meshbay.git/packages/meshbay-node/tests/test_security_regressions.py, branch 0.15

style: the 98 ruff could not fix, so the linter is a signal again

2026-09-19T12:39:38Z

The pass before this applied ruff's own fixes. These are the ones needing a decision, and the point of doing them is that `ruff check .` now passes: a linter reporting 98 known-acceptable findings reports nothing, because the next real one arrives invisible. **Lines over 100 (70).** Mostly wrapped where they stood. Two exceptions: the aligned trailing comments in `protocol.py`'s message table were shortened rather than wrapped, because wrapping one row of a table breaks the table; and in `models.py` the column comments moved above their columns for the same reason. **Imports below the first statement (14).** `csam.py` kept its FastAPI imports under a section header halfway down the file; two node tests had a constant and a `pytestmark` wedged between two import blocks. Moved, not suppressed. **Bindings nothing reads (4).** Three in tests, where the call stays and only the name goes — `_user(client, "listener")` is there to create the user, not to return one. The fourth was in `revocation.py` and was not a lint finding at all: `_connect_and_listen` opened an httpx stream to the WebSocket URL, did `pass`, and then opened the real connection through the `websockets` library. One pointless request per connect, left over from before that library was used directly. Removed, and `httpx` with it. **`l` as a name (4)**, **semicolons (6)** in the POC spikes, and the rest. 2893 passed, the same count as the two commits before it. `meshbay_node/revocation.py` is worth a decision separately: 154 lines that nothing imports, superseded by `hub_client.maintain_ws`'s `on_revocation`. This commit only stopped it failing the linter. Co-Authored-By: Claude Opus 5

style: ruff's own fixes, mechanically applied

2026-09-19T12:24:13Z

`ruff check .` had gone unrun long enough to report 568 errors, which is the same as having no linter: the next real finding would have been invisible in the noise. This is the 521 it fixes by itself, in 173 files, and nothing else — the 98 it cannot fix are the next commit. What actually changed: import sorting (225), imports nobody used (87, none of them a re-export — no `__init__.py` is touched, which was the one way this could have broken an import elsewhere), `datetime.timezone.utc` to `datetime.UTC` (69) and `asyncio.TimeoutError` to `TimeoutError` (18), both plain aliases on the 3.12 this project requires, `Optional[X]` to `X | None` (24), and f-strings with nothing to interpolate (19). Checked rather than assumed: every module in the three packages still imports, and the suite is 2893 passed — the same count, test for test, as the merge before it. Co-Authored-By: Claude Opus 5

docs: cite MESHBAY_DESIGN.md and a section instead of the merged notes

2026-09-19T00:12:47Z

The per-feature design notes were merged into docs/MESHBAY_DESIGN.md and deleted from the tree on 2026-09-11, but ~230 comments across the three packages still named them — usually written `docs/musicbay.md §3.2`, as though the file were still in docs/. A reader had to know §16 existed to resolve any of them. They now name the section directly. Every mapping comes from §16, the concordance, which already records where each old section landed: musicbay -> §9.8, mediacenter -> §9.7 for the Videos app and §6.5 where the subject is derived data, photos -> §9.9, auth-confirm -> §3.6, refactoring-search -> §9.11, invite-pairing-v1 -> §3.4, per-node-identity-v1 -> §3.2, captcha -> §7.7, chat-sender-keys -> §4.5, apps/refactor-groups -> §9.1–§9.4, desktop-client-v1 per section. Bare citations of the same documents (`draft-v6 §2.11`, `§4.8`, `§3.4`) are retargeted too: those collide with real section numbers in the design document, so leaving them would have been worse than the named form. Four cases the concordance does not cover, each decided rather than guessed: Sub-item references into documents that no longer exist — mediacenter's `§3.3 row 4`, `§3.4b/c`, `apps.md §3b` — name rows and sub-items §9.7 and §9.2 do not reproduce. The module-level citation stays; the sub-item pointer is dropped. The V-findings keep their labels but lose the dead `§10.1/` prefix. §13.8 lists V1–V13 as per-application open items, which is not what the labels mean in these comments, so pointing them at §13.8 would have been a false citation. `apps.md §5`'s virtualization requirement has no counterpart anywhere in the design document. The requirement is stated in the comment itself, so the citation is dropped rather than aimed at a section that does not say it. Comments that attributed a *sentence* to an old note — musicbay's "several thousand files" example, its "what got measured" note, its measured ~11%/~26% cover-art figures, the "original no root, whole shared tree" call — state the fact without attribution now. §9.8 does not contain those sentences and citing it for them would have been wrong. CLAUDE.md's "a reference to a document that no longer exists" row now says the concordance is for git history and out-of-tree material; the code cites sections directly. Verified: 2851 passed, 4 skipped. The 12 errors in the run are the Firefox leg of test_sticky_header.py's browser harness, which is broken at the browser level on this machine — headless Firefox (snap) dies with `[GFX1-]: RenderCompositorSWGL failed mapping default framebuffer`, renders nothing, and the probe exits `{"error": "no measurement"}` after its full 90s wait. Chrome runs the same 12 assertions in 3.2s and passes. Nothing here can affect it: every changed line in style.css is inside a comment. Also checked: ast.parse on every changed .py, `node --check` on every changed .js, the /* */ balance in style.css, and that no changed line exceeds the width its file already used. Co-Authored-By: Claude Opus 5

