OPSAWG Q. Ma Internet-Draft Q. Wu Intended status: Standards Track Huawei Expires: 17 August 2023 M. Boucadair Orange D. King Old Dog Consulting 13 February 2023 A Policy-based Network Access Control draft-ma-opsawg-ucl-acl-01 Abstract This document defines a YANG module for policy-based network access control, which provides consistent and efficient enforcement of network access control policies based on group identity. In addition, this document defines a mechanism to ease the maintenance of the mapping between a user-group ID and a set of IP/MAC addresses to enforce policy-based network access control. Also, the document defines a common schedule YANG module which is designed to be applicable for policy activation based on date and time conditions. In addition, the document defines a RADIUS attribute that is used to communicate the user group identifier as part of identification and authorization information. 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 17 August 2023. Ma, et al. Expires 17 August 2023 [Page 1] Internet-Draft A Policy-based NACL February 2023 Copyright Notice Copyright (c) 2023 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions and Definitions . . . . . . . . . . . . . . . . . 4 3. Sample Usage . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Policy-based Network Access Control . . . . . . . . . . . . . 5 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2. Endpoint Group . . . . . . . . . . . . . . . . . . . . . 7 4.2.1. User Group . . . . . . . . . . . . . . . . . . . . . 7 4.2.2. Device Group . . . . . . . . . . . . . . . . . . . . 8 5. YANG Modules . . . . . . . . . . . . . . . . . . . . . . . . 9 5.1. The Schedule YANG Module . . . . . . . . . . . . . . . . 9 5.1.1. Module Overview . . . . . . . . . . . . . . . . . . . 9 5.1.2. The YANG Module . . . . . . . . . . . . . . . . . . . 10 5.2. The UCL Extension to the ACL Model . . . . . . . . . . . 17 5.2.1. Module Overview . . . . . . . . . . . . . . . . . . . 17 5.2.2. The YANG Module . . . . . . . . . . . . . . . . . . . 18 6. User Access Control Group ID RADIUS Attribute . . . . . . . . 22 7. RADIUS Attributes . . . . . . . . . . . . . . . . . . . . . . 23 8. Security Considerations . . . . . . . . . . . . . . . . . . . 23 8.1. YANG . . . . . . . . . . . . . . . . . . . . . . . . . . 24 8.2. RADIUS . . . . . . . . . . . . . . . . . . . . . . . . . 24 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 9.1. YANG . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9.2. RADIUS . . . . . . . . . . . . . . . . . . . . . . . . . 25 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 10.1. Normative References . . . . . . . . . . . . . . . . . . 26 10.2. Informative References . . . . . . . . . . . . . . . . . 27 Appendix A. Changes between Revisions . . . . . . . . . . . . . 29 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 29 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30 Ma, et al. Expires 17 August 2023 [Page 2] Internet-Draft A Policy-based NACL February 2023 1. Introduction With the increased adoption of remote access technologies (e.g., Virtual Private Networks (VPNs)) and Bring Your Own Device (BYOD) policies, enterprises adopted more flexibility related to how, where, and when employees work and collaborate. However, more flexibility comes with increased risks. Enabling office flexibility (e.g., mobility across many access locations) for large-scale employees induces a set of challenges compared to conventional network access management approaches. Examples of such challenges are listed below: * Endpoints do not have a stable IP address. For example, Wireless LAN (WLAN) and VPN clients, as well as back-end Virtual Machine (VM)-based servers, can move; their IP addresses could change as a result. This means that relying on IP/transport fields (e.g., the 5-tuple) is inadequate to ensure consistent and efficient security policy enforcement. IP address-based policies may not be flexible enough to accommodate endpoints with volatile IP addresses. * With the massive adoption of teleworking, there is now a need to apply different security policies to the same set of users under different circumstances (e.g., prevent relaying attacks against a local attachment point to the Enterprise network). For example, network access might be granted based upon criteria such as users' access location, source network reputation, users' role, time-of- day, type of network device used (e.g., corporate issued device versus personal device), device's security posture, etc. This means the network needs to recognize the users' identity and their current context, and map the users to their correct access entitlement to the network. This document defines a common schedule YANG module which is designed to be applicable for policy activation based on date and time condition. This model