SACM Working Group                                           H. Birkholz
Internet-Draft                                            Fraunhofer SIT
Intended status: Standards Track                     J. Fitzgerald-McKay
Expires: August 20, 2017 January 5, 2018                           Department of Defense
                                                              C. Schmidt
                                                   The MITRE Corporation
                                                           D. Waltermire
                                                                    NIST
                                                       February 16,
                                                           July 04, 2017

                      Concise Software Identifiers
                       draft-ietf-sacm-coswid-01
                       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

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Concise SWID Extensions . . . . . . . . . . . . . . . . .   4
     1.2.  Requirements notation Notation . . . . . . . . . . . . . . . . . .   3   4
   2.  Concise SWID CDDL specification Data Definition  . . . . . . . . . . . . . . . .   4
   3.  Encoding hashes for Concise  Description of the SWID tags Attribute Vocabulary Definition . . .   9
   4.  IANA Considerations . . . . . . . . .   9
   4.  CoSWID used as Reference Integrity Measurements (CoSWID RIM)    9
   5.  Firmware SWID tags . . . . . . . . . . . .   9
   5.  Security Considerations . . . . . . . . .   9
   6.  COSE signatures for Concise SWID tags . . . . . . . . . .   9
   6.  Acknowledgements  . .  10
   7.  CBOR Web Token for Concise SWID tags . . . . . . . . . . . .  11
   8.  IANA considerations . . . . . . . .  11
   7.  Change Log  . . . . . . . . . . . . .  11
   9.  Security Considerations . . . . . . . . . . . .  11
   8.  Contributors  . . . . . . .  12
   10. Acknowledgements . . . . . . . . . . . . . . . . .  12
   9.  References  . . . . .  13
   11. Change Log . . . . . . . . . . . . . . . . . . . .  12
     9.1.  Normative References  . . . . . .  13
   12. Contributors . . . . . . . . . . . .  12
     9.2.  Informative References  . . . . . . . . . . . . .  14
   13. 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
     13.1.  Normative References
   Appendix C.  Signed Concise SWID Tags using COSE  . . . . . . . .  16
   Appendix D.  CoSWID used as Reference Integrity Measurements
                (CoSWID RIM) . . . . . . . . . . .  14
     13.2.  Informative References . . . . . . . . .  17
   Appendix E.  CBOR Web Token for Concise SWID Tags . . . . . . . .  15  18
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15  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 instances. 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].

   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 lifecycle. 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 CBOR 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 Concise SWID 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.  Concise SWID  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
   SWID tags to be part of an enterprise security solution for a wider
   range of endpoints and environments.

1.1.  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 CDDL specification

   The following is Extensions

   This document specifies a CDDL representation of standard equivalent to the ISO-19770-2:2015 [SWID]
   XML schema
   standard.  The corresponding CoSWID data definition of SWID tags.  This representation includes all
   SWID tag fields and thus supports 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 CDDL specification).  The human-
   readable 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 CDDL specification.
   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.

   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,
   }

NMTOKEN = text
NMTOKENS = text

date-time = time

   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 = (
     ? lang,
     * any-attribute,
   )

   resource-collection = (
     ? directory-entry,
     ? file-entry,
     ? process-entry,
     ? resource-entry
  ? firmware-entry
     * $$resource-extension
   )

   file = {
     filesystem-item,
     ? size,
     ? version,
     ? file-hash,
   }

   filesystem-item = (
     global-attributes,
     ? key,
     ? location,
     fs-name,
     ? root,
   )

   directory = {
     filesystem-item,
     path-elements,
   }

firmware

   process = {
  firmware-name,                  ; inherited from RFC4108
     global-attributes,
     process-name,
     ? firmware-version, pid,
   }

   resource = {
     global-attributes,
     type,
   }

   entity = {
     global-attributes,
     extended-data,
     entity-name,
     ? firmware-package-identifier,  ; inherited from RFC4108 reg-id,
     role,
     ? 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!
}

process = {
  global-attributes,
  process-name,
  ? pid,
}

resource = {
  global-attributes,
  type,
}

entity = {
  global-attributes,
  meta-elements,
  entity-name,
  ? reg-id,
  role,
  ? thumbprint,
}