fix(node): creating and removing a folder are syscalls too

2026-09-18T14:13:53Z

The last two handlers on the loop. Both were synchronous, so a member creating a folder on a root that had spun down held the node for the spin-up, exactly as a chunk read did. Where a check and an act belong together they are now one call rather than two awaits, and the single disk thread is what makes that atomic: `_mkdir_if_absent` so two members creating the same name cannot both find nothing there and have the second `mkdir` raise where a refusal was meant, and `_rmdir_if_empty` for the reason the caller already re-tested emptiness — the first test happened before a round trip to the operator's browser, and a file can land in between. Two awaits would reopen that window one size smaller. The guard is now the whole class rather than the calls that were fixed. It walks the module's syntax tree and fails on any filesystem call outside the handful of functions written to be run through `off_disk` — a new handler that stats a root inline would pass every measured test, because those exercise the handlers that exist today. Checked by putting a call back: it names the function and the line. It leaves ffmpeg's own scratch files out, listed rather than silently allowed: they are under `tempfile.mkstemp` on the system disk, not on a group root, so they are not what spins down — but they do read a whole transcode into memory from the loop, and the day that matters it is a different measurement from this one. Co-Authored-By: Claude Opus 5

fix(node): take the availability poll and every upload write off the loop

2026-09-18T13:59:24Z

The rest of AV9's disk half. Serving a file left the loop in the commit before this one; two paths were still on it. **The availability poll.** `RootSet.refresh_availability` stats every root, and eleven call sites reached it from `async def` — the reconcile loop among them, on a timer. On a sleeping disk that is a stall once per tick, and the stat is also what keeps the disk awake, so a node paid spin-up for a library nobody was reading. All eleven now go through `off_disk`, `Root.is_live` included. **The upload write.** `open`/`write`, and the resolve, the stat, the free-name search, the rename and the unlink around it. This one could not simply be awaited: the handler was synchronous, so nothing could come between the `chunk_index != state.next_index` check and the `advance` that answers it, and that is the whole of the chunk-ordering rule. Awaiting the write opens the gap — chunk 1 arriving while chunk 0 is in the disk thread reads a position that has not moved and is refused as out of order, so an upload would fail on a slow disk and nowhere else. Verified, not assumed: without the lock the new ordering test refuses three chunks of four. So the check, the write and the advance are one critical section again, under a lock held **per group**. Not per session: `partial_uploads` lives in the group context so a reconnecting client finds its upload where it left it, which means two sessions of one member share the position of one `.part` file. Arrival order is preserved by construction — the dispatcher creates one task per message as it arrives, tasks start in creation order, and the lock is the first thing each one waits on, so its waiters queue in arrival order too. `_do_file_upload` is a coroutine now, which is why forty-two test call sites gain an `await`. Their outcomes are unchanged, file by file, against the run before the change. `test_ops.py` asked which public coroutines `ops` exposes and got `off_disk`, imported rather than defined there. It now asks for the ones written in the module, which is what its own docstring means; all forty-three operations are still checked. Co-Authored-By: Claude Opus 5

