package types import ( "bytes" "errors" "fmt" "strings" "time" amino "github.com/tendermint/go-amino" "github.com/tendermint/tendermint/crypto" cryptoenc "github.com/tendermint/tendermint/crypto/encoding" "github.com/tendermint/tendermint/crypto/merkle" "github.com/tendermint/tendermint/crypto/tmhash" tmjson "github.com/tendermint/tendermint/libs/json" tmmath "github.com/tendermint/tendermint/libs/math" tmproto "github.com/tendermint/tendermint/proto/types" ) const ( // MaxEvidenceBytes is a maximum size of any evidence (including amino overhead). MaxEvidenceBytes int64 = 444 // An invalid field in the header from LunaticValidatorEvidence. // Must be a function of the ABCI application state. ValidatorsHashField = "ValidatorsHash" NextValidatorsHashField = "NextValidatorsHash" ConsensusHashField = "ConsensusHash" AppHashField = "AppHash" LastResultsHashField = "LastResultsHash" ) // ErrEvidenceInvalid wraps a piece of evidence and the error denoting how or why it is invalid. type ErrEvidenceInvalid struct { Evidence Evidence ErrorValue error } // NewErrEvidenceInvalid returns a new EvidenceInvalid with the given err. func NewErrEvidenceInvalid(ev Evidence, err error) *ErrEvidenceInvalid { return &ErrEvidenceInvalid{ev, err} } // Error returns a string representation of the error. func (err *ErrEvidenceInvalid) Error() string { return fmt.Sprintf("Invalid evidence: %v. Evidence: %v", err.ErrorValue, err.Evidence) } // ErrEvidenceOverflow is for when there is too much evidence in a block. type ErrEvidenceOverflow struct { MaxNum int GotNum int } // NewErrEvidenceOverflow returns a new ErrEvidenceOverflow where got > max. func NewErrEvidenceOverflow(max, got int) *ErrEvidenceOverflow { return &ErrEvidenceOverflow{max, got} } // Error returns a string representation of the error. func (err *ErrEvidenceOverflow) Error() string { return fmt.Sprintf("Too much evidence: Max %d, got %d", err.MaxNum, err.GotNum) } //------------------------------------------- // Evidence represents any provable malicious activity by a validator. type Evidence interface { Height() int64 // height of the equivocation Time() time.Time // time of the equivocation Address() []byte // address of the equivocating validator Bytes() []byte // bytes which comprise the evidence Hash() []byte // hash of the evidence Verify(chainID string, pubKey crypto.PubKey) error // verify the evidence Equal(Evidence) bool // check equality of evidence ValidateBasic() error String() string } type CompositeEvidence interface { VerifyComposite(committedHeader *Header, valSet *ValidatorSet) error Split(committedHeader *Header, valSet *ValidatorSet, valToLastHeight map[string]int64) []Evidence } func EvidenceToProto(evidence Evidence) (*tmproto.Evidence, error) { if evidence == nil { return nil, errors.New("nil evidence") } switch evi := evidence.(type) { case *DuplicateVoteEvidence: voteB := evi.VoteB.ToProto() voteA := evi.VoteA.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_DuplicateVoteEvidence{ DuplicateVoteEvidence: &tmproto.DuplicateVoteEvidence{ VoteA: voteA, VoteB: voteB, }, }, } return tp, nil case ConflictingHeadersEvidence: pbh1 := evi.H1.ToProto() pbh2 := evi.H2.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_ConflictingHeadersEvidence{ ConflictingHeadersEvidence: &tmproto.ConflictingHeadersEvidence{ H1: pbh1, H2: pbh2, }, }, } return tp, nil case *ConflictingHeadersEvidence: pbh1 := evi.H1.ToProto() pbh2 := evi.H2.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_ConflictingHeadersEvidence{ ConflictingHeadersEvidence: &tmproto.ConflictingHeadersEvidence{ H1: pbh1, H2: pbh2, }, }, } return tp, nil case *LunaticValidatorEvidence: h := evi.Header.ToProto() v := evi.Vote.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_LunaticValidatorEvidence{ LunaticValidatorEvidence: &tmproto.LunaticValidatorEvidence{ Header: h, Vote: v, InvalidHeaderField: evi.InvalidHeaderField, }, }, } return tp, nil case LunaticValidatorEvidence: h := evi.Header.ToProto() v := evi.Vote.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_LunaticValidatorEvidence{ LunaticValidatorEvidence: &tmproto.LunaticValidatorEvidence{ Header: h, Vote: v, InvalidHeaderField: evi.InvalidHeaderField, }, }, } return tp, nil case *PotentialAmnesiaEvidence: voteB := evi.VoteB.ToProto() voteA := evi.VoteA.