Mirrors/MeshCore-Solo
1
0
Fork 0
mirror of https://github.com/MarekZegare4/MeshCore-Solo.git synced 2026-09-14 15:16:40 +00:00
Code Issues Packages Projects Releases Wiki Activity

feat(sim): sim_radio_get_params export + fix identity-collision RNG bug

Browse Source 
meshcore-solo-site's new cross-visitor relay bridge (Phase 3) needs a way
to read a sim instance's live freq/bw/sf/cr so a WebSocket relay server
can fan traffic out only to other visitors tuned to the same params,
mirroring real LoRa channel isolation. Added sim_radio_get_params()
(examples/companion_radio/main.cpp), reading NodePrefs directly -- the
real live source of truth, since SimRadio::setParams() has always been a
complete no-op (accepts and discards its arguments). Out-params via
pointer, same buffer-pointer idiom sim_radio_poll_tx() already uses;
build_wasm.sh needed HEAPF32/HEAP32 added to EXPORTED_RUNTIME_METHODS so
JS can read them back.

While testing the relay bridge with two independent browser contexts, hit
a real bug: sim_instance_salt() (SimInstance.h) is a pure function of the
simInstanceTag STRING ('hero'/'B'/'R'), so it's only useful for telling
apart same-tab instances -- it's identical for two genuinely different
visitors who both boot a 'hero' instance. Combined with SimRNG::begin()'s
other seed ingredients -- time(NULL) (1-second resolution) and a WASM
heap pointer (no ASLR inside the sandbox, so it's fully deterministic
across independent boots of the same binary) -- two different visitors
landing on the same wall-clock second reliably generated byte-identical
Ed25519 identities (confirmed: two fresh browser contexts launched
together produced provably identical advert packets end to end).

Fixed by mixing in real crypto.getRandomValues()-sourced entropy from the
host page (new sim_instance_entropy(), read the same way simInstanceTag
already is) into both SimRNG::begin() and the twin seeding pattern in
SimRadio::getRngSeed(). Applies to every sim instance uniformly (hero/B/R
all get proper per-session entropy now), not just the new relay path --
strictly an improvement with no compatibility concern, since identity
generation only ever runs once per fresh/empty IDBFS.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018iubftDmKNWmkNnhJRz8UH
This commit is contained in:
Jakub
2026-09-04 19:12:36 +02:00
co-authored by Claude Sonnet 5
parent 80c375427a
commit cc01583d53
5 changed files with 69 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
variants/sim/SimRadio.h
+8 -1
View File
@@ -116,7 +116,14 @@ public:
// time(NULL) second, same `rand()` process state, often the same
// `this` address across independent-but-identically-laid-out linear
// memories) and end up with correlated "random" behaviour.
return (uint32_t)time(NULL) ^ (uint32_t)(uintptr_t)this ^ (uint32_t)rand() ^ sim_instance_salt();
// sim_instance_entropy(): same reasoning, but for two genuinely
// different browser tabs/machines both booting a same-tagged instance
// (e.g. two different visitors' 'hero') -- salt alone is a pure
// function of the tag string, identical for both; this mixes in real
// crypto.getRandomValues()-sourced entropy from the host page. See
// SimInstance.h and SimRNG.h for the full story (found while testing
// meshcore-solo-site's cross-visitor relay bridge).
return (uint32_t)time(NULL) ^ (uint32_t)(uintptr_t)this ^ (uint32_t)rand() ^ sim_instance_salt() ^ sim_instance_entropy();
}
void getFreqBounds(float& min_mhz, float& max_mhz) const {