draft-ietf-sacm-arch-01.txt   draft-ietf-sacm-arch-02.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: August 26, 2019 February 22, 2019 Expires: January 27, 2020 July 26, 2019
Security Automation and Continuous Monitoring (SACM) Architecture Security Automation and Continuous Monitoring (SACM) Architecture
draft-ietf-sacm-arch-01 draft-ietf-sacm-arch-02
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 (SACM) architecture. This work is built upon [RFC8600], and is
[I-D.ietf-mile-xmpp-grid], and is predicated upon information gleaned predicated upon information gleaned from SACM Use Cases and
from SACM Use Cases and Requirements ([RFC7632] and [RFC8248] Requirements ([RFC7632] and [RFC8248] respectively), and terminology
respectively), and terminology as found in as found in [I-D.ietf-sacm-terminology].
[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.
Suggested changes should be submitted as pull requests at Suggested changes should be submitted as pull requests at
https://github.com/sacmwg/ietf-mandm-sacm-arch/. Instructions are on https://github.com/sacmwg/ietf-mandm-sacm-arch/. Instructions are on
that page as well. that page as well.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
skipping to change at page 1, line 40 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
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working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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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 August 26, 2019. This Internet-Draft will expire on January 27, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
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 . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Open Questions . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3
1.2. Requirements notation . . . . . . . . . . . . . . . . . . 3 2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 3
2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 4 3. Architectural Overview . . . . . . . . . . . . . . . . . . . 3
3. Architectural Overview . . . . . . . . . . . . . . . . . . . 4 4. Relevant Workflows . . . . . . . . . . . . . . . . . . . . . 5
3.1. SACM Roles . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. IT Asset Management . . . . . . . . . . . . . . . . . . . 5
3.2. Exploring An XMPP-based Solution . . . . . . . . . . . . 5 4.2. Vulnerability Management . . . . . . . . . . . . . . . . 5
3.3. Example Architecture using XMPP-Grid and Endpoint Posture 4.3. Configuration Management . . . . . . . . . . . . . . . . 6
Collection Protocol . . . . . . . . . . . . . . . . . . . 8 5. Configuration Management Components, Interactions, and
4. Components, Capabilities, Interfaces, and Workflows . . . . . 10 Capabilities . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Components . . . . . . . . . . . . . . . . . . . . . . . 10 5.1. Components . . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Capabilities . . . . . . . . . . . . . . . . . . . . . . 11 5.2. Interactions . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Interfaces . . . . . . . . . . . . . . . . . . . . . . . 11 5.3. Capabilities . . . . . . . . . . . . . . . . . . . . . . 8
4.4. Workflows . . . . . . . . . . . . . . . . . . . . . . . . 12 6. Configuration Assessment Workflow . . . . . . . . . . . . . . 9
4.4.1. IT Asset Management . . . . . . . . . . . . . . . . . 12 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 10
4.4.2. Vulnerability Management . . . . . . . . . . . . . . 12 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10
4.4.3. Configuration Management . . . . . . . . . . . . . . 14 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 15 10.1. Normative References . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 10.2. Informative References . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 13
8.1. Normative References . . . . . . . . . . . . . . . . . . 16 Appendix B. Example Components . . . . . . . . . . . . . . . . . 16
8.2. Informative References . . . . . . . . . . . . . . . . . 16 B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 16
Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 18 B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 17
Appendix B. Example Components . . . . . . . . . . . . . . . . . 21 B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 18
B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 21 B.4. Network Configuration Collection . . . . . . . . . . . . 18
B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 22 Appendix C. Exploring An XMPP-based Solution . . . . . . . . . . 19
B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 23 C.1. Example Architecture using XMPP-Grid and Endpoint Posture
B.4. Network Configuration Collection . . . . . . . . . . . . 23 Collection Protocol . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
1. Introduction 1. Introduction
The purpose of this draft is to define an architectural solution for The purpose of this draft is to define an architectural approach for
a SACM Domain. This draft also defines an implementation of the a SACM Domain, based on the spirit of use cases found in [RFC7632]
architecutre, built upon [I-D.ietf-mile-xmpp-grid] and and requirements found in [RFC8248]. This approach gains the most
[I-D.ietf-sacm-ecp]. These approaches complement each other to more advantage by supporting a variety of collection systems, and intends
completely meet the spirit of [RFC7632] and requirements found in
[RFC8248].
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 to enable a cooperative ecosystem of tools from disparate sources
with minimal operator configuration. The solution described in this with minimal operator configuration.
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 1.1. Requirements notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in RFC "OPTIONAL" in this document are to be interpreted as described in RFC
2119, BCP 14 [RFC2119]. 2119, BCP 14 [RFC2119].
2. Terms and Definitions 2. Terms and Definitions
This draft defers to [I-D.ietf-sacm-terminology] for terms and This draft defers to [I-D.ietf-sacm-terminology] for terms and
definitions. definitions.
