Open Command and Control (OpenC2) Language Specification Version 1.0

Committee Specification Draft 09 /
Public Review Draft 03

31 May 2019

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Abstract:

Cyberattacks are increasingly sophisticated, less expensive to execute, dynamic and automated. The provision of cyber defense via statically configured products operating in isolation is untenable. Standardized interfaces, protocols and data models will facilitate the integration of the functional blocks within a system and between systems. Open Command and Control (OpenC2) is a concise and extensible language to enable machine-to-machine communications for purposes of command and control of cyber defense components, subsystems and/or systems in a manner that is agnostic of the underlying products, technologies, transport mechanisms or other aspects of the implementation. It should be understood that a language such as OpenC2 is necessary but insufficient to enable coordinated cyber responses that occur within cyber relevant time. Other aspects of coordinated cyber response such as sensing, analytics, and selecting appropriate courses of action are beyond the scope of OpenC2.

Status:

This document was last revised or approved by the OASIS Open Command and Control (OpenC2) TC on the above date. The level of approval is also listed above. Check the "Latest version" location noted above for possible later revisions of this document. Any other numbered Versions and other technical work produced by the Technical Committee (TC) are listed at https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=openc2#technical.

TC members should send comments on this specification to the TC's email list. Others should send comments to the TC's public comment list, after subscribing to it by following the instructions at the "Send A Comment" button on the TC's web page at https://www.oasis-open.org/committees/openc2/.

This specification is provided under the Non-Assertion Mode of the OASIS IPR Policy, the mode chosen when the Technical Committee was established. For information on whether any patents have been disclosed that may be essential to implementing this specification, and any offers of patent licensing terms, please refer to the Intellectual Property Rights section of the TC's web page (https://www.oasis-open.org/committees/openc2/ipr.php).

Note that any machine-readable content (Computer Language Definitions) declared Normative for this Work Product is provided in separate plain text files. In the event of a discrepancy between any such plain text file and display content in the Work Product's prose narrative document(s), the content in the separate plain text file prevails.

Citation format:

When referencing this specification the following citation format should be used:

[OpenC2-Lang-v1.0]

Open Command and Control (OpenC2) Language Specification Version 1.0. Edited by Jason Romano and Duncan Sparrell. 31 May 2019. OASIS Committee Specification Draft 09 / Public Review Draft 03. http://docs.oasis-open.org/openc2/oc2ls/v1.0/csprd03/oc2ls-v1.0-csprd03.html. Latest version: http://docs.oasis-open.org/openc2/oc2ls/v1.0/oc2ls-v1.0.html.


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Table of Contents


1 Introduction

The content in this section is non-normative, except where it is marked normative.

OpenC2 is a suite of specifications that enables command and control of cyber defense systems and components. OpenC2 typically uses a request-response paradigm where a Command is encoded by a Producer (managing application) and transferred to a Consumer (managed device or virtualized function) using a secure transfer protocol, and the Consumer can respond with status and any requested information.

OpenC2 allows the application producing the commands to discover the set of capabilities supported by the managed devices. These capabilities permit the managing application to adjust its behavior to take advantage of the features exposed by the managed device. The capability definitions can be easily extended in a noncentralized manner, allowing standard and non-standard capabilities to be defined with semantic and syntactic rigor.

1.1 IPR Policy

This specification is provided under the Non-Assertion Mode of the OASIS IPR Policy, the mode chosen when the Technical Committee was established. For information on whether any patents have been disclosed that may be essential to implementing this specification, and any offers of patent licensing terms, please refer to the Intellectual Property Rights section of the TC's web page (https://www.oasis-open.org/committees/openc2/ipr.php).

1.2 Terminology

This section is normative.

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

1.3 Normative References

[OpenC2-HTTPS-v1.0]

Specification for Transfer of OpenC2 Messages via HTTPS Version 1.0. Edited by David Lemire. Latest version: http://docs.oasis-open.org/openc2/open-impl-https/v1.0/open-impl-https-v1.0.html

[OpenC2-SLPF-v1.0]

Open Command and Control (OpenC2) Profile for Stateless Packet Filtering Version 1.0. Edited by Joe Brule, Duncan Sparrell, and Alex Everett. Latest version: http://docs.oasis-open.org/openc2/oc2slpf/v1.0/oc2slpf-v1.0.html

[RFC0768]

Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, https://www.rfc-editor.org/info/rfc768.

[RFC0791]

Postel, J., "Internet Protocol", STD 5, RFC 791, DOI 10.17487/RFC0791, September 1981, https://www.rfc-editor.org/info/rfc791.

[RFC0792]

Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, DOI 10.17487/RFC0792, September 1981, https://www.rfc-editor.org/info/rfc792.

[RFC0793]

Postel, J., "Transmission Control Protocol", STD 7, RFC 793, DOI 10.17487/RFC0793, September 1981, https://www.rfc-editor.org/info/rfc793.

[RFC1034]

Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987, https://www.rfc-editor.org/info/rfc1034.

[RFC1123]

Braden, R., Ed., "Requirements for Internet Hosts - Application and Support", STD 3, RFC 1123, DOI 10.17487/RFC1123, October 1989, https://www.rfc-editor.org/info/rfc1123.

[RFC1321]

Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, DOI 10.17487/RFC1321, April 1992, https://www.rfc-editor.org/info/rfc1321.

[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.

[RFC2673]

Crawford, M., "Binary Labels in the Domain Name System", RFC 2673, August 1999, https://tools.ietf.org/html/rfc2673

[RFC3986]

Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, https://www.rfc-editor.org/info/rfc3986.

[RFC3987]

Duerst, M. and M. Suignard, "Internationalized Resource Identifiers (IRIs)", RFC 3987, DOI 10.17487/RFC3987, January 2005, https://www.rfc-editor.org/info/rfc3987.

[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.

[RFC4291]

Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, February 2006, https://www.rfc-editor.org/info/rfc4291.

[RFC4632]

Fuller, V. and T. Li, "Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August 2006, https://www.rfc-editor.org/info/rfc4632.

[RFC4648]

Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, https://www.rfc-editor.org/info/rfc4648.

[RFC4960]

Stewart, R., Ed., "Stream Control Transmission Protocol", RFC 4960, DOI 10.17487/RFC4960, September 2007, https://www.rfc-editor.org/info/rfc4960.

[RFC5237]

Arkko, J. and S. Bradner, "IANA Allocation Guidelines for the Protocol Field", BCP 37, RFC 5237, DOI 10.17487/RFC5237, February 2008, https://www.rfc-editor.org/info/rfc5237.

[RFC5322]

Resnick, P., Ed., "Internet Message Format", RFC 5322, DOI 10.17487/RFC5322, October 2008, https://www.rfc-editor.org/info/rfc5322.

