key-cape/history/2026-09-09-scope-reassessment.md

# KeyCape scope reassessment — 2026-09-09

Source baseline: **5ae80d3**. Supersedes the
[2026-09-05 assessment](2026-09-05-011726-scope-intent-assessment.md) against
`b989de4`, which remains the record of the ten-gap backlog and its closures.

## Why now

SCOPE.md still declared itself reviewed against `b989de4`, 63 commits behind. Its
limits section had been kept honest by appending to bullets, which works until the
header asserts a review date that no longer describes what was reviewed. That is
the drift this document exists to prevent, in the file whose only job is to say
accurately what this repository does.

## Method

Every capability claim was checked against source at this revision rather than
carried forward from the previous text: routes from the mux registrations in
`cmd/keycape/main.go`, subcommands from the dispatch in `main.go` and
`internal/authclient/cli.go`, flags from the flag sets, claim behaviour from
`token.go` and `userinfo.go`. Live claims were checked against `docs/evidence/`.
Where the existing prose and the code disagreed, the code won.

That method was chosen because the opposite failed repeatedly over the preceding
two days: four times a statement about current state was written from a workplan
paragraph, a partial `git status`, or an inference about what was admitted,
without reading the authoritative artifact. Every one was wrong and every one was
cheap to check.

## What changed since 2026-09-05

Gaps G01 through G09 are closed; G10 is external and remains open. The
capabilities that reached SCOPE only piecemeal, now stated:

- the authorization-code grant binds the redirect URI, refuses clients not
  registered for it, authenticates confidential clients and consumes codes
  atomically; UserInfo checks algorithm, issuer and token purpose (G01);
- upstream Authelia ID tokens are verified — signature, issuer, audience,
  validity window — failing closed and independently of transport, on an explicit
  operator decision not to police the transport instead (G01);
- `/readyz` probes LLDAP by bind, plus Authelia and privacyIDEA, distinct from
  `/healthz`; `SIGTERM` drains for 15s (G08);
- `keycape verify-client` checks a live registration's subject, tenant, roles,
  lifetime and scope refusals without emitting values;
- a human tenant may be supplied by a client registration where the directory has
  placed the user nowhere, and issuance is refused when the two conflict;
  `assurance.at` is the authentication time rather than the mint time;
- `internal/jose` is the single RS256/JWKS verifier behind both the caller path
  and upstream verification;
- the container packages all five binaries, and the dev stack is bootstrappable
  from a clean checkout.

Three corrections to claims SCOPE previously made: caller commands omitted
`verify-client`; the container was said to package only `keycape`, untrue since
KEY-WP-0026; and the issuer API row omitted `/readyz`.

## The distinction this revision adds

SCOPE now states plainly that it describes **source**, and that source behaviour
and deployed behaviour are different claims. The evidence for each is different
too: 390 Go tests across 23 packages and the named harness runs for the first;
committed receipts in `docs/evidence/` for the second.

What is actually proven live is narrower than what the source does, and worth
stating exactly:

- the upstream issuer was probed and pinned in `sso/keycape-config`. The pre-pin
  state did not match, so the fail-closed login outage that risk described was
  real and was averted rather than hypothetical;
- both approval service clients were verified in an attended owner process: JWKS
  signature verification, exact claims, excess-scope and wrong-secret denial at a
  900s lifetime, no credential values emitted.

Those receipts also decline what they did not test — no real predecessor rotation,
no observed wall-clock expiry — and this document declines it with them.

The deployed image predates this revision, so the authorization-code bindings,
upstream verification, readiness, graceful shutdown and both tenant-related
changes are running nowhere yet. Two of them fail closed at startup, which is why
they are listed in `docs/operations.md` under "Unreleased fail-closed startup
changes" rather than only in a hub message.

## What remains

G10 is owner work: KEY-WP-0013-T05 waits on `informed-decision` for the approver
client ID and deployed callback, and KEY-WP-0014-T04 has no admitted execution
authority for a real predecessor rotation. Neither can be closed from this
repository.

From G04, relying-party behaviour and MFA against a migrated realm are still
unexercised, and credential and MFA migration is not supplied at all, so no
harness can establish it. Complete profile conformance and drop-in Keycloak
interchangeability remain unestablished — and the conformance suite found a
concrete reason they are not the same question: stock Keycloak advertises the
`implicit` and `password` grants this profile excludes, as server capabilities no
realm configuration removes.