// Copyright 2019 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum 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 go-ethereum 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 go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package checkpointoracle
import (
"bytes"
"crypto/ecdsa"
"encoding/binary"
"errors"
"math/big"
"reflect"
"sort"
"testing"
"time"
"github.com/ethereum/go-ethereum/accounts/abi/bind"
"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/contracts/checkpointoracle/contract"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/params"
)
var (
emptyHash = [32]byte{}
checkpoint0 = params.TrustedCheckpoint{
SectionIndex: 0,
SectionHead: common.HexToHash("0x7fa3c32f996c2bfb41a1a65b3d8ea3e0a33a1674cde43678ad6f4235e764d17d"),
CHTRoot: common.HexToHash("0x98fc5d3de23a0fecebad236f6655533c157d26a1aedcd0852a514dc1169e6350"),
BloomRoot: common.HexToHash("0x99b5adb52b337fe25e74c1c6d3835b896bd638611b3aebddb2317cce27a3f9fa"),
}
checkpoint1 = params.TrustedCheckpoint{
SectionIndex: 1,
SectionHead: common.HexToHash("0x2d4dee68102125e59b0cc61b176bd89f0d12b3b91cfaf52ef8c2c82fb920c2d2"),
CHTRoot: common.HexToHash("0x7d428008ece3b4c4ef5439f071930aad0bb75108d381308df73beadcd01ded95"),
BloomRoot: common.HexToHash("0x652571f7736de17e7bbb427ac881474da684c6988a88bf51b10cca9a2ee148f4"),
}
checkpoint2 = params.TrustedCheckpoint{
SectionIndex: 2,
SectionHead: common.HexToHash("0x61c0de578c0115b1dff8ef39aa600588c7c6ecb8a2f102003d7cf4c4146e9291"),
CHTRoot: common.HexToHash("0x407a08a407a2bc3838b74ca3eb206903c9c8a186ccf5ef14af07794efff1970b"),
BloomRoot: common.HexToHash("0x058b4161f558ce295a92925efc57f34f9210d5a30088d7475c183e0d3e58f5ac"),
}
)
var (
// The block frequency for creating checkpoint(only used in test)
sectionSize = big.NewInt(512)
// The number of confirmations needed to generate a checkpoint(only used in test).
processConfirms = big.NewInt(4)
)
// validateOperation executes the operation, watches and delivers all events fired by the backend and ensures the
// correctness by assert function.
func validateOperation(t *testing.T, c *contract.CheckpointOracle, backend *backends.SimulatedBackend, operation func(),
assert func(<-chan *contract.CheckpointOracleNewCheckpointVote) error, opName string) {
// Watch all events and deliver them to assert function
var (
sink = make(chan *contract.CheckpointOracleNewCheckpointVote)
sub, _ = c.WatchNewCheckpointVote(nil, sink, nil)
)
defer func() {
// Close all subscribers
sub.Unsubscribe()
}()
operation()
// flush pending block
backend.Commit()
if err := assert(sink); err != nil {
t.Errorf("operation {%s} failed, err %s", opName, err)
}
}
// validateEvents checks that the correct number of contract events
// fired by contract backend.
func validateEvents(target int, sink interface{}) (bool, []reflect.Value) {
chanval := reflect.ValueOf(sink)
chantyp := chanval.Type()
if chantyp.Kind() != reflect.Chan || chantyp.ChanDir()&reflect.RecvDir == 0 {
return false, nil
}
count := 0
var recv []reflect.Value
timeout := time.After(1 * time.Second)
cases := []reflect.SelectCase{{Chan: chanval, Dir: reflect.SelectRecv}, {Chan: reflect.ValueOf(timeout), Dir: reflect.SelectRecv}}
for {
chose, v, _ := reflect.Select(cases)
if chose == 1 {
// Not enough event received
return false, nil
}
count += 1
recv = append(recv, v)
if count == target {
break
}
}
done := time.After(50 * time.Millisecond)
cases = cases[:1]
cases = append(cases, reflect.SelectCase{Chan: reflect.ValueOf(done), Dir: reflect.SelectRecv})
chose, _, _ := reflect.Select(cases)
// If chose equal 0, it means receiving redundant events.