evidence = {
  global-attributes,
  resource-collection, 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)
   entity-entry = (2: entity / [ 2* entity ])
   evidence-entry = (3: evidence / [ 2* evidence ]) evidence)
   link-entry = (4: link / [ * 2* link ])
   software-meta-entry = (5: software-meta / [ 2* software-meta ])
   payload-entry = (6: payload / [ 2* payload ]) 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: NMTOKEN) 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: { * directory-entry,
                       * file-entry,
                          * directory-entry,
                        }
                   )
   process-name = (26: text)
   pid = (27: integer)
   type = (28: text)
meta-elements
   extended-data = (29: any-element-map / [ 2* any-element-map ])
   entity-name = (30: text)
   reg-id = (31: any-uri)
   role = (32: NMTOKENS) text / [2* text])
   thumbprint = (33: text)
   date = (34: date-time) time)
   device-id = (35: text)
   artifact = (36: text)
   href = (37: any-uri)
   ownership = (38: "shared" / "private" / "abandon")
   rel = (39: NMTOKEN) 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)
   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,
                    ]
               )

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>

3.  Encoding hashes for Concise  Description of the SWID tags

   Concise Attribute Vocabulary Definition

   Yet to be written still...

4.  IANA Considerations

   This document will include requests to IANA:

   o  Integer indices for SWID add explicit support content attributes and information
      elements.

   o  Content-Type for the representation of file-
   hashes using algorithms that are registered at the Named Information
   Hash Algorithm Registry via the file-hash item (label 56).  The
   number CoAP to be used as a value for hash-alg-id refers the ID in the Named
   Information Hash Algorithm table.

4.  CoSWID used COSE.

5.  Security Considerations

   SWID tags contain public information about software products and, 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
   such, do not need to be used as a RIM
   (reference integrity measurement).  A RIM is a type of declarative
   guidance that can protected against disclosure on an endpoint.
   Similarly, SWID tags are intended to be used easily discoverable by
   applications and users on an endpoint in order to assert the compliance make it easy to
   identify and collect all of an endpoint by
   assessing the installed software.  In endpoint's SWID tags.  As such, any
   security considerations regarding SWID tags focus on the context application
   of remote
   attestation based on an attestation via a hardware SWID tags to address security module
   (hardware rooted trust), a verifier can appraise challenges, and the integrity possible
   disclosure of the
   conveyed measurements results of software components using a CoSWID RIM
   provided by a source, such as
   [I-D.banghart-sacm-rolie-softwaredescriptor].

5.  Firmware those applications.

   A signed SWID tags

   The metadata defined in [RFC4108] tag whose signature is incorporated in intact can be relied upon to be
   unchanged since it was signed.  If the resource-
   collection structure SWID tag was created by the
   software author, this generally means that semantically differentiates content stored
   in a Concise Software Identifier.  The optional attributes it has undergone no change
   since the software application with which the tag is associated was
   installed.  By implication, this means that
   annoate a firmware package addresse specific characteristics the signed tag reflects
   the software author's understanding of
   pieces the details of firmware stored directly on a block-device in contrast to that software deployed in a file-system.  Trees of relative path-elements
   expressed by
   product.  This can be useful assurance when the directory and file structure information in CoSWID the
   tag needs to be trusted, such as when the tag is being used to convey
   golden measurements.  By contrast, the data contained in unsigned
   tags cannot be trusted to be unmodified.

   SWID tags are
   typically unable designed to represent the location of a firmware on a
   constrained-node (small thing).  The composite nature of firmware be easily added and
   also removed from an
   endpoint along with the actual composition installation or removal of small things require a set software products.
   On endpoints where addition or removal of
   attributes to identify software products is
   tightly controlled, the correct component in a composite thing for
   each individual piece of firmware.  A single component also
   potentially requires a number addition or removal of distinct firmware parts that might
   depend on each other(s version).  These dependencies SWID tags can be limited
   to the scope of
   similarly controlled.  On more open systems, where many users can
   manage the component itself or extend software inventory, SWID tags may be easier to the scope of a
   small composite device.  In addition, add or
   remove.  On such systems, it might not may be possible (or
   feasible) to store add or remove SWID
   tags in a CoSWID tag document (permanently) 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 small
   thing along with the corresponding piece SWID tag.  As such,
   any collection of firmware.  Hence, CoSWID SWID tags can cannot automatically be used as a concise and flexible metadata document that
   functions as a wrapper containing assumed to
   represent either a (potentially compressed, signed,
   and/or encrypted) piece of firmware and its corresponding CoSWID
   attributes.  A CoSWID tag about firmware can be transmitted as an
   identifying document across endpoints complete or used as 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 reference
   integrity measurement as usual.  Alternatively, it can also convey easy way to provide an
   actual piece preliminary understanding of firmware, serve its intended purpose as a
   that endpoint's software inventory.

