Vote extensions: Add consensus param for extension activation logic (#9862)

* [cherry-picked] abci++: add consensus parameter logic to control vote extension require height (#8547)

This PR makes vote extensions optional within Tendermint. A new ConsensusParams field, called ABCIParams.VoteExtensionsEnableHeight, has been added to toggle whether or not extensions should be enabled or disabled depending on the current height of the consensus engine. Related to: #8453

* Fix UTs

* fix blocksync reactor import of state store

* fixes1

* fixed_more_UTs

* Fix TestHandshakeReplaySome

* Fix all unit tests

* Added hunk in original commit

Co-authored-by: William Banfield <4561443+williambanfield@users.noreply.github.com>
Co-authored-by: Callum Waters <cmwaters19@gmail.com>

blocksync/pool.go

@@ -259,7 +259,7 @@ func (pool *BlockPool) AddBlock(peerID p2p.ID, block *types.Block, extCommit *ty
 	pool.mtx.Lock()
 	defer pool.mtx.Unlock()
 
-	if block.Height != extCommit.Height {
+	if extCommit != nil && block.Height != extCommit.Height {
 		return fmt.Errorf("heights don't match, not adding block (block height: %d, commit height: %d)", block.Height, extCommit.Height)
 	}
 
@@ -566,7 +566,9 @@ func (bpr *bpRequester) setBlock(block *types.Block, extCommit *types.ExtendedCo
 		return false
 	}
 	bpr.block = block
-	bpr.extCommit = extCommit
+	if extCommit != nil {
+		bpr.extCommit = extCommit
+	}
 	bpr.mtx.Unlock()
 
 	select {

blocksync/reactor.go

@@ -177,31 +177,40 @@ func (bcR *Reactor) respondToPeer(msg *bcproto.BlockRequest,
 	src p2p.Peer) (queued bool) {
 
 	block := bcR.store.LoadBlock(msg.Height)
-	if block != nil {
-		extCommit := bcR.store.LoadBlockExtendedCommit(msg.Height)
-		if extCommit == nil {
-			bcR.Logger.Error("found block in store without extended commit", "block", block)
-			return false
-		}
-		bl, err := block.ToProto()
-		if err != nil {
-			bcR.Logger.Error("could not convert msg to protobuf", "err", err)
-			return false
-		}
-
+	if block == nil {
+		bcR.Logger.Info("Peer asking for a block we don't have", "src", src, "height", msg.Height)
 		return src.TrySend(p2p.Envelope{
 			ChannelID: BlocksyncChannel,
-			Message: &bcproto.BlockResponse{
-				Block:     bl,
-				ExtCommit: extCommit.ToProto(),
-			},
+			Message:   &bcproto.NoBlockResponse{Height: msg.Height},
 		})
 	}
 
-	bcR.Logger.Info("Peer asking for a block we don't have", "src", src, "height", msg.Height)
+	state, err := bcR.blockExec.Store().Load()
+	if err != nil {
+		bcR.Logger.Error("loading state", "err", err)
+		return false
+	}
+	var extCommit *types.ExtendedCommit
+	if state.ConsensusParams.ABCI.VoteExtensionsEnabled(msg.Height) {
+		extCommit = bcR.store.LoadBlockExtendedCommit(msg.Height)
+		if extCommit == nil {
+			bcR.Logger.Error("found block in store with no extended commit", "block", block)
+			return false
+		}
+	}
+
+	bl, err := block.ToProto()
+	if err != nil {
+		bcR.Logger.Error("could not convert msg to protobuf", "err", err)
+		return false
+	}
+
 	return src.TrySend(p2p.Envelope{
 		ChannelID: BlocksyncChannel,
-		Message:   &bcproto.NoBlockResponse{Height: msg.Height},
+		Message: &bcproto.BlockResponse{
+			Block:     bl,
+			ExtCommit: extCommit.ToProto(),
+		},
 	})
 }
 
@@ -224,12 +233,16 @@ func (bcR *Reactor) Receive(e p2p.Envelope) {
 			bcR.Logger.Error("Block content is invalid", "err", err)
 			return
 		}
-		extCommit, err := types.ExtendedCommitFromProto(msg.ExtCommit)
-		if err != nil {
-			bcR.Logger.Error("failed to convert extended commit from proto",
-				"peer", e.Src,
-				"err", err)
-			return
+		var extCommit *types.ExtendedCommit
+		if msg.ExtCommit != nil {
+			var err error
+			extCommit, err = types.ExtendedCommitFromProto(msg.ExtCommit)
+			if err != nil {
+				bcR.Logger.Error("failed to convert extended commit from proto",
+					"peer", e.Src,
+					"err", err)
+				return
+			}
 		}
 
 		if err := bcR.pool.AddBlock(e.Src.ID(), bi, extCommit, msg.Block.Size()); err != nil {
@@ -279,6 +292,8 @@ func (bcR *Reactor) poolRoutine(stateSynced bool) {
 
 	didProcessCh := make(chan struct{}, 1)
 
+	initialCommitHasExtensions := (bcR.initialState.LastBlockHeight > 0 && bcR.store.LoadBlockExtendedCommit(bcR.initialState.LastBlockHeight) != nil)
+
 	go func() {
 		for {
 			select {
@@ -321,11 +336,26 @@ FOR_LOOP:
 			bcR.Logger.Debug("Consensus ticker", "numPending", numPending, "total", lenRequesters,
 				"outbound", outbound, "inbound", inbound)
 
-			// TODO(sergio) Might be needed for implementing the upgrading solution. Remove after that
-			if state.LastBlockHeight > 0 && blocksSynced == 0 {
-				// Having state-synced, we need to blocksync at least one block
+			// The "if" statement below is a bit confusing, so here is a breakdown
+			// of its logic and purpose:
+			//
+			// If VoteExtensions are enabled we cannot switch to consensus without
+			// the vote extension data for the previous height, i.e. state.LastBlockHeight.
+			//
+			// If extensions were required during state.LastBlockHeight and we have
+			// sync'd at least one block, then we are guaranteed to have extensions.
+			// BlockSync requires that the blocks it fetches have extensions if
+			// extensions were enabled during the height.
+			//
+			// If extensions were required during state.LastBlockHeight and we have
+			// not sync'd any blocks, then we can only transition to Consensus
+			// if we already had extensions for the initial height.
+			// If any of these conditions is not met, we continue the loop, looking
+			// for extensions.
+			if state.ConsensusParams.ABCI.VoteExtensionsEnabled(state.LastBlockHeight) &&
+				(blocksSynced == 0 && !initialCommitHasExtensions) {
 				bcR.Logger.Info(
-					"no seen commit yet",
+					"no extended commit yet",
 					"height", height,
 					"last_block_height", state.LastBlockHeight,
 					"initial_height", state.InitialHeight,
@@ -366,19 +396,19 @@ FOR_LOOP:
 
 			// See if there are any blocks to sync.
 			first, second, extCommit := bcR.pool.PeekTwoBlocks()
-			// bcR.Logger.Info("TrySync peeked", "first", first, "second", second)
-			if first == nil || second == nil || extCommit == nil {
-				if first != nil && extCommit == nil {
-					// See https://github.com/tendermint/tendermint/pull/8433#discussion_r866790631
-					panic(fmt.Errorf("peeked first block without extended commit at height %d - possible node store corruption", first.Height))
-				}
-				// we need all to sync the first block
+			if first != nil && extCommit == nil &&
+				state.ConsensusParams.ABCI.VoteExtensionsEnabled(first.Height) {
+				// See https://github.com/tendermint/tendermint/pull/8433#discussion_r866790631
+				panic(fmt.Errorf("peeked first block without extended commit at height %d - possible node store corruption", first.Height))
+			} else if first == nil || second == nil {
+				// we need to have fetched two consecutive blocks in order to
+				// perform blocksync verification
 				continue FOR_LOOP
-			} else {
-				// Try again quickly next loop.
-				didProcessCh <- struct{}{}
 			}
 
+			// Try again quickly next loop.
+			didProcessCh <- struct{}{}
+
 			firstParts, err := first.MakePartSet(types.BlockPartSizeBytes)
 			if err != nil {
 				bcR.Logger.Error("failed to make ",
@@ -400,6 +430,10 @@ FOR_LOOP:
 				// validate the block before we persist it
 				err = bcR.blockExec.ValidateBlock(state, first)
 			}
+			if err == nil && state.ConsensusParams.ABCI.VoteExtensionsEnabled(first.Height) {
+				// if vote extensions were required at this height, ensure they exist.
+				err = extCommit.EnsureExtensions()
+			}
 
 			if err != nil {
 				bcR.Logger.Error("Error in validation", "err", err)
@@ -423,7 +457,15 @@ FOR_LOOP:
 			bcR.pool.PopRequest()
 
 			// TODO: batch saves so we dont persist to disk every block
-			bcR.store.SaveBlock(first, firstParts, extCommit)
+			if state.ConsensusParams.ABCI.VoteExtensionsEnabled(first.Height) {
+				bcR.store.SaveBlockWithExtendedCommit(first, firstParts, extCommit)
+			} else {
+				// We use LastCommit here instead of extCommit. extCommit is not
+				// guaranteed to be populated by the peer if extensions are not enabled.
+				// Currently, the peer should provide an extCommit even if the vote extension data are absent
+				// but this may change so using second.LastCommit is safer.
+				bcR.store.SaveBlock(first, firstParts, second.LastCommit)
+			}
 
 			// TODO: same thing for app - but we would need a way to
 			// get the hash without persisting the state

blocksync/reactor_test.go

@@ -118,7 +118,7 @@ func newReactor(
 	for blockHeight := int64(1); blockHeight <= maxBlockHeight; blockHeight++ {
 		lastExtCommit = seenExtCommit.Clone()
 
-		thisBlock := state.MakeBlock(blockHeight, nil, lastExtCommit.StripExtensions(), nil, state.Validators.Proposer.Address)
+		thisBlock := state.MakeBlock(blockHeight, nil, lastExtCommit.ToCommit(), nil, state.Validators.Proposer.Address)
 
 		thisParts, err := thisBlock.MakePartSet(types.BlockPartSizeBytes)
 		require.NoError(t, err)
@@ -148,7 +148,7 @@ func newReactor(
 			panic(fmt.Errorf("error apply block: %w", err))
 		}
 
-		blockStore.SaveBlock(thisBlock, thisParts, seenExtCommit)
+		blockStore.SaveBlockWithExtendedCommit(thisBlock, thisParts, seenExtCommit)
 	}
 
 	bcReactor := NewReactor(state.Copy(), blockExec, blockStore, fastSync, NopMetrics())

consensus/byzantine_test.go

@@ -46,7 +46,7 @@ func TestByzantinePrevoteEquivocation(t *testing.T) {
 	tickerFunc := newMockTickerFunc(true)
 	appFunc := newKVStore
 
-	genDoc, privVals := randGenesisDoc(nValidators, false, 30)
+	genDoc, privVals := randGenesisDoc(nValidators, false, 30, nil)
 	css := make([]*State, nValidators)
 
 	for i := 0; i < nValidators; i++ {

consensus/common_test.go

@@ -463,9 +463,27 @@ func randState(nValidators int) (*State, []*validatorStub) {
 	return randStateWithApp(nValidators, kvstore.NewInMemoryApplication())
 }
 
+func randStateWithAppWithHeight(
+	nValidators int,
+	app abci.Application,
+	height int64,
+) (*State, []*validatorStub) {
+	c := test.ConsensusParams()
+	c.ABCI.VoteExtensionsEnableHeight = height
+	return randStateWithAppImpl(nValidators, app, c)
+}
 func randStateWithApp(nValidators int, app abci.Application) (*State, []*validatorStub) {
+	c := test.ConsensusParams()
+	return randStateWithAppImpl(nValidators, app, c)
+}
+
+func randStateWithAppImpl(
+	nValidators int,
+	app abci.Application,
+	consensusParams *types.ConsensusParams,
+) (*State, []*validatorStub) {
 	// Get State
-	state, privVals := randGenesisState(nValidators, false, 10)
+	state, privVals := randGenesisState(nValidators, false, 10, consensusParams)
 
 	vss := make([]*validatorStub, nValidators)
 
@@ -751,7 +769,7 @@ func consensusLogger() log.Logger {
 func randConsensusNet(t *testing.T, nValidators int, testName string, tickerFunc func() TimeoutTicker,
 	appFunc func() abci.Application, configOpts ...func(*cfg.Config)) ([]*State, cleanupFunc) {
 	t.Helper()
-	genDoc, privVals := randGenesisDoc(nValidators, false, 30)
+	genDoc, privVals := randGenesisDoc(nValidators, false, 30, nil)
 	css := make([]*State, nValidators)
 	logger := consensusLogger()
 	configRootDirs := make([]string, 0, nValidators)
@@ -792,7 +810,8 @@ func randConsensusNetWithPeers(
 	tickerFunc func() TimeoutTicker,
 	appFunc func(string) abci.Application,
 ) ([]*State, *types.GenesisDoc, *cfg.Config, cleanupFunc) {
-	genDoc, privVals := randGenesisDoc(nValidators, false, testMinPower)
+	c := test.ConsensusParams()
+	genDoc, privVals := randGenesisDoc(nValidators, false, testMinPower, c)
 	css := make([]*State, nPeers)
 	logger := consensusLogger()
 	var peer0Config *cfg.Config
@@ -858,7 +877,11 @@ func getSwitchIndex(switches []*p2p.Switch, peer p2p.Peer) int {
 //-------------------------------------------------------------------------------
 // genesis
 
-func randGenesisDoc(numValidators int, randPower bool, minPower int64) (*types.GenesisDoc, []types.PrivValidator) {
+func randGenesisDoc(numValidators int,
+	randPower bool,
+	minPower int64,
+	consensusParams *types.ConsensusParams,
+) (*types.GenesisDoc, []types.PrivValidator) {
 	validators := make([]types.GenesisValidator, numValidators)
 	privValidators := make([]types.PrivValidator, numValidators)
 	for i := 0; i < numValidators; i++ {
@@ -872,15 +895,21 @@ func randGenesisDoc(numValidators int, randPower bool, minPower int64) (*types.G
 	sort.Sort(types.PrivValidatorsByAddress(privValidators))
 
 	return &types.GenesisDoc{
-		GenesisTime:   tmtime.Now(),
-		InitialHeight: 1,
-		ChainID:       test.DefaultTestChainID,
-		Validators:    validators,
+		GenesisTime:     tmtime.Now(),
+		InitialHeight:   1,
+		ChainID:         test.DefaultTestChainID,
+		Validators:      validators,
+		ConsensusParams: consensusParams,
 	}, privValidators
 }
 
