draft-ietf-sacm-arch-02.txt   draft-ietf-sacm-arch-03.txt 
SACM Working Group A. Montville SACM Working Group A. Montville
Internet-Draft B. Munyan Internet-Draft B. Munyan
Intended status: Standards Track CIS Intended status: Standards Track CIS
Expires: January 27, 2020 July 26, 2019 Expires: March 9, 2020 September 06, 2019
Security Automation and Continuous Monitoring (SACM) Architecture Security Automation and Continuous Monitoring (SACM) Architecture
draft-ietf-sacm-arch-02 draft-ietf-sacm-arch-03
Abstract Abstract
This memo defines a Security Automation and Continuous Monitoring This memo defines a Security Automation and Continuous Monitoring
(SACM) architecture. This work is built upon [RFC8600], and is (SACM) architecture. This work is built upon [RFC8600], and is
predicated upon information gleaned from SACM Use Cases and predicated upon information gleaned from SACM Use Cases and
Requirements ([RFC7632] and [RFC8248] respectively), and terminology Requirements ([RFC7632] and [RFC8248] respectively), and terminology
as found in [I-D.ietf-sacm-terminology]. as found in [I-D.ietf-sacm-terminology].
WORKING GROUP: The source for this draft is maintained in GitHub. WORKING GROUP: The source for this draft is maintained in GitHub.
skipping to change at page 1, line 39 skipping to change at page 1, line 39
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 27, 2020. This Internet-Draft will expire on March 9, 2020.
Copyright Notice Copyright Notice
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document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3
2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 3 2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 3
3. Architectural Overview . . . . . . . . . . . . . . . . . . . 3 3. Architectural Overview . . . . . . . . . . . . . . . . . . . 3
4. Relevant Workflows . . . . . . . . . . . . . . . . . . . . . 5 3.1. Architectural Components . . . . . . . . . . . . . . . . 4
4.1. IT Asset Management . . . . . . . . . . . . . . . . . . . 5 3.1.1. Orchestrator . . . . . . . . . . . . . . . . . . . . 5
4.2. Vulnerability Management . . . . . . . . . . . . . . . . 5 3.1.2. Repositories/CMDBs . . . . . . . . . . . . . . . . . 5
4.3. Configuration Management . . . . . . . . . . . . . . . . 6 3.1.3. Component Integration Service . . . . . . . . . . . . 5
5. Configuration Management Components, Interactions, and 3.2. Sub-Architectures . . . . . . . . . . . . . . . . . . . . 6
Capabilities . . . . . . . . . . . . . . . . . . . . . . . . 7 3.3. Downstream Uses . . . . . . . . . . . . . . . . . . . . . 6
5.1. Components . . . . . . . . . . . . . . . . . . . . . . . 7 3.3.1. Reporting . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Interactions . . . . . . . . . . . . . . . . . . . . . . 8 3.3.2. Analytics . . . . . . . . . . . . . . . . . . . . . . 7
5.3. Capabilities . . . . . . . . . . . . . . . . . . . . . . 8 4. Sub-Architectural Components . . . . . . . . . . . . . . . . 7
6. Configuration Assessment Workflow . . . . . . . . . . . . . . 9 4.1. Collection Sub-Architecture . . . . . . . . . . . . . . . 7
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 10 4.1.1. Posture Collection Service . . . . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 4.1.2. Endpoint . . . . . . . . . . . . . . . . . . . . . . 9
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 4.1.3. Posture Attribute Repository . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2. Evaluation Sub-Architecture . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 11 4.2.1. Posture Evaluation Service . . . . . . . . . . . . . 10
10.2. Informative References . . . . . . . . . . . . . . . . . 11 4.2.2. Policy Repository . . . . . . . . . . . . . . . . . . 10
Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 13 4.2.3. Evaluation Results Repository . . . . . . . . . . . . 11
Appendix B. Example Components . . . . . . . . . . . . . . . . . 16 5. Interactions . . . . . . . . . . . . . . . . . . . . . . . . 11
B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 16 6. Security Domain Workflows . . . . . . . . . . . . . . . . . . 12
B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 17 6.1. IT Asset Management . . . . . . . . . . . . . . . . . . . 12
B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 18 6.2. Vulnerability Management . . . . . . . . . . . . . . . . 13
B.4. Network Configuration Collection . . . . . . . . . . . . 18 6.3. Configuration Management . . . . . . . . . . . . . . . . 13
Appendix C. Exploring An XMPP-based Solution . . . . . . . . . . 19 7. Configuration Management Components and Capabilities . . . . 14
7.1. Components . . . . . . . . . . . . . . . . . . . . . . . 15
7.2. Capabilities . . . . . . . . . . . . . . . . . . . . . . 15
8. Configuration Assessment Workflow . . . . . . . . . . . . . . 15
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 17
10. Security Considerations . . . . . . . . . . . . . . . . . . . 17
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 18
12.1. Normative References . . . . . . . . . . . . . . . . . . 18
12.2. Informative References . . . . . . . . . . . . . . . . . 18
Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 20
Appendix B. Example Components . . . . . . . . . . . . . . . . . 23
B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 23
B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 24
B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 25
B.4. Network Configuration Collection . . . . . . . . . . . . 25
Appendix C. Exploring An XMPP-based Solution . . . . . . . . . . 25
C.1. Example Architecture using XMPP-Grid and Endpoint Posture C.1. Example Architecture using XMPP-Grid and Endpoint Posture
Collection Protocol . . . . . . . . . . . . . . . . . . . 22 Collection Protocol . . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
1. Introduction 1. Introduction
The purpose of this draft is to define an architectural approach for 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] a SACM Domain, based on the spirit of use cases found in [RFC7632]
and requirements found in [RFC8248]. This approach gains the most and requirements found in [RFC8248]. This approach gains the most
advantage by supporting a variety of collection systems, and intends advantage by supporting a variety of collection systems, and intends
to enable a cooperative ecosystem of tools from disparate sources to enable a cooperative ecosystem of tools from disparate sources
with minimal operator configuration. with minimal operator configuration.
