Security Automation and Continuous Monitoring (SACM) Architecture
draft-ietf-sacm-arch-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Expired".
|
|
|---|---|---|---|
| Authors | Adam W. Montville , Bill Munyan | ||
| Last updated | 2018-08-24 | ||
| Replaces | draft-mandm-sacm-architecture | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Associated WG milestone |
|
||
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-sacm-arch-00
SACM Working Group A. Montville
Internet-Draft B. Munyan
Intended status: Standards Track CIS
Expires: February 25, 2019 August 24, 2018
Security Automation and Continuous Monitoring (SACM) Architecture
draft-ietf-sacm-arch-00
Abstract
This memo defines a Security Automation and Continuous Monitoring
(SACM) architecture. This work is built upon
[I-D.ietf-mile-xmpp-grid], 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 http://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 February 25, 2019.
Copyright Notice
Copyright (c) 2018 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
(http://trustee.ietf.org/license-info) in effect on the date of
Montville & Munyan Expires February 25, 2019 [Page 1]
Internet-Draft SACM Architecture August 2018
publication of this document. Please review these documents
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. Open Questions . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements notation . . . . . . . . . . . . . . . . . . 3
2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 4
3. Architectural Overview . . . . . . . . . . . . . . . . . . . 4
3.1. SACM Roles . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. Exploring An XMPP-based Solution . . . . . . . . . . . . 5
4. Components, Capabilities, Interfaces, and Workflows . . . . . 7
4.1. Components . . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Capabilities . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Interfaces . . . . . . . . . . . . . . . . . . . . . . . 9
4.4. Workflows . . . . . . . . . . . . . . . . . . . . . . . . 9
4.4.1. IT Asset Management . . . . . . . . . . . . . . . . . 9
4.4.2. Vulnerability Management . . . . . . . . . . . . . . 10
4.4.3. Configuration Management . . . . . . . . . . . . . . 12
5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
8.1. Normative References . . . . . . . . . . . . . . . . . . 13
8.2. Informative References . . . . . . . . . . . . . . . . . 14
Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 15
Appendix B. Example Components . . . . . . . . . . . . . . . . . 18
B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 18
B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 19
B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 20
B.4. Network Configuration Collection . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
The purpose of this draft is to define an architectural solution for
a SACM Domain. This draft also defines an implementation of the
architecutre, built upon [I-D.ietf-mile-xmpp-grid] and
[I-D.ietf-sacm-ecp]. These approaches complement each other to more
completely meet the spirit of [RFC7632] and requirements found in
[RFC8248].
Montville & Munyan Expires February 25, 2019 [Page 2]
Internet-Draft SACM Architecture August 2018
This solution gains the most advantage by supporting a variety of
collection mechanisms. In this sense, the solution ideally intends
to enable a cooperative ecosystem of tools from disparate sources
with minimal operator configuration. The solution described in this
document seeks to accommodate these recognitions by first defining a
generic abstract architecture, then making that solution somewhat
more concrete.
Keep in mind that, at this point, the draft is tracking ongoing work
being performed primarily 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 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.
1.1. Open Questions
[NOTE: This section will eventually be removed.]
The following is a list of open questions we still have about the
path forward with this exploration:
o Should workflows be documented in this draft or separate drafts?
o Should interfaces be documented in workflow drafts or separate
drafts (or even this draft)?
1.2. 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].
Montville & Munyan Expires February 25, 2019 [Page 3]
Internet-Draft SACM Architecture August 2018
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 state collection mechanisms, 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.
+----------+ +------+ +------------+
|Repository| |Policy| |Orchestrator|
+----^-----+ +--^---+ +----^-------+ +----------------+
A | B | C | | Downstream Uses|
| | | | +-----------+ |
+----v---------------v------------v-------+ | |Evaluations| |
| Message Transfer <-------> +-----------+ |
+----------------^------------------------+ D | +---------+ |
| | |Analytics| |
| | +---------+ |
+-------v--------- | +---------+ |
| Transfer System | | |Reporting| |
| Connector | | +---------+ |
+-------^---------+ +----------------+
|
|
+-------v-------+
| Collection |
| System |
+---------------+
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.
While not depicted, 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.
Additionally, component-specific interfaces (i.e. such as A, B, C,
and D in Figure 1) are expected to be specified logically then bound
Montville & Munyan Expires February 25, 2019 [Page 4]
Internet-Draft SACM Architecture August 2018
to one or more specific implementations. This SHOULD be done for
each capability related to the given SACM Component.
3.1. SACM Roles
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. The "Components, Capabilities, Interfaces, and
Workflows" section provides more details about SACM Components that
play these types of roles.
3.2. Exploring An XMPP-based Solution
Figure 2 depicts a more detailed view of the architecture - one that
fosters the development 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 2, this
architecture does allow point-to-point interfaces. In fact,
[I-D.ietf-mile-xmpp-grid] provides brokering capabilities to
facilitate such point-to-point data transfers). Additionally, each
of the SACM Components depicted in Figure 2 may be a provider, a
consumer, or both, depending on the workflow in context.
Montville & Munyan Expires February 25, 2019 [Page 5]
Internet-Draft SACM Architecture August 2018
+----------+ +------+ +------------+
|Repository| |Policy| |Orchestrator|
+----^-----+ +--^---+ +----^-------+
| | |
| | |
+----v---------------v------------v-----------------+ +-----------------+
| XMPP-Grid+ <-----> Downstream Uses |
+-----^-------------^-------------^-------------^---+ +-----------------+
| | | |
| | | |
+----v----+ +----v----+ +----v----+ +----v----+
|XMPP-Grid| |XMPP-Grid| |XMPP-Grid| |XMPP-Grid|
/~~|Connector|~~~|Connector|~~~|Connector|~~~|Connector|~~\
| +----^----+ +----^----+ +----^----+ +----^----+ |
| | | | | |
| +----v-----+ +----v-----+ +----v----+ +----v----+ |
| |EPCP/SWIMA| |Datastream| |YANG Push| | IPFIX | |
| +----------+ +----------+ +---------+ +---------+ |
| Collectors |
\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~/
Figure 2: Detailed Architecture
At this point, [I-D.ietf-mile-xmpp-grid] 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 2 we therefore use "XMPP-Grid+" to indicate something more
than [I-D.ietf-mile-xmpp-grid] 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)
[I-D.ietf-mile-xmpp-grid] to include additional XEPs - possibly the
following:
o Entity Capabilities (XEP-0115): May be used to express the
specific capabilities that a particular client embodies.
o Form Discovery and Publishing (XEP-0346): May be used for
datastream examples requiring some expression of a request
followed by an expected response.
o Ad Hoc Commands (XEP-0050): May be usable for simple orchestration
(i.e. "do assessment").
o File Repository and Sharing (XEP-0214): Appears to be needed for
handling large amounts of data (if not fragmenting).
o Publishing Stream Initiation Requests (XEP-0137): Provides ability
to stream information between two XMPP entities.
Montville & Munyan Expires February 25, 2019 [Page 6]
Internet-Draft SACM Architecture August 2018
o PubSub Collection Nodes (XEP-0248): Nested topics for
specialization to the leaf node level.
o Security Labels In Pub/Sub (XEP-0314): Enables tagging data with
classification categories.
o PubSub Since (XEP-0312): Persists published items, which may be
useful in intermittent connection scenarios
o PubSub Chaining (XEP-0253): Federation of publishing nodes
enabling a publish node of one server to be a subscriber to a
publishing node of another server
o Easy User Onboarding (XEP-401): Simplified client registration
4. Components, Capabilities, Interfaces, and Workflows
The SACM Architecture consists of a variety of SACM Components, and
named components are intended to embody one or more specific
capabilities. Interacting with these capabilities will require at
least two levels of interface specification. The first is a logical
interface specification, and the second is at least one binding to a
specific transfer mechanism. An example transfer mechanism is XMPP-
Grid+.
The following subsections describe some of the components,
capabilities, and interfaces we may expect to see participating in a
SACM Domain.
4.1. Components
The following is a list of suggested SACM Component classes and
specializations.
o Repository
* Vulnerability Information Repository
* Asset Inventory Repository
+ Software Inventory Repository
+ Device Inventory Repository
* Configuration Policy Repository
* Configuration State Repository
Montville & Munyan Expires February 25, 2019 [Page 7]
Internet-Draft SACM Architecture August 2018
o Collector
* Vulnerability State Collector
* Asset Inventory Collector
+ Software Inventory Collector
+ Device Inventory Collector
* Configuration State Collector
o Evaluator
* Vulnerability State Evaluator
* Asset Inventory Evaluator
+ Software Inventory Evaluator
+ Device Inventory Evaluator
* Configuration State Evaluator
o Orchestrator
* Vulnerability Management Orchestrator
* Asset Management Orchestrator
+ Software Inventory Evaluator
+ Device Inventory Evaluator
* Configuration Management Orchestrator
4.2. Capabilities
Repositories will have a need for fairly standard CRUD operations and
query by attribute operations. Collector interfaces may enable ad
hoc assessment (on-demand processing), state item watch actions (i.e.
watch a particular item for particular change), persisting other
behaviors (i.e. setting some mandatory reporting period). Evaluators
may have their own set of interfaces, and an Assessor would represent
both Collector and Evaluation interfaces, and may have additional
concerns added to an Assessor Interface.
Montville & Munyan Expires February 25, 2019 [Page 8]
Internet-Draft SACM Architecture August 2018
Not to be overlooked, whatever solution at which we arrive, per
[RFC8248], MUST support capability negotiation. While not explicitly
treated here, each interface will understand specific serializations,
and other component needs to express those serializations to other
components.
A capability language is fully explored in mandl-sacm-tool-
capability-language (to be submitted).
4.3. Interfaces
Interfaces should be derived directly from identified workflows,
several of which are described in this document.
4.4. Workflows
The workflows described in this document should be considered as
candidate workflows - informational for the purpose of discovering
the necessary components and specifying their interfaces.
4.4.1. 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)
Montville & Munyan Expires February 25, 2019 [Page 9]
Internet-Draft SACM Architecture August 2018
o Represent cloud hybrid environments
4.4.2. Vulnerability Management
Vulnerability management is a relatively established process.
According to the [CISCONTROLS], continuous vulnerability management
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.
4.4.2.1. Vulnerability Assessment Workflow Assumptions
A number of assumptions must be stated to clarify the scope of a
vulnerability assessment workflow:
o The enterprise has received vulnerability description information,
and that the information has already been processed into
vulnerability detection data that the enterprise's security
software tools can understand and use.
o The enterprise has a suitable IT Asset Management capability
o The enterprise has a means of extracting relevant information
about enterprise endpoints in a form that is compatible with the
vulnerability description data (appropriate Collectors for their
technologies)
o All information described in this scenario is available in the
vulnerability description data and serves as the basis of
assessments.
o The enterprise can provide all relevant information about any
endpoint needed to perform the described assessment (the
appropriate Repositories are available)
o The enterprise has a mechanism for long-term storage of
vulnerability description information, vulnerability detection
data, and vulnerability assessment results.
o The enterprise has a procedure for reassessment of endpoints at
some point after initial assessment
4.4.2.2. Vulnerability Assessment Workflow
When new vulnerability description information is received by the
enterprise, affected endpoints are identified and assessed. The
vulnerability is said to apply to an endpoint if the endpoint
Montville & Munyan Expires February 25, 2019 [Page 10]
Internet-Draft SACM Architecture August 2018
satisfies the conditions expressed in the vulnerability detection
data.
A vulnerability assessment (i.e. vulnerability detection) is
performed in two steps:
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 many 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 collect it from the target
endpoint. Of course, some implementations of endpoint management
capabilities may prefer to enable operators to perform this
collection under certain circumstances, even when sufficient
information can be provided by the endpoint management capabilities
(e.g. there may be freshness requirements for information).
The collection of additional endpoint information for the purpose of
vulnerability assessment does not necessarily need to be a pull by
the vulnerability assessment capabilities. Over time, some new
pieces of information that are needed during common types of
assessments might be identified. Endpoint management capabilities
can be reconfigured to have this information delivered automatically.
This avoids the need to trigger additional Collection Tasks to gather
this information during assessments, streamlining the assessment
process. Likewise, it might be observed that certain information
delivered by endpoint management capabilities is rarely used. In
this case, it might be useful to re-configure the endpoint management
Montville & Munyan Expires February 25, 2019 [Page 11]
Internet-Draft SACM Architecture August 2018
capabilities to no longer collect this information to reduce network
and processing overhead. Instead, a new Collection Task can be
triggered to gather this data on the rare occasions when it is
needed.
4.4.3. Configuration Management
Configuration management involves configuration assessment, which
requires state assessment (TODO: Tie to SACM use cases). The
[CISCONTROLS] specify two high-level controls conerning configuration
managment (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 a requirement to: "Establish, implement, and
actively manage (track, report on, correct) the security
configuration of (endpoints) 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
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.
Montville & Munyan Expires February 25, 2019 [Page 12]
Internet-Draft SACM Architecture August 2018
5. Privacy Considerations
TODO
6. Security Considerations
TODO
7. IANA Considerations
IANA tables can probably be used to make life a little easier. We
would like a place to enumerate:
o Capability/operation semantics
o SACM Component implementation identifiers
o SACM Component versions
o Associations of SACM Components (and versions) to specific
Capabilities
8. References
8.1. Normative References
[I-D.ietf-mile-xmpp-grid]
Cam-Winget, N., Appala, S., Pope, S., and P. Saint-Andre,
"Using XMPP for Security Information Exchange", draft-
ietf-mile-xmpp-grid-06 (work in progress), June 2018.
[I-D.ietf-sacm-ecp]
Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin,
"Endpoint Posture Collection Profile", draft-ietf-sacm-
ecp-02 (work in progress), July 2018.
[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>.
Montville & Munyan Expires February 25, 2019 [Page 13]
Internet-Draft SACM Architecture August 2018
8.2. 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>.
[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-15 (work in progress), June 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>.
Montville & Munyan Expires February 25, 2019 [Page 14]
Internet-Draft SACM Architecture August 2018
[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 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
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
Montville & Munyan Expires February 25, 2019 [Page 15]
Internet-Draft SACM Architecture August 2018
If there is no entry in 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 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 |
Montville & Munyan Expires February 25, 2019 [Page 16]
Internet-Draft SACM Architecture August 2018
| | | |
| ARCH-007 | Role-Based Authorization | XMPP-Core |
| | | |
| 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 |
Montville & Munyan Expires February 25, 2019 [Page 17]
Internet-Draft SACM Architecture August 2018
| | | |
| DM-016 | Transfer Agnostic | N/A |
| | | |
| 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
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 February 25, 2019 [Page 18]
Internet-Draft SACM Architecture August 2018
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
[I-D.ietf-mile-xmpp-grid] or some other pub/sub mechanism.
Similarly, the store connection from the Posture Manager to the
Montville & Munyan Expires February 25, 2019 [Page 19]
Internet-Draft SACM Architecture August 2018
Repository could be performed internally 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], [I-D.ietf-mile-xmpp-grid], 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 February 25, 2019 [Page 20]
Internet-Draft SACM Architecture August 2018
This is a specific example of an existing collection mechanism being
adapted to the XMPP-Grid message transfer system.
Authors' Addresses
Adam W. Montville
Center for Internet Security
31 Tech Valley Drive
East Greenbush, NY 12061
USA
Email: adam.w.montville@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 February 25, 2019 [Page 21]