Review fix (Important secret-hygiene finding): export_state_bytes built a
PersistedDeviceState via state.signing_private.as_str().to_owned(), creating
non-zeroized heap copies of the device ed25519 private keys (signing + deploy)
that lingered as plaintext residue after the struct dropped.
- Cargo.toml: enable zeroize "derive" feature (zeroize_derive already in lock tree)
- device.rs: PersistedDeviceState now derives Zeroize + ZeroizeOnDrop, wiping all
String fields on every drop path (success, serde_json::to_vec ? error path, panic)
- device.rs: import_state_bytes uses std::mem::take per field (ZeroizeOnDrop adds a
Drop impl, so fields can no longer be moved out — E0509); mem::take transfers the
heap buffers without copying, leaving empty Strings the drop-zeroize no-ops
- doc-comments updated to describe the ZeroizeOnDrop / mem::take hygiene
Hygiene-only; no behavior change. Gates: cargo test -p relicario-wasm 15/15,
clippy -D warnings clean, build --target wasm32-unknown-unknown clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014s527M917W47LDrfQ4t47g
e6ec210736