added checks on proofs parameters like epoch, nonce and shard

common/common.go

@@ -1,7 +1,10 @@
 package common
 
 import (
+	"fmt"
+
 	"github.com/multiversx/mx-chain-core-go/core"
+	"github.com/multiversx/mx-chain-core-go/core/check"
 	"github.com/multiversx/mx-chain-core-go/data"
 )
 
@@ -24,3 +27,25 @@ func IsFlagEnabledAfterEpochsStartBlock(header data.HeaderHandler, enableEpochsH
 func ShouldBlockHavePrevProof(header data.HeaderHandler, enableEpochsHandler EnableEpochsHandler, flag core.EnableEpochFlag) bool {
 	return IsFlagEnabledAfterEpochsStartBlock(header, enableEpochsHandler, flag) && header.GetNonce() > 1
 }
+
+// VerifyProofAgainstHeader verifies the fields on the proof match the ones on the header
+func VerifyProofAgainstHeader(proof data.HeaderProofHandler, header data.HeaderHandler) error {
+	if check.IfNilReflect(proof) {
+		return ErrInvalidHeaderProof
+	}
+
+	if proof.GetHeaderNonce() != header.GetNonce() {
+		return fmt.Errorf("%w, nonce mismatch", ErrInvalidHeaderProof)
+	}
+	if proof.GetHeaderShardId() != header.GetShardID() {
+		return fmt.Errorf("%w, shard id mismatch", ErrInvalidHeaderProof)
+	}
+	if proof.GetHeaderEpoch() != header.GetEpoch() {
+		return fmt.Errorf("%w, epoch mismatch", ErrInvalidHeaderProof)
+	}
+	if proof.GetHeaderRound() != header.GetRound() {
+		return fmt.Errorf("%w, round mismatch", ErrInvalidHeaderProof)
+	}
+
+	return nil
+}

common/errors.go

@@ -10,3 +10,6 @@ var ErrNilWasmChangeLocker = errors.New("nil wasm change locker")
 
 // ErrNilStateSyncNotifierSubscriber signals that a nil state sync notifier subscriber has been provided
 var ErrNilStateSyncNotifierSubscriber = errors.New("nil state sync notifier subscriber")
+
+// ErrInvalidHeaderProof signals that an invalid equivalent proof has been provided
+var ErrInvalidHeaderProof = errors.New("invalid equivalent proof")

consensus/spos/bls/v2/subroundBlock.go

@@ -389,19 +389,27 @@ func isProofEmpty(proof data.HeaderProofHandler) bool {
 		len(proof.GetHeaderHash()) == 0
 }
 
-func (sr *subroundBlock) saveProofForPreviousHeaderIfNeeded(header data.HeaderHandler) {
+func (sr *subroundBlock) saveProofForPreviousHeaderIfNeeded(header data.HeaderHandler, prevHeader data.HeaderHandler) {
 	hasProof := sr.EquivalentProofsPool().HasProof(sr.ShardCoordinator().SelfId(), header.GetPrevHash())
 	if hasProof {
 		log.Debug("saveProofForPreviousHeaderIfNeeded: no need to set proof since it is already saved")
 		return
 	}
 
 	proof := header.GetPreviousProof()
-	err := sr.EquivalentProofsPool().AddProof(proof)
+	err := common.VerifyProofAgainstHeader(proof, prevHeader)
+	if err != nil {
+		log.Debug("saveProofForPreviousHeaderIfNeeded: invalid proof, %w", err)
+		return
+	}
+
+	err = sr.EquivalentProofsPool().AddProof(proof)
 	if err != nil {
 		log.Debug("saveProofForPreviousHeaderIfNeeded: failed to add proof, %w", err)
 		return
 	}
+
+	return
 }
 
 // receivedBlockBody method is called when a block body is received through the block body channel
@@ -445,30 +453,30 @@ func (sr *subroundBlock) receivedBlockBody(ctx context.Context, cnsDta *consensu
 	return blockProcessedWithSuccess
 }
 
-func (sr *subroundBlock) isHeaderForCurrentConsensus(header data.HeaderHandler) bool {
+func (sr *subroundBlock) isHeaderForCurrentConsensus(header data.HeaderHandler) (bool, data.HeaderHandler) {
 	if check.IfNil(header) {
-		return false
+		return false, nil
 	}
 	if header.GetShardID() != sr.ShardCoordinator().SelfId() {
-		return false
+		return false, nil
 	}
 	if header.GetRound() != uint64(sr.RoundHandler().Index()) {
-		return false
+		return false, nil
 	}
 
 	prevHeader, prevHash := sr.getPrevHeaderAndHash()
 	if check.IfNil(prevHeader) {
-		return false
+		return false, nil
 	}
 	if !bytes.Equal(header.GetPrevHash(), prevHash) {
-		return false
+		return false, nil
 	}
 	if header.GetNonce() != prevHeader.GetNonce()+1 {
-		return false
+		return false, nil
 	}
 	prevRandSeed := prevHeader.GetRandSeed()
 
-	return bytes.Equal(header.GetPrevRandSeed(), prevRandSeed)
+	return bytes.Equal(header.GetPrevRandSeed(), prevRandSeed), prevHeader
 }
 
 func (sr *subroundBlock) getLeaderForHeader(headerHandler data.HeaderHandler) ([]byte, error) {
@@ -495,7 +503,8 @@ func (sr *subroundBlock) receivedBlockHeader(headerHandler data.HeaderHandler) {
 		return
 	}
 
