Addresses nesquena-hermes Round-2 review on #6979. All three MUST-FIX
items reproduced end-to-end are fixed; three SHOULD-FIX items folded in.
MUST-FIX 1 (data exfiltration) — capture/serve deny parity + source binding:
- The #3234 state/profile deny model is extracted into a single shared
predicate (routes._media_deny_reason) used by BOTH /api/media serving and
snapshot capture, so anything the serve path refuses is never captured in
the first place (STATE_DIR subdirs, webui_state subdirs, named-profile
roots, secret basenames, the snapshot store itself).
- Every captured digest now carries a server-owned canonical source-path
association (<digest>.src.json sidecar, tmp+rename atomic). /api/media
serves a digest only for the exact path it was captured from — replaying
a valid digest through a different allowed path falls back to the live
file instead of leaking stored bytes.
- Snapshot blobs are opened ANCHORED inside the store root (no-follow).
- Committed end-to-end regression: capture a denied state file and prove it
cannot be served through any path.
MUST-FIX 2 (data exfiltration) — configured store root denied regardless of name:
- get_snapshot_dir() is resolved and any bare path= target at or below it is
rejected BEFORE the allow/serve decision, so a custom
HERMES_WEBUI_MEDIA_SNAPSHOT_DIR (e.g. /tmp/custom-store-name) can no
longer be read via a plain path= request.
MUST-FIX 3 (silent corruption) — prefix-safe URL stamping:
- _stampMediaSnapshots now rewrites each COMPLETE path= query value
atomically (boundary-aware regex, decode whole value, exact map lookup)
instead of substring split/join. One path being a prefix of another
(/tmp/a.png vs /tmp/a.png.backup) can no longer corrupt the longer URL or
drop its digest. data-path placeholders use the same value-level rewrite
with HTML-entity unescaping. Prefix-path regression test committed.
SHOULD-FIX folded in:
- A recorded digest is FINAL: quota eviction no longer causes a later settle
to re-capture the current live bytes and rebind the historical message
(immutability restored + no quota-thrash I/O).
- is_valid_digest uses whole-string fullmatch (\Z) — a trailing newline can
no longer pass the gate.
- PDF/HTML fallback, download and open-full-page links now carry snap so
they open/download the frozen bytes.
Deferred (noted in review thread): emission-time capture (streaming.py) and
worklog scene-prose stamping — scene rows do not carry parent-message
snapshot metadata; threading it through the scene reconciler is a separate
data-pipeline change. Main transcript + transparent ordered segments remain
the old/new comparison surface.
Tests: +11 backend/frontend regressions (36 total in
test_media_message_snapshots.py), incl. the exact Round-2 repros.
Reverse-verified: the new tests fail on the round-1 head (8 failed).
happy5318
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