jwk #4: jwk update quorum certification

crates/aptos-jwk-consensus/src/lib.rs

@@ -31,4 +31,6 @@ pub fn start_jwk_consensus_runtime(
 
 pub mod network;
 pub mod network_interface;
+pub mod observation_aggregation;
 pub mod types;
+pub mod update_certifier;

crates/aptos-jwk-consensus/src/observation_aggregation/mod.rs

@@ -0,0 +1,97 @@
+// Copyright © Aptos Foundation
+
+use crate::types::{
+    JWKConsensusMsg, ObservedUpdate, ObservedUpdateRequest, ObservedUpdateResponse,
+};
+use anyhow::{anyhow, ensure};
+use aptos_consensus_types::common::Author;
+use aptos_infallible::Mutex;
+use aptos_reliable_broadcast::BroadcastStatus;
+use aptos_types::{
+    aggregate_signature::PartialSignatures,
+    epoch_state::EpochState,
+    jwks::{ProviderJWKs, QuorumCertifiedUpdate},
+};
+use move_core_types::account_address::AccountAddress;
+use std::{collections::BTreeSet, sync::Arc};
+
+/// The aggregation state of reliable broadcast where a validator broadcast JWK observation requests
+/// and produce quorum-certified JWK updates.
+pub struct ObservationAggregationState {
+    epoch_state: Arc<EpochState>,
+    local_view: ProviderJWKs,
+    inner_state: Mutex<PartialSignatures>,
+}
+
+impl ObservationAggregationState {
+    pub fn new(epoch_state: Arc<EpochState>, local_view: ProviderJWKs) -> Self {
+        Self {
+            epoch_state,
+            local_view,
+            inner_state: Mutex::new(PartialSignatures::empty()),
+        }
+    }
+}
+
+impl BroadcastStatus<JWKConsensusMsg> for Arc<ObservationAggregationState> {
+    type Aggregated = QuorumCertifiedUpdate;
+    type Message = ObservedUpdateRequest;
+    type Response = ObservedUpdateResponse;
+
+    fn add(
+        &self,
+        sender: Author,
+        response: Self::Response,
+    ) -> anyhow::Result<Option<Self::Aggregated>> {
+        let ObservedUpdateResponse { epoch, update } = response;
+        let ObservedUpdate {
+            author,
+            observed: peer_view,
+            signature,
+        } = update;
+        ensure!(
+            epoch == self.epoch_state.epoch,
+            "adding peer observation failed with invalid epoch",
+        );
+        ensure!(
+            author == sender,
+            "adding peer observation failed with mismatched author",
+        );
+
+        let mut partial_sigs = self.inner_state.lock();
+        if partial_sigs.contains_voter(&sender) {
+            return Ok(None);
+        }
+
+        ensure!(
+            self.local_view == peer_view,
+            "adding peer observation failed with mismatched view"
+        );
+
+        // Verify peer signature.
+        self.epoch_state
+            .verifier
+            .verify(sender, &peer_view, &signature)?;
+
+        // All checks passed. Aggregating.
+        partial_sigs.add_signature(sender, signature);
+        let voters: BTreeSet<AccountAddress> = partial_sigs.signatures().keys().copied().collect();
+        if self
+            .epoch_state
+            .verifier
+            .check_voting_power(voters.iter(), true)
+            .is_err()
+        {
+            return Ok(None);
+        }
+        let multi_sig = self.epoch_state.verifier.aggregate_signatures(&partial_sigs).map_err(|e|anyhow!("adding peer observation failed with partial-to-aggregated conversion error: {e}"))?;
+
+        Ok(Some(QuorumCertifiedUpdate {
+            update: peer_view,
+            multi_sig,
+        }))
+    }
+}
+
+#[cfg(test)]
+mod tests;

