SACM Working Group                                          A. Montville
Internet-Draft                                                 B. Munyan
Intended status: Standards Track                                     CIS
Expires: 12 November 2020                                    11 May 1, 2020                                    October 29, 2019

   Security Automation and Continuous Monitoring (SACM) Architecture
                        draft-ietf-sacm-arch-04
                        draft-ietf-sacm-arch-05

Abstract

   This document defines an architecture enabling a cooperative Security
   Automation and Continuous Monitoring (SACM) ecosystem.  This work is
   predicated upon information gleaned from SACM Use Cases and
   Requirements ([RFC7632] and [RFC8248] respectively), and terminology
   as found in [I-D.ietf-sacm-terminology].

   WORKING GROUP: The source for this draft is maintained in GitHub.
   Suggested changes should be submitted as pull requests at
   https://github.com/sacmwg/ietf-mandm-sacm-arch/.  Instructions are on
   that page as well.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements notation . . . . . . . . . . . . . . . . . .   3
   2.  Terms and Definitions . . . . . . . . . . . . . . . . . . . .   3
   3.  Architectural Overview  . . . . . . . . . . . . . . . . . . .   3   4
     3.1.  SACM Role-based Architecture  . . . . . . . . . . . . . .   4
     3.2.  Architectural Roles/Components  . . . . . . . . . . . . .   5
       3.2.1.  Orchestrator(s) . . . . . . . . . . . . . . . . . . .   5   6
       3.2.2.  Repositories/CMDBs  . . . . . . . . . . . . . . . . .   5   6
       3.2.3.  Integration Service . . . . . . . . . . . . . . . . .   5   6
     3.3.  Downstream Uses . . . . . . . . . . . . . . . . . . . . .   6   7
       3.3.1.  Reporting . . . . . . . . . . . . . . . . . . . . . .   6   7
       3.3.2.  Analytics . . . . . . . . . . . . . . . . . . . . . .   6   7
     3.4.  Sub-Architectures . . . . . . . . . . . . . . . . . . . .   7
       3.4.1.  Collection Sub-Architecture . . . . . . . . . . . . .   7
       3.4.2.  Evaluation Sub-Architecture . . . . . . . . . . . . .   9  10
   4.  Interactions  . . . . . . . . . . . . . . . . . . . . . . . .  11
   5.  Security Domain Workflows .  12
     4.1.  Interaction Categories  . . . . . . . . . . . . . . . . .  12
     5.1.  IT Asset Management
       4.1.1.  Broadcast . . . . . . . . . . . . . . . . . . . . . .  12
       5.1.1.  Components, Capabilities and Workflow(s)
       4.1.2.  Directed  . . . . . . . . . . . . . . . . . . . . . .  13
     5.2.  Vulnerability
     4.2.  Management Plane Functions  . . . . . . . . . . . . . . .  13
       4.2.1.  Orchestrator Onboarding . . . . . . . . . . . . . . .  13
       5.2.1.  Components, Capabilities and Workflow(s)
       4.2.2.  Component Onboarding  . . . . . . . . . . . . . . . .  14
     5.3.  Configuration Management
     4.3.  Component Interactions  . . . . . . . . . . . . . . . . .  15
       5.3.1.  Components, Capabilities and Workflow(s)
       4.3.1.  Initiate Ad-Hoc Collection  . . . . . . . . . . . . .  15
       4.3.2.  Coordinate Periodic Collection  . . . . . . . . . . .  15
       4.3.3.  Coordinate Observational/Event-based
               Collection  . . . . . . . . . . . . . . . . . . . . .  16
   6.  Privacy Considerations
       4.3.4.  Persist Collected Posture Attributes  . . . . . . . .  16
       4.3.5.  Initiate Ad-Hoc Evaluation  . . . . . . . . . . .  18
   7.  Security Considerations . .  16
       4.3.6.  Queries . . . . . . . . . . . . . . . . .  18
   8.  IANA Considerations . . . . . .  16
   5.  Taxonomy  . . . . . . . . . . . . . . .  18
   9.  References . . . . . . . . . . .  16
     5.1.  Orchestrator Registration . . . . . . . . . . . . . .  19
     9.1.  Normative References . .  17
       5.1.1.  Topic . . . . . . . . . . . . . . . .  19
     9.2.  Informative References . . . . . . . .  17
       5.1.2.  Interaction Type  . . . . . . . . .  19
   Appendix A.  Mapping to RFC8248 . . . . . . . . .  17
       5.1.3.  Initiator . . . . . . . .  21
   Appendix B.  Example Components . . . . . . . . . . . . . .  17
       5.1.4.  Request Payload . . .  24
     B.1.  Policy Services . . . . . . . . . . . . . . . .  17
       5.1.5.  Receiver  . . . . .  24
     B.2.  Software Inventory . . . . . . . . . . . . . . . . .  17
       5.1.6.  Process Description . .  25
     B.3.  Datastream Collection . . . . . . . . . . . . . . .  17
       5.1.7.  Response Payload  . . .  26
     B.4.  Network Configuration Collection . . . . . . . . . . . .  26
   Appendix C.  Exploring An XMPP-based Solution . . .  18
       5.1.8.  Response Processing . . . . . . .  27
     C.1.  Example Architecture using XMPP-Grid and Endpoint Posture
           Collection Protocol . . . . . . . . . .  18
     5.2.  Component Registration  . . . . . . . . .  30
   Authors' Addresses . . . . . . . .  18
       5.2.1.  Topic . . . . . . . . . . . . . . .  32

1.  Introduction

   The purpose of this draft is to define an architectural approach for
   a SACM Domain, based on the spirit of use cases found in [RFC7632]
   and requirements found in [RFC8248].  This approach gains the most
   advantage by supporting a variety of collection systems, and intends
   to enable a cooperative ecosystem of tools from disparate sources
   with minimal operator configuration.

1.1.  Requirements notation

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in RFC
   2119, BCP 14 [RFC2119].

2.  Terms and Definitions

   This draft defers to [I-D.ietf-sacm-terminology] for terms and
   definitions.

3.  Architectural Overview

   The generic approach proposed herein recognizes the need to obtain
   information from existing and future state collection systems, and
   makes every attempt to respect [RFC7632] and [RFC8248].  At the
   foundation of any architecture are entities, or components, that need
   to communicate.  They communicate by sharing information, where, in a
   given flow, one or more components are consumers of information and
   one or more components are providers of information.

          +----------------+
          | SACM Component |
          |   (Provider)   |
          +-------+--------+
                  |
                  |
   +--------------v----------------+
   |      Integration Service      |
   +--------------+----------------+
                  |
                  |
          +-------v--------+
          | SACM Component |
          |   (Consumer)   |
          +----------------+

                  Figure 1: Basic Architectural Structure

   A provider can be described as an abstraction that refers to an
   entity capable of sending SACM-relevant information to one or many
   consumers.  Consumers can be described as an abstraction that refers
   to an entity capable of receiving SACM-relevant information from one
   or many providers.  Different roles within a cooperative ecosystem
   may act as both providers and consumers of SACM-relevant information.

3.1.  SACM Role-based Architecture

   Within the cooperative SACM ecosystem, a number of roles act in
   coordination to provide relevant policy/guidance, perform data
   collection, storage, evaluation, and support downstream analytics and
   reporting.

              +--------------------+
              | Feeds/Repositories |
              |  of External Data  |
              +---------+----------+
                        |
******************************************* Boundary of Responsibility ******
                        |
   +-----------------+  |  +--------------------+
   | Orchestrator(s) |  |  | Repositories/CMDBs |
   +---------^-------+  |  +----------^---------+
             |          |             |             +--------------------+
             |          |             |             |  Downstream Uses   |
             |          |             |             | +----------------+ |
 +-----------v----------v-------------v------+      | |   Analytics    | |
 |             Integration Service           <------> +----------------+ |
 +-----------^--------------------------^----+      | +----------------+ |
             |                          |           | |   Reporting    | |
             |                          |           | +----------------+ |
 +-----------v-------------------+      |           +--------------------+
 |  Collection Sub-Architecture  |      |
 +-------------------------------+      |
                        +---------------v---------------+
                        |  Evaluation Sub-Architecture  |
                        +-------------------------------+

                Figure 2: Notional Role-based Architecture

   As shown in Figure 2, the SACM role-based architecture consists of
   some basic SACM Components communicating using an integration
   service.  The integration service is expected to maximally align with
   the requirements described in [RFC8248], which means that the
   integration service will support brokered (i.e. point-to-point) and
   proxied data exchange.

   The boundary of responsibility is not intended to imply a physical
   boundary.  Rather, it is intended to be inclusive of various cloud/
   virtualized environments, BYOD and vendor-provided services in
   addition to any physical systems the enterprise operates.

3.2.  Architectural Roles/Components

   This document suggests a variety of players in a cooperative
   ecosystem; these players are known as SACM Components.  SACM
   Components may be composed of other SACM Components, and each SACM
   Component plays one, or more, of several roles relevant to the
   ecosystem.  Roles may act as providers of information, consumers of
   information, or both provider and consumer.  Figure 2 depicts a
   number of SACM components which are architecturally significant and
   therefore warrant discussion and clarification.

3.2.1.  Orchestrator(s)

   Orchestration components exists to aid in the automation of
   configuration, coordination, and management for the ecosystem of SACM
   components.  The Orchestrator performs control-plane operations,
   administration of an implementing organization's components
   (including endpoints, posture collection services, and downstream
   activities), scheduling of automated tasks, and any ad-hoc activities
   such as the initiation of collection or evaluation activities.  The
   Orchestrator is the key administrative interface into the SACM
   architecture.

3.2.2.  Repositories/CMDBs

   Figure 2 only includes a single reference to "Repositories/CMDBs",
   but in practice, a number of separate data repositories may exist,
   including posture attribute repositories, policy repositories, local
   vulnerability definition data repositories, and state assessment
   results repositories.  These data repositories may exist separately
   or together in a single representation, and the design of these
   repositories may be as distinct as their intended purpose, such as
   the use of relational database management systems or graph/map
   implementations focused on the relationships between data elements.
   Each implementation of a SACM repository should focus on the
   relationships between data elements and implement the SACM
   information and data model(s).

3.2.3.  Integration Service

   If each SACM component represents a set of capabilities, the
   Integration Service represents the "fabric" by which all those
   services are woven together.  The Integration Service acts as a
   message broker, combining a set of common message categories and
   infrastructure to allow SACM components to communicate using a shared
   set of interfaces.  The Integration Service's brokering capabilities
   enable the exchange of various information payloads, orchestration of
   component capabilities, message routing and reliable delivery.  The
   Integration Service minimizes the dependencies from one system to
   another through the loose coupling of applications through messaging.
   SACM components will "attach" to the Integration Service either
   through native support for the integration implementation, or through
   the use of "adapters" which provide a proxied attachment.

   The Integration Service should provide mechanisms for synchronous
   "request/response"-style messaging, asynchronous "send and forget"
   messaging, or publish/subscribe.  It is the responsibility of the
   Integration Service to coordinate and manage the sending and
   receiving of messages.  The Integration Service should allow
   components the ability to directly connect and produce or consume
   messages, or connect via message translators which can act as a
   proxy, transforming messages from a component format to one
   implementing a SACM data model.

   The Integration Service MUST provide routing capabilities for
   payloads between producers and consumers.  The Integration Service
   MAY provide further capabilities within the payload delivery
   pipeline.  Examples of these capabilities include, but are not
   limited to, intermediate processing, message transformation, type
   conversion, validation, etc.

3.3.  Downstream Uses

   As depicted by Figure 2, a number of downstream uses exist in the
   cooperative ecosystem.  Each notional SACM component represents
   distinct sub-architectures which will exchange information via the
   integration services, using interactions described in this draft.

3.3.1.  Reporting

   The Reporting component represents capabilities outside of the SACM
   architecture scope dealing with the query and retrieval of collected
   posture attribute information, evaluation results, etc. in various
   display formats that are useful to a wide range of stakeholders.

3.3.2.  Analytics

   The Analytics component represents capabilities outside of the SACM
   architecture scope dealing with the discovery, interpretation, and
   communication of any meaningful patterns of data in order to inform
   effective decision making within the organization.

