| SACM Working Group | A. Montville |
| Internet-Draft | B. Munyan |
| Intended status: Standards Track | CIS |
| Expires: May 1, 2020 | October 29, 2019 |
Security Automation and Continuous Monitoring (SACM) Architecture
draft-ietf-sacm-arch-04
This document defines an architecture enabling a cooperative Security Automation and Continuous Monitoring (SACM) ecosystem. This work is predicated upon information gleaned from SACM Use Cases and Requirements ([RFC7632] and [RFC8248] respectively), and terminology as found in [I-D.ietf-sacm-terminology].
WORKING GROUP: The source for this draft is maintained in GitHub. Suggested changes should be submitted as pull requests at https://github.com/sacmwg/ietf-mandm-sacm-arch/. Instructions are on that page as well.
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 1, 2020.
Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.
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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] and requirements found in [RFC8248]. This approach gains the most advantage by supporting a variety of collection systems, and intends to enable a cooperative ecosystem of tools from disparate sources with minimal operator configuration.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119, BCP 14 [RFC2119].
This draft defers to [I-D.ietf-sacm-terminology] for terms and definitions.
The generic approach proposed herein recognizes the need to obtain information from existing and future state collection systems, and makes every attempt to respect [RFC7632] and [RFC8248]. At the foundation of any architecture are entities, or components, that need to communicate. They communicate by sharing information, where, in a given flow, one or more components are consumers of information and one or more components are providers of information.
+----------------+
| SACM Component |
| (Provider) |
+-------+--------+
|
|
+--------------v----------------+
| Integration Service |
+--------------+----------------+
|
|
+-------v--------+
| SACM Component |
| (Consumer) |
+----------------+
Figure 1: Basic Architectural Structure
A provider can be described as an abstraction that refers to an entity capable of sending SACM-relevant information to one or many consumers. Consumers can be described as an abstraction that refers to an entity capable of receiving SACM-relevant information from one or many providers. Different roles within a cooperative ecosystem may act as both providers and consumers of SACM-relevant information.
Within the cooperative SACM ecosystem, a number of roles act in coordination to provide relevant policy/guidance, perform data collection, storage, evaluation, and support downstream analytics and reporting.
+--------------------+
| Feeds/Repositories |
| of External Data |
+---------+----------+
|
******************************************* Boundary of Responsibility ******
|
+-----------------+ | +--------------------+
| Orchestrator(s) | | | Repositories/CMDBs |
+---------^-------+ | +----------^---------+
| | | +--------------------+
| | | | Downstream Uses |
| | | | +----------------+ |
+-----------v----------v-------------v------+ | | Analytics | |
| Integration Service <------> +----------------+ |
+-----------^--------------------------^----+ | +----------------+ |
| | | | Reporting | |
| | | +----------------+ |
+-----------v-------------------+ | +--------------------+
| Collection Sub-Architecture | |
+-------------------------------+ |
+---------------v---------------+
| Evaluation Sub-Architecture |
+-------------------------------+
Figure 2: Notional Role-based Architecture
As shown in Figure 2, the SACM role-based architecture consists of some basic SACM Components communicating using an integration service. The integration service is expected to maximally align with the requirements described in [RFC8248], which means that the integration service will support brokered (i.e. point-to-point) and proxied data exchange.
The boundary of responsibility is not intended to imply a physical boundary. Rather, it is intended to be inclusive of various cloud/virtualized environments, BYOD and vendor-provided services in addition to any physical systems the enterprise operates.
This document suggests a variety of players in a cooperative ecosystem; these players are known as SACM Components. SACM Components may be composed of other SACM Components, and each SACM Component plays one, or more, of several roles relevant to the ecosystem. Roles may act as providers of information, consumers of information, or both provider and consumer. Figure 2 depicts a number of SACM components which are architecturally significant and therefore warrant discussion and clarification.
Orchestration components 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.
Figure 2 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).
If each SACM component represents a set of capabilities, the Integration Service represents the "fabric" by which all those services are woven together. The Integration Service acts as a message broker, combining a set of common message categories and infrastructure to allow SACM components to communicate using a shared set of interfaces. The Integration Service's brokering capabilities enable the exchange of various information payloads, orchestration of component capabilities, message routing and reliable delivery. The Integration Service minimizes the dependencies from one system to another through the loose coupling of applications through messaging. SACM components will "attach" to the Integration Service either through native support for the integration implementation, or through the use of "adapters" which provide a proxied attachment.