return chose == 1, recv
}
func signCheckpoint(addr common.Address, privateKey *ecdsa.PrivateKey, index uint64, hash common.Hash) []byte {
// EIP 191 style signatures
//
// Arguments when calculating hash to validate
// 1: byte(0x19) - the initial 0x19 byte
// 2: byte(0) - the version byte (data with intended validator)
// 3: this - the validator address
// -- Application specific data
// 4 : checkpoint section_index(uint64)
// 5 : checkpoint hash (bytes32)
// hash = keccak256(checkpoint_index, section_head, cht_root, bloom_root)
buf := make([]byte, 8)
binary.BigEndian.PutUint64(buf, index)
data := append([]byte{0x19, 0x00}, append(addr.Bytes(), append(buf, hash.Bytes()...)...)...)
sig, _ := crypto.Sign(crypto.Keccak256(data), privateKey)
sig[64] += 27 // Transform V from 0/1 to 27/28 according to the yellow paper
return sig
}
// assertSignature verifies whether the recovered signers are equal with expected.
func assertSignature(addr common.Address, index uint64, hash [32]byte, r, s [32]byte, v uint8, expect common.Address) bool {
buf := make([]byte, 8)
binary.BigEndian.PutUint64(buf, index)
data := append([]byte{0x19, 0x00}, append(addr.Bytes(), append(buf, hash[:]...)...)...)
pubkey, err := crypto.Ecrecover(crypto.Keccak256(data), append(r[:], append(s[:], v-27)...))
if err != nil {
return false
}
var signer common.Address
copy(signer[:], crypto.Keccak256(pubkey[1:])[12:])
return bytes.Equal(signer.Bytes(), expect.Bytes())
}
type Account struct {
key *ecdsa.PrivateKey
addr common.Address
}
type Accounts []Account
func (a Accounts) Len() int { return len(a) }
func (a Accounts) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a Accounts) Less(i, j int) bool { return bytes.Compare(a[i].addr.Bytes(), a[j].addr.Bytes()) < 0 }
func TestCheckpointRegister(t *testing.T) {
// Initialize test accounts
var accounts Accounts
for i := 0; i < 3; i++ {
key, _ := crypto.GenerateKey()
addr := crypto.PubkeyToAddress(key.PublicKey)
accounts = append(accounts, Account{key: key, addr: addr})
}
sort.Sort(accounts)
// Deploy registrar contract
contractBackend := backends.NewSimulatedBackend(core.GenesisAlloc{accounts[0].addr: {Balance: big.NewInt(1000000000)}, accounts[1].addr: {Balance: big.NewInt(1000000000)}, accounts[2].addr: {Balance: big.NewInt(1000000000)}}, 10000000)
defer contractBackend.Close()
transactOpts := bind.NewKeyedTransactor(accounts[0].key)
// 3 trusted signers, threshold 2
contractAddr, _, c, err := contract.DeployCheckpointOracle(transactOpts, contractBackend, []common.Address{accounts[0].addr, accounts[1].addr, accounts[2].addr}, sectionSize, processConfirms, big.NewInt(2))
if err != nil {
t.Error("Failed to deploy registrar contract", err)
}
contractBackend.Commit()
// getRecent returns block height and hash of the head parent.
getRecent := func() (*big.Int, common.Hash) {
parentNumber := new(big.Int).Sub(contractBackend.Blockchain().CurrentHeader().Number, big.NewInt(1))
parentHash := contractBackend.Blockchain().CurrentHeader().ParentHash
return parentNumber, parentHash
}
// collectSig generates specified number signatures.
collectSig := func(index uint64, hash common.Hash, n int, unauthorized *ecdsa.PrivateKey) (v []uint8, r [][32]byte, s [][32]byte) {
for i := 0; i < n; i++ {
sig := signCheckpoint(contractAddr, accounts[i].key, index, hash)
if unauthorized != nil {
sig = signCheckpoint(contractAddr, unauthorized, index, hash)
}
r = append(r, common.BytesToHash(sig[:32]))
s = append(s, common.BytesToHash(sig[32:64]))
v = append(v, sig[64])
}
return v, r, s
}
// insertEmptyBlocks inserts a batch of empty blocks to blockchain.
insertEmptyBlocks := func(number int) {
for i := 0; i < number; i++ {
contractBackend.Commit()
}
}
// assert checks whether the current contract status is same with
// the expected.