3.4.  Sub-Architectures

   Figure 2 shows two components representing sub-architectural roles
   involved in a cooperative ecosystem of SACM components: Collection
   and Evaluation.

3.4.1.  Collection Sub-Architecture

   The Collection sub-architecture, in a SACM context, is the mechanism
   by which posture attributes are collected from applicable endpoints
   and persisted to a repository, such as a configuration management
   database (CMDB).  Orchestration components will choreograph endpoint
   data collection via interactions using the Integration Service as a
   message broker.  Instructions to perform endpoint data collection are
   directed to a Posture Collection Service capable of performing
   collection activities utilizing any number of methods, such as SNMP,
   NETCONF/RESTCONF, SSH, WinRM, or host-based.

   +----------------------------------------------------------+
   |                    Orchestrator(s)                       |
   +-----------+----------------------------------------------+
               |               +------------------------------+
               |               | Posture Attribute Repository |
               |               +--------------^---------------+
            Perform                           |
           Collection                         |
               |                       Collected Data
               |                              ^
               |                              |
   +-----------v------------------------------+---------------+
   |                    Integration Service                   |
   +----+------------------^-----------+------------------^---+
        |                  |           |                  |
        v                  |           v                  |
     Perform           Collected    Perform           Collected
    Collection           Data      Collection           Data
        |                  ^           |                  ^
        |                  |           |                  |
   +----v-----------------------+ +----v------------------+------+
   | Posture Collection Service | |          Endpoint            |
   +---^------------------------+ | +--------------------------+ |
       |                   |      | |Posture Collection Service| |
       |                   v      | +--------------------------+ |
     Events             Queries   +------------------------------+
       ^                   |
       |                   |
   +---+-------------------v----+
   |          Endpoint          |
   +----------------------------+

             Figure 3: Decomposed Collection Sub-Architecture

3.4.1.1.  Posture Collection Service

   The Posture Collection Service (PCS) is the SACM component
   responsible for the collection of posture attributes from an endpoint
   or set of endpoints.  A single PCS may be responsible for management
   of posture attribute collection from many endpoints.  The PCS will
   interact with the Integration Service to receive collection
   instructions and to provide collected posture data for persistence to
   the Posture Attribute Repository.  Collection instructions may be
   supplied in a variety of forms, including subscription to a publish/
   subscribe topic to which the Integration Service has published
   instructions, via request/response-style synchronous messaging, or
   via asynchronous "send-and-forget" messaging.  Collected posture
   information may then be supplied to the Integration Service via
   similar channels.  The various interaction types are discussed later
   in this draft (TBD).

3.4.1.2.  Endpoint

   Building upon [I-D.ietf-sacm-terminology], the SACM Collection Sub-
   Architecture augments the definition of an Endpoint as a component
   within an organization's management domain from which a Posture
   Collection Service will collect relevant posture attributes.

3.4.1.3.  Posture Attribute Repository

   The Posture Attribute Repository is a SACM component responsible for
   the persistent storage of posture attributes collected via
   interactions between the Posture Collection Service and Endpoints.

3.4.1.4.  Posture Collection Workflow

   Posture collection may be triggered from a number of components, but
   commonly begin either via event-based triggering on an endpoint or
   through manual orchestration, both illustrated in Figure 3 above.
   Once orchestration has provided the directive to perform collection,
   posture collection services consume the directives.  Posture
   collection is invoked for those endpoints overseen by the respective
   posture collection services.  Collected data is then provided to the
   Integration Service, with a directive to store that information in an
   appropriate repository.

3.4.2.  Evaluation Sub-Architecture

   The Evaluation Sub-Architecture, in the SACM context, is the
   mechanism by which policy, expressed in the form of expected state,
   is compared with collected posture attributes to yield an evaluation
   result, that result being contextually dependent on the policy being
   evaluated.

                     +------------------+
                     |    Collection    |    +-------------------------------+
                     | Sub-Architecture |    | Evaluation Results Repository |
+--------------+     +--------^---------+    +-----------------^-------------+
| Orchestrator |              |                                |
+------+-------+              |                                |
       |                   Perform                 Store Evaluation Results
    Perform . . . . . . . . .  18
       5.2.2.  Interaction Type  . . . . . . . . . . . . . . . . . .  18
       5.2.3.  Initiator . . . . . . . . . . . . . . . . . . . . . .  18
       5.2.4.  Request Payload . . . . . . . . . . . . . . . . . . .  18
       5.2.5.  Receiver  . . . . . . . . . . . . . . . . . . . . . .  18
       5.2.6.  Process Description . . . . . . . . . . . . . . . . .  19
       5.2.7.  Response Payload  . . . . . . . . . . . . . . . . . .  19
       5.2.8.  Response Processing . . . . . . . . . . . . . . . . .  19
     5.3.  Orchestrator-to-Component Administrative Interface  . . .  19
       5.3.1.  Capability Advertisement Handshake  . . . . . . . . .  19
       5.3.2.  Directed Collection                           |
   Evaluation                 |                                |
       |                      |                                |
+------v----------------------v--------------------------------+-------------+
|                             Integration Service                            |
+--------+----------------------------^----------------------^---------------+
         |                            |                      |
         |                            |                      |
      Perform                  Retrieve Posture              |
     Evaluation                   Attributes          Retrieve Policy
         |                            |                      |
         |                            |                      |
+--------v-------------------+  +-----v------+        +------v-----+
| Posture Evaluation Service |  |  Posture   |        |   Policy   |
+----------------------------+  | Attribute  |        | Repository |
                                | Repository |        +------------+
                                +------------+

             Figure 4: Decomposed Evaluation Sub-Architecture

3.4.2.1.  Posture Evaluation Service

   The Posture Evaluation Service (PES) represents the SACM component
   responsible for coordinating the policy to be evaluated . . . . . . . . . . . . . . . . .  20
     5.4.  [Taxonomy Name] . . . . . . . . . . . . . . . . . . . . .  20
       5.4.1.  Topic . . . . . . . . . . . . . . . . . . . . . . . .  21
   6.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  21
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  21
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  21
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  21
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  21
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  22
   Appendix A.  Security Domain Workflows  . . . . . . . . . . . . .  24
     A.1.  IT Asset Management . . . . . . . . . . . . . . . . . . .  24
       A.1.1.  Components, Capabilities and the
   collected posture attributes relevant to that policy, as well as the
   comparison engine responsible for correctly determining compliance
   with the expected state.

3.4.2.2.  Policy Repository

   The Policy Repository represents a persistent storage mechanism for
   the policy to be assessed against collected posture attributes to
   determine if an endpoint meets the defined expected state.  Examples
   of information contained in a Policy Repository would be Workflow(s)  . . . . . .  24
     A.2.  Vulnerability Definition Data or configuration recommendations as
   part of a CIS Benchmark or DISA STIG.

3.4.2.3.  Evaluation Results Repository Management  . . . . . . . . . . . . . . . .  25
       A.2.1.  Components, Capabilities and Workflow(s)  . . . . . .  26
     A.3.  Configuration Management  . . . . . . . . . . . . . . . .  26
       A.3.1.  Components, Capabilities and Workflow(s)  . . . . . .  27
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  29

1.  Introduction

   The Evaluation Results Repository persists the information
   representing the results purpose of a particular posture assessment,
   indicating those posture attributes collected from various endpoints
   which either meet or do not meet the expected state defined by the
   assessed policy.  Consideration should be made this draft is to define an architectural approach for
   a SACM Domain, based on the context spirit of
   individual results.  For example, meeting use cases found in [RFC7632]
   and requirements found in [RFC8248].  This approach gains the expected state for a
   configuration attribute indicates most
   advantage by supporting a correct configuration variety of the
   endpoint, whereas meeting an expected state for a vulnerable software
   version indicates an incorrect collection systems, and therefore vulnerable
   configuration.

3.4.2.4.  Posture Evaluation Workflow

   Posture evaluation is orchestrated through the Integration Service intends
   to
   the appropriate Posture Evaluation Service.  The PES will, through
   coordination enable a cooperative ecosystem of tools from disparate sources
   with the Integration Service, query both the Posture
   Attribute Repository and the Policy Repository to obtain relevant
   state data for comparison.  If necessary, the PES may be required to
   invoke further posture collection.  Once all relevant posture
   information has been collected, it is compared to expected state
   based on applicable policy.  Comparison results are then persisted to
   an evaluation results repository for further downstream use minimal operator configuration.

1.1.  Requirements notation

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   analysis.

4.  Interactions

   SACM Components
   "OPTIONAL" in this document are intended to interact with other SACM Components.
   These interactions can be thought of, at the architectural level, interpreted as
   the combination of interfaces with their supported operations.  Each
   interaction will convey a payload of information. described in RFC
   2119, BCP 14 [RFC2119].

2.  Terms and Definitions

   This draft defers to [I-D.ietf-sacm-terminology] for terms and
   definitions.

3.  Architectural Overview

   The payload generic approach proposed herein recognizes the need to obtain
   information is expected from existing and future state collection systems, and
   makes every attempt to contain sub-domain-specific
   characteristics respect [RFC7632] and instructions.

   Two categories of interactions SHOULD be supported by [RFC8248].  At the Integration
   Service; broadcast interactions, and directed interactions.

   o  *Broadcast*: A broadcast interaction, commonly known as "publish/
      subscribe", allows for a wider distribution
   foundation of a message payload.
      When a payload is published any architecture are entities, or components, that need
   to communicate.  They communicate by sharing information, where, in a topic on the Integration Service,
      all subscribers to that topic
   given flow, one or more components are alerted consumers of information and may consume the
      message payload.  A broadcast interaction may also simulate a
      "directed" interaction when a topic only has a single subscriber.
      An example
   one or more components are providers of a broadcast interaction could information.

          +----------------+
          | SACM Component |
          |   (Provider)   |
          +-------+--------+
                  |
                  |
   +--------------v----------------+
   |      Integration Service      |
   +--------------+----------------+
                  |
                  |
          +-------v--------+
          | SACM Component |
          |   (Consumer)   |
          +----------------+

                  Figure 1: Basic Architectural Structure

   A provider can be to publish to a
      topic described as an abstraction that new configuration assessment content is available.
      Subscribing consumers receive the notification, and proceed refers to
      collect endpoint configuration posture based on the new content.

   o  *Directed*: The intent an
   entity capable of a directed interaction is sending SACM-relevant information to one or many
   consumers.  Consumers can be described as an abstraction that refers
   to enable
      point-to-point communications between an entity capable of receiving SACM-relevant information from one
   or many providers.  Different roles within a producer cooperative ecosystem
   may act as both providers and consumer,
      through the standard interfaces provided by consumers of SACM-relevant information.

3.1.  SACM Role-based Architecture

   Within the Integration
      Service.  The provider component indicates which consumer is
      intended cooperative SACM ecosystem, a number of roles act in
   coordination to receive the payload, provide relevant policy/guidance, perform data
   collection, storage, evaluation, and the support downstream analytics and
   reporting.

      +-----------------+     +--------------------+
      | Orchestrator(s) |     | Repositories/CMDBs |
      +---------^-------+     +----------^---------+
                |                        |             +--------------------+
                |                        |             |  Downstream Uses   |
                |                        |             | +----------------+ |
    +-----------v------------------------v------+      | |   Analytics    | |
    |             Integration Service
      routes           <------> +----------------+ |
    +-----------^--------------------------^----+      | +----------------+ |
                |                          |           | |   Reporting    | |
                |                          |           | +----------------+ |
    +-----------v-------------------+      |           +--------------------+
    |  Collection Sub-Architecture  |      |
    +-------------------------------+      |
                           +---------------v---------------+
                           |  Evaluation Sub-Architecture  |
                           +-------------------------------+

                 Figure 2: Notional Role-based Architecture

   As shown in Figure 2, the payload directly to that consumer.  Two "styles" SACM role-based architecture consists of
      directed interaction exist, differing only by the response from
   some basic SACM Components communicating using an integration
   service.  The integration service is expected to maximally align with
   the payload consumer:

      *  *Synchronous (Request/Response)*: Synchronous, request/response
         style interaction requires requirements described in [RFC8248], which means that the requesting component block
   integration service will support brokered (i.e. point-to-point) and wait for the receiving component to respond, or to time out
         when that response is delayed past
   proxied data exchange.

