--- 1/draft-ietf-sacm-arch-01.txt 2019-07-26 08:13:06.054606286 -0700 +++ 2/draft-ietf-sacm-arch-02.txt 2019-07-26 08:13:06.110607699 -0700 @@ -1,27 +1,26 @@ SACM Working Group A. Montville Internet-Draft B. Munyan Intended status: Standards Track CIS -Expires: August 26, 2019 February 22, 2019 +Expires: January 27, 2020 July 26, 2019 Security Automation and Continuous Monitoring (SACM) Architecture - draft-ietf-sacm-arch-01 + draft-ietf-sacm-arch-02 Abstract This memo defines a Security Automation and Continuous Monitoring - (SACM) architecture. This work is built upon - [I-D.ietf-mile-xmpp-grid], and is predicated upon information gleaned - from SACM Use Cases and Requirements ([RFC7632] and [RFC8248] - respectively), and terminology as found in - [I-D.ietf-sacm-terminology]. + (SACM) architecture. This work is built upon [RFC8600], and is + predicated upon information gleaned from SACM Use Cases and + Requirements ([RFC7632] and [RFC8248] respectively), and terminology + as found in [I-D.ietf-sacm-terminology]. WORKING GROUP: The source for this draft is maintained in GitHub. Suggested changes should be submitted as pull requests at https://github.com/sacmwg/ietf-mandm-sacm-arch/. Instructions are on that page as well. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. @@ -29,474 +28,154 @@ 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 August 26, 2019. + This Internet-Draft will expire on January 27, 2020. Copyright Notice Copyright (c) 2019 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 and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 - 1.1. Open Questions . . . . . . . . . . . . . . . . . . . . . 3 - 1.2. Requirements notation . . . . . . . . . . . . . . . . . . 3 - 2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 4 - 3. Architectural Overview . . . . . . . . . . . . . . . . . . . 4 - 3.1. SACM Roles . . . . . . . . . . . . . . . . . . . . . . . 5 - 3.2. Exploring An XMPP-based Solution . . . . . . . . . . . . 5 - 3.3. Example Architecture using XMPP-Grid and Endpoint Posture - Collection Protocol . . . . . . . . . . . . . . . . . . . 8 - 4. Components, Capabilities, Interfaces, and Workflows . . . . . 10 - 4.1. Components . . . . . . . . . . . . . . . . . . . . . . . 10 - 4.2. Capabilities . . . . . . . . . . . . . . . . . . . . . . 11 - 4.3. Interfaces . . . . . . . . . . . . . . . . . . . . . . . 11 - 4.4. Workflows . . . . . . . . . . . . . . . . . . . . . . . . 12 - 4.4.1. IT Asset Management . . . . . . . . . . . . . . . . . 12 - 4.4.2. Vulnerability Management . . . . . . . . . . . . . . 12 - 4.4.3. Configuration Management . . . . . . . . . . . . . . 14 - 5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 15 - 6. Security Considerations . . . . . . . . . . . . . . . . . . . 15 - 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 - 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 - 8.1. Normative References . . . . . . . . . . . . . . . . . . 16 - 8.2. Informative References . . . . . . . . . . . . . . . . . 16 - Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 18 - Appendix B. Example Components . . . . . . . . . . . . . . . . . 21 - B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 21 - B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 22 - B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 23 - B.4. Network Configuration Collection . . . . . . . . . . . . 23 + 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 + 2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 3 + 3. Architectural Overview . . . . . . . . . . . . . . . . . . . 3 + 4. Relevant Workflows . . . . . . . . . . . . . . . . . . . . . 5 + 4.1. IT Asset Management . . . . . . . . . . . . . . . . . . . 5 + 4.2. Vulnerability Management . . . . . . . . . . . . . . . . 5 + 4.3. Configuration Management . . . . . . . . . . . . . . . . 6 + 5. Configuration Management Components, Interactions, and + Capabilities . . . . . . . . . . . . . . . . . . . . . . . . 7 + 5.1. Components . . . . . . . . . . . . . . . . . . . . . . . 7 + 5.2. Interactions . . . . . . . . . . . . . . . . . . . . . . 8 + 5.3. Capabilities . . . . . . . . . . . . . . . . . . . . . . 8 + 6. Configuration Assessment Workflow . . . . . . . . . . . . . . 9 + 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 10 + 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 + 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 11 + 10.2. Informative References . . . . . . . . . . . . . . . . . 11 + Appendix A. Mapping to RFC8248 . . . . . . . . . . . . . . . . . 13 + Appendix B. Example Components . . . . . . . . . . . . . . . . . 16 + B.1. Policy Services . . . . . . . . . . . . . . . . . . . . . 16 + B.2. Software Inventory . . . . . . . . . . . . . . . . . . . 17 + B.3. Datastream Collection . . . . . . . . . . . . . . . . . . 18 + B.4. Network Configuration Collection . . . . . . . . . . . . 18 + Appendix C. Exploring An XMPP-based Solution . . . . . . . . . . 19 + C.1. Example Architecture using XMPP-Grid and Endpoint Posture + Collection Protocol . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 1. Introduction - The purpose of this draft is to define an architectural solution for - a SACM Domain. This draft also defines an implementation of the - architecutre, built upon [I-D.ietf-mile-xmpp-grid] and - [I-D.ietf-sacm-ecp]. These approaches complement each other to more - completely meet the spirit of [RFC7632] and requirements found in - [RFC8248]. - - This solution gains the most advantage by supporting a variety of - collection mechanisms. In this sense, the solution ideally intends + 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 solution described in this - document seeks to accommodate these recognitions by first defining a - generic abstract architecture, then making that solution somewhat - more concrete. - - Keep in mind that, at this point, the draft is tracking ongoing work - being performed primarily around and during IETF hackathons. The - list of hackathon efforts follows: - - o [HACK99]: A partial implementation of a vulnerability assessment - scenario involving an [I-D.ietf-sacm-ecp] implementation, a - [RFC8322] implementation, and a proprietary evaluator to pull the - pieces together. - - o [HACK100]: Work to combine the vulnerability assessment scenario - from [HACK99] with an XMPP-based YANG push model. - - o [HACK101]: A fully automated configuration assessment - implementation using XMPP as a communication mechanism. - - o [HACK102]: An exploration of how we might model assessment, - collection, and evaluation abstractly, and then rely on YANG - expressions for the attributes of traditional endpoints. - -1.1. Open Questions - - [NOTE: This section will eventually be removed.] - - The following is a list of open questions we still have about the - path forward with this exploration: - - o Should workflows be documented in this draft or separate drafts? - - o Should interfaces be documented in workflow drafts or separate - drafts (or even this draft)? + with minimal operator configuration. -1.2. Requirements notation +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]. 