From 815c07511247921a6436957c3c8be8463e2675c4 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sat, 11 Jul 2020 10:48:25 +0300
Subject: [PATCH 1/6] consensus: update dbft, use millisecond-precision time,
 add CV reason

---
 go.mod                                 |  2 +-
 go.sum                                 |  4 ++--
 pkg/consensus/change_view.go           | 19 ++++++++++++++-----
 pkg/consensus/change_view_test.go      |  4 ++--
 pkg/consensus/consensus_test.go        |  2 +-
 pkg/consensus/payload_test.go          |  6 +++---
 pkg/consensus/recovery_message.go      |  8 ++++----
 pkg/consensus/recovery_request.go      | 10 +++++-----
 pkg/consensus/recovery_request_test.go |  4 ++--
 9 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/go.mod b/go.mod
index de9fc5226..b6c004c6d 100644
--- a/go.mod
+++ b/go.mod
@@ -9,7 +9,7 @@ require (
 	github.com/go-yaml/yaml v2.1.0+incompatible
 	github.com/gorilla/websocket v1.4.2
 	github.com/mr-tron/base58 v1.1.2
-	github.com/nspcc-dev/dbft v0.0.0-20200623100921-5a182c20965e
+	github.com/nspcc-dev/dbft v0.0.0-20200711144034-c526ccc6f570
 	github.com/nspcc-dev/rfc6979 v0.2.0
 	github.com/pierrec/lz4 v2.5.2+incompatible
 	github.com/pkg/errors v0.8.1
diff --git a/go.sum b/go.sum
index 4950195d0..57963dec3 100644
--- a/go.sum
+++ b/go.sum
@@ -137,8 +137,8 @@ github.com/nspcc-dev/dbft v0.0.0-20200117124306-478e5cfbf03a h1:ajvxgEe9qY4vvoSm
 github.com/nspcc-dev/dbft v0.0.0-20200117124306-478e5cfbf03a/go.mod h1:/YFK+XOxxg0Bfm6P92lY5eDSLYfp06XOdL8KAVgXjVk=
 github.com/nspcc-dev/dbft v0.0.0-20200219114139-199d286ed6c1 h1:yEx9WznS+rjE0jl0dLujCxuZSIb+UTjF+005TJu/nNI=
 github.com/nspcc-dev/dbft v0.0.0-20200219114139-199d286ed6c1/go.mod h1:O0qtn62prQSqizzoagHmuuKoz8QMkU3SzBoKdEvm3aQ=
-github.com/nspcc-dev/dbft v0.0.0-20200623100921-5a182c20965e h1:QOT9slflIkEKb5wY0ZUC0dCmCgoqGlhOAh9+xWMIxfg=
-github.com/nspcc-dev/dbft v0.0.0-20200623100921-5a182c20965e/go.mod h1:1FYQXSbb6/9HQIkoF8XO7W/S8N7AZRkBsgwbcXRvk0E=
+github.com/nspcc-dev/dbft v0.0.0-20200711144034-c526ccc6f570 h1:EHBwlOyd2m06C3dnxhpPokpYqlNg7u5ZX/uPBhjYuZ4=
+github.com/nspcc-dev/dbft v0.0.0-20200711144034-c526ccc6f570/go.mod h1:1FYQXSbb6/9HQIkoF8XO7W/S8N7AZRkBsgwbcXRvk0E=
 github.com/nspcc-dev/neo-go v0.73.1-pre.0.20200303142215-f5a1b928ce09/go.mod h1:pPYwPZ2ks+uMnlRLUyXOpLieaDQSEaf4NM3zHVbRjmg=
 github.com/nspcc-dev/neofs-crypto v0.2.0 h1:ftN+59WqxSWz/RCgXYOfhmltOOqU+udsNQSvN6wkFck=
 github.com/nspcc-dev/neofs-crypto v0.2.0/go.mod h1:F/96fUzPM3wR+UGsPi3faVNmFlA9KAEAUQR7dMxZmNA=
diff --git a/pkg/consensus/change_view.go b/pkg/consensus/change_view.go
index 30ecf4eb0..a292619e9 100644
--- a/pkg/consensus/change_view.go
+++ b/pkg/consensus/change_view.go
@@ -8,19 +8,22 @@ import (
 // changeView represents dBFT ChangeView message.
 type changeView struct {
 	newViewNumber byte
-	timestamp     uint32
+	timestamp     uint64
+	reason        payload.ChangeViewReason
 }
 
 var _ payload.ChangeView = (*changeView)(nil)
 
