governance: implement delegate/undelegate function and add tests (#33)

Implement delegate/undelegate function to allow others to delegate it's
fund to stake on a node. Also added governance contract tests.

9 files changed, 1162 insertions, 121 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index 09b08aa9f..a0fa146f7 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1714,7 +1714,7 @@ func (bc *BlockChain) GetPendingHeight() uint64 {
 	return bc.lastPendingHeight
 }
 
-func (bc *BlockChain) GetPendingBlock() *types.Block {
+func (bc *BlockChain) PendingBlock() *types.Block {
 	bc.pendingBlockMu.RLock()
 	defer bc.pendingBlockMu.RUnlock()
 
@@ -1729,7 +1729,10 @@ func (bc *BlockChain) GetPendingBlockByNumber(number uint64) *types.Block {
 }
 
 func (bc *BlockChain) GetPending() (*types.Block, *state.StateDB) {
-	block := bc.GetPendingBlock()
+	block := bc.PendingBlock()
+	if block == nil {
+		block = bc.CurrentBlock()
+	}
 	s, err := state.New(block.Header().Root, bc.stateCache)
 	if err != nil {
 		panic(err)
diff --git a/core/genesis.go b/core/genesis.go
index 440ff1a64..e7d26d4c2 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -303,8 +303,8 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 		}
 
 		// Genesis CRS.
-		crs := crypto.Keccak256([]byte(g.Config.Dexcon.GenesisCRSText))
-		govStateHelper.PushCRS(common.BytesToHash(crs))
+		crs := crypto.Keccak256Hash([]byte(g.Config.Dexcon.GenesisCRSText))
+		govStateHelper.PushCRS(crs)
 
 		// Round 0 height.
 		govStateHelper.PushRoundHeight(big.NewInt(0))
diff --git a/core/vm/governance.go b/core/vm/governance.go
index b6a5038c5..36b37b53c 100644
--- a/core/vm/governance.go
+++ b/core/vm/governance.go
@@ -37,12 +37,34 @@ import (
 )
 
 var GovernanceContractAddress = common.HexToAddress("5765692d4e696e6720536f6e696320426f6a6965")
-var minStake = big.NewInt(10000000000000)
 
 const GovernanceABIJSON = `
 [
   {
     "constant": true,
+    "inputs": [
+      {
+        "name": "",
+        "type": "address"
+      },
+      {
+        "name": "",
+        "type": "address"
+      }
+    ],
+    "name": "delegatorsOffset",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
     "inputs": [],
     "name": "blockReward",
     "outputs": [
@@ -216,12 +238,20 @@ const GovernanceABIJSON = `
       {
         "name": "",
         "type": "address"
+      },
+      {
+        "name": "",
+        "type": "uint256"
       }
     ],
-    "name": "offset",
+    "name": "delegators",
     "outputs": [
       {
-        "name": "",
+        "name": "owner",
+        "type": "address"
+      },
+      {
+        "name": "value",
         "type": "uint256"
       }
     ],
@@ -273,6 +303,25 @@ const GovernanceABIJSON = `
   },
   {
     "constant": true,
+    "inputs": [
+      {
+        "name": "",
+        "type": "address"
+      }
+    ],
+    "name": "nodesOffset",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
     "inputs": [],
     "name": "lambdaDKG",
     "outputs": [
@@ -422,12 +471,12 @@ const GovernanceABIJSON = `
     "inputs": [
       {
         "indexed": true,
-        "name": "round",
+        "name": "Round",
         "type": "uint256"
       },
       {
         "indexed": false,
-        "name": "crs",
+        "name": "CRS",
         "type": "bytes32"
       }
     ],
@@ -435,6 +484,69 @@ const GovernanceABIJSON = `
     "type": "event"
   },
   {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": true,
+        "name": "NodeAddress",
+        "type": "address"
+      }
+    ],
+    "name": "Staked",
+    "type": "event"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": true,
+        "name": "NodeAddress",
+        "type": "address"
+      }
+    ],
+    "name": "Unstaked",
+    "type": "event"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": true,
+        "name": "NodeAddress",
+        "type": "address"
+      },
+      {
+        "indexed": true,
+        "name": "DelegatorAddress",
+        "type": "address"
+      },
+      {
+        "indexed": false,
+        "name": "Amount",
+        "type": "uint256"
+      }
+    ],
+    "name": "Delegated",
+    "type": "event"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": true,
+        "name": "NodeAddress",
+        "type": "address"
+      },
+      {
+        "indexed": true,
+        "name": "DelegatorAddress",
+        "type": "address"
+      }
+    ],
+    "name": "Undelegated",
+    "type": "event"
+  },
+  {
     "constant": false,
     "inputs": [
       {
@@ -507,6 +619,39 @@ const GovernanceABIJSON = `
     "type": "function"
   },
   {
+    "constant": true,
+    "inputs": [],
+    "name": "nodesLength",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "name": "NodeAddress",
+        "type": "address"
+      }
+    ],
+    "name": "delegatorsLength",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
     "constant": false,
     "inputs": [
       {
@@ -636,17 +781,31 @@ const GovernanceABIJSON = `
     "type": "function"
   },
   {
-    "constant": true,
-    "inputs": [],
-    "name": "nodesLength",
-    "outputs": [
+    "constant": false,
+    "inputs": [
       {
-        "name": "",
-        "type": "uint256"
+        "name": "NodeAddress",
+        "type": "address"
       }
     ],
+    "name": "delegate",
+    "outputs": [],
+    "payable": true,
+    "stateMutability": "payable",
+    "type": "function"
+  },
+  {
+    "constant": false,
+    "inputs": [
+      {
+        "name": "NodeAddress",
+        "type": "address"
+      }
+    ],
+    "name": "undelegate",
+    "outputs": [],
     "payable": false,
-    "stateMutability": "view",
+    "stateMutability": "nonpayable",
     "type": "function"
   }
 ]
@@ -658,8 +817,10 @@ var sig2Method map[string]abi.Method
 var events map[string]abi.Event
 
 func init() {
+	var err error
+
 	// Parse governance contract ABI.
-	abiObject, err := abi.JSON(strings.NewReader(GovernanceABIJSON))
+	abiObject, err = abi.JSON(strings.NewReader(GovernanceABIJSON))
 	if err != nil {
 		panic(err)
 	}
@@ -682,8 +843,7 @@ func init() {
 }
 
 // RunGovernanceContract executes governance contract.
-func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (
-	ret []byte, err error) {
+func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (ret []byte, err error) {
 	if len(input) < 4 {
 		return nil, nil
 	}
@@ -726,8 +886,24 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (
 			return nil, errExecutionReverted
 		}
 		return g.addDKGFinalize(args.Round, args.Finalize)
+	case "delegate":
+		address := common.Address{}
+		if err := method.Inputs.Unpack(&address, arguments); err != nil {
+			return nil, errExecutionReverted
+		}
+		return g.delegate(address)
+	case "delegatorsLength":
+		address := common.Address{}
+		if err := method.Inputs.Unpack(&address, arguments); err != nil {
+			return nil, errExecutionReverted
+		}
+		res, err := method.Outputs.Pack(g.state.LenDelegators(address))
+		if err != nil {
+			return nil, errExecutionReverted
+		}
+		return res, nil
 	case "nodesLength":
-		res, err := method.Outputs.Pack(g.state.NodesLength())
+		res, err := method.Outputs.Pack(g.state.LenNodes())
 		if err != nil {
 			return nil, errExecutionReverted
 		}
@@ -768,14 +944,20 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (
 			return nil, errExecutionReverted
 		}
 		return g.transferOwnership(newOwner)
+	case "undelegate":
+		address := common.Address{}
+		if err := method.Inputs.Unpack(&address, arguments); err != nil {
+			return nil, errExecutionReverted
+		}
+		return g.undelegate(address)
 	case "unstake":
 		return g.unstake()
 	case "updateConfiguration":
-		var cfg params.DexconConfig
+		var cfg rawConfigStruct
 		if err := method.Inputs.Unpack(&cfg, arguments); err != nil {
 			return nil, errExecutionReverted
 		}
-		g.updateConfiguration(&cfg)
+		return g.updateConfiguration(&cfg)
 