The 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 Integration Service to coordinate and manage the sending and receiving of messages. The 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.
The Integration Service MUST provide routing capabilities for payloads between producers and consumers. The Integration Service MAY provide further capabilities within the payload delivery pipeline. Examples of these capabilities include, but are not limited to, intermediate processing, message transformation, type conversion, validation, etc.
As depicted by Figure 2, a number of downstream uses exist in the cooperative ecosystem. Each notional SACM component represents distinct sub-architectures which will exchange information via the integration services, using interactions described in this draft.
The Reporting component represents capabilities outside of the SACM architecture scope 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.
The Analytics component represents capabilities outside of the SACM architecture scope dealing with the discovery, interpretation, and communication of any meaningful patterns of data in order to inform effective decision making within the organization.
Figure 2 shows two components representing sub-architectural roles involved in a cooperative ecosystem of SACM components: Collection and Evaluation.
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 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(s) |
+-----------+----------------------------------------------+
| +------------------------------+
| | Posture Attribute Repository |
| +--------------^---------------+
Perform |
Collection |
| Collected Data
| ^
| |
+-----------v------------------------------+---------------+
| Integration Service |
+----+------------------^-----------+------------------^---+
| | | |
v | v |
Perform Collected Perform Collected
Collection Data Collection Data
| ^ | ^
| | | |
+----v-----------------------+ +----v------------------+------+
| Posture Collection Service | | Endpoint |
+---^------------------------+ | +--------------------------+ |
| | | |Posture Collection Service| |
| v | +--------------------------+ |
Events Queries +------------------------------+
^ |
| |
+---+-------------------v----+
| Endpoint |
+----------------------------+
Figure 3: Decomposed Collection Sub-Architecture
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 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 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 Integration Service via similar channels. The various interaction types are discussed later in this draft (TBD).
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.
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.
Posture collection may be triggered from a number of components, but commonly begin either via event-based triggering on an endpoint or through manual orchestration, both illustrated in Figure 3 above. Once orchestration has provided the directive to perform collection, posture collection services consume the directives. Posture collection is invoked for those endpoints overseen by the respective posture collection services. Collected data is then provided to the Integration Service, with a directive to store that information in an appropriate repository.
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.
+------------------+
| Collection | +-------------------------------+
| Sub-Architecture | | Evaluation Results Repository |
+--------------+ +--------^---------+ +-----------------^-------------+
| Orchestrator | | |
+------+-------+ | |
| Perform Store Evaluation Results
Perform Collection |
Evaluation | |
| | |
+------v----------------------v--------------------------------+-------------+
| Integration Service |
+--------+----------------------------^----------------------^---------------+
| | |
| | |
Perform Retrieve Posture |
Evaluation Attributes Retrieve Policy
| | |
| | |
+--------v-------------------+ +-----v------+ +------v-----+
| Posture Evaluation Service | | Posture | | Policy |
+----------------------------+ | Attribute | | Repository |
| Repository | +------------+
+------------+
Figure 4: Decomposed Evaluation Sub-Architecture
The Posture Evaluation Service (PES) 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.
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.
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.
Posture evaluation is orchestrated through the Integration Service to the appropriate Posture Evaluation Service. The PES will, through coordination with the Integration Service, query both the Posture Attribute Repository and the Policy Repository to obtain relevant state data for comparison. If necessary, the PES may be required to invoke further posture collection. Once all relevant posture information has been collected, it is compared to expected state based on applicable policy. Comparison results are then persisted to an evaluation results repository for further downstream use and analysis.
SACM Components are intended to interact with other SACM Components. These interactions can be thought of, at the architectural level, 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.
Two categories of interactions SHOULD be supported by the Integration Service; broadcast interactions, and directed interactions.
Each interaction will convey a payload of information. The payload is expected to contain specific characteristics and instructions to be interpreted by receiving components.
This section describes three primary information security domains from which workflows may be derived: IT Asset Management, Vulnerability Management, and Configuration Management.