can be used in other scheduling contexts. The document also defines a YANG module for policy-based Network Access Control ([NIST-ABAC]), which extends the IETF Access Control Lists (ACLs) module defined in [RFC8519]. This module defined in Section 5.2 is meant to ensure consistent enforcement of ACL policies based on group identity. In addition, this document defines a mechanism to establish a mapping between the user-group ID and common IP packet headers and other enclosed packet data (e.g., MAC address) to execute the policy-based access control. Last, the document defines a RADIUS attribute that is used to communicate the user group identifier as part of identification and authorization information (Section 6). Ma, et al. Expires 17 August 2023 [Page 3] Internet-Draft A Policy-based NACL February 2023 As the ACL notion has been generalized, not to be device-specific, but also be defined at network/administrative domain levels [I-D.dbb-netmod-acl], the YANG module for policy-based network access control defined in this document does not limit how it can be used. 2. Conventions and Definitions 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 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. The meanings of the symbols in tree diagrams are defined in [RFC8340]. The document uses the terms defined in [RFC8519]. In the current version of the draft, the term "endpoint" refers also to a host device or end user that actually connect to a network. While host device here refers to servers, IoTs and other devices owned by the enterprise. 3. Sample Usage Access to some networks (e.g., Enterprise Networks) require to recognize the users' identities no matter how, where, and when they connect to the network resources. Then, the network maps the (conencting) users to their access authorization rights. Such rights are defined following local policies. As discussed in the introduction, because there is a large number of users and the source IP addresses of the same user are in different network segments, deploying a network access control policy for each IP address or network segment is heavy workload. An alternative approach is to configure endpoint groups to classify users and enterprise devices and associate ACLs with endpoint groups so that endpoint in each group can share a group of ACL rules. This approach greatly reduces the workload of the administrators and optimizes the ACL resources. The Network ACLs (NACLs) can be provisioned on devices using specific mechanisms, such as [RFC8519] or [I-D.dbb-netmod-acl]. Ma, et al. Expires 17 August 2023 [Page 4] Internet-Draft A Policy-based NACL February 2023 Network access control policies may need to vary over time. For example, companies may restrict/grant employees access to specific resources (internal and/or external resources) during work hours, while another policy is adopted during off-hours and weekends. A network administrator may also require to enforce traffic shaping (Section 2.3.3.3 of [RFC2475]) and policing (Section 2.3.3.4 of [RFC2475]) during peak hours in order not to affect other data services. 4. Policy-based Network Access Control 4.1. Overview To provide real-time and consistent enforcement of access control policies, the following functional entities and interfaces are involved: * A Service Orchestrator which coordinates the overall service, including security policies. The service may be connectivity or any other resources that can be hosted and offerd by a newtork. * The SDN Controller is responsible for maintaining endpoint-group based ACLs and mapping the endpoint-group to the associated attributes information (e.g., IP/MAC address). The SDN Controller also works as the Policy Decision Point (PDP) [RFC3198] and pushes the required access control policies to relevant PEPs (Policy Enforcement Points) that need them. A PDP is also known as "policy server" [RFC2753]. The SDN Controller may interact with AAA server or NAS. * A Network Access Server (NAS) entity which handles authentication requests. The NAS interacts with an AAA server to complete user authentication using Remote Authentication Dial-in User Service (RADIUS) [RFC2865]. When access is granted, the AAA server provides the group identifier (group ID) to which the user belongs when the user first logs onto the network. A new attribute is defined in Section 6. Ma, et al. Expires 17 August 2023 [Page 5] Internet-Draft A Policy-based NACL February 2023 * The Policy Enforcement Point (PEP) [RFC3198] is the central entity which is responsible for enforcing appropriate access control policies. In some cases, A PEP may map incoming packets to their associated source or destination endpoint-group IDs, and acts on the endpoint-group ID based ACL policies, e.g., a NAS as the PEP or a group identifier could be carried in packet header (see Section 6.2.3 in [I-D.ietf-nvo3-encap]). While in other cases, the SDN controller maps group ID to the related common packet header and delivers IP/MAC address based ACL policies to the required PEPs. Multiple PEPs can be involved in a network. A PEP exposes a NETCONF interface to the SDN Controller [RFC6241]. Figure 1 provides the overall architecture and procedure for policy- based access control management. +------------+ |Orchestrator| +------+-----+ Service | (Step 1) ------------------------------------------+------------- ------------------------------------------+------------- Network | (Step 4) | +-------+ +--------+ +--------+-----------+ |User #1+--+ | AAA | | SDN Controller | +-------+ | | Server +-----+ (PDP) | | +----+---+ +--------+-----------+ | | | | | +---------------+(Step 5) (Step 2) | |(Step 3) | | | | | | | +-+-----------+---------------+------------+ | | +----------------------+ +------------+| +-------+ +--------+ | Network Access Server| |firewall,etc|| |User #2+-----------+ | (NAS) | +------------+| +-------+ | +----------------------+ | | (PEP) | +------------------------------------------+ Figure 1: An Architecture for Group-based Policy Management In reference to Figure 1, the following typical flow is experienced: Ma, et al. Expires 17 August 2023 [Page 6] Internet-Draft A Policy-based NACL February 2023 Step 1: Administrators (or the Orchestrator) configure an SDN controller with network-level ACLs using the YANG module defined in Section 5.2. Step 2: When a user first logs onto the network, the user is required to be authenticated (e.g., using user name and password) at the NAS. Step 3: The authentication request is then relayed to the AAA server using RADIUS [RFC2865]. It is assumed that the AAA server has been appropriately configured to store user credentials, e.g., user name, password, group information and other user attributes. If the authentication request succeeds, the user is placed in a user-group which is returned to the network access server as the authentication result (see Section 6). If the authentication fails, the user is not assigned a user- group, which also means that the user has no or limited access permissions for the network (as a fucntion of the local policy). ACLs are enforced so that flows from that IP address are discarded (or rate-limited) by the network. In some implementations, AAA server can be integrated with an SDN controller. Step 4: Either the AAA server or the NAS notify the SDN controller the mapping between the user-group ID and related common packet header attributes (e.g., IP/MAC address). Step 5: Either group or IP/MAC address based access control policies are maintained on relevant PEPs under the controller's management. 4.2. Endpoint Group 4.2.1. User Group The user-group ID is an identifier that represents the collective identity of a group of users. It is determined by a set of predefined policy criteria (e.g., source IP address, geolocation data, time of day, or device certificate). Users may be moved to different user-groups if their composite attributes, environment, and/or local enterprise policy change. A user is authenticated, and classified at the AAA server, and assigned to a user-group. A user's group membership may change as aspects of the user change. For example, if the user-group membership is determined solely by the source IP address, then a given user's user-group ID will change when the user moves to a new IP address that falls outside of the range of addresses of the previous user-group. Ma, et al. Expires 17 August 2023 [Page 7] Internet-Draft A Policy-based NACL February 2023 This document does not make any assumption about how user groups are defined. Such considerations are deployment specific and are out of scope. However, and for illustration purposes, Table 1 shows an example of how user-group definitions may be characterized. User- groups may share several common criteria. That is, user-group criteria are not mutually exclusive. For example, the policy criteria of user-groups R&D Regular and R&D BYOD may share the same set of users that belong to the R&D organization, and differ only in the type of clients (firm-issued clients vs. users' personal clients). Likewise, the same user may be assigned to different user- groups depending on the time of day or the type of day (e.g., weekdays versus weekends), etc. +============+==========+===================================+ | Group Name | Group ID | Group Role | +============+==========+===================================+ | R&D | 10 | R&D employees | +------------+----------+-----------------------------------+ | R&D BYOD | 11 | Personal devices of R&D employees | +------------+----------+-----------------------------------+ | Sales | 20 | Sales employees | +------------+----------+-----------------------------------+ | VIP | 30 | VIP employees | +------------+----------+-----------------------------------+ Table 1: User-Group Example 4.2.2. Device Group The device-group ID is an identifier that represents the collective identity of a group of enterprise end devices. An enterprise device could be an server that hosts applications or software that deliver services to enterprise users. It could also be an enterprise IoT device that serve a limited purpose, e.g., a printer that allows users to scan, print and send emails. Table 2 shows an example of how device-group definitions may be characterized. +================+==========+===========================+ | Group Name | Group ID | Group Type | +================+==========+===========================+ | Workflow | 40 | Workflow resource servers | +----------------+----------+---------------------------+ | R&D Resource | 50 | R&D resource servers | +----------------+----------+---------------------------+ | Sales Resource | 54 | Sales resource servers | +----------------+----------+---------------------------+ Table 2: Device-Group Example Ma, et al. Expires 17 August 2023 [Page 8] Internet-Draft A Policy-based NACL February 2023 Users accessing to enterprise device should be strictly controlled. Matching abstract device group ID instead of specified addresses in ACL polices helps shield the consequences of address change (e.g., back-end Virtual Machine (VM)-based server migration). 5. YANG Modules 5.1. The Schedule YANG Module This module defines a common schedule YANG module. It is inspired from the "period of time" and "recurrence rule" format defined in [RFC5545]. This module is defined as a standalone module rather than in the UCL module with the intention that the time/date definition can be reused. 5.1.1. Module Overview Figure 2 provides an overview of the tree structure of the "ietf- schedule" module. Ma, et al. Expires 17 August 2023 [Page 9] Internet-Draft A Policy-based NACL February 2023 module: ietf-schedule grouping period +-- period-of-time +-- (forms)? +--:(period-explicit) | +-- explicit-start? yang:date-and-time | +-- explicit-end? yang:date-and-time +--:(period-start) +-- start? yang:date-and-time +-- duration? yang:time-no-zone grouping recurrence +-- recurrence +-- freq enumeration +-- (until-or-count)? | +--:(until) | | +-- until? union | +--:(count) | +-- count? uint32 +-- interval? uint32 +-- bysecond* uint32 +-- byminute* uint32 +-- byhour* uint32 +-- byday* [weekday] | +-- direction? int32 | +-- weekday? schedule:weekday +-- bymonthday* int32 +-- byyearday* int32 +-- byyearweek* int32 +-- byyearmonth* uint32 +-- bysetpos* int32 +-- wkst* schedule:weekday Figure 2: UCL Tree Diagram 5.1.2. The YANG Module This module imports types defined in [I-D.ietf-netmod-rfc6991-bis]. file="ietf-schedule@2023-01-19.yang" module ietf-schedule { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-schedule"; prefix schedule; import ietf-yang-types { prefix yang; Ma, et al. Expires 17 August 2023 [Page 10] Internet-Draft A Policy-based NACL February 2023 revision-date 2023-01-23; reference "RFC XXXX: Common YANG Data Types"; } organization "IETF OPSAWG Working Group"; contact "WG Web: WG List: "; description "This YANG module defines two properties of an iSchedule object:period of time and recurrence rule. Copyright (c) 2023 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; revision 2023-01-19 { description "Initial revision."; reference "RFC XXXX: A Policy-based Network Access Control"; } typedef weekday { type enumeration { enum sunday { description "Sunday of the week."; } enum monday { description "Monday of the week."; } enum tuesday { description "Tuesday of the week."; Ma, et al. Expires 17 August 2023 [Page 11] Internet-Draft A Policy-based NACL February 2023 } enum wednesday { description "Wednesday of the week."; } enum thursday { description "Thursday of the week."; } enum friday { description "Friday of the week."; } enum saturday { description "Saturday of the week."; } } description "Seven days of the week."; } grouping period { description "This grouping is defined for period of time property."; container period-of-time { description "This container is defined to identify period values that contain a precise period of time."; choice forms { description "Two forms of period of time."; case period-explicit { description "A period of time is identified by its start and its end."; leaf explicit-start { type yang:date-and-time; description "Period start time."; } leaf explicit-end { type yang:date-and-time; description "Period end time."; } } case period-start { Ma, et al. Expires 17 August 2023 [Page 12] Internet-Draft A Policy-based NACL February 2023 description "A period of time is defined by a start and a positive duration of time."; leaf start { type yang:date-and-time; description "Period start time."; } leaf duration { type yang:time-no-zone; description "Duration of the time."; } } } } } grouping recurrence { description "This grouping is defined to identify properties that contain a recurrence rule specification"; container recurrence { description "Recurrence rule definition."; leaf freq { type enumeration { enum secondly { value 1; description "Repeating events based on an interval of a second or more."; } enum minutely { value 2; description "Repeating events based on an interval of a minute or more."; } enum hourly { value 3; description "Repeating events based on an interval of an hour or more."; } enum daily { value 4; description Ma, et al. Expires 17 August 2023 [Page 13] Internet-Draft A Policy-based NACL February 2023 "Repeating events based on an interval of a day or more."; } enum weekly { value 5; description "Repeating events based on an interval of a week or more."; } enum monthly { value 6; description "Repeating events based on an interval of a month or more."; } enum yearly { value 7; description "Repeating events based on an interval of a year or more."; } } mandatory true; description "This parameter is defined to identify the type of recurrence rule."; } choice until-or-count { description "Modes to bound the recurrence rule."; case until { description "This case defines a way that bounds the recurrence rule in a inclusive manner."; leaf until { type union { type yang:date-no-zone; type yang:date-and-time; } description "This parameter specifies a date-no-zone or date-time value to bounds the recurrence."; } } case count { description "This case defines the number of occurrences at which to range-bound the recurrence."; Ma, et al. Expires 17 August 2023 [Page 14] Internet-Draft A Policy-based NACL February 2023 leaf count { type uint32; description "The positive number of occurrences at which to range-bound the recurrence."; } } } leaf interval { type uint32; default "1"; description "A positive integer representing at which intervals the recurrence rule repeats."; } leaf-list bysecond { type uint32 { range "0..60"; } description "A list of seconds within a minute."; } leaf-list byminute { type uint32 { range "0..59"; } description "A list of minutes within an hour."; } leaf-list byhour { type uint32 { range "0..23"; } description "Specify a list of hours of the day."; } list byday { key "weekday"; description "Specify a list of days of the week."; leaf direction { when '(enum-value(../../freq) >= 6) and ' + '(enum-value(../../freq) = 7) and not(../../byyearweek)'; type int32 { range "-53..-1|1..53"; } description "When specified, it indicates the nth occurrence of a Ma, et al. Expires 17 August 2023 [Page 15] Internet-Draft A Policy-based NACL February 2023 specific day within the MONTHLY or YEARLY 'RRULE'."; } leaf weekday { type schedule:weekday; description "Corresponding to seven days of the week."; } } leaf-list bymonthday { type int32 { range "-31..-1|1..31"; } description "Specifies a list of days of the month."; } leaf-list byyearday { type int32 { range "-366..-1|1..366"; } description "Specifies a list of days of the year."; } leaf-list byyearweek { when 'enum-value(../freq)=7'; type int32 { range "-53..-1|1..53"; } description "Specifies a list of weeks of the year."; } leaf-list byyearmonth { type uint32 { range "1..12"; } description "Specifies a list of months of the year."; } leaf-list bysetpos { type int32 { range "-366..-1|1..366"; } description "Specifies a list of values that corresponds to the nth occurrence within the set of recurrence instances specified by the rule."; } leaf-list wkst { type schedule:weekday; Ma, et al. Expires 17 August 2023 [Page 16] Internet-Draft A Policy-based NACL February 2023 default "monday"; description "Specifies the day on which the workweek starts."; } } } } 5.2. The UCL Extension to the ACL Model 5.2.1. Module Overview Figure 3 provides the tree strcuture of the "ietf-ucl-acl" module. module: ietf-ucl-acl augment /acl:acls/acl:acl: +--rw endpoint-groups +--rw endpoint-group* [endpoint-group-id] +--rw endpoint-group-id uint32 +--rw (group-type)? +--:(user-group) | +--rw user-group | +--rw role? string +--:(device-group) +--rw device-group +--rw device-type? string augment /acl:acls/acl:acl/acl:aces/acl:ace/acl:matches: +--rw endpoint-group {match-on-endpoint-group}? +--rw source-match | +--rw endpoint-group-id? leafref +--rw destination-match +--rw endpoint-group-id? leafref augment /acl:acls/acl:acl/acl:aces/acl:ace: +--rw time-range {match-on-time}? +--rw (time-range-type)? +--:(periodic-range) | +--rw recurrence | +--rw freq enumeration | +--rw (until-or-count)? | | +--:(until) | | | +--rw until? union | | +--:(count) | | +--rw count? uint32 | +--rw interval? uint32 | +--rw bysecond* uint32 | +--rw byminute* uint32 | +--rw byhour* uint32 Ma, et al. Expires 17 August 2023 [Page 17] Internet-Draft A Policy-based NACL February 2023 | +--rw