[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-mandm-sacm-architecture) 00 01 02

SACM Working Group                                          A. Montville
Internet-Draft                                                 B. Munyan
Intended status: Standards Track                                     CIS
Expires: January 27, 2020                                  July 26, 2019


   Security Automation and Continuous Monitoring (SACM) Architecture
                        draft-ietf-sacm-arch-02

Abstract

   This memo defines a Security Automation and Continuous Monitoring
   (SACM) architecture.  This work is built upon [RFC8600], and 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

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 27, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents



Montville & Munyan      Expires January 27, 2020                [Page 1]


Internet-Draft              SACM Architecture                  July 2019


   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements notation . . . . . . . . . . . . . . . . . .   3
   2.  Terms and Definitions . . . . . . . . . . . . . . . . . . . .   3
   3.  Architectural Overview  . . . . . . . . . . . . . . . . . . .   3
   4.  Relevant Workflows  . . . . . . . . . . . . . . . . . . . . .   5
     4.1.  IT Asset Management . . . . . . . . . . . . . . . . . . .   5
     4.2.  Vulnerability Management  . . . . . . . . . . . . . . . .   5
     4.3.  Configuration Management  . . . . . . . . . . . . . . . .   6
   5.  Configuration Management Components, Interactions, and
       Capabilities  . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  Components  . . . . . . . . . . . . . . . . . . . . . . .   7
     5.2.  Interactions  . . . . . . . . . . . . . . . . . . . . . .   8
     5.3.  Capabilities  . . . . . . . . . . . . . . . . . . . . . .   8
   6.  Configuration Assessment Workflow . . . . . . . . . . . . . .   9
   7.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  11
     10.2.  Informative References . . . . . . . . . . . . . . . . .  11
   Appendix A.  Mapping to RFC8248 . . . . . . . . . . . . . . . . .  13
   Appendix B.  Example Components . . . . . . . . . . . . . . . . .  16
     B.1.  Policy Services . . . . . . . . . . . . . . . . . . . . .  16
     B.2.  Software Inventory  . . . . . . . . . . . . . . . . . . .  17
     B.3.  Datastream Collection . . . . . . . . . . . . . . . . . .  18
     B.4.  Network Configuration Collection  . . . . . . . . . . . .  18
   Appendix C.  Exploring An XMPP-based Solution . . . . . . . . . .  19
     C.1.  Example Architecture using XMPP-Grid and Endpoint Posture
           Collection Protocol . . . . . . . . . . . . . . . . . . .  22
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  24

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.




Montville & Munyan      Expires January 27, 2020                [Page 2]


Internet-Draft              SACM Architecture                  July 2019


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.






























Montville & Munyan      Expires January 27, 2020                [Page 3]


Internet-Draft              SACM Architecture                  July 2019


                  +--------------------+
                  | Feeds/Repositories |
                  |  of External Data  |
                  +--------------------+
                             |
                             |
*****************************v**************** Enterprise Boundary ************
*                            |                                                *
*  +---------------+         |     +--------------+                           *
*  | Orchestrators |         |     | Repositories |                           *
*  +------^--------+         |     +----^---------+                           *
*         |                  |          |              +----------------+     *
*         |                  |          |              | Downstream Uses|     *
*         |                  |          |              | +-----------+  |     *
*  +------v------------------v----------v------+       | |Evaluations|  |     *
*  |           Message Transfer System         <-------> +-----------+  |     *
*  +----------------------^--------------------+       | +-----------+  |     *
*                         |                            | | Analytics |  |     *
*                         |                            | +-----------+  |     *
*           +-------------v------+                     | +-----------+  |     *
*           | Collection Systems |                     | | Reporting |  |     *
*           +--------------------+                     | +-----------+  |     *
*                                                      +----------------+     *
*******************************************************************************


                      Figure 1: Notional Architecture

   As shown in Figure 1, the notional SACM architecture consists of some
   basic SACM Components using a message transfer system to communicate.
   The message transfer system is expected to maximally align with the
   requirements described in [RFC8248], which means that the message
   transfer system will support brokered (i.e. point-to-point) and
   proxied data exchange.

