SACM Working Group                                           H. Birkholz
Internet-Draft                                            Fraunhofer SIT
Intended status: Standards Track                     J. Fitzgerald-McKay
Expires: November 13, December 26, 2019                         Department of Defense
                                                              C. Schmidt
                                                   The MITRE Corporation
                                                           D. Waltermire
                                                                    NIST
                                                            May 12,
                                                           June 24, 2019

                  Concise Software Identification Tags
                       draft-ietf-sacm-coswid-09
                       draft-ietf-sacm-coswid-10

Abstract

   This document defines a concise representation of ISO/IEC
   19770-2:2015 Software Identification (SWID) tags that are
   interoperable with the XML schema definition of ISO/IEC 19770-2:2015.
   Next to the inherent capability of SWID tags to express arbitrary
   context information, Concise SWID (CoSWID) tags support the
   definition of additional semantics via well-defined data definitions
   incorporated by extension points.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on November 13, December 26, 2019.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  The SWID and CoSWID Tag Lifecycle . . . . . . . . . . . .   4
     1.2.  Concise SWID Format . . . . . . . . . . . . . . . . . . .   6
     1.3.  Requirements Notation . . . . . . . . . . . . . . . . . .   7
   2.  Concise SWID Data Definition  . . . . . . . . . . . . . . . .   7
     2.1.  Concise SWID Extensions . . . . . . . . . . . . . . . . .   8
     2.2.  The concise-swid-tag Group  . . . . . . . . . . . . . . .   9
     2.3.  concise-swid-tag Co-constraints . . . . . . . . . . . . .  13
     2.4.  The global-attributes Group . . . . . . . . . . . . . . .  14
     2.5.  The entity-entry Group  . . . . . . . . . . . . . . . . .  14  15
     2.6.  The link-entry Map  . . . . . . . . . . . . . . . . . . .  16  17
     2.7.  The software-meta-entry Map . . . . . . . . . . . . . . .  19  21
     2.8.  The Resource Collection Definition  . . . . . . . . . . .  22  24
       2.8.1.  The hash-entry Array  . . . . . . . . . . . . . . . .  22  24
       2.8.2.  The resource-collection Group . . . . . . . . . . . .  23  24
       2.8.3.  The payload-entry Group . . . . . . . . . . . . . . .  26  27
       2.8.4.  The evidence-entry Group  . . . . . . . . . . . . . .  26  28
     2.9.  Full CDDL Definition  . . . . . . . . . . . . . . . . . .  27  28
   3.  Determining the Type of CoSWID  . . . . . . . . . . . . . . .  33  34
   4.  CoSWID Indexed Label Values . . . . . . . . . . . . . . . . .  33  34
     4.1.  Version Scheme  . . . . . . . . . . . . . . . . . . . . .  33  34
     4.2.  Entity Role Values  . . . . . . . . . . . . . . . . . . .  34  35
     4.3.  Use  Link Ownership Values . . . . . . . . . . . . . . . . . .  36
     4.4.  Link Rel Values . . . . .  35 . . . . . . . . . . . . . . . .  37
     4.5.  Link Use Values . . . . . . . . . . . . . . . . . . . . .  39
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  36  39
     5.1.  CoSWID Items Registry . . . . . . . . . . . . . . . . . .  36  39
     5.2.  SWID/CoSWID Value Registries  . . . . . . . . . . . . . .  42
       5.2.1.  SWID/CoSWID Version Schema Values Scheme Value Registry . . . . . . .  39
     5.3.  43
       5.2.2.  SWID/CoSWID Entity Role Values Value Registry  . . . . . . .  44
       5.2.3.  SWID/CoSWID Link Ownership Value Registry . . . . .  40
     5.4. .  45
       5.2.4.  SWID/CoSWID Link Use Values Relationship Value Registry  . . . .  46
       5.2.5.  SWID/CoSWID Link Use Value Registry . . . . . .  41
     5.5. . . .  47
     5.3.  swid+cbor Media Type Registration . . . . . . . . . . . .  42
     5.6.  48
     5.4.  CoAP Content-Format Registration  . . . . . . . . . . . .  43
     5.7.  49
     5.5.  CBOR Tag Registration . . . . . . . . . . . . . . . . . .  44  50
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  44  50
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  46  52
   8.  Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .  46  52
   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  50  55
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  50  56
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  50  56
     10.2.  Informative References . . . . . . . . . . . . . . . . .  51  57
   Appendix A.  Signed Concise SWID Tags using COSE  . . . . . . . .  52  58
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  53  59

1.  Introduction

   SWID tags have several use-applications including but not limited to:

   o  Software Inventory Management, a part of a 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 software components
      installed on 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-rats-tuda].

   SWID tags, as defined in ISO-19770-2:2015 [SWID], provide a
   standardized XML-based record format that identifies and describes a
   specific release of a software component.  Different software
   components, and even different releases of a particular software
   component, each have a different SWID tag record associated with
   them.  SWID tags are meant to be flexible and able to express a broad
   set of metadata about a software component.

   While there are very few required fields in SWID tags, there are many
   optional fields that support different use scenarios.  A SWID tag
   consisting of only required fields might be a few hundred bytes in
   size; however, a tag containing many of the optional fields can be
   many orders of magnitude larger.  Thus, real-world instances of SWID
   tags can be fairly large, and the communication of SWID tags in use-
   applications
   applications, such as those described earlier 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 enabled through the use of CBOR,
   which maps the human-readable labels of SWID data items to more
   concise integer labels (indices).  The use of CBOR to express SWID
   information in CoSWID tags allows both CoSWID and SWID tags to be
   part of an enterprise security solution for a wider range of
   endpoints and environments.

1.1.  The SWID and CoSWID Tag Lifecycle

   In addition to defining the format of a SWID tag record, ISO/IEC
   19770-2:2015 defines requirements concerning the SWID tag lifecycle.
   Specifically, when a software component is installed on an endpoint,
   that software component's SWID tag is also installed.  Likewise, when
   the software component is uninstalled or replaced, the SWID tag is
   deleted or replaced, as appropriate.  As a result, ISO/IEC
   19770-2:2015 describes a system wherein there is a correspondence
   between the set of installed software components on an endpoint, and
   the presence of the corresponding SWID tags for these components on
   that endpoint.  CoSWIDs share the same lifecycle requirements as a
   SWID tag.

      The SWID specification and supporting guidance provided in NIST
      Internal Report (NISTIR) 8060: Guidelines for the Creation of
      Interoperable SWID Tags [SWID-GUIDANCE] defines four types of SWID
      tags: primary, patch, corpus, and supplemental.

   1.  Primary Tag - A SWID or CoSWID tag that identifies and describes
       a software component is installed on a computing device.  A
       primary tag is intended to be installed on an endpoint along with
       the corresponding software component.

   2.  Patch Tag - A SWID or CoSWID tag that identifies and describes an
       installed patch which has made incremental changes to a software
       component installed on an endpoint.  A patch tag is intended to
       be installed on an endpoint along with the corresponding software
       component patch.

   3.  Corpus Tag - A SWID or CoSWID tag that identifies and describes
       an installable software component in its pre-installation state.
       A corpus tag can be used to represent metadata about an
       installation package or installer for a software component, a
       software update, or a patch.

   4.  Supplemental Tag - A SWID or CoSWID tag that allows additional
       information to be associated with a referenced SWID tag.  This
       helps to ensure that SWID Primary and Patch Tags provided by a
       software provider are not modified by software management tools,
       while allowing these tools to provide their own software
       metadata.

   The type of a tag is determined by specific data elements, which is
   discussed in Section 3.

      Corpus, primary, and patch tags have similar functions in that
      they describe the existence and/or presence of different types of
      software (e.g., software installers, software installations,
      software patches), and, potentially, different states of software
      components.  In contrast, supplemental tags furnish additional
      information not contained in corpus, primary, or patch tags.  All
      four tag types come into play at various points in the software
      lifecycle, and support software management processes that depend
      on the ability to accurately determine where each software
      component is in its lifecycle.

                                    +------------+
                                    v            |
  Installation     Product       Product      Product       Product
    Media      -> Installed  ->  Patched   -> Upgraded   -> Removed
   Deployed

   Corpus         Primary        Primary      xPrimary      xPrimary
                  Supplemental   Supplemental xSupplemental xSuplemental
                                 Patch        xPatch
                                              Primary
                                              Supplemental

           Figure 1: Use of Tag Types in the Software Lifecycle

      Figure 1 illustrates the steps in the software lifecycle and the
      relationships among those lifecycle events supported by the four
      types of SWID and CoSWID tags, as follows:

      *  Software Deployment.  Before the software component is
         installed (i.e., pre-installation), and while the product is
         being deployed, a corpus tag provides information about the
         installation files and distribution media (e.g., CD/DVD,
         distribution package).

      *  Software Installation.  A primary tag will be installed with
         the software component (or subsequently created) to uniquely
         identify and describe the software component.  Supplemental
         tags are created to augment primary tags with additional site-
         specific or extended information.  While not illustrated in the
         figure, patch tags can also be installed during software
         installation to provide information about software fixes
         deployed along with the base software installation.

      *  Software Patching.  When a new patch is applied to the software
         component, a new patch tag is provided, supplying details about
         the patch and its dependencies.  While not illustrated in the
         figure, a corpus tag can also provide information about the
         patch installer, and patching dependencies that need to be
         installed before the patch.

      *  Software Upgrading.  As a software component is upgraded to a
         new version, new primary and supplemental tags replace existing
         tags, enabling timely and accurate tracking of updates to
         software inventory.  While not illustrated in the figure, a
         corpus tag can also provide information about the upgrade
         installer, and dependencies that need to be installed before
         the upgrade.

      *  Software Removal.  Upon removal of the software component,
         relevant SWID tags are removed.  This removal event can trigger
         timely updates to software inventory reflecting the removal of
         the product and any associated patch or supplemental tags.

   Note: While not fully illustrated in the figure, supplemental tags
   can be associated with any corpus, primary, or patch tag to provide
   additional metadata about an installer, installed software, or
   installed patch respectively.

   Understanding the use of CoSWIDs in the software lifecycle provides a
   basis for understanding the information provided in a CoSWID and the
   associated semantics of this information.  Each of the different SWID
   and CoSWID tag types provide different sets of information.  For
   example, a "corpus tag" is used to describe a software component's
   installation image on an installation media, while a "patch tag" is
   meant to describe a patch that modifies some other software
   component.

1.2.  Concise SWID Format

   This document defines the CoSWID tag format, a more concise
   representation of SWID information in the Concise Binary Object
   Representation (CBOR) [RFC7049].  The structure of a CoSWID is
   described via the Concise Data Definition Language (CDDL)
   [I-D.ietf-cbor-cddl]. [RFC8610].
   The resulting CoSWID data definition is aligned to the information
   able to be expressed with the XML schema definition of ISO-19770-2:2015 ISO-
   19770-2:2015 [SWID].  This alignment allows both SWID and CoSWID tags
   to represent a common set of SWID information and to support all SWID
   tag use cases.  To achieve this end, the CDDL representation includes
   every SWID tag field and attribute.

   The vocabulary, i.e., the CDDL names of the types and members used in
   the CoSWID data definition, are mapped to more concise labels
   represented as small integer values.  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/IEC 19770-2:2015.

1.3.  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
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  Concise SWID Data Definition

   The following is a CDDL representation for a CoSWID tag.  The
   CamelCase [CamelCase] notation used in the XML schema definition is
   changed to a hyphen-separated notation [KebabCase] (e.g.
   ResourceCollection is named resource-collection) in the CoSWID data
   definition.  In essence, [KebabCase] "looks-like-this".  This
   deviation from the original notation used in the XML representation
   reduces ambiguity when referencing certain attributes in
   corresponding textual descriptions.  An attribute referred to by its
   name in CamelCase notation explicitly relates to XML SWID tags, tags; an
   attribute referred to by its name in KebabCase notation explicitly
   relates to CoSWID tags.  This approach simplifies the composition of
   further work that reference both XML SWID and CoSWID documents.

   Human-readable labels of members in CDDL map data definitions are
   mapped to integer indices via a block of rules at the bottom of the
   definition.  The 57 character strings of the SWID vocabulary that are
   replacesm which would have to be stored or transported in full if
   using the original
   vocabulary are replaced. vocabulary.