byday* [weekday] | | +--rw direction? int32 | | +--rw weekday schedule:weekday | +--rw bymonthday* int32 | +--rw byyearday* int32 | +--rw byyearweek* int32 | +--rw byyearmonth* uint32 | +--rw bysetpos* int32 | +--rw wkst* schedule:weekday +--:(absolute-range) +--rw period-of-time +--rw (forms)? +--:(period-explicit) | +--rw explicit-start? yang:date-and-time | +--rw explicit-end? yang:date-and-time +--:(period-start) +--rw start? yang:date-and-time +--rw duration? yang:time-no-zone Figure 3: UCL Extension This module specifies an extension to the IETF ACL model [RFC8519] such that the UCL group index can be referenced by augmenting the "match" data node. 5.2.2. The YANG Module This module imports types defined in [RFC6991], [RFC8194], and [RFC8519]. file="ietf-ucl-acl@2023-01-19.yang" module ietf-ucl-acl { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ucl-acl"; prefix uacl; import ietf-access-control-list { prefix acl; reference "RFC 8519: YANG Data Model for Network Access Control Lists (ACLs)"; } import ietf-schedule { prefix schedule; reference "RFC XXXX: A Policy-based Network Access Control"; } Ma, et al. Expires 17 August 2023 [Page 18] Internet-Draft A Policy-based NACL February 2023 organization "IETF OPSWG Working Group"; contact "WG Web: WG List: "; description "This YANG module defines XXX. Copyright (c) 2023 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; revision 2023-01-19 { description "Initial revision."; reference "RFC XXXX: A Policy-based Network Access Control"; } feature match-on-endpoint-group { description "The device can support matching on endpoint groups."; } feature match-on-time { description "The device can support a time-based condition match."; } augment "/acl:acls/acl:acl" { description "add a new container to store endpoint group information."; container endpoint-groups { description "Container definition for the endpoint group."; list endpoint-group { key "endpoint-group-id"; description Ma, et al. Expires 17 August 2023 [Page 19] Internet-Draft A Policy-based NACL February 2023 "Definition of the endpoint group list."; leaf endpoint-group-id { type uint32 { range "0..4294967294"; } description "The endpoint group ID that uniquely identifies an endpoint group."; } choice group-type { description "Choice of each different type of endpoint."; case user-group { description "The employee that actually connects to the network."; container user-group { description "Defines the user-group container."; leaf role { type string; description "The common role of this user-group."; } } } case device-group { description "The static resources in a network, such as a specific application."; container device-group { description "Defines the device-group container."; leaf device-type { type string; description "The type of the static resource."; } } } } } } } augment "/acl:acls/acl:acl/acl:aces/acl:ace/acl:matches" { description "Add another choice to allow ace match based on endpoint group id."; Ma, et al. Expires 17 August 2023 [Page 20] Internet-Draft A Policy-based NACL February 2023 container endpoint-group { if-feature "match-on-endpoint-group"; description "Add new match types."; container source-match { description "The source matched information."; leaf endpoint-group-id { type leafref { path "../../../../../../endpoint-groups/endpoint-group/"+ "endpoint-group-id"; } description "The matched source endpoint group ID."; } } container destination-match { description "The destination matched information."; leaf endpoint-group-id { type leafref { path "../../../../../../endpoint-groups/endpoint-group/"+ "endpoint-group-id"; } description "The matched destination endpoint group ID."; } } } } augment "/acl:acls/acl:acl/acl:aces/acl:ace" { if-feature "match-on-time"; description "Add a new parameter to the Access Control Entry (ACE)."; container time-range { description "This container defines when the access control entry rules are in effect. If it is not configured, the access control entry is immediately and always in effect."; choice time-range-type { description "Choice based on the type of the time range."; case periodic-range { description "A periodic range of time to take effect."; Ma, et al. Expires 17 August 2023 [Page 21] Internet-Draft A Policy-based NACL February 2023 uses schedule:recurrence; } case absolute-range { description "A single precise period of time to take effect."; uses schedule:period; } } } } } 6. User Access Control Group ID RADIUS Attribute The User-Access-Group-ID RADIUS attribute and its embedded TLVs are defined with globally unique names. The definition of the attribute follows the guidelines in Section 2.7.1 of [RFC6929]. This attribute is used to indicate the user-group ID to be used by the NAS. When the User-Access-Group-ID RADIUS attribute is present in the RADIUS Access-Accept, the system applies the