Internet-Draft Mission AuthZEN Profile June 2026
McGuinness Expires 25 December 2026 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-mcguinness-oauth-mission-authzen-latest
Published:
Intended Status:
Standards Track
Expires:
Author:
K. McGuinness
Independent

Mission-Bound Runtime Enforcement: AuthZEN Profile

Abstract

Mission-Bound Runtime Enforcement for OAuth 2.0 ([I-D.draft-mcguinness-oauth-mission-runtime]) specifies a substrate-independent decision contract: before each consequential action runs, a Policy Enforcement Point (PEP) obtains a permit from a Policy Decision Point (PDP) that evaluates the action against the Mission the acting token is bound to. That contract is independent of the decision wire format. This document is the concrete OpenID AuthZEN binding of that contract. It defines how a Mission is materialized into an evaluable policy view, how the abstract decision inputs map onto the AuthZEN Authorization API request and response, the Decision Evidence and Execution Evidence objects a deployment emits and their integrity, how runtime denials map onto AuthZEN error and Insufficient-Claims responses, and the AuthZEN representation of the runtime metering the base profile meters. It does not restate the enforcement semantics the base profile owns.

About This Document

This note is to be removed before publishing as an RFC.

The latest revision of this draft can be found at https://mcguinness.github.io/draft-mcguinness-oauth-mission/draft-mcguinness-oauth-mission-authzen.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-mcguinness-oauth-mission-authzen/.

Source for this draft and an issue tracker can be found at https://github.com/mcguinness/draft-mcguinness-oauth-mission.

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 25 December 2026.

Table of Contents

1. Introduction

Mission-Bound Runtime Enforcement for OAuth 2.0 [I-D.draft-mcguinness-oauth-mission-runtime] (the "runtime profile") specifies the runtime enforcement layer for Mission-bound access tokens issued under Mission-Bound Authorization for OAuth 2.0 [I-D.draft-mcguinness-oauth-mission] (the "issuance profile"). The runtime profile is deliberately substrate-independent: it defines the decision contract, action classification, PEP placement, parameter binding and the time-of-check to time-of-use gap, consumption metering, failure modes, runtime enforcement evidence, and the runtime conformance scope, but it states that the decision API wire format is a deployment choice and that it is "not an AuthZEN profile".

This document is that AuthZEN profile. It binds the runtime profile's abstract decision contract (Section 6 of [I-D.draft-mcguinness-oauth-mission-runtime]) to the OpenID AuthZEN Authorization API [AUTHZEN]. It carries only the AuthZEN-binding deltas:

This document does not restate the enforcement contract. It does not redefine which actions are consequential, where the PEP MUST sit, the semantics of parameter binding, the semantics of metering, the failure modes, or the runtime conformance scope; those are normatively defined in [I-D.draft-mcguinness-oauth-mission-runtime] and are referenced, not duplicated, here.

1.1. Requirements Language

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.

2. Conventions and Definitions

This document uses JSON [RFC8259] as the data model for all PDP requests, responses, and evidence objects. JCS canonicalization [RFC8785] applies wherever an integrity hash is computed, under the canonicalization rules of [I-D.draft-mcguinness-oauth-mission]; this document does not define a second canonicalization.

"SHA-256" refers to [RFC6234]. A digest is encoded in the integrity-anchor encoded form of [I-D.draft-mcguinness-oauth-mission]: sha-256: followed by the base64url, no-padding encoding of the digest.

The terms Policy Enforcement Point (PEP), Policy Decision Point (PDP), consequential action, Resource policy, decision, Mission state source, and enforcement scope are used as defined in [I-D.draft-mcguinness-oauth-mission-runtime]. The Mission claim (id, origin, authority_hash), the integrity anchors (intent_hash, authority_hash), and authorization_details entries of type mission_resource_access are used as defined in [I-D.draft-mcguinness-oauth-mission].

Additional terms specific to this binding:

Materialized policy view:

The reproducible, evaluable form of a Mission's approved authority produced by the issuing Authorization Server or a trusted compiler and consumed by the PDP (Section 3).

Decision Evidence:

The runtime enforcement evidence record (Section 10 of [I-D.draft-mcguinness-oauth-mission-runtime]) emitted by the PDP, in the concrete object form of Section 5.

