Mission Consent Evidence for OAuth 2.0

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 26 December 2026.¶

Copyright Notice

Copyright (c) 2026 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

The issuance profile [I-D.draft-mcguinness-oauth-mission] binds a Mission to an approval event and commits two objects: the approved Mission Intent and the approved Authority Set. It deliberately notes a remaining gap: the exact consent disclosure rendered to the Approver is not itself committed. A faulty or malicious rendering layer could show a narrower task than the Authority Set actually records.¶

This document narrows that gap. It defines a structured consent disclosure object and a Consent Evidence object. The disclosure object is what the Authorization Server renders or commits to rendering. The evidence object records the approval event, the rendering context, the Mission anchors, and an integrity envelope over the evidence.¶

This profile commits the structured disclosure that the Authorization Server says it rendered, and binds it to the same Mission anchors used for authority. It does not, and cannot, prove that the pixels actually presented to the Approver matched that structured object, that the Approver read or understood it, or that the rendering layer was honest. A faulty or malicious rendering layer that lies about what it displayed remains outside the reach of any server-side commitment. What this profile provides is a durable, integrity-protected record that ties a specific structured disclosure to a specific approval decision and Authority Set, so that divergence between the recorded disclosure and the enforced authority becomes detectable in audit.¶

Consent Evidence does not grant authority. Authority remains the approved Mission and its Authority Set under [I-D.draft-mcguinness-oauth-mission]. Consent Evidence lets auditors verify that the recorded approval surface corresponded to the authority later enforced.¶

2. Scope

This document defines:¶

• the consent disclosure object (Section 4);¶

• the consent_rendering_hash commitment (Section 5);¶

• the Consent Evidence object (Section 6);¶

• binding rules for initial Mission approval and expansion approval (Section 7);¶

• retention and audit reconstruction requirements (Section 8); and¶

• conformance for a Consent-Evidence-capable Mission Issuer (Section 9).¶

This document does not define user-interface layout, a legal consent standard, or any new OAuth grant. It does not change the Authority Set or Mission lifecycle.¶

3. Conventions and Terminology

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.¶

This document uses JSON [RFC8259] for the disclosure and evidence objects. JCS [RFC8785] is used when computing consent_rendering_hash.¶

The terms Mission, Mission Intent, Authority Set, Mission Issuer, Approver, and approval event are used as defined in [I-D.draft-mcguinness-oauth-mission].¶

Consent Disclosure:

A structured object describing the approval surface rendered to the Approver.¶

Consent Evidence:

A durable, integrity-protected record of the consent disclosure and approval event.¶

4. Consent Disclosure Object

A Consent Disclosure object has these members:¶

disclosure_id:

REQUIRED. A string. Unique identifier for this rendered disclosure.¶

template_id:

REQUIRED. A string identifying the disclosure template.¶

template_version:

REQUIRED. A string identifying the template version.¶

locale:

REQUIRED. A string identifying the locale used for presentation.¶

mission_summary:

REQUIRED. An object. The human-readable task summary presented to the Approver.¶

authority_summary:

REQUIRED. An object. The rendered summary of resources, actions, constraints, delegation, expiry, and material consumption bounds.¶

material_notices:

REQUIRED. An array. Notices that materially affect the Approver's decision, such as irreversible actions, external commitments, privileged administration, cross-domain disclosure, broad reads, or delegation.¶

risk_summary:

REQUIRED. An object summarizing action classes and risk dimensions presented to the Approver. It MUST identify at least irreversible actions, external commitments, privileged administration, broad or bulk reads, cross-domain disclosure, delegation, and consumption bounds when present.¶

delegation_summary:

REQUIRED when the Authority Set permits delegation. An object describing who may receive delegated authority, maximum depth, and whether child Missions or further delegation are permitted.¶

runtime_summary:

OPTIONAL. An object describing runtime enforcement expectations shown to the Approver, such as per-action checks, status freshness, audit evidence, or human-review steps.¶

subject:

REQUIRED when the Approver is not the Subject. The rendered identification of the Subject on whose behalf authority is granted.¶

approver:

REQUIRED. The rendered identity of the Approver.¶

source_hashes:

REQUIRED. An object containing the intent_hash and authority_hash values the disclosure corresponds to. The disclosure object carries these two hashes rather than the full mission container (Section 6) because it is constructed before approval commits the Mission: the Mission id and lifecycle do not yet exist, and the disclosure must commit only to the proposed Intent and Authority Set it actually renders. The Consent Evidence object, recorded at or after the decision, carries the resolved mission container with id, origin, and the same anchors.¶

shaping_evidence_hash:

OPTIONAL. A string. A commitment to Shaping Evidence when shaping was used ([I-D.draft-mcguinness-oauth-mission-shaping]).¶

predecessor:

OPTIONAL. A string. The predecessor Mission identifier when this disclosure is for an expansion approval ([I-D.draft-mcguinness-oauth-mission-expansion]).¶

display_context:

REQUIRED. An object containing presentation context, including at least channel (for example, web, device, api, or admin_console) and rendered_at.¶

approver_actions:

OPTIONAL. An array describing explicit approver interactions required by policy, such as checking a high-risk notice or confirming an expansion delta.¶

A Consent Disclosure object MUST NOT omit material authority. If the Authority Set includes delegation, external commitments, irreversible actions, privileged administration, cross-domain authority, or consumption bounds, the disclosure MUST include a material notice or a rendered authority summary entry covering that fact.¶

5. consent_rendering_hash

consent_rendering_hash is the integrity-anchor encoded form of the SHA-256 [RFC6234] of the JCS [RFC8785] canonical bytes of this envelope:¶

{
  "typ": "mission-consent-disclosure",
  "iss": <mission.origin>,
  "value": <Consent Disclosure object>
}

The value uses the same algorithm-agile integrity-anchor encoding the issuance profile [I-D.draft-mcguinness-oauth-mission] defines for intent_hash and authority_hash: a collision-resistant hash-name prefix and the base64url digest, for example sha-256:.... A consumer MUST treat the prefix as identifying the hash function and MUST NOT assume SHA-256; this lets the commitment migrate to a stronger function without ambiguity.¶

The hash commits the disclosure object, not pixels or browser state. A deployment MAY additionally retain screenshots or UI telemetry, but the interoperable commitment is the structured disclosure object.¶

The Mission Issuer SHOULD record consent_rendering_hash on the Mission record. When the Mission claim is extended to carry the value, it MUST carry the same prefixed integrity-anchor form, and consumers MUST treat it as audit data only; it MUST NOT grant or widen authority.¶

The Consent Disclosure object MUST be constructed after Authority Set derivation and before approval. If the Authority Set changes after the disclosure is constructed, the Mission Issuer MUST discard the disclosure and construct a new one; it MUST NOT reuse the prior consent_rendering_hash.¶

6. Consent Evidence Object

A Consent Evidence object has these members:¶

evidence_id:

REQUIRED. A string. Unique evidence identifier.¶

mission:

REQUIRED. An object binding the evidence to what was approved. Its shape depends on decision, because a Mission exists only after an approval ([I-D.draft-mcguinness-oauth-mission]): - When decision is approved, it contains id, origin, intent_hash, authority_hash, and, when this profile records it on the Mission, consent_rendering_hash. - When decision is declined, no Mission was created (Section 7.1), so there is no id. It instead contains origin and the intent_hash and authority_hash the disclosure corresponded to, matching the disclosure object's source_hashes (Section 4). It MUST NOT contain id.¶

This descriptor follows the evidence-descriptor convention of the issuance profile ([I-D.draft-mcguinness-oauth-mission]): it is the mission claim shape extended with the collision-resistantly named audit members intent_hash and consent_rendering_hash, and it is not authority-bearing on its own.¶

approver:

REQUIRED. An object identifying the authenticated Approver.¶

subject:

REQUIRED when different from the Approver. An object identifying the Subject.¶

client:

REQUIRED when known. An object identifying the client or agent requesting the Mission.¶

authentication_context:

REQUIRED. An object recording the acr, amr, and authentication time used for the approval event when available.¶

disclosure:

REQUIRED. The Consent Disclosure object, or an object containing a durable reference and the consent_rendering_hash.¶

approved_at:

REQUIRED when decision is approved. An RFC 3339 [RFC3339] timestamp.¶

declined_at:

REQUIRED when decision is declined. An RFC 3339 timestamp.¶

decision:

REQUIRED. One of approved or declined.¶

decline_reason:

OPTIONAL. A string. Present when decision is declined and the deployment records a reason.¶

policy_version:

REQUIRED when known. The approval policy version in effect at the approval event.¶

sequence:

REQUIRED. An integer. A per-Mission-Issuer consent evidence sequence value or another deployment-defined monotonic indicator sufficient to reconstruct evidence order.¶

evidence_envelope:

REQUIRED when retained as a portable record. An object carrying format and value. This document defines jws-compact, a JWS Compact Serialization [RFC7515] over the JCS canonical bytes of the Consent Evidence object with evidence_envelope removed.¶

Example:¶

{
  "evidence_id": "cns_7rP2kL9mQ4",
  "mission": {
    "id": "msn_8RfX2Lqv9TqMv4z7sA2bN1k0YpEdHc9-",
    "origin": "https://as.example.com",
    "intent_hash": "sha-256:wQ7p4LHnX9Md0LqJ6sZJ8b8mZ3rN2xT5pV4lE6sQqYY",
    "authority_hash": "sha-256:l3KvZ4mP5x0wQrR6tY2nD9bM7sX1cF8gH2vJ4kE5pNQ",
    "consent_rendering_hash":
      "sha-256:CnS3nT9sQ7nM2vL4tY6bD1eF8jC5wH0pV2nR3kQ4xVz"
  },
  "approver": {
    "iss": "https://idp.example.com",
    "sub": "alice"
  },
  "authentication_context": {
    "acr": "urn:example:acr:phishing-resistant",
    "amr": ["pwd", "hwk"],
    "auth_time": "2026-06-30T17:54:00Z"
  },
  "approved_at": "2026-06-30T17:55:00Z",
  "decision": "approved",
  "policy_version": "approval-policy:v12",
  "sequence": 88127,
  "disclosure": {
    "disclosure_id": "disc_4pQ9z",
    "consent_rendering_hash":
      "sha-256:CnS3nT9sQ7nM2vL4tY6bD1eF8jC5wH0pV2nR3kQ4xVz"
  },
  "evidence_envelope": {
    "format": "jws-compact",
    "value": "eyJhbGciOiJFUzI1NiIsImtpZCI6ImNvbnNlbnQt..."
  }
}

7. Binding to Mission Approval

At an approval event, a Consent-Evidence-capable Mission Issuer MUST:¶

1. derive the Authority Set and compute intent_hash and authority_hash under [I-D.draft-mcguinness-oauth-mission];¶

2. construct the Consent Disclosure object from that exact Authority Set and Mission Intent;¶

3. compute consent_rendering_hash;¶

4. render the disclosure to the Approver;¶

5. record Consent Evidence for approved or declined; and¶

6. when approved, bind the Mission record to the consent_rendering_hash.¶

For expansion approvals, the disclosure MUST identify the predecessor Mission and distinguish retained authority from newly requested authority.¶

8. Audit Reconstruction

A deployment claiming this profile MUST retain enough information for an authorized auditor to reconstruct:¶

• the Mission Intent and Authority Set approved;¶

• the Consent Disclosure object;¶

• the template, template version, and locale;¶

• the material notices presented;¶

• the Approver, Subject, and approval authentication context; and¶

• the integrity path from Consent Evidence to the Mission record.¶

Retention MUST last at least as long as the Mission's audit horizon.¶

9. Conformance

A conforming Consent-Evidence-capable Mission Issuer MUST:¶

• construct a Consent Disclosure object for each approval event;¶

• compute consent_rendering_hash;¶

• record Consent Evidence for approval and decline decisions;¶

• bind approved Mission records to consent_rendering_hash;¶

• include material notices for high-risk authority; and¶

• retain evidence for audit reconstruction.¶

A conforming verifier of Consent Evidence MUST implement the checks in Section 6.1 and MUST treat failure to retrieve a referenced disclosure during the retention window as an audit failure.¶

10. Security Considerations

11. Privacy Considerations

Consent Evidence can contain sensitive task descriptions, business context, approver identity, subject identity, and high-risk authority details. Deployments SHOULD protect it at least as strongly as Mission records and runtime evidence. Where possible, portable records SHOULD carry hashes or references rather than full rendered text, while still allowing authorized audit reconstruction.¶

12. IANA Considerations

This document makes no IANA request.¶

Future versions may request registration for application/mission-consent-evidence+json if portable exchange of Consent Evidence becomes an interoperability requirement. Until such a registration exists, deployments using this media type do so by local agreement.¶

13. References

Acknowledgments

This document is part of the Mission-Bound Authorization for OAuth 2.0 set and binds the approval surface to the Mission authority record.¶

Author's Address