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3. Architectural Overview 3. Architectural Overview
The generic approach proposed herein recognizes the need to obtain The generic approach proposed herein recognizes the need to obtain
information from existing and future state collection systems, and information from existing and future state collection systems, and
makes every attempt to respect [RFC7632] and [RFC8248]. At the makes every attempt to respect [RFC7632] and [RFC8248]. At the
foundation of any architecture are entities, or components, that need foundation of any architecture are entities, or components, that need
to communicate. They communicate by sharing information, where, in a to communicate. They communicate by sharing information, where, in a
given flow, one or more components are consumers of information and given flow, one or more components are consumers of information and
one or more components are providers of information. one or more components are providers of information.
+--------------------+ +--------------------+
| Feeds/Repositories | | Feeds/Repositories |
| of External Data | | of External Data |
+--------------------+ +---------+----------+
| +
| ****************************************************** Enterprise Boundary ***
*****************************v**************** Enterprise Boundary ************ +
* | * +--------------+ | +--------------------+
* +---------------+ | +--------------+ * | Orchestrator | | | Repositories/CMDBs |
* | Orchestrators | | | Repositories | * +------^-------+ | +----------^---------+
* +------^--------+ | +----^---------+ * | | | +--------------------+
* | | | +----------------+ * | | | | Downstream Uses |
* | | | | Downstream Uses| * | | | | +----------------+ |
* | | | | +-----------+ | * +-----------v----------v-------------v------+ | | Analytics | |
* +------v------------------v----------v------+ | |Evaluations| | * | Component Integration Service <------> +----------------+ |
* | Message Transfer System <-------> +-----------+ | * +----- -----^--------------------------^----+ | +----------------+ |
* +----------------------^--------------------+ | +-----------+ | * | | | | Reporting | |
* | | | Analytics | | * | | | +----------------+ |
* | | +-----------+ | * +-----------v-------------------+ | +--------------------+
* +-------------v------+ | +-----------+ | * | Collection Sub-Architecture | |
* | Collection Systems | | | Reporting | | * +-------------------------------+ |
* +--------------------+ | +-----------+ | * +---------------------v---------+
* +----------------+ * | Evaluation Sub-Architecture |
******************************************************************************* +-------------------------------+
Figure 1: Notional Architecture Figure 1: Notional Architecture
As shown in Figure 1, the notional SACM architecture consists of some As shown in Figure 1, the SACM architecture consists of some basic
basic SACM Components using a message transfer system to communicate. SACM Components communicating using a component integration service.
The message transfer system is expected to maximally align with the The component integration service is expected to maximally align with
requirements described in [RFC8248], which means that the message the requirements described in [RFC8248], which means that the
transfer system will support brokered (i.e. point-to-point) and component integration service will support brokered (i.e. point-to-
proxied data exchange. point) and proxied data exchange.
The enterprise boundary is not intended to imply a physical boundary. The enterprise boundary is not intended to imply a physical boundary.
Rather, the enterprise boundary is intended to be inclusive of Rather, the enterprise boundary is intended to be inclusive of
various cloud environments and vendor-provided services in addition various cloud environments and vendor-provided services in addition
to any physical systems the enterprise operates. to any physical systems the enterprise operates.
3.1. Architectural Components
This document suggests a variety of players in a cooperative This document suggests a variety of players in a cooperative
ecosystem - we call these players SACM Components. SACM Components ecosystem - we call these players SACM Components. SACM Components
may be composed of other SACM Components, and each SACM Component may be composed of other SACM Components, and each SACM Component
plays one, or more, of several roles relevant to the ecosystem. plays one, or more, of several roles relevant to the ecosystem.
Generally each role is either a consumer of information or a provider Generally each role is either a consumer of information or a provider
of information. of information. The Figure 1 diagram illustrates a number of SACM
components which are architecturally significant and therefore
warrant discussion and clarification.
4. Relevant Workflows 3.1.1. Orchestrator
An Orchestration component exists to aid in the automation of
configuration, coordination, and management for the ecosystem of SACM
components. The Orchestrator performs control-plane operations,
administration of an implementing organization's components
(including endpoints, posture collection services, and downstream
activities), scheduling of automated tasks, and any ad-hoc activities
such as the initiation of collection or evaluation activities. The
Orchestrator is the key administrative interface into the SACM
architecture.
3.1.2. Repositories/CMDBs
The Figure 1 diagram only includes a single reference to
"Repositories/CMDBs", but in practice, a number of separate data
repositories may exist, including posture attribute repositories,
policy repositories, local vulnerability definition data
repositories, and state assessment results repositories. These data
repositories may exist separately or together in a single
representation, and the design of these repositories may be as
distinct as their intended purpose, such as the use of relational
database management systems or graph/map implementations focused on
the relationships between data elements. Each implementation of a
SACM repository should focus on the relationships between data
elements and implement the SACM information and data model(s).