2. Terms and Definitions This draft defers to [I-D.ietf-sacm-terminology] for terms and definitions. 3. Architectural Overview The generic approach proposed herein recognizes the need to obtain - information from existing state collection mechanisms, and makes - every attempt to respect [RFC7632] and [RFC8248]. At the foundation - of any architecture are entities, or components, that need to - communicate. They communicate by sharing information, where, in a - given flow one or more components are consumers of information and + 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. +--------------------+ | Feeds/Repositories | | of External Data | +--------------------+ | | *****************************v**************** Enterprise Boundary ************ * | * -* +--------------+ | +--------------+ * -* | Orchestrator | | | Repositories | * -* +------^-------+ | +----^---------+ * +* +---------------+ | +--------------+ * +* | Orchestrators | | | Repositories | * +* +------^--------+ | +----^---------+ * * | | | +----------------+ * -* A | B | C | | Downstream Uses| * +* | | | | Downstream Uses| * * | | | | +-----------+ | * * +------v------------------v----------v------+ | |Evaluations| | * * | Message Transfer System <-------> +-----------+ | * -* +----------------------^--------------------+ D | +-----------+ | * -* E | | | Analytics | | * +* +----------------------^--------------------+ | +-----------+ | * +* | | | Analytics | | * * | | +-----------+ | * -* +-------------v---------+ | +-----------+ | * -* | Collection Subsystems | | | Reporting | | * -* +-----------------------+ | +-----------+ | * +* +-------------v------+ | +-----------+ | * +* | Collection Systems | | | Reporting | | * +* +--------------------+ | +-----------+ | * * +----------------+ * ******************************************************************************* Figure 1: Notional Architecture As shown in Figure 1, the notional SACM architecture consists of some basic SACM Components using a message transfer system to communicate. - While not depicted, the message transfer system is expected to - maximally align with the requirements described in [RFC8248], which - means that the message transfer system will support brokered (i.e. - point-to-point) and proxied data exchange. - - Additionally, component-specific interfaces (i.e. such as A, B, C, D, - and E in Figure 1) are expected to be specified logically then bound - to one or more specific implementations. This SHOULD be done for - each capability related to the given SACM Component. + The message transfer system is expected to maximally align with the + requirements described in [RFC8248], which means that the message + transfer system will support brokered (i.e. point-to-point) and + proxied data exchange. -3.1. SACM Roles + The enterprise boundary is not intended to imply a physical boundary. + Rather, the enterprise boundary is intended to be inclusive of + various cloud environments and vendor-provided services in addition + to any physical systems the enterprise operates. This document suggests a variety of players in a cooperative ecosystem - we call these players SACM Components. SACM Components may be composed of other SACM Components, and each SACM Component plays one, or more, of several roles relevant to the ecosystem. Generally each role is either a consumer of information or a provider - of information. The "Components, Capabilities, Interfaces, and - Workflows" section provides more details about SACM Components that - play these types of roles. - -3.2. Exploring An XMPP-based Solution - - Figure 2 depicts a slightly more detailed view of the architecture - (within the enterprise boundary) - one that fosters the development - of a pluggable ecosystem of cooperative tools. Existing collection - mechanisms can be brought into this architecture by specifying the - interface of the collector and creating the XMPP-Grid Connector - binding for that interface. - - Additionally, while not directly depicted in Figure 2, this - architecture does allow point-to-point interfaces. In fact, - [I-D.ietf-mile-xmpp-grid] provides brokering capabilities to - facilitate such point-to-point data transfers). Additionally, each - of the SACM Components depicted in Figure 2 may be a provider, a - consumer, or both, depending on the workflow in context. - - +--------------+ +--------------+ - | Orchestrator | | Repositories | - +------^-------+ +------^-------+ - | | - | | - +-------v--------------------------v--------+ +-----------------+ - | XMPP-Grid+ <-----> Downstream Uses | - +------------------------^------------------+ +-----------------+ - | - | - +-------v------+ - | XMPP-Grid | - | Connector(s) | - +------^-------+ - | - +------v-------+ - | Collector(s) | - +--------------+ - - Figure 2: XMPP-based Architecture - - [I-D.ietf-mile-xmpp-grid] details a number of XMPP extensions (XEPs) - that MUST be utilized to meet the needs of [RFC7632] and [RFC8248]: - - o Service Discovery (XEP-0030): Service Discovery allows XMPP - entities to discover information about other XMPP entities. Two - kinds of information can be discovered: the identity and - capabilities of an entity, such as supported features, and items - associated with an entity. - - o Publish-Subscribe (XEP-0060): The PubSub extension enables - entities to create nodes (topics) at