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_PotentialAmnesiaEvidence{ PotentialAmnesiaEvidence: &tmproto.PotentialAmnesiaEvidence{ VoteA: voteA, VoteB: voteB, }, }, } return tp, nil case PotentialAmnesiaEvidence: voteB := evi.VoteB.ToProto() voteA := evi.VoteA.ToProto() tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_PotentialAmnesiaEvidence{ PotentialAmnesiaEvidence: &tmproto.PotentialAmnesiaEvidence{ VoteA: voteA, VoteB: voteB, }, }, } return tp, nil case MockEvidence: if err := evi.ValidateBasic(); err != nil { return nil, err } tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_MockEvidence{ MockEvidence: &tmproto.MockEvidence{ EvidenceHeight: evi.Height(), EvidenceTime: evi.Time(), EvidenceAddress: evi.Address(), }, }, } return tp, nil case MockRandomEvidence: if err := evi.ValidateBasic(); err != nil { return nil, err } tp := &tmproto.Evidence{ Sum: &tmproto.Evidence_MockRandomEvidence{ MockRandomEvidence: &tmproto.MockRandomEvidence{ EvidenceHeight: evi.Height(), EvidenceTime: evi.Time(), EvidenceAddress: evi.Address(), RandBytes: evi.randBytes, }, }, } return tp, nil default: return nil, fmt.Errorf("toproto: evidence is not recognized: %T", evi) } } func EvidenceFromProto(evidence *tmproto.Evidence) (Evidence, error) { if evidence == nil { return nil, errors.New("nil evidence") } switch evi := evidence.Sum.(type) { case *tmproto.Evidence_DuplicateVoteEvidence: vA, err := VoteFromProto(evi.DuplicateVoteEvidence.VoteA) if err != nil { return nil, err } vB, err := VoteFromProto(evi.DuplicateVoteEvidence.VoteB) if err != nil { return nil, err } dve := DuplicateVoteEvidence{ VoteA: vA, VoteB: vB, } return &dve, dve.ValidateBasic() case *tmproto.Evidence_ConflictingHeadersEvidence: h1, err := SignedHeaderFromProto(evi.ConflictingHeadersEvidence.H1) if err != nil { return nil, fmt.Errorf("from proto err: %w", err) } h2, err := SignedHeaderFromProto(evi.ConflictingHeadersEvidence.H2) if err != nil { return nil, fmt.Errorf("from proto err: %w", err) } tp := ConflictingHeadersEvidence{ H1: h1, H2: h2, } return tp, tp.ValidateBasic() case *tmproto.Evidence_LunaticValidatorEvidence: h, err := HeaderFromProto(evi.LunaticValidatorEvidence.GetHeader()) if err != nil { return nil, err } v, err := VoteFromProto(evi.LunaticValidatorEvidence.GetVote()) if err != nil { return nil, err } tp := LunaticValidatorEvidence{ Header: &h, Vote: v, InvalidHeaderField: evi.LunaticValidatorEvidence.InvalidHeaderField, } return &tp, tp.ValidateBasic() case *tmproto.Evidence_PotentialAmnesiaEvidence: voteA, err := VoteFromProto(evi.PotentialAmnesiaEvidence.GetVoteA()) if err != nil { return nil, err } voteB, err := VoteFromProto(evi.PotentialAmnesiaEvidence.GetVoteB()) if err != nil { return nil, err } tp := PotentialAmnesiaEvidence{ VoteA: voteA, VoteB: voteB, } return &tp, tp.ValidateBasic() case *tmproto.Evidence_MockEvidence: me := MockEvidence{ EvidenceHeight: evi.MockEvidence.GetEvidenceHeight(), EvidenceAddress: evi.MockEvidence.GetEvidenceAddress(), EvidenceTime: evi.MockEvidence.GetEvidenceTime(), } return me, me.ValidateBasic() case *tmproto.Evidence_MockRandomEvidence: mre := MockRandomEvidence{ MockEvidence: MockEvidence{ EvidenceHeight: evi.MockRandomEvidence.GetEvidenceHeight(), EvidenceAddress: evi.MockRandomEvidence.GetEvidenceAddress(), EvidenceTime: evi.MockRandomEvidence.GetEvidenceTime(), }, randBytes: evi.MockRandomEvidence.RandBytes, } return mre, mre.ValidateBasic() default: return nil, errors.New("evidence is not recognized") } } func RegisterEvidences(cdc *amino.Codec) { cdc.RegisterInterface((*Evidence)(nil), nil) cdc.RegisterConcrete(&DuplicateVoteEvidence{}, "tendermint/DuplicateVoteEvidence", nil) cdc.RegisterConcrete(&ConflictingHeadersEvidence{}, "tendermint/ConflictingHeadersEvidence", nil) cdc.RegisterConcrete(&PhantomValidatorEvidence{}, "tendermint/PhantomValidatorEvidence", nil) cdc.RegisterConcrete(&LunaticValidatorEvidence{}, "tendermint/LunaticValidatorEvidence", nil) cdc.RegisterConcrete(&PotentialAmnesiaEvidence{}, "tendermint/PotentialAmnesiaEvidence", nil) } func init() { tmjson.RegisterType(&DuplicateVoteEvidence{}, "tendermint/DuplicateVoteEvidence") tmjson.RegisterType(&ConflictingHeadersEvidence{}, "tendermint/ConflictingHeadersEvidence") tmjson.RegisterType(&PhantomValidatorEvidence{}, "tendermint/PhantomValidatorEvidence") tmjson.RegisterType(&LunaticValidatorEvidence{}, "tendermint/LunaticValidatorEvidence") tmjson.RegisterType(&PotentialAmnesiaEvidence{}, "tendermint/PotentialAmnesiaEvidence") } func RegisterMockEvidences(cdc *amino.Codec) { cdc.RegisterConcrete(MockEvidence{}, "tendermint/MockEvidence", nil) cdc.RegisterConcrete(MockRandomEvidence{}, "tendermint/MockRandomEvidence", nil) } //------------------------------------------- // DuplicateVoteEvidence contains evidence a validator signed two conflicting // votes. type DuplicateVoteEvidence struct { VoteA *Vote `json:"vote_a"` VoteB *Vote `json:"vote_b"` } var _ Evidence = &DuplicateVoteEvidence{} // NewDuplicateVoteEvidence creates DuplicateVoteEvidence with right ordering given // two conflicting votes. If one of the votes is nil, evidence returned is nil as well func NewDuplicateVoteEvidence(vote1 *Vote, vote2 *Vote) *DuplicateVoteEvidence { var voteA, voteB *Vote if vote1 == nil || vote2 == nil { return nil } if strings.Compare(vote1.BlockID.Key(), vote2.BlockID.Key()) == -1 { voteA = vote1 voteB = vote2 } else { voteA = vote2 voteB = vote1 } return &DuplicateVoteEvidence{ VoteA: voteA, VoteB: voteB, } } // String returns a string representation of the evidence. func (dve *DuplicateVoteEvidence) String() string { return fmt.Sprintf("DuplicateVoteEvidence{VoteA: %v, VoteB: %v}", dve.VoteA, dve.VoteB) } // Height returns the height this evidence refers to. func (dve *DuplicateVoteEvidence) Height() int64 { return dve.VoteA.Height } // Time returns the time the evidence was created. func (dve *DuplicateVoteEvidence) Time() time.Time { return dve.VoteA.Timestamp } // Address returns the address of the validator. func (dve *DuplicateVoteEvidence) Address() []byte { return dve.VoteA.ValidatorAddress } // Hash returns the hash of the evidence. func (dve *DuplicateVoteEvidence) Bytes() []byte { return cdcEncode(dve) } // Hash returns the hash of the evidence. func (dve *DuplicateVoteEvidence) Hash() []byte { return tmhash.Sum(cdcEncode(dve)) } // Verify returns an error if the two votes aren't conflicting. // // To be conflicting, they must be from the same validator, for the same H/R/S, // but for different blocks. func (dve *DuplicateVoteEvidence) Verify(chainID string, pubKey crypto.PubKey) error { // H/R/S must be the same if dve.VoteA.Height != dve.VoteB.Height || dve.VoteA.Round != dve.VoteB.Round || dve.VoteA.Type != dve.VoteB.Type { return fmt.Errorf("h/r/s does not match: %d/%d/%v vs %d/%d/%v", dve.VoteA.Height, dve.VoteA.Round, dve.VoteA.Type, dve.VoteB.Height, dve.VoteB.Round, dve.VoteB.Type) } // Address must be the same if !bytes.Equal(dve.VoteA.ValidatorAddress, dve.VoteB.ValidatorAddress) { return fmt.Errorf("validator addresses do not match: %X vs %X", dve.VoteA.ValidatorAddress, dve.VoteB.ValidatorAddress, ) } // Index must be the same if dve.VoteA.ValidatorIndex != dve.VoteB.ValidatorIndex { return fmt.Errorf( "validator indices do not match: %d and %d", dve.VoteA.ValidatorIndex, dve.VoteB.ValidatorIndex, ) } // BlockIDs must be different if dve.VoteA.BlockID.Equals(dve.VoteB.BlockID) { return fmt.Errorf( "block IDs are the same (%v) - not a real duplicate vote", dve.VoteA.BlockID, ) } // pubkey must match address (this should already be true, sanity check) addr := dve.VoteA.ValidatorAddress if !bytes.Equal(pubKey.Address(), addr) { return fmt.Errorf("address (%X) doesn't match pubkey (%v - %X)", addr, pubKey, pubKey.Address()) } // Signatures must be valid if !pubKey.VerifyBytes(dve.VoteA.SignBytes(chainID), dve.VoteA.Signature) { return fmt.Errorf("verifying VoteA: %w", ErrVoteInvalidSignature) } if !pubKey.VerifyBytes(dve.VoteB.SignBytes(chainID), dve.VoteB.Signature) { return fmt.Errorf("verifying VoteB: %w", ErrVoteInvalidSignature) } return nil } // Equal checks if two pieces of evidence are equal. func (dve *DuplicateVoteEvidence) Equal(ev Evidence) bool { if _, ok := ev.(*DuplicateVoteEvidence); !ok { return false } // just check their hashes dveHash := tmhash.Sum(cdcEncode(dve)) evHash := tmhash.Sum(cdcEncode(ev)) fmt.Println(dveHash, evHash) return bytes.Equal(dveHash, evHash) } // ValidateBasic performs basic validation. func (dve *DuplicateVoteEvidence) ValidateBasic() error { if dve.VoteA == nil || dve.VoteB == nil { return fmt.Errorf("one or both of the votes are empty %v, %v", dve.VoteA, dve.VoteB) } if err := dve.VoteA.ValidateBasic(); err != nil { return fmt.Errorf("invalid VoteA: %w", err) } if err := dve.VoteB.ValidateBasic(); err != nil { return fmt.Errorf("invalid VoteB: %w", err) } // Enforce Votes are lexicographically sorted on blockID if strings.Compare(dve.VoteA.BlockID.Key(), dve.VoteB.BlockID.Key()) >= 0 { return errors.New("duplicate votes in invalid order") } return nil } //------------------------------------------- // EvidenceList is a list of Evidence. Evidences is not a word. type EvidenceList []Evidence // Hash returns the simple merkle root hash of the EvidenceList. func (evl EvidenceList) Hash() []byte { // These allocations are required because Evidence is not of type Bytes, and // golang slices can't be typed cast. This shouldn't be a performance problem since // the Evidence size is capped. evidenceBzs := make([][]byte, len(evl)) for i := 0; i < len(evl); i++ { evidenceBzs[i] = evl[i].Bytes() } return merkle.SimpleHashFromByteSlices(evidenceBzs) } func (evl EvidenceList) String() string { s := "" for _, e := range evl { s += fmt.Sprintf("%s\t\t", e) } return s } // Has returns true if the evidence is in the EvidenceList. func (evl EvidenceList) Has(evidence Evidence) bool { for _, ev := range evl { if ev.Equal(evidence) { return true } } return false } //------------------------------------------- // ConflictingHeadersEvidence is primarily used by the light client when it // observes two conflicting headers, both having 1/3+ of the voting power of // the currently trusted validator set. type ConflictingHeadersEvidence struct { H1 *SignedHeader `json:"h_1"` H2 *SignedHeader `json:"h_2"` } var _ Evidence = ConflictingHeadersEvidence{} var _ CompositeEvidence = ConflictingHeadersEvidence{} // Split breaks up eviddence into smaller chunks (one per validator except for // PotentialAmnesiaEvidence): PhantomValidatorEvidence, // LunaticValidatorEvidence, DuplicateVoteEvidence and // PotentialAmnesiaEvidence. // // committedHeader - header at height H1.Height == H2.Height // valSet - validator set at height H1.Height == H2.Height // valToLastHeight - map between active validators and respective last heights func (ev ConflictingHeadersEvidence) Split(committedHeader *Header, valSet *ValidatorSet, valToLastHeight map[string]int64) []Evidence { evList := make([]Evidence, 0) var alternativeHeader *SignedHeader if bytes.Equal(committedHeader.Hash(), ev.H1.Hash()) { alternativeHeader = ev.H2 } else { alternativeHeader = ev.H1 } // If there are signers(alternativeHeader) that are not part of // validators(committedHeader), they misbehaved as they are signing protocol // messages in heights they are not validators => immediately slashable // (#F4). for i, sig := range alternativeHeader.Commit.Signatures { if sig.Absent() { continue } lastHeightValidatorWasInSet, ok := valToLastHeight[string(sig.ValidatorAddress)] if !ok { continue } if !valSet.HasAddress(sig.ValidatorAddress) { evList = append(evList, &PhantomValidatorEvidence{ Vote: alternativeHeader.Commit.GetVote(int32(i)), LastHeightValidatorWasInSet: lastHeightValidatorWasInSet, }) } } // If ValidatorsHash, NextValidatorsHash, ConsensusHash, AppHash, and // LastResultsHash in alternativeHeader are different (incorrect application // state transition), then it is a lunatic misbehavior => immediately // slashable (#F5). var invalidField string switch { case !bytes.Equal(committedHeader.ValidatorsHash, alternativeHeader.ValidatorsHash): invalidField = "ValidatorsHash" case !bytes.Equal(committedHeader.NextValidatorsHash, alternativeHeader.NextValidatorsHash): invalidField = "NextValidatorsHash" case !bytes.Equal(committedHeader.ConsensusHash, alternativeHeader.ConsensusHash): invalidField = "ConsensusHash" case !bytes.Equal(committedHeader.AppHash, alternativeHeader.AppHash): invalidField = "AppHash" case !bytes.Equal(committedHeader.LastResultsHash, alternativeHeader.LastResultsHash): invalidField = "LastResultsHash" } if invalidField != "" { for i, sig := range alternativeHeader.Commit.Signatures { if sig.Absent() { continue } evList = append(evList, &LunaticValidatorEvidence{ Header: alternativeHeader.Header, Vote: alternativeHeader.Commit.GetVote(int32(i)), InvalidHeaderField: invalidField, }) } return evList } // Use the fact that signatures are sorted by ValidatorAddress. var ( i = 0 j = 0 ) OUTER_LOOP: for i < len(ev.H1.Commit.Signatures) { sigA := ev.H1.Commit.Signatures[i] if sigA.Absent() { i++ continue } // FIXME: Replace with HasAddress once DuplicateVoteEvidence#PubKey is // removed. _, val := valSet.GetByAddress(sigA.ValidatorAddress) if val == nil { i++ continue } for j < len(ev.H2.Commit.Signatures) { sigB := ev.H2.Commit.Signatures[j] if sigB.Absent() { j++ continue } switch bytes.Compare(sigA.ValidatorAddress, sigB.ValidatorAddress) { case 0: // if H1.Round == H2.Round, and some signers signed different precommit // messages in both commits, then it is an equivocation misbehavior => // immediately slashable (#F1). if ev.H1.Commit.Round == ev.H2.Commit.Round { evList = append(evList, &DuplicateVoteEvidence{ VoteA: ev.H1.Commit.GetVote(int32(i)), VoteB: ev.H2.Commit.GetVote(int32(j)), }) } else { // if H1.Round != H2.Round we need to run full detection procedure => not // immediately slashable. evList = append(evList, &PotentialAmnesiaEvidence{ VoteA: ev.H1.Commit.GetVote(int32(i)), VoteB: ev.H2.Commit.GetVote(int32(j)), }) } i++ j++ continue OUTER_LOOP case 1: i++ continue OUTER_LOOP case -1: j++ } } } return evList } func (ev ConflictingHeadersEvidence) Height() int64 { return ev.H1.Height } // XXX: this is not the time of equivocation func (ev ConflictingHeadersEvidence) Time() time.Time { return ev.H1.Time } func (ev ConflictingHeadersEvidence) Address() []byte { panic("use ConflictingHeadersEvidence#Split to split evidence into individual pieces") } func (ev ConflictingHeadersEvidence) Bytes() []byte { return cdcEncode(ev) } func (ev ConflictingHeadersEvidence) Hash() []byte { bz := make([]byte, tmhash.Size*2) copy(bz[:tmhash.Size-1], ev.H1.Hash().Bytes()) copy(bz[tmhash.Size:], ev.H2.Hash().Bytes()) return tmhash.Sum(bz) } func (ev ConflictingHeadersEvidence) Verify(chainID string, _ crypto.PubKey) error { panic("use ConflictingHeadersEvidence#VerifyComposite to verify composite evidence") } // VerifyComposite verifies that both headers belong to the same chain, same // height and signed by 1/3+ of validators at height H1.Height == H2.Height. func (ev ConflictingHeadersEvidence) VerifyComposite(committedHeader *Header, valSet *ValidatorSet) error { var alternativeHeader *SignedHeader switch { case bytes.Equal(committedHeader.Hash(), ev.H1.Hash()): alternativeHeader = ev.H2 case bytes.Equal(committedHeader.Hash(), ev.H2.Hash()): alternativeHeader = ev.H1 default: return errors.New("none of the headers are committed from this node's perspective") } // ChainID must be the same if committedHeader.ChainID != alternativeHeader.ChainID { return errors.New("alt header is from a different chain") } // Height must be the same if committedHeader.Height != alternativeHeader.Height { return errors.New("alt header is from a different height") } // Limit the number of signatures to avoid DoS attacks where a header // contains too many signatures. // // Validator set size = 100 [node] // Max validator set size = 100 * 2 = 200 [fork?] maxNumValidators := valSet.Size() * 2 if len(alternativeHeader.Commit.Signatures) > maxNumValidators { return fmt.Errorf("alt commit contains too many signatures: %d, expected no more than %d", len(alternativeHeader.Commit.Signatures), maxNumValidators) } // Header must be signed by at least 1/3+ of voting power of currently // trusted validator set. if err := valSet.VerifyCommitTrusting( alternativeHeader.ChainID, alternativeHeader.Commit, tmmath.Fraction{Numerator: 1, Denominator: 3}); err != nil { return fmt.Errorf("alt header does not have 1/3+ of voting power of our validator set: %w", err) } return nil } func (ev ConflictingHeadersEvidence) Equal(ev2 Evidence) bool { switch e2 := ev2.(type) { case ConflictingHeadersEvidence: return bytes.Equal(ev.H1.Hash(), e2.H1.Hash()) && bytes.Equal(ev.H2.Hash(), e2.H2.Hash()) case *ConflictingHeadersEvidence: return bytes.Equal(ev.H1.Hash(), e2.H1.Hash()) && bytes.Equal(ev.H2.Hash(), e2.H2.Hash()) default: return false } } func (ev ConflictingHeadersEvidence) ValidateBasic() error { if ev.H1 == nil { return errors.New("first header is missing") } if ev.H2 == nil { return errors.New("second header is missing") } if err := ev.H1.ValidateBasic(ev.H1.ChainID); err != nil { return fmt.Errorf("h1: %w", err) } if err := ev.H2.ValidateBasic(ev.H2.ChainID); err != nil { return fmt.Errorf("h2: %w", err) } return nil } func (ev ConflictingHeadersEvidence) String() string { return fmt.Sprintf("ConflictingHeadersEvidence{H1: %d#%X, H2: %d#%X}", ev.H1.Height, ev.H1.Hash(), ev.H2.Height, ev.H2.Hash()) } //------------------------------------------- type PhantomValidatorEvidence struct { Vote *Vote `json:"vote"` LastHeightValidatorWasInSet int64 `json:"last_height_validator_was_in_set"` } var _ Evidence = PhantomValidatorEvidence{} func (e PhantomValidatorEvidence) Height() int64 { return e.Vote.Height } func (e PhantomValidatorEvidence) Time() time.Time { return e.Vote.Timestamp } func (e PhantomValidatorEvidence) Address() []byte { return e.Vote.ValidatorAddress } func (e PhantomValidatorEvidence) Hash() []byte { return tmhash.Sum(cdcEncode(e)) } func (e PhantomValidatorEvidence) Bytes() []byte { return cdcEncode(e) } func (e PhantomValidatorEvidence) Verify(chainID string, pubKey crypto.PubKey) error { // signature must be verified to the chain ID if !pubKey.VerifyBytes(e.Vote.SignBytes(chainID), e.Vote.Signature) { return errors.New("invalid signature") } return nil } func (e PhantomValidatorEvidence) Equal(ev Evidence) bool { switch e2 := ev.(type) { case PhantomValidatorEvidence: return e.Vote.Height == e2.Vote.Height && bytes.Equal(e.Vote.ValidatorAddress, e2.Vote.ValidatorAddress) case *PhantomValidatorEvidence: return e.Vote.Height == e2.Vote.Height && bytes.Equal(e.Vote.ValidatorAddress, e2.Vote.ValidatorAddress) default: return false } } func (e PhantomValidatorEvidence) ValidateBasic() error { if e.Vote == nil { return errors.New("empty vote") } if err := e.Vote.ValidateBasic(); err != nil { return fmt.Errorf("invalid signature: %v", err) } if !e.Vote.BlockID.IsComplete() { return errors.New("expected vote for block") } if e.LastHeightValidatorWasInSet <= 0 { return errors.New("negative or zero LastHeightValidatorWasInSet") } return nil } func (e PhantomValidatorEvidence) String() string { return fmt.Sprintf("PhantomValidatorEvidence{%X voted at height %d}", e.Vote.ValidatorAddress, e.Vote.Height) } //------------------------------------------- type LunaticValidatorEvidence struct { Header *Header `json:"header"` Vote *Vote `json:"vote"` InvalidHeaderField string `json:"invalid_header_field"` } var _ Evidence = LunaticValidatorEvidence{} func (e LunaticValidatorEvidence) Height() int64 { return e.Header.Height } func (e LunaticValidatorEvidence) Time() time.Time { return e.Header.Time } func (e LunaticValidatorEvidence) Address() []byte { return e.Vote.ValidatorAddress } func (e LunaticValidatorEvidence) Hash() []byte { bz := make([]byte, tmhash.Size+crypto.AddressSize) copy(bz[:tmhash.Size-1], e.Header.Hash().Bytes()) copy(bz[tmhash.Size:], e.Vote.ValidatorAddress.Bytes()) return tmhash.Sum(bz) } func (e LunaticValidatorEvidence) Bytes() []byte { return cdcEncode(e) } func (e LunaticValidatorEvidence) Verify(chainID string, pubKey crypto.PubKey) error { // chainID must be the same if chainID != e.Header.ChainID { return fmt.Errorf("chainID do not match: %s vs %s", chainID, e.Header.ChainID, ) } if !pubKey.VerifyBytes(e.Vote.SignBytes(chainID), e.Vote.Signature) { return errors.New("invalid signature") } return nil } func (e LunaticValidatorEvidence) Equal(ev Evidence) bool { switch e2 := ev.(type) { case LunaticValidatorEvidence: return bytes.Equal(e.Header.Hash(), e2.Header.Hash()) && bytes.Equal(e.Vote.ValidatorAddress, e2.Vote.ValidatorAddress) case *LunaticValidatorEvidence: return bytes.Equal(e.Header.Hash(), e2.Header.Hash()) && bytes.Equal(e.Vote.ValidatorAddress, e2.Vote.ValidatorAddress) default: return false } } func (e LunaticValidatorEvidence) ValidateBasic() error { if e.Header == nil { return errors.New("empty header") } if e.Vote == nil { return errors.New("empty vote") } if err := e.Header.ValidateBasic(); err != nil { return fmt.Errorf("invalid header: %v", err) } if err := e.Vote.ValidateBasic(); err != nil { return fmt.Errorf("invalid signature: %v", err) } if !e.Vote.BlockID.IsComplete() { return errors.New("expected vote for block") } if e.Header.Height != e.Vote.Height { return fmt.Errorf("header and vote have different heights: %d vs %d", e.Header.Height, e.Vote.Height, ) } switch e.InvalidHeaderField { case "ValidatorsHash", "NextValidatorsHash", "ConsensusHash", "AppHash", "LastResultsHash": return nil default: return errors.New("unknown invalid header field") } } func (e LunaticValidatorEvidence) String() string { return fmt.Sprintf("LunaticValidatorEvidence{%X voted for %d/%X, which contains invalid %s}", e.Vote.ValidatorAddress, e.Header.Height, e.Header.Hash(), e.InvalidHeaderField) } func (e LunaticValidatorEvidence) VerifyHeader(committedHeader *Header) error { matchErr := func(field string) error { return fmt.Errorf("%s matches committed hash", field) } if committedHeader == nil { return errors.New("committed header is nil") } switch e.InvalidHeaderField { case ValidatorsHashField: if bytes.Equal(committedHeader.ValidatorsHash, e.Header.ValidatorsHash) { return matchErr(ValidatorsHashField) } case NextValidatorsHashField: if bytes.Equal(committedHeader.NextValidatorsHash, e.Header.NextValidatorsHash) { return matchErr(NextValidatorsHashField) } case ConsensusHashField: if bytes.Equal(committedHeader.ConsensusHash, e.Header.ConsensusHash) { return matchErr(ConsensusHashField) } case AppHashField: if bytes.Equal(committedHeader.AppHash, e.Header.AppHash) { return matchErr(AppHashField) } case LastResultsHashField: if bytes.Equal(committedHeader.LastResultsHash, e.Header.LastResultsHash) { return matchErr(LastResultsHashField) } default: return errors.New("unknown InvalidHeaderField") } return nil } //------------------------------------------- type PotentialAmnesiaEvidence struct { VoteA *Vote `json:"vote_a"` VoteB *Vote `json:"vote_b"` } var _ Evidence = PotentialAmnesiaEvidence{} func (e PotentialAmnesiaEvidence) Height() int64 { return e.VoteA.Height } func (e PotentialAmnesiaEvidence) Time() time.Time { if e.VoteA.Timestamp.Before(e.VoteB.Timestamp) { return e.VoteA.Timestamp } return e.VoteB.Timestamp } func (e PotentialAmnesiaEvidence) Address() []byte { return e.VoteA.ValidatorAddress } func (e PotentialAmnesiaEvidence) Hash() []byte { return tmhash.Sum(cdcEncode(e)) } func (e PotentialAmnesiaEvidence) Bytes() []byte { return cdcEncode(e) } func (e PotentialAmnesiaEvidence) Verify(chainID string, pubKey crypto.PubKey) error { // pubkey must match address (this should already be true, sanity check) addr := e.VoteA.ValidatorAddress if !bytes.Equal(pubKey.Address(), addr) { return fmt.Errorf("address (%X) doesn't match pubkey (%v - %X)", addr, pubKey, pubKey.Address()) } // Signatures must be valid if !pubKey.VerifyBytes(e.VoteA.SignBytes(chainID), e.VoteA.Signature) { return fmt.Errorf("verifying VoteA: %w", ErrVoteInvalidSignature) } if !pubKey.VerifyBytes(e.VoteB.SignBytes(chainID), e.VoteB.Signature) { return fmt.Errorf("verifying VoteB: %w", ErrVoteInvalidSignature) } return nil } func (e PotentialAmnesiaEvidence) Equal(ev Evidence) bool { switch e2 := ev.