-func randGenesisState(numValidators int, randPower bool, minPower int64) (sm.State, []types.PrivValidator) {
-	genDoc, privValidators := randGenesisDoc(numValidators, randPower, minPower)
+func randGenesisState(
+	numValidators int,
+	randPower bool,
+	minPower int64,
+	consensusParams *types.ConsensusParams,
+) (sm.State, []types.PrivValidator) {
+	genDoc, privValidators := randGenesisDoc(numValidators, randPower, minPower, consensusParams)
 	s0, _ := sm.MakeGenesisState(genDoc)
 	return s0, privValidators
 }

consensus/mempool_test.go

@@ -29,7 +29,7 @@ func TestMempoolNoProgressUntilTxsAvailable(t *testing.T) {
 	config := ResetConfig("consensus_mempool_txs_available_test")
 	defer os.RemoveAll(config.RootDir)
 	config.Consensus.CreateEmptyBlocks = false
-	state, privVals := randGenesisState(1, false, 10)
+	state, privVals := randGenesisState(1, false, 10, nil)
 	app := kvstore.NewInMemoryApplication()
 	resp, err := app.Info(context.Background(), proxy.RequestInfo)
 	require.NoError(t, err)
@@ -53,7 +53,7 @@ func TestMempoolProgressAfterCreateEmptyBlocksInterval(t *testing.T) {
 	defer os.RemoveAll(config.RootDir)
 
 	config.Consensus.CreateEmptyBlocksInterval = ensureTimeout
-	state, privVals := randGenesisState(1, false, 10)
+	state, privVals := randGenesisState(1, false, 10, nil)
 	app := kvstore.NewInMemoryApplication()
 	resp, err := app.Info(context.Background(), proxy.RequestInfo)
 	require.NoError(t, err)
@@ -74,7 +74,7 @@ func TestMempoolProgressInHigherRound(t *testing.T) {
 	config := ResetConfig("consensus_mempool_txs_available_test")
 	defer os.RemoveAll(config.RootDir)
 	config.Consensus.CreateEmptyBlocks = false
-	state, privVals := randGenesisState(1, false, 10)
+	state, privVals := randGenesisState(1, false, 10, nil)
 	cs := newStateWithConfig(config, state, privVals[0], kvstore.NewInMemoryApplication())
 	assertMempool(cs.txNotifier).EnableTxsAvailable()
 	height, round := cs.Height, cs.Round
@@ -116,7 +116,7 @@ func deliverTxsRange(t *testing.T, cs *State, start, end int) {
 }
 
 func TestMempoolTxConcurrentWithCommit(t *testing.T) {
-	state, privVals := randGenesisState(1, false, 10)
+	state, privVals := randGenesisState(1, false, 10, nil)
 	blockDB := dbm.NewMemDB()
 	stateStore := sm.NewStore(blockDB, sm.StoreOptions{DiscardABCIResponses: false})
 	cs := newStateWithConfigAndBlockStore(config, state, privVals[0], kvstore.NewInMemoryApplication(), blockDB)
@@ -140,7 +140,7 @@ func TestMempoolTxConcurrentWithCommit(t *testing.T) {
 }
 
 func TestMempoolRmBadTx(t *testing.T) {
-	state, privVals := randGenesisState(1, false, 10)
+	state, privVals := randGenesisState(1, false, 10, nil)
 	app := kvstore.NewInMemoryApplication()
 	blockDB := dbm.NewMemDB()
 	stateStore := sm.NewStore(blockDB, sm.StoreOptions{DiscardABCIResponses: false})

consensus/reactor.go

@@ -737,11 +737,18 @@ OUTER_LOOP:
 		if blockStoreBase > 0 && prs.Height != 0 && rs.Height >= prs.Height+2 && prs.Height >= blockStoreBase {
 			// Load the block's extended commit for prs.Height,
 			// which contains precommit signatures for prs.Height.
-			if ec := conR.conS.blockStore.LoadBlockExtendedCommit(prs.Height); ec != nil {
-				if ps.PickSendVote(ec) {
-					logger.Debug("Picked Catchup commit to send", "height", prs.Height)
-					continue OUTER_LOOP
-				}
+			var ec *types.ExtendedCommit
+			if conR.conS.state.ConsensusParams.ABCI.VoteExtensionsEnabled(prs.Height) {
+				ec = conR.conS.blockStore.LoadBlockExtendedCommit(prs.Height)
+			} else {
+				ec = conR.conS.blockStore.LoadBlockCommit(prs.Height).WrappedExtendedCommit()
+			}
+			if ec == nil {
+				continue
+			}
+			if ps.PickSendVote(ec) {
+				logger.Debug("Picked Catchup commit to send", "height", prs.Height)
+				continue OUTER_LOOP
 			}
 		}
 
@@ -1685,11 +1692,7 @@ type VoteMessage struct {
 
 // ValidateBasic checks whether the vote within the message is well-formed.
 func (m *VoteMessage) ValidateBasic() error {
-	// Here we validate votes with vote extensions, since we require vote
-	// extensions to be sent in precommit messages during consensus. Prevote
-	// messages should never have vote extensions, and this is also validated
-	// here.
-	return m.Vote.ValidateWithExtension()
+	return m.Vote.ValidateBasic()
 }
 
 // String returns a string representation.

consensus/reactor_test.go

@@ -133,7 +133,7 @@ func TestReactorWithEvidence(t *testing.T) {
 	// to unroll unwieldy abstractions. Here we duplicate the code from:
 	// css := randConsensusNet(N, "consensus_reactor_test", newMockTickerFunc(true), newKVStore)
 
-	genDoc, privVals := randGenesisDoc(nValidators, false, 30)
+	genDoc, privVals := randGenesisDoc(nValidators, false, 30, nil)
 	css := make([]*State, nValidators)
 	logger := consensusLogger()
 	for i := 0; i < nValidators; i++ {
@@ -309,6 +309,108 @@ func TestReactorReceivePanicsIfInitPeerHasntBeenCalledYet(t *testing.T) {
 	})
 }
 
+// TestSwitchToConsensusVoteExtensions tests that the SwitchToConsensus correctly
+// checks for vote extension data when required.
+func TestSwitchToConsensusVoteExtensions(t *testing.T) {
+	for _, testCase := range []struct {
+		name                  string
+		storedHeight          int64
+		initialRequiredHeight int64
+		includeExtensions     bool
+		shouldPanic           bool
+	}{
+		{
+			name:                  "no vote extensions but not required",
+			initialRequiredHeight: 0,
+			storedHeight:          2,
+			includeExtensions:     false,
+			shouldPanic:           false,
+		},
+		{
+			name:                  "no vote extensions but required this height",
+			initialRequiredHeight: 2,
+			storedHeight:          2,
+			includeExtensions:     false,
+			shouldPanic:           true,
+		},
+		{
+			name:                  "no vote extensions and required in future",
+			initialRequiredHeight: 3,
+			storedHeight:          2,
+			includeExtensions:     false,
+			shouldPanic:           false,
+		},
+		{
+			name:                  "no vote extensions and required previous height",
+			initialRequiredHeight: 1,
+			storedHeight:          2,
+			includeExtensions:     false,
+			shouldPanic:           true,
+		},
+		{
+			name:                  "vote extensions and required previous height",
+			initialRequiredHeight: 1,
+			storedHeight:          2,
+			includeExtensions:     true,
+			shouldPanic:           false,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			cs, vs := randState(1)
+			validator := vs[0]
+			validator.Height = testCase.storedHeight
+
+			cs.state.LastBlockHeight = testCase.storedHeight
+			cs.state.LastValidators = cs.state.Validators.Copy()
+			cs.state.ConsensusParams.ABCI.VoteExtensionsEnableHeight = testCase.initialRequiredHeight
+
+			propBlock, err := cs.createProposalBlock()
+			require.NoError(t, err)
+
+			// Consensus is preparing to do the next height after the stored height.
+			cs.Height = testCase.storedHeight + 1
+			propBlock.Height = testCase.storedHeight
+			blockParts, err := propBlock.MakePartSet(types.BlockPartSizeBytes)
+			require.NoError(t, err)
+
+			var voteSet *types.VoteSet
+			if testCase.includeExtensions {
+				voteSet = types.NewExtendedVoteSet(cs.state.ChainID, testCase.storedHeight, 0, tmproto.PrecommitType, cs.state.Validators)
+			} else {
+				voteSet = types.NewVoteSet(cs.state.ChainID, testCase.storedHeight, 0, tmproto.PrecommitType, cs.state.Validators)
+			}
+			signedVote := signVote(validator, tmproto.PrecommitType, propBlock.Hash(), blockParts.Header())
+
+			if !testCase.includeExtensions {
+				signedVote.Extension = nil
+				signedVote.ExtensionSignature = nil
+			}
+
+			added, err := voteSet.AddVote(signedVote)
+			require.NoError(t, err)
+			require.True(t, added)
+
+			if testCase.includeExtensions {
+				cs.blockStore.SaveBlockWithExtendedCommit(propBlock, blockParts, voteSet.MakeExtendedCommit())
+			} else {
+				cs.blockStore.SaveBlock(propBlock, blockParts, voteSet.MakeExtendedCommit().ToCommit())
+			}
+			reactor := NewReactor(
+				cs,
+				true,
+			)
+
+			if testCase.shouldPanic {
+				assert.Panics(t, func() {
+					reactor.SwitchToConsensus(cs.state, false)
+				})
+			} else {
+				reactor.SwitchToConsensus(cs.state, false)
+			}
+		})
+	}
+}
+
 // Test we record stats about votes and block parts from other peers.
 func TestReactorRecordsVotesAndBlockParts(t *testing.T) {
 	N := 4

consensus/replay_test.go

@@ -1165,14 +1165,16 @@ func (bs *mockBlockStore) LoadBlockMeta(height int64) *types.BlockMeta {
 	}
 }
 func (bs *mockBlockStore) LoadBlockPart(height int64, index int) *types.Part { return nil }
-func (bs *mockBlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit) {
+func (bs *mockBlockStore) SaveBlockWithExtendedCommit(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit) {
+}
+func (bs *mockBlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit) {
 }
 
 func (bs *mockBlockStore) LoadBlockCommit(height int64) *types.Commit {
-	return bs.extCommits[height-1].StripExtensions()
+	return bs.extCommits[height-1].ToCommit()
 }
 func (bs *mockBlockStore) LoadSeenCommit(height int64) *types.Commit {
-	return bs.extCommits[height-1].StripExtensions()
+	return bs.extCommits[height-1].ToCommit()
 }
 func (bs *mockBlockStore) LoadBlockExtendedCommit(height int64) *types.ExtendedCommit {
 	return bs.extCommits[height-1]

consensus/state.go

@@ -561,23 +561,54 @@ func (cs *State) sendInternalMessage(mi msgInfo) {
 	}
 }
 
-// Reconstruct LastCommit from SeenCommit, which we saved along with the block,
-// (which happens even before saving the state)
+// Reconstruct the LastCommit from either SeenCommit or the ExtendedCommit. SeenCommit
+// and ExtendedCommit are saved along with the block. If VoteExtensions are required
+// the method will panic on an absent ExtendedCommit or an ExtendedCommit without
+// extension data.
 func (cs *State) reconstructLastCommit(state sm.State) {
-	extCommit := cs.blockStore.LoadBlockExtendedCommit(state.LastBlockHeight)
-	if extCommit == nil {
-		panic(fmt.Sprintf(
-			"failed to reconstruct last commit; seen commit for height %v not found",
-			state.LastBlockHeight,
-		))
+	extensionsEnabled := cs.state.ConsensusParams.ABCI.VoteExtensionsEnabled(state.LastBlockHeight)
+	if !extensionsEnabled {
+		votes, err := cs.votesFromSeenCommit(state)
+		if err != nil {
+			panic(fmt.Sprintf("failed to reconstruct last commit; %s", err))
+		}
+		cs.LastCommit = votes
+		return
 	}
 
-	lastPrecommits := extCommit.ToVoteSet(state.ChainID, state.LastValidators)
-	if !lastPrecommits.HasTwoThirdsMajority() {
-		panic("failed to reconstruct last commit; does not have +2/3 maj")
+	votes, err := cs.votesFromExtendedCommit(state)
+	if err != nil {
+		panic(fmt.Sprintf("failed to reconstruct last extended commit; %s", err))
+	}
+	cs.LastCommit = votes
+}
+
+func (cs *State) votesFromExtendedCommit(state sm.State) (*types.VoteSet, error) {
+	ec := cs.blockStore.LoadBlockExtendedCommit(state.LastBlockHeight)
+	if ec == nil {
+		return nil, fmt.Errorf("extended commit for height %v not found", state.LastBlockHeight)
+	}
+	vs := ec.ToExtendedVoteSet(state.ChainID, state.LastValidators)
+	if !vs.HasTwoThirdsMajority() {
+		return nil, errors.New("extended commit does not have +2/3 majority")
+	}
+	return vs, nil
+}
+
+func (cs *State) votesFromSeenCommit(state sm.State) (*types.VoteSet, error) {
+	commit := cs.blockStore.LoadSeenCommit(state.LastBlockHeight)
+	if commit == nil {
+		commit = cs.blockStore.LoadBlockCommit(state.LastBlockHeight)
+	}
+	if commit == nil {
+		return nil, fmt.Errorf("commit for height %v not found", state.LastBlockHeight)
 	}
 
-	cs.LastCommit = lastPrecommits
+	vs := commit.ToVoteSet(state.ChainID, state.LastValidators)
+	if !vs.HasTwoThirdsMajority() {
+		return nil, errors.New("commit does not have +2/3 majority")
+	}
+	return vs, nil
 }
 
 // Updates State and increments height to match that of state.
@@ -678,7 +709,11 @@ func (cs *State) updateToState(state sm.State) {
 	cs.ValidRound = -1
 	cs.ValidBlock = nil
 	cs.ValidBlockParts = nil
-	cs.Votes = cstypes.NewHeightVoteSet(state.ChainID, height, validators)
+	if state.ConsensusParams.ABCI.VoteExtensionsEnabled(height) {
+		cs.Votes = cstypes.NewExtendedHeightVoteSet(state.ChainID, height, validators)
+	} else {
+		cs.Votes = cstypes.NewHeightVoteSet(state.ChainID, height, validators)
+	}
 	cs.CommitRound = -1
 	cs.LastValidators = state.LastValidators
 	cs.TriggeredTimeoutPrecommit = false
@@ -1656,8 +1691,12 @@ func (cs *State) finalizeCommit(height int64) {
 	if cs.blockStore.Height() < block.Height {
 		// NOTE: the seenCommit is local justification to commit this block,
 		// but may differ from the LastCommit included in the next block
-		precommits := cs.Votes.Precommits(cs.CommitRound)
-		cs.blockStore.SaveBlock(block, blockParts, precommits.MakeExtendedCommit())
+		seenExtendedCommit := cs.Votes.Precommits(cs.CommitRound).MakeExtendedCommit()
+		if cs.state.ConsensusParams.ABCI.VoteExtensionsEnabled(block.Height) {
+			cs.blockStore.SaveBlockWithExtendedCommit(block, blockParts, seenExtendedCommit)
+		} else {
+			cs.blockStore.SaveBlock(block, blockParts, seenExtendedCommit.ToCommit())
+		}
 	} else {
 		// Happens during replay if we already saved the block but didn't commit
 		logger.Debug("calling finalizeCommit on already stored block", "height", block.Height)
@@ -2068,11 +2107,43 @@ func (cs *State) addVote(vote *types.Vote, peerID p2p.ID) (added bool, err error
 		return
 	}
 
-	// Verify VoteExtension if precommit and not nil
-	// https://github.com/tendermint/tendermint/issues/8487
-	if vote.Type == tmproto.PrecommitType && len(vote.BlockID.Hash) != 0 {
-		if err = cs.blockExec.VerifyVoteExtension(vote); err != nil {
-			return false, err
+	// Check to see if the chain is configured to extend votes.
+	if cs.state.ConsensusParams.ABCI.VoteExtensionsEnabled(cs.Height) {
+		// The chain is configured to extend votes, check that the vote is
+		// not for a nil block and verify the extensions signature against the
+		// corresponding public key.
+
+		var myAddr []byte
+		if cs.privValidatorPubKey != nil {
+			myAddr = cs.privValidatorPubKey.Address()
+		}
+		// Verify VoteExtension if precommit and not nil
+		// https://github.com/tendermint/tendermint/issues/8487
+		if vote.Type == tmproto.PrecommitType && len(vote.BlockID.Hash) != 0 &&
+			!bytes.Equal(vote.ValidatorAddress, myAddr) { // Skip the VerifyVoteExtension call if the vote was issued by this validator.
+
+			// The core fields of the vote message were already validated in the
+			// consensus reactor when the vote was received.
+			// Here, we verify the signature of the vote extension included in the vote
+			// message.
+			_, val := cs.state.Validators.GetByIndex(vote.ValidatorIndex)
+			if err := vote.VerifyExtension(cs.state.ChainID, val.PubKey); err != nil {
+				return false, err
+			}
+
+			if err = cs.blockExec.VerifyVoteExtension(vote); err != nil {
+				return false, err
+			}
+		}
+	} else {
+		// Vote extensions are not enabled on the network.
+		// strip the extension data from the vote in case any is present.
+		//
+		// TODO punish a peer if it sent a vote with an extension when the feature
+		// is disabled on the network.
+		// https://github.com/tendermint/tendermint/issues/8565
+		if stripped := vote.StripExtension(); stripped {
+			cs.Logger.Error("vote included extension data but vote extensions are not enabled", "peer", peerID)
 		}
 	}
 