crates/aptos-jwk-consensus/src/observation_aggregation/tests.rs

@@ -0,0 +1,132 @@
+// Copyright © Aptos Foundation
+
+use crate::{
+    observation_aggregation::ObservationAggregationState,
+    types::{ObservedUpdate, ObservedUpdateResponse},
+};
+use aptos_crypto::{bls12381, SigningKey, Uniform};
+use aptos_reliable_broadcast::BroadcastStatus;
+use aptos_types::{
+    epoch_state::EpochState,
+    jwks::{
+        jwk::{JWKMoveStruct, JWK},
+        unsupported::UnsupportedJWK,
+        ProviderJWKs, QuorumCertifiedUpdate,
+    },
+    validator_verifier::{ValidatorConsensusInfo, ValidatorVerifier},
+};
+use move_core_types::account_address::AccountAddress;
+use std::sync::Arc;
+
+#[test]
+fn test_observation_aggregation_state() {
+    let num_validators = 5;
+    let epoch = 999;
+    let addrs: Vec<AccountAddress> = (0..num_validators)
+        .map(|_| AccountAddress::random())
+        .collect();
+    let private_keys: Vec<bls12381::PrivateKey> = (0..num_validators)
+        .map(|_| bls12381::PrivateKey::generate_for_testing())
+        .collect();
+    let public_keys: Vec<bls12381::PublicKey> = (0..num_validators)
+        .map(|i| bls12381::PublicKey::from(&private_keys[i]))
+        .collect();
+    let voting_powers = [1, 1, 1, 6, 6]; // total voting power: 15, default threshold: 11
+    let validator_infos: Vec<ValidatorConsensusInfo> = (0..num_validators)
+        .map(|i| ValidatorConsensusInfo::new(addrs[i], public_keys[i].clone(), voting_powers[i]))
+        .collect();
+    let verifier = ValidatorVerifier::new(validator_infos);
+    let epoch_state = Arc::new(EpochState { epoch, verifier });
+    let view_0 = ProviderJWKs {
+        issuer: b"https::/alice.com".to_vec(),
+        version: 123,
+        jwks: vec![JWKMoveStruct::from(JWK::Unsupported(
+            UnsupportedJWK::new_for_testing("id1", "payload1"),
+        ))],
+    };
+    let view_1 = ProviderJWKs {
+        issuer: b"https::/alice.com".to_vec(),
+        version: 123,
+        jwks: vec![JWKMoveStruct::from(JWK::Unsupported(
+            UnsupportedJWK::new_for_testing("id2", "payload2"),
+        ))],
+    };
+    let ob_agg_state = Arc::new(ObservationAggregationState::new(
+        epoch_state.clone(),
+        view_0.clone(),
+    ));
+
+    // `ObservedUpdate` with incorrect epoch should be rejected.
+    let result = ob_agg_state.add(addrs[0], ObservedUpdateResponse {
+        epoch: 998,
+        update: ObservedUpdate {
+            author: addrs[0],
+            observed: view_0.clone(),
+            signature: private_keys[0].sign(&view_0).unwrap(),
+        },
+    });
+    assert!(result.is_err());
+
+    // `ObservedUpdate` authored by X but sent by Y should be rejected.
+    let result = ob_agg_state.add(addrs[1], ObservedUpdateResponse {
+        epoch: 999,
+        update: ObservedUpdate {
+            author: addrs[0],
+            observed: view_0.clone(),
+            signature: private_keys[0].sign(&view_0).unwrap(),
+        },
+    });
+    assert!(result.is_err());
+
+    // `ObservedUpdate` that cannot be verified should be rejected.
+    let result = ob_agg_state.add(addrs[2], ObservedUpdateResponse {
+        epoch: 999,
+        update: ObservedUpdate {
+            author: addrs[2],
+            observed: view_0.clone(),
+            signature: private_keys[2].sign(&view_1).unwrap(),
+        },
+    });
+    assert!(result.is_err());
+
+    // Good `ObservedUpdate` should be accepted.
+    let result = ob_agg_state.add(addrs[3], ObservedUpdateResponse {
+        epoch: 999,
+        update: ObservedUpdate {
+            author: addrs[3],
+            observed: view_0.clone(),
+            signature: private_keys[3].sign(&view_0).unwrap(),
+        },
+    });
+    assert!(matches!(result, Ok(None)));
+
+    // `ObservedUpdate` from contributed author should be ignored.
+    let result = ob_agg_state.add(addrs[3], ObservedUpdateResponse {
+        epoch: 999,
+        update: ObservedUpdate {
+            author: addrs[3],
+            observed: view_0.clone(),
+            signature: private_keys[3].sign(&view_0).unwrap(),
+        },
+    });
+    assert!(matches!(result, Ok(None)));
+
+    // Quorum-certified update should be returned if after adding an `ObservedUpdate`, the threshold is exceeded.
+    let result = ob_agg_state.add(addrs[4], ObservedUpdateResponse {
+        epoch: 999,
+        update: ObservedUpdate {
+            author: addrs[4],
+            observed: view_0.clone(),
+            signature: private_keys[4].sign(&view_0).unwrap(),
+        },
+    });
+    let QuorumCertifiedUpdate {
+        update: observed,
+        multi_sig,
+    } = result.unwrap().unwrap();
+    assert_eq!(view_0, observed);
+    assert!(epoch_state
+        .verifier
+        .verify_multi_signatures(&observed, &multi_sig)
+        .is_ok());
+}

