fix: exclude correlation fields from the flex-auth request digest
All checks were successful
CI Smoke / host-smoke (push) Successful in 0s
CI Smoke / container-smoke (push) Successful in 2s

Verified the digest join against flex-auth's T03 replay fixtures and found
request_digest was hashing fields docs/canonical-request-digest.md excludes.
The material is tenant, subject, action, resource, context only: id is
correlation, policy_version lives in provenance, caring_context is hashed
separately. This engine included all three when present.

Because the join adopts the served request id, every real production request
would have carried one, so the computed digest would have matched no issued
decision and failed closed against every correct allow. Same unsatisfiable
shape as the removed AUTHORITY constant.

The old pinned constant was computed with the id inside the material, so it
was wrong and its passing proved nothing. Replaced with fixture-driven tests
over two real envelopes (vendored with provenance) plus a structural test
that correlation fields do not move the digest. Both fixtures are needed:
input_claim_digests.context appears only with a non-empty context.

Also stops computing the native claim digest. The claim's binding.action and
binding.target speak approval-engine's vocabulary while ours speaks the
catalog's, and no mapping is published; flex-auth makes no cross-check and
states the correspondence is ours via pdp_digest. A claim recording no
pdp_digest now fails closed naming the missing mapping rather than comparing
two different languages. That mapping is a prerequisite for destroy.

274 tests pass. Production still fails closed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M65ovP3eiiPHubibvWs9mD

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 393550@bnt-lap001
Assistant-Session: 4bb359f9-1f12-4410-9e76-079cf23c82e4
This commit is contained in:
tegwick 2026-09-06 14:17:38 +02:00
parent 083bee7333
commit 6e9c15228c
11 changed files with 562 additions and 24 deletions

View file

@ -43,9 +43,28 @@ never compared to each other:
of `{action, actor, principal, purpose, target}`.
- `decision.binding.request_digest` — flex-auth canonical CheckRequest digest.
When the issuer recorded `claim.binding.pdp_digest`, that comparison is
preferred. The CheckRequest mapping onto the claim binding is published in
`approval-engine/docs/approval-claim.md`.
`claim.binding.pdp_digest` is the **only** comparison usable today, and its
absence fails the action closed. The claim's `binding.action` and
`binding.target` speak approval-engine's vocabulary (`secrets.kv.destroy`,
`{"id": ..., "stage": ...}`) while ours speaks the catalog's (`destroy`,
`catalog:<id>`), and no mapping between them is published. flex-auth makes no
cross-check either and states the correspondence is ours. Computing a native
digest from our own vocabulary would compare two different languages and never
match, so this engine does not compute one. Closing that gap needs a published
mapping co-authored by approval-engine and flex-auth; it is a prerequisite for
`SECRETS-WP-0007-T04` making `destroy` reachable.
### What is hashed in the flex-auth digest
`tenant`, `subject`, `action`, `resource`, `context` — and nothing else.
`id` is correlation only, `policy_version` lives in provenance, and
`caring_context` is hashed separately. Including any of them yields a digest
that matches no issued decision. `digest_material` enforces the exclusion and
`tests/test_decision_replay.py` pins it against two real envelopes.
A consumer re-hashing the *original unenriched* request will not match a
decision that turned on registry attributes: the binding is the evaluator's
statement of what it hashed, so recompute from the binding tuple.
The approval-engine object id is never inferred from a State Hub decision UUID.
It comes from catalog `approval.authorization_id`, and is the value in the

View file

@ -144,8 +144,18 @@ def validate_approval_claim(
raise DecisionError("approval claim binding must be an object")
native = str(binding.get("digest", "") or "")
pdp = str(binding.get("pdp_digest", "") or "")
# Prefer the PDP digest when the issuer recorded one at issue time.
if expected_pdp_digest and pdp:
# Prefer the PDP digest: it is expressed in flex-auth's vocabulary, which is
# the one the caller actually proposed. The native digest is over
# approval-engine's own vocabulary and is only comparable when the caller
# supplies a binding built in that vocabulary (see the note in
# resolve_consume_binding about the missing mapping).
if expected_pdp_digest:
if not pdp:
raise DecisionError(
"approval claim records no pdp_digest, and no published mapping "
"exists between approval-engine and secrets-engine action/target "
"vocabularies; the claim cannot be tied to this exact action"
)
if pdp != expected_pdp_digest:
raise DecisionError("approval claim pdp digest does not match the request")
elif expected_binding_digest:

View file

@ -18,11 +18,7 @@ from typing import Any, Callable
from urllib.error import HTTPError, URLError
from urllib.request import Request, urlopen
from secrets_engine.approval_claim import (
binding_from_check_request,
claim_binding_digest,
validate_approval_claim,
)
from secrets_engine.approval_claim import validate_approval_claim
from secrets_engine.authorization import build_action_request, request_digest
from secrets_engine.errors import DecisionError
from secrets_engine.openbao import read_strict_token_file
@ -193,10 +189,19 @@ def resolve_consume_binding(
policy_targets=policy_targets,
auth_targets=auth_targets,
)
# Two different digests over the same proposed action, by contract: the
# approval-engine native binding digest, and the flex-auth CheckRequest
# digest. They are not interchangeable and are never compared to each other.
native_digest = claim_binding_digest(**binding_from_check_request(expected_request))
# Two different digests over the same proposed action, by contract; they are
# never compared to each other.
#
# Only the PDP digest is usable for the action/target correspondence today.
# The claim's binding.action and binding.target speak approval-engine's
# vocabulary ("secrets.kv.destroy", {"id": ..., "stage": ...}) while ours
# speaks the catalog's ("destroy", "catalog:<id>"), and no mapping between
# them is published. flex-auth makes no cross-check either and states the
# correspondence is ours, via pdp_digest. Computing a native digest from our
# own vocabulary would compare two different languages and never match --
# the same unsatisfiable-rule defect flex-auth fixed in 68ad039 -- so we do
# not compute one, and validate_approval_claim fails closed with a named
# reason when the issuer recorded no pdp_digest.
pdp_digest = request_digest(expected_request)
claim = fetch_approval_claim(
@ -208,7 +213,6 @@ def resolve_consume_binding(
validate_approval_claim(
claim,
approval_id=authorization_id,
expected_binding_digest=native_digest,
expected_pdp_digest=pdp_digest,
)
binding = claim.get("binding") or {}

View file

@ -156,8 +156,26 @@ def canonical_check_request(request: object) -> dict[str, Any]:
return canonical
def request_digest(request: object) -> str:
#: Correlation-only or separately-hashed fields, excluded from the digest
#: material by docs/canonical-request-digest.md "What is hashed".
_UNHASHED_FIELDS = ("id", "policy_version", "caring_context")
def digest_material(request: object) -> dict[str, Any]:
"""The exact tuple flex-auth hashes: tenant, subject, action, resource, context.
``id`` is correlation only, ``policy_version`` is recorded in provenance, and
``caring_context`` is hashed separately as
``provenance.input_claim_digests.caring_context``. Including any of them
produces a digest that matches no real DecisionEnvelope, which fails closed
against every correctly issued decision.
"""
canonical = canonical_check_request(request)
return {k: v for k, v in canonical.items() if k not in _UNHASHED_FIELDS}
def request_digest(request: object) -> str:
canonical = digest_material(request)
encoded = json.dumps(
canonical, ensure_ascii=False, separators=(",", ":")
).encode("utf-8")

View file

@ -0,0 +1,17 @@
# flex-auth T03 replay fixtures
Copied verbatim from `flex-auth/examples/secrets-engine/replay/` (commit
`9e10d1c`, `FLEX-WP-0021-T03`). Real `DecisionEnvelope`s emitted by the
published `secrets-engine.catalog-lane.lifecycle` v1 package via
`go run ./cmd/flex-auth check`, from `flex-auth/local` in `standalone` mode.
Vendored so the digest contract test is hermetic. Regenerate upstream and
re-copy if the contract version changes.
**Pinned here** (stable across runs, per the upstream README):
`binding.request_digest`, `provenance.policy_package_digest`,
`provenance.registry_snapshot_digest`, and the presence/absence of
`provenance.input_claim_digests.context`.
**Never pin:** `id`, `provenance.decision_time`, `lifetime.not_before`,
`lifetime.expires_at` — all move with the clock.