related access control to the users after it authenticates. The value fields of the Attribute are encoded in clear and not encrypted as, for example, Tunnel- Password Attribute [RFC2868]. The User-Access-Group-ID Attribute is of type "string" as defined in Section 3.5 of [RFC8044]. The User-Access-Group-ID Attribute MAY appear in a RADIUS Access- Accept packet. It MAY also appear in a RADIUS Access-Request packet as a hint to the RADIUS server to indicate a preference. However, the server is not required to honor such a preference. The User-Access-Group-ID Attribute MAY appear in a RADIUS CoA-Request packet. The User-Access-Group-ID Attribute MAY appear in a RADIUS Accounting- Request packet. The User-Access-Group-ID Attribute MUST NOT appear in any other RADIUS packet. The User-Access-Group-ID Attribute is structured as follows: Ma, et al. Expires 17 August 2023 [Page 22] Internet-Draft A Policy-based NACL February 2023 Type 241 Length This field indicates the total length, in octets, of all fields of this attribute, including the Type, Length, Extended-Type, and the "Value". Extended-Type TBA1 Value This field contains the user group ID. The User-Access-Group-ID Attribute is associated with the following identifier: 241.TBA1. 7. RADIUS Attributes The following table provides a guide as what type of RADIUS packets that may contain User-Access-Group-ID Attribute, and in what quantity. Access- Access- Access- Challenge Acct. # Attribute Request Accept Reject Request 0+ 0+ 0 0 0+ 241.TBA1 User-Access-Group-ID CoA-Request CoA-ACK CoA-NACK # Attribute 0+ 0 0 241.TBA2 User-Access-Group-ID The following table defines the meaning of the above table entries: 0 This attribute MUST NOT be present in packet. 0+ Zero or more instances of this attribute MAY be present in packet. 8. Security Considerations Ma, et al. Expires 17 August 2023 [Page 23] Internet-Draft A Policy-based NACL February 2023 8.1. YANG The YANG modules specified in this document defines schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. The "ietf-schedule" module defines a set of types and groupings. These nodes are intended to be reused by other YANG modules. The module by itself does not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. As such, there are no additional security issues related to the "ietf- schedule" module that need to be considered. There are a number of data nodes defined in the "ietf-ucl-acl" YANG module that are writable, creatable, and deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations to these data nodes could have a negative effect on network and security operations. * TBC * TBC Some of the readable data nodes in the "ietf-ucl-acl" YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: * * 8.2. RADIUS RADIUS-related security considerations are discussed in [RFC2865]. Ma, et al. Expires 17 August 2023 [Page 24] Internet-Draft A Policy-based NACL February 2023 This document targets deployments where a trusted relationship is in place between the RADIUS client and server with communication optionally secured by IPsec or Transport Layer Security (TLS) [RFC6614]. 9. IANA Considerations 9.1. YANG This document registers the following URIs in the "IETF XML Registry" [RFC3688]. URI: urn:ietf:params:xml:ns:yang:ietf-schedule Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-ucl-acl Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document registers the following YANG modules in the "YANG Module Names" registry [RFC6020]. name: ietf-schedule namespace: urn:ietf:params:xml:ns:yang:ietf-schedule prefix: schedule maintained by IANA: N reference: RFC XXXX name: ietf-ucl-acl namespace: urn:ietf:params:xml:ns:yang:ietf-ucl-acl prefix: uacl maintained by IANA: N reference: RFC XXXX 9.2. RADIUS This document requests IANA to assign a new RADIUS attribute types from the IANA registry "Radius Attribute Types" [RADIUS-Types]: +==========+======================+===========+===============+ | Value | Description | Data Type | Reference | +==========+======================+===========+===============+ | 241.TBA1 | User-Access-Group-ID | string | This-Document | +----------+----------------------+-----------+---------------+ Table 3: RADIUS Attribute Ma, et al. Expires 17 August 2023 [Page 25] Internet-Draft A Policy-based NACL February 2023 10. References 10.1. Normative References [I-D.ietf-netmod-rfc6991-bis] Schönwälder, J., "Common YANG Data Types", Work in Progress, Internet-Draft, draft-ietf-netmod-rfc6991-bis- 15, 23 January 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, DOI 10.17487/RFC2865, June 2000, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6929] DeKok, A. and A. Lior, "Remote Authentication Dial In User Service (RADIUS) Protocol Extensions", RFC 6929, DOI 10.17487/RFC6929, April 2013, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . Ma, et al. Expires 17 August 2023 [Page 26] Internet-Draft A Policy-based NACL February 2023 [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8044] DeKok, A., "Data Types in RADIUS", RFC 8044, DOI 10.17487/RFC8044, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8194] Schoenwaelder, J. and V. Bajpai, "A YANG Data Model for LMAP Measurement Agents", RFC 8194, DOI 10.17487/RFC8194, August 2017, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8519] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair, "YANG Data Model for Network Access Control Lists (ACLs)", RFC 8519, DOI 10.17487/RFC8519, March 2019, . 