3.1.3. Component Integration Service
If each SACM component represents a set of services, capabilities,
and/or functions, the Component Integration Service represents the
"fabric" by which all those services, capabilities and functions are
woven together. The Component Integration Service acts as a message
broker, combining a canonical data model, a common command set, and a
messaging infrastructure to allow other SACM components to
communicate using a shared set of interfaces. The Component
Integration Service's brokering capabilities enable the exchange of
information, the orchestration of capabilities, message routing and
reliable delivery. The Component Integration Service minimizes the
dependencies from one system to another through the loose coupling of
applications through messaging.
The Component Integration Service should provide mechanisms for
synchronous "request/response"-style messaging, asynchronous "send
and forget" messaging, or publish/subscribe. It is the
responsibility of the Component Integration Service to coordinate and
manage the sending and receiving of messages. The Component
Integration Service should allow components the ability to directly
connect and produce or consume messages, or connect via message
translators which can act as a proxy, transforming messages from a
component format to one implementing a SACM data model.
A number of pieces come together to form the Component Integration
Service:
1. Common communication infrastructure: The physical communications
infrastructure, providing a cross-platform, cross-language
universal adapter between SACM components. This infrastructure
commonly includes message routing capabilities to facilitate the
correct routing of messages from SACM component to SACM
component, as well as using Publish/Subscribe functionality to
facilitate sending messages to all receivers.
2. Adapters: The use of a standard, canonical data model will likely
require SACM components to translate component-specific
information into the canonical format used by the message broker.
3. Common command/interaction structure: Just as PC architectures
have a common set of commands to represent the different
operations possible on a physical bus, there must be common
interactions that all SACM components can understand.
3.2. Sub-Architectures
The Figure 1 shows two components representing the architectural
workflows involved in a cooperative ecosystem of SACM components:
Collection and Evaluation. The following section, Architectural
Workflows (TBD - ADD LINK) further expands on these components/
workflows.
3.3. Downstream Uses
As depicted by Figure 1, a number of downstream uses exist in the
cooperative ecosystem. Each notional SACM component represents
distinct sub-architectures which will exchange information via the
component integration services, using interactions described in this
draft.
3.3.1. Reporting
The Reporting component represents the capabilities of the SACM
architecture dealing with the query and retrieval of collected
posture attribute information, evaluation results, etc. in various
display formats that are useful to a wide range of stakeholders.
3.3.2. Analytics
The Analytics component represents the capabilities of the SACM
architecture dealing with the discovery, interpretation, and
communication of any meaningful patterns of data in order to inform
effective decision making within the organization.
4. Sub-Architectural Components
This section describes the workflows derived from the interactions
with the two sub-architectures depicted in the Figure 1: Collection
and Evaluation.
4.1. Collection Sub-Architecture
The Collection sub-architecture, in a SACM context, is the mechanism
by which posture attributes are collected from applicable endpoints
and persisted to a repository, such as a configuration management
database (CMDB). Orchestration components will choreograph endpoint
data collection via interactions using the Component Integration
Service as a message broker. Instructions to perform endpoint data
collection are directed to a Posture Collection Service capable of
performing collection activities utilizing any number of methods,
such as SNMP, NETCONF/RESTCONF, SSH, WinRM, or host-based.
+----------------------------------------------------------+
| Orchestrator |
+-----------+----------------------------------------------+
| +------------------------------+
| | Posture Attribute Repository |
| +--------------^---------------+
| |
| |
| Collected Data
| ^
| |
+-----------v------------------------------+---------------+
| Component Integration Service |
+----+------------------^-----------+------------------^---+
| | | |
| | | |
v | v |
Perform Collected Perform Collected
Collection Data Collection Data
| ^ | ^
| | | |
| | | |
+----v------------------+----+ +----v------------------+----+
| Posture Collection Service | | Posture Collection Service |
+---^------------------------+ | |
| | | +------------------------+ |
| v | | Endpoint | |
Events Queries | +------------------------+ |
^ | +----------------------------+
| |
+---+-------------------v----+
| Endpoint |
+----------------------------+
Figure 2: Collection Sub-Architecture
4.1.1. Posture Collection Service
The Posture Collection Service (PCS) is the SACM component
responsible for the collection of posture attributes from an endpoint
or set of endpoints. A single PCS may be responsible for management
of posture attribute collection from many endpoints. The PCS will
interact with the Component Integration Service to receive collection
instructions and to provide collected posture data for persistence to
the Posture Attribute Repository. Collection instructions may be
supplied in a variety of forms, including subscription to a publish/
subscribe topic to which the Component Integration Service has
published instructions, via request/response-style synchronous
messaging, or via asynchronous "send-and-forget" messaging.
Collected posture information may then be supplied to the Component
Integration Service via similar channels. The various interaction
types are discussed later in this draft (TBD).
4.1.2. Endpoint
Building upon [I-D.ietf-sacm-terminology], the SACM Collection Sub-
Architecture augments the definition of an Endpoint as a component
within an organization's management domain from which a Posture
Collection Service will collect relevant posture attributes.
4.1.3. Posture Attribute Repository
The Posture Attribute Repository is a SACM component responsible for
the persistent storage of posture attributes collected via
interactions between the Posture Collection Service and Endpoints.
4.2. Evaluation Sub-Architecture
The Evaluation Sub-Architecture, in the SACM context, is the
mechanism by which policy, expressed in the form of expected state,
is compared with collected posture attributes to yield an evaluation
result, that result being contextually dependent on the policy being
evaluated.