Execution Evidence:

The record emitted by the PEP or executor after the authorized action's outcome is determined (Section 6).

HTTP message examples follow the AuthZEN specification [AUTHZEN] for the decision request and response, and [RFC9457] for problem-details error bodies where a deployment carries them outside the AuthZEN envelope.

3. Mission-to-Policy Materialization

The PDP evaluates a Mission against an action. The issuing Authorization Server, or a trusted compiler, reproducibly materializes the Mission's approved authority as an evaluable policy view the PDP loads and addresses.

3.1. Inputs

  • The Mission's approved Authority Set (the authorization_details entries, including mission_resource_access entries with their resource, actions, and constraints), as committed by authority_hash ([I-D.draft-mcguinness-oauth-mission]).

  • The derivation policy_version recorded at the approval event.

3.2. Properties

The materialized policy view MUST satisfy:

  • Reproducibility: the same inputs produce byte-identical materialized output under the canonicalization of [I-D.draft-mcguinness-oauth-mission].

  • Identifiable: the materialized view carries a policy_view_id so PDP cache entries are addressable.

  • Bounded: materialization is faithful and does not enlarge the Authority Set's semantic bounds. A materialized view is an evaluation aid, never new authority.

3.2.1. policy_view_id

policy_view_id is the integrity-anchor encoded form ([I-D.draft-mcguinness-oauth-mission]) of the SHA-256 of the JCS-canonical bytes of the materialized view envelope:

SHA-256(JCS({
  "typ":   "mission-policy-view",
  "iss":   <mission.origin>,
  "value": <materialized view payload>
}))

The envelope reuses the domain-separated, issuer-bound integrity-anchor envelope of [I-D.draft-mcguinness-oauth-mission] with a new typ; this document defines no second canonicalization. Because policy_view_id is a content hash, it uniquely addresses the materialized form: any change to the view yields a new policy_view_id, so equality on policy_view_id is the cache identity and freshness test.

3.3. Wire form

This profile does not pick a concrete policy-language wire form for the materialized view. Implementations MAY use canonical input bundles the AuthZEN PDP consumes directly, or an engine-native artifact. Compiling a Mission into an engine-native policy artifact and standardizing a policy-view carriage format are out of scope (Section 12 of [I-D.draft-mcguinness-oauth-mission-runtime]).

4. PDP Request

The PDP request realizes the runtime profile's abstract decision contract (Section 6 of [I-D.draft-mcguinness-oauth-mission-runtime]) over the OpenID AuthZEN Authorization API [AUTHZEN]. AuthZEN defines a top-level envelope with subject, resource, action, and context members. This profile binds the Mission-bound decision inputs into that envelope. It does not change which inputs MUST be evaluated; those are defined by the runtime profile.

This binding is used after ordinary access-token validation (Section 5 of [I-D.draft-mcguinness-oauth-mission-runtime]): the PEP MUST NOT ask a PDP to authorize an action from unverified token claims, and the PEP-PDP channel MUST be integrity-protected and mutually authenticated as that section requires.

4.1. AuthZEN envelope binding

Table 1
AuthZEN member Mission-bound binding
subject The principal the decision is requested for.
resource The target resource, with the canonical resource identifier the PEP supplies.
action The requested action identifier (for example, journal-entries.write), which the PDP evaluates against the approved actions per [I-D.draft-mcguinness-oauth-mission].
context Carries the Mission-bound context object defined below.

4.2. context.mission

The mission member identifies the governance record and its current materialized view:

id:

REQUIRED. A string. the Mission's id.

origin:

REQUIRED. A string containing a URI. the Mission's origin.

authority_hash:

REQUIRED. A string. the Authority Set integrity anchor, in the integrity-anchor encoded form ([I-D.draft-mcguinness-oauth-mission]).

state:

REQUIRED. A string. the current Mission lifecycle state the PEP established from its Mission state source (Section 6.1 of [I-D.draft-mcguinness-oauth-mission-runtime]).

policy_version:

REQUIRED. A string. the policy_version recorded at the approval event.

policy_view_id:

REQUIRED. A string. the materialized view identifier (Section 3).

4.3. context.actor

The actor member carries the authenticated actor context when delegation is in effect, reconstructed from the access token's act claim and the token's authenticated client identity per [I-D.draft-mcguinness-oauth-mission]:

client_id:

A string. the authenticated client identity, and a client-instance identifier when present.

act:

An object or array. the delegation chain, ordered root to leaf.

