribute referred by its name in hyphen-separated notation
explicitly relates to CoSWID tags. This approach simplifies the
composition of further work that reference both XML SWID and CoSWID
documents.
Human-readable names of members in the CDDL data definition are
mapped to integer indices via a block of rules at the bottom of the
definition. The 66 character strings of the SWID vocabulary that
would have to be stored or transported in full if using the original
vocabulary are replaced.
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Concise Software Identifiers are tailored to be used in the domain of
constrained-node networks. A typical endpoint is capable of storing
the CoSWID tag of installed software, a constrained-node might lack
that capability. CoSWID address these constraints and the
corresponding specification is augmented to retain their usefulness
in the thing-2-thing domain. Specific examples include, but are not
limited to limiting the scope of hash algorithms to the IANA Named
Information tables or including firmware attributes addressing
devices that do not necessarily provide a file-system to store a
CoSWID tag in.
In order to create a valid CoSWID document the structure of the
corresponding CBOR message MUST adhere to the following CDDL data
definition.
<CODE BEGINS>
concise-software-identity = {
global-attributes,
? entity-entry,
? evidence-entry,
? link-entry,
? software-meta-entry,
? payload-entry,
? any-element-entry,
? corpus,
? patch,
? media,
swid-name,
? supplemental,
tag-id,
? tag-version,
? version,
? version-scheme,
}
any-uri = text
label = text / int
any-attribute = (
label => text / int / [ 2* text ] / [ 2* int ]
)
any-element-map = {
global-attributes,
* label => any-element-map / [ 2* any-element-map ],
}
global-attributes = (
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? lang,
* any-attribute,
)
resource-collection = (
? directory-entry,
? file-entry,
? process-entry,
? resource-entry
* $$resource-extension
)
file = {
filesystem-item,
? size,
? version,
? file-hash,
}
filesystem-item = (
global-attributes,
? key,
? location,
fs-name,
? root,
)
directory = {
filesystem-item,
path-elements,
}
process = {
global-attributes,
process-name,
? pid,
}
resource = {
global-attributes,
type,
}
entity = {
global-attributes,
extended-data,
entity-name,
? reg-id,
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role,
? thumbprint,
}
evidence = {
global-attributes,
resource-collection,
? date,
? device-id,
}
link = {
global-attributes,
? artifact,
href,
? media,
? ownership,
rel,
? type,
? use,
}
software-meta = {
global-attributes,
? activation-status,
? channel-type,
? colloquial-version,
? description,
? edition,
? entitlement-data-required,
? entitlement-key,
? generator,
? persistent-id,
? product,
? product-family,
? revision,
? summary,
? unspsc-code,
? unspsc-version,
}
payload = {
global-attributes,
resource-collection,
}
tag-id = (0: text)
swid-name = (1: text)
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entity-entry = (2: entity / [ 2* entity ])
evidence-entry = (3: evidence)
link-entry = (4: link / [ 2* link ])
software-meta-entry = (5: software-meta / [ 2* software-meta ])
payload-entry = (6: payload)
any-element-entry = (7: any-element-map / [ 2* any-element-map ])
corpus = (8: bool)
patch = (9: bool)
media = (10: text)
supplemental = (11: bool)
tag-version = (12: integer)
version = (13: text)
version-scheme = (14: text)
lang = (15: text)
directory-entry = (16: directory / [ 2* directory ])
file-entry = (17: file / [ 2* file ])
process-entry = (18: process / [ 2* process ])
resource-entry = (19: resource / [ 2* resource ])
size = (20: integer)
key = (21: bool)
location = (22: text)
fs-name = (23: text)
root = (24: text)
path-elements = (25: { * file-entry,
* directory-entry,
}
)
process-name = (26: text)
pid = (27: integer)
type = (28: text)
extended-data = (29: any-element-map / [ 2* any-element-map ])
entity-name = (30: text)
reg-id = (31: any-uri)
role = (32: text / [2* text])
thumbprint = (33: text)
date = (34: time)
device-id = (35: text)
artifact = (36: text)
href = (37: any-uri)
ownership = (38: "shared" / "private" / "abandon")
rel = (39: text)
use = (40: "optional" / "required" / "recommended")
activation-status = (41: text)
channel-type = (42: text)
colloquial-version = (43: text)
description = (44: text)
edition = (45: text)
entitlement-data-required = (46: bool)
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entitlement-key = (47: text)
generator = (48: text)
persistent-id = (49: text)
product = (50: text)
product-family = (51: text)
revision = (52: text)
summary = (53: text)
unspsc-code = (54: text)
unspsc-version = (55: text)
file-hash = (56: [ hash-alg-id: int,
hash-value: bstr,
]
)
<CODE ENDS>
3. Description of the SWID Attribute Vocabulary Definition
Yet to be written still...