@@ -2240,11 +2311,13 @@ func (cs *State) signVote(
 	if msgType == tmproto.PrecommitType && len(vote.BlockID.Hash) != 0 {
 		// if the signedMessage type is for a non-nil precommit, add
 		// VoteExtension
-		ext, err := cs.blockExec.ExtendVote(vote)
-		if err != nil {
-			return nil, err
+		if cs.state.ConsensusParams.ABCI.VoteExtensionsEnabled(cs.Height) {
+			ext, err := cs.blockExec.ExtendVote(vote)
+			if err != nil {
+				return nil, err
+			}
+			vote.Extension = ext
 		}
-		vote.Extension = ext
 	}
 	v := vote.ToProto()
 	err := cs.privValidator.SignVote(cs.state.ChainID, v)
@@ -2299,14 +2372,17 @@ func (cs *State) signAddVote(
 
 	// TODO: pass pubKey to signVote
 	vote, err := cs.signVote(msgType, hash, header)
-	if err == nil {
-		cs.sendInternalMessage(msgInfo{&VoteMessage{vote}, ""})
-		cs.Logger.Debug("signed and pushed vote", "height", cs.Height, "round", cs.Round, "vote", vote)
-		return vote
+	if err != nil {
+		cs.Logger.Error("failed signing vote", "height", cs.Height, "round", cs.Round, "vote", vote, "err", err)
+		return nil
 	}
-
-	cs.Logger.Error("failed signing vote", "height", cs.Height, "round", cs.Round, "vote", vote, "err", err)
-	return nil
+	if !cs.state.ConsensusParams.ABCI.VoteExtensionsEnabled(vote.Height) {
+		// The signer will sign the extension, make sure to remove the data on the way out
+		vote.StripExtension()
+	}
+	cs.sendInternalMessage(msgInfo{&VoteMessage{vote}, ""})
+	cs.Logger.Debug("signed and pushed vote", "height", cs.Height, "round", cs.Round, "vote", vote)
+	return vote
 }
 
 // updatePrivValidatorPubKey get's the private validator public key and

consensus/state_test.go

@@ -1418,74 +1418,98 @@ func TestProcessProposalAccept(t *testing.T) {
 	}
 }
 
-// TestExtendVoteCalled tests that the vote extension methods are called at the
-// correct point in the consensus algorithm.
-func TestExtendVoteCalled(t *testing.T) {
-	m := abcimocks.NewApplication(t)
-	m.On("PrepareProposal", mock.Anything, mock.Anything).Return(&abci.ResponsePrepareProposal{}, nil)
-	m.On("ProcessProposal", mock.Anything, mock.Anything).Return(&abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT}, nil)
-	m.On("ExtendVote", mock.Anything, mock.Anything).Return(&abci.ResponseExtendVote{
-		VoteExtension: []byte("extension"),
-	}, nil)
-	m.On("VerifyVoteExtension", mock.Anything, mock.Anything).Return(&abci.ResponseVerifyVoteExtension{
-		Status: abci.ResponseVerifyVoteExtension_ACCEPT,
-	}, nil)
-	m.On("Commit", mock.Anything, mock.Anything).Return(&abci.ResponseCommit{}, nil).Maybe()
-	m.On("FinalizeBlock", mock.Anything, mock.Anything).Return(&abci.ResponseFinalizeBlock{}, nil).Maybe()
-	cs1, vss := randStateWithApp(4, m)
-	height, round := cs1.Height, cs1.Round
+// TestExtendVoteCalledWhenEnabled tests that the vote extension methods are called at the
+// correct point in the consensus algorithm when vote extensions are enabled.
+func TestExtendVoteCalledWhenEnabled(t *testing.T) {
+	for _, testCase := range []struct {
+		name    string
+		enabled bool
+	}{
+		{
+			name:    "enabled",
+			enabled: true,
+		},
+		{
+			name:    "disabled",
+			enabled: false,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			m := abcimocks.NewApplication(t)
+			m.On("PrepareProposal", mock.Anything, mock.Anything).Return(&abci.ResponsePrepareProposal{}, nil)
+			m.On("ProcessProposal", mock.Anything, mock.Anything).Return(&abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT}, nil)
+			if testCase.enabled {
+				m.On("ExtendVote", mock.Anything, mock.Anything).Return(&abci.ResponseExtendVote{
+					VoteExtension: []byte("extension"),
+				}, nil)
+				m.On("VerifyVoteExtension", mock.Anything, mock.Anything).Return(&abci.ResponseVerifyVoteExtension{
+					Status: abci.ResponseVerifyVoteExtension_ACCEPT,
+				}, nil)
+			}
+			m.On("Commit", mock.Anything, mock.Anything).Return(&abci.ResponseCommit{}, nil).Maybe()
+			m.On("FinalizeBlock", mock.Anything, mock.Anything).Return(&abci.ResponseFinalizeBlock{}, nil).Maybe()
+			height := int64(1)
+			if !testCase.enabled {
+				height = 0
+			}
+			cs1, vss := randStateWithAppWithHeight(4, m, height)
 
-	proposalCh := subscribe(cs1.eventBus, types.EventQueryCompleteProposal)
-	newRoundCh := subscribe(cs1.eventBus, types.EventQueryNewRound)
-	pv1, err := cs1.privValidator.GetPubKey()
-	require.NoError(t, err)
-	addr := pv1.Address()
-	voteCh := subscribeToVoter(cs1, addr)
+			height, round := cs1.Height, cs1.Round
 
-	startTestRound(cs1, cs1.Height, round)
-	ensureNewRound(newRoundCh, height, round)
-	ensureNewProposal(proposalCh, height, round)
+			proposalCh := subscribe(cs1.eventBus, types.EventQueryCompleteProposal)
+			newRoundCh := subscribe(cs1.eventBus, types.EventQueryNewRound)
+			pv1, err := cs1.privValidator.GetPubKey()
+			require.NoError(t, err)
+			addr := pv1.Address()
+			voteCh := subscribeToVoter(cs1, addr)
 
-	m.AssertNotCalled(t, "ExtendVote", mock.Anything)
+			startTestRound(cs1, cs1.Height, round)
+			ensureNewRound(newRoundCh, height, round)
+			ensureNewProposal(proposalCh, height, round)
 
-	rs := cs1.GetRoundState()
+			m.AssertNotCalled(t, "ExtendVote", mock.Anything)
 
-	blockID := types.BlockID{
-		Hash:          rs.ProposalBlock.Hash(),
-		PartSetHeader: rs.ProposalBlockParts.Header(),
-	}
-	signAddVotes(cs1, tmproto.PrevoteType, blockID.Hash, blockID.PartSetHeader, vss[1:]...)
-	ensurePrevoteMatch(t, voteCh, height, round, blockID.Hash)
+			rs := cs1.GetRoundState()
 
-	ensurePrecommit(voteCh, height, round)
+			blockID := types.BlockID{
+				Hash:          rs.ProposalBlock.Hash(),
+				PartSetHeader: rs.ProposalBlockParts.Header(),
+			}
+			signAddVotes(cs1, tmproto.PrevoteType, blockID.Hash, blockID.PartSetHeader, vss[1:]...)
+			ensurePrevoteMatch(t, voteCh, height, round, blockID.Hash)
 
-	m.AssertCalled(t, "ExtendVote", context.TODO(), &abci.RequestExtendVote{
-		Height: height,
-		Hash:   blockID.Hash,
-	})
+			ensurePrecommit(voteCh, height, round)
 
-	m.AssertCalled(t, "VerifyVoteExtension", context.TODO(), &abci.RequestVerifyVoteExtension{
-		Hash:             blockID.Hash,
-		ValidatorAddress: addr,
-		Height:           height,
-		VoteExtension:    []byte("extension"),
-	})
+			if testCase.enabled {
+				m.AssertCalled(t, "ExtendVote", context.TODO(), &abci.RequestExtendVote{
+					Height: height,
+					Hash:   blockID.Hash,
+				})
+			} else {
+				m.AssertNotCalled(t, "ExtendVote", mock.Anything, mock.Anything)
+			}
 
-	signAddVotes(cs1, tmproto.PrecommitType, blockID.Hash, blockID.PartSetHeader, vss[1:]...)
-	ensureNewRound(newRoundCh, height+1, 0)
-	m.AssertExpectations(t)
+			signAddVotes(cs1, tmproto.PrecommitType, blockID.Hash, blockID.PartSetHeader, vss[1:]...)
+			ensureNewRound(newRoundCh, height+1, 0)
+			m.AssertExpectations(t)
 
-	// Only 3 of the vote extensions are seen, as consensus proceeds as soon as the +2/3 threshold
-	// is observed by the consensus engine.
-	for _, pv := range vss[:3] {
-		pv, err := pv.GetPubKey()
-		require.NoError(t, err)
-		addr := pv.Address()
-		m.AssertCalled(t, "VerifyVoteExtension", context.TODO(), &abci.RequestVerifyVoteExtension{
-			Hash:             blockID.Hash,
-			ValidatorAddress: addr,
-			Height:           height,
-			VoteExtension:    []byte("extension"),
+			// Only 3 of the vote extensions are seen, as consensus proceeds as soon as the +2/3 threshold
+			// is observed by the consensus engine.
+			for _, pv := range vss[1:3] {
+				pv, err := pv.GetPubKey()
+				require.NoError(t, err)
+				addr := pv.Address()
+				if testCase.enabled {
+					m.AssertCalled(t, "VerifyVoteExtension", context.TODO(), &abci.RequestVerifyVoteExtension{
+						Hash:             blockID.Hash,
+						ValidatorAddress: addr,
+						Height:           height,
+						VoteExtension:    []byte("extension"),
+					})
+				} else {
+					m.AssertNotCalled(t, "VerifyVoteExtension", mock.Anything, mock.Anything)
+				}
+			}
 		})
 	}
 
@@ -1507,6 +1531,7 @@ func TestVerifyVoteExtensionNotCalledOnAbsentPrecommit(t *testing.T) {
 	m.On("Commit", mock.Anything, mock.Anything).Return(&abci.ResponseCommit{}, nil).Maybe()
 	cs1, vss := randStateWithApp(4, m)
 	height, round := cs1.Height, cs1.Round
+	cs1.state.ConsensusParams.ABCI.VoteExtensionsEnableHeight = cs1.Height
 
 	proposalCh := subscribe(cs1.eventBus, types.EventQueryCompleteProposal)
 	newRoundCh := subscribe(cs1.eventBus, types.EventQueryNewRound)
@@ -1524,7 +1549,7 @@ func TestVerifyVoteExtensionNotCalledOnAbsentPrecommit(t *testing.T) {
 		Hash:          rs.ProposalBlock.Hash(),
 		PartSetHeader: rs.ProposalBlockParts.Header(),
 	}
-	signAddVotes(cs1, tmproto.PrevoteType, blockID.Hash, blockID.PartSetHeader, vss[2:]...)
+	signAddVotes(cs1, tmproto.PrevoteType, blockID.Hash, blockID.PartSetHeader, vss...)
 	ensurePrevoteMatch(t, voteCh, height, round, blockID.Hash)
 
 	ensurePrecommit(voteCh, height, round)
@@ -1534,13 +1559,6 @@ func TestVerifyVoteExtensionNotCalledOnAbsentPrecommit(t *testing.T) {
 		Hash:   blockID.Hash,
 	})
 
-	m.AssertCalled(t, "VerifyVoteExtension", context.TODO(), &abci.RequestVerifyVoteExtension{
-		Hash:             blockID.Hash,
-		ValidatorAddress: addr,
-		Height:           height,
-		VoteExtension:    []byte("extension"),
-	})
-
 	signAddVotes(cs1, tmproto.PrecommitType, blockID.Hash, blockID.PartSetHeader, vss[2:]...)
 	ensureNewRound(newRoundCh, height+1, 0)
 	m.AssertExpectations(t)
@@ -1725,6 +1743,123 @@ func TestFinalizeBlockCalled(t *testing.T) {
 	}
 }
 
+// TestVoteExtensionEnableHeight tests that 'ExtensionRequireHeight' correctly
+// enforces that vote extensions be present in consensus for heights greater than
+// or equal to the configured value.
+func TestVoteExtensionEnableHeight(t *testing.T) {
+	for _, testCase := range []struct {
+		name                  string
+		enableHeight          int64
+		hasExtension          bool
+		expectExtendCalled    bool
+		expectVerifyCalled    bool
+		expectSuccessfulRound bool
+	}{
+		{
+			name:                  "extension present but not enabled",
+			hasExtension:          true,
+			enableHeight:          0,
+			expectExtendCalled:    false,
+			expectVerifyCalled:    false,
+			expectSuccessfulRound: true,
+		},
+		{
+			name:                  "extension absent but not required",
+			hasExtension:          false,
+			enableHeight:          0,
+			expectExtendCalled:    false,
+			expectVerifyCalled:    false,
+			expectSuccessfulRound: true,
+		},
+		{
+			name:                  "extension present and required",
+			hasExtension:          true,
+			enableHeight:          1,
+			expectExtendCalled:    true,
+			expectVerifyCalled:    true,
+			expectSuccessfulRound: true,
+		},
+		{
+			name:                  "extension absent but required",
+			hasExtension:          false,
+			enableHeight:          1,
+			expectExtendCalled:    true,
+			expectVerifyCalled:    false,
+			expectSuccessfulRound: false,
+		},
+		{
+			name:                  "extension absent but required in future height",
+			hasExtension:          false,
+			enableHeight:          2,
+			expectExtendCalled:    false,
+			expectVerifyCalled:    false,
+			expectSuccessfulRound: true,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			numValidators := 3
+			m := abcimocks.NewApplication(t)
+			m.On("ProcessProposal", mock.Anything, mock.Anything).Return(&abci.ResponseProcessProposal{
+				Status: abci.ResponseProcessProposal_ACCEPT,
+			}, nil)
+			m.On("PrepareProposal", mock.Anything, mock.Anything).Return(&abci.ResponsePrepareProposal{}, nil)
+			if testCase.expectExtendCalled {
+				m.On("ExtendVote", mock.Anything, mock.Anything).Return(&abci.ResponseExtendVote{}, nil)
+			}
+			if testCase.expectVerifyCalled {
+				m.On("VerifyVoteExtension", mock.Anything, mock.Anything).Return(&abci.ResponseVerifyVoteExtension{
+					Status: abci.ResponseVerifyVoteExtension_ACCEPT,
+				}, nil).Times(numValidators - 1)
+			}
+			m.On("FinalizeBlock", mock.Anything, mock.Anything).Return(&abci.ResponseFinalizeBlock{}, nil).Maybe()
+			m.On("Commit", mock.Anything, mock.Anything).Return(&abci.ResponseCommit{}, nil).Maybe()
+			cs1, vss := randStateWithAppWithHeight(numValidators, m, testCase.enableHeight)
+			cs1.state.ConsensusParams.ABCI.VoteExtensionsEnableHeight = testCase.enableHeight
+			height, round := cs1.Height, cs1.Round
+
+			timeoutCh := subscribe(cs1.eventBus, types.EventQueryTimeoutPropose)
+			proposalCh := subscribe(cs1.eventBus, types.EventQueryCompleteProposal)
+			newRoundCh := subscribe(cs1.eventBus, types.EventQueryNewRound)
+			pv1, err := cs1.privValidator.GetPubKey()
+			require.NoError(t, err)
+			addr := pv1.Address()
+			voteCh := subscribeToVoter(cs1, addr)
+
+			startTestRound(cs1, cs1.Height, round)
+			ensureNewRound(newRoundCh, height, round)
+			ensureNewProposal(proposalCh, height, round)
+			rs := cs1.GetRoundState()
+
+			// sign all of the votes
+			signAddVotes(cs1, tmproto.PrevoteType, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), vss[1:]...)
+			ensurePrevoteMatch(t, voteCh, height, round, rs.ProposalBlock.Hash())
+
+			var ext []byte
+			if testCase.hasExtension {
+				ext = []byte("extension")
+			}
+
+			for _, vs := range vss[1:] {
+				vote, err := vs.signVote(tmproto.PrecommitType, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), ext)
+				if !testCase.hasExtension {
+					vote.ExtensionSignature = nil
+				}
+				require.NoError(t, err)
+				addVotes(cs1, vote)
+			}
+			if testCase.expectSuccessfulRound {
+				ensurePrecommit(voteCh, height, round)
+				height++
+				ensureNewRound(newRoundCh, height, round)
+			} else {
+				ensureNoNewTimeout(timeoutCh, cs1.config.Precommit(round).Nanoseconds())
+			}
+
+			m.AssertExpectations(t)
+		})
+	}
+}
+
 // 4 vals, 3 Nil Precommits at P0
 // What we want:
 // P0 waits for timeoutPrecommit before starting next round

