package consensus import ( "context" "fmt" "os" "path" "sync" "testing" "time" "github.com/stretchr/testify/assert" "github.com/stretchr/testify/require" dbm "github.com/tendermint/tm-db" abcicli "github.com/tendermint/tendermint/abci/client" abci "github.com/tendermint/tendermint/abci/types" "github.com/tendermint/tendermint/evidence" "github.com/tendermint/tendermint/libs/log" "github.com/tendermint/tendermint/libs/service" tmsync "github.com/tendermint/tendermint/libs/sync" mempl "github.com/tendermint/tendermint/mempool" "github.com/tendermint/tendermint/p2p" tmproto "github.com/tendermint/tendermint/proto/tendermint/types" sm "github.com/tendermint/tendermint/state" "github.com/tendermint/tendermint/store" "github.com/tendermint/tendermint/types" ) //---------------------------------------------- // byzantine failures // Byzantine node sends two different prevotes (nil and blockID) to the same validator func TestByzantinePrevoteEquivocation(t *testing.T) { const nValidators = 4 const byzantineNode = 0 const prevoteHeight = int64(2) testName := "consensus_byzantine_test" tickerFunc := newMockTickerFunc(true) appFunc := newCounter genDoc, privVals := randGenesisDoc(nValidators, false, 30) css := make([]*State, nValidators) for i := 0; i < nValidators; i++ { logger := consensusLogger().With("test", "byzantine", "validator", i) stateDB := dbm.NewMemDB() // each state needs its own db stateStore := sm.NewStore(stateDB) state, _ := stateStore.LoadFromDBOrGenesisDoc(genDoc) thisConfig := ResetConfig(fmt.Sprintf("%s_%d", testName, i)) defer os.RemoveAll(thisConfig.RootDir) ensureDir(path.Dir(thisConfig.Consensus.WalFile()), 0700) // dir for wal app := appFunc() vals := types.TM2PB.ValidatorUpdates(state.Validators) app.InitChain(abci.RequestInitChain{Validators: vals}) blockDB := dbm.NewMemDB() blockStore := store.NewBlockStore(blockDB) // one for mempool, one for consensus mtx := new(tmsync.Mutex) proxyAppConnMem := abcicli.NewLocalClient(mtx, app) proxyAppConnCon := abcicli.NewLocalClient(mtx, app) // Make Mempool mempool := mempl.NewCListMempool(thisConfig.Mempool, proxyAppConnMem, 0) mempool.SetLogger(log.TestingLogger().With("module", "mempool")) if thisConfig.Consensus.WaitForTxs() { mempool.EnableTxsAvailable() } // Make a full instance of the evidence pool evidenceDB := dbm.NewMemDB() evpool, err := evidence.NewPool(logger.With("module", "evidence"), evidenceDB, stateStore, blockStore) require.NoError(t, err) // Make State blockExec := sm.NewBlockExecutor(stateStore, log.TestingLogger(), proxyAppConnCon, mempool, evpool) cs := NewState(thisConfig.Consensus, state, blockExec, blockStore, mempool, evpool) cs.SetLogger(cs.Logger) // set private validator pv := privVals[i] cs.SetPrivValidator(pv) eventBus := types.NewEventBus() eventBus.SetLogger(log.TestingLogger().With("module", "events")) err = eventBus.Start() require.NoError(t, err) cs.SetEventBus(eventBus) cs.SetTimeoutTicker(tickerFunc()) cs.SetLogger(logger) css[i] = cs } // initialize the reactors for each of the validators reactors := make([]*Reactor, nValidators) blocksSubs := make([]types.Subscription, 0) eventBuses := make([]*types.EventBus, nValidators) for i := 0; i < nValidators; i++ { reactors[i] = NewReactor(css[i], true) // so we dont start the consensus states reactors[i].SetLogger(css[i].Logger) // eventBus is already started with the cs eventBuses[i] = css[i].eventBus reactors[i].SetEventBus(eventBuses[i]) blocksSub, err := eventBuses[i].Subscribe(context.Background(), testSubscriber, types.EventQueryNewBlock, 100) require.NoError(t, err) blocksSubs = append(blocksSubs, blocksSub) if css[i].state.LastBlockHeight == 0 { // simulate handle initChain in handshake err = css[i].blockExec.Store().Save(css[i].state) require.NoError(t, err) } } // make connected switches and start all reactors p2p.MakeConnectedSwitches(config.P2P, nValidators, func(i int, s *p2p.Switch) *p2p.Switch { s.AddReactor("CONSENSUS", reactors[i]) s.SetLogger(reactors[i].conS.Logger.With("module", "p2p")) return s }, p2p.Connect2Switches) // create byzantine validator bcs := css[byzantineNode] // alter prevote so that the byzantine node double votes when height is 2 bcs.doPrevote = func(height int64, round int32) { // allow first height to happen normally