Information Technology asset management is easier said than done. The [CISCONTROLS] have two controls dealing with IT asset management. Control 1, Inventory and Control of Hardware Assets, states, "Actively manage (inventory, track, and correct) all hardware devices on the network so that only authorized devices are given access, and unauthorized and unmanaged devices are found and prevented from gaining access." Control 2, Inventory and Control of Software Assets, states, "Actively manage (inventory, track, and correct) all software on the network so that only authorized software is installed and can execute, and that unauthorized and unmanaged software is found and prevented from installation or execution."
In spirit, this covers all of the processing entities on your network (as opposed to things like network cables, dongles, adapters, etc.), whether physical or virtual, on-premises or in the cloud.
TBD
TBD
An IT asset management capability needs to be able to:
TBD
Vulnerability management is a relatively established process. To paraphrase the [CISCONTROLS], continuous vulnerability management is the act of continuously acquiring, assessing, and taking subsequent action on new information in order to identify and remediate vulnerabilities, therefore minimizing the window of opportunity for attackers.
A vulnerability assessment (i.e. vulnerability detection) is performed in two steps:
Vulnerability detection relies on the examination of different endpoint information depending on the nature of a specific vulnerability. Common endpoint information used to detect a vulnerability includes:
In some cases, the endpoint information needed to determine an endpoint's vulnerability status will have been previously collected by the endpoint management capabilities and available in a Repository. However, in other cases, the necessary endpoint information will not be readily available in a Repository and a Collection Task will be triggered to perform collection from the target endpoint. Of course, some implementations of endpoint management capabilities may prefer to enable operators to perform this collection even when sufficient information can be provided by the endpoint management capabilities (e.g. there may be freshness requirements for information).
TBD
TBD
TBD
TBD
Configuration management involves configuration assessment, which requires state assessment. The [CISCONTROLS] specify two high-level controls concerning configuration management (Control 5 for non-network devices and Control 11 for network devices). As an aside, these controls are listed separately because many enterprises have different organizations for managing network infrastructure and workload endpoints. Merging the two controls results in the following paraphrasing: Establish, implement, and actively manage (track, report on, correct) the security configuration of systems using a rigorous configuration management and change control process in order to prevent attackers from exploiting vulnerable services and settings.
Typically, an enterprise will use configuration guidance from a reputable source, and from time to time they may tailor the guidance from that source prior to adopting it as part of their enterprise standard. The enterprise standard is then provided to the appropriate configuration assessment tools and they assess endpoints and/or appropriate endpoint information.
A preferred flow follows:
The SACM architecture needs to support varying deployment models to accommodate the current state of the industry, but should strongly encourage event-driven approaches to monitoring configuration.
This section provides more detail about the components and capabilities required when considering the aforementioned configuration management workflow.
The following is a minimal list of SACM Components required to implement the aforementioned configuration assessment workflow.
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".
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 | | Orchestrator | | Evaluation | | Evaluation |
+------+------+ +-------+--------+ | Sub-Architecture | | Results |
| | +---^----------+---+ | Repository |
| | | | +------^-----+
| | | | |
1.| 3.| 8.| 9.| 10.|
| | | | |
| | | | |
+------v-----------------v---------------+----------v-------------+-----+
| Integration Service |
+-----+----------------------------------+----------^---------+------^--+
| | | | |
| | | | |
2.| 4.| 5.| 6.| 7.|
| | | | |
| | | | |
+-----v------+ +---v----------+---+ +--v------+--+
| Policy | | Collection | | Posture |
| Repository | | Sub-Architecture | | Attribute |
+------------+ +------------------+ | Repository |
+------------+
Figure 5: Configuration Assessment Component Interactions
Figure 5 depicts configuration assessment components and their interactions, which are further described below.
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, a directed 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.
TODO
TODO
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 would like a place to enumerate:
| [I-D.ietf-sacm-ecp] | Haynes, D., Fitzgerald-McKay, J. and L. Lorenzin, "Endpoint Posture Collection Profile", Internet-Draft draft-ietf-sacm-ecp-05, June 2019. |
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC8412] | Schmidt, C., Haynes, D., Coffin, C., Waltermire, D. and J. Fitzgerald-McKay, "Software Inventory Message and Attributes (SWIMA) for PA-TNC", RFC 8412, DOI 10.17487/RFC8412, July 2018. |
| [RFC8600] | Cam-Winget, N., 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. |
TODO: Consider removing or placing in a separate solution draft.