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

   This document suggests a variety of players in a cooperative
   ecosystem - we call these players 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.
   Generally each role is either a consumer of information or a provider
   of information.





Montville & Munyan      Expires January 27, 2020                [Page 4]


Internet-Draft              SACM Architecture                  July 2019


4.  Relevant Workflows

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

4.1.  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 Hardware Assets, states,
   "Actively manage (inventory, track, and correct) all hardware devices
   on the 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 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 processing entities on your network
   (as opposed to things like network cables, dongles, adapters, etc.),
   whether physical or virtual.

   An IT asset management capability needs to be able to:

   o  Identify 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

4.2.  Vulnerability Management

   Vulnerability management is a relatively established process.  To
   paraphrase the [CISCONTROLS], continuous vulnerability management is
   the act of continuously acquiring, assessing, and taking subsequent
   action on new information in order to identify and remediate
   vulnerabilities, therefore minimizing the window of opportunity for
   attackers.

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




Montville & Munyan      Expires January 27, 2020                [Page 5]


Internet-Draft              SACM Architecture                  July 2019


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

   o  If the data possessed by the endpoint management capabilities is
      insufficient, a Collection Task is triggered and the necessary
      data is collected from the target endpoint.

   Vulnerability detection relies on the examination of different
   endpoint information depending on the nature of a specific
   vulnerability.  Common endpoint information used to detect a
   vulnerability includes:

   o  A specific software version is installed on the endpoint

   o  File system attributes

   o  Specific state attributes

   In some cases, the endpoint information needed to determine an
   endpoint's vulnerability status will have been previously collected
   by the endpoint management capabilities and available in a
   Repository.  However, in other cases, the necessary endpoint
   information will not be readily available in a Repository and a
   Collection Task will be triggered to perform collection 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 endpoint management capabilities (e.g. there may be freshness
   requirements for information).

4.3.  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 for network devices).  As an aside,
   these controls are listed separately because many enterprises have
   different organizations for managing network infrastructure and
   workload endpoints.  Merging the two controls results in the
   following paraphrasing: Establish, implement, and actively manage
   (track, report on, correct) the security configuration of systems
   using a rigorous configuration management and change control process
   in order to prevent attackers from exploiting vulnerable services and
   settings.

   Typically, an enterprise will use configuration guidance from a
   reputable source, and from time to time they may tailor the guidance



Montville & Munyan      Expires January 27, 2020                [Page 6]


Internet-Draft              SACM Architecture                  July 2019


   from that source prior to adopting it as part of their enterprise
   standard.  The enterprise standard 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 is tailored for enterprise-
      specific needs

   o  Configuration assessment tool queries asset inventory repository
      to retrieve a list of affected endpoints

   o  Configuration assessment tool queries configuration state
      repository to evaluate compliance

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

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

5.  Configuration Management Components, Interactions, and Capabilities

   This section provides more detail about the components, interactions,
   and capabilities required when considering the aforementioned
   configuration management workflow.

5.1.  Components

   The following is a minimal list of SACM Components required to
   implement the aforementioned configuration assessment workflow.

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

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

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




Montville & Munyan      Expires January 27, 2020                [Page 7]


Internet-Draft              SACM Architecture                  July 2019


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

   o  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.

5.2.  Interactions

   SACM Components are intended to interact with other SACM Components.
   These interactions can be thought of, at the level of this
   architectural approach, as the combination of interfaces with their
   supported operations.

   o  Store: One component stores information in another.

   o  Ask: A component requests information from another.

   o  Notify/Ask: A component notifies another component, which then
      asks the notifying component (or another component) for
      information.

   o  Publish/Subscribe: A component publishes information to a
      messaging system and a set of other components, subscribed to that
      information type, receive the published information.

   o  Tell: A component instructs another.

   TODO: Consider breaking out Notify, Publish, and Subscribe into
   separate line items, and adding Error (a type of Notify).  Then
   consider explaining the necessary combinations relevant to the
   configuration assessment workflow below.

   Each interaction will convey a payload of information.  The payload
   information is expected to contain sub-domain-specific
   characteristics and instructions.