so that byzantine validator is no longer proposer if height == prevoteHeight { bcs.Logger.Info("Sending two votes") prevote1, err := bcs.signVote(tmproto.PrevoteType, bcs.ProposalBlock.Hash(), bcs.ProposalBlockParts.Header()) require.NoError(t, err) prevote2, err := bcs.signVote(tmproto.PrevoteType, nil, types.PartSetHeader{}) require.NoError(t, err) peerList := reactors[byzantineNode].Switch.Peers().List() bcs.Logger.Info("Getting peer list", "peers", peerList) // send two votes to all peers (1st to one half, 2nd to another half) for i, peer := range peerList { if i < len(peerList)/2 { bcs.Logger.Info("Signed and pushed vote", "vote", prevote1, "peer", peer) peer.Send(VoteChannel, MustEncode(&VoteMessage{prevote1})) } else { bcs.Logger.Info("Signed and pushed vote", "vote", prevote2, "peer", peer) peer.Send(VoteChannel, MustEncode(&VoteMessage{prevote2})) } } } else { bcs.Logger.Info("Behaving normally") bcs.defaultDoPrevote(height, round) } } // introducing a lazy proposer means that the time of the block committed is different to the // timestamp that the other nodes have. This tests to ensure that the evidence that finally gets // proposed will have a valid timestamp lazyProposer := css[1] lazyProposer.decideProposal = func(height int64, round int32) { lazyProposer.Logger.Info("Lazy Proposer proposing condensed commit") if lazyProposer.privValidator == nil { panic("entered createProposalBlock with privValidator being nil") } var commit *types.Commit switch { case lazyProposer.Height == lazyProposer.state.InitialHeight: // We're creating a proposal for the first block. // The commit is empty, but not nil. commit = types.NewCommit(0, 0, types.BlockID{}, nil) case lazyProposer.LastCommit.HasTwoThirdsMajority(): // Make the commit from LastCommit commit = lazyProposer.LastCommit.MakeCommit() default: // This shouldn't happen. lazyProposer.Logger.Error("enterPropose: Cannot propose anything: No commit for the previous block") return } // omit the last signature in the commit commit.Signatures[len(commit.Signatures)-1] = types.NewCommitSigAbsent() if lazyProposer.privValidatorPubKey == nil { // If this node is a validator & proposer in the current round, it will // miss the opportunity to create a block. lazyProposer.Logger.Error(fmt.Sprintf("enterPropose: %v", errPubKeyIsNotSet)) return } proposerAddr := lazyProposer.privValidatorPubKey.Address() block, blockParts := lazyProposer.blockExec.CreateProposalBlock( lazyProposer.Height, lazyProposer.state, commit, proposerAddr, ) // Flush the WAL. Otherwise, we may not recompute the same proposal to sign, // and the privValidator will refuse to sign anything. if err := lazyProposer.wal.FlushAndSync(); err != nil { lazyProposer.Logger.Error("Error flushing to disk") } // Make proposal propBlockID := types.BlockID{Hash: block.Hash(), PartSetHeader: blockParts.Header()} proposal := types.NewProposal(height, round, lazyProposer.ValidRound, propBlockID) p := proposal.ToProto() if err := lazyProposer.privValidator.SignProposal(lazyProposer.state.ChainID, p); err == nil { proposal.Signature = p.Signature // send proposal and block parts on internal msg queue lazyProposer.sendInternalMessage(msgInfo{&ProposalMessage{proposal}, ""}) for i := 0; i < int(blockParts.Total()); i++ { part := blockParts.GetPart(i) lazyProposer.sendInternalMessage(msgInfo{&BlockPartMessage{lazyProposer.Height, lazyProposer.Round, part}, ""}) } lazyProposer.Logger.Info("Signed proposal", "height", height, "round", round, "proposal", proposal) lazyProposer.Logger.Debug(fmt.Sprintf("Signed proposal block: %v", block)) } else if !lazyProposer.replayMode { lazyProposer.Logger.Error("enterPropose: Error signing proposal", "height", height, "round", round, "err", err) } } // start the consensus reactors for i := 0; i < nValidators; i++ { s := reactors[i].conS.GetState() reactors[i].SwitchToConsensus(s, false) } defer stopConsensusNet(log.TestingLogger(), reactors, eventBuses) // Evidence should be submitted and committed at the third height but // we will check the first six just in case evidenceFromEachValidator := make([]types.Evidence, nValidators) wg := new(sync.WaitGroup) for i := 0; i < nValidators; i++ { wg.Add(1) go func(i int) { defer wg.Done() for msg := range blocksSubs[i].Out() { block := msg.Data().