   In CBOR, an array is encoded using bytes that identify the array, and
   the array's length or stop point (see [RFC7049]).  To make items that
   support 1 or more values, the following CDDL notion is used.

   _name_ = (_label_: _data_ / [ 2* _data_ ])

   The CDDL rule above allows for a more efficient CBOR encoding of the
   data when a single value is used used.  This is accomplished by avoiding
   the need to first encode the array.  Conversely, an array is used for hen two or more values.
   values are encoded, the bytes identifing the array are used.  This
   modeling pattern is used frequently in the CoSWID CDDL data
   definition in such cases. to allow for more effecient encoding of single values.

   The following subsections describe the different parts of the CoSWID
   model.

2.1.  Concise SWID Extensions

   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 Section 2.4.

   o  The inclusion of extension points in the CoSWID data definition
      using CDDL sockets (see [I-D.ietf-cbor-cddl] [RFC8610] section 3.9).  The use of CDDL
      sockets allow for well-formed extensions to be defined in
      supplementary CDDL descriptions that support additional uses of
      CoSWID tags that go beyond the original scope of ISO-19770-2:2015
      tags.  This extension mechanism can also be used to update the
      CoSWID format as revisions to ISO-19770-2 are published.

   The following CDDL sockets (extension points) are defined in this
   document, which allow the addition of new information structures to
   their respective CDDL groups.

      +---------------------+-----------------------+---------------+
      | Map Name            | CDDL Socket           | Defined in    |
      +---------------------+-----------------------+---------------+
      | concise-swid-tag    | $$coswid-extension    | Section 2.2   |
      |                     |                       |               |
      | entity-entry        | $$entity-extension    | Section 2.5   |
      |                     |                       |               |
      | link-entry          | $$link-extension      | Section 2.6   |
      |                     |                       |               |
      | software-meta-entry | $$meta-extension      | Section 2.7   |
      |                     |                       |               |
      | file-entry          | $$file-extension      | Section 2.8.2 |
      |                     |                       |               |
      | directory-entry     | $$directory-extension | Section 2.8.2 |
      |                     |                       |               |
      | process-entry       | $$process-extension   | Section 2.8.2 |
      |                     |                       |               |
      | resource-entry      | $$resource-extension  | Section 2.8.2 |
      |                     |                       |               |
      | payload-entry       | $$payload-extension   | Section 2.8.3 |
      |                     |                       |               |
      | evidence-entry      | $$evidence-extension  | Section 2.8.4 |
      +---------------------+-----------------------+---------------+

   The following CDDL sockets CoSWID Items Registry defined in this document allow for adding Section 5.1 provides a
   registration mechanism allowing new values items, and their associated index
   values, to corresponding type-choices (i.e. be added to represent
   enumerations) via custom the CoSWID model through the use of the CDDL
   sockets described above.  This registration mechanism provides for
   well-known index values for data items in CoSWID extensions, allowing
   these index values to be recognized by implementations supporting a
   given extension.

   The following CDDL sockets defined in this document allow for adding
   new values to corresponding type-choices (i.e. to represent
   enumerations) via custom CDDL data definitions.

           +------------------+-----------------+-------------+
           | Enumeration Name | CDDL Socket     | Defined in  |
           +------------------+-----------------+-------------+
           | version-scheme   | $version-scheme | Section 4.1 |
           |                  |                 |             |
           | role             | $role           | Section 4.2 |
           |                  |                 |             |
           | ownership        | $ownership      | Section 2.6 4.3 |
           |                  |                 |             |
           | rel              | $rel            | Section 4.3 4.4 |
           |                  |                 |             |
           | use              | $use            | Section 2.6 4.5 |
           +------------------+-----------------+-------------+

   The CoSWID Items Registry

   A number of SWID/CoSWID value registries are also defined in
   Section 5.1 provides a
   registration mechanism allowing 5.2 that allow new items, and their associated index
   values, valid values to be added to the CoSWID model through the use of registered with IANA
   for the CDDL
   sockets described enumerations above.  This registration mechanism will provide
   for supports the
   definition of new well-known index values and names for data items in CoSWID extensions,
   allowing these index new
   enumeration values used by SWID and CoSWID.  This registration
   mechanism allows new standardized enumerated values to be recognized by implementations
   supporting a given extension. shared
   between both specifications (and implementations) over time.

2.2.  The concise-swid-tag Group

   The CDDL data definition for the root concise-swid-tag map is as
   follows and this rule and its constraints MUST be followed when
   creating or validating a CoSWID tag:

 concise-swid-tag = {
   global-attributes,
   tag-id => text,
   tag-version => integer,
   ? corpus => bool,
   ? patch => bool,
   ? supplemental => bool,
   swid-name
   software-name => text,
   ? software-version => text,
   ? version-scheme => $version-scheme,
   ? media => text,
   ? software-meta =>  software-meta-entry / [ 2* software-meta-entry ],
   entity => entity-entry / [ 2* entity-entry ],
   ? link => link-entry / [ 2* link-entry ],
   ? (( payload => payload-entry ) // ( evidence => evidence-entry )),
   * $$coswid-extension
 }

 tag-id = 0
 swid-name
 software-name = 1
 entity = 2
 evidence = 3
 link = 4
 software-meta = 5
 payload = 6
 corpus = 8
 patch = 9
 media = 10
 supplemental = 11
 tag-version = 12
 software-version = 13
 version-scheme = 14

 $version-scheme /= multipartnumeric
 $version-scheme /= multipartnumeric-suffix
 $version-scheme /= alphanumeric
 $version-scheme /= decimal
 $version-scheme /= semver
 $version-scheme /= uint / text
 multipartnumeric = 1
 multipartnumeric-suffix = 2
 alphanumeric = 3
 decimal = 4
 semver = 16384

   The following describes each member of the concise-swid-tag root map.

   o  global-attributes: A list of items including an optional language
      definition to support the processing of text-string values and an
      unbounded set of any-attribute items.  Described in Section 2.4.

   o  tag-id (index 0): A textual identifier uniquely referencing a
      (composite) software component.  The tag identifier MUST be
      globally unique.  There are no strict guidelines on how this
      identifier is structured, but examples include a 16 byte GUID
      (e.g.  class 4 UUID) [RFC4122], or a text string appended to a DNS
      domain name to ensure uniqueness across organizations.

   o  tag-version (index 12): An integer value that indicates if a indicate the
      specific release revision of a software component has more than one tag
      that can represent that specific release. the tag.  Typically, the initial
      value of this field is set to 0, and the value is monotonically
      increased for subsequent tags produced for the same software
      component release.  This value is changed when allows a CoSWID tag producer creates and releases to
      correct an incorrect tag that they
      subsequently want to fix, but no underlying changes have been made previously released, without indicating a
      change to the product underlying software component the CoSWID tag represents.  This could happen if,
      for
      For example, a patch is distributed that has a link reference that
      does not cover all the various software releases it can patch.  A
      newer CoSWID tag for that patch can version would be generated and changed to add new metadata,
      to correct a broken link, to add a missing payload entry, etc.
      When producing a revised tag, the tag-
      version new tag-version value incremented to indicate that MUST be
      greater than the data has been
      updated. old tag-version value.

   o  corpus (index 8): A boolean value that indicates if the tag
      identifies and describes an installable software component in its
      pre-installation state.  Installable software includes a
      installation package or installer for a software component, a
      software update, or a patch.  If the CoSWID tag represents
      installable software, the corpus item MUST be set to "true".  If
      not provided the default value MUST be considered "false".

   o  patch (index 9): A boolean value that indicates if the tag
      identifies and describes an installed patch which has made
      incremental changes to a software component installed on a
      computing device.  Typically, an installed patch has made a set of
      file modifications to pre-installed software, and does not alter
      the version number or the descriptive metadata of an installed
      software component.  If a CoSWID tag is for a patch, the patch
      item MUST be set to "true".  If not provided the default value
      MUST be considered "false".

   o  supplemental (index 11): A boolean value that indicates if the tag
      is providing additional information to be associated with another
      referenced SWID or CoSWID tag.  Tags using this item help to
      ensure that primary and patch tags provided by a software provider
      are not modified by software management tools, while allowing
      these tools to provide their own software metadata for a software
      component.  If a CoSWID tag is a supplemental tag, the
      supplemental item MUST be set to "true".  If not provided the
      default value MUST be considered "false".

   o  swid-name  software-name (index 1): This textual item provides the software
      component
      component's name.  This name as it would typically be referenced.  For example,
      what would be seen in the add/remove software dialog in an
      operating system, or what is specified as likely the same name of a packaged
      software component or that would
      appear in a patch identifier name. package management tool.

   o  software-version (index 13): A textual value representing the
      specific release or development version of the software component.

   o  version-scheme (index 14): An 8-bit integer or textual value
      representing the versioning scheme used for the software-version
      item.  If an integer value is used it MUST be a value from the
      SWID/CoSWID Version Schema Values Scheme Value Registry (see section
      Section 5.2 5.2.1 or a value in the private use range: 32768-65535.

      An initial set of pre-defined version-scheme index and text values
      are defined in Section 4.1 that are based on the version-scheme
      values defined in [SWID].  These pre-defined version-scheme values
      are registered with IANA in the "SWID/CoSWID Version Scheme Value"
      registry Section 5.2.1, and MAY be expanded in the future.

      The value of an ownership item MUST be one of the following:

      *  The index (preferred) or string value of a role from the IANA
         in the "SWID/CoSWID Version Scheme Value" registry.

      *  An index value in the range 32768 through 65535, to indicate
         that a private use index value is used.

      *  A string value prefixed with "x_", to indicate that a private
         use string value is used.

   o  media (index 10): This text value is a hint to the tag consumer to
      understand what this tag applies to.  This item represents a query
      as defined by the W3C Media Queries Recommendation (see
      [W3C.REC-css3-mediaqueries-20120619]).

   o  software-meta (index 5): An open-ended map of key/value data
      pairs.  A number of predefined keys can be used within this item
      providing for common usage and semantics across the industry.  The
      data definition  Use
      of this entry map allows for any additional attribute to be included, though it included in the
      tag.  It is recommended expected that industry norms for
      new attributes are defined and followed groups will use a common set of
      attribute names to the degree possible. allow for interoperability within their
      communities.  Described in Section 2.7.

   o  entity (index 2): Provides information about one or more
      organizations related to responsible for producing the CoSWID tag tag, and
      producing or releasing the software component referenced by this
      CoSWID tag.  Described in Section 2.5.

   o  link (index 4): Provides a means to establish relationship arcs
      between the tag and another items.  A given link can be used to
      establish the relationship between tags or to reference another
      resource that is related to the CoSWID tag, e.g.  vulnerability
      database association, ROLIE feed [RFC8322], MUD resource
      [RFC8520], software download location, etc).  This is modeled
      after the HTML "link" element.  Described in Section 2.6.

   o  payload (index 6): This item represents the software artifacts
      that compose the target software.  For example, the files included
      with an installer for a corpus tag or installed on an endpoint
      when the software component is installed for a primary or patch
      tag.  Note that the  The artifacts listed in a payload can represent may be a superset of the
      software artifacts that are actually installed.  Based on user
      selections at install time, an installation might not include
      every artifact that could be created or executed on the endpoint
      when the software component is installed (i.e. if a particular optional sub-component is not
      installed, the files associated with that software component might
      be included in payload, but not installed on the endpoint). or run.  Described in
      Section 2.8.3.

   o  evidence  evidence-entry (index 3): This item is used to provide records the results from a
      scan of a system where
      software that does not have a CoSWID tag is
      discovered.  In such a case, a CoSWID tag can be created by the discovery process when the endpoint is scanned. used to identify untagged software on
      an endpoint.  This item
      represents evidence provides a means to represent indicators
      for why software is believed to be installed on the endpoint.  In
      such a case, a CoSWID tag is created when the endpoint is scanned
      by the tool performing the scan.  Described in Section 2.8.4.

   o  $$coswid-extension: This CDDL socket is used to add new
      information structures to the concise-swid-tag root map.  See
      Section 2.1.

2.3.  concise-swid-tag Co-constraints

   The following co-constraints apply to the information provided by in
   the concise-swid-tag group.

   o  Only one of the patch and supplemental items MUST be set to
      "true", or the  The patch and supplemental items MUST NOT both be set to "false"
      or be omitted. "true".

   o  If the patch item is set to "true", the tag SHOULD contain at
      least one link item with the rel(ation) item value of "patches"
      and an href item specifying an association with the software that
      was patched.

   o  If the supplemental item is set to "true", the tag SHOULD contain
      at least one link item with the rel(ation) item value of
      "supplements" and an href item specifying an association with the
      software that is supplemented.

   o  If all of the corpus, patch, and supplemental items are "false",
      or if the corpus item is set to "true", then a software-version
      item MUST be included with a value set to the version of the
      software component.  This ensures that primary and corpus tags
      have an identifiable software version.

2.4.  The global-attributes Group

   The global-attributes group provides a list of items including an
   optional language definition to support the processing of text-string
   values and an unbounded set of any-attribute items allowing for
   additional items to be provided as a general point of extension in
   the model.

   The CDDL for the global-attributes follows:

   global-attributes = (
     ? lang,
     * any-attribute,
   )

   any-attribute = (
     label => text / int / [ 2* text ] / [ 2* int ]
   )

   label = text / int

   The following describes each child item of this group.

   o  lang (index 15): A textual language tag that conforms with IANA
      "Language Subtag Registry" [RFC5646].  The context of the
      specified language applies to all sibling and descendant textual
      values, unless a descendant object has defined a different
      language tag.  Thus, a new context is established when a
      descendant object redefines a new language tag.  All textual
      values within a given context MUST be considered expressed in the
      specified language.

   o  any-attribute: This sub-group provides a means to include
      arbitrary information via label ("key") value pairs.  Labels can
      be either a single integer or text string.  Values can be either a
      single integer or text string, or an array of integers or text
      strings.

2.5.  The entity-entry Group

   The CDDL for the entity-entry group follows:

   entity-entry = {
     global-attributes,
     entity-name => text,
     ? reg-id => any-uri,
     role => $role / [ 2* $role ],
     ? thumbprint => hash-entry,
     * $$entity-extension,
   }
   entity-name = 31
   reg-id = 32
   role = 33
   thumbprint = 34

   $role /= tag-creator
   $role /= software-creator
   $role /= aggregator
   $role /= distributor
   $role /= licensor
   $role /= uint / text
   tag-creator=1
   software-creator=2
   aggregator=3
   distributor=4
   licensor=5

   The following describes each child item of this group.

   o  global-attributes: The global-attributes group described in
      Section 2.4.

   o  entity-name (index 32): The text-string textual name of the organization organizational
      entity claiming a particular role, the roles specified by the role item, in item for the
      CoSWID tag.

   o  reg-id (index 32): The registration id value is intended to
      uniquely identify a naming authority in a given scope (e.g.
      global, organization, vendor, customer, administrative domain,
      etc.) for the referenced entity.  The value of an registration ID
      MUST be a RFC 3986 URI.  The scope SHOULD be the scope of an
      organization.  In a given scope, the registration id MUST be used
      consistently for CoSWID tag production.

   o  role (index 33): The relationship(s) between this organization the entity, and this
      tag or the referenced software component.  The role  Use of an
      entity MAY include any role value, but the index values
      instead of text for these pre-defined roles
      include: "aggregator", "distributor", "licensor", "software-
      creator", and "tag-creator".  All allows a CoSWID to be
      more concise.

      An initial set of pre-defined role index and text values are
      defined in Section 4.2 that are based on the roles defined in
      [SWID].  These pre-defined roles are registered with IANA in the
      "SWID/CoSWID Entity Role Values" Value" registry Section 4.2.  Use 5.2.2, and MAY be
      expanded in the future.

      The value of a role item MUST be one of the following:

      *  The index values instead (preferred) or string value of text for
      these pre-defined roles allows a CoSWID role from the IANA
         in the "SWID/CoSWID Entity Role Value" registry.

      *  An index value in the range 128 through 255, to be more concise. indicate that a
         private use index value is used.

      *  A string value prefixed with "x_", to indicate that a private
         use string value is used.

      The following additional requirements exist for the use of the
      "role" item:

      *  An entity item MUST be provided with the role of "tag-creator"
         for every CoSWID tag.  This indicates the organization that
         created the CoSWID tag.

      *  An entity item SHOULD be provided with the role of "software-
         creator" for every CoSWID tag, if this information is known to
         the tag creator.  This indicates the organization that created
         the referenced software component.

   o  thumbprint (index 34): The value of the thumbprint item provides
      an integer-based hash algorithm identifier (hash-alg-id) and a
      byte string value (hash-value) that contains the corresponding
      hash value (i.e. the thumbprint) of the signing entity's public
      key certificate.  This provides an indicator of which entity
      signed the CoSWID tag, which will typically be the tag creator.
      If the hash-alg-id is not known, then the integer value "0" MUST
      be used.  This ensures parity between the SWID tag specification
      [SWID], which does not allow an algorithm to be identified for
      this field.  See Section 2.8.1 for more details on the use of the
      hash-entry data structure.

   o  $$entity-extension: This CDDL socket can be used to extend the
      entity-entry group model.  See Section 2.1.

2.6.  The link-entry Map

   The CDDL for the link-entry map follows:

   link-entry = {
     global-attributes,
     ? artifact => text,
     href => any-uri,
     ? media => text,
     ? ownership => $ownership,
     rel => $rel,
     ? media-type => text,
     ? use => $use,
     * $$link-extension,
   }
   media = 10
   artifact = 37
   href = 38
   ownership = 39
   rel = 40
   media-type = 41
   use = 42

   $ownership /= shared
   $ownership /= private
   $ownership /= abandon
   $ownership /= uint / text
   shared=1
   private=2
   abandon=3

   $rel /= ancestor
   $rel /= component
   $rel /= feature
   $rel /= installationmedia
   $rel /= packageinstaller
   $rel /= parent
   $rel /= patches
   $rel /= requires
   $rel /= see-also
   $rel /= supersedes
   $rel /= rel-supplemental supplemental
   $rel /= uint / text
   ancestor=1
   component=2
   feature=3
   installationmedia=4
   packageinstaller=5
   parent=6
   patches=7
   requires=8
   see-also=9
   supersedes=10
   rel-supplemental=11
   supplemental=11

   $use /= optional
   $use /= required
   $use /= recommended
   $use /= uint / text
   optional=1
   required=2
   recommended=3

   The following describes each member of this map.

   o  global-attributes: The global-attributes group described in
      Section 2.4.

   o  artifact (index (index: 37): For installation media (rel="installation-
      media"), To be used with rel="installation-media",
      this item value indicates can provide the path of to the installer executable
      or script that can be run to launch the referenced installation.
      Links with the same artifact name SHOULD MUST be considered mirrors of
      each other, allowing the installation media to be acquired from
      any of the described sources.

   o  href (index 38): A URI for the item being referenced. referenced resource.  The "href"
      item's value can point to several different things, and can be any
      of be, but is not limited to, the following: following (which
      is a slightly modified excerpt from [SWID]):

      *  If no URI scheme is provided, then the URI is to be interpreted
         as being relative to the URI of the CoSWID tag.  For example,
         "./folder/supplemental.coswid".

      *  a physical resource location with any acceptable URI scheme
         (e.g., file:// http:// https:// ftp://)

      *  a URI with "coswid:" as the scheme, which refers to another
         CoSWID by tag-id.  This URI would need to be resolved in the
         context of the endpoint by software that can lookup other
         CoSWID tags.  For example, "coswid:2df9de35-0aff-
         4a86-ace6-f7dddd1ade4c" references the tag with the tag-id
         value "2df9de35-0aff-4a86-ace6-f7dddd1ade4c".

      *  a URI with "swidpath:" as the scheme, which refers to another
         CoSIWD via an XPATH query.  This URI would need to be resolved
         in the context of the system entity via software components
         that can lookup other CoSWID tags and select the appropriate
         tag based on an XPATH query [W3C.REC-xpath20-20101214].
         Examples include:

      *  swidpath://SoftwareIdentity[Entity/@regid='http://contoso.com']
         would retrieve all CoSWID tags that include an entity where the
         regid is "Contoso" or swidpath://SoftwareIdentity[Meta/@persist
         entId='b0c55172-38e9-4e36-be86-92206ad8eddb'] would match
         CoSWID tags with the persistent-id value
         "b0c55172-38e9-4e36-be86-92206ad8eddb".

   o  media (index 10): A hint to the consumer of the link to what the
      target item is applicable for.  This item represents a query as
      defined by the W3C Media Queries Recommendation (see
      [W3C.REC-css3-mediaqueries-20120619]).  See also media defined in
      Section 2.2.

   o  ownership (index 39): Determines the relative strength of
      ownership between Used when the software "href" item references another
      software component to indicate the degree of ownership between the
      software component referenced by the COSWID tag and the software
      component referenced by the link.  Valid
      enumerations are: abandon, private, shared.

   The enumerated

      An initial set of pre-defined ownership index and text values have are
      defined in Section 4.3 that are based on the following meanings:

   +-----------+-------------------------------------------------------+
   | ownership | semantics                                             |
   +-----------+-------------------------------------------------------+
   | abandon   | If the software component referenced by the CoSWID    |
   |           | tag is uninstalled, then values
      defined in [SWID].  These pre-defined ownership values are
      registered with IANA in the referenced software      |
   |           | SHOULD not "SWID/CoSWID Link Ownership Value"
      registry Section 5.2.3, and MAY be uninstalled                             |
   |           |                                                       |
   | private   | If the software component referenced by the CoSWID    |
   |           | tag is uninstalled, then expanded in the referenced software      |
   |           | SHOULD future.

      The value of an ownership item MUST be uninstalled too.                            |
   |           |                                                       |
   | shared    | If one of the software component referenced by following:

      *  The index (preferred) or string value of a role from the CoSWID    |
   |           | tag is uninstalled, then IANA
         in the referenced software      |
   |           | SHOULD be uninstalled if no other components sharing  |
   |           | "SWID/CoSWID Link Ownership Value" registry.

      *  An index value in the software.                                         |
   +-----------+-------------------------------------------------------+ range 128 through 255, to indicate that a
         private use index value is used.

      *  A string value prefixed with "x_", to indicate that a private
         use string value is used.

   o  rel (index 40): The Identifies the relationship between this CoSWID
      and the target resource as defined by [RFC8288].  Relationships can be
      identified indicated by referencing a "Relation Name" from the IANA "Link
      Relation Types" registry: https://www.iana.org/assignments/link-
      relations/link-relations.xhtml.

   o  media-type (index 41): The media type for the target resource.
      This provides the consumer with a hint "href" item.

      An initial set of what pre-defined rel index and text values are
      defined in Section 4.4 that are based on the rel values defined in
      [SWID].  These pre-defined rel values are registered with IANA in
      the "SWID/CoSWID Link Relationship Value" registry Section 5.2.4,
      and MAY be expanded in the future.

      The value of a rel item MUST be one of the following:

      *  The index (preferred) or string value of a role from the IANA
         in the "SWID/CoSWID Link Relationship Value" registry.

      *  An index value in the range 128 through 255, to indicate that a
         private use index value is used.

      *  A string value prefixed with "x_", to indicate that a private
         use string value is used.

      *  A string value, as defined by [RFC8288], corresponding to a
         "Relation Name" from the IANA "Link Relation Types" registry:
         https://www.iana.org/assignments/link-relations/link-
         relations.xhtml.  When a string value defined in the IANA
         "SWID/CoSWID Link Relationship Value" registry matches a
         Relation Name defined in the IANA "Link Relation Types"
         registry, the value in the IANA "SWID/CoSWID Link Relationship
         Value" registry MUST be used instead, as this relationship has
         a specialized meaning in the context of a SWID/CoSWID tag.

   o  media-type (index 41): The media type for the target resource,
      providing a resource consumer with a hint of what type of resource
      to expect.  Media types are identified by referencing a "Name"
      from the IANA "Media Types" registry: http://www.iana.org/assignments/
      media-types/media-types.xhtml.
      http://www.iana.org/assignments/media-types/media-types.xhtml.

   o  use (index 42): Determines if the target referenced software is a hard
      requirement or not component
      has to be installed before installing the tagged software
      component.  Valid enumerations are: required,
      recommended, optional, which

      An initial set of pre-defined use index and text values are
      defined in Section 4.3.

   o  $$link-extension: This CDDL socket can be used to extend 4.5 that are based on the link-
      entry map model.  See use values defined in
      [SWID].  These pre-defined use values are registered with IANA in
      the "SWID/CoSWID Link Use Value" registry Section 2.1.

2.7.  The software-meta-entry Map 5.2.5, and MAY
      be expanded in the future.

      The CDDL value of an ownership item MUST be one of the following:

      *  The index (preferred) or string value of a role from the IANA
         in the "SWID/CoSWID Link Use Value" registry.

      *  An index value in the range 128 through 255, to indicate that a
         private use index value is used.

      *  A string value prefixed with "x_", to indicate that a private
         use string value is used.

   o  $$link-extension: This CDDL socket can be used to extend the link-
      entry map model.  See Section 2.1.

2.7.  The software-meta-entry Map

   The CDDL for the software-meta-entry map follows:

   software-meta-entry = {
     global-attributes,
     ? activation-status => text,
     ? channel-type => text,
     ? colloquial-version => text,
     ? description => text,
     ? edition => text,
     ? entitlement-data-required => bool,
     ? entitlement-key => text,
     ? generator => text,
     ? persistent-id => text,
     ? product => text,
     ? product-family => text,
     ? revision => text,
     ? summary => text,
     ? unspsc-code => text,
     ? unspsc-version => text,
     * $$meta-extension,
   }
   activation-status = 43
   channel-type = 44
   colloquial-version = 45
   description = 46
   edition = 47
   entitlement-data-required = 48
   entitlement-key = 49
   generator = 50
   persistent-id = 51
   product = 52
   product-family = 53
   revision = 54
   summary = 55
   unspsc-code = 56
   unspsc-version = 57

   The following describes each child item of this group.

   o  global-attributes: The global-attributes group described in
      Section 2.4.

   o  activation-status (index 43): A textual value that identifies how
      the
      activation status of this software title component has been activated, which might relate to
      specific terms and conditions for its use (e.g.  Trial,
      Serialized, Licensed, Unlicensed, etc).  Typically, this etc) and relate to an
      entitlement.  This attribute is typically used in supplemental tags.
      tags as it contains information that might be selected during a
      specific install.

   o  channel-type (index 44): A textual value that provides information
      on identfies which
      sales, licensing, or marketing channel this particular the software was component has
      been targeted for (e.g.  Volume, Retail, OEM, Academic, etc).  Typically
      This attribute is typically used in supplemental tags. tags as it
      contains information that might be selected during a specific
      install.

   o  colloquial-version (index 45): A textual value for an the software
      component's informal or colloquial version.  Examples may include
      a year value, a major version number, or similar value that are
      used to identify a group of the product (i.e. 2013).  Note specific software component releases
      that this are part of the same release/support cycle.  This version can
      be the same through multiple releases of a software component,
      while the software-version specified in the concise-
      swid-tag concise-swid-tag group
      is much more specific and will change for each software component
      release.  This representation of version is typically
      used intended to identify a group of specific software releases that are
      part of the same release/support infrastructure (i.e.  Fabrikam
      Office 2013).  This version is be used for string comparisons only
      comparison only, and is not compared intended to be an used to determine if a
      specific value is earlier or later release (that is
      done via the concise-swid-tag group's software-version item). in a sequence.

   o  description (index 46): A longer, detailed textual value that provides a detailed
      description of the software.  This description software component, which can be multiple sentences
      (differentiated from summary, which is a very short, one-sentence
      description).
      sentences.

   o  edition (index 47): A textual value indicating that the software
      component represents a functional variation of the product (e.g., Extended, Enterprise, Professional, Standard,
      etc). code base used
      to support multiple software components.  For examplem, this item
      can be used to differentiate enterprise, standard, or professional
      variants of a software component.

   o  entitlement-data-required (index 48): A boolean value that proof
      of indicator to determine if accompanying proof of entitlement is
      needed when a software license reconciliation process is completed.
      performed.

   o  entitlement-key (index 49): A vendor-specific textual key that can
      be used to reconcile the validity of identify and establish a relationship to an
      entitlement. (e.g.,  Examples of an entitlement-key might include a
      serial number, product key, or license key).  For values that
      relate to a given software component install (i.e., license key),
      a supplemental tag will typically contain this information.  In
      other cases where a general-purpose key can be provided that
      applies to all possible installs of the software component on
      different endpoints, a primary tag will typically contain this
      information.

   o  generator (index 50): The name (or tag-id) of the software tool
      component that created the CoSWID tag.  If the generating software
      component has a SWID or CoSWID tag, then the tag-id for the
      generating software component SHOULD be provided.

   o  persistent-id (index 51): A GUID used to represent products
      installed where identify a related set of
      software components.  Software components sharing the products are related, but same
      persistent-id can be different versions.

   o  product (index 52): The base A basic name of for the product. software component that
      can be common across multiple tagged software components (e.g.,
      Apache HTTPD).

   o  product-family (index 53): A textual value indicating the overall
      product family this software belongs to.  Product family is not
      used to identify that a
      components overall product is part of a suite, but is instead family.  This should be used when
      multiple related software components form a set of products larger capability that are all related can be
      is installed on multiple different endpoints.  For example, an enterprise
      backup system can some
      software families may consist of a backup services, multiple different
      backup services that support mail services, databases server, client, and ERP
      systems, as well as individual software components that backup
      client system entities.  In such an usage scenario, all software shared
      service components that are part of the a larger capability.  Email
      systems, enterprise applications, backup system would have the same
      product-family name so they can be grouped together in respect to
      reporting systems. services, web
      conferencing, and similar capabilities are examples of families.

   o  revision (index 54): A textual string value indicating the an informal or
      colloquial representation of the sub-version release version of the given product
      (ie, SP1, R2, RC1, Beta 2, etc).  Note that the software-version
      specified in the concise-swid-tag group will software.  This value can
      provide very exact a different version details.  Conversely, value as compared to the revision item is intended for
      use software-
      version specified in environments where reporting on the informal or colloquial
      representation of the software concise-swid-tag group.  This is important.  For example, useful
      when an
      organization needs "ServicePack 1" one or later of a specific product
      installed on all devices, they can use the revision data value more releases need to
      quickly identify any devices have an informal version label
      that do not meet this requirement.

   Depending on how a software organizations distributes revisions, this differs from the specific exact version value could be specified in a primary (if distributed as an upgrade)
   or supplemental (if distributed as a patch) CoSWID tag. by
      software-version.  Examples can include SP1, RC1, Beta, etc.

   o  summary (index 55): A short (one-sentence) description of the
      software. software component.
      This MUST be a single sentence suitable for display in a user
      interface.

   o  unspsc-code (index 56): An 8 digit code that provides UNSPSC classification of code for
      the software component this SWID tag identifies. component.  For more information see,
      http://www.unspsc.org/.

   o  unspsc-version (index 57): The version of the UNSPSC code used to define
      the UNSPSC code unspsc-code value.  For more information see,
      http://www.unspsc.org/.

   o  $$meta-extension: This CDDL socket can be used to extend the
      software-meta-entry group model.  See Section 2.1.

2.8.  The Resource Collection Definition

2.8.1.  The hash-entry Array

   CoSWID adds explicit support for the representation of hash entries
   using algorithms that are registered in the IANA "Named Information
   Hash Algorithm Registry" using the hash-entry member (label 58).

   hash-entry = [ hash-alg-id: int, hash-value: bytes, bytes ]

   The number used as a value for hash-alg-id MUST refer an ID in the
   "Named Information Hash Algorithm Registry" (see
   https://www.iana.org/assignments/named-information/named-
   information.xhtml); other hash algorithms MUST NOT be used.  The
   hash-value MUST represent the raw hash value of the hashed resource
   generated using the hash algorithm indicated by the hash-alg-id.

2.8.2.  The resource-collection Group

   A list of items both used in evidence (created by a software
   discovery process) and payload (installed in an endpoint) content of
   a CoSWID tag document to structure and differentiate the content of
   specific CoSWID tag types.  Potential content includes directories,
   files, processes, or resources.

   The CDDL for the resource-collection group follows:

   resource-collection = (
     ? directory => directory-entry,
     ? file => file-entry,
     ? process => process-entry,
     ? resource => resource-entry,
   )

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

   path-elements-entry = [ [ * file-entry ],
                           [ * directory-entry ],
                         ]

   file-entry = {
     filesystem-item,
     ? size => integer,
     ? file-version => text,
     ? hash => hash-entry,
     * $$file-extension
   }

   directory-entry = {
     filesystem-item,
     path-elements => path-elements-entry,
     * $$directory-extension
   }

   process-entry = {
     global-attributes,
     process-name => text,
     ? pid => integer,
     * $$process-extension
   }

   resource-entry = {
     global-attributes,
     type => text,
     * $$resource-extension
   }

   directory = 16
   file = 17
   process = 18
   resource = 19
   size = 20
   file-version = 21
   key = 22
   location = 23
   fs-name = 24
   root = 25
   path-elements = 26
   process-name = 27
   pid = 28
   type = 29

   The following describes each member of the groups and maps
   illustrated above.

   o  filesystem-item: A list of items both used in representing the
      nodes of a file-system hierarchy (i.e., directory items that allow
      one or more directories to be defined in the file structure), and
      file items that allow one or more files to be specified for a
      given location.

   o  global-attributes: The global-attributes group described in
      Section 2.4.

   o  directory (index 16): A directory item allows one or more
      directories child directory and
      file items to be defined in within a directory hierarchy for the file structure.
      software component.

   o  file (index 17): A file item that allows one or more files details about a file to be
      specified
      provided for a given location. the software component.

   o  process (index 18): Provides A process (software component in
      execution) item allows details to be provided
      about the runtime behavior of the software component, such as
      information for data that will show up appear in a devices process list. listing on a device.

   o  resource (index 19): A set of items that resource item can be used to provide
      arbitrary resource information
      details about an application installed a resource expected to be found on
      in an endpoint, or
      evidence collected from an endpoint. related to the software component.

   o  size (index 20): The file's size of the file in bytes.

   o  file-version (index 21): The file's version of as reported by
      querying information on the file. file from the operating system.

   o  key (index 22): A boolean indicator for when files value indicating if a file or directories
      are considered important directory
      is significant or required for the use of the software
      component referenced by the CoSWID.  Typical key files or
      directories would be those which, if not available on an endpoint,
      would cause the software component not to execute
      or function properly.  Key  These are files or directories will typically that can be
      used to
      validate that affirmatively determine if the software component referenced by the CoSWID tag is actually
      installed on a specific an endpoint.

   o  location (index 23): The location filesystem path where a file was found or can is expected
      to be located.  This text-string is intended to include
      the filename itself. located when installed or copied.  This path SHOULD be the
      relative path from to the location represented by of the root item parent directory item, or if the root item no
      parent is
      omitted defined, the location MUST be relative to the location
      of the CoSWID tag.  The location MUST not include a file's name,
      which is provided by the fs-name item.

   o  fs-name (index 24): The file name or of the directory name or file without any
      path characters. information.

   o  root (index 25): A system-specific filesystem-specific name for the root folder that of the
      filesystem.  The location item is an offset from.  If considered relative to this is
      location if specified.  If not specified provided, the assumption
      is value provided by the root
      location item is the same folder as expected to be relative to its parent or the
      location of the CoSWID tag.
      The text-string value represents a path expression relative to the
      CoSWID tag document location in the (composite) file-system
      hierarchy. if no parent is provided.

   o  path-elements (index 26): This group provides the ability to apply
      define a directory structure to the path expressions for files defined in
      a payload or
      evidence items.

   o  process-name (index 27): The software component's process name as
      it will be found appear in
      the an endpoint's process table. list.

   o  pid (index 28): The process ID identified for a running instance
      of the process in execution that
      can be included software component in the endpoint's process item list.  This is
      used as part of an the evidence tag. item.

   o  type (index 29): The A string indicating the type of resource represented via a text-
      string (typically, registry-key, port or root-uri). resource.

   o  $$resource-collection-extension: This CDDL socket can be used to
      extend the resource-collection group model.  This can be used to
      add new specialized types of resources.  See Section 2.1.

   o  $$file-extension: This CDDL socket can be used to extend the file-
      entry group model.  See Section 2.1.

   o  $$directory-extension: This CDDL socket can be used to extend the
      directory-entry group model.  See Section 2.1.

   o  $$process-extension: This CDDL socket can be used to extend the
      process-entry group model.  See Section 2.1.

   o  $$resource-extension: This CDDL socket can be used to extend the
      group model.  See Section 2.1.

   o  $$-extension: This CDDL socket can be used to extend the resource-
      entry group model.  See Section 2.1.

2.8.3.  The payload-entry Group

   The CDDL for the payload-entry group follows:

   payload-entry = {
     global-attributes,
     resource-collection,
     * $$payload-extension
   }

   The following describes each child item of this group.

   o  global-attributes: The global-attributes group described in
      Section 2.4.

   o  resource-collection: The resource-collection group described in
      Section 2.8.2.

   o  $$payload-extension: This CDDL socket can be used to extend the
      payload-entry group model.  See Section 2.1.

2.8.4.  The evidence-entry Group

   The CDDL for the evidence-entry group follows:

   evidence-entry = {
     global-attributes,
     resource-collection,
     ? date => time,
     ? device-id => text,
     * $$evidence-extension
   }
   date = 35
   device-id = 36

   The following describes each child item of this group.

   o  global-attributes: The global-attributes group described in
      Section 2.4.

   o  resource-collection: The resource-collection group described in
      Section 2.8.2.

   o  date (index 35): The date and time evidence represented by an
      evidence item the information was gathered. collected
      pertaining to the evidence item.

   o  device-id (index 36): A textual The endpoint's string identifier for a device from which
      the evidence was gathered from. collected.

   o  $$evidence-extension: This CDDL socket can be used to extend the
      evidence-entry group model.  See Section 2.1.

2.9.  Full CDDL Definition

   In order to create a valid CoSWID document the structure of the
   corresponding CBOR message MUST adhere to the following CDDL data
   definition.

 concise-swid-tag = {
   global-attributes,
   tag-id => text,
   tag-version => integer,
   ? corpus => bool,
   ? patch => bool,
   ? supplemental => bool,
   swid-name
   software-name => text,
   ? software-version => text,
   ? version-scheme => $version-scheme,
   ? media => text,
   ? software-meta =>  software-meta-entry / [ 2* software-meta-entry ],
   entity => entity-entry / [ 2* entity-entry ],
   ? link => link-entry / [ 2* link-entry ],
   ? (( payload => payload-entry ) // ( evidence => evidence-entry )),
   * $$coswid-extension
 }

 any-uri = text
 label = text / int

 $version-scheme /= multipartnumeric
 $version-scheme /= multipartnumeric-suffix
 $version-scheme /= alphanumeric
 $version-scheme /= decimal
 $version-scheme /= semver
 $version-scheme /= uint / text

 any-attribute = (
   label => text / int / [ 2* text ] / [ 2* int ]
 )

 global-attributes = (
   ? lang => text,
   * any-attribute,
 )

 hash-entry = [ hash-alg-id: int,
                hash-value: bytes,
              ]

 entity-entry = {
   global-attributes,
   entity-name => text,
   ? reg-id => any-uri,
   role => $role / [ 2* $role ],
   ? thumbprint => hash-entry,
   * $$entity-extension,
 }

 $role /= tag-creator
 $role /= software-creator
 $role /= aggregator
 $role /= distributor
 $role /= licensor
 $role /= uint / text

 link-entry = {
   global-attributes,
   ? artifact => text,
   href => any-uri,
   ? media => text,
   ? ownership => $ownership,
   rel => $rel,
   ? media-type => text,
   ? use => $use,
   * $$link-extension
 }

 $ownership /= shared
 $ownership /= private
 $ownership /= abandon
 $ownership /= uint / text

 $rel /= ancestor
 $rel /= component
 $rel /= feature
 $rel /= installationmedia
 $rel /= packageinstaller
 $rel /= parent
 $rel /= patches
 $rel /= requires
 $rel /= see-also
 $rel /= supersedes
 $rel /= rel-supplemental supplemental
 $rel /= uint / text

 $use /= optional
 $use /= required
 $use /= recommended
 $use /= uint / text

 software-meta-entry = {
   global-attributes,
   ? activation-status => text,
   ? channel-type => text,
   ? colloquial-version => text,
   ? description => text,
   ? edition => text,
   ? entitlement-data-required => bool,
   ? entitlement-key => text,
   ? generator => text,
   ? persistent-id => text,
   ? product => text,
   ? product-family => text,
   ? revision => text,
   ? summary => text,
   ? unspsc-code => text,
   ? unspsc-version => text,
   * $$meta-extension,
 }

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

 file-entry = {
   filesystem-item,
   ? size => integer,
   ? file-version => text,
   ? hash => hash-entry,
   * $$file-extension
 }

 path-elements-entry = [ [ * file-entry ],
                         [ * directory-entry ],
                       ]

 directory-entry = {
   filesystem-item,
   path-elements => path-elements-entry,
   * $$directory-extension
 }

 process-entry = {
   global-attributes,
   process-name => text,
   ? pid => integer,
   * $$process-extension
 }

 resource-entry = {
   global-attributes,
   type => text,
   * $$resource-extension
 }

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

 payload-entry = {
   global-attributes,
   resource-collection,
   * $$payload-extension
 }

 evidence-entry = {
   global-attributes,
   resource-collection,
   ? date => time,
   ? device-id => text,
   * $$evidence-extension
 }

 ; "global map member" integer indexes
 tag-id = 0
 swid-name
 software-name = 1
 entity = 2
 evidence = 3
 link = 4
 software-meta = 5
 payload = 6
 hash = 7
 corpus = 8
 patch = 9
 media = 10
 supplemental = 11
 tag-version = 12
 software-version = 13
 version-scheme = 14
 lang = 15
 directory = 16
 file = 17
 process = 18
 resource = 19
 size = 20
 file-version = 21
 key = 22
 location = 23
 fs-name = 24
 root = 25
 path-elements = 26
 process-name = 27
 pid = 28
 type = 29
 entity-name = 31
 reg-id = 32
 role = 33
 thumbprint = 34
 date = 35
 device-id = 36
 artifact = 37
 href = 38
 ownership = 39
 rel = 40
 media-type = 41
 use = 42
 activation-status = 43
 channel-type = 44
 colloquial-version = 45
 description = 46
 edition = 47
 entitlement-data-required = 48
 entitlement-key = 49
 generator = 50
 persistent-id = 51
 product = 52
 product-family = 53
 revision = 54
 summary = 55
 unspsc-code = 56
 unspsc-version = 57

 ; "version-scheme" integer indexes
 multipartnumeric = 1
 multipartnumeric-suffix = 2
 alphanumeric = 3
 decimal = 4
 semver = 16384

 ; "role" integer indexes
 tag-creator=1
 software-creator=2
 aggregator=3
 distributor=4
 licensor=5

 ; ownership integer indexes
 shared=1
 private=2
 abandon=3
 ; "rel" integer indexes
 ancestor=1
 component=2
 feature=3
 installationmedia=4
 packageinstaller=5
 parent=6
 patches=7
 requires=8
 see-also=9
 supersedes=10
 rel-supplemental=11
 supplemental=11

 ; "use" integer indexes
 optional=1
 required=2
 recommended=3

3.  Determining the Type of CoSWID

   The operational model for SWID and CoSWID tags was introduced in
   Section 1.1, which described four different CoSWID tag types.  The
   following additional rules apply to the use of CoSWID tags to ensure
   that created tags properly identify the tag type.

   The first matching rule MUST determine the type of the CoSWID tag.

   1.  Primary Tag: A CoSWID tag MUST be considered a primary tag if the
       corpus, patch, and supplemental items are "false".

   2.  Supplemental Tag: A CoSWID tag MUST be considered a supplemental
       tag if the supplemental item is set to "true".

   3.  Corpus Tag: A CoSWID tag MUST be considered a corpus tag if corpus tag if the
       corpus item is "true".

   4.  Patch Tag: A CoSWID tag MUST be considered a patch tag if the
       patch item is "true".

4.  CoSWID Indexed Label Values

4.1.  Version Scheme

   The following table contains a set of values for use in the concise-
   swid-tag group's version-scheme item.  These values match the version
   schemes defined in the ISO/IEC 19770-2:2015 [SWID] specification.
   Index value indicates the value to use as the version-scheme item's
   value.  The Version Scheme Name provides human-readable text for the
   value.  The Definition describes the syntax of allowed values for
   each entry.

   +-------+-------------------------+---------------------------------+
   | Index | Version Scheme Name     | Definition                      |
   +-------+-------------------------+---------------------------------+
   | 1     | multipartnumeric        | Numbers separated by dots,      |
   |       |                         | where the numbers are           |
   |       |                         | interpreted as integers         |
   |       |                         | (e.g.,1.2.3, 1.4.5,             |
   |       |                         | 1.2.3.4.5.6.7)                  |
   |       |                         |                                 |
   | 2     | multipartnumeric+suffix | Numbers separated by dots,      |
   |       |                         | where the numbers are           |
   |       |                         | interpreted as integers with an |
   |       |                         | additional textual suffix       |
   |       |                         | (e.g., 1.2.3a)                  |
   |       |                         |                                 |
   | 3     | alphanumeric            | Strictly a string, sorting is   |
   |       |                         | done alphanumerically           |
   |       |                         |                                 |
   | 4     | decimal                 | A floating point number (e.g.,  |
   |       |                         | 1.25 is less than 1.3)          |
   |       |                         |                                 |
   | 16384 | semver                  | Follows the [SEMVER]            |
   |       |                         | specification                   |
   +-------+-------------------------+---------------------------------+

   The values above are registered in the IANA "SWID/CoSWID Version
   Scheme Value" registry defined in section Section 5.2.1.  Additional
   entires will likely be registered over time in this registry.
   Additionally, the index values 32768 through 65535 have been reserved
   for private use.

4.2.  Entity Role Values

   The following table indicates the index value to use for the entity-
   entry group's role item (see Section 2.5).  These values match the
   entity roles defined in the ISO/IEC 19770-2:2015 [SWID]
   specification.  The "Index" value indicates the value to use as the
   role item's value.  The "Role Name" provides human-readable text for
   the value.  The "Definition" describes the semantic meaning of each
   entry.

   +-------+-----------------+-----------------------------------------+
   | Index | Role Name       | Definition                              |
   +-------+-----------------+-----------------------------------------+
   | 1     | tagCreator      | The person or organization that created |
   |       |                 | the containing SWID or CoSWID tag       |
   |       |                 |                                         |
   | 2     | softwareCreator | From [SAM], "person or organization     |
   |       |                 | that creates a software product (3.46)  |
   |       |                 | or package"                             |
   |       |                 |                                         |
   | 3     | aggregator      | From {{SWID}, "An organization or       |
   |       |                 | system that encapsulates software from  |
   |       |                 | their own and/or other organizations    |
   |       |                 | into a different distribution process   |
   |       |                 | (as in the case of virtualization), or  |
   |       |                 | as a completed system to accomplish a   |
   |       |                 | specific task (as in the case of a      |
   |       |                 | value added reseller)."                 |
   |       |                 |                                         |
   | 4     | distributor     | From [SWID], "An entity that furthers   |
   |       |                 | the marketing, selling and/or           |
   |       |                 | distribution of software from the       |
   |       |                 | original place of manufacture to the    |
   |       |                 | ultimate user without modifying the     |
   |       |                 | software, its packaging or its          |
   |       |                 | labelling."                             |
   |       |                 |                                         |
   | 5     | licensor        | From [SAM] as "software licensor", a    |
   |       |                 | "person or organization who owns or     |
   |       |                 | holds the rights to issue a software    |
   |       |                 | license for a specific software         |
   |       |                 | package"                                |
   +-------+-----------------+-----------------------------------------+

   The values above are registered in the
       corpus item is "true".

   4.  Patch Tag: A CoSWID tag MUST IANA "SWID/CoSWID Entity Role
   Value" registry defined in section Section 5.2.2.  Additional valid
   values will likely be considered a patch tag if registered over time.  Additionally, the
       patch item is "true".

4.  CoSWID Indexed Label index
   values 128 through 255 have been reserved for private use.

4.3.  Link Ownership Values

4.1.  Version Scheme

   The following table contains a set of values for indicates the index value to use in for the concise-
   swid-tag link-
   entry group's version-scheme item. ownership item (see Section 2.6).  These values match
   the version
   schemes link ownership values defined in the ISO/IEC 19770-2:2015 [SWID]
   specification.
   Index  The "Index" value indicates the value to use as the version-scheme
   link-entry group ownership item's value.  The Version Scheme Name "Ownership Type"
   provides human-readable text for the value.  The Definition "Definition"
   describes the syntax semantic meaning of allowed values for each entry.

   +-------+-------------------------+---------------------------------+

   +-------+-----------+-----------------------------------------------+
   | Index | Version Scheme Name Ownership | Definition                                    |
   +-------+-------------------------+---------------------------------+
   | 1       | multipartnumeric Type      | Numbers separated by dots,                                               |
   +-------+-----------+-----------------------------------------------+
   | 1     | abandon   | where If the software component referenced by the numbers are           |
   |       |                         | interpreted as integers   |
   |       |           | (e.g.,1.2.3, 1.4.5, CoSWID tag is uninstalled, then the           |
   |       |           | 1.2.3.4.5.6.7) referenced software SHOULD not be uninstalled |
   |       |           |                                               |
   | 2     | multipartnumeric+suffix private   | Numbers separated If the software component referenced by dots, the   |
   |       |           | where CoSWID tag is uninstalled, then the numbers are           |
   |       |           | interpreted referenced software SHOULD be uninstalled as integers with an |
   |       |                         | additional textual suffix  |
   |       |           | (e.g., 1.2.3a) well.                                         |
   |       |           |                                               |
   | 3     | alphanumeric            | Strictly a string, sorting is   |
   |       |                         | done alphanumerically           |
   |       |                         |                                 |
   | 4     | decimal shared    | A floating point number (e.g., If the software component referenced by the   |
   |       |           | 1.25 CoSWID tag is less than 1.3) uninstalled, then the           |
   |       |           | referenced software SHOULD be uninstalled if  |
   | 16384       | semver           | Follows no other components sharing the [SEMVER]            |
   |       |                         | specification software.     |
   +-------+-------------------------+---------------------------------+
   +-------+-----------+-----------------------------------------------+

   The values above are registered in the IANA "SWID/CoSWID Version
   Schema Values" Link
   Ownership Value" registry defined in section Section 5.2. 5.2.3.
   Additional
   entires valid values will likely be registered over time in this registry. time.
   Additionally, the index values 32768 128 through 65535 255 have been reserved for
   private use.

4.2.  Entity Role

4.4.  Link Rel Values

   The following table indicates the index value to use for the entity- link-
   entry group's role rel item (see Section 2.5). 2.6).  These values match the
   entity roles
   link rel values defined in the ISO/IEC 19770-2:2015 [SWID]
   specification.  Index  The "Index" value indicates the value to use as the role
   link-entry group ownership item's value.  The Role Name "Relationship Type"
   provides human-readable text for the value.  The Definition "Definition"
   describes the semantic meaning of each entry.

   +-------+-----------------+-----------------------------------------+

   +-------+-------------------+---------------------------------------+
   | Index | Role Name Relationship Type | Definition                            |
   +-------+-----------------+-----------------------------------------+
   +-------+-------------------+---------------------------------------+
   | 1     | ancestor          | The link references a SWID/CoSWID tag |
   |       |                   | for an ancestor of this software.     |
   |       |                   | This can be useful to define an       |
   |       |                   | upgrade path.                         |
   |       |                   |                                       |
   | 2     | component         | The link references a SWID/CoSWID tag |
   |       |                   | for a separate component of this      |
   |       |                   | software.                             |
   |       |                   |                                       |
   | 3     | feature           | The link references a configurable    |
   |       |                   | feature of this software, that can be |
   |       |                   | enabled or disabled without changing  |
   |       |                   | the installed files.                  |
   |       |                   |                                       |
   | 4     | installationmedia | The link references the installation  |
   |       |                   | package that can be used to install   |
   |       |                   | this software.                        |
   |       |                   |                                       |
   | 5     | packageinstaller  | The link references the installation  |
   |       |                   | software needed to install this       |
   |       |                   | software.                             |
   |       |                   |                                       |
   | 6     | parent            | The link references a SWID/CoSWID tag |
   | 1       | tagCreator                   | The person or organization that created is the parent of this            |
   |       |                   | the containing SWID or CoSWID tag SWID/CoSWID tag.                      |
   |       |                   |                                       |
   | 2 7     | softwareCreator patches           | From [SAM], "person or organization The link references a SWID/CoSWID tag |
   |       |                   | that creates a this software product (3.46) patches. Typically |
   |       |                   | or package" only used for patch SWID/CoSWID tags  |
   |       |                   | (see Section 1.1).                    |
   | 3       | aggregator                   | From {{SWID}, "An organization or                                       |
   | 8     | requires          | system that encapsulates software from The link references a prerequisite    |
   |       |                   | their own and/or other organizations for installing this software. A patch |
   |       |                   | into a different distribution process SWID/CoSWID tag (see Section 1.1) can |
   |       |                   | (as in the case of virtualization), or use this to represent base software   |
   |       |                   | as a completed system or another patch that needs to accomplish a be     |
   |       |                   | specific task (as in the case of a installed first.                      |
   |       |                   | value added reseller)."                                       |
   | 9     | see-also          | The link references other software    |
   | 4       | distributor                   | From [SWID], "An entity that furthers may be of interest that relates  |
   |       |                   | the marketing, selling and/or to this software.                     |
   |       |                   | distribution of software from the                                       |
   | 10    | supersedes        | original place of manufacture to the The link references another software  |
   |       |                   | ultimate user without modifying the that this software replaces. A patch  |
   |       |                   | software, its packaging or its SWID/CoSWID tag (see Section 1.1) can |
   |       |                   | labelling." use this to represent another patch   |
   |       |                   | that this patch incorporates or       |
   | 5       | licensor                   | From [SAM] as "software licensor", a replaces.                             |
   |       |                   | "person or organization who owns or                                       |
   | 11    | supplemental      | holds the rights to issue The link references a software SWID/CoSWID tag |
   |       |                   | license for a specific software that this tag supplements. Used on    |
   |       |                   | package" supplemental SWID/CoSWID tags (see    |
   +-------+-----------------+-----------------------------------------+
   |       |                   | Section 1.1).                         |
   +-------+-------------------+---------------------------------------+

   The values above are registered in the IANA "SWID/CoSWID Entity Role
   Values" Link
   Relationship Value" registry defined in section Section 5.3. 5.2.4.
   Additional valid values will likely be registered over time.

   Additionally, the index values 128 32768 through 255 65535 have been reserved
   for private use.

4.3.

4.5.  Link Use Values

   The following table indicates the index value to use for the link-
   entry group's use item (see Section 2.6).  These values match the
   link use values defined in the ISO/IEC 19770-2:2015 [SWID]
   specification.  Index  The "Index" value indicates the value to use as the link-
   entry
   link-entry group use item's value.  The Use Type "Use Type" provides human-readable human-
   readable text for the value.  The Definition "Definition" describes the semantic
   meaning of each entry.

   +-------+-------------+---------------------------------------------+
   | Index | Use Type    | Definition                                  |
   +-------+-------------+---------------------------------------------+
   | 1     | optional    | From [SWID], "Not absolutely required; the  |
   |       |             | [Link]'d software is installed only when    |
   |       |             | specified."                                 |
   |       |             |                                             |
   | 2     | required    | From [SWID], "The [Link]'d software is      |
   |       |             | absolutely required for an operation        |
   |       |             | software installation."                     |
   |       |             |                                             |
   | 3     | recommended | From [SWID], "Not absolutely required; the  |
   |       |             | [Link]'d software is installed unless       |
   |       |             | specified otherwise."                       |
   +-------+-------------+---------------------------------------------+

   The values above are registered in the IANA "SWID/CoSWID Link Use
   Values"
   Value" registry defined in section Section 5.4. 5.2.5.  Additional valid
   values will likely be registered over time.  Additionally, the index
   values 128 through 255 have been reserved for private use.

5.  IANA Considerations

   This document has a number of IANA considerations, as described in
   the following subsections.

5.1.  CoSWID Items Registry

   This document uses integer values as index values in CBOR maps.

   This document defines a new a new registry titled "CoSWID Items".
   Future registrations for this registry are to be made based on
   [RFC8126] as follows:

              +------------------+-------------------------+
              | Range            | Registration Procedures |
              +------------------+-------------------------+
              | 0-32767          | Standards Action        |
              |                  |                         |
              | 32768-4294967295 | Specification Required  |
              +------------------+-------------------------+

   All negative values are reserved for Private Use.

   Initial registrations for the "CoSWID Items" registry are provided
   below.  Assignments consist of an integer index value, the item name,
   and a reference to the defining specification.

       +---------------+---------------------------+---------------+
       | Index         | Item Name                 | Specification |
       +---------------+---------------------------+---------------+
       | 0             | tag-id                    | RFC-AAAA      |
       |               |                           |               |
       | 1             | swid-name software-name             | RFC-AAAA      |
       |               |                           |               |
       | 2             | entity                    | RFC-AAAA      |
       |               |                           |               |
       | 3             | evidence                  | RFC-AAAA      |
       |               |                           |               |
       | 4             | link                      | RFC-AAAA      |
       |               |                           |               |
       | 5             | software-meta             | RFC-AAAA      |
       |               |                           |               |
       | 6             | payload                   | RFC-AAAA      |
       |               |                           |               |
       | 7             | hash                      | RFC-AAAA      |
       |               |                           |               |
       | 8             | corpus                    | RFC-AAAA      |
       |               |                           |               |
       | 9             | patch                     | RFC-AAAA      |
       |               |                           |               |
       | 10            | media                     | RFC-AAAA      |
       |               |                           |               |
       | 11            | supplemental              | RFC-AAAA      |
       |               |                           |               |
       | 12            | tag-version               | RFC-AAAA      |
       |               |                           |               |
       | 13            | software-version          | RFC-AAAA      |
       |               |                           |               |
       | 14            | version-scheme            | RFC-AAAA      |
       |               |                           |               |
       | 15            | lang                      | RFC-AAAA      |
       |               |                           |               |
       | 16            | directory                 | RFC-AAAA      |
       |               |                           |               |
       | 17            | file                      | RFC-AAAA      |
       |               |                           |               |
       | 18            | process                   | RFC-AAAA      |
       |               |                           |               |
       | 19            | resource                  | RFC-AAAA      |
       |               |                           |               |
       | 20            | size                      | RFC-AAAA      |
       |               |                           |               |
       | 21            | file-version              | RFC-AAAA      |
       |               |                           |               |
       | 22            | key                       | RFC-AAAA      |
       |               |                           |               |
       | 23            | location                  | RFC-AAAA      |
       |               |                           |               |
       | 24            | fs-name                   | RFC-AAAA      |
       |               |                           |               |
       | 25            | root                      | RFC-AAAA      |
       |               |                           |               |
       | 26            | path-elements             | RFC-AAAA      |
       |               |                           |               |
       | 27            | process-name              | RFC-AAAA      |
       |               |                           |               |
       | 28            | pid                       | RFC-AAAA      |
       |               |                           |               |
       | 29            | type                      | RFC-AAAA      |
       |               |                           |               |
       | 31            | entity-name               | RFC-AAAA      |
       |               |                           |               |
       | 32            | reg-id                    | RFC-AAAA      |
       |               |                           |               |
       | 33            | role                      | RFC-AAAA      |
       |               |                           |               |
       | 34            | thumbprint                | RFC-AAAA      |
       |               |                           |               |
       | 35 35            | date                      | RFC-AAAA      |
       |               |                           |               |
       | 36            | device-id                 | RFC-AAAA      |
       |               |                           |               |
       | 37            | artifact                  | RFC-AAAA      |
       |               |                           |               |
       | 38            | href                      | RFC-AAAA      |
       |               |                           |               |
       | 39            | ownership                 | RFC-AAAA      |
       |               |                           |               |
       | 40            | rel                       | RFC-AAAA      |
       |               |                           |               |
       | 41            | media-type                | RFC-AAAA      |
       |               |                           |               |
       | 42            | use                       | RFC-AAAA      |
       |               |                           |               |
       | 43            | activation-status         | RFC-AAAA      |
       |               |                           |               |
       | 44            | channel-type              | RFC-AAAA      |
       |               |                           |               |
       | 45            | colloquial-version        | RFC-AAAA      |
       |               |                           |               |
       | 46            | description               | RFC-AAAA      |
       |               |                           |               |
       | 47            | edition                   | RFC-AAAA      |
       |               |                           |               |
       | 48            | entitlement-data-required | RFC-AAAA      |
       |               |                           |               |
       | 49            | entitlement-key           | RFC-AAAA      |
       |               |                           |               |
       | 50            | generator                 | RFC-AAAA      |
       |               |                           |               |
       | 51            | persistent-id             | RFC-AAAA      |
       |               |                           |               |
       | 52            | product                   | RFC-AAAA      |
       |               |                           |               |
       | 53            | product-family            | RFC-AAAA      |
       |               |                           |               |
       | 54            | revision                  | RFC-AAAA      |
       |               |                           |               |
       | 55            | summary                   | RFC-AAAA      |
       |               |                           |               |
       | 56            | unspsc-code               | RFC-AAAA      |
       |               |                           |               |
       | 57            | date unspsc-version            | RFC-AAAA      |
       |               |                           |               |
       | 36            | device-id                 | RFC-AAAA      |
       | 58-4294967295 | Unassigned                |               |
       +---------------+---------------------------+---------------+

5.2.  SWID/CoSWID Value Registries

   The following IANA registries provide a mechanism for new valid
   values to be added over time to common enumerations used by SWID and
   CoSWID.

5.2.1.  SWID/CoSWID Version Scheme Value Registry

   This document uses unsigned 16-bit index values to represent version-
   scheme item values.  The initial set of version-scheme values are
   derived from the textual version scheme names defined in the ISO/IEC
   19770-2:2015 specification [SWID].

   This document defines a new a new registry titled "SWID/CoSWID
   Version Scheme Values".  Future registrations for this registry are
   to be made based on [RFC8126] as follows:

   [TO BE REMOVED: This registration should take place at the following
   location: https://www.iana.org/assignments/swid]

                +-------------+--------------------------+
                | 37 Range       | artifact Registration Procedures  | RFC-AAAA
                +-------------+--------------------------+
                | 0-16383     | Standards Action         |
                |             |                          | 38
                | href 16384-32767 | RFC-AAAA Specification Required   |
                |             |                          |
                | 32768-65535 | 39 Reserved for Private Use | ownership
                +-------------+--------------------------+

   Initial registrations for the "SWID/CoSWID Version Scheme Value"
   registry are provided below.  Assignments consist of an integer Index
   value, the Version Scheme Name, and a reference to the defining
   specification.

       +-------------+--------------------------+-----------------+
       | RFC-AAAA Index       | Version Scheme Name      | Specification   |
       +-------------+--------------------------+-----------------+
       | 0           | Reserved                 | 40                 | rel
       | RFC-AAAA             |                          |                 |
       | 1           | multipartnumeric         | 41 See Section 4.1 | media-type
       | RFC-AAAA             |                          |                 |
       | 2           | multipartnumeric+suffix  | 42 See Section 4.1 | use
       | RFC-AAAA             |                          |                 |
       | 3           | alphanumeric             | 43 See Section 4.1 | activation-status
       | RFC-AAAA             |                          |                 |
       | 4           | decimal                  | 44 See Section 4.1 | channel-type
       | RFC-AAAA             |                          |                 |
       | 5-16383     | Unassigned               | 45                 | colloquial-version
       | RFC-AAAA             |                          |                 |
       | 16384       | semver                   | 46 [SEMVER]        | description
       | RFC-AAAA             |                          |                 |
       | 16385-32767 | Unassigned               | 47                 | edition
       | RFC-AAAA             |                          |                 |
       | 32768-65535 | Reserved for Private Use | 48                 | entitlement-data-required
       +-------------+--------------------------+-----------------+

5.2.2.  SWID/CoSWID Entity Role Value Registry

   This document uses unsigned 8-bit index values to represent entity-
   entry role item values.  The initial set of Entity roles are derived
   from the textual role names defined in the ISO/IEC 19770-2:2015
   specification [SWID].

   This document defines a new a new registry titled "SWID/CoSWID Entity
   Role Values".  Future registrations for this registry are to be made
   based on [RFC8126] as follows:

   [TO BE REMOVED: This registration should take place at the following
   location: https://www.iana.org/assignments/swid]

                  +---------+--------------------------+
                  | RFC-AAAA Range   | Registration Procedures  |
                  +---------+--------------------------+
                  | 0-31    | Standards Action         |
                  | 49         | entitlement-key                          | RFC-AAAA
                  | 32-127  | Specification Required   |
                  |         |                          | 50
                  | generator 128-255 | RFC-AAAA Reserved for Private Use |
                  +---------+--------------------------+

   Initial registrations for the "SWID/CoSWID Entity Role Value"
   registry are provided below.  Assignments consist of an integer Index
   value, a Role Name, and a reference to the defining specification.

         +---------+--------------------------+-----------------+
         | Index   | Role Name                | Specification   |
         +---------+--------------------------+-----------------+
         | 51 0       | persistent-id Reserved                 | RFC-AAAA                 |
         |         |                          |                 |
         | 52 1       | product tagCreator               | RFC-AAAA See Section 4.2 |
         |         |                          |                 |
         | 53 2       | product-family softwareCreator          | RFC-AAAA See Section 4.2 |
         |         |                          |                 |
         | 54 3       | revision aggregator               | RFC-AAAA See Section 4.2 |
         |         |                          |                 |
         | 55 4       | summary distributor              | RFC-AAAA See Section 4.2 |
         |         |                          |                 |
         | 56 5       | unspsc-code licensor                 | RFC-AAAA See Section 4.2 |
         |         |                          |                 |
         | 57 6-127   | unspsc-version Unassigned               | RFC-AAAA                 |
         |         |                          |                 |
         | 58-4294967295 128-255 | Unassigned Reserved for Private Use |                 |
       +---------------+---------------------------+---------------+

5.2.
         +---------+--------------------------+-----------------+

5.2.3.  SWID/CoSWID Version Schema Values Link Ownership Value Registry

   This document uses unsigned 16-bit 8-bit index values to version-scheme represent link-
   entry ownership item values.  The initial set of version-scheme Link ownership
   values are derived from the textual version scheme ownership names defined in the
   ISO/IEC 19770-2:2015 specification [SWID].

   This document defines a new a new registry titled "SWID/CoSWID
   Version Schema Link
   Ownership Values".  Future registrations for this registry are to be
   made based on [RFC8126] as follows:

   [TO BE REMOVED: This registration should take place at the following
   location: https://www.iana.org/assignments/swid]

                +-------------+--------------------------+

                  +---------+--------------------------+
                  | Range   | Registration Procedures  |
                +-------------+--------------------------+
                  +---------+--------------------------+
                  | 0-16383 0-31    | Standards Action         |
                  |         |                          |
                  | 16384-32767 32-127  | Specification Required   |
                  |         |                          |
                  | 32768-65535 128-255 | Reserved for Private Use |
                +-------------+--------------------------+
                  +---------+--------------------------+

   Initial registrations for the "SWID/CoSWID Version Schema Values" Link Ownership Value"
   registry are provided below.  Assignments consist of an integer index Index
   value, the version scheme name, an Ownership Type Name, and a reference to the defining
   specification.

       +-------------+--------------------------+-----------------+
       | Index       | Version Scheme Ownership Type Name      | Specification Definition      |
       +-------------+--------------------------+-----------------+
       | 0           | Reserved                 |                 |
       |             |                          |                 |
       | 1           | multipartnumeric abandon                  | See Section 4.1 4.3 |
       |             |                          |                 |
       | 2           | multipartnumeric+suffix  | See Section 4.1 |
       |             |                          |                 |
       | 3           | alphanumeric             | See Section 4.1 |
       |             |                          |                 |
       | 4           | decimal private                  | See Section 4.1 4.3 |
       |             |                          |                 |
       | 5-16383 3           | Unassigned shared                   | See Section 4.3 |
       |             |                          |                 |
       | 16384 4-16384     | semver Unassigned               | [SEMVER]                 |
       |             |                          |                 |
       | 16385-32767 | Unassigned               |                 |
       |             |                          |                 |
       | 32768-65535 | Reserved for Private Use |                 |
       +-------------+--------------------------+-----------------+

5.3.

5.2.4.  SWID/CoSWID Entity Role Values Link Relationship Value Registry

   This document uses unsigned 8-bit 16-bit index values to represent entity-
   role link-
   entry rel item values.  The initial set of Entity roles rel values are derived
   from the textual role rel names defined in the ISO/IEC 19770-2:2015
   specification [SWID].

   This document defines a new a new registry titled "SWID/CoSWID Entity
   Role Link
   Relationship Values".  Future registrations for this registry are to
   be made based on [RFC8126] as follows:

   [TO BE REMOVED: This registration should take place at the following
   location: https://www.iana.org/assignments/swid]
                  +---------+--------------------------+

                +-------------+--------------------------+
                | Range       | Registration Procedures  |
                  +---------+--------------------------+
                +-------------+--------------------------+
                | 0-31 0-16383     | Standards Action         |
                |             |                          |
                | 32-127 16384-32767 | Specification Required   |
                |             |                          |
                | 128-255 32768-65535 | Reserved for Private Use |
                  +---------+--------------------------+
                +-------------+--------------------------+

   Initial registrations for the "SWID/CoSWID Entity Role Values" Link Relationship Value"
   registry are provided below.  Assignments consist of an integer index Index
   value, a role name, the Relationship Type Name, and a reference to the defining
   specification.

         +---------+--------------------------+-----------------+

       +-------------+--------------------------+-----------------+
       | Index       | Role Relationship Type Name   | Specification   |
         +---------+--------------------------+-----------------+
       +-------------+--------------------------+-----------------+
       | 0           | Reserved                 |                 |
       |             |                          |                 |
       | 1           | tagCreator ancestor                 | See Section 4.2 4.4 |
       |             |                          |                 |
       | 2           | softwareCreator component                | See Section 4.2 4.4 |
       |             |                          |                 |
       | 3           | aggregator feature                  | See Section 4.2 4.4 |
       |             |                          |                 |
       | 4           | distributor installationmedia        | See Section 4.2 4.4 |
       |             |                          |                 |
       | 5           | licensor packageinstaller         | See Section 4.2 4.4 |
       |             |                          |                 |
       | 6           | parent                   | See Section 4.4 |
       |             |                          |                 |
       | 7           | patches                  | See Section 4.4 |
       |             |                          |                 |
       | 8           | requires                 | See Section 4.4 |
       |             |                          |                 |
       | 9           | see-also                 | See Section 4.4 |
       |             |                          |                 |
       | 10          | supersedes               | See Section 4.4 |
       |             |                          |                 |
       | 11          | supplemental             | See Section 4.4 |
       |             |                          |                 |
       | 6-31 12-16384    | Unassigned               |                 |
       |             |                          |                 |
       | 32-127 16385-32767 | Unassigned               |                 |
       |             |                          |                 |
       | 128-255 32768-65535 | Reserved for Private Use |                 |
         +---------+--------------------------+-----------------+

5.4.
       +-------------+--------------------------+-----------------+

5.2.5.  SWID/CoSWID Link Use Values Value Registry

   This document uses unsigned 8-bit index values to represent link-use link-
   entry use item values.  The initial set of Link use values are
   derived from the textual names defined in the ISO/IEC 19770-2:2015
   specification [SWID].

   This document defines a new a new registry titled "SWID/CoSWID Link
   Use Values".  Future registrations for this registry are to be made
   based on [RFC8126] as follows:

   [TO BE REMOVED: This registration should take place at the following
   location: https://www.iana.org/assignments/swid]

                  +---------+--------------------------+
                  | Range   | Registration Procedures  |
                  +---------+--------------------------+
                  | 0-31    | Standards Action         |
                  |         |                          |
                  | 32-127  | Specification Required   |
                  |         |                          |
                  | 128-255 | Reserved for Private Use |
                  +---------+--------------------------+

   Initial registrations for the "SWID/CoSWID Entity Role Values" Value"
   registry are provided below.  Assignments consist of an integer index Index
   value, the link use name, Link Use Type Name, and a reference to the defining
   specification.

         +---------+--------------------------+-----------------+
         | Index   | Link Use Type Name       | Specification   |
         +---------+--------------------------+-----------------+
         | 0       | Reserved                 |                 |
         |         |                          |                 |
         | 1       | optional                 | See Section 4.3 4.5 |
         |         |                          |                 |
         | 2       | required                 | See Section 4.3 4.5 |
         |         |                          |                 |
         | 3       | recommended              | See Section 4.3 |
         |         |                          |                 |
         | 4-31    | Unassigned 4.5 |
         |         |                          |                 |
         |
         | 32-127 4-127   | Unassigned               |                 |
         |         |                          |                 |
         | 128-255 | Reserved for Private Use |                 |
         +---------+--------------------------+-----------------+

5.5.

5.3.  swid+cbor Media Type Registration

   IANA is requested add the following to the IANA "Media Types"
   registry.

   Type name: application

   Subtype name: swid+cbor

   Required parameters: none
   Optional parameters: none

   Encoding considerations: Must be encoded as using [RFC7049].  See
   RFC-AAAA for details.

   Security considerations: See Section 6 of RFC-AAAA.

   Interoperability considerations: Applications MAY ignore any key
   value pairs that they do not understand.  This allows backwards
   compatible extensions to this specification.

   Published specification: RFC-AAAA

   Applications that use this media type: The type is used by Software
   asset management systems, Vulnerability assessment systems, and in
   applications that use remote integrity verification.

   Fragment identifier considerations: Fragment identification for
   application/swid+cbor is supported by using fragment identifiers as
   specified by RFC-AAAA.  [Section to be defined]

   Additional information:

   Magic number(s): first five bytes in hex: da 53 57 49 44

   File extension(s): coswid

   Macintosh file type code(s): none

   Macintosh Universal Type Identifier code: org.ietf.coswid conforms to
   public.data

   Person & email address to contact for further information: Henk
   Birkholz <henk.birkholz@sit.fraunhofer.de>

   Intended usage: COMMON

   Restrictions on usage: None

   Author: Henk Birkholz <henk.birkholz@sit.fraunhofer.de>

   Change controller: IESG

5.6.

5.4.  CoAP Content-Format Registration

   IANA is requested to assign a CoAP Content-Format ID for the CoSWID
   media type in the "CoAP Content-Formats" sub-registry, from the "IETF
   Review or IESG Approval" space (256..999), within the "CoRE
   Parameters" registry [RFC7252]:

          +-----------------------+----------+------+-----------+
          | Media type            | Encoding | ID   | Reference |
          +-----------------------+----------+------+-----------+
          | application/swid+cbor | -        | TBD1 | RFC-AAAA  |
          +-----------------------+----------+------+-----------+

                     Table 1: CoAP Content-Format IDs

5.7.

5.5.  CBOR Tag Registration

   IANA is requested to allocate a tag in the "CBOR Tags" registry",
   preferably with the specific value requested:

   +------------+----------+-------------------------------------------+
   | Tag        | Data     | Semantics                                 |
   |            | Item     |                                           |
   +------------+----------+-------------------------------------------+
   | 1398229316 | map      | Concise Software Identifier (CoSWID)      |
   |            |          | [RFC-AAAA]                                |
   +------------+----------+-------------------------------------------+

6.  Security Considerations

   SWID and CoSWID tags contain public information about software
   components 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 has been validated can be relied
   upon to be unchanged since it was signed.  If the SWID tag was
   created by the software provider, is signed, and the software
   provider can be authenticated as the originator of the signature,
   then the tag can be considered authoritative.  In this way, an
   authoritative SWID tag contains information about a software product
   provided by the maintainer of the product, who is expected to be an
   expert in their own product.  Thus, authoritative SWID tags can be
   trusted to represent authoritative information about the software
   product.  Having an authoritative SWID tag can be useful when the
   information in the tag needs to be trusted, such as when the tag is
   being used to convey reference integrity measurements for software
   components.  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
   components.  On endpoints where addition or removal of software
   components 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 can be easier to
   add or remove.  On such systems, it can be possible to add or remove
   SWID tags in a way that does not reflect the actual presence or
   absence of corresponding software components.  Similarly, not all
   software products automatically install SWID tags, so products can 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,  For this reason, 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 intent
   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
   ought to treat the tag contents as potentially malicious and employ
   input sanitizing on the tags they ingest.

7.  Acknowledgments

   TBD

8.  Change Log

   Changes from version 03 to version 09:

   o  Reduced representation complexity of the media-entry type and
      removed the section describing the older data structure.

   o  Added more signature schemes from COSE

   o  Included a minimal required set of normative language

   o  Reordering of attribute name to integer label by priority
      according to semantics.

   o  Added an IANA registry for CoSWID items supporting future
      extension.

   o  Cleaned up IANA registrations, fixing some inconsistencies in the
      table labels.

   o  Added additional CDDL sockets for resource collection entries
      providing for additional extension points to address future SWID/
      CoSWID extensions.

   o  Updated section on extension points to address new CDDL sockets
      and to reference the new IANA registry for items.

   o  Removed unused references and added new references to address
      placeholder comments.

   o  Added table with semantics for the link ownership item.

   o  Clarified language, made term use more consistent, fixed
      references, and replacing lowercase RFC2119 keywords.

   o  Added enumeration table

   o  Moved CBOR specific indexes to the end of the CDDL data definition

   o  Updated Examples

   Changes from version 02 to version 03:

   o  Updated core CDDL including the CDDL design pattern according to
      RFC 8428.

   Changes from version 01 to version 02:

   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

   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 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 06 to version 07:

   o  Added type choices/enumerations based on textual definitions in
      19770-2:2015

   o  Added value registry request

   o  Added media type registration request

   o  Added content format registration request

   o  Added CBOR tag registration request

   o  Removed RIM appedix to be addressed in complementary draft

   o  Removed CWT appendix

   o  Flagged firmware resource colletion appendix for revision

   o  Made use of terminology more consistent

   o  Better defined use of extension points in the CDDL

   o  Added definitions for indexed values

   o  Added IANA registry for Link use indexed values

   Changes from version 05 to version 06:

   o  Improved quantities

   o  Included proposals for implicet enumerations that were NMTOKENS

   o  Added extension points

   o  Improved exemplary firmware-resource extension

   Changes from version 04 to version 05:

   o  Clarified language around SWID and CoSWID to make more consistent
      use of these terms.

   o  Added language describing CBOR optimizations for single vs. arrays
      in the model front matter.

   o  Fixed a number of grammatical, spelling, and wording issues.

   o  Documented extension points that use CDDL sockets.

   o  Converted IANA registration tables to markdown tables, reserving
      the 0 value for use when a value is not known.

   o  Updated a number of references to their current versions.

   Changes from version 03 to version 04:

   o  Re-index label values in the CDDL.

   o  Added a section describing the CoSWID model in detail.

   o  Created IANA registries for entity-role and version-scheme

   Changes from version 02 to version 03:

   o  Updated CDDL to allow for a choice between a payload or evidence

   o  Re-index label values in the CDDL.

   o  Added item definitions

   o  Updated references for COSE, CBOR Web Token, and CDDL.

   Changes from version 01 to version 02:

   o  Added extensions for Firmware and CoSWID use as Reference
      Integrity Measurements (CoSWID RIM)

   o  Changes meta handling in CDDL from use of an explicit use of items
      to a more flexible unconstrained collection of items.

   o  Added sections discussing use of COSE Signatures and CBOR Web
      Tokens

   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

9.  Contributors
10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
              Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
              September 2009, <https://www.rfc-editor.org/info/rfc5646>.

   [RFC7049]  Bormann, C. and P. Hoffman, "Concise Binary Object
              Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
              October 2013, <https://www.rfc-editor.org/info/rfc7049>.

   [RFC7252]  Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
              Application Protocol (CoAP)", RFC 7252,
              DOI 10.17487/RFC7252, June 2014,
              <https://www.rfc-editor.org/info/rfc7252>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8152]  Schaad, J., "CBOR Object Signing and Encryption (COSE)",
              RFC 8152, DOI 10.17487/RFC8152, July 2017,
              <https://www.rfc-editor.org/info/rfc8152>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8288]  Nottingham, M., "Web Linking", RFC 8288,
              DOI 10.17487/RFC8288, October 2017,
              <https://www.rfc-editor.org/info/rfc8288>.

   [RFC8610]  Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
              Definition Language (CDDL): A Notational Convention to
              Express Concise Binary Object Representation (CBOR) and
              JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
              June 2019, <https://www.rfc-editor.org/info/rfc8610>.

   [SAM]      "Information technology - Software asset management - Part
              5: Overview and vocabulary", ISO/IEC 19770-5:2015,
              November 2013.

   [SEMVER]   Preston-Werner, T., "Semantic Versioning 2.0.0", n.d.,
              <https://semver.org/spec/v2.0.0.html>.

   [SWID]     "Information technology - Software asset management - Part
              2: Software identification tag", ISO/IEC 19770-2:2015,
              October 2015.

   [SWID-GUIDANCE]
              Waltermire, D., Cheikes, B., Feldman, L., and G. Witte,
              "Guidelines for the Creation of Interoperable Software
              Identification (SWID) Tags", NISTIR 8060, April 2016,
              <https://doi.org/10.6028/NIST.IR.8060>.

   [W3C.REC-css3-mediaqueries-20120619]
              Rivoal, F., "Media Queries", World Wide Web Consortium
              Recommendation REC-css3-mediaqueries-20120619, June 2012,
              <http://www.w3.org/TR/2012/
              REC-css3-mediaqueries-20120619>.

   [W3C.REC-xpath20-20101214]
              Berglund, A., Boag, S., Chamberlin, D., Fernandez, M.,
              Kay, M., Robie, J., and J. Simeon, "XML Path Language
              (XPath) 2.0 (Second Edition)", World Wide Web Consortium
              Recommendation REC-xpath20-20101214, December 2010,
              <http://www.w3.org/TR/2010/REC-xpath20-20101214>.

   [X.1520]   "Recommendation ITU-T X.1520 (2014), Common
              vulnerabilities and exposures", April 2011.

10.2.  Informative References

   [CamelCase]
              "UpperCamelCase", August 2014,
              <http://wiki.c2.com/?CamelCase>.

   [I-D.birkholz-rats-tuda]
              Fuchs, A., Birkholz, H., McDonald, I., and C. Bormann,
              "Time-Based Uni-Directional Attestation", draft-birkholz-
              rats-tuda-00 (work in progress), March 2019.

   [I-D.ietf-cbor-cddl]
              Birkholz, H., Vigano, C., and C. Bormann, "Concise data
              definition language (CDDL): a notational convention to
              express CBOR and JSON data structures", draft-ietf-cbor-
              cddl-08 (work in progress), March 2019.

   [KebabCase]
              "KebabCase", December 2014,
              <http://wiki.c2.com/?KebabCase>.

   [RFC4122]  Leach, P., Mealling, M., and R. Salz, "A Universally
              Unique IDentifier (UUID) URN Namespace", RFC 4122,
              DOI 10.17487/RFC4122, July 2005,
              <https://www.rfc-editor.org/info/rfc4122>.

   [RFC8322]  Field, J., Banghart, S., and D. Waltermire, "Resource-
              Oriented Lightweight Information Exchange (ROLIE)",
              RFC 8322, DOI 10.17487/RFC8322, February 2018,
              <https://www.rfc-editor.org/info/rfc8322>.

   [RFC8520]  Lear, E., Droms, R., and D. Romascanu, "Manufacturer Usage
              Description Specification", RFC 8520,
              DOI 10.17487/RFC8520, March 2019,
              <https://www.rfc-editor.org/info/rfc8520>.

Appendix A.  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 component 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 measurements 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 [RFC8152].  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 tags.

   <CODE BEGINS>
   signed-coswid = #6.18(COSE-Sign1-coswid)

   cose-label = int / tstr
   cose-values = any

   protected-signed-coswid-header = {
       1 => int,                      ; algorithm identifier
       3 => "application/swid+cbor",
       * cose-label => cose-values,
   }

   unprotected-signed-coswid-header = {
       4 => bstr,                     ; key identifier
       * cose-label => cose-values,
   }

   COSE-Sign1-coswid = [
       protected: bstr .cbor protected-signed-coswid-header,
       unprotected: unprotected-signed-coswid-header,
       payload: bstr .cbor concise-swid-tag,
       signature: bstr,
   ]
   <CODE ENDS>

   Optionally, the COSE_Sign structure that allows for more than one
   signature to be applied to a CoSWID tag MAY be used.  The
   corresponding usage scenarios are domain-specific and require well-
   defined application guidance.  Representation of the corresponding
   guidance is out-of-scope of this document.

   Additionally, the COSE Header counter signature MAY be used as an
   attribute in the unprotected header map of the COSE envelope of a
   CoSWID.  The application of counter signing enables second parties to
   provide a signature on a signature allowing for a proof that a
   signature existed at a given time (i.e., a timestamp).

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