 // EncodeBinary implements io.Serializable interface.
 func (c *changeView) EncodeBinary(w *io.BinWriter) {
-	w.WriteU32LE(c.timestamp)
+	w.WriteU64LE(c.timestamp)
+	w.WriteB(byte(c.reason))
 }
 
 // DecodeBinary implements io.Serializable interface.
 func (c *changeView) DecodeBinary(r *io.BinReader) {
-	c.timestamp = r.ReadU32LE()
+	c.timestamp = r.ReadU64LE()
+	c.reason = payload.ChangeViewReason(r.ReadB())
 }
 
 // NewViewNumber implements payload.ChangeView interface.
@@ -30,7 +33,13 @@ func (c changeView) NewViewNumber() byte { return c.newViewNumber }
 func (c *changeView) SetNewViewNumber(view byte) { c.newViewNumber = view }
 
 // Timestamp implements payload.ChangeView interface.
-func (c changeView) Timestamp() uint32 { return c.timestamp }
+func (c changeView) Timestamp() uint64 { return c.timestamp * 1000000 }
 
 // SetTimestamp implements payload.ChangeView interface.
-func (c *changeView) SetTimestamp(ts uint32) { c.timestamp = ts }
+func (c *changeView) SetTimestamp(ts uint64) { c.timestamp = ts / 1000000 }
+
+// Reason implements payload.ChangeView interface.
+func (c changeView) Reason() payload.ChangeViewReason { return c.reason }
+
+// SetReason implements payload.ChangeView interface.
+func (c *changeView) SetReason(reason payload.ChangeViewReason) { c.reason = reason }
diff --git a/pkg/consensus/change_view_test.go b/pkg/consensus/change_view_test.go
index 4d1142f39..70fd117ec 100644
--- a/pkg/consensus/change_view_test.go
+++ b/pkg/consensus/change_view_test.go
@@ -9,8 +9,8 @@ import (
 func TestChangeView_Setters(t *testing.T) {
 	var c changeView
 
-	c.SetTimestamp(123)
-	require.EqualValues(t, 123, c.Timestamp())
+	c.SetTimestamp(123 * 1000000)
+	require.EqualValues(t, 123*1000000, c.Timestamp())
 
 	c.SetNewViewNumber(2)
 	require.EqualValues(t, 2, c.NewViewNumber())
diff --git a/pkg/consensus/consensus_test.go b/pkg/consensus/consensus_test.go
index 902a31546..f6221894c 100644
--- a/pkg/consensus/consensus_test.go
+++ b/pkg/consensus/consensus_test.go
@@ -63,7 +63,7 @@ func TestService_GetVerified(t *testing.T) {
 			p.SetPayload(&prepareRequest{transactionHashes: hashes})
 		} else {
 			p.SetType(payload.ChangeViewType)
-			p.SetPayload(&changeView{newViewNumber: 1, timestamp: uint32(time.Now().Unix())})
+			p.SetPayload(&changeView{newViewNumber: 1, timestamp: uint64(time.Now().UnixNano() / 1000000)})
 		}
 		p.SetHeight(1)
 		p.SetValidatorIndex(uint16(i))
diff --git a/pkg/consensus/payload_test.go b/pkg/consensus/payload_test.go
index 45d44c6cc..6dc2b0985 100644
--- a/pkg/consensus/payload_test.go
+++ b/pkg/consensus/payload_test.go
@@ -224,7 +224,7 @@ func randomMessage(t *testing.T, mt messageType) io.Serializable {
 	switch mt {
 	case changeViewType:
 		return &changeView{
-			timestamp: rand.Uint32(),
+			timestamp: rand.Uint64(),
 		}
 	case prepareRequestType:
 		return randomPrepareRequest(t)
@@ -235,7 +235,7 @@ func randomMessage(t *testing.T, mt messageType) io.Serializable {
 		random.Fill(c.signature[:])
 		return &c
 	case recoveryRequestType:
-		return &recoveryRequest{timestamp: rand.Uint32()}
+		return &recoveryRequest{timestamp: rand.Uint64()}
 	case recoveryMessageType:
 		return randomRecoveryMessage(t)
 	default:
@@ -289,7 +289,7 @@ func randomRecoveryMessage(t *testing.T) *recoveryMessage {
 		},
 		changeViewPayloads: []*changeViewCompact{
 			{
-				Timestamp:          rand.Uint32(),
+				Timestamp:          rand.Uint64(),
 				ValidatorIndex:     3,
 				OriginalViewNumber: 3,
 				InvocationScript:   random.Bytes(4),
diff --git a/pkg/consensus/recovery_message.go b/pkg/consensus/recovery_message.go
index 8e894b884..a9ce3f569 100644
--- a/pkg/consensus/recovery_message.go
+++ b/pkg/consensus/recovery_message.go
@@ -21,7 +21,7 @@ type (
 	changeViewCompact struct {
 		ValidatorIndex     uint16
 		OriginalViewNumber byte
-		Timestamp          uint32
+		Timestamp          uint64
 		InvocationScript   []byte
 	}
 
