verify validators info at checkpoint block

consensus/posv/api.go

@@ -71,7 +71,7 @@ func (api *API) GetSigners(number *rpc.BlockNumber) ([]common.Address, error) {
 	if err != nil {
 		return nil, err
 	}
-	return snap.signers(), nil
+	return snap.GetSigners(), nil
 }
 
 // GetSignersAtHash retrieves the state snapshot at a given block.
@@ -84,7 +84,7 @@ func (api *API) GetSignersAtHash(hash common.Hash) ([]common.Address, error) {
 	if err != nil {
 		return nil, err
 	}
-	return snap.signers(), nil
+	return snap.GetSigners(), nil
 }
 
 // Proposals returns the current proposals the node tries to uphold and vote on.

consensus/posv/posv.go

@@ -136,6 +136,8 @@ var (
 	// on an instant chain (0 second period). It's important to refuse these as the
 	// block reward is zero, so an empty block just bloats the chain... fast.
 	errWaitTransactions = errors.New("waiting for transactions")
+
+	ErrInvalidCheckpointValidators = errors.New("invalid validators list on checkpoint block")
 )
 
 // SignerFn is a signer callback function to request a hash to be signed by a
@@ -216,6 +218,7 @@ type Posv struct {
 	HookReward       func(chain consensus.ChainReader, state *state.StateDB, header *types.Header) error
 	HookPenalty      func(chain consensus.ChainReader, blockNumberEpoc uint64) ([]common.Address, error)
 	HookPrepare      func(header *types.Header, signers []common.Address) error
+	VerifyValidators func(header *types.Header, signers []common.Address) error
 }
 
 // New creates a Posv proof-of-stake-voting consensus engine with the initial
@@ -379,7 +382,7 @@ func (c *Posv) verifyCascadingFields(chain consensus.ChainReader, header *types.
 				return errInvalidCheckpointPenalties
 			}
 		}
-		signers := snap.signers()
+		signers := snap.GetSigners()
 		signers = common.RemoveItemFromArray(signers, penPenalties)
 		for i := 1; i <= common.LimitPenaltyEpoch; i++ {
 			if number > uint64(i)*c.config.Epoch {
@@ -391,6 +394,12 @@ func (c *Posv) verifyCascadingFields(chain consensus.ChainReader, header *types.
 		if !bytes.Equal(header.Extra[extraVanity:extraSuffix], byteMasterNodes) {
 			return errInvalidCheckpointSigners
 		}
+		if c.VerifyValidators != nil {
+			err := c.VerifyValidators(header, signers)
+			if err != nil {
+				return err
+			}
+		}
 	}
 	// All basic checks passed, verify the seal and return
 	return c.verifySeal(chain, header, parents)
@@ -581,7 +590,7 @@ func (c *Posv) verifySeal(chain consensus.ChainReader, header *types.Header, par
 		mstring = append(mstring, m.String())
 	}
 	nstring := []string{}
-	for _, n := range snap.signers() {
+	for _, n := range snap.GetSigners() {
 		nstring = append(nstring, n.String())
 	}
 	if _, ok := snap.Signers[signer]; !ok {
@@ -656,7 +665,7 @@ func (c *Posv) Prepare(chain consensus.ChainReader, header *types.Header) error
 		header.Extra = append(header.Extra, bytes.Repeat([]byte{0x00}, extraVanity-len(header.Extra))...)
 	}
 	header.Extra = header.Extra[:extraVanity]
-	signers := snap.signers()
+	signers := snap.GetSigners()
 	if number%c.config.Epoch == 0 {
 		if c.HookPenalty != nil {
 			penSigners, err := c.HookPenalty(chain, number)
@@ -698,6 +707,9 @@ func (c *Posv) Prepare(chain consensus.ChainReader, header *types.Header) error
 	}
 	if c.HookPrepare != nil {
 		c.HookPrepare(header, signers)
+		if err != nil {
+			return err
+		}
 	}
 	return nil
 }
@@ -710,7 +722,7 @@ func (c *Posv) UpdateMasternodes(chain consensus.ChainReader, header *types.Head
 	if err != nil {
 		return err
 	}
-	currentSigners := snap.signers()
+	currentSigners := snap.GetSigners()
 	proposedSigners := make(map[common.Address]struct{})
 	// count all addresses in ms to be masternode
 	for _, m := range ms {
@@ -724,7 +736,7 @@ func (c *Posv) UpdateMasternodes(chain consensus.ChainReader, header *types.Head
 		}
 	}
 	nm := []string{}
-	newSigners := snap.signers()
+	newSigners := snap.GetSigners()
 	for _, n := range newSigners {
 		nm = append(nm, n.String())
 	}

consensus/posv/snapshot.go

@@ -286,7 +286,7 @@ func (s *Snapshot) apply(headers []*types.Header) (*Snapshot, error) {
 }
 