[RFC5890]

Klensin, J., "Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework", RFC 5890, DOI 10.17487/RFC5890, August 2010, https://www.rfc-editor.org/info/rfc5890.

[RFC5952]

Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 Address Text Representation", RFC 5952, DOI 10.17487/RFC5952, August 2010, https://www.rfc-editor.org/info/rfc5952.

[RFC6234]

Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms (SHA and SHA-based HMAC and HKDF)", RFC 6234, DOI 10.17487/RFC6234, May 2011, https://www.rfc-editor.org/info/rfc6234.

[RFC6335]

Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S. Cheshire, "Internet Assigned Numbers Authority (IANA) Procedures for the Management of the Service Name and Transport Protocol Port Number Registry", BCP 165, RFC 6335, DOI 10.17487/RFC6335, August 2011, https://www.rfc-editor.org/info/rfc6335.

[RFC6531]

Yao, J. and W. Mao, "SMTP Extension for Internationalized Email", RFC 6531, DOI 10.17487/RFC6531, February 2012, https://www.rfc-editor.org/info/rfc6531.

[RFC6838]

Freed, N., Klensin, J., and T. Hansen, "Media Type Specifications and Registration Procedures", BCP 13, RFC 6838, DOI 10.17487/RFC6838, January 2013, https://www.rfc-editor.org/info/rfc6838.

[RFC7493]

Bray, T., Ed., "The I-JSON Message Format", RFC 7493, DOI 10.17487/RFC7493, March 2015, https://www.rfc-editor.org/info/rfc7493.

[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.

[RFC8200]

Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, https://www.rfc-editor.org/info/rfc8200.

[RFC8259]

Bray, T., Ed., "The JavaScript Object Notation (JSON) Data Interchange Format", STD 90, RFC 8259, DOI 10.17487/RFC8259, December 2017, https://www.rfc-editor.org/info/rfc8259.

[EUI]

"IEEE Registration Authority Guidelines for use of EUI, OUI, and CID", IEEE, August 2017, https://standards.ieee.org/content/dam/ieee-standards/standards/web/documents/tutorials/eui.pdf

1.4 Non-Normative References

[IACD]

M. J. Herring, K. D. Willett, "Active Cyber Defense: A Vision for Real-Time Cyber Defense," Journal of Information Warfare, vol. 13, Issue 2, p. 80, April 2014.https://www.semanticscholar.org/paper/Active-Cyber-Defense-%3A-A-Vision-for-Real-Time-Cyber-Herring-Willett/7c128468ae42584f282578b86439dbe9e8c904a8.

Willett, Keith D., "Integrated Adaptive Cyberspace Defense: Secure Orchestration", International Command and Control Research and Technology Symposium, June 2015 https://www.semanticscholar.org/paper/Integrated-Adaptive-Cyberspace-Defense-%3A-Secure-by-Willett/a22881b8a046e7eab11acf647d530c2a3b03b762.

[UML]

"UML Multiplicity and Collections", https://www.uml-diagrams.org/multiplicity.html

1.5 Document Conventions

1.5.1 Naming Conventions

1.5.2 Font Colors and Style

The following color, font and font style conventions are used in this document:

Example:

{
    "action": "deny",
    "target": {
        "file": {
            "hashes": {
                "sha256": "22fe72a34f006ea67d26bb7004e2b6941b5c3953d43ae7ec24d41b1a928a6973"
            }
        }
    }
}

1.6 Overview

In general, there are two types of participants involved in the exchange of OpenC2 Messages, as depicted in Figure 1-1:

  1. Producers: A Producer is an entity that creates Commands to provide instruction to one or more systems to act in accordance with the content of the Command. A Producer may receive and process Responses in conjunction with a Command.
  2. Consumers: A Consumer is an entity that receives and may act upon a Command. A Consumer may create Responses that provide any information captured or necessary to send back to the Producer.

OpenC2 Message Exchange

Figure 1-1. OpenC2 Message Exchange

OpenC2 is a suite of specifications for Producers and Consumers to command and execute cyber defense functions. These specifications include the OpenC2 Language Specification, Actuator Profiles, and Transfer Specifications. The OpenC2 Language Specification and Actuator Profile specifications focus on the language content and meaning at the Producer and Consumer of the Command and Response while the transfer specifications focus on the protocols for their exchange.

The OpenC2 Language Specification defines a language used to compose Messages for command and control of cyber defense systems and components. A Message consists of a header and a payload (defined as a Message body in the OpenC2 Language Specification Version 1.0 and specified in one or more Actuator profiles).

The language defines two payload structures:

  1. Command: An instruction from one system known as the Producer, to one or more systems, the Consumer(s), to act on the content of the Command.
  2. Response: Any information sent back to the Producer as a result of the Command.

OpenC2 implementations integrate the related OpenC2 specifications described above with related industry specifications, protocols, and standards. Figure 1-2 depicts the relationships among OpenC2 specifications, and their relationships to other industry standards and environment-specific implementations of OpenC2. Note that the layering of implementation aspects in the diagram is notional, and not intended to preclude any particular approach to implementing the needed functionality (for example, the use of an application-layer message signature function to provide message source authentication and integrity).

OpenC2 Documentation and Layering Model

Figure 1-2. OpenC2 Documentation and Layering Model

OpenC2 is conceptually partitioned into four layers as shown in Table 1-1.

Table 1-1. OpenC2 Protocol Layers

Layer Examples
Function-Specific Content Actuator Profiles
([OpenC2-SLPF-v1.0], ...)
Common Content Language Specification
(this document)
Message Transfer Specifications
([OpenC2-HTTPS-v1.0], OpenC2-over-CoAP, ...)
Secure Transport HTTPS, CoAP, MQTT, OpenDXL, ...

The components of a Command are an Action (what is to be done), a Target (what is being acted upon), an optional Actuator (what is performing the command), and Command Arguments, which influence how the Command is to be performed. An Action coupled with a Target is sufficient to describe a complete Command. Though optional, the inclusion of an Actuator and/or Command Arguments provides additional precision to a Command.

The components of a Response are a numerical status code, an optional status text string, and optional results. The format of the results, if included, depend on the type of Response being transferred.

1.7 Goal

The goal of the OpenC2 Language Specification is to provide a language for interoperating between functional elements of cyber defense systems. This language used in conjunction with OpenC2 Actuator Profiles and OpenC2 Transfer Specifications allows for vendor-agnostic cybertime response to attacks.