View file

@ -0,0 +1,121 @@
{
"id": "decision:669a12badaa3d82e",
"contract_version": "flex-auth.decision-record.v1",
"request_id": "check:secrets-engine-destroy",
"effect": "allow",
"reason": "catalog_lane_policy_matched",
"matched_policy_version": "v1",
"matched_rule": "catalog_lane_policy_matched",
"resource": {
"id": "lane:glas-primary",
"type": "secret-catalog-lane",
"system": "secrets-engine",
"tenant": "tenant:platform",
"attributes": {
"auth_targets": [],
"fields": [],
"policy_targets": [],
"stage": "prod"
}
},
"subject": {
"id": "secrets-engine",
"type": "service",
"tenant": "tenant:platform",
"attributes": {
"description": "secrets-engine's own service identity, the single calling identity for the twelve gated catalog-lane actions it sends to POST /v1/check. Because it is the only subject, the package has no action_not_granted branch (FLEX-WP-0021-T02); registering a second identity is the revisit trigger.",
"display_name": "secrets-engine service principal",
"groups": [
"group:secrets-engine-lane-operators"
],
"organization_relation": "ServiceProvider",
"roles": [
"Operator"
]
}
},
"binding": {
"tenant": "tenant:platform",
"subject": {
"id": "secrets-engine",
"type": "service",
"tenant": "tenant:platform",
"attributes": {
"description": "secrets-engine's own service identity, the single calling identity for the twelve gated catalog-lane actions it sends to POST /v1/check. Because it is the only subject, the package has no action_not_granted branch (FLEX-WP-0021-T02); registering a second identity is the revisit trigger.",
"display_name": "secrets-engine service principal",
"groups": [
"group:secrets-engine-lane-operators"
],
"organization_relation": "ServiceProvider",
"roles": [
"Operator"
]
}
},
"action": "destroy",
"resource": {
"id": "lane:glas-primary",
"type": "secret-catalog-lane",
"system": "secrets-engine",
"tenant": "tenant:platform",
"attributes": {
"auth_targets": [],
"fields": [],
"policy_targets": [],
"stage": "prod"
}
},
"context": {
"approval": {
"approval_id": "3d1c0a8e-6b7f-4c21-9a0e-1f2b3c4d5e6f",
"consumed": false,
"issuer": "approval-engine",
"kind": "approval-claim",
"reason_code": "ok",
"schema_version": "0.1",
"state": "valid",
"valid_now": true
}
},
"request_digest": "sha256:570d112890586d3cbf00c0e81c85ae7806f40f00afa1a2c0a23fd5e077a27f56"
},
"lifetime": {
"kind": "ttl",
"ttl": "15m",
"not_before": "2026-09-06T06:13:43Z",
"expires_at": "2026-09-06T06:28:43Z"
},
"diagnostics": {
"action": "destroy",
"matched_relationship": "",
"policy_package": "secrets-engine.catalog-lane.lifecycle",
"policy_status": "ready",
"registry_resource": false,
"registry_subject": true
},
"provenance": {
"evaluator": "flex-auth/local",
"mode": "standalone",
"policy_package": "secrets-engine.catalog-lane.lifecycle",
"policy_version": "v1",
"policy_package_digest": "sha256:fe0070b79f66442ae6c218697a49c470c6c8f670aa57a30c078a5284d097bd8c",
"registry_snapshot_digest": "sha256:f5a309bc0b36721fd6d9ad7f53eb21222162bc2eac62a0ab0802a9a1d51340bb",
"input_claim_digests": {
"context": "sha256:45fa9f41271c684f2c26570be11869a8eda28e7b3b25f11e01f9378b6f89fdc8"
},
"decision_time": "2026-09-06T06:13:43Z"
},
"caring": {
"profile": "caring-0.4.0-rc2",
"conformance_findings": [
{
"code": "CARING-DESCRIPTOR-MISSING",
"severity": "warning",
"message": "no CARING descriptor matched the request",
"fields": [
"caring_context"
]
}
]
}
}