-	if !sr.isHeaderForCurrentConsensus(headerHandler) {
+	isHeaderForCurrentConsensus, prevHeader := sr.isHeaderForCurrentConsensus(headerHandler)
+	if !isHeaderForCurrentConsensus {
 		return
 	}
 
@@ -539,7 +548,7 @@ func (sr *subroundBlock) receivedBlockHeader(headerHandler data.HeaderHandler) {
 	sr.SetData(sr.Hasher().Compute(string(marshalledHeader)))
 	sr.SetHeader(headerHandler)
 
-	sr.saveProofForPreviousHeaderIfNeeded(headerHandler)
+	sr.saveProofForPreviousHeaderIfNeeded(headerHandler, prevHeader)
 
 	log.Debug("step 1: block header has been received",
 		"nonce", sr.GetHeader().GetNonce(),

process/block/baseProcess.go

@@ -222,7 +222,16 @@ func (bp *baseProcessor) checkBlockValidity(
 		return process.ErrEpochDoesNotMatch
 	}
 
-	return nil
+	return bp.checkPrevProofValidity(currentBlockHeader, headerHandler)
+}
+
+func (bp *baseProcessor) checkPrevProofValidity(prevHeader, headerHandler data.HeaderHandler) error {
+	if !common.ShouldBlockHavePrevProof(headerHandler, bp.enableEpochsHandler, common.EquivalentMessagesFlag) {
+		return nil
+	}
+
+	prevProof := headerHandler.GetPreviousProof()
+	return common.VerifyProofAgainstHeader(prevProof, prevHeader)
 }
 
 // checkScheduledRootHash checks if the scheduled root hash from the given header is the same with the current user accounts state root hash

process/block/interceptedBlocks/interceptedEquivalentProof.go

@@ -1,13 +1,15 @@
 package interceptedBlocks
 
 import (
+	"encoding/hex"
 	"fmt"
 
 	"github.com/multiversx/mx-chain-core-go/core"
 	"github.com/multiversx/mx-chain-core-go/core/check"
 	"github.com/multiversx/mx-chain-core-go/data"
 	"github.com/multiversx/mx-chain-core-go/data/block"
 	"github.com/multiversx/mx-chain-core-go/marshal"
+	"github.com/multiversx/mx-chain-go/common"
 	"github.com/multiversx/mx-chain-go/consensus"
 	"github.com/multiversx/mx-chain-go/dataRetriever"
 	proofscache "github.com/multiversx/mx-chain-go/dataRetriever/dataPool/proofsCache"
@@ -25,13 +27,15 @@ type ArgInterceptedEquivalentProof struct {
 	ShardCoordinator  sharding.Coordinator
 	HeaderSigVerifier consensus.HeaderSigVerifier
 	Proofs            dataRetriever.ProofsPool
+	Headers           dataRetriever.HeadersPool
 }
 
 type interceptedEquivalentProof struct {
 	proof             *block.HeaderProof
 	isForCurrentShard bool
 	headerSigVerifier consensus.HeaderSigVerifier
 	proofsPool        dataRetriever.ProofsPool
+	headersPool       dataRetriever.HeadersPool
 }
 
 // NewInterceptedEquivalentProof returns a new instance of interceptedEquivalentProof
@@ -51,6 +55,7 @@ func NewInterceptedEquivalentProof(args ArgInterceptedEquivalentProof) (*interce
 		isForCurrentShard: extractIsForCurrentShard(args.ShardCoordinator, equivalentProof),
 		headerSigVerifier: args.HeaderSigVerifier,
 		proofsPool:        args.Proofs,
+		headersPool:       args.Headers,
 	}, nil
 }
 
@@ -70,6 +75,9 @@ func checkArgInterceptedEquivalentProof(args ArgInterceptedEquivalentProof) erro
 	if check.IfNil(args.Proofs) {
 		return process.ErrNilProofsPool
 	}
+	if check.IfNil(args.Headers) {
+		return process.ErrNilHeadersDataPool
+	}
 
 	return nil
 }
@@ -115,9 +123,23 @@ func (iep *interceptedEquivalentProof) CheckValidity() error {
 		return proofscache.ErrAlreadyExistingEquivalentProof
 	}
 
+	err = iep.checkHeaderParamsFromProof()
+	if err != nil {
+		return err
+	}
+
 	return iep.headerSigVerifier.VerifyHeaderProof(iep.proof)
 }
 
+func (iep *interceptedEquivalentProof) checkHeaderParamsFromProof() error {
+	header, err := iep.headersPool.GetHeaderByHash(iep.proof.GetHeaderHash())
+	if err != nil {
+		return fmt.Errorf("%w while getting header for proof hash %s", err, hex.EncodeToString(iep.proof.GetHeaderHash()))
+	}
+
+	return common.VerifyProofAgainstHeader(iep.proof, header)
+}
+
 func (iep *interceptedEquivalentProof) integrity() error {
 	isProofValid := len(iep.proof.AggregatedSignature) > 0 &&
 		len(iep.proof.PubKeysBitmap) > 0 &&