The Integrated Adaptive Cyber Defense (IACD) framework defines a collection of activities, based on the traditional OODA (Observe–Orient–Decide–Act) Loop [IACD]:

The goal of OpenC2 is to enable coordinated defense in cyber-relevant time between decoupled blocks that perform cyber defense functions. OpenC2 focuses on the Acting portion of the IACD framework; the assumption that underlies the design of OpenC2 is that the sensing/analytics have been provisioned and the decision to act has been made. This goal and these assumptions guide the design of OpenC2:

1.8 Purpose and Scope

The OpenC2 Language Specification defines the set of components to assemble a complete command and control Message and provides a framework so that the language can be extended. To achieve this purpose, the scope of this specification includes:

  1. the set of Actions and options that may be used in Commands
  2. the set of Targets and Target Specifiers
  3. a syntax that defines the structure of Commands and Responses
  4. a JSON serialization of Commands and Responses
  5. the procedures for extending the language

The OpenC2 language assumes that the event has been detected, a decision to act has been made, the act is warranted, and the initiator and recipient of the Commands are authenticated and authorized. The OpenC2 language was designed to be agnostic of the other aspects of cyber defense implementations that realize these assumptions. The following items are beyond the scope of this specification:

  1. Language elements applicable to some Actuators, which may be defined in individual Actuator profiles.
  2. Alternate serializations of Commands and Responses.
  3. The enumeration of the protocols required for transport, information assurance, sensing, analytics and other external dependencies.

2 OpenC2 Language Description

The content in this section is non-normative.

The OpenC2 language has two distinct content types: Command and Response. The Command is sent from a Producer to a Consumer and describes an Action to be performed by an Actuator on a Target. The Response is sent from a Consumer, usually back to the Producer, and is a means to provide information (such as acknowledgment, status, etc.) as a result of a Command.

2.1 OpenC2 Command

The Command describes an Action to be performed on a Target and may include information identifying the Actuator or Actuators that are to execute the Command.

A Command has four main components, two required and two optional. The required components are the Action and the Target. The optional components are Command Arguments and the Actuator. A Command can also contain an optional Command identifier, if necessary. Section 3.3.1 defines the syntax of an OpenC2 Command.

The following list summarizes the main four components of a Command.

The Action and Target components are required and are populated by one of the Actions in Section 3.3.1.1 and the Targets in Section 3.3.1.2. A particular Target may be further refined by the Target type definitions in Section 3.4.1. Procedures to extend the Targets are described in Section 3.1.4.

Command Arguments, if present, influence the Command by providing information such as timing, periodicity, duration, or other details on what is to be executed. They can also be used to convey the need for acknowledgment or additional status information about the execution of a Command. The valid Arguments defined in this specification are in Section 3.3.1.4. Procedures to extend Arguments are described in Section 3.1.4.

An Actuator is an implementation of a cyber defense function that executes the Command. An Actuator Profile is a specification that identifies the subset of Actions, Targets and other aspects of this language specification that are required or optional in the context of a particular Actuator. An Actuator Profile may extend the language by defining additional Targets, Arguments, and Actuator Specifiers that are meaningful and possibly unique to the Actuator.

The Actuator may be omitted from a Command and typically will not be included in implementations where the identities of the endpoints are unambiguous or when a high-level effects-based Command is desired and the tactical decisions on how the effect is achieved is left to the recipient.

2.2 OpenC2 Response

The Response is a Message sent from the recipient of a Command. Response messages provide acknowledgment, status, results from a query, or other information. At a minimum, a Response will contain a status code to indicate the result of performing the Command. Additional status text and response fields optionally provide more detailed information that is specific to or requested by the Command. Section 3.3.2 defines the syntax of an OpenC2 Response.


3 OpenC2 Language Definition

The content in this section is normative.

3.1 Base Components and Structures

3.1.1 Data Types

OpenC2 data types are defined using an abstract notation that is independent of both their representation within applications ("API" values) and their format for transmission between applications ("serialized" values). The data types used in OpenC2 Messages are:

Type Description
Primitive Types
Any Anything, used to designate fields with an unspecified value.
Binary A sequence of octets. Length is the number of octets.
Boolean An element with one of two values: true and false.
Integer A whole number.
Number A real number.
Null Nothing, used to designate fields with no value.
String A sequence of characters, each of which has a Unicode codepoint. Length is the number of characters.
Structures
Array An ordered list of unnamed fields with positionally-defined semantics. Each field has a position, label, and type.
ArrayOf(vtype) An ordered list of fields with the same semantics. Each field has a position and type vtype.
Choice One field selected from a set of named fields. The API value has a name and a type.
Choice.ID One field selected from a set of fields. The API value has an id and a type.
Enumerated A set of named integral constants. The API value is a name.
Enumerated.ID A set of unnamed integral constants. The API value is an id.
Map An unordered map from a set of specified keys to values with semantics bound to each key. Each field has an id, name and type.
Map.ID An unordered set of fields. The API value of each field has an id, label, and type.
MapOf(ktype, vtype) An unordered set of keys to values with the same semantics. Each key has key type ktype and is mapped to value type vtype.
Record An ordered map from a list of keys with positions to values with positionally-defined semantics. Each key has a position and name, and is mapped to a type. Represents a row in a spreadsheet or database table.

Types defined with an ".ID" suffix (Choice.ID, Enumerated.ID, Map.ID) are equivalent to the non-suffixed types except:

  1. Field definitions and API values are identified only by ID. The non-normative description may include a suggested name.
  2. Serialized values of Enumerated types and keys of Choice/Map types are IDs regardless of serialization format.

OpenC2 type definitions are presented in table format. All table columns except Description are Normative. The Description column is always Non-normative.

For types without individual field definitions (Primitive types and ArrayOf), the type definition includes the name of the type being defined and the definition of that type. This table defines a type called Email-Addr that is a String that has a semantic value constraint of email:

Type Name Type Definition Description
Email-Addr String (email) Email address

For Structure types, the definition includes the name of the type being defined, the built-in type on which it is based, and options applicable to the type as a whole. This is followed by a table defining each of the fields in the structure. This table defines a type called Args that is a Map containing at least one field. Each of the fields has an integer Tag/ID, a Name, and a Type. Each field in this definition is optional (Multiplicity = 0..1), but per the type definition at least one must be present.

Type: Args (Map) [1..*]

ID Name Type # Description
1 start_time Date-Time 0..1 The specific date/time to initiate the action
2 stop_time Date-Time 0..1 The specific date/time to terminate the action
3 duration Duration 0..1 The length of time for an action to be in effect

The field columns present in a structure definition depends on the base type:

Base Type Field Definition Columns
Enumerated.ID ID, Description
Enumerated ID, Name, Description
Array, Choice.ID, Map.ID ID, Type, Multiplicity (#), Description
Choice, Map, Record ID, Name, Type, Multiplicity (#), Description

The ID column of Array and Record types contains the ordinal position of the field, numbered sequentially starting at 1. The ID column of Choice, Enumerated, and Map types contains tags with arbitrary integer values. IDs and Names are unique within each type definition.

