proactive refresh (#413)

* proactive refresh

* spec out proactive refresh endpoint

* testing framework

* store fake key

* add send key

* setup websockets

* update synedrion

* working

* errors

* more negative tests

crypto/kvdb/src/kv_manager/value.rs

@@ -1,8 +1,8 @@
 use std::{convert::TryFrom, path::PathBuf};
 
-use entropy_protocol::{KeyParams, PartyId};
+use entropy_protocol::PartyId;
 use serde::{Deserialize, Serialize};
-use synedrion::KeyShare;
+use synedrion::{KeyShare, ProductionParams};
 use tracing::{info, span, Level, Span};
 use zeroize::Zeroize;
 
@@ -24,7 +24,7 @@ pub struct Entropy(pub Vec<u8>);
 pub struct PartyInfo {
     // TODO: in the future this will probably be a mapping {party_id: [share_id, share_id, ...]}
     pub party_ids: Vec<PartyId>,
-    pub share: KeyShare<KeyParams>,
+    pub share: KeyShare<ProductionParams>,
 }
 
 /// Kv manager for grpc services

crypto/protocol/src/execute_protocol.rs

@@ -8,8 +8,8 @@ use subxt::utils::AccountId32;
 use subxt_signer::sr25519;
 use synedrion::{
     sessions::{
-        make_interactive_signing_session, make_keygen_and_aux_session, FinalizeOutcome,
-        PrehashedMessage, ToSend,
+        make_interactive_signing_session, make_key_refresh_session, make_keygen_and_aux_session,
+        FinalizeOutcome, PrehashedMessage, ToSend,
     },
     signature::{
         self,
@@ -245,3 +245,91 @@ pub async fn execute_dkg(
         }
     }
 }
+
+/// Execute proactive refresh.
+#[instrument(skip(chans, threshold_signer))]
+pub async fn execute_proactive_refresh(
+    mut chans: Channels,
+    threshold_signer: &sr25519::Keypair,
+    threshold_accounts: Vec<AccountId32>,
+    my_idx: &u8,
+    old_key: KeyShare<KeyParams>,
+) -> Result<KeyShare<KeyParams>, ProtocolExecutionErr> {
+    let party_ids: Vec<PartyId> =
+        threshold_accounts.clone().into_iter().map(PartyId::new).collect();
+    let my_id = PartyId::new(threshold_accounts[*my_idx as usize].clone());
+    let id_to_index = party_ids
+        .iter()
+        .enumerate()
+        .map(|(idx, id)| (id, PartyIdx::from_usize(idx)))
+        .collect::<HashMap<_, _>>();
+
+    let tx = &chans.0;
+    let rx = &mut chans.1;
+
+    let signer = SignerWrapper(threshold_signer.clone());
+    // TODO (#376): while `Public::from_raw` happens to work here, it is not the correct way.
+    // We should have `Public` objects at this point, not `AccountId32`.
+    let verifiers = threshold_accounts
+        .into_iter()
+        .map(|acc| VerifierWrapper(sr25519::PublicKey(acc.0)))
+        .collect::<Vec<_>>();
+
+    // TODO (#375): this should come from whoever initiates the signing process,
+    // (or as some deterministic function, e.g. the hash of the last block mined)
+    // and be the same for all participants.
+    let shared_randomness = b"123456";
+
+    let mut sending = make_key_refresh_session(
+        &mut OsRng,
+        shared_randomness,
+        signer,
+        &verifiers,
+        PartyIdx::from_usize(*my_idx as usize),
+    )
+    .map_err(ProtocolExecutionErr::SessionCreationError)?;
+    let key_change = loop {
+        let (mut receiving, to_send) =
+            sending.start_receiving(&mut OsRng).map_err(ProtocolExecutionErr::SynedrionSession)?;
+
+        match to_send {
+            ToSend::Broadcast(message) => {
+                tx.send(ProtocolMessage::new_bcast(&my_id, message))?;
+            },
+            ToSend::Direct(msgs) =>
+                for (id_to, message) in msgs.into_iter() {
+                    tx.send(ProtocolMessage::new_p2p(
+                        &my_id,
+                        &party_ids[id_to.as_usize()],
+                        message,
+                    ))?;
+                },
+        };
+
+        while receiving.has_cached_messages() {
+            receiving.receive_cached_message().map_err(ProtocolExecutionErr::SynedrionSession)?;
+        }
+
+        while !receiving.can_finalize() {
+            let signing_message = rx.recv().await.ok_or_else(|| {
+                ProtocolExecutionErr::IncomingStream(format!("{:?}", receiving.current_stage()))
+            })?;
+
+            // TODO: we shouldn't send broadcasts to ourselves in the first place.
+            if signing_message.from == my_id {
+                continue;
+            }
+            let from_idx = id_to_index[&signing_message.from];
+            receiving
+                .receive(from_idx, signing_message.payload)
+                .map_err(ProtocolExecutionErr::SynedrionSession)?;
+        }
+
+        match receiving.finalize(&mut OsRng).map_err(ProtocolExecutionErr::SynedrionSession)? {
+            FinalizeOutcome::Result(res) => break res,
+            FinalizeOutcome::AnotherRound(new_sending) => sending = new_sending,
+        }
+    };
+
+    Ok(old_key.update(key_change))
+}

