F30-MT: Yes
Rationale
The selected firmware supplies object-level authenticity for signable channel broadcasts. Router.cpp perhapsEncode signs locally originated non-PKI broadcasts when signedDataFits succeeds. CryptoEngine buildSigningBuffer binds the payload to version, sender, packet ID, recipient, port, request/reply IDs, emoji, bitfield and flags. xeddsa_verify needs that retained envelope, signature and sender public key, not a live transport session. Preserving these inputs therefore permits verification after relay delivery or storage, satisfying F30 at this bounded object scope.
Assessment method
Pinned signing and verification source trace; no runtime test
Source context
Selected Meshtastic firmware; signable broadcast witness
Outstanding qualification
Yes for XEdDSA-enabled builds and broadcasts fitting the signed encoding, with the sender public key independently trusted. Normal-mode PKI direct messages are not automatically signed by this branch and do not inherit the witness. Preserve the signed envelope, not just the payload or a serialized xeddsa_signed flag. Hop/relay fields and channel representation are outside the signature; changing covered fields invalidates it. A stored signature supplies no freshness, anti-replay guarantee, civil identity, key-revocation history or secure archival storage. This is a source-qualified capability, not an executed archive/restore test or cryptographic audit.
Public sources
- https://raw.githubusercontent.com/meshtastic/firmware/8e6a88d06f44cad26f1e8d7cd402939ccacb9b4c/src/mesh/CryptoEngine.cpp
- https://raw.githubusercontent.com/meshtastic/firmware/8e6a88d06f44cad26f1e8d7cd402939ccacb9b4c/src/mesh/Router.cpp
- https://raw.githubusercontent.com/meshtastic/firmware/8e6a88d06f44cad26f1e8d7cd402939ccacb9b4c/src/mesh/generated/meshtastic/mesh.pb.h
Editorial evidence references
The following identifiers refer to research records not included in this public package; they are not public links.
- round481.html
- round481-sources.json