go/consensus/cometbft/abci: Include all events in the events root

The events root in block metadata system transaction now includes all events,
not just provable ones.

Author: peternose

.changelog/6289.breaking.0.md

@@ -0,0 +1,4 @@
+go/consensus/cometbft/abci: Include all events in the events root
+
+The events root in block metadata system transaction now includes all events,
+not just provable ones.

go/consensus/api/meta.go

@@ -23,7 +23,7 @@ const BlockMetadataMaxSize = 16_384
 type BlockMetadata struct {
 	// StateRoot is the state root after executing all logic in the block.
 	StateRoot hash.Hash `json:"state_root"`
-	// EventsRoot is the provable events root.
+	// EventsRoot is the root hash of all events emitted in the block.
 	EventsRoot []byte `json:"events_root"`
 }
 

go/consensus/cometbft/abci/system.go

@@ -13,6 +13,7 @@ import (
 	"github.com/oasisprotocol/oasis-core/go/consensus/cometbft/api"
 	cmtcrypto "github.com/oasisprotocol/oasis-core/go/consensus/cometbft/crypto"
 	"github.com/oasisprotocol/oasis-core/go/consensus/cometbft/crypto/merkle"
+	"github.com/oasisprotocol/oasis-core/go/upgrade/migrations"
 )
 
 // prepareSystemTxs prepares a list of system transactions to be included in a proposed block in
@@ -28,9 +29,9 @@ func (mux *abciMux) prepareSystemTxs() ([][]byte, []*types.ResponseDeliverTx, er
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to compute working state root: %w", err)
 	}
-	eventsRoot, err := mux.computeProvableEventsRoot()
+	eventsRoot, err := mux.computeEventsRoot()
 	if err != nil {
-		return nil, nil, fmt.Errorf("failed to compute provable events root: %w", err)
+		return nil, nil, fmt.Errorf("failed to compute events root: %w", err)
 	}
 
 	blockMeta := consensus.NewBlockMetadataTx(&consensus.BlockMetadata{
@@ -119,10 +120,10 @@ func (mux *abciMux) validateSystemTxs() error {
 				return fmt.Errorf("invalid state root in block metadata (expected: %s got: %s)", stateRoot, meta.StateRoot)
 			}
 
-			// Verify provable events root.
-			eventsRoot, err := mux.computeProvableEventsRoot()
+			// Verify events root.
+			eventsRoot, err := mux.computeEventsRoot()
 			if err != nil {
-				return fmt.Errorf("failed to compute provable events root: %w", err)
+				return fmt.Errorf("failed to compute events root: %w", err)
 			}
 			if !bytes.Equal(eventsRoot, meta.EventsRoot) {
 				return fmt.Errorf("invalid events root in block metadata (expected: %x got: %x)", eventsRoot, meta.EventsRoot)
@@ -143,11 +144,30 @@ func (mux *abciMux) validateSystemTxs() error {
 	return nil
 }
 
-func (mux *abciMux) computeProvableEventsRoot() ([]byte, error) {
-	provable := mux.state.blockCtx.ProvableEvents
-	provableEvents := make([][]byte, len(provable))
-	for i, pe := range provable {
-		provableEvents[i] = cbor.Marshal(pe.ProvableRepresentation())
+func (mux *abciMux) computeEventsRoot() ([]byte, error) {
+	if !mux.state.ConsensusParameters().IsFeatureVersion(migrations.Version256) {
+		// Events root used to be computed only from provable events.
+		provable := mux.state.blockCtx.ProvableEvents
+		provableEvents := make([][]byte, len(provable))
+		for i, pe := range provable {
+			provableEvents[i] = cbor.Marshal(pe.ProvableRepresentation())
+		}
+		return merkle.RootHash(provableEvents), nil
+	}
+
+	// Events root is now computed from all emitted events.
+	var events [][]byte
+	for _, ev := range mux.state.proposal.resultsBeginBlock.Events {
+		events = append(events, cbor.Marshal(ev))
 	}
-	return merkle.RootHash(provableEvents), nil
+	for _, res := range mux.state.proposal.resultsDeliverTx {
+		for _, ev := range res.Events {
+			events = append(events, cbor.Marshal(ev))
+		}
+	}
+	for _, ev := range mux.state.proposal.resultsEndBlock.Events {
+		events = append(events, cbor.Marshal(ev))
+	}
+
+	return merkle.RootHash(events), nil
 }

go/upgrade/migrations/consensus_256.go

@@ -14,6 +14,8 @@ import (
 // This upgrade includes:
 //   - The `MayQuery“ field in the CHURP SGX policy, which defines which enclave identities
 //     are allowed to query runtime key shares.
+//   - An updated events root in the block metadata system transaction to capture all events
+//     emitted in the block.
 const Consensus256 = "consensus256"
 
 // Version256 is the Oasis Core 25.6 version.

runtime/src/consensus/mod.rs

@@ -47,6 +47,6 @@ pub enum Event {
 pub struct BlockMetadata {
     /// State root after executing all logic in the block.
     pub state_root: Hash,
-    // EventsRoot is the provable events root.
+    // Root hash of all events emitted in the block.
     pub events_root: Vec<u8>,
 }