package main import ( "bytes" "context" "errors" "fmt" "io/ioutil" "math/rand" "path/filepath" "time" "github.com/tendermint/tendermint/crypto" "github.com/tendermint/tendermint/crypto/tmhash" "github.com/tendermint/tendermint/internal/test/factory" tmjson "github.com/tendermint/tendermint/libs/json" "github.com/tendermint/tendermint/privval" tmproto "github.com/tendermint/tendermint/proto/tendermint/types" e2e "github.com/tendermint/tendermint/test/e2e/pkg" "github.com/tendermint/tendermint/types" "github.com/tendermint/tendermint/version" ) // 1 in 4 evidence is light client evidence, the rest is duplicate vote evidence const lightClientEvidenceRatio = 4 // InjectEvidence takes a running testnet and generates an amount of valid // evidence and broadcasts it to a random node through the rpc endpoint `/broadcast_evidence`. // Evidence is random and can be a mixture of LightClientAttackEvidence and // DuplicateVoteEvidence. func InjectEvidence(ctx context.Context, r *rand.Rand, testnet *e2e.Testnet, amount int) error { // select a random node var targetNode *e2e.Node for _, idx := range r.Perm(len(testnet.Nodes)) { targetNode = testnet.Nodes[idx] if targetNode.Mode == e2e.ModeSeed || targetNode.Mode == e2e.ModeLight { targetNode = nil continue } break } if targetNode == nil { return errors.New("could not find node to inject evidence into") } logger.Info(fmt.Sprintf("Injecting evidence through %v (amount: %d)...", targetNode.Name, amount)) client, err := targetNode.Client() if err != nil { return err } // request the latest block and validator set from the node blockRes, err := client.Block(context.Background(), nil) if err != nil { return err } evidenceHeight := blockRes.Block.Height waitHeight := blockRes.Block.Height + 3 nValidators := 100 valRes, err := client.Validators(context.Background(), &evidenceHeight, nil, &nValidators) if err != nil { return err } valSet, err := types.ValidatorSetFromExistingValidators(valRes.Validators) if err != nil { return err } // get the private keys of all the validators in the network privVals, err := getPrivateValidatorKeys(testnet) if err != nil { return err } wctx, cancel := context.WithTimeout(ctx, time.Minute) defer cancel() // wait for the node to reach the height above the forged height so that // it is able to validate the evidence _, err = waitForNode(wctx, targetNode, waitHeight) if err != nil { return err } var ev types.Evidence for i := 1; i <= amount; i++ { if i%lightClientEvidenceRatio == 0 { ev, err = generateLightClientAttackEvidence( privVals, evidenceHeight, valSet, testnet.Name, blockRes.Block.Time, ) } else { ev, err = generateDuplicateVoteEvidence( privVals, evidenceHeight, valSet, testnet.Name, blockRes.Block.Time, ) } if err != nil { return err } _, err := client.BroadcastEvidence(context.Background(), ev) if err != nil { return err } } wctx, cancel = context.WithTimeout(ctx, 30*time.Second) defer cancel() // wait for the node to reach the height above the forged height so that // it is able to validate the evidence _, err = waitForNode(wctx, targetNode, blockRes.Block.Height+2) if err != nil { return err } logger.Info(fmt.Sprintf("Finished sending evidence (height %d)", blockRes.Block.Height+2)) return nil } func getPrivateValidatorKeys(testnet *e2e.Testnet) ([]types.MockPV, error) { privVals := []types.MockPV{} for _, node := range testnet.Nodes { if node.Mode == e2e.ModeValidator { privKeyPath := filepath.Join(testnet.Dir, node.Name, PrivvalKeyFile) privKey, err := readPrivKey(privKeyPath) if err != nil { return nil, err } // Create mock private validators from the validators private key. MockPV is // stateless which means we can double vote and do other funky stuff privVals = append(privVals, types.NewMockPVWithParams(privKey, false, false)) } } return privVals, nil } // creates evidence of a lunatic attack. The height provided is the common height. // The forged height happens 2 blocks later. func generateLightClientAttackEvidence( privVals []types.MockPV, height int64, vals *types.ValidatorSet, chainID string, evTime time.Time, ) (*types.LightClientAttackEvidence, error) { // forge a random header forgedHeight := height + 2 forgedTime := evTime.Add(1 * time.Second) header := makeHeaderRandom(chainID, forgedHeight) header.Time = forgedTime // add a new bogus validator and remove an existing one to // vary the validator set slightly pv, conflictingVals, err := mutateValidatorSet(privVals, vals) if err != nil { return nil, err } header.ValidatorsHash = conflictingVals.Hash() // create a commit for the forged header blockID := makeBlockID(header.Hash(), 1000, []byte("partshash")) voteSet := types.NewVoteSet(chainID, forgedHeight, 0, tmproto.SignedMsgType(2), conflictingVals) commit, err := factory.MakeCommit(blockID, forgedHeight, 0, voteSet, pv, forgedTime) if err != nil { return nil, err } ev := &types.LightClientAttackEvidence{ ConflictingBlock: &types.LightBlock{ SignedHeader: &types.SignedHeader{ Header: header, Commit: commit, }, ValidatorSet: conflictingVals, }, CommonHeight: height, TotalVotingPower: vals.TotalVotingPower(), Timestamp: evTime, } ev.ByzantineValidators = ev.GetByzantineValidators(vals, &types.SignedHeader{ Header: makeHeaderRandom(chainID, forgedHeight), }) return ev, nil } // generateDuplicateVoteEvidence picks a random validator from the val set and // returns duplicate vote evidence against the validator func generateDuplicateVoteEvidence( privVals []types.MockPV, height int64, vals *types.ValidatorSet, chainID string, time time.Time, ) (*types.DuplicateVoteEvidence, error) { privVal, valIdx, err := getRandomValidatorIndex(privVals, vals) if err != nil { return nil, err } voteA, err := factory.MakeVote(privVal, chainID, valIdx, height, 0, 2, makeRandomBlockID(), time) if err != nil { return nil, err } voteB, err := factory.MakeVote(privVal, chainID, valIdx, height, 0, 2, makeRandomBlockID(), time) if err != nil { return nil, err } ev, err := types.NewDuplicateVoteEvidence(voteA, voteB, time, vals) if err != nil { return nil, fmt.Errorf("could not generate evidence: %w", err) } return ev, nil } // getRandomValidatorIndex picks a random validator from a slice of mock PrivVals that's // also part of the validator set, returning the PrivVal and its index in the validator set func getRandomValidatorIndex(privVals []types.MockPV, vals *types.ValidatorSet) (types.MockPV, int32, error) { for _, idx := range rand.Perm(len(privVals)) { pv := privVals[idx] valIdx, _ := vals.GetByAddress(pv.PrivKey.PubKey().Address()) if valIdx >= 0 { return pv, valIdx, nil } } return types.MockPV{}, -1, errors.New("no private validator found in validator set") } func readPrivKey(keyFilePath string) (crypto.PrivKey, error) { keyJSONBytes, err := ioutil.ReadFile(keyFilePath) if err != nil { return nil, err } pvKey := privval.FilePVKey{} err = tmjson.Unmarshal(keyJSONBytes, &pvKey) if err != nil { return nil, fmt.Errorf("error reading PrivValidator key from %v: %w", keyFilePath, err) } return pvKey.PrivKey, nil } func makeHeaderRandom(chainID string, height int64) *types.Header { return &types.Header{ Version: version.Consensus{Block: version.BlockProtocol, App: 1}, ChainID: chainID, Height: height, Time: time.Now(), LastBlockID: makeBlockID([]byte("headerhash"), 1000, []byte("partshash")), LastCommitHash: crypto.CRandBytes(tmhash.Size), DataHash: crypto.CRandBytes(tmhash.Size), ValidatorsHash: crypto.CRandBytes(tmhash.Size), NextValidatorsHash: crypto.CRandBytes(tmhash.Size), ConsensusHash: crypto.CRandBytes(tmhash.Size), AppHash: crypto.CRandBytes(tmhash.Size), LastResultsHash: crypto.CRandBytes(tmhash.Size), EvidenceHash: crypto.CRandBytes(tmhash.Size), ProposerAddress: crypto.CRandBytes(crypto.AddressSize), } } func makeRandomBlockID() types.BlockID { return makeBlockID(crypto.CRandBytes(tmhash.Size), 100, crypto.CRandBytes(tmhash.Size)) } func makeBlockID(hash []byte, partSetSize uint32, partSetHash []byte) types.BlockID { var ( h = make([]byte, tmhash.Size) psH = make([]byte, tmhash.Size) ) copy(h, hash) copy(psH, partSetHash) return types.BlockID{ Hash: h, PartSetHeader: types.PartSetHeader{ Total: partSetSize, Hash: psH, }, } } func mutateValidatorSet(privVals []types.MockPV, vals *types.ValidatorSet, ) ([]types.PrivValidator, *types.ValidatorSet, error) { newVal, newPrivVal := factory.RandValidator(false, 10) var newVals *types.ValidatorSet if vals.Size() > 2 { newVals = types.NewValidatorSet(append(vals.Copy().Validators[:vals.Size()-1], newVal)) } else { newVals = types.NewValidatorSet(append(vals.Copy().Validators, newVal)) } // we need to sort the priv validators with the same index as the validator set pv := make([]types.PrivValidator, newVals.Size()) for idx, val := range newVals.Validators { found := false for _, p := range append(privVals, newPrivVal.(types.MockPV)) { if bytes.Equal(p.PrivKey.PubKey().Address(), val.Address) { pv[idx] = p found = true break } } if !found { return nil, nil, fmt.Errorf("missing priv validator for %v", val.Address) } } return pv, newVals, nil }