   Any report of an endpoint's SWID tag
   and then - due to collection provides information
   about the lack software inventory of that endpoint.  If such a location report is
   exposed to store it - be discarded.

6.  COSE signatures for Concise SWID tags

   SWID tags, as defined in the ISO-19770-2:2015 XML schema, an attacker, this can include
   cryptographic signatures to protect tell them which software products
   and versions thereof are present on the integrity 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 tag.
   In general,
   tags are signed designed to be easily discoverable by the tag creator (typically, although an endpoint, but this
   does not exclusively, present a significant risk since an attacker would already
   need to have access to the vendor of endpoint to view that information.
   However, when the endpoint transmits its software product 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
   identifies).  Cryptographic signatures can make any modification of
   the tag detectable, which is especially important if information that has been
   collected from an endpoint, not because those tags individually
   contain sensitive information, but because the integrity collection of SWID
   tags and their association with an endpoint reveals information about
   that endpoint's attack surface.

   Finally, both the tag is important, such as when the tag is providing golden
   measurements for files.

   The ISO-19770-2:2015 XML schema uses XML DSIG to support
   cryptographic signatures. definition and the
   Concise SWID data definition allow for the construction of "infinite"
   SWID tags require a different
   signature scheme than this.  COSE (CBOR Encoded Message Syntax)
   provides or SWID tags that contain malicious content with the required mechanism [I-D.ietf-cose-msg].  Concise 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 wrapped in created by any party and the SWID tags
   collected from an endpoint could contain a COSE Single Signer Data Object (cose-sign1) mixture of vendor and non-
   vendor created tags.  For this reason, tools that
   contains consume SWID tags
   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 single signature.  The following CDDL defines 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 subset of header attributes allowed by COSE tailored item (any-element-map) to
   suit represent
      custom maps, increased restriction on types for the requirements any-attribute,
      accordingly

   o  Fixed X.1520 reference

   o  Minor type changes of Concise SWID.

<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 some attributes (e.g.  NMTOKENS)

   o  Added semantic differentiation of various name types (e,g. fs-
      name)

   Changes from version 00 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>

7.  CBOR Web Token version 01:

   o  Ambiguity between evidence and payload eliminated by introducing
      explicit members (while still

   o  allowing for Concise "empty" 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 tags)

   o  Added a relatively restrictive COSE envelope using cose_sign1 to
      define signed CoSWID tag document in (single signer only, at the moment)

   o  Added a file system in order definition how to derive absolute paths of files represented
   in the corresponding CoSWID tag.  The absolute path of an evidence
   CoSWID tag encode hashes that can be included as a claim stored 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>

8.
      any-member using existing IANA considerations

   This document will include requests tables to IANA: reference hash-algorithms

   Changes from version 01 to version 02:

   o  Integer indices for SWID  Enforced a more strict separation between the core CoSWID
      definition and additional usage by moving content attributes 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 information
      elements. type
      choices where possible

   o  Content-Type for CoAP  Minor reordering of map members

   o  Added a first extension point to be used in COSE. address requested flexibility for
      extensions beyond the any-element

8.  Contributors

9.  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  References

9.1.  Normative References

   [I-D.ietf-ace-cbor-web-token]
              Jones, M., Wahlstroem, E., Erdtman, S., and users on an endpoint H. Tschofenig,
              "CBOR Web Token (CWT)", draft-ietf-ace-cbor-web-token-07
              (work in order to make it easy to
   identify progress), July 2017.

   [I-D.ietf-cose-msg]
              Schaad, J., "CBOR Object Signing and collect all of an endpoint's SWID tags.  As such, any
   security considerations regarding SWID tags focus on the application
   of SWID tags Encryption (COSE)",
              draft-ietf-cose-msg-24 (work in progress), November 2016.

   [RFC2119]  Bradner, S., "Key words for use in RFCs 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 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 be
   unchanged since it was signed.  If
              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>.

