Files
firmware/test/test_admin_session_repro
Thomas Göttgens 8147970957 AdminModule: only accept admin responses to requests we sent (#11024)
* AdminModule: only accept admin responses to requests we sent

An admin *_response short-circuited the auth and session-passkey checks that gate
every other admin message, so any node could deliver one. On a channel the module
listens to unauthenticated, a get_module_config_response drives the remote-hardware
pin handler with attacker-supplied values.

Track the destination of outgoing admin requests (per remote, with the pinned PKC
key when there is one) and accept a response only from a node with a matching
outstanding request, inside the same window as the session passkey. Local (from == 0)
admin is unchanged; PhoneAPI already gates it.

Also fix the response dispatch: get_module_config_response.which_payload_variant is a
ModuleConfig oneof tag, but it was compared against the AdminMessage ModuleConfigType
enum (different numbering), so the handler never ran. Compare against the oneof tag.

* AdminModule: rollover-safe request window, bind response to request type

Two review refinements to the request/response pairing:

Use Throttle::isWithinTimespanMs for the outstanding-request expiry instead of
comparing millis()/1000 sums, which mis-expired across the millis() rollover.

Bind each accepted response to a request type actually sent to that node. Each
outstanding record now carries a bitmask of the response variants its requests
authorize, so a get_owner request no longer admits a get_module_config response.
The mask accumulates per remote, so a client may still pipeline several request
types to one node and have every answer accepted.

* AdminModule: track admin requests per-request, not per-node

Reworks the outstanding-request table so each request is its own entry with its own
expiry window and pinned key, replacing the per-node bitmask that shared one timestamp
and one key across every response variant.

That sharing let a later request to the same node extend an earlier one's window and,
worse, clear its PKC pin: an unpinned request cleared keyValid, so a plaintext response
to an earlier PKC-pinned request was then accepted. Per-request entries keep each pin
intact. Identical requests are de-duplicated (a client may fetch several config subtypes,
all answered by one response variant) and eviction compares elapsed time, which is
rollover-safe.

Test: a pinned request's response still requires its key after an unpinned request to the
same node.

* AdminModule: match module-config subtype and consume answered requests

Two refinements to the request/response pairing:

Only remote_hardware get_module_config_response mutates state (the pin table), so it
must answer a request for that exact ModuleConfigType, not just any module-config
request. Each entry records the requested subtype and the gate checks it.

A matched request is now consumed on accept, so a node cannot replay a state-mutating
response within the window. Because one request yields one response, request de-dup is
dropped (a client's N indexed get_channel requests are N entries, each consumed once).

Tests: a non-remote-hardware request does not admit a remote_hardware response, and a
second copy of an answered response is rejected.
2026-07-17 07:50:41 -05:00
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