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tendermint/types/evidence.go

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package types
import (
"bytes"
"errors"
"fmt"
"strings"
"time"
"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"
tmrand "github.com/tendermint/tendermint/libs/rand"
tmproto "github.com/tendermint/tendermint/proto/tendermint/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:
pbevi := evi.ToProto()
tp := &tmproto.Evidence{
Sum: &tmproto.Evidence_DuplicateVoteEvidence{
DuplicateVoteEvidence: pbevi,
},
}
return tp, nil
case *ConflictingHeadersEvidence:
pbevi := evi.ToProto()
tp := &tmproto.Evidence{
Sum: &tmproto.Evidence_ConflictingHeadersEvidence{
ConflictingHeadersEvidence: pbevi,
},
}
return tp, nil
case *LunaticValidatorEvidence:
pbevi := evi.ToProto()
tp := &tmproto.Evidence{
Sum: &tmproto.Evidence_LunaticValidatorEvidence{
LunaticValidatorEvidence: pbevi,
},
}
return tp, nil
case *PhantomValidatorEvidence:
pbevi := evi.ToProto()
tp := &tmproto.Evidence{
Sum: &tmproto.Evidence_PhantomValidatorEvidence{
PhantomValidatorEvidence: pbevi,
},
}
return tp, nil
case *PotentialAmnesiaEvidence:
pbevi := evi.ToProto()
tp := &tmproto.Evidence{
Sum: &tmproto.Evidence_PotentialAmnesiaEvidence{
PotentialAmnesiaEvidence: pbevi,
},
}
return tp, nil
case *AmnesiaEvidence:
aepb := evi.ToProto()
tp := &tmproto.Evidence{
Sum: &tmproto.Evidence_AmnesiaEvidence{
AmnesiaEvidence: aepb,
},
}
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:
return DuplicateVoteEvidenceFromProto(evi.DuplicateVoteEvidence)
case *tmproto.Evidence_ConflictingHeadersEvidence:
return ConflictingHeadersEvidenceFromProto(evi.ConflictingHeadersEvidence)
case *tmproto.Evidence_LunaticValidatorEvidence:
return LunaticValidatorEvidenceFromProto(evi.LunaticValidatorEvidence)
case *tmproto.Evidence_PotentialAmnesiaEvidence:
return PotentialAmnesiaEvidenceFromProto(evi.PotentialAmnesiaEvidence)
case *tmproto.Evidence_AmnesiaEvidence:
return AmnesiaEvidenceFromProto(evi.AmnesiaEvidence)
case *tmproto.Evidence_PhantomValidatorEvidence:
return PhantomValidatorEvidenceFromProto(evi.PhantomValidatorEvidence)
default:
return nil, errors.New("evidence is not recognized")
}
}
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")
tmjson.RegisterType(&AmnesiaEvidence{}, "tendermint/AmnesiaEvidence")
}
//-------------------------------------------
// 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 time of the latest vote.
func (dve *DuplicateVoteEvidence) Time() time.Time {
return maxTime(dve.VoteA.Timestamp, dve.VoteB.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 {
pbe := dve.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return bz
}
// Hash returns the hash of the evidence.
func (dve *DuplicateVoteEvidence) Hash() []byte {
pbe := dve.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return tmhash.Sum(bz)
}
// 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())
}
va := dve.VoteA.ToProto()
vb := dve.VoteB.ToProto()
// Signatures must be valid
if !pubKey.VerifyBytes(VoteSignBytes(chainID, va), dve.VoteA.Signature) {
return fmt.Errorf("verifying VoteA: %w", ErrVoteInvalidSignature)
}
if !pubKey.VerifyBytes(VoteSignBytes(chainID, vb), 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
}
pbdev := dve.ToProto()
bz, err := pbdev.Marshal()
if err != nil {
panic(err)
}
var evbz []byte
if ev, ok := ev.(*DuplicateVoteEvidence); ok {
evpb := ev.ToProto()
evbz, err = evpb.Marshal()
if err != nil {
panic(err)
}
}
// just check their hashes
dveHash := tmhash.Sum(bz)
evHash := tmhash.Sum(evbz)
return bytes.Equal(dveHash, evHash)
}
// ValidateBasic performs basic validation.