5.3.  Capabilities

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



Montville & Munyan      Expires January 27, 2020                [Page 8]


Internet-Draft              SACM Architecture                  July 2019


   other components participating in the ecosystem; for example, "As a
   component in the ecosystem, I can assess the configuration of
   Windows, MacOS, and AWS using OVAL".

6.  Configuration Assessment Workflow

   This section describes the components and interactions 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 expected to be
   handled appropriately unless there is an error condition, or other
   notification, messaged in return.

+-------------+
| Policy Feed |
+-----+-------+
      |                     5.1
  1   |   +----------------------------------------+
      |   |                                        |
+-----v------+  2   +----------------+  5  +-----v-----+  6   +------------+
|   Policy   +------>  Orchestrator  +-----> Evaluator +------> Evaluation |
| Repository |      +-------+--------+     +-----^-----+      |   Results  |
+------------+              |                    |            | Repository |
                            | 3                  |            +------------+
                            |                    | 5.2
                 +----------|--------+           |
                 | +--------v------+ |           |
                 | |   Collector   | |           |
                 | +-------+-------+ |   4   +------------+
                 |         |         +-------> Posture    |
                 | +-------+-------+ |       | Attribute  |
                 | | Target System | |       | Repository |
                 | +---------------+ |       +------------+
                 +-------------------+
              Collection Sub-Architecture

         Figure 2: Configuration Assessment Component Interactions

   Figure 2 depicts configuration assessment components and their
   interactions, which are further described below.

   1.  Policy is stored in the Policy Repository: TODO - add specific
       interaction options here.

   2.  The Orchestrator obtains collection information from the Policy
       Repository: TODO - add specific interaction options here.





Montville & Munyan      Expires January 27, 2020                [Page 9]


Internet-Draft              SACM Architecture                  July 2019


   3.  The Orchestrator initiates collection to be performed by the
       Collection Sub-Architecture: TODO - add specific interaction
       options here.

   4.  Collected posture attributes are stored n the Posture Attribute
       Repository: TODO - add specific interaction options here.

   5.  The Orchestrator initiates the Evaluator (optionally with
       evaluation information gathered from the Policy Repository): TODO
       - add specific interaction options here

       1.  The Evaluator obtains evaluation information from the Policy
           Repository (optionally): TODO - add specific interaction
           options here

       2.  The Evaluator obtains relevant posture attributes from the
           Posture Attribute Repository: TODO - add specific interaction
           options here

   6.  Evaluation results are stored in the Evaluation Results
       Repository: TODO - add specific interaction options here

   In the above flow, the payload information is expected to convey the
   context required by the receiving component for the action being
   taken under different circumstances.  For example, the Tell message
   sent from an Orchestrator to a Collection sub-architecture might be
   telling that Collector to watch a specific posture attribute and
   report only specific detected changes to the Posture Attribute
   Repository, or it might be telling the Collector to gather that
   posture attribute immediately.  Such details are expected to be
   handled as part of that payload, not as part of the architecture
   described herein.

7.  Privacy Considerations

   TODO

8.  Security Considerations

   TODO

9.  IANA Considerations

   TODO: Revamp this section after the configuration assessment workflow
   is fleshed out.

   IANA tables can probably be used to make life a little easier.  We
   would like a place to enumerate:



Montville & Munyan      Expires January 27, 2020               [Page 10]


Internet-Draft              SACM Architecture                  July 2019


   o  Capability/operation semantics

   o  SACM Component implementation identifiers

   o  SACM Component versions

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

   o  Collection sub-architecture Identification

10.  References

10.1.  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), June 2019.

   [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
              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 and Presence Protocol
              (XMPP) for Security Information Exchange", RFC 8600,
              DOI 10.17487/RFC8600, June 2019,
              <https://www.rfc-editor.org/info/rfc8600>.

10.2.  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>.



Montville & Munyan      Expires January 27, 2020               [Page 11]


Internet-Draft              SACM Architecture                  July 2019


   [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/IETF104-Client>.

   [HACK105]  "IETF 105 Hackathon - A more robust XMPP client including
              collection extensions", n.d.,
              <https://github.com/CISecurity/IETF104-Client>.

   [HACK99]   "IETF 99 Hackathon - 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 Technical Specification
              for 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., and M. Johnson, "NISTIR
              7694 Specification 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>.



