SACM Working Group A. Montville Internet-Draft B. Munyan Intended status: Standards Track CIS Expires: 14 March 2021 10 September 2020 Security Automation and Continuous Monitoring (SACM) Architecture draft-ietf-sacm-arch-07 Abstract 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. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at 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 14 March 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights Montville & Munyan Expires 14 March 2021 [Page 1] Internet-Draft SACM Architecture September 2020 and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 4 3. Architectural Overview . . . . . . . . . . . . . . . . . . . 4 3.1. SACM Role-based Architecture . . . . . . . . . . . . . . 4 3.2. Architectural Roles/Components . . . . . . . . . . . . . 5 3.2.1. Orchestrator(s) . . . . . . . . . . . . . . . . . . . 6 3.2.2. Repositories/Configuration Management Databases (CMDBs) . . . . . . . . . . . . . . . . . . . . . . . 6 3.2.3. Integration Service . . . . . . . . . . . . . . . . . 6 3.3. Downstream Uses . . . . . . . . . . . . . . . . . . . . . 7 3.3.1. Reporting . . . . . . . . . . . . . . . . . . . . . . 7 3.3.2. Analytics . . . . . . . . . . . . . . . . . . . . . . 7 3.4. Sub-Architectures . . . . . . . . . . . . . . . . . . . . 7 3.4.1. Collection Sub-Architecture . . . . . . . . . . . . . 8 3.4.2. Evaluation Sub-Architecture . . . . . . . . . . . . . 10 4. Interactions . . . . . . . . . . . . . . . . . . . . . . . . 12 4.1. Interaction Categories . . . . . . . . . . . . . . . . . 12 4.1.1. Broadcast . . . . . . . . . . . . . . . . . . . . . . 13 4.1.2. Directed . . . . . . . . . . . . . . . . . . . . . . 13 4.2. Management Plane Functions . . . . . . . . . . . . . . . 14 4.2.1. Orchestrator Onboarding . . . . . . . . . . . . . . . 14 4.2.2. Component Onboarding . . . . . . . . . . . . . . . . 15 4.3. Component Interactions . . . . . . . . . . . . . . . . . 16 4.3.1. Initiate Ad-Hoc Collection . . . . . . . . . . . . . 16 4.3.2. Coordinate Periodic Collection . . . . . . . . . . . 16 4.3.3. Coordinate Observational/Event-based Collection . . . 17 4.3.4. Persist Collected Posture Attributes . . . . . . . . 18 4.3.5. Initiate Ad-Hoc Evaluation . . . . . . . . . . . . . 18 4.3.6. Coordinate Periodic Evaluation . . . . . . . . . . . 18 4.3.7. Coordinate Change-based Evaluation . . . . . . . . . 19 4.3.8. Queries . . . . . . . . . . . . . . . . . . . . . . . 19 5. Taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.1. Orchestrator Registration . . . . . . . . . . . . . . . . 19 5.1.1. Interaction . . . . . . . . . . . . . . . . . . . . . 20 5.1.2. Request Payload . . . . . . . . . . . . . . . . . . . 20 5.1.3. Request Processing . . . . . . . . . . . . . . . . . 20 5.1.4. Response Payload . . . . . . . . . . . . . . . . . . 21 5.1.5. Response Processing . . . . . . . . . . . . . . . . . 21 5.2. Component Registration . . . . . . . . . . . . . . . . . 21 5.2.1. Interaction . . . . . . . . . . . . . . . . . . . . . 21 Montville & Munyan Expires 14 March 2021 [Page 2] Internet-Draft SACM Architecture September 2020 5.2.2. Request Payload . . . . . . . . . . . . . . . . . . . 21 5.2.3. Request Processing . . . . . . . . . . . . . . . . . 22 5.2.4. Response Payload . . . . . . . . . . . . . . . . . . 22 5.2.5. Response Processing . . . . . . . . . . . . . . . . . 23 5.3. Orchestrator-Component Administrative Interface . . . . . 23 5.3.1. Capability Advertisement Handshake . . . . . . . . . 23 5.3.2. Heartbeat . . . . . . . . . . . . . . . . . . . . . . 25 5.4. Collection . . . . . . . . . . . . . . . . . . . . . . . 27 5.4.1. Ad-Hoc . . . . . . . . . . . . . . . . . . . . . . . 27 5.4.2. Periodic . . . . . . . . . . . . . . . . . . . . . . 29 5.4.3. Observational/Event-based . . . . . . . . . . . . . . 31 5.5. Evaluation . . . . . . . . . . . . . . . . . . . . . . . 31 5.5.1. Ad-Hoc . . . . . . . . . . . . . . . . . . . . . . . 32 5.5.2. Periodic . . . . . . . . . . . . . . . . . . . . . . 32 5.5.3. Change/Event-based . . . . . . . . . . . . . . . . . 32 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 32 7. Security Considerations . . . . . . . . . . . . . . . . . . . 32 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 9.1. Normative References . . . . . . . . . . . . . . . . . . 32 9.2. Informative References . . . . . . . . . . . . . . . . . 33 Appendix A. Security Domain Workflows . . . . . . . . . . . . . 34 A.1. IT Asset Management . . . . . . . . . . . . . . . . . . . 35 A.1.1. Components, Capabilities and Workflow(s) . . . . . . 35 A.2. Vulnerability Management . . . . . . . . . . . . . . . . 36 A.2.1. Components, Capabilities and Workflow(s) . . . . . . 36 A.3. Configuration Management . . . . . . . . . . . . . . . . 37 A.3.1. Components, Capabilities and Workflow(s) . . . . . . 38 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40 1. Introduction 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. 1.1. Requirements notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119, BCP 14 [RFC2119]. Montville & Munyan Expires 14 March 2021 [Page 3] Internet-Draft SACM Architecture September 2020 2. Terms and Definitions This draft defers to [I-D.ietf-sacm-terminology] for terms and definitions. 3. Architectural Overview The generic approach proposed herein recognizes the need to obtain information from existing 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. A Consumer 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. 3.1. SACM Role-based Architecture 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. Montville & Munyan Expires 14 March 2021 [Page 4] Internet-Draft SACM Architecture September 2020 +-----------------+ +--------------------+ | Orchestrator(s) | | Repositories/CMDBs | +---------^-------+ +----------^---------+ | | +--------------------+ | | | Downstream Uses | | | | +----------------+ | +-----------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. 3.2. Architectural Roles/Components This document suggests a variety of players in a cooperative ecosystem; 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. Montville & Munyan Expires 14 March 2021 [Page 5] Internet-Draft SACM Architecture September 2020 3.2.1. Orchestrator(s) Orchestrator 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. Topic authorization policies established by the Integration Service should dictate that only the component acting as the Orchestrator has access to receive messages on the administrative topic(s) used for component onboarding (i.e. the "/orchestrator/registration" topic). 3.2.2. Repositories/Configuration Management Databases (CMDBs) 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). 3.2.3. Integration Service If each SACM component represents a set of capabilities, then the Integration Service represents the "fabric" by which SACM components 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. Montville & Munyan Expires 14 March 2021 [Page 6] Internet-Draft SACM Architecture September 2020 The Integration Service should provide mechanisms for both synchronous and asynchronous request/response-style messaging, and a publish/subscribe mechanism to implement event-based messaging. It is the responsibility of the Integration Service to coordinate and manage the sending and receiving of messages. The Integration Service should allow components 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, or other enterprise integration patterns. 