]> Telefónica

lucia.cabanillasrodriguez@telefonica.com

Telefónica

diego.r.lopez@telefonica.com

Telefónica

ana.mendezperez@telefonica.com

Operations and Management Network Management Operations policy authorization lifecycle This document defines mechanisms and conventions for the representation, lifecycle management, and distribution of authorization policies in distributed and automated environments. It specifies a consistent, machine-readable, and interoperable framework that enables policies to be validated, exchanged, and removed across heterogeneous systems and areas. The framework defines how authorization policies, expressed in declarative Policy-as-Code (PaC) languages, are encapsulated, managed, and distributed using YANG as the canonical representation format. This separation allows independent evolution of policy languages, enforcement architectures, and trust models. The model also defines extensible Policy-as-Code language identities using YANG identity and identityref mechanisms, enabling future policy languages to be incorporated without modifying the core schema. About This Document The latest revision of this draft can be found at . Status information for this document may be found at . Discussion of this document takes place on the Network Management Operations Working Group mailing list (), which is archived at . Subscribe at . Source for this draft and an issue tracker can be found at .

Introduction The increasing complexity and automation of distributed systems, such as programmable networks, multi-cloud platforms, and intent-based infrastructures, require scalable and interoperable mechanisms for managing authorization policies. In these environments, policies are no longer confined to static configuration files or manually managed. Instead, they are dynamic artifacts that must be created, validated, distributed, updated, and eliminated programmatically. Authorization policies increasingly govern not only access control but also operational behavior, compliance requirements, and governance constraints across multiple areas. These policies may be authored in one area, distributed through another, and enforced in many. As a result, consistent handling of policies throughout their lifecycle becomes critical. Existing approaches often rely on system-specific policy formats and ad hoc distribution mechanisms, leading to several challenges:

• Fragmentation: Incompatible representations and semantics hinder interoperability and auditability.
• Limited lifecycle control: Many systems lack standardized mechanisms for validation, versioning, and decommissioning.
• Trust ambiguity: In multi-domain environments, it is often unclear whether a policy source is authorized or trustworthy.
• Governance gaps: Systems frequently lack mechanisms to verify whether a policy author is permitted to define policies for a specific domain.

To address these challenges, this document defines a structured and interoperable framework for representing and managing authorization policies as governed artifacts. YANG is used as the canonical representation format for policy artifacts. A YANG-defined policy encapsulates its metadata together with embedded declarative Policy-as-Code content, which is treated as opaque executable logic. This structured representation enables schema-based validation, provenance verification, and interoperable lifecycle management while remaining agnostic to the underlying evaluation engine.

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 when, and only when, they appear in all capitals, as shown here. 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 when, and only when, they appear in all capitals, as shown here.

• Policy: A rule or set of rules that define behavior, access, or operational constraints within a system.
• Authorization policy: A policy that governs access or permissions based on user/agent, resource, or environmental attributes.
• Policy lifecycle: The set of stages through which a policy passes, including creation, validation, distribution, update, rollback, and removal.
• Policy-as-Code (PaC): A paradigm in which policies are represented as declarative code artifacts, allowing automation, versioning, and testing.

Requirements for Policy Management Systems that manage or exchange authorization policies across domains MUST satisfy the following requirements:

• Granularity: Policies SHOULD be able to express fine-grained authorization rules over users, resources, and contextual conditions.
• Lifecycle control: Policies SHOULD support creation, validation, update, rollback, distribution, and removal.
• Interoperability: Policy representations SHOULD be portable and interpretable across different administrative areas.
• Verifiability: The framework SHOULD provide mechanisms to verify policy integrity and provenance.

Policy-as-Code and Declarative Policy Languages Declarative Policy-as-Code (PaC) languages, such as Rego , Cedar , or ALFA , are widely used to express authorization logic in distributed systems. Although these languages differ in syntax, evaluation models, and execution environments, they share common lifecycle and governance requirements when used in distributed and multi-domain environments. This framework treats PaC content as opaque executable logic embedded within a YANG-defined policy artifact. The YANG representation does not interpret, validate, or constrain the internal semantics of the policy language. Instead, it provides a structured and interoperable container for lifecycle governance, version control, provenance binding, and distribution. The policy language itself is modeled using YANG identities and identity references. This approach follows extensibility patterns, allowing implementations to introduce additional Policy-as-Code languages without modifying the base model. By separating policy handling from policy semantics, including evaluation logic and decision outcomes, this framework enables interoperability without constraining innovation in policy languages or enforcement technologies. Example in Rego syntax: The policy logic above is treated as opaque content by the YANG representation. Its evaluation behavior is determined exclusively by the target execution environment, while lifecycle and governance properties such as version and ownership are managed independently.