Montville & Munyan      Expires January 27, 2020               [Page 12]


Internet-Draft              SACM Architecture                  July 2019


   [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 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", n.d., <https://xmpp.org/extensions/>.

Appendix A.  Mapping to RFC8248

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

   This section provides a mapping of XMPP and XMPP Extensions to the
   relevant requirements from [RFC8248].  In the table below, the ID and
   Name columns provide the ID and Name of the requirement directly out
   of [RFC8248].  The Supported By column may contain one of several
   values:

   o  N/A: The requirement is not applicable 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 by a core XMPP feature

   o  XEP-nnnn: The requirement is satisfied by a numbered XMPP
      extension (see [XMPPEXT])

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

   o  Implementation: The requirement is an implementation concern

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



Montville & Munyan      Expires January 27, 2020               [Page 13]


Internet-Draft              SACM Architecture                  July 2019


   +----------+----------------------------------------+---------------+
   | 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 and Network Topology |               |
   |          |                                        |               |
   | G-014    | Target Endpoint Identity               |   XMPP-Core   |
   |          |                                        |               |
   | G-015    | Data Access Control                    |               |
   |          |                                        |               |
   | ARCH-001 | Component Functions                    |      XMPP     |
   |          |                                        |               |
   | ARCH-002 | Scalability                            |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-003 | Flexibility                            |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-004 | Separation of Data and Management      |               |
   |          | Functions                              |               |
   |          |                                        |               |
   | ARCH-005 | Topology Flexibility                   |   XMPP-Core   |
   |          |                                        |               |
   | ARCH-006 | Capability Negotiation                 | XEP-0115/0030 |
   |          |                                        |               |
   | ARCH-007 | Role-Based Authorization               |   XMPP-Core   |
   |          |                                        |               |



Montville & Munyan      Expires January 27, 2020               [Page 14]


Internet-Draft              SACM Architecture                  July 2019


   | ARCH-008 | Context-Based Authorization            |               |
   |          |                                        |               |
   | ARCH-009 | Time Synchronization                   |  Operational  |
   |          |                                        |               |
   | IM-001   | Extensible Attribute Vocabulary        |      N/A      |
   |          |                                        |               |
   | IM-002   | 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 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                           |      N/A      |
   |          |                                        |               |
   | DM-013   | Multiple Collectors                    |      N/A      |
   |          |                                        |               |
   | DM-014   | Attribute Extensibility                |      N/A      |
   |          |                                        |               |
   | DM-015   | Solicited vs. Unsolicited Updates      |      N/A      |
   |          |                                        |               |
   | DM-016   | Transfer Agnostic                      |      N/A      |
   |          |                                        |               |



Montville & Munyan      Expires January 27, 2020               [Page 15]


Internet-Draft              SACM Architecture                  July 2019


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

   Consider a policy server conforming to [RFC8322].  [RFC8322]
   describes a RESTful way based on the ATOM Publishing Protocol
   ([RFC5023]) to find specific data collections.  While this represents
   a specific binding (i.e.  RESTful API based on [RFC5023]), there is a
   more abstract way to look at ROLIE.

   ROLIE provides notional workspaces and collections, and provides the
   concept of information categories 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.




Montville & Munyan      Expires January 27, 2020               [Page 16]


Internet-Draft              SACM Architecture                  July 2019


   GET workspace, GET collection, SET entry, and so on) to a specific
   mechanism (namely an ATOM Publication 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 for a policy source inside the organization as well,
   and it may be preferred for such a policy source to be connected
   directly to the ecosystem's communication infrastructure.

B.2.  Software Inventory

   The SACM working group has accepted work on the Endpoint Posture
   Collection Profile [I-D.ietf-sacm-ecp], which describes a collection
   architecture 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 | | Posture   | |
|      |        |        |      | | Collection| |        | | Collection| |
|      |<-----> |        |<-----| | Manager   | | query  | | Engine    | |
|      |request/|        | store| +-----------+ |------->| +-----------+ |
|      |respond |        |      |               |        |               |
|      |        |        |      |               |        |               |
+------+        +--------+      +---------------+        +---------------+


                  Figure 3: EPCP Collection Architecture

   In Figure 3, any of the communications between the Posture Manager
   and EPCP components to its left could be performed directly or
   indirectly using a given message transfer mechanism.  For example,
   the pub/sub interface between the Orchestrator and the Posture
   Manager could be using a proprietary method or using [RFC8600] or
   some other pub/sub mechanism.  Similarly, the store connection from
   the Posture Manager to the Repository could be performed internally



Montville & Munyan      Expires January 27, 2020               [Page 17]


Internet-Draft              SACM Architecture                  July 2019


   to a given implementation, via a RESTful API invocation over HTTPS,
   or even over a pub/sub mechanism.