3.3. Downstream Uses 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. 3.3.1. Reporting 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. 3.3.2. Analytics 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. 3.4. Sub-Architectures Figure 2 shows two components representing sub-architectural roles involved in a cooperative ecosystem of SACM components: Collection and Evaluation. Montville & Munyan Expires 14 March 2021 [Page 7] Internet-Draft SACM Architecture September 2020 3.4.1. Collection Sub-Architecture The Collection sub-architecture is, in a SACM context, 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 defined 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, packet capture, 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-----------------------+ +----|------------------|------+ | Posture Collection Service | | | Endpoint | | +---^------------------------+ | +--v------------------+----+ | | | | |Posture Collection Service| | | v | +--------------------------+ | Events Queries +------------------------------+ ^ | (PCS resides on Endpoint) | | +---+-------------------v----+ | Endpoint | +----------------------------+ (PCS does not reside on Endpoint) Figure 3: Decomposed Collection Sub-Architecture Montville & Munyan Expires 14 March 2021 [Page 8] Internet-Draft SACM Architecture September 2020 3.4.1.1. Posture Collection Service The Posture Collection Service (PCS) is the SACM component responsible for the collection of posture attributes from an endpoint or set of endpoints. A single PCS may be responsible for management of posture attribute collection from many endpoints. The PCS will interact with the 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, or via request/response-style messaging (either synchronous or asynchronous). Four classifications of posture collections MAY be supported. 3.4.1.1.1. Ad-Hoc Ad-Hoc collection is defined as a single colletion of posture attributes, collected at a particular time. An example of ad-hoc collection is the single collection of a specific registry key. 3.4.1.1.2. Continuous/Scheduled Continuous/Scheduled collection is defined as the ongoing, periodic collection of posture attributes. An example of scheduled collection is the collection of a specific registry key value every day at a given time. 3.4.1.1.3. Observational This classification of collection is triggered by the observation, external to an endpoint, of information asserting posture attribute values for that endpoint. An example of observational collection is examination of netflow data for particular packet captures and/or specific information within those captures. 3.4.1.1.4. Event-based Event-based collection may be triggered either internally or externally to the endpoint. Internal event-based collection is triggered when a posture attribute of interest is added, removed, or modified on an endpoint. This modification indicates a change in the current state of the endpoint, potentially affecting its adherence to some defined policy. Modification of the endpoint's minimum password length is an example of an attribute change which could trigger collection. Montville & Munyan Expires 14 March 2021 [Page 9] Internet-Draft SACM Architecture September 2020 External event-based collection can be described as a collector being subscribed to an external source of information, receiving events from that external source on a periodic or continuous basis. An example of event-based collection is subscription to YANG Push notifications. 3.4.1.2. Endpoint Building upon [I-D.ietf-sacm-terminology], the SACM Collection Sub- Architecture augments the definition of an Endpoint as a component within an organization's management domain from which a Posture Collection Service will collect relevant posture attributes. 3.4.1.3. Posture Attribute Repository The Posture Attribute Repository is a SACM component responsible for the persistent storage of posture attributes collected via interactions between the Posture Collection Service and Endpoints. 3.4.1.4. Posture Collection Workflow 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. 3.4.2. Evaluation Sub-Architecture The Evaluation Sub-Architecture, in the SACM context, is the mechanism by which policy, expressed in the form of expected state, is compared with collected posture attributes to yield an evaluation result, that result being contextually dependent on the policy being evaluated. Montville & Munyan Expires 14 March 2021 [Page 10] Internet-Draft SACM Architecture September 2020 +------------------+ | Collection | +-------------------------------+ | Sub-Architecture | | Evaluation Results Repository | +--------------+ +--------^---------+ +-----------------^-------------+ | Orchestrator | | | +------+-------+ (Potentially) | | Perform Store Evaluation Results Perform Collection | Evaluation | | | | | +------v----------------------v--------------------------------+-------------+ | Integration Service | +--------^----------------------^-----------------------^--------------------+ | | | | | | | Retrieve Posture Perform Retrieve Policy Attributes Evaluation | | | | | | +------v-----+ +-----v------+ +--------v-------------------+ | Policy | | Posture | | Posture Evaluation Service | | Repository | | Attribute | +----------------------------+ +------------+ | Repository | +------------+ Figure 4: Decomposed Evaluation Sub-Architecture 3.4.2.1. Posture Evaluation Service 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. 3.4.2.2. Policy Repository The Policy Repository represents a persistent storage mechanism for the policy to be assessed against collected posture attributes to determine if an endpoint meets the desired 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. Montville & Munyan Expires 14 March 2021 [Page 11] Internet-Draft SACM Architecture September 2020 3.4.2.3. Evaluation Results Repository The Evaluation Results Repository persists the information representing the results of a particular posture assessment, indicating those posture attributes collected from various endpoints which either meet or do not meet the expected state defined by the assessed policy. Consideration should be made for the context of individual results. For example, meeting the expected state for a configuration attribute indicates a correct configuration of the endpoint, whereas meeting an expected state for a vulnerable software version indicates an incorrect configuration. 3.4.2.4. Posture Evaluation Workflow Posture evaluation is orchestrated through the Integration Service to the appropriate Posture Evaluation Service (PES). The PES will, using interactions defined by the applicable taxonomy, 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. 4. Interactions 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/or instructions. 