@@ -95,7 +95,7 @@ func (m *recoveryMessage) EncodeBinary(w *io.BinWriter) {
 func (p *changeViewCompact) DecodeBinary(r *io.BinReader) {
 	p.ValidatorIndex = r.ReadU16LE()
 	p.OriginalViewNumber = r.ReadB()
-	p.Timestamp = r.ReadU32LE()
+	p.Timestamp = r.ReadU64LE()
 	p.InvocationScript = r.ReadVarBytes(1024)
 }
 
@@ -103,7 +103,7 @@ func (p *changeViewCompact) DecodeBinary(r *io.BinReader) {
 func (p *changeViewCompact) EncodeBinary(w *io.BinWriter) {
 	w.WriteU16LE(p.ValidatorIndex)
 	w.WriteB(p.OriginalViewNumber)
-	w.WriteU32LE(p.Timestamp)
+	w.WriteU64LE(p.Timestamp)
 	w.WriteVarBytes(p.InvocationScript)
 }
 
@@ -164,7 +164,7 @@ func (m *recoveryMessage) AddPayload(p payload.ConsensusPayload) {
 		m.changeViewPayloads = append(m.changeViewPayloads, &changeViewCompact{
 			ValidatorIndex:     p.ValidatorIndex(),
 			OriginalViewNumber: p.ViewNumber(),
-			Timestamp:          p.GetChangeView().Timestamp(),
+			Timestamp:          p.GetChangeView().Timestamp() / 1000000,
 			InvocationScript:   p.(*Payload).Witness.InvocationScript,
 		})
 	case payload.CommitType:
diff --git a/pkg/consensus/recovery_request.go b/pkg/consensus/recovery_request.go
index d40c6f9e4..630775b86 100644
--- a/pkg/consensus/recovery_request.go
+++ b/pkg/consensus/recovery_request.go
@@ -7,23 +7,23 @@ import (
 
 // recoveryRequest represents dBFT RecoveryRequest message.
 type recoveryRequest struct {
-	timestamp uint32
+	timestamp uint64
 }
 
 var _ payload.RecoveryRequest = (*recoveryRequest)(nil)
 
 // DecodeBinary implements io.Serializable interface.
 func (m *recoveryRequest) DecodeBinary(r *io.BinReader) {
-	m.timestamp = r.ReadU32LE()
+	m.timestamp = r.ReadU64LE()
 }
 
 // EncodeBinary implements io.Serializable interface.
 func (m *recoveryRequest) EncodeBinary(w *io.BinWriter) {
-	w.WriteU32LE(m.timestamp)
+	w.WriteU64LE(m.timestamp)
 }
 
 // Timestamp implements payload.RecoveryRequest interface.
-func (m *recoveryRequest) Timestamp() uint32 { return m.timestamp }
+func (m *recoveryRequest) Timestamp() uint64 { return m.timestamp * 1000000 }
 
 // SetTimestamp implements payload.RecoveryRequest interface.
-func (m *recoveryRequest) SetTimestamp(ts uint32) { m.timestamp = ts }
+func (m *recoveryRequest) SetTimestamp(ts uint64) { m.timestamp = ts / 1000000 }
diff --git a/pkg/consensus/recovery_request_test.go b/pkg/consensus/recovery_request_test.go
index e061711ff..8bae99aa6 100644
--- a/pkg/consensus/recovery_request_test.go
+++ b/pkg/consensus/recovery_request_test.go
@@ -9,6 +9,6 @@ import (
 func TestRecoveryRequest_Setters(t *testing.T) {
 	var r recoveryRequest
 
-	r.SetTimestamp(123)
-	require.EqualValues(t, 123, r.Timestamp())
+	r.SetTimestamp(123 * 1000000)
+	require.EqualValues(t, 123*1000000, r.Timestamp())
 }

From ae497228f06ef2ac466fd08ac7be0b2ef66853d0 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sat, 11 Jul 2020 12:29:06 +0300
Subject: [PATCH 2/6] core: use native NEO GetValidators for bc.GetValidators

NextBlockValidators are updated before the new block persist, so we need to
use GetValidators to get the list corresponding to the current state of the
chain.
---
 pkg/core/blockchain.go        |  2 +-
 pkg/core/native/native_neo.go | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index bbfa38219..7446799de 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -1242,7 +1242,7 @@ func (bc *Blockchain) GetStandByValidators() keys.PublicKeys {
 
