jwinterm
e2beb17dda
Phase 0 of grin support, reworked clean from the chain-audit playbook. The
open backend is NON-CUSTODIAL and holds no Grin spend key, so this is a
VIEW-ONLY client — NOT a port of the reference's spend-capable Owner-API
driver. Rationale + the grin-lws plan: docs/private/GRIN_LWS_DESIGN.md.
Model: Grin has had view/spend separation since 2021 (grin_keychain::ViewKey;
rewind_hash = blake2b of the PUBLIC root key). grin-wallet's Owner API
scan_rewind_hash(rewind_hash, start_height) does the chain scan and returns a
ViewWallet{output_result, total_balance, last_pmmr_index} (incremental). This
client drives that; the wallet builds + signs txs locally and hands the backend
only the finalized tx to broadcast.
Surface (view-only): open_wallet (operator scan-engine token, cached),
scan_rewind_hash -> ViewWallet, node get_status/get_height, broadcast
(node Foreign push_transaction). DROPPED: all spend methods (init_send_tx,
finalize, balance, cancel) and the node rangeproof-scan paths (scan_rewind_hash
does the scanning).
Hardened Owner-API v3 secure transport (ECDH secp256k1 + AES-256-GCM):
- session init is TOCTOU-free (re-checked under the write lock);
- AES-GCM nonce counter advances with checked_add and is never reused
(overflow -> error, not wrap);
- the ECDH shared key, wallet password, and response bodies are NEVER logged
or interpolated into errors (errors carry a static label + numeric code);
- tokio (non-poisoning) RwLock for the token + session;
- typed Ok/Err envelopes deserialized directly (no Value clone of ViewWallet);
- bounded streaming response read (16 MiB) + request/connect timeouts;
- secrets wrapped in core::secret::Secret.
8 L2 tests: AES-GCM encrypt/decrypt round-trip, nonce monotonicity + byte
layout, nonce-exhaustion-errors-not-panics, wrong-key auth rejection, bad
nonce/ciphertext rejection, Ok/Err/rpc-error envelope mapping (message not
surfaced), construction without I/O, confirmation math (tip/zero/future).
smirk-backend-core
Open, self-hostable backend for the Smirk non-custodial, multi-chain wallet. It provides the chain-access and identity surface a Smirk wallet needs — authentication, per-chain wallet access (Bitcoin, Litecoin, Monero, Wownero, Grin), the Grin slatepack relay, and Nostr-based identity — so anyone can run their own backend and a Smirk wallet can connect to it.
Status: early, under active development. Interfaces and the database schema may change before the first tagged release. Not yet recommended for production self-hosting.
What it is
- Non-custodial. The server never holds spend keys or seeds. It brokers access to blockchain data and relays wallet-to-wallet messages.
- Open core, feature-flagged. Every feature ships in this codebase and is
toggled per deployment; the wallet reads
GET /api/v1/capabilitiesand adapts to what a given backend offers. - Identity via "Sign in with Smirk". Authentication uses a seed-derived Nostr key (NIP-98); the server stores only public keys.
- Privacy first. No PII is required to use it; operator and user privacy are explicit design goals.
Architecture
Rust + Axum, PostgreSQL via sqlx. The public HTTP contract is generated from the handlers with utoipa (OpenAPI), which in turn drives the wallet's generated TypeScript client — one source of truth, checked for drift in CI.
Quickstart
cp .env.example .env # then fill in DATABASE_URL, JWT_SECRET, node URLs
cargo run # starts the API server
A full self-hosting guide (node requirements, reverse proxy, Tor admin onion,
backups) will live in docs/ as it stabilises.
Security
Please report vulnerabilities privately — see SECURITY.md. Do not open public issues for security reports.
License
To be finalized (MIT vs AGPL-3.0-or-later). Until a LICENSE file is added,
all rights are reserved.