View file

@ -0,0 +1,110 @@
{
"id": "decision:49309356905a2ad3",
"contract_version": "flex-auth.decision-record.v1",
"request_id": "check:secrets-engine-rotate",
"effect": "allow",
"reason": "catalog_lane_policy_matched",
"matched_policy_version": "v1",
"matched_rule": "catalog_lane_policy_matched",
"resource": {
"id": "lane:glas-primary",
"type": "secret-catalog-lane",
"system": "secrets-engine",
"tenant": "tenant:platform",
"attributes": {
"auth_targets": [],
"fields": [
"password"
],
"policy_targets": [],
"stage": "prod"
}
},
"subject": {
"id": "secrets-engine",
"type": "service",
"tenant": "tenant:platform",
"attributes": {
"description": "secrets-engine's own service identity, the single calling identity for the twelve gated catalog-lane actions it sends to POST /v1/check. Because it is the only subject, the package has no action_not_granted branch (FLEX-WP-0021-T02); registering a second identity is the revisit trigger.",
"display_name": "secrets-engine service principal",
"groups": [
"group:secrets-engine-lane-operators"
],
"organization_relation": "ServiceProvider",
"roles": [
"Operator"
]
}
},
"binding": {
"tenant": "tenant:platform",
"subject": {
"id": "secrets-engine",
"type": "service",
"tenant": "tenant:platform",
"attributes": {
"description": "secrets-engine's own service identity, the single calling identity for the twelve gated catalog-lane actions it sends to POST /v1/check. Because it is the only subject, the package has no action_not_granted branch (FLEX-WP-0021-T02); registering a second identity is the revisit trigger.",
"display_name": "secrets-engine service principal",
"groups": [
"group:secrets-engine-lane-operators"
],
"organization_relation": "ServiceProvider",
"roles": [
"Operator"
]
}
},
"action": "rotate",
"resource": {
"id": "lane:glas-primary",
"type": "secret-catalog-lane",
"system": "secrets-engine",
"tenant": "tenant:platform",
"attributes": {
"auth_targets": [],
"fields": [
"password"
],
"policy_targets": [],
"stage": "prod"
}
},
"request_digest": "sha256:de67324f54187055307a833235f83ced9fcd3a20952a27b3d19493ed39734345"
},
"lifetime": {
"kind": "ttl",
"ttl": "15m",
"not_before": "2026-09-06T06:13:21Z",
"expires_at": "2026-09-06T06:28:21Z"
},
"diagnostics": {
"action": "rotate",
"matched_relationship": "",
"policy_package": "secrets-engine.catalog-lane.lifecycle",
"policy_status": "ready",
"registry_resource": false,
"registry_subject": true
},
"provenance": {
"evaluator": "flex-auth/local",
"mode": "standalone",
"policy_package": "secrets-engine.catalog-lane.lifecycle",
"policy_version": "v1",
"policy_package_digest": "sha256:fe0070b79f66442ae6c218697a49c470c6c8f670aa57a30c078a5284d097bd8c",
"registry_snapshot_digest": "sha256:f5a309bc0b36721fd6d9ad7f53eb21222162bc2eac62a0ab0802a9a1d51340bb",
"decision_time": "2026-09-06T06:13:21Z"
},
"caring": {
"profile": "caring-0.4.0-rc2",
"conformance_findings": [
{
"code": "CARING-DESCRIPTOR-MISSING",
"severity": "warning",
"message": "no CARING descriptor matched the request",
"fields": [
"caring_context"
]
}
]
}
}

