Vss

[dcorral]

VSS Cloud Backup Integration

Adds optional cloud backup support using LDK's VSS (Versioned Storage Service). When enabled, the node replicates its state to a remote VSS server for disaster recovery on a new device.

What it does

• LDK channel state backup: A SyncedKvStore wrapper writes every KVStoreSync operation to both local SQLite and a remote VSS server. Local is primary; VSS replication is best-effort. On a fresh start with an empty local DB, state is automatically restored from VSS.
• RGB wallet backup: Configures rgb-lib's built-in VSS backup (configure_vss_backup()) for automatic backups after every state-changing wallet operation.
• Both streams use the same VSS server with separate store IDs. Backups are encrypted by default (XChaCha20-Poly1305). Signing key derived at m/535'/1'.

New files

• src/synced_kv_store.rs — KVStore wrapper: local + optional VSS replication
• src/vss_kv_store.rs — KVStore implementation backed by a VSS server
• src/test/vss.rs — Unit and integration tests
• docker/vss-server/ — Dockerfile for the VSS server (sigs-auth)

API

• POST /vssbackup — trigger manual RGB wallet backup
• GET /vssbackupinfo — check backup status

Usage

cargo build --features vss
cargo run --features vss -- /tmp/rlndata --vss-url http://localhost:8081/vss

Entirely opt-in: --features vss at compile time + --vss-url at runtime. Without these, the node behaves exactly as before.