Probing the handed-over Service DNS name from the workstation found that every *.svc.cluster.local name resolves here to one unrelated public address via the ad.binect.de search suffix -- including names of services that do not exist, which proves it is suffix expansion and not a record. Pointing SECRETS_ENGINE_PDP_URL at the Service name would send the CheckRequest body (subject, tenant, lane ids, stage, field names, purpose) and the static Bearer token to that host. Decision envelopes are structurally validated but not signed, so a responder knowing the package and version can return a well-formed allow; the fail-closed posture assumes the PDP is the PDP. Not mitigated here: choosing the transport control is the owners' call, not this consumer's. Recommended to FLEX-WP-0021-T05 that the handover be a trailing-dot FQDN or explicit address, with the response channel's authentication stated. Our pin stays unset, so the hazard is theoretical. 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
7.6 KiB
Tenant alignment
Answer to the GLAS-WP-0015 production-dependency handoff question, which asked
this engine to state its exact tenant values and produce wrong-tenant denial
evidence rather than assume a mapping. Related: KEY-WP-0013-T02,
APPROVAL-WP-0002-T01, SECRETS-WP-0009-T03, FLEX-WP-0021-T05.
The handoff's framing is adopted here without reservation: spelling similarity
is not a mapping, and JWT/store comparison is exact. A tenant "mapping"
invented by a consumer is the same fail-open shape gate-house rejected for
action vocabularies in GH-DEC-2026-008 — a translation can be confidently
wrong — arriving by a different road.
The three values, as this repo actually holds them
| Value | Where it lives | Owner |
|---|---|---|
| CheckRequest tenant | authorization.REQUEST_TENANT = tenant:platform |
flex-auth package |
| KeyCape JWT tenant | service_auth.TENANT = tenant:coulomb |
key-cape |
| Approval store tenant | platform (not held here) |
approval-engine |
CheckRequest tenant: tenant:platform, and it was missing entirely
secrets-engine.catalog-lane.lifecycle v2 reads
known_tenant := "tenant:platform"
request_tenant := object.get(input, "tenant", "")
and its wrong_tenant first-denial branch fires on anything else. object.get
with a "" default is deliberate: an absent tenant is a denial, not an
ignored field.
build_action_request emitted no tenant field at all. Every gated action
this engine sent would have been denied wrong_tenant by the deployed v2
package — and, worse, the omission also produced a request_digest that could
match no correctly issued decision, because tenant is hashed material. Fixed:
the request now carries REQUEST_TENANT, an empty tenant is refused at build
time, and the constant is pinned against the vendored allow envelopes so a
package retenanting surfaces as a test failure rather than a production denial.
KeyCape JWT tenant: tenant:coulomb — and that is the value the package denies
This is the uncomfortable part and it is stated plainly rather than smoothed
over. service_auth.TENANT is tenant:coulomb, preflighted on the KeyCape
client_credentials token for the accepted secrets-engine-openbao service
identity. tenant:coulomb is exactly the value flex-auth used to
demonstrate a wrong-tenant denial (decision_wrong_tenant_deny.json,
matched_rule: wrong_tenant).
Two readings are possible and this engine does not choose between them:
- They name two different layers — an identity/tenancy tenant for the KeyCape client, and a resource-scoping tenant for the policy package — which happen to use one namespace format.
- One of the two constants is wrong.
Reading 1 is plausible and is probably right, but "probably right" is not a contract. Both constants stay as they are, deliberately not unified behind one symbol, until an owner-reviewed mapping exists with a decision reference. This engine will consume that mapping; it will not author it.
Approval store tenant: platform
Not held in this repo. Noted only because the handoff asked for all three: the
comparison between platform and tenant:platform is a prefix difference, and
a prefix difference is precisely the kind of similarity that must not be treated
as identity without an owner saying so.