View file

@ -77,7 +77,15 @@ def _validate(envelope, expected=None):
)
def test_digest_matches_flex_auth_contract_example():
def test_digest_is_stable_and_ignores_correlation_fields():
"""The pinned digest contract now lives in tests/test_decision_replay.py.
That file verifies against two real DecisionEnvelopes issued by the
published package. The constant previously pinned here was computed with
the request `id` inside the hashed material, which
docs/canonical-request-digest.md excludes -- it matched no issued decision.
Kept here: the structural property, checked without a hand-maintained pin.
"""
request = {
"id": "check:secrets-engine-destroy-example",
"subject": {"id": "user:alice", "type": "Human"},
@ -95,12 +103,11 @@ def test_digest_matches_flex_auth_contract_example():
},
"context": {"purpose": "contract-test"},
}
# Generated independently with flex-auth's Go api.CheckRequest and
# encoding/json. The action_authorization.json example carried a stale
# digest when this consumer contract was implemented.
assert request_digest(request) == (
"sha256:73d5d7d5b3363f1a1db8f4c0e79c8f33dae5d77ffb97f21e449438bc0defa4c3"
)
baseline = request_digest(request)
assert baseline.startswith("sha256:") and len(baseline) == 71
assert request_digest({k: v for k, v in request.items() if k != "id"}) == baseline
assert request_digest({**request, "action": "deactivate"}) != baseline
def test_valid_allow_envelope_passes():
result = _validate(_envelope())

View file

@ -77,7 +77,14 @@ def _served(entry=None, action="deactivate", fields=("api_token",), **over):
"state": "valid",
"valid_now": True,
"consumed": False,
"binding": {**binding, "digest": claim_binding_digest(**binding)},
"binding": {
**binding,
"digest": claim_binding_digest(**binding),
# The issuer recorded the PDP digest at issue time. That is the only
# comparison usable today: the native digest speaks
# approval-engine's vocabulary and no mapping to ours is published.
"pdp_digest": request_digest(request),
},
"freshness": {
"observed_at": now.strftime("%Y-%m-%dT%H:%M:%SZ"),
"ttl_seconds": 30,
@ -182,3 +189,25 @@ def test_unreachable_approval_engine_fails_closed(tmp_path):
def test_superseded_claim_fails_closed(tmp_path):
with pytest.raises(DecisionError):
_resolve(_Cfg(_token(tmp_path)), _entry(), _served(valid_now=False, reason_code="superseded"))
def test_claim_without_pdp_digest_fails_closed_naming_the_missing_mapping(tmp_path):
"""No published vocabulary mapping means the claim cannot be tied to this action.
approval-engine's binding.action/target use their vocabulary
("secrets.kv.destroy", {"id":..., "stage":...}); ours uses the catalog's.
flex-auth makes no cross-check and states the correspondence is ours via
pdp_digest. Without one there is nothing sound to compare, so this must
refuse rather than fall back to comparing two different languages.
"""
claim = _served()
claim["binding"].pop("pdp_digest")
with pytest.raises(DecisionError, match="no published mapping"):
_resolve(_Cfg(_token(tmp_path)), _entry(), claim)
def test_wrong_pdp_digest_fails_closed(tmp_path):
claim = _served()
claim["binding"]["pdp_digest"] = "sha256:" + "c" * 64
with pytest.raises(DecisionError, match="pdp digest does not match"):
_resolve(_Cfg(_token(tmp_path)), _entry(), claim)

