Extract MPC into a separate crate

crates/e2e-tests/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2024"
 
 [dependencies]
 hashi = { path = "../hashi" }
+mpc = { path = "../mpc" }
 hashi-screener = { path = "../hashi-screener", features = ["test-utils"] }
 hashi-types = { path = "../hashi-types" }
 

crates/e2e-tests/src/lib.rs

@@ -655,7 +655,7 @@ mod tests {
                 mgr.committee.clone()
             };
             let (refill_tx, _) = tokio::sync::watch::channel(0u32);
-            let signing_manager = hashi::mpc::SigningManager::new(
+            let signing_manager = mpc::SigningManager::new(
                 info.address,
                 committee,
                 t,
@@ -679,9 +679,8 @@ mod tests {
         epoch: u64,
         sui_request_id: sui_sdk_types::Address,
         global_presig_index: u64,
-    ) -> Vec<
-        hashi::mpc::types::SigningResult<fastcrypto::groups::secp256k1::schnorr::SchnorrSignature>,
-    > {
+    ) -> Vec<mpc::types::SigningResult<fastcrypto::groups::secp256k1::schnorr::SchnorrSignature>>
+    {
         let beacon_value = S::rand(&mut rand::thread_rng());
         let sign_futures: Vec<_> = nodes
             .iter()
@@ -691,7 +690,7 @@ mod tests {
                     .signing_manager_for(epoch)
                     .unwrap_or_else(|| panic!("SigningManager not initialized for epoch {epoch}"));
                 let onchain_state = node.hashi().onchain_state().clone();
-                let p2p_channel = hashi::mpc::rpc::RpcP2PChannel::new(
+                let p2p_channel = hashi::mpc_p2p_channel::RpcP2PChannel::new(
                     onchain_state,
                     epoch,
                     hashi::metrics::MPC_LABEL_SIGNING,
@@ -709,7 +708,7 @@ mod tests {
                             &beacon,
                             None,
                             SIGNING_TIMEOUT,
-                            &metrics,
+                            &metrics.mpc,
                         )
                         .await
                 }
@@ -720,9 +719,7 @@ mod tests {
 
     fn assert_all_signatures_match(
         results: Vec<
-            hashi::mpc::types::SigningResult<
-                fastcrypto::groups::secp256k1::schnorr::SchnorrSignature,
-            >,
+            mpc::types::SigningResult<fastcrypto::groups::secp256k1::schnorr::SchnorrSignature>,
         >,
     ) {
         let mut signatures = Vec::new();

crates/hashi/Cargo.toml

@@ -12,6 +12,7 @@ sui-transaction-builder.workspace = true
 sui-futures = { workspace = true }
 
 hashi-types = { path = "../hashi-types" }
+mpc = { path = "../mpc" }
 
 # Bitcoin dependencies
 bitcoin.workspace = true

crates/hashi/src/constants.rs

@@ -19,9 +19,7 @@ pub const BITCOIN_SIGNET_CHAIN_ID: &str =
 pub const BITCOIN_REGTEST_CHAIN_ID: &str =
     "0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206";
 
-/// Trigger presignature refill when remaining presignatures drop to
-/// `initial_pool_size / PRESIG_REFILL_DIVISOR`.
-pub const PRESIG_REFILL_DIVISOR: usize = 2;
+pub use mpc::constants::PRESIG_REFILL_DIVISOR;
 
 pub fn is_production_sui_chain(chain_id: &str) -> bool {
     chain_id == SUI_MAINNET_CHAIN_ID || chain_id == SUI_TESTNET_CHAIN_ID

crates/hashi/src/db.rs

@@ -18,7 +18,7 @@ use hashi_types::committee::EncryptionPrivateKey;
 
 use serde::de::DeserializeOwned;
 
-use crate::mpc::types::RotationMessages;
+use mpc::types::RotationMessages;
 
 pub struct Database {
     db: fjall::Database,
@@ -442,13 +442,13 @@ fn prune_keyspace(keyspace: &Keyspace, cutoff_epoch: u64) -> Result<()> {
 
 #[cfg(test)]
 mod tests {
-    use crate::mpc::EncryptionGroupElement;
     use fastcrypto_tbls::nodes::Node;
     use fastcrypto_tbls::nodes::Nodes;
     use fastcrypto_tbls::threshold_schnorr::avss;
     use fastcrypto_tbls::threshold_schnorr::batch_avss;
     use hashi_types::committee::EncryptionPrivateKey;
     use hashi_types::committee::EncryptionPublicKey;
+    use mpc::EncryptionGroupElement;
     use sui_sdk_types::Address;
 
     use super::Database;
@@ -1069,7 +1069,7 @@ mod tests {
     #[test]
     fn test_epoch_store_writes_at_explicit_epoch_not_self_epoch() {
         use crate::storage::EpochPublicMessagesStore;
-        use crate::storage::PublicMessagesStore;
+        use mpc::PublicMessagesStore;
         use std::collections::BTreeMap;
         use std::num::NonZeroU16;
 

crates/hashi/src/grpc/mod.rs

@@ -42,19 +42,19 @@ impl HttpService {
         Self { inner: hashi }
     }
 
-    pub(crate) fn metrics(&self) -> &crate::metrics::Metrics {
-        &self.inner.metrics
-    }
-
     pub async fn start(self) -> (std::net::SocketAddr, Service) {
         let router = {
             let max_decoding_message_size = self.inner.config.grpc_max_decoding_message_size();
             let bridge_service =
                 hashi_types::proto::bridge_service_server::BridgeServiceServer::new(self.clone())
                     .max_decoding_message_size(max_decoding_message_size);
-            let mpc_service =
-                hashi_types::proto::mpc_service_server::MpcServiceServer::new(self.clone())
-                    .max_decoding_message_size(max_decoding_message_size);
+            let mpc_service = hashi_types::proto::mpc_service_server::MpcServiceServer::new(
+                mpc::MpcServiceImpl::new(
+                    self.inner.mpc_state.clone(),
+                    Arc::new(self.inner.metrics.mpc.clone()),
+                ),
+            )
+            .max_decoding_message_size(max_decoding_message_size);
 
             let (health_reporter, health_service) = tonic_health::server::health_reporter();
 
@@ -136,32 +136,9 @@ impl HttpService {
         (local_addr, service)
     }
 
-    pub fn mpc_manager(
-        &self,
-    ) -> Result<Arc<std::sync::RwLock<crate::mpc::MpcManager>>, tonic::Status> {
-        self.inner
-            .mpc_manager()
-            .ok_or_else(|| tonic::Status::unavailable("DKG manager not yet initialized"))
-    }
-
-    pub fn signing_manager_for(
-        &self,
-        epoch: u64,
-    ) -> Result<Arc<crate::mpc::SigningManager>, tonic::Status> {
-        self.inner.signing_manager_for(epoch).ok_or_else(|| {
-            tonic::Status::unavailable(format!(
-                "SigningManager not available for epoch {epoch}; retry"
-            ))
-        })
-    }
-
     pub fn btc_monitor(&self) -> &crate::btc_monitor::monitor::MonitorClient {
         self.inner.btc_monitor()
     }
-
-    pub fn get_reconfig_signature(&self, epoch: u64) -> Option<Vec<u8>> {
-        self.inner.get_reconfig_signature(epoch)
-    }
 }
 
 async fn health() -> impl axum::response::IntoResponse {