(type) { case PotentialAmnesiaEvidence: return bytes.Equal(e.Hash(), e2.Hash()) case *PotentialAmnesiaEvidence: return bytes.Equal(e.Hash(), e2.Hash()) default: return false } } func (e PotentialAmnesiaEvidence) ValidateBasic() error { if e.VoteA == nil || e.VoteB == nil { return fmt.Errorf("one or both of the votes are empty %v, %v", e.VoteA, e.VoteB) } if err := e.VoteA.ValidateBasic(); err != nil { return fmt.Errorf("invalid VoteA: %v", err) } if err := e.VoteB.ValidateBasic(); err != nil { return fmt.Errorf("invalid VoteB: %v", err) } // Enforce Votes are lexicographically sorted on blockID if strings.Compare(e.VoteA.BlockID.Key(), e.VoteB.BlockID.Key()) >= 0 { return errors.New("amnesia votes in invalid order") } // H/S must be the same if e.VoteA.Height != e.VoteB.Height || e.VoteA.Type != e.VoteB.Type { return fmt.Errorf("h/s do not match: %d/%v vs %d/%v", e.VoteA.Height, e.VoteA.Type, e.VoteB.Height, e.VoteB.Type) } // R must be different if e.VoteA.Round == e.VoteB.Round { return fmt.Errorf("expected votes from different rounds, got %d", e.VoteA.Round) } // Address must be the same if !bytes.Equal(e.VoteA.ValidatorAddress, e.VoteB.ValidatorAddress) { return fmt.Errorf("validator addresses do not match: %X vs %X", e.VoteA.ValidatorAddress, e.VoteB.ValidatorAddress, ) } // Index must be the same // https://github.com/tendermint/tendermint/issues/4619 if e.VoteA.ValidatorIndex != e.VoteB.ValidatorIndex { return fmt.Errorf( "duplicateVoteEvidence Error: Validator indices do not match. Got %d and %d", e.VoteA.ValidatorIndex, e.VoteB.ValidatorIndex, ) } // BlockIDs must be different if e.VoteA.BlockID.Equals(e.VoteB.BlockID) { return fmt.Errorf( "block IDs are the same (%v) - not a real duplicate vote", e.VoteA.BlockID, ) } return nil } func (e PotentialAmnesiaEvidence) String() string { return fmt.Sprintf("PotentialAmnesiaEvidence{VoteA: %v, VoteB: %v}", e.VoteA, e.VoteB) } // ProofOfLockChange (POLC) proves that a node followed the consensus protocol and voted for a precommit in two // different rounds because the node received a majority of votes for a different block in the latter round. In cases of // amnesia evidence, a suspected node will need ProofOfLockChange to prove that the node did not break protocol. type ProofOfLockChange struct { Votes []Vote `json:"votes"` PubKey crypto.PubKey `json:"pubkey"` } // MakePOLCFromVoteSet can be used when a majority of prevotes or precommits for a block is seen // that the node has itself not yet voted for in order to process the vote set into a proof of lock change func MakePOLCFromVoteSet(voteSet *VoteSet, pubKey crypto.PubKey, blockID BlockID) (ProofOfLockChange, error) { polc := makePOLCFromVoteSet(voteSet, pubKey, blockID) return polc, polc.ValidateBasic() } func makePOLCFromVoteSet(voteSet *VoteSet, pubKey crypto.PubKey, blockID BlockID) ProofOfLockChange { var votes []Vote valSetSize := voteSet.Size() for valIdx := int32(0); int(valIdx) < valSetSize; valIdx++ { vote := voteSet.GetByIndex(valIdx) if vote != nil && vote.BlockID.Equals(blockID) { votes = append(votes, *vote) } } return ProofOfLockChange{ Votes: votes, PubKey: pubKey, } } func (e ProofOfLockChange) Height() int64 { return e.Votes[0].Height } // returns the time of the last vote func (e ProofOfLockChange) Time() time.Time { latest := e.Votes[0].Timestamp for _, vote := range e.Votes { if vote.Timestamp.After(latest) { latest = vote.Timestamp } } return latest } func (e ProofOfLockChange) Round() int32 { return e.Votes[0].Round } func (e ProofOfLockChange) Address() []byte { return e.PubKey.Address() } func (e ProofOfLockChange) BlockID() BlockID { return e.Votes[0].BlockID } // In order for a ProofOfLockChange to be valid, a validator must have received +2/3 majority of votes // MajorityOfVotes checks that there were sufficient votes in order to change locks func (e ProofOfLockChange) MajorityOfVotes(valSet *ValidatorSet) bool { talliedVotingPower := int64(0) votingPowerNeeded := valSet.TotalVotingPower() * 2 / 3 for _, validator := range valSet.Validators { for _, vote := range e.Votes { if bytes.Equal(validator.Address, vote.ValidatorAddress) { talliedVotingPower += validator.VotingPower if talliedVotingPower > votingPowerNeeded { return true } } } } return false } func (e ProofOfLockChange) Equal(e2 ProofOfLockChange) bool { return bytes.Equal(e.Address(), e2.Address()) && e.Height() == e2.Height() && e.Round() == e2.Round() } func (e ProofOfLockChange) ValidateBasic() error { if e.PubKey == nil { return errors.New("missing public key") } // validate basic doesn't count the number of votes and their voting power, this is to be done by VerifyEvidence