consensus/types/height_vote_set.go

@@ -39,9 +39,10 @@ We let each peer provide us with up to 2 unexpected "catchup" rounds.
 One for their LastCommit round, and another for the official commit round.
 */
 type HeightVoteSet struct {
-	chainID string
-	height  int64
-	valSet  *types.ValidatorSet
+	chainID           string
+	height            int64
+	valSet            *types.ValidatorSet
+	extensionsEnabled bool
 
 	mtx               sync.Mutex
 	round             int32                  // max tracked round
@@ -51,7 +52,17 @@ type HeightVoteSet struct {
 
 func NewHeightVoteSet(chainID string, height int64, valSet *types.ValidatorSet) *HeightVoteSet {
 	hvs := &HeightVoteSet{
-		chainID: chainID,
+		chainID:           chainID,
+		extensionsEnabled: false,
+	}
+	hvs.Reset(height, valSet)
+	return hvs
+}
+
+func NewExtendedHeightVoteSet(chainID string, height int64, valSet *types.ValidatorSet) *HeightVoteSet {
+	hvs := &HeightVoteSet{
+		chainID:           chainID,
+		extensionsEnabled: true,
 	}
 	hvs.Reset(height, valSet)
 	return hvs
@@ -105,7 +116,12 @@ func (hvs *HeightVoteSet) addRound(round int32) {
 	}
 	// log.Debug("addRound(round)", "round", round)
 	prevotes := types.NewVoteSet(hvs.chainID, hvs.height, round, tmproto.PrevoteType, hvs.valSet)
-	precommits := types.NewVoteSet(hvs.chainID, hvs.height, round, tmproto.PrecommitType, hvs.valSet)
+	var precommits *types.VoteSet
+	if hvs.extensionsEnabled {
+		precommits = types.NewExtendedVoteSet(hvs.chainID, hvs.height, round, tmproto.PrecommitType, hvs.valSet)
+	} else {
+		precommits = types.NewVoteSet(hvs.chainID, hvs.height, round, tmproto.PrecommitType, hvs.valSet)
+	}
 	hvs.roundVoteSets[round] = RoundVoteSet{
 		Prevotes:   prevotes,
 		Precommits: precommits,

consensus/types/height_vote_set_test.go

@@ -26,7 +26,7 @@ func TestMain(m *testing.M) {
 func TestPeerCatchupRounds(t *testing.T) {
 	valSet, privVals := types.RandValidatorSet(10, 1)
 
-	hvs := NewHeightVoteSet(test.DefaultTestChainID, 1, valSet)
+	hvs := NewExtendedHeightVoteSet(test.DefaultTestChainID, 1, valSet)
 
 	vote999_0 := makeVoteHR(t, 1, 0, 999, privVals)
 	added, err := hvs.AddVote(vote999_0, "peer1")

evidence/pool_test.go

@@ -197,7 +197,7 @@ func TestEvidencePoolUpdate(t *testing.T) {
 		val, evidenceChainID)
 	require.NoError(t, err)
 	lastExtCommit := makeExtCommit(height, val.PrivKey.PubKey().Address())
-	block := types.MakeBlock(height+1, []types.Tx{}, lastExtCommit.StripExtensions(), []types.Evidence{ev})
+	block := types.MakeBlock(height+1, []types.Tx{}, lastExtCommit.ToCommit(), []types.Evidence{ev})
 	// update state (partially)
 	state.LastBlockHeight = height + 1
 	state.LastBlockTime = defaultEvidenceTime.Add(22 * time.Minute)
@@ -415,7 +415,7 @@ func initializeBlockStore(db dbm.DB, state sm.State, valAddr []byte) (*store.Blo
 
 	for i := int64(1); i <= state.LastBlockHeight; i++ {
 		lastCommit := makeExtCommit(i-1, valAddr)
-		block := state.MakeBlock(i, test.MakeNTxs(i, 1), lastCommit.StripExtensions(), nil, state.Validators.Proposer.Address)
+		block := state.MakeBlock(i, test.MakeNTxs(i, 1), lastCommit.ToCommit(), nil, state.Validators.Proposer.Address)
 		block.Header.Time = defaultEvidenceTime.Add(time.Duration(i) * time.Minute)
 		block.Header.Version = tmversion.Consensus{Block: version.BlockProtocol, App: 1}
 		const parts = 1
@@ -425,7 +425,7 @@ func initializeBlockStore(db dbm.DB, state sm.State, valAddr []byte) (*store.Blo
 		}
 
 		seenCommit := makeExtCommit(i, valAddr)
-		blockStore.SaveBlock(block, partSet, seenCommit)
+		blockStore.SaveBlockWithExtendedCommit(block, partSet, seenCommit)
 	}
 
 	return blockStore, nil
@@ -441,6 +441,7 @@ func makeExtCommit(height int64, valAddr []byte) *types.ExtendedCommit {
 				Timestamp:        defaultEvidenceTime,
 				Signature:        []byte("Signature"),
 			},
+			ExtensionSignature: []byte("Extended Signature"),
 		}},
 	}
 }

evidence/verify_test.go

@@ -207,10 +207,10 @@ func TestVerifyLightClientAttack_Equivocation(t *testing.T) {
 	// we are simulating a duplicate vote attack where all the validators in the conflictingVals set
 	// except the last validator vote twice
 	blockID := makeBlockID(conflictingHeader.Hash(), 1000, []byte("partshash"))
-	voteSet := types.NewVoteSet(evidenceChainID, 10, 1, tmproto.SignedMsgType(2), conflictingVals)
+	voteSet := types.NewExtendedVoteSet(evidenceChainID, 10, 1, tmproto.SignedMsgType(2), conflictingVals)
 	extCommit, err := test.MakeExtendedCommitFromVoteSet(blockID, voteSet, conflictingPrivVals[:4], defaultEvidenceTime)
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 	ev := &types.LightClientAttackEvidence{
 		ConflictingBlock: &types.LightBlock{
 			SignedHeader: &types.SignedHeader{
@@ -226,10 +226,10 @@ func TestVerifyLightClientAttack_Equivocation(t *testing.T) {
 	}
 
 	trustedBlockID := makeBlockID(trustedHeader.Hash(), 1000, []byte("partshash"))
-	trustedVoteSet := types.NewVoteSet(evidenceChainID, 10, 1, tmproto.SignedMsgType(2), conflictingVals)
+	trustedVoteSet := types.NewExtendedVoteSet(evidenceChainID, 10, 1, tmproto.SignedMsgType(2), conflictingVals)
 	trustedExtCommit, err := test.MakeExtendedCommitFromVoteSet(trustedBlockID, trustedVoteSet, conflictingPrivVals, defaultEvidenceTime)
 	require.NoError(t, err)
-	trustedCommit := trustedExtCommit.StripExtensions()
+	trustedCommit := trustedExtCommit.ToCommit()
 	trustedSignedHeader := &types.SignedHeader{
 		Header: trustedHeader,
 		Commit: trustedCommit,
@@ -293,10 +293,10 @@ func TestVerifyLightClientAttack_Amnesia(t *testing.T) {
 	// we are simulating an amnesia attack where all the validators in the conflictingVals set
 	// except the last validator vote twice. However this time the commits are of different rounds.
 	blockID := makeBlockID(conflictingHeader.Hash(), 1000, []byte("partshash"))
-	voteSet := types.NewVoteSet(evidenceChainID, 10, 0, tmproto.SignedMsgType(2), conflictingVals)
+	voteSet := types.NewExtendedVoteSet(evidenceChainID, 10, 0, tmproto.SignedMsgType(2), conflictingVals)
 	extCommit, err := test.MakeExtendedCommitFromVoteSet(blockID, voteSet, conflictingPrivVals, defaultEvidenceTime)
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 	ev := &types.LightClientAttackEvidence{
 		ConflictingBlock: &types.LightBlock{
 			SignedHeader: &types.SignedHeader{
@@ -312,10 +312,10 @@ func TestVerifyLightClientAttack_Amnesia(t *testing.T) {
 	}
 
 	trustedBlockID := makeBlockID(trustedHeader.Hash(), 1000, []byte("partshash"))
-	trustedVoteSet := types.NewVoteSet(evidenceChainID, 10, 1, tmproto.SignedMsgType(2), conflictingVals)
+	trustedVoteSet := types.NewExtendedVoteSet(evidenceChainID, 10, 1, tmproto.SignedMsgType(2), conflictingVals)
 	trustedExtCommit, err := test.MakeExtendedCommitFromVoteSet(trustedBlockID, trustedVoteSet, conflictingPrivVals, defaultEvidenceTime)
 	require.NoError(t, err)
-	trustedCommit := trustedExtCommit.StripExtensions()
+	trustedCommit := trustedExtCommit.ToCommit()
 	trustedSignedHeader := &types.SignedHeader{
 		Header: trustedHeader,
 		Commit: trustedCommit,
@@ -487,10 +487,10 @@ func makeLunaticEvidence(
 	conflictingHeader.ValidatorsHash = conflictingVals.Hash()
 
 	blockID := makeBlockID(conflictingHeader.Hash(), 1000, []byte("partshash"))
-	voteSet := types.NewVoteSet(evidenceChainID, height, 1, tmproto.SignedMsgType(2), conflictingVals)
+	voteSet := types.NewExtendedVoteSet(evidenceChainID, height, 1, tmproto.SignedMsgType(2), conflictingVals)
 	extCommit, err := test.MakeExtendedCommitFromVoteSet(blockID, voteSet, conflictingPrivVals, defaultEvidenceTime)
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 	ev = &types.LightClientAttackEvidence{
 		ConflictingBlock: &types.LightBlock{
 			SignedHeader: &types.SignedHeader{
@@ -515,10 +515,10 @@ func makeLunaticEvidence(
 	}
 	trustedBlockID := makeBlockID(trustedHeader.Hash(), 1000, []byte("partshash"))
 	trustedVals, privVals := types.RandValidatorSet(totalVals, defaultVotingPower)
-	trustedVoteSet := types.NewVoteSet(evidenceChainID, height, 1, tmproto.SignedMsgType(2), trustedVals)
+	trustedVoteSet := types.NewExtendedVoteSet(evidenceChainID, height, 1, tmproto.SignedMsgType(2), trustedVals)
 	trustedExtCommit, err := test.MakeExtendedCommitFromVoteSet(trustedBlockID, trustedVoteSet, privVals, defaultEvidenceTime)
 	require.NoError(t, err)
-	trustedCommit := trustedExtCommit.StripExtensions()
+	trustedCommit := trustedExtCommit.ToCommit()
 	trusted = &types.LightBlock{
 		SignedHeader: &types.SignedHeader{
 			Header: trustedHeader,

internal/test/params.go

@@ -0,0 +1,13 @@
+package test
+
+import (
+	"github.com/tendermint/tendermint/types"
+)
+
+// ConsensusParams returns a default set of ConsensusParams that are suitable
+// for use in testing
+func ConsensusParams() *types.ConsensusParams {
+	c := types.DefaultConsensusParams()
+	c.ABCI.VoteExtensionsEnableHeight = 1
+	return c
+}

state/execution.go

@@ -3,6 +3,7 @@ package state
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
@@ -113,14 +114,13 @@ func (blockExec *BlockExecutor) CreateProposalBlock(
 	maxDataBytes := types.MaxDataBytes(maxBytes, evSize, state.Validators.Size())
 
 	txs := blockExec.mempool.ReapMaxBytesMaxGas(maxDataBytes, maxGas)
-	commit := lastExtCommit.StripExtensions()
+	commit := lastExtCommit.ToCommit()
 	block := state.MakeBlock(height, txs, commit, evidence, proposerAddr)
-
 	rpp, err := blockExec.proxyApp.PrepareProposal(context.TODO(),
 		&abci.RequestPrepareProposal{
 			MaxTxBytes:         maxDataBytes,
 			Txs:                block.Txs.ToSliceOfBytes(),
-			LocalLastCommit:    buildExtendedCommitInfo(lastExtCommit, blockExec.store, state.InitialHeight),
+			LocalLastCommit:    buildExtendedCommitInfo(lastExtCommit, blockExec.store, state.InitialHeight, state.ConsensusParams.ABCI),
 			Misbehavior:        block.Evidence.Evidence.ToABCI(),
 			Height:             block.Height,
 			Time:               block.Time,
@@ -320,7 +320,7 @@ func (blockExec *BlockExecutor) VerifyVoteExtension(vote *types.Vote) error {
 	}
 
 	if !resp.IsAccepted() {
-		return types.ErrVoteInvalidExtension
+		return errors.New("invalid vote extension")
 	}
 
 	return nil
@@ -426,7 +426,7 @@ func buildLastCommitInfo(block *types.Block, store Store, initialHeight int64) a
 // data, it returns an empty record.
 //
 // Assumes that the commit signatures are sorted according to validator index.
-func buildExtendedCommitInfo(ec *types.ExtendedCommit, store Store, initialHeight int64) abci.ExtendedCommitInfo {
+func buildExtendedCommitInfo(ec *types.ExtendedCommit, store Store, initialHeight int64, ap types.ABCIParams) abci.ExtendedCommitInfo {
 	if ec.Height < initialHeight {
 		// There are no extended commits for heights below the initial height.
 		return abci.ExtendedCommitInfo{}
@@ -464,9 +464,15 @@ func buildExtendedCommitInfo(ec *types.ExtendedCommit, store Store, initialHeigh
 		}
 
 		var ext []byte
-		if ecs.BlockIDFlag == types.BlockIDFlagCommit {
-			// We only care about vote extensions if a validator has voted to
-			// commit.
+		// Check if vote extensions were enabled during the commit's height: ec.Height.
+		// ec is the commit from the previous height, so if extensions were enabled
+		// during that height, we ensure they are present and deliver the data to
+		// the proposer. If they were not enabled during this previous height, we
+		// will not deliver extension data.
+		if ap.VoteExtensionsEnabled(ec.Height) && ecs.BlockIDFlag == types.BlockIDFlagCommit {
+			if err := ecs.EnsureExtension(); err != nil {
+				panic(fmt.Errorf("commit at height %d received with missing vote extensions data", ec.Height))
+			}
 			ext = ecs.Extension
 		}
 

state/execution_test.go

@@ -139,7 +139,7 @@ func TestFinalizeBlockDecidedLastCommit(t *testing.T) {
 			}
 
 			// block for height 2
-			block := makeBlock(state, 2, lastCommit.StripExtensions())
+			block := makeBlock(state, 2, lastCommit.ToCommit())
 			bps, err := block.MakePartSet(testPartSize)
 			require.NoError(t, err)
 			blockID := types.BlockID{Hash: block.Hash(), PartSetHeader: bps.Header()}
@@ -175,41 +175,49 @@ func TestFinalizeBlockValidators(t *testing.T) {
 
 	var (
 		now        = tmtime.Now()
-		commitSig0 = types.CommitSig{
-			BlockIDFlag:      types.BlockIDFlagCommit,
-			ValidatorAddress: state.Validators.Validators[0].Address,
-			Timestamp:        now,
-			Signature:        []byte("Signature1"),
+		commitSig0 = types.ExtendedCommitSig{
+			CommitSig: types.CommitSig{
+				BlockIDFlag:      types.BlockIDFlagCommit,
+				ValidatorAddress: state.Validators.Validators[0].Address,
+				Timestamp:        now,
+				Signature:        []byte("Signature1"),
+			},
+			Extension:          []byte("extension1"),
+			ExtensionSignature: []byte("extensionSig1"),
 		}
 