4.1. Interaction Categories Two categories of interactions SHOULD be supported by the Integration Service: broadcast and directed. Broadcast interactions are asynchronous by default, and directed interactions may be invoked either synchronously or asynchronously. Each interaction category SHOULD adhere to topic naming conventions described below. Montville & Munyan Expires 14 March 2021 [Page 12] Internet-Draft SACM Architecture September 2020 4.1.1. Broadcast A broadcast interaction, commonly known as publish/subscribe, allows for a wider distribution of a message payload. When a payload is published to a topic on the Integration Service, all subscribers to that topic are alerted and may consume the message payload. This category of interaction can also be described as a "unicast" interaction when a topic only has a single subscriber. An example of a broadcast interaction could be to publish Linux OVAL objects to a posture collection topic. Subscribing consumers receive the notification, and proceed to collect endpoint configuration posture based on the new content. When interacting via broadcast, topic naming conventions should provide an adequate amount of information to be deterministic regarding the purpose of the interaction. For example, a broadcast topic named "/collection/oval" would indicate that (a) the payloads published to the topic are represented as OVAL definitions, and that (b) subscribers to that topic have advertised capabilities to perform collection using an OVAL-compliant engine. 4.1.2. Directed The intent of a directed interaction is to enable point-to-point communications between a producer and consumer, through the standard interfaces provided by the Integration Service. The provider component indicates which consumer is intended to receive the payload, and the Integration Service routes the payload directly to that consumer. Two "styles" of directed interaction exist, differing only by the response from the payload consumer. When interacting via directed messaging, topic naming conventions should provide an adequate amount of information to be deterministic regarding the operation(s) to be performed, and the component performing them. For example, a topic named "/collector-1234/ad-hoc- collection" would indicate a payload of collection instructions, provided to a specific component identified as "collector-1234", directing that component to perform Ad-Hoc Collection. 4.1.2.1. Synchronous Synchronous, request/response style interaction requires that the requesting component block and wait for the receiving component to respond, or to time out when that response is delayed past a given time threshold. A synchronous interaction example may be querying a CMDB for posture attribute information in order to perform an evaluation. Montville & Munyan Expires 14 March 2021 [Page 13] Internet-Draft SACM Architecture September 2020 4.1.2.2. Asynchronous An asynchronous interaction involves the payload producer directing the message to a consumer, but not blocking or waiting for an immediate response. This style of interaction allows the producer to continue on to other activities without the need to wait for responses. This style is particularly useful when the interaction payload invokes a potentially long-running task, such as data collection, report generation, or policy evaluation. The receiving component may reply later via callbacks or further interactions, but it is not mandatory. 4.2. Management Plane Functions Mangement plane functions describe a component's interactions with the ecosystem itself, not necessarily relating to collection, evaluation, or downstream analytical processes. 4.2.1. Orchestrator Onboarding The Orchestrator component, being a specialized role in the architecture, onboards to the SACM ecosystem in such a manner as to enable the onboarding and capability management of the other component roles. The Orchestrator must support the set of capabilities needed to manage the functions of the ecosystem. With this in mind, the Orchestrator must first authenticate to the Integration Service. Once authentication has succeeded, the Orchestrator must establish "service handlers" per the component registration taxonomy (Section 5.2). Once "service handlers" have been established, the Orchestrator is then equipped to handle component registration, onboarding, capability discovery, and topic subscription policy. The following requirements exist for the Orchestrator to establish "service handlers" supporting the component registration taxonomy (Section 5.2): * The Orchestrator MUST enable the capability to receive onboarding requests via the "/orchestrator/registration" topic, * The Orchestrator MUST have the capability to generate, manage, and persist unique identifiers for all registered components, * The Orchestrator MUST have the capability to inventory and manage its "roster" (the list of registered components), Montville & Munyan Expires 14 March 2021 [Page 14] Internet-Draft SACM Architecture September 2020 * The Orchestrator MUST have the capability to manage its roster's advertised capabilities, including those endpoints to which those capabilities apply. In addition to supporting component registration, Orchestrators are responsible for many of the operational functions of the architecture, including initiating collection or evaluation, queries for repository data, or the assembly of information for downstream use. * The Orchestrator MUST support making directed requests to registered components over the component's administrative interface, as configured by the "/orchestrator/[component-unique- identifier]" topic. Administrative interface functions are described by their taxonomy, below. * The Orchestrator MUST support the publication of broadcast messages to topics configured by implementations of this ecosystem. * The Orchestrator MUST support the subscription to topics configured by implementations of this ecosystem as needed. 4.2.2. Component Onboarding Component onboarding describes how an individual component becomes part of the SACM ecosystem; registering with the Orchestrator, advertising capabilities, establishing its administrative interface, and subscribing to relevant topics. The component onboarding workflow involves multiple steps: * The component first authenticates to the Integration Service, and * The component initiates registration with the Orchestrator, per the component registration taxonomy (Section 5.2). Montville & Munyan Expires 14 March 2021 [Page 15] Internet-Draft SACM Architecture September 2020 Once the component has onboarded and registered with the Orchestrator, its administrative interface will have been established via the "/orchestrator/[component-unique-identifier]" topic. This administrative interface allows the component to advertise its capabilities to the Orchestrator and in return, allow the Orchestrator to direct capability-specific topic registration to the component. This is performed using the "capability advertisement handshake" (Section 5.3.1) taxonomy. Further described below, the "capability advertisement handshake" first assumes the onboarding component has the ability to describe its capabilities so they may be understood by the Orchestrator (TBD on capability advertisement methodology). * The component sends a message with its operational capabilities over the administrative interface: "/orchestrator/[component- unique-identifier]" * The Orchestrator receives the component's capabilities, persists them, and responds with the list of topics to which the component should subscribe, in order to receive notifications, instructions, or other directives intended to invoke the component's supported capabilities. * The component then subscribes to the topics provided by the Orchestrator in order to enable receipt of broadcast instructions. 