 // signers retrieves the list of authorized signers in ascending order.
-func (s *Snapshot) signers() []common.Address {
+func (s *Snapshot) GetSigners() []common.Address {
 	signers := make([]common.Address, 0, len(s.Signers))
 	for signer := range s.Signers {
 		signers = append(signers, signer)
@@ -303,7 +303,7 @@ func (s *Snapshot) signers() []common.Address {
 
 // inturn returns if a signer at a given block height is in-turn or not.
 func (s *Snapshot) inturn(number uint64, signer common.Address) bool {
-	signers, offset := s.signers(), 0
+	signers, offset := s.GetSigners(), 0
 	for offset < len(signers) && signers[offset] != signer {
 		offset++
 	}

core/error.go

@@ -34,4 +34,6 @@ var (
 	ErrNonceTooHigh = errors.New("nonce too high")
 
 	ErrNotPoSV = errors.New("Posv not found in config")
+
+	ErrNotFoundM1 = errors.New("list M1 not found ")
 )

eth/backend.go

@@ -25,6 +25,7 @@ import (
 	"sync"
 	"sync/atomic"
 
+	"bytes"
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -211,36 +212,13 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 
 		// Hook will process when preparing block.
 		c.HookPrepare = func(header *types.Header, signers []common.Address) error {
-			client, err := eth.blockchain.GetClient()
-			if err != nil {
-				log.Error("Fail to connect IPC client for penalty.", "error", err)
-			}
 			number := header.Number.Int64()
-			// Check m2 exists on chaindb.
-			// Get secrets and opening at epoc block checkpoint.
 			if number > 0 && number%common.EpocBlockRandomize == 0 {
-				var candidates []int64
+				validators, err := GetValidators(eth.blockchain, signers)
-				lenSigners := int64(len(signers))
-
-				if lenSigners > 0 {
-					for _, addr := range signers {
-						random, err := contracts.GetRandomizeFromContract(client, addr)
 				if err != nil {
-							log.Error("Fail to get random m2 from contract.", "error", err)
+					return err
-						}
-						candidates = append(candidates, random)
-					}
-
-					// Get randomize m2 list.
-					m2, err := contracts.GenM2FromRandomize(candidates, lenSigners)
-					if err != nil {
-						log.Error("Can not get m2 from randomize SC", "error", err)
-					}
-					if len(m2) > 0 {
-						header.Validators = contracts.BuildValidatorFromM2(m2)
-						log.Debug("New set Validators", "m2", m2, "number", header.Number.Uint64())
-					}
 				}
+				header.Validators = validators
 			}
 			return nil
 		}
@@ -330,6 +308,19 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 
 			return nil
 		}
+		c.VerifyValidators = func(header *types.Header, signers []common.Address) error {
+			number := header.Number.Int64()
+			if number > 0 && number%common.EpocBlockRandomize == 0 {
+				validators, err := GetValidators(eth.blockchain, signers)
+				if err != nil {
+					return err
+				}
+				if !bytes.Equal(header.Validators, validators) {
+					return posv.ErrInvalidCheckpointValidators
+				}
+			}
+			return nil
+		}
 	}
 
 	return eth, nil
@@ -606,3 +597,37 @@ func (s *Ethereum) Stop() error {
 
 	return nil
 }
+
+func GetValidators(bc *core.BlockChain, masternodes []common.Address) ([]byte, error) {
+	if bc.Config().Posv == nil {
+		return nil, core.ErrNotPoSV
+	}
+	client, err := bc.GetClient()
+	if err != nil {
+		return nil, err
+	}
+	// Check m2 exists on chaindb.
+	// Get secrets and opening at epoc block checkpoint.
+
+	var candidates []int64
+	if err != nil {
+		return nil, err
+	}
+	lenSigners := int64(len(masternodes))
+	if lenSigners > 0 {
+		for _, addr := range masternodes {
+			random, err := contracts.GetRandomizeFromContract(client, addr)
+			if err != nil {
+				return nil, err
+			}
+			candidates = append(candidates, random)
+		}
+		// Get randomize m2 list.
+		m2, err := contracts.GenM2FromRandomize(candidates, lenSigners)
+		if err != nil {
+			return nil, err
+		}
+		return contracts.BuildValidatorFromM2(m2), nil
+	}
+	return nil, core.ErrNotFoundM1
+}