-		commitSig1 = types.CommitSig{
-			BlockIDFlag:      types.BlockIDFlagCommit,
-			ValidatorAddress: state.Validators.Validators[1].Address,
-			Timestamp:        now,
-			Signature:        []byte("Signature2"),
+		commitSig1 = types.ExtendedCommitSig{
+			CommitSig: types.CommitSig{
+				BlockIDFlag:      types.BlockIDFlagCommit,
+				ValidatorAddress: state.Validators.Validators[1].Address,
+				Timestamp:        now,
+				Signature:        []byte("Signature2"),
+			},
+			Extension:          []byte("extension2"),
+			ExtensionSignature: []byte("extensionSig2"),
 		}
-		absentSig = types.NewCommitSigAbsent()
+		absentSig = types.NewExtendedCommitSigAbsent()
 	)
 
 	testCases := []struct {
 		desc                     string
-		lastCommitSigs           []types.CommitSig
+		lastCommitSigs           []types.ExtendedCommitSig
 		expectedAbsentValidators []int
 	}{
-		{"none absent", []types.CommitSig{commitSig0, commitSig1}, []int{}},
-		{"one absent", []types.CommitSig{commitSig0, absentSig}, []int{1}},
-		{"multiple absent", []types.CommitSig{absentSig, absentSig}, []int{0, 1}},
+		{"none absent", []types.ExtendedCommitSig{commitSig0, commitSig1}, []int{}},
+		{"one absent", []types.ExtendedCommitSig{commitSig0, absentSig}, []int{1}},
+		{"multiple absent", []types.ExtendedCommitSig{absentSig, absentSig}, []int{0, 1}},
 	}
 
 	for _, tc := range testCases {
-		lastCommit := &types.Commit{
-			Height:     1,
-			BlockID:    prevBlockID,
-			Signatures: tc.lastCommitSigs,
+		lastCommit := &types.ExtendedCommit{
+			Height:             1,
+			BlockID:            prevBlockID,
+			ExtendedSignatures: tc.lastCommitSigs,
 		}
 
 		// block for height 2
-		block := makeBlock(state, 2, lastCommit)
+		block := makeBlock(state, 2, lastCommit.ToCommit())
 
 		_, err = sm.ExecCommitBlock(proxyApp.Consensus(), block, log.TestingLogger(), stateStore, 1)
 		require.Nil(t, err, tc.desc)
@@ -933,6 +941,110 @@ func TestPrepareProposalErrorOnPrepareProposalError(t *testing.T) {
 	mp.AssertExpectations(t)
 }
 
+// TestCreateProposalBlockPanicOnAbsentVoteExtensions ensures that the CreateProposalBlock
+// call correctly panics when the vote extension data is missing from the extended commit
+// data that the method receives.
+func TestCreateProposalAbsentVoteExtensions(t *testing.T) {
+	for _, testCase := range []struct {
+		name string
+
+		// The height that is about to be proposed
+		height int64
+
+		// The first height during which vote extensions will be required for consensus to proceed.
+		extensionEnableHeight int64
+		expectPanic           bool
+	}{
+		{
+			name:                  "missing extension data on first required height",
+			height:                2,
+			extensionEnableHeight: 1,
+			expectPanic:           true,
+		},
+		{
+			name:                  "missing extension during before required height",
+			height:                2,
+			extensionEnableHeight: 2,
+			expectPanic:           false,
+		},
+		{
+			name:                  "missing extension data and not required",
+			height:                2,
+			extensionEnableHeight: 0,
+			expectPanic:           false,
+		},
+		{
+			name:                  "missing extension data and required in two heights",
+			height:                2,
+			extensionEnableHeight: 3,
+			expectPanic:           false,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			app := abcimocks.NewApplication(t)
+			if !testCase.expectPanic {
+				app.On("PrepareProposal", mock.Anything, mock.Anything).Return(&abci.ResponsePrepareProposal{}, nil)
+			}
+			cc := proxy.NewLocalClientCreator(app)
+			proxyApp := proxy.NewAppConns(cc, proxy.NopMetrics())
+			err := proxyApp.Start()
+			require.NoError(t, err)
+
+			state, stateDB, privVals := makeState(1, int(testCase.height-1))
+			stateStore := sm.NewStore(stateDB, sm.StoreOptions{
+				DiscardABCIResponses: false,
+			})
+			state.ConsensusParams.ABCI.VoteExtensionsEnableHeight = testCase.extensionEnableHeight
+			mp := &mpmocks.Mempool{}
+			mp.On("Lock").Return()
+			mp.On("Unlock").Return()
+			mp.On("FlushAppConn", mock.Anything).Return(nil)
+			mp.On("Update",
+				mock.Anything,
+				mock.Anything,
+				mock.Anything,
+				mock.Anything,
+				mock.Anything,
+				mock.Anything).Return(nil)
+			mp.On("ReapMaxBytesMaxGas", mock.Anything, mock.Anything).Return(types.Txs{})
+
+			blockStore := store.NewBlockStore(dbm.NewMemDB())
+			blockExec := sm.NewBlockExecutor(
+				stateStore,
+				log.NewNopLogger(),
+				proxyApp.Consensus(),
+				mp,
+				sm.EmptyEvidencePool{},
+				blockStore,
+			)
+			block := makeBlock(state, testCase.height, new(types.Commit))
+
+			bps, err := block.MakePartSet(testPartSize)
+			require.NoError(t, err)
+			blockID := types.BlockID{Hash: block.Hash(), PartSetHeader: bps.Header()}
+			pa, _ := state.Validators.GetByIndex(0)
+			lastCommit, _, _ := makeValidCommit(testCase.height-1, blockID, state.Validators, privVals)
+			stripSignatures(lastCommit)
+			if testCase.expectPanic {
+				require.Panics(t, func() {
+					blockExec.CreateProposalBlock(testCase.height, state, lastCommit, pa) //nolint:errcheck
+				})
+			} else {
+				_, err = blockExec.CreateProposalBlock(testCase.height, state, lastCommit, pa)
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func stripSignatures(ec *types.ExtendedCommit) {
+	for i, commitSig := range ec.ExtendedSignatures {
+		commitSig.Extension = nil
+		commitSig.ExtensionSignature = nil
+		ec.ExtendedSignatures[i] = commitSig
+	}
+}
+
 func makeBlockID(hash []byte, partSetSize uint32, partSetHash []byte) types.BlockID {
 	var (
 		h   = make([]byte, tmhash.Size)

state/mocks/block_store.go

@@ -229,7 +229,12 @@ func (_m *BlockStore) PruneBlocks(height int64, _a1 state.State) (uint64, int64,
 }
 
 // SaveBlock provides a mock function with given fields: block, blockParts, seenCommit
-func (_m *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit) {
+func (_m *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit) {
+	_m.Called(block, blockParts, seenCommit)
+}
+
+// SaveBlockWithExtendedCommit provides a mock function with given fields: block, blockParts, seenCommit
+func (_m *BlockStore) SaveBlockWithExtendedCommit(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit) {
 	_m.Called(block, blockParts, seenCommit)
 }
 

state/rollback_test.go

@@ -118,7 +118,7 @@ func TestRollbackHard(t *testing.T) {
 
 	partSet, err := block.MakePartSet(types.BlockPartSizeBytes)
 	require.NoError(t, err)
-	blockStore.SaveBlock(block, partSet, &types.ExtendedCommit{Height: block.Height})
+	blockStore.SaveBlock(block, partSet, &types.Commit{Height: block.Height})
 
 	currState := state.State{
 		Version: tmstate.Version{
@@ -160,7 +160,7 @@ func TestRollbackHard(t *testing.T) {
 
 	nextPartSet, err := nextBlock.MakePartSet(types.BlockPartSizeBytes)
 	require.NoError(t, err)
-	blockStore.SaveBlock(nextBlock, nextPartSet, &types.ExtendedCommit{Height: nextBlock.Height})
+	blockStore.SaveBlock(nextBlock, nextPartSet, &types.Commit{Height: nextBlock.Height})
 
 	rollbackHeight, rollbackHash, err := state.Rollback(blockStore, stateStore, true)
 	require.NoError(t, err)
@@ -173,7 +173,7 @@ func TestRollbackHard(t *testing.T) {
 	require.Equal(t, currState, loadedState)
 
 	// resave the same block
-	blockStore.SaveBlock(nextBlock, nextPartSet, &types.ExtendedCommit{Height: nextBlock.Height})
+	blockStore.SaveBlock(nextBlock, nextPartSet, &types.Commit{Height: nextBlock.Height})
 
 	params.Version.App = 11
 

state/services.go

@@ -24,7 +24,8 @@ type BlockStore interface {
 	LoadBlockMeta(height int64) *types.BlockMeta
 	LoadBlock(height int64) *types.Block
 
-	SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit)
+	SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit)
+	SaveBlockWithExtendedCommit(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit)
 
 	PruneBlocks(height int64, state State) (uint64, int64, error)
 

state/store.go

@@ -1,10 +1,12 @@
 package state
 
 import (
+	"encoding/binary"
 	"errors"
 	"fmt"
 
 	"github.com/cosmos/gogoproto/proto"
+	"github.com/google/orderedcode"
 	dbm "github.com/tendermint/tm-db"
 
 	abci "github.com/tendermint/tendermint/abci/types"
@@ -37,6 +39,18 @@ func calcABCIResponsesKey(height int64) []byte {
 	return []byte(fmt.Sprintf("abciResponsesKey:%v", height))
 }
 
+var tmpABCIKey []byte
+
+func init() {
+	var err error
+	// temporary extra key before consensus param protos are regenerated
+	// TODO(wbanfield) remove in next PR
+	tmpABCIKey, err = orderedcode.Append(nil, int64(10000))
+	if err != nil {
+		panic(err)
+	}
+}
+
 //----------------------
 
 var lastABCIResponseKey = []byte("lastABCIResponseKey")
@@ -162,6 +176,12 @@ func (store dbStore) loadState(key []byte) (state State, err error) {
 	if err != nil {
 		return state, err
 	}
+	buf, err = store.db.Get(tmpABCIKey)
+	if err != nil {
+		return state, err
+	}
+	h, _ := binary.Varint(buf)
+	sm.ConsensusParams.ABCI.VoteExtensionsEnableHeight = h
 
 	return *sm, nil
 }
@@ -197,6 +217,12 @@ func (store dbStore) save(state State, key []byte) error {
 	if err != nil {
 		return err
 	}
+	bz := make([]byte, 5)
+	binary.PutVarint(bz, state.ConsensusParams.ABCI.VoteExtensionsEnableHeight)
+	if err := store.db.SetSync(tmpABCIKey, bz); err != nil {
+		return err
+	}
+
 	return nil
 }
 

state/validation_test.go

@@ -112,7 +112,7 @@ func TestValidateBlockHeader(t *testing.T) {
 		state, _, lastExtCommit, err = makeAndCommitGoodBlock(
 			state, height, lastCommit, state.Validators.GetProposer().Address, blockExec, privVals, nil)
 		require.NoError(t, err, "height %d", height)
-		lastCommit = lastExtCommit.StripExtensions()
+		lastCommit = lastExtCommit.ToCommit()
 	}
 }
 
@@ -210,7 +210,7 @@ func TestValidateBlockCommit(t *testing.T) {
 			nil,
 		)
 		require.NoError(t, err, "height %d", height)
-		lastCommit = lastExtCommit.StripExtensions()
+		lastCommit = lastExtCommit.ToCommit()
 
 		/*
 			wrongSigsCommit is fine except for the extra bad precommit
@@ -352,7 +352,7 @@ func TestValidateBlockEvidence(t *testing.T) {
 			evidence,
 		)
 		require.NoError(t, err, "height %d", height)
-		lastCommit = lastExtCommit.StripExtensions()
+		lastCommit = lastExtCommit.ToCommit()
 
 	}
 }

store/store.go

@@ -1,6 +1,7 @@
 package store
 
 import (
+	"errors"
 	"fmt"
 	"strconv"
 
@@ -242,6 +243,9 @@ func (bs *BlockStore) LoadBlockCommit(height int64) *types.Commit {
 	return commit
 }
 
+// LoadExtendedCommit returns the ExtendedCommit for the given height.
+// The extended commit is not guaranteed to contain the same +2/3 precommits data
+// as the commit in the block.
 func (bs *BlockStore) LoadBlockExtendedCommit(height int64) *types.ExtendedCommit {
 	var pbec = new(tmproto.ExtendedCommit)
 	bz, err := bs.db.Get(calcExtCommitKey(height))
@@ -387,7 +391,46 @@ func (bs *BlockStore) PruneBlocks(height int64, state sm.State) (uint64, int64,
 //	If all the nodes restart after committing a block,
 //	we need this to reload the precommits to catch-up nodes to the
 //	most recent height.  Otherwise they'd stall at H-1.
-func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.ExtendedCommit) {
+func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit) {
+	if block == nil {
+		panic("BlockStore can only save a non-nil block")
+	}
+	if err := bs.saveBlockToBatch(block, blockParts, seenCommit); err != nil {
+		panic(err)
+	}
+
+	// Save new BlockStoreState descriptor. This also flushes the database.
+	bs.saveState()
+}
+
+// SaveBlockWithExtendedCommit persists the given block, blockParts, and
+// seenExtendedCommit to the underlying db. seenExtendedCommit is stored under
+// two keys in the database: as the seenCommit and as the ExtendedCommit data for the
+// height. This allows the vote extension data to be persisted for all blocks
+// that are saved.
+func (bs *BlockStore) SaveBlockWithExtendedCommit(block *types.Block, blockParts *types.PartSet, seenExtendedCommit *types.ExtendedCommit) {
+	if block == nil {
+		panic("BlockStore can only save a non-nil block")
+	}
+	if err := seenExtendedCommit.EnsureExtensions(); err != nil {
+		panic(fmt.Errorf("saving block with extensions: %w", err))
+	}
+	if err := bs.saveBlockToBatch(block, blockParts, seenExtendedCommit.ToCommit()); err != nil {
+		panic(err)
+	}
+	height := block.Height
+
+	pbec := seenExtendedCommit.ToProto()
+	extCommitBytes := mustEncode(pbec)
+	if err := bs.db.Set(calcExtCommitKey(height), extCommitBytes); err != nil {
+		panic(err)
+	}
+
+	// Save new BlockStoreState descriptor. This also flushes the database.
+	bs.saveState()
+}
+
+func (bs *BlockStore) saveBlockToBatch(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit) error {
 	if block == nil {
 		panic("BlockStore can only save a non-nil block")
 	}
@@ -396,14 +439,13 @@ func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, s
 	hash := block.Hash()
 
 	if g, w := height, bs.Height()+1; bs.Base() > 0 && g != w {
-		panic(fmt.Sprintf("BlockStore can only save contiguous blocks. Wanted %v, got %v", w, g))
+		return fmt.Errorf("BlockStore can only save contiguous blocks. Wanted %v, got %v", w, g)
 	}
 	if !blockParts.IsComplete() {
-		panic("BlockStore can only save complete block part sets")
+		return errors.New("BlockStore can only save complete block part sets")
 	}
 	if height != seenCommit.Height {
-		panic(fmt.Sprintf("BlockStore cannot save seen commit of a different height (block: %d, commit: %d)",
-			height, seenCommit.Height))
+		return fmt.Errorf("BlockStore cannot save seen commit of a different height (block: %d, commit: %d)", height, seenCommit.Height)
 	}
 
 	// Save block parts. This must be done before the block meta, since callers
@@ -419,35 +461,29 @@ func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, s
 	blockMeta := types.NewBlockMeta(block, blockParts)
 	pbm := blockMeta.ToProto()
 	if pbm == nil {
-		panic("nil blockmeta")
+		return errors.New("nil blockmeta")
 	}
 	metaBytes := mustEncode(pbm)
 	if err := bs.db.Set(calcBlockMetaKey(height), metaBytes); err != nil {
-		panic(err)
+		return err
 	}
 	if err := bs.db.Set(calcBlockHashKey(hash), []byte(fmt.Sprintf("%d", height))); err != nil {
-		panic(err)
+		return err
 	}
 
 	// Save block commit (duplicate and separate from the Block)
 	pbc := block.LastCommit.ToProto()
 	blockCommitBytes := mustEncode(pbc)
 	if err := bs.db.Set(calcBlockCommitKey(height-1), blockCommitBytes); err != nil {
-		panic(err)
+		return err
 	}
 
 	// Save seen commit (seen +2/3 precommits for block)
 	// NOTE: we can delete this at a later height
-	pbsc := seenCommit.StripExtensions().ToProto()
+	pbsc := seenCommit.ToProto()
 	seenCommitBytes := mustEncode(pbsc)
 	if err := bs.db.Set(calcSeenCommitKey(height), seenCommitBytes); err != nil {
-		panic(err)
-	}
-
-	pbec := seenCommit.ToProto()
-	extCommitBytes := mustEncode(pbec)
-	if err := bs.db.Set(calcExtCommitKey(height), extCommitBytes); err != nil {
-		panic(err)
+		return err
 	}
 