3.1.2 Semantic Value Constraints

Structural validation alone may be insufficient to validate that an instance meets all the requirements of an application. Semantic validation keywords specify value constraints for which an authoritative definition exists.

Keyword Applies to Type Constraint
email String Value must be an email address as defined in [RFC5322], Section 3.4.1
eui Binary Value must be an EUI-48 or EUI-64 as defined in [EUI]
hostname String Value must be a hostname as defined in [RFC1034], Section 3.1
idn-email String Value must be an internationalized email address as defined in [RFC6531]
idn-hostname String Value must be an internationalized hostname as defined in [RFC5890], Section 2.3.2.3
iri String Value must be an Internationalized Resource Identifier (IRI) as defined in [RFC3987]
uri String Value must be a Uniform Resource Identifier (URI) as defined in [RFC3986]

3.1.3 Multiplicity

Property tables for types based on Array, Choice, Map and Record include a multiplicity column (#) that specifies the minimum and maximum cardinality (number of elements) of a field. As used in the Unified Modeling Language ([UML]), typical examples of multiplicity are:

Multiplicity Description Keywords
1 Exactly one instance Required
0..1 No instances or one instance Optional
1..* At least one instance Required, Repeatable
0..* Zero or more instances Optional, Repeatable
m..n At least m but no more than n instances Required, Repeatable

When used with a Type, multiplicity is enclosed in square brackets, e.g.,:

Type Name Base Type Description
Features ArrayOf(Feature) [0..10] An array of zero to ten names used to query an actuator for its supported capabilities.

A multiplicity of 0..1 denotes a single optional value of the specified type. A multiplicity of 0..n denotes a field that is either omitted or is an array containing one or more values of the specified type.

An array containing zero or more values of a specified type cannot be created implicitly using multiplicity, it must be defined explicitly as a named ArrayOf type. The named type can then be used as the type of a required field (multiplicity 1). Results are unspecified if an optional field (multiplicity 0..1) is a named ArrayOf type with a minimum length of zero.

3.1.4 Extensions

One of the main design goals of OpenC2 was extensibility. Actuator profiles define the language extensions that are meaningful and possibly unique to the Actuator.

Each Actuator profile has a unique name used to identify the profile document and a short reference called a namespace identifier (NSID). The NSID is used to separate extensions from the core language defined in this specification.

All extensions MUST be identified with a short namespace reference, called a namespace identifier (NSID).

For example, the OASIS standard Stateless Packet Filtering actuator profile has:

The namespace identifier for non-standard extensions MUST be prefixed with "x-".

For example, the fictional, non-standard Superwidget actuator profile has:

The list of Actions in Section 3.3.1.1 SHALL NOT be extended.

Targets, defined in Section 3.3.1.2, MAY be extended. Extended Target names MUST be prefixed with a namespace identifier followed by a colon (":").

Example: In this example Command, the extended Target, rule_number, is defined within the Stateless Packet Filtering Profile with the namespace identifier, slpf.

{
    "action": "delete",
    "target": {
        "slpf:rule_number": 1234
    }
}

Command Arguments, defined in Section 3.3.1.4, MAY be extended using the namespace identifier as the Argument name, called an extended Argument namespace. Extended Arguments MUST be defined within the extended Argument namespace.

Example: In this example Command, the extended Argument, direction, is defined within the Stateless Packet Filtering Profile namespace, slpf.

{
    "action": "deny",
    "target": {
        "ipv6_net": {...}
    },
    "args": {
        "slpf": {
            "direction": "ingress"
        }
    }
}

The Actuator property of a Command, defined in Section 3.3.1.3, MUST be extended using the namespace identifier as the Actuator name, called an extended Actuator namespace. Actuator Specifiers MUST be defined within the extended Actuator namespace.

Example: In this example Command, the Actuator Specifier asset_id is defined within the Stateless Packet Filtering Profile namespace, slpf.

{
    "action": "deny",
    "target": {
        "ipv4_connection": {...}
    },
    "actuator": {
        "slpf": {
            "asset_id": "30"
        }
    }
}

Response results, defined in Section TBD, MAY be extended using the namespace identifier as the results name, called an extended results namespace. Extended results MUST be defined within the extended results namespace.

Example: In this example Response, the Response results property, rule_number, is defined within the Stateless Packet Filtering Profile namespace, slpf.

{
    "status": 200,
    "results": {
        "slpf": {
            "rule_number": 1234
        }
    }
}

3.1.5 Serialization

OpenC2 is agnostic of any particular serialization; however, implementations MUST support JSON serialization in accordance with [RFC7493] and additional requirements specified in the following table.

JSON Serialization Requirements:

OpenC2 Data Type JSON Serialization Requirement
Binary JSON string containing Base64url encoding of the binary value as defined in [RFC4648], Section 5.
Binary /x JSON string containing Base16 (hex) encoding of a binary value as defined in [RFC4648], Section 8. Note that the Base16 alphabet does not include lower-case letters.
IPv4-Addr JSON string containing the "dotted-quad" representation of an IPv4 address as specified in [RFC2673], Section 3.2.
IPv6-Addr JSON string containing the text representation of an IPv6 address as specified in [RFC5952], Section 4.
MAC-Addr JSON string containing the text representation of a MAC Address in colon hexadecimal format as defined in [EUI].
Boolean JSON true or false
Integer JSON number
Number JSON number
Null JSON null
String JSON string
Array JSON array
Array /ipv4-net JSON string containing the text representation of an IPv4 address range as specified in [RFC4632], Section 3.1.
Array /ipv6-net JSON string containing the text representation of an IPv6 address range as specified in [RFC4291], Section 2.3.
ArrayOf JSON array
Choice JSON object with one member. Member key is the field name.
Choice.ID JSON object with one member. Member key is the integer field id converted to string.
Enumerated JSON string
Enumerated.ID JSON integer
Map JSON object. Member keys are field names.
Map.ID JSON object. Member keys are integer field ids converted to strings.
MapOf JSON object. Member keys are as defined in the specified key type.
Record JSON object. Member keys are field names.

3.1.5.1 ID and Name Serialization

Instances of Enumerated types and keys for Choice and Map types are serialized as ID values except when using serialization formats intended for human consumption, where Name strings are used instead. Defining a type using ".ID" appended to the base type (e.g., Enumerated.ID, Map.ID) indicates that:

  1. Type definitions and application values use only the ID. There is no corresponding name except as an optional part of the description.
  2. Instances of Enumerated values and Choice/Map keys are serialized as IDs regardless of serialization format.

3.2 Message

This language specification and one or more Actuator profiles define the content of Commands and Responses, while transfer specifications define the on-the-wire format of a Message over specific secure transport protocols. Transfer specifications are agnostic with regard to content, and content is agnostic with regard to transfer protocol. This decoupling is accomplished by defining a standard message interface used to transfer any type of content over any transfer protocol.

