1 files changed, 637 insertions, 0 deletions
diff --git a/vendor/github.com/tangerine-network/tangerine-consensus/core/crypto/dkg/dkg.go b/vendor/github.com/tangerine-network/tangerine-consensus/core/crypto/dkg/dkg.go
new file mode 100644
index 000000000..8011e18d3
--- /dev/null
+++ b/vendor/github.com/tangerine-network/tangerine-consensus/core/crypto/dkg/dkg.go
@@ -0,0 +1,637 @@
+// Copyright 2018 The dexon-consensus Authors
+// This file is part of the dexon-consensus library.
+//
+// The dexon-consensus 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 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 library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package dkg
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"sync"
+	"sync/atomic"
+
+	"github.com/tangerine-network/bls/ffi/go/bls"
+	"github.com/tangerine-network/go-tangerine/rlp"
+
+	"github.com/tangerine-network/tangerine-consensus/common"
+	"github.com/tangerine-network/tangerine-consensus/core/crypto"
+)
+
+var (
+	// ErrDuplicatedShare is reported when adding an private key share of same id.
+	ErrDuplicatedShare = fmt.Errorf("invalid share")
+	// ErrNoIDToRecover is reported when no id is provided for recovering private
+	// key.
+	ErrNoIDToRecover = fmt.Errorf("no id to recover private key")
+	// ErrShareNotFound is reported when the private key share of id is not found
+	// when recovering private key.
+	ErrShareNotFound = fmt.Errorf("share not found")
+)
+
+const cryptoType = "bls"
+
+var publicKeyLength int
+
+func init() {
+	if err := bls.Init(curve); err != nil {
+		panic(err)
+	}
+
+	pubKey := &bls.PublicKey{}
+	publicKeyLength = len(pubKey.Serialize())
+}
+
+// PrivateKey represents a private key structure implments
+// Crypto.PrivateKey interface.
+type PrivateKey struct {
+	privateKey bls.SecretKey
+	publicKey  PublicKey
+}
+
+// EncodeRLP implements rlp.Encoder
+func (prv *PrivateKey) EncodeRLP(w io.Writer) error {
+	return rlp.Encode(w, prv.Bytes())
+}
+
+// DecodeRLP implements rlp.Decoder
+func (prv *PrivateKey) DecodeRLP(s *rlp.Stream) error {
+	var b []byte
+	if err := s.Decode(&b); err != nil {
+		return err
+	}
+	return prv.SetBytes(b)
+}
+
+// MarshalJSON implements json.Marshaller.
+func (prv *PrivateKey) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&prv.privateKey)
+}
+
+// UnmarshalJSON implements json.Unmarshaller.
+func (prv *PrivateKey) UnmarshalJSON(data []byte) error {
+	return json.Unmarshal(data, &prv.privateKey)
+}
+
+// ID is the id for DKG protocol.
+type ID = bls.ID
+
+// IDs is an array of ID.
+type IDs []ID
+
+// PublicKey represents a public key structure implements
+// Crypto.PublicKey interface.
+type PublicKey struct {
+	publicKey bls.PublicKey
+}
+
+// PrivateKeyShares represents a private key shares for DKG protocol.
+type PrivateKeyShares struct {
+	shares           []PrivateKey
+	shareIndex       map[ID]int
+	masterPrivateKey []bls.SecretKey
+}
+
+// Equal check equality between two PrivateKeyShares instances.
+func (prvs *PrivateKeyShares) Equal(other *PrivateKeyShares) bool {
+	// Check shares.
+	if len(prvs.shareIndex) != len(other.shareIndex) {
+		return false
+	}
+	for dID, idx := range prvs.shareIndex {
+		otherIdx, exists := other.shareIndex[dID]
+		if !exists {
+			return false
+		}
+		if !prvs.shares[idx].privateKey.IsEqual(
+			&other.shares[otherIdx].privateKey) {
+			return false
+		}
+	}
+	// Check master private keys.