crates/aptos-jwk-consensus/src/update_certifier.rs

@@ -0,0 +1,63 @@
+// Copyright © Aptos Foundation
+
+use crate::{
+    observation_aggregation::ObservationAggregationState,
+    types::{JWKConsensusMsg, ObservedUpdateRequest},
+};
+use aptos_channels::aptos_channel;
+use aptos_reliable_broadcast::ReliableBroadcast;
+use aptos_types::{
+    epoch_state::EpochState,
+    jwks::{ProviderJWKs, QuorumCertifiedUpdate},
+};
+use futures_util::future::{AbortHandle, Abortable};
+use std::sync::Arc;
+use tokio_retry::strategy::ExponentialBackoff;
+
+/// A sub-process of the whole JWK consensus process.
+/// Once invoked by `JWKConsensusManager` to `start_produce`,
+/// it starts producing a `QuorumCertifiedUpdate` and returns an abort handle.
+/// Once an `QuorumCertifiedUpdate` is available, it is sent back via a channel given earlier.
+pub trait TUpdateCertifier: Send + Sync {
+    fn start_produce(
+        &self,
+        epoch_state: Arc<EpochState>,
+        payload: ProviderJWKs,
+        qc_update_tx: aptos_channel::Sender<(), QuorumCertifiedUpdate>,
+    ) -> AbortHandle;
+}
+
+pub struct CertifiedUpdateProducer {
+    reliable_broadcast: Arc<ReliableBroadcast<JWKConsensusMsg, ExponentialBackoff>>,
+}
+
+impl CertifiedUpdateProducer {
+    pub fn new(reliable_broadcast: ReliableBroadcast<JWKConsensusMsg, ExponentialBackoff>) -> Self {
+        Self {
+            reliable_broadcast: Arc::new(reliable_broadcast),
+        }
+    }
+}
+
+impl TUpdateCertifier for CertifiedUpdateProducer {
+    fn start_produce(
+        &self,
+        epoch_state: Arc<EpochState>,
+        payload: ProviderJWKs,
+        qc_update_tx: aptos_channel::Sender<(), QuorumCertifiedUpdate>,
+    ) -> AbortHandle {
+        let rb = self.reliable_broadcast.clone();
+        let req = ObservedUpdateRequest {
+            epoch: epoch_state.epoch,
+            issuer: payload.issuer.clone(),
+        };
+        let agg_state = Arc::new(ObservationAggregationState::new(epoch_state, payload));
+        let task = async move {
+            let qc_update = rb.broadcast(req, agg_state).await;
+            let _ = qc_update_tx.push((), qc_update);
+        };
+        let (abort_handle, abort_registration) = AbortHandle::new_pair();
+        tokio::spawn(Abortable::new(task, abort_registration));
+        abort_handle
+    }
+}

types/src/aggregate_signature.rs

@@ -97,4 +97,8 @@ impl PartialSignatures {
     pub fn signatures(&self) -> &BTreeMap<AccountAddress, bls12381::Signature> {
         &self.signatures
     }
+
+    pub fn contains_voter(&self, voter: &AccountAddress) -> bool {
+        self.signatures.contains_key(voter)
+    }
 }