 	// --------------------------------
 	// Solidity auto generated methods.
@@ -803,6 +985,29 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (
 			return nil, errExecutionReverted
 		}
 		return res, nil
+	case "delegators":
+		nodeAddr, index := common.Address{}, new(big.Int)
+		args := []interface{}{&nodeAddr, &index}
+		if err := method.Inputs.Unpack(&args, arguments); err != nil {
+			return nil, errExecutionReverted
+		}
+		delegator := g.state.Delegator(nodeAddr, index)
+		res, err := method.Outputs.Pack(delegator.Owner, delegator.Value)
+		if err != nil {
+			return nil, errExecutionReverted
+		}
+		return res, nil
+	case "delegatorsOffset":
+		nodeAddr, delegatorAddr := common.Address{}, common.Address{}
+		args := []interface{}{&nodeAddr, &delegatorAddr}
+		if err := method.Inputs.Unpack(&args, arguments); err != nil {
+			return nil, errExecutionReverted
+		}
+		res, err := method.Outputs.Pack(g.state.DelegatorsOffset(nodeAddr, delegatorAddr))
+		if err != nil {
+			return nil, errExecutionReverted
+		}
+		return res, nil
 	case "dkgComplaints":
 		round, index := new(big.Int), new(big.Int)
 		args := []interface{}{&round, &index}
@@ -913,18 +1118,18 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (
 			return nil, errExecutionReverted
 		}
 		return res, nil
-	case "notarySetSize":
-		res, err := method.Outputs.Pack(g.state.NotarySetSize())
-		if err != nil {
+	case "nodesOffset":
+		address := common.Address{}
+		if err := method.Inputs.Unpack(&address, arguments); err != nil {
 			return nil, errExecutionReverted
 		}
-		return res, nil
-	case "offset":
-		addr := common.Address{}
-		if err := method.Inputs.Unpack(&addr, arguments); err != nil {
+		res, err := method.Outputs.Pack(g.state.NodesOffset(address))
+		if err != nil {
 			return nil, errExecutionReverted
 		}
-		res, err := method.Outputs.Pack(g.state.Offset(addr))
+		return res, nil
+	case "notarySetSize":
+		res, err := method.Outputs.Pack(g.state.NotarySetSize())
 		if err != nil {
 			return nil, errExecutionReverted
 		}
@@ -965,7 +1170,9 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (
 const (
 	roundHeightLoc = iota
 	nodesLoc
-	offsetLoc
+	nodesOffsetLoc
+	delegatorsLoc
+	delegatorsOffsetLoc
 	crsLoc
 	dkgMasterPublicKeysLoc
 	dkgComplaintsLoc
@@ -1013,29 +1220,28 @@ func (s *GovernanceStateHelper) getSlotLoc(loc *big.Int) *big.Int {
 }
 
 func (s *GovernanceStateHelper) getMapLoc(pos *big.Int, key []byte) *big.Int {
-	return new(big.Int).SetBytes(crypto.Keccak256(
-		key, common.BigToHash(pos).Bytes()))
+	return new(big.Int).SetBytes(crypto.Keccak256(key, common.BigToHash(pos).Bytes()))
 }
 
 func (s *GovernanceStateHelper) readBytes(loc *big.Int) []byte {
-	// length of the dynamic array (bytes).
+	// Length of the dynamic array (bytes).
 	rawLength := s.getStateBigInt(loc)
 	lengthByte := new(big.Int).Mod(rawLength, big.NewInt(256))
 
-	// bytes length <= 31, lengthByte % 2 == 0
+	// Bytes length <= 31, lengthByte % 2 == 0
 	// return the high 31 bytes.
 	if new(big.Int).Mod(lengthByte, big.NewInt(2)).Cmp(big.NewInt(0)) == 0 {
 		length := new(big.Int).Div(lengthByte, big.NewInt(2)).Uint64()
 		return rawLength.Bytes()[:length]
 	}
 
-	// actual length = (rawLength - 1) / 2
+	// Actual length = (rawLength - 1) / 2
 	length := new(big.Int).Div(new(big.Int).Sub(rawLength, big.NewInt(1)), big.NewInt(2)).Uint64()
 
-	// data address.
+	// Data address.
 	dataLoc := s.getSlotLoc(loc)
 
-	// read continiously for length bytes.
+	// Read continuously for length bytes.
 	carry := int64(0)
 	if length%32 > 0 {
 		carry = 1
@@ -1053,7 +1259,12 @@ func (s *GovernanceStateHelper) readBytes(loc *big.Int) []byte {
 func (s *GovernanceStateHelper) writeBytes(loc *big.Int, data []byte) {
 	length := int64(len(data))
 
-	// short bytes (length <= 31)
+	if length == 0 {
+		s.setState(common.BigToHash(loc), common.Hash{})
+		return
+	}
+
+	// Short bytes (length <= 31).
 	if length < 32 {
 		data2 := append([]byte(nil), data...)
 		// Right pad with zeros
@@ -1065,11 +1276,11 @@ func (s *GovernanceStateHelper) writeBytes(loc *big.Int, data []byte) {
 		return
 	}
 
-	// write 2 * length + 1
+	// Write 2 * length + 1.
 	storedLength := new(big.Int).Add(new(big.Int).Mul(
 		big.NewInt(length), big.NewInt(2)), big.NewInt(1))
 	s.setStateBigInt(loc, storedLength)
-	// write data chunck.
+	// Write data chunck.
 	dataLoc := s.getSlotLoc(loc)
 	carry := int64(0)
 	if length%32 > 0 {
@@ -1083,7 +1294,7 @@ func (s *GovernanceStateHelper) writeBytes(loc *big.Int, data []byte) {
 			maxLoc = length
 		}
 		data2 := data[i*32 : maxLoc]
-		// Right pad with zeros
+		// Right pad with zeros.
 		for len(data2) < 32 {
 			data2 = append(data2, byte(0))
 		}
@@ -1111,11 +1322,11 @@ func (s *GovernanceStateHelper) appendTo2DByteArray(pos, index *big.Int, data []
 	baseLoc := s.getSlotLoc(pos)
 	loc := new(big.Int).Add(baseLoc, index)
 
-	// increase length by 1.
+	// Increase length by 1.
 	arrayLength := s.getStateBigInt(loc)
 	s.setStateBigInt(loc, new(big.Int).Add(arrayLength, big.NewInt(1)))
 
-	// write element.
+	// Write element.
 	dataLoc := s.getSlotLoc(loc)
 	elementLoc := new(big.Int).Add(dataLoc, arrayLength)
 	s.writeBytes(elementLoc, data)
@@ -1131,7 +1342,7 @@ func (s *GovernanceStateHelper) RoundHeight(round *big.Int) *big.Int {
 	return s.getStateBigInt(loc)
 }
 func (s *GovernanceStateHelper) PushRoundHeight(height *big.Int) {
-	// increase length by 1.
+	// Increase length by 1.
 	length := s.getStateBigInt(big.NewInt(roundHeightLoc))
 	s.setStateBigInt(big.NewInt(roundHeightLoc), new(big.Int).Add(length, big.NewInt(1)))
 
@@ -1163,9 +1374,9 @@ type nodeInfo struct {
 	Url       string
 }
 
-const nodesInfoSize = 7
+const nodeStructSize = 7
 
-func (s *GovernanceStateHelper) NodesLength() *big.Int {
+func (s *GovernanceStateHelper) LenNodes() *big.Int {
 	return s.getStateBigInt(big.NewInt(nodesLoc))
 }
 func (s *GovernanceStateHelper) Node(index *big.Int) *nodeInfo {
@@ -1173,97 +1384,194 @@ func (s *GovernanceStateHelper) Node(index *big.Int) *nodeInfo {
 
 	arrayBaseLoc := s.getSlotLoc(big.NewInt(nodesLoc))
 	elementBaseLoc := new(big.Int).Add(arrayBaseLoc,
-		new(big.Int).Mul(index, big.NewInt(nodesInfoSize)))
+		new(big.Int).Mul(index, big.NewInt(nodeStructSize)))
 
-	// owner.
+	// Owner.
 	loc := elementBaseLoc
 	node.Owner = common.BytesToAddress(s.getState(common.BigToHash(elementBaseLoc)).Bytes())
 
-	// publicKey.
+	// PublicKey.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(1))
 	node.PublicKey = s.readBytes(loc)
 
-	// staked.
+	// Staked.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(2))
 	node.Staked = s.getStateBigInt(loc)
 
-	// name.
+	// Name.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(3))
 	node.Name = string(s.readBytes(loc))
 
-	// email.
+	// Email.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(4))
 	node.Email = string(s.readBytes(loc))
 
-	// location.
+	// Location.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(5))
 	node.Location = string(s.readBytes(loc))
 
-	// url.
+	// Url.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(6))
 	node.Url = string(s.readBytes(loc))
 
 	return node
 }
 func (s *GovernanceStateHelper) PushNode(n *nodeInfo) {
-	// increase length by 1
-	arrayLength := s.NodesLength()
+	// Increase length by 1.
+	arrayLength := s.LenNodes()
 	s.setStateBigInt(big.NewInt(nodesLoc), new(big.Int).Add(arrayLength, big.NewInt(1)))
 
 	s.UpdateNode(arrayLength, n)
 }
 func (s *GovernanceStateHelper) UpdateNode(index *big.Int, n *nodeInfo) {
 	arrayBaseLoc := s.getSlotLoc(big.NewInt(nodesLoc))
-	elementBaseLoc := new(big.Int).Add(arrayBaseLoc,
-		new(big.Int).Mul(index, big.NewInt(nodesInfoSize)))
+	elementBaseLoc := new(big.Int).Add(arrayBaseLoc, new(big.Int).Mul(index, big.NewInt(nodeStructSize)))
 
