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Specification for Transfer of OpenC2 Messages via HTTPS Version 1.0

Committee Specification Draft 04 /
Public Review Draft 02

04 April 2019

This Version:

https://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd02/open-impl-https-v1.0-csprd02.md (Authoritative)
https://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd02/open-impl-https-v1.0-csprd02.html
https://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd02/open-impl-https-v1.0-csprd02.pdf

Previous Version:

http://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd01/open-impl-https-v1.0-csprd01.md (Authoritative)
http://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd01/open-impl-https-v1.0-csprd01.html
http://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd01/open-impl-https-v1.0-csprd01.pdf

Latest Version:

https://docs.oasis-open.org/openc2/open-impl-https/v1.0/open-impl-https-v1.0.md (Authoritative)
https://docs.oasis-open.org/openc2/open-impl-https/v1.0/open-impl-https-v1.0.html
https://docs.oasis-open.org/openc2/open-impl-https/v1.0/open-impl-https-v1.0.pdf

Technical Committee:

OASIS Open Command and Control (OpenC2) TC

Chairs:

Joe Brule (jmbrule@nsa.gov), National Security Agency
Sounil Yu (sounil.yu@bankofamerica.com), Bank of America

Editor:

David Lemire (dave.lemire@g2-inc.com), G2, Inc.

This specification is related to:

Abstract:

Open Command and Control (OpenC2) is a concise and extensible language to enable the 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. HTTP over TLS is a widely deployed transfer protocol that provides an authenticated, ordered, lossless delivery of uniquely-identified messages. This document specifies the use of HTTP over TLS as a transfer mechanism for OpenC2 Messages.

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-HTTPS-v1.0]

Specification for Transfer of OpenC2 Messages via HTTPS Version 1.0. Edited by David Lemire. 04 April 2019. OASIS Committee Specification Draft 04 / Public Review Draft 02. https://docs.oasis-open.org/openc2/open-impl-https/v1.0/csprd02/open-impl-https-v1.0-csprd02.html. Latest version: https://docs.oasis-open.org/openc2/open-impl-https/v1.0/open-impl-https-v1.0.html.


Notices

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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 an OpenC2 Producer (managing application) and transferred to an OpenC2 Consumer (managed device or virtualized function) using a secure transport 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 [BCP 14, RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

A list of acronyms is provided in Annex A.

1.3 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, <http://www.rfc-editor.org/info/rfc2119>.

[RFC2818]

Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/RFC2818, May 2000, <https://www.rfc-editor.org/info/rfc2818>.

[RFC5246]

Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, <https://www.rfc-editor.org/info/rfc5246>.

[RFC7230]

Fielding, R., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing", RFC 7230, DOI 10.17487/RFC7230, June 2014, https://www.rfc-editor.org/info/rfc7230.

[RFC7231]

Fielding, R., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content", RFC 7231, DOI 10.17487/RFC7231, June 2014, https://www.rfc-editor.org/info/rfc7231.

[RFC7235]

Fielding, R., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Authentication", RFC 7235, DOI 10.17487/RFC7235, June 2014, https://www.rfc-editor.org/info/rfc7235.

[RFC7540]

Belshe, M., Peon, R., and Thompson, M., "Hypertext Transfer Protocol Version 2 (HTTP/2)", RFC 7540, DOI 10.17487/RFC7540, May 2015, <https://www.rfc-editor.org/info/rfc7540>.

[RFC8174]

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

[RFC8446]

Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, <http://www.rfc-editor.org/info/rfc8446>

[OpenC2-Lang-v1.0]

Open Command and Control (OpenC2) Language Specification Version 1.0. Edited by Jason Romano and Duncan Sparrell. Latest version: http://docs.oasis-open.org/openc2/oc2ls/v1.0/oc2ls-v1.0.html.

1.4 Non-Normative References

[RFC3205]

Moore, K., "On the use of HTTP as a Substrate", BCP 56, RFC 3205, DOI 10.17487/RFC3205, February 2002, https://www.rfc-editor.org/info/rfc3205.