4.3. Component Interactions Component interactions describe functionality between components relating to collection, evaluation, or other downstream processes. 4.3.1. Initiate Ad-Hoc Collection The Orchestrator supplies a payload of collection instructions to a topic or set of topics to which Posture Collection Services are subscribed. The receiving PCS components perform the required collection based on their capabilities. Each PCS then forms a payload of collected posture attributes (including endpoint identifying information) and publishes that payload to the topic(s) to which the Posture Attribute Repository is subscribed, for persistence. 4.3.2. Coordinate Periodic Collection Similar to ad-hoc collection, the Orchestrator supplies a payload of collection instructions similar to those of ad-hoc collection. Additional information elements containing collection identification and periodicity are included. Montville & Munyan Expires 14 March 2021 [Page 16] Internet-Draft SACM Architecture September 2020 4.3.2.1. Schedule Periodic Collection To enable operations on periodic collection, the scheduling payload MUST include both a unique identifier for the set of collection instructions, as well as a periodicity expression to enable the collection schedule. An optional "immediate collection" flag will indicate to the collection component that, upon receipt of the collection instructions, a collection will automatically be initiated prior to engagement of the scheduled collection. 4.3.2.2. Cancel Periodic Collection The Orchestrator disables the periodic collection of posture attributes by supplying collector(s) the unique identifier of previously scheduled collection instructions. An optional "final collection" flag will indicate to the collection component that, upon receipt of the cancellation instructions, a final ad-hoc collection is to take place. 4.3.3. Coordinate Observational/Event-based Collection In these scenarios, the Posture Collection Service acts as the "observer". Interactions with the observer could specify a time period of observation and potentially information intended to filter observed posture attributes to aid the PCS in determining those attributes that are applicable for collection and persistence to the Posture Attribute Repository. 4.3.3.1. Initiate Observational/Event-based Collection The Orchestrator supplies a payload of instructions to a topic or set of topics to which Posture Collection Services (observers) are subscribed. This payload could include specific instructions based on the observer's capabilities to determine specific posture attributes to observe and collect. 4.3.3.2. Cancel Observational/Event-based Collection The Orchestrator supplies a payload of instructions to a topic or set of topics to which Posture Collection Services are subscribed. The receiving PCS components cancel the identified observational/event- based collection executing on those PCS components. Montville & Munyan Expires 14 March 2021 [Page 17] Internet-Draft SACM Architecture September 2020 4.3.4. Persist Collected Posture Attributes Following successful collection, Posture Collection Services (PCS) will supply the payload of collected posture attributes to the interface(s) supporting the persistent storage of those attributes to the Posture Attribute Repository. Information in this payload should include identifying information of the computing resource(s) for which attributes were collected. 4.3.5. Initiate Ad-Hoc Evaluation The Orchestrator supplies a payload of evaluation instructions to a topic or set of topics to which Posture Evaluation Services (PES) are subscribed. The receiving PES components perform the required evaluation based on their capabilities. The PES generates a payload of posture evaluation results and publishes that payload to the appropriate topic(s), to which the Evaluation Results Repository is subscribed, for persistence. 4.3.6. Coordinate Periodic Evaluation Similar to ad-hoc evaluation, the Orchestrator supplies a payload of evaluation instructions similar to those of ad-hoc evaluation. Additional information elements containing evaluation identification and periodicity are included. 4.3.6.1. Schedule Periodic Evaluation To enable operations on periodic evaluation, the scheduling payload MUST include both a unique identifier for the set of evaluation instructions, as well as a periodicity expression to enable the evaluation schedule. An optional "immediate evaluation" flag will indicate to the Posture Evaluation Service (PES) that, upon receipt of the evaluation instructions, an evaluation will automatically be initiated prior to engagement of the scheduled evaluation. 4.3.6.2. Cancel Periodic Evaluation The Orchestrator disables the periodic evaluation of posture attributes by supplying Posture Evaluation Service(s) the unique identifier of previously scheduled evaluation instructions. An optional "final evaluation" flag will indicate to the PES that, upon receipt of the cancellation instructions, a final ad-hoc evaluation is to take place. Montville & Munyan Expires 14 March 2021 [Page 18] Internet-Draft SACM Architecture September 2020 4.3.7. Coordinate Change-based Evaluation A more fine-grained approach to periodic evaluation may be enabled through the triggering of Posture Evaluation based on changes to posture attribute values at the time of their collection and persistence to the Posture Attribute Repository. 4.3.7.1. Identify Attributes The Orchestrator enables change-based evaluation through a payload published to Posture Attribute Repository component(s). This payload includes appropriate information elements describing the posture attributes on which changes in value will trigger posture evaluation. 4.3.7.2. Cancel Change-based Evaluation An Orchestrator may disable change-based evaluation through a payload published to Posture Attribute Repository component(s), including those information elements necessary to identify those posture attributes for which change-based evaluation no longer applies. 4.3.8. Queries Queries should allow for a "freshness" time period, allowing the requesting entity to determine if/when posture attributes must be re- collected prior to performing evaluation. This freshness time period can be "zeroed out" for the purpose of automatically triggering re- collection regardless of the most recent collection. 5. Taxonomy The following sections describe a number of operations required to enable a cooperative ecosystem of posture attribute collection and evaluation functions. 