+---------------------------------------+
| Orchestrator |
+-------------------+-------------------+
|
|
|
+-------------------v-------------------+
| Component Integration Service |
+--------+------------^--------^--------+
| | |
| | |
v | Retrieve +--------------------------------+
Perform | Posture <-------+ Posture Attribute Repository |
Evaluation | Attributes +--------------------------------+
| |
| |
| | +--------------------------------+
| +-----Retrieve <------+ Policy Repository |
| Policy +--------------------------------+
|
+--------v------------------------------+
| Posture Evaluation Service |
+----------------------------+----------+
|
v
Evaluation
Results
|
|
+--------------------v----------+
| Evaluation Results Repository |
+-------------------------------+
Figure 3: Evaluation Sub-Architecture
4.2.1. Posture Evaluation Service
The Posture Evaluation Service represents the SACM component
responsible for coordinating the policy to be evaluated and the
collected posture attributes relevant to that policy, as well as the
comparison engine responsible for correctly determining compliance
with the expected state.
4.2.2. Policy Repository
The Policy Repository represents a persistent storage mechanism for
the policy to be assessed against collected posture attributes to
determine if an endpoint meets the defined expected state. Examples
of information contained in a Policy Repository would be
Vulnerability Definition Data or configuration recommendations as
part of a CIS Benchmark or DISA STIG.
4.2.3. Evaluation Results Repository
The Evaluation Results Repository persists the information
representing the results of a particular posture assessment,
indicating those posture attributes collected from various endpoints
which either meet or do not meet the expected state defined by the
assessed policy. Consideration should be made for the context of
individual results. For example, meeting the expected state for a
configuration attribute indicates a correct configuration of the
endpoint, whereas meeting an expected state for a vulnerable software
version indicates an incorrect and therefore vulnerable
configuration.
5. 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. Each interaction will convey a payload of
information. The payload information is expected to contain sub-
domain-specific characteristics and instructions.
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 *Request/Response*: A request/response interaction can take a
number of forms, but will always be synchronous operations
involving the requesting component waiting/blocking until a
response is received from the requested component or a timeout
occurs.
* *Information Request*: An information request is simply one
component requesting information from another component, such
as an Orchestrator requesting collection capabilities from a
Posture Collection Service.
* *Query*: A query interaction can take one of two forms,
"selection" or "storage".
+ _Selection_: A component requests data from a repository.
+ _Storage_: A component provides data to be persisted in a
repository.
o *Directive*: Commonly referred to as "Send-and-Forget", a
directive is an asynchronous interaction whereby a component
requests information from another component but does not wait/
block for a response. The receiving component may reply later via
callbacks or further interactions, but it is not mandatory.
Each interaction will convey a payload of information. The payload
information is expected to contain sub-domain-specific
characteristics and instructions.
6. Security Domain Workflows
This section describes three primary information security domains This section describes three primary information security domains
from which workflows may be derived: IT Asset Management, from which workflows may be derived: IT Asset Management,
Vulnerability Management, and Configuration Management. Vulnerability Management, and Configuration Management.
4.1. IT Asset Management 6.1. IT Asset Management
Information Technology asset management is easier said than done. Information Technology asset management is easier said than done.
The [CISCONTROLS] have two controls dealing with IT asset management. The [CISCONTROLS] have two controls dealing with IT asset management.
Control 1, Inventory and Control of Hardware Assets, states, Control 1, Inventory and Control of Hardware Assets, states,
"Actively manage (inventory, track, and correct) all hardware devices "Actively manage (inventory, track, and correct) all hardware devices
on the network so that only authorized devices are given access, and on the network so that only authorized devices are given access, and
unauthorized and unmanaged devices are found and prevented from unauthorized and unmanaged devices are found and prevented from
gaining access." Control 2, Inventory and Control of Software gaining access." Control 2, Inventory and Control of Software
Assets, states, "Actively manage (inventory, track, and correct) all Assets, states, "Actively manage (inventory, track, and correct) all
software on the network so that only authorized software is installed software on the network so that only authorized software is installed
skipping to change at page 5, line 41 skipping to change at page 13, line 5
o Identify and catalog new assets by executing Target Endpoint o Identify and catalog new assets by executing Target Endpoint
Discovery Tasks Discovery Tasks
o Provide information about its managed assets, including uniquely o Provide information about its managed assets, including uniquely
identifying information (for that enterprise) identifying information (for that enterprise)
o Handle software and/or hardware (including virtual assets) o Handle software and/or hardware (including virtual assets)
o Represent cloud hybrid environments o Represent cloud hybrid environments
4.2. Vulnerability Management 6.2. Vulnerability Management
Vulnerability management is a relatively established process. To Vulnerability management is a relatively established process. To
paraphrase the [CISCONTROLS], continuous vulnerability management is paraphrase the [CISCONTROLS], continuous vulnerability management is
the act of continuously acquiring, assessing, and taking subsequent the act of continuously acquiring, assessing, and taking subsequent
action on new information in order to identify and remediate action on new information in order to identify and remediate
vulnerabilities, therefore minimizing the window of opportunity for vulnerabilities, therefore minimizing the window of opportunity for
attackers. attackers.
A vulnerability assessment (i.e. vulnerability detection) is A vulnerability assessment (i.e. vulnerability detection) is
performed in two steps: performed in two steps:
skipping to change at page 6, line 36 skipping to change at page 13, line 48
by the endpoint management capabilities and available in a by the endpoint management capabilities and available in a
Repository. However, in other cases, the necessary endpoint Repository. However, in other cases, the necessary endpoint
information will not be readily available in a Repository and a information will not be readily available in a Repository and a
Collection Task will be triggered to perform collection from the Collection Task will be triggered to perform collection from the
target endpoint. Of course, some implementations of endpoint target endpoint. Of course, some implementations of endpoint
management capabilities may prefer to enable operators to perform management capabilities may prefer to enable operators to perform
this collection even when sufficient information can be provided by this collection even when sufficient information can be provided by
the endpoint management capabilities (e.g. there may be freshness the endpoint management capabilities (e.g. there may be freshness
requirements for information). requirements for information).