3.2.  Architectural Roles/Components

   This document suggests a variety of players in a given time threshold.  A
         synchronous interaction example cooperative
   ecosystem; known as SACM Components.  SACM Components may be querying a CMDB for
         posture attribute information in order composed
   of other SACM Components, and each SACM Component plays one, or more,
   of several roles relevant to perform an
         evaluation.

      *  *Asynchronous (Fire-and-Forget)*: An asynchronous interaction
         involves the payload producer directing the message to a
         consumer, but not blocking ecosystem.  Roles may act as
   providers of information, consumers of information, or waiting for both provider
   and consumer.  Figure 2 depicts a response.  This
         style number of interaction allows the producer to continue on SACM components which are
   architecturally significant and therefore warrant discussion and
   clarification.

3.2.1.  Orchestrator(s)

   Orchestration components exists to
         other activities without aid in the need to wait automation of
   configuration, coordination, and management for responses.  This
         style is particularly useful when the interaction payload
         invokes a potentially long-running task, ecosystem of SACM
   components.  The Orchestrator performs control-plane operations,
   administration of an implementing organization's components
   (including endpoints, posture collection services, and downstream
   activities), scheduling of automated tasks, and any ad-hoc activities
   such as data
         collection, report generation, the initiation of collection or policy evaluation. evaluation activities.  The
         receiving component may reply later via callbacks or further
         interactions, but it
   Orchestrator is not mandatory.

   Each interaction will convey the key administrative interface into the SACM
   architecture.

3.2.2.  Repositories/CMDBs

   Figure 2 only includes a payload of information.  The payload
   is expected single reference to contain specific characteristics "Repositories/CMDBs",
   but in practice, a number of separate data repositories may exist,
   including posture attribute repositories, policy repositories, local
   vulnerability definition data repositories, and state assessment
   results repositories.  These data repositories may exist separately
   or together in a single representation, and instructions to
   be interpreted by receiving components.

5.  Security Domain Workflows

   This section describes three primary information security domains
   from which workflows the design of these
   repositories may be derived: IT Asset Management,
   Vulnerability Management, and Configuration Management.

5.1.  IT Asset Management

   Information Technology asset as distinct as their intended purpose, such as
   the use of relational database management is easier said than done.
   The [CISCONTROLS] have two controls dealing with IT asset management.
   Control 1, Inventory and Control systems or graph/map
   implementations focused on the relationships between data elements.
   Each implementation of Hardware Assets, states,
   "Actively manage (inventory, track, and correct) all hardware devices a SACM repository should focus on the network so that only authorized devices are given access,
   relationships between data elements and
   unauthorized implement the SACM
   information and unmanaged devices data model(s).

3.2.3.  Integration Service

   If each SACM component represents a set of capabilities, the
   Integration Service represents the "fabric" by which all those
   services are found and prevented from
   gaining access."  Control 2, Inventory and Control woven together.  The Integration Service acts as a
   message broker, combining a set of Software
   Assets, states, "Actively manage (inventory, track, common message categories and correct) all
   software on
   infrastructure to allow SACM components to communicate using a shared
   set of interfaces.  The Integration Service's brokering capabilities
   enable the network so that only authorized software is installed
   and can execute, and that unauthorized and unmanaged software is
   found exchange of various information payloads, orchestration of
   component capabilities, message routing and prevented reliable delivery.  The
   Integration Service minimizes the dependencies from installation or execution."

   In spirit, this covers all of one system to
   another through the processing entities on your network
   (as opposed loose coupling of applications through messaging.
   SACM components will "attach" to things like network cables, dongles, adapters, etc.),
   whether physical or virtual, on-premises the Integration Service either
   through native support for the integration implementation, or in through
   the cloud.

5.1.1.  Components, Capabilities use of "adapters" which provide a proxied attachment.

   The Integration Service should provide mechanisms for both
   synchronous and Workflow(s)

   TBD

5.1.1.1.  Components

   TBD

5.1.1.2.  Capabilities

   An IT asset management capability needs to be able to:

   o  Identify asynchronous "request/response"-style messaging, and catalog new assets by executing Target Endpoint
      Discovery Tasks

   o  Provide information about its managed assets, including uniquely
      identifying information (for that enterprise)

   o  Handle software and/or hardware (including virtual assets)

   o  Represent cloud hybrid environments

5.1.1.3.  Workflow(s)

   TBD

5.2.  Vulnerability Management

   Vulnerability management is
   a relatively established process.  To
   paraphrase the [CISCONTROLS], continuous vulnerability management publish/subscribe mechanism to implement event-based messaging.  It
   is the act responsibility of continuously acquiring, assessing, and taking subsequent
   action on new information in order the Integration Service to identify coordinate and remediate
   vulnerabilities, therefore minimizing
   manage the window sending and receiving of opportunity for
   attackers.

   A vulnerability assessment (i.e. vulnerability detection) is
   performed in two steps:

   o  Endpoint information collected by messages.  The Integration
   Service should allow components the endpoint management ability to directly connect and
   produce or consume messages, or connect via message translators which
   can act as a proxy, transforming messages from a component format to
   one implementing a SACM data model.

   The Integration Service MUST provide routing capabilities for
   payloads between producers and consumers.  The Integration Service
   MAY provide further capabilities is examined by within the vulnerability management payload delivery
   pipeline.  Examples of these capabilities through Evaluation Tasks.

   o  If the data possessed include, but are not
   limited to, intermediate processing, message transformation, type
   conversion, validation, or other enterprise integration patterns.

3.3.  Downstream Uses

   As depicted by the endpoint management capabilities is
      insufficient, Figure 2, a Collection Task is triggered and the necessary
      data is collected from number of downstream uses exist in the target endpoint.

   Vulnerability detection relies on
   cooperative ecosystem.  Each notional SACM component represents
   distinct sub-architectures which will exchange information via the examination
   integration services, using interactions described in this draft.

3.3.1.  Reporting

   The Reporting component represents capabilities outside of different
   endpoint information depending on the nature SACM
   architecture scope dealing with the query and retrieval of a specific
   vulnerability.  Common endpoint information used collected
   posture attribute information, evaluation results, etc. in various
   display formats that are useful to detect a
   vulnerability includes:

   o  A specific software version is installed on wide range of stakeholders.

3.3.2.  Analytics

   The Analytics component represents capabilities outside of the endpoint

   o  File system attributes

   o  Specific state attributes

   In some cases, SACM
   architecture scope dealing with the endpoint information needed discovery, interpretation, and
   communication of any meaningful patterns of data in order to determine an
   endpoint's vulnerability status will have been previously collected
   by inform
   effective decision making within the endpoint management capabilities and available organization.

3.4.  Sub-Architectures

   Figure 2 shows two components representing sub-architectural roles
   involved in a
   Repository.  However, in other cases, the necessary endpoint
   information will not be readily available cooperative ecosystem of SACM components: Collection
   and Evaluation.

3.4.1.  Collection Sub-Architecture

   The Collection sub-architecture is, in a Repository SACM context, the mechanism
   by which posture attributes are collected from applicable endpoints
   and persisted to a
   Collection Task repository, such as a configuration management
   database (CMDB).  Orchestration components will be triggered to perform choreograph endpoint
   data collection from via defined interactions, using the
   target endpoint.  Of course, some implementations of endpoint
   management capabilities may prefer to enable operators Integration
   Service as a message broker.  Instructions to perform
   this collection even when sufficient information can be provided by
   the endpoint management capabilities (e.g. there may be freshness
   requirements for information).

5.2.1.  Components, Capabilities and Workflow(s)

   TBD

5.2.1.1.  Components

   TBD

5.2.1.2.  Capabilities

   TBD

5.2.1.3.  Workflow(s)

   TBD

5.3.  Configuration Management

   Configuration management involves configuration assessment, which
   requires state assessment.  The [CISCONTROLS] specify two high-level
   controls concerning configuration management (Control 5 for non-
   network devices and Control 11 data
   collection are directed to a Posture Collection Service capable of
   performing collection activities utilizing any number of methods,
   such as SNMP, NETCONF/RESTCONF, SSH, WinRM, packet capture, or host-
   based.

     +----------------------------------------------------------+
     |                    Orchestrator(s)                       |
     +-----------+----------------------------------------------+
                 |               +------------------------------+
                 |               | Posture Attribute Repository |
                 |               +--------------^---------------+
              Perform                           |
             Collection                         |
                 |                       Collected Data
                 |                              ^
                 |                              |
     +-----------v------------------------------+---------------+
     |                    Integration Service                   |
     +----+------------------^-----------+------------------^---+
          |                  |           |                  |
          v                  |           v                  |
       Perform           Collected    Perform           Collected
      Collection           Data      Collection           Data
          |                  ^           |                  ^
          |                  |           |                  |
     +----v-----------------------+ +----|------------------|------+
     | Posture Collection Service | |    |     Endpoint     |      |
     +---^------------------------+ | +--v------------------+----+ |
         |                   |      | |Posture Collection Service| |
         |                   v      | +--------------------------+ |
       Events             Queries   +------------------------------+
         ^                   |          (PCS resides on Endpoint)
         |                   |
     +---+-------------------v----+
     |          Endpoint          |
     +----------------------------+
   (PCS does not reside on Endpoint)

              Figure 3: Decomposed Collection Sub-Architecture

3.4.1.1.  Posture Collection Service

   The Posture Collection Service (PCS) is the SACM component
   responsible for network devices).  As the collection of posture attributes from an aside,
   these controls are listed separately because many enterprises have
   different organizations endpoint
   or set of endpoints.  A single PCS may be responsible for managing network infrastructure and
   workload management
   of posture attribute collection from many endpoints.  Merging the two controls results in  The PCS will
   interact with the
   following paraphrasing: Establish, implement, Integration Service to receive collection
   instructions and actively manage
   (track, report on, correct) to provide collected posture data for persistence to
   the security configuration of systems
   using a rigorous configuration management and change control process Posture Attribute Repository.  Collection instructions may be
   supplied in order a variety of forms, including subscription to prevent attackers from exploiting vulnerable services and
   settings.

   Typically, an enterprise will use configuration guidance from a
   reputable source, and from time publish/
   subscribe topic to time they may tailor which the guidance
   from that source prior to adopting it Integration Service has published
   instructions, or via request/response-style messaging (either
   synchronous or asynchronous).

   Four classifications of posture collections MAY be supported.

3.4.1.1.1.  Ad-Hoc

   Ad-Hoc collection is defined as part a single colletion of their enterprise
   standard.  The enterprise standard posture
   attributes, collected at a particular time.  An example of ad-hoc
   collection is then provided to the
   appropriate configuration assessment tools and they assess endpoints
   and/or appropriate endpoint information.

   A preferred flow follows:

   o  Reputable source publishes new or updated configuration guidance

   o  Enterprise configuration assessment capability retrieves
      configuration guidance from reputable source

   o  Optional: Configuration guidance single collection of a specific registry key.

3.4.1.1.2.  Continuous/Scheduled

   Continuous/Scheduled collection is defined as the ongoing, periodic
   collection of posture attributes.  An example of scheduled collection
   is the collection of a specific registry key value every day at a
   given time.

3.4.1.1.3.  Observational

   This classification of collection is tailored triggered by the observation,
   external to an endpoint, of information asserting posture attribute
   values for enterprise- that endpoint.  An example of observational collection is
   examination of netflow data for particular packet captures and/or
   specific needs

   o  Configuration assessment tool queries asset inventory repository information within those captures.

3.4.1.1.4.  Event-based

   Event-based collection may be triggered either internally or
   externally to retrieve the endpoint.  Internal event-based collection is
   triggered when a list posture attribute of affected endpoints

   o  Configuration assessment tool queries configuration state
      repository to evaluate compliance

   o  If information interest is stale added, removed, or unavailable, configuration assessment
      tool triggers
   modified on an ad hoc assessment

   The SACM architecture needs to support varying deployment models to
   accommodate endpoint.  This modification indicates a change in the
   current state of the industry, but should strongly
   encourage event-driven approaches endpoint, potentially affecting its adherence to monitoring configuration.

