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buzz/crates/buzz-media
Will Pfleger a38707d35c fix(relay): close community ban gaps across audio, agents and HTTP (#8005)
🤖 Community bans had gaps. Audio sockets never checked them: the audio
join path didn't look up ban state, and a ban closed only the member's
root sockets, so a banned member could join a huddle or stay in one. An
agent's access comes from its owner, but the ban and timeout checks only
looked at the pubkey that signed the event. Several write paths returned
before those checks ran, admission could miss a ban that landed
mid-AUTH, and removing or losing a member left live sockets open. This
PR closes those gaps.

## Audio

- `handlers/auth.rs`: the root socket's ban lookup, including the NIP-OA
owner cascade and fail-closed DB handling, is `community_ban_outcome`.
Root auth and audio join both call it, so the two checks can't drift
apart.
- `audio/handler.rs`: audio join runs the ban check after the write-free
channel membership check and before any huddle lease or durable write. A
ban is refused with `AuthorizationDenied` and a DB error with
`AuthorizationUnavailable`. With no FI assertion, the refusal is the
root route's text (`blocked: you are banned from this community` /
`error: internal error checking restriction state`).
- `state.rs`: `CommunityConnectionControl` holds the authenticated
pubkey. `CommunityConnectionRegistry::disconnect_pubkey` closes bound
audio sockets for one pubkey in one community with a 1008 `access
revoked` close. `AppState::disconnect_pubkey_local` closes everything a
pubkey has open in a community on this pod (root and audio); the
clusterwide disconnect and the conn-control Redis subscriber in
`main.rs` both use it, so remote pods close audio sockets too. Root
sockets are still closed through `ConnectionManager`, so nothing is
closed twice. A socket that proved a NIP-FI identity instead gets the
standard NIP-FI denial (the restricted frame, then 1008 `authorization
denied`), and a ban never overwrites a close reason already chosen.

## Behavior

- **Owner restrictions carry to agents.** `restriction_state` folds in
the restriction row of the agent's owner (`users.agent_owner_pubkey`) at
read time. Nothing is copied onto the agent, so unbanning or
un-timing-out the owner restores the agent immediately. Every hot-path
caller (AUTH, ingest, audio, HTTP) picks this up.
- **Admission is fenced against a concurrent ban.** Root AUTH and audio
admission bind the proven pubkey to the socket first, then make the
final ban and relay-membership decision
(`handlers::auth::final_admission_denial`), then refuse if a disconnect
already cancelled the socket. A ban or removal whose disconnect ran
before the bind is visible to those fresh reads; one that runs after it
finds and closes the bound socket. Both reads come from the writer,
never the bounded-stale replica, so a removal that committed before the
bind cannot be undone by a lagging replica. Both fail closed, and the
check covers a delegated agent's owner. Each admitted socket records the
agent's owner, from the NIP-OA tag or the stored link.
- **Agents are always linked to their owner before admission.** Root
AUTH and audio both record `users.agent_owner_pubkey` for a NIP-OA agent
before admitting it, and refuse admission (`error: internal error
recording agent owner`) if that write fails, because revoking the owner
finds the agent's sockets through that link.
- **Revoking live access covers agents without a database read.**
`AppState::revoke_live_access` sends one clusterwide disconnect that
closes, on every pod, each root and audio socket in the community whose
principal **or recorded owner** is the target. An agent socket admitted
before its owner link existed carries no recorded owner, so recording an
owner for the first time (`materialize_nip_oa_owner`, the single writer
used by root AUTH, audio admission and HTTP NIP-OA) closes that agent's
ownerless root and audio sockets clusterwide; they reconnect with the
owner attached. That disconnect skips owner-bound sockets. Admission
with a NIP-OA owner records it on the socket before binding the pubkey,
so the socket survives its own link; admission without one binds the
pubkey first and then reads the stored owner, so a concurrent link
either closes the socket or is seen by the read. A
`users.agent_owner_pubkey` sweep still runs as a secondary path; if its
lookup fails, the error is returned and there is no retry task. The
kind-9040 ban, the report-action ban (left non-terminal so recovery
re-runs it), relay-admin removal (9031), and NIP-43 self-leave all use
it and report an incomplete revoke instead of claiming success. Each
revokes right after its change commits; the ban no longer waits on its
audit insert, whose error is still returned.
- **NIP-43 self-leave works over WebSocket.** Kind 28936 is in the
ephemeral range, so `handle_event` used to fan it out and answer `OK
true` without removing membership. It is now routed to ingest; no other
ephemeral kind changes.
- **The write gate runs before every kind-specific branch.**
`enforce_write_restriction` runs ahead of command routing (DM open, DM
add member, DM hide, workflow definitions and triggers, approvals),
product feedback, reports, and moderation or relay-admin commands.
Ephemeral events and agent observer frames return before ingest in
`handle_event`, so they go through the same gate there.
  - A ban exempts nothing.
- A timeout admits only reports (kind 1984), unban (9041) and untimeout
(9043). A timed-out admin cannot send relay-admin commands (9030–9033)
until the timeout ends.
- **HTTP refuses banned principals.** `enforce_relay_membership` runs a
ban check after the membership decision, including on open relays: 403
`blocked: you are banned from this community` for a ban, 503 for a
failed lookup. Media upload, media GET/HEAD and Git transport keep that
503 instead of reporting it as "not a relay member": in NIP-FI Enforce
mode they send the canonical `AuthorizationUnavailable` response
(`text/plain; charset=utf-8`, `authorization unavailable\n`), and in Off
mode each keeps its legacy unavailable response. Media storage failures
are not reclassified. Git transport checks membership and then runs its
own ban check once per request. The NIP-OA owner is resolved from
`x-auth-tag` when present. HTTP checks **bans only**: a timeout blocks
writes, HTTP writes already reach the ingest gate, and reading stays
allowed under a timeout.