The actor member carries the delegation chain only. Provenance beyond the delegation chain -- the tool a request invoked, a named workflow step, a human approver -- MUST NOT be encoded inside the act chain; the PDP evaluates the act chain as defined by the runtime profile, and provenance is recorded in dedicated evidence fields where the deployment captures it.

4.4. context.parameters and context.parameter_digest

When parameter binding is required for the requested action's class (Section 3 of [I-D.draft-mcguinness-oauth-mission-runtime]), the PEP supplies:

parameters:

CONDITIONAL. An object. the action's parameters as a JSON object. The shape is action-specific. The PEP MAY omit parameters and supply only parameter_digest where the raw values are sensitive (Section 12).

parameter_digest:

REQUIRED for parameter-bound classes. A string. the parameter_digest defined by Section 7 of [I-D.draft-mcguinness-oauth-mission-runtime]. This profile carries that value on the wire; it does not define a second digest or canonicalization. The executing PEP recomputes and reverifies the digest immediately before acting, and the PDP recomputes it over any supplied parameters, both as that section requires.

4.5. context.audience and context.freshness

audience:

REQUIRED. A string. the PEP's audience or protected-resource identifier.

freshness:

REQUIRED. An object. the freshness of the Mission state the PEP relied on, conveying the runtime profile's freshness inputs (Section 6.1 of [I-D.draft-mcguinness-oauth-mission-runtime]) on the wire. Members:

mission_status_issued_at:

An RFC 3339 [RFC3339] timestamp.

mission_status_expires_at:

An RFC 3339 timestamp.

mode:

A string. one of fresh, cached, or event_driven (Section 10).

freshness_at:

An RFC 3339 timestamp. when the PEP's view of the Mission state was current.

The deployment's maximum staleness bound, and the rule that a consequential action MUST fail closed when the Mission cannot be established as active within that bound, are defined by the runtime profile (Section 6.1 of [I-D.draft-mcguinness-oauth-mission-runtime]); the freshness object is only their wire representation.

4.6. Worked PDP request

For a Q3 invoicing Mission:

POST /pdp/access/v1/evaluation HTTP/1.1
Host: pdp.example.com
Content-Type: application/json
Authorization: ...

{
  "subject": {
    "type": "user",
    "id": "user_3p2q8mN1a0kV7tR",
    "properties": {
      "iss": "https://idp.example.com"
    }
  },
  "resource": {
    "type": "journal-entry",
    "id": "je_2026Q3_inv_8421"
  },
  "action": {
    "name": "journal-entries.write"
  },
  "context": {
    "mission": {
      "id": "msn_8RfX2Lqv9TqMv4z7sA2bN1k0YpEd",
      "origin": "https://as.example.com",
      "authority_hash":
        "sha-256:l3KvZ4mP5x0wQrR6tY2nD9bM7sX1cF8gH2vJ4kE",
      "state": "active",
      "policy_version": "deploy-policy:v17",
      "policy_view_id":
        "sha-256:kP3xR9sQ7nM2vL4tY6bD1eF8jC5wH0pV2nR3kQ4"
    },
    "actor": {
      "client_id": "client_erp-recon-agent",
      "act": {
        "iss": "https://as.example.com",
        "sub": "client_erp-recon-agent"
      }
    },
    "parameters": {
      "amount_usd": 423.50,
      "source_invoice_id": "inv_2026Q3_842"
    },
    "parameter_digest":
      "sha-256:t2Wq9pK7sR3mL6xT4bN1eY8jC5vH0nF2pV9zKqA",
    "audience": "https://erp.example.com",
    "freshness": {
      "mission_status_issued_at": "2026-11-02T08:14:00Z",
      "mission_status_expires_at": "2026-11-02T08:15:00Z",
      "mode": "cached",
      "freshness_at": "2026-11-02T08:14:00Z"
    }
  }
}

4.7. PDP-side consistency checks

In addition to evaluating the decision inputs the runtime profile requires (Section 6 of [I-D.draft-mcguinness-oauth-mission-runtime]), the PDP MUST verify that the AuthZEN-carried envelope is self-consistent:

  1. The Mission state conveyed in context.mission.state is active; otherwise the PDP returns mission_inactive (Section 7).

