core: Add vote type and add field to block. (#76)

8 files changed, 139 insertions, 4 deletions

diff --git a/core/consensus.go b/core/consensus.go
index 122f0b0..c15d0e5 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -102,6 +102,11 @@ func NewConsensus(
 	}
 }
 
+// ProcessVote is the entry point to submit ont vote to a Consensus instance.
+func (con *Consensus) ProcessVote(vote *types.Vote) (err error) {
+	return
+}
+
 // sanityCheck checks if the block is a valid block
 func (con *Consensus) sanityCheck(blockConv types.BlockConverter) (err error) {
 	b := blockConv.Block()
diff --git a/core/crypto.go b/core/crypto.go
index 4fc49d7..17426f7 100644
--- a/core/crypto.go
+++ b/core/crypto.go
@@ -51,8 +51,8 @@ func verifyNotarySignature(pubkey crypto.PublicKey,
 
 func hashBlock(blockConv types.BlockConverter) (common.Hash, error) {
 	block := blockConv.Block()
-	binaryHeight := make([]byte, 8)
-	binary.LittleEndian.PutUint64(binaryHeight, block.Height)
+
+	hashPosition := hashPosition(block.ShardID, block.ChainID, block.Height)
 	// Handling Block.Acks.
 	acks := make(common.Hashes, 0, len(block.Acks))
 	for ack := range block.Acks {
@@ -85,7 +85,7 @@ func hashBlock(blockConv types.BlockConverter) (common.Hash, error) {
 	hash := crypto.Keccak256Hash(
 		block.ProposerID.Hash[:],
 		block.ParentHash[:],
-		binaryHeight,
+		hashPosition[:],
 		hashAcks[:],
 		hashTimestamps[:],
 		payloadHash[:])
@@ -100,3 +100,45 @@ func verifyBlockSignature(pubkey crypto.PublicKey,
 	}
 	return pubkey.VerifySignature(hash, sig), nil
 }
+
+func hashVote(vote *types.Vote) common.Hash {
+	binaryPeriod := make([]byte, 8)
+	binary.LittleEndian.PutUint64(binaryPeriod, vote.Period)
+
+	hash := crypto.Keccak256Hash(
+		vote.ProposerID.Hash[:],
+		vote.BlockHash[:],
+		binaryPeriod,
+		[]byte{byte(vote.Type)},
+	)
+	return hash
+}
+
+func verifyVoteSignature(vote *types.Vote, sigToPub SigToPubFn) (bool, error) {
+	hash := hashVote(vote)
+	pubKey, err := sigToPub(hash, vote.Signature)
+	if err != nil {
+		return false, err
+	}
+	if vote.ProposerID != types.NewValidatorID(pubKey) {
+		return false, nil
+	}
+	return true, nil
+}
+
+func hashPosition(shardID, chainID, height uint64) common.Hash {
+	binaryShardID := make([]byte, 8)
+	binary.LittleEndian.PutUint64(binaryShardID, shardID)
+
+	binaryChainID := make([]byte, 8)
+	binary.LittleEndian.PutUint64(binaryChainID, chainID)
+
+	binaryHeight := make([]byte, 8)
+	binary.LittleEndian.PutUint64(binaryHeight, height)
+
+	return crypto.Keccak256Hash(
+		binaryShardID,
+		binaryChainID,
+		binaryHeight,
+	)
+}
diff --git a/core/types/block.go b/core/types/block.go
index 557974f..92b0f8a 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -33,6 +33,8 @@ type Block struct {
 	ProposerID ValidatorID               `json:"proposer_id"`
 	ParentHash common.Hash               `json:"parent_hash"`
 	Hash       common.Hash               `json:"hash"`
+	ShardID    uint64                    `json:"shard_id"`
+	ChainID    uint64                    `json:"chain_id"`
 	Height     uint64                    `json:"height"`
 	Timestamps map[ValidatorID]time.Time `json:"timestamps"`
 	Acks       map[common.Hash]struct{}  `json:"acks"`
@@ -77,7 +79,7 @@ func (b *Block) Clone() *Block {
 		Height:     b.Height,
 		Timestamps: make(map[ValidatorID]time.Time),
 		Acks:       make(map[common.Hash]struct{}),
-		Signature:  b.Signature,
+		Signature:  b.Signature.Clone(),
 		Notary: Notary{
 			Timestamp: b.Notary.Timestamp,
 			Height:    b.Notary.Height,
diff --git a/core/types/vote.go b/core/types/vote.go
new file mode 100644
index 0000000..1247f84
--- /dev/null
+++ b/core/types/vote.go
@@ -0,0 +1,62 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core library is free software: you can redistribute it
+// and/or modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The dexon-consensus-core library is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package types
+
+import (
+	"fmt"
+
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/crypto"
+)
+
+// VoteType is the type of vote.
+type VoteType byte
+
+// VoteType enum.
+const (
+	VoteAck VoteType = iota
+	VoteConfirm
+	VotePass
+	// Do not add any type below MaxVoteType.
+	MaxVoteType
+)
+
+// Vote is the vote structure defined in Crypto Shuffle Algorithm.
+type Vote struct {
+	ProposerID ValidatorID
+	Type       VoteType
+	BlockHash  common.Hash
+	Period     uint64
+	Signature  crypto.Signature
+}
+
+func (v *Vote) String() string {
+	return fmt.Sprintf("Vote(%d:%d):%s",
+		v.Period, v.Type, v.BlockHash.String()[:6])
+}
+
+// Clone returns a deep copy of a vote.
+func (v *Vote) Clone() *Vote {
+	return &Vote{
+		ProposerID: v.ProposerID,
+		Type:       v.Type,
+		BlockHash:  v.BlockHash,
+		Period:     v.Period,
+		Signature:  v.Signature.Clone(),
+	}
+}
diff --git a/crypto/utils.go b/crypto/utils.go
index 5534ece..dfb4987 100644
--- a/crypto/utils.go
+++ b/crypto/utils.go
@@ -28,3 +28,8 @@ import (
 func Keccak256Hash(data ...[]byte) (h common.Hash) {
 	return common.Hash(crypto.Keccak256Hash(data...))
 }
+
+// Clone returns a deep copy of a signature.
+func (sig Signature) Clone() Signature {
+	return append(Signature{}, sig...)
+}
diff --git a/simulation/network.go b/simulation/network.go
index f08b638..687dd90 100644
--- a/simulation/network.go
+++ b/simulation/network.go
@@ -81,6 +81,7 @@ type Network interface {
 	Join(endpoint Endpoint) chan interface{}
 	BroadcastBlock(block *types.Block)
 	BroadcastNotaryAck(notaryAck *types.NotaryAck)
+	BroadcastVote(vote *types.Vote)
 	Endpoints() types.ValidatorIDs
 }
 
diff --git a/simulation/tcp-network.go b/simulation/tcp-network.go
index 2da9e3a..bb63bd1 100644
--- a/simulation/tcp-network.go
+++ b/simulation/tcp-network.go
@@ -257,6 +257,9 @@ func (n *TCPNetwork) Send(destID types.ValidatorID, msg interface{}) {
 	case *types.NotaryAck:
 		message.Type = "notaryAck"
 		message.Payload = v
+	case *types.Vote:
+		message.Type = "vote"
+		message.Payload = v
 	default:
 		fmt.Println("error: invalid message type")
 		return
@@ -318,6 +321,17 @@ func (n *TCPNetwork) BroadcastNotaryAck(notaryAck *types.NotaryAck) {
 	}
 }
 
+// BroadcastVote broadcast vote into the network.
+func (n *TCPNetwork) BroadcastVote(vote *types.Vote) {
+	vote = vote.Clone()
+	for endpoint := range n.endpoints {
+		if endpoint == vote.ProposerID {
+			continue
+		}
+		n.Send(endpoint, vote)
+	}
+}
+
 // DeliverBlocks sends blocks to peerServer.
 func (n *TCPNetwork) DeliverBlocks(blocks BlockList) {
 	messageJSON, err := json.Marshal(blocks)
diff --git a/simulation/validator.go b/simulation/validator.go
index fb5f6cd..b26603a 100644
--- a/simulation/validator.go
+++ b/simulation/validator.go
@@ -159,6 +159,10 @@ func (v *Validator) MsgServer(
 			if err := v.consensus.ProcessNotaryAck(val); err != nil {
 				fmt.Println(err)
 			}
+		case *types.Vote:
+			if err := v.consensus.ProcessVote(val); err != nil {
+				fmt.Println(err)
+			}
 		}
 	}
 }