func (dve *DuplicateVoteEvidence) ValidateBasic() error {
if dve == nil {
return errors.New("empty duplicate vote evidence")
}
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
}
func (dve *DuplicateVoteEvidence) ToProto() *tmproto.DuplicateVoteEvidence {
voteB := dve.VoteB.ToProto()
voteA := dve.VoteA.ToProto()
tp := tmproto.DuplicateVoteEvidence{
VoteA: voteA,
VoteB: voteB,
}
return &tp
}
func DuplicateVoteEvidenceFromProto(pb *tmproto.DuplicateVoteEvidence) (*DuplicateVoteEvidence, error) {
if pb == nil {
return nil, errors.New("nil duplicate vote evidence")
}
vA, err := VoteFromProto(pb.VoteA)
if err != nil {
return nil, err
}
vB, err := VoteFromProto(pb.VoteB)
if err != nil {
return nil, err
}
dve := new(DuplicateVoteEvidence)
dve.VoteA = vA
dve.VoteB = vB
return dve, dve.ValidateBasic()
}
// 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{}
// NewConflictingHeadersEvidence creates a new instance of the respective evidence
func NewConflictingHeadersEvidence(h1, h2 *SignedHeader) *ConflictingHeadersEvidence {
return &ConflictingHeadersEvidence{H1: h1, H2: h2}
}
// Split breaks up evidence 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.
firstVote := ev.H1.Commit.GetVote(int32(i))
secondVote := ev.H2.Commit.GetVote(int32(j))
newEv := NewPotentialAmnesiaEvidence(firstVote, secondVote)
// has the validator incorrectly voted for a previous round
if newEv.VoteA.Round > newEv.VoteB.Round {
evList = append(evList, NewAmnesiaEvidence(newEv, NewEmptyPOLC()))
} else {
evList = append(evList, newEv)
}
}
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 }
// Time returns time of the latest header.
func (ev *ConflictingHeadersEvidence) Time() time.Time {
return maxTime(ev.H1.Time, ev.H2.Time)
}
func (ev *ConflictingHeadersEvidence) Address() []byte {
panic("use ConflictingHeadersEvidence#Split to split evidence into individual pieces")
}
func (ev *ConflictingHeadersEvidence) Bytes() []byte {
pbe := ev.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return bz
}
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.VerifyCommitLightTrusting(
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 {
if e2, ok := ev2.(*ConflictingHeadersEvidence); ok {
return bytes.Equal(ev.H1.Hash(), e2.H1.Hash()) && bytes.Equal(ev.H2.Hash(), e2.H2.Hash())
}
return false
}
func (ev *ConflictingHeadersEvidence) ValidateBasic() error {
if ev == nil {
return errors.New("empty conflicting headers evidence")
}
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())
}
func (ev *ConflictingHeadersEvidence) ToProto() *tmproto.ConflictingHeadersEvidence {
pbh1 := ev.H1.ToProto()
pbh2 := ev.H2.ToProto()
tp := &tmproto.ConflictingHeadersEvidence{
H1: pbh1,
H2: pbh2,
}
return tp
}
func ConflictingHeadersEvidenceFromProto(pb *tmproto.ConflictingHeadersEvidence) (*ConflictingHeadersEvidence, error) {
if pb == nil {
return &ConflictingHeadersEvidence{}, errors.New("nil ConflictingHeadersEvidence")
}
h1, err := SignedHeaderFromProto(pb.H1)
if err != nil {
return &ConflictingHeadersEvidence{}, fmt.Errorf("from proto err: %w", err)
}
h2, err := SignedHeaderFromProto(pb.H2)
if err != nil {
return &ConflictingHeadersEvidence{}, fmt.Errorf("from proto err: %w", err)
}
tp := &ConflictingHeadersEvidence{
H1: h1,
H2: h2,
}
return tp, tp.ValidateBasic()
}
//-------------------------------------------
type PhantomValidatorEvidence struct {
Vote *Vote `json:"vote"`
LastHeightValidatorWasInSet int64 `json:"last_height_validator_was_in_set"`
}
var _ Evidence = &PhantomValidatorEvidence{}
// NewPhantomValidatorEvidence creates a new instance of the respective evidence
func NewPhantomValidatorEvidence(vote *Vote, lastHeightValidatorWasInSet int64) *PhantomValidatorEvidence {
return &PhantomValidatorEvidence{
Vote: vote,
LastHeightValidatorWasInSet: lastHeightValidatorWasInSet,
}
}
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 {
pbe := e.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return tmhash.Sum(bz)
}
func (e *PhantomValidatorEvidence) Bytes() []byte {
pbe := e.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return bz
}
func (e *PhantomValidatorEvidence) Verify(chainID string, pubKey crypto.PubKey) error {
v := e.Vote.ToProto()