10.2. Informative References [I-D.dbb-netmod-acl] de Dios, O. G., Barguil, S., and M. Boucadair, "Extensions to the Access Control Lists (ACLs) YANG Model", Work in Progress, Internet-Draft, draft-dbb-netmod-acl-03, 24 October 2022, . [I-D.ietf-nvo3-encap] Boutros, S. and D. E. Eastlake, "Network Virtualization Overlays (NVO3) Encapsulation Considerations", Work in Progress, Internet-Draft, draft-ietf-nvo3-encap-09, 7 October 2022, . Ma, et al. Expires 17 August 2023 [Page 27] Internet-Draft A Policy-based NACL February 2023 [I-D.yizhou-anima-ip-to-access-control-groups] Li, Y., Shen, L., and Y. Zhou, "Autonomic IP Address To Access Control Group ID Mapping", Work in Progress, Internet-Draft, draft-yizhou-anima-ip-to-access-control- groups-02, 15 November 2021, . [I-D.you-i2nsf-user-group-based-policy] You, J., Zarny, M., Jacquenet, C., Boucadair, M., Li, Y., Strassner, J., and S. Majee, "User-group-based Security Policy for Service Layer", Work in Progress, Internet- Draft, draft-you-i2nsf-user-group-based-policy-02, 8 July 2016, . [NIST-ABAC] Hu, V. C., "Guide to Attribute Based Access Control (ABAC) Definition and Considerations", January 2014, . [RADIUS-Types] IANA, "RADIUS Types", . [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, DOI 10.17487/RFC2475, December 1998, . [RFC2753] Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework for Policy-based Admission Control", RFC 2753, DOI 10.17487/RFC2753, January 2000, . [RFC2868] Zorn, G., Leifer, D., Rubens, A., Shriver, J., Holdrege, M., and I. Goyret, "RADIUS Attributes for Tunnel Protocol Support", RFC 2868, DOI 10.17487/RFC2868, June 2000, . [RFC3198] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M., Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J., and S. Waldbusser, "Terminology for Policy-Based Management", RFC 3198, DOI 10.17487/RFC3198, November 2001, . Ma, et al. Expires 17 August 2023 [Page 28] Internet-Draft A Policy-based NACL February 2023 [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and Scheduling Core Object Specification (iCalendar)", RFC 5545, DOI 10.17487/RFC5545, September 2009, . [RFC6614] Winter, S., McCauley, M., Venaas, S., and K. Wierenga, "Transport Layer Security (TLS) Encryption for RADIUS", RFC 6614, DOI 10.17487/RFC6614, May 2012, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . Appendix A. Changes between Revisions v00 - v01 * Define a common schedule yang module and reuse in UCL yang module to support time/date-based activation condition. * Either group-based or address-based ACL policies could be enforced at PEP, and allow group-based ACL policies maintained at the network controller. * Optimize the process in section 4.1. * Extend ACL module to support a generalized endpoint-group to cover both end users (e.g., enterprise employees) and enterprise hosts (e.g., IoT devices or servers); * Simplify the definition of group in UCL model with only the most necessary group ID retained. Acknowledgments This work has benefited from the discussions of User-group-based Security Policy over the years. In particular, [I-D.you-i2nsf-user-group-based-policy] and [I-D.yizhou-anima-ip-to-access-control-groups] provide mechanisms to establish the mapping between the IP address/prefix of user and access control group ID. Jianjie You, Myo Zarny, Christian Jacquenet, Mohamed Boucadair, and Yizhou Li contributed to an earlier version of [I-D.you-i2nsf-user-group-based-policy]. We would like to thank the authors of that draft on modern network access control mechanisms for material that assisted in thinking about this document. Ma, et al. Expires 17 August 2023 [Page 29] Internet-Draft A Policy-based NACL February 2023 The authors would like to thank Joe Clarke, Bill Fenner, Benoit Claise, Rob Wiltion, David Somers-Harris for their valuable comments and great input to this work. Authors' Addresses Qiufang Ma Huawei 101 Software Avenue, Yuhua District Jiangsu 210012 China Email: maqiufang1@huawei.com Qin Wu Huawei 101 Software Avenue, Yuhua District Jiangsu 210012 China Email: bill.wu@huawei.com Mohamed Boucadair Orange 35000 Rennes France Email: mohamed.boucadair@orange.com Daniel King Old Dog Consulting United Kingdom Email: daniel@olddog.co.uk Ma, et al. Expires 17 August 2023 [Page 30]