-	// owner.
+	// Owner.
 	loc := elementBaseLoc
 	s.setState(common.BigToHash(loc), n.Owner.Hash())
 
-	// publicKey.
+	// PublicKey.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(1))
 	s.writeBytes(loc, n.PublicKey)
 
-	// staked.
+	// Staked.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(2))
 	s.setStateBigInt(loc, n.Staked)
 
-	// name.
+	// Name.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(3))
 	s.writeBytes(loc, []byte(n.Name))
 
-	// email.
+	// Email.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(4))
 	s.writeBytes(loc, []byte(n.Email))
 
-	// location.
+	// Location.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(5))
 	s.writeBytes(loc, []byte(n.Location))
 
-	// url.
+	// Url.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(6))
 	s.writeBytes(loc, []byte(n.Url))
 }
+func (s *GovernanceStateHelper) PopLastNode() {
+	// Decrease length by 1.
+	arrayLength := s.LenNodes()
+	newArrayLength := new(big.Int).Sub(arrayLength, big.NewInt(1))
+	s.setStateBigInt(big.NewInt(nodesLoc), newArrayLength)
+
+	s.UpdateNode(newArrayLength, &nodeInfo{Staked: big.NewInt(0)})
+}
 func (s *GovernanceStateHelper) Nodes() []*nodeInfo {
 	var nodes []*nodeInfo
-	for i := int64(0); i < int64(s.NodesLength().Uint64()); i++ {
+	for i := int64(0); i < int64(s.LenNodes().Uint64()); i++ {
 		nodes = append(nodes, s.Node(big.NewInt(i)))
 	}
 	return nodes
 }
+func (s *GovernanceStateHelper) QualifiedNodes() []*nodeInfo {
+	var nodes []*nodeInfo
+	for i := int64(0); i < int64(s.LenNodes().Uint64()); i++ {
+		node := s.Node(big.NewInt(i))
+		if node.Staked.Cmp(s.MinStake()) >= 0 {
+			nodes = append(nodes, node)
+		}
+	}
+	return nodes
+}
 
-// mapping(address => uint256) public offset;
-func (s *GovernanceStateHelper) Offset(addr common.Address) *big.Int {
-	loc := s.getMapLoc(big.NewInt(offsetLoc), addr.Bytes())
+// mapping(address => uint256) public nodeOffset;
+func (s *GovernanceStateHelper) NodesOffset(addr common.Address) *big.Int {
+	loc := s.getMapLoc(big.NewInt(nodesOffsetLoc), addr.Bytes())
 	return new(big.Int).Sub(s.getStateBigInt(loc), big.NewInt(1))
 }
-func (s *GovernanceStateHelper) PutOffset(addr common.Address, offset *big.Int) {
-	loc := s.getMapLoc(big.NewInt(offsetLoc), addr.Bytes())
+func (s *GovernanceStateHelper) PutNodesOffset(addr common.Address, offset *big.Int) {
+	loc := s.getMapLoc(big.NewInt(nodesOffsetLoc), addr.Bytes())
 	s.setStateBigInt(loc, new(big.Int).Add(offset, big.NewInt(1)))
 }
-func (s *GovernanceStateHelper) DeleteOffset(addr common.Address) {
-	loc := s.getMapLoc(big.NewInt(offsetLoc), addr.Bytes())
+func (s *GovernanceStateHelper) DeleteNodesOffset(addr common.Address) {
+	loc := s.getMapLoc(big.NewInt(nodesOffsetLoc), addr.Bytes())
+	s.setStateBigInt(loc, big.NewInt(0))
+}
+
+// struct Delegator {
+//     address node;
+//     address owner;
+//     uint256 value;
+// }
+
+type delegatorInfo struct {
+	Owner common.Address
+	Value *big.Int
+}
+
+const delegatorStructSize = 2
+
+// mapping(address => Delegator[]) public delegators;
+func (s *GovernanceStateHelper) LenDelegators(nodeAddr common.Address) *big.Int {
+	loc := s.getMapLoc(big.NewInt(delegatorsLoc), nodeAddr.Bytes())
+	return s.getStateBigInt(loc)
+}
+func (s *GovernanceStateHelper) Delegator(nodeAddr common.Address, offset *big.Int) *delegatorInfo {
+	delegator := new(delegatorInfo)
+
+	loc := s.getMapLoc(big.NewInt(delegatorsLoc), nodeAddr.Bytes())
+	arrayBaseLoc := s.getSlotLoc(loc)
+	elementBaseLoc := new(big.Int).Add(arrayBaseLoc, new(big.Int).Mul(big.NewInt(delegatorStructSize), offset))
+
+	// Owner.
+	loc = elementBaseLoc
+	delegator.Owner = common.BytesToAddress(s.getState(common.BigToHash(elementBaseLoc)).Bytes())
+
+	// Value.
+	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(1))
+	delegator.Value = s.getStateBigInt(loc)
+
+	return delegator
+}
+func (s *GovernanceStateHelper) PushDelegator(nodeAddr common.Address, delegator *delegatorInfo) {
+	// Increase length by 1.
+	arrayLength := s.LenDelegators(nodeAddr)
+	loc := s.getMapLoc(big.NewInt(delegatorsLoc), nodeAddr.Bytes())
+	s.setStateBigInt(loc, new(big.Int).Add(arrayLength, big.NewInt(1)))
+
+	s.UpdateDelegator(nodeAddr, arrayLength, delegator)
+}
+func (s *GovernanceStateHelper) UpdateDelegator(nodeAddr common.Address, offset *big.Int, delegator *delegatorInfo) {
+	loc := s.getMapLoc(big.NewInt(delegatorsLoc), nodeAddr.Bytes())
+	arrayBaseLoc := s.getSlotLoc(loc)
+	elementBaseLoc := new(big.Int).Add(arrayBaseLoc, new(big.Int).Mul(big.NewInt(delegatorStructSize), offset))
+
+	// Owner.
+	loc = elementBaseLoc
+	s.setState(common.BigToHash(loc), delegator.Owner.Hash())
+
+	// Value.
+	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(1))
+	s.setStateBigInt(loc, delegator.Value)
+}
+func (s *GovernanceStateHelper) PopLastDelegator(nodeAddr common.Address) {
+	// Decrease length by 1.
+	arrayLength := s.LenDelegators(nodeAddr)
+	newArrayLength := new(big.Int).Sub(arrayLength, big.NewInt(1))
+	loc := s.getMapLoc(big.NewInt(delegatorsLoc), nodeAddr.Bytes())
+	s.setStateBigInt(loc, newArrayLength)
+
+	s.UpdateDelegator(nodeAddr, newArrayLength, &delegatorInfo{Value: big.NewInt(0)})
+}
+
+// mapping(address => mapping(address => uint256)) delegatorsOffset;
+func (s *GovernanceStateHelper) DelegatorsOffset(nodeAddr, delegatorAddr common.Address) *big.Int {
+	loc := s.getMapLoc(s.getMapLoc(big.NewInt(delegatorsOffsetLoc), nodeAddr.Bytes()), delegatorAddr.Bytes())
+	return new(big.Int).Sub(s.getStateBigInt(loc), big.NewInt(1))
+}
+func (s *GovernanceStateHelper) PutDelegatorOffset(nodeAddr, delegatorAddr common.Address, offset *big.Int) {
+	loc := s.getMapLoc(s.getMapLoc(big.NewInt(delegatorsOffsetLoc), nodeAddr.Bytes()), delegatorAddr.Bytes())
+	s.setStateBigInt(loc, new(big.Int).Add(offset, big.NewInt(1)))
+}
+func (s *GovernanceStateHelper) DeleteDelegatorsOffset(nodeAddr, delegatorAddr common.Address) {
+	loc := s.getMapLoc(s.getMapLoc(big.NewInt(delegatorsOffsetLoc), nodeAddr.Bytes()), delegatorAddr.Bytes())
 	s.setStateBigInt(loc, big.NewInt(0))
 }
 
@@ -1418,7 +1726,7 @@ func (s *GovernanceStateHelper) MinBlockInterval() *big.Int {
 func (s *GovernanceStateHelper) Stake(
 	addr common.Address, publicKey []byte, staked *big.Int,
 	name, email, location, url string) {
-	offset := s.NodesLength()
+	offset := s.LenNodes()
 	s.PushNode(&nodeInfo{
 		Owner:     addr,
 		PublicKey: publicKey,
@@ -1428,20 +1736,22 @@ func (s *GovernanceStateHelper) Stake(
 		Location:  location,
 		Url:       url,
 	})
-	s.PutOffset(addr, offset)
+	s.PutNodesOffset(addr, offset)
 }
 