(types.EventDataNewBlock).Block if len(block.Evidence.Evidence) != 0 { evidenceFromEachValidator[i] = block.Evidence.Evidence[0] return } } }(i) } done := make(chan struct{}) go func() { wg.Wait() close(done) }() pubkey, err := bcs.privValidator.GetPubKey() require.NoError(t, err) select { case <-done: for idx, ev := range evidenceFromEachValidator { if assert.NotNil(t, ev, idx) { ev, ok := ev.(*types.DuplicateVoteEvidence) assert.True(t, ok) assert.Equal(t, pubkey.Address(), ev.VoteA.ValidatorAddress) assert.Equal(t, prevoteHeight, ev.Height()) } } case <-time.After(20 * time.Second): for i, reactor := range reactors { t.Logf("Consensus Reactor %d\n%v", i, reactor) } t.Fatalf("Timed out waiting for validators to commit evidence") } } // 4 validators. 1 is byzantine. The other three are partitioned into A (1 val) and B (2 vals). // byzantine validator sends conflicting proposals into A and B, // and prevotes/precommits on both of them. // B sees a commit, A doesn't. // Heal partition and ensure A sees the commit func TestByzantineConflictingProposalsWithPartition(t *testing.T) { N := 4 logger := consensusLogger().With("test", "byzantine") app := newCounter css, cleanup := randConsensusNet(N, "consensus_byzantine_test", newMockTickerFunc(false), app) defer cleanup() // give the byzantine validator a normal ticker ticker := NewTimeoutTicker() ticker.SetLogger(css[0].Logger) css[0].SetTimeoutTicker(ticker) p2pLogger := logger.With("module", "p2p") blocksSubs := make([]types.Subscription, N) reactors := make([]p2p.Reactor, N) for i := 0; i < N; i++ { // enable txs so we can create different proposals assertMempool(css[i].txNotifier).EnableTxsAvailable() eventBus := css[i].eventBus eventBus.SetLogger(logger.With("module", "events", "validator", i)) var err error blocksSubs[i], err = eventBus.Subscribe(context.Background(), testSubscriber, types.EventQueryNewBlock) require.NoError(t, err) conR := NewReactor(css[i], true) // so we don't start the consensus states conR.SetLogger(logger.With("validator", i)) conR.SetEventBus(eventBus) var conRI p2p.Reactor = conR // make first val byzantine if i == 0 { conRI = NewByzantineReactor(conR) } reactors[i] = conRI err = css[i].blockExec.Store().Save(css[i].state) // for save height 1's validators info require.NoError(t, err) } switches := p2p.MakeConnectedSwitches(config.P2P, N, func(i int, sw *p2p.Switch) *p2p.Switch { sw.SetLogger(p2pLogger.With("validator", i)) sw.AddReactor("CONSENSUS", reactors[i]) return sw }, func(sws []*p2p.Switch, i, j int) { // the network starts partitioned with globally active adversary if i != 0 { return } p2p.Connect2Switches(sws, i, j) }) // make first val byzantine // NOTE: Now, test validators are MockPV, which by default doesn't // do any safety checks. css[0].privValidator.(types.MockPV).DisableChecks() css[0].decideProposal = func(j int32) func(int64, int32) { return func(height int64, round int32) { byzantineDecideProposalFunc(t, height, round, css[j], switches[j]) } }(int32(0)) // We are setting the prevote function to do nothing because the prevoting // and precommitting are done alongside the proposal. css[0].doPrevote = func(height int64, round int32) {} defer func() { for _, sw := range switches { err := sw.Stop() require.NoError(t, err) } }() // start the non-byz state machines. // note these must be started before the byz for i := 1; i < N; i++ { cr := reactors[i].(*Reactor) cr.SwitchToConsensus(cr.conS.GetState(), false) } // start the byzantine state machine byzR := reactors[0].(*ByzantineReactor) s := byzR.reactor.conS.GetState() byzR.reactor.SwitchToConsensus(s, false) // byz proposer sends one block to peers[0] // and the other block to peers[1] and peers[2]. // note peers and switches order don't match. peers := switches[0].Peers().List() // partition A ind0 := getSwitchIndex(switches, peers[0]) // partition B ind1 := getSwitchIndex(switches, peers[1]) ind2 := getSwitchIndex(switches, peers[2]) p2p.Connect2Switches(switches, ind1, ind2) // wait for someone in the big partition (B) to make a block <-blocksSubs[ind2].Out() t.Log("A block has been committed. Healing partition") p2p.Connect2Switches(switches, ind0, ind1) p2p.Connect2Switches(switches, ind0, ind2) // wait till everyone