a PubSub service and publish - information at those nodes. Once published, an event notification - is broadcast to all entities that have subscribed to that node. - - At this point, [I-D.ietf-mile-xmpp-grid] specifies fewer features - than SACM requires, and there are other XMPP extensions (XEPs) we - need to consider to meet the needs of [RFC7632] and [RFC8248]. In - Figure 2 we therefore use "XMPP-Grid+" to indicate something more - than [I-D.ietf-mile-xmpp-grid] alone, even though we are not yet - fully confident in the exact set of XMPP-related extensions we will - require. The authors propose work to extend (or modify) - [I-D.ietf-mile-xmpp-grid] to include additional XEPs - possibly the - following: - - o Entity Capabilities (XEP-0115): This extension defines the methods - for broadcasting and dynamically discovering an entities' - capabilities. This information is transported via standard XMPP - presence. Example capabilities that could be discovered could - include support for posture attribute collection, support for - specific types of posture attribute collection such as EPCP, - SWIMA, OVAL, or YANG. Other capabilities are still to be - determined. - - o Ad Hoc Commands (XEP-0050): This extension allows an XMPP entity - to advertise and execute application-specific commands. Typically - the commands contain data forms (XEP-0004) in order to structure - the information exchange. This extension may be usable for simple - orchestration (i.e. "do assessment"). - - o HTTP File Upload (XEP-0363): The HTTP File Upload extension allows - for large data sets to be published to a specific path on an HTTP - server, and receive a URL from which that file can later be - downloaded again. XMPP messages and IQs are meant to be compact, - and large data sets, such as collected posture attributes, may - exceed a message size threshold. Usage of this XEP allows those - larger data sets to be persisted, thus necessitating only the - download URL to be passed via XMPP messages. - - o Personal Eventing Protocol (XEP-0163): The Personal Eventing - Protocol can be thought of as a virtual PubSub service, allowing - an XMPP account to publish events only to their roster instead of - a generic PubSub topic. This XEP may be useful in the cases when - collection requests or queries are only intended for a subset of - endpoints and not an entire subscriber set. - - o File Repository and Sharing (XEP-0214): This extension defines a - method for XMPP entities to designate a set of file available for - retrieval by other users of their choosing, and is based on PubSub - Collections. - - o Easy User Onboarding (XEP-401): The goal of this extension is - simplified client registration, and may be useful when adding new - endpoints or SACM components to the ecosystem. - - o Bidirectional-streams Over Synchronous HTTP (BOSH) (XEP-0124): - BOSH emulates the semantics of a long-lived, bidirectional TCP - connection between two entities (aka "long polling"). Consider a - SACM component that is updated dynamically, i.e. an internal - vulnerability definition repository ingesting data from a Feed/ - Repository of External Data, and a second SACM component such as - an Orchestrator. Using BOSH, the Orchestrator can effectively - continuously poll the vulnerability definition repository for - changes/updates. - - o PubSub Collection Nodes (XEP-0248): Effectively an extension to - XEP-0060 (Publish-Subscribe), PubSub Collections aim to simplify - an entities' subscription to multiple related topics, and - establishes a "node graph" relating parent nodes to its - descendents. An example "node graph" could be rooted in a - "vulnerability definitions" topic, and contain descendent topics - for OS family-level vulnerability definitions (i.e. Windows), and - further for OS family version-level definitions (i.e. Windows 10 - or Windows Server 2016). - - o PubSub Since (XEP-0312): This extension enables a subscriber to - automatically receive PubSub and Personal Eventing Protocol (PEP) - notifications since its last logout time. This extension may be - useful in intermittent connection scenarios, or when entities - disconnect and reconnect to the ecosystem. - - o PubSub Chaining (XEP-0253): This extension describes the - federation of publishing nodes, enabling a publish node of one - server to be a subscriber to a publishing node of another server. - -3.3. Example Architecture using XMPP-Grid and Endpoint Posture - Collection Protocol - - Figure 3 depicts a further detailed view of the architecture - including the Endpoint Posture Collection Protocol as the collection - subsystem, illustrating the idea of a pluggable ecosystem of - cooperative tools. - - +--------------------+ - | Feeds/Repositories | - | of External Data | - +--------------------+ - | -********************v************************* Enterprise Boundary ************ -* | * -* +--------------+ | +-------------------+ +-------------+ * -* | Orchestrator | | | Posture Attr Repo | | Policy Repo | * -* +------^-------+ | +---------^---------+ +---^---------+ * -* | | | | +----------------+ * -* | | | | | Downstream Uses| * -* | | | | | +-----------+ | * -* +------v---------v-----------v---------------v--+ | |Evaluations| | * -* | XMPP-Grid <-------> +-----------+ | * -* +----------------^-------------------^----------+ | +-----------+ | * -* | | | | Analytics | | * -* | | | +-----------+ | * -* | +-----v--------+ | +-----------+ | * -* | | Results Repo | | | Reporting | | * -* | +--------------+ | +-----------+ | * -* | +----------------+ * -* +---------v-----------+ * -* | XMPP-Grid Connector | * -* +---------^-----------+ * -* | * -* +-----------------v-------------------------------------------------------+ * -* | | * -* | +--Posture Collection Manager------------------------------------------+| * -* | |+-----------------------+ +----------------+ +----------------------+ || * -* | || Communications Server | | Posture Server | | Posture Validator(s) | || * -* | |+----------^------------+ +----------------+ +----------------------+ || * -* | +-----------|----------------------------------------------------------+| * -* | | | * -* | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| * -* | |+----------v------------+ +----------------+ +----------------------+ || * -* | || Communications Client | | Posture Client | | Posture Collector(s) | || * -* | |+-----------------------+ +----------------+ +----------------------+ || * -* | +----------------------------------------------------------------------+| * -* +-----------------Endpoint Posture Collection Profile---------------------+ * -* * -******************************************************************************* - - Figure 3: XMPP-based Architecture including EPCP - -4. Components, Capabilities, Interfaces, and Workflows - - The SACM Architecture consists of a variety of SACM Components, and - named components are intended to embody one or more specific - capabilities. Interacting with these capabilities will require at - least two levels of interface specification. The first is a logical - interface specification, and the second is at least one binding to a - specific transfer mechanism. An example transfer mechanism is XMPP- - Grid+. - - The following subsections describe some of the components, - capabilities, and interfaces we may expect to see participating in a - SACM Domain. - -4.1. Components - - The following is a list of suggested SACM Component classes and - specializations. - - o Repository - - * Vulnerability Information Repository - - * Asset Inventory Repository - - + Software Inventory Repository - - + Device Inventory Repository - - * Configuration Policy Repository - - * Configuration State Repository - - o Collector - - * Vulnerability State Collector - - * Asset Inventory Collector - - + Software Inventory Collector - - + Device Inventory Collector - - * Configuration State Collector - - o Evaluator - - * Vulnerability State Evaluator - * Asset Inventory Evaluator - - + Software Inventory Evaluator - - + Device Inventory Evaluator - - * Configuration State Evaluator - - o Orchestrator - - * Vulnerability Management Orchestrator - - * Asset Management Orchestrator - - + Software Inventory Evaluator - - + Device Inventory Evaluator - - * Configuration Management Orchestrator - -4.2. Capabilities - - Repositories will have a need for fairly standard CRUD operations and - query by attribute operations. Collector interfaces may enable ad - hoc assessment (on-demand processing), state item watch actions (i.e. - watch a particular item for particular change), persisting other - behaviors (i.e. setting some mandatory reporting period). Evaluators - may have their own set of interfaces, and an Assessor would represent - both Collector and Evaluation interfaces, and may have additional - concerns added to an Assessor Interface. - - Not to be overlooked, whatever solution at which we arrive, per - [RFC8248], MUST support capability negotiation. While not explicitly - treated here, each interface will understand specific serializations, - and other component needs to express those serializations to other - components. - - A capability language is fully explored in mandl-sacm-tool- - capability-language (to be submitted). - -4.3. Interfaces - - Interfaces should be derived directly from identified workflows, - several of which are described in this document. + of information. -4.4. Workflows +4. Relevant Workflows - The workflows described in this document should be considered as - candidate workflows - informational for the purpose of discovering - the necessary components and specifying their interfaces. + This section describes three primary information security domains + from which workflows may be derived: IT Asset Management, + Vulnerability Management, and Configuration Management. -4.4.1. IT Asset Management +4.1. IT Asset Management Information Technology asset management is easier said than done. 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 @@ -512,69 +191,29 @@ o Identify and catalog new assets by executing Target Endpoint Discovery Tasks o Provide information about its managed assets, including uniquely identifying information (for that enterprise) o Handle software and/or hardware (including virtual assets) o Represent cloud hybrid environments -4.4.2. Vulnerability Management +4.2. Vulnerability Management - Vulnerability management is a relatively established process. - According to the [CISCONTROLS], continuous 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. -4.4.2.1. Vulnerability Assessment Workflow Assumptions - - A number of assumptions must be stated to clarify the scope of a - vulnerability assessment workflow: - - o The enterprise has received vulnerability description information, - and that the information has already been processed into - vulnerability detection data that the enterprise's security - software tools can understand and use. - - o The enterprise has a suitable IT Asset Management capability - - o The enterprise has a means of extracting relevant information - about enterprise endpoints in a form that is compatible with the - vulnerability description data (appropriate Collectors for their - technologies) - - o All information described in this scenario is available in the - vulnerability description data and serves as the basis of - assessments. - - o The enterprise can provide all relevant information about any - endpoint needed to perform the described assessment (the - appropriate Repositories are available) - - o The enterprise has a mechanism for long-term storage of - vulnerability description information, vulnerability detection - data, and vulnerability assessment results. - - o The enterprise has a procedure for reassessment of endpoints at - some point after initial assessment - -4.4.2.2. Vulnerability Assessment Workflow - - When new vulnerability description information is received by the - enterprise, affected endpoints are identified and assessed. The - vulnerability is said to apply to an endpoint if the endpoint - satisfies the conditions expressed in the vulnerability detection - data. - A vulnerability assessment (i.e. vulnerability detection) is performed in two steps: o Endpoint information collected by the endpoint management capabilities is examined by the vulnerability management capabilities through Evaluation Tasks. o If the data possessed by the endpoint management capabilities is insufficient, a