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 state collection mechanisms, and makes information from existing and future state collection systems, and
every attempt to respect [RFC7632] and [RFC8248]. At the foundation makes every attempt to respect [RFC7632] and [RFC8248]. At the
of any architecture are entities, or components, that need to foundation of any architecture are entities, or components, that need
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 |
+--------------------+ +--------------------+
| |
| |
*****************************v**************** Enterprise Boundary ************ *****************************v**************** Enterprise Boundary ************
* | * * | *
* +--------------+ | +--------------+ * * +---------------+ | +--------------+ *
* | Orchestrator | | | Repositories | * * | Orchestrators | | | Repositories | *
* +------^-------+ | +----^---------+ * * +------^--------+ | +----^---------+ *
* | | | +----------------+ * * | | | +----------------+ *
* A | B | C | | Downstream Uses| * * | | | | Downstream Uses| *
* | | | | +-----------+ | * * | | | | +-----------+ | *
* +------v------------------v----------v------+ | |Evaluations| | * * +------v------------------v----------v------+ | |Evaluations| | *
* | Message Transfer System <-------> +-----------+ | * * | Message Transfer System <-------> +-----------+ | *
* +----------------------^--------------------+ D | +-----------+ | * * +----------------------^--------------------+ | +-----------+ | *
* E | | | Analytics | | * * | | | Analytics | | *
* | | +-----------+ | * * | | +-----------+ | *
* +-------------v---------+ | +-----------+ | * * +-------------v------+ | +-----------+ | *
* | Collection Subsystems | | | Reporting | | * * | Collection Systems | | | Reporting | | *
* +-----------------------+ | +-----------+ | * * +--------------------+ | +-----------+ | *
* +----------------+ * * +----------------+ *
******************************************************************************* *******************************************************************************
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 notional SACM architecture consists of some
basic SACM Components using a message transfer system to communicate. basic SACM Components using a message transfer system to communicate.
While not depicted, the message transfer system is expected to The message transfer system is expected to maximally align with the
maximally align with the requirements described in [RFC8248], which requirements described in [RFC8248], which means that the message
means that the message transfer system will support brokered (i.e. transfer system will support brokered (i.e. point-to-point) and
point-to-point) and proxied data exchange. proxied data exchange.
Additionally, component-specific interfaces (i.e. such as A, B, C, D,
and E in Figure 1) are expected to be specified logically then bound
to one or more specific implementations. This SHOULD be done for
each capability related to the given SACM Component.
3.1. SACM Roles The enterprise boundary is not intended to imply a physical boundary.
Rather, the enterprise boundary is intended to be inclusive of
various cloud environments and vendor-provided services in addition
to any physical systems the enterprise operates.
This document suggests a variety of players in a cooperative 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. The "Components, Capabilities, Interfaces, and of information.
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 slightly more detailed view of the architecture
(within the enterprise boundary) - 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.
+--------------+ +--------------+
| Orchestrator | | Repositories |
+------^-------+ +------^-------+
| |
| |
+-------v--------------------------v--------+ +-----------------+
| XMPP-Grid+ <-----> Downstream Uses |
+------------------------^------------------+ +-----------------+
|
|
+-------v------+
| XMPP-Grid |
| Connector(s) |
+------^-------+
|
+------v-------+
| Collector(s) |
+--------------+
Figure 2: XMPP-based Architecture
[I-D.ietf-mile-xmpp-grid] details a number of XMPP extensions (XEPs)
that MUST be utilized to meet the needs of [RFC7632] and [RFC8248]:
o Service Discovery (XEP-0030): Service Discovery allows XMPP
entities to discover information about other XMPP entities. Two
kinds of information can be discovered: the identity and
capabilities of an entity, such as supported features, and items
associated with an entity.
o Publish-Subscribe (XEP-0060): The PubSub extension enables
entities to create nodes (topics) at a PubSub service and publish
information at those nodes. Once published, an event notification
is broadcast to all entities that have subscribed to that node.
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): This extension defines the methods
for broadcasting and dynamically discovering an entities'
capabilities. This information is transported via standard XMPP
presence. Example capabilities that could be discovered could
include support for posture attribute collection, support for
specific types of posture attribute collection such as EPCP,
SWIMA, OVAL, or YANG. Other capabilities are still to be
determined.
o Ad Hoc Commands (XEP-0050): This extension allows an XMPP entity
to advertise and execute application-specific commands. Typically
the commands contain data forms (XEP-0004) in order to structure
the information exchange. This extension may be usable for simple
orchestration (i.e. "do assessment").
o HTTP File Upload (XEP-0363): The HTTP File Upload extension allows
for large data sets to be published to a specific path on an HTTP
server, and receive a URL from which that file can later be
downloaded again. XMPP messages and IQs are meant to be compact,
and large data sets, such as collected posture attributes, may
exceed a message size threshold. Usage of this XEP allows those
larger data sets to be persisted, thus necessitating only the
download URL to be passed via XMPP messages.
o Personal Eventing Protocol (XEP-0163): The Personal Eventing
Protocol can be thought of as a virtual PubSub service, allowing
an XMPP account to publish events only to their roster instead of
a generic PubSub topic. This XEP may be useful in the cases when
collection requests or queries are only intended for a subset of
endpoints and not an entire subscriber set.