5.3.1.  Components, Capabilities and Workflow(s)

   This section provides more detail about the components and
   capabilities required when considering
   some defined policy.  Modification of the aforementioned
   configuration management workflow.

5.3.1.1.  Components

   The following endpoint's minimum password
   length is a minimal list an example of SACM Components required an attribute change which could trigger
   collection.

   External event-based collection can be described as a collector being
   subscribed to
   implement the aforementioned configuration assessment workflow.

   o  Configuration Policy Feed: An an external source of authoritative
      configuration recommendations.

   o  Configuration Policy Repository: information, receiving events
   from that external source on a periodic or continuous basis.  An internal repository
   example of
      enterprise standard configurations.

   o  Configuration Assessment Orchestrator: A event-based collection is subscription to YANG Push
   notifications.

3.4.1.2.  Endpoint

   Building upon [I-D.ietf-sacm-terminology], the SACM Collection Sub-
   Architecture augments the definition of an Endpoint as a component responsible for
      orchestrating assessments.

   o
   within an organization's management domain from which a Posture
   Collection Service will collect relevant posture attributes.

3.4.1.3.  Posture Attribute Collection Subsystem: A Repository

   The Posture Attribute Repository is a SACM component responsible for collection
   the persistent storage of posture attributes from systems.

   o collected via
   interactions between the Posture Attribute Repository: A component used for storing system
      posture attribute values.

   o  Configuration Assessment Evaluator: A component responsible for
      evaluating system posture attribute values against expected
      posture attribute values.

   o  Configuration Assessment Results Repository: A component used for
      storing evaluation results.

5.3.1.2.  Capabilities

   Per [RFC8248], solutions MUST support capability negotiation.
   Components implementing specific interfaces Collection Service and operations (i.e.
   interactions) will need Endpoints.

3.4.1.4.  Posture Collection Workflow

   Posture collection may be triggered from a method number of describing their capabilities to
   other components participating components, but
   commonly begin either via event-based triggering on an endpoint or
   through manual orchestration, both illustrated in Figure 3 above.
   Once orchestration has provided the ecosystem; directive to perform collection,
   posture collection services consume the directives.  Posture
   collection is invoked for example, "As those endpoints overseen by the respective
   posture collection services.  Collected data is then provided to the
   Integration Service, with a
   component directive to store that information in an
   appropriate repository.

3.4.2.  Evaluation Sub-Architecture

   The Evaluation Sub-Architecture, in the ecosystem, I can assess the configuration of
   Windows, MacOS, and AWS using OVAL".

5.3.1.3.  Configuration Assessment Workflow

   This section describes SACM context, is the components and interactions
   mechanism by which policy, expressed in a basic
   configuration assessment workflow.  For simplicity, error conditions
   are recognized as being necessary and are not depicted.  When one
   component messages another component, the message is form of expected to be
   handled appropriately unless there state,
   is compared with collected posture attributes to yield an error condition, or other
   notification, messaged in return.

+-------------+  +----------------+ evaluation
   result, that result being contextually dependent on the policy being
   evaluated.

                        +------------------+  +------------+
| Policy Feed |  |  Orchestrator  |  |    Evaluation
                        |    Collection    | Evaluation |
+------+------+  +-------+--------+    +-------------------------------+
                        | Sub-Architecture |    | Evaluation Results  |
       |                 |           +---^----------+---+  | Repository |
   +--------------+     +--------^---------+    +-----------------^-------------+
   | Orchestrator |              |                                |      +------^-----+
       |                 |               |          |             |
     1.|               3.|             8.|        9.|          10.|
       |                 |
   +------+-------+        (Potentially)                          |
          |                   Perform                 Store Evaluation Results
       Perform               Collection                           |
      Evaluation                 |                                |
          |                      |                                |
+------v-----------------v---------------+----------v-------------+-----+
   +------v----------------------v--------------------------------+-------------+
   |                             Integration Service                            |
+-----+----------------------------------+----------^---------+------^--+
      |                                  |          |         |
   +--------^----------------------^-----------------------^--------------------+
            |                      |                       |
            |                      |                       |
    2.|                                4.|        5.|       6.|    7.|
      |                                  |          |
            |               Retrieve Posture            Perform
     Retrieve Policy           Attributes              Evaluation
            |                      |                       |
            |                      |                       |
     +------v-----+          +-----v------+                       +---v----------+---+  +--v------+--+       +--------v-------------------+
     |   Policy   |          |    Collection  Posture   |       | Posture Evaluation Service |
     | Repository |          | Sub-Architecture |  | Attribute  |       +----------------------------+
     +------------+                       +------------------+          | Repository |
                             +------------+

              Figure 5: Configuration Assessment Component Interactions

   Figure 5 depicts 4: Decomposed Evaluation Sub-Architecture

3.4.2.1.  Posture Evaluation Service

   The Posture Evaluation Service (PES) represents the SACM component
   responsible for coordinating the policy to be evaluated and the
   collected posture attributes relevant to that policy, as well as the
   comparison engine responsible for correctly determining compliance
   with the expected state.

3.4.2.2.  Policy Repository

   The Policy Repository represents a persistent storage mechanism for
   the policy to be assessed against collected posture attributes to
   determine if an endpoint meets the desired expected state.  Examples
   of information contained in a Policy Repository would be
   Vulnerability Definition Data or configuration recommendations as
   part of a CIS Benchmark or DISA STIG.

3.4.2.3.  Evaluation Results Repository

   The Evaluation Results Repository persists the information
   representing the results of a particular posture assessment,
   indicating those posture attributes collected from various endpoints
   which either meet or do not meet the expected state defined by the
   assessed policy.  Consideration should be made for the context of
   individual results.  For example, meeting the expected state for a
   configuration assessment components and their
   interactions, which are further described below.

   1.   A policy feed provides attribute indicates a correct configuration assessment policy payload
        to of the
   endpoint, whereas meeting an expected state for a vulnerable software
   version indicates an incorrect configuration.

3.4.2.4.  Posture Evaluation Workflow

   Posture evaluation is orchestrated through the Integration Service.

   2. Service to
   the appropriate Posture Evaluation Service (PES).  The Policy Repository, a consumer of Policy Feed information,
        receives PES will,
   using interactions defined by the applicable taxonomy, query both the
   Posture Attribute Repository and persists the Policy Feed's payload.

   3.   Orchestration component(s), either manually invoked, scheduled,
        or event-based, publish a payload Repository to begin the configuration
        assessment process.

   4. obtain
   relevant state data for comparison.  If necessary, Collection Sub-Architecture components the PES may be
        invoked
   required to collect neeeded invoke further posture attribute information.

   5.   If necessary, collection.  Once all relevant
   posture information has been collected, it is compared to expected
   state based on applicable policy.  Comparison results are then
   persisted to an evaluation results repository for further downstream
   use and analysis.

4.  Interactions

   SACM Components are intended to interact with other SACM Components.
   These interactions can be thought of, at the Collection Sub-Architecture architectural level, as
   the combination of interfaces with their supported operations.  Each
   interaction will provide
        collected posture attributes convey a payload of information.  The payload
   information is expected to contain sub-domain-specific
   characteristics and/or instructions.

4.1.  Interaction Categories

   Two categories of interactions SHOULD be supported by the Integration
   Service; broadcast and directed.

4.1.1.  Broadcast

   A broadcast interaction, commonly known as "publish/subscribe",
   allows for a wider distribution of a message payload.  When a payload
   is published to a topic on the Integration Service for
        persistence Service, all subscribers
   to the Posture Attribute Repository.

   6.   The Posture Attribute Repository will that topic are alerted and may consume the message payload.  This
   category of interaction can also be described as a "unicast"
   interaction when a topic only has a single subscriber.  An example of
   a broadcast interaction could be to publish Linux OVAL objects to a payload querying
        for relevant
   posture attribute information.

   7.   The Posture Attribute Repository will provide collection topic.  Subscribing consumers receive the requested
        information
   notification, and proceed to collect endpoint configuration posture
   based on the Integration Service, allowing further
        orchestration payloads requesting the Evaluation Sub-
        Architecture perform evaluation tasks.

   8. new content.

4.1.2.  Directed

   The Evaluation Sub-Architecture consumes the evaluation payload
        and performs component-specific state comparison operations intent of a directed interaction is to
        produce evaluation results.

   9.   A payload containing evaluation results are enable point-to-point
   communications between a producer and consumer, through the standard
   interfaces provided by the
        Evaluation Sub-Architecture to the Integration Service

   10.  Evaluation results are consumed by/persisted Service.  The provider
   component indicates which consumer is intended to receive the Evaluation
        Results Repository

   In
   payload, and the above flow, Integration Service routes the payload information is expected directly to convey the
   context required
   that consumer.  Two "styles" of directed interaction exist, differing
   only by the receiving response from the payload consumer.

4.1.2.1.  Synchronous

   Synchronous, request/response style interaction requires that the
   requesting component block and wait for the action being
   taken under different circumstances.  For example, a directed message
   sent from an Orchestrator receiving component to
   respond, or to time out when that response is delayed past a Collection sub-architecture might given
   time threshold.  A synchronous interaction example may be
   telling that Collector to watch querying a specific
   CMDB for posture attribute and
   report only specific detected changes information in order to perform an
   evaluation.

4.1.2.2.  Asynchronous

   An asynchronous interaction involves the Posture Attribute
   Repository, or it might be telling payload producer directing
   the Collector to gather that
   posture attribute immediately.  Such details are expected message to be
   handled as part of that payload, a consumer, but not as part blocking or waiting for an
   immediate response.  This style of interaction allows the architecture
   described herein.

6.  Privacy Considerations

   TODO

7.  Security Considerations

   TODO

8.  IANA Considerations

   TODO: Revamp this section after producer to
   continue on to other activities without the configuration assessment workflow
   is fleshed out.

   IANA tables can probably be used need to make life wait for
   responses.  This style is particularly useful when the interaction
   payload invokes a little easier.  We
   would like potentially long-running task, such as data
   collection, report generation, or policy evaluation.  The receiving
   component may reply later via callbacks or further interactions, but
   it is not mandatory.

4.2.  Management Plane Functions

   Mangement plane functions describe a place component's interactions with
   the ecosystem itself, not necessarily relating to enumerate:

   o  Capability/operation semantics

   o  SACM Component implementation identifiers
   o  SACM Component versions

   o  Associations of SACM Components (and versions) collection,
   evaluation, or downstream analytical processes.

4.2.1.  Orchestrator Onboarding

   The Orchestrator component, being a specialized role in the
   architecture, onboards to specific
      Capabilities

   o  Collection sub-architecture Identification

9.  References

9.1.  Normative References

   [I-D.ietf-sacm-ecp]
              Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin,
              "Endpoint Posture Collection Profile", draft-ietf-sacm-
              ecp-05 (work the ecosystem in progress), June 2019.

   [RFC2119]  Bradner, S., "Key words for use such a manner as to enable
   the onboarding and capabilities of the other component roles.  The
   Orchestrator must be enabled with the set of capabilities needed to
   manage the functions of the ecosystem.

   With this in RFCs mind, the Orchestrator must first authenticate to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8412]  Schmidt, C., Haynes, D., Coffin, C., Waltermire, D., and
              J. Fitzgerald-McKay, "Software Inventory Message and
              Attributes (SWIMA) for PA-TNC", RFC 8412,
              DOI 10.17487/RFC8412, July 2018,
              <https://www.rfc-editor.org/info/rfc8412>.

   [RFC8600]  Cam-Winget, N., Ed., Appala, S., Pope, S., and P. Saint-
              Andre, "Using Extensible Messaging the
   Integration Service.  Once authentication has succeeded, the
   Orchestrator must establish "service handlers" per the Section 5.2.
   Once "service handlers" have been established, the Orchestrator is
   then equipped to handle component registration, onboarding,
   capability discovery, and Presence Protocol
              (XMPP) topic subscription policy.

   The following requirements exist for Security Information Exchange", RFC 8600,
              DOI 10.17487/RFC8600, June 2019,
              <https://www.rfc-editor.org/info/rfc8600>.

9.2.  Informative References

   [CISCONTROLS]
              "CIS Controls v7.0", n.d.,
              <https://www.cisecurity.org/controls>.

