core: Block randomness generation. (#178)

4 files changed, 73 insertions, 7 deletions

diff --git a/core/agreement-state_test.go b/core/agreement-state_test.go
index b4619d6..2178b36 100644
--- a/core/agreement-state_test.go
+++ b/core/agreement-state_test.go
@@ -52,7 +52,8 @@ func (r *agreementStateTestReceiver) ProposeBlock() {
 	r.s.blockChan <- block.Hash
 }
 
-func (r *agreementStateTestReceiver) ConfirmBlock(block common.Hash) {
+func (r *agreementStateTestReceiver) ConfirmBlock(block common.Hash,
+	_ map[types.NodeID]*types.Vote) {
 	r.s.confirmChan <- block
 }
 
diff --git a/core/agreement.go b/core/agreement.go
index 9a673ad..aa1d1dc 100644
--- a/core/agreement.go
+++ b/core/agreement.go
@@ -67,7 +67,7 @@ func newVoteListMap() []map[types.NodeID]*types.Vote {
 type agreementReceiver interface {
 	ProposeVote(vote *types.Vote)
 	ProposeBlock()
-	ConfirmBlock(common.Hash)
+	ConfirmBlock(common.Hash, map[types.NodeID]*types.Vote)
 }
 
 type pendingBlock struct {
@@ -294,7 +294,8 @@ func (a *agreement) processVote(vote *types.Vote) error {
 			if len(a.data.votes[vote.Period][types.VoteConfirm]) >=
 				a.data.requiredVote {
 				a.hasOutput = true
-				a.data.recv.ConfirmBlock(vote.BlockHash)
+				a.data.recv.ConfirmBlock(vote.BlockHash,
+					a.data.votes[vote.Period][types.VoteConfirm])
 			}
 		}
 		return true
diff --git a/core/agreement_test.go b/core/agreement_test.go
index 5a14cda..db5bd42 100644
--- a/core/agreement_test.go
+++ b/core/agreement_test.go
@@ -41,7 +41,8 @@ func (r *agreementTestReceiver) ProposeBlock() {
 	r.s.blockChan <- block.Hash
 }
 
-func (r *agreementTestReceiver) ConfirmBlock(block common.Hash) {
+func (r *agreementTestReceiver) ConfirmBlock(block common.Hash,
+	_ map[types.NodeID]*types.Vote) {
 	r.s.confirmChan <- block
 }
 
diff --git a/core/consensus.go b/core/consensus.go
index c53d151..ae30619 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -50,6 +50,8 @@ var (
 		"not enought votes")
 	ErrIncorrectVoteProposer = fmt.Errorf(
 		"incorrect vote proposer")
+	ErrIncorrectBlockRandomnessResult = fmt.Errorf(
+		"incorrect block randomness result")
 )
 
 // consensusBAReceiver implements agreementReceiver.
@@ -59,6 +61,7 @@ type consensusBAReceiver struct {
 	agreementModule  *agreement
 	chainID          uint32
 	changeNotaryTime time.Time
+	round            uint64
 	restartNotary    chan bool
 }
 
@@ -86,17 +89,34 @@ func (recv *consensusBAReceiver) ProposeBlock() {
 	recv.consensus.network.BroadcastBlock(block)
 }
 
-func (recv *consensusBAReceiver) ConfirmBlock(hash common.Hash) {
-	block, exist := recv.consensus.baModules[recv.chainID].findCandidateBlock(hash)
+func (recv *consensusBAReceiver) ConfirmBlock(
+	hash common.Hash, votes map[types.NodeID]*types.Vote) {
+	block, exist := recv.consensus.baModules[recv.chainID].
+		findCandidateBlock(hash)
 	if !exist {
 		log.Println(ErrUnknownBlockConfirmed, hash)
 		return
 	}
+	voteList := make([]types.Vote, 0, len(votes))
+	for _, vote := range votes {
+		voteList = append(voteList, *vote)
+	}
+	recv.consensus.network.BroadcastRandomnessRequest(&types.AgreementResult{
+		BlockHash: hash,
+		Round:     recv.round,
+		Position:  block.Position,
+		Votes:     voteList,
+	})
 	if err := recv.consensus.processBlock(block); err != nil {
 		log.Println(err)
 		return
 	}
-	recv.restartNotary <- block.Timestamp.After(recv.changeNotaryTime)
+	if block.Timestamp.After(recv.changeNotaryTime) {
+		recv.round++
+		recv.restartNotary <- true
+	} else {
+		recv.restartNotary <- false
+	}
 }
 
 // consensusDKGReceiver implements dkgReceiver.
@@ -554,12 +574,55 @@ func (con *Consensus) ProcessAgreementResult(
 			return ErrIncorrectVoteSignature
 		}
 	}
+	psig, err := con.cfgModule.preparePartialSignature(rand.Round, rand.BlockHash)
+	if err != nil {
+		return err
+	}
+	if err = con.authModule.SignDKGPartialSignature(psig); err != nil {
+		return err
+	}
+	if err = con.cfgModule.processPartialSignature(psig); err != nil {
+		return err
+	}
+	con.network.BroadcastDKGPartialSignature(psig)
+	go func() {
+		tsig, err := con.cfgModule.runTSig(rand.Round, rand.BlockHash)
+		if err != nil {
+			if err != ErrTSigAlreadyRunning {
+				log.Println(err)
+			}
+			return
+		}
+		result := &types.BlockRandomnessResult{
+			BlockHash:  rand.BlockHash,
+			Round:      rand.Round,
+			Randomness: tsig.Signature,
+		}
+		if err := con.ProcessBlockRandomnessResult(result); err != nil {
+			log.Println(err)
+			return
+		}
+		con.network.BroadcastRandomnessResult(result)
+	}()
 	return nil
 }
 
 // ProcessBlockRandomnessResult processes the randomness result.
 func (con *Consensus) ProcessBlockRandomnessResult(
 	rand *types.BlockRandomnessResult) error {
+	// TODO(jimmy-dexon): reuse the GPK.
+	round := rand.Round
+	gpk, err := NewDKGGroupPublicKey(round,
+		con.gov.DKGMasterPublicKeys(round),
+		con.gov.DKGComplaints(round),
+		con.gov.Configuration(round).NumDKGSet/3)
+	if err != nil {
+		return err
+	}
+	if !gpk.VerifySignature(
+		rand.BlockHash, crypto.Signature{Signature: rand.Randomness}) {
+		return ErrIncorrectBlockRandomnessResult
+	}
 	return nil
 }