Collection Task is triggered and the necessary data is collected from the target endpoint. @@ -583,69 +222,55 @@ endpoint information depending on the nature of a specific vulnerability. Common endpoint information used to detect a vulnerability includes: o A specific software version is installed on the endpoint o File system attributes o Specific state attributes - In many cases, the endpoint information needed to determine an + 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 collect it from the target - endpoint. Of course, some implementations of endpoint management - capabilities may prefer to enable operators to perform this - collection under certain circumstances, even when sufficient - information can be provided by the endpoint management capabilities - (e.g. there may be freshness requirements for information). - - The collection of additional endpoint information for the purpose of - vulnerability assessment does not necessarily need to be a pull by - the vulnerability assessment capabilities. Over time, some new - pieces of information that are needed during common types of - assessments might be identified. Endpoint management capabilities - can be reconfigured to have this information delivered automatically. - This avoids the need to trigger additional Collection Tasks to gather - this information during assessments, streamlining the assessment - process. Likewise, it might be observed that certain information - delivered by endpoint management capabilities is rarely used. In - this case, it might be useful to re-configure the endpoint management - capabilities to no longer collect this information to reduce network - and processing overhead. Instead, a new Collection Task can be - triggered to gather this data on the rare occasions when it is - needed. + 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). -4.4.3. Configuration Management +4.3. Configuration Management Configuration management involves configuration assessment, which - requires state assessment (TODO: Tie to SACM use cases). The - [CISCONTROLS] specify two high-level controls 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 a requirement to: - "Establish, implement, and actively manage (track, report on, - correct) the security configuration of (endpoints) using a rigorous - configuration management and change control process in order to - prevent attackers from exploiting vulnerable services and settings." + 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: + and/or appropriate endpoint information. + + A preferred flow follows: o Reputable source publishes new or updated configuration guidance o Enterprise configuration assessment capability retrieves configuration guidance from reputable source o Optional: Configuration guidance is tailored for enterprise- specific needs o Configuration assessment tool queries asset inventory repository @@ -654,68 +279,222 @@ o Configuration assessment tool queries configuration state repository to evaluate compliance o If information is stale or unavailable, configuration assessment tool triggers an ad hoc assessment The SACM architecture needs to support varying deployment models to accommodate the current state of the industry, but should strongly encourage event-driven approaches to monitoring configuration. -5. Privacy Considerations +5. Configuration Management Components, Interactions, and Capabilities + + This section provides more detail about the components, interactions, + and capabilities required when considering the aforementioned + configuration management workflow. + +5.1. Components + + The following is a minimal list of SACM Components required to + implement the aforementioned configuration assessment workflow. + + o Configuration Policy Feed: An external source of authoritative + configuration recommendations. + + o Configuration Policy Repository: An internal repository of + enterprise standard configurations. + + o Configuration Assessment Orchestrator: A component responsible for + orchestrating assessments. + + o Posture Attribute Collection Subsystem: A component responsible + for collection of posture attributes from systems. + + o Posture Attribute Repository: A component used for storing system + posture attribute values. + + o Configuration Assessment Evaluator: A component responsible for + evaluating system posture attribute values against expected + posture attribute values. + + o Configuration Assessment Results Repository: A component used for + storing evaluation results. + +5.2. Interactions + + SACM Components are intended to interact with other SACM Components. + These interactions can be thought of, at the level of this + architectural approach, as the combination of interfaces with their + supported operations. + + o Store: One component stores information in another. + + o Ask: A component requests information from another. + + o Notify/Ask: A component notifies another component, which then + asks the notifying component (or another component) for + information. + + o Publish/Subscribe: A component publishes information to a + messaging system and a set of other components, subscribed to that + information type, receive the published information. + + o Tell: A component instructs another. + + TODO: Consider breaking out Notify, Publish, and Subscribe into + separate line items, and adding Error (a type of Notify). Then + consider explaining the necessary combinations relevant to the + configuration assessment workflow below. + + Each interaction will convey a payload of information. The payload + information is expected to contain sub-domain-specific + characteristics and instructions. + +5.3. Capabilities + + Per [RFC8248], solutions MUST support capability negotiation. + Components implementing specific interfaces and operations (i.e. + interactions) will need a method of describing their capabilities to + other components participating in the ecosystem; for example, "As a + component in the ecosystem, I can assess the configuration of + Windows, MacOS, and AWS using OVAL". + +6. Configuration Assessment Workflow + + This section describes the components and interactions in a basic + configuration assessment workflow. For simplicity, error conditions + are recognized as being necessary and are not depicted. When one + component messages another component, the message is expected to be + handled appropriately unless there is an error condition, or other + notification, messaged in return. + ++-------------+ +| Policy Feed | ++-----+-------+ + | 5.1 + 1 | +----------------------------------------+ + | | | ++-----v------+ 2 +----------------+ 5 +-----v-----+ 6 +------------+ +| Policy +------> Orchestrator +-----> Evaluator +------> Evaluation | +| Repository | +-------+--------+ +-----^-----+ | Results | ++------------+ | | | Repository | + | 3 | +------------+ + | | 5.2 + +----------|--------+ | + | +--------v------+ | | + | | Collector | | | + | +-------+-------+ | 4 +------------+ + | | +-------> Posture | + | +-------+-------+ | | Attribute | + | | Target System | | | Repository | + | +---------------+ | +------------+ + +-------------------+ + Collection Sub-Architecture + + Figure 2: Configuration Assessment Component Interactions + + Figure 2 depicts configuration assessment components and their + interactions, which are further described below. + + 1. Policy is stored in the Policy Repository: TODO - add specific + interaction options here. + + 2. The Orchestrator obtains collection information from the Policy + Repository: TODO - add specific interaction options here. + + 3. The Orchestrator initiates collection to be performed by the + Collection Sub-Architecture: TODO - add specific interaction + options here. + + 4. Collected posture attributes are stored n the Posture Attribute + Repository: TODO - add specific interaction options here. + + 5. The Orchestrator initiates the Evaluator (optionally with + evaluation information gathered from the Policy Repository): TODO + - add specific interaction options here + + 1. The Evaluator obtains evaluation information from the Policy + Repository (optionally): TODO - add specific interaction + options here + + 2. The Evaluator obtains relevant posture attributes from the + Posture Attribute Repository: TODO - add specific interaction + options here + + 6. Evaluation results are stored in the Evaluation Results + Repository: TODO - add specific interaction options here + + In the above flow, the payload information is expected to convey the + context required by the receiving component for the action being + taken under different circumstances. For example, the Tell message + sent from an Orchestrator to a Collection sub-architecture might be + telling that Collector to watch a specific posture attribute and + report only specific detected changes to the Posture Attribute + Repository, or it might be telling the Collector to gather that + posture attribute immediately. Such details are expected to be + handled as part of that payload, not as part of the architecture + described herein. + +7. Privacy Considerations TODO -6. Security Considerations +8. Security Considerations TODO -7. IANA Considerations +9. IANA Considerations + + TODO: Revamp this section after the configuration assessment workflow + is fleshed out. IANA tables can probably be used to make life a little easier. We would like a place to enumerate: o Capability/operation semantics o SACM Component implementation identifiers o SACM Component versions o Associations of SACM Components (and versions) to specific Capabilities -8. References + o Collection sub-architecture Identification -8.1. Normative References +10. References - [I-D.ietf-mile-xmpp-grid] - Cam-Winget, N., Appala, S., Pope, S., and P. Saint-Andre, - "Using XMPP for Security Information Exchange", draft- - ietf-mile-xmpp-grid-09 (work in progress), December 2018. +10.1. Normative References [I-D.ietf-sacm-ecp] Haynes, D., Fitzgerald-McKay, J., and L. Lorenzin, "Endpoint Posture Collection Profile", draft-ietf-sacm- - ecp-04 (work in progress), February 2019. + ecp-05 (work in progress), June 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 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, . -8.2. Informative References + [RFC8600] Cam-Winget, N., Ed., Appala, S., Pope, S., and P. Saint- + Andre, "Using Extensible Messaging and Presence Protocol + (XMPP) for Security Information Exchange", RFC 8600, + DOI 10.17487/RFC8600, June 2019, + . + +10.2. Informative References [CISCONTROLS] "CIS Controls v7.0", n.d., . [draft-birkholz-sacm-yang-content] Birkholz, H. and N. Cam-Winget, "YANG subscribed notifications via SACM Statements", n.d., . @@ -724,20 +503,30 @@ 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., . [I-D.ietf-sacm-terminology] Birkholz, H., Lu, J., Strassner, J., Cam-Winget, N., and A. Montville, "Security Automation and Continuous Monitoring (SACM) Terminology", draft-ietf-sacm- terminology-16 (work in progress), December 2018. @@ -771,20 +560,22 @@ [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. Mapping to RFC8248 + TODO: Consider removing or placing in a separate solution draft. + This section provides a mapping of XMPP and XMPP Extensions to the relevant requirements from [RFC8248]. In the table below, the ID and Name columns provide the ID and Name of the requirement directly out of [RFC8248]. The Supported By column may contain one of several values: o N/A: The requirement is not applicable to this architectural exploration o Architecture: This architecture (possibly assuming some @@ -928,20 +719,22 @@ | | | | | T-005 | Transfer Reliability | | | | | | | T-006 | Transfer-Layer Requirements | | | | | | | T-007 | Transfer Protocol Adoption | Architecture | +----------+----------------------------------------+---------------+ Appendix B. Example Components + TODO: Consider removing. + B.1. Policy Services Consider a policy server conforming to [RFC8322]. [RFC8322] describes a RESTful way based on the ATOM Publishing Protocol ([RFC5023]) to find specific data collections. While this represents a specific binding (i.e. RESTful API based on [RFC5023]), there is a more abstract way to look at ROLIE. ROLIE provides notional workspaces and collections, and provides the concept of information categories and links. Strictly speaking, @@ -978,38 +772,37 @@ Evaluator Repository | | | | | | +------+ +--------+ | +-----------+ |<-------| +-----------+ | | | | | | | Posture | | report | | Posture | | | | | | | | Collection| | | | Collection| | | |<-----> | |<-----| | Manager | | query | | Engine | | | |request/| | store| +-----------+ |------->| +-----------+ | | |respond | | | | | | | | | | | | | | +------+ +--------+ +---------------+ +---------------+ - Figure 4: EPCP Collection Architecture + Figure 3: EPCP Collection Architecture - In Figure 4, any of the communications between the Posture Manager + In Figure 3, any of the communications between the Posture Manager and EPCP components to its left could be performed directly or indirectly using a given message transfer mechanism. For example, the pub/sub interface between the Orchestrator and the Posture - Manager could be using a proprietary method or using - [I-D.ietf-mile-xmpp-grid] or some other pub/sub mechanism. - Similarly, the store connection from the Posture Manager to the - Repository could be performed internally to a given implementation, - via a RESTful API invocation over HTTPS, or even over a pub/sub - mechanism. + 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], [I-D.ietf-mile-xmpp-grid], and so on). + API, [RFC8322], [RFC8600], and so on). B.3. Datastream Collection [NIST800126], also known as SCAP 1.3, provides the technical specifications for a "datastream collection". The specification describes the "datastream collection" as being "composed of SCAP data streams and SCAP source components". A "datastream" provides an encapsulation of the SCAP source components required to, for example, perform configuration assessment on a given endpoint. These source components include XCCDF checklists, OVAL Definitions, and CPE @@ -1038,27 +831,251 @@ 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. +Appendix C. Exploring An XMPP-based Solution + + TODO: Consider removing or placing in a separate draft. + + Ongoing work has been taking place around and during IETF hackathons. + The list of hackathon efforts follows: + + o [HACK99]: A partial implementation of a vulnerability assessment + scenario involving an [I-D.ietf-sacm-ecp] implementation, a + [RFC8322] implementation, and a proprietary evaluator to pull the + pieces together. + + o [HACK100]: Work to combine the vulnerability assessment scenario + from [HACK99] with an XMPP-based YANG push model. + + o [HACK101]: A fully automated configuration assessment + implementation using XMPP (specifically Publish/Subscribe + capabilities) as a communication mechanism. + + o [HACK102]: An exploration of how we might model assessment, + collection, and evaluation abstractly, and then rely on YANG + expressions for the attributes of traditional endpoints. + + o [HACK103]: No SACM participation at the Bangkok hackathon. + + o [HACK104]: Basic XMPP-to-Concise MAP - Created an XMPP adapter + that can accept basic posture attributes and translate them to + Concise MAP. This hackathon only proved the concept that system + characteristics information can be transported via XMPP and + translated to a (very basic) concise MAP implementation. + + o [HACK105]: Advanced XMPP-to-Concise MAP: Full orchestration of + collection capabilities using XMPP. Collector implementations + extend the core XMPP structure to allow OVAL collection + instructions (OVAL objects) to inform posture attribute + collection. Collected system characteristics can be provided to + the Concise MAP XMPP adapter using all 3 available XMPP + capabilities: Publish/Subscribe, Information Query (iq - request/ + response) stanzas, or direct Message stanzas. CDDL was created to + map collected posture attributes to Concise MAP structure. The + XMPP adapter translates the incoming system characteristics and + stores the information in the MAP. + + Figure 4 depicts a slightly more detailed view of the architecture + (within the enterprise boundary) - one that fosters the development + of a pluggable ecosystem of cooperative tools. Existing collection + mechanisms can be brought into this architecture by specifying the + interface of the collector and creating the XMPP-Grid Connector + binding for that interface. + + Additionally, while not directly depicted in Figure 4, this + architecture does allow point-to-point interfaces. In fact, + [RFC8600] provides brokering capabilities to facilitate such point- + to-point data transfers). Additionally, each of the SACM Components + depicted in Figure 4 may be a provider, a consumer, or both, + depending on the workflow in context. + + +--------------+ +--------------+ + | Orchestrator | | Repositories | + +------^-------+ +------^-------+ + | | + | | + +-------v--------------------------v--------+ +-----------------+ + | XMPP-Grid+ <-----> Downstream Uses | + +------------------------^------------------+ +-----------------+ + | + | + +-------v------+ + | XMPP-Grid | + | Connector(s) | + +------^-------+ + | + +------v-------+ + | Collector(s) | + +--------------+ + + Figure 4: XMPP-based Architecture + + [RFC8600] details a number of XMPP extensions (XEPs) that MUST be + utilized to meet the needs of [RFC7632] and [RFC8248]: + + o Service Discovery (XEP-0030): Service Discovery allows XMPP + entities to discover information about other XMPP entities. Two + kinds of information can be discovered: the identity and + capabilities of an entity, such as supported features, and items + associated with an entity. + + o Publish-Subscribe (XEP-0060): The PubSub extension enables + entities to create nodes (topics) at a PubSub service and publish + information at those nodes. Once published, an event notification + is broadcast to all entities that have subscribed to that node. + + At this point, [RFC8600] specifies fewer features than SACM requires, + and there are other XMPP extensions (XEPs) we need to consider to + meet the needs of [RFC7632] and [RFC8248]. In Figure 4 we therefore + use "XMPP-Grid+" to indicate something more than [RFC8600] alone, + even though we are not yet fully confident in the exact set of XMPP- + related extensions we will require. The authors propose work to + extend (or modify) [RFC8600] to include additional XEPs - possibly + the following: + + o Entity Capabilities (XEP-0115): This extension defines the methods + for broadcasting and dynamically discovering an entities' + capabilities. This