meshbay.git/packages/meshbay-common/src/meshbay_common/handshake.py, branch 0.3

feat!: identity keys per node — C4's blast radius drops to one operator

2026-08-14T15:51:48Z

One keypair was copied to every node its owner joined, so cracking the bundle on any single node yielded the identity used on all of them: their content on other operators' machines, and the ability to sign as them anywhere. That lateral reach was the part of C4 worth attacking. Each node now gets its own keypair, generated the first time its owner joins it and left with that node alone. An operator who cracks what sits on their own disk holds a key that is a stranger to every other node — and on their own node, one that unlocks nothing they did not already hold: they serve the content, the index and every byte of it by design. Nothing changes for the user. A first contact with a node already needed that operator's code, and the key is created in the same step; a second browser still recovers it from the node with the passphrase alone. Two operators can also no longer tell they host the same person by comparing keys. BREAKING, and deliberately without a compatibility path — the deployment is wiped for the next demo: - users.pk_ed25519 / pk_x25519 dropped (migration a7c31f9e40b2) - registration no longer sends or stores a key - PUT /v1/users/me/keys and regenerateKeys() gone; rotation is now `member unpin` plus a fresh code, decided on the machine that pinned it - /pubkeys returns an account id and a node's linking key. It was the directory H3 read, and nothing wraps for it any more - the pk_user JWT claim is gone That last one closed a live defect the inventory turned up: the node recorded pk_user as the uploader's identity and authorized deletion against it, so a hub issuing a token naming its own key could delete anyone's uploads on any node. Attribution now uses the key the node itself pinned. A simplification falls out. Registration generates nothing, so a scripted signup is a real account: `demo.py bootstrap` takes a wiped hub and node to a working demo with no browser, which was impossible while keys were born in one. Also fixes, found by running it on a wiped deployment: the key handed back on a join now belongs to the group the connection is for, not the group named in the invitation — an operator pairs node-wide but redeems the code while opening a group, and expects to read it. Tests: 343, including the two that state the property — a key pinned by one node is refused at another, and someone else's code does not admit it. Verified end to end against a wiped hub and node: bootstrap, pair, invite, join, download, stream, second browser, revoke. Design: docs/per-node-identity-v1.md Co-Authored-By: Claude Opus 5

fix(client): refresh the token when the node says "not a member"

2026-08-14T01:40:43Z

A member added to a group after they signed in was refused by the node, told "Not a member of this group", and had no way forward but to log out and back in. The hub bakes `groups` into the access token at login and never pushes updates, so the token said they were in nothing while the database said otherwise. This lands on every newly invited member, at their first action, and the message tells them the opposite of the truth — toto2 was a member of newdemo on the hub and read that they were not. The refusal now carries a code the client can act on (`not_a_member`) rather than prose it would have to string-match, and the SPA refreshes the access token once and retries. Refreshing re-reads membership from the database, so the retry succeeds. Once per mount: if a fresh token still says not a member, that is the truth and it gets shown. The SPA had stored a refresh token since Phase 8 and never used it. It does now. Found in a browser, doing the ordinary thing — the automated run never sees it, because e2e.py logs in after being added to the group. Tests: 233 node+common, including a handshake test that the refusal carries the code, and the full e2e run against the live deployment. 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