Policy representation in YANG YANG provides a structured and schema-driven mechanism for representing authorization policies as managed and governed artifacts. In this framework, YANG serves as the canonical container format for policy definitions, encapsulating:

• Policy metadata, including owner, area, and description.
• The declarative language used to express the policy logic.
• The embedded Policy-as-Code (PaC) content, treated as opaque data.
• Optional leaf for validation and provenance.

In addition, each policy instance MUST include an explicit owner attribute that identifies the authority responsible for the policy definition, ensuring accountability within and across domains. By associating a policy with a clearly identified authority, the framework enables governance controls and allows systems to determine whether the policy source is authorized within a given scope. The owner attribute MUST be expressed as a URI that uniquely identifies the authoritative entity responsible for the policy. The policy language is represented using YANG identities and identity references rather than fixed enumerations. This design follows common extensibility practices in YANG models, enabling future Policy-as-Code languages to be introduced dynamically without requiring modifications to the base schema. The specific URI structure is determined by the administrative environment. Ownership metadata MAY be cryptographically linked to the policy provenance, enabling verification against the provenance signature key. This mechanism ensures that the policy origin and integrity can be independently verified and trusted. The YANG model below illustrates a simplified structure for representing authorization policies as managed artifacts: WG List: Authors: Lucía Cabanillas Diego López Ana Méndez Pérez "; description "Illustrative YANG model for representing distributed authorization policies as managed artifacts."; revision 2026-05-27 { description "Third revision."; reference "RFC XXXX: Model for distributed authorization policy sharing"; } /* * Identities */ identity policy-language { description "Abstract base identity for Policy-as-Code languages."; } identity rego { base policy-language; description "Rego policy language."; } identity cedar { base policy-language; description "Cedar policy language."; } identity alfa { base policy-language; description "ALFA authorization language."; } /* * Typedefs */ typedef policy-language-ref { type identityref { base policy-language; } description "Reference to a Policy-as-Code language identity."; } /* * Policy model */ container policy { description "Container representing an authorization policy artifact."; leaf area { type string; mandatory true; description "Administrative or operational area to which the policy belongs."; } leaf description { type string; description "Optional human-readable description of the policy."; } leaf language { type policy-language-ref; mandatory true; description "Specifies the Policy-as-Code language used to express the policy."; } leaf pac { type string; mandatory true; description "Opaque Policy-as-Code content. Example: package example default allow = false allow if{ input.user.role == \"read\" }"; } leaf owner { type uri; mandatory true; description "URI identifying the authoritative entity responsible for this policy."; } leaf policy-provenance { type iyangprov:provenance-signature; description "Cryptographic provenance signature associated with the policy."; } } } ]]> This YANG snippet demonstrates how policy content can be represented as structured data while keeping the logic in a declarative format. By explicitly indicating the language, management systems can validate and process policies appropriately, enabling interoperability between tools and engines.

Example JSON Encoding The following example illustrates how a policy instance can be represented using JSON encoding for the YANG model: In this example, the language leaf references the rego identity defined in the YANG module through an identityref. Additional Policy-as-Code languages may be introduced by defining new identities derived from the policy-language base identity.

Architecture Overview Policy management in distributed environments relies on a set of functional components that cooperate to define, govern, distribute, evaluate, and enforce authorization policies across administrative areas . This framework adopts that functional separation while introducing structured policy representation and lifecycle governance based on YANG.

Functional Roles Policy Author: The entity (human or automated system/agent) responsible for creating the policy definition. The author produces a YANG-encoded policy document that includes metadata (description, area, language, owner) and the actual declarative rule. Policy Administration Point (PAP): The Policy Administration Point manages the lifecycle and governance of policy artifacts. Upon receiving a YANG-encoded policy, it performs schema validation and, where applicable, verifies provenance using cryptographic mechanisms such as those described in . The PAP MAY maintain historical policy revisions through external version-control systems in order to support rollback, auditing, and policy recovery operations. Before accepting or distributing a policy artifact, the Policy Administration Point (PAP) MAY perform an authorization verification step. In this step, the PAP queries a Policy Decision Point to determine whether the declared owner or submitting entity is authorized to define or modify policies within the relevant area. All lifecycle events, including creation, update, activation, rollback, and decommissioning, MAY be recorded in an append-only accounting ledger to ensure traceability and auditability. Once validated and authorized, the PAP distributes the executable policy artifact to the appropriate decision components. Policy Decision Point (PDP): The Policy Decision Point evaluates policy logic at runtime. It receives validated policy artifacts and processes authorization requests based on contextual attributes, claims, or environmental information. The PDP produces authorization decisions such as Permit or Deny, optionally including obligations or advice. Policy Enforcement Point (PEP): The PEP enforces the decisions issued by the PDP. Enforcement may include granting or denying access, applying configurations, or triggering operational actions.

