// 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 utils
import (
"bytes"
"encoding/binary"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/crypto"
"github.com/dexon-foundation/dexon-consensus/core/types"
typesDKG "github.com/dexon-foundation/dexon-consensus/core/types/dkg"
)
func hashWitness(witness *types.Witness) (common.Hash, error) {
binaryHeight := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryHeight, witness.Height)
return crypto.Keccak256Hash(
binaryHeight,
witness.Data), nil
}
// HashBlock generates hash of a types.Block.
func HashBlock(block *types.Block) (common.Hash, error) {
hashPosition := HashPosition(block.Position)
binaryTimestamp, err := block.Timestamp.UTC().MarshalBinary()
if err != nil {
return common.Hash{}, err
}
binaryWitness, err := hashWitness(&block.Witness)
if err != nil {
return common.Hash{}, err
}
hash := crypto.Keccak256Hash(
block.ProposerID.Hash[:],
block.ParentHash[:],
hashPosition[:],
binaryTimestamp[:],
block.PayloadHash[:],
binaryWitness[:])
return hash, nil
}
// VerifyBlockSignature verifies the signature of types.Block.
func VerifyBlockSignature(b *types.Block) (err error) {
payloadHash := crypto.Keccak256Hash(b.Payload)
if payloadHash != b.PayloadHash {
err = ErrIncorrectHash
return
}
return VerifyBlockSignatureWithoutPayload(b)
}
// VerifyBlockSignatureWithoutPayload verifies the signature of types.Block but
// does not check if PayloadHash is correct.
func VerifyBlockSignatureWithoutPayload(b *types.Block) (err error) {
hash, err := HashBlock(b)
if err != nil {
return
}
if hash != b.Hash {
err = ErrIncorrectHash
return
}
pubKey, err := crypto.SigToPub(b.Hash, b.Signature)
if err != nil {
return
}
if !b.ProposerID.Equal(types.NewNodeID(pubKey)) {
err = ErrIncorrectSignature
return
}
return
}
// HashVote generates hash of a types.Vote.
func HashVote(vote *types.Vote) common.Hash {
binaryPeriod := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryPeriod, vote.Period)
hashPosition := HashPosition(vote.Position)
hash := crypto.Keccak256Hash(
vote.ProposerID.Hash[:],
vote.BlockHash[:],
binaryPeriod,
hashPosition[:],
vote.PartialSignature.Signature[:],
[]byte{byte(vote.Type)},
)
return hash
}
// VerifyVoteSignature verifies the signature of types.Vote.
func VerifyVoteSignature(vote *types.Vote) (bool, error) {
hash := HashVote(vote)
pubKey, err := crypto.SigToPub(hash, vote.Signature)
if err != nil {
return false, err
}
if vote.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
func hashCRS(block *types.Block, crs common.Hash) common.Hash {
hashPos := HashPosition(block.Position)
if block.Position.Round < dkgDelayRound {
return crypto.Keccak256Hash(crs[:], hashPos[:], block.ProposerID.Hash[:])
}
return crypto.Keccak256Hash(crs[:], hashPos[:])
}
// VerifyCRSSignature verifies the CRS signature of types.Block.
func VerifyCRSSignature(
block *types.Block, crs common.Hash, npks *typesDKG.NodePublicKeys) bool {
hash := hashCRS(block, crs)
if block.Position.Round < dkgDelayRound {
return bytes.Compare(block.CRSSignature.Signature[:], hash[:]) == 0
}
if npks == nil {
return false
}
pubKey, exist := npks.PublicKeys[block.ProposerID]
if !exist {
return false
}
return pubKey.VerifySignature(hash, block.CRSSignature)
}
// HashPosition generates hash of a types.Position.
func HashPosition(position types.Position) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, position.Round)
binaryHeight := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryHeight, position.Height)
return crypto.Keccak256Hash(
binaryRound,
binaryHeight,
)
}
func hashDKGPrivateShare(prvShare *typesDKG.PrivateShare) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, prvShare.Round)
binaryReset := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryReset, prvShare.Reset)
return crypto.Keccak256Hash(
prvShare.ProposerID.Hash[:],
prvShare.ReceiverID.Hash[:],
binaryRound,
binaryReset,
prvShare.PrivateShare.Bytes(),
)
}
// VerifyDKGPrivateShareSignature verifies the signature of
// typesDKG.PrivateShare.
