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SACM                                                       N. Cam-Winget
Internet-Draft                                             Cisco Systems
Intended status: Informational                         February 15, 2014
Expires: August 19, 2014

    Secure Automation and Continuous Monitoring (SACM) Requirements


   This document defines the scope and set of requirements for the
   Secure Automation and Continuous Monitoring working group.  The
   requirements and scope are based on the agreed upon use cases and
   architecture defined.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on August 19, 2014.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   2
     2.1.  Reference Architecture Model  . . . . . . . . . . . . . .   2
     2.2.  General SACM requirements . . . . . . . . . . . . . . . .   4
     2.3.  Requirements based on Use Cases . . . . . . . . . . . . .   5
   3.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   Today's challenges of evolving threats and improved analytics to
   address such threats highlight a need to automate the securing of
   both information and the systems that store, process and transmit the
   information.  SACM's charter focuses on addressing some of these
   challenges in a narrower scope by bounding the task to address use
   cases that pertain to the posture assessment of endpoints.

   This document focuses on describing the requirements for facilitating
   the exchange of posture assessment information, in particular, for
   the use cases as exemplified in [I-D.ietf-sacm-use-cases].Also, this
   document uses terminology defined in [I-D.ietf-sacm-terminology].

2.  Requirements

   This document defines requirements based on the SACM use cases
   defined in [I-D.ietf-sacm-use-cases].  This section describes the
   requirements used by SACM to assess and compare candidate information
   models and protocols to suit the architecture.  These requirements
   express characteristics or features that a candidate protocol or data
   model must be capable of offering so as to ensure security and

2.1.  Reference Architecture Model

   A proposed architecture model is provided to highlight the functions
   and focus for SACM.  More specifically to highlight the transport,
   protocols and data model by which:

   o  Endpoints cam be discovered for the purpose of collection of
      posture attributes (or values) by a general collector, a posture

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      attribute collector or a posture attribute evaluator.  The
      communications is shown as "A" in the diagram below.

   o  An (Posture) Assessment Consumer (which could also be a collector)
      can retrieve posture attributes either directly from a Posture
      Assessment Repository (shown as D below) or indirectly from an
      Evaluator (shown as B below).

   How a system determines what posture attributes are to be collected
   or evaluated is out of scope for SACM.

            +-----------+             +-----------+              +---------------------+
            | Endpoint  | <....A....> | Evaluator | <....B....>  | Assessment Consumer |
            +-----------+             |  Service  |              |                     |
                                      +-----------+              +---------------------+
                                +-------|   ^                                ^
            +-----------+       |           | C                              |
            | Endpoint  | <-----+           v                                |
            +-----------+            +-------------+                         |
                                     | Repository  |                         |
                                     +-------------+                         |
                                 +--------------------+           D          |
                                 | Posture Assessment |<---------------------+
                                 |     Repository     |

                        Simple Architectural Model

   The functional components in the proposed architecture are defined

   o  Endpoint: is the endpoint of interest that is posture validated.

   o  Evaluator Service: is the service that determines what posture
      attributes it must collect and evaluate to provide a posture
      assessment of an endpoint.  In order to evaluate posture, this
      service must determine the posture attributes it must assess; in
      addition, it may also provide the collection function as needed to
      evaluate the posture attributes.  Conversely, this service need
      only provide the "collection" function if the posture attribute
      values are the result of an already determined posture attribute

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      evaluation (for instance, if the endpoint can provide that

   o  Repository: is the storage component bound to the Evaluator that
      contains the posture assessment information.

   o  Posture Assessment Repository: is another type of repository (or a
      Collector type) that holds posture assessment information.  While
      not bound to the Evaluator, it is another source of posture
      assessment information (e.g. a data aggregation point aggregating
      posture assessment with other attributes) that can provide
      information to serve SACM use cases.

   o  Assessment Consumer: is the service that requires the posture
      assessments information of one or more assets.

   Using this architectural reference model, the interfaces, data models
   and transports used to affect the posture assessment, e.g. A in the
   figure above have already been defined by different mechanisms, for
   example, an IETF defined one through NEA.  As the focus of SACM is
   the information exchange to obtain the posture assessment
   information, it can be achieved through the interfaces shown as B.
   That is, it is not clear that there is a requirement for the
   Assessment Consumer to tap directly into the Repository.  Similarly,
   it is not clear that SACM is chartered to define the interfaces and
   data model for how an Evaluator stores and transports the assessment
   results to the Repository.  Thus, the focus of the requirements will
   revolve around the data models, protocols and transports for B, the
   communication of posture assessment from an Evaluator to an
   Assessment Consumer.

2.2.  General SACM requirements

   The use cases defined in [I-D.ietf-sacm-use-cases] apply to many
   deployment scenarios.  To ensure interoperability, scalability and
   flexibility in any of these deployments, the following requirements
   are defined for all use cases:

   G-001  The data models, protocols and transports defined by SACM must
    be extensible to allow support for non-standard and future

   G-002  The data models, protocols and transports must be specified
    with enough details and state machine to ensure interoperability.