5.1. Orchestrator Registration The Orchestrator Registration taxonomy describes how an Orchestrator onboards to the SACM ecosystem, or how it returns from a non- operational state. Montville & Munyan Expires 14 March 2021 [Page 19] Internet-Draft SACM Architecture September 2020 5.1.1. Interaction +=====================+=============================+ | Property | Value | +=====================+=============================+ | Type | Directed (Request/Response) | +---------------------+-----------------------------+ | Topic | N/A | +---------------------+-----------------------------+ | Source Component | Orchestrator | +---------------------+-----------------------------+ | Target Component(s) | N/A | +---------------------+-----------------------------+ Table 1 5.1.2. Request Payload N/A; 5.1.3. Request Processing Once the Orchestrator has authenticated to the Integration Service, it must establish (or re-establish) any service handlers interacting with administrative interfaces and/or general operational interfaces. For initial registration, the Orchestrator MUST enable capabilities to: * Receive onboarding requests via the "/orchestrator/registration" topic, * Generate, manage, and persist unique identifiers for all registered components, * Inventory and manage its "roster" (the list of registered components), and * Support making directed requests to registered components over the component's administrative interface, as configured by the "/orchestrator/[component-unique-identifier]" topic. Administrative interfaces are to be re-established through the inventory of previously registered components, such as Posture Collection Services, Repositories, or Posture Evaluation Services. Montville & Munyan Expires 14 March 2021 [Page 20] Internet-Draft SACM Architecture September 2020 5.1.4. Response Payload N/A 5.1.5. Response Processing N/A 5.2. Component Registration Component onboarding describes how an individual component becomes part of the SACM ecosystem; registering with the orchestrator, advertising capabilities, establishing its administrative interface, and subscribing to relevant topics. 5.2.1. Interaction +==============+==============================================+ | Property | Value | +==============+==============================================+ | Type | Directed (Request/Response) | +--------------+----------------------------------------------+ | Topic | /orchestrator/registration | +--------------+----------------------------------------------+ | Source | Any component wishing to join the ecosystem, | | Component | such as Posture Collection Services, | | | Repositories (policy, collection content, | | | posture attribute, evaluation results, | | | etc.), Posture Evaluation Services and more. | +--------------+----------------------------------------------+ | Target | Orchestrator | | Component(s) | | +--------------+----------------------------------------------+ Table 2 5.2.2. Request Payload When a component registers with the Orchestrator and enters the ecosystem, it must first identify itself to the Orchestrator. Montville & Munyan Expires 14 March 2021 [Page 21] Internet-Draft SACM Architecture September 2020 component-registration-request: component-unique-identifier (if re-establishing communication) #-OR-# {:component-identification:} component-identification: component-type {:component-type:} component-name component-description (optional) component-type: enumeration: - posture-collection-service - posture-evaluation-service - repository - orchestrator - others? When registering for the first time, the component will send identifying information including the component type and a name. If the component is reestablishing communications, for example after a restart of the component or deployment of a new version, the component only needs to supply its previously generated unique identifier. 5.2.3. Request Processing When the Orchestrator receives the component's request for onboarding, it will: * Generate a unique identifier, "[component-unique-identifier]", for the onboarding component, * Persist required information (TBD probably need more specifics), including the "[component-unique-identifier]" to its component inventory, enabling an up-to-date roster of components being orchestrated, * Establish the administrative interface via the "/orchestrator/[component-unique-identifier]" topic. 5.2.4. Response Payload The Orchestrator will respond to the component with a payload including the component's unique identifier. At this point, the Orchestrator is aware of the component's existence in the ecosystem, and the component is self-aware by virtue of receiving its unique identifier. Montville & Munyan Expires 14 March 2021 [Page 22] Internet-Draft SACM Architecture September 2020 component-registration-response: component-unique-identifier: [component-unique-identifier] 5.2.5. Response Processing Successful receipt of the Orchestrator's response, including the "[component-unique-identifier]" indicates the component is onboarded to the ecosystem. Using the response payload, the component can then establish its end of the administrative interface with the Orchestrator, using the "/orchestrator/[component-unique-identifier]" topic. Given this administrative interface, the component can then initiate the Section 5.3.1 5.3. Orchestrator-Component Administrative Interface A number of functions may take place which, instead of being published to a multi-subscriber topic, may require direct interaction between an Orchestrator and a registered component. During component onboarding, this direct channel is established first by the Orchestrator and subsequently complemented by the component entering the ecosystem. 5.3.1. Capability Advertisement Handshake Capability advertisement, otherwise known as service discovery, is necessary to establish and maintain a cooperative ecosystem of tools by allowing components to register and maintain supported capabilities with the orchestrator. Using this capability advertisement "handshake", the Orchestrator becomes knowledgeable of a component's operational capabilities, the endpoints/services with which the component interacts, and establishes a direct mode of contact for invoking those capabilities. Once initially established, orchestrators and components can maintain this capability matrix using the administrative interface. 5.3.1.1. Interaction +==================+=============================================+ | Property | Value | +==================+=============================================+ | Type | Directed (Request/Response) | +------------------+---------------------------------------------+ | Topic | /orchestrator/[component-unique-identifier] | +------------------+---------------------------------------------+ | Source Component | Any ecosystem component (minus the | | | Orchestrator) | +------------------+---------------------------------------------+ | Target | Orchestrator | Montville & Munyan Expires 14 March 2021 [Page 23] Internet-Draft SACM Architecture September 2020 | Component(s) | | +------------------+---------------------------------------------+ Table 3 5.3.1.2. Request Payload capability-advertisement-request: component-unique-identifier: [component-unique-identifier] component-type: {:component-type:} capabilities: capability-urn: [urn] capability-urn: [urn] capability-urn: [urn] ... [TBD] Start adding capability URNs to IANA considerations section? 5.3.1.3. Request Processing Upon receipt of the component's capability advertisement, it SHOULD: * Persist the component's capabilities to the Orchestrator's inventory * Coordinate, based on the supplied capabilities, a list of topics to which the component should subscribe [TBD] What if the component supplies a "capability-urn" that the Orchestrator doesn't know about? 5.3.1.4. Response Payload When responding, the Orchestrator will indicate to the component, which capabilities were successfully registered, and the topics to which those capabilities apply. Any failures to register capabilities will also be noted per capability URN, including any relevant error messages. Montville & Munyan Expires 14 March 2021 [Page 24] Internet-Draft SACM Architecture September 2020 capability-advertisement-response: capabilities: capability: capability-urn: [urn] registration-status: (success | failure) capability-topic: /capability/topic/name messages: [messages] capability: capability-urn: [urn] registration-status: (success | failure) capability-topic: /capability/topic/name messages: [messages] ... 