A message is a content- and transport-independent set of elements conveyed between Producers and Consumers. To ensure interoperability all transfer specifications must unambiguously define how the Message elements in Table 3-1 are represented within the secure transport protocol. This does not imply that all Message elements must be used in all Messages. Content, content_type, and msg_type are required in all Messages. Other Message elements are not required by this specification but may be required by other specifications. The internal representation of a Message does not affect interoperability and is therefore beyond the scope of OpenC2.

Table 3-1. Common Message Elements
Name Type Description
content Message body as specified by content_type and msg_type.
content_type String Media Type that identifies the format of the content, including major version. Incompatible content formats must have different content_types. Content_type application/openc2 identifies content defined by OpenC2 language specification versions 1.x, i.e., all versions that are compatible with version 1.0.
msg_type Message-Type The type of OpenC2 Message.
status Status-Code Populated with a numeric status code in Responses.
request_id String A unique identifier created by the Producer and copied by Consumer into all Responses, in order to support reference to a particular Command, transaction, or event chain.
created Date-Time Creation date/time of the content.
from String Authenticated identifier of the creator of or authority for execution of a message.
to ArrayOf(String) Authenticated identifier(s) of the authorized recipient(s) of a message.

Usage Requirements:

3.3 Content

The purpose of this specification is to define the Action and Target portions of a Command and the common portions of a Response. The properties of the Command are defined in Section 3.3.1 and the properties of the Response are defined in Section 3.3.2.

In addition to the Action and Target, a Command has an optional Actuator. Other than identification of namespace identifier, the semantics associated with the Actuator Specifiers are defined in Actuator Profiles. The Actuators and Actuator-specific results contained in a Response are specified in 'Actuator Profile Specifications' such as StateLess Packet Filtering Profile, Routing Profile etc.

3.3.1 OpenC2 Command

The Command defines an Action to be performed on a Target.

Type: OpenC2-Command (Record)

ID Name Type # Description
1 action Action 1 The task or activity to be performed (i.e., the 'verb').
2 target Target 1 The object of the Action. The Action is performed on the Target.
3 args Args 0..1 Additional information that applies to the Command.
4 actuator Actuator 0..1 The subject of the Action. The Actuator executes the Action on the Target.
5 command_id String 0..1 An identifier of this Command.

Usage Requirements:

3.3.1.1 Action

Type: Action (Enumerated)

ID Name Description
1 scan Systematic examination of some aspect of the entity or its environment.
2 locate Find an object physically, logically, functionally, or by organization.
3 query Initiate a request for information.
6 deny Prevent a certain event or action from completion, such as preventing a flow from reaching a destination or preventing access.
7 contain Isolate a file, process, or entity so that it cannot modify or access assets or processes.
8 allow Permit access to or execution of a Target.
9 start Initiate a process, application, system, or activity.
10 stop Halt a system or end an activity.
11 restart Stop then start a system or an activity.
14 cancel Invalidate a previously issued Action.
15 set Change a value, configuration, or state of a managed entity.
16 update Instruct a component to retrieve, install, process, and operate in accordance with a software update, reconfiguration, or other update.
18 redirect Change the flow of traffic to a destination other than its original destination.
19 create Add a new entity of a known type (e.g., data, files, directories).
20 delete Remove an entity (e.g., data, files, flows).
22 detonate Execute and observe the behavior of a Target (e.g., file, hyperlink) in an isolated environment.
23 restore Return a system to a previously known state.
28 copy Duplicate an object, file, data flow, or artifact.
30 investigate Task the recipient to aggregate and report information as it pertains to a security event or incident.
32 remediate Task the recipient to eliminate a vulnerability or attack point.

Usage Requirements:

3.3.1.2 Target

Type: Target (Choice)

ID Name Type # Description
1 artifact Artifact 1 An array of bytes representing a file-like object or a link to that object.
2 command String 1 A reference to a previously issued Command.
3 device Device 1 The properties of a hardware device.
7 domain_name Domain-Name 1 A network domain name.
8 email_addr Email-Addr 1 A single email address.
9 features Features 1 A set of items used with the query Action to determine an Actuator's capabilities.
10 file File 1 Properties of a file.
11 idn_domain_name IDN-Domain-Name 1 An internationalized domain name.
12 idn_email_addr IDN-Email-Addr 1 A single internationalized email address.
13 ipv4_net IPv4-Net 1 An IPv4 address range including CIDR prefix length.
14 ipv6_net IPv6-Net 1 An IPv6 address range including prefix length.
15 ipv4_connection IPv4-Connection 1 A 5-tuple of source and destination IPv4 address ranges, source and destination ports, and protocol
16 ipv6_connection IPv6-Connection 1 A 5-tuple of source and destination IPv6 address ranges, source and destination ports, and protocol
20 iri IRI 1 An internationalized resource identifier (IRI).
17 mac_addr MAC-Addr 1 A Media Access Control (MAC) address - EUI-48 or EUI-64 as defined in [EUI]
18 process Process 1 Common properties of an instance of a computer program as executed on an operating system.
25 properties Properties 1 Data attribute associated with an Actuator
19 uri URI 1 A uniform resource identifier (URI).

Usage Requirements:

3.3.1.3 Actuator

Type: Actuator (Choice)

ID Name Type # Description
1024 slpf slpf:Actuator 1 Example: Actuator Specifiers defined in the Stateless Packet Filtering Profile

3.3.1.4 Command Arguments

Type: Args (Map)

ID Name Type # Description
1 start_time Date-Time 0..1 The specific date/time to initiate the Command
2 stop_time Date-Time 0..1 The specific date/time to terminate the Command
3 duration Duration 0..1 The length of time for an Command to be in effect
4 response_requested Response-Type 0..1 The type of Response required for the Command: none, ack, status, complete.

Usage Requirements:

3.3.2 OpenC2 Response

Type: OpenC2-Response (Map)

ID Name Type # Description
1 status Status-Code 1 An integer status code
2 status_text String 0..1 A free-form human-readable description of the Response status
3 results Results 0..1 Map of key:value pairs that contain additional results based on the invoking Command.

Example:

{
    "status": 200,
    "results": {
        "versions": ["1.0"]
    }
}

Usage Requirements:

3.3.2.1 Response Status Code

Type: Status-Code (Enumerated.ID)

ID Description
102 Processing - an interim Response used to inform the Producer that the Consumer has accepted the Command but has not yet completed it.
200 OK - the Command has succeeded.
400 Bad Request - the Consumer cannot process the Command due to something that is perceived to be a Producer error (e.g., malformed Command syntax).
401 Unauthorized - the Command Message lacks valid authentication credentials for the target resource or authorization has been refused for the submitted credentials.
403 Forbidden - the Consumer understood the Command but refuses to authorize it.
404 Not Found - the Consumer has not found anything matching the Command.
500 Internal Error - the Consumer encountered an unexpected condition that prevented it from performing the Command.
501 Not Implemented - the Consumer does not support the functionality required to perform the Command.
503 Service Unavailable - the Consumer is currently unable to perform the Command due to a temporary overloading or maintenance of the Consumer.