  2. authority_hash, policy_version, and policy_view_id carried in context.mission are consistent with the materialized policy view the PDP has loaded for this Mission; otherwise the PDP returns stale_state.

  3. The context.freshness the PEP supplied is within the deployment's staleness bound (Section 6.1 of [I-D.draft-mcguinness-oauth-mission-runtime]); otherwise the PDP returns stale_state, with the freshness-window violation in the denial reason.

  4. When context.parameters is present, the PDP-recomputed digest matches context.parameter_digest; otherwise the PDP returns parameter_violation.

5. Decision Evidence Object

The runtime profile requires a decision evidence record for every PDP decision on a consequential action, and fixes its content, canonical form, and integrity (Section 10 of [I-D.draft-mcguinness-oauth-mission-runtime]). This section gives the concrete object an AuthZEN deployment emits.

5.1. Members

decision_id:

REQUIRED. A string. unique decision identifier. ABNF: 1*64( ALPHA / DIGIT / "-" / "_" ). At least 128 bits of entropy.

mission:

REQUIRED. An object. the PDP request's context.mission object (id, origin, authority_hash, and, when known, policy_version and policy_view_id), extended with intent_hash and, when known, a consent-disclosure commitment, so the evidence chains back to the exact approved Mission. Within mission, id, origin, and authority_hash are required; the others are optional. These hashes are the issuing AS's commitments cited as anchors; the PDP does not recompute them (Section 10 of [I-D.draft-mcguinness-oauth-mission-runtime]).

subject:

REQUIRED. An object. PDP inputs as supplied, after PDP-side normalization.

resource:

REQUIRED. An object. PDP inputs as supplied, after PDP-side normalization.

action:

REQUIRED. An object. PDP inputs as supplied, after PDP-side normalization.

audience:

REQUIRED. A string. PDP inputs as supplied, after PDP-side normalization.

actor:

OPTIONAL. An object. PDP inputs as supplied, after PDP-side normalization.

parameter_digest:

OPTIONAL. A string. PDP inputs as supplied, after PDP-side normalization.

decision:

REQUIRED. A string. one of permit or deny.

contributing_constraints:

REQUIRED when the decision turned on one or more authority or constraint entries. An array of strings. the identifiers of the constraints the PDP evaluated (constraints keys, authorization_details entry types). For a permit this records what was checked; for a deny, what failed.

sequence:

REQUIRED. An integer. the per-Mission sequence indicator the runtime profile requires (Section 10 of [I-D.draft-mcguinness-oauth-mission-runtime]), so the decision stream has a verifiable order and gaps are detectable. MUST be zero or greater.

denial_reason:

CONDITIONAL. A string. present when decision is deny. A value from Section 7 or a constraints key.

evaluated_at:

REQUIRED. An RFC 3339 [RFC3339] timestamp.

evidence_envelope:

REQUIRED. An object. integrity protection (Section 5.2), carrying a format (string, required) and a value (string, required).

A Decision Evidence Object is a closed object: it MUST NOT contain members other than those defined above.

5.2. Integrity

The evidence_envelope carries the integrity protection over the Decision Evidence content; it satisfies the runtime profile's requirement that the record be serialized with JCS and integrity-protected (Section 10 of [I-D.draft-mcguinness-oauth-mission-runtime]). The default format is jws-compact, a JWS Compact Serialization [RFC7515] whose payload is the JCS [RFC8785] canonical bytes of the Decision Evidence object with the evidence_envelope member removed during signing. Verification re-removes evidence_envelope and verifies the JWS against the PDP's published signing key.

{
  "evidence_envelope": {
    "format": "jws-compact",
    "value": "eyJhbGciOiJFUzI1NiIsImtpZCI6InBkcC1rZXkt..."
  }
}

Profiles MAY register additional formats (for example, jws-flattened). Implementations MUST reject envelopes with unregistered formats.