5.3.1.5. Response Processing Once the component has received the response to its capability advertisement, it should subscribe to the Orchestrator-provided topics. Once the applicable topics have been subscribed, the component is considered fully onboarded to the ecosystem. 5.3.2. Heartbeat As time passes and ecosystem components which have previously registered with the ecosystem are brought offline (perhaps for maintenance or redeployment) and back online, it is important that the Orchestrator maintains knowledge of all registered component's current operational status. The heartbeat taxonomy describes the efforts taken by an Orchestrator to maintain the most up-to-date inventory of operational components, and to potentially alert users or other outside systems of unavailable components. 5.3.2.1. Interaction +=====================+=============================================+ | Property | Value | +=====================+=============================================+ | Type | Directed (Request/Response) | +---------------------+---------------------------------------------+ | Topic | /orchestrator/[component-unique-identifier] | +---------------------+---------------------------------------------+ | Source Component | Orchestrator | +---------------------+---------------------------------------------+ | Target | Any non-Orchestrator component maintained | | Component(s) | in the current operational inventory | +---------------------+---------------------------------------------+ Table 4 Montville & Munyan Expires 14 March 2021 [Page 25] Internet-Draft SACM Architecture September 2020 5.3.2.2. Request Payload The request payload defines the hearbeat action to be taken: heartbeat-request: action: (ping | ping-with-capabilities) 5.3.2.3. Request Processing When the target component receives the hearbeat request, it will determine based on action, the processing required. A simple "ping" request indicates the target component need only respond that it is operational and connected to the integration service. This is a simple "Are you listening? Yes, I am" interaction. The heartbeat request from the Orchestrator should be made with an appropriately small timeout indicator; only an operational component will be able to respond to the request, so if that component is offline and cannot respond, the Orchestrator should not be kept waiting for an extended amount of time. When the requested action is "ping-with-capabilities", the receiving component is instructed to respond that it is operational and to immediately follow the response with a re-initiation of the Section 5.3.1 process. This interaction enables an Orchestrator the ability to perform capability discovery from components. 5.3.2.4. Response Payload When responding to the heartbeat request, the initial response payload will simply indicate success: ~~~~~~ heartbeat-response: response: success ~~~~~~ If the "ping-with-capabilities" action was requested, the responding component will immediately initiate the Section 5.3.1 process. 5.3.2.5. Response Processing Upon receipt of the "heartbeat-response" payload, the Orchestrator will update its inventory of currently operational components with the timestamp of the receipt. If the Orchestrator originally requested the component's capabilities as well, further interactions will initiate and complete the Section 5.3.1 process. Montville & Munyan Expires 14 March 2021 [Page 26] Internet-Draft SACM Architecture September 2020 5.4. Collection The following sections detail the interactions supporting the collection of posture attributes from one or many endpoints within the ecosystem. Collector capabilities will determine both the set of endpoints each collector from which posture attributes may be collected, as well as the various methods of collection used by those collectors. 5.4.1. Ad-Hoc Collection components support ad-hoc collection activities when receiving collection instructions from an Orchestrator and by acting upon those instructions immediately, collecting posture attributes as they exist on targeted endpoints at the moment of collection. Ad-Hoc collection may potentially be invoked by a number of components, including Orchestrators or even Posture Evaluation Services, and may be requested of Collectors either directly or through the Collector's subscription to topics as established by the Section 5.3.1 process. 5.4.1.1. Interaction +==============+===================================================+ | Property | Value | +==============+===================================================+ | Type | Directed or Broadcast | +--------------+---------------------------------------------------+ | Topic | | +--------------+---------------------------------------------------+ | Source | Orchestrator, Posture Evaluation Service | | Component | | +--------------+---------------------------------------------------+ | Target | Collector | | Component(s) | | +--------------+---------------------------------------------------+ Table 5 Montville & Munyan Expires 14 March 2021 [Page 27] Internet-Draft SACM Architecture September 2020 5.4.1.2. Request Payload Ad-Hoc collection requests take the form of collection instructions corresponding to the SACM information model. Collection instruction payloads MAY be serialized as a specific collection language supported by the Collector (taking into account any implementation- specific payload size limitations), as a generic serialization to be interpreted by the Collector, or as ID references to content persisted in a Repository. Instructions MAY include a "response topic" to which collection results are published/directed. This can allow the requesting component to direct a Collector (or Collectors) to publish results directly to a Posture Attribute Repository component, or to simply respond to the requesting component. collection-request: [TBD] response-topic: [response-topic] 5.4.1.3. Request Processing Upon receipt of collection instructions, the Collector will need to determine whether or not any normalization or retrieval of specific instructions is required. This normalization may be required if collection instructions are not formatted specifically to the capabilities of the Collector. For example, if a payload is delivered containing a set of OVAL "object" IDs, the Collector would need to retrieve the instructions from the Repository and format them into a well-formed, valid OVAL definitions serialization for processing. Once the collection instructions have been received and any pre- processing/normalization has occurred, the Collector will perform the actual retrieval of posture attributes. Once collected, posture attributes will need to be published back to the topic named in the request payload. This response topic could represent a callback to the component invoking collection, or a destination for the posture attributes to be persisted, i.e. a Repository. 