[RFC7525]

Sheffer, Y., Holz, R., and P. Saint-Andre, "Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May 2015, https://www.rfc-editor.org/info/rfc7525.

[RFC8259]

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

[SLPF]

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

[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.
Willett, Keith D., "Integrated Adaptive Cyberspace Defense: Secure Orchestration", International Command and Control Research and Technology Symposium, June 2015.

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:

HTTP/1.1 200 OK
Date: Wed, 19 Dec 2018 22:15:00 GMT
Content-type: application/openc2-cmd+json;version=1.0
X-Request-ID: id_1234
{   
    "action": "contain",
    "target": {
        "user_account": {
            "user_id": "fjbloggs",
            "account_type": "windows-local"
        }
    }
}

1.6 Overview

OpenC2 is a suite of specifications to command actuators that 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.
In general, there are two types of participants involved in the exchange of OpenC2 Messages, as depicted in Figure 1-1:

  1. OpenC2 Producers: An OpenC2 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. An OpenC2 Producer may receive and process Responses in conjunction with a Command.
  2. OpenC2 Consumers: An OpenC2 Consumer is an entity that receives and may act upon an OpenC2 Command. An OpenC2 Consumer may create Responses that provide any information captured or necessary to send back to the OpenC2 Producer.

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 OpenC2 "Producer", to one or more systems, the OpenC2 "Consumer(s)", to act on the content of the Command.
  2. Response: Any information sent back to the OpenC2 Producer as a result of the Command.

Figure 1-1. OpenC2 Message Exchange

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).

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
(standard and extensions)
Common Content OpenC2 Language Specification
Message Transfer Specifications
(OpenC2-over-HTTPS, OpenC2-over-CoAP, …)
Secure Transport HTTPS, CoAP, MQTT, OpenDXL, ...

The components of an OpenC2 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 OpenC2 Command. Though optional, the inclusion of an actuator and/or command arguments provides additional precision to a command, when needed.

The components of an OpenC2 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 guides the design of OpenC2:

1.8 Suitability

This document specifies the use of Hypertext Transfer Protocol (HTTP) over Transport Layer Security (TLS) as a transfer mechanism for OpenC2 Messages; this HTTP/TLS layering is typically referred to as HTTPS [RFC2818]. As described in [RFC3205], HTTP has become a common "substrate" for information transfer for other application-level protocols. The broad availability of HTTP makes it a useful option for OpenC2 Message transport in support of prototyping, interoperability testing, and for operational use in environments where appropriate security protections can be provided. Similarly, TLS is a mature and widely-used protocol for securing information transfers in TCP/IP network environments. This specification provides guidance to the OpenC2 implementation community when utilizing HTTPS for OpenC2 Message transport. It includes guidance for selection of TLS versions and options suitable for use with OpenC2.

This OpenC2 over HTTPS transfer specification is suitable for operational environments where:

An additional application for this transfer specification is interoperability test environments.


2 Operating Model

This section is non-normative.

This section describes the operating model used when transferring OpenC2 Commands and Responses using HTTPS.

Each endpoint of an OpenC2-over-HTTPS interaction has both an OpenC2 role and an HTTP function. OpenC2 Consumers will be HTTP listeners so that they can accept connections and receive unsolicited Commands from OpenC2 Producers. OpenC2 Producers act as 'HTTP clients' and transmit Commands to Consumers.

Figure 2 illustrates the Producer / Consumer interactions. A Producer that needs to send OpenC2 Commands initiates a TCP connection to the Consumer. Once the TCP connection is created, a TLS session is initiated to authenticate the endpoints and provide connection confidentiality. The Producer can then issue OpenC2 Commands by sending HTTP requests using the POST method, with Consumer OpenC2 Responses returned in the HTTP response.

Figure 2 -- OpenC2 Producer / Consumer Interactions


3 Protocol Mappings

The section defines the requirements for using HTTP and TLS with OpenC2, including general requirements and protocol mappings for the operating configuration described in Section 2.