   [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 tag was created by Tags (label
             56)

   CoSWID add explicit support for the
   software author, this generally means representation of file-hashes
   using algorithms that it has undergone no change
   since are registered at the software application with which Named Information Hash
   Algorithm Registry via the tag is associated was
   installed.  By implication, this means that file-hash member (label 56).

   file-hash = (56: [ hash-alg-id: int, hash-value: bstr ] )
   The number used as a value for hash-alg-id MUST refer the signed tag reflects ID in the software author's understanding of
   Named Information Hash Algorithm table; other hash algorithms MUST
   NOT be used.  The hash-value MUST represent the details raw hash value of that software
   product.  This can be useful assurance when the information in the
   tag needs to be trusted, such as when
   file-entry the tag file-hash type is being used to convey
   golden measurements.  By contrast, the data contained in unsigned
   tags cannot be trusted to be unmodified. included in.

Appendix B.  CoSWID Attributes for Firmware (label 57)

   The ISO-19770-2:2015 specification of SWID tags are designed to be easily added and removed from an
   endpoint along with assumes the installation or removal of software products.
   On endpoints where addition or removal existence
   of a file system a software products component is
   tightly controlled, installed and stored in.  In
   the addition or removal case 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 constrained-node networks [RFC7228] or remove SWID
   tags in a way that does network equipment
   this assumption might not reflect apply.  Concise software instances in the actual presence or absence
   form of
   corresponding software products.  Similarly, not all software
   products automatically install SWID tags, so products may be present (modular) firmware are often stored directly on an endpoint without providing a corresponding SWID tag.  As such,
   any collection of SWID tags cannot automatically be assumed to
   represent either block
   device that is a complete or fully accurate representation of the
   software inventory hardware component of the endpoint.  However, especially on constrained-node or
   network equipment.  Multiple differentiable block devices
   that more strictly control the ability to add or remove applications,
   SWID tags
   segmented block devices that contain parts of modular firmware
   components (potentially each with their own instance version) are an easy way to provide an preliminary understanding
   already common at the time of this writing.

   The optional attributes that endpoint's software inventory.

   Any report annotate a firmware package address
   specific characteristics of an endpoint's SWID tag collection provides information
   about the software inventory pieces of that endpoint.  If such firmware stored directly on a report is
   exposed
   block-device in contrast to an attacker, this can tell them which software products deployed in a file-system.  In
   essence, trees of relative path-elements expressed by the directory
   and versions thereof file structure in CoSWID tags are present on the endpoint.  By examining this
   list, typically unable to represent
   the attacker might learn location of the presence a firmware on a constrained-node (small thing).  The
   composite nature of applications that
   are vulnerable to certain types firmware and also the actual composition of attacks.  As noted earlier, SWID
   tags are designed to be easily discoverable by an endpoint, but this
   does not present small
   things require a significant risk since an attacker would already
   need to have access set of attributes to address the endpoint to view that information.
   However, when identification of
   the endpoint transmits its software inventory to
   another party, or that inventory is stored on correct component in a server composite thing for later
   analysis, this can each individual piece
   of firmware.  A single component also potentially expose this information requires a number
   of distinct firmware parts that might depend on each other
   (versions).  These dependencies can be limited to attackers
   who do not yet have access the scope of the
   component itself or extend to the endpoint.  As such, scope of a larger composite device.
   In addition, it is important might not be possible (or feasible) to protect store a CoSWID
   tag document (permanently) on a small thing along with the confidentiality
   corresponding piece of SWID tag information that has been
   collected from an endpoint, not because those tags individually
   contain sensitive information, but because firmware.

   To address the collection specific characteristics 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 firmware, the
   Concise SWID data definition extension
   point "$$resource-extension" is used to allow for the construction an additional type
   of "infinite"
   SWID tags or SWID tags that contain malicious content with resource description--firmware-entry--thereby increasing the intend
   if creating non-deterministic states during validation or processing
   of SWID tags.  While software product vendors are unlikely to do
   this, SWID tags can be created by any party self-
   descriptiveness and the SWID tags
   collected from an endpoint could contain a mixture flexibility of CoSWID.  The optional use of vendor and non-
   vendor created tags.  For this reason, tools that consume SWID tags
   ought to treat the tag contents as potentially malicious and should
   employ input sanitizing on
   extension point "$$resource-extension" in respect to firmware MUST
   adhere to the tags they ingest.