func VerifyDKGPrivateShareSignature(
prvShare *typesDKG.PrivateShare) (bool, error) {
hash := hashDKGPrivateShare(prvShare)
pubKey, err := crypto.SigToPub(hash, prvShare.Signature)
if err != nil {
return false, err
}
if prvShare.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
func hashDKGMasterPublicKey(mpk *typesDKG.MasterPublicKey) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, mpk.Round)
binaryReset := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryReset, mpk.Reset)
return crypto.Keccak256Hash(
mpk.ProposerID.Hash[:],
mpk.DKGID.GetLittleEndian(),
mpk.PublicKeyShares.MasterKeyBytes(),
binaryRound,
binaryReset,
)
}
// VerifyDKGMasterPublicKeySignature verifies DKGMasterPublicKey signature.
func VerifyDKGMasterPublicKeySignature(
mpk *typesDKG.MasterPublicKey) (bool, error) {
hash := hashDKGMasterPublicKey(mpk)
pubKey, err := crypto.SigToPub(hash, mpk.Signature)
if err != nil {
return false, err
}
if mpk.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
func hashDKGComplaint(complaint *typesDKG.Complaint) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, complaint.Round)
binaryReset := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryReset, complaint.Reset)
hashPrvShare := hashDKGPrivateShare(&complaint.PrivateShare)
return crypto.Keccak256Hash(
complaint.ProposerID.Hash[:],
binaryRound,
binaryReset,
hashPrvShare[:],
)
}
// VerifyDKGComplaintSignature verifies DKGCompliant signature.
func VerifyDKGComplaintSignature(
complaint *typesDKG.Complaint) (bool, error) {
if complaint.Round != complaint.PrivateShare.Round {
return false, nil
}
if complaint.Reset != complaint.PrivateShare.Reset {
return false, nil
}
hash := hashDKGComplaint(complaint)
pubKey, err := crypto.SigToPub(hash, complaint.Signature)
if err != nil {
return false, err
}
if complaint.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
if !complaint.IsNack() {
return VerifyDKGPrivateShareSignature(&complaint.PrivateShare)
}
return true, nil
}
func hashDKGPartialSignature(psig *typesDKG.PartialSignature) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, psig.Round)
return crypto.Keccak256Hash(
psig.ProposerID.Hash[:],
binaryRound,
psig.Hash[:],
psig.PartialSignature.Signature[:],
)
}
// VerifyDKGPartialSignatureSignature verifies the signature of
// typesDKG.PartialSignature.
func VerifyDKGPartialSignatureSignature(
psig *typesDKG.PartialSignature) (bool, error) {
hash := hashDKGPartialSignature(psig)
pubKey, err := crypto.SigToPub(hash, psig.Signature)
if err != nil {
return false, err
}
if psig.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
func hashDKGMPKReady(ready *typesDKG.MPKReady) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, ready.Round)
binaryReset := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryReset, ready.Reset)
return crypto.Keccak256Hash(
ready.ProposerID.Hash[:],
binaryRound,
binaryReset,
)
}
// VerifyDKGMPKReadySignature verifies DKGMPKReady signature.
func VerifyDKGMPKReadySignature(
ready *typesDKG.MPKReady) (bool, error) {
hash := hashDKGMPKReady(ready)
pubKey, err := crypto.SigToPub(hash, ready.Signature)
if err != nil {
return false, err
}
if ready.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
func hashDKGFinalize(final *typesDKG.Finalize) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, final.Round)
binaryReset := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryReset, final.Reset)
return crypto.Keccak256Hash(
final.ProposerID.Hash[:],
binaryRound,
binaryReset,
)
}
// VerifyDKGFinalizeSignature verifies DKGFinalize signature.
func VerifyDKGFinalizeSignature(
final *typesDKG.Finalize) (bool, error) {
hash := hashDKGFinalize(final)
pubKey, err := crypto.SigToPub(hash, final.Signature)
if err != nil {
return false, err
}
if final.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
// Rehash hashes the hash again and again and again...
func Rehash(hash common.Hash, count uint) common.Hash {
result := hash
for i := uint(0); i < count; i++ {
result = crypto.Keccak256Hash(result[:])
}
return result
}
