Open Security Controls Assessment Language OSCAL

NIST, in collaboration with the industry, is developing the Open Security Controls Assessment Language (OSCAL), a set of hierarchical, formatted, XML- JSON- and YAML-based formats that provide a standardized representation for different categories of security information pertaining to the publication, implementation, and assessment of security controls.

The OSCAL website provides an overview of the OSCAL project, including tutorials, concepts, references, downloads, and much more.

OSCAL is organized in a series of layers that each provides a set of models. 

A model represents an information structure supporting a specific operational purpose or concept.

Each model is comprised of information structures that form an information model for each OSCAL model. This information model is then bound to multiple serialization formats (i.e., XML, JSON, YAML), which represent a concrete data model. Thus, a data model defines how to represent an OSCAL information model in a serialized format. While the syntax of each format differs, all formats for a given model represent the same set of information or information model. In this way, OSCAL content expressed in one of the supported formats ( XML, JSON, or YAML) can be translated into any of the other supported formats without data loss.

The OSCAL layers and models are:

• Control Layer
  • Catalog model 
  •  Profile model 
• Implementation Layer
  • Component Definition model 
  • System Security Plan (SSP) model
• Assessment Layer
  •  Assessment Plan model
  •  Assessment Results model
  •  Plan of Action and Milestones (POA&M) model

The release state of each model, along with download links for the latest versions of XML and JSON schema for each model are provided in the table, below. YAML is also supported through conversion between JSON and YAML. Since YAML is a superset of JSON, some YAML tooling allows JSON schema to be used for YAML validation. In this way, the provided JSON schema supports both JSON and YAML.

The OSCAL GitHub repository holds the actual OSCAL schemas, examples, documentation source files, and other resources. The NIST team welcomes public contributions to this project. If you are interested in contributing, please review the site for ideas and information on how to get started.

NIST also maintains several public GitHub repositories associated with the OSCAL project:

OSCAL content maintained by NIST:

OSCAL tools and libraries:

• Converter utilities into JSON from XML and into XML from JSON
• Command line data conversion tool: OSCAL Java CLI
• A Java API for OSCAL
• OSCAL Deep Diff - CLI application and library that can produce schema-agnostic comparisons of JSON artifacts (OSCAL JSON included)
• CSX and XSLT OSCAL Tools 

OSCAL Metaschema:

• Metaschema modeling language - a language developed by NIST, used to generate a schema for a corresponding information model in a format-specific serializable form (e.g., XML, JSON, YAML) expressed as an XML or JSON Schema. OSCAL Schemas are generated using Metaschema modeling language.
• Metaschema Java framework which provides:
  • Java objects for loading and working with XML-based Metaschema constructs. This functionality is provided by the Metaschema XML model.
  • Java bean code generation based on one or more Metaschema using Maven. This functionality is provided by the Metaschema Maven plugin.
  • A Java parser for reading and writing XML, JSON, or YAML into Java beans generated by the Metaschema Java framework. This functionality is provided by the Metaschema Java Binding Parser.
  • XML and JSON schema generation based on a Metaschema provided by Metaschema Schema Generator.

The NIST team welcomes public contributions to this project. If you are interested in contributing, please review the contributor documentation for ideas and information on how to get started.

OSCAL Events:

The NIST OSCAL team is hosting several types of events:

• International, annually-held OSCAL conferences and/or workshops
  • Open Security Controls Assessment Language (OSCAL) Workshop (2019)
  • 2nd Open Security Controls Assessment Language (OSCAL) Workshop (2021)
  • 3rd Open Security Controls Assessment Language (OSCAL) Workshop (2022)
  • 4th Open Security Controls Assessment Language (OSCAL) Conference and Workshop (2023)
• An OSCAL Adopters' Mini Workshop Series opened primarily to our community members to present their OSCAL adoption
• An OSCAL 101 (Educational) Workshop Series.

OSCAL Public Meetings:

In addition to the monthly OSCAL workshops, the NIST OSCAL team hosts meetings with the OSCAL community on different topics related to the OSCAL development. All meetings are announced through our mailing list. Please subscribe to NIST OSCAL mailing lists to stay informed and to receive invitations to OSCAL meetings.

OSCAL mailing lists: 

-- oscal-dev@list.nist.gov for communication among parties interested in contributing to the development of OSCAL or exchanging ideas. Subscribe by sending an email to oscal-dev+subscribe@list.nist.gov. To unsubscribe send an email to oscal-dev+unsubscribe@list.nist.gov. 

-- oscal-updates@list.nist.gov for low-frequency updates on the status of the OSCAL project. Subscribe by sending an email to oscal-updates+subscribe@list.nist.gov. To unsubscribe send an email to oscal-updates+unsubscribe@list.nist.gov.

Other Resources:

NIST OSCAL GitHub (public): https://www.github.com/usnistgov/OSCAL  and  https://www.github.com/usnistgov/oscal-content

OSCAL lobby on Gitter (chat channel with the community): https://gitter.im/usnistgov-OSCAL/Lobby  (STRONGLY RECOMMENDED) 

OSCAL Community Websites:

US OSCAL Community-maintained: https://github.com/oscal-club/awesome-oscal

US OSCAL Community-maintained: https://oscal.io

EU OSCAL Community-maintained: https://euroscal.eu