View file

@ -0,0 +1,159 @@
"""Digest join verified against real flex-auth DecisionEnvelopes (FLEX-WP-0021-T03).
These replace a hand-maintained pin that was computed *including* the request
`id`. docs/canonical-request-digest.md excludes `id`, `policy_version` and
`caring_context` from the hashed material, and both real envelopes confirm it:
a digest computed over the old material matches no issued decision, which would
have failed closed against every correct allow.
Both fixtures are required. `provenance.input_claim_digests.context` appears
only when the request carries a non-empty context, so a validator asserting it
is always present passes `destroy` and fails `rotate`.
"""
import json
from datetime import datetime, timedelta, timezone
from pathlib import Path
import pytest
from secrets_engine.authorization import (
digest_material,
request_digest,
validate_decision_envelope,
)
from secrets_engine.errors import DecisionError
FIXTURES = Path(__file__).parent / "fixtures" / "flex-auth-replay"
PACKAGE_DIGEST = "sha256:fe0070b79f66442ae6c218697a49c470c6c8f670aa57a30c078a5284d097bd8c"
SNAPSHOT_DIGEST = "sha256:f5a309bc0b36721fd6d9ad7f53eb21222162bc2eac62a0ab0802a9a1d51340bb"
CASES = {
"rotate": {
"file": "decision_rotate.json",
"digest": "sha256:de67324f54187055307a833235f83ced9fcd3a20952a27b3d19493ed39734345",
"action": "rotate",
"context_claim_digest": None,
},
"destroy": {
"file": "decision_destroy_dual_control.json",
"digest": "sha256:570d112890586d3cbf00c0e81c85ae7806f40f00afa1a2c0a23fd5e077a27f56",
"action": "destroy",
"context_claim_digest": "sha256:45fa9f41271c684f2c26570be11869a8eda28e7b3b25f11e01f9378b6f89fdc8",
},
}
def _envelope(name):
return json.loads((FIXTURES / CASES[name]["file"]).read_text())
def _request_from(envelope):
"""Rebuild the normalized tuple the binding carries.
Per the contract, a consumer re-hashing the *original unenriched* request
will not match a decision that turned on registry attributes; the binding is
the evaluator's statement of what it hashed.
"""
binding = envelope["binding"]
request = {"id": envelope["request_id"]}
for key in ("tenant", "subject", "action", "resource"):
if binding.get(key) is not None:
request[key] = binding[key]
if binding.get("context") is not None:
request["context"] = binding["context"]
return request
def _refresh_lifetime(envelope):
"""Lifetime moves with the clock and must never be pinned."""
now = datetime.now(timezone.utc)
envelope["lifetime"]["not_before"] = (now - timedelta(minutes=1)).strftime(
"%Y-%m-%dT%H:%M:%SZ"
)
envelope["lifetime"]["expires_at"] = (now + timedelta(minutes=14)).strftime(
"%Y-%m-%dT%H:%M:%SZ"
)
return envelope
@pytest.mark.parametrize("name", list(CASES))
def test_request_digest_matches_the_issued_decision(name):
envelope = _envelope(name)
expected = CASES[name]["digest"]
assert envelope["binding"]["request_digest"] == expected, "fixture drifted"
assert request_digest(_request_from(envelope)) == expected
@pytest.mark.parametrize("name", list(CASES))
def test_correlation_fields_are_not_hashed(name):
"""id, policy_version and caring_context must not move the digest."""
request = _request_from(envelope := _envelope(name))
baseline = request_digest(request)
assert baseline == envelope["binding"]["request_digest"]
for field, value in (
("id", "check:some-other-correlation-id"),
("policy_version", "v99"),
("caring_context", {"anything": "here"}),
):
assert request_digest({**request, field: value}) == baseline, field
stripped = {k: v for k, v in request.items() if k != "id"}
assert request_digest(stripped) == baseline
@pytest.mark.parametrize("name", list(CASES))
def test_digest_material_is_exactly_the_published_tuple(name):
material = digest_material(_request_from(_envelope(name)))
assert set(material) <= {"tenant", "subject", "action", "resource", "context"}
assert "id" not in material
@pytest.mark.parametrize("name", list(CASES))
def test_real_envelope_validates_against_the_published_package(name):
envelope = _refresh_lifetime(_envelope(name))
result = validate_decision_envelope(
envelope,
_request_from(envelope),
accepted_policy_packages={"secrets-engine.catalog-lane.lifecycle"},
accepted_policy_versions={"v1"},
)
assert result.action == CASES[name]["action"]
assert result.subject_id == "secrets-engine"
@pytest.mark.parametrize("name", list(CASES))
def test_provenance_digests_are_pinned(name):
provenance = _envelope(name)["provenance"]
assert provenance["policy_package_digest"] == PACKAGE_DIGEST
assert provenance["registry_snapshot_digest"] == SNAPSHOT_DIGEST
assert provenance["evaluator"] == "flex-auth/local"
assert provenance["mode"] == "standalone"
@pytest.mark.parametrize("name", list(CASES))
def test_input_claim_digest_is_present_only_with_a_context(name):
"""The reason two fixtures exist: this field is conditional."""
provenance = _envelope(name)["provenance"]
expected = CASES[name]["context_claim_digest"]
actual = (provenance.get("input_claim_digests") or {}).get("context")
assert actual == expected
@pytest.mark.parametrize("name", list(CASES))
def test_a_tampered_binding_field_breaks_the_digest(name):
envelope = _envelope(name)
request = _request_from(envelope)
request["action"] = "handoff"
assert request_digest(request) != envelope["binding"]["request_digest"]
def test_expired_real_envelope_fails_closed():
"""The shipped lifetime is 15m from allow_ttl and has long since passed."""
with pytest.raises(DecisionError, match="lifetime has expired"):
envelope = _envelope("rotate")
validate_decision_envelope(
envelope,
_request_from(envelope),
accepted_policy_packages={"secrets-engine.catalog-lane.lifecycle"},
accepted_policy_versions={"v1"},
)