if e.Votes == nil { return errors.New("missing votes") } // height, round and vote type must be the same for all votes height := e.Height() round := e.Round() if round == 0 { return errors.New("can't have a polc for the first round") } voteType := e.Votes[0].Type for idx, vote := range e.Votes { if err := vote.ValidateBasic(); err != nil { return fmt.Errorf("invalid vote#%d: %w", idx, err) } if vote.Height != height { return fmt.Errorf("invalid height for vote#%d: %d instead of %d", idx, vote.Height, height) } if vote.Round != round { return fmt.Errorf("invalid round for vote#%d: %d instead of %d", idx, vote.Round, round) } if vote.Type != voteType { return fmt.Errorf("invalid vote type for vote#%d: %d instead of %d", idx, vote.Type, voteType) } if !vote.BlockID.Equals(e.BlockID()) { return fmt.Errorf("vote must be for the same block id: %v instead of %v", e.BlockID(), vote.BlockID) } if bytes.Equal(vote.ValidatorAddress.Bytes(), e.PubKey.Address().Bytes()) { return fmt.Errorf("vote validator address cannot be the same as the public key address: %X all votes %v", vote.ValidatorAddress.Bytes(), e.Votes) } for i := idx + 1; i < len(e.Votes); i++ { if bytes.Equal(vote.ValidatorAddress.Bytes(), e.Votes[i].ValidatorAddress.Bytes()) { return fmt.Errorf("duplicate votes: %v", vote) } } } return nil } func (e ProofOfLockChange) String() string { return fmt.Sprintf("ProofOfLockChange {Address: %X, Height: %d, Round: %d", e.Address(), e.Height(), e.Votes[0].Round) } func (e *ProofOfLockChange) ToProto() (*tmproto.ProofOfLockChange, error) { if e == nil { return nil, errors.New("nil proof of lock change") } plc := new(tmproto.ProofOfLockChange) vpb := make([]*tmproto.Vote, len(e.Votes)) for i, v := range e.Votes { pb := v.ToProto() if pb != nil { vpb[i] = pb } } pk, err := cryptoenc.PubKeyToProto(e.PubKey) if err != nil { return nil, err } plc.PubKey = &pk plc.Votes = vpb return plc, nil } func ProofOfLockChangeFromProto(pb *tmproto.ProofOfLockChange) (*ProofOfLockChange, error) { if pb == nil { return nil, errors.New("nil proof of lock change") } plc := new(ProofOfLockChange) vpb := make([]Vote, len(pb.Votes)) for i, v := range pb.Votes { vi, err := VoteFromProto(v) if err != nil { return nil, err } vpb[i] = *vi } if pb.PubKey == nil { return nil, errors.New("proofOfLockChange: nil PubKey") } pk, err := cryptoenc.PubKeyFromProto(*pb.PubKey) if err != nil { return nil, err } plc.PubKey = pk plc.Votes = vpb return plc, nil } //----------------------------------------------------------------- // UNSTABLE type MockRandomEvidence struct { MockEvidence randBytes []byte } var _ Evidence = &MockRandomEvidence{} // UNSTABLE func NewMockRandomEvidence(height int64, eTime time.Time, address []byte, randBytes []byte) MockRandomEvidence { return MockRandomEvidence{ MockEvidence{ EvidenceHeight: height, EvidenceTime: eTime, EvidenceAddress: address}, randBytes, } } func (e MockRandomEvidence) Hash() []byte { return []byte(fmt.Sprintf("%d-%x", e.EvidenceHeight, e.randBytes)) } func (e MockRandomEvidence) Equal(ev Evidence) bool { return false } // UNSTABLE type MockEvidence struct { EvidenceHeight int64 EvidenceTime time.Time EvidenceAddress []byte } var _ Evidence = &MockEvidence{} // UNSTABLE func NewMockEvidence(height int64, eTime time.Time, address []byte) MockEvidence { return MockEvidence{ EvidenceHeight: height, EvidenceTime: eTime, EvidenceAddress: address, } } func (e MockEvidence) Height() int64 { return e.EvidenceHeight } func (e MockEvidence) Time() time.Time { return e.EvidenceTime } func (e MockEvidence) Address() []byte { return e.EvidenceAddress } func (e MockEvidence) Hash() []byte { return []byte(fmt.Sprintf("%d-%x-%s", e.EvidenceHeight, e.EvidenceAddress, e.EvidenceTime)) } func (e MockEvidence) Bytes() []byte { return []byte(fmt.Sprintf("%d-%x-%s", e.EvidenceHeight, e.EvidenceAddress, e.EvidenceTime)) } func (e MockEvidence) Verify(chainID string, pubKey crypto.PubKey) error { return nil } func (e MockEvidence) Equal(ev Evidence) bool { return e.EvidenceHeight == ev.Height() && bytes.Equal(e.EvidenceAddress, ev.Address()) } func (e MockEvidence) ValidateBasic() error { return nil } func (e MockEvidence) String() string { return fmt.Sprintf("Evidence: %d/%s/%s", e.EvidenceHeight, e.Time(), e.EvidenceAddress) } // mock polc - fails validate basic, not stable func NewMockPOLC(height int64, time time.Time, pubKey crypto.PubKey) ProofOfLockChange { voteVal := NewMockPV() pKey, _ := voteVal.GetPubKey() vote := Vote{Type: tmproto.PrecommitType, Height: height, Round: 1, BlockID: BlockID{}, Timestamp: time, ValidatorAddress: pKey.Address(), ValidatorIndex: 1, Signature: []byte{}} _ = voteVal.SignVote("mock-chain-id", &vote) return ProofOfLockChange{ Votes: []Vote{vote}, PubKey: pubKey, } }