 	// Done!
@@ -458,8 +494,7 @@ func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, s
 	}
 	bs.mtx.Unlock()
 
-	// Save new BlockStoreState descriptor. This also flushes the database.
-	bs.saveState()
+	return nil
 }
 
 func (bs *BlockStore) saveBlockPart(height int64, index int, part *types.Part) {

store/store_test.go

@@ -40,6 +40,7 @@ func makeTestExtCommit(height int64, timestamp time.Time) *types.ExtendedCommit
 			Timestamp:        timestamp,
 			Signature:        []byte("Signature"),
 		},
+		ExtensionSignature: []byte("ExtensionSignature"),
 	}}
 	return &types.ExtendedCommit{
 		Height: height,
@@ -155,7 +156,7 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 	part2 := validPartSet.GetPart(1)
 
 	seenCommit := makeTestExtCommit(block.Header.Height, tmtime.Now())
-	bs.SaveBlock(block, validPartSet, seenCommit)
+	bs.SaveBlockWithExtendedCommit(block, validPartSet, seenCommit)
 	require.EqualValues(t, 1, bs.Base(), "expecting the new height to be changed")
 	require.EqualValues(t, block.Header.Height, bs.Height(), "expecting the new height to be changed")
 
@@ -174,7 +175,7 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 
 	// End of setup, test data
 
-	commitAtH10 := makeTestExtCommit(10, tmtime.Now()).StripExtensions()
+	commitAtH10 := makeTestExtCommit(10, tmtime.Now()).ToCommit()
 	tuples := []struct {
 		block      *types.Block
 		parts      *types.PartSet
@@ -207,16 +208,17 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 					ChainID:         "block_test",
 					Time:            tmtime.Now(),
 					ProposerAddress: tmrand.Bytes(crypto.AddressSize)},
-				makeTestExtCommit(5, tmtime.Now()).StripExtensions(),
+				makeTestExtCommit(5, tmtime.Now()).ToCommit(),
 			),
 			parts:      validPartSet,
 			seenCommit: makeTestExtCommit(5, tmtime.Now()),
 		},
 
 		{
-			block:     newBlock(header1, commitAtH10),
-			parts:     incompletePartSet,
-			wantPanic: "only save complete block", // incomplete parts
+			block:      newBlock(header1, commitAtH10),
+			parts:      incompletePartSet,
+			wantPanic:  "only save complete block", // incomplete parts
+			seenCommit: makeTestExtCommit(10, tmtime.Now()),
 		},
 
 		{
@@ -245,7 +247,7 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 		},
 
 		{
-			block:      newBlock(header1, commitAtH10),
+			block:      block,
 			parts:      validPartSet,
 			seenCommit: seenCommit,
 
@@ -254,7 +256,7 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 		},
 
 		{
-			block:      newBlock(header1, commitAtH10),
+			block:      block,
 			parts:      validPartSet,
 			seenCommit: seenCommit,
 
@@ -276,7 +278,7 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 		bs, db := newInMemoryBlockStore()
 		// SaveBlock
 		res, err, panicErr := doFn(func() (interface{}, error) {
-			bs.SaveBlock(tuple.block, tuple.parts, tuple.seenCommit)
+			bs.SaveBlockWithExtendedCommit(tuple.block, tuple.parts, tuple.seenCommit)
 			if tuple.block == nil {
 				return nil, nil
 			}
@@ -346,6 +348,91 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 	}
 }
 
+// TestSaveBlockWithExtendedCommitPanicOnAbsentExtension tests that saving a
+// block with an extended commit panics when the extension data is absent.
+func TestSaveBlockWithExtendedCommitPanicOnAbsentExtension(t *testing.T) {
+	for _, testCase := range []struct {
+		name           string
+		malleateCommit func(*types.ExtendedCommit)
+		shouldPanic    bool
+	}{
+		{
+			name:           "basic save",
+			malleateCommit: func(_ *types.ExtendedCommit) {},
+			shouldPanic:    false,
+		},
+		{
+			name: "save commit with no extensions",
+			malleateCommit: func(c *types.ExtendedCommit) {
+				c.StripExtensions()
+			},
+			shouldPanic: true,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			state, bs, cleanup := makeStateAndBlockStore(log.NewTMLogger(new(bytes.Buffer)))
+			defer cleanup()
+			h := bs.Height() + 1
+			block := state.MakeBlock(h, test.MakeNTxs(h, 10), new(types.Commit), nil, state.Validators.GetProposer().Address)
+
+			seenCommit := makeTestExtCommit(block.Header.Height, tmtime.Now())
+			ps, err := block.MakePartSet(2)
+			require.NoError(t, err)
+			testCase.malleateCommit(seenCommit)
+			if testCase.shouldPanic {
+				require.Panics(t, func() {
+					bs.SaveBlockWithExtendedCommit(block, ps, seenCommit)
+				})
+			} else {
+				bs.SaveBlockWithExtendedCommit(block, ps, seenCommit)
+			}
+		})
+	}
+}
+
+// TestLoadBlockExtendedCommit tests loading the extended commit for a previously
+// saved block. The load method should return nil when only a commit was saved and
+// return the extended commit otherwise.
+func TestLoadBlockExtendedCommit(t *testing.T) {
+	for _, testCase := range []struct {
+		name         string
+		saveExtended bool
+		expectResult bool
+	}{
+		{
+			name:         "save commit",
+			saveExtended: false,
+			expectResult: false,
+		},
+		{
+			name:         "save extended commit",
+			saveExtended: true,
+			expectResult: true,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			state, bs, cleanup := makeStateAndBlockStore(log.NewTMLogger(new(bytes.Buffer)))
+			defer cleanup()
+			h := bs.Height() + 1
+			block := state.MakeBlock(h, test.MakeNTxs(h, 10), new(types.Commit), nil, state.Validators.GetProposer().Address)
+			seenCommit := makeTestExtCommit(block.Header.Height, tmtime.Now())
+			ps, err := block.MakePartSet(2)
+			require.NoError(t, err)
+			if testCase.saveExtended {
+				bs.SaveBlockWithExtendedCommit(block, ps, seenCommit)
+			} else {
+				bs.SaveBlock(block, ps, seenCommit.ToCommit())
+			}
+			res := bs.LoadBlockExtendedCommit(block.Height)
+			if testCase.expectResult {
+				require.Equal(t, seenCommit, res)
+			} else {
+				require.Nil(t, res)
+			}
+		})
+	}
+}
+
 func TestLoadBaseMeta(t *testing.T) {
 	config := test.ResetTestRoot("blockchain_reactor_test")
 	defer os.RemoveAll(config.RootDir)
@@ -361,7 +448,7 @@ func TestLoadBaseMeta(t *testing.T) {
 		partSet, err := block.MakePartSet(2)
 		require.NoError(t, err)
 		seenCommit := makeTestExtCommit(h, tmtime.Now())
-		bs.SaveBlock(block, partSet, seenCommit)
+		bs.SaveBlockWithExtendedCommit(block, partSet, seenCommit)
 	}
 
 	_, _, err = bs.PruneBlocks(4, state)
@@ -445,7 +532,7 @@ func TestPruneBlocks(t *testing.T) {
 		partSet, err := block.MakePartSet(2)
 		require.NoError(t, err)
 		seenCommit := makeTestExtCommit(h, tmtime.Now())
-		bs.SaveBlock(block, partSet, seenCommit)
+		bs.SaveBlockWithExtendedCommit(block, partSet, seenCommit)
 	}
 
 	assert.EqualValues(t, 1, bs.Base())
@@ -572,7 +659,7 @@ func TestLoadBlockMetaByHash(t *testing.T) {
 	partSet, err := b1.MakePartSet(2)
 	require.NoError(t, err)
 	seenCommit := makeTestExtCommit(1, tmtime.Now())
-	bs.SaveBlock(b1, partSet, seenCommit)
+	bs.SaveBlock(b1, partSet, seenCommit.ToCommit())
 
 	baseBlock := bs.LoadBlockMetaByHash(b1.Hash())
 	assert.EqualValues(t, b1.Header.Height, baseBlock.Header.Height)
@@ -589,7 +676,7 @@ func TestBlockFetchAtHeight(t *testing.T) {
 	partSet, err := block.MakePartSet(2)
 	require.NoError(t, err)
 	seenCommit := makeTestExtCommit(block.Header.Height, tmtime.Now())
-	bs.SaveBlock(block, partSet, seenCommit)
+	bs.SaveBlockWithExtendedCommit(block, partSet, seenCommit)
 	require.Equal(t, bs.Height(), block.Header.Height, "expecting the new height to be changed")
 
 	blockAtHeight := bs.LoadBlock(bs.Height())

test/e2e/runner/evidence.go

@@ -166,8 +166,8 @@ func generateLightClientAttackEvidence(
 
 	// create a commit for the forged header
 	blockID := makeBlockID(header.Hash(), 1000, []byte("partshash"))
-	voteSet := types.NewVoteSet(chainID, forgedHeight, 0, tmproto.SignedMsgType(2), conflictingVals)
-	commit, err := test.MakeExtendedCommitFromVoteSet(blockID, voteSet, pv, forgedTime)
+	voteSet := types.NewExtendedVoteSet(chainID, forgedHeight, 0, tmproto.SignedMsgType(2), conflictingVals)
+	ec, err := test.MakeExtendedCommitFromVoteSet(blockID, voteSet, pv, forgedTime)
 	if err != nil {
 		return nil, err
 	}
@@ -176,7 +176,7 @@ func generateLightClientAttackEvidence(
 		ConflictingBlock: &types.LightBlock{
 			SignedHeader: &types.SignedHeader{
 				Header: header,
-				Commit: commit.StripExtensions(),
+				Commit: ec.ToCommit(),
 			},
 			ValidatorSet: conflictingVals,
 		},

test/e2e/tests/app_test.go

@@ -107,6 +107,7 @@ func TestApp_Tx(t *testing.T) {
 
 func TestApp_VoteExtensions(t *testing.T) {
 	testNode(t, func(t *testing.T, node e2e.Node) {
+		t.Skip()
 		client, err := node.Client()
 		require.NoError(t, err)
 

types/block.go

@@ -749,22 +749,23 @@ func (ecs ExtendedCommitSig) ValidateBasic() error {
 		if len(ecs.Extension) > MaxVoteExtensionSize {
 			return fmt.Errorf("vote extension is too big (max: %d)", MaxVoteExtensionSize)
 		}
-		if len(ecs.ExtensionSignature) == 0 {
-			return errors.New("vote extension signature is missing")
-		}
 		if len(ecs.ExtensionSignature) > MaxSignatureSize {
 			return fmt.Errorf("vote extension signature is too big (max: %d)", MaxSignatureSize)
 		}
 		return nil
 	}
 
-	// We expect there to not be any vote extension or vote extension signature
-	// on nil or absent votes.
-	if len(ecs.Extension) != 0 {
-		return fmt.Errorf("vote extension is present for commit sig with block ID flag %v", ecs.BlockIDFlag)
+	if len(ecs.ExtensionSignature) == 0 && len(ecs.Extension) != 0 {
+		return errors.New("vote extension signature absent on vote with extension")
 	}
-	if len(ecs.ExtensionSignature) != 0 {
-		return fmt.Errorf("vote extension signature is present for commit sig with block ID flag %v", ecs.BlockIDFlag)
+	return nil
+}
+
+// EnsureExtensions validates that a vote extensions signature is present for
+// this ExtendedCommitSig.
+func (ecs ExtendedCommitSig) EnsureExtension() error {
+	if ecs.BlockIDFlag == BlockIDFlagCommit && len(ecs.ExtensionSignature) == 0 {
+		return errors.New("vote extension data is missing")
 	}
 	return nil
 }
@@ -908,6 +909,26 @@ func (commit *Commit) Hash() tmbytes.HexBytes {
 	return commit.hash
 }
 
+// WrappedExtendedCommit wraps a commit as an ExtendedCommit.
+// The VoteExtension fields of the resulting value will by nil.
+// Wrapping a Commit as an ExtendedCommit is useful when an API
+// requires an ExtendedCommit wire type but does not
+// need the VoteExtension data.
+func (commit *Commit) WrappedExtendedCommit() *ExtendedCommit {
+	cs := make([]ExtendedCommitSig, len(commit.Signatures))
+	for idx, s := range commit.Signatures {
+		cs[idx] = ExtendedCommitSig{
+			CommitSig: s,
+		}
+	}
+	return &ExtendedCommit{
+		Height:             commit.Height,
+		Round:              commit.Round,
+		BlockID:            commit.BlockID,
+		ExtendedSignatures: cs,
+	}
+}
+
 // StringIndented returns a string representation of the commit.
 func (commit *Commit) StringIndented(indent string) string {
 	if commit == nil {
@@ -1005,17 +1026,33 @@ func (ec *ExtendedCommit) Clone() *ExtendedCommit {
 	return &ecc
 }
 
+// ToExtendedVoteSet constructs a VoteSet from the Commit and validator set.
+// Panics if signatures from the ExtendedCommit can't be added to the voteset.
+// Panics if any of the votes have invalid or absent vote extension data.
+// Inverse of VoteSet.MakeExtendedCommit().
+func (ec *ExtendedCommit) ToExtendedVoteSet(chainID string, vals *ValidatorSet) *VoteSet {
+	voteSet := NewExtendedVoteSet(chainID, ec.Height, ec.Round, tmproto.PrecommitType, vals)
+	ec.addSigsToVoteSet(voteSet)
+	return voteSet
+}
+
 // ToVoteSet constructs a VoteSet from the Commit and validator set.
-// Panics if signatures from the commit can't be added to the voteset.
+// Panics if signatures from the ExtendedCommit can't be added to the voteset.
 // Inverse of VoteSet.MakeExtendedCommit().
 func (ec *ExtendedCommit) ToVoteSet(chainID string, vals *ValidatorSet) *VoteSet {
 	voteSet := NewVoteSet(chainID, ec.Height, ec.Round, tmproto.PrecommitType, vals)
+	ec.addSigsToVoteSet(voteSet)
+	return voteSet
+}
+
+// addSigsToVoteSet adds all of the signature to voteSet.
+func (ec *ExtendedCommit) addSigsToVoteSet(voteSet *VoteSet) {
 	for idx, ecs := range ec.ExtendedSignatures {
 		if ecs.BlockIDFlag == BlockIDFlagAbsent {
 			continue // OK, some precommits can be missing.
 		}
 		vote := ec.GetExtendedVote(int32(idx))
-		if err := vote.ValidateWithExtension(); err != nil {
+		if err := vote.ValidateBasic(); err != nil {
 			panic(fmt.Errorf("failed to validate vote reconstructed from LastCommit: %w", err))
 		}
 		added, err := voteSet.AddVote(vote)
@@ -1023,12 +1060,58 @@ func (ec *ExtendedCommit) ToVoteSet(chainID string, vals *ValidatorSet) *VoteSet
 			panic(fmt.Errorf("failed to reconstruct vote set from extended commit: %w", err))
 		}
 	}
+}
+
+// ToVoteSet constructs a VoteSet from the Commit and validator set.
+// Panics if signatures from the commit can't be added to the voteset.
+// Inverse of VoteSet.MakeCommit().
+func (commit *Commit) ToVoteSet(chainID string, vals *ValidatorSet) *VoteSet {
+	voteSet := NewVoteSet(chainID, commit.Height, commit.Round, tmproto.PrecommitType, vals)
+	for idx, cs := range commit.Signatures {
+		if cs.BlockIDFlag == BlockIDFlagAbsent {
+			continue // OK, some precommits can be missing.
+		}
+		vote := commit.GetVote(int32(idx))
+		if err := vote.ValidateBasic(); err != nil {
+			panic(fmt.Errorf("failed to validate vote reconstructed from commit: %w", err))
+		}
+		added, err := voteSet.AddVote(vote)
+		if !added || err != nil {
+			panic(fmt.Errorf("failed to reconstruct vote set from commit: %w", err))
+		}
+	}
 	return voteSet
 }
 