3.3.2.2 Response Results

Type: Results (Map [1..*])

ID Name Type # Description
1 versions Version 0..* List of OpenC2 language versions supported by this Actuator
2 profiles ArrayOf(Nsid) 0..1 List of profiles supported by this Actuator
3 pairs Action-Targets 0..* List of targets applicable to each supported Action
4 rate_limit Number 0..1 Maximum number of requests per minute supported by design or policy
1024 slpf slpf:Results 0..1 Example: Result properties defined in the Stateless Packet Filtering Profile

3.4 Type Definitions

3.4.1 Target Types

3.4.1.1 Artifact

Type: Artifact (Record) [1..*]

ID Name Type # Description
1 mime_type String 0..1 Permitted values specified in the IANA Media Types registry, [RFC6838]
2 payload Payload 0..1 Choice of literal content or URL
3 hashes Hashes 0..1 Hashes of the payload content

Usage Requirement:

3.4.1.2 Device

Type: Device (Map) [0..*]

ID Name Type # Description
1 hostname Hostname 0..1 A hostname that can be used to connect to this device over a network
2 idn_hostname IDN-Hostname 0..1 An internationalized hostname that can be used to connect to this device over a network
3 device_id String 0..1 An identifier that refers to this device within an inventory or management system

Usage Requirement:

3.4.1.3 Domain Name

Type Name Type Definition Description
Domain-Name String (hostname) [RFC1034], Section 3.5

3.4.1.4 Email Address

Type Name Type Definition Description
Email-Addr String (email) Email address, [RFC5322], Section 3.4.1

3.4.1.5 Features

Type Name Type Definition Description
Features ArrayOf(Feature) [0..10] An array of zero to ten names used to query an Actuator for its supported capabilities.

Usage Requirements:

3.4.1.6 File

Type: File (Map) [0..*]

ID Name Type # Description
1 name String 0..1 The name of the file as defined in the file system
2 path String 0..1 The absolute path to the location of the file in the file system
3 hashes Hashes 0..1 One or more cryptographic hash codes of the file contents

Usage Requirement:

3.4.1.7 Internationalized Domain Name

Type Name Type Definition Description
IDN-Domain-Name String (idn-hostname) Internationalized Domain Name, [RFC5890], Section 2.3.2.3.

3.4.1.8 Internationalized Email Address

Type Name Type Definition Description
IDN-Email-Addr String (idn-email) Internationalized email address, [RFC6531]

3.4.1.9 IPv4 Address Range

An IPv4 address range is a CIDR block per "Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan" [RFC4632] and consists of two values, an IPv4 address and a prefix.

For example, "192.168.17.0/24" is range of IP addresses with a prefix of 24 (i.e. 192.168.17.0 - 192.168.17.255).

JSON serialization of an IPv4 address range SHALL use the 'dotted/slash' textual representation of [RFC4632].

CBOR serialization of an IPv4 address range SHALL use a binary representation of the IP address and the prefix, each in their own field.

Type: IPv4-Net (Array /ipv4-net)

ID Type # Description
1 IPv4-Addr 1 IPv4 address as defined in [RFC0791]
2 Integer 0..1 CIDR prefix-length. If omitted, refers to a single host address.

3.4.1.10 IPv4 Connection

Type: IPv4-Connection (Record) [0..*]

ID Name Type # Description
1 src_addr IPv4-Net 0..1 IPv4 source address range
2 src_port Port 0..1 source service per [RFC6335]
3 dst_addr IPv4-Net 0..1 IPv4 destination address range
4 dst_port Port 0..1 destination service per [RFC6335]
5 protocol L4-Protocol 0..1 layer 4 protocol (e.g., TCP) - see Section 3.4.2.10

Usage Requirement:

3.4.1.11 IPv6 Address Range

Type: IPv6-Net (Array /ipv6-net)

ID Type # Description
1 IPv6-Addr 1 IPv6 address as defined in [RFC8200]
2 Integer 0..1 prefix-length. If omitted, refers to a single host address.

3.4.1.12 IPv6 Connection

Type: IPv6-Connection (Record) [0..*]

ID Name Type # Description
1 src_addr IPv6-Net 0..1 IPv6 source address range
2 src_port Port 0..1 source service per [RFC6335]
3 dst_addr IPv6-Net 0..1 IPv6 destination address range
4 dst_port Port 0..1 destination service per [RFC6335]
5 protocol L4-Protocol 0..1 layer 4 protocol (e.g., TCP) - Section 3.4.2.10

Usage Requirement:

3.4.1.13 IRI

Type Name Type Definition Description
IRI String (iri) Internationalized Resource Identifier, [RFC3987].

3.4.1.14 MAC Address

Type Name Type Definition Description
MAC-Addr Binary (eui) Media Access Control / Extended Unique Identifier address - EUI-48 or EUI-64 as defined in [EUI].

3.4.1.15 Process

Type: Process (Map) [0..*]

ID Name Type # Description
1 pid Integer 0..1 Process ID of the process
2 name String 0..1 Name of the process
3 cwd String 0..1 Current working directory of the process
4 executable File 0..1 Executable that was executed to start the process
5 parent Process 0..1 Process that spawned this one
6 command_line String 0..1 The full command line invocation used to start this process, including all arguments

Usage Requirement:

3.4.1.16 Properties

Type Name Type Definition Description
Properties ArrayOf(String) A list of names that uniquely identify properties of an Actuator.

3.4.1.17 URI

Type Name Type Definition Description
URI String (uri) Uniform Resource Identifier, [RFC3986].

3.4.2 Data Types

3.4.2.1 Action-Targets

Type Name Type Definition Description
Action-Targets MapOf(Action, Targets) Map of each action supported by this actuator to the list of targets applicable to that action.
Type Name Type Definition Description
Targets ArrayOf(Target.Enum) [1..*] List of Target fields

3.4.2.2 Date-Time

Type Name Type Definition Description
Date-Time Integer Date and Time

Usage Requirements:

3.4.2.3 Duration

Type Name Type Definition Description
Duration Integer A length of time

Usage Requirements:

3.4.2.4 Feature

Specifies the results to be returned from a query features Command.