if !pubKey.VerifyBytes(VoteSignBytes(chainID, v), e.Vote.Signature) {
return errors.New("invalid signature")
}
return nil
}
func (e *PhantomValidatorEvidence) Equal(ev Evidence) bool {
if e2, ok := ev.(*PhantomValidatorEvidence); ok {
return e.Vote.Height == e2.Vote.Height &&
bytes.Equal(e.Vote.ValidatorAddress, e2.Vote.ValidatorAddress)
}
return false
}
func (e *PhantomValidatorEvidence) ValidateBasic() error {
if e == nil {
return errors.New("empty phantom validator evidence")
}
if e.Vote == nil {
return errors.New("empty vote")
}
if err := e.Vote.ValidateBasic(); err != nil {
return fmt.Errorf("invalid vote: %w", 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)
}
func (e *PhantomValidatorEvidence) ToProto() *tmproto.PhantomValidatorEvidence {
vpb := e.Vote.ToProto()
tp := &tmproto.PhantomValidatorEvidence{
Vote: vpb,
LastHeightValidatorWasInSet: e.LastHeightValidatorWasInSet,
}
return tp
}
func PhantomValidatorEvidenceFromProto(pb *tmproto.PhantomValidatorEvidence) (*PhantomValidatorEvidence, error) {
if pb == nil {
return nil, errors.New("nil PhantomValidatorEvidence")
}
vpb, err := VoteFromProto(pb.Vote)
if err != nil {
return nil, err
}
tp := &PhantomValidatorEvidence{
Vote: vpb,
LastHeightValidatorWasInSet: pb.LastHeightValidatorWasInSet,
}
return tp, tp.ValidateBasic()
}
//-------------------------------------------
type LunaticValidatorEvidence struct {
Header *Header `json:"header"`
Vote *Vote `json:"vote"`
InvalidHeaderField string `json:"invalid_header_field"`
}
var _ Evidence = &LunaticValidatorEvidence{}
// NewLunaticValidatorEvidence creates a new instance of the respective evidence
func NewLunaticValidatorEvidence(header *Header, vote *Vote, invalidHeaderField string) *LunaticValidatorEvidence {
return &LunaticValidatorEvidence{
Header: header,
Vote: vote,
InvalidHeaderField: invalidHeaderField,
}
}
func (e *LunaticValidatorEvidence) Height() int64 {
return e.Header.Height
}
// Time returns the maximum between the header's time and vote's time.
func (e *LunaticValidatorEvidence) Time() time.Time {
return maxTime(e.Header.Time, e.Vote.Timestamp)
}
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 {
pbe := e.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return bz
}
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,
)
}
v := e.Vote.ToProto()
if !pubKey.VerifyBytes(VoteSignBytes(chainID, v), e.Vote.Signature) {
return errors.New("invalid signature")
}
return nil
}
func (e *LunaticValidatorEvidence) Equal(ev Evidence) bool {
if e2, ok := ev.(*LunaticValidatorEvidence); ok {
return bytes.Equal(e.Header.Hash(), e2.Header.Hash()) &&
bytes.Equal(e.Vote.ValidatorAddress, e2.Vote.ValidatorAddress)
}
return false
}
func (e *LunaticValidatorEvidence) ValidateBasic() error {
if e == nil {
return errors.New("empty lunatic validator evidence")
}
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":
break
default:
return errors.New("unknown invalid header field")
}
if !bytes.Equal(e.Header.Hash(), e.Vote.BlockID.Hash) {
return fmt.Errorf("vote was not for header: %X != %X",
e.Vote.BlockID.Hash,
e.Header.Hash(),
)
}
return nil
}
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
}
func (e *LunaticValidatorEvidence) ToProto() *tmproto.LunaticValidatorEvidence {
h := e.Header.ToProto()
v := e.Vote.ToProto()
tp := &tmproto.LunaticValidatorEvidence{
Header: h,
Vote: v,
InvalidHeaderField: e.InvalidHeaderField,
}
return tp
}
func LunaticValidatorEvidenceFromProto(pb *tmproto.LunaticValidatorEvidence) (*LunaticValidatorEvidence, error) {
if pb == nil {
return nil, errors.New("nil LunaticValidatorEvidence")
}
h, err := HeaderFromProto(pb.GetHeader())
if err != nil {
return nil, err
}
v, err := VoteFromProto(pb.GetVote())
if err != nil {
return nil, err
}
tp := LunaticValidatorEvidence{
Header: &h,
Vote: v,
InvalidHeaderField: pb.InvalidHeaderField,
}
return &tp, tp.ValidateBasic()
}
//-------------------------------------------
// PotentialAmnesiaEvidence is constructed when a validator votes on two different blocks at different rounds
// in the same height. PotentialAmnesiaEvidence can then evolve into AmnesiaEvidence if the indicted validator
// is incapable of providing the proof of lock change that validates voting twice in the allotted trial period.