Wrong-tenant denial evidence
From flex-auth's real v2 deny envelope, vendored at
tests/fixtures/flex-auth-replay/decision_wrong_tenant_deny.json:
decision:7d56b7fc274ddfd6 effect: deny reason: wrong_tenant
matched_rule: wrong_tenant policy_version: v2
binding.tenant: tenant:coulomb
binding.request_digest: sha256:c9c6e6f8...0d20
flex-auth's fixture varies the tenant on an otherwise-valid rotate, so a deny
proves the tenant alone carried it. tests/test_decision_replay.py asserts our
consumer refuses it on effect before anything else, and separately pins that a
deny carries no lifetime — a consumer checking lifetime before effect would
raise a confusing missing-field error on a well-formed denial.
Why v1 must not be pinned
v1 shipped and was deployed with no reference to input.tenant at all. Every
fixture carried tenant:platform, so the package's own coverage could not
notice, and FLEX-WP-0021-T02's "wrong-tenant deny" gate was recorded as met
when it was not. A rotate under tenant:coulomb returned allow against the
deployed v1 package (decision:066e629bbf0c0924).
flex-auth superseded v1 rather than amending it, on the principle that a
fail-open correction has to be visible as a version change; a fail-closed one
does not. A consumer still pinned to v1 would keep receiving allows it should
never have had, unable to tell from the version string that the rule moved
underneath it. test_the_superseded_v1_package_is_not_accepted pins that this
engine refuses a v1 decision.
Note the ownership point flex-auth recorded with it: the evaluator hashes
tenant and carries it in the decision record, but nothing in the evaluation
path compares it. Tenant scoping is the policy package's job, and a package
that omits it is not scoped to a tenant at all. Our own omission was the
mirror-image defect on the consumer side, and neither side's tests could see it
alone.
Still open
- The owner-reviewed JWT/store/CheckRequest mapping, with a decision reference. Until it exists, no live client or policy subject changes here.
- A supported owner access path to
flex-auth-secrets-enginefor a workstation CLI. Service DNS is not workstation connectivity, so the tenant fix above is necessary but not sufficient for activation (FLEX-WP-0021-T05).
Hazard: the Service DNS name resolves here, to the wrong host
Probed from the workstation 2026-09-06. This is worse than "not reachable" and is the reason the access path must be handed over explicitly rather than assumed from a Service name.
$ getent hosts flex-auth-secrets-engine.flex-auth.svc.cluster.local
80.158.43.29 flex-auth-secrets-engine.flex-auth.svc.cluster.local.ad.binect.de
$ getent hosts this-service-does-not-exist.flex-auth.svc.cluster.local
80.158.43.29 this-service-does-not-exist.flex-auth.svc.cluster.local.ad.binect.de
$ getent hosts flex-auth-secrets-engine.flex-auth.svc.cluster.local. # trailing dot
(no resolution)
/etc/resolv.conf carries search ad.binect.de fritz.box, and ad.binect.de
answers wildcard, so every *.svc.cluster.local name resolves on this
workstation to one unrelated public address. A nonexistent service resolves
identically, which proves it is suffix expansion rather than any real record.
Consequences if SECRETS_ENGINE_PDP_URL were pointed at the Service name from a
workstation:
- The
POST /v1/checkbody — subject id/type, tenant, lane/resource ids, stage, declared field names, purpose — would go to an arbitrary internet host. It contains no secret values, but it is a structural map of the estate's credential lanes. - The static Bearer token would be sent to that host.
- Decision envelopes are structurally validated but not signed. A responder
that knows the package name and version can return a well-formed
effect: allow, and this engine's checks would pass it. The fail-closed production posture assumes the PDP is the PDP.
This is not fixed here, because choosing the transport control is the owners'
call, not this consumer's. Recommended for FLEX-WP-0021-T05: hand over a
trailing-dot FQDN or an explicit address, and state the authentication of the
response channel (mTLS, or a signed envelope) rather than leaving an unsigned
allow over plaintext HTTP as the contract. This engine keeps its pin unset in
the meantime, which is why the hazard is currently theoretical.