   [draft-birkholz-sacm-yang-content]
              Birkholz, H. and N. Cam-Winget, "YANG subscribed
              notifications via SACM Statements", n.d.,
              <https://tools.ietf.org/html/draft-birkholz-sacm-yang-
              content-01>.

   [HACK100]  "IETF 100 Hackathon - Vulnerability Scenario EPCP+XMPP",
              n.d., <https://www.github.com/sacmwg/vulnerability-
              scenario/ietf-hackathon>.

   [HACK101]  "IETF 101 Hackathon - Configuration Assessment XMPP",
              n.d., <https://www.github.com/CISecurity/Integration>.

   [HACK102]  "IETF 102 Hackathon - YANG Collection on Traditional
              Endpoints", n.d.,
              <https://www.github.com/CISecurity/YANG>.

   [HACK103]  "IETF 103 Hackathon - N/A", n.d.,
              <https://www.ietf.org/how/meetings/103/>.

   [HACK104]  "IETF 104 Hackathon - A simple XMPP client", n.d.,
              <https://github.com/CISecurity/SACM-Architecture>.

   [HACK105]  "IETF 105 Hackathon - A more robust XMPP client including
              collection extensions", n.d.,
              <https://github.com/CISecurity/SACM-Architecture>.

   [HACK99]   "IETF 99 Hackathon the Orchestrator to establish
   "service handlers" supporting the Section 5.2: - Vulnerability Scenario EPCP", n.d.,
              <https://www.github.com/sacmwg/vulnerability-scenario/
              ietf-hackathon>.

   [I-D.ietf-sacm-terminology]
              Birkholz, H., Lu, J., Strassner, J., Cam-Winget, N., and
              A. Montville, "Security Automation and Continuous
              Monitoring (SACM) Terminology", draft-ietf-sacm-
              terminology-16 (work in progress), December 2018.

   [NIST800126]
              Waltermire, D., Quinn, S., Booth, H., Scarfone, K., and D.
              Prisaca, "SP 800-126 Rev. 3 The Orchestrator
   MUST enable the capability to receive onboarding requests via the
   "/orchestrator/registration" topic, - The Technical Specification
              for Orchestrator MUST have the Security Content Automation Protocol (SCAP) - SCAP
              Version 1.3", February 2018,
              <https://csrc.nist.gov/publications/detail/sp/800-126/rev-
              3/final>.

   [NISTIR7694]
              Halbardier, A., Waltermire, D.,
   capability to generate, manage, and M. Johnson, "NISTIR
              7694 Specification persist unique identifiers for Asset Reporting Format 1.1", n.d.,
              <https://csrc.nist.gov/publications/detail/nistir/7694/
              final>.

   [RFC5023]  Gregorio, J., Ed. and B. de hOra, Ed., "The Atom
              Publishing Protocol", RFC 5023, DOI 10.17487/RFC5023,
              October 2007, <https://www.rfc-editor.org/info/rfc5023>.

   [RFC7632]  Waltermire, D. and D. Harrington, "Endpoint Security
              Posture Assessment: Enterprise Use Cases", RFC 7632,
              DOI 10.17487/RFC7632, September 2015,
              <https://www.rfc-editor.org/info/rfc7632>.

   [RFC8248]  Cam-Winget, N. and L. Lorenzin, "Security Automation
   all registered components, - The Orchestrator MUST have the
   capability to inventory and
              Continuous Monitoring (SACM) Requirements", RFC 8248,
              DOI 10.17487/RFC8248, September 2017,
              <https://www.rfc-editor.org/info/rfc8248>.

   [RFC8322]  Field, J., Banghart, S., manage its "roster" (the list of
   registered components), - The Orchestrator MUST support making
   directed requests to registered components over the component's
   administrative interface, as configured by the
   "/orchestrator/[component-unique-identifier]" topic.  Administrative
   interface functions are described by their taxonomy, below.

4.2.2.  Component Onboarding

   Component onboarding describes how an individual component becomes
   part of the ecosystem; registering with the orchestrator, advertising
   capabilities, establishing its administrative interface, and D. Waltermire, "Resource-
              Oriented Lightweight Information Exchange (ROLIE)",
              RFC 8322, DOI 10.17487/RFC8322, February 2018,
              <https://www.rfc-editor.org/info/rfc8322>.

   [XMPPEXT]  "XMPP Extensions", n.d., <https://xmpp.org/extensions/>.

Appendix A.  Mapping
   subscribing to RFC8248

   TODO: Consider removing or placing in a separate solution draft. relevant topics.

   The component onboarding workflow involves multiple steps: - The
   component first authenticates to the Integration Service - The
   component then initiates registration with the Orchestrator, per the
   Section 5.2

   Once the component has onboarded and registered with the
   Orchestrator, its administrative interface will have been established
   via the "/orchestrator/[component-unique-identifier]" topic.  This section provides a mapping of XMPP
   administrative interface allows the component to advertise its
   capabilities to the Orchestrator and XMPP Extensions in return, allow the
   Orchestrator to direct capability-specific topic registration to the
   relevant requirements from [RFC8248].  In
   component.  This is performed using the table Section 5.3.1 taxonomy.
   Further described below, the ID and
   Name columns provide "capability advertisement handshake"
   first assumes the ID and Name of onboarding component has the requirement directly out
   of [RFC8248].  The Supported By column may contain one of several
   values:

   o  N/A: The requirement is not applicable ability to this architectural
      exploration

   o  Architecture: This architecture (possibly assuming some
      components) should meet the requirement

   o  XMPP: The set of XMPP Core specifications and the collection of
      applicable extensions, deployment, and operational considerations.

   o  XMPP-Core: The requirement is satisfied describe
   its capabilities so they may be understood by a core XMPP feature

   o  XEP-nnnn: the Orchestrator (TBD
   on capability advertisement methodology).

   *  The requirement is satisfied by component sends a numbered XMPP
      extension (see [XMPPEXT])

   o  Operational: The requirement is an operational concern or can be
      addressed by an message with its operational deployment

   o  Implementation: capabilities
      over the administrative interface: "/orchestrator/[component-
      unique-identifier]"

   *  The requirement is an implementation concern

   If there is no entry in Orchestrator receives the Supported By column, then there is a gap
   that must be filled.

   +----------+----------------------------------------+---------------+
   | ID       | Name                                   |  Supported By |
   +----------+----------------------------------------+---------------+
   | G-001    | Solution Extensibility                 |   XMPP-Core   |
   |          |                                        |               |
   | G-002    | Interoperability                       |      XMPP     |
   |          |                                        |               |
   | G-003    | Scalability                            |      XMPP     |
   |          |                                        |               |
   | G-004    | Versatility                            |   XMPP-Core   |
   |          |                                        |               |
   | G-005    | Information Extensibility              |   XMPP-Core   |
   |          |                                        |               |
   | G-006    | Data Protection                        |  Operational  |
   |          |                                        |               |
   | G-007    | Data Partitioning                      |  Operational  |
   |          |                                        |               |
   | G-008    | Versioning and Backward Compatibility  | XEP-0115/0030 |
   |          |                                        |               |
   | G-009    | Information Discovery                  |    XEP-0030   |
   |          |                                        |               |
   | G-010    | Target Endpoint Discovery              |   XMPP-Core   |
   |          |                                        |               |
   | G-011    | Push and Pull Access                   | XEP-0060/0312 |
   |          |                                        |               |
   | G-012    | SACM Component Interface               |      N/A      |
   |          |                                        |               |
   | G-013    | Endpoint Location component's capabilities, persists
      them, and Network Topology |               |
   |          |                                        |               |
   | G-014    | Target Endpoint Identity               |   XMPP-Core   |
   |          |                                        |               |
   | G-015    | Data Access Control                    |               |
   |          |                                        |               |
   | ARCH-001 | responds with the list of topics to which the component
      should subscribe, in order to receive notifications, instructions,
      or other directives intended to invoke the component's supported
      capabilities.

   *  The component subscribes to the topics provided by the
      Orchestrator

4.3.  Component Functions                    |      XMPP     |
   |          |                                        |               |
   | ARCH-002 | Scalability                            |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-003 | Flexibility                            |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-004 | Separation Interactions

   Component interactions describe functionality between components
   relating to collection, evaluation, or other downstream processes.

4.3.1.  Initiate Ad-Hoc Collection

   The Orchestrator supplies a payload of Data collection instructions to a
   topic or set of topics to which Posture Collection Services are
   subscribed.  The receiving PCS components perform the required
   collection based on their capabilities.  The PCS then forms a payload
   of collected posture attributes (including endpoint identifying
   information) and Management      |               |
   |          | Functions                              |               |
   |          |                                        |               |
   | ARCH-005 | Topology Flexibility                   |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-006 | Capability Negotiation                 | XEP-0115/0030 |
   |          |                                        |               |
   | ARCH-007 | Role-Based Authorization               |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-008 | Context-Based Authorization            |               |
   |          |                                        |               |
   | ARCH-009 | Time Synchronization                   |  Operational  |
   |          |                                        |               |
   | IM-001   | Extensible publishes that payload to the topic(s) to which the
   Posture Attribute Repository is subscribed, for persistence.

4.3.2.  Coordinate Periodic Collection

   Similar to ad-hoc collection, the Orchestrator supplies a payload of
   collection instructions containing additional information regarding
   collection periodicity, to the topic or topics to which Posture
   Collection Services are subscribed.

4.3.2.1.  Schedule Periodic Collection

   Collection instructions include information regarding the schedule
   for collection, for example, every day at Noon, or every hour at 32
   minutes past the hour.

4.3.2.2.  Cancel Periodic Collection

   The Orchestrator supplies a payload of instructions to a topic or set
   of topics to which Posture Collection Services are subscribed.  The
   receiving PCS components cancel the identified periodic collection
   executing on that PCS.

4.3.3.  Coordinate Observational/Event-based Collection

   In these scenarios, the "observer" acts as the Posture Collection
   Service.  Interactions with the observer could specify a time period
   of observation and potentially information intended to filter
   observed posture attributes to aid the PCS in determining those
   attributes that are applicable for collection and persistence to the
   Posture Attribute Vocabulary        |      N/A      |
   |          |                                        |               |
   | IM-002   | Repository.

4.3.3.1.  Initiate Observational/Event-based Collection

   The Orchestrator supplies a payload of instructions to a topic or set
   of topics to which Posture Data Publication               |      N/A      |
   |          |                                        |               |
   | IM-003   | Data Model Negotiation                 |      N/A      |
   |          |                                        |               |
   | IM-004   | Data Model Identification              |      N/A      |
   |          |                                        |               |
   | IM-005   | Data Lifetime Management               |      N/A      |
   |          |                                        |               |
   | IM-006   | Singularity Collection Services (observers) are
   subscribed.  This payload could include specific instructions based
   on the observer's capabilities to determine specific posture
   attributes to observe and Modularity             |      N/A      |
   |          |                                        |               |
   | DM-001   | Element Association                    |      N/A      |
   |          |                                        |               |
   | DM-002   | Data Model Structure                   |      N/A      |
   |          |                                        |               |
   | DM-003   | Search Flexibility                     |      N/A      |
   |          |                                        |               |
   | DM-004   | Full vs. Partial Updates               |      N/A      |
   |          |                                        |               |
   | DM-005   | Loose Coupling                         |      N/A      |
   |          |                                        |               |
   | DM-006   | Data Cardinality                       |      N/A      |
   |          |                                        |               |
   | DM-007   | Data Model Negotiation                 |      N/A      |
   |          |                                        |               |
   | DM-008   | Data Origin                            |      N/A      |
   |          |                                        |               |
   | DM-009   | Origination Time                       |      N/A      |
   |          |                                        |               |
   | DM-010   | Data Generation                        |      N/A      |
   |          |                                        |               |
   | DM-011   | Data Source                            |      N/A      |
   |          |                                        |               |
   | DM-012   | Data Updates                           | collect.

4.3.3.2.  Cancel Observational/Event-based Collection

   The Orchestrator supplies a payload of instructions to a topic or set
   of topics to which Posture Collection Services are subscribed.  The
   receiving PCS components cancel the identified observational/event-
   based collection executing on that PCS.