+	if len(prvs.masterPrivateKey) != len(other.masterPrivateKey) {
+		return false
+	}
+	for idx, m := range prvs.masterPrivateKey {
+		if m.GetHexString() != other.masterPrivateKey[idx].GetHexString() {
+			return false
+		}
+	}
+	return true
+}
+
+// EncodeRLP implements rlp.Encoder
+func (prvs *PrivateKeyShares) EncodeRLP(w io.Writer) error {
+	data := make([][][]byte, 3)
+	shares := make([][]byte, len(prvs.shares))
+	for i, s := range prvs.shares {
+		shares[i] = s.Bytes()
+	}
+	data[0] = shares
+
+	shareIndex := make([][]byte, 0)
+	for k, v := range prvs.shareIndex {
+		shareIndex = append(shareIndex, k.GetLittleEndian())
+
+		vBytes, err := rlp.EncodeToBytes(uint64(v))
+		if err != nil {
+			return err
+		}
+		shareIndex = append(shareIndex, vBytes)
+	}
+	data[1] = shareIndex
+
+	mpks := make([][]byte, len(prvs.masterPrivateKey))
+	for i, m := range prvs.masterPrivateKey {
+		mpks[i] = m.GetLittleEndian()
+	}
+	data[2] = mpks
+	return rlp.Encode(w, data)
+}
+
+// DecodeRLP implements rlp.Decoder
+func (prvs *PrivateKeyShares) DecodeRLP(s *rlp.Stream) error {
+	*prvs = PrivateKeyShares{}
+	var dec [][][]byte
+	if err := s.Decode(&dec); err != nil {
+		return err
+	}
+
+	var shares []PrivateKey
+	for _, bs := range dec[0] {
+		var key PrivateKey
+		err := key.SetBytes(bs)
+		if err != nil {
+			return err
+		}
+		shares = append(shares, key)
+	}
+	(*prvs).shares = shares
+
+	sharesIndex := map[ID]int{}
+	for i := 0; i < len(dec[1]); i += 2 {
+		var key ID
+		err := key.SetLittleEndian(dec[1][i])
+		if err != nil {
+			return err
+		}
+
+		var value uint64
+		err = rlp.DecodeBytes(dec[1][i+1], &value)
+		if err != nil {
+			return err
+		}
+
+		sharesIndex[key] = int(value)
+	}
+	(*prvs).shareIndex = sharesIndex
+
+	var mpks []bls.SecretKey
+	for _, bs := range dec[2] {
+		var key bls.SecretKey
+		if err := key.SetLittleEndian(bs); err != nil {
+			return err
+		}
+		mpks = append(mpks, key)
+	}
+	(*prvs).masterPrivateKey = mpks
+
+	return nil
+}
+
+type publicKeySharesCache struct {
+	share []PublicKey
+	index map[ID]int
+}
+
+// PublicKeyShares represents a public key shares for DKG protocol.
+type PublicKeyShares struct {
+	cache           atomic.Value
+	lock            sync.Mutex
+	masterPublicKey []bls.PublicKey
+}
+
+// Equal checks equality of two PublicKeyShares instance.
+func (pubs *PublicKeyShares) Equal(other *PublicKeyShares) bool {
+	cache := pubs.cache.Load().(*publicKeySharesCache)
+	cacheOther := other.cache.Load().(*publicKeySharesCache)
+	// Check shares.
+	for dID, idx := range cache.index {
+		otherIdx, exists := cacheOther.index[dID]
+		if !exists {
+			continue
+		}
+		if !cache.share[idx].publicKey.IsEqual(
+			&cacheOther.share[otherIdx].publicKey) {
+			return false
+		}
+	}
+	// Check master public keys.
+	if len(pubs.masterPublicKey) != len(other.masterPublicKey) {
+		return false
+	}
+	for idx, m := range pubs.masterPublicKey {
+		if m.GetHexString() != other.masterPublicKey[idx].GetHexString() {
+			return false
+		}
+	}
+	return true
+}
+
+// EncodeRLP implements rlp.Encoder
+func (pubs *PublicKeyShares) EncodeRLP(w io.Writer) error {
+	mpks := make([][]byte, len(pubs.masterPublicKey))
+	for i, m := range pubs.masterPublicKey {
+		mpks[i] = m.Serialize()
+	}
+	return rlp.Encode(w, mpks)
+}
+
+// DecodeRLP implements rlp.Decoder
+func (pubs *PublicKeyShares) DecodeRLP(s *rlp.Stream) error {
+	var dec [][]byte
+	if err := s.Decode(&dec); err != nil {
+		return err
+	}
+
+	ps := NewEmptyPublicKeyShares()
+	for _, k := range dec {
+		var key bls.PublicKey
+		if err := key.Deserialize(k); err != nil {
+			return err
+		}
+		ps.masterPublicKey = append(ps.masterPublicKey, key)
+	}
+
+	*pubs = *ps.Move()
+	return nil
+}
+
+// MarshalJSON implements json.Marshaller.
