Drops irpc from alknet-vault entirely. The vault's dispatch is now direct
method calls on VaultServiceHandle — no VaultProtocol enum, no
VaultMessage, no VaultServiceActor, no mpsc channel, no Service trait, no
RemoteService trait, no postcard serialization. The vault is local-only by
construction.
The core security argument: irpc made the vault remote-capable by default
(RemoteService generated unless no_rpc is passed). The IrohProtocol handler
forwards all messages without auth. The docs framed 'register an ALPN' as a
server-setup change. This is the default-insecure anti-pattern — security
should be opt-in, not opt-out. ADR-025 inverts the default: local-only is
the only mode, and remote access requires building a separate vault-server
crate (a visible architectural act, not a flag flip).
The actor path was already dead code — service.md said 'prefer
VaultServiceHandle directly — no channel, no serialization.' The actor
existed only to make irpc's Service trait work, which existed only to make
RemoteService work, which was the footgun. VaultServiceHandle's
Arc<RwLock> provides concurrent reads and exclusive writes — better
throughput than the actor's sequential processing.
DerivedKey serialization simplifies: always redact on serialize (for
logging safety), reject '[REDACTED]' on deserialize with an error. No
'postcard preserves bytes' path. This resolves review #002 W8 (silent
corruption on JSON-deserialized DerivedKey).
Resolves:
- OQ-21: remote vault access — resolved (not deferred). Not a vault crate
feature; if needed, a separate vault-server crate with its own ADR.
- C7: vault-server-crate question decided — not created now, not precluded.
- C8: operation access policy table dissolved — all operations local-only
by default; if a vault-server crate exposes some remotely, that crate
defines the policy.
- W8: DerivedKey JSON deserialization — resolved (reject redacted payloads).
Amends ADR-005 (irpc remains for alknet-call, not for alknet-vault),
ADR-018 (vault is even more standalone — zero RPC framework deps),
ADR-019 (vault is the only layer, not just the only direct-caller layer),
ADR-008 (vault integration point unchanged, but now local-only by
construction).
Spec the vault crate from its existing implementation. The vault is
stable (implementation exists); this spec documents what IS so the
implementation-sync agent can reconcile source drift.
New spec documents (crates/vault/):
- README.md — crate index, security constraints, public API
- mnemonic-derivation.md — BIP39, SLIP-0010, BIP-0032, derivation paths
- encryption.md — AES-256-GCM, EncryptedData, key versioning, salt
- service.md — VaultServiceHandle lifecycle, actor dispatch, cache
- protocol.md — VaultProtocol irpc messages, DerivedKey redaction
New ADRs:
- ADR-018: Vault as standalone crate (zero alknet deps; own types/errors)
- ADR-019: Vault assembly-layer-only access (CLI is sole caller)
New open questions:
- OQ-20: Salt/KDF Phase B (open, low priority — salt field reserved)
- OQ-21: Remote vault administration (deferred — needs ADR if ever needed)
- OQ-22: Key rotation mechanism (open, low priority — workflow not specced)
Spec-vs-source drift explicitly flagged (for the sync agent):
- rand::random() used for IVs instead of OsRng (security-critical)
- unwrap() on every RwLock acquisition (must use unwrap_or_else)
- ADR-038 / OQ-SVC-03 references in source comments are stale (old numbering)
- VaultServiceActor::spawn returns a non-functional second actor (source bug)
- KeyVersionMismatch error variant is defined but unused in v1
