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Merge upstream develop into packet authentication policy

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This commit is contained in:
Benjamin Faershtein
2026-07-20 11:48:59 -07:00
parent 59ab12675a 0199a1f3ff
commit 08cfb3d683
74 changed files with 836 additions and 939 deletions
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src/mesh/Router.cpp
+65 -19
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@@ -359,15 +359,6 @@ ErrorCode Router::sendLocal(meshtastic_MeshPacket *p, RxSource src)
return send(p);
}
}
/**
* Send a packet on a suitable interface.
*/
ErrorCode Router::rawSend(meshtastic_MeshPacket *p)
{
assert(iface); // This should have been detected already in sendLocal (or we just received a packet from outside)
return iface->send(p);
}
/**
* Send a packet on a suitable interface. This routine will
* later free() the packet to pool. This routine is not allowed to stall.
@@ -531,6 +522,62 @@ void Router::sniffReceived(const meshtastic_MeshPacket *p, const meshtastic_Rout
}
#if !(MESHTASTIC_EXCLUDE_PKI) && !(MESHTASTIC_EXCLUDE_XEDDSA)
/** Size a decoded Data as the sender's signedDataFits() gate would have, with padding stripped:
* unknown fields inside Data.payload survive in payload.size and would otherwise let a forger
* inflate an unsigned broadcast past the signable budget. Returns false only if sizing failed.
* Sizing only what this build's schema decodes, so a signable type that later grows needs its
* legitimate maximum re-checked against the budget or honest unsigned broadcasts get dropped. */
static bool canonicalSignableSize(meshtastic_Data *d, size_t *size)
{
const pb_msgdesc_t *fields = nullptr;
switch (d->portnum) {
case meshtastic_PortNum_POSITION_APP:
fields = &meshtastic_Position_msg;
break;
case meshtastic_PortNum_TELEMETRY_APP:
fields = &meshtastic_Telemetry_msg;
break;
case meshtastic_PortNum_WAYPOINT_APP:
fields = &meshtastic_Waypoint_msg;
break;
case meshtastic_PortNum_NODEINFO_APP:
fields = &meshtastic_User_msg;
break;
default:
break;
}
if (fields) {
// Scratch kept off the stack: these decoded structs are large for the smaller MCU targets.
// Safe as file-static state because both callers of checkXeddsaReceivePolicy hold cryptLock.
static union {
// cppcheck-suppress unusedStructMember ; written by pb_decode through &inner
meshtastic_Position position;
// cppcheck-suppress unusedStructMember ; written by pb_decode through &inner
meshtastic_Telemetry telemetry;
// cppcheck-suppress unusedStructMember ; written by pb_decode through &inner
meshtastic_Waypoint waypoint;
// cppcheck-suppress unusedStructMember ; written by pb_decode through &inner
meshtastic_User user;
} inner;
memset(&inner, 0, sizeof(inner));
size_t canonicalPayload;
if (pb_decode_from_bytes(d->payload.bytes, d->payload.size, fields, &inner) &&
pb_get_encoded_size(&canonicalPayload, fields, &inner) && canonicalPayload <= d->payload.size) {
// Only the length matters when sizing a bytes field, so swap it in place instead of
// copying the whole Data; restored below because modules still need the real payload.
const pb_size_t prevSize = d->payload.size;
d->payload.size = (pb_size_t)canonicalPayload;
const bool sized = pb_get_encoded_size(size, &meshtastic_Data_msg, d);
d->payload.size = prevSize;
return sized;
}
}
return pb_get_encoded_size(size, &meshtastic_Data_msg, d);
}
enum class NodeInfoBootstrapResult { NOT_APPLICABLE, VERIFIED, INVALID };
static NodeInfoBootstrapResult verifyFirstContactNodeInfo(meshtastic_MeshPacket *p)
@@ -557,7 +604,7 @@ static NodeInfoBootstrapResult verifyFirstContactNodeInfo(meshtastic_MeshPacket
return NodeInfoBootstrapResult::VERIFIED;
}
bool checkXeddsaReceivePolicy(meshtastic_MeshPacket *p, size_t encodedDataSize)
bool checkXeddsaReceivePolicy(meshtastic_MeshPacket *p)
{
const auto policy = config.security.packet_signature_policy;
const bool strict = policy == meshtastic_Config_SecurityConfig_PacketSignaturePolicy_PACKET_SIGNATURE_POLICY_STRICT;
@@ -617,15 +664,14 @@ bool checkXeddsaReceivePolicy(meshtastic_MeshPacket *p, size_t encodedDataSize)
return true;
// In Balanced, preserve legacy unsigned-unicast compatibility and only reject a signable
// unsigned broadcast from a known signer. encodedDataSize is
// the size of the encoded Data exactly as the sender built it (or 0 to size p->decoded
// canonically); with no signature field present it is the unsigned base, and adding
// XEDDSA_SIGNATURE_FIELD_BYTES mirrors the sender-side signedDataFits() gate per packet,
// whatever fields the Data carried. Oversized broadcasts remain compatible.
// unsigned broadcast from a known signer. Canonical sizing removes unknown protobuf
// fields before mirroring the sender-side signedDataFits() gate. Oversized broadcasts
// remain compatible.
if (nodeDB->hasSeenXeddsaSigner(p->from) && isBroadcast(p->to)) {
if (encodedDataSize == 0 && !pb_get_encoded_size(&encodedDataSize, &meshtastic_Data_msg, &p->decoded))
size_t canonicalSize;
if (!canonicalSignableSize(&p->decoded, &canonicalSize))
return true; // can't size it; never drop on a sizing failure
if (encodedDataSize + XEDDSA_SIGNATURE_FIELD_BYTES + MESHTASTIC_HEADER_LENGTH <= MAX_LORA_PAYLOAD_LEN) {
if (canonicalSize + XEDDSA_SIGNATURE_FIELD_BYTES + MESHTASTIC_HEADER_LENGTH <= MAX_LORA_PAYLOAD_LEN) {
LOG_WARN("Dropping unsigned broadcast from 0x%08x that previously signed", p->from);
return false;
}
@@ -813,8 +859,8 @@ DecodeState perhapsDecode(meshtastic_MeshPacket *p)
p->channel = chIndex; // change to store the index instead of the hash
#if !(MESHTASTIC_EXCLUDE_PKI) && !(MESHTASTIC_EXCLUDE_XEDDSA)
// Use the encoded Data size before merging local-only bitfield state.
if (!checkXeddsaReceivePolicy(p, rawSize))
// Run before merging local-only bitfield state into the decoded Data.
if (!checkXeddsaReceivePolicy(p))
return DecodeState::DECODE_POLICY_REJECT;
#endif