4.3.4.  Persist Collected Posture Attributes

   [TBD] Normalization?

4.3.5.  Initiate Ad-Hoc Evaluation

   [TBD] ### Coordinate Periodic Evaluation [TBD] #### Schedule [TBD]
   #### Cancel [TBD] ### Coordinate Change-based Evaluation [TBD] i.e.
   if a posture attribute in the repository is changed, trigger an
   evaluation of particular policy items

4.3.6.  Queries

   [TBD] Queries should allow for a "freshness" time period, allowing
   the requesting entity to determine if/when posture attributes must be
   re-collected prior to performing evaluation.  This freshness time
   period can be "zeroed out" for the purpose of automatically
   triggering re-collection regardless of the most recent collection.

5.  Taxonomy
5.1.  Orchestrator Registration

   The Orchestrator Registration taxonomy describes how an Orchestrator
   onboards to the ecosystem, or how it returns from a non-operational
   state.

5.1.1.  Topic

   N/A      |
   |          |                                        |               |
   | DM-013   | Multiple Collectors                    |

5.1.2.  Interaction Type

   Directed (Request/Response)

5.1.3.  Initiator

   Orchestrator

5.1.4.  Request Payload

   N/A      |
   |          |                                        |               |
   | DM-014   | Attribute Extensibility                |

5.1.5.  Receiver

   N/A      |
   |          |                                        |               |
   | DM-015   | Solicited vs. Unsolicited Updates      |

5.1.6.  Process Description

   Once the Orchestrator has authenticated to the Integration Service,
   it must establish (or re-establish) any service handlers interacting
   with administrative interfaces and/or general operational interfaces.

   For initial registration, the Orchestrator MUST enable capabilities
   to:

   *  Receive onboarding requests via the "/orchestrator/registration"
      topic,

   *  Generate, manage, and persist unique identifiers for all
      registered components,

   *  Inventory and manage its "roster" (the list of registered
      components), and

   *  Support making directed requests to registered components over the
      component's administrative interface, as configured by the
      "/orchestrator/[component-unique-identifier]" topic.

   Administrative interfaces are to be re-established through the
   inventory of previously registered components, such as Posture
   Collection Services, Repositories, or Posture Evaluation Services.

5.1.7.  Response Payload

   N/A      |
   |          |                                        |               |
   | DM-016   | Transfer Agnostic                      |

5.1.8.  Response Processing

   N/A      |
   |          |                                        |               |
   | OP-001   | Time Synchronization                   |               |
   |          |                                        |               |
   | OP-002   | Collection Abstraction                 |               |
   |          |                                        |               |
   | OP-003   | Collection Composition                 |               |
   |          |                                        |               |
   | OP-004   | Attribute-Based Query                  |               |
   |          |                                        |               |
   | OP-005   | Information-Based Query

5.2.  Component Registration

   Component onboarding describes how an individual component becomes
   part of the ecosystem; registering with Filtering |               |
   |          |                                        |               |
   | OP-006   | Operation Scalability                  |               |
   |          |                                        |               |
   | OP-007   | Data Abstraction                       |               |
   |          |                                        |               |
   | OP-008   | Provider Restriction                   |               |
   |          |                                        |               |
   | T-001    | Multiple Transfer Protocol Support     |  Architecture |
   |          |                                        |               |
   | T-002    | Data Integrity                         |  Operational  |
   |          |                                        |               |
   | T-003    | Data Confidentiality                   |  Operational  |
   |          |                                        |               |
   | T-004    | Transfer Protection                    |               |
   |          |                                        |               |
   | T-005    | Transfer Reliability                   |               |
   |          |                                        |               |
   | T-006    | Transfer-Layer Requirements            |               |
   |          |                                        |               |
   | T-007    | Transfer Protocol Adoption             |  Architecture |
   +----------+----------------------------------------+---------------+

Appendix B.  Example Components

   TODO: Consider removing.

B.1.  Policy the orchestrator, advertising
   capabilities, establishing its administrative interface, and
   subscribing to relevant topics.

5.2.1.  Topic

   "/orchestrator/registration"

   "[component-type]" includes "pcs", "repository", "pes", and MORE TBD

5.2.2.  Interaction Type

   Directed (Request/Response)

5.2.3.  Initiator

   Any component wishing to join the ecosystem, such as Posture
   Collection Services, Repositories (policy, collection content,
   posture attribute, etc), Posture Evaluation Services

   Consider and more.

5.2.4.  Request Payload

   [TBD] Information Elements, such as - identifying-information -
   component-type (pcs, pes, repository, etc) - name - description

5.2.5.  Receiver

   Orchestrator

5.2.6.  Process Description

   When the Orchestrator receives the component's request for
   onboarding, it will: - Generate a unique identifier, "[component-
   unique-identifier]", for the onboarding component, - Persist required
   information (TBD probably need more specifics), including the
   "[component-unique-identifier]" to its component inventory, enabling
   an up-to-date roster of components being orchestrated, - Establish
   the administrative interface via the "/orchestrator/[component-
   unique-identifier]" topic.

5.2.7.  Response Payload

   [TBD] Information Elements - component-unique-identifier

5.2.8.  Response Processing

   Successful receipt of the Orchestrator's response, including the
   "[component-unique-identifier]" indicates the component is onboarded
   to the ecosystem.  Using the response payload, the component can then
   establish its end of the administrative interface with the
   Orchestrator, using the "/orchestrator/[component-unique-identifier]"
   topic.  Given this administrative interface, the component can then
   initiate the Section 5.3.1

5.3.  Orchestrator-to-Component Administrative Interface

   A number of functions may take place which, instead of being
   published to a multi-subscriber topic, may require direct interaction
   between an Orchestrator and a registered component.  During component
   onboarding, this direct channel is established first by the
   Orchestrator and subsequently complemented by the onboarding
   component.

5.3.1.  Capability Advertisement Handshake

   Capability advertisement, otherwise known as service discovery, is
   necessary to establish and maintain a cooperative ecosystem of tools.
   Using this capability advertisement "handshake", the Orchestrator
   becomes knowledgeable of a policy server conforming to [RFC8322].  [RFC8322]
   describes component's operational capabilities, the
   endpoints/services with which the component interacts, and
   establishes a RESTful way based on direct mode of contact for invoking those capabilities.

5.3.1.1.  Topic

   "/orchestrator/[component-unique-identifier]"

5.3.1.2.  Interaction Type

   Directed (Request/Response)

5.3.1.3.  Initiator

   Any ecosystem component (minus the ATOM Publishing Protocol
   ([RFC5023]) Orchestrator)

5.3.1.4.  Request Payload

   [TBD] Information Elements - component-type - component-unique-
   identifier - interaction-type (capability-advertisement): - list of
   capabilities - list of endpoints/services

5.3.1.5.  Receiver

   Orchestrator

5.3.1.6.  Process Description

   Upon receipt of the component's capability advertisement, it SHOULD:
   - Persist the component's capabilities to find specific data collections.  While this represents
   a specific binding (i.e.  RESTful API the Orchestrator's
   inventory - Coordinate, based on [RFC5023]), the supplied capabilities, a list of
   topics to which the component should subscribe

5.3.1.7.  Response Payload

   [TBD] Information Elements - list of topics to subscribe

5.3.1.8.  Response Processing

   Once the component has received the response to its capability
   advertisement, it should subscribe to the Orchestrator-provided
   topics.

5.3.2.  Directed Collection

   ### Directed Evaluation ### Heartbeat

5.4.  [Taxonomy Name]

   DESCRIPTION OF TAXONOMY

5.4.1.  Topic

   "/name/of/topic" ### Interaction Type [Directed (Request/Response)
   -or- Publish/Subscribe] ### Initiator [Component sending/publishing
   the payload] ### Request Payload DESCRIPTION OF INFORMATION MODEL OF
   REQUEST PAYLOAD; i.e. what elements need to be in whatever format in
   the payload. ### Receiver [Component receiving/subscribed-to the
   payload] ### Process Description [What the receiver does with the
   payload] ### Response Payload DESCRIPTION OF INFORMATION MODEL OF
   RESPONSE PAYLOAD; i.e. what elements need to be in whatever format in
   the payload. ### Response Processing [What the initiator does with
   any response, if there is one]

6.  Privacy Considerations

   [TBD]

7.  Security Considerations

   [TBD]

8.  IANA Considerations

   [TBD] Revamp this section after the configuration assessment workflow
   is fleshed out.

   IANA tables can probably be used to make life a
   more abstract way little easier.  We
   would like a place to look at ROLIE.

   ROLIE provides notional workspaces enumerate:

   *  Capability/operation semantics

   *  SACM Component implementation identifiers

   *  SACM Component versions

   *  Associations of SACM Components (and versions) to specific
      Capabilities

   *  Collection sub-architecture Identification

9.  References

9.1.  Normative References

   [I-D.ietf-sacm-ecp]
              Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin,
              "Endpoint Posture Collection Profile", draft-ietf-sacm-
              ecp-05 (work in progress), 21 June 2019,
              <http://www.ietf.org/internet-drafts/draft-ietf-sacm-ecp-
              05.txt>.

   [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>.

   [RFC8412]  Schmidt, C., Haynes, D., Coffin, C., Waltermire, D., and collections,
              J. Fitzgerald-McKay, "Software Inventory Message and provides the
   concept of information categories
              Attributes (SWIMA) for PA-TNC", RFC 8412,
              DOI 10.17487/RFC8412, July 2018,
              <https://www.rfc-editor.org/info/rfc8412>.

   [RFC8600]  Cam-Winget, N., Ed., Appala, S., Pope, S., and links.  Strictly speaking,
   these are logical concepts independent of the RESTful binding ROLIE
   specifies.  In other words, ROLIE binds a logical interface (i.e.

   GET workspace, GET collection, SET entry, P. Saint-
              Andre, "Using Extensible Messaging and so on) to a specific
   mechanism (namely an ATOM Publication Presence Protocol extension).

   It is not inconceivable to believe there could be a different
   interface mechanism, or a connector, providing these same operations
   using XMPP-Grid as the transfer mechanism.

   Even if a [RFC8322] server were external to an organization, there
   would be a need
              (XMPP) for a policy source inside the organization as well, Security Information Exchange", RFC 8600,
              DOI 10.17487/RFC8600, June 2019,
              <https://www.rfc-editor.org/info/rfc8600>.

9.2.  Informative References

   [CISCONTROLS]
              "CIS Controls v7.0", May 2020,
              <https://www.cisecurity.org/controls>.

   [draft-birkholz-sacm-yang-content]
              Birkholz, H. and it may be preferred for such a policy source to be connected
   directly to the ecosystem's communication infrastructure.

B.2.  Software Inventory N. Cam-Winget, "YANG subscribed
              notifications via SACM Statements", May 2020,
              <https://tools.ietf.org/html/draft-birkholz-sacm-yang-
              content-01>.

   [HACK100]  "IETF 100 Hackathon - Vulnerability Scenario EPCP+XMPP",
              May 2020,
              <https://www.github.com/sacmwg/vulnerability-scenario/
              ietf-hackathon>.

   [HACK101]  "IETF 101 Hackathon - Configuration Assessment XMPP", May
              2020, <https://www.github.com/CISecurity/Integration>.

   [HACK102]  "IETF 102 Hackathon - YANG Collection on Traditional
              Endpoints", May 2020,
              <https://www.github.com/CISecurity/YANG>.

   [HACK103]  "IETF 103 Hackathon - N/A", May 2020,
              <https://www.ietf.org/how/meetings/103/>.

   [HACK104]  "IETF 104 Hackathon - A simple XMPP client", May 2020,
              <https://github.com/CISecurity/SACM-Architecture>.

   [HACK105]  "IETF 105 Hackathon - A more robust XMPP client including
              collection extensions", May 2020,
              <https://github.com/CISecurity/SACM-Architecture>.

   [HACK99]   "IETF 99 Hackathon - Vulnerability Scenario EPCP", May
              2020,
              <https://www.github.com/sacmwg/vulnerability-scenario/
              ietf-hackathon>.

