diff options
Diffstat (limited to 'packages/meshbay-node')
3 files changed, 199 insertions, 19 deletions
diff --git a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py index d36b812..59198d5 100644 --- a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py +++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py @@ -2656,12 +2656,18 @@ class WebRTCPeerSession: # ── Node management (D5) ───────────────────────────────────────────────── async def _do_node_status(self, msg: dict) -> None: - """All groups, roots, peers — the operator's overview.""" + """All groups, roots, peers — the operator's overview. + + Including every root's absolute path, which is why this is gated on a + proved operator device and not on an account the hub named. + """ node_uid = self._ctx.get("node_user_id") - log.info("node_status: user=%s node_user=%s admin=%s", - self._user_id, node_uid, self._is_node_admin()) - if not self._is_node_admin(): - self._send({"type": "error", "detail": "Not the node operator"}) + log.info("node_status: user=%s node_user=%s owner=%s device=%s", + self._user_id, node_uid, self._is_node_admin(), + "confirmed" if self._device_confirmed else "unidentified") + if not await self._operator_device(): + self._send({"type": "error", "detail": "Not the node operator", + "code": "not_operator"}) return try: result = await self._run_op(ops.list_groups) @@ -2673,8 +2679,9 @@ class WebRTCPeerSession: self._send({"type": "error", "detail": "Internal error"}) async def _do_node_settings_set(self, msg: dict) -> None: - if not self._is_node_admin(): - self._send({"type": "error", "detail": "Not the node operator"}) + if not await self._operator_device(): + self._send({"type": "error", "detail": "Not the node operator", + "code": "not_operator"}) return settings = msg.get("settings", {}) if not settings: @@ -2691,8 +2698,9 @@ class WebRTCPeerSession: self._send({"type": "error", "detail": "Internal error"}) async def _do_roster_read(self, msg: dict) -> None: - if not self._is_node_admin(): - self._send({"type": "error", "detail": "Not the node operator"}) + if not await self._operator_device(): + self._send({"type": "error", "detail": "Not the node operator", + "code": "not_operator"}) return group_id = str(msg.get("group_id", "")).strip() try: @@ -2705,8 +2713,9 @@ class WebRTCPeerSession: self._send({"type": "error", "detail": "Internal error"}) async def _do_denylist_read(self, msg: dict) -> None: - if not self._is_node_admin(): - self._send({"type": "error", "detail": "Not the node operator"}) + if not await self._operator_device(): + self._send({"type": "error", "detail": "Not the node operator", + "code": "not_operator"}) return try: result = await self._run_op(ops.read_denylist) @@ -2718,8 +2727,9 @@ class WebRTCPeerSession: self._send({"type": "error", "detail": "Internal error"}) async def _do_denylist_clear(self, msg: dict) -> None: - if not self._is_node_admin(): - self._send({"type": "error", "detail": "Not the node operator"}) + if not await self._operator_device(): + self._send({"type": "error", "detail": "Not the node operator", + "code": "not_operator"}) return subject = str(msg.get("subject", "")).strip() try: @@ -2815,8 +2825,9 @@ class WebRTCPeerSession: log.error("Reload after group_detach failed: %s", e) async def _do_node_reload(self, msg: dict) -> None: - if not self._is_node_admin(): - self._send({"type": "error", "detail": "Not the node operator"}) + if not await self._operator_device(): + self._send({"type": "error", "detail": "Not the node operator", + "code": "not_operator"}) return state = self._ctx.get("daemon_state") reload_fn = state.get("reload_fn") if state else None @@ -5173,15 +5184,56 @@ class WebRTCPeerSession: def _is_node_admin(self) -> bool: """ - Whether the peer on this connection is the node's operator. + Whether the **account** on this connection is the one the node belongs to. - Was written out twice — once in the handshake ack and once at the gate - below it — which is how the two come to disagree. From the node's own - record of who it belongs to, never from a hub claim. + This is a display hint and half of a check — never authority on its own. + `self._user_id` is the `sub` of a JWT the hub issued, so read alone it + says "the hub says you are the owner", which is the one thing NS4 and + M3 rule out: a hub that can name the operator can install itself as + node administrator. It rides the handshake ack so a client knows whether + to offer the Node page at all, and every operation is gated on + `_operator_device()` below. """ node_user_id = self._ctx.get("node_user_id") return bool(node_user_id and self._user_id == node_user_id) + async def _operator_device(self) -> bool: + """ + Whether this connection may run the node's own controls. + + Two things, and the second is the one that cannot be forged: + + - the account is the one this node belongs to (`_is_node_admin`), which + is what keeps node-wide controls with the machine's owner rather than + with every paired operator of every group on it; and + - **the device on this connection proved a key the node pinned as an + operator**. `device_hello` is signed over a transcript naming this + node, this 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 second clause is the fix for the door this used to leave open. + `node_status`, `node_settings_set`, `roster_read`, `denylist_read`, + `denylist_clear` and `node_reload` were gated on the account id alone — + a value the hub chooses. An active hub that can also reach the group key + (which §3.5 concedes it can in an open-join group) could therefore mint + a token for the owner's account and read `node_status`, which lists + every group on the node with the operator's **absolute paths**, or clear + the denylist, which is the persisted revocation H4 exists to keep. + + It holds no user keys and cannot countersign anything, so it cannot + produce a `device_hello` — which is the same property device linking + rests on (§3.3), applied to the node's own surface. + """ + if not self._is_node_admin(): + return False + if not self._device_confirmed or not self._pinned_pk: + return False + roster = self._ctx.get("roster") + if roster is None: + return False + return self._pinned_pk in await roster.operator_pks() + def _has_admin_authority(self) -> bool: """ Cheap synchronous pre-check: is there anyone who could authorize this? diff --git a/packages/meshbay-node/tests/test_node_status.py b/packages/meshbay-node/tests/test_node_status.py index 091b1db..897be33 100644 --- a/packages/meshbay-node/tests/test_node_status.py +++ b/packages/meshbay-node/tests/test_node_status.py @@ -110,6 +110,13 @@ async def _session( session._group_id = GROUP session._user_id = "grenet" if operator else "mallory" session._username = session._user_id + # The device on the connection, as `device_hello` leaves it. Node-wide + # controls are gated on a key the node pinned as an operator and *proved* + # on this connection, not on the account id in the token — a hub can choose + # the second and cannot produce the first (NS4, M3). A fixture that sets + # only the account tests a check that is no longer the check. + session._pinned_pk = pk_op if operator else "" + session._device_confirmed = bool(operator) session._pk_user = "" session._uploads = {} session._admin_ops = {} diff --git a/packages/meshbay-node/tests/test_security_regressions.py b/packages/meshbay-node/tests/test_security_regressions.py index 988aa46..fa55ff6 100644 --- a/packages/meshbay-node/tests/test_security_regressions.py +++ b/packages/meshbay-node/tests/test_security_regressions.py @@ -837,3 +837,124 @@ def test_node_control_api_serves_no_html(): for gone in ("_render_page", "_render_audit_page", "_render_roster", "_AUDIT_HTML"): assert not hasattr(ui_app, gone), f"{gone} came back — HTML surface" + + +# ── NS4 / M3: the node's own controls take no authority from the hub ───────── + +async def _owner_session(tmp_path, roster, *, device: str = "", + confirmed: bool = False): + """A session whose token says it is the account this node belongs to. + + Which is all a hub can decide: `_user_id` is the `sub` of a JWT it issued, + so this is what an active hub forging a token arrives holding. Whether the + *device* on the connection is one the node pinned as an operator is the + other half, and no token can assert it. + """ + from meshbay_node.indexer.group_index import GroupIndex + + shared = tmp_path / "shared" + shared.mkdir(exist_ok=True) + index = GroupIndex(group_id="g" * 32, sk_node=Ed25519PrivateKey.generate()) + session = WebRTCPeerSession.__new__(WebRTCPeerSession) + session._ctx = { + "roots": one_root(shared), "index": index, "sk_node": index.sk_node, + "gek": generate_gek(), "roster": roster, + "node_user_id": "the-owner", + "daemon_state": {"groups_ctx": {}, "reload_fn": None}, + } + session._group_id = "g" * 32 + session._user_id = "the-owner" + session._username = "the-owner" + session._pinned_pk = device + session._device_confirmed = confirmed + session._pk_user = "" + session.sent = [] + session._send = session.sent.append + session._audit = lambda *a, **k: None + return session + + +@pytest.mark.asyncio +async def test_a_token_naming_the_owner_is_not_node_authority(tmp_path): + """ + The hub holds no user keys, so it cannot countersign a device — but it does + choose what a token says. Six node-wide controls used to be gated on the + account id alone, which is the hub's to decide: `node_status` (every group + on the machine, with the operator's absolute paths), `node_settings_set`, + `roster_read`, `denylist_read`, `denylist_clear` (the persisted revocation + H4 exists to keep) and `node_reload`. + + An active hub reaches a completed handshake wherever it can also obtain the + group key, which §3.5 concedes it can in an open-join group. From there, + "the hub says you are the owner" was the whole of the check. + """ + from meshbay_node.roster import Roster + + roster = Roster(db_path=tmp_path / "roster.db") + await roster.open() + try: + forged = await _owner_session(tmp_path, roster) + await forged._do_node_status({}) + assert forged.sent[-1]["type"] == "error" + assert forged.sent[-1]["code"] == "not_operator" + + forged.sent.clear() + await forged._do_denylist_read({}) + assert forged.sent[-1]["type"] == "error" + + forged.sent.clear() + await forged._do_denylist_clear({"subject": ""}) + assert forged.sent[-1]["type"] == "error", ( + "clearing the denylist undoes a revocation every node enforces") + finally: + await roster.close() + + +@pytest.mark.asyncio +async def test_an_identified_device_that_is_not_an_operator_is_refused(tmp_path): + """Being a pinned member of the group is not being the node's operator. + + The device proof is real here; what it proves is an ordinary member's key, + and `operator_pks()` is rebuilt from the roster on every call so a revoked + one stops working at once. + """ + from meshbay_node.roster import Roster + from meshbay_common.crypto import pk_to_b64 + + roster = Roster(db_path=tmp_path / "roster.db") + await roster.open() + try: + sk = Ed25519PrivateKey.generate() + member_pk = pk_to_b64(sk.public_key()) + await roster.pin_identity("the-owner", "the-owner", member_pk, + member_pk, "code") + session = await _owner_session(tmp_path, roster, device=member_pk, + confirmed=True) + await session._do_node_status({}) + assert session.sent[-1]["type"] == "error" + finally: + await roster.close() + + +@pytest.mark.asyncio +async def test_a_paired_operator_device_is_what_opens_it(tmp_path): + """The positive case, so the test above is about authority and not about + everything being refused.""" + from meshbay_node.roster import Roster + from meshbay_common.join import ROLE_OPERATOR + from meshbay_common.crypto import pk_to_b64 + + roster = Roster(db_path=tmp_path / "roster.db") + await roster.open() + try: + sk = Ed25519PrivateKey.generate() + pk = pk_to_b64(sk.public_key()) + await roster.pin_identity("the-owner", "the-owner", pk, pk, "code") + await roster.set_member("", "the-owner", ROLE_OPERATOR, "active", + "local-cli") + session = await _owner_session(tmp_path, roster, device=pk, + confirmed=True) + await session._do_denylist_read({}) + assert session.sent[-1]["type"] != "error", session.sent[-1] + finally: + await roster.close() |