Secure Automation and Continuous Monitoring (SACM) Requirements
draft-ietf-sacm-requirements-00

SACM                                                       N. Cam-Winget
Internet-Draft                                             Cisco Systems
Intended status: Informational                               L. Lorenzin
Expires: March 12, 2015                                 Juniper Networks
                                                       September 8, 2014

    Secure Automation and Continuous Monitoring (SACM) Requirements
                    draft-ietf-sacm-requirements-00

Abstract

   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.

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   This Internet-Draft will expire on March 12, 2015.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   2
     2.1.  General SACM requirements . . . . . . . . . . . . . . . .   2
     2.2.  Requirements based on Use Cases . . . . . . . . . . . . .   5
     2.3.  Requirements for the Information Model  . . . . . . . . .   6
   3.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   Today's challenges of evolving threats and improved analytics
   highlight a need to automate the securing of both information and the
   systems that store, process and transmit the information that can and
   is being leveraged to improve on both threats and analytics to detect
   such threats.  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
   interoperability.

2.1.  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:

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   G-001  Extensibility: the data models, protocols and transports
    defined by SACM must be extensible to allow support for non-standard
    and future extensions.  The transport protocol must support easily
    adding new operations while maintaining backwards compatibility.
    The query language must allow general inquiries as well as
    expression of specific paths to follow; retrieval of specific
    information based on an event, as well as on a continuous basis; and
    the ability to retrieve specific pieces of information, specific
    classes of information, and/or the entirety of available
    information.  The information model must accommodate the addition of
    new data types and/or schemas in a backwards compatible fashion.

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

   G-003  Scalability: The data models, protocols and transports must be
    scalable.  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 datagram) size to a very large datagram or a very large
    set of assessments and must be addressed by the SACM specifications
    defined.

   G-004  Agility: 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.  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.

   G-005  Transport variability: Different transports must be supported
    to address different deployment and time constraints.  Supporting
    transports at the Layer 2, Layer 3 and higher application layers.

   G-006  Extensibility: a method for expressing both standard and non-
    standard (implementer-specific) data attributes while avoiding
    collisions should be defined.  For interoperability and scope
    boundary, an explicit set of data attributes as mandatory to
    implement should be defined and focused on Posture Assessment should
    be described to allow for interoprability too.

   G-007  Data Integrity: A method for ensuring data integrity must be
    provided.  This method is required to be available (i.e. all data-
    handling components must support it), but is not required to be used
    in all cases.

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   G-008  Data Protection: Transport protocols must ensure data
    protection for data in transit by encryption and robustness against
    protocol-based attacks (such as reputation or store-and-forward
    attacks).  Protection for data at rest is not in scope for SACM.
    Data protection may be used for both privacy and non-privacy
    scenarios.

   G-009  Topology Flexibility: Both centralized and decentralized
    (peer-to-peer) information exchange must be supported.  Centralized
    data exchange enables use of a common data format to bridge together
    data exchange between diverse systems, and can leverage a virtual
    data store that centralizes and offloads all data access, storage,
    and maintenance to a dedicated resource.  Decentralized data
    exchange enables simplicity of sharing data between relatively
    uniform systems, and between small numbers of systems, especially
    within a single enterprise domain; systems can utilize an already
    established mutually agreed upon native data format, which may be
    standard or implementation-specific.

   G-010  Data Isolation: A method for partitioning of data must be
    supported, to accommodate considerations such as geographic,
    regulatory, overlay boundaries and federation, where an organization
    may want to differentiate between information that can be shared
    outside its own domain and information that cannot.  As with the
    requirement for data integrity, this method is required to be
    available (i.e. all data-handling components must support it), but
    is not required to be used in all cases.

   G-011  Modularity: Announcement and negotiation of functional
    capabilities (such as authentication protocols, authorization
    schemes, data models, transport protocols, etc.) must be supported,
    enabling a SACM component to make inquiries about the capabilities
    of other components in the SACM ecosystem.

   G-012  Versioning and Backward Compatibility: Announcement and
    negotiation of versions, includsive of exisiting capabilities (such
    as transport protocols, data models, specific attributes within data
    models, standar attribute expression sets, etc.) must be supported.
    Negotiation for both versioning and capability negotiation is needed
    to accommodate future growth and ecosystems with mixed capabilities.

   G-013  Discovery: The solution must provide a mechanism for
    components to discover what information is available across the
    ecosystem (i.e. a method for cataloging data available in the
    ecosystem and advertising it to consumers), and where to go to get a
    specific piece of that information.  For example, providing a method
    by which a node can locate the advertised information so that

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    consumers do not have to have a priori knowledge to find available
    information.