crypto/server/src/helpers/signing.rs

@@ -34,13 +34,11 @@ pub async fn do_signing(
     let info =
         SignInit::new(message.clone(), sig_hash.clone(), tx_id.clone(), user_address.clone())?;
     let signing_service = ThresholdSigningService::new(state, kv_manager);
-    let signer =
-        get_signer(kv_manager).await.map_err(|_| ProtocolErr::UserError("Error getting Signer"))?;
+    let signer = get_signer(kv_manager).await.map_err(|e| ProtocolErr::UserError(e.to_string()))?;
 
     let x25519_secret_key = derive_static_secret(signer.signer());
-    let subxt_signer = get_subxt_signer(kv_manager)
-        .await
-        .map_err(|_| ProtocolErr::UserError("Error getting Signer"))?;
+    let subxt_signer =
+        get_subxt_signer(kv_manager).await.map_err(|e| ProtocolErr::UserError(e.to_string()))?;
 
     let account_id = AccountId32(subxt_signer.public_key().0);
 

crypto/server/src/helpers/user.rs

@@ -5,6 +5,7 @@ use entropy_protocol::{
     KeyParams, ValidatorInfo,
 };
 use entropy_shared::{KeyVisibility, SETUP_TIMEOUT_SECONDS};
+use parity_scale_codec::Encode;
 use sp_core::crypto::AccountId32;
 use subxt::{
     ext::sp_core::{sr25519, Bytes},
@@ -134,3 +135,17 @@ pub async fn send_key(
     }
     Ok(())
 }
+
+/// Checks if a validator is in the current selected registration committee
+pub fn check_in_registration_group(
+    validators_info: &[entropy_shared::ValidatorInfo],
+    validator_address: &SubxtAccountId32,
+) -> Result<(), UserErr> {
+    let is_proper_signer = validators_info
+        .iter()
+        .any(|validator_info| validator_info.tss_account == validator_address.encode());
+    if !is_proper_signer {
+        return Err(UserErr::InvalidSigner("Invalid Signer in Signing group"));
+    }
+    Ok(())
+}

crypto/server/src/main.rs

@@ -177,6 +177,7 @@ async fn main() {
         }
         // TODO: find a proper batch size
         let batch_size = 10;
+        let key_amount = 10_000;
         let signer = get_signer(&kv_store).await.expect("Issue acquiring threshold signer key");
         let has_fee_balance = check_balance_for_fees(&api, signer.account_id(), MIN_BALANCE)
             .await
@@ -199,15 +200,14 @@ async fn main() {
         let ip_address =
             String::from_utf8(key_server_info.endpoint).expect("failed to parse IP address.");
         let recip_key = x25519_dalek::PublicKey::from(key_server_info.x25519_public_key);
-        let all_keys = get_all_keys(&api, batch_size).await.expect("failed to get all keys.");
+        let all_keys = get_all_keys(&api, key_amount).await.expect("failed to get all keys.");
         let _ = get_and_store_values(
             all_keys, &kv_store, ip_address, batch_size, args.dev, &recip_key, &signer,
         )
         .await;
         tell_chain_syncing_is_done(&api, &signer).await.expect("failed to finish chain sync.");
     }
 
-    // TODO: unhardcode endpoint
     let addr = SocketAddr::from_str(&args.threshold_url).expect("failed to parse threshold url.");
     tracing::info!("listening on {}", addr);
     axum::Server::bind(&addr)
@@ -221,6 +221,7 @@ pub fn app(app_state: AppState) -> Router {
         .route("/user/sign_tx", post(sign_tx))
         .route("/user/new", post(new_user))
         .route("/user/receive_key", post(receive_key))
+        .route("/signer/proactive_refresh", post(proactive_refresh))
         .route("/validator/sync_kvdb", post(sync_kvdb))
         .route("/healthz", get(healthz))
         .route("/ws", get(ws_handler));