3.1 Layering Overview

When using HTTPS for OpenC2 Message transfer, the layering model is:

Layer Description
OpenC2 Content The OpenC2 Language Specification defines the overall OpenC2 language, and the Actuator Profile(s) implemented by any particular endpoint scopes the OpenC2 actions, targets, arguments, and specifiers that apply when commanding that type of Actuator.
Serialization Serialization converts internal representations of OpenC2 content into a form that can be transmitted and received. The OpenC2 default serialization is JSON.
Message The message layer provides a content- and transport-independent mechanism for conveying requests and responses. A Message consists of content plus a set of meta items such as content type and version, sender, timestamp, and correlation id. This layer maps the transport-independent definition of each message element to its transport-specific on-the-wire representation.
HTTP The HTTP layer is responsible for conveying request and response Messages, as described in this specification.
TLS The TLS layer is responsible for authentication of connection endpoints and confidentiality and integrity of transferred Messages.
Lower Layer Transport The lower protocol layers are responsible for end-to-end delivery of Messages. TCP/IP is the most common suite of lower layer protocols used with HTTPS.

3.2 General Requirements

This section defines serialization, HTTP, and TLS requirements.

3.2.1 Serialization and Content Types

While the OpenC2 language is agnostic of serialization, when transferring OpenC2 Messages over HTTP/TLS as described in this specification, the default JSON serialization described in [OpenC2-Lang-v1.0] MUST be supported.

As described in [OpenC2-Lang-v1.0], transfer protocols must convey message elements. Two content types are defined here to support that requirement:

When OpenC2 Command Messages sent over HTTPS use the default JSON serialization the message MUST specify the content type "application/openc2-cmd+json;version=1.0".

When OpenC2 Response Messages sent over HTTPS use the default JSON serialization the message MUST specify the content type "application/openc2-rsp+json;version=1.0".

3.2.2 HTTP Usage

OpenC2 Consumers MUST be HTTP listeners, to implement the operating model described in Section 2. OpenC2 Consumers acting as HTTP listeners SHOULD listen on port 443, the registered port for HTTPS.

OpenC2 endpoints MUST implement all HTTP functionality required by this specification in accordance with HTTP/1.1 ([RFC7230], et. al.). As described in the Table 3-1, the only HTTP request methods utilized are GET and POST.

HTTP Method Utilized
GET Yes
HEAD No
POST Yes
PUT No
DELETE No
CONNECT No
OPTIONS No
TRACE No

Table 3-1: HTTP Method Use

Each HTTP message body MUST contain only a single OpenC2 Command or Response message. This does not preclude a Producer and Consumer exchanging multiple OpenC2 Command and Response Messages over time during a single HTTPS session. Depending on the set-up, a server and client can have multiple connections, but a sequence of OpenC2 interactions can spread over multiple connections. In some cases the connection may drop, but the session remains open (in an idle state).

All HTTP request and response messages containing OpenC2 payloads SHOULD include the "Cache-control:" header with a value of "no-cache".

The HTTP X-Request-ID header SHALL be populated with the request_id string supplied by the Producer.

3.2.3 TLS Usage

HTTPS, the transmission of HTTP over TLS, is specified in Section 2 of [RFC2818]. OpenC2 endpoints MUST accept TLS version 1.2 [RFC5246] connections or higher for confidentiality, identification, and authentication when sending OpenC2 Messages over HTTPS, and SHOULD accept TLS Version 1.3 [RFC8446] or higher connections.

OpenC2 endpoints MUST NOT support any version of TLS prior to v1.2 and MUST NOT support any version of Secure Sockets Layer (SSL).

The implementation and use of TLS SHOULD align with the best currently available security guidance, such as that provided in [RFC7525]/BCP 195.

The TLS session MUST use non-NULL ciphersuites for authentication, integrity, and confidentiality. Sessions MAY be renegotiated within these constraints.

OpenC2 endpoints supporting TLS v1.2 MUST NOT use any of the blacklisted ciphersuites identified in Appendix A of [RFC7540].