5.4.1.4. Response Payload The response payload generated by the Collector may take one of 2 forms: * Collection results using the data model supported by the collection system indicated in the collection instructions. For example, if the collection instructions were formatted as OVAL Montville & Munyan Expires 14 March 2021 [Page 28] Internet-Draft SACM Architecture September 2020 definitions (or more specifically OVAL objects), then collection results would be formatted as OVAL system characteristics. Each collector is responsible for maintaining the capabilities necessary to produce results formats based on its collection capabilities. * Collection results using a "normalized" [TBD] format as defined by the SACM information model/data models. 5.4.1.5. Response Processing Handling a payload of collected posture attributes will vary based on the component receiving that payload: * Posture Attribute Repository: If collection results are not "normalized" the Repository component MUST be able to perform normalization processing prior to persisting the results. * Non-Repository Components: The receiving component must also be capable of "normalizing" collected posture attributes 5.4.2. Periodic Periodic collection builds upon Ad-Hoc collection by allowing Orchestration of collection activities given a periodicity. Architecturally, periodic collection is orchestrated through either the scheduling of collection or canceling an already-existing schedule. Modifications to a scheduled collection MUST be made by first canceling the existing schedule and establishing the updated schedule. 5.4.2.1. Schedule Periodic Collection Scheduling periodic collection is established by an Orchestrator delivering collection instructions and the collection periodicity to a Collector. These instructions may be received by the Collector through a number of topics, described below. 5.4.2.1.1. Interaction +==============+===================================================+ | Property | Value | +==============+===================================================+ | Type | Directed or Broadcast | +--------------+---------------------------------------------------+ | Topic | | +--------------+---------------------------------------------------+ | Source | Orchestrator | | Component | | +--------------+---------------------------------------------------+ | Target | Collector | | Component(s) | | +--------------+---------------------------------------------------+ Table 6 5.4.2.1.2. Request Payload The request to schedule periodic collection is represented as a wrapper of the collection instructions used to initiate ad-hoc collection. Additional elements indicate the establishment of the schedule, the collection schedule itself, and whether or not to perform an immediate collection upon receipt of the payload. periodic-collection: collection-identifier: 12345 operation: schedule collection-schedule: TBD (cron formatted? other scheduling formats?) collect-upon-acknowledgement: true/false collection-instructions: # Formatted per Ad-Hoc Collection taxonomy 5.4.2.1.3. Request Processing Upon receipt of the request to establish periodic collection, the Collector must first determine if the "collection-identifier" is unique. If an existing periodic collection, using the same identifier, is already present, an error payload MUST be returned to the Orchestrator. Once the collection identifier has been validated, the schedule is established within the scope of the Collector receiving the instructions. If the "collect-upon-acknowledgement" flag is set to "true", the Collector MUST perform an immediate ad-hoc collection based on the instructions passed in the payload and the collected posture attributes are provided to the "response-topic" per the "collection-instructions". Montville & Munyan Expires 14 March 2021 [Page 30] Internet-Draft SACM Architecture September 2020 5.4.2.1.4. Response Payload Essentially, two payloads could be provided in ##### Response Processing 5.4.2.2. Cancel Periodic Collection TBD 5.4.2.2.1. Interaction +==============+===================================================+ | Property | Value | +==============+===================================================+ | Type | Directed or Broadcast | +--------------+---------------------------------------------------+ | Topic | | +--------------+---------------------------------------------------+ | Source | Orchestrator | | Component | | +--------------+---------------------------------------------------+ | Target | Collector | | Component(s) | | +--------------+---------------------------------------------------+ Table 7 5.4.2.2.2. Request Payload periodic-collection: collection-identifier: 12345 operation: cancel collect-upon-acknowledgement: true/false 5.4.2.2.3. Request Processing ##### Response Payload ##### Response Processing 5.4.3. Observational/Event-based 5.5. Evaluation Montville & Munyan Expires 14 March 2021 [Page 31] Internet-Draft SACM Architecture September 2020 5.5.1. Ad-Hoc 5.5.2. Periodic 5.5.3. Change/Event-based 6. Privacy Considerations [TBD] 7. Security Considerations [TBD] 8. IANA Considerations [TBD] 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: * Capability/operation semantics * SACM Component implementation identifiers * SACM Component versions * Associations of SACM Components (and versions) to specific Capabilities * Collection sub-architecture Identification 9. References 9.1. Normative References [I-D.ietf-sacm-ecp] Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin, "Endpoint Posture Collection Profile", Work in Progress, Internet-Draft, draft-ietf-sacm-ecp-05, 21 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, . Montville & Munyan Expires 14 March 2021 [Page 32] Internet-Draft SACM Architecture September 2020 [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., 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, . 9.2. Informative References [CISCONTROLS] "CIS Controls v7.1", n.d., . [draft-birkholz-sacm-yang-content] Birkholz, H. and N. Cam-Winget, "YANG subscribed notifications via SACM Statements", n.d., . [HACK100] "IETF 100 Hackathon - Vulnerability Scenario EPCP+XMPP", n.d., . [HACK101] "IETF 101 Hackathon - Configuration Assessment XMPP", n.d., . [HACK102] "IETF 102 Hackathon - YANG Collection on Traditional Endpoints", n.d., . [HACK103] "IETF 103 Hackathon - N/A", n.d., . [HACK104] "IETF 104 Hackathon - A simple XMPP client", n.d., . [HACK105] "IETF 105 Hackathon - A more robust XMPP client including collection extensions", n.d., . [HACK99] "IETF 99 Hackathon - Vulnerability Scenario EPCP", n.d., . Montville & Munyan Expires 14 March 2021 [Page 33] Internet-Draft SACM Architecture September 2020 [I-D.ietf-sacm-terminology] Birkholz, H., Lu, J., Strassner, J., Cam-Winget, N., and A. Montville, "Security Automation and Continuous Monitoring (SACM) Terminology", Work in Progress, Internet-Draft, draft-ietf-sacm-terminology-16, 14 December 2018, . [NIST800126] Waltermire, D., Quinn, S., Booth, H., Scarfone, K., and D. Prisaca, "SP 800-126 Rev. 3 - The Technical Specification for the Security Content Automation Protocol (SCAP) - SCAP Version 1.3", February 2018, . [NISTIR7694] Halbardier, A., Waltermire, D., and M. Johnson, "NISTIR 7694 Specification for Asset Reporting Format 1.1", n.d., . [RFC5023] Gregorio, J., Ed. and B. de hOra, Ed., "The Atom Publishing Protocol", RFC 5023, DOI 10.17487/RFC5023, October 2007, . [RFC7632] Waltermire, D. and D. Harrington, "Endpoint Security Posture Assessment: Enterprise Use Cases", RFC 7632, DOI 10.17487/RFC7632, September 2015, . [RFC8248] Cam-Winget, N. and L. Lorenzin, "Security Automation