 // GetValidators returns next block validators.
 func (bc *Blockchain) GetValidators() ([]*keys.PublicKey, error) {
-	return bc.contracts.NEO.GetNextBlockValidatorsInternal(bc, bc.dao)
+	return bc.contracts.NEO.GetValidatorsInternal(bc, bc.dao)
 }
 
 // GetEnrollments returns all registered validators.
diff --git a/pkg/core/native/native_neo.go b/pkg/core/native/native_neo.go
index 6d169eaa4..75930277e 100644
--- a/pkg/core/native/native_neo.go
+++ b/pkg/core/native/native_neo.go
@@ -142,7 +142,7 @@ func (n *NEO) Initialize(ic *interop.Context) error {
 
 // OnPersist implements Contract interface.
 func (n *NEO) OnPersist(ic *interop.Context) error {
-	pubs, err := n.getValidatorsInternal(ic.Chain, ic.DAO)
+	pubs, err := n.GetValidatorsInternal(ic.Chain, ic.DAO)
 	if err != nil {
 		return err
 	}
@@ -385,8 +385,8 @@ func (n *NEO) getRegisteredValidatorsCall(ic *interop.Context, _ []stackitem.Ite
 	return stackitem.NewArray(arr)
 }
 
-// getValidatorsInternal returns a list of current validators.
-func (n *NEO) getValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
+// GetValidatorsInternal returns a list of current validators.
+func (n *NEO) GetValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
 	if vals := n.validators.Load().(keys.PublicKeys); vals != nil {
 		return vals, nil
 	}
@@ -442,7 +442,7 @@ func (n *NEO) getValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (ke
 }
 
 func (n *NEO) getValidators(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
-	result, err := n.getValidatorsInternal(ic.Chain, ic.DAO)
+	result, err := n.GetValidatorsInternal(ic.Chain, ic.DAO)
 	if err != nil {
 		panic(err)
 	}
@@ -470,7 +470,7 @@ func (n *NEO) GetNextBlockValidatorsInternal(bc blockchainer.Blockchainer, d dao
 func (n *NEO) getNextBlockValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
 	si := d.GetStorageItem(n.ContractID, nextValidatorsKey)
 	if si == nil {
-		return n.getValidatorsInternal(bc, d)
+		return n.GetValidatorsInternal(bc, d)
 	}
 	pubs := keys.PublicKeys{}
 	err := pubs.DecodeBytes(si.Value)

From 2278cd5700e773974ad03d010d4ad3dc06daf49c Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sat, 11 Jul 2020 12:32:53 +0300
Subject: [PATCH 3/6] consensus: drop NextConsensus from the prepareRequest

Follow neo-project/neo#744 to make our requests compatible with C# node.
---
 pkg/consensus/consensus.go             | 22 ++++++++++++----------
 pkg/consensus/payload_test.go          |  1 -
 pkg/consensus/prepare_request.go       |  7 ++-----
 pkg/consensus/prepare_request_test.go  |  2 +-
 pkg/consensus/recovery_message_test.go |  1 -
 5 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/pkg/consensus/consensus.go b/pkg/consensus/consensus.go
index c0a74e666..7fee372c9 100644
--- a/pkg/consensus/consensus.go
+++ b/pkg/consensus/consensus.go
@@ -464,15 +464,8 @@ func (s *service) getValidators(_ ...block.Transaction) []crypto.PublicKey {
 	return pubs
 }
 
-func (s *service) getConsensusAddress(validators ...crypto.PublicKey) (h util.Uint160) {
-	pubs := convertKeys(validators)
-
-	script, err := smartcontract.CreateMultiSigRedeemScript(s.dbft.M(), pubs)
-	if err != nil {
-		return
-	}
-
-	return crypto.Hash160(script)
+func (s *service) getConsensusAddress(validators ...crypto.PublicKey) util.Uint160 {
+	return util.Uint160{}
 }
 
 func convertKeys(validators []crypto.PublicKey) (pubs []*keys.PublicKey) {
@@ -493,7 +486,16 @@ func (s *service) newBlockFromContext(ctx *dbft.Context) block.Block {
 	block.Block.Network = s.network
 	block.Block.Timestamp = ctx.Timestamp / 1000000
 	block.Block.Index = ctx.BlockIndex
-	block.Block.NextConsensus = ctx.NextConsensus
+
+	validators, err := s.Chain.GetValidators()
+	if err != nil {
+		return nil
+	}
+	script, err := smartcontract.CreateMultiSigRedeemScript(len(validators)-(len(validators)-1)/3, validators)
+	if err != nil {
+		return nil
+	}
+	block.Block.NextConsensus = crypto.Hash160(script)
 	block.Block.PrevHash = ctx.PrevHash
 	block.Block.Version = ctx.Version
 	block.Block.ConsensusData.Nonce = ctx.Nonce
diff --git a/pkg/consensus/payload_test.go b/pkg/consensus/payload_test.go
index 6dc2b0985..1cbe97a3b 100644
--- a/pkg/consensus/payload_test.go
+++ b/pkg/consensus/payload_test.go
@@ -256,7 +256,6 @@ func randomPrepareRequest(t *testing.T) *prepareRequest {
 	for i := 0; i < txCount; i++ {
 		req.transactionHashes[i] = random.Uint256()
 	}
-	req.nextConsensus = random.Uint160()
 
 	return req
 }
diff --git a/pkg/consensus/prepare_request.go b/pkg/consensus/prepare_request.go
index fb1d314f9..26be085ad 100644
--- a/pkg/consensus/prepare_request.go
+++ b/pkg/consensus/prepare_request.go
@@ -11,7 +11,6 @@ type prepareRequest struct {
 	timestamp         uint64
 	nonce             uint64
 	transactionHashes []util.Uint256
-	nextConsensus     util.Uint160
 }
 
 var _ payload.PrepareRequest = (*prepareRequest)(nil)
@@ -20,7 +19,6 @@ var _ payload.PrepareRequest = (*prepareRequest)(nil)
 func (p *prepareRequest) EncodeBinary(w *io.BinWriter) {
 	w.WriteU64LE(p.timestamp)
 	w.WriteU64LE(p.nonce)
-	w.WriteBytes(p.nextConsensus[:])
 	w.WriteArray(p.transactionHashes)
 }
 
@@ -28,7 +26,6 @@ func (p *prepareRequest) EncodeBinary(w *io.BinWriter) {
 func (p *prepareRequest) DecodeBinary(r *io.BinReader) {
 	p.timestamp = r.ReadU64LE()
 	p.nonce = r.ReadU64LE()
-	r.ReadBytes(p.nextConsensus[:])
 	r.ReadArray(&p.transactionHashes)
 }
 
@@ -51,7 +48,7 @@ func (p *prepareRequest) TransactionHashes() []util.Uint256 { return p.transacti
 func (p *prepareRequest) SetTransactionHashes(hs []util.Uint256) { p.transactionHashes = hs }
 
 // NextConsensus implements payload.PrepareRequest interface.
-func (p *prepareRequest) NextConsensus() util.Uint160 { return p.nextConsensus }
+func (p *prepareRequest) NextConsensus() util.Uint160 { return util.Uint160{} }
 
 // SetNextConsensus implements payload.PrepareRequest interface.
-func (p *prepareRequest) SetNextConsensus(nc util.Uint160) { p.nextConsensus = nc }
+func (p *prepareRequest) SetNextConsensus(_ util.Uint160) {}
diff --git a/pkg/consensus/prepare_request_test.go b/pkg/consensus/prepare_request_test.go
index 4b91e6cfb..188e32d97 100644
--- a/pkg/consensus/prepare_request_test.go
+++ b/pkg/consensus/prepare_request_test.go
@@ -20,7 +20,7 @@ func TestPrepareRequest_Setters(t *testing.T) {
 	require.EqualValues(t, 1000000, p.Timestamp())
 
 	p.SetNextConsensus(util.Uint160{5, 6, 7})
-	require.Equal(t, util.Uint160{5, 6, 7}, p.NextConsensus())
+	require.Equal(t, util.Uint160{}, p.NextConsensus())
 
 	p.SetNonce(8765)
 	require.EqualValues(t, 8765, p.Nonce())
diff --git a/pkg/consensus/recovery_message_test.go b/pkg/consensus/recovery_message_test.go
index 203edf45c..54544edb0 100644
--- a/pkg/consensus/recovery_message_test.go
+++ b/pkg/consensus/recovery_message_test.go
@@ -31,7 +31,6 @@ func TestRecoveryMessage_Setters(t *testing.T) {
 		timestamp:         87,
 		nonce:             321,
 		transactionHashes: []util.Uint256{{1}},
-		nextConsensus:     util.Uint160{1, 2},
 	}
 	p1 := new(Payload)
 	p1.message = &message{}

From 7eef8950612b37f83da2f3639d32fd61800a6670 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sat, 11 Jul 2020 13:10:57 +0300
Subject: [PATCH 4/6] consensus: use GetNextBlockValidators where appropriate

GetValidators without parameter is called upon DBFT initialization and it
should receive validators for the next block (that will create it),
parameterized GetValidators is used for NextConsensus calculation where we
need a list for the current state of the chain.
---
 pkg/consensus/consensus.go            | 8 ++++++--
 pkg/core/blockchain.go                | 7 ++++++-
 pkg/core/blockchainer/blockchainer.go | 1 +
 pkg/network/helper_test.go            | 3 +++
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/pkg/consensus/consensus.go b/pkg/consensus/consensus.go
index 7fee372c9..be9545cff 100644
--- a/pkg/consensus/consensus.go
+++ b/pkg/consensus/consensus.go
@@ -446,12 +446,16 @@ func (s *service) getVerifiedTx() []block.Transaction {
 	return res
 }
 
-func (s *service) getValidators(_ ...block.Transaction) []crypto.PublicKey {
+func (s *service) getValidators(txes ...block.Transaction) []crypto.PublicKey {
 	var (
 		pKeys []*keys.PublicKey
 		err   error
 	)
-	pKeys, err = s.Chain.GetValidators()
+	if txes == nil {
+		pKeys, err = s.Chain.GetNextBlockValidators()
+	} else {
+		pKeys, err = s.Chain.GetValidators()
+	}
 	if err != nil {
 		s.log.Error("error while trying to get validators", zap.Error(err))
 	}
diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 7446799de..a8646e571 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -1240,11 +1240,16 @@ func (bc *Blockchain) GetStandByValidators() keys.PublicKeys {
 	return bc.sbValidators.Copy()
 }
 
-// GetValidators returns next block validators.
+// GetValidators returns current validators.
 func (bc *Blockchain) GetValidators() ([]*keys.PublicKey, error) {
 	return bc.contracts.NEO.GetValidatorsInternal(bc, bc.dao)
 }
 
+// GetNextBlockValidators returns next block validators.
+func (bc *Blockchain) GetNextBlockValidators() ([]*keys.PublicKey, error) {
+	return bc.contracts.NEO.GetNextBlockValidatorsInternal(bc, bc.dao)
+}
+
 // GetEnrollments returns all registered validators.
 func (bc *Blockchain) GetEnrollments() ([]state.Validator, error) {
 	return bc.contracts.NEO.GetRegisteredValidators(bc.dao)
diff --git a/pkg/core/blockchainer/blockchainer.go b/pkg/core/blockchainer/blockchainer.go
index ce723614b..9dcac9e33 100644
--- a/pkg/core/blockchainer/blockchainer.go
+++ b/pkg/core/blockchainer/blockchainer.go
@@ -36,6 +36,7 @@ type Blockchainer interface {
 	HasTransaction(util.Uint256) bool
 	GetAccountState(util.Uint160) *state.Account
 	GetAppExecResult(util.Uint256) (*state.AppExecResult, error)
+	GetNextBlockValidators() ([]*keys.PublicKey, error)
 	GetNEP5TransferLog(util.Uint160) *state.NEP5TransferLog
 	GetNEP5Balances(util.Uint160) *state.NEP5Balances
 	GetValidators() ([]*keys.PublicKey, error)
diff --git a/pkg/network/helper_test.go b/pkg/network/helper_test.go
index cc7dbcb7c..6004c44a4 100644
--- a/pkg/network/helper_test.go
+++ b/pkg/network/helper_test.go
@@ -77,6 +77,9 @@ func (chain testChain) GetHeader(hash util.Uint256) (*block.Header, error) {
 func (chain testChain) GetAccountState(util.Uint160) *state.Account {
 	panic("TODO")
 }
+func (chain testChain) GetNextBlockValidators() ([]*keys.PublicKey, error) {
+	panic("TODO")
+}
 func (chain testChain) GetNEP5TransferLog(util.Uint160) *state.NEP5TransferLog {
 	panic("TODO")
 }

From 579630a3fa7e1c8ccfa86a04e0080458eb889c82 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sat, 11 Jul 2020 14:07:48 +0300
Subject: [PATCH 5/6] native: don't expose internal slices to the outside world

They should be hidden.
---
 pkg/core/native/native_neo.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkg/core/native/native_neo.go b/pkg/core/native/native_neo.go
index 75930277e..747025315 100644
--- a/pkg/core/native/native_neo.go
+++ b/pkg/core/native/native_neo.go
@@ -388,13 +388,13 @@ func (n *NEO) getRegisteredValidatorsCall(ic *interop.Context, _ []stackitem.Ite
 // GetValidatorsInternal returns a list of current validators.
 func (n *NEO) GetValidatorsInternal(bc blockchainer.Blockchainer, d dao.DAO) (keys.PublicKeys, error) {
 	if vals := n.validators.Load().(keys.PublicKeys); vals != nil {
-		return vals, nil
+		return vals.Copy(), nil
 	}
 	standByValidators := bc.GetStandByValidators()
 	si := d.GetStorageItem(n.ContractID, validatorsCountKey)
 	if si == nil {
 		n.validators.Store(standByValidators)
-		return standByValidators, nil
+		return standByValidators.Copy(), nil
 	}
 	validatorsCount, err := ValidatorsCountFromBytes(si.Value)
 	if err != nil {

From a43e374ac6282ada67d71d4090204d24ec921a76 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sat, 11 Jul 2020 15:22:14 +0300
Subject: [PATCH 6/6] consensus: replace magic 1000000 with something more
 meaningful

---
 pkg/consensus/block.go                 | 2 +-
 pkg/consensus/change_view.go           | 4 ++--
 pkg/consensus/change_view_test.go      | 4 ++--
 pkg/consensus/consensus.go             | 5 ++++-
 pkg/consensus/consensus_test.go        | 2 +-
 pkg/consensus/prepare_request.go       | 4 ++--
 pkg/consensus/recovery_message.go      | 2 +-
 pkg/consensus/recovery_request.go      | 4 ++--
 pkg/consensus/recovery_request_test.go | 4 ++--
 9 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/pkg/consensus/block.go b/pkg/consensus/block.go
index cc4a77f99..390846fc6 100644
--- a/pkg/consensus/block.go
+++ b/pkg/consensus/block.go
@@ -65,7 +65,7 @@ func (n *neoBlock) PrevHash() util.Uint256 { return n.Block.PrevHash }
 func (n *neoBlock) MerkleRoot() util.Uint256 { return n.Block.MerkleRoot }
 
 // Timestamp implements block.Block interface.
-func (n *neoBlock) Timestamp() uint64 { return n.Block.Timestamp * 1000000 }
+func (n *neoBlock) Timestamp() uint64 { return n.Block.Timestamp * nsInMs }
 
 // Index implements block.Block interface.
 func (n *neoBlock) Index() uint32 { return n.Block.Index }
diff --git a/pkg/consensus/change_view.go b/pkg/consensus/change_view.go
index a292619e9..fedc72c8e 100644
--- a/pkg/consensus/change_view.go
+++ b/pkg/consensus/change_view.go
@@ -33,10 +33,10 @@ func (c changeView) NewViewNumber() byte { return c.newViewNumber }
 func (c *changeView) SetNewViewNumber(view byte) { c.newViewNumber = view }
 
 // Timestamp implements payload.ChangeView interface.
-func (c changeView) Timestamp() uint64 { return c.timestamp * 1000000 }
+func (c changeView) Timestamp() uint64 { return c.timestamp * nsInMs }
 
 // SetTimestamp implements payload.ChangeView interface.
-func (c *changeView) SetTimestamp(ts uint64) { c.timestamp = ts / 1000000 }
+func (c *changeView) SetTimestamp(ts uint64) { c.timestamp = ts / nsInMs }
 
 // Reason implements payload.ChangeView interface.
 func (c changeView) Reason() payload.ChangeViewReason { return c.reason }
diff --git a/pkg/consensus/change_view_test.go b/pkg/consensus/change_view_test.go
index 70fd117ec..eaad6b2db 100644
--- a/pkg/consensus/change_view_test.go
+++ b/pkg/consensus/change_view_test.go
@@ -9,8 +9,8 @@ import (
 func TestChangeView_Setters(t *testing.T) {
 	var c changeView
 
-	c.SetTimestamp(123 * 1000000)
-	require.EqualValues(t, 123*1000000, c.Timestamp())
+	c.SetTimestamp(123 * nsInMs)
+	require.EqualValues(t, 123*nsInMs, c.Timestamp())
 
 	c.SetNewViewNumber(2)
 	require.EqualValues(t, 2, c.NewViewNumber())
diff --git a/pkg/consensus/consensus.go b/pkg/consensus/consensus.go
index be9545cff..921da8659 100644
--- a/pkg/consensus/consensus.go
+++ b/pkg/consensus/consensus.go
@@ -32,6 +32,9 @@ const cacheMaxCapacity = 100
 // defaultTimePerBlock is a period between blocks which is used in NEO.
 const defaultTimePerBlock = 15 * time.Second
 
+// Number of nanoseconds in millisecond.
+const nsInMs = 1000000
+
 // Service represents consensus instance.
 type Service interface {
 	// Start initializes dBFT and starts event loop for consensus service.
@@ -488,7 +491,7 @@ func (s *service) newBlockFromContext(ctx *dbft.Context) block.Block {
 	}
 
 	block.Block.Network = s.network
-	block.Block.Timestamp = ctx.Timestamp / 1000000
+	block.Block.Timestamp = ctx.Timestamp / nsInMs
 	block.Block.Index = ctx.BlockIndex
 
 	validators, err := s.Chain.GetValidators()
diff --git a/pkg/consensus/consensus_test.go b/pkg/consensus/consensus_test.go
index f6221894c..569c1acac 100644
--- a/pkg/consensus/consensus_test.go
+++ b/pkg/consensus/consensus_test.go
@@ -63,7 +63,7 @@ func TestService_GetVerified(t *testing.T) {
 			p.SetPayload(&prepareRequest{transactionHashes: hashes})
 		} else {
 			p.SetType(payload.ChangeViewType)
-			p.SetPayload(&changeView{newViewNumber: 1, timestamp: uint64(time.Now().UnixNano() / 1000000)})
+			p.SetPayload(&changeView{newViewNumber: 1, timestamp: uint64(time.Now().UnixNano() / nsInMs)})
 		}
 		p.SetHeight(1)
 		p.SetValidatorIndex(uint16(i))
diff --git a/pkg/consensus/prepare_request.go b/pkg/consensus/prepare_request.go
index 26be085ad..cded41ed2 100644
--- a/pkg/consensus/prepare_request.go
+++ b/pkg/consensus/prepare_request.go
@@ -30,10 +30,10 @@ func (p *prepareRequest) DecodeBinary(r *io.BinReader) {
 }
 
 // Timestamp implements payload.PrepareRequest interface.
-func (p *prepareRequest) Timestamp() uint64 { return p.timestamp * 1000000 }
+func (p *prepareRequest) Timestamp() uint64 { return p.timestamp * nsInMs }
 
 // SetTimestamp implements payload.PrepareRequest interface.
-func (p *prepareRequest) SetTimestamp(ts uint64) { p.timestamp = ts / 1000000 }
+func (p *prepareRequest) SetTimestamp(ts uint64) { p.timestamp = ts / nsInMs }
 
 // Nonce implements payload.PrepareRequest interface.
 func (p *prepareRequest) Nonce() uint64 { return p.nonce }
diff --git a/pkg/consensus/recovery_message.go b/pkg/consensus/recovery_message.go
index a9ce3f569..817e241e8 100644
--- a/pkg/consensus/recovery_message.go
+++ b/pkg/consensus/recovery_message.go
@@ -164,7 +164,7 @@ func (m *recoveryMessage) AddPayload(p payload.ConsensusPayload) {
 		m.changeViewPayloads = append(m.changeViewPayloads, &changeViewCompact{
 			ValidatorIndex:     p.ValidatorIndex(),
 			OriginalViewNumber: p.ViewNumber(),
-			Timestamp:          p.GetChangeView().Timestamp() / 1000000,
+			Timestamp:          p.GetChangeView().Timestamp() / nsInMs,
 			InvocationScript:   p.(*Payload).Witness.InvocationScript,
 		})
 	case payload.CommitType:
diff --git a/pkg/consensus/recovery_request.go b/pkg/consensus/recovery_request.go
index 630775b86..52e0fb269 100644
--- a/pkg/consensus/recovery_request.go
+++ b/pkg/consensus/recovery_request.go
@@ -23,7 +23,7 @@ func (m *recoveryRequest) EncodeBinary(w *io.BinWriter) {
 }
 
 // Timestamp implements payload.RecoveryRequest interface.
-func (m *recoveryRequest) Timestamp() uint64 { return m.timestamp * 1000000 }
+func (m *recoveryRequest) Timestamp() uint64 { return m.timestamp * nsInMs }
 
 // SetTimestamp implements payload.RecoveryRequest interface.
-func (m *recoveryRequest) SetTimestamp(ts uint64) { m.timestamp = ts / 1000000 }
+func (m *recoveryRequest) SetTimestamp(ts uint64) { m.timestamp = ts / nsInMs }
diff --git a/pkg/consensus/recovery_request_test.go b/pkg/consensus/recovery_request_test.go
index 8bae99aa6..adfc57c51 100644
--- a/pkg/consensus/recovery_request_test.go
+++ b/pkg/consensus/recovery_request_test.go
@@ -9,6 +9,6 @@ import (
 func TestRecoveryRequest_Setters(t *testing.T) {
 	var r recoveryRequest
 
-	r.SetTimestamp(123 * 1000000)
-	require.EqualValues(t, 123*1000000, r.Timestamp())
+	r.SetTimestamp(123 * nsInMs)
+	require.EqualValues(t, 123*nsInMs, r.Timestamp())
 }