   Our assertion is that the Evaluator, Repository, Orchestrator, and
   Posture Manager all have the potential to represent SACM Components
   with specific capability interfaces that can be logically specified,
   then bound to one or more specific transfer mechanisms (i.e.  RESTful
   API, [RFC8322], [RFC8600], and so on).

B.3.  Datastream Collection

   [NIST800126], also known as SCAP 1.3, provides the technical
   specifications for a "datastream collection".  The specification
   describes the "datastream collection" as being "composed of SCAP data
   streams and SCAP source components".  A "datastream" provides an
   encapsulation of the SCAP source components required to, for example,
   perform configuration assessment on a given endpoint.  These source
   components include XCCDF checklists, OVAL Definitions, and CPE
   Dictionary information.  A single "datastream collection" may
   encapsulate multiple "datastreams", 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 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 the interface for finding or
   acquiring source datastream information, nor an interface for
   publishing result information.  Discovering the actual resources for
   this information could be done via ROLIE, as described in the Policy
   Services section above, but other repositories of SCAP data exist as
   well.

B.4.  Network Configuration Collection

   [draft-birkholz-sacm-yang-content] illustrates a SACM Component
   incorporating a YANG Push client function and an XMPP-grid publisher
   function. [draft-birkholz-sacm-yang-content] further states "the
   output of the YANG Push client function is encapsulated in a SACM
   Content Element envelope, which is again encapsulated in a SACM
   statement envelope" which are published, essentially, via an XMPP-
   Grid Connector for SACM Components also part of the XMPP-Grid.





Montville & Munyan      Expires January 27, 2020               [Page 18]


Internet-Draft              SACM Architecture                  July 2019


   This is a specific example of an existing collection mechanism being
   adapted to 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 and during IETF hackathons.
   The list of hackathon efforts follows:

   o  [HACK99]: A partial implementation of a vulnerability assessment
      scenario involving an [I-D.ietf-sacm-ecp] implementation, a
      [RFC8322] implementation, and a proprietary evaluator to pull the
      pieces together.

   o  [HACK100]: Work to combine the vulnerability assessment scenario
      from [HACK99] with an XMPP-based YANG push model.

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

   o  [HACK102]: An exploration of how we might model assessment,
      collection, and evaluation abstractly, 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 an XMPP adapter
      that can accept basic posture attributes and translate them to
      Concise MAP.  This hackathon only proved the concept that system
      characteristics information can be transported via XMPP and
      translated to a (very basic) concise MAP implementation.

   o  [HACK105]: Advanced XMPP-to-Concise MAP: Full orchestration 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 provided to
      the Concise MAP XMPP adapter using all 3 available XMPP
      capabilities: Publish/Subscribe, Information Query (iq - request/
      response) stanzas, or direct Message stanzas.  CDDL was created to
      map collected posture attributes to Concise MAP structure.  The
      XMPP adapter translates the incoming system characteristics and
      stores the information in the MAP.

   Figure 4 depicts a slightly more detailed view of the architecture
   (within the enterprise boundary) - one that fosters the development



Montville & Munyan      Expires January 27, 2020               [Page 19]


Internet-Draft              SACM Architecture                  July 2019


   of a pluggable ecosystem of cooperative tools.  Existing collection
   mechanisms can be brought into this architecture by specifying the
   interface of the collector and creating the XMPP-Grid Connector
   binding for that interface.

