// 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 core
import (
"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
}
func hashBlock(block *types.Block) (common.Hash, error) {
hashPosition := hashPosition(block.Position)
// Handling Block.Acks.
binaryAcks := make([][]byte, len(block.Acks))
for idx, ack := range block.Acks {
binaryAcks[idx] = ack[:]
}
hashAcks := crypto.Keccak256Hash(binaryAcks...)
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[:],
hashAcks[:],
binaryTimestamp[:],
block.PayloadHash[:],
binaryWitness[:])
return hash, nil
}
func verifyBlockSignature(pubkey crypto.PublicKey,
block *types.Block, sig crypto.Signature) (bool, error) {
hash, err := hashBlock(block)
if err != nil {
return false, err
}
return pubkey.VerifySignature(hash, sig), nil
}
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[:],
[]byte{byte(vote.Type)},
)
return hash
}
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)
return crypto.Keccak256Hash(crs[:], hashPos[:])
}
func verifyCRSSignature(block *types.Block, crs common.Hash) (
bool, error) {
hash := hashCRS(block, crs)
pubKey, err := crypto.SigToPub(hash, block.CRSSignature)
if err != nil {
return false, err
}
if block.ProposerID != types.NewNodeID(pubKey) {
return false, nil
}
return true, nil
}
func hashPosition(position types.Position) common.Hash {
binaryChainID := make([]byte, 4)
binary.LittleEndian.PutUint32(binaryChainID, position.ChainID)
binaryHeight := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryHeight, position.Height)
return crypto.Keccak256Hash(
binaryChainID,
binaryHeight,
)
}
func hashDKGPrivateShare(prvShare *typesDKG.PrivateShare) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, prvShare.Round)
return crypto.Keccak256Hash(
prvShare.ProposerID.Hash[:],
prvShare.ReceiverID.Hash[:],
binaryRound,
prvShare.PrivateShare.Bytes(),
)
}
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)
return crypto.Keccak256Hash(
mpk.ProposerID.Hash[:],
mpk.DKGID.GetLittleEndian(),
mpk.PublicKeyShares.MasterKeyBytes(),
binaryRound,
)
}
// 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)
hashPrvShare := hashDKGPrivateShare(&complaint.PrivateShare)
return crypto.Keccak256Hash(
complaint.ProposerID.Hash[:],
binaryRound,
hashPrvShare[:],
)
}
// VerifyDKGComplaintSignature verifies DKGCompliant signature.
func VerifyDKGComplaintSignature(
complaint *typesDKG.Complaint) (bool, error) {
if complaint.Round != complaint.PrivateShare.Round {
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[:],
)
}
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 hashDKGFinalize(final *typesDKG.Finalize) common.Hash {
binaryRound := make([]byte, 8)
binary.LittleEndian.PutUint64(binaryRound, final.Round)
return crypto.Keccak256Hash(
final.ProposerID.Hash[:],
binaryRound,
)
}
// 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
}