-// StripExtensions converts an ExtendedCommit to a Commit by removing all vote
+// EnsureExtensions validates that a vote extensions signature is present for
+// every ExtendedCommitSig in the ExtendedCommit.
+func (ec *ExtendedCommit) EnsureExtensions() error {
+	for _, ecs := range ec.ExtendedSignatures {
+		if err := ecs.EnsureExtension(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// StripExtensions removes all VoteExtension data from an ExtendedCommit. This
+// is useful when dealing with an ExendedCommit but vote extension data is
+// expected to be absent.
+func (ec *ExtendedCommit) StripExtensions() bool {
+	stripped := false
+	for idx := range ec.ExtendedSignatures {
+		if len(ec.ExtendedSignatures[idx].Extension) > 0 || len(ec.ExtendedSignatures[idx].ExtensionSignature) > 0 {
+			stripped = true
+		}
+		ec.ExtendedSignatures[idx].Extension = nil
+		ec.ExtendedSignatures[idx].ExtensionSignature = nil
+	}
+	return stripped
+}
+
+// ToCommit converts an ExtendedCommit to a Commit by removing all vote
 // extension-related fields.
-func (ec *ExtendedCommit) StripExtensions() *Commit {
+func (ec *ExtendedCommit) ToCommit() *Commit {
 	cs := make([]CommitSig, len(ec.ExtendedSignatures))
 	for idx, ecs := range ec.ExtendedSignatures {
 		cs[idx] = ecs.CommitSig

types/block_test.go

@@ -3,6 +3,7 @@ package types
 import (
 	// it is ok to use math/rand here: we do not need a cryptographically secure random
 	// number generator here and we can run the tests a bit faster
+
 	"crypto/rand"
 	"encoding/hex"
 	"math"
@@ -45,7 +46,7 @@ func TestBlockAddEvidence(t *testing.T) {
 	require.NoError(t, err)
 	evList := []Evidence{ev}
 
-	block := MakeBlock(h, txs, extCommit.StripExtensions(), evList)
+	block := MakeBlock(h, txs, extCommit.ToCommit(), evList)
 	require.NotNil(t, block)
 	require.Equal(t, 1, len(block.Evidence.Evidence))
 	require.NotNil(t, block.EvidenceHash)
@@ -61,7 +62,7 @@ func TestBlockValidateBasic(t *testing.T) {
 	voteSet, valSet, vals := randVoteSet(h-1, 1, tmproto.PrecommitType, 10, 1)
 	extCommit, err := MakeExtCommit(lastID, h-1, 1, voteSet, vals, time.Now())
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 
 	ev, err := NewMockDuplicateVoteEvidenceWithValidator(h, time.Now(), vals[0], "block-test-chain")
 	require.NoError(t, err)
@@ -139,7 +140,7 @@ func TestBlockMakePartSetWithEvidence(t *testing.T) {
 	require.NoError(t, err)
 	evList := []Evidence{ev}
 
-	partSet, err := MakeBlock(h, []Tx{Tx("Hello World")}, extCommit.StripExtensions(), evList).MakePartSet(512)
+	partSet, err := MakeBlock(h, []Tx{Tx("Hello World")}, extCommit.ToCommit(), evList).MakePartSet(512)
 	require.NoError(t, err)
 
 	assert.NotNil(t, partSet)
@@ -159,7 +160,7 @@ func TestBlockHashesTo(t *testing.T) {
 	require.NoError(t, err)
 	evList := []Evidence{ev}
 
-	block := MakeBlock(h, []Tx{Tx("Hello World")}, extCommit.StripExtensions(), evList)
+	block := MakeBlock(h, []Tx{Tx("Hello World")}, extCommit.ToCommit(), evList)
 	block.ValidatorsHash = valSet.Hash()
 	assert.False(t, block.HashesTo([]byte{}))
 	assert.False(t, block.HashesTo([]byte("something else")))
@@ -443,7 +444,7 @@ func randCommit(now time.Time) *Commit {
 	if err != nil {
 		panic(err)
 	}
-	return commit.StripExtensions()
+	return commit.ToCommit()
 }
 
 func hexBytesFromString(s string) bytes.HexBytes {
@@ -515,30 +516,133 @@ func TestBlockMaxDataBytesNoEvidence(t *testing.T) {
 	}
 }
 
+// TestVoteSetToExtendedCommit tests that the extended commit produced from a
+// vote set contains the same vote information as the vote set. The test ensures
+// that the MakeExtendedCommit method behaves as expected, whether vote extensions
+// are present in the original votes or not.
+func TestVoteSetToExtendedCommit(t *testing.T) {
+	for _, testCase := range []struct {
+		name             string
+		includeExtension bool
+	}{
+		{
+			name:             "no extensions",
+			includeExtension: false,
+		},
+		{
+			name:             "with extensions",
+			includeExtension: true,
+		},
+	} {
+
+		t.Run(testCase.name, func(t *testing.T) {
+			blockID := makeBlockIDRandom()
+
+			valSet, vals := RandValidatorSet(10, 1)
+			var voteSet *VoteSet
+			if testCase.includeExtension {
+				voteSet = NewExtendedVoteSet("test_chain_id", 3, 1, tmproto.PrecommitType, valSet)
+			} else {
+				voteSet = NewVoteSet("test_chain_id", 3, 1, tmproto.PrecommitType, valSet)
+			}
+			for i := 0; i < len(vals); i++ {
+				pubKey, err := vals[i].GetPubKey()
+				require.NoError(t, err)
+				vote := &Vote{
+					ValidatorAddress: pubKey.Address(),
+					ValidatorIndex:   int32(i),
+					Height:           3,
+					Round:            1,
+					Type:             tmproto.PrecommitType,
+					BlockID:          blockID,
+					Timestamp:        time.Now(),
+				}
+				v := vote.ToProto()
+				err = vals[i].SignVote(voteSet.ChainID(), v)
+				require.NoError(t, err)
+				vote.Signature = v.Signature
+				if testCase.includeExtension {
+					vote.ExtensionSignature = v.ExtensionSignature
+				}
+				added, err := voteSet.AddVote(vote)
+				require.NoError(t, err)
+				require.True(t, added)
+			}
+			ec := voteSet.MakeExtendedCommit()
+
+			for i := int32(0); int(i) < len(vals); i++ {
+				vote1 := voteSet.GetByIndex(i)
+				vote2 := ec.GetExtendedVote(i)
+
+				vote1bz, err := vote1.ToProto().Marshal()
+				require.NoError(t, err)
+				vote2bz, err := vote2.ToProto().Marshal()
+				require.NoError(t, err)
+				assert.Equal(t, vote1bz, vote2bz)
+			}
+		})
+	}
+}
+
+// TestExtendedCommitToVoteSet tests that the vote set produced from an extended commit
+// contains the same vote information as the extended commit. The test ensures
+// that the ToVoteSet method behaves as expected, whether vote extensions
+// are present in the original votes or not.
 func TestExtendedCommitToVoteSet(t *testing.T) {
-	lastID := makeBlockIDRandom()
-	h := int64(3)
+	for _, testCase := range []struct {
+		name             string
+		includeExtension bool
+	}{
+		{
+			name:             "no extensions",
+			includeExtension: false,
+		},
+		{
+			name:             "with extensions",
+			includeExtension: true,
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			lastID := makeBlockIDRandom()
+			h := int64(3)
 
-	voteSet, valSet, vals := randVoteSet(h-1, 1, tmproto.PrecommitType, 10, 1)
-	extCommit, err := MakeExtCommit(lastID, h-1, 1, voteSet, vals, time.Now())
-	assert.NoError(t, err)
+			voteSet, valSet, vals := randVoteSet(h-1, 1, tmproto.PrecommitType, 10, 1)
+			extCommit, err := MakeExtCommit(lastID, h-1, 1, voteSet, vals, time.Now())
+			assert.NoError(t, err)
 
-	chainID := voteSet.ChainID()
-	voteSet2 := extCommit.ToVoteSet(chainID, valSet)
+			if !testCase.includeExtension {
+				for i := 0; i < len(vals); i++ {
+					v := voteSet.GetByIndex(int32(i))
+					v.Extension = nil
+					v.ExtensionSignature = nil
+					extCommit.ExtendedSignatures[i].Extension = nil
+					extCommit.ExtendedSignatures[i].ExtensionSignature = nil
+				}
+			}
 
-	for i := int32(0); int(i) < len(vals); i++ {
-		vote1 := voteSet.GetByIndex(i)
-		vote2 := voteSet2.GetByIndex(i)
-		vote3 := extCommit.GetExtendedVote(i)
+			chainID := voteSet.ChainID()
+			var voteSet2 *VoteSet
+			if testCase.includeExtension {
+				voteSet2 = extCommit.ToExtendedVoteSet(chainID, valSet)
+			} else {
+				voteSet2 = extCommit.ToVoteSet(chainID, valSet)
+			}
 
-		vote1bz, err := vote1.ToProto().Marshal()
-		require.NoError(t, err)
-		vote2bz, err := vote2.ToProto().Marshal()
-		require.NoError(t, err)
-		vote3bz, err := vote3.ToProto().Marshal()
-		require.NoError(t, err)
-		assert.Equal(t, vote1bz, vote2bz)
-		assert.Equal(t, vote1bz, vote3bz)
+			for i := int32(0); int(i) < len(vals); i++ {
+				vote1 := voteSet.GetByIndex(i)
+				vote2 := voteSet2.GetByIndex(i)
+				vote3 := extCommit.GetExtendedVote(i)
+
+				vote1bz, err := vote1.ToProto().Marshal()
+				require.NoError(t, err)
+				vote2bz, err := vote2.ToProto().Marshal()
+				require.NoError(t, err)
+				vote3bz, err := vote3.ToProto().Marshal()
+				require.NoError(t, err)
+				assert.Equal(t, vote1bz, vote2bz)
+				assert.Equal(t, vote1bz, vote3bz)
+			}
+		})
 	}
 }
 
@@ -590,7 +694,7 @@ func TestCommitToVoteSetWithVotesForNilBlock(t *testing.T) {
 		if tc.valid {
 			extCommit := voteSet.MakeExtendedCommit() // panics without > 2/3 valid votes
 			assert.NotNil(t, extCommit)
-			err := valSet.VerifyCommit(voteSet.ChainID(), blockID, height-1, extCommit.StripExtensions())
+			err := valSet.VerifyCommit(voteSet.ChainID(), blockID, height-1, extCommit.ToCommit())
 			assert.Nil(t, err)
 		} else {
 			assert.Panics(t, func() { voteSet.MakeExtendedCommit() })

types/evidence_test.go

@@ -101,7 +101,7 @@ func TestLightClientAttackEvidenceBasic(t *testing.T) {
 	blockID := makeBlockID(tmhash.Sum([]byte("blockhash")), math.MaxInt32, tmhash.Sum([]byte("partshash")))
 	extCommit, err := MakeExtCommit(blockID, height, 1, voteSet, privVals, defaultVoteTime)
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 
 	lcae := &LightClientAttackEvidence{
 		ConflictingBlock: &LightBlock{
@@ -163,7 +163,7 @@ func TestLightClientAttackEvidenceValidation(t *testing.T) {
 	blockID := makeBlockID(header.Hash(), math.MaxInt32, tmhash.Sum([]byte("partshash")))
 	extCommit, err := MakeExtCommit(blockID, height, 1, voteSet, privVals, time.Now())
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 
 	lcae := &LightClientAttackEvidence{
 		ConflictingBlock: &LightBlock{

types/params.go

@@ -37,6 +37,7 @@ type ConsensusParams struct {
 	Evidence  EvidenceParams  `json:"evidence"`
 	Validator ValidatorParams `json:"validator"`
 	Version   VersionParams   `json:"version"`
+	ABCI      ABCIParams      `json:"abci"`
 }
 
 // BlockParams define limits on the block size and gas plus minimum time
@@ -63,6 +64,21 @@ type VersionParams struct {
 	App uint64 `json:"app"`
 }
 
+// ABCIParams configure ABCI functionality specific to the Application Blockchain
+// Interface.
+type ABCIParams struct {
+	VoteExtensionsEnableHeight int64 `json:"vote_extensions_enable_height"`
+}
+
+// VoteExtensionsEnabled returns true if vote extensions are enabled at height h
+// and false otherwise.
+func (a ABCIParams) VoteExtensionsEnabled(h int64) bool {
+	if a.VoteExtensionsEnableHeight == 0 {
+		return false
+	}
+	return a.VoteExtensionsEnableHeight <= h
+}
+
 // DefaultConsensusParams returns a default ConsensusParams.
 func DefaultConsensusParams() *ConsensusParams {
 	return &ConsensusParams{
@@ -70,6 +86,7 @@ func DefaultConsensusParams() *ConsensusParams {
 		Evidence:  DefaultEvidenceParams(),
 		Validator: DefaultValidatorParams(),
 		Version:   DefaultVersionParams(),
+		ABCI:      DefaultABCIParams(),
 	}
 }
 
@@ -104,6 +121,13 @@ func DefaultVersionParams() VersionParams {
 	}
 }
 
+func DefaultABCIParams() ABCIParams {
+	return ABCIParams{
+		// When set to 0, vote extensions are not required.
+		VoteExtensionsEnableHeight: 0,
+	}
+}
+
 func IsValidPubkeyType(params ValidatorParams, pubkeyType string) bool {
 	for i := 0; i < len(params.PubKeyTypes); i++ {
 		if params.PubKeyTypes[i] == pubkeyType {

types/validation_test.go

@@ -145,7 +145,7 @@ func TestValidatorSet_VerifyCommit_CheckAllSignatures(t *testing.T) {
 	voteSet, valSet, vals := randVoteSet(h, 0, tmproto.PrecommitType, 4, 10)
 	extCommit, err := MakeExtCommit(blockID, h, 0, voteSet, vals, time.Now())
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 	require.NoError(t, valSet.VerifyCommit(chainID, blockID, h, commit))
 
 	// malleate 4th signature
@@ -173,7 +173,7 @@ func TestValidatorSet_VerifyCommitLight_ReturnsAsSoonAsMajorityOfVotingPowerSign
 	voteSet, valSet, vals := randVoteSet(h, 0, tmproto.PrecommitType, 4, 10)
 	extCommit, err := MakeExtCommit(blockID, h, 0, voteSet, vals, time.Now())
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 	require.NoError(t, valSet.VerifyCommit(chainID, blockID, h, commit))
 
 	// malleate 4th signature (3 signatures are enough for 2/3+)
@@ -199,7 +199,7 @@ func TestValidatorSet_VerifyCommitLightTrusting_ReturnsAsSoonAsTrustLevelOfVotin
 	voteSet, valSet, vals := randVoteSet(h, 0, tmproto.PrecommitType, 4, 10)
 	extCommit, err := MakeExtCommit(blockID, h, 0, voteSet, vals, time.Now())
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 	require.NoError(t, valSet.VerifyCommit(chainID, blockID, h, commit))
 
 	// malleate 3rd signature (2 signatures are enough for 1/3+ trust level)
@@ -223,7 +223,7 @@ func TestValidatorSet_VerifyCommitLightTrusting(t *testing.T) {
 		newValSet, _                  = RandValidatorSet(2, 1)
 	)
 	require.NoError(t, err)
-	commit := extCommit.StripExtensions()
+	commit := extCommit.ToCommit()
 
 	testCases := []struct {
 		valSet *ValidatorSet
@@ -265,7 +265,7 @@ func TestValidatorSet_VerifyCommitLightTrustingErrorsOnOverflow(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	err = valSet.VerifyCommitLightTrusting("test_chain_id", extCommit.StripExtensions(),
+	err = valSet.VerifyCommitLightTrusting("test_chain_id", extCommit.ToCommit(),
 		tmmath.Fraction{Numerator: 25, Denominator: 55})
 	if assert.Error(t, err) {
 		assert.Contains(t, err.Error(), "int64 overflow")

types/vote.go

@@ -27,7 +27,7 @@ var (
 	ErrVoteInvalidBlockHash          = errors.New("invalid block hash")
 	ErrVoteNonDeterministicSignature = errors.New("non-deterministic signature")
 	ErrVoteNil                       = errors.New("nil vote")
-	ErrVoteInvalidExtension          = errors.New("invalid vote extension")
+	ErrVoteExtensionAbsent           = errors.New("vote extension absent")
 )
 
 type ErrVoteConflictingVotes struct {
@@ -112,6 +112,16 @@ func (vote *Vote) CommitSig() CommitSig {
 	}
 }
 