4. IANA Considerations
This document will include requests to IANA:
o Integer indices for SWID content attributes and information
elements.
o Content-Type for CoAP to be used in COSE.
5. Security Considerations
SWID tags contain public information about software products and, as
such, do not need to be protected against disclosure on an endpoint.
Similarly, SWID tags are intended to be easily discoverable by
applications and users on an endpoint in order to make it easy to
identify and collect all of an endpoint's SWID tags. As such, any
security considerations regarding SWID tags focus on the application
of SWID tags to address security challenges, and the possible
disclosure of the results of those applications.
A signed SWID tag whose signature is intact can be relied upon to be
unchanged since it was signed. If the SWID tag was created by the
software author, this generally means that it has undergone no change
since the software application with which the tag is associated was
installed. By implication, this means that the signed tag reflects
the software author's understanding of the details of that software
product. This can be useful assurance when the information in the
tag needs to be trusted, such as when the tag is being used to convey
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golden measurements. By contrast, the data contained in unsigned
tags cannot be trusted to be unmodified.
SWID tags are designed to be easily added and removed from an
endpoint along with the installation or removal of software products.
On endpoints where addition or removal of software products is
tightly controlled, the addition or removal of SWID tags can be
similarly controlled. On more open systems, where many users can
manage the software inventory, SWID tags may be easier to add or
remove. On such systems, it may be possible to add or remove SWID
tags in a way that does not reflect the actual presence or absence of
corresponding software products. Similarly, not all software
products automatically install SWID tags, so products may be present
on an endpoint without providing a corresponding SWID tag. As such,
any collection of SWID tags cannot automatically be assumed to
represent either a complete or fully accurate representation of the
software inventory of the endpoint. However, especially on devices
that more strictly control the ability to add or remove applications,
SWID tags are an easy way to provide an preliminary understanding of
that endpoint's software inventory.
Any report of an endpoint's SWID tag collection provides information
about the software inventory of that endpoint. If such a report is
exposed to an attacker, this can tell them which software products
and versions thereof are present on the endpoint. By examining this
list, the attacker might learn of the presence of applications that
are vulnerable to certain types of attacks. As noted earlier, SWID
tags are designed to be easily discoverable by an endpoint, but this
does not present a significant risk since an attacker would already
need to have access to the endpoint to view that information.
However, when the endpoint transmits its software inventory to
another party, or that inventory is stored on a server for later
analysis, this can potentially expose this information to attackers
who do not yet have access to the endpoint. As such, it is important
to protect the confidentiality of SWID tag information that has been
collected from an endpoint, not because those tags individually
contain sensitive information, but because the collection of SWID
tags and their association with an endpoint reveals information about
that endpoint's attack surface.
Finally, both the ISO-19770-2:2015 XML schema definition and the
Concise SWID data definition allow for the construction of "infinite"
SWID tags or SWID tags that contain malicious content with the intend
if creating non-deterministic states during validation or processing
of SWID tags. While software product vendors are unlikely to do
this, SWID tags can be created by any party and the SWID tags
collected from an endpoint could contain a mixture of vendor and non-
vendor created tags. For this reason, tools that consume SWID tags
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ought to treat the tag contents as potentially malicious and should
employ input sanitizing on the tags they ingest.