and Continuous Monitoring (SACM) Requirements", RFC 8248, DOI 10.17487/RFC8248, September 2017, . [RFC8322] Field, J., Banghart, S., and D. Waltermire, "Resource- Oriented Lightweight Information Exchange (ROLIE)", RFC 8322, DOI 10.17487/RFC8322, February 2018, . [XMPPEXT] "XMPP Extensions", n.d., . Appendix A. Security Domain Workflows This section describes three primary information security domains from which workflows may be derived: IT Asset Management, Vulnerability Management, and Configuration Management. Montville & Munyan Expires 14 March 2021 [Page 34] Internet-Draft SACM Architecture September 2020 A.1. IT Asset Management Information Technology asset management is easier said than done. The [CISCONTROLS] have two controls dealing with IT asset management. Control 1, Inventory and Control of Hardware Assets, states, "Actively manage (inventory, track, and correct) all hardware devices on the network so that only authorized devices are given access, and unauthorized and unmanaged devices are found and prevented from gaining access." Control 2, Inventory and Control of Software Assets, states, "Actively manage (inventory, track, and correct) all software on the network so that only authorized software is installed and can execute, and that unauthorized and unmanaged software is found and prevented from installation or execution." In spirit, this covers all of the processing entities on your network (as opposed to things like network cables, dongles, adapters, etc.), whether physical or virtual, on-premises or in the cloud. A.1.1. Components, Capabilities and Workflow(s) TBD A.1.1.1. Components TBD A.1.1.2. Capabilities An IT asset management capability needs to be able to: * Identify and catalog new assets by executing Target Endpoint Discovery Tasks * Provide information about its managed assets, including uniquely identifying information (for that enterprise) * Handle software and/or hardware (including virtual assets) * Represent cloud hybrid environments A.1.1.3. Workflow(s) TBD Montville & Munyan Expires 14 March 2021 [Page 35] Internet-Draft SACM Architecture September 2020 A.2. Vulnerability Management 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: * Endpoint information collected by the endpoint management capabilities is examined by the vulnerability management capabilities through Evaluation Tasks. * If the data possessed by the endpoint management capabilities is insufficient, a Collection Task is triggered and the necessary data is collected from the target endpoint. Vulnerability detection relies on the examination of different endpoint information depending on the nature of a specific vulnerability. Common endpoint information used to detect a vulnerability includes: * A specific software version is installed on the endpoint * File system attributes * Specific state attributes 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). A.2.1. Components, Capabilities and Workflow(s) TBD Montville & Munyan Expires 14 March 2021 [Page 36] Internet-Draft SACM Architecture September 2020 A.2.1.1. Components TBD A.2.1.2. Capabilities TBD A.2.1.3. Workflow(s) TBD A.3. Configuration Management 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: * Reputable source publishes new or updated configuration guidance * Enterprise configuration assessment capability retrieves configuration guidance from reputable source * Optional: Configuration guidance is tailored for enterprise- specific needs * Configuration assessment tool queries asset inventory repository to retrieve a list of affected endpoints Montville & Munyan Expires 14 March 2021 [Page 37] Internet-Draft SACM Architecture September 2020 * Configuration assessment tool queries configuration state repository to evaluate compliance * If information is stale or unavailable, configuration assessment tool triggers an ad hoc assessment The SACM architecture needs to support varying deployment models to accommodate the current state of the industry, but should strongly encourage event-driven approaches to monitoring configuration. A.3.1. Components, Capabilities and Workflow(s) This section provides more detail about the components and capabilities required when considering the aforementioned configuration management workflow. A.3.1.1. Components The following is a minimal list of SACM Components required to implement the aforementioned configuration assessment workflow. * Configuration Policy Feed: An external source of authoritative configuration recommendations. * Configuration Policy Repository: An internal repository of enterprise standard configurations. * Configuration Assessment Orchestrator: A component responsible for orchestrating assessments. * Posture Attribute Collection Subsystem: A component responsible for collection of posture attributes from systems. * Posture Attribute Repository: A component used for storing system posture attribute values. * Configuration Assessment Evaluator: A component responsible for evaluating system posture attribute values against expected posture attribute values. * Configuration Assessment Results Repository: A component used for storing evaluation results. Montville & Munyan Expires 14 March 2021 [Page 38] Internet-Draft SACM Architecture September 2020 A.3.1.2. 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". A.3.1.3. 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 | | 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. 1. A policy feed provides a configuration assessment policy payload to the Integration Service. Montville & Munyan Expires 14 March 2021 [Page 39] Internet-Draft SACM Architecture September 2020 2. The Policy Repository, a consumer of Policy Feed information, receives and persists the Policy Feed's payload. 3. Orchestration component(s), either manually invoked, scheduled, or event-based, publish a payload to begin the configuration assessment process. 4. If necessary, Collection Sub-Architecture components may be invoked to collect neeeded posture attribute information. 5. If necessary, the Collection Sub-Architecture will provide collected posture attributes to the Integration Service for persistence to the Posture Attribute Repository. 6. The Posture Attribute Repository will consume a payload querying for relevant posture attribute information. 7. The Posture Attribute Repository will provide the requested information to the Integration Service, allowing further orchestration payloads requesting the Evaluation Sub- Architecture perform evaluation tasks. 8. The Evaluation Sub-Architecture consumes the evaluation payload and performs component-specific state comparison operations to produce evaluation results. 9. A payload containing evaluation results are provided by the Evaluation Sub-Architecture to the Integration Service 10. Evaluation results are consumed by/persisted to the Evaluation Results Repository 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. Authors' Addresses Adam W. Montville Center for Internet Security 31 Tech Valley Drive Montville & Munyan Expires 14 March 2021 [Page 40] Internet-Draft SACM Architecture September 2020 East Greenbush, NY 12061 United States of America Email: adam.montville.sdo@gmail.com Bill Munyan Center for Internet Security 31 Tech Valley Drive East Greenbush, NY 12061 United States of America Email: bill.munyan.ietf@gmail.com Montville & Munyan Expires 14 March 2021 [Page 41]