Unchanged by design: a lost Redis fan-out can leave another pod's socket
open until it reconnects, and there is no recurring ban recheck on open
sockets.

## Path table

| Path | Category | Ban check |
|---|---|---|
| Root WebSocket AUTH and audio admission, including NIP-OA owner
binding | community admission | final fenced check after bind; owner
link required |
| `POST /events`, `/query`, `/count` (`bridge.rs`) | community HTTP |
existing `enforce_relay_membership` caller |
| GIF search and `POST /gifs/share` (`gifs.rs`), media upload and fetch
(`media.rs`), workflows (`workflows.rs`) | community HTTP | existing
caller; media keeps 503 on lookup failure |
| Git transport (`git/transport.rs`), git settings (`git/settings.rs`) |
community HTTP | existing caller; transport keeps 503 on lookup failure
|
| `GET /moderation/reports`, `/moderation/audit`,
`/moderation/restricted` | community HTTP | **newly covered** |
| `POST /api/invites` (invite mint) | community HTTP | **newly covered**
|
| NIP-43 self-leave (WebSocket and `POST /events`, both via ingest) |
roster change | revokes live access like admin removal |
| Invite claim, accept-policy, `/api/join-policy*` | pre-membership
invite and policy flows | none; ban state is checked when the caller
authenticates |
| `/`, `/info`, `/.well-known/nostr.json`, `/health`, `/_liveness`,
`/_readiness` | public metadata and health | none |
| `/hooks/{id}` | secret-authenticated webhooks | none; no community
pubkey |
| `/operator/*`, `/api/admin/v1`, `/internal/git/policy` | operator,
admin and internal routes | none; separate auth plane |
| `/_mesh/demo/echo` | demo only (mesh plus `mesh_demo_echo`) | none |

## Known limits

- Cross-pod closure depends on the Redis fan-out; the tests prove the
pod-local close by principal and recorded owner.
- Live delivery to existing subscriptions depends on the disconnect.
Events are not rechecked one by one.

---------

Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Co-authored-by: Hayt <211b96e6a2b7f45fd4047988976c7bbbeeda0c15f3ae7b32eec20834b5a55118@buzz.block.builderlab.xyz>
2026-10-01 23:24:56 +00:00
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