View file

@ -409,6 +409,50 @@ package/version to configure. Next inbound is the `T03` replay fixture — a rea
DecisionEnvelope from this package including `provenance.registry_snapshot_digest`
— to verify the digest join unchanged.
Verified 2026-09-06 against flex-auth's `T03` replay fixtures
(`FLEX-WP-0021-T03`, commit `9e10d1c`), vendored to
`tests/fixtures/flex-auth-replay/`. Running them found a defect of exactly the
class we had just been warning about.
- **`request_digest` was hashing fields the contract excludes.** The material is
`tenant`, `subject`, `action`, `resource`, `context` only; `id` is correlation,
`policy_version` lives in provenance, and `caring_context` is hashed
separately. This engine included all three when present. Because the join
adopts the served request id, every real production request would have carried
one, so the computed digest would have matched no issued decision and failed
closed against every correct allow — the same unsatisfiable-rule shape as the
removed `AUTHORITY` constant and as flex-auth's own destroy rule in `68ad039`.
Fixed by `digest_material`; both fixtures now reproduce their published
digests exactly.
- The previously pinned digest constant was computed *with* the id inside the
material, so it was wrong and its passing was not evidence. It is replaced by
fixture-driven contract tests over two real envelopes plus a structural test
that correlation fields do not move the digest. Both fixtures are required:
`provenance.input_claim_digests.context` appears only with a non-empty context.
- **The native claim digest is unusable and is no longer computed.** The claim's
`binding.action`/`binding.target` speak approval-engine's vocabulary while ours
speaks the catalog's, and no mapping is published; flex-auth makes no
cross-check and states the correspondence is ours via `pdp_digest`. A claim
recording no `pdp_digest` now fails closed naming the missing mapping rather
than comparing two vocabularies. **A published mapping is a prerequisite for
making `destroy` reachable under this task.** flex-auth offered to co-author it
with approval-engine.
- Narrowing accepted from approval-engine: `entries` is UNIQUE on
`(approval_id, subject_id)`, so approver distinctness is a storage invariant,
not a count this engine was previously protecting. What we stopped verifying is
that approval-engine applies its own invariant correctly — still a real
reduction in defence in depth, but narrower than "the threshold is now
unverified". They also added `threshold` objects to issuance and use events
(`87e55e2`) so the evaluation is reconstructable under §9.6.
- flex-auth corrected the `destroy` dual-control rule (`68ad039`) before
generating these fixtures: it had required `context.approval.status ==
'approved'` and an approver list, neither of which exists in the claim schema.
Our acknowledgement of the earlier rule crossed that fix. The corrected rule
requires only kind/issuer/`valid_now`, and our claim validation is unchanged.
- One global pin confirmed correct: `secrets-engine.catalog-lane.lifecycle` v1 is
one package covering all twelve actions. Do not build per-action pin
configuration for a distinction that does not exist.
Define and enforce the decision contract needed by production commands. A
resolved approval must bind at least: