[#19] alphabet: Add signature collection in Vote method

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

alphabet/alphabet.tpl

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = {{ .Index }}
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts * 2 / 3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,21 +145,31 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
-
 
 	return
 }
@@ -133,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/az/az_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 0
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/buky/buky_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 1
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/dobro/dobro_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 4
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/glagoli/glagoli_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 3
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/jest/jest_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 5
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/vedi/vedi_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 2
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}

alphabet/zhivete/zhivete_contract.go

@@ -1,16 +1,26 @@
 package alphabetcontract
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/binary"
+	"github.com/nspcc-dev/neo-go/pkg/interop/blockchain"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/interop/engine"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/interop/util"
 )
 
 type (
 	irNode struct {
 		key []byte
 	}
+
+	ballot struct {
+		id    []byte   // id of the voting decision
+		n     [][]byte // already voted inner ring nodes
+		block int      // block with the last vote
+	}
 )
 
 const (
@@ -24,6 +34,13 @@ const (
 	index = 6
 
 	netmapContractKey = "netmapScriptHash"
+
+	blockDiff = 20 // amount of blocks when ballot get discarded
+
+	threshold = totalAlphabetContracts*2/3 + 1
+	voteKey   = "ballots"
+
+	totalAlphabetContracts = 7
 )
 
 var (
@@ -49,6 +66,8 @@ func Init(addrNetmap []byte) {
 
 	storage.Put(ctx, netmapContractKey, addrNetmap)
 
+	setSerialized(ctx, voteKey, []ballot{})
+
 	runtime.Log(name + " contract initialized")
 }
 
@@ -81,6 +100,21 @@ func checkPermission(ir []irNode) bool {
 	return runtime.CheckWitness(node.key)
 }
 
+func innerRingInvoker(ir []irNode) []byte {
+	for i := 0; i < len(ir); i++ {
+		if i >= totalAlphabetContracts {
+			return nil
+		}
+
+		node := ir[i]
+		if runtime.CheckWitness(node.key) {
+			return node.key
+		}
+	}
+
+	return nil
+}
+
 func Emit() bool {
 	innerRingKeys := irList()
 	if !checkPermission(innerRingKeys) {
@@ -111,19 +145,30 @@ func Emit() bool {
 	return true
 }
 
-func Vote(candidate []byte) {
+func Vote(epoch int, candidates [][]byte) {
 	innerRingKeys := irList()
-	if !checkPermission(innerRingKeys) {
+
+	key := innerRingInvoker(innerRingKeys)
+	if len(key) == 0 {
 		panic("invalid invoker")
 	}
 
+	id := voteID(epoch, candidates)
+	n := vote(ctx, id, key)
+
+	if n >= threshold {
+		candidate := candidates[index%len(candidates)]
 		address := runtime.GetExecutingScriptHash()
 
 		ok := engine.AppCall([]byte(neoHash), "vote", address, candidate).(bool)
 		if ok {
-		runtime.Log("successfully voted for validator")
+			runtime.Log(name + ": successfully voted for validator")
+			removeVotes(ctx, id)
 		} else {
-		runtime.Log("vote has been failed")
+			runtime.Log(name + ": vote has been failed")
+		}
+	} else {
+		runtime.Log(name + ": saved vote for validator")
 	}
 
 	return
@@ -132,3 +177,97 @@ func Vote(candidate []byte) {
 func Name() string {
 	return name
 }
+
+func vote(ctx storage.Context, id, from []byte) int {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+		found         = -1
+		blockHeight   = blockchain.GetHeight()
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if bytesEqual(cnd.id, id) {
+			voters := cnd.n
+
+			for j := range voters {
+				if bytesEqual(voters[j], from) {
+					return len(voters)
+				}
+			}
+
+			voters = append(voters, from)
+			cnd = ballot{id: id, n: voters, block: blockHeight}
+			found = len(voters)
+		}
+
+		// do not add old ballots, they are invalid
+		if blockHeight-cnd.block <= blockDiff {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	if found < 0 {
+		voters := [][]byte{from}
+		newCandidates = append(newCandidates, ballot{
+			id:    id,
+			n:     voters,
+			block: blockHeight})
+		found = 1
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+
+	return found
+}
+
+func removeVotes(ctx storage.Context, id []byte) {
+	var (
+		newCandidates []ballot
+		candidates    = getBallots(ctx)
+	)
+
+	for i := 0; i < len(candidates); i++ {
+		cnd := candidates[i]
+		if !bytesEqual(cnd.id, id) {
+			newCandidates = append(newCandidates, cnd)
+		}
+	}
+
+	setSerialized(ctx, voteKey, newCandidates)
+}
+
+func getBallots(ctx storage.Context) []ballot {
+	data := storage.Get(ctx, voteKey)
+	if data != nil {
+		return binary.Deserialize(data.([]byte)).([]ballot)
+	}
+
+	return []ballot{}
+}
+
+func setSerialized(ctx storage.Context, key interface{}, value interface{}) {
+	data := binary.Serialize(value)
+	storage.Put(ctx, key, data)
+}
+
+// neo-go#1176
+func bytesEqual(a []byte, b []byte) bool {
+	return util.Equals(string(a), string(b))
+}
+
+func voteID(epoch interface{}, args [][]byte) []byte {
+	var (
+		result     []byte
+		epochBytes = epoch.([]byte)
+	)
+
+	result = append(result, epochBytes...)
+
+	for i := range args {
+		result = append(result, args[i]...)
+	}
+
+	return crypto.SHA256(result)
+}