Type: Feature (Enumerated)

ID Name Description
1 versions List of OpenC2 Language versions supported by this Actuator
2 profiles List of profiles supported by this Actuator
3 pairs List of supported Actions and applicable Targets
4 rate_limit Maximum number of Commands per minute supported by design or policy

3.4.2.5 Hashes

Type: Hashes (Map) [0..*]

ID Name Type # Description
1 md5 Binary /x 0..1 MD5 hash as defined in [RFC1321]
2 sha1 Binary /x 0..1 SHA1 hash as defined in [RFC6234]
3 sha256 Binary /x 0..1 SHA256 hash as defined in [RFC6234]

Usage Requirement:

3.4.2.6 Hostname

Type Name Type Definition Description
Hostname String (hostname) Internet host name as specified in [RFC1123]

3.4.2.7 Internationalized Hostname

Type Name Type Definition Description
IDN-Hostname String (idn-hostname) Internationalized Internet host name as specified in [RFC5890], Section 2.3.2.3.

3.4.2.8 IPv4 Address

Type Name Base Type Description
IPv4-Addr Binary /ipv4-addr 32 bit IPv4 address as defined in [RFC0791]

3.4.2.9 IPv6 Address

Type Name Base Type Description
IPv6-Addr Binary /ipv6-addr 128 bit IPv6 address as defined in [RFC8200]

3.4.2.10 L4 Protocol

Value of the protocol (IPv4) or next header (IPv6) field in an IP packet. Any IANA value, [RFC5237]

Type: L4-Protocol (Enumerated)

ID Name Description
1 icmp Internet Control Message Protocol - [RFC0792]
6 tcp Transmission Control Protocol - [RFC0793]
17 udp User Datagram Protocol - [RFC0768]
132 sctp Stream Control Transmission Protocol - [RFC4960]

3.4.2.11 Message-Type

Identifies the type of Message.

Type: Message-Type (Enumerated)

ID Name Description
1 command The Message content is an OpenC2 Command
2 response The Message content is an OpenC2 Response

3.4.2.12 Namespace Identifier

Type Name Base Type Description
Nsid String [1..16] A short identifier that refers to a namespace.

3.4.2.13 Payload

Type: Payload (Choice)

ID Name Type # Description
1 bin Binary 1 Specifies the data contained in the artifact
2 url URI 1 MUST be a valid URL that resolves to the un-encoded content

3.4.2.14 Port

Type Name Type Definition Description
Port Integer [0..65535] Transport Protocol Port Number, [RFC6335]

3.4.2.15 Response-Type

Type: Response-Type (Enumerated)

ID Name Description
0 none No response
1 ack Respond when Command received
2 status Respond with progress toward Command completion
3 complete Respond when all aspects of Command completed

3.4.2.16 Version

Type Name Type Definition Description
Version String Major.Minor version number

4 Mandatory Commands/Responses

The content in this section is normative, except where it is marked non-normative.

A Command consists of an Action/Target pair and associated Specifiers and Arguments. This section enumerates the allowed Commands, identifies which are required or optional to implement, and presents the associated responses.

4.1 Implementation of 'query features' Command

The 'query features' Command is REQUIRED for all Producers and Consumers implementing OpenC2. This section defines the REQUIRED and OPTIONAL aspects of the 'query features' Command and associated response for Producers and Consumers.

The 'query features' Command is REQUIRED for all Producers. The 'query features' Command MAY include one or more Features as defined in Section 3.4.2.4. The 'query features' Command MAY include the "response_requested": "complete" Argument. The 'query features' Command MUST NOT include any other Argument.

The 'query features' Command is REQUIRED for all Consumers. Consumers that receive and parse the 'query features':

4.2 Examples of 'query features' Commands and Responses

This section is non-normative.

This sub-section provides examples of 'query features' Commands and Responses. The examples provided in this section are for illustrative purposes only and are not to be interpreted as operational examples for actual systems.

4.2.1 Example 1

There are no features specified in the 'query features' Command. A simple "OK" Response Message is returned.

Command:

{
    "action": "query",
    "target": {
        "features": []
    }
}

Response:

{
    "status": 200
}

4.2.2 Example 2

There are several features requested in the 'query features' Command. All requested features can be returned in a single Response Message.

Command:

{
    "action": "query",
    "target": {
        "features": ["versions", "profiles", "rate_limit"]
    }
}

Response:

{
    "status": 200,
    "results": {
        "versions": ["1.0"],
        "profiles": ["slpf", "x-lock"],
        "rate_limit": 30
    }
}

5 Conformance

This content in this section is normative.

5.1 Conformance Clause 1: Command

A conformant Command

5.2 Conformance Clause 2: Response

A conformant Response

5.3 Conformance Clause 3: Producer

A conformant Producer

5.4 Conformance Clause 4: Consumer

A conformant Consumer


Annex A. Examples

The content in this section is non-normative.

A.1 Example 1

This Command would be used to quarantine a device on the network.

{
    "action": "contain",
    "target": {
        "device": {
            "device_id": "9BCE8431AC106FAA3861C7E771D20E53"
        }
    }
}

A.2 Example 2

This Command blocks a particular connection within the domain. The standard Actuator profile defines the extended Command Argument, drop_process, and the Actuator Specifier, asset_id. The Response is a simple acknowledgment that was requested in the Command.

Command:

{
    "action": "deny",
    "target": {
        "ipv4_connection": {
            "protocol": "tcp",
            "src_addr": "1.2.3.4",
            "src_port": 10996,
            "dst_addr": "198.2.3.4",
            "dst_port": 80
        }
    },
    "args": {
        "start_time": 1534775460000,
        "duration": 500,
        "response_requested": "ack",
        "slpf": {
            "drop_process": "none"
        }
    },
    "actuator": {
        "slpf": {
            "asset_id": "30"
        }
    }
}

Response:

{
    "status": 102
}

A.3 Example 3

This is a notional example of a Command issued to a non-standard Actuator. A Producer sends a 'query properties' Command to request detail about a 'battery'. The Consumer responses with the battery information extended in the results of the Response.

Command:

{
    "action": "query",
    "target": {
        "properties": ["battery"]
    },
    "actuator": {
        "x-esm": {
            "asset_id": "TGEadsasd"
        }
    }
}

Response:

{
    "status": 200,
    "results": {
        "x-esm": {
            "battery": {
                "capacity": 0.577216,
                "charged_at": 1547506988,
                "status": 12,
                "mode": {
                    "output": "high",
                    "supported": [ "high", "trickle" ]
                },
                "visible_on_display": true
            },
            "asset_id": "TGEadsasd"
        }
    }
}

