meshbay.git/packages/meshbay-hub/src/meshbay_hub/static/crypto.js, branch 0.16

feat: the node signs its handshake challenge (MNP 3.4)

2026-09-23T15:14:26Z

node_pk in handshake_challenge is now signed over the channel binding and both nonces, so a client can check the node key before a join rather than only at the ack. Both transports; the browser and the QUIC client refuse a wrong signature and treat an absent one as an older node. Co-Authored-By: Claude Opus 5.5

feat(chat): Tier 2 — a member verifies another member's device itself

2026-09-07T19:04:56Z

Chat messages have been signed by the sending device since MNP 2.0, but a reader had no way to know that the device belonged to the account the node named: the signature proved *a device*, and `sender_id` was still the node's word. This closes that for any account a client has already seen. **What was blocking it was not effort — the evidence was not being kept.** `_do_device_add` verified the countersignature that admits a second device and stored only `added_by_pk`: *which* key approved, never the proof. And `device_add_transcript` binds `nonce_node`, the approving connection's handshake nonce, so even a stored signature was unverifiable by anyone who had not been on that connection. `identities` gains `add_sig`, `add_nonce` and `add_ts`, added before the migration's early return — which fires on every roster widened since 2026-08-18, i.e. all of them, so putting them inside it would have meant they never arrived. `group_roster_req`/`resp` relays, sealed under a new groupbox purpose and answered to **any member of the group**, every live device of every active member with the evidence that admitted it. The node decides nothing: it hands over evidence and the client walks the chain from each account's root outwards (`_verifyRoster`). That is deliberate — the node is the party the property holds against, so it is not asked to assert trust. Two holes the tests caught while this was being built: - "no signature" was being treated as a trust root, so a node that writes the roster could put any key in an account's row and have it laundered straight into the verified set. A root is a device that names **no** countersigner. - pinning only the verified subset at first sight raised "key changed" on legitimate second devices whose countersignature predates this change. First sight pins everything the node says, because that is what trust-on-first-use means and an alarm that fires on normal events stops being read. The property, and it must not be rounded up: **once a client has seen an account, a node that later substitutes a key for it is detected. Nothing is gained at first sight**, where there is nothing to compare against — the same boundary `per-node-identity-v1.md` draws, unmoved. The cost, stated because it is real: the roster is member-visible, so every member learns how many devices the others hold and their public keys. It stays inside the group, the hub is not involved, and it is scoped per group. A member who cannot see the keys cannot check them. User-visible surface: one notice, "this account is using a key you have not seen before", in ten languages. Nothing else. 16 tests — 7 on the node (the evidence is stored, it verifies from the roster alone, a fabricated device carries none, another group's members are not disclosed), 9 running the shipped `_verifyRoster` under node against rosters built by the shipped Python: a chain of three in any order, a signature by the wrong key, one for another node, one for another account, and two fabricated devices signing each other admitting nothing. Tier 3 (operator-signed roster attestation) stays deferred, with nothing depending on it. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01TZZxYjz8YeWRz13xDi8LJr

Merge origin/main into the chat encryption work

2026-09-07T16:03:52Z

Both sides landed a breaking MNP change and both called it 2.0, which is right: the sealed upload, the removal of `stream_seg` and mandatory chat encryption share one flag day. They are recorded as one version in `__init__.py` rather than as a race between two. The resolutions that were decisions rather than mechanics: * **`MNP_MIN_SUPPORTED` moves to "2.0".** The sealed upload alone was a *confined* break — a 1.x peer could still connect, browse, download, stream and chat, with only its uploads refused by `upload_not_sealed` — so the floor deliberately stayed at "1.0". Mandatory chat encryption ends that confinement: a 1.x peer can neither produce a sealed chat message nor read one, so it would connect, look fine, and be unable to say anything. Refusing it at the handshake is the honest form. The per-message `upload_not_sealed` path is untouched and still right if the floor is ever lowered. * **`sendChat` throws on an `error` reply**, from origin, applied to the sealed send. It matters more after this change, not less: the node now refuses a stale epoch, a malformed envelope and a device claim that is not the connection's own, so there are three new ways for a message to be rejected and none of them may look like a message that was sent. * **`req_id` supersedes the per-type routing** this branch added for `chat_keys_resp` and `device_hello_ack`. Both blocks are kept beside the existing `chat_hist_resp` one, for the same stated reason — a node too old to stamp — and their comments no longer claim to be the mechanism that closes the class. `req_id` is. * **`chat_send_probe.py` is rebuilt on origin's structure**, not beside it: two scenarios, a stub that stamps `req_id`, `music_meta_req` as the older pending request. The encrypted path is layered on — a real Ed25519 device key generated in the page, and a `chat_keys_resp` sealed by the shipped Python, because a payload the page built itself would prove only that the page agrees with the page. * **`test_reply_correlation.py` now sends a sealed message.** Its subject is which of the two messages leaving that handler carries the id; plaintext chat was only the fixture, and the node refuses one now. * `groupbox` keeps both new purposes (`upload`, `chat_keys`); `protocol.py` keeps origin's removal of `STREAM_SEGMENT` and this branch's correction of the "Double Ratchet message" comment on `CHAT_MESSAGE`, which was wrong when it was written and is wrong differently now. Full suite on the merged tree: 1993 passed, 11 failed — the same 11 that fail on a pristine checkout (2 Windows service tests, 1 apps-enabled policy, 7 transcode tests that pass in isolation, and the WebRTC invite test that hangs on its own). Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01TZZxYjz8YeWRz13xDi8LJr