   [I-D.ietf-sacm-terminology]
              Birkholz, H., Lu, J., Strassner, J., Cam-Winget, N., and
              A. Montville, "Security Automation and Continuous
              Monitoring (SACM) Terminology", draft-ietf-sacm-
              terminology-16 (work in progress), 14 December 2018,
              <http://www.ietf.org/internet-drafts/draft-ietf-sacm-
              terminology-16.txt>.

   [NIST800126]
              Waltermire, D., Quinn, S., Booth, H., Scarfone, K., and D.
              Prisaca, "SP 800-126 Rev. 3 - The SACM working group has accepted work on Technical Specification
              for the Endpoint Posture
   Collection Profile [I-D.ietf-sacm-ecp], which describes a collection
   architecture Security Content Automation Protocol (SCAP) - SCAP
              Version 1.3", February 2018,
              <https://csrc.nist.gov/publications/detail/sp/800-126/rev-
              3/final>.

   [NISTIR7694]
              Halbardier, A., Waltermire, D., and may be viewed as a collector coupled with a
   collection-specific repository.

                                 Posture Manager              Endpoint
                Orchestrator    +---------------+        +---------------+
                +--------+      |               |        |               |
                |        |      | +-----------+ |        | +-----------+ |
                |        |<---->| | Posture   | |        | | Posture   | |
                |        | pub/ | | Validator | |        | | Collector | |
                |        | sub  | +-----------+ |        | +-----------+ |
                +--------+      |      |        |        |      |        |
                                |      |        |        |      |        |
Evaluator       Repository      |      |        |        |      |        |
+------+        +--------+      | +-----------+ |<-------| +-----------+ |
|      |        |        |      | | Posture   | | report | | M. Johnson, "NISTIR
              7694 Specification for Asset Reporting Format 1.1", May
              2020,
              <https://csrc.nist.gov/publications/detail/nistir/7694/
              final>.

   [RFC5023]  Gregorio, J., Ed. and B. de hOra, Ed., "The Atom
              Publishing Protocol", RFC 5023, DOI 10.17487/RFC5023,
              October 2007, <https://www.rfc-editor.org/info/rfc5023>.

   [RFC7632]  Waltermire, D. and D. Harrington, "Endpoint Security
              Posture   | |
|      |        |        |      | | Collection| |        | | Collection| |
|      |<-----> |        |<-----| | Manager   | | query  | | Engine    | |
|      |request/|        | store| +-----------+ |------->| +-----------+ |
|      |respond |        |      |               |        |               |
|      |        |        |      |               |        |               |
+------+        +--------+      +---------------+        +---------------+

                  Figure 6: EPCP Collection Architecture

   In Figure 6, any Assessment: Enterprise Use Cases", RFC 7632,
              DOI 10.17487/RFC7632, September 2015,
              <https://www.rfc-editor.org/info/rfc7632>.

   [RFC8248]  Cam-Winget, N. and L. Lorenzin, "Security Automation and
              Continuous Monitoring (SACM) Requirements", RFC 8248,
              DOI 10.17487/RFC8248, September 2017,
              <https://www.rfc-editor.org/info/rfc8248>.

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

   [XMPPEXT]  "XMPP Extensions", May 2020,
              <https://xmpp.org/extensions/>.

Appendix A.  Security Domain Workflows

   This section describes three primary information security domains
   from which workflows may be derived: IT Asset Management,
   Vulnerability Management, and Configuration Management.

A.1.  IT Asset Management

   Information Technology asset management is easier said than done.
   The [CISCONTROLS] have two controls dealing with IT asset management.
   Control 1, Inventory and Control of the communications between the Posture Manager Hardware Assets, states,
   "Actively manage (inventory, track, and EPCP components to its left could be performed directly or
   indirectly using a given message transfer mechanism.  For example, correct) all hardware devices
   on the pub/sub interface between network so that only authorized devices are given access, and
   unauthorized and unmanaged devices are found and prevented from
   gaining access."  Control 2, Inventory and Control of Software
   Assets, states, "Actively manage (inventory, track, and correct) all
   software on the Orchestrator network so that only authorized software is installed
   and can execute, and that unauthorized and unmanaged software is
   found and prevented from installation or execution."

   In spirit, this covers all of the Posture
   Manager could be using a proprietary method processing entities on your network
   (as opposed to things like network cables, dongles, adapters, etc.),
   whether physical or using [RFC8600] virtual, on-premises or
   some other pub/sub mechanism.  Similarly, the store connection from in the Posture Manager cloud.

A.1.1.  Components, Capabilities and Workflow(s)

   TBD

A.1.1.1.  Components

   TBD

A.1.1.2.  Capabilities

   An IT asset management capability needs to the Repository could be performed internally
   to a given implementation, via a RESTful API invocation over HTTPS,
   or even over able to:

   *  Identify and catalog new assets by executing Target Endpoint
      Discovery Tasks

   *  Provide information about its managed assets, including uniquely
      identifying information (for that enterprise)

   *  Handle software and/or hardware (including virtual assets)

   *  Represent cloud hybrid environments

A.1.1.3.  Workflow(s)

   TBD

A.2.  Vulnerability Management

   Vulnerability management is a pub/sub mechanism.

   Our assertion relatively established process.  To
   paraphrase the [CISCONTROLS], continuous vulnerability management is that
   the Evaluator, Repository, Orchestrator, act of continuously acquiring, assessing, and
   Posture Manager all have the potential to represent SACM Components
   with specific capability interfaces that can be logically specified,
   then bound taking subsequent
   action on new information in order to one or more specific transfer mechanisms (i.e.  RESTful
   API, [RFC8322], [RFC8600], identify and so on).

B.3.  Datastream Collection

   [NIST800126], also known as SCAP 1.3, provides remediate
   vulnerabilities, therefore minimizing the technical
   specifications window of opportunity for a "datastream collection".  The specification
   describes
   attackers.

   A vulnerability assessment (i.e. vulnerability detection) is
   performed in two steps:

   *  Endpoint information collected by the endpoint management
      capabilities is examined by the vulnerability management
      capabilities through Evaluation Tasks.

   *  If the "datastream collection" as being "composed of SCAP data
   streams and SCAP source components".  A "datastream" provides an
   encapsulation of possessed by the SCAP source components required to, for example,
   perform configuration assessment on endpoint management capabilities is
      insufficient, a given endpoint.  These source
   components include XCCDF checklists, OVAL Definitions, and CPE
   Dictionary information.  A single "datastream collection" may
   encapsulate multiple "datastreams", Collection Task is triggered and reference any number of SCAP
   components.  Datastream collections were intended to provide an
   envelope enabling transfer of SCAP data more easily.

   The [NIST800126] specification also defines the "SCAP result necessary
      data
   stream" as being conformant to the Asset Reporting Format
   specification, defined in [NISTIR7694].  The Asset Reporting Format
   provides an encapsulation of the SCAP source components, Asset
   Information, and SCAP result components, such as system
   characteristics and state evaluation results.

   What [NIST800126]did not do is specify collected from the interface for finding or
   acquiring source datastream information, nor an interface for
   publishing result information.  Discovering target endpoint.

   Vulnerability detection relies on the actual resources for
   this examination of different
   endpoint information could be done via ROLIE, as described in depending on the Policy
   Services section above, but other repositories nature of SCAP data exist as
   well.

B.4.  Network Configuration Collection

   [draft-birkholz-sacm-yang-content] illustrates a SACM Component
   incorporating specific
   vulnerability.  Common endpoint information used to detect a YANG Push client function and
   vulnerability includes:

   *  A specific software version is installed on the endpoint

   *  File system attributes

   *  Specific state attributes

   In some cases, the endpoint information needed to determine an XMPP-grid publisher
   function. [draft-birkholz-sacm-yang-content] further states "the
   output of
   endpoint's vulnerability status will have been previously collected
   by the YANG Push client function is encapsulated endpoint management capabilities and available in a SACM
   Content Element envelope, which is again encapsulated
   Repository.  However, in a SACM
   statement envelope" which are published, essentially, via an XMPP-
   Grid Connector for SACM Components also part of other cases, the XMPP-Grid.

   This is necessary endpoint
   information will not be readily available in a specific example of an existing Repository and a
   Collection Task will be triggered to perform collection mechanism being
   adapted from the
   target endpoint.  Of course, some implementations of endpoint
   management capabilities may prefer to enable operators to perform
   this collection even when sufficient information can be provided by
   the XMPP-Grid message transfer system.

Appendix C.  Exploring An XMPP-based Solution

   TODO: Consider removing or placing in a separate draft.

   Ongoing work has been taking place around endpoint management capabilities (e.g. there may be freshness
   requirements for information).

A.2.1.  Components, Capabilities and during IETF hackathons. Workflow(s)

   TBD

A.2.1.1.  Components

   TBD

A.2.1.2.  Capabilities

   TBD

A.2.1.3.  Workflow(s)

   TBD

A.3.  Configuration Management

   Configuration management involves configuration assessment, which
   requires state assessment.  The list of hackathon efforts follows:

   o  [HACK99]: A partial implementation of a vulnerability assessment
      scenario involving [CISCONTROLS] specify two high-level
   controls concerning configuration management (Control 5 for non-
   network devices and Control 11 for network devices).  As an [I-D.ietf-sacm-ecp] implementation, a
      [RFC8322] implementation, aside,
   these controls are listed separately because many enterprises have
   different organizations for managing network infrastructure and a proprietary evaluator to pull
   workload endpoints.  Merging the two controls results in the
      pieces together.

   o  [HACK100]: Work to combine
   following paraphrasing: Establish, implement, and actively manage
   (track, report on, correct) the vulnerability assessment scenario
      from [HACK99] with an XMPP-based YANG push model.

   o  [HACK101]: A fully automated security configuration assessment
      implementation of systems
   using XMPP (specifically Publish/Subscribe
      capabilities) as a communication mechanism.

   o  [HACK102]: An exploration of how we might model assessment,
      collection, rigorous configuration management and evaluation abstractly, change control process
   in order to prevent attackers from exploiting vulnerable services and then rely on YANG
      expressions for the attributes of traditional endpoints.

   o  [HACK103]: No SACM participation at the Bangkok hackathon.

   o  [HACK104]: Basic XMPP-to-Concise MAP - Created
   settings.

   Typically, an XMPP adapter
      that can accept basic posture attributes enterprise will use configuration guidance from a
   reputable source, and translate them from time to
      Concise MAP.  This hackathon only proved time they may tailor the concept guidance
   from that system
      characteristics information can be transported via XMPP and
      translated source prior to a (very basic) concise MAP implementation.

   o  [HACK105]: Advanced XMPP-to-Concise MAP: Full orchestration adopting it as part of
      collection capabilities using XMPP.  Collector implementations
      extend the core XMPP structure to allow OVAL collection
      instructions (OVAL objects) to inform posture attribute
      collection.  Collected system characteristics can be their enterprise
   standard.  The enterprise standard is then provided to the Concise MAP XMPP adapter using all 3 available XMPP
      capabilities: Publish/Subscribe, Information Query (iq - request/
      response) stanzas,
   appropriate configuration assessment tools and they assess endpoints
   and/or appropriate endpoint information.

   A preferred flow follows:

   *  Reputable source publishes new or direct Message stanzas.  CDDL was created to
      map collected posture attributes updated configuration guidance
   *  Enterprise configuration assessment capability retrieves
      configuration guidance from reputable source

   *  Optional: Configuration guidance is tailored for enterprise-
      specific needs

   *  Configuration assessment tool queries asset inventory repository
      to Concise MAP structure.  The
      XMPP adapter translates the incoming system characteristics and
      stores the information in the MAP.

   Figure 7 depicts a slightly more detailed view of the architecture
   (within the enterprise boundary) - one that fosters the development
   of retrieve a pluggable ecosystem list of cooperative tools.  Existing collection
   mechanisms can be brought into this affected endpoints

   *  Configuration assessment tool queries configuration state
      repository to evaluate compliance

   *  If information is stale or unavailable, configuration assessment
      tool triggers an ad hoc assessment

   The SACM architecture by specifying needs to support varying deployment models to
   accommodate the
   interface current state of the collector industry, but should strongly
   encourage event-driven approaches to monitoring configuration.

