crypto: Add crypto module. (#34)

1 files changed, 116 insertions, 0 deletions

diff --git a/core/crypto_test.go b/core/crypto_test.go
new file mode 100644
index 0000000..0ee28e4
--- /dev/null
+++ b/core/crypto_test.go
@@ -0,0 +1,116 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core 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-core 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-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"testing"
+	"time"
+
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+	"github.com/dexon-foundation/dexon-consensus-core/crypto"
+	"github.com/dexon-foundation/dexon-consensus-core/crypto/eth"
+	"github.com/stretchr/testify/suite"
+)
+
+type CryptoTestSuite struct {
+	suite.Suite
+}
+
+func (s *CryptoTestSuite) newBlock(prevBlock *types.Block) *types.Block {
+	if prevBlock == nil {
+		return &types.Block{
+			Hash: common.NewRandomHash(),
+			ConsensusInfo: types.ConsensusInfo{
+				Timestamp: time.Now(),
+				Height:    0,
+			},
+		}
+	}
+	parentHash, err := hashCompactionChainAck(prevBlock)
+	s.Require().Nil(err)
+	return &types.Block{
+		Hash: common.NewRandomHash(),
+		ConsensusInfoParentHash: parentHash,
+		CompactionChainAck: types.CompactionChainAck{
+			AckingBlockHash: prevBlock.Hash,
+		},
+		ConsensusInfo: types.ConsensusInfo{
+			Timestamp: time.Now(),
+			Height:    prevBlock.ConsensusInfo.Height + 1,
+		},
+	}
+}
+
+func (s *CryptoTestSuite) generateCompactionChain(
+	length int, prv crypto.PrivateKey) []*types.Block {
+	blocks := make([]*types.Block, length)
+	var prevBlock *types.Block
+	for idx := range blocks {
+		block := s.newBlock(prevBlock)
+		blocks[idx] = block
+		var err error
+		if idx > 0 {
+			block.ConsensusInfoParentHash, err = hashCompactionChainAck(blocks[idx-1])
+			s.Require().Nil(err)
+			block.CompactionChainAck.ConsensusSignature, err =
+				signCompactionChainAck(blocks[idx-1], prv)
+			s.Require().Nil(err)
+		}
+	}
+	return blocks
+}
+
+func (s *CryptoTestSuite) TestSignature() {
+	prv, err := eth.NewPrivateKey()
+	pub := prv.PublicKey()
+	s.Require().Nil(err)
+	blocks := s.generateCompactionChain(10, prv)
+	blockMap := make(map[common.Hash]*types.Block)
+	for _, block := range blocks {
+		blockMap[block.Hash] = block
+	}
+	for _, block := range blocks {
+		if block.ConsensusInfo.Height == 0 {
+			continue
+		}
+		ackingBlock, exist := blockMap[block.CompactionChainAck.AckingBlockHash]
+		s.Require().True(exist)
+		s.True(ackingBlock.ConsensusInfo.Height == block.ConsensusInfo.Height-1)
+		hash, err := hashCompactionChainAck(ackingBlock)
+		s.Require().Nil(err)
+		s.Equal(hash, block.ConsensusInfoParentHash)
+		s.True(verifyCompactionChainAckSignature(
+			pub, ackingBlock, block.CompactionChainAck.ConsensusSignature))
+	}
+	// Modify Block.ConsensusTime and verify signature again.
+	for _, block := range blocks {
+		block.ConsensusInfo.Timestamp = time.Time{}
+		if block.ConsensusInfo.Height == 0 {
+			continue
+		}
+		ackingBlock, exist := blockMap[block.CompactionChainAck.AckingBlockHash]
+		s.Require().True(exist)
+		s.False(verifyCompactionChainAckSignature(
+			pub, ackingBlock, block.CompactionChainAck.ConsensusSignature))
+	}
+}
+
+func TestCrypto(t *testing.T) {
+	suite.Run(t, new(CryptoTestSuite))
+}