header: verify NextValidatorsHash for light nodes (cosmos#844)

Fixes: cosmos#835 --------- Co-authored-by: Ganesha Upadhyaya <[email protected]>
caelus-labs · Sep 29, 2023 · d9eb2da · d9eb2da
1 parent 497c015
commit d9eb2da
Show file tree

Hide file tree

Showing 11 changed files with 187 additions and 94 deletions.
diff --git a/block/manager.go b/block/manager.go
@@ -371,7 +371,11 @@ func (m *Manager) trySyncNextBlock(ctx context.Context, daHeight uint64) error {
 	if b != nil && commit != nil {
 		bHeight := uint64(b.Height())
 		m.logger.Info("Syncing block", "height", bHeight)
-		newState, responses, err := m.applyBlock(ctx, b)
+		// Validate the received block before applying
+		if err := m.executor.Validate(m.lastState, b); err != nil {
+			return fmt.Errorf("failed to validate block: %w", err)
+		}
+		newState, responses, err := m.executor.ApplyBlock(ctx, m.lastState, b)
 		if err != nil {
 			return fmt.Errorf("failed to ApplyBlock: %w", err)
 		}
@@ -607,6 +611,7 @@ func (m *Manager) publishBlock(ctx context.Context) error {
 		if err != nil {
 			return nil
 		}
+		block.SignedHeader.Header.NextAggregatorsHash = m.getNextAggregatorsHash()
 		commit, err = m.getCommit(block.SignedHeader.Header)
 		if err != nil {
 			return err
@@ -636,6 +641,8 @@ func (m *Manager) publishBlock(ctx context.Context) error {
 		return err
 	}
 
+	block.SignedHeader.Header.NextAggregatorsHash = newState.NextValidators.Hash()
+
 	commit, err = m.getCommit(block.SignedHeader.Header)
 	if err != nil {
 		return err
@@ -758,6 +765,12 @@ func (m *Manager) getLastStateValidators() *cmtypes.ValidatorSet {
 	return m.lastState.Validators
 }
 
+func (m *Manager) getNextAggregatorsHash() types.Hash {
+	m.lastStateMtx.RLock()
+	defer m.lastStateMtx.RUnlock()
+	return m.lastState.NextValidators.Hash()
+}
+
 func (m *Manager) getLastBlockTime() time.Time {
 	m.lastStateMtx.RLock()
 	defer m.lastStateMtx.RUnlock()

diff --git a/conv/abci/block.go b/conv/abci/block.go
@@ -29,7 +29,7 @@ func ToABCIHeaderPB(header *types.Header) (cmproto.Header, error) {
 		LastCommitHash:     header.LastHeaderHash[:],
 		DataHash:           header.DataHash[:],
 		ValidatorsHash:     header.AggregatorsHash[:],
-		NextValidatorsHash: nil,
+		NextValidatorsHash: header.NextAggregatorsHash[:],
 		ConsensusHash:      header.ConsensusHash[:],
 		AppHash:            header.AppHash[:],
 		LastResultsHash:    header.LastResultsHash[:],
@@ -59,7 +59,7 @@ func ToABCIHeader(header *types.Header) (cmtypes.Header, error) {
 		LastCommitHash:     cmbytes.HexBytes(header.LastCommitHash),
 		DataHash:           cmbytes.HexBytes(header.DataHash),
 		ValidatorsHash:     cmbytes.HexBytes(header.AggregatorsHash),
-		NextValidatorsHash: nil,
+		NextValidatorsHash: cmbytes.HexBytes(header.NextAggregatorsHash),
 		ConsensusHash:      cmbytes.HexBytes(header.ConsensusHash),
 		AppHash:            cmbytes.HexBytes(header.AppHash),
 		LastResultsHash:    cmbytes.HexBytes(header.LastResultsHash),

diff --git a/node/full_client_test.go b/node/full_client_test.go
@@ -832,6 +832,15 @@ func checkValSet(rpc *FullClient, assert *assert.Assertions, h int64, expectedVa
 	assert.EqualValues(expectedValCount, vals.Total)
 	assert.Len(vals.Validators, expectedValCount)
 	assert.EqualValues(vals.BlockHeight, h)
+
+	commit, err := rpc.Commit(context.Background(), &h)
+	assert.NoError(err)
+	assert.NotNil(vals)
+
+	h1 := h + 1
+	vals, err = rpc.Validators(context.Background(), &h1, nil, nil)
+	assert.NoError(err)
+	assert.Equal(commit.NextValidatorsHash.Bytes(), cmtypes.NewValidatorSet(vals.Validators).Hash())
 }
 
 func checkValSetLatest(rpc *FullClient, assert *assert.Assertions, lastBlockHeight int64, expectedValCount int) {
@@ -885,6 +894,8 @@ func TestValidatorSetHandling(t *testing.T) {
 		checkValSet(rpc, assert, h, numNodes-1)
 	}
 
+	// test next val set hash in block 4, 5
+
 	// 5th EndBlock adds validator back
 	for h := int64(6); h <= 9; h++ {
 		checkValSet(rpc, assert, h, numNodes)

diff --git a/proto/rollkit/rollkit.proto b/proto/rollkit/rollkit.proto
@@ -52,8 +52,11 @@ message Header {
 	// Hash of block aggregator set, at a time of block creation
 	bytes aggregators_hash = 11;
 