makes the first new block // (one of them already has) wg := new(sync.WaitGroup) for i := 1; i < N-1; i++ { wg.Add(1) go func(j int) { <-blocksSubs[j].Out() wg.Done() }(i) } done := make(chan struct{}) go func() { wg.Wait() close(done) }() tick := time.NewTicker(time.Second * 10) select { case <-done: case <-tick.C: for i, reactor := range reactors { t.Log(fmt.Sprintf("Consensus Reactor %v", i)) t.Log(fmt.Sprintf("%v", reactor)) } t.Fatalf("Timed out waiting for all validators to commit first block") } } //------------------------------- // byzantine consensus functions func byzantineDecideProposalFunc(t *testing.T, height int64, round int32, cs *State, sw *p2p.Switch) { // byzantine user should create two proposals and try to split the vote. // Avoid sending on internalMsgQueue and running consensus state. // Create a new proposal block from state/txs from the mempool. block1, blockParts1 := cs.createProposalBlock() polRound, propBlockID := cs.ValidRound, types.BlockID{Hash: block1.Hash(), PartSetHeader: blockParts1.Header()} proposal1 := types.NewProposal(height, round, polRound, propBlockID) p1 := proposal1.ToProto() if err := cs.privValidator.SignProposal(cs.state.ChainID, p1); err != nil { t.Error(err) } proposal1.Signature = p1.Signature // some new transactions come in (this ensures that the proposals are different) deliverTxsRange(cs, 0, 1) // Create a new proposal block from state/txs from the mempool. block2, blockParts2 := cs.createProposalBlock() polRound, propBlockID = cs.ValidRound, types.BlockID{Hash: block2.Hash(), PartSetHeader: blockParts2.Header()} proposal2 := types.NewProposal(height, round, polRound, propBlockID) p2 := proposal2.ToProto() if err := cs.privValidator.SignProposal(cs.state.ChainID, p2); err != nil { t.Error(err) } proposal2.Signature = p2.Signature block1Hash := block1.Hash() block2Hash := block2.Hash() // broadcast conflicting proposals/block parts to peers peers := sw.Peers().List() t.Logf("Byzantine: broadcasting conflicting proposals to %d peers", len(peers)) for i, peer := range peers { if i < len(peers)/2 { go sendProposalAndParts(height, round, cs, peer, proposal1, block1Hash, blockParts1) } else { go sendProposalAndParts(height, round, cs, peer, proposal2, block2Hash, blockParts2) } } } func sendProposalAndParts( height int64, round int32, cs *State, peer p2p.Peer, proposal *types.Proposal, blockHash []byte, parts *types.PartSet, ) { // proposal msg := &ProposalMessage{Proposal: proposal} peer.Send(DataChannel, MustEncode(msg)) // parts for i := 0; i < int(parts.Total()); i++ { part := parts.GetPart(i) msg := &BlockPartMessage{ Height: height, // This tells peer that this part applies to us. Round: round, // This tells peer that this part applies to us. Part: part, } peer.Send(DataChannel, MustEncode(msg)) } // votes cs.mtx.Lock() prevote, _ := cs.signVote(tmproto.PrevoteType, blockHash, parts.Header()) precommit, _ := cs.signVote(tmproto.PrecommitType, blockHash, parts.Header()) cs.mtx.Unlock() peer.Send(VoteChannel, MustEncode(&VoteMessage{prevote})) peer.Send(VoteChannel, MustEncode(&VoteMessage{precommit})) } //---------------------------------------- // byzantine consensus reactor type ByzantineReactor struct { service.Service reactor *Reactor } func NewByzantineReactor(conR *Reactor) *ByzantineReactor { return &ByzantineReactor{ Service: conR, reactor: conR, } } func (br *ByzantineReactor) SetSwitch(s *p2p.Switch) { br.reactor.SetSwitch(s) } func (br *ByzantineReactor) GetChannels() []*p2p.ChannelDescriptor { return br.reactor.GetChannels() } func (br *ByzantineReactor) AddPeer(peer p2p.Peer) { if !br.reactor.IsRunning() { return } // Create peerState for peer peerState := NewPeerState(peer).SetLogger(br.reactor.Logger) peer.Set(types.PeerStateKey, peerState) // Send our state to peer. // If we're syncing, broadcast a RoundStepMessage later upon SwitchToConsensus(). if !br.reactor.waitSync { br.reactor.sendNewRoundStepMessage(peer) } } func (br *ByzantineReactor) RemovePeer(peer p2p.Peer, reason interface{}) { br.reactor.RemovePeer(peer, reason) } func (br *ByzantineReactor) Receive(chID byte, peer p2p.Peer, msgBytes []byte) { br.reactor.Receive(chID, peer, msgBytes) } func (br *ByzantineReactor) InitPeer(peer p2p.Peer) p2p.Peer { return peer }