o File Repository and Sharing (XEP-0214): This extension defines a
method for XMPP entities to designate a set of file available for
retrieval by other users of their choosing, and is based on PubSub
Collections.
o Easy User Onboarding (XEP-401): The goal of this extension is
simplified client registration, and may be useful when adding new
endpoints or SACM components to the ecosystem.
o Bidirectional-streams Over Synchronous HTTP (BOSH) (XEP-0124):
BOSH emulates the semantics of a long-lived, bidirectional TCP
connection between two entities (aka "long polling"). Consider a
SACM component that is updated dynamically, i.e. an internal
vulnerability definition repository ingesting data from a Feed/
Repository of External Data, and a second SACM component such as
an Orchestrator. Using BOSH, the Orchestrator can effectively
continuously poll the vulnerability definition repository for
changes/updates.
o PubSub Collection Nodes (XEP-0248): Effectively an extension to
XEP-0060 (Publish-Subscribe), PubSub Collections aim to simplify
an entities' subscription to multiple related topics, and
establishes a "node graph" relating parent nodes to its
descendents. An example "node graph" could be rooted in a
"vulnerability definitions" topic, and contain descendent topics
for OS family-level vulnerability definitions (i.e. Windows), and
further for OS family version-level definitions (i.e. Windows 10
or Windows Server 2016).
o PubSub Since (XEP-0312): This extension enables a subscriber to
automatically receive PubSub and Personal Eventing Protocol (PEP)
notifications since its last logout time. This extension may be
useful in intermittent connection scenarios, or when entities
disconnect and reconnect to the ecosystem.
o PubSub Chaining (XEP-0253): This extension describes the
federation of publishing nodes, enabling a publish node of one
server to be a subscriber to a publishing node of another server.
3.3. Example Architecture using XMPP-Grid and Endpoint Posture
Collection Protocol
Figure 3 depicts a further detailed view of the architecture
including the Endpoint Posture Collection Protocol as the collection
subsystem, illustrating the idea of a pluggable ecosystem of
cooperative tools.
+--------------------+
| Feeds/Repositories |
| of External Data |
+--------------------+
|
********************v************************* Enterprise Boundary ************
* | *
* +--------------+ | +-------------------+ +-------------+ *
* | Orchestrator | | | Posture Attr Repo | | Policy Repo | *
* +------^-------+ | +---------^---------+ +---^---------+ *
* | | | | +----------------+ *
* | | | | | Downstream Uses| *
* | | | | | +-----------+ | *
* +------v---------v-----------v---------------v--+ | |Evaluations| | *
* | XMPP-Grid <-------> +-----------+ | *
* +----------------^-------------------^----------+ | +-----------+ | *
* | | | | Analytics | | *
* | | | +-----------+ | *
* | +-----v--------+ | +-----------+ | *
* | | Results Repo | | | Reporting | | *
* | +--------------+ | +-----------+ | *
* | +----------------+ *
* +---------v-----------+ *
* | XMPP-Grid Connector | *
* +---------^-----------+ *
* | *
* +-----------------v-------------------------------------------------------+ *
* | | *
* | +--Posture Collection Manager------------------------------------------+| *
* | |+-----------------------+ +----------------+ +----------------------+ || *
* | || Communications Server | | Posture Server | | Posture Validator(s) | || *
* | |+----------^------------+ +----------------+ +----------------------+ || *
* | +-----------|----------------------------------------------------------+| *
* | | | *
* | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| *
* | |+----------v------------+ +----------------+ +----------------------+ || *
* | || Communications Client | | Posture Client | | Posture Collector(s) | || *
* | |+-----------------------+ +----------------+ +----------------------+ || *
* | +----------------------------------------------------------------------+| *
* +-----------------Endpoint Posture Collection Profile---------------------+ *
* *
*******************************************************************************
Figure 3: XMPP-based Architecture including EPCP
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
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.
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 4. Relevant Workflows
The workflows described in this document should be considered as This section describes three primary information security domains
candidate workflows - informational for the purpose of discovering from which workflows may be derived: IT Asset Management,
the necessary components and specifying their interfaces. Vulnerability Management, and Configuration Management.
4.4.1. IT Asset Management 4.1. 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 12, line 41 skipping to change at page 5, line 41
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
4.4.2. Vulnerability Management 4.2. Vulnerability Management
Vulnerability management is a relatively established process. Vulnerability management is a relatively established process. To
According to the [CISCONTROLS], continuous vulnerability management 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.
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
satisfies the conditions expressed in the vulnerability detection
data.
A vulnerability assessment (i.e. vulnerability detection) is A vulnerability assessment (i.e. vulnerability detection) is
performed in two steps: performed in two steps:
o Endpoint information collected by the endpoint management o Endpoint information collected by the endpoint management
capabilities is examined by the vulnerability management capabilities is examined by the vulnerability management
capabilities through Evaluation Tasks. capabilities through Evaluation Tasks.
o If the data possessed by the endpoint management capabilities is o If the data possessed by the endpoint management capabilities is
insufficient, a Collection Task is triggered and the necessary insufficient, a Collection Task is triggered and the necessary
data is collected from the target endpoint. data is collected from the target endpoint.
skipping to change at page 14, line 20 skipping to change at page 6, line 24
endpoint information depending on the nature of a specific endpoint information depending on the nature of a specific
vulnerability. Common endpoint information used to detect a vulnerability. Common endpoint information used to detect a
vulnerability includes: vulnerability includes:
o A specific software version is installed on the endpoint o A specific software version is installed on the endpoint
o File system attributes o File system attributes
o Specific state attributes o Specific state attributes
In many cases, the endpoint information needed to determine an In some cases, the endpoint information needed to determine an
endpoint's vulnerability status will have been previously collected endpoint's vulnerability status will have been previously collected
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 collect it from the target Collection Task will be triggered to perform collection from the
endpoint. Of course, some implementations of endpoint management target endpoint. Of course, some implementations of endpoint
capabilities may prefer to enable operators to perform this management capabilities may prefer to enable operators to perform
collection under certain circumstances, even when sufficient this collection even when sufficient information can be provided by
information can be provided by the endpoint management capabilities the endpoint management capabilities (e.g. there may be freshness
(e.g. there may be freshness requirements for information). 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
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 4.3. Configuration Management
Configuration management involves configuration assessment, which Configuration management involves configuration assessment, which
requires state assessment (TODO: Tie to SACM use cases). The requires state assessment. The [CISCONTROLS] specify two high-level
[CISCONTROLS] specify two high-level controls concerning controls concerning configuration management (Control 5 for non-
configuration management (Control 5 for non-network devices and network devices and Control 11 for network devices). As an aside,
Control 11 for network devices). As an aside, these controls are these controls are listed separately because many enterprises have
listed separately because many enterprises have different different organizations for managing network infrastructure and
organizations for managing network infrastructure and workload workload endpoints. Merging the two controls results in the
endpoints. Merging the two controls results in a requirement to: following paraphrasing: Establish, implement, and actively manage
"Establish, implement, and actively manage (track, report on, (track, report on, correct) the security configuration of systems
correct) the security configuration of (endpoints) using a rigorous using a rigorous configuration management and change control process
configuration management and change control process in order to in order to prevent attackers from exploiting vulnerable services and
prevent attackers from exploiting vulnerable services and settings." settings.
Typically, an enterprise will use configuration guidance from a Typically, an enterprise will use configuration guidance from a
reputable source, and from time to time they may tailor the guidance reputable source, and from time to time they may tailor the guidance
from that source prior to adopting it as part of their enterprise from that source prior to adopting it as part of their enterprise
standard. The enterprise standard is then provided to the standard. The enterprise standard is then provided to the
appropriate configuration assessment tools and they assess endpoints appropriate configuration assessment tools and they assess endpoints
and/or appropriate endpoint information. A preferred flow follows: and/or appropriate endpoint information.
A preferred flow follows:
o Reputable source publishes new or updated configuration guidance o Reputable source publishes new or updated configuration guidance
o Enterprise configuration assessment capability retrieves o Enterprise configuration assessment capability retrieves
configuration guidance from reputable source configuration guidance from reputable source
o Optional: Configuration guidance is tailored for enterprise- o Optional: Configuration guidance is tailored for enterprise-
specific needs specific needs
o Configuration assessment tool queries asset inventory repository o Configuration assessment tool queries asset inventory repository
skipping to change at page 15, line 42 skipping to change at page 7, line 32
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. Privacy Considerations 5. Configuration Management Components, Interactions, and Capabilities
This section provides more detail about the components, interactions,
and capabilities required when considering the aforementioned
configuration management workflow.
5.1. Components
The following is a minimal list of SACM Components required to
implement the aforementioned configuration assessment workflow.
o Configuration Policy Feed: An external source of authoritative
configuration recommendations.
o Configuration Policy Repository: An internal repository of
enterprise standard configurations.
o Configuration Assessment Orchestrator: A component responsible for
orchestrating assessments.
o Posture Attribute Collection Subsystem: A component responsible
for collection of posture attributes from systems.
o Posture Attribute Repository: A component used for storing system
posture attribute values.
o Configuration Assessment Evaluator: A component responsible for
evaluating system posture attribute values against expected
posture attribute values.
o Configuration Assessment Results Repository: A component used for
storing evaluation results.
5.2. Interactions
SACM Components are intended to interact with other SACM Components.
These interactions can be thought of, at the level of this
architectural approach, as the combination of interfaces with their
supported operations.
o Store: One component stores information in another.
o Ask: A component requests information from another.
o Notify/Ask: A component notifies another component, which then
asks the notifying component (or another component) for
information.
o Publish/Subscribe: A component publishes information to a
messaging system and a set of other components, subscribed to that
information type, receive the published information.
o Tell: A component instructs another.
TODO: Consider breaking out Notify, Publish, and Subscribe into
separate line items, and adding Error (a type of Notify). Then
consider explaining the necessary combinations relevant to the
configuration assessment workflow below.
Each interaction will convey a payload of information. The payload
information is expected to contain sub-domain-specific
characteristics and instructions.
5.3. Capabilities
Per [RFC8248], solutions MUST support capability negotiation.
Components implementing specific interfaces and operations (i.e.
interactions) will need a method of describing their capabilities to
other components participating in the ecosystem; for example, "As a
component in the ecosystem, I can assess the configuration of
Windows, MacOS, and AWS using OVAL".
6. Configuration Assessment Workflow
This section describes the components and interactions in a basic
configuration assessment workflow. For simplicity, error conditions
are recognized as being necessary and are not depicted. When one
component messages another component, the message is expected to be
handled appropriately unless there is an error condition, or other
notification, messaged in return.
+-------------+
| Policy Feed |
+-----+-------+
| 5.1
1 | +----------------------------------------+
| | |
+-----v------+ 2 +----------------+ 5 +-----v-----+ 6 +------------+
| Policy +------> Orchestrator +-----> Evaluator +------> Evaluation |
| Repository | +-------+--------+ +-----^-----+ | Results |
+------------+ | | | Repository |
| 3 | +------------+
| | 5.2
+----------|--------+ |
| +--------v------+ | |
| | Collector | | |
| +-------+-------+ | 4 +------------+
| | +-------> Posture |
| +-------+-------+ | | Attribute |
| | Target System | | | Repository |
| +---------------+ | +------------+
+-------------------+
Collection Sub-Architecture
Figure 2: Configuration Assessment Component Interactions
Figure 2 depicts configuration assessment components and their
interactions, which are further described below.
1. Policy is stored in the Policy Repository: TODO - add specific
interaction options here.
2. The Orchestrator obtains collection information from the Policy
Repository: TODO - add specific interaction options here.
3. The Orchestrator initiates collection to be performed by the
Collection Sub-Architecture: TODO - add specific interaction
options here.
4. Collected posture attributes are stored n the Posture Attribute
Repository: TODO - add specific interaction options here.
5. The Orchestrator initiates the Evaluator (optionally with
evaluation information gathered from the Policy Repository): TODO
- add specific interaction options here
1. The Evaluator obtains evaluation information from the Policy
Repository (optionally): TODO - add specific interaction
options here
2. The Evaluator obtains relevant posture attributes from the
Posture Attribute Repository: TODO - add specific interaction
options here
6. Evaluation results are stored in the Evaluation Results
Repository: TODO - add specific interaction options here
In the above flow, the payload information is expected to convey the
context required by the receiving component for the action being
taken under different circumstances. For example, the Tell message
sent from an Orchestrator to a Collection sub-architecture might be
telling that Collector to watch a specific posture attribute and
report only specific detected changes to the Posture Attribute
Repository, or it might be telling the Collector to gather that
posture attribute immediately. Such details are expected to be
handled as part of that payload, not as part of the architecture
described herein.
7. Privacy Considerations
TODO TODO
6. Security Considerations 8. Security Considerations
TODO TODO
7. IANA Considerations 9. IANA Considerations
TODO: Revamp this section after the configuration assessment workflow
is fleshed out.
IANA tables can probably be used to make life a little easier. We 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
8. References o Collection sub-architecture Identification
8.1. Normative References 10. References
[I-D.ietf-mile-xmpp-grid] 10.1. Normative References
Cam-Winget, N., Appala, S., Pope, S., and P. Saint-Andre,
"Using XMPP for Security Information Exchange", draft-
ietf-mile-xmpp-grid-09 (work in progress), December 2018.
[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-04 (work in progress), February 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>.
[RFC8412] Schmidt, C., Haynes, D., Coffin, C., Waltermire, D., and [RFC8412] Schmidt, C., Haynes, D., Coffin, C., Waltermire, D., and
J. Fitzgerald-McKay, "Software Inventory Message and J. Fitzgerald-McKay, "Software Inventory Message and
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>.
8.2. Informative References [RFC8600] Cam-Winget, N., Ed., Appala, S., Pope, S., and P. Saint-
Andre, "Using Extensible Messaging and Presence Protocol
(XMPP) for Security Information Exchange", RFC 8600,
DOI 10.17487/RFC8600, June 2019,
<https://www.rfc-editor.org/info/rfc8600>.
10.2. Informative References
[CISCONTROLS] [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 17, line 22 skipping to change at page 12, line 16
n.d., <https://www.github.com/sacmwg/vulnerability- n.d., <https://www.github.com/sacmwg/vulnerability-
scenario/ietf-hackathon>. scenario/ietf-hackathon>.
[HACK101] "IETF 101 Hackathon - Configuration Assessment XMPP", [HACK101] "IETF 101 Hackathon - Configuration Assessment XMPP",
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.,
<https://www.ietf.org/how/meetings/103/>.
[HACK104] "IETF 104 Hackathon - A simple XMPP client", n.d.,
<https://github.com/CISecurity/IETF104-Client>.
[HACK105] "IETF 105 Hackathon - A more robust XMPP client including
collection extensions", n.d.,
<https://github.com/CISecurity/IETF104-Client>.
[HACK99] "IETF 99 Hackathon - Vulnerability Scenario EPCP", n.d., [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 18, line 24 skipping to change at page 13, line 24
[RFC8322] Field, J., Banghart, S., and D. Waltermire, "Resource- [RFC8322] Field, J., Banghart, S., and D. Waltermire, "Resource-
Oriented Lightweight Information Exchange (ROLIE)", Oriented Lightweight Information Exchange (ROLIE)",
RFC 8322, DOI 10.17487/RFC8322, February 2018, RFC 8322, DOI 10.17487/RFC8322, February 2018,
<https://www.rfc-editor.org/info/rfc8322>. <https://www.rfc-editor.org/info/rfc8322>.
[XMPPEXT] "XMPP Extensions", n.d., <https://xmpp.org/extensions/>. [XMPPEXT] "XMPP Extensions", n.d., <https://xmpp.org/extensions/>.
Appendix A. Mapping to RFC8248 Appendix A. Mapping to RFC8248
TODO: Consider removing or placing in a separate solution draft.
This section provides a mapping of XMPP and XMPP Extensions to the This section provides a mapping of XMPP and XMPP Extensions to the
relevant requirements from [RFC8248]. In the table below, the ID and relevant requirements from [RFC8248]. In the table below, the ID and
Name columns provide the ID and Name of the requirement directly out Name columns provide the ID and Name of the requirement directly out
of [RFC8248]. The Supported By column may contain one of several of [RFC8248]. The Supported By column may contain one of several
values: values:
o N/A: The requirement is not applicable to this architectural o N/A: The requirement is not applicable to this architectural
exploration exploration
o Architecture: This architecture (possibly assuming some o Architecture: This architecture (possibly assuming some
skipping to change at page 21, line 36 skipping to change at page 16, line 37
| | | | | | | |
| T-005 | Transfer Reliability | | | T-005 | Transfer Reliability | |
| | | | | | | |
| T-006 | Transfer-Layer Requirements | | | T-006 | Transfer-Layer Requirements | |
| | | | | | | |
| T-007 | Transfer Protocol Adoption | Architecture | | T-007 | Transfer Protocol Adoption | Architecture |
+----------+----------------------------------------+---------------+ +----------+----------------------------------------+---------------+
Appendix B. Example Components Appendix B. Example Components
TODO: Consider removing.
B.1. Policy Services B.1. Policy Services
Consider a policy server conforming to [RFC8322]. [RFC8322] Consider a policy server conforming to [RFC8322]. [RFC8322]
describes a RESTful way based on the ATOM Publishing Protocol describes a RESTful way based on the ATOM Publishing Protocol
([RFC5023]) to find specific data collections. While this represents ([RFC5023]) to find specific data collections. While this represents
a specific binding (i.e. RESTful API based on [RFC5023]), there is a a specific binding (i.e. RESTful API based on [RFC5023]), there is a
more abstract way to look at ROLIE. more abstract way to look at ROLIE.
ROLIE provides notional workspaces and collections, and provides the ROLIE provides notional workspaces and collections, and provides the
concept of information categories and links. Strictly speaking, concept of information categories and links. Strictly speaking,
skipping to change at page 22, line 40 skipping to change at page 17, line 43
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 4: EPCP Collection Architecture Figure 3: EPCP Collection Architecture
In Figure 4, any of the communications between the Posture Manager In Figure 3, 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 Manager could be using a proprietary method or using [RFC8600] or
[I-D.ietf-mile-xmpp-grid] or some other pub/sub mechanism. some other pub/sub mechanism. Similarly, the store connection from
Similarly, the store connection from the Posture Manager to the the Posture Manager to the Repository could be performed internally
Repository could be performed internally to a given implementation, to a given implementation, via a RESTful API invocation over HTTPS,
via a RESTful API invocation over HTTPS, or even over a pub/sub or even over a pub/sub mechanism.
mechanism.
Our assertion is that the Evaluator, Repository, Orchestrator, and Our assertion is that the Evaluator, Repository, Orchestrator, and
Posture Manager all have the potential to represent SACM Components Posture Manager all have the potential to represent SACM Components
with specific capability interfaces that can be logically specified, with specific capability interfaces that can be logically specified,
then bound to one or more specific transfer mechanisms (i.e. RESTful then bound to one or more specific transfer mechanisms (i.e. RESTful
API, [RFC8322], [I-D.ietf-mile-xmpp-grid], and so on). API, [RFC8322], [RFC8600], and so on).
B.3. Datastream Collection B.3. Datastream Collection
[NIST800126], also known as SCAP 1.3, provides the technical [NIST800126], also known as SCAP 1.3, provides the technical
specifications for a "datastream collection". The specification specifications for a "datastream collection". The specification
describes the "datastream collection" as being "composed of SCAP data describes the "datastream collection" as being "composed of SCAP data
streams and SCAP source components". A "datastream" provides an streams and SCAP source components". A "datastream" provides an
encapsulation of the SCAP source components required to, for example, encapsulation of the SCAP source components required to, for example,
perform configuration assessment on a given endpoint. These source perform configuration assessment on a given endpoint. These source
components include XCCDF checklists, OVAL Definitions, and CPE components include XCCDF checklists, OVAL Definitions, and CPE
skipping to change at page 24, line 5 skipping to change at page 19, line 8
incorporating a YANG Push client function and an XMPP-grid publisher incorporating a YANG Push client function and an XMPP-grid publisher
function. [draft-birkholz-sacm-yang-content] further states "the function. [draft-birkholz-sacm-yang-content] further states "the
output of the YANG Push client function is encapsulated in a SACM output of the YANG Push client function is encapsulated in a SACM
Content Element envelope, which is again encapsulated in a SACM Content Element envelope, which is again encapsulated in a SACM
statement envelope" which are published, essentially, via an XMPP- statement envelope" which are published, essentially, via an XMPP-
Grid Connector for SACM Components also part of the XMPP-Grid. Grid Connector for SACM Components also part of the XMPP-Grid.
This is a specific example of an existing collection mechanism being This is a specific example of an existing collection mechanism being
adapted to the XMPP-Grid message transfer system. adapted to the XMPP-Grid message transfer system.
Appendix C. Exploring An XMPP-based Solution
TODO: Consider removing or placing in a separate draft.
Ongoing work has been taking place around and during IETF hackathons.
The list of hackathon efforts follows:
o [HACK99]: A partial implementation of a vulnerability assessment
scenario involving an [I-D.ietf-sacm-ecp] implementation, a
[RFC8322] implementation, and a proprietary evaluator to pull the
pieces together.
o [HACK100]: Work to combine the vulnerability assessment scenario
from [HACK99] with an XMPP-based YANG push model.
o [HACK101]: A fully automated configuration assessment
implementation using XMPP (specifically Publish/Subscribe
capabilities) as a communication mechanism.
o [HACK102]: An exploration of how we might model assessment,
collection, and evaluation abstractly, and then rely on YANG
expressions for the attributes of traditional endpoints.
o [HACK103]: No SACM participation at the Bangkok hackathon.
o [HACK104]: Basic XMPP-to-Concise MAP - Created an XMPP adapter
that can accept basic posture attributes and translate them to
Concise MAP. This hackathon only proved the concept that system
characteristics information can be transported via XMPP and
translated to a (very basic) concise MAP implementation.
o [HACK105]: Advanced XMPP-to-Concise MAP: Full orchestration of
collection capabilities using XMPP. Collector implementations
extend the core XMPP structure to allow OVAL collection
instructions (OVAL objects) to inform posture attribute
collection. Collected system characteristics can be provided to
the Concise MAP XMPP adapter using all 3 available XMPP
capabilities: Publish/Subscribe, Information Query (iq - request/
response) stanzas, or direct Message stanzas. CDDL was created to
map collected posture attributes to Concise MAP structure. The
XMPP adapter translates the incoming system characteristics and
stores the information in the MAP.
Figure 4 depicts a slightly more detailed view of the architecture
(within the enterprise boundary) - one that fosters the development
of a pluggable ecosystem of cooperative tools. Existing collection
mechanisms can be brought into this architecture by specifying the
interface of the collector and creating the XMPP-Grid Connector
binding for that interface.
Additionally, while not directly depicted in Figure 4, this
architecture does allow point-to-point interfaces. In fact,
[RFC8600] provides brokering capabilities to facilitate such point-
to-point data transfers). Additionally, each of the SACM Components
depicted in Figure 4 may be a provider, a consumer, or both,
depending on the workflow in context.
+--------------+ +--------------+
| Orchestrator | | Repositories |
+------^-------+ +------^-------+
| |
| |
+-------v--------------------------v--------+ +-----------------+
| XMPP-Grid+ <-----> Downstream Uses |
+------------------------^------------------+ +-----------------+
|
|
+-------v------+
| XMPP-Grid |
| Connector(s) |
+------^-------+
|
+------v-------+
| Collector(s) |
+--------------+
Figure 4: XMPP-based Architecture
[RFC8600] details a number of XMPP extensions (XEPs) that MUST be
utilized to meet the needs of [RFC7632] and [RFC8248]:
o Service Discovery (XEP-0030): Service Discovery allows XMPP
entities to discover information about other XMPP entities. Two
kinds of information can be discovered: the identity and
capabilities of an entity, such as supported features, and items
associated with an entity.
o Publish-Subscribe (XEP-0060): The PubSub extension enables
entities to create nodes (topics) at a PubSub service and publish
information at those nodes. Once published, an event notification
is broadcast to all entities that have subscribed to that node.
At this point, [RFC8600] specifies fewer features than SACM requires,
and there are other XMPP extensions (XEPs) we need to consider to
meet the needs of [RFC7632] and [RFC8248]. In Figure 4 we therefore
use "XMPP-Grid+" to indicate something more than [RFC8600] alone,
even though we are not yet fully confident in the exact set of XMPP-
related extensions we will require. The authors propose work to
extend (or modify) [RFC8600] to include additional XEPs - possibly
the following:
o Entity Capabilities (XEP-0115): This extension defines the methods
for broadcasting and dynamically discovering an entities'
capabilities. This information is transported via standard XMPP
presence. Example capabilities that could be discovered could
include support for posture attribute collection, support for
specific types of posture attribute collection such as EPCP,
SWIMA, OVAL, or YANG. Other capabilities are still to be
determined.
o Ad Hoc Commands (XEP-0050): This extension allows an XMPP entity
to advertise and execute application-specific commands. Typically
the commands contain data forms (XEP-0004) in order to structure
the information exchange. This extension may be usable for simple
orchestration (i.e. "do assessment").
o HTTP File Upload (XEP-0363): The HTTP File Upload extension allows
for large data sets to be published to a specific path on an HTTP
server, and receive a URL from which that file can later be
downloaded again. XMPP messages and IQs are meant to be compact,
and large data sets, such as collected posture attributes, may
exceed a message size threshold. Usage of this XEP allows those
larger data sets to be persisted, thus necessitating only the
download URL to be passed via XMPP messages.
o Personal Eventing Protocol (XEP-0163): The Personal Eventing
Protocol can be thought of as a virtual PubSub service, allowing
an XMPP account to publish events only to their roster instead of
a generic PubSub topic. This XEP may be useful in the cases when
collection requests or queries are only intended for a subset of
endpoints and not an entire subscriber set.
o File Repository and Sharing (XEP-0214): This extension defines a
method for XMPP entities to designate a set of file available for
retrieval by other users of their choosing, and is based on PubSub
Collections.
o Easy User Onboarding (XEP-401): The goal of this extension is
simplified client registration, and may be useful when adding new
endpoints or SACM components to the ecosystem.
o Bidirectional-streams Over Synchronous HTTP (BOSH) (XEP-0124):
BOSH emulates the semantics of a long-lived, bidirectional TCP
connection between two entities (aka "long polling"). Consider a
SACM component that is updated dynamically, i.e. an internal
vulnerability definition repository ingesting data from a Feed/
Repository of External Data, and a second SACM component such as
an Orchestrator. Using BOSH, the Orchestrator can effectively
continuously poll the vulnerability definition repository for
changes/updates.
o PubSub Collection Nodes (XEP-0248): Effectively an extension to
XEP-0060 (Publish-Subscribe), PubSub Collections aim to simplify
an entities' subscription to multiple related topics, and
establishes a "node graph" relating parent nodes to its
descendents. An example "node graph" could be rooted in a
"vulnerability definitions" topic, and contain descendent topics
for OS family-level vulnerability definitions (i.e. Windows), and
further for OS family version-level definitions (i.e. Windows 10
or Windows Server 2016).
o PubSub Since (XEP-0312): This extension enables a subscriber to
automatically receive PubSub and Personal Eventing Protocol (PEP)
notifications since its last logout time. This extension may be
useful in intermittent connection scenarios, or when entities
disconnect and reconnect to the ecosystem.
o PubSub Chaining (XEP-0253): This extension describes the
federation of publishing nodes, enabling a publish node of one
server to be a subscriber to a publishing node of another server.
C.1. Example Architecture using XMPP-Grid and Endpoint Posture
Collection Protocol
Figure 5 depicts a further detailed view of the architecture
including the Endpoint Posture Collection Protocol as the collection
subsystem, illustrating the idea of a pluggable ecosystem of
cooperative tools.
+--------------------+
| Feeds/Repositories |
| of External Data |
+--------------------+
|
********************v************************* Enterprise Boundary ************
* | *
* +--------------+ | +-------------------+ +-------------+ *
* | Orchestrator | | | Posture Attr Repo | | Policy Repo | *
* +------^-------+ | +---------^---------+ +---^---------+ *
* | | | | +----------------+ *
* | | | | | Downstream Uses| *
* | | | | | +-----------+ | *
* +------v---------v-----------v---------------v--+ | |Evaluations| | *
* | XMPP-Grid <-------> +-----------+ | *
* +----------------^-------------------^----------+ | +-----------+ | *
* | | | | Analytics | | *
* | | | +-----------+ | *
* | +-----v--------+ | +-----------+ | *
* | | Results Repo | | | Reporting | | *
* | +--------------+ | +-----------+ | *
* | +----------------+ *
* +---------v-----------+ *
* | XMPP-Grid Connector | *
* +---------^-----------+ *
* | *
* +-----------------v-------------------------------------------------------+ *
* | | *
* | +--Posture Collection Manager------------------------------------------+| *
* | |+-----------------------+ +----------------+ +----------------------+ || *
* | || Communications Server | | Posture Server | | Posture Validator(s) | || *
* | |+----------^------------+ +----------------+ +----------------------+ || *
* | +-----------|----------------------------------------------------------+| *
* | | | *
* | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| *
* | |+----------v------------+ +----------------+ +----------------------+ || *
* | || Communications Client | | Posture Client | | Posture Collector(s) | || *
* | |+-----------------------+ +----------------+ +----------------------+ || *
* | +----------------------------------------------------------------------+| *
* +-----------------Endpoint Posture Collection Profile---------------------+ *
* *
*******************************************************************************
Figure 5: XMPP-based Architecture including EPCP
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.w.montville@gmail.com Email: adam.montville.sdo@gmail.com
Bill Munyan Bill Munyan
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: bill.munyan.ietf@gmail.com Email: bill.munyan.ietf@gmail.com
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