+	// Hash of next block aggregator set, at a time of block creation
+	bytes next_aggregators_hash = 12;
+
 	// Chain ID the block belongs to
-	string chain_id = 12;
+	string chain_id = 13;
 }
 
 message Commit {

diff --git a/state/executor_test.go b/state/executor_test.go
@@ -71,6 +71,7 @@ func doTestCreateBlock(t *testing.T) {
 		},
 	}
 	state.Validators = cmtypes.NewValidatorSet(validators)
+	state.NextValidators = cmtypes.NewValidatorSet(validators)
 
 	// empty block
 	block := executor.CreateBlock(1, &types.Commit{}, []byte{}, state)

diff --git a/types/hashing.go b/types/hashing.go
@@ -26,7 +26,7 @@ func (h *Header) Hash() Hash {
 		LastCommitHash:     cmbytes.HexBytes(h.LastCommitHash),
 		DataHash:           cmbytes.HexBytes(h.DataHash),
 		ValidatorsHash:     cmbytes.HexBytes(h.AggregatorsHash),
-		NextValidatorsHash: nil,
+		NextValidatorsHash: cmbytes.HexBytes(h.NextAggregatorsHash),
 		ConsensusHash:      cmbytes.HexBytes(h.ConsensusHash),
 		AppHash:            cmbytes.HexBytes(h.AppHash),
 		LastResultsHash:    cmbytes.HexBytes(h.LastResultsHash),

diff --git a/types/header.go b/types/header.go
@@ -1,7 +1,9 @@
 package types
 
 import (
+	"bytes"
 	"encoding"
+	"fmt"
 	"time"
 
 	"github.com/celestiaorg/go-header"
@@ -47,6 +49,9 @@ type Header struct {
 
 	// Hash of block aggregator set, at a time of block creation
 	AggregatorsHash Hash
+
+	// Hash of next block aggregator set, at a time of block creation
+	NextAggregatorsHash Hash
 }
 
 func (h *Header) New() *Header {
@@ -74,20 +79,19 @@ func (h *Header) Time() time.Time {
 	return time.Unix(0, int64(h.BaseHeader.Time))
 }
 
-func (h *Header) Verify(_ *Header) error {
-
-	// Check the validator hashes are the same in the case headers are adjacent
-	// TODO: next validator set is not available, disable this check until NextValidatorHash is enabled
-	// if untrstH.Height() == h.Height()+1 {
-	// if !bytes.Equal(untrstH.AggregatorsHash[:], h.AggregatorsHash[:]) {
-	// 	return &header.VerifyError{
-	// 		Reason: fmt.Errorf("expected old header next validators (%X) to match those from new header (%X)",
-	// 			h.AggregatorsHash,
-	// 			untrstH.AggregatorsHash,
-	// 		),
-	// 	}
-	// }
-	// }
+func (h *Header) Verify(untrstH *Header) error {
+	// perform actual verification
+	if untrstH.Height() == h.Height()+1 {
+		// Check the validator hashes are the same in the case headers are adjacent
+		if !bytes.Equal(untrstH.AggregatorsHash[:], h.NextAggregatorsHash[:]) {
+			return &header.VerifyError{
+				Reason: fmt.Errorf("expected old header validators (%X) to match those from new header (%X)",
+					h.NextAggregatorsHash,
+					untrstH.AggregatorsHash,
+				),
+			}
+		}
+	}
 
 	// TODO: There must be a way to verify non-adjacent headers
 	// Ensure that untrusted commit has enough of trusted commit's power.

diff --git a/types/pb/rollkit/rollkit.pb.go b/types/pb/rollkit/rollkit.pb.go
diff --git a/types/serialization.go b/types/serialization.go
@@ -139,17 +139,18 @@ func (h *Header) ToProto() *pb.Header {
 			Block: h.Version.Block,
 			App:   h.Version.App,
 		},
-		Height:          h.BaseHeader.Height,
-		Time:            h.BaseHeader.Time,
-		LastHeaderHash:  h.LastHeaderHash[:],
-		LastCommitHash:  h.LastCommitHash[:],
-		DataHash:        h.DataHash[:],
-		ConsensusHash:   h.ConsensusHash[:],
-		AppHash:         h.AppHash[:],
-		LastResultsHash: h.LastResultsHash[:],
-		ProposerAddress: h.ProposerAddress[:],
-		AggregatorsHash: h.AggregatorsHash[:],
-		ChainId:         h.BaseHeader.ChainID,
+		Height:              h.BaseHeader.Height,
+		Time:                h.BaseHeader.Time,
+		LastHeaderHash:      h.LastHeaderHash[:],
+		LastCommitHash:      h.LastCommitHash[:],
+		DataHash:            h.DataHash[:],
+		ConsensusHash:       h.ConsensusHash[:],
+		AppHash:             h.AppHash[:],
+		LastResultsHash:     h.LastResultsHash[:],
+		ProposerAddress:     h.ProposerAddress[:],
+		AggregatorsHash:     h.AggregatorsHash[:],
+		NextAggregatorsHash: h.NextAggregatorsHash[:],
+		ChainId:             h.BaseHeader.ChainID,
 	}
 }
 
@@ -167,6 +168,7 @@ func (h *Header) FromProto(other *pb.Header) error {
 	h.AppHash = other.AppHash
 	h.LastResultsHash = other.LastResultsHash
 	h.AggregatorsHash = other.AggregatorsHash
+	h.NextAggregatorsHash = other.NextAggregatorsHash
 	if len(other.ProposerAddress) > 0 {
 		h.ProposerAddress = make([]byte, len(other.ProposerAddress))
 		copy(h.ProposerAddress, other.ProposerAddress)