6. Acknowledgements
7. Change Log
Changes from version 00 to version 01:
o Added CWT usage for absolute SWID paths on a device
o Fixed cardinality of type-choices including arrays
o Included first iteration of firmware resource-collection
Changes since adopted as a WG I-D -00:
o Removed redundant any-attributes originating from the ISO-
19770-2:2015 XML schema definition
o Fixed broken multi-map members
o Introduced a more restrictive item (any-element-map) to represent
custom maps, increased restriction on types for the any-attribute,
accordingly
o Fixed X.1520 reference
o Minor type changes of some attributes (e.g. NMTOKENS)
o Added semantic differentiation of various name types (e,g. fs-
name)
Changes from version 00 to version 01:
o Ambiguity between evidence and payload eliminated by introducing
explicit members (while still
o allowing for "empty" SWID tags)
o Added a relatively restrictive COSE envelope using cose_sign1 to
define signed CoSWID (single signer only, at the moment)
o Added a definition how to encode hashes that can be stored in the
any-member using existing IANA tables to reference hash-algorithms
Changes from version 01 to version 02:
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o Enforced a more strict separation between the core CoSWID
definition and additional usage by moving content to corresponding
appendices.
o Removed artifacts inherited from the reference schema provided by
ISO (e.g. NMTOKEN(S))
o Simplified the core data definition by removing group and type
choices where possible
o Minor reordering of map members
o Added a first extension point to address requested flexibility for
extensions beyond the any-element
8. Contributors
9. References
9.1. Normative References
[I-D.ietf-ace-cbor-web-token]
Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
"CBOR Web Token (CWT)", draft-ietf-ace-cbor-web-token-07
(work in progress), July 2017.
[I-D.ietf-cose-msg]
Schaad, J., "CBOR Object Signing and Encryption (COSE)",
draft-ietf-cose-msg-24 (work in progress), November 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC4108] Housley, R., "Using Cryptographic Message Syntax (CMS) to
Protect Firmware Packages", RFC 4108,
DOI 10.17487/RFC4108, August 2005,
<http://www.rfc-editor.org/info/rfc4108>.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
<http://www.rfc-editor.org/info/rfc4949>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <http://www.rfc-editor.org/info/rfc7049>.
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[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<http://www.rfc-editor.org/info/rfc7228>.
[SAM] "Information technology - Software asset management - Part
5: Overview and vocabulary", ISO/IEC 19770-5:2013,
November 2013.
[SWID] "Information technology - Software asset management - Part
2: Software identification tag'", ISO/IEC 19770-2:2015,
October 2015.
[X.1520] "Recommendation ITU-T X.1520 (2014), Common
vulnerabilities and exposures", April 2011.
9.2. Informative References
[I-D.banghart-sacm-rolie-softwaredescriptor]
Waltermire, D. and S. Banghart, "Definition of the ROLIE
Software Descriptor Extension", draft-banghart-sacm-rolie-
softwaredescriptor-01 (work in progress), May 2017.
[I-D.birkholz-tuda]
Fuchs, A., Birkholz, H., McDonald, I., and C. Bormann,
"Time-Based Uni-Directional Attestation", draft-birkholz-
tuda-04 (work in progress), March 2017.
[I-D.greevenbosch-appsawg-cbor-cddl]
Birkholz, H., Vigano, C., and C. Bormann, "CBOR data
definition language (CDDL): a notational convention to
express CBOR data structures", draft-greevenbosch-appsawg-
cbor-cddl-10 (work in progress), March 2017.
[I-D.ietf-sacm-terminology]
Birkholz, H., Lu, J., Strassner, J., and N. Cam-Winget,
"Security Automation and Continuous Monitoring (SACM)
Terminology", draft-ietf-sacm-terminology-12 (work in
progress), March 2017.