+func (pubs *PublicKeyShares) MarshalJSON() ([]byte, error) {
+	type Alias PublicKeyShares
+	data := &struct {
+		MasterPublicKeys []*bls.PublicKey `json:"master_public_keys"`
+	}{
+		make([]*bls.PublicKey, len(pubs.masterPublicKey)),
+	}
+	for i := range pubs.masterPublicKey {
+		data.MasterPublicKeys[i] = &pubs.masterPublicKey[i]
+	}
+	return json.Marshal(data)
+}
+
+// UnmarshalJSON implements json.Unmarshaller.
+func (pubs *PublicKeyShares) UnmarshalJSON(data []byte) error {
+	type Alias PublicKeyShares
+	aux := &struct {
+		MasterPublicKeys []*bls.PublicKey `json:"master_public_keys"`
+	}{}
+	if err := json.Unmarshal(data, &aux); err != nil {
+		return err
+	}
+	mpk := make([]bls.PublicKey, len(aux.MasterPublicKeys))
+	for i, pk := range aux.MasterPublicKeys {
+		mpk[i] = *pk
+	}
+	pubs.masterPublicKey = mpk
+	return nil
+}
+
+// Clone clones every fields of PublicKeyShares. This method is mainly
+// for testing purpose thus would panic when error.
+func (pubs *PublicKeyShares) Clone() *PublicKeyShares {
+	b, err := rlp.EncodeToBytes(pubs)
+	if err != nil {
+		panic(err)
+	}
+	pubsCopy := NewEmptyPublicKeyShares()
+	if err := rlp.DecodeBytes(b, pubsCopy); err != nil {
+		panic(err)
+	}
+	return pubsCopy
+}
+
+// NewID creates a ew ID structure.
+func NewID(id []byte) ID {
+	var blsID bls.ID
+	// #nosec G104
+	blsID.SetLittleEndian(id)
+	return blsID
+}
+
+// BytesID creates a new ID structure,
+// It returns err if the byte slice is not valid.
+func BytesID(id []byte) (ID, error) {
+	var blsID bls.ID
+	// #nosec G104
+	err := blsID.SetLittleEndian(id)
+	return blsID, err
+}
+
+// NewPrivateKey creates a new PrivateKey structure.
+func NewPrivateKey() *PrivateKey {
+	var key bls.SecretKey
+	key.SetByCSPRNG()
+	return &PrivateKey{
+		privateKey: key,
+		publicKey:  *newPublicKey(&key),
+	}
+}
+
+// NewPrivateKeyShares creates a DKG private key shares of threshold t.
+func NewPrivateKeyShares(t int) (*PrivateKeyShares, *PublicKeyShares) {
+	var prv bls.SecretKey
+	prv.SetByCSPRNG()
+	msk := prv.GetMasterSecretKey(t)
+	mpk := bls.GetMasterPublicKey(msk)
+	pubShare := NewEmptyPublicKeyShares()
+	pubShare.masterPublicKey = mpk
+	return &PrivateKeyShares{
+		masterPrivateKey: msk,
+		shareIndex:       make(map[ID]int),
+	}, pubShare
+}
+
+// NewEmptyPrivateKeyShares creates an empty private key shares.
+func NewEmptyPrivateKeyShares() *PrivateKeyShares {
+	return &PrivateKeyShares{
+		shareIndex: make(map[ID]int),
+	}
+}
+
+// SetParticipants sets the DKG participants.
+func (prvs *PrivateKeyShares) SetParticipants(IDs IDs) {
+	prvs.shares = make([]PrivateKey, len(IDs))
+	prvs.shareIndex = make(map[ID]int, len(IDs))
+	for idx, ID := range IDs {
+		// #nosec G104
+		prvs.shares[idx].privateKey.Set(prvs.masterPrivateKey, &ID)
+		prvs.shareIndex[ID] = idx
+	}
+}
+
+// AddShare adds a share.