OpenC2 endpoints supporting TLS 1.3 MUST NOT implement zero round trip time resumption (0-RTT).

3.2.4 Authentication

Each participant in an OpenC2 communication MUST authenticate the other participant.

3.3 OpenC2 Consumer as HTTP/TLS Server

This section defines HTTP requirements that apply when the OpenC2 Consumer is the HTTP server.

As the OpenC2 Consumer is the HTTP server, the Producer initiates a connection to a specific Consumer and directly transmits OpenC2 Messages containing Commands; the HTTP POST method is used, with the OpenC2 Command body contained in the POST body.

The following HTTP request headers MUST be populated when transferring OpenC2 Commands:

The following HTTP response headers MUST be populated when transferring OpenC2 Responses:

The following HTTP request and response headers SHOULD be populated when transferring OpenC2 Commands and Responses when the Consumer is the HTTP/TLS server:

Example messages can be found in Annex B, section B.1.


4 Conformance

A conformant implementation of this transfer specification MUST:

  1. Support JSON serialization as specified in Section 3.2.1.
  2. Transfer OpenC2 Messages using the content types defined in Section 3.2.1 appropriately, as specified in Section 3.3.
  3. Listen for HTTPS connections as specified in Section 3.2.2.
  4. Use HTTP GET and POST methods as specified in Sections 3.2.2, and 3.3, and no other HTTP methods.
  5. Ensure HTTP request and response messages only contain a single OpenC2 message, as specified in Section 3.2.2.
  6. Implement TLS in accordance with the requirements and restrictions specified in Sections 3.2.3.
  7. Employ HTTP methods to send and receive OpenC2 Messages as specified in Section 3.3.
  8. Employ only the HTTP response codes as specified in Sections 3.3.
  9. Support authentication of remote parties as specified in Section 3.2.4
  10. Instantiate the message elements defined in Table 3-1 of [OpenC2-Lang-v1.0] as follows:
Name HTTPS Implementation
content JSON serialization of OpenC2 Commands and Responses carried in the HTTP message body
content_type /
msg_type
Combined and carried in the HTTP Content-type and Accepted headers:
Command: application/openc2-cmd+json;version=1.0
Response: application/openc2-rsp+json;version=1.0
status Numeric status code supplied by OpenC2 Consumers is carried in the HTTP response start line status code.
request_id String value originally supplied by the OpenC2 Producer is carried in HTTP X-Request-ID header.
created Carried in the HTTP Date header in the preferred IMF-fixdate format as defined by Section 7.1.1.1 of RFC 7231.
from Populated with the authenticated identity of the peer entity, consistent with the configured authentication scheme.
to Carried in the HTTP Host header.

Table 4-1 - Message Element Implementation


Annex A. Acronyms

This section is non-normative.

Term Expansion
0-RTT Zero Round Trip Time
API Application Programming Interface
HTTP Hypertext Transfer Protocol
HTTPS HTTP over TLS
IETF Internet Engineering Task Force
IPR Intellectual Property Rights
JSON JavaScript Object Notation
RFC Request For Comment
RID Real-time Inter-network Defense
TC Technical Committee
TCP Transmission Control Protocol
TLS Transport Layer Security

Annex B. Examples

This section is non-normative.

OpenC2 Messages consist of a set of "message elements" defined in Section 3.2 of [OpenC2-Lang-v1.0]. Table 4-1 of this specification defines how the message elements are handled with HTTPS transfer. Broadly speaking the message content (i.e., Commands and Responses) is carried in the HTTP message body while the remaining elments are handled in HTTP headers. The example Messages below illustrate how this is handled in practice.

A Request-URI ending in /openc2 is used in all example HTTP requests.

B.1 HTTP Request / Response Examples: Consumer as HTTP Server

This section presents the HTTP message structures used when the OpenC2 Consumer acts as the HTTP listener.