10.  Acknowledgements

11.  Change Log

   Changes following CDDL data definition.

<CODE BEGINS>
$$resource-extension //= (firmware-entry,)

firmware = {
  firmware-name,                  ; inherited from version 00 RFC4108
  ? firmware-version,
  ? firmware-package-identifier,  ; inherited from RFC4108
  ? dependency,                   ; inherited from RFC4108
  ? component-index,              ; equivalent to version 01:

   o  Added CWT usage RFC4108 fwPkgType
  ? block-device-identifier,
  ? target-hardware-identifier,   ; an RFC4108 alternative to model-label
  model-label,
  ? firmware-hash,                ; a hash for absolute SWID paths on a device

   o  Fixed cardinality of type-choices including arrays

   o  Included first iteration of single, incl. NI hash-algo index
  ? cms-firmware-package,         ; RCF4108, experimental, this is an actual 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 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

   o  Introduced a more restrictive item (any-element-map) to represent
      custom maps, increased restriction on types for of the any-attribute,
      accordingly

   o  Fixed X.1520 reference
   o  Minor type changes firmware group that constitutes the content of some attributes (e.g.  NMTOKENS)

   o  Added 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 various name types (e,g. fs-
      name)

   Changes from version 00 firmware-entry is
   optional.  It is REQUIRED not to version 01:

   o  Ambiguity between evidence instantiate more than one firmware-
   entry, as the firmware group is used in a map and payload eliminated by introducing
      explicit members (while still allowing therefore only
   allows for "empty" swid tags)

   o  Added a relatively restrictive COSE envelope using cose_sign1 unique labels.

   The optional cms-firmware-package member allows to
      define signed coswids (single signer only, at include the moment)

   o  Added actual
   firmware in the CoSWID tag that also expresses its metadata as a defintion how
   byte-string.  This option enables a CoSWID tag to encode hashes be used as a
   container or wrapper that composes both firmware and its metadata in
   a single document (which again can be stored in the
      any-member using existing IANA tables to reference hash-algorithms

   First version -00

12.  Contributors

13.  References

13.1.  Normative References

   [I-D.ietf-ace-cbor-web-token]
              Jones, M., Wahlstroem, E., Erdtman, S., 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 H. Tschofenig,
              "CBOR Web Token (CWT)", draft-ietf-ace-cbor-web-token-02
              (work 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 progress), January 2017.

   [I-D.ietf-cose-msg]
              Schaad, J., "CBOR 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 (COSE)",
              draft-ietf-cose-msg-24 (work in progress), November 2016.

   [RFC2119]  Bradner, S., "Key words for use Encryption) provides
   the required mechanism [I-D.ietf-cose-msg].  Concise SWID can be
   wrapped in RFCs 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 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)
   suit the requirements of Concise SWID.

<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
              Protect Firmware Packages", RFC 4108,
              DOI 10.17487/RFC4108, August 2005,
              <http://www.rfc-editor.org/info/rfc4108>.

   [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>.

   [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.

13.2.  Informative References

   [I-D.banghart-sacm-rolie-softwaredescriptor]
              Waltermire, 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. and S. Banghart, "Definition  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 ROLIE
              Software Descriptor Extension", draft-banghart-sacm-rolie-
              softwaredescriptor-00 (work in progress), October 2016.

   [I-D.birkholz-tuda]
              Fuchs, A., Birkholz, H., McDonald, I., 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 C. Bormann,
              "Time-Based Uni-Directional Attestation", draft-birkholz-
              tuda-03 (work constitutes declarative guidance
      in progress), January 2017.

   [I-D.greevenbosch-appsawg-cbor-cddl]
              Vigano, C. and H. Birkholz, "CBOR respect to a specific (target) endpoint (compare
      [I-D.ietf-sacm-terminology]).

   If multiple CoSWID compose a RIMM, the following CDDL data definition language
              (CDDL):
   SHOULD be used.

   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 notational convention 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 express 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 data
              structures", draft-greevenbosch-appsawg-cbor-cddl-09 (work Web
   Token [I-D.ietf-ace-cbor-web-token].  Depending on the source of the
   token, the claim can be in progress), September 2016. 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
   David Waltermire
   National Institute of Standards and Technology
   100 Bureau Drive
   Gaithersburg, Maryland  20877
   USA

   Email: david.waltermire@nist.gov