5.3. Worked example

{
  "decision_id": "dec_8K2nP4qV9rL3tY6sB1zN0eF7jB",
  "mission": {
    "id": "msn_8RfX2Lqv9TqMv4z7sA2bN1k0YpEd",
    "origin": "https://as.example.com",
    "authority_hash":
      "sha-256:l3KvZ4mP5x0wQrR6tY2nD9bM7sX1cF8gH2vJ4kE",
    "intent_hash":
      "sha-256:wQ7p4LHnX9Md0LqJ6sZJ8b8mZ3rN2xT5pV4lE6s",
    "policy_version": "deploy-policy:v17",
    "policy_view_id":
      "sha-256:kP3xR9sQ7nM2vL4tY6bD1eF8jC5wH0pV2nR3kQ4"
  },
  "subject": {
    "type": "user",
    "id": "user_3p2q8mN1a0kV7tR"
  },
  "actor": {
    "client_id": "client_erp-recon-agent",
    "act": {
      "iss": "https://as.example.com",
      "sub": "client_erp-recon-agent"
    }
  },
  "resource": {
    "type": "journal-entry",
    "id": "je_2026Q3_inv_8421"
  },
  "action": { "name": "journal-entries.write" },
  "parameter_digest":
    "sha-256:t2Wq9pK7sR3mL6xT4bN1eY8jC5vH0nF2pV9zKqA",
  "audience": "https://erp.example.com",
  "decision": "permit",
  "contributing_constraints": [
    "mission_resource_access", "max_amount_usd"
  ],
  "sequence": 42,
  "evaluated_at": "2026-11-02T08:14:03Z",
  "evidence_envelope": {
    "format": "jws-compact",
    "value": "eyJhbGciOiJFUzI1NiIsImtpZCI6InBkcC1rZXkt..."
  }
}

Decision Evidence is durable and integrity-protected. It is the authoritative record of what the PDP evaluated, not proof that the action occurred.

6. Execution Evidence Object

The PEP or executor emits an Execution Evidence Object after the authorized action's outcome is determined. It records whether the permitted action was attempted, completed, failed, or suppressed, linked to the Decision Evidence by decision_id.

6.1. Members

execution_id:

REQUIRED. A string. unique execution identifier. ABNF: 1*64( ALPHA / DIGIT / "-" / "_" ). At least 128 bits of entropy.

decision_id:

REQUIRED. A string. the linked Decision Evidence.

mission_id:

REQUIRED. A string. the Mission id, mirrored from the linked Decision Evidence for join-key convenience.

parameter_digest:

CONDITIONAL. A string. MUST be present when the linked Decision Evidence carries one, and MUST match it.

outcome:

REQUIRED. A string. one of attempted, completed, failed, or suppressed. suppressed means the action was permitted but the executor chose not to attempt it (for example, a kill-switch or a secondary deny).

outcome_at:

REQUIRED. An RFC 3339 [RFC3339] timestamp.

error:

CONDITIONAL. A string. error identifier when outcome is failed.

attempted_at:

OPTIONAL. An RFC 3339 timestamp. timing context.

completed_at:

OPTIONAL. An RFC 3339 timestamp. timing context.

result_summary:

OPTIONAL. An object. minimal action result metadata (for example, affected resource counts). MUST NOT carry user-content payloads.

evidence_envelope:

REQUIRED. An object. integrity protection in the same form as Decision Evidence (Section 5.2), carrying a format (string, required) and a value (string, required).

An Execution Evidence Object is a closed object: it MUST NOT contain members other than those defined above.

6.2. Worked example

{
  "execution_id": "exe_4r9SqLm8tY2pXkV3nR0eF7jB1zN6cQ5w",
  "decision_id":  "dec_8K2nP4qV9rL3tY6sB1zN0eF7jB",
  "mission_id":   "msn_8RfX2Lqv9TqMv4z7sA2bN1k0YpEd",
  "parameter_digest":
    "sha-256:t2Wq9pK7sR3mL6xT4bN1eY8jC5vH0nF2pV9zKqA",
  "outcome":      "completed",
  "attempted_at": "2026-11-02T08:14:04Z",
  "completed_at": "2026-11-02T08:14:05Z",
  "outcome_at":   "2026-11-02T08:14:05Z",
  "result_summary": {
    "rows_affected": 1
  },
  "evidence_envelope": {
    "format": "jws-compact",
    "value": "eyJhbGciOiJFUzI1NiIsImtpZCI6InBlcC1rZXkt..."
  }
}

Decision Evidence and Execution Evidence are linked but distinct. Authorization is not proof that an action occurred; a Decision Evidence record with no corresponding Execution Evidence record indicates the action was not attempted, or that the executor failed to emit evidence.

