Per ADR-038, DerivedKey.private_key now derives Zeroize with #[zeroize(drop)]
ensuring sensitive key material is zeroized before deallocation. DerivedKey
is now move-only (no Clone), and JSON/debug output redacts private_key as
"[REDACTED]". Deserialization still works for postcard/irpc wire format.
Also fixes clippy needless_borrows_for_generic_args in encryption.rs and
applies cargo fmt to existing code.
Create the alknet-secret crate with BIP39 mnemonic generation, SLIP-0010
Ed25519 HD key derivation, AES-256-GCM encryption, and SecretProtocol
irpc service definition. This is Phase 3.1 from the integration plan.
Architecture changes:
- Promote secret-service.md to reviewed status with full spec format
(crate structure, public API, security model, phase progression,
ADR/OQ cross-references, wire format compatibility section)
- Add ADR-038 (seed lifecycle and memory security): zeroize for v1,
mlock deferred to Phase B
- Add OQ-SEC-01 (mlock/VirtualLock for seed RAM) to open-questions.md
- Update README.md with ADR-038 and secret-service status
Crate structure:
- src/mnemonic.rs: BIP39 phrase generation, validation, seed derivation
- src/derivation.rs: SLIP-0010 HD key derivation, path constants (74')
- src/encryption.rs: AES-256-GCM encrypt/decrypt, EncryptedData type
- src/protocol.rs: SecretProtocol irpc enum, DerivedKey, KeyType
- src/service.rs: SecretServiceHandle with Unlock/Lock lifecycle
- 40 passing tests (unit + integration + doc)