+const phiRatioMultiplier = 1000000.0
+
 // Configuration returns the current configuration.
 func (s *GovernanceStateHelper) Configuration() *params.DexconConfig {
 	return &params.DexconConfig{
 		MinStake:         s.getStateBigInt(big.NewInt(minStakeLoc)),
 		BlockReward:      s.getStateBigInt(big.NewInt(blockRewardLoc)),
-		BlockGasLimit:    uint64(s.getStateBigInt(big.NewInt(blockGasLimitLoc)).Uint64()),
+		BlockGasLimit:    s.getStateBigInt(big.NewInt(blockGasLimitLoc)).Uint64(),
 		NumChains:        uint32(s.getStateBigInt(big.NewInt(numChainsLoc)).Uint64()),
 		LambdaBA:         s.getStateBigInt(big.NewInt(lambdaBALoc)).Uint64(),
 		LambdaDKG:        s.getStateBigInt(big.NewInt(lambdaDKGLoc)).Uint64(),
-		K:                int(s.getStateBigInt(big.NewInt(kLoc)).Uint64()),
-		PhiRatio:         float32(s.getStateBigInt(big.NewInt(phiRatioLoc)).Uint64()) / 1000000.0,
+		K:                uint32(s.getStateBigInt(big.NewInt(kLoc)).Uint64()),
+		PhiRatio:         float32(s.getStateBigInt(big.NewInt(phiRatioLoc)).Uint64()) / phiRatioMultiplier,
 		NotarySetSize:    uint32(s.getStateBigInt(big.NewInt(notarySetSizeLoc)).Uint64()),
 		DKGSetSize:       uint32(s.getStateBigInt(big.NewInt(dkgSetSizeLoc)).Uint64()),
 		RoundInterval:    s.getStateBigInt(big.NewInt(roundIntervalLoc)).Uint64(),
@@ -1458,13 +1768,44 @@ func (s *GovernanceStateHelper) UpdateConfiguration(cfg *params.DexconConfig) {
 	s.setStateBigInt(big.NewInt(lambdaBALoc), big.NewInt(int64(cfg.LambdaBA)))
 	s.setStateBigInt(big.NewInt(lambdaDKGLoc), big.NewInt(int64(cfg.LambdaDKG)))
 	s.setStateBigInt(big.NewInt(kLoc), big.NewInt(int64(cfg.K)))
-	s.setStateBigInt(big.NewInt(phiRatioLoc), big.NewInt(int64(cfg.PhiRatio)))
+	s.setStateBigInt(big.NewInt(phiRatioLoc), big.NewInt(int64(cfg.PhiRatio*phiRatioMultiplier)))
 	s.setStateBigInt(big.NewInt(notarySetSizeLoc), big.NewInt(int64(cfg.NotarySetSize)))
 	s.setStateBigInt(big.NewInt(dkgSetSizeLoc), big.NewInt(int64(cfg.DKGSetSize)))
 	s.setStateBigInt(big.NewInt(roundIntervalLoc), big.NewInt(int64(cfg.RoundInterval)))
 	s.setStateBigInt(big.NewInt(minBlockIntervalLoc), big.NewInt(int64(cfg.MinBlockInterval)))
 }
 
+type rawConfigStruct struct {
+	MinStake         *big.Int
+	BlockReward      *big.Int
+	BlockGasLimit    *big.Int
+	NumChains        *big.Int
+	LambdaBA         *big.Int
+	LambdaDKG        *big.Int
+	K                *big.Int
+	PhiRatio         *big.Int
+	NotarySetSize    *big.Int
+	DKGSetSize       *big.Int
+	RoundInterval    *big.Int
+	MinBlockInterval *big.Int
+}
+
+// UpdateConfigurationRaw updates system configuration.
+func (s *GovernanceStateHelper) UpdateConfigurationRaw(cfg *rawConfigStruct) {
+	s.setStateBigInt(big.NewInt(minStakeLoc), cfg.MinStake)
+	s.setStateBigInt(big.NewInt(blockRewardLoc), cfg.BlockReward)
+	s.setStateBigInt(big.NewInt(blockGasLimitLoc), cfg.BlockGasLimit)
+	s.setStateBigInt(big.NewInt(numChainsLoc), cfg.NumChains)
+	s.setStateBigInt(big.NewInt(lambdaBALoc), cfg.LambdaBA)
+	s.setStateBigInt(big.NewInt(lambdaDKGLoc), cfg.LambdaDKG)
+	s.setStateBigInt(big.NewInt(kLoc), cfg.K)
+	s.setStateBigInt(big.NewInt(phiRatioLoc), cfg.PhiRatio)
+	s.setStateBigInt(big.NewInt(notarySetSizeLoc), cfg.NotarySetSize)
+	s.setStateBigInt(big.NewInt(dkgSetSizeLoc), cfg.DKGSetSize)
+	s.setStateBigInt(big.NewInt(roundIntervalLoc), cfg.RoundInterval)
+	s.setStateBigInt(big.NewInt(minBlockIntervalLoc), cfg.MinBlockInterval)
+}
+
 // event ConfigurationChanged();
 func (s *GovernanceStateHelper) emitConfigurationChangedEvent() {
 	s.StateDB.AddLog(&types.Log{
@@ -1483,6 +1824,42 @@ func (s *GovernanceStateHelper) emitCRSProposed(round *big.Int, crs common.Hash)
 	})
 }
 
+// event Staked(address indexed NodeAddress, uint256 Amount);
+func (s *GovernanceStateHelper) emitStaked(nodeAddr common.Address) {
+	s.StateDB.AddLog(&types.Log{
+		Address: GovernanceContractAddress,
+		Topics:  []common.Hash{events["Staked"].Id(), nodeAddr.Hash()},
+		Data:    []byte{},
+	})
+}
+
+// event Unstaked(address indexed NodeAddress);
+func (s *GovernanceStateHelper) emitUnstaked(nodeAddr common.Address) {
+	s.StateDB.AddLog(&types.Log{
+		Address: GovernanceContractAddress,
+		Topics:  []common.Hash{events["Unstaked"].Id(), nodeAddr.Hash()},
+		Data:    []byte{},
+	})
+}
+
+// event Delegated(address indexed NodeAddress, address indexed DelegatorAddress, uint256 Amount);
+func (s *GovernanceStateHelper) emitDelegated(nodeAddr, delegatorAddr common.Address, amount *big.Int) {
+	s.StateDB.AddLog(&types.Log{
+		Address: GovernanceContractAddress,
+		Topics:  []common.Hash{events["Delegated"].Id(), nodeAddr.Hash(), delegatorAddr.Hash()},
+		Data:    common.BigToHash(amount).Bytes(),
+	})
+}
+
+// event Undelegated(address indexed NodeAddress, address indexed DelegatorAddress);
+func (s *GovernanceStateHelper) emitUndelegated(nodeAddr, delegatorAddr common.Address) {
+	s.StateDB.AddLog(&types.Log{
+		Address: GovernanceContractAddress,
+		Topics:  []common.Hash{events["Undelegated"].Id(), nodeAddr.Hash(), delegatorAddr.Hash()},
+		Data:    []byte{},
+	})
+}
+
 // GovernanceContract represents the governance contract of DEXCON.
 type GovernanceContract struct {
 	evm      *EVM
@@ -1498,7 +1875,20 @@ func newGovernanceContract(evm *EVM, contract *Contract) *GovernanceContract {
 	}
 }
 
-func (g *GovernanceContract) UseGas(gas uint64) ([]byte, error) {
+func (g *GovernanceContract) Address() common.Address {
+	return GovernanceContractAddress
+}
+
+func (g *GovernanceContract) transfer(from, to common.Address, amount *big.Int) bool {
+	// TODO(w): add this to debug trace so it shows up as internal transaction.
+	if g.evm.CanTransfer(g.evm.StateDB, from, amount) {
+		g.evm.Transfer(g.evm.StateDB, from, to, amount)
+		return true
+	}
+	return false
+}
+
+func (g *GovernanceContract) useGas(gas uint64) ([]byte, error) {
 	if !g.contract.UseGas(gas) {
 		return nil, ErrOutOfGas
 	}
@@ -1506,7 +1896,7 @@ func (g *GovernanceContract) UseGas(gas uint64) ([]byte, error) {
 }
 
 func (g *GovernanceContract) penalize() ([]byte, error) {
-	g.UseGas(g.contract.Gas)
+	g.useGas(g.contract.Gas)
 	return nil, errExecutionReverted
 }
 
@@ -1519,13 +1909,13 @@ func (g *GovernanceContract) inDKGSet(round *big.Int, nodeID coreTypes.NodeID) b
 		configRound = new(big.Int).Sub(round, big.NewInt(int64(core.ConfigRoundShift)))
 	}
 
-	statedb, err := g.evm.Context.StateAtNumber(g.state.RoundHeight(configRound).Uint64())
+	statedb, err := g.evm.StateAtNumber(g.state.RoundHeight(configRound).Uint64())
 	if err != nil {
 		panic(err)
 	}
 
 	state := GovernanceStateHelper{statedb}
-	for _, x := range state.Nodes() {
+	for _, x := range state.QualifiedNodes() {
 		mpk, err := ecdsa.NewPublicKeyFromByteSlice(x.PublicKey)
 		if err != nil {
 			panic(err)
@@ -1578,7 +1968,7 @@ func (g *GovernanceContract) addDKGComplaint(round *big.Int, comp []byte) ([]byt
 	g.state.PushDKGComplaint(round, comp)
 
 	// Set this to relatively high to prevent spamming
-	return g.UseGas(5000000)
+	return g.useGas(5000000)
 }
 
 func (g *GovernanceContract) addDKGMasterPublicKey(round *big.Int, mpk []byte) ([]byte, error) {
@@ -1588,7 +1978,7 @@ func (g *GovernanceContract) addDKGMasterPublicKey(round *big.Int, mpk []byte) (
 	}
 
 	caller := g.contract.Caller()
-	offset := g.state.Offset(caller)
+	offset := g.state.NodesOffset(caller)
 
 	// Can not add dkg mpk if not staked.
 	if offset.Cmp(big.NewInt(0)) < 0 {
@@ -1612,7 +2002,7 @@ func (g *GovernanceContract) addDKGMasterPublicKey(round *big.Int, mpk []byte) (
 
 	g.state.PushDKGMasterPublicKey(round, mpk)
 
-	return g.UseGas(100000)
+	return g.useGas(100000)
 }
 
 func (g *GovernanceContract) addDKGFinalize(round *big.Int, finalize []byte) ([]byte, error) {
@@ -1642,16 +2032,48 @@ func (g *GovernanceContract) addDKGFinalize(round *big.Int, finalize []byte) ([]
 		g.state.IncDKGFinalizedsCount(round)
 	}
 
-	return g.UseGas(100000)
+	return g.useGas(100000)
 }
 
-func (g *GovernanceContract) updateConfiguration(config *params.DexconConfig) ([]byte, error) {
+func (g *GovernanceContract) delegate(nodeAddr common.Address) ([]byte, error) {
+	offset := g.state.NodesOffset(nodeAddr)
+	if offset.Cmp(big.NewInt(0)) < 0 {
+		return nil, errExecutionReverted
+	}
+
+	caller := g.contract.Caller()
+	value := g.contract.Value()
+
+	// Can not delegate if already delegated.
+	delegatorOffset := g.state.DelegatorsOffset(nodeAddr, caller)
+	if delegatorOffset.Cmp(big.NewInt(0)) >= 0 {
+		return nil, errExecutionReverted
+	}
+
+	// Add to the total staked of node.
+	node := g.state.Node(offset)
+	node.Staked = new(big.Int).Add(node.Staked, g.contract.Value())
+	g.state.UpdateNode(offset, node)
+
+	// Push delegator record.
+	offset = g.state.LenDelegators(nodeAddr)
+	g.state.PushDelegator(nodeAddr, &delegatorInfo{
+		Owner: caller,
+		Value: value,
+	})
+	g.state.PutDelegatorOffset(nodeAddr, caller, offset)
+	g.state.emitDelegated(nodeAddr, caller, value)
+
+	return g.useGas(200000)
+}
+
+func (g *GovernanceContract) updateConfiguration(cfg *rawConfigStruct) ([]byte, error) {
 	// Only owner can update configuration.
 	if g.contract.Caller() != g.state.Owner() {
 		return nil, errExecutionReverted
 	}
 
-	g.state.UpdateConfiguration(config)
+	g.state.UpdateConfigurationRaw(cfg)
 	g.state.emitConfigurationChangedEvent()
 	return nil, nil
 }
@@ -1665,57 +2087,116 @@ func (g *GovernanceContract) stake(
 	}
 
 	caller := g.contract.Caller()
-	offset := g.state.Offset(caller)
+	offset := g.state.NodesOffset(caller)
 
-	// Need to stake at least minStake.
-	if g.contract.Value().Cmp(g.state.MinStake()) < 0 {
+	// Check if public key is valid.
+	if _, err := crypto.UnmarshalPubkey(publicKey); err != nil {
 		return g.penalize()
 	}
 
 	// Can not stake if already staked.
 	if offset.Cmp(big.NewInt(0)) >= 0 {
-		return g.penalize()
+		return nil, errExecutionReverted
 	}
 
-	offset = g.state.NodesLength()
+	offset = g.state.LenNodes()
 	g.state.PushNode(&nodeInfo{
 		Owner:     caller,
 		PublicKey: publicKey,
-		Staked:    g.contract.Value(),
+		Staked:    big.NewInt(0),
 		Name:      name,
 		Email:     email,
 		Location:  location,
 		Url:       url,
 	})
-	g.state.PutOffset(caller, offset)
+	g.state.PutNodesOffset(caller, offset)
 
-	return g.UseGas(0)
+	// Delegate fund to itself.
+	if g.contract.Value().Cmp(big.NewInt(0)) > 0 {
+		if ret, err := g.delegate(caller); err != nil {
+			return ret, err
+		}
+	}
+
+	g.state.emitStaked(caller)
+	return g.useGas(100000)
+}
+
+func (g *GovernanceContract) undelegateHelper(nodeAddr, owner common.Address) ([]byte, error) {
+	nodeOffset := g.state.NodesOffset(nodeAddr)
+	if nodeOffset.Cmp(big.NewInt(0)) < 0 {
+		return nil, errExecutionReverted
+	}
+
+	offset := g.state.DelegatorsOffset(nodeAddr, owner)
+	if offset.Cmp(big.NewInt(0)) < 0 {
+		return nil, errExecutionReverted
+	}
+
+	delegator := g.state.Delegator(nodeAddr, offset)
+	length := g.state.LenDelegators(nodeAddr)
+	lastIndex := new(big.Int).Sub(length, big.NewInt(1))
+
+	// Delete the delegator.
+	if offset.Cmp(lastIndex) != 0 {
+		lastNode := g.state.Delegator(nodeAddr, lastIndex)
+		g.state.UpdateDelegator(nodeAddr, offset, lastNode)
+		g.state.PutDelegatorOffset(nodeAddr, lastNode.Owner, offset)
+	}
+	g.state.DeleteDelegatorsOffset(nodeAddr, owner)
+	g.state.PopLastDelegator(nodeAddr)
+
+	// Subtract from the total staked of node.
+	node := g.state.Node(nodeOffset)
+	node.Staked = new(big.Int).Sub(node.Staked, delegator.Value)
+	g.state.UpdateNode(nodeOffset, node)
+
+	// Return the staked fund.
+	if !g.transfer(GovernanceContractAddress, delegator.Owner, delegator.Value) {
+		return nil, errExecutionReverted
+	}
+
+	g.state.emitUndelegated(nodeAddr, owner)
+	return g.useGas(100000)
+}
+
+func (g *GovernanceContract) undelegate(nodeAddr common.Address) ([]byte, error) {
+	return g.undelegateHelper(nodeAddr, g.contract.Caller())
 }
 
 func (g *GovernanceContract) unstake() ([]byte, error) {
 	caller := g.contract.Caller()
-	offset := g.state.Offset(caller)
+	offset := g.state.NodesOffset(caller)
 	if offset.Cmp(big.NewInt(0)) < 0 {
 		return nil, errExecutionReverted
 	}
 
-	node := g.state.Node(offset)
-	length := g.state.NodesLength()
+	// Undelegate all delegators.
+	lenDelegators := g.state.LenDelegators(caller)
+	i := new(big.Int).Sub(lenDelegators, big.NewInt(1))
+	for i.Cmp(big.NewInt(0)) >= 0 {
+		delegator := g.state.Delegator(caller, i)
+		if ret, err := g.undelegateHelper(caller, delegator.Owner); err != nil {
+			return ret, err
+		}
+		i = i.Sub(i, big.NewInt(1))
+	}
+
+	length := g.state.LenNodes()
 	lastIndex := new(big.Int).Sub(length, big.NewInt(1))
 
 	// Delete the node.
-	if offset != lastIndex {
+	if offset.Cmp(lastIndex) != 0 {
 		lastNode := g.state.Node(lastIndex)
 		g.state.UpdateNode(offset, lastNode)
-		g.state.PutOffset(lastNode.Owner, offset)
-		g.state.DeleteOffset(caller)
+		g.state.PutNodesOffset(lastNode.Owner, offset)
 	}
+	g.state.DeleteNodesOffset(caller)
+	g.state.PopLastNode()
 
-	// Return the staked fund.
-	// TODO(w): add this to debug trace so it shows up as internal transaction.
-	g.evm.Transfer(g.evm.StateDB, GovernanceContractAddress, caller, node.Staked)
+	g.state.emitUnstaked(caller)
 
-	return g.UseGas(0)
+	return g.useGas(100000)
 }
 
 func (g *GovernanceContract) proposeCRS(nextRound *big.Int, signedCRS []byte) ([]byte, error) {
@@ -1774,11 +2255,11 @@ func (g *GovernanceContract) proposeCRS(nextRound *big.Int, signedCRS []byte) ([
 	crs := common.BytesToHash(newCRS)
 
 	g.state.PushCRS(crs)
-	g.state.emitCRSProposed(g.state.LenCRS(), crs)
+	g.state.emitCRSProposed(nextRound, crs)
 
 	// To encourage DKG set to propose the correct value, correctly submitting
 	// this should cause nothing.
-	return g.UseGas(0)
+	return g.useGas(0)
 }
 
 func (g *GovernanceContract) transferOwnership(newOwner common.Address) ([]byte, error) {
@@ -1793,7 +2274,7 @@ func (g *GovernanceContract) transferOwnership(newOwner common.Address) ([]byte,
 func (g *GovernanceContract) snapshotRound(round, height *big.Int) ([]byte, error) {
 	// Validate if this mapping is correct. Only block proposer need to verify this.
 	if g.evm.IsBlockProposer() {
-		realHeight, ok := g.evm.Context.GetRoundHeight(round.Uint64())
+		realHeight, ok := g.evm.GetRoundHeight(round.Uint64())
 		if !ok {
 			return g.penalize()
 		}
diff --git a/core/vm/governance_test.go b/core/vm/governance_test.go
index ebdca7fd8..7718e99d2 100644
--- a/core/vm/governance_test.go
+++ b/core/vm/governance_test.go
@@ -19,6 +19,7 @@ package vm
 
 import (
 	"bytes"
+	"crypto/ecdsa"
 	"math/big"
 	"math/rand"
 	"testing"
@@ -26,7 +27,9 @@ import (
 
 	"github.com/dexon-foundation/dexon/common"
 	"github.com/dexon-foundation/dexon/core/state"
+	"github.com/dexon-foundation/dexon/crypto"
 	"github.com/dexon-foundation/dexon/ethdb"
+	"github.com/dexon-foundation/dexon/params"
 	"github.com/stretchr/testify/suite"
 )
 
@@ -79,3 +82,557 @@ func (g *GovernanceStateHelperTestSuite) TestReadWriteBytes() {
 func TestGovernanceStateHelper(t *testing.T) {
 	suite.Run(t, new(GovernanceStateHelperTestSuite))
 }
+
+type GovernanceContractTestSuite struct {
+	suite.Suite
+
+	config  *params.DexconConfig
+	memDB   *ethdb.MemDatabase
+	stateDB *state.StateDB
+	s       *GovernanceStateHelper
+}
+
+func (g *GovernanceContractTestSuite) SetupTest() {
+	memDB := ethdb.NewMemDatabase()
+	stateDB, err := state.New(common.Hash{}, state.NewDatabase(memDB))
+	if err != nil {
+		panic(err)
+	}
+	g.memDB = memDB
+	g.stateDB = stateDB
+	g.s = &GovernanceStateHelper{stateDB}
+
+	config := params.TestnetChainConfig.Dexcon
+	g.config = config
+
+	// Give governance contract balance so it will not be deleted because of being an empty state object.
+	stateDB.AddBalance(GovernanceContractAddress, big.NewInt(1))
+
+	// Genesis CRS.
+	crs := crypto.Keccak256Hash([]byte(config.GenesisCRSText))
+	g.s.PushCRS(crs)
+
+	// Round 0 height.
+	g.s.PushRoundHeight(big.NewInt(0))
+
+	// Owner.
+	g.s.SetOwner(g.config.Owner)
+
+	// Governance configuration.
+	g.s.UpdateConfiguration(config)
+
+	g.stateDB.Commit(true)
+}
+
+func (g *GovernanceContractTestSuite) newPrefundAccount() (*ecdsa.PrivateKey, common.Address) {
+	privKey, err := crypto.GenerateKey()
+	if err != nil {
+		panic(err)
+	}
+	address := crypto.PubkeyToAddress(privKey.PublicKey)
+
+	g.stateDB.AddBalance(address, new(big.Int).Mul(big.NewInt(1e18), big.NewInt(2e5)))
+	return privKey, address
+}
+
+func (g *GovernanceContractTestSuite) call(caller common.Address, input []byte, value *big.Int) ([]byte, error) {
+	context := Context{
+		CanTransfer: func(db StateDB, addr common.Address, amount *big.Int) bool {
+			return db.GetBalance(addr).Cmp(amount) >= 0
+		},
+		Transfer: func(db StateDB, sender common.Address, recipient common.Address, amount *big.Int) {
+			db.SubBalance(sender, amount)
+			db.AddBalance(recipient, amount)
+		},
+		GetRoundHeight: func(round uint64) (uint64, bool) {
+			switch round {
+			case 0:
+				return 0, true
+			case 1:
+				return 1000, true
+			case 2:
+				return 2000, true
+			}
+			return 0, false
+		},
+		Time:        big.NewInt(time.Now().UnixNano() / 1000000000),
+		BlockNumber: big.NewInt(0),
+	}
+
+	evm := NewEVM(context, g.stateDB, params.TestChainConfig, Config{IsBlockProposer: true})
+	ret, _, err := evm.Call(AccountRef(caller), GovernanceContractAddress, input, 10000000, value)
+	return ret, err
+}
+
+func (g *GovernanceContractTestSuite) TestTransferOwnership() {
+	_, addr := g.newPrefundAccount()
+
+	input, err := abiObject.Pack("transferOwnership", addr)
+	g.Require().Nil(err)
+
+	// Call with non-owner.
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NotNil(err)
+
+	// Call with owner.
+	_, err = g.call(g.config.Owner, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(addr, g.s.Owner())
+}
+
+func (g *GovernanceContractTestSuite) TestStakeUnstakeWithoutDelegators() {
+	privKey, addr := g.newPrefundAccount()
+	pk := crypto.FromECDSAPub(&privKey.PublicKey)
+
+	// Stake.
+	amount := new(big.Int).Mul(big.NewInt(1e18), big.NewInt(5e4))
+	balanceBeforeStake := g.stateDB.GetBalance(addr)
+	input, err := abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, amount)
+	g.Require().Nil(err)
+
+	// Node staked but staked fund < MinStake so is still unqualified.
+	g.Require().Equal(1, int(g.s.LenNodes().Uint64()))
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+	g.Require().Equal("Test1", g.s.Node(big.NewInt(0)).Name)
+
+	// Check balance.
+	g.Require().Equal(new(big.Int).Sub(balanceBeforeStake, amount), g.stateDB.GetBalance(addr))
+	g.Require().Equal(new(big.Int).Add(big.NewInt(1), amount), g.stateDB.GetBalance(GovernanceContractAddress))
+
+	// Staking again should fail.
+	_, err = g.call(addr, input, amount)
+	g.Require().NotNil(err)
+
+	// Unstake.
+	input, err = abiObject.Pack("unstake")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(0, int(g.s.LenNodes().Uint64()))
+
+	// Stake 2 nodes, and unstake the first then the second.
+
+	// 2nd node Stake.
+	privKey2, addr2 := g.newPrefundAccount()
+	pk2 := crypto.FromECDSAPub(&privKey2.PublicKey)
+	input, err = abiObject.Pack("stake", pk2, "Test2", "test2@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	g.Require().Nil(err)
+	_, err = g.call(addr2, input, amount)
+	g.Require().Nil(err)
+	g.Require().Equal("Test2", g.s.Node(big.NewInt(0)).Name)
+	g.Require().Equal(0, int(g.s.NodesOffset(addr2).Int64()))
+
+	// 1st node Stake.
+	input, err = abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, amount)
+	g.Require().Nil(err)
+
+	// 2nd node Unstake.
+	input, err = abiObject.Pack("unstake")
+	g.Require().Nil(err)
+	_, err = g.call(addr2, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(1, int(g.s.LenNodes().Uint64()))
+	g.Require().Equal("Test1", g.s.Node(big.NewInt(0)).Name)
+	g.Require().Equal(-1, int(g.s.NodesOffset(addr2).Int64()))
+
+	// 1st node Unstake.
+	input, err = abiObject.Pack("unstake")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(0, int(g.s.LenNodes().Uint64()))
+	g.Require().Equal(-1, int(g.s.NodesOffset(addr).Int64()))
+	g.Require().Equal(-1, int(g.s.DelegatorsOffset(addr, addr).Int64()))
+
+	// Check balance.
+	g.Require().Equal(balanceBeforeStake, g.stateDB.GetBalance(addr))
+	g.Require().Equal(balanceBeforeStake, g.stateDB.GetBalance(addr2))
+	g.Require().Equal(big.NewInt(1), g.stateDB.GetBalance(GovernanceContractAddress))
+}
+
+func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
+	privKey, addr := g.newPrefundAccount()
+	pk := crypto.FromECDSAPub(&privKey.PublicKey)
+
+	// Stake.
+	input, err := abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	g.Require().Nil(err)
+	ownerStaked := new(big.Int).Mul(big.NewInt(1e18), big.NewInt(5e4))
+	_, err = g.call(addr, input, ownerStaked)
+	g.Require().Nil(err)
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+	g.Require().Equal(addr, g.s.Delegator(addr, big.NewInt(0)).Owner)
+	g.Require().Equal(ownerStaked, g.s.Node(big.NewInt(0)).Staked)
+
+	// 1st delegator delegate to 1st node.
+	_, addrDelegator := g.newPrefundAccount()
+
+	balanceBeforeDelegate := g.stateDB.GetBalance(addrDelegator)
+	amount := new(big.Int).Mul(big.NewInt(1e18), big.NewInt(3e4))
+	input, err = abiObject.Pack("delegate", addr)
+	g.Require().Nil(err)
+
+	_, err = g.call(addrDelegator, input, amount)
+	g.Require().Nil(err)
+	g.Require().Equal(new(big.Int).Sub(balanceBeforeDelegate, amount), g.stateDB.GetBalance(addrDelegator))
+	g.Require().Equal(addrDelegator, g.s.Delegator(addr, big.NewInt(1)).Owner)
+	g.Require().Equal(new(big.Int).Add(amount, ownerStaked), g.s.Node(big.NewInt(0)).Staked)
+	g.Require().Equal(1, int(g.s.DelegatorsOffset(addr, addrDelegator).Int64()))
+
+	// Same person delegate the 2nd time should fail.
+	_, err = g.call(addrDelegator, input, big.NewInt(1e18))
+	g.Require().NotNil(err)
+
+	// Not yet qualified.
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+
+	// 2nd delegator delegate to 1st node.
+	_, addrDelegator2 := g.newPrefundAccount()
+	_, err = g.call(addrDelegator2, input, amount)
+	g.Require().Nil(err)
+	g.Require().Equal(new(big.Int).Sub(balanceBeforeDelegate, amount), g.stateDB.GetBalance(addrDelegator2))
+	g.Require().Equal(addrDelegator2, g.s.Delegator(addr, big.NewInt(2)).Owner)
+	g.Require().Equal(new(big.Int).Add(ownerStaked, new(big.Int).Mul(amount, big.NewInt(2))),
+		g.s.Node(big.NewInt(0)).Staked)
+	g.Require().Equal(2, int(g.s.DelegatorsOffset(addr, addrDelegator2).Int64()))
+
+	// Qualified.
+	g.Require().Equal(1, len(g.s.QualifiedNodes()))
+
+	// Undelegate addrDelegator.
+	balanceBeforeUnDelegate := g.stateDB.GetBalance(addrDelegator)
+	input, err = abiObject.Pack("undelegate", addr)
+	g.Require().Nil(err)
+	_, err = g.call(addrDelegator, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(2, int(g.s.LenDelegators(addr).Uint64()))
+	g.Require().Equal(new(big.Int).Add(balanceBeforeUnDelegate, amount), g.stateDB.GetBalance(addrDelegator))
+	g.Require().Equal(-1, int(g.s.DelegatorsOffset(addr, addrDelegator).Int64()))
+
+	// Undelegate addrDelegator2.
+	balanceBeforeUnDelegate = g.stateDB.GetBalance(addrDelegator2)
+	input, err = abiObject.Pack("undelegate", addr)
+	g.Require().Nil(err)
+	_, err = g.call(addrDelegator2, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(1, int(g.s.LenDelegators(addr).Uint64()))
+	g.Require().Equal(new(big.Int).Add(balanceBeforeUnDelegate, amount), g.stateDB.GetBalance(addrDelegator2))
+	g.Require().Equal(-1, int(g.s.DelegatorsOffset(addr, addrDelegator2).Int64()))
+
+	// Unqualified
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+}
+
+func (g *GovernanceContractTestSuite) TestUnstakeWithDelegators() {
+	privKey, addr := g.newPrefundAccount()
+	pk := crypto.FromECDSAPub(&privKey.PublicKey)
+
+	// Stake.
+	amount := new(big.Int).Mul(big.NewInt(1e18), big.NewInt(5e4))
+	input, err := abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, amount)
+	g.Require().Nil(err)
+
+	// 1st delegator delegate to 1st node.
+	_, addrDelegator := g.newPrefundAccount()
+
+	balanceBeforeDelegate := g.stateDB.GetBalance(addrDelegator)
+	amount = new(big.Int).Mul(big.NewInt(1e18), big.NewInt(3e4))
+	input, err = abiObject.Pack("delegate", addr)
+	g.Require().Nil(err)
+
+	_, err = g.call(addrDelegator, input, amount)
+	g.Require().Nil(err)
+	g.Require().Equal(new(big.Int).Sub(balanceBeforeDelegate, amount), g.stateDB.GetBalance(addrDelegator))
+	g.Require().Equal(addrDelegator, g.s.Delegator(addr, big.NewInt(1)).Owner)
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+
+	// 2st delegator delegate to 1st node.
+	_, addrDelegator2 := g.newPrefundAccount()
+
+	balanceBeforeDelegate = g.stateDB.GetBalance(addrDelegator2)
+	input, err = abiObject.Pack("delegate", addr)
+	g.Require().Nil(err)
+
+	_, err = g.call(addrDelegator2, input, amount)
+	g.Require().Nil(err)
+	g.Require().Equal(new(big.Int).Sub(balanceBeforeDelegate, amount), g.stateDB.GetBalance(addrDelegator2))
+	g.Require().Equal(addrDelegator2, g.s.Delegator(addr, big.NewInt(2)).Owner)
+
+	// Node is now qualified.
+	g.Require().Equal(1, len(g.s.QualifiedNodes()))
+
+	// Unstake.
+	input, err = abiObject.Pack("unstake")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	g.Require().Equal(0, int(g.s.LenDelegators(addr).Uint64()))
+	g.Require().Equal(0, int(g.s.LenNodes().Uint64()))
+
+	// Check balance.
+	g.Require().Equal(balanceBeforeDelegate, g.stateDB.GetBalance(addr))
+	g.Require().Equal(balanceBeforeDelegate, g.stateDB.GetBalance(addrDelegator))
+	g.Require().Equal(balanceBeforeDelegate, g.stateDB.GetBalance(addrDelegator2))
+	g.Require().Equal(big.NewInt(1), g.stateDB.GetBalance(GovernanceContractAddress))
+}
+
+func (g *GovernanceContractTestSuite) TestUpdateConfiguration() {
+	_, addr := g.newPrefundAccount()
+
+	input, err := abiObject.Pack("updateConfiguration",
+		new(big.Int).Mul(big.NewInt(1e18), big.NewInt(1e5)),
+		big.NewInt(1e18), big.NewInt(8000000), big.NewInt(6), big.NewInt(250), big.NewInt(2500),
+		big.NewInt(0), big.NewInt(667000), big.NewInt(4), big.NewInt(4), big.NewInt(600000), big.NewInt(900))
+	g.Require().Nil(err)
+
+	// Call with non-owner.
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NotNil(err)
+
+	// Call with owner.
+	_, err = g.call(g.config.Owner, input, big.NewInt(0))
+	g.Require().Nil(err)
+}
+
+func (g *GovernanceContractTestSuite) TestSnapshotRound() {
+	_, addr := g.newPrefundAccount()
+
+	// Wrong height.
+	input, err := abiObject.Pack("snapshotRound", big.NewInt(1), big.NewInt(666))
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NotNil(err)
+
+	// Invalid round.
+	input, err = abiObject.Pack("snapshotRound", big.NewInt(2), big.NewInt(2000))
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NotNil(err)
+
+	// Correct.
+	input, err = abiObject.Pack("snapshotRound", big.NewInt(1), big.NewInt(1000))
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+
+	// Duplicate round.
+	input, err = abiObject.Pack("snapshotRound", big.NewInt(1), big.NewInt(1000))
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NotNil(err)
+
+	// Invalid round.
+	input, err = abiObject.Pack("snapshotRound", big.NewInt(3), big.NewInt(3000))
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NotNil(err)
+
+	// Correct.
+	input, err = abiObject.Pack("snapshotRound", big.NewInt(2), big.NewInt(2000))
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+}
+
+func (g *GovernanceContractTestSuite) TestConfigurationReading() {
+	_, addr := g.newPrefundAccount()
+
+	// CRS.
+	input, err := abiObject.Pack("crs", big.NewInt(0))
+	g.Require().Nil(err)
+	res, err := g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	var crs0 [32]byte
+	err = abiObject.Unpack(&crs0, "crs", res)
+	g.Require().Nil(err)
+	g.Require().Equal(crypto.Keccak256Hash([]byte(g.config.GenesisCRSText)), common.BytesToHash(crs0[:]))
+
+	// Owner.
+	input, err = abiObject.Pack("owner")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	var owner common.Address
+	err = abiObject.Unpack(&owner, "owner", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.Owner, owner)
+
+	// MinStake.
+	input, err = abiObject.Pack("minStake")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	var value *big.Int
+	err = abiObject.Unpack(&value, "minStake", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.MinStake.String(), value.String())
+
+	// BlockReward.
+	input, err = abiObject.Pack("blockReward")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "blockReward", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.BlockReward.String(), value.String())
+
+	// BlockGasLimit.
+	input, err = abiObject.Pack("blockGasLimit")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "blockGasLimit", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.BlockGasLimit, value.Uint64())
+
+	// NumChains.
+	input, err = abiObject.Pack("numChains")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "numChains", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.NumChains, uint32(value.Uint64()))
+
+	// LambdaBA.
+	input, err = abiObject.Pack("lambdaBA")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "lambdaBA", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.LambdaBA, value.Uint64())
+
+	// LambdaDKG.
+	input, err = abiObject.Pack("lambdaDKG")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "lambdaDKG", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.LambdaDKG, value.Uint64())
+
+	// K.
+	input, err = abiObject.Pack("k")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "k", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.K, uint32(value.Uint64()))
+
+	// PhiRatio.
+	input, err = abiObject.Pack("phiRatio")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "phiRatio", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.PhiRatio, float32(value.Uint64())/phiRatioMultiplier)
+
+	// NotarySetSize.
+	input, err = abiObject.Pack("notarySetSize")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "notarySetSize", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.NotarySetSize, uint32(value.Uint64()))
+
+	// DKGSetSize.
+	input, err = abiObject.Pack("dkgSetSize")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "dkgSetSize", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.DKGSetSize, uint32(value.Uint64()))
+
+	// RoundInterval.
+	input, err = abiObject.Pack("roundInterval")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "roundInterval", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.RoundInterval, value.Uint64())
+
+	// MinBlockInterval.
+	input, err = abiObject.Pack("minBlockInterval")
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "minBlockInterval", res)
+	g.Require().Nil(err)
+	g.Require().Equal(g.config.MinBlockInterval, value.Uint64())
+}
+
+func (g *GovernanceContractTestSuite) TestMiscVariableReading() {
+	privKey, addr := g.newPrefundAccount()
+	pk := crypto.FromECDSAPub(&privKey.PublicKey)
+
+	// Stake.
+	amount := new(big.Int).Mul(big.NewInt(1e18), big.NewInt(5e4))
+	input, err := abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	g.Require().Nil(err)
+	_, err = g.call(addr, input, amount)
+	g.Require().Nil(err)
+
+	// 1st delegator delegate to 1st node.
+	_, addrDelegator := g.newPrefundAccount()
+	amount = new(big.Int).Mul(big.NewInt(1e18), big.NewInt(3e4))
+	input, err = abiObject.Pack("delegate", addr)
+	g.Require().Nil(err)
+	_, err = g.call(addrDelegator, input, amount)
+	g.Require().Nil(err)
+
+	// 2st delegator delegate to 1st node.
+	_, addrDelegator2 := g.newPrefundAccount()
+	input, err = abiObject.Pack("delegate", addr)
+	g.Require().Nil(err)
+	_, err = g.call(addrDelegator2, input, amount)
+	g.Require().Nil(err)
+
+	input, err = abiObject.Pack("nodesLength")
+	g.Require().Nil(err)
+	res, err := g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	var value *big.Int
+	err = abiObject.Unpack(&value, "nodesLength", res)
+	g.Require().Nil(err)
+	g.Require().Equal(1, int(value.Uint64()))
+
+	input, err = abiObject.Pack("nodesOffset", addr)
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "nodesOffset", res)
+	g.Require().Nil(err)
+	g.Require().Equal(0, int(value.Uint64()))
+
+	input, err = abiObject.Pack("delegatorsLength", addr)
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "delegatorsLength", res)
+	g.Require().Nil(err)
+	g.Require().Equal(3, int(value.Uint64()))
+
+	input, err = abiObject.Pack("delegatorsOffset", addr, addrDelegator2)
+	g.Require().Nil(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().Nil(err)
+	err = abiObject.Unpack(&value, "delegatorsOffset", res)
+	g.Require().Nil(err)
+	g.Require().Equal(2, int(value.Uint64()))
+}
+
+func TestGovernanceContract(t *testing.T) {
+	suite.Run(t, new(GovernanceContractTestSuite))
+}
diff --git a/dex/app.go b/dex/app.go
index e0280dc2c..99514ed83 100644
--- a/dex/app.go
+++ b/dex/app.go
@@ -245,7 +245,7 @@ func (d *DexconApp) PrepareWitness(consensusHeight uint64) (witness coreTypes.Wi
 	if lastPendingHeight == 0 && consensusHeight == 0 {
 		witnessBlock = d.blockchain.CurrentBlock()
 	} else if lastPendingHeight >= consensusHeight {
-		witnessBlock = d.blockchain.GetPendingBlock()
+		witnessBlock = d.blockchain.PendingBlock()
 	} else {
 		log.Error("last pending height too low", "lastPendingHeight", lastPendingHeight,
 			"consensusHeight", consensusHeight)
diff --git a/dex/governance.go b/dex/governance.go
index f555b3508..db33f7820 100644
--- a/dex/governance.go
+++ b/dex/governance.go
@@ -100,7 +100,7 @@ func (d *DexconGovernance) Configuration(round uint64) *coreTypes.Config {
 		NumChains:        c.NumChains,
 		LambdaBA:         time.Duration(c.LambdaBA) * time.Millisecond,
 		LambdaDKG:        time.Duration(c.LambdaDKG) * time.Millisecond,
-		K:                c.K,
+		K:                int(c.K),
 		PhiRatio:         c.PhiRatio,
 		NotarySetSize:    c.NotarySetSize,
 		DKGSetSize:       c.DKGSetSize,
@@ -172,12 +172,12 @@ func (d *DexconGovernance) ProposeCRS(round uint64, signedCRS []byte) {
 	}
 }
 
-// NodeSet returns the current notary set.
+// NodeSet returns the current node set.
 func (d *DexconGovernance) NodeSet(round uint64) []coreCrypto.PublicKey {
 	s := d.getGovStateAtRound(round)
 	var pks []coreCrypto.PublicKey
 
-	for _, n := range s.Nodes() {
+	for _, n := range s.QualifiedNodes() {
 		pk, err := coreEcdsa.NewPublicKeyFromByteSlice(n.PublicKey)
 		if err != nil {
 			panic(err)
diff --git a/params/config.go b/params/config.go
index 1d2496a58..68af7143c 100644
--- a/params/config.go
+++ b/params/config.go
@@ -54,7 +54,7 @@ var (
 			LambdaBA:         250,
 			LambdaDKG:        2500,
 			K:                0,
-			PhiRatio:         667000,
+			PhiRatio:         0.667,
 			NotarySetSize:    4,
 			DKGSetSize:       4,
 			RoundInterval:    600000,
@@ -93,7 +93,7 @@ var (
 			LambdaBA:         250,
 			LambdaDKG:        2500,
 			K:                0,
-			PhiRatio:         667000,
+			PhiRatio:         0.667,
 			NotarySetSize:    4,
 			DKGSetSize:       4,
 			RoundInterval:    600000,
@@ -202,7 +202,7 @@ type DexconConfig struct {
 	NumChains        uint32         `json:"numChains"`
 	LambdaBA         uint64         `json:"lambdaBA"`
 	LambdaDKG        uint64         `json:"lambdaDKG"`
-	K                int            `json:"k"`
+	K                uint32         `json:"k"`
 	PhiRatio         float32        `json:"phiRatio"`
 	NotarySetSize    uint32         `json:"notarySetSize"`
 	DKGSetSize       uint32         `json:"dkgSetSize"`
diff --git a/params/gen_dexcon_config.go b/params/gen_dexcon_config.go
index 6633b38f3..9cd9395cc 100644
--- a/params/gen_dexcon_config.go
+++ b/params/gen_dexcon_config.go
@@ -23,7 +23,7 @@ func (d DexconConfig) MarshalJSON() ([]byte, error) {
 		NumChains        uint32                `json:"numChains"`
 		LambdaBA         uint64                `json:"lambdaBA"`
 		LambdaDKG        uint64                `json:"lambdaDKG"`
-		K                int                   `json:"k"`
+		K                uint32                `json:"k"`
 		PhiRatio         float32               `json:"phiRatio"`
 		NotarySetSize    uint32                `json:"notarySetSize"`
 		DKGSetSize       uint32                `json:"dkgSetSize"`
@@ -59,7 +59,7 @@ func (d *DexconConfig) UnmarshalJSON(input []byte) error {
 		NumChains        *uint32               `json:"numChains"`
 		LambdaBA         *uint64               `json:"lambdaBA"`
 		LambdaDKG        *uint64               `json:"lambdaDKG"`
-		K                *int                  `json:"k"`
+		K                *uint32               `json:"k"`
 		PhiRatio         *float32              `json:"phiRatio"`
 		NotarySetSize    *uint32               `json:"notarySetSize"`
 		DKGSetSize       *uint32               `json:"dkgSetSize"`
diff --git a/test/genesis.json b/test/genesis.json
index c4e110e84..bc3e740ea 100644
--- a/test/genesis.json
+++ b/test/genesis.json
@@ -19,7 +19,7 @@
       "lambdaBA": 250,
       "lambdaDKG": 2500,
       "k": 0,
-      "phiRatio": 667000,
+      "phiRatio": 0.667,
       "notarySetSize": 4,
       "dkgSetSize": 4,
       "roundInterval": 600000,