6.3. TOCTOU and parameter binding

The semantics of parameter binding and the time-of-check to time-of-use gap are defined by the runtime profile (Section 7 of [I-D.draft-mcguinness-oauth-mission-runtime]). In this binding, the parameter_digest chain runs from the PDP request through Decision Evidence to Execution Evidence: if the executed action's effective parameters differ from those the PDP evaluated, the digest mismatch is detectable in audit.

The PEP MUST refuse to emit Execution Evidence with a parameter_digest that does not match the linked Decision Evidence. When the values nonetheless diverge across the chain, the audit consumer MUST classify the action as parameter-mismatch and treat it as equivalent to an unauthorized action for compliance purposes.

6.4. Retention

Decision Evidence and Execution Evidence MUST be retained for at least the deployment's audit retention window, which the runtime profile requires to be no shorter than the Mission's effective audit horizon (Section 10 of [I-D.draft-mcguinness-oauth-mission-runtime]). Regulated deployments MAY require longer retention.

7. Runtime Denial Classification

When the PDP denies a consequential action, the failure condition is one defined by the runtime profile (Section 9 of [I-D.draft-mcguinness-oauth-mission-runtime]). This section binds those conditions to AuthZEN responses and gives the denial-reason identifiers carried in Decision Evidence:

A deny is terminal for the attempted action; Mission expansion and the authority-expandable-denial workflow are out of scope (Section 6 of [I-D.draft-mcguinness-oauth-mission-runtime]).

7.1. Insufficient Claims composition

For an acr_insufficient or amr_insufficient denial, the PDP MAY signal which authenticated claims would lift the denial, so the caller can satisfy the Mission's acr or amr constraint through OAuth step-up authentication challenge [RFC9470] at the protected resource and re-authenticate without a Mission expansion.

7.2. Error response shape

The PDP returns its decision and any denial reason in the AuthZEN response [AUTHZEN]. A deployment MAY additionally carry [RFC9457] problem details for structured error information when the PDP is consumed over HTTP outside the AuthZEN envelope.

8. Capability Source Binding

Consequential actions an agent discovers at runtime -- through a Model Context Protocol tool catalog, an OpenAPI document, a Protected Resource Metadata-linked catalog, or an equivalent capability source -- identify the source they came from, so a Mission's approved authority stays bound to concrete tools rather than to bare action names a later catalog revision could redefine. The runtime profile assigns capability identity to the approved actions and refuses an invoked identity outside them (Section 6 of [I-D.draft-mcguinness-oauth-mission-runtime]); this section gives the concrete binding an AuthZEN deployment presents for catalog-sourced actions.

The minimum binding, committed by the validating server at derivation and presented by the executing component at request time, is:

{
  "tool_id": "mcp://docs.example.com/tools/write_document",
  "source_uri": "https://docs.example.com/.well-known/mcp",
  "source_digest": "sha-256:Qm0a...base64url-no-pad",
  "operation_ref": "tools/write_document"
}
tool_id:

A string. a stable capability identifier the executing component asserts the action invokes.

source_uri:

A string. the discovery source the capability was resolved from.

source_digest:

A string. the integrity-anchor encoded form ([I-D.draft-mcguinness-oauth-mission]) over the exact retrieved source representation, recorded at derivation time.

operation_ref:

A string. the source-format-specific operation reference (MCP tool name, OpenAPI operationId, or equivalent).

Rules:

Cross-format canonicalization, signed capability manifests, and media-type negotiation across catalog formats are out of scope (Section 12 of [I-D.draft-mcguinness-oauth-mission-runtime]); this binding requires only the stable identifier plus source evidence above.

9. AuthZEN binding of consumption metering

The runtime profile owns consumption-metering semantics: it meters the Mission's max_budget, max_calls, and max_duration bounds, defines the atomic check-and-decrement, the single-versus-distributed-PDP consistency posture, retry and idempotency behavior, and the rule that an unmetered or unrecognized bound MUST cause refusal (Section 8 of [I-D.draft-mcguinness-oauth-mission-runtime]). This section adds only the AuthZEN wire representation; it defines no new metering semantics and no new constraint.