assert := func(index uint64, hash [32]byte, height *big.Int) error {
lindex, lhash, lheight, err := c.GetLatestCheckpoint(nil)
if err != nil {
return err
}
if lindex != index {
return errors.New("latest checkpoint index mismatch")
}
if !bytes.Equal(lhash[:], hash[:]) {
return errors.New("latest checkpoint hash mismatch")
}
if lheight.Cmp(height) != 0 {
return errors.New("latest checkpoint height mismatch")
}
return nil
}
// Test future checkpoint registration
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
v, r, s := collectSig(0, checkpoint0.Hash(), 2, nil)
c.SetCheckpoint(transactOpts, number, hash, checkpoint0.Hash(), 0, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
return assert(0, emptyHash, big.NewInt(0))
}, "test future checkpoint registration")
insertEmptyBlocks(int(sectionSize.Uint64() + processConfirms.Uint64()))
// Test transaction replay protection
validateOperation(t, c, contractBackend, func() {
number, _ := getRecent()
v, r, s := collectSig(0, checkpoint0.Hash(), 2, nil)
hash := common.HexToHash("deadbeef")
c.SetCheckpoint(transactOpts, number, hash, checkpoint0.Hash(), 0, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
return assert(0, emptyHash, big.NewInt(0))
}, "test transaction replay protection")
// Test unauthorized signature checking
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
u, _ := crypto.GenerateKey()
v, r, s := collectSig(0, checkpoint0.Hash(), 2, u)
c.SetCheckpoint(transactOpts, number, hash, checkpoint0.Hash(), 0, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
return assert(0, emptyHash, big.NewInt(0))
}, "test unauthorized signature checking")
// Test un-multi-signature checkpoint registration
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
v, r, s := collectSig(0, checkpoint0.Hash(), 1, nil)
c.SetCheckpoint(transactOpts, number, hash, checkpoint0.Hash(), 0, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
return assert(0, emptyHash, big.NewInt(0))
}, "test un-multi-signature checkpoint registration")
// Test valid checkpoint registration
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
v, r, s := collectSig(0, checkpoint0.Hash(), 2, nil)
c.SetCheckpoint(transactOpts, number, hash, checkpoint0.Hash(), 0, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
if valid, recv := validateEvents(2, events); !valid {
return errors.New("receive incorrect number of events")
} else {
for i := 0; i < len(recv); i++ {
event := recv[i].Interface().(*contract.CheckpointOracleNewCheckpointVote)
if !assertSignature(contractAddr, event.Index, event.CheckpointHash, event.R, event.S, event.V, accounts[i].addr) {
return errors.New("recover signer failed")
}
}
}
number, _ := getRecent()
return assert(0, checkpoint0.Hash(), number.Add(number, big.NewInt(1)))
}, "test valid checkpoint registration")
distance := 3*sectionSize.Uint64() + processConfirms.Uint64() - contractBackend.Blockchain().CurrentHeader().Number.Uint64()
insertEmptyBlocks(int(distance))
// Test uncontinuous checkpoint registration
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
v, r, s := collectSig(2, checkpoint2.Hash(), 2, nil)
c.SetCheckpoint(transactOpts, number, hash, checkpoint2.Hash(), 2, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
if valid, recv := validateEvents(2, events); !valid {
return errors.New("receive incorrect number of events")
} else {
for i := 0; i < len(recv); i++ {
event := recv[i].Interface().(*contract.CheckpointOracleNewCheckpointVote)
if !assertSignature(contractAddr, event.Index, event.CheckpointHash, event.R, event.S, event.V, accounts[i].addr) {
return errors.New("recover signer failed")
}
}
}
number, _ := getRecent()
return assert(2, checkpoint2.Hash(), number.Add(number, big.NewInt(1)))
}, "test uncontinuous checkpoint registration")
// Test old checkpoint registration
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
v, r, s := collectSig(1, checkpoint1.Hash(), 2, nil)
c.SetCheckpoint(transactOpts, number, hash, checkpoint1.Hash(), 1, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
number, _ := getRecent()
return assert(2, checkpoint2.Hash(), number)
}, "test uncontinuous checkpoint registration")
// Test stale checkpoint registration
validateOperation(t, c, contractBackend, func() {
number, hash := getRecent()
v, r, s := collectSig(2, checkpoint2.Hash(), 2, nil)
c.SetCheckpoint(transactOpts, number, hash, checkpoint2.Hash(), 2, v, r, s)
}, func(events <-chan *contract.CheckpointOracleNewCheckpointVote) error {
number, _ := getRecent()
return assert(2, checkpoint2.Hash(), number.Sub(number, big.NewInt(1)))
}, "test stale checkpoint registration")
}
