zooqueen
861db0f621
Two halves of opening a secret were missing, and both showed up the first time this ran against the real ring rather than an in-process one. The request reached no party. Parties subscribed to "mpc.reveal_request.*" and the requester published to "mpc.reveal_request.<session>". This transport delivers by exact map lookup on the topic — it has no wildcards — so the subscription matched nothing, every node stayed silent, and the opening failed as "0 of 2 answered" with all three shares present and nobody having been asked. That reads like a quorum fault and is a routing one. Both sides name one literal now; the session rides in the body, where a reader wants it anyway. The pattern came from the NATS-era topics next door, where wildcards do work. And nothing could seal. mpcrek requires a sealed root to bring and no tool in the estate produced one, so the protocol had no beginning. reveal.Seal takes the published group key and a secret — no share, no node, no round, because writing to the committee needs none of that — and `mpcd seal` is that from a shell, with the secret on stdin so it never becomes an argument other processes can read. Sealing to the identity is refused. It decodes as a valid point, so the decoder lets it through, and every answer verifies against it: a secret sealed there is readable by anyone. A test asked for that and the first version did not do it.
mpcd — MPC Daemon
mpcd is a threshold-signature daemon. It speaks ZAP wire protocol over
TLS 1.3 directly between peers — no NATS, no Consul, no PostgreSQL in the
critical path. The daemon is the same binary in every deployment shape;
the operating mode is selected entirely by flags.
Operating modes
There is exactly one start command (mpcd start) and the topology is
determined by the --peer and --threshold flags:
| Topology | Flags | Use |
|---|---|---|
| Standalone (1-of-1 self-loop) | --threshold 1 (no --peer) |
Smoke tests, dev sandbox |
| Networked t-of-n cluster | --threshold t --peer ... (n−1 peers) |
Production |
In all cases mpcd runs the consensus-embedded transport
(pkg/transport). The "consensus" here is local PoA membership over the
node's own Ed25519 identities — it is intentionally not the Lux mainnet
chain, because key shares must never leave the cluster.
Standalone (1-of-1)
mpcd start \
--node-id solo \
--listen :9999 \
--api :9800 \
--data /var/lib/mpcd \
--threshold 1
Starts mpcd with itself as the only quorum member. /healthz will report
signing_quorum: true immediately. Keygen and signing of fresh wallets
require ≥2 parties — CGGMP21 and FROST cannot produce shares with a
single party — so this mode exists only for boot-up smoke tests, e2e
harness fixtures, and verifying TLS / membership / API plumbing. For real
signing, run a multi-node cluster.
Networked (t-of-n)
# Node 0
mpcd start --node-id node0 --listen :9999 --api :9800 \
--data /data/node0 --threshold 2 \
--peer [email protected]:9999 --peer [email protected]:9999
# Node 1
mpcd start --node-id node1 --listen :9999 --api :9800 \
--data /data/node1 --threshold 2 \
--peer [email protected]:9999 --peer [email protected]:9999
# Node 2 — same pattern
The daemon expects the cluster size n = len(peers) + 1 and rejects start
when threshold > n. See pkg/transport/registry.go::HasSigningQuorum for
the quorum arithmetic.
Smoke test
go test -tags=integration ./cmd/mpcd/... -count=1 -timeout 90s
standalone_test.go builds mpcd, runs it with --threshold 1 on free
ports and a fresh data directory, polls /healthz until quorum holds,
and asserts the response shape. It does not exercise keygen — see e2e/
for that.