* feat(extensions): token-v1 proxy->sidecar auth boundary
Mint a per-extension secret core injects (X-Hermes-Sidecar-Token) on every
proxied request; sidecars validate it. Closes the hole where a loopback sidecar
port is reachable by any local process and cannot distinguish a proxied request
from a direct one.
- api/extension_sidecar_auth.py: per-extension token lifecycle (atomic mint,
re-read-verified so an unpersisted token is never injected, per-request
mtime-cached read for live rotation, path-escape-safe)
- manifest proxy_auth negotiation: absent=legacy, token-v1=enforce, unknown=fail-closed
- proxy: inject token, strip inbound + response x-hermes-*, auth-off posture
(loopback-only local_unprotected, else 503), fail-closed when token unavailable
- consent-time auth_required in status payload; mint-on-consent
- docs/EXTENSIONS.md proxy_auth section
- 7 new tests (26/26 green)
* fix(extensions): address Codex+Fable gate on token-v1 (6 findings)
- align token-module extension-id grammar with core _EXTENSION_ID_RE (was
narrower -> legally-named ext consented then 503'd forever)
- resolve token dir dynamically (mirror _extension_state_dir) -> real test
isolation, no import-time STATE_DIR cache
- cross-process mint: O_CREAT|O_EXCL no-clobber claim (was os.replace clobber)
- rotation cache keyed on full fingerprint (ino/dev/mtime/ctime/size) +
re-fingerprint after read -> same-size/mtime replacement no longer stale
- validate token format on read (url-safe, 16-256) -> malformed file can't
leak via a ValueError echoed in a 502
- consent fails 503 when token can't be provisioned (was silent-swallow ->
persisted consent then 503 forever)
- rename status auth_required -> posture enum (protected|local_unprotected):
nothing is blocked for loopback, so 'required' was misleading
- panels.js: render local_unprotected warning on the consent row (+ CSS)
- docs: token-path resolution order, 401-vs-503, explicit 'legacy' acceptance
- tests: route-level token-injection+response-strip test; fix illusory isolation
in token-module test; 27/27 green
* fix(extensions): close 2 token-mint races (Codex re-gate round 2)
- mint via temp-file + atomic os.replace (not O_CREAT|O_EXCL) so the final
path is never observed empty/half-written — a concurrent loser can no longer
read an empty token file and 503
- single _stable_read helper (fingerprint-read-refingerprint, bounded retry on
mid-read change) used by BOTH ensure_token and current_token — a token that
changes during the read is never returned or cached stale
- stress-verified: 20 concurrent first-mints converge on 1 persisted token; 27/27
* fix(extensions): atomic no-clobber token publish via os.link (Codex re-gate round 3)
os.replace fixed empty-file exposure but still clobbered cross-process: two
processes could both write+replace and a reader between them got a token no
longer on disk -> 401. Switch to the repo's TOCTOU-safe os.link create-or-fail
idiom (session_recovery.py:627): write temp -> link into place (fails if a
winner already published) -> loser drops its temp and reads the winner via
_stable_read. Proven: 16 concurrent PROCESSES converge on 1 persisted token,
all matching disk. 27/27 tests green.
* fix(extensions): resolve Frank+Greptile #6331 review — token-v1 fail-closed when auth off (consent+resolution), token-v1-only proxy_auth/posture status fields, fullmatch ext-id validator
* fix(extensions): finish Frank and Greptile sidecar review
---------
Co-authored-by: nesquena-hermes <nesquena-hermes@users.noreply.github.com>
Co-authored-by: nesquena-hermes <agent@nesquena-hermes>