fix(node): the node's own controls take no authority from a hub token

2026-09-13T14:29:36Z

`_is_node_admin()` is `self._user_id == node_user_id`, and `_user_id` is the `sub` of a JWT the hub issued. Six node-wide controls were gated on that alone: `node_status` — which lists every group on the machine with each root's **absolute path** — plus `node_settings_set`, `roster_read`, `denylist_read`, `denylist_clear` and `node_reload`. So the answer to "are you the operator of this node" was "the hub says so", which NS4 and M3 rule out in as many words: operator authority comes from the node's roster and from nowhere else, and asking the hub is how the hub installs itself as node administrator. The reach is bounded — a completed handshake also needs the group key — but an active hub obtains one legitimately in an open-join group, which §3.5 concedes, and from there it could read the operator's directory layout or clear the denylist, which is the persisted revocation H4 exists to keep. `_operator_device()` requires both halves now: the account is the one the node belongs to, *and* the device on this connection has proved a key the roster holds as an operator. `device_hello` is signed over a transcript naming the node, the group and this connection's nonce, and `operator_pks()` is rebuilt from the roster on each call, so an unpinned browser and a revoked one are both refused at once. The hub holds no user keys and cannot countersign a device. Keeping the account check as well is deliberate: dropping it would widen these node-wide controls to any paired operator of any group on the machine, which is a separate decision. `_is_node_admin()` stays as what it is in the handshake ack — a hint telling a client whether to offer the Node page — and says so. Nothing changes for a paired operator: `device_hello` runs unconditionally after the ack, and anyone using the Node page's controls is already paired, since `root_add` and every other signed op has always verified against `operator_pks()`. A browser that never paired now reads nothing there, which is the state in which it could already write nothing. test_node_status.py's fixture set the account and not the device, which is how it went on passing; it now wires the device the way `device_hello` leaves it. The adversary itself is in test_security_regressions.py — a token naming the owner's account with no proved device, which the previous source answered with `node_status_ack`. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01UMxEQadpzPkYLFf5CYKhpW

feat(mnp)!: seal the upload under the group key

2026-09-07T15:46:33Z

Downloads have been encrypted under a GEK-derived key since the beginning: `file_chunk` and `stream_data` both go through `chunk_ciphertext`. Uploads never were. `file_upload` carried the filename and the raw bytes in plain msgpack, and `file_upload_ack` carried the name the node stored them under — so the same file was ciphertext leaving a node and plaintext arriving at one. There was no threat model behind that asymmetry. Both halves now travel sealed under a third groupbox purpose, HKDF(GEK, info="meshbay:upload:v1"). The filename, the destination folder and the bytes are all inside the seal; only `upload_id` and `chunk_index` stay in clear, because the node routes and orders on them before it can decrypt. This direction seals *towards* the node — it holds the GEK for its own group — and it opens the payload before it picks a destination or touches the disk. What that forced, and why none of it is optional: - `filename` was the correlation key on both sides. It cannot be: matching an ack to its request by name would hand back exactly what the seal hides. `upload_id` replaces it — client-drawn, opaque to the node, unique within a connection, never an authorization input. The property it guarded (one refusal fails one upload, not every upload in flight) is unchanged. - Refusals can no longer quote what they refused. `No directory named 'X'` becomes `No such directory in this group` plus the `code` that was already there; the client knows what it sent. - No plaintext fallback. A path that still accepts plaintext is not a sealed path, so an unsealed `file_upload` is refused with `upload_not_sealed`. Hardened while here, because what comes out of a seal is authenticated but not validated — a member can seal anything: `filename` and `data` have their types checked before any upload state is created, and `chunk_index`/`total_chunks`, which are outside the seal by necessity, can no longer raise where a refusal was meant. Tests. `test_upload_sealed.py` pins the node half: nothing identifying on the wire, tamper/wrong-key/wrong-group all refused with nothing written, and multi-chunk reassembly unchanged. `test_upload_seal_client.py` drives the shipped `uploadFile` over the shipped `crypto.js` under node and feeds its real frames to the real `_do_file_upload` — the file lands intact, and the ack the node actually produced comes back with the name it chose for a collision, which is the half a source-reading test cannot see. Both upload purposes join the JS/Python groupbox parity vectors. BREAKING CHANGE: MNP 2.0. `file_upload`/`file_upload_ack` change shape on the wire every deployed client speaks, which is MAJOR by the same rule 1.0 was — but the break is confined to uploads. `MNP_MIN_SUPPORTED` stays at "1.0", so a 1.x peer still connects, browses, downloads, streams and chats; only its uploads are refused, with a message saying which side is old. The client checks the node's version before sending a chunk, so neither side meets this as a timeout. This is the version negotiation shipped in 1.0 earning its keep: 1.0 cost a flag day, 2.0 costs a refusal code. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01AsoWC3GmhNdwVFomW3QjH3