   G-014  Synchronization: Request and response operations must be
    timestamped, and published information must capture time of
    publication.  Actions or decisions based on time-sensitive data
    (such as user logon/logoff, endpoint connection/disconnection,
    endpoint behavior events, etc.) are all predicated on a synchronized
    understanding of time.  A method for detecting and reporting time
    discrepancies must be provided.

   G-015  Collection separation: The request for a data item must
    include enough information to properly identify the item to collect,
    but the request shall not be a command to directly execute nor
    directly applied as arguments to a command.  The purpose of this
    requirement is primarily to reduce the potential attack vectors, but
    has the additional benefit of abstracting the request for collection
    from the collection method thereby allowing more flexibility in how
    collection is implemented.

   G-016  Collection composition A collection request can be composed of
    other collection requests (which yield collected values).  This must
    be able to be expressed as part of the collection request so that
    these references can be resolved at the point of collection without
    having to interact with the requester.

2.2.  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  Attribute Dictionary: 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  Information Model: 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  Data Model to Protocol mapping: 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  Endpoint Discovery: Use Case 2.1.2 describes the need to
    discover endpoints and their composition.

   REQ-005  Attribute based query: 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  Information based query with filtering: 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  Asynchronous publication, updates or change modifications
    with filtering: 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  Data model scalability: 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 targets.

   REQ-009  Separation of Collection Request and Collection Action: the
    data model must distinguish the means to request for a data item to
    include enough information to properly identify the item to collect
    but the request could be separate and distinct from the actual
    method or process used to fulfill the request.

2.3.  Requirements for the Information Model

   It is expected that as applications may produce Posture assessment
   information, they may share it using a specific data model.
   Similarly, applications consuming or requesting Posture Assessment
   information, may require it based on a specific data model.  Thus,
   while there may exist different data models and schemas, they should

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   adhere to a SACM information model that meets a set of requirements
   defined in this section.

   The specific requirements include:

   IM-001  Uniqueness of objects of reference, such as endpoints, IP
    addresses, etc.

   IM-002  Mechanism to resolve or tolerate ambiguity in referents (e.g.
    same IP address used in two separate networks)

   IM-003  Support for rootless searches and wildcard searches

   IM-004  Ability to start a search anywhere in the tree, rather than
    at a specific leaf

   IM-005  Data lifetime management (longevity or expiration of data)

   IM-006  Data ephemerality (update vs. notify)

   IM-007  Looseness of coupling between producer and consumer

   IM-008  Ability to identify data from a specific producer

   IM-009  Metadata cardinality - single-valued vs. multi-valued

   IM-010  Capability negotiation - what data types and schemas are
    supported

   IM-011  Provenance of data - for example:

    *  Publisher identity, classification, trustworthiness,
       authoritativeness

    *  Freshness of data

    *  Method by which data was generated (i.e. self-reported, reported
       by aggregator, result of scan, etc.)

    *  Location of data

    *  Delta results vs. total results

   IM-012  Freshness: Published data must be associated with the time of
    origination - separately from the time of publication required in
    G-014 - so consumers can make decisions about the relevance of the
    data based on its currency and/or age.

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

   To address security and privacy considerations, the data model,
   protocols and transport must consider authorization based on consumer
   function and privileges, to only allow authorized consumers and
   providers to access specific information being requested or
   published.

   To enable federation across multiple entities (such as across
   organizational or geographic boundaries) authorization must also
   extend to infrastructure elements themselves, such as central
   controllers / brokers / data repositories.

   In addition, authorization needs to extend to specific information or
   resources available in the environment.  In other words,
   authorization should be based on both subject (the information
   requestor) and object (the information requested).  The method by
   which this authorization is applied is unspecified.

6.  References

6.1.  Normative References

   [I-D.ietf-sacm-terminology]
              Waltermire, D., Montville, A., Harrington, D., and N. Cam-
              Winget, "Terminology for Security Assessment", draft-ietf-
              sacm-terminology-05 (work in progress), August 2014.

   [I-D.ietf-sacm-use-cases]
              Waltermire, D. and D. Harrington, "Endpoint Security
              Posture Assessment - Enterprise Use Cases", draft-ietf-
              sacm-use-cases-07 (work in progress), April 2014.

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   [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
              2003.

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

Authors' Addresses

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

   Email: ncamwing@cisco.com

   Lisa Lorenzin
   Juniper Networks
   3614 Laurel Creek Way
   Durham, NC  27712
   US

   Email: llorenzin@juniper.net

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