Appendix A. Explicit file-hash Type Used in Concise SWID Tags (label
56)
CoSWID add explicit support for the representation of file-hashes
using algorithms that are registered at the Named Information Hash
Algorithm Registry via the file-hash member (label 56).
file-hash = (56: [ hash-alg-id: int, hash-value: bstr ] )
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The number used as a value for hash-alg-id MUST refer the ID in the
Named Information Hash Algorithm table; other hash algorithms MUST
NOT be used. The hash-value MUST represent the raw hash value of the
file-entry the file-hash type is included in.
Appendix B. CoSWID Attributes for Firmware (label 57)
The ISO-19770-2:2015 specification of SWID tags assumes the existence
of a file system a software component is installed and stored in. In
the case of constrained-node networks [RFC7228] or network equipment
this assumption might not apply. Concise software instances in the
form of (modular) firmware are often stored directly on a block
device that is a hardware component of the constrained-node or
network equipment. Multiple differentiable block devices or
segmented block devices that contain parts of modular firmware
components (potentially each with their own instance version) are
already common at the time of this writing.
The optional attributes that annotate a firmware package address
specific characteristics of pieces of firmware stored directly on a
block-device in contrast to software deployed in a file-system. In
essence, trees of relative path-elements expressed by the directory
and file structure in CoSWID tags are typically unable to represent
the location of a firmware on a constrained-node (small thing). The
composite nature of firmware and also the actual composition of small
things require a set of attributes to address the identification of
the correct component in a composite thing for each individual piece
of firmware. A single component also potentially requires a number
of distinct firmware parts that might depend on each other
(versions). These dependencies can be limited to the scope of the
component itself or extend to the scope of a larger composite device.
In addition, it might not be possible (or feasible) to store a CoSWID
tag document (permanently) on a small thing along with the
corresponding piece of firmware.
To address the specific characteristics of firmware, the extension
point "$$resource-extension" is used to allow for an additional type
of resource description--firmware-entry--thereby increasing the self-
descriptiveness and flexibility of CoSWID. The optional use of the
extension point "$$resource-extension" in respect to firmware MUST
adhere to the following CDDL data definition.
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<CODE BEGINS>
$$resource-extension //= (firmware-entry,)
firmware = {
firmware-name, ; inherited from RFC4108
? firmware-version,
? firmware-package-identifier, ; inherited from RFC4108
? dependency, ; inherited from RFC4108
? component-index, ; equivalent to RFC4108 fwPkgType
? block-device-identifier,
? target-hardware-identifier, ; an RFC4108 alternative to model-label
model-label,
? firmware-hash, ; a hash for a single, incl. NI hash-algo index
? cms-firmware-package, ; RCF4108, experimental, this is an actual firmware blob!
}
firmware-entry = (57: firmware / [ 2* firmware ])
firmware-hash = (58: [ hash-alg-id: int,
hash-value: bstr,
]
)
firmware-name = (59 : text)
firmware-version = (60 : text / int)
component-index = (61 : int)
model-label = (62: text / int)
block-device-identifier = (63 : text / int)
cms-firmware-package = (64: bstr)
firmware-package-identifier = (65: text)
target-hardware-identifier = (66: text)
dependency = (67: { ? firmware-name,
? firmware-version,
? firmware-package-identifier,
}
)
<CODE ENDS>
The members of the firmware group that constitutes the content of the
firmware-entry is based on the metadata about firmware defined in
[RFC4108]. As with every semantic differentiation that is supported
by the resource-collection type, the use of firmware-entry is
optional. It is REQUIRED not to instantiate more than one firmware-
entry, as the firmware group is used in a map and therefore only
allows for unique labels.
The optional cms-firmware-package member allows to include the actual
firmware in the CoSWID tag that also expresses its metadata as a
byte-string. This option enables a CoSWID tag to be used as a
container or wrapper that composes both firmware and its metadata in
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a single document (which again can be signed, encrypted and/or
compressed). In consequence, a CoSWID tag about firmware can be
conveyed as an identifying document across endpoints or used as a
reference integrity measurement as usual. Alternatively, it can also
convey an actual piece of firmware, serve its intended purpose as a
SWID tag and then - due to the lack of a location to store it - be
discarded.