A deployment that meters a per-action invocation cap evaluates the cap as part of the decision. When metering the cap would exceed it, the PDP MUST deny with quota_exceeded (Section 7) instead of returning a permit, and MUST record quota_exceeded as the denial_reason in Decision Evidence. Because the runtime profile counts a metered permit at decision time, the AuthZEN response surfaces the cap purely as the permit-or-quota_exceeded outcome; a permitted-but-failed action still counted, consistent with the runtime profile's metering rules. The exactness of the cap is the consistency bound the runtime profile's topology rules establish, not a property of this wire binding.

10. Mission Status Composition

The PDP relies on Mission state to decide. The runtime profile defines the Mission state source, the maximum staleness bound, and the fail-closed rule (Section 6.1 of [I-D.draft-mcguinness-oauth-mission-runtime]). This binding conveys that state and its freshness on the wire through context.mission.state and context.freshness (Section 4), using a mode member with one of three values that describe how the PEP obtained the state:

When freshness cannot be established within the bound, the PDP fails closed for consequential actions as the runtime profile requires; in this binding that surfaces as a stale_state denial (Section 7).

11. Security Considerations

The runtime profile's Security Considerations (Section 13 of [I-D.draft-mcguinness-oauth-mission-runtime]) apply in full: placement and bypass, classification integrity, freshness and consumption honesty, Resource policy authority, TOCTOU and replay, and the limits of a compromised PEP or PDP. This section addresses only threats specific to the AuthZEN binding and the evidence objects.

11.1. Decision Evidence versus Execution Evidence

Decision Evidence is not proof an action occurred. Implementations MUST emit Execution Evidence to record outcomes, and auditors MUST NOT treat Decision Evidence alone as evidence of action. An audit consumer MUST classify orphaned Decision Evidence (no matching Execution Evidence within the deployment's reconciliation window) as undetermined-outcome or, per deployment policy, as action-attempted; it MUST NOT treat it as proof of action.

11.2. Evidence integrity and PDP signing keys

The evidence_envelope binds each record to the emitting PDP or PEP. The PDP's jws-compact signing key MUST be resolvable in the PDP's published JWKS so a verifier can check Decision Evidence independently. Implementations MUST reject evidence whose format is unregistered rather than accepting it unverified.

11.3. Materialized view fidelity

A PDP that evaluates against a materialized view enlarging the Authority Set's bounds violates the bounded property of Section 3. authority_hash is the upper bound; policy_view_id lets the PDP detect that the view it loaded does not match the Mission the PEP referenced and deny with stale_state.

11.4. Transport

The PDP endpoint and the audit channels carrying Decision Evidence and Execution Evidence MUST be served over TLS 1.2 or later (TLS 1.3 RECOMMENDED). PEP-to-PDP authentication MUST be mutual, satisfying the integrity and mutual-authentication requirement the runtime profile places on the PEP-PDP channel (Section 5 of [I-D.draft-mcguinness-oauth-mission-runtime]). Evidence at rest MUST be encrypted per the deployment's data-protection posture.

12. Privacy Considerations

The runtime profile's evidence-privacy guidance (Section 13 of [I-D.draft-mcguinness-oauth-mission-runtime]) applies in full. This section addresses the concrete evidence objects.

12.1. Evidence as PII sinks

Decision Evidence and Execution Evidence carry the authenticated subject, actor chain, resource and action identifiers, parameter_digest, and timing. These records are PII sinks and SHOULD be access-controlled to audit consumers with a legitimate need, encrypted at rest, and retained per the window of Section 6.

12.2. Parameter exposure

The durable Decision Evidence record MUST NOT contain the raw parameters object; it carries only parameter_digest and, at most, parameter-class metadata, consistent with the runtime profile's rule that raw parameters never appear in the record. Where raw parameters must be retained for audit, they are held in a separately access-controlled store keyed by decision_id. When the parameters are themselves PII, the PEP SHOULD supply only context.parameter_digest to the PDP, omitting context.parameters, so the PDP evaluates against parameter-class policy without observing the raw values. The Execution Evidence result_summary MUST NOT carry user-content payloads.