4.3. Configuration Management 6.3. Configuration Management
Configuration management involves configuration assessment, which Configuration management involves configuration assessment, which
requires state assessment. The [CISCONTROLS] specify two high-level requires state assessment. The [CISCONTROLS] specify two high-level
controls concerning configuration management (Control 5 for non- controls concerning configuration management (Control 5 for non-
network devices and Control 11 for network devices). As an aside, network devices and Control 11 for network devices). As an aside,
these controls are listed separately because many enterprises have these controls are listed separately because many enterprises have
different organizations for managing network infrastructure and different organizations for managing network infrastructure and
workload endpoints. Merging the two controls results in the workload endpoints. Merging the two controls results in the
following paraphrasing: Establish, implement, and actively manage following paraphrasing: Establish, implement, and actively manage
(track, report on, correct) the security configuration of systems (track, report on, correct) the security configuration of systems
skipping to change at page 7, line 32 skipping to change at page 14, line 44
o Configuration assessment tool queries configuration state o Configuration assessment tool queries configuration state
repository to evaluate compliance repository to evaluate compliance
o If information is stale or unavailable, configuration assessment o If information is stale or unavailable, configuration assessment
tool triggers an ad hoc assessment tool triggers an ad hoc assessment
The SACM architecture needs to support varying deployment models to The SACM architecture needs to support varying deployment models to
accommodate the current state of the industry, but should strongly accommodate the current state of the industry, but should strongly
encourage event-driven approaches to monitoring configuration. encourage event-driven approaches to monitoring configuration.
5. Configuration Management Components, Interactions, and Capabilities 7. Configuration Management Components and Capabilities
This section provides more detail about the components, interactions, This section provides more detail about the components and
and capabilities required when considering the aforementioned capabilities required when considering the aforementioned
configuration management workflow. configuration management workflow.
5.1. Components 7.1. Components
The following is a minimal list of SACM Components required to The following is a minimal list of SACM Components required to
implement the aforementioned configuration assessment workflow. implement the aforementioned configuration assessment workflow.
o Configuration Policy Feed: An external source of authoritative o Configuration Policy Feed: An external source of authoritative
configuration recommendations. configuration recommendations.
o Configuration Policy Repository: An internal repository of o Configuration Policy Repository: An internal repository of
enterprise standard configurations. enterprise standard configurations.
skipping to change at page 8, line 18 skipping to change at page 15, line 32
o Posture Attribute Repository: A component used for storing system o Posture Attribute Repository: A component used for storing system
posture attribute values. posture attribute values.
o Configuration Assessment Evaluator: A component responsible for o Configuration Assessment Evaluator: A component responsible for
evaluating system posture attribute values against expected evaluating system posture attribute values against expected
posture attribute values. posture attribute values.
o Configuration Assessment Results Repository: A component used for o Configuration Assessment Results Repository: A component used for
storing evaluation results. storing evaluation results.
5.2. Interactions 7.2. Capabilities
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. Per [RFC8248], solutions MUST support capability negotiation.
Components implementing specific interfaces and operations (i.e. Components implementing specific interfaces and operations (i.e.
interactions) will need a method of describing their capabilities to interactions) will need a method of describing their capabilities to
other components participating in the ecosystem; for example, "As a other components participating in the ecosystem; for example, "As a
component in the ecosystem, I can assess the configuration of component in the ecosystem, I can assess the configuration of
Windows, MacOS, and AWS using OVAL". Windows, MacOS, and AWS using OVAL".
6. Configuration Assessment Workflow 8. Configuration Assessment Workflow
This section describes the components and interactions in a basic This section describes the components and interactions in a basic
configuration assessment workflow. For simplicity, error conditions configuration assessment workflow. For simplicity, error conditions
are recognized as being necessary and are not depicted. When one are recognized as being necessary and are not depicted. When one
component messages another component, the message is expected to be component messages another component, the message is expected to be
handled appropriately unless there is an error condition, or other handled appropriately unless there is an error condition, or other
notification, messaged in return. notification, messaged in return.
+-------------+ +-------------+
| Policy Feed | | Policy Feed |
skipping to change at page 9, line 40 skipping to change at page 16, line 28
| +--------v------+ | | | +--------v------+ | |
| | Collector | | | | | Collector | | |
| +-------+-------+ | 4 +------------+ | +-------+-------+ | 4 +------------+
| | +-------> Posture | | | +-------> Posture |
| +-------+-------+ | | Attribute | | +-------+-------+ | | Attribute |
| | Target System | | | Repository | | | Target System | | | Repository |
| +---------------+ | +------------+ | +---------------+ | +------------+
+-------------------+ +-------------------+
Collection Sub-Architecture Collection Sub-Architecture
Figure 2: Configuration Assessment Component Interactions Figure 4: Configuration Assessment Component Interactions
Figure 2 depicts configuration assessment components and their Figure 4 depicts configuration assessment components and their
interactions, which are further described below. interactions, which are further described below.
1. Policy is stored in the Policy Repository: TODO - add specific 1. Policy is stored in the Policy Repository: TODO - add specific
interaction options here. interaction options here.
2. The Orchestrator obtains collection information from the Policy 2. The Orchestrator obtains collection information from the Policy
Repository: TODO - add specific interaction options here. Repository: TODO - add specific interaction options here.