+func (prvs *PrivateKeyShares) AddShare(ID ID, share *PrivateKey) error {
+	if idx, exist := prvs.shareIndex[ID]; exist {
+		if !share.privateKey.IsEqual(&prvs.shares[idx].privateKey) {
+			return ErrDuplicatedShare
+		}
+		return nil
+	}
+	prvs.shareIndex[ID] = len(prvs.shares)
+	prvs.shares = append(prvs.shares, *share)
+	return nil
+}
+
+// RecoverPrivateKey recovers private key from the shares.
+func (prvs *PrivateKeyShares) RecoverPrivateKey(qualifyIDs IDs) (
+	*PrivateKey, error) {
+	var prv PrivateKey
+	if len(qualifyIDs) == 0 {
+		return nil, ErrNoIDToRecover
+	}
+	for i, ID := range qualifyIDs {
+		idx, exist := prvs.shareIndex[ID]
+		if !exist {
+			return nil, ErrShareNotFound
+		}
+		if i == 0 {
+			prv.privateKey = prvs.shares[idx].privateKey
+			continue
+		}
+		prv.privateKey.Add(&prvs.shares[idx].privateKey)
+	}
+	return &prv, nil
+}
+
+// RecoverPublicKey recovers public key from the shares.
+func (prvs *PrivateKeyShares) RecoverPublicKey(qualifyIDs IDs) (
+	*PublicKey, error) {
+	var pub PublicKey
+	if len(qualifyIDs) == 0 {
+		return nil, ErrNoIDToRecover
+	}
+	for i, ID := range qualifyIDs {
+		idx, exist := prvs.shareIndex[ID]
+		if !exist {
+			return nil, ErrShareNotFound
+		}
+		if i == 0 {
+			pub.publicKey = *prvs.shares[idx].privateKey.GetPublicKey()
+			continue
+		}
+		pub.publicKey.Add(prvs.shares[idx].privateKey.GetPublicKey())
+	}
+	return &pub, nil
+}
+
+// Share returns the share for the ID.
+func (prvs *PrivateKeyShares) Share(ID ID) (*PrivateKey, bool) {
+	idx, exist := prvs.shareIndex[ID]
+	if !exist {
+		return nil, false
+	}
+	return &prvs.shares[idx], true
+}
+
+// NewEmptyPublicKeyShares creates an empty public key shares.
+func NewEmptyPublicKeyShares() *PublicKeyShares {
+	pubShares := &PublicKeyShares{}
+	pubShares.cache.Store(&publicKeySharesCache{
+		index: make(map[ID]int),
+	})
+	return pubShares
+}
+
+// Move will invalidate itself. Do not access to original reference.
+func (pubs *PublicKeyShares) Move() *PublicKeyShares {
+	return pubs
+}
+
+// Share returns the share for the ID.
+func (pubs *PublicKeyShares) Share(ID ID) (*PublicKey, error) {
+	cache := pubs.cache.Load().(*publicKeySharesCache)
+	idx, exist := cache.index[ID]
+	if exist {
+		return &cache.share[idx], nil
+	}
+	var pk PublicKey
+	if err := pk.publicKey.Set(pubs.masterPublicKey, &ID); err != nil {
+		return nil, err
+	}
+	if err := pubs.AddShare(ID, &pk); err != nil {
+		return nil, err
+	}
+	return &pk, nil
+}
+
+// AddShare adds a share.
+func (pubs *PublicKeyShares) AddShare(shareID ID, share *PublicKey) error {
+	cache := pubs.cache.Load().(*publicKeySharesCache)
+	if idx, exist := cache.index[shareID]; exist {
+		if !share.publicKey.IsEqual(&cache.share[idx].publicKey) {
+			return ErrDuplicatedShare
+		}
+		return nil
+	}
+	pubs.lock.Lock()
+	defer pubs.lock.Unlock()
+	cache = pubs.cache.Load().(*publicKeySharesCache)
+	newCache := &publicKeySharesCache{
+		index: make(map[ID]int, len(cache.index)+1),
+		share: make([]PublicKey, len(cache.share), len(cache.share)+1),
+	}
+	for k, v := range cache.index {
+		newCache.index[k] = v
+	}
+	copy(newCache.share, cache.share)
+	newCache.index[shareID] = len(newCache.share)
+	newCache.share = append(newCache.share, *share)
+	pubs.cache.Store(newCache)
+	return nil
+}
+
+// VerifyPrvShare verifies if the private key shares is valid.
+func (pubs *PublicKeyShares) VerifyPrvShare(ID ID, share *PrivateKey) (
+	bool, error) {
+	var pk bls.PublicKey
+	if err := pk.Set(pubs.masterPublicKey, &ID); err != nil {
+		return false, err
+	}
+	return pk.IsEqual(share.privateKey.GetPublicKey()), nil
+}
+
+// VerifyPubShare verifies if the public key shares is valid.
+func (pubs *PublicKeyShares) VerifyPubShare(ID ID, share *PublicKey) (
+	bool, error) {
+	var pk bls.PublicKey
+	if err := pk.Set(pubs.masterPublicKey, &ID); err != nil {
+		return false, err
+	}
+	return pk.IsEqual(&share.publicKey), nil
+}
+
+// RecoverPublicKey recovers private key from the shares.
+func (pubs *PublicKeyShares) RecoverPublicKey(qualifyIDs IDs) (
+	*PublicKey, error) {
+	var pub PublicKey
+	if len(qualifyIDs) == 0 {
+		return nil, ErrNoIDToRecover
+	}
+	for i, ID := range qualifyIDs {
+		pk, err := pubs.Share(ID)
+		if err != nil {
+			return nil, err
+		}
+		if i == 0 {
+			pub.publicKey = pk.publicKey
+			continue
+		}
+		pub.publicKey.Add(&pk.publicKey)
+	}
+	return &pub, nil
+}
+
+// MasterKeyBytes returns []byte representation of master public key.
+func (pubs *PublicKeyShares) MasterKeyBytes() []byte {
+	bytes := make([]byte, 0, len(pubs.masterPublicKey)*publicKeyLength)
+	for _, pk := range pubs.masterPublicKey {
+		bytes = append(bytes, pk.Serialize()...)
+	}
+	return bytes
+}
+
+// newPublicKey creates a new PublicKey structure.
+func newPublicKey(prvKey *bls.SecretKey) *PublicKey {
+	return &PublicKey{
+		publicKey: *prvKey.GetPublicKey(),
+	}
+}
+
+// newPublicKeyFromBytes create a new PublicKey structure
+// from bytes representation of bls.PublicKey
+func newPublicKeyFromBytes(b []byte) (*PublicKey, error) {
+	var pub PublicKey
+	err := pub.publicKey.Deserialize(b)
+	return &pub, err
+}
+
+// PublicKey returns the public key associate this private key.
+func (prv *PrivateKey) PublicKey() crypto.PublicKey {
+	return prv.publicKey
+}
+
+// Sign calculates a signature.
+func (prv *PrivateKey) Sign(hash common.Hash) (crypto.Signature, error) {
+	msg := string(hash[:])
+	sign := prv.privateKey.Sign(msg)
+	return crypto.Signature{
+		Type:      cryptoType,
+		Signature: sign.Serialize(),
+	}, nil
+}
+
+// Bytes returns []byte representation of private key.
+func (prv *PrivateKey) Bytes() []byte {
+	return prv.privateKey.GetLittleEndian()
+}
+
+// SetBytes sets the private key data to []byte.
+func (prv *PrivateKey) SetBytes(bytes []byte) error {
+	var key bls.SecretKey
+	if err := key.SetLittleEndian(bytes); err != nil {
+		return err
+	}
+	prv.privateKey = key
+	prv.publicKey = *newPublicKey(&prv.privateKey)
+	return nil
+}
+
+// String returns string representation of privat key.
+func (prv *PrivateKey) String() string {
+	return prv.privateKey.GetHexString()
+}
+
+// VerifySignature checks that the given public key created signature over hash.
+func (pub PublicKey) VerifySignature(
+	hash common.Hash, signature crypto.Signature) bool {
+	if len(signature.Signature) == 0 {
+		return false
+	}
+	var sig bls.Sign
+	if err := sig.Deserialize(signature.Signature[:]); err != nil {
+		fmt.Println(err)
+		return false
+	}
+	msg := string(hash[:])
+	return sig.Verify(&pub.publicKey, msg)
+}
+
+// Bytes returns []byte representation of public key.
+func (pub PublicKey) Bytes() []byte {
+	return pub.publicKey.Serialize()
+}
+
+// Serialize return bytes representation of public key.
+func (pub *PublicKey) Serialize() []byte {
+	return pub.publicKey.Serialize()
+}
+
+// Deserialize parses bytes representation of public key.
+func (pub *PublicKey) Deserialize(b []byte) error {
+	return pub.publicKey.Deserialize(b)
+}