   Additionally, while not directly depicted in Figure 4, this
   architecture does allow point-to-point interfaces.  In fact,
   [RFC8600] provides brokering capabilities to facilitate such point-
   to-point data transfers).  Additionally, each of the SACM Components
   depicted in Figure 4 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 4: XMPP-based Architecture

   [RFC8600] details a number of XMPP extensions (XEPs) that MUST be
   utilized to meet the needs of [RFC7632] and [RFC8248]:

   o  Service Discovery (XEP-0030): Service Discovery allows XMPP
      entities to discover information about other XMPP entities.  Two
      kinds of information can be discovered: the identity and
      capabilities 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 and publish
      information at those nodes.  Once published, an event notification
      is broadcast to all entities that have subscribed to that node.





Montville & Munyan      Expires January 27, 2020               [Page 20]


Internet-Draft              SACM Architecture                  July 2019


   At this point, [RFC8600] specifies fewer features than SACM requires,
   and there are other XMPP extensions (XEPs) we need to consider to
   meet the needs of [RFC7632] and [RFC8248].  In Figure 4 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 the methods
      for broadcasting and dynamically discovering an entities'
      capabilities.  This information 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 to be
      determined.

   o  Ad Hoc Commands (XEP-0050): This extension allows an XMPP entity
      to advertise and execute application-specific commands.  Typically
      the commands contain data forms (XEP-0004) 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, and receive a URL from 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 a message size threshold.  Usage of this XEP allows those
      larger data sets to be persisted, thus necessitating only the
      download URL to be passed via XMPP messages.

   o  Personal Eventing Protocol (XEP-0163): The Personal Eventing
      Protocol can be thought of as a virtual PubSub service, allowing
      an XMPP account to publish events only to their roster instead of
      a generic PubSub topic.  This XEP may be useful in the cases when
      collection requests 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 a
      method for XMPP entities 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 may be useful when adding new
      endpoints or SACM components to the ecosystem.



Montville & Munyan      Expires January 27, 2020               [Page 21]


Internet-Draft              SACM Architecture                  July 2019


   o  Bidirectional-streams Over Synchronous HTTP (BOSH) (XEP-0124):
      BOSH emulates 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/
      Repository of External Data, and a second SACM component such as
      an Orchestrator.  Using BOSH, the Orchestrator can effectively
      continuously poll the vulnerability definition repository for
      changes/updates.

   o  PubSub Collection Nodes (XEP-0248): Effectively an extension to
      XEP-0060 (Publish-Subscribe), PubSub Collections aim to simplify
      an entities' subscription to multiple related topics, and
      establishes a "node graph" relating parent nodes 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 for OS family version-level definitions (i.e.  Windows 10
      or Windows Server 2016).

   o  PubSub Since (XEP-0312): This extension enables a subscriber to
      automatically receive PubSub and Personal Eventing Protocol (PEP)
      notifications since its last logout time.  This extension may be
      useful in intermittent connection scenarios, or when entities
      disconnect and reconnect to the ecosystem.

   o  PubSub Chaining (XEP-0253): This extension describes the
      federation of publishing nodes, enabling a publish node of one
      server to be a subscriber to a publishing node of another server.

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

   Figure 5 depicts a further detailed view of the architecture
   including the Endpoint Posture Collection Protocol as the collection
   subsystem, illustrating the idea of a pluggable ecosystem of
   cooperative tools.














Montville & Munyan      Expires January 27, 2020               [Page 22]


Internet-Draft              SACM Architecture                  July 2019


          +--------------------+
          | Feeds/Repositories |
          |  of External Data  |
          +--------------------+
                    |
********************v************************* Enterprise Boundary ************
*                   |                                                         *
*  +--------------+ | +-------------------+ +-------------+                   *
*  | 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 5: XMPP-based Architecture including EPCP







Montville & Munyan      Expires January 27, 2020               [Page 23]


Internet-Draft              SACM Architecture                  July 2019


Authors' Addresses

   Adam W. Montville
   Center for Internet Security
   31 Tech Valley Drive
   East Greenbush, NY  12061
   USA

   Email: adam.montville.sdo@gmail.com


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

   Email: bill.munyan.ietf@gmail.com

































Montville & Munyan      Expires January 27, 2020               [Page 24]


Html markup produced by rfcmarkup 1.129c, available from https://tools.ietf.org/tools/rfcmarkup/