3. The Orchestrator initiates collection to be performed by the 3. The Orchestrator initiates collection to be performed by the
Collection Sub-Architecture: TODO - add specific interaction Collection Sub-Architecture: TODO - add specific interaction
skipping to change at page 10, line 38 skipping to change at page 17, line 23
context required by the receiving component for the action being context required by the receiving component for the action being
taken under different circumstances. For example, the Tell message taken under different circumstances. For example, the Tell message
sent from an Orchestrator to a Collection sub-architecture might be sent from an Orchestrator to a Collection sub-architecture might be
telling that Collector to watch a specific posture attribute and telling that Collector to watch a specific posture attribute and
report only specific detected changes to the Posture Attribute report only specific detected changes to the Posture Attribute
Repository, or it might be telling the Collector to gather that Repository, or it might be telling the Collector to gather that
posture attribute immediately. Such details are expected to be posture attribute immediately. Such details are expected to be
handled as part of that payload, not as part of the architecture handled as part of that payload, not as part of the architecture
described herein. described herein.
7. Privacy Considerations 9. Privacy Considerations
TODO TODO
8. Security Considerations 10. Security Considerations
TODO TODO
9. IANA Considerations 11. IANA Considerations
TODO: Revamp this section after the configuration assessment workflow TODO: Revamp this section after the configuration assessment workflow
is fleshed out. is fleshed out.
IANA tables can probably be used to make life a little easier. We IANA tables can probably be used to make life a little easier. We
would like a place to enumerate: would like a place to enumerate:
o Capability/operation semantics o Capability/operation semantics
o SACM Component implementation identifiers o SACM Component implementation identifiers
o SACM Component versions o SACM Component versions
o Associations of SACM Components (and versions) to specific o Associations of SACM Components (and versions) to specific
Capabilities Capabilities
o Collection sub-architecture Identification o Collection sub-architecture Identification
10. References 12. References
10.1. Normative References 12.1. Normative References
[I-D.ietf-sacm-ecp] [I-D.ietf-sacm-ecp]
Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin, Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin,
"Endpoint Posture Collection Profile", draft-ietf-sacm- "Endpoint Posture Collection Profile", draft-ietf-sacm-
ecp-05 (work in progress), June 2019. ecp-05 (work in progress), June 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 11, line 42 skipping to change at page 18, line 31
Attributes (SWIMA) for PA-TNC", RFC 8412, Attributes (SWIMA) for PA-TNC", RFC 8412,
DOI 10.17487/RFC8412, July 2018, DOI 10.17487/RFC8412, July 2018,
<https://www.rfc-editor.org/info/rfc8412>. <https://www.rfc-editor.org/info/rfc8412>.
[RFC8600] Cam-Winget, N., Ed., Appala, S., Pope, S., and P. Saint- [RFC8600] Cam-Winget, N., Ed., Appala, S., Pope, S., and P. Saint-
Andre, "Using Extensible Messaging and Presence Protocol Andre, "Using Extensible Messaging and Presence Protocol
(XMPP) for Security Information Exchange", RFC 8600, (XMPP) for Security Information Exchange", RFC 8600,
DOI 10.17487/RFC8600, June 2019, DOI 10.17487/RFC8600, June 2019,
<https://www.rfc-editor.org/info/rfc8600>. <https://www.rfc-editor.org/info/rfc8600>.
10.2. Informative References 12.2. Informative References
[CISCONTROLS] [CISCONTROLS]
"CIS Controls v7.0", n.d., "CIS Controls v7.0", n.d.,
<https://www.cisecurity.org/controls>. <https://www.cisecurity.org/controls>.
[draft-birkholz-sacm-yang-content] [draft-birkholz-sacm-yang-content]
Birkholz, H. and N. Cam-Winget, "YANG subscribed Birkholz, H. and N. Cam-Winget, "YANG subscribed
notifications via SACM Statements", n.d., notifications via SACM Statements", n.d.,
<https://tools.ietf.org/html/ <https://tools.ietf.org/html/
draft-birkholz-sacm-yang-content-01>. draft-birkholz-sacm-yang-content-01>.
skipping to change at page 12, line 20 skipping to change at page 19, line 9
n.d., <https://www.github.com/CISecurity/Integration>. n.d., <https://www.github.com/CISecurity/Integration>.
[HACK102] "IETF 102 Hackathon - YANG Collection on Traditional [HACK102] "IETF 102 Hackathon - YANG Collection on Traditional
Endpoints", n.d., Endpoints", n.d.,
<https://www.github.com/CISecurity/YANG>. <https://www.github.com/CISecurity/YANG>.
[HACK103] "IETF 103 Hackathon - N/A", n.d., [HACK103] "IETF 103 Hackathon - N/A", n.d.,
<https://www.ietf.org/how/meetings/103/>. <https://www.ietf.org/how/meetings/103/>.
[HACK104] "IETF 104 Hackathon - A simple XMPP client", n.d., [HACK104] "IETF 104 Hackathon - A simple XMPP client", n.d.,
<https://github.com/CISecurity/IETF104-Client>. <https://github.com/CISecurity/SACM-Architecture>.
[HACK105] "IETF 105 Hackathon - A more robust XMPP client including [HACK105] "IETF 105 Hackathon - A more robust XMPP client including
collection extensions", n.d., collection extensions", n.d.,
<https://github.com/CISecurity/IETF104-Client>. <https://github.com/CISecurity/SACM-Architecture>.