refactor(mnp)!: remove stream_seg, the last unencrypted content message

2026-09-07T15:45:54Z

`stream_seg` answered with an MPEG-TS segment as base64 with no encryption at all — the one message on the content plane that never went through a GEK-derived key. Live on both transports, answering any authenticated member. It predates `stream_data`, which does the same job properly (`chunk_ciphertext`, keyed per segment, AES-256-GCM) and has since Phase 12. Its only browser caller, `fetchStreamSegment`, was defined and never once invoked — a plaintext media endpoint with no client. Removed rather than repaired. Gone with it: `_extract_segment` and the ffmpeg semaphore in quic_server, the `fetch_stream_segment` QUIC client method, and `_b64decode` in transport.js, which had no other caller. The H6 regression test lived on this handler — it pinned `_do_stream_segment_async` to a coroutine so `subprocess.run` could not stall the event loop for thirty seconds per request. It is replaced by the property that outlives the handler: no transport carries media outside an AEAD, asserted on `stream_seg` and `data_b64` across all three transport modules. The half of H6 that survives — the live streaming path still spawns ffmpeg — keeps its own test. BREAKING CHANGE: `stream_seg` is no longer answered on either transport. No shipping client sends it. Recorded as part of MNP 2.0, whose other half — the sealed upload — carries the version bump. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01AsoWC3GmhNdwVFomW3QjH3

feat(node): an upload lands in the folder it was sent to

2026-09-06T20:06:45Z

There is no `uploads/` subdirectory any more, and the client names the folder rather than the root. It was the last of v5's quarantine — the per-user layer went on 2026-08-14 for the same reason — and it goes on the same grounds: a folder appearing beside the operator's library because somebody sent a file is the node deciding how their disk is arranged. Somebody dropping a file into the folder they are looking at expects it to be in that folder. **What made the quarantine worth having was never the subdirectory.** It is the filename allowlist, the size cap, the chunk ordering and the no-overwrite rule, and all four are untouched: an existing file is never replaced, the second sender of IMG_1234.jpg gets a free name, and the check still sits at the write. Letting the client choose the destination is safe for one reason and only one: it is resolved through `RootSet.resolve()`, which refuses `..`, absolute segments and anything whose resolved form escapes its root, symlinks included. A member answers "which of this group's folders", never "which path on the operator's disk" — and the test that used to assert the node chose now asserts that, with six shapes of escape. `direct` goes with it. Its only job was to say "no subdirectory for this root", which is now every root, and a config flag that does nothing is worse than none. Chat's attachment folder finally does something: the directory the operator picks in the Chat settings pane is where attachments are written, falling back to the first writable root while they have not chosen one, or if the one they chose has since been made read-only or ejected — a stale choice should not become a refusal at send time. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_011pvMdvLBG92jyhvD5pD6us

fix(groups): finish Phase 1 — MNP root management, upload targets, eject state

2026-09-06T15:48:36Z

Review of the Phase 1 commit found the RO/RW model sound but three paths unfinished, each of which broke the flow the phase exists to deliver. Plus 29 test failures it introduced and no coverage for anything it added. Uploads went to the wrong directory. The node read a `root` field on file_upload that no client ever sent, so every upload landed in the first writable root while the Files toolbar offered its button based on the root being browsed — with two writable roots, uploading from one wrote into the other. Files now names the root it is showing; Chat names one chosen in the shell (an operator-configured directory arrives in Phase 2); the node refuses an unknown name rather than falling back, and refuses read-only and ejected roots by code. Shared directories were unreachable on the web. The table read its roots only from the loopback API, which resolves to "not available" in a browser, so the section rendered for nobody there — while the Uploads controls it replaced had worked — and the transport.updateRoot/ejectRoot/plugRoot methods beside it were dead. MNP is now the path, loopback the fallback for a local node with no live connection, and adding a root over MNP takes a typed path since no web page can browse a remote disk. Ejecting updated nobody's screen. transport.js resolves an admin ack against the pending request and returns, which is right for every op whose caller knows the value it chose; the root acks carry state only the node can compute, so the operator who clicked Eject was the one client that never saw it happen. And the ejected flag reached roster.db but was never read back, so a restart undid it and the next scan read an empty mount point as an erased library. Also: the member-upload endpoint answered 200 and did nothing (removed); the wizard ignored the first root's RW switch; reload compared roots on name and path, so editing writable in node.toml did nothing; the table had no path column, which is the only thing separating two libraries sharing a basename; apps_enabled normalisation differed between the two sides of a signed subject. Tests: eject/plug, per-root upload refusal and the node.toml rewrite had no coverage at all. test_member_upload_policy.py is replaced by test_root_writable_policy.py — it tested a removed feature — and every property worth keeping from it moved rather than being dropped. Docs: draft-v6 structural decision 9 is annotated as superseded (the operator can no longer have a directory only they may write to — a real capability removed, flagged rather than hidden), the man page documents the root verb and the RO/RW fields, and refactor-groups.md §7b records what the plan got wrong. Suite: 41 failures before, 13 after — all 13 pre-existing on main. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_011pvMdvLBG92jyhvD5pD6us