Final wallet-handler slice. An async store-and-forward mailbox for interactive
Grin transfers between two registered Smirk users, over the grin_slatepacks db.
Reworked clean from the legacy relay — NOT a port.
Endpoints (under /api/v1/wallet/grin/relay, JWT-gated):
- POST create {recipient_user_id, slate_id, slatepack, amount_nanogrin}
- GET pending -> the caller's inbox
- POST get {slate_id} -> poll a relay's state (sender/recipient)
- POST respond {slate_id, response_slatepack} (recipient)
- POST finalize {slate_id, tx_hash} (sender; RECORDS the txid only)
- POST cancel {slate_id} (sender or recipient)
Non-custodial: stores only opaque (encrypted) slatepacks + lifecycle status;
never holds keys, finalizes, or broadcasts. The wallet broadcasts locally (via
/wallet/grin/broadcast) and reports the txid here — diverging from the legacy
server-side post_tx (see docs/private/OWN_BACKEND_CONVERGENCE.md).
Controls + hardening (incl. fixes from the adversarial review workflow):
- Per-action authz: caller must be the slate's sender/recipient; a non-party
gets 404 (no existence oracle).
- slate_id is UNIQUE (+ validated as a UUID) and mutations key on the
authorized row's PRIMARY KEY, not slate_id — so a duplicate slate_id can't
brick a relay (fetch_optional-on-2-rows 500) or let a slate_id-keyed UPDATE
touch another row. create maps the unique violation to 409.
- State transitions are ATOMIC: the status + expiry preconditions live in the
UPDATE WHERE clause (not a Rust read-check-write), so respond-twice and
cancel-races-finalize cannot occur; a non-qualifying transition -> 409.
- TTL enforced at the action boundary (respond/finalize require expires_at >
now) + a periodic expire_old_slatepacks sweep in main.rs (relay-enabled only).
- Recipient must be a registered user; slatepack sizes capped (64 KiB).
- Behind FEATURE_GRIN_RELAY (default on).
6 paths + schemas + grin_relay tag in openapi (drift-clean). 4 L1 integration
tests against live Postgres: full lifecycle, unregistered-recipient 400, auth
gate, non-party/non-recipient 404s.
Third wallet-handler slice. Authenticated, view-only proxies over the
GrinClient — the backend holds no Grin spend key; the wallet exports its
rewind_hash (a public-derived view credential) per scan, the backend forwards
it to grin-wallet's scan_rewind_hash and stores no secret. Spending happens in
the wallet; the backend only broadcasts the finalized tx.
Endpoints (under /api/v1/wallet/grin):
- POST scan {rewind_hash, start_height?} -> {outputs, total_balance,
last_pmmr_index} (incremental resume index)
- GET height -> {height}
- POST broadcast {tx} -> {ok} (node push_transaction)
- JWT-gated. rewind_hash is a view credential: GrinScanRequest omits Debug and
is skipped from every span (never logged), and is validated as 64 hex before
any grin call (applying the wallet-handler review's secret-DTO lesson).
- Feature-gated: grin disabled -> 400.
- Shared validate_hex64 in wallet/mod.rs (view_key + rewind_hash); 3 paths +
schemas + grin tag registered; spec regenerated, drift-clean.
4 L1 integration tests (auth gate on scan/height/broadcast; malformed
rewind_hash 400).
Also: dropped Debug from the xmr_wow view_key-bearing request DTOs
(ViewRequest/RegisterRequest) per the review — defense-in-depth against a
cleartext view_key dump.
First wallet-handler slice. Thin, non-custodial, JWT-gated proxies over the
ElectrumClient — the wallet derives addresses and signs locally; these
endpoints only relay reads and a finalized broadcast.
Endpoints (POST, under /api/v1/wallet/utxo, asset = btc|ltc in body):
- balance -> {confirmed, unconfirmed} (separate integers; client sums)
- utxos -> [{txid, vout, value, height}]
- history -> [{txid, height, fee}]
- tip -> {height}
- fee -> {sat_per_vb}
- broadcast-> {txid}
- JWT-gated for abuse control; the client-supplied address is NOT persisted
against the user (no address<->identity graph stored here).
- Feature-gated dispatch: unknown/disabled asset -> 400; the Electrum client
validates the address + network before any network call.
- broadcast validates tx_hex (non-empty, even-length, hex, <=200 KB) before
reaching the node.
- Registered in build_router + openapi.json (6 paths, btc_ltc tag); spec
regenerated, drift-clean.
5 L1 integration tests (auth gate on balance/broadcast/fee; unknown-asset and
malformed-tx-hex 400s — all deterministic, no network) + tx_hex unit test.
- api/website.rs: sign-in-with-wallet (dapp connect). challenge bound to origin
+ short TTL; verify is single-use (remove-before-verify, race-safe), expiry-
checked, signature via Result<(),AppError> verifiers (no oracle), resolves an
EXISTING user by the proven key's pubkey_hash (never mints identity), mints a
Platform::Web session.
- api/users.rs: username set/get + by-username lookup (JWT-gated, 409 on taken,
constant-shape lookup); per-asset key registration bound to the JWT user
(no spoofable user_id) + public key-directory reads.
- api/nip05.rs: /.well-known/nostr.json directory (username -> nostr_pubkey).
- Wired into api/mod.rs; website+users nested at /api/v1, nip05 at root; all
paths/schemas registered (openapi.json now 17 endpoints).
- main.rs: periodic GC of expired web challenges (bounds the in-memory store).
Adversarially reviewed (register_key authz + website identity-binding both
hold; no critical/high). 69 tests green. Deferred LOW: per-IP rate-limit on the
website routes lands with the router-assembly unit.
api/middleware.rs: Bearer access-token extraction; client_ip() trusts XFF only
behind config.trusted_proxies (fail-closed against spoofing).
api/auth.rs: extension_register (PoW-gated; derivation-rotation requires a
signature from the on-file key, no fingerprint hijack), check_restore (per-IP +
per-fingerprint rate limits, enumeration/timing-resistant), pow_challenge,
refresh_token (re-checks active session + revoke-then-issue rotation, race-safe),
logout, get_me, nostr_login (login-grade NIP-98, never creates a user, bound to
config public_api_url), nostr_link (JWT + state-change verify_signed_action,
fail-closed nonce stub) + DTOs + routes().
Wired into api/mod.rs + nested at /api/v1 in main.rs; all 8 paths registered in
ApiDoc so openapi.json covers the auth surface (was vacuous).
Drafted+hardened via draft->adversarial-review->revise workflow; independently
re-reviewed (no critical/high). 58 tests, all gates green.
Known LOW (tracked): concurrent first-registration of the same new pubkey_hash
can 500 instead of idempotent re-read; client-retryable.
- minimal Axum server exposing GET /health
- OpenAPI contract generated from handlers (gen_openapi -> openapi.json),
drift-gated in CI so the spec can never silently diverge from the code
- CI: secret-scan + gitleaks, openapi drift gate, fmt/clippy/build/test/doc-test, cargo-deny
- Cargo.lock tracked for reproducible builds; publish=false; pinned toolchain
- README, SECURITY.md, deny.toml, .env.example
jwinterm