feat(chat): encrypt group chat under per-device epoch keys (MNP 2.0)

2026-09-07T15:50:28Z

Chat messages are sealed with AES-256-GCM under a key derived per group, per epoch, per *device*, and signed over the ciphertext with the device key the node pinned. The node relays and archives; it cannot read a message. There is no switch. MNP goes to 2.0 and MNP_MIN_SUPPORTED moves with it, so a 1.x peer is refused at the handshake with `version_too_old` rather than admitted and then unable to speak. An opt-in flag was designed and rejected: every node is a test node, so it would have bought nothing and left a plaintext branch reachable — C6's lesson one feature later. A test reads the source and refuses any code that consults a `chat_encrypted` setting. Not Sender Keys, and `senderkeys.py` is now documented as unused. With distribution under the group key and a node that serves history to devices which were not present, the node must retain each chain's earliest key, and a chain key at iteration i yields every message key from i on by pure HKDF — forward secrecy is zero either way. What the ratchet was left buying was stateful client code with silent failure modes, three of them reproduced: any member could sign as any other, a second device dropped the first's chain, and the skipped-key cache grew without bound. The reasoning is in docs/chat-sender-keys.md, which is the specification and the decision record. Epochs, not rotation: the epoch key is wrapped under the group key at delivery and never stored under it, so `gek_rotate` is a re-wrap. A group-key-derived archive key would have made every message ever sent unreadable on the first `member unpin`, which is the documented step after removing a member. A new epoch opens on member revoke/unpin, device revoke and `gek_rotate`; old epochs are kept and still delivered, so history stays readable to everyone who could already read it, and nothing anywhere deletes one. Three prerequisites this needed, each a live defect on its own: * The peer registry was keyed by user_id, so one account's second device evicted the first and the broadcast skipped recipients by account — a person's phone never saw what they typed on their laptop. * The handshake authenticated an account, never a device. `device_hello` (additive, signed, refused unless the key is a live device of this account in the node's own roster) is what lets the node refuse a member claiming somebody else's key. * `_admin_exec_file_delete` authorized against the exact uploading key, so device linking had already broken deleting your own file from your other device. It now authorizes against any non-revoked device of `uploader_id`. Found by driving the real panel over the real transport, not by reading source: `chat_keys_resp` was routed by arrival order and handed to an unanswered `media_meta_req` — the original frozen-tab defect in a message type that did not exist when that probe was written. And `_asText` had been deleted with an unrelated helper beside it; its only caller sits inside a promise the panel catches, so every conversation rendered empty with nothing in the console. Existing node data is migrated by QE/migration/migrate_chat_encryption.py (not versioned, per the QE rule), run with the node stopped. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01TZZxYjz8YeWRz13xDi8LJr

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

feat!: MNP 1.0 — seal index and handshake_ack under the group key

2026-09-03T14:16:55Z

`index_sync`, `index_delta` and the `handshake_ack` config payload now travel sealed under a GEK-derived subkey (`meshbay_common/groupbox.py`, mirrored by `sealGroup`/`openGroup` in `crypto.js`). Only `type`, `v`, `group_id` and the ack's `node_pk`/`proof`/`sig` stay in clear — a receiver must route and authenticate before it would trust a decryption. Verify, then decrypt. The ack line is integrity, not confidentiality: the signed handshake transcript names no ack field, so `is_node_admin`, `enabled_apps`, `video_root` and the rest were authenticated by the DTLS channel alone. The index line is defence in depth against a repeat of C1/C6 — a peer served before the handshake completes now gets ciphertext, not filenames. Nothing against an observer, the hub, or a member; that is the whole claim. `index_progress` stays clear (D3, counters only). Chat is out of scope. Failure is fatal: a payload that does not open ends the session naming the message type — never an empty index or an empty `enabled_apps`, both of which are legitimate states. Version negotiation ships here too (phase 15.6, brought forward): `v` + `v_min` on `handshake` and `handshake_challenge`, refused with `version_too_old` / `version_too_new` / `version_unreadable`. The flag day was already being paid for; the next breaking change now costs a refusal message. BREAKING CHANGE: breaks the WebRTC wire every deployed client speaks. Hub and every node must deploy together; the SPA is served by the hub, so a browser picks up the new client on reload. See MESHBAY_NODE_PROTOCOL.md §11.1a, §13.1. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01HkzbhmMmK8PqQBtGz5zCvY