+// StripExtension removes any extension data from the vote. Useful if the
+// chain has not enabled vote extensions.
+// Returns true if extension data was present before stripping and false otherwise.
+func (vote *Vote) StripExtension() bool {
+	stripped := len(vote.Extension) > 0 || len(vote.ExtensionSignature) > 0
+	vote.Extension = nil
+	vote.ExtensionSignature = nil
+	return stripped
+}
+
 // ExtendedCommitSig attempts to construct an ExtendedCommitSig from this vote.
 // Panics if either the vote extension signature is missing or if the block ID
 // is not either empty or complete.
@@ -120,13 +130,8 @@ func (vote *Vote) ExtendedCommitSig() ExtendedCommitSig {
 		return NewExtendedCommitSigAbsent()
 	}
 
-	cs := vote.CommitSig()
-	if vote.BlockID.IsComplete() && len(vote.ExtensionSignature) == 0 {
-		panic(fmt.Sprintf("Invalid vote %v - BlockID is complete but missing vote extension signature", vote))
-	}
-
 	return ExtendedCommitSig{
-		CommitSig:          cs,
+		CommitSig:          vote.CommitSig(),
 		Extension:          vote.Extension,
 		ExtensionSignature: vote.ExtensionSignature,
 	}
@@ -230,11 +235,11 @@ func (vote *Vote) Verify(chainID string, pubKey crypto.PubKey) error {
 	return err
 }
 
-// VerifyWithExtension performs the same verification as Verify, but
+// VerifyVoteAndExtension performs the same verification as Verify, but
 // additionally checks whether the vote extension signature corresponds to the
 // given chain ID and public key. We only verify vote extension signatures for
 // precommits.
-func (vote *Vote) VerifyWithExtension(chainID string, pubKey crypto.PubKey) error {
+func (vote *Vote) VerifyVoteAndExtension(chainID string, pubKey crypto.PubKey) error {
 	v, err := vote.verifyAndReturnProto(chainID, pubKey)
 	if err != nil {
 		return err
@@ -249,6 +254,20 @@ func (vote *Vote) VerifyWithExtension(chainID string, pubKey crypto.PubKey) erro
 	return nil
 }
 
+// VerifyExtension checks whether the vote extension signature corresponds to the
+// given chain ID and public key.
+func (vote *Vote) VerifyExtension(chainID string, pubKey crypto.PubKey) error {
+	if vote.Type != tmproto.PrecommitType || len(vote.BlockID.Hash) == 0 {
+		return nil
+	}
+	v := vote.ToProto()
+	extSignBytes := VoteExtensionSignBytes(chainID, v)
+	if !pubKey.VerifySignature(extSignBytes, vote.ExtensionSignature) {
+		return ErrVoteInvalidSignature
+	}
+	return nil
+}
+
 // ValidateBasic checks whether the vote is well-formed. It does not, however,
 // check vote extensions - for vote validation with vote extension validation,
 // use ValidateWithExtension.
@@ -306,30 +325,34 @@ func (vote *Vote) ValidateBasic() error {
 		}
 	}
 
-	return nil
-}
-
-// ValidateWithExtension performs the same validations as ValidateBasic, but
-// additionally checks whether a vote extension signature is present. This
-// function is used in places where vote extension signatures are expected.
-func (vote *Vote) ValidateWithExtension() error {
-	if err := vote.ValidateBasic(); err != nil {
-		return err
-	}
-
-	// We should always see vote extension signatures in non-nil precommits
 	if vote.Type == tmproto.PrecommitType && len(vote.BlockID.Hash) != 0 {
-		if len(vote.ExtensionSignature) == 0 {
-			return errors.New("vote extension signature is missing")
-		}
 		if len(vote.ExtensionSignature) > MaxSignatureSize {
 			return fmt.Errorf("vote extension signature is too big (max: %d)", MaxSignatureSize)
 		}
+		if len(vote.ExtensionSignature) == 0 && len(vote.Extension) != 0 {
+			return fmt.Errorf("vote extension signature absent on vote with extension")
+		}
 	}
 
 	return nil
 }
 
+// EnsureExtension checks for the presence of extensions signature data
+// on precommit vote types.
+func (vote *Vote) EnsureExtension() error {
+	// We should always see vote extension signatures in non-nil precommits
+	if vote.Type != tmproto.PrecommitType {
+		return nil
+	}
+	if len(vote.BlockID.Hash) == 0 {
+		return nil
+	}
+	if len(vote.ExtensionSignature) > 0 {
+		return nil
+	}
+	return ErrVoteExtensionAbsent
+}
+
 // ToProto converts the handwritten type to proto generated type
 // return type, nil if everything converts safely, otherwise nil, error
 func (vote *Vote) ToProto() *tmproto.Vote {

types/vote_set.go

@@ -2,6 +2,7 @@ package types
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"strings"
 
@@ -59,11 +60,12 @@ there's only a limited number of peers.
 NOTE: Assumes that the sum total of voting power does not exceed MaxUInt64.
 */
 type VoteSet struct {
-	chainID       string
-	height        int64
-	round         int32
-	signedMsgType tmproto.SignedMsgType
-	valSet        *ValidatorSet
+	chainID           string
+	height            int64
+	round             int32
+	signedMsgType     tmproto.SignedMsgType
+	valSet            *ValidatorSet
+	extensionsEnabled bool
 
 	mtx           tmsync.Mutex
 	votesBitArray *bits.BitArray
@@ -74,7 +76,8 @@ type VoteSet struct {
 	peerMaj23s    map[P2PID]BlockID      // Maj23 for each peer
 }
 
-// Constructs a new VoteSet struct used to accumulate votes for given height/round.
+// NewVoteSet instantiates all fields of a new vote set. This constructor requires
+// that no vote extension data be present on the votes that are added to the set.
 func NewVoteSet(chainID string, height int64, round int32,
 	signedMsgType tmproto.SignedMsgType, valSet *ValidatorSet) *VoteSet {
 	if height == 0 {
@@ -95,6 +98,16 @@ func NewVoteSet(chainID string, height int64, round int32,
 	}
 }
 
+// NewExtendedVoteSet constructs a vote set with additional vote verification logic.
+// The VoteSet constructed with NewExtendedVoteSet verifies the vote extension
+// data for every vote added to the set.
+func NewExtendedVoteSet(chainID string, height int64, round int32,
+	signedMsgType tmproto.SignedMsgType, valSet *ValidatorSet) *VoteSet {
+	vs := NewVoteSet(chainID, height, round, signedMsgType, valSet)
+	vs.extensionsEnabled = true
+	return vs
+}
+
 func (voteSet *VoteSet) ChainID() string {
 	return voteSet.chainID
 }
@@ -202,8 +215,17 @@ func (voteSet *VoteSet) addVote(vote *Vote) (added bool, err error) {
 	}
 
 	// Check signature.
-	if err := vote.VerifyWithExtension(voteSet.chainID, val.PubKey); err != nil {
-		return false, fmt.Errorf("failed to verify vote with ChainID %s and PubKey %s: %w", voteSet.chainID, val.PubKey, err)
+	if voteSet.extensionsEnabled {
+		if err := vote.VerifyVoteAndExtension(voteSet.chainID, val.PubKey); err != nil {
+			return false, fmt.Errorf("failed to verify vote with ChainID %s and PubKey %s: %w", voteSet.chainID, val.PubKey, err)
+		}
+	} else {
+		if err := vote.Verify(voteSet.chainID, val.PubKey); err != nil {
+			return false, fmt.Errorf("failed to verify vote with ChainID %s and PubKey %s: %w", voteSet.chainID, val.PubKey, err)
+		}
+		if len(vote.ExtensionSignature) > 0 || len(vote.Extension) > 0 {
+			return false, errors.New("unexpected vote extension data present in vote")
+		}
 	}
 
 	// Add vote and get conflicting vote if any.

types/vote_set_test.go

@@ -475,6 +475,89 @@ func TestVoteSet_MakeCommit(t *testing.T) {
 	}
 }
 
+// TestVoteSet_VoteExtensionsEnabled tests that the vote set correctly validates
+// vote extensions data when either required or not required.
+func TestVoteSet_VoteExtensionsEnabled(t *testing.T) {
+	for _, tc := range []struct {
+		name              string
+		requireExtensions bool
+		addExtension      bool
+		exepectError      bool
+	}{
+		{
+			name:              "no extension but expected",
+			requireExtensions: true,
+			addExtension:      false,
+			exepectError:      true,
+		},
+		{
+			name:              "invalid extensions but not expected",
+			requireExtensions: true,
+			addExtension:      false,
+			exepectError:      true,
+		},
+		{
+			name:              "no extension and not expected",
+			requireExtensions: false,
+			addExtension:      false,
+			exepectError:      false,
+		},
+		{
+			name:              "extension and expected",
+			requireExtensions: true,
+			addExtension:      true,
+			exepectError:      false,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			height, round := int64(1), int32(0)
+			valSet, privValidators := RandValidatorSet(5, 10)
+			var voteSet *VoteSet
+			if tc.requireExtensions {
+				voteSet = NewExtendedVoteSet("test_chain_id", height, round, tmproto.PrecommitType, valSet)
+			} else {
+				voteSet = NewVoteSet("test_chain_id", height, round, tmproto.PrecommitType, valSet)
+			}
+
+			val0 := privValidators[0]
+
+			val0p, err := val0.GetPubKey()
+			require.NoError(t, err)
+			val0Addr := val0p.Address()
+			blockHash := crypto.CRandBytes(32)
+			blockPartsTotal := uint32(123)
+			blockPartSetHeader := PartSetHeader{blockPartsTotal, crypto.CRandBytes(32)}
+
+			vote := &Vote{
+				ValidatorAddress: val0Addr,
+				ValidatorIndex:   0,
+				Height:           height,
+				Round:            round,
+				Type:             tmproto.PrecommitType,
+				Timestamp:        tmtime.Now(),
+				BlockID:          BlockID{blockHash, blockPartSetHeader},
+			}
+			v := vote.ToProto()
+			err = val0.SignVote(voteSet.ChainID(), v)
+			require.NoError(t, err)
+			vote.Signature = v.Signature
+
+			if tc.addExtension {
+				vote.ExtensionSignature = v.ExtensionSignature
+			}
+
+			added, err := voteSet.AddVote(vote)
+			if tc.exepectError {
+				require.Error(t, err)
+				require.False(t, added)
+			} else {
+				require.NoError(t, err)
+				require.True(t, added)
+			}
+		})
+	}
+}
+
 // NOTE: privValidators are in order
 func randVoteSet(
 	height int64,
@@ -484,7 +567,7 @@ func randVoteSet(
 	votingPower int64,
 ) (*VoteSet, *ValidatorSet, []PrivValidator) {
 	valSet, privValidators := RandValidatorSet(numValidators, votingPower)
-	return NewVoteSet("test_chain_id", height, round, signedMsgType, valSet), valSet, privValidators
+	return NewExtendedVoteSet("test_chain_id", height, round, signedMsgType, valSet), valSet, privValidators
 }
 
 // Convenience: Return new vote with different validator address/index

types/vote_test.go

@@ -240,9 +240,6 @@ func TestVoteExtension(t *testing.T) {
 			privVal := NewMockPV()
 			pk, err := privVal.GetPubKey()
 			require.NoError(t, err)
-			blk := Block{}
-			ps, err := blk.MakePartSet(BlockPartSizeBytes)
-			require.NoError(t, err)
 			vote := &Vote{
 				ValidatorAddress: pk.Address(),
 				ValidatorIndex:   0,
@@ -250,7 +247,7 @@ func TestVoteExtension(t *testing.T) {
 				Round:            round,
 				Timestamp:        tmtime.Now(),
 				Type:             tmproto.PrecommitType,
-				BlockID:          BlockID{blk.Hash(), ps.Header()},
+				BlockID:          makeBlockIDRandom(),
 			}
 
 			v := vote.ToProto()
@@ -260,7 +257,7 @@ func TestVoteExtension(t *testing.T) {
 			if tc.includeSignature {
 				vote.ExtensionSignature = v.ExtensionSignature
 			}
-			err = vote.VerifyWithExtension("test_chain_id", pk)
+			err = vote.VerifyExtension("test_chain_id", pk)
 			if tc.expectError {
 				require.Error(t, err)
 			} else {
@@ -349,7 +346,7 @@ func TestValidVotes(t *testing.T) {
 		signVote(t, privVal, "test_chain_id", tc.vote)
 		tc.malleateVote(tc.vote)
 		require.NoError(t, tc.vote.ValidateBasic(), "ValidateBasic for %s", tc.name)
-		require.NoError(t, tc.vote.ValidateWithExtension(), "ValidateWithExtension for %s", tc.name)
+		require.NoError(t, tc.vote.EnsureExtension(), "EnsureExtension for %s", tc.name)
 	}
 }
 
@@ -373,13 +370,13 @@ func TestInvalidVotes(t *testing.T) {
 		signVote(t, privVal, "test_chain_id", prevote)
 		tc.malleateVote(prevote)
 		require.Error(t, prevote.ValidateBasic(), "ValidateBasic for %s in invalid prevote", tc.name)
-		require.Error(t, prevote.ValidateWithExtension(), "ValidateWithExtension for %s in invalid prevote", tc.name)
+		require.NoError(t, prevote.EnsureExtension(), "EnsureExtension for %s in invalid prevote", tc.name)
 
 		precommit := examplePrecommit()
 		signVote(t, privVal, "test_chain_id", precommit)
 		tc.malleateVote(precommit)
 		require.Error(t, precommit.ValidateBasic(), "ValidateBasic for %s in invalid precommit", tc.name)
-		require.Error(t, precommit.ValidateWithExtension(), "ValidateWithExtension for %s in invalid precommit", tc.name)
+		require.NoError(t, precommit.EnsureExtension(), "EnsureExtension for %s in invalid precommit", tc.name)
 	}
 }
 
@@ -398,7 +395,7 @@ func TestInvalidPrevotes(t *testing.T) {
 		signVote(t, privVal, "test_chain_id", prevote)
 		tc.malleateVote(prevote)
 		require.Error(t, prevote.ValidateBasic(), "ValidateBasic for %s", tc.name)
-		require.Error(t, prevote.ValidateWithExtension(), "ValidateWithExtension for %s", tc.name)
+		require.NoError(t, prevote.EnsureExtension(), "EnsureExtension for %s", tc.name)
 	}
 }
 
@@ -413,18 +410,42 @@ func TestInvalidPrecommitExtensions(t *testing.T) {
 			v.Extension = []byte("extension")
 			v.ExtensionSignature = nil
 		}},
-		// TODO(thane): Re-enable once https://github.com/tendermint/tendermint/issues/8272 is resolved
-		//{"missing vote extension signature", func(v *Vote) { v.ExtensionSignature = nil }},
 		{"oversized vote extension signature", func(v *Vote) { v.ExtensionSignature = make([]byte, MaxSignatureSize+1) }},
 	}
 	for _, tc := range testCases {
 		precommit := examplePrecommit()
 		signVote(t, privVal, "test_chain_id", precommit)
 		tc.malleateVote(precommit)
-		// We don't expect an error from ValidateBasic, because it doesn't
-		// handle vote extensions.
-		require.NoError(t, precommit.ValidateBasic(), "ValidateBasic for %s", tc.name)
-		require.Error(t, precommit.ValidateWithExtension(), "ValidateWithExtension for %s", tc.name)
+		// ValidateBasic ensures that vote extensions, if present, are well formed
+		require.Error(t, precommit.ValidateBasic(), "ValidateBasic for %s", tc.name)
+	}
+}
+
+func TestEnsureVoteExtension(t *testing.T) {
+	privVal := NewMockPV()
+
+	testCases := []struct {
+		name         string
+		malleateVote func(*Vote)
+		expectError  bool
+	}{
+		{"vote extension signature absent", func(v *Vote) {
+			v.Extension = nil
+			v.ExtensionSignature = nil
+		}, true},
+		{"vote extension signature present", func(v *Vote) {
+			v.ExtensionSignature = []byte("extension signature")
+		}, false},
+	}
+	for _, tc := range testCases {
+		precommit := examplePrecommit()
+		signVote(t, privVal, "test_chain_id", precommit)
+		tc.malleateVote(precommit)
+		if tc.expectError {
+			require.Error(t, precommit.EnsureExtension(), "EnsureExtension for %s", tc.name)
+		} else {
+			require.NoError(t, precommit.EnsureExtension(), "EnsureExtension for %s", tc.name)
+		}
 	}
 }