B.1.1 Producer HTTP POST with OpenC2 Command

Example message:

POST /openc2 HTTP/1.1
Host: oc2consumer.company.net
Content-type: application/openc2-cmd+json;version=1.0
Date: Wed, 19 Dec 2018 22:15:00 GMT
X-Request-ID: id_1234

{   
    "action": ...
    "target": …
    "args": ...
}

B.1.2 Consumer HTTP Response with OpenC2 Response

Example message:

HTTP/1.1 200 OK
Date: Wed, 19 Dec 2018 22:15:10 GMT
Content-type: application/openc2-rsp+json;version=1.0
X-Request-ID: id_1234

{   
    "status": 200
    "status_text": ...
    "results": { ...
}

Annex C. Acknowledgments

The Implementation Considerations Subcommittee was tasked by the OASIS Open Command and Control Technical Committee (OpenC2 TC) which at the time of this submission, had 132 members. The editor wishes to express their gratitude to the members of the OpenC2 TC.

The following individuals are acknowledged for providing comments, suggested text, and/or participation in CSD ballots or face-to-face meetings:


Annex D. Revision History

Revision Date Editor Changes Made
v1.0-wd01-wip 6/15/2018 Lemire Initial working draft
v1.0-wd01-wip 6/29/2018 Lemire Added Suitability section (1.6), responded to SC member comments
v1.0-wd01-wip 7/20/2018 Lemire Additional responses to member comments; formatting clean-up for easier conversion to Markdown.
v1.0-wd01-wip 8/9/2018 Lemire Implementing feedback from the July 2018 face-to-face meeting and resolving other comments to reach WD01 version to submit for CSD ballot.
v1.0-wd02-wip 8/24/2018 Lemire Various edits to clarify interactions when the producer is HTTP listener; other edits and cleanup in response to document comments and Slack forum discussions.
v1.0-wd02-wip 8/29/2018 Lemire 1) Adjustments to content type definitions to distinguish commands and responses;
2) Made corresponding adjustments to message flow descriptions and sample messages.
3) Added acknowledgements.
v1.0-wd02-wip 8/30/2018 Lemire Inserted proposed replacements for sequence diagrams (Figures 2 and 3).
v1.0-wd02-wip 8/31/2018 Lemire 1) Inserted initial draft conformance language (section 4).
2) Revised Section 1 content for greater consistency with related OpenC2 specifications.
3) Revised section 2.1 to merge proposed endpoint role descriptions
4) General edit for formatting, readability, consistency, etc.
v1.0-wd02-wip 9/11/2018 Lemire 1) Reviewed and accepted / rejected comments.
2) Added placeholders for addressing use of "From" field.
3) Added statements about using Cache-control
v1.0-wd02-wip 9/17/2018 Lemire 1) Added table to conformance section specifying mapping of Language Spec message elements.
2) Clarified certificate mutual authentication requirement.
3) Removed language about unsolicited responses from Consumers
4) Numbered the conformance items
v1.0-wd02-wip 9/17/2018 Lemire 1) Removed used of the HTTP "From:" field, and mapped the OpenC2 "from" message element to the authenticated identity of the peer entity
2) Updated examples to remove HTTP From:
v1.0-wd02-wip 9/19/2018 Lemire 1) Final clean-up of residual comments and edits to create WD02 package for CSD ballot.
2) Renamed document to WD03-wip
v1.0-wd03-wip 10/15/2018 Lemire 1) Reorganized section 1 to align with other OpenC2 specifications
2) Reworded section 3.2.1 to properly use MUST / SHALL language
3) Clarified requirements wording section 3.2.3 to better indicate TLS version requirements and preferences, and authentication requirements.
4) Updated Table 4-1 to align with changes to Language Specification Table 3-1.
v1.0-wd03-wip 10/16/2018 Lemire 1) Final clean-up of residual edits to create WD03 package for CSD approval and release for public review.
v1.0-wd03-wip 3/27/2019 Lemire Resolution of issues from public review 1.
v1.0-wd03-wip 3/28/2019 Lemire Incremented WD version number to 05 prior to CSD ballot to eliminate ambiguity.