A.3.1.  Components, Capabilities and creating the XMPP-Grid Connector
   binding for that interface.

   Additionally, while not directly depicted in Figure 7, this
   architecture does allow point-to-point interfaces.  In fact,
   [RFC8600] Workflow(s)

   This section provides brokering more detail about the components and
   capabilities to facilitate such point-
   to-point data transfers).  Additionally, each of required when considering the SACM aforementioned
   configuration management workflow.

A.3.1.1.  Components
   depicted in Figure 7 may be a provider, a consumer, or both,
   depending on the workflow in context.

    +--------------+           +--------------+
    | Orchestrator |           | Repositories |
    +------^-------+           +------^-------+
           |                          |
           |                          |
   +-------v--------------------------v--------+     +-----------------+
   |                XMPP-Grid+                 <-----> Downstream Uses |
   +------------------------^------------------+     +-----------------+
                            |
                            |
                    +-------v------+
                    |  XMPP-Grid   |
                    | Connector(s) |
                    +------^-------+
                           |
                    +------v-------+
                    | Collector(s) |
                    +--------------+

                     Figure 7: XMPP-based Architecture

   [RFC8600] details

   The following is a number minimal list of XMPP extensions (XEPs) that MUST be
   utilized SACM Components required to meet
   implement the needs aforementioned configuration assessment workflow.

   *  Configuration Policy Feed: An external source of authoritative
      configuration recommendations.

   *  Configuration Policy Repository: An internal repository of
      enterprise standard configurations.

   *  Configuration Assessment Orchestrator: A component responsible for
      orchestrating assessments.

   *  Posture Attribute Collection Subsystem: A component responsible
      for collection of posture attributes from systems.

   *  Posture Attribute Repository: A component used for storing system
      posture attribute values.

   *  Configuration Assessment Evaluator: A component responsible for
      evaluating system posture attribute values against expected
      posture attribute values.

   *  Configuration Assessment Results Repository: A component used for
      storing evaluation results.

A.3.1.2.  Capabilities

   Per [RFC8248], solutions MUST support capability negotiation.
   Components implementing specific interfaces and operations (i.e.
   interactions) will need a method of [RFC7632] and [RFC8248]:

   o  Service Discovery (XEP-0030): Service Discovery allows XMPP
      entities describing their capabilities to discover information about
   other XMPP entities.  Two
      kinds of information components participating in the ecosystem; for example, "As a
   component in the ecosystem, I can be discovered: assess the identity and
      capabilities configuration of an entity, such as supported features, and items
      associated with an entity.

   o  Publish-Subscribe (XEP-0060): The PubSub extension enables
      entities to create nodes (topics) at a PubSub service
   Windows, MacOS, and publish
      information at those nodes.  Once published, an event notification
      is broadcast to all entities that have subscribed to that node.

   At this point, [RFC8600] specifies fewer features than SACM requires, AWS using OVAL".

A.3.1.3.  Configuration Assessment Workflow

   This section describes the components and there interactions in a basic
   configuration assessment workflow.  For simplicity, error conditions
   are other XMPP extensions (XEPs) we need to consider to
   meet the needs of [RFC7632] recognized as being necessary and [RFC8248].  In Figure 7 we therefore
   use "XMPP-Grid+" to indicate something more than [RFC8600] alone,
   even though we are not yet fully confident in the exact set of XMPP-
   related extensions we will require.  The authors propose work to
   extend (or modify) [RFC8600] to include additional XEPs - possibly
   the following:

   o  Entity Capabilities (XEP-0115): This extension defines depicted.  When one
   component messages another component, the methods
      for broadcasting and dynamically discovering an entities'
      capabilities.  This information message is transported via standard XMPP
      presence.  Example capabilities that could be discovered could
      include support for posture attribute collection, support for
      specific types of posture attribute collection such as EPCP,
      SWIMA, OVAL, or YANG.  Other capabilities are still expected to be
      determined.

   o  Ad Hoc Commands (XEP-0050): This extension allows
   handled appropriately unless there is an XMPP entity
      to advertise and execute application-specific commands.  Typically
      the commands contain data forms (XEP-0004) error condition, or other
   notification, messaged in order to structure
      the information exchange.  This extension may be usable for simple
      orchestration (i.e. "do assessment").

   o  HTTP File Upload (XEP-0363): The HTTP File Upload extension allows
      for large data sets to be published to a specific path on an HTTP
      server, return.

   +-------------+  +----------------+  +------------------+  +------------+
   | Policy Feed |  |  Orchestrator  |  |    Evaluation    |  | Evaluation |
   +------+------+  +-------+--------+  | Sub-Architecture |  |   Results  |
          |                 |           +---^----------+---+  | Repository |
          |                 |               |          |      +------^-----+
          |                 |               |          |             |
        1.|               3.|             8.|        9.|          10.|
          |                 |               |          |             |
          |                 |               |          |             |
   +------v-----------------v---------------+----------v-------------+-----+
   |                           Integration Service                         |
   +-----+----------------------------------+----------^---------+------^--+
         |                                  |          |         |      |
         |                                  |          |         |      |
       2.|                                4.|        5.|       6.|    7.|
         |                                  |          |         |      |
         |                                  |          |         |      |
   +-----v------+                       +---v----------+---+  +--v------+--+
   |   Policy   |                       |    Collection    |  |  Posture   |
   | Repository |                       | Sub-Architecture |  | Attribute  |
   +------------+                       +------------------+  | Repository |
                                                              +------------+

         Figure 5: Configuration Assessment Component Interactions

   Figure 5 depicts configuration assessment components and receive a URL from their
   interactions, which that file can later be
      downloaded again.  XMPP messages and IQs are meant to be compact,
      and large data sets, such as collected posture attributes, may
      exceed further described below.

   1.   A policy feed provides a message size threshold.  Usage of this XEP allows those
      larger data sets configuration assessment policy payload
        to be persisted, thus necessitating only the
      download URL to be passed via XMPP messages.

   o  Personal Eventing Protocol (XEP-0163): Integration Service.

   2.   The Personal Eventing
      Protocol can be thought of as Policy Repository, a virtual PubSub service, allowing
      an XMPP account to publish events only to their roster instead consumer of
      a generic PubSub topic.  This XEP may be useful in Policy Feed information,
        receives and persists the cases when
      collection requests Policy Feed's payload.

   3.   Orchestration component(s), either manually invoked, scheduled,
        or queries are only intended for a subset of
      endpoints and not an entire subscriber set.

   o  File Repository and Sharing (XEP-0214): This extension defines event-based, publish a
      method for XMPP entities payload to designate a set of file available for
      retrieval by other users of their choosing, and is based on PubSub
      Collections.

   o  Easy User Onboarding (XEP-401): The goal of this extension is
      simplified client registration, and begin the configuration
        assessment process.

   4.   If necessary, Collection Sub-Architecture components may be useful when adding new
      endpoints or SACM components
        invoked to collect neeeded posture attribute information.

   5.   If necessary, the ecosystem.

   o  Bidirectional-streams Over Synchronous HTTP (BOSH) (XEP-0124):
      BOSH emulates Collection Sub-Architecture will provide
        collected posture attributes to the semantics of a long-lived, bidirectional TCP
      connection between two entities (aka "long polling").  Consider a
      SACM component that is updated dynamically, i.e. an internal
      vulnerability definition repository ingesting data from a Feed/ Integration Service for
        persistence to the Posture Attribute Repository.

   6.   The Posture Attribute Repository of External Data, and will consume a second SACM component such as
      an Orchestrator.  Using BOSH, payload querying
        for relevant posture attribute information.

   7.   The Posture Attribute Repository will provide the Orchestrator can effectively
      continuously poll requested
        information to the vulnerability definition repository for
      changes/updates.

   o  PubSub Collection Nodes (XEP-0248): Effectively an extension Integration Service, allowing further
        orchestration payloads requesting the Evaluation Sub-
        Architecture perform evaluation tasks.

   8.   The Evaluation Sub-Architecture consumes the evaluation payload
        and performs component-specific state comparison operations to
      XEP-0060 (Publish-Subscribe), PubSub Collections aim
        produce evaluation results.

   9.   A payload containing evaluation results are provided by the
        Evaluation Sub-Architecture to simplify
      an entities' subscription the Integration Service

   10.  Evaluation results are consumed by/persisted to multiple related topics, and
      establishes a "node graph" relating parent nodes the Evaluation
        Results Repository

   In the above flow, the payload information is expected to its
      descendents.  An example "node graph" could be rooted in a
      "vulnerability definitions" topic, and contain descendent topics
      for OS family-level vulnerability definitions (i.e.  Windows), and
      further convey the
   context required by the receiving component for OS family version-level definitions (i.e.  Windows 10
      or Windows Server 2016).

   o  PubSub Since (XEP-0312): This extension enables the action being
   taken under different circumstances.  For example, a subscriber directed message
   sent from an Orchestrator to
      automatically receive PubSub and Personal Eventing Protocol (PEP)
      notifications since its last logout time.  This extension may a Collection sub-architecture might be
      useful in intermittent connection scenarios, or when entities
      disconnect and reconnect
   telling that Collector to the ecosystem.

   o  PubSub Chaining (XEP-0253): This extension describes the
      federation of publishing nodes, enabling watch a publish node of one
      server specific posture attribute and
   report only specific detected changes to the Posture Attribute
   Repository, or it might be a subscriber telling the Collector to a publishing node gather that
   posture attribute immediately.  Such details are expected to be
   handled as part of another server.

C.1.  Example Architecture using XMPP-Grid and Endpoint Posture
      Collection Protocol

   Figure 8 depicts a further detailed view that payload, not as part of the architecture
   including the Endpoint Posture Collection Protocol as the collection
   subsystem, illustrating the idea of a pluggable ecosystem of
   cooperative tools.

          +--------------------+
          | Feeds/Repositories |
          |  of External Data  |
          +--------------------+
                    |
********************v*********************** Boundary of Responsibility *******
*                   |                                                         *
*  +--------------+ | +-------------------+ +-------------+                   *
*  | Orchestrator | | | Posture Attr Repo | | Policy Repo |                   *
*  +------^-------+ | +---------^---------+ +---^---------+                   *
*         |         |           |               |          +----------------+ *
*         |         |           |               |          | Downstream Uses| *
*         |         |           |               |          | +-----------+  | *
*  +------v---------v-----------v---------------v--+       | |Evaluations|  | *
*  |                    XMPP-Grid                  <-------> +-----------+  | *
*  +----------------^-------------------^----------+       | +-----------+  | *
*                   |                   |                  | | Analytics |  | *
*                   |                   |                  | +-----------+  | *
*                   |             +-----v--------+         | +-----------+  | *
*                   |             | Results Repo |         | | Reporting |  | *
*                   |             +--------------+         | +-----------+  | *
*                   |                                      +----------------+ *
*         +---------v-----------+                                             *
*         | XMPP-Grid Connector |                                             *
*         +---------^-----------+                                             *
*                   |                                                         *
* +-----------------v-------------------------------------------------------+ *
* |                                                                         | *
* | +--Posture Collection Manager------------------------------------------+| *
* | |+-----------------------+ +----------------+ +----------------------+ || *
* | || Communications Server | | Posture Server | | Posture Validator(s) | || *
* | |+----------^------------+ +----------------+ +----------------------+ || *
* | +-----------|----------------------------------------------------------+| *
* |             |                                                           | *
* | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| *
* | |+----------v------------+ +----------------+ +----------------------+ || *
* | || Communications Client | | Posture Client | | Posture Collector(s) | || *
* | |+-----------------------+ +----------------+ +----------------------+ || *
* | +----------------------------------------------------------------------+| *
* +-----------------Endpoint Posture Collection Profile---------------------+ *
*                                                                             *
*******************************************************************************

             Figure 8: XMPP-based Architecture including EPCP
   described herein.

Authors' Addresses
   Adam W. Montville
   Center for Internet Security
   31 Tech Valley Drive
   East Greenbush, NY 12061
   USA
   United States of America

   Email: adam.montville.sdo@gmail.com

   Bill Munyan
   Center for Internet Security
   31 Tech Valley Drive
   East Greenbush, NY 12061
   USA
   United States of America

   Email: bill.munyan.ietf@gmail.com