refactor(hub): drop the base64 chunk fallback and the dead HTTP file client

2026-09-03T13:20:52Z

With MNP 0.15 no node can emit a base64 `file_chunk`, so the browser's fallback for that shape is unreachable. Three things go with it: - `file-utils.js` kept a third branch below the fallback that base64-decoded `chunkMsg.ct_b64 || chunkMsg.data_b64` when neither was present, i.e. decoded `undefined` and wrote the result into the file the user was saving. A chunk we cannot decrypt now stops the download with an error naming the file and suggesting the node is older than the page. Deliberately not in `_isRetryableTransportError`: this is a version mismatch, not a bad moment on the link. - `crypto.js` `decryptChunk` (base64) was the real path until Phase 9.15 and has had no caller since. - `crypto.js` `decryptFile` was never called in any commit. It fetched `${nodeUrl}/file/${id}/${chunk}?token=` in a loop — the node's unauthenticated HTTP file API, which is finding C1 and was deleted in Phase 11.5. A client for an endpoint that no longer exists, kept alive by being exported. `decryptChunkBin` — every file download and every video segment — is untouched. `packages/meshbay-client/ui/` was resynchronised with `npm run sync-ui`. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01AsoWC3GmhNdwVFomW3QjH3

feat: device linking, and signing in to the hub with a device key

2026-08-18T01:24:55Z

Stage C. Identity keys are per node, so a browser and a desktop client are two keys on one account there — and the node refused the second where it accepted the first. Without this, an account created natively could never be opened in a browser without an operator code per node, and "a native client must not prevent web use" would have been dead on arrival. Device linking (node) --------------------- `identities` is keyed by `(user_id, pk_ed25519)` instead of `user_id` alone. The old shape did `INSERT OR REPLACE`, so a second device overwrote the first silently; SQLite cannot change a primary key in place, so the table is rebuilt. Existing pins are carried over — verified against a live roster with 10 of them, nobody re-pairs. A new device files a request bound by `sha256(code ‖ its own keys)`, and a key the node **already pinned** countersigns it. The hub cannot: it has stored no user keys since 2026-08-14, which is what makes this safe to do without an operator in the loop. **The code never reaches the node.** It lists this account's pending requests with their stored hashes; the approver recomputes and keeps the match. A node offering fabricated keys would have to produce a hash over a code it has never seen. Nothing rests on a human comparing digits — that ritual was dropped in 12.1 as "correct, unusable as the default" and must not return by the back door. The design document had the approver look a request up *by* its hash, which is circular: computing it needs the keys being asked about. Corrected in both. Revocation marks rather than deletes, because a deleted row is a key the node would happily pin again — which is the laptop somebody just reported lost. Your last device cannot be revoked: coming back would need an operator's code. Hub — the only change in the whole plan --------------------------------------- `POST /v1/users/auth` signs in with a device Ed25519 key, on the same pattern as `/v1/nodes/auth`, plus `/v1/users/devices` to register, list and retire. New `user_devices` table with an Alembic migration, because `create_all()` is not one. This is **not** the key directory that was H3, and the tests say so: nothing reads it but the hub, no group key is ever wrapped for one, and it is a different key from the per-node identities. What it does cost is metadata — the hub now knows how many devices an account has and when each last signed in. Also `client.minimum` / `client.recommended` in `GET /v1/hub/version`: an installed client meets a newer hub the day the interface ships in a package, and that is cheap now and awkward to retrofit. Browser ------- The `key_changed` refusal becomes `unknown_device` and offers a linking code instead of telling someone to find their operator. The Members panel lists this account's devices here, approves one by code, and retires one. 773 tests pass. `e2e.py` gained a step that links a device end to end against the live deployment — file, list, recompute, countersign, then open the group with the new keys and no code — and it also gained `recv_type`, because a step that assumes the next message is its own answer reads an ack left by the step before. Co-Authored-By: Claude Opus 5

feat(node)!: the node wraps the group key — closes H3 and M3

2026-08-13T23:27:21Z

The invite flow fetched the invitee's pk_x25519 from the hub and wrapped the GEK for whatever came back (app.js:1466, and gek-init did the same server-side). The hub is the key directory, so a hub answering with its own key was handed the group key by an honest member following the protocol exactly. No forgery, no injection, nothing for the client to notice. That was H3. The fix is not safety numbers. Nobody reads the directory any more: - the node holds the GEK and wraps it itself, on every connection, for the X25519 key the joiner signed with their Ed25519 identity in one transcript (meshbay:join:v1), so the identity key vouches for the encryption key; - identities are bound to accounts by a one-time code the hub never sees — 40 bits, single use, one account, bounded per connection AND node-wide; - the node's own roster decides who may receive the key. Hub membership lets someone reach a node; it no longer gets them anything. A hub that invents an account and mints it a token is answered not_authorized_for_group. Safety numbers would have made substitution detectable by a human who checks, at the moment there is nothing to check against — first contact. Removing the lookup makes it impossible, and costs the user one code to pass along. M3 falls out of the same work. The daemon auto-pinned its own keystore key as admin_pk_ed25519 while the browser signs with the user identity key, so every privileged operation failed closed with a signature error that looked like a bug somewhere else; the demo only worked because a deploy script overwrote the value. Authority now comes from the roster, established locally by `operator pair`. Asking the hub for the operator's key — the obvious-looking fix — would have let the hub install itself as node administrator. BREAKING: gek_bundle_store is deleted, not gated. No member hands the node key material at all, so C5b becomes structural rather than an authorization to check. Existing stored bundles are still served, so current deployments keep working. Also: - join_policy (invite|open) is read from node.toml, never from the hub — a hub able to declare a group open would be handed its key. Unknown group ⇒ invite. - admin signatures are verified against the roster on every check, so unpinning takes effect without a restart. admin_pk_ed25519 stays readable as legacy. - two C5b tests were rewritten, deliberately: they asserted that gek_bundle_store demanded an operator signature, and the message is gone. They now assert the stronger property. The file says not to fix these tests, so this is the record of why they changed. - a slice-1 bug found while writing slice 2: connect() never passed skEdB64, so pairing would have failed at runtime with no test able to catch it. Tests: 152 node+common here, including an end-to-end DataChannel run where a member who has never held the group key redeems a code in the pre-proof window and receives the key wrapped for a key only they can open. Design: docs/invite-pairing-v1.md Co-Authored-By: Claude Opus 5

feat(mnp): unified handshake with mutual authentication

2026-08-13T09:46:12Z

Phase 11.5.4/5/7/8 — findings C6 (WebRTC half), C3, L4, M1, M9. New meshbay_common/handshake.py is the single implementation of authorization and proof: JWT verify, scope, denylist, mandatory group_id, membership, hosting. The handshake previously existed three times over and only the newest copy enforced the GEK proof. C3 — mutual authentication. Authentication ran one way: the client proved itself, the node proved nothing. handshake_ack.node_pk was never verified against anything and per-chunk signatures had been dropped in Phase 9.15, so a peer that had hijacked signaling (C2) or been substituted by the hub could accept the client's proof, ignore it, and serve a forged index, forged chat history and a forged is_node_admin flag. The client now sends a nonce; the node answers with its own GEK proof over that nonce AND an Ed25519 signature over the transcript; the browser verifies both and refuses otherwise. It also refuses an unchallenged handshake_ack, which previously let a peer skip proving anything at all. L4 — the proof was nonce ‖ offer_fp ‖ answer_fp: bare concatenation, and a missing fingerprint silently degraded it to nonce-only, dropping MitM detection (NS5). Every field is now length-prefixed and domain-separated, the role is bound so a client proof cannot be replayed as a node proof, and an absent channel binding is refused rather than tolerated. M1 — group_id was optional; omitting it skipped the membership check entirely and fell back to the node's first group. Now mandatory. M9 — node-scoped daemon tokens are refused on the client path. NOT DONE: quic_server.py still runs its own JWT-only handshake, so C6 remains open — a forged or stolen token reaches a node over QUIC and can inject chat without holding the GEK. quic_binding() is written and unit-tested but unwired. 11.5.6 (whether the certificate-hash anchor works with aioquic, or an RFC 5705 exporter is reachable) is unproven. 11.5.8 TOFU pinning of pk_node is not done: the client verifies the node's signature but does not yet remember which key it saw last. Adds packages/meshbay-common/tests/test_handshake.py (18 tests) covering the properties every transport must inherit. WebRTC test helpers rewritten around the shared module; _make_jwt now defaults to the test group, since group_id is mandatory. Tests: 24 webrtc, 176+ node+common. Co-Authored-By: Claude Opus 5