Annex B. Acronyms

Acronym Definition
API Application Programming Interface
ASCII American Standard Code for Information Interchange
BCP Best Current Practice
CBOR Concise Binary Object Representation
CIDR Classless Inter-Domain Routing
CoAP Constrained Application Protocol
DOI Digital Object Identifier
EUI Extended Unique Identifier
HTTP Hyper Text Transfer Protocol
HTTPS Hyper Text Transfer Protocol Secure
IACD Integrated Adaptive Cyber Defense
IANA Internet Assigned Numbers Authority
ICMP Internet Control Message Protocol
ID Identifier
IP Internet Protocol
IPR Intellectual Property Rights
JSON JavaScript Object Notation
MAC Media Access Control
MD5 Message Digest
MQTT Message Queuing Telemetry Transfer
OASIS Organization for the Advancement of Structured Information Standards
OODA Observe-Orient-Decide-Act
OpenC2 Open Command and Control
OpenDXL Open Data eXchange Layer
PDF Portable Document Format
RFC Request for Comment
SCTP Stream Control Transmission Protocol
SHA Security Hash Algorithm
SLPF StateLess Packet Filtering
STD Standard
TC Technical Committee
TCP Transmission Control Protocol
UDP User Datagram Control Protocol
UML Unified Modeling Language
URI Uniform Resource Identifier
UTC Coordinated Universal Time
UUID Universally Unique IDentifier
XML eXtensibel Markup Language

Annex C. Design Elements

C.1 Derived Enumerations

It is sometimes useful to reference the fields of a structure definition, for example to list fields that are usable in a particular context, or to read or update the value of a specific field. An instance of a reference can be validated against the set of valid references using either an explicit or a derived Enumerated type. A derived enumeration is created by appending ".Enum" to the type being referenced, and it results in an Enumerated type containing the ID and Name columns of the referenced type.

This is the design element that defines the "Action-Targets" data type. The "Action-Targets" data type is a map of each action supported by an actuator to a list of targets implemented for each action. The list of Actions, defined in Section 3.3.1.1, is appropriately an enumerated list of possible Actions. The list of Targets, defined in Section 3.3.1.2, is a Choice data structure where each element is a complex data type of its own. A derived enumeration is used in this case to signify that the list of Targets for the "Action-Targets" data type should be an enumerated list of the possible Targets

Definition of "Action-Targets" Data Type: The Targets data type is defined as an array of "Target" enumerations. The "Target" enumerations are derived from the "Target" data type.

Type Name Type Definition Description
Action-Targets MapOf(Action, Targets) Map of each action supported by this actuator to the list of targets applicable to that action.
Type Name Type Definition Description
Targets ArrayOf(Target.Enum) [1..*] List of Target fields

Example: The "pairs" property is defined as an "Action-Targets" data type.

{
    "status": 200,
    "results": {
        "pairs": {
            "allow": ["ipv6_net", "ipv6_connection"],
            "deny": ["ipv6_net", "ipv6_connection"],
            "query": ["features"],
            "delete": ["slpf:rule_number"],
            "update": ["file"]
        }
    }
}

Annex D. Revision History

The content in this section is non-normative.

Revision Date Editor Changes Made
v1.0-wd01 10/31/2017 Romano, Sparrell Initial working draft
v1.0-csd01 11/14/2017 Romano, Sparrell approved wd01
v1.0-wd02 01/12/2018 Romano, Sparrell csd01 ballot comments
Targets
v1.0-wd03 01/31/2018 Romano, Sparrell wd02 review comments
v1.0-csd02 02/14/2018 Romano, Sparrell approved wd03
v1.0-wd04 03/02/2018 Romano, Sparrell Property tables
threads (cmd/resp) from use cases
previous comments
v1.0-wd05 03/21/2018 Romano, Sparrell wd04 review comments
v1.0-csd03 04/03/2018 Romano, Sparrell approved wd05
v1.0-wd06 05/15/2018 Romano, Sparrell Finalizing message structure
message=header+body
Review comments
Using word 'arguments' instead of 'options'
v1.0-csd04 5/31/2018 Romano, Sparrell approved wd06
v1.0-wd07 7/11/2018 Romano, Sparrell Continued refinement of details
Review comments
Moved some Actions and Targets to reserved lists
v1.0-wd08 10/05/2018 Romano, Sparrell Continued refinement of details
Review comments
v1.0-wd09 10/17/2018 Romano, Sparrell Additional review comments to create wd09 for CSD approval and release for public review.
v1.0-wd10 03/04/2019 Romano, Sparrell Produce interim working draft.
v1.0-wd11 03/21/2019 Romano, Sparrell Produce interim working draft.
v1.0-wd12 03/27/2019 Romano, Sparrell Produce candidate working draft for next public review.
v1.0-wd13 05/14/2019 Romano, Sparrell Incorporated comments from CSPRD02.
v1.0-wd14 05/23/2019 Romano, Sparrell Incorporated comments from WD13 ballot.

Annex E. Acknowledgments

The content in this section is non-normative.

The following individuals have participated in the creation of this specification and are gratefully acknowledged:

OpenC2 TC Members:

First Name Last Name Company
Philippe Alcoy Arbor Networks
Darren Anstee Arbor Networks
Michelle Barry AT&T
Brian Berliner Symantec Corp.
Adam Bradbury EclecticIQ
Joe Brule National Security Agency
Michael Butt NC4
Toby Considine University of North Carolina at Chapel Hill
Trey Darley New Context Services Inc.
David Darnell North American Energy Standards Board
Sudeep Das McAfee
Andrea De Bernardi Moviri SPA
Blake Essing AT&T
Alex Everett University of North Carolina at Chapel Hill
Joyce Fai National Security Agency
Travis Farral Anomali
David Girard Trend Micro
Andy Gray ForeScout
John-Mark Gurney New Context Services Inc.
Stefan Hagen Individual
David Hamilton AT&T
Nick Humphrey Huntsman Security
Christian Hunt New Context Services Inc.
April Jackson G2
Sridhar Jayanthi Individual
Bret Jordan Symantec Corp.
Jason Keirstead IBM
David Kemp National Security Agency
David Lemire G2
Jason Liu Northrop Grumman
Radu Marian Bank of America
Danny Martinez G2
Lisa Mathews National Security Agency
James Meck FireEye Inc.
Efrain Ortiz Symantec Corp.
Paul Patrick FireEye Inc.
Michael Pepin NC4
Nirmal Rajarathnam ForeScout
Chris Ricard Financial Services Information Sharing and Analysis Center (FS-ISAC)
Daniel Riedel New Context Services Inc.
Jason Romano National Security Agency
Philip Royer Splunk Inc.
Thomas Schreck Siemens AG
Duane Skeen Northrop Grumman
Duncan Sparrell sFractal Consulting LLC
Michael Stair AT&T
Andrew Storms New Context Services Inc.
Gerald Stueve Fornetix
Rodney Sullivan NCI Agency
Allan Thomson LookingGlass
Bill Trost AT&T
Raymon van der Velde EclecticIQ
Jyoti Verma Cisco Systems
David Waltermire NIST
Jason Webb LookingGlass
Sean Welsh AT&T
Charles White Fornetix
Sounil Yu Bank of America