Appendix C. Signed Concise SWID Tags using COSE
SWID tags, as defined in the ISO-19770-2:2015 XML schema, can include
cryptographic signatures to protect the integrity of the SWID tag.
In general, tags are signed by the tag creator (typically, although
not exclusively, the vendor of the software product that the SWID tag
identifies). Cryptographic signatures can make any modification of
the tag detectable, which is especially important if the integrity of
the tag is important, such as when the tag is providing reference
integrity measurments for files.
The ISO-19770-2:2015 XML schema uses XML DSIG to support
cryptographic signatures. CoSWID tags require a different signature
scheme than this. COSE (CBOR Object Signing and Encryption) provides
the required mechanism [I-D.ietf-cose-msg]. Concise SWID can be
wrapped in a COSE Single Signer Data Object (cose-sign1) that
contains a single signature. The following CDDL defines a more
restrictive subset of header attributes allowed by COSE tailored to
suit the requirements of Concise SWID.
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<CODE BEGINS>
signed-coswid = #6.997(COSE-Sign1-coswid) ; see TBS7 in current COSE I-D
label = int / tstr ; see COSE I-D 1.4.
values = any ; see COSE I-D 1.4.
unprotected-signed-coswid-header = {
1 => int, ; algorithm identifier
3 => "application/coswid", ; request for CoAP IANA registry to become an int
* label => values,
}
protected-signed-coswid-header = {
4 => bstr, ; key identifier
* label => values,
}
COSE-Sign1-coswid = [
protected: bstr .cbor protected-signed-coswid-header,
unprotected: unprotected-signed-coswid-header,
payload: bstr .cbor concise-software-identity,
signature: bstr,
]
<CODE ENDS>
Appendix D. CoSWID used as Reference Integrity Measurements (CoSWID
RIM)
A vendor supplied signed CoSWID tag that includes hash-values for the
files that compose a software component can be used as a RIM
(reference integrity measurement). A RIM is a type of declarative
guidance that can be used to assert the compliance of an endpoint by
assessing the installed software. In the context of remote
attestation based on an attestation via hardware rooted trust, a
verifier can appraise the integrity of the conveyed measurements of
software components using a CoSWID RIM provided by a source, such as
[I-D.banghart-sacm-rolie-softwaredescriptor].
RIM Manifests (RIMM): A group of SWID tags about the same
(sub-)system, system entity, or (sub-)component (compare
[RFC4949]). A RIMM manifest is a distinct document that is
typically conveyed en-block and constitutes declarative guidance
in respect to a specific (target) endpoint (compare
[I-D.ietf-sacm-terminology]).
If multiple CoSWID compose a RIMM, the following CDDL data definition
SHOULD be used.
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RIMM = [ + concise-software-identity / signed-coswid ]
Appendix E. CBOR Web Token for Concise SWID Tags
A typical requirement regarding specific instantiations of endpoints
- and, as a result, specific instantiations of software components -
is a representation of the absolute path of a CoSWID tag document in
a file system in order to derive absolute paths of files represented
in the corresponding CoSWID tag. The absolute path of an evidence
CoSWID tag can be included as a claim in the header of a CBOR Web
Token [I-D.ietf-ace-cbor-web-token]. Depending on the source of the
token, the claim can be in the protected or unprotected header
portion.
<CODE BEGINS>
CDDL TBD
<CODE ENDS>
Authors' Addresses
Henk Birkholz
Fraunhofer SIT
Rheinstrasse 75
Darmstadt 64295
Germany
Email: henk.birkholz@sit.fraunhofer.de
Jessica Fitzgerald-McKay
Department of Defense
9800 Savage Road
Ft. Meade, Maryland
USA
Email: jmfitz2@nsa.gov
Charles Schmidt
The MITRE Corporation
202 Burlington Road
Bedford, Maryland 01730
USA
Email: cmschmidt@mitre.org
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David Waltermire
National Institute of Standards and Technology
100 Bureau Drive
Gaithersburg, Maryland 20877
USA
Email: david.waltermire@nist.gov
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