Functional Interaction The interaction among the architectural components reflects a strict separation between policy governance and runtime decision-making. Policy artifacts are first validated, governed, and recorded as managed entities before being distributed for evaluation. The following diagram illustrates the logical interaction flow: | Accounting Ledger | |-----------------------------------| |-------------------------| | - Schema validation | | - create / update | | - Provenance verification | | - rollback / remove | | - Version enforcement | +-------------------------+ | - Lifecycle state management | |-----------------------------------| | Governance Authorization Check | | (PAP -> PDP query) | +------------------+----------------+ | | Authorized policy v +-----------------------------------+ | Policy Decision Point (PDP) | |-----------------------------------| | - Runtime policy evaluation | +------------------+----------------+ ^ | Authorization request | v Authorization decision +-----------------------------------+ | Policy Enforcement Point (PEP) | |-----------------------------------| | - Enforcement of decisions | +-----------------------------------+ ]]>

Other Models Existing data models demonstrate that YANG can be effectively used to carry authorization-related information in operational environments. The OpenConfig gNSI authorization model defines a YANG module that represents metadata associated with gRPC authorization policies installed on network devices. That model focuses on device-level state and observability, including policy metadata, operational status, and evaluation counters. This document is complementary to that approach. While the OpenConfig model concentrates on operational visibility for a specific enforcement technology, the framework defined here focuses on the representation, lifecycle management, provenance, and distribution of authorization policy artifacts across systems and administrative areas.

Security Considerations Ensuring the integrity, authenticity, and provenance of policy data is critical to prevent unauthorized modification. Policies SHOULD include cryptographic protection mechanisms that allow their origin and validity to be verified. The mechanisms defined in — Applying COSE Signatures for YANG Data Provenance — provide a suitable foundation for these protections. That document specifies how COSE signatures are used to include digital signatures within the YANG data, enabling, in this case, verifiable provenance and ensuring the integrity of the YANG-based distributed authorization policy sharing model proposed in this draft. When such provenance mechanisms are applied to policy definitions, each policy instance can include a verifiable signature providing proof of origin and integrity of the provided policy. By treating policies as signed and governed artifacts, this framework reduces the risk associated with automated and cross-domain policy exchange, including the additional risks in multi-domain deployments such as determining whether a policy has been modified in transit and whether the policy issuer is authorized to define policies applicable to the receiving area.

IANA Considerations This document has no IANA actions.

References Normative References This memo serves as the base requirements for Authorization of Internet Resources and Services (AIRS). It presents an architectural framework for understanding the authorization of Internet resources and services and derives requirements for authorization protocols. This memo provides information for the Internet community. Concise Binary Object Representation (CBOR) is a data format designed for small code size and small message size. There is a need to be able to define basic security services for this data format. This document defines the CBOR Object Signing and Encryption (COSE) protocol. This specification describes how to create and process signatures, message authentication codes, and encryption using CBOR for serialization. This specification additionally describes how to represent cryptographic keys using CBOR. This document, along with RFC 9053, obsoletes RFC 8152. Telefonica Telefonica INSA-Lyon Telefonica Fraunhofer SIT This document defines a mechanism based on CBOR Object Signing and Encryption (COSE) signatures to provide and verify the provenance of YANG data, so it is possible to verify the origin and integrity of a dataset, even when those data are going to be processed and/or applied in workflows where a crypto-enabled data transport directly from the original data source is not available. As the application of evidence-based OAM automation and the use of tools such as AI/ML grow, provenance validation becomes more relevant in all scenarios, in support of the assuring the origin and integrity of data. The use of compact signatures facilitates the inclusion of provenance strings in any YANG schema requiring them. In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. Informative References n.d. n.d. n.d. n.d.

Acknowledgments This document is based on work partially funded by the iTrust6G project (Grant agreement N 101097083) and the ROBUST-6G project (Grant agreement N 101139068).