core: validate DKG set with correct nodeset in round-2 (#19)

* vendor: sync consensus core
* core: validate DKG set with correct nodeset in round-2

4 files changed, 63 insertions, 32 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index 3c9e9701d..3b71cb64b 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -2165,7 +2165,11 @@ func (bc *BlockChain) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscript
 	return bc.scope.Track(bc.logsFeed.Subscribe(ch))
 }
 
-// GetRoundHeightMap returns the mapping between round and height.
-func (bc *BlockChain) GetRoundHeightMap() sync.Map {
-	return bc.roundHeightMap
+// GetRoundHeight returns the height of a given round.
+func (bc *BlockChain) GetRoundHeight(round uint64) (uint64, bool) {
+	h, ok := bc.roundHeightMap.Load(round)
+	if !ok {
+		return 0, false
+	}
+	return h.(uint64), true
 }
diff --git a/core/evm.go b/core/evm.go
index 5e8cf9063..80b0eaa7a 100644
--- a/core/evm.go
+++ b/core/evm.go
@@ -18,11 +18,10 @@ package core
 
 import (
 	"math/big"
-	"reflect"
-	"sync"
 
 	"github.com/dexon-foundation/dexon/common"
 	"github.com/dexon-foundation/dexon/consensus"
+	"github.com/dexon-foundation/dexon/core/state"
 	"github.com/dexon-foundation/dexon/core/types"
 	"github.com/dexon-foundation/dexon/core/vm"
 )
@@ -36,8 +35,14 @@ type ChainContext interface {
 	// GetHeader returns the hash corresponding to their hash.
 	GetHeader(common.Hash, uint64) *types.Header
 
-	// GetRoundHeightMap returns the mapping between round and height.
-	GetRoundHeightMap() sync.Map
+	// StateAt returns the statedb given a root hash.
+	StateAt(common.Hash) (*state.StateDB, error)
+
+	// GetHeaderByNumber returns the header given a block number.
+	GetHeaderByNumber(number uint64) *types.Header
+
+	// GetRoundHeight returns the mapping between round and height.
+	GetRoundHeight(uint64) (uint64, bool)
 }
 
 // NewEVMContext creates a new context for use in the EVM.
@@ -50,24 +55,29 @@ func NewEVMContext(msg Message, header *types.Header, chain ChainContext, author
 		beneficiary = *author
 	}
 
-	var roundHeight sync.Map
-	if !reflect.ValueOf(chain).IsNil() {
-		roundHeight = chain.GetRoundHeightMap()
+	return vm.Context{
+		CanTransfer:    CanTransfer,
+		Transfer:       Transfer,
+		GetHash:        GetHashFn(header, chain),
+		StateAtNumber:  StateAtNumberFn(chain),
+		GetRoundHeight: chain.GetRoundHeight,
+		Origin:         msg.From(),
+		Coinbase:       beneficiary,
+		BlockNumber:    new(big.Int).Set(header.Number),
+		Time:           new(big.Int).SetUint64(header.Time),
+		Randomness:     header.Randomness,
+		Difficulty:     new(big.Int).Set(header.Difficulty),
+		GasLimit:       header.GasLimit,
+		GasPrice:       new(big.Int).Set(msg.GasPrice()),
 	}
+}
 
-	return vm.Context{
-		CanTransfer: CanTransfer,
-		Transfer:    Transfer,
-		GetHash:     GetHashFn(header, chain),
-		Origin:      msg.From(),
-		Coinbase:    beneficiary,
-		BlockNumber: new(big.Int).Set(header.Number),
-		Time:        new(big.Int).SetUint64(header.Time),
-		Randomness:  header.Randomness,
-		Difficulty:  new(big.Int).Set(header.Difficulty),
-		RoundHeight: roundHeight,
-		GasLimit:    header.GasLimit,
-		GasPrice:    new(big.Int).Set(msg.GasPrice()),
+// StateAtNumberFn returns a StateAtNumberFunc which allows the retrieval of
+// statedb at a given block height.
+func StateAtNumberFn(chain ChainContext) func(n uint64) (*state.StateDB, error) {
+	return func(n uint64) (*state.StateDB, error) {
+		header := chain.GetHeaderByNumber(n)
+		return chain.StateAt(header.Root)
 	}
 }
 
diff --git a/core/vm/evm.go b/core/vm/evm.go
index a75d0f1d3..865ab0d5b 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -18,11 +18,11 @@ package vm
 
 import (
 	"math/big"
-	"sync"
 	"sync/atomic"
 	"time"
 
 	"github.com/dexon-foundation/dexon/common"
+	"github.com/dexon-foundation/dexon/core/state"
 	"github.com/dexon-foundation/dexon/crypto"
 	"github.com/dexon-foundation/dexon/params"
 )
@@ -39,6 +39,10 @@ type (
 	// GetHashFunc returns the nth block hash in the blockchain
 	// and is used by the BLOCKHASH EVM op code.
 	GetHashFunc func(uint64) common.Hash
+	// StateAtFunc returns the statedb given a root hash.
+	StateAtNumberFunc func(uint64) (*state.StateDB, error)
+	// GetRoundHeightFunc returns the round height.
+	GetRoundHeightFunc func(uint64) (uint64, bool)
 )
 
 // run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter.
@@ -81,6 +85,10 @@ type Context struct {
 	Transfer TransferFunc
 	// GetHash returns the hash corresponding to n
 	GetHash GetHashFunc
+	// StateAtNumber returns the statedb given a root hash.
+	StateAtNumber StateAtNumberFunc
+	// GetRoundHeight returns the round height.
+	GetRoundHeight GetRoundHeightFunc
 
 	// Message information
 	Origin   common.Address // Provides information for ORIGIN
@@ -93,7 +101,6 @@ type Context struct {
 	Time        *big.Int       // Provides information for TIME
 	Randomness  []byte         // Provides information for RAND
 	Difficulty  *big.Int       // Provides information for DIFFICULTY
-	RoundHeight sync.Map       // Provides information of round height mapping.
 }
 
 // EVM is the Ethereum Virtual Machine base object and provides
diff --git a/core/vm/governance.go b/core/vm/governance.go
index 49141761f..b38733e1a 100644
--- a/core/vm/governance.go
+++ b/core/vm/governance.go
@@ -1467,11 +1467,22 @@ func (g *GovernanceContract) penalize() {
 	g.contract.UseGas(g.contract.Gas)
 }
 
-func (g *GovernanceContract) inDKGSet(nodeID coreTypes.NodeID) bool {
+func (g *GovernanceContract) inDKGSet(round *big.Int, nodeID coreTypes.NodeID) bool {
 	target := coreTypes.NewDKGSetTarget(coreCommon.Hash(g.state.CurrentCRS()))
 	ns := coreTypes.NewNodeSet()
 
-	for _, x := range g.state.Nodes() {
+	configRound := big.NewInt(0) // If round < core.ConfigRoundShift, use 0.
+	if round.Uint64() >= core.ConfigRoundShift {
+		configRound = new(big.Int).Sub(round, big.NewInt(int64(core.ConfigRoundShift)))
+	}
+
+	statedb, err := g.evm.Context.StateAtNumber(g.state.RoundHeight(configRound).Uint64())
+	if err != nil {
+		panic(err)
+	}
+
+	state := GovernanceStateHelper{statedb}
+	for _, x := range state.Nodes() {
 		mpk, err := ecdsa.NewPublicKeyFromByteSlice(x.PublicKey)
 		if err != nil {
 			panic(err)
@@ -1515,7 +1526,7 @@ func (g *GovernanceContract) addDKGComplaint(round *big.Int, comp []byte) ([]byt
 	}
 
 	// DKGComplaint must belongs to someone in DKG set.
-	if !g.inDKGSet(dkgComplaint.ProposerID) {
+	if !g.inDKGSet(round, dkgComplaint.ProposerID) {
 		g.penalize()
 		return nil, errExecutionReverted
 	}
@@ -1555,7 +1566,7 @@ func (g *GovernanceContract) addDKGMasterPublicKey(round *big.Int, mpk []byte) (
 	}
 
 	// DKGMasterPublicKey must belongs to someone in DKG set.
-	if !g.inDKGSet(dkgMasterPK.ProposerID) {
+	if !g.inDKGSet(round, dkgMasterPK.ProposerID) {
 		g.penalize()
 		return nil, errExecutionReverted
 	}
@@ -1588,7 +1599,7 @@ func (g *GovernanceContract) addDKGFinalize(round *big.Int, finalize []byte) ([]
 	}
 
 	// DKGFInalize must belongs to someone in DKG set.
-	if !g.inDKGSet(dkgFinalize.ProposerID) {
+	if !g.inDKGSet(round, dkgFinalize.ProposerID) {
 		g.penalize()
 		return nil, errExecutionReverted
 	}
@@ -1757,13 +1768,12 @@ func (g *GovernanceContract) transferOwnership(newOwner common.Address) ([]byte,
 
 func (g *GovernanceContract) snapshotRound(round, height *big.Int) ([]byte, error) {
 	// Validate if this mapping is correct.
-	rawHeight, ok := g.evm.Context.RoundHeight.Load(round)
+	realHeight, ok := g.evm.Context.GetRoundHeight(round.Uint64())
 	if !ok {
 		g.penalize()
 		return nil, errExecutionReverted
 	}
 
-	realHeight := rawHeight.(uint64)
 	if height.Cmp(new(big.Int).SetUint64(realHeight)) != 0 {
 		g.penalize()
 		return nil, errExecutionReverted