information is transported via standard XMPP + presence. Example capabilities that could be discovered could + include support for posture attribute collection, support for + specific types of posture attribute collection such as EPCP, + SWIMA, OVAL, or YANG. Other capabilities are still to be + determined. + + o Ad Hoc Commands (XEP-0050): This extension allows an XMPP entity + to advertise and execute application-specific commands. Typically + the commands contain data forms (XEP-0004) in order to structure + the information exchange. This extension may be usable for simple + orchestration (i.e. "do assessment"). + + o HTTP File Upload (XEP-0363): The HTTP File Upload extension allows + for large data sets to be published to a specific path on an HTTP + server, and receive a URL from which that file can later be + downloaded again. XMPP messages and IQs are meant to be compact, + and large data sets, such as collected posture attributes, may + exceed a message size threshold. Usage of this XEP allows those + larger data sets to be persisted, thus necessitating only the + download URL to be passed via XMPP messages. + + o Personal Eventing Protocol (XEP-0163): The Personal Eventing + Protocol can be thought of as a virtual PubSub service, allowing + an XMPP account to publish events only to their roster instead of + a generic PubSub topic. This XEP may be useful in the cases when + collection requests or queries are only intended for a subset of + endpoints and not an entire subscriber set. + + o File Repository and Sharing (XEP-0214): This extension defines a + method for XMPP entities to designate a set of file available for + retrieval by other users of their choosing, and is based on PubSub + Collections. + + o Easy User Onboarding (XEP-401): The goal of this extension is + simplified client registration, and may be useful when adding new + endpoints or SACM components to the ecosystem. + + o Bidirectional-streams Over Synchronous HTTP (BOSH) (XEP-0124): + BOSH emulates the semantics of a long-lived, bidirectional TCP + connection between two entities (aka "long polling"). Consider a + SACM component that is updated dynamically, i.e. an internal + vulnerability definition repository ingesting data from a Feed/ + Repository of External Data, and a second SACM component such as + an Orchestrator. Using BOSH, the Orchestrator can effectively + continuously poll the vulnerability definition repository for + changes/updates. + + o PubSub Collection Nodes (XEP-0248): Effectively an extension to + XEP-0060 (Publish-Subscribe), PubSub Collections aim to simplify + an entities' subscription to multiple related topics, and + establishes a "node graph" relating parent nodes to its + descendents. An example "node graph" could be rooted in a + "vulnerability definitions" topic, and contain descendent topics + for OS family-level vulnerability definitions (i.e. Windows), and + further for OS family version-level definitions (i.e. Windows 10 + or Windows Server 2016). + + o PubSub Since (XEP-0312): This extension enables a subscriber to + automatically receive PubSub and Personal Eventing Protocol (PEP) + notifications since its last logout time. This extension may be + useful in intermittent connection scenarios, or when entities + disconnect and reconnect to the ecosystem. + + o PubSub Chaining (XEP-0253): This extension describes the + federation of publishing nodes, enabling a publish node of one + server to be a subscriber to a publishing node of another server. + +C.1. Example Architecture using XMPP-Grid and Endpoint Posture + Collection Protocol + + Figure 5 depicts a further detailed view of the architecture + including the Endpoint Posture Collection Protocol as the collection + subsystem, illustrating the idea of a pluggable ecosystem of + cooperative tools. + + +--------------------+ + | Feeds/Repositories | + | of External Data | + +--------------------+ + | +********************v************************* Enterprise Boundary ************ +* | * +* +--------------+ | +-------------------+ +-------------+ * +* | Orchestrator | | | Posture Attr Repo | | Policy Repo | * +* +------^-------+ | +---------^---------+ +---^---------+ * +* | | | | +----------------+ * +* | | | | | Downstream Uses| * +* | | | | | +-----------+ | * +* +------v---------v-----------v---------------v--+ | |Evaluations| | * +* | XMPP-Grid <-------> +-----------+ | * +* +----------------^-------------------^----------+ | +-----------+ | * +* | | | | Analytics | | * +* | | | +-----------+ | * +* | +-----v--------+ | +-----------+ | * +* | | Results Repo | | | Reporting | | * +* | +--------------+ | +-----------+ | * +* | +----------------+ * +* +---------v-----------+ * +* | XMPP-Grid Connector | * +* +---------^-----------+ * +* | * +* +-----------------v-------------------------------------------------------+ * +* | | * +* | +--Posture Collection Manager------------------------------------------+| * +* | |+-----------------------+ +----------------+ +----------------------+ || * +* | || Communications Server | | Posture Server | | Posture Validator(s) | || * +* | |+----------^------------+ +----------------+ +----------------------+ || * +* | +-----------|----------------------------------------------------------+| * +* | | | * +* | +-----------|-------------------------Endpoint or Endpoint Proxy-------+| * +* | |+----------v------------+ +----------------+ +----------------------+ || * +* | || Communications Client | | Posture Client | | Posture Collector(s) | || * +* | |+-----------------------+ +----------------+ +----------------------+ || * +* | +----------------------------------------------------------------------+| * +* +-----------------Endpoint Posture Collection Profile---------------------+ * +* * +******************************************************************************* + + Figure 5: XMPP-based Architecture including EPCP + Authors' Addresses Adam W. Montville Center for Internet Security 31 Tech Valley Drive East Greenbush, NY 12061 USA - Email: adam.w.montville@gmail.com + Email: adam.montville.sdo@gmail.com Bill Munyan Center for Internet Security 31 Tech Valley Drive East Greenbush, NY 12061 USA Email: bill.munyan.ietf@gmail.com