   G-003  SACM must support a broad set of deployment scenarios.  As
    such, it is possible that the size or posture assessment information
    can vary from a single assessment that is small in (record or

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    datagram) size to a very large datagram or a very large set of
    assessments and must be addressed by the SACM specifications
    defined.  Thus, the data models, protocols and transports must be

   G-004  Considerations for the lightweight implementations of data
    models and transports is required.  Use cases, especially in the
    vulnerability assessment and threat defense applications require
    time criticality in both obtaining the information as well as
    consuming (e.g. parsing) the data.  The agility requirement is to
    ensure that the data model, protocols, transports and its
    implementations are suitable to fit in different deployment models
    and scenarios.

   G-005  Different transports must be supported to address different
    deployment and time constraints.  Supporting the link layer,
    transport and application layers.

   G-006  For interoperability and scope boundary, an explicit set of
    data attributes as mandatory to implement should be defined.  While
    the SACM charter defines the focus to be on posture assessment,
    attributes corresponding to Posture Assessment should be described.

   G-007  To address security and privacy considerations, the data
    model, protocols and transport must consider authorization based on
    roles to only allow authorized requestors and publishers to access
    the information being requested or published.

2.3.  Requirements based on Use Cases

   This section describes the requirements that may apply to information
   models, data models, protocols or transports as identified by the use
   cases in [I-D.ietf-sacm-use-cases] and referenced by the section
   numbers from that draft.

   REQ-001  Use Cases in the whole of Section 2 describe the need for an
    Attribute Dictionary.  With SACM's scope focused on Posture
    Assessment, the attribute collection and aggregation must have a
    well understood set of attributes inclusive of their meaning or
    usage intent.

   REQ-002  Use Case 2.1.1 describes the need for an Information Model
    to drive content definition.  As SACM endeavors to reuse already
    existing standards which may have their own data models defined by
    instantiating an information model, the data models can be mapped to
    SACM's information model.  See [RFC3444] for a description and
    distinctions between an information and data model.

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   REQ-003  Use Case 2.1.1 describes the need to instantiate a data
    model that can map to the SACM protocols for posture content
    operations such as publication, query, change detection and
    asynchronous notifications.

   REQ-004  Use Case 2.1.2 describes the need to discover endpoints and
    their composition.

   REQ-005  Use Case 2.1.2 describes the need for the data model to
    support a query operation based on a set of attributes to facilitate
    collection of information such as posture assessment, inventory (of
    endpoints or endpoint components) and configuration checklist. .

   REQ-006  Use Case 2.1.3 describes the need for the data model to
    support the means for the information to be collected through a
    query mechanism.  Furthermore, the query operation requires
    filtering capabilities to allow for only a subset of information to
    be retrieved.  The query operation may be a synchronous request or
    asynchronous request.

   REQ-007  Use Cases 2.1.3, 2.1.4 and 2.1.5 describe the need for the
    data model to support the means for the information to be published
    asynchronously.  Similarly, the data model must support the means
    for a requestor to obtain updates or change modifications
    asynchronously.  Like the query operation, these update
    notifications can be set up with a filter to allow for only a subset
    of posture assessment information to be obtained.

   REQ-008  Use Cases 2.1.4 and 2.1.5 describes the need for the data
    model to support scalability.  For example, the query operation may
    result in a very large set of attributes as well as a large set of

3.  Acknowledgements

   The authors would like to thank Barbara Fraser, Jim Bieda and Adam
   Montville for reviewing and contributing to this draft.

4.  IANA Considerations

   This memo includes no request to IANA.

5.  Security Considerations

   This document defines the requirements for SACM.  As such, it is
   expected that several data models, protocols and transports may be
   defined or reused from already existing standards.  This section will

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   highlight security considerations that may apply to SACM based on the
   architecture and standards applied in SACM.

6.  References

6.1.  Normative References

              Waltermire, D., Montville, A., and D. Harrington,
              "Terminology for Security Assessment", draft-ietf-sacm-
              terminology-02 (work in progress), January 2014.

              Waltermire, D. and D. Harrington, "Endpoint Security
              Posture Assessment - Enterprise Use Cases", draft-ietf-
              sacm-use-cases-05 (work in progress), November 2013.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

6.2.  Informative References

   [RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
              Information Models and Data Models", RFC 3444, January

   [RFC5209]  Sangster, P., Khosravi, H., Mani, M., Narayan, K., and J.
              Tardo, "Network Endpoint Assessment (NEA): Overview and
              Requirements", RFC 5209, June 2008.

Author's Address

   Nancy Cam-Winget
   Cisco Systems
   3550 Cisco Way
   San Jose, CA  95134

   Email: ncamwing@cisco.com

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