// Heightstamp is used for each node to keep a track of how much time has passed so as to know when the trial period
// is finished and is set when the node first receives the evidence. Votes are ordered based on their timestamp
type PotentialAmnesiaEvidence struct {
VoteA *Vote `json:"vote_a"`
VoteB *Vote `json:"vote_b"`
HeightStamp int64
}
var _ Evidence = &PotentialAmnesiaEvidence{}
// NewPotentialAmnesiaEvidence creates a new instance of the evidence and orders the votes correctly
func NewPotentialAmnesiaEvidence(voteA *Vote, voteB *Vote) *PotentialAmnesiaEvidence {
if voteA == nil || voteB == nil {
return nil
}
if voteA.Timestamp.Before(voteB.Timestamp) {
return &PotentialAmnesiaEvidence{VoteA: voteA, VoteB: voteB}
}
return &PotentialAmnesiaEvidence{VoteA: voteB, VoteB: voteA}
}
func (e *PotentialAmnesiaEvidence) Height() int64 {
return e.VoteA.Height
}
func (e *PotentialAmnesiaEvidence) Time() time.Time {
return e.VoteB.Timestamp
}
func (e *PotentialAmnesiaEvidence) Address() []byte {
return e.VoteA.ValidatorAddress
}
// NOTE: Heightstamp must not be included in hash
func (e *PotentialAmnesiaEvidence) Hash() []byte {
v1, err := e.VoteA.ToProto().Marshal()
if err != nil {
panic(fmt.Errorf("trying to hash potential amnesia evidence, err: %w", err))
}
v2, err := e.VoteB.ToProto().Marshal()
if err != nil {
panic(fmt.Errorf("trying to hash potential amnesia evidence, err: %w", err))
}
return tmhash.Sum(append(v1, v2...))
}
func (e *PotentialAmnesiaEvidence) Bytes() []byte {
pbe := e.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(err)
}
return bz
}
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())
}
va := e.VoteA.ToProto()
vb := e.VoteB.ToProto()
// Signatures must be valid
if !pubKey.VerifyBytes(VoteSignBytes(chainID, va), e.VoteA.Signature) {
return fmt.Errorf("verifying VoteA: %w", ErrVoteInvalidSignature)
}
if !pubKey.VerifyBytes(VoteSignBytes(chainID, vb), e.VoteB.Signature) {
return fmt.Errorf("verifying VoteB: %w", ErrVoteInvalidSignature)
}
return nil
}
func (e *PotentialAmnesiaEvidence) Equal(ev Evidence) bool {
if e2, ok := ev.(*PotentialAmnesiaEvidence); ok {
return e.Height() == e2.Height() && e.VoteA.Round == e2.VoteA.Round && e.VoteB.Round == e2.VoteB.Round &&
bytes.Equal(e.Address(), e2.Address())
}
return false
}
func (e *PotentialAmnesiaEvidence) ValidateBasic() error {
if e == nil {
return errors.New("empty potential amnesia evidence")
}
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)
}
// H/S must be the same
if e.VoteA.Height != e.VoteB.Height {
return fmt.Errorf("heights do not match: %d vs %d",
e.VoteA.Height, e.VoteB.Height)
}
if e.VoteA.Round == e.VoteB.Round {
return fmt.Errorf("votes must be for different rounds: %d",
e.VoteA.Round)
}
// Enforce that vote A came before vote B
if e.VoteA.Timestamp.After(e.VoteB.Timestamp) {
return fmt.Errorf("vote A should have a timestamp before vote B, but got %s > %s",
e.VoteA.Timestamp, e.VoteB.Timestamp)
}
// 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,
)
}
if e.VoteA.BlockID.IsZero() {
return errors.New("first vote is for a nil block - voter hasn't locked on a block")
}
// 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)
}
// Primed finds whether the PotentialAmnesiaEvidence is ready to be upgraded to Amnesia Evidence. It is decided if
// either the prosecuted node voted in the past or if the allocated trial period has expired without a proof of lock
// change having been provided.
func (e *PotentialAmnesiaEvidence) Primed(trialPeriod, currentHeight int64) bool {
// voted in the past can be instantly punishable
if e.VoteA.Round > e.VoteB.Round {
return true
}
// has the trial period expired
if e.HeightStamp > 0 {
return e.HeightStamp+trialPeriod <= currentHeight
}
return false
}
func (e *PