]> National Institute of Standards and Technology

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National Institute of Standards and Technology

100 Bureau Drive Gaithersburg Maryland 20877 USA david.waltermire@nist.gov

Security SACM Working Group rolie software software descriptor swid This document uses the "information-type" extension point as defined in the Resource-Oriented Lightweight Information Exchange (ROLIE) Section 7.1.2 to better support Software Record and Software Inventory use cases. This specification registers a new ROLIE information-type, "software-descriptor", that allows for the categorization of information relevant to software description activities and formats. In particular, the usage of the ISO 19770-2:2015 (SWID Tag) and the Concise SWID (COSWID) formats in ROLIE are standardized. Additionally, this document discusses requirements and usage of other ROLIE elements in order to best syndicate software description information.

This document defines an extension to the Resource-Oriented Lightweight Information Exchange (ROLIE) to support the publication of software descriptor information. Software descriptor information is information that characterizes static software components, packages, and installers; including identifying, versioning, software creation and publication, and file artifact information. Software descriptor information provides data about what might be installed, but doesn't describe a specific software installation's configuration or execution. This static approach to software description is a smaller state space that covers the majority of current use cases for software inventory and record keeping. Some possible use cases for software descriptor information ROLIE Feeds include: Software providers can publish software descriptor information so that software researchers, enterprises, and users of software can understand the collection of software produced by that software provider. Organizations can aggregate and syndicate collections of software descriptor information provided by multiple software providers to support software-related analysis processes (e.g., vulnerability analysis) and value added information (e.g., software configuration checklist repositories) using identification and characterization information derived from software descriptor information. End user organizations can consume sources of software descriptor information, and other related software vulnerability and configuration information to provide the data needed to automate software asset, patch, and configuration management practices. Organizations can use software descriptors to support verification of other entities, thru mechanisms such as RIM or other integrity measurements. This document supports these use cases by describing the content requirements for Feeds and Entries of software descriptor information that are to be published to or retrieved from a ROLIE repository.

The key words "MUST," "MUST NOT," "REQUIRED," "SHALL," "SHALL NOT," "SHOULD," "SHOULD NOT," "RECOMMENDED," "MAY," and "OPTIONAL" in this document are to be interpreted as described in . Several places in this document refer to the "information-type" of a Resource (Entry or Feed). This refers to the "value" attribute of an "atom:category" element whose scheme is "urn:ietf:params:rolie:category:information-type". For an Entry, this value can be inherited from it's containing Feed as per .

In order to effectively protect and secure an endpoint, it is vital to know what the software load of that endpoint is. This software load, the combination of software, patches and installers on a device, represents the majority of the endpoint's attack surface. Unfortunately, without a reliable and secure package manager, or otherwise a secured and managed operating system, tracking what software is installed on an endpoint is currently not feasible without undue effort. Even attempting to whitelist software is difficult without a way of identifying software and its editions, versions and hotfixes. Software descriptor information, such as that standardized in the ISO 19770-2:2015 SWID Tag format, or expressed in proprietary enterprise databases, attempts to provide as much data about this software as possible. Once this information is expressed, it needs to be stored and shared to internal and external parties. ROLIE provides a mechanism to handle this sharing in an automation-friendly way.

When an "atom:category" element has the scheme "urn:ietf:params:rolie:category:information-type", the value is considered to be the information type of the associated resource. The new information type value "software-descriptor", is described in this section, and registered in . The "software-descriptor" information type represents any static information that describes a piece of software. This document uses the definition of software provided by . Note that as per this definition, this information type pertains to static software, that is, code on the disc. The "software-descriptor" information type is intended to provide a category for information that does one or more of the following: This software identification and characterization information can be provided by a large variety of data, but always describes software in a pre-installed state. This represents information about software used to install other software. This metadata identifies, and characterizes a software installation package or media. Information that describes the software post-deployment, such as files that may be deployed during an installation. It is expected that this metadata is produced generally for a given installation, and may not exactly match the actual installed files on a given endpoint. Provided below is a non-exhaustive list of information that may be considered to be of a software-descriptor information type. Naming information: IDs and names that aid in the identification of a piece of software Version and patching information: Version numbers, patch identifiers, or other information that Vendor and source information: Includes where the software was developed or distributed from, as well as where the software installation media may be located. Payload and file information: information that describes or enumerates the files and folders that make up the piece of software, and information about those files. Descriptive information and data: Any information that otherwise characterizes a piece of software, such as libraries, runtime environments, target OSes, intended purpose or audience, etc. Note again that this list is not exhaustive, any information that in is the abstract realm of an incident should be classified under this information-type. It is important to note that software descriptor information is static for a given piece of software. That is, the information expressed is the data that doesn't change from the publication of the software to its final install. Information about the current status (e.g. install location, memory usage, CPU usage, launch parameters, job progress, etc.), is out of scope of this information type.

This document registers new valid rolie:property names as follows:

This property provides an exposure point for the plain text name of the software being described. Naming of software is not a well standardized process, and software names can change between product versions or editions. As such, care should be taken that this value is set as consistently as possible by generating it directly from an attached software descriptor resource.

This property provides an exposure point for the version of the software being described. This value should be generated or taken from the software descriptor linked to by the entry. This helps avoid, but does not prevent, inconsistent versioning schemes being shared.

This property provides an exposure point for a plain text name of the creator of the software being described. This is in many cases an organization or company, but certainly could be a single person. Most software descriptor formats include this information, and where possible, this property should be set equal to that value.

This section defines usage guidance and additional requirements related to data formats above and beyond those specified in . The following formats are expected to be commonly used to express software descriptor information. For this reason, this document specifies additional requirements to ensure interoperability.

ISO/IEC 19770-2:2015 defines a software record data format referred to as a "SWID Tag". It provides several tag types: primary: provides descriptive and naming information about software, patch: describes non-standalone software meant to patch existing software, corpus:describes the software installation media that installs a given piece of software, supplemental: provides additional metadata to be deployed alongside a tag. For a more complete overview as well as normative requirements, refer to ISO/IEC 19770-2:2015 . For additional requirements and guidance around creation of SWID Tags, consult NIST Internal Report 8060 .

For an Entry to be considered as a "SWID Tag Entry", it MUST fulfill the following conditions: The information-type of the Entry is "software-descriptor". For a typical Entry, this is derived from the information type of the Feed it is contained in. For a standalone Entry, this is provided by an "atom:category" element. The document linked to by the "href" attribute of the "atom:content" element is a 2015 SWID Tag as per ISO/IEC 19770-2:2015. A "SWID Tag Entry" MUST conform to the following requirements: The value of the "type" attribute of the "atom:content" element MUST be "application/swid2015+xml"[TODO]. There MUST be one "rolie:property" with the "name" attribute equal to "urn:ietf:params:rolie:property:content-id" and the "value" attribute exactly equal to the "<tagid>" element in the attached SWID Tag. This allows for ROLIE consumers to more easily search for SWID tags without needing to download the tag itself. There MUST be one "rolie:property" with the "name" attribute equal to "urn:ietf:params:rolie:property:swd:swname", and the "value" attribute equal to the value of the "<name>" element in the attached SWID Tag. As above, this field aids ROLIE consumers in search and filtering Entries. There MAY be a property element with the "name" attribute equal to "urn:ietf:params:rolie:property:swd:swversion". When this property appears, it's value MUST be equal to the value of the "TODO-version" element in the attached SWID Tag.

The Concise SWID (COSWID) format is an alternative representation of the SWID Tag format using a Concise Binary Object Representation (CBOR) encoding. This provides the format with a reduced size that is more suitable for constrained devices. It provides the same features and attributes as are specified in ISO 19770-2:2015, plus: a straight forward method to sign and encrypt using COSE, and additional attributes that provide an improved structure to include file hashes intended to be used as Reference Integrity Measurements (RIM). For more information and the complete specification, refer to the COSWID internet draft .

For an Entry to be considered as a "COSWID Tag Entry", it MUST fulfill the following conditions: The information-type of the Entry is "software-descriptor". For a typical Entry, this is derived from the information-type of the Feed it is contained in. For a standalone Entry, this is provided by an "atom:category" element. The document linked to by the "href" attribute of the "atom:content" element is a COSWID Tag as per A "COSWID Tag Entry" MUST conform to the following requirements: The value of the "type" attribute of the atom:content element MUST be "application/coswid+cbor". There MUST be one "rolie:property" with the "name" attribute equal to "urn:ietf:params:rolie:property:content-id" and the "value" attribute exactly equal to the "tag-id" element in the attached COSWID Tag. This allows for ROLIE consumers to more easily search for COSWID tags without needing to download the tag itself. There MUST be one "rolie:property" with the "name" attribute equal to "urn:ietf:params:rolie:property:swd:swname", and the "value" attribute equal to the value of the "swid-name" element in the attached COSWID Tag. As above, this field aids ROLIE consumers in searching and filtering Entries. There MAY be a property element with the "name" attribute equal to "urn:ietf:params:rolie:property:swd:swversion". When this property appears, it's value MUST be equal to the value of the "TODO-version" element in the attached COSWID Tag.

This section defines additional link relationships that implementations MUST support. These relationships are not registered in the Link Relation IANA table as their use case is too narrow. Each relationship is named and described. These relations come in related pairs. The first of each pair is expected to be more common, as they can be determined at the time that the Entry is created. The second of each pair will often need to be added retroactively to an Entry. Name Description ancestor Links to a software descriptor resource that defines an ancestor of the software being described by this Entry. This is usually a previous version of the software. descendent Links to a software descriptor resource that defines an descendent of the software being described by this Entry. This is usually a more recent version or edition of the software. patches Links to a software descriptor resource that defines the software being patched by this software patchedby Links to a software descriptor resource that defines the patch or update itself that can be or has been applied to this software. requires Links to a software descriptor resource that defines a piece of software required for this software to function properly, i.e., a dependency. requiredBy Links to a software descriptor resource that defines a piece of software that requires this software to function properly. installs Links to a software descriptor resource that defines the software that is installed by this software. installedBy Links to a software descriptor resource that defines the software package that installs this software. patchesVulnerability Links to a vulnerability that this software update fixes. Used for software descriptors that are describing software patches or updates. hasVulnerability Links to a vulnerability description object that details a vulnerability that this software has.

IANA has added an entry to the "ROLIE Security Resource Information Type Sub-Registry" registry located at . The entry is as follows: name: software-descriptor index: TBD reference: This document,

IANA has added an entry to the "ROLIE URN Parameters" registry located in . The entry is as follows: name: property:swd:swname Extension IRI: urn:ietf:params:rolie:property:swd:swname Reference: This document, Subregistry: None

IANA has added an entry to the "ROLIE URN Parameters" registry located in . The entry is as follows: name: property:swd:swversion Extension IRI: urn:ietf:params:rolie:property:swd:swversion Reference: This document, Subregistry: None

IANA has added an entry to the "ROLIE URN Parameters" registry located in . The entry is as follows: name: property:swd:swcreator Extension IRI: urn:ietf:params:rolie:property:swd:swcreator Reference: This document, Subregistry: None

Use of this extension implies dealing with the security implications of both ROLIE and of software descriptors in general. As with any data, care should be taken to verify the trustworthiness and veracity of the descriptor information to the fullest extent possible. Ideally, software descriptors should have been signed by the software manufacturer, or signed by whichever agent processed the source code. Software descriptor documents from these sources are more likely to be accurate than those generated by scraping installed software. These "authoritative" sources of software descriptor content should consider additional security for their ROLIE repository beyond the typical recommendations, as the central importance of the repository is likely to make it a target. Version information is often represented differently across manufacturers and even across product releases. If using software version information for low fault tolerance comparisons and searches, care should be taken that the correct version scheme is being utilized.

&RFC2119;&RFC5070;&RFC4949;&RFC8322;&I-D.ietf-sacm-coswid; National Institute for Standards and Technology The MITRE Corporation G2, Inc G2, Inc

This document does not require any schema extensions.

Use of this extension in a ROLIE repository will not typically change that repository's operation. As such, the general examples provided by the ROLIE core document would serve as examples. Provided below is a sample software descriptor ROLIE entry:

dd786dba-88e6-440b-9158-b8fae67ef67c 2015-08-04T18:13:51.0Z 2015-08-05T18:13:51.0Z

A descriptor for a piece of software published by this organization.

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