The live proof in 03c0569 showed validate_decision_envelope rejecting every
real allow. The evaluator normalizes before hashing -- the request tenant is
copied onto subject and resource, and a registry hit copies type, tenant and
selected attributes onto the refs -- so binding.request_digest covers
material we never sent. Byte-equality against our unenriched request was
unsatisfiable, not merely mismatched.
THE RULE WAS ALREADY PUBLISHED. flex-auth's canonical-request-digest.md
section "Normalization" states the enrichment and tells consumers what to do
instead: compare structured binding fields to the proposed action, treat
request_digest as the evaluator's statement of what it hashed, and recompute
independently over the tuple the binding carries. I raised this with them as
an unpublished gap and asked them to pick between three shapes; it was in
their contract already and the answer was the first of the three. Nothing
was blocked on them, and this follows the published rule rather than one I
inferred.
- _require_binding_corresponds: everything we proposed must survive
unchanged -- tenant, action, context, subject.id/type,
resource.id/type/system, and every attribute we sent.
- Enrichment may add only type, tenant, attributes. Any other added field is
refused, and an enriched tenant must be the request tenant, so a
cross-tenant binding cannot arrive wearing our request's clothes.
- request_digest is still verified, now against binding_tuple(binding) for
self-consistency rather than against material we never sent.
- The envelope's top-level subject/resource get the same rule; they are
enriched too.
Proved against the artifact: the real decision:0f9c98f14545c42d now
validates, and the unrefreshed envelope is refused on lifetime -- reaching
the lifetime check at all is the evidence the binding checks pass on a real
decision. Negatives cover a restated resource.attributes.stage, a foreign
subject.tenant, and an unexpected enrichment field.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E4tNMAYcSQmZWUE4wqP4ij
Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 715726@bnt-lap001
Assistant-Session: 80a42b32-cba6-4b23-8be0-68819b1a6092
Adoption asked for by flex-auth (FLEX-WP-0021-T05) and glas-harness
(GLAS-WP-0015), plus the first real decision this engine has obtained from
the deployed pin -- which found a defect the fixtures could not.
ACCESS PATH. require_supported_pdp_address refuses in-cluster Service names
and any non-loopback host. This is no longer a unilateral call: the owner
path is documented as loopback kubectl port-forward over the authenticated
Kubernetes API, which is what authenticates the responder transitively
(FLEX-DEC-2026-010). A Service name from a workstation does not fail, it
resolves through the DNS search suffix to an unrelated public host, and
since decision records carry no signature, a responder knowing the
published package and version can return an allow that passes every check
we make. Fail-closed protects against a PDP that is absent, not one that
lies. The guard runs before the token is read, so a misdirected request
cannot leak it; a test pins that ordering.
LIVE PROOF. Minted a 10-minute TokenRequest token (audience flex-auth, SA
secrets-engine/secrets-engine, mode 0600 outside the worktree, shredded
after), forwarded to the named pod, and sent a real CheckRequest for
glas-claude-agent-dev-anthropic. Result: allow, catalog_lane_policy_matched,
served by v2 (sha256:bd11c5fe...) -- so the redeploy flex-auth flagged as
outstanding has landed and the pin no longer serves the tenant-blind v1.
Our tenant fix is confirmed against the real service: binding.tenant is
tenant:platform.
THE DEFECT IT FOUND. The evaluator enriches from its registry before
hashing -- subject gains attributes and tenant, resource gains tenant --
so binding.request_digest is over material we never sent and cannot
reproduce. validate_decision_envelope rejects every real allow.
Every replay test passes because _request_from() rebuilds the request out
of the binding, i.e. the enriched form: a self-consistent fake agreeing
with itself, which hid this through three rounds of digest work. Third
time a real artifact has beaten a fake in this integration.
NOT FIXED, DELIBERATELY. Rejecting a valid allow is wrong in the safe
direction. Which fields may be enriched is flex-auth's contract to publish;
inferring it means accepting a binding that differs from our proposal in a
way we decided was benign -- the fail-open shape GH-DEC-2026-008 rejected
for vocabularies and FLEX-DEC-2026-007 for digests. Raised with them.
Tenant question closed by operator decision 5ed3fb35: tenant:platform
exactly, and service_auth.TENANT stays tenant:coulomb because the two
identity layers are to remain distinct. Declining to author that mapping
was right -- the answer was neither reading offered.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E4tNMAYcSQmZWUE4wqP4ij
Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 715726@bnt-lap001
Assistant-Session: 80a42b32-cba6-4b23-8be0-68819b1a6092