This section provides a mapping of XMPP and XMPP Extensions to the relevant requirements from [RFC8248]. In the table below, the ID and Name columns provide the ID and Name of the requirement directly out of [RFC8248]. The Supported By column may contain one of several values:
If there is no entry in the Supported By column, then there is a gap that must be filled.
| ID | Name | Supported By |
|---|---|---|
| G-001 | Solution Extensibility | XMPP-Core |
| G-002 | Interoperability | XMPP |
| G-003 | Scalability | XMPP |
| G-004 | Versatility | XMPP-Core |
| G-005 | Information Extensibility | XMPP-Core |
| G-006 | Data Protection | Operational |
| G-007 | Data Partitioning | Operational |
| G-008 | Versioning and Backward Compatibility | XEP-0115/0030 |
| G-009 | Information Discovery | XEP-0030 |
| G-010 | Target Endpoint Discovery | XMPP-Core |
| G-011 | Push and Pull Access | XEP-0060/0312 |
| G-012 | SACM Component Interface | N/A |
| G-013 | Endpoint Location and Network Topology | |
| G-014 | Target Endpoint Identity | XMPP-Core |
| G-015 | Data Access Control | |
| ARCH-001 | Component Functions | XMPP |
| ARCH-002 | Scalability | XMPP-Core |
| ARCH-003 | Flexibility | XMPP-Core |
| ARCH-004 | Separation of Data and Management Functions | |
| ARCH-005 | Topology Flexibility | XMPP-Core |
| ARCH-006 | Capability Negotiation | XEP-0115/0030 |
| ARCH-007 | Role-Based Authorization | XMPP-Core |
| ARCH-008 | Context-Based Authorization | |
| ARCH-009 | Time Synchronization | Operational |
| IM-001 | Extensible Attribute Vocabulary | N/A |
| IM-002 | Posture Data Publication | N/A |
| IM-003 | Data Model Negotiation | N/A |
| IM-004 | Data Model Identification | N/A |
| IM-005 | Data Lifetime Management | N/A |
| IM-006 | Singularity and Modularity | N/A |
| DM-001 | Element Association | N/A |
| DM-002 | Data Model Structure | N/A |
| DM-003 | Search Flexibility | N/A |
| DM-004 | Full vs. Partial Updates | N/A |
| DM-005 | Loose Coupling | N/A |
| DM-006 | Data Cardinality | N/A |
| DM-007 | Data Model Negotiation | N/A |
| DM-008 | Data Origin | N/A |
| DM-009 | Origination Time | N/A |
| DM-010 | Data Generation | N/A |
| DM-011 | Data Source | N/A |
| DM-012 | Data Updates | N/A |
| DM-013 | Multiple Collectors | N/A |
| DM-014 | Attribute Extensibility | N/A |
| DM-015 | Solicited vs. Unsolicited Updates | N/A |
| DM-016 | Transfer Agnostic | N/A |
| OP-001 | Time Synchronization | |
| OP-002 | Collection Abstraction | |
| OP-003 | Collection Composition | |
| OP-004 | Attribute-Based Query | |
| OP-005 | Information-Based Query with Filtering | |
| OP-006 | Operation Scalability | |
| OP-007 | Data Abstraction | |
| OP-008 | Provider Restriction | |
| T-001 | Multiple Transfer Protocol Support | Architecture |
| T-002 | Data Integrity | Operational |
| T-003 | Data Confidentiality | Operational |
| T-004 | Transfer Protection | |
| T-005 | Transfer Reliability | |
| T-006 | Transfer-Layer Requirements | |
| T-007 | Transfer Protocol Adoption | Architecture |
TODO: Consider removing.
Consider a policy server conforming to [RFC8322]. [RFC8322] describes a RESTful way based on the ATOM Publishing Protocol ([RFC5023]) to find specific data collections. While this represents a specific binding (i.e. RESTful API based on [RFC5023]), there is a more abstract way to look at ROLIE.
ROLIE provides notional workspaces and collections, and provides the concept of information categories and links. Strictly speaking, these are logical concepts independent of the RESTful binding ROLIE specifies. In other words, ROLIE binds a logical interface (i.e. GET workspace, GET collection, SET entry, and so on) to a specific mechanism (namely an ATOM Publication Protocol extension).
It is not inconceivable to believe there could be a different interface mechanism, or a connector, providing these same operations using XMPP-Grid as the transfer mechanism.
Even if a [RFC8322] server were external to an organization, there would be a need for a policy source inside the organization as well, and it may be preferred for such a policy source to be connected directly to the ecosystem's communication infrastructure.
The SACM working group has accepted work on the Endpoint Posture Collection Profile [I-D.ietf-sacm-ecp], which describes a collection architecture and may be viewed as a collector coupled with a collection-specific repository.
Posture Manager Endpoint
Orchestrator +---------------+ +---------------+
+--------+ | | | |
| | | +-----------+ | | +-----------+ |
| |<---->| | Posture | | | | Posture | |
| | pub/ | | Validator | | | | Collector | |
| | sub | +-----------+ | | +-----------+ |
+--------+ | | | | | |
| | | | | |
Evaluator Repository | | | | | |
+------+ +--------+ | +-----------+ |<-------| +-----------+ |
| | | | | | Posture | | report | | Posture | |
| | | | | | Collection| | | | Collection| |
| |<-----> | |<-----| | Manager | | query | | Engine | |
| |request/| | store| +-----------+ |------->| +-----------+ |
| |respond | | | | | |
| | | | | | | |
+------+ +--------+ +---------------+ +---------------+
Figure 6: EPCP Collection Architecture
In Figure 6, any of the communications between the Posture Manager and EPCP components to its left could be performed directly or indirectly using a given message transfer mechanism. For example, the pub/sub interface between the Orchestrator and the Posture Manager could be using a proprietary method or using [RFC8600] or some other pub/sub mechanism. Similarly, the store connection from the Posture Manager to the Repository could be performed internally to a given implementation, via a RESTful API invocation over HTTPS, or even over a pub/sub mechanism.
Our assertion is that the Evaluator, Repository, Orchestrator, and Posture Manager all have the potential to represent SACM Components with specific capability interfaces that can be logically specified, then bound to one or more specific transfer mechanisms (i.e. RESTful API, [RFC8322], [RFC8600], and so on).
[NIST800126], also known as SCAP 1.3, provides the technical specifications for a "datastream collection". The specification describes the "datastream collection" as being "composed of SCAP data streams and SCAP source components". A "datastream" provides an encapsulation of the SCAP source components required to, for example, perform configuration assessment on a given endpoint. These source components include XCCDF checklists, OVAL Definitions, and CPE Dictionary information. A single "datastream collection" may encapsulate multiple "datastreams", and reference any number of SCAP components. Datastream collections were intended to provide an envelope enabling transfer of SCAP data more easily.
The [NIST800126] specification also defines the "SCAP result data stream" as being conformant to the Asset Reporting Format specification, defined in [NISTIR7694]. The Asset Reporting Format provides an encapsulation of the SCAP source components, Asset Information, and SCAP result components, such as system characteristics and state evaluation results.
What [NIST800126]did not do is specify the interface for finding or acquiring source datastream information, nor an interface for publishing result information. Discovering the actual resources for this information could be done via ROLIE, as described in the Policy Services section above, but other repositories of SCAP data exist as well.
[draft-birkholz-sacm-yang-content] illustrates a SACM Component incorporating a YANG Push client function and an XMPP-grid publisher function. [draft-birkholz-sacm-yang-content] further states "the output of the YANG Push client function is encapsulated in a SACM Content Element envelope, which is again encapsulated in a SACM statement envelope" which are published, essentially, via an XMPP-Grid Connector for SACM Components also part of the XMPP-Grid.
This is a specific example of an existing collection mechanism being adapted to the XMPP-Grid message transfer system.
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:
Figure 7 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 7, 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 7 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 7: XMPP-based Architecture
[RFC8600] details a number of XMPP extensions (XEPs) that MUST be utilized to meet the needs of [RFC7632] and [RFC8248]:
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 7 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:
Figure 8 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*********************** Boundary of Responsibility *******
* | *
* +--------------+ | +-------------------+ +-------------+ *
* | 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 8: XMPP-based Architecture including EPCP