12.3. Actor chain and Mission correlation

The actor member carries the delegation chain, which MAY reveal service accounts, client instances, and organizational structure. Evidence carrying the same Mission id and authority_hash across resource boundaries can correlate a subject's activity; this is inherent to the Mission's role as a governance handle. Deployments that require unlinkability need an additional privacy design outside this profile.

13. IANA Considerations

This document requests the following IANA actions.

13.1. Media Type Registry

This document registers two media types per [RFC6838].

13.1.1. application/mission-decision-evidence+json

  • Type name: application

  • Subtype name: mission-decision-evidence+json

  • Required parameters: none

  • Optional parameters: none

  • Encoding considerations: UTF-8 JSON

  • Security considerations: see Section 11

  • Interoperability considerations: see this document

  • Published specification: this document

  • Applications that use this media type: Mission-bound runtime enforcement deployments

  • Person & email address to contact for further information: Karl McGuinness public@karlmcguinness.com

  • Intended usage: COMMON

  • Author/Change controller: IETF

13.1.2. application/mission-execution-evidence+json

Registration fields are identical to the Decision Evidence media type except the subtype name is mission-execution-evidence+json.

The non-normative context.mission, context.actor, context.parameters, context.parameter_digest, context.audience, and context.freshness members carried inside the AuthZEN context object (Section 4) are AuthZEN extension data and are not registered in an IETF registry. The Mission-bound token claims this profile consumes are registered by [I-D.draft-mcguinness-oauth-mission].

14. References

14.1. Normative References

[AUTHZEN]
OpenID Foundation, "OpenID AuthZEN Authorization API 1.0", , <https://openid.net/specs/authorization-api-1_0-final.html>.
[I-D.draft-mcguinness-oauth-mission]
McGuinness, K., "Mission-Bound Authorization for OAuth 2.0", Work in Progress, Internet-Draft, draft-mcguinness-oauth-mission, , <https://datatracker.ietf.org/doc/html/draft-mcguinness-oauth-mission>.
[I-D.draft-mcguinness-oauth-mission-runtime]
McGuinness, K., "Mission-Bound Runtime Enforcement for OAuth 2.0", Work in Progress, Internet-Draft, draft-mcguinness-oauth-mission-runtime, , <https://datatracker.ietf.org/doc/html/draft-mcguinness-oauth-mission-runtime>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3339]
Klyne, G. and C. Newman, "Date and Time on the Internet: Timestamps", RFC 3339, DOI 10.17487/RFC3339, , <https://www.rfc-editor.org/rfc/rfc3339>.
[RFC6234]
Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms (SHA and SHA-based HMAC and HKDF)", RFC 6234, DOI 10.17487/RFC6234, , <https://www.rfc-editor.org/rfc/rfc6234>.
[RFC6838]
Freed, N., Klensin, J., and T. Hansen, "Media Type Specifications and Registration Procedures", BCP 13, RFC 6838, DOI 10.17487/RFC6838, , <https://www.rfc-editor.org/rfc/rfc6838>.
[RFC7515]
Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, , <https://www.rfc-editor.org/rfc/rfc7515>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8259]
Bray, T., Ed., "The JavaScript Object Notation (JSON) Data Interchange Format", STD 90, RFC 8259, DOI 10.17487/RFC8259, , <https://www.rfc-editor.org/rfc/rfc8259>.
[RFC8785]
Rundgren, A., Jordan, B., and S. Erdtman, "JSON Canonicalization Scheme (JCS)", RFC 8785, DOI 10.17487/RFC8785, , <https://www.rfc-editor.org/rfc/rfc8785>.

14.2. Informative References

[RFC9457]
Nottingham, M., Wilde, E., and S. Dalal, "Problem Details for HTTP APIs", RFC 9457, DOI 10.17487/RFC9457, , <https://www.rfc-editor.org/rfc/rfc9457>.
[RFC9470]
Bertocci, V. and B. Campbell, "OAuth 2.0 Step Up Authentication Challenge Protocol", RFC 9470, DOI 10.17487/RFC9470, , <https://www.rfc-editor.org/rfc/rfc9470>.

Acknowledgments

This document is the AuthZEN binding of Mission-Bound Runtime Enforcement for OAuth 2.0 and builds on the OpenID AuthZEN Authorization API. The author thanks the OpenID AuthZEN community and the Mission-Bound Authorization implementer community for feedback.

Author's Address

Karl McGuinness
Independent