[HACK99] "IETF 99 Hackathon - Vulnerability Scenario EPCP", n.d., [HACK99] "IETF 99 Hackathon - Vulnerability Scenario EPCP", n.d.,
<https://www.github.com/sacmwg/vulnerability-scenario/ <https://www.github.com/sacmwg/vulnerability-scenario/
ietf-hackathon>. ietf-hackathon>.
[I-D.ietf-sacm-terminology] [I-D.ietf-sacm-terminology]
Birkholz, H., Lu, J., Strassner, J., Cam-Winget, N., and Birkholz, H., Lu, J., Strassner, J., Cam-Winget, N., and
A. Montville, "Security Automation and Continuous A. Montville, "Security Automation and Continuous
Monitoring (SACM) Terminology", draft-ietf-sacm- Monitoring (SACM) Terminology", draft-ietf-sacm-
terminology-16 (work in progress), December 2018. terminology-16 (work in progress), December 2018.
skipping to change at page 17, line 43 skipping to change at page 24, line 33
Evaluator Repository | | | | | | Evaluator Repository | | | | | |
+------+ +--------+ | +-----------+ |<-------| +-----------+ | +------+ +--------+ | +-----------+ |<-------| +-----------+ |
| | | | | | Posture | | report | | Posture | | | | | | | | Posture | | report | | Posture | |
| | | | | | Collection| | | | Collection| | | | | | | | Collection| | | | Collection| |
| |<-----> | |<-----| | Manager | | query | | Engine | | | |<-----> | |<-----| | Manager | | query | | Engine | |
| |request/| | store| +-----------+ |------->| +-----------+ | | |request/| | store| +-----------+ |------->| +-----------+ |
| |respond | | | | | | | |respond | | | | | |
| | | | | | | | | | | | | | | |
+------+ +--------+ +---------------+ +---------------+ +------+ +--------+ +---------------+ +---------------+
Figure 3: EPCP Collection Architecture Figure 5: EPCP Collection Architecture
In Figure 3, any of the communications between the Posture Manager In Figure 5, any of the communications between the Posture Manager
and EPCP components to its left could be performed directly or and EPCP components to its left could be performed directly or
indirectly using a given message transfer mechanism. For example, indirectly using a given message transfer mechanism. For example,
the pub/sub interface between the Orchestrator and the Posture the pub/sub interface between the Orchestrator and the Posture
Manager could be using a proprietary method or using [RFC8600] or Manager could be using a proprietary method or using [RFC8600] or
some other pub/sub mechanism. Similarly, the store connection from some other pub/sub mechanism. Similarly, the store connection from
the Posture Manager to the Repository could be performed internally the Posture Manager to the Repository could be performed internally
to a given implementation, via a RESTful API invocation over HTTPS, to a given implementation, via a RESTful API invocation over HTTPS,
or even over a pub/sub mechanism. or even over a pub/sub mechanism.
Our assertion is that the Evaluator, Repository, Orchestrator, and Our assertion is that the Evaluator, Repository, Orchestrator, and
skipping to change at page 19, line 51 skipping to change at page 26, line 41
extend the core XMPP structure to allow OVAL collection extend the core XMPP structure to allow OVAL collection
instructions (OVAL objects) to inform posture attribute instructions (OVAL objects) to inform posture attribute
collection. Collected system characteristics can be provided to collection. Collected system characteristics can be provided to
the Concise MAP XMPP adapter using all 3 available XMPP the Concise MAP XMPP adapter using all 3 available XMPP
capabilities: Publish/Subscribe, Information Query (iq - request/ capabilities: Publish/Subscribe, Information Query (iq - request/
response) stanzas, or direct Message stanzas. CDDL was created to response) stanzas, or direct Message stanzas. CDDL was created to
map collected posture attributes to Concise MAP structure. The map collected posture attributes to Concise MAP structure. The
XMPP adapter translates the incoming system characteristics and XMPP adapter translates the incoming system characteristics and
stores the information in the MAP. stores the information in the MAP.
Figure 4 depicts a slightly more detailed view of the architecture Figure 6 depicts a slightly more detailed view of the architecture
(within the enterprise boundary) - one that fosters the development (within the enterprise boundary) - one that fosters the development
of a pluggable ecosystem of cooperative tools. Existing collection of a pluggable ecosystem of cooperative tools. Existing collection
mechanisms can be brought into this architecture by specifying the mechanisms can be brought into this architecture by specifying the
interface of the collector and creating the XMPP-Grid Connector interface of the collector and creating the XMPP-Grid Connector
binding for that interface. binding for that interface.
Additionally, while not directly depicted in Figure 4, this Additionally, while not directly depicted in Figure 6, this
architecture does allow point-to-point interfaces. In fact, architecture does allow point-to-point interfaces. In fact,
[RFC8600] provides brokering capabilities to facilitate such point- [RFC8600] provides brokering capabilities to facilitate such point-
to-point data transfers). Additionally, each of the SACM Components to-point data transfers). Additionally, each of the SACM Components
depicted in Figure 4 may be a provider, a consumer, or both, depicted in Figure 6 may be a provider, a consumer, or both,
depending on the workflow in context. depending on the workflow in context.
+--------------+ +--------------+ +--------------+ +--------------+
| Orchestrator | | Repositories | | Orchestrator | | Repositories |
+------^-------+ +------^-------+ +------^-------+ +------^-------+
| | | |
| | | |
+-------v--------------------------v--------+ +-----------------+ +-------v--------------------------v--------+ +-----------------+
| XMPP-Grid+ <-----> Downstream Uses | | XMPP-Grid+ <-----> Downstream Uses |
+------------------------^------------------+ +-----------------+ +------------------------^------------------+ +-----------------+
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| |
+-------v------+ +-------v------+
| XMPP-Grid | | XMPP-Grid |
| Connector(s) | | Connector(s) |
+------^-------+ +------^-------+
| |
+------v-------+ +------v-------+
| Collector(s) | | Collector(s) |
+--------------+ +--------------+
Figure 4: XMPP-based Architecture Figure 6: XMPP-based Architecture
[RFC8600] details a number of XMPP extensions (XEPs) that MUST be [RFC8600] details a number of XMPP extensions (XEPs) that MUST be
utilized to meet the needs of [RFC7632] and [RFC8248]: utilized to meet the needs of [RFC7632] and [RFC8248]:
o Service Discovery (XEP-0030): Service Discovery allows XMPP o Service Discovery (XEP-0030): Service Discovery allows XMPP
entities to discover information about other XMPP entities. Two entities to discover information about other XMPP entities. Two
kinds of information can be discovered: the identity and kinds of information can be discovered: the identity and
capabilities of an entity, such as supported features, and items capabilities of an entity, such as supported features, and items
associated with an entity. associated with an entity.
o Publish-Subscribe (XEP-0060): The PubSub extension enables o Publish-Subscribe (XEP-0060): The PubSub extension enables
entities to create nodes (topics) at a PubSub service and publish entities to create nodes (topics) at a PubSub service and publish
information at those nodes. Once published, an event notification information at those nodes. Once published, an event notification
is broadcast to all entities that have subscribed to that node. is broadcast to all entities that have subscribed to that node.
At this point, [RFC8600] specifies fewer features than SACM requires, At this point, [RFC8600] specifies fewer features than SACM requires,
and there are other XMPP extensions (XEPs) we need to consider to and there are other XMPP extensions (XEPs) we need to consider to
meet the needs of [RFC7632] and [RFC8248]. In Figure 4 we therefore meet the needs of [RFC7632] and [RFC8248]. In Figure 6 we therefore
use "XMPP-Grid+" to indicate something more than [RFC8600] alone, use "XMPP-Grid+" to indicate something more than [RFC8600] alone,
even though we are not yet fully confident in the exact set of XMPP- even though we are not yet fully confident in the exact set of XMPP-
related extensions we will require. The authors propose work to related extensions we will require. The authors propose work to
extend (or modify) [RFC8600] to include additional XEPs - possibly extend (or modify) [RFC8600] to include additional XEPs - possibly
the following: the following:
o Entity Capabilities (XEP-0115): This extension defines the methods o Entity Capabilities (XEP-0115): This extension defines the methods
for broadcasting and dynamically discovering an entities' for broadcasting and dynamically discovering an entities'
capabilities. This information is transported via standard XMPP capabilities. This information is transported via standard XMPP
presence. Example capabilities that could be discovered could presence. Example capabilities that could be discovered could
skipping to change at page 22, line 38 skipping to change at page 29, line 30
useful in intermittent connection scenarios, or when entities useful in intermittent connection scenarios, or when entities
disconnect and reconnect to the ecosystem. disconnect and reconnect to the ecosystem.
o PubSub Chaining (XEP-0253): This extension describes the o PubSub Chaining (XEP-0253): This extension describes the
federation of publishing nodes, enabling a publish node of one federation of publishing nodes, enabling a publish node of one
server to be a subscriber to a publishing node of another server. server to be a subscriber to a publishing node of another server.
C.1. Example Architecture using XMPP-Grid and Endpoint Posture C.1. Example Architecture using XMPP-Grid and Endpoint Posture
Collection Protocol Collection Protocol
Figure 5 depicts a further detailed view of the architecture Figure 7 depicts a further detailed view of the architecture
including the Endpoint Posture Collection Protocol as the collection including the Endpoint Posture Collection Protocol as the collection
subsystem, illustrating the idea of a pluggable ecosystem of subsystem, illustrating the idea of a pluggable ecosystem of
cooperative tools. cooperative tools.
+--------------------+ +--------------------+
| Feeds/Repositories | | Feeds/Repositories |
| of External Data | | of External Data |
+--------------------+ +--------------------+
| |
********************v************************* Enterprise Boundary ************ ********************v************************* Enterprise Boundary ************
skipping to change at page 23, line 48 skipping to change at page 30, line 48
* | | | * * | | | *
* | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| * * | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| *
* | |+----------v------------+ +----------------+ +----------------------+ || * * | |+----------v------------+ +----------------+ +----------------------+ || *
* | || Communications Client | | Posture Client | | Posture Collector(s) | || * * | || Communications Client | | Posture Client | | Posture Collector(s) | || *
* | |+-----------------------+ +----------------+ +----------------------+ || * * | |+-----------------------+ +----------------+ +----------------------+ || *
* | +----------------------------------------------------------------------+| * * | +----------------------------------------------------------------------+| *
* +-----------------Endpoint Posture Collection Profile---------------------+ * * +-----------------Endpoint Posture Collection Profile---------------------+ *
* * * *
******************************************************************************* *******************************************************************************
Figure 5: XMPP-based Architecture including EPCP Figure 7: XMPP-based Architecture including EPCP
Authors' Addresses Authors' Addresses
Adam W. Montville Adam W. Montville
Center for Internet Security Center for Internet Security
31 Tech Valley Drive 31 Tech Valley Drive
East Greenbush, NY 12061 East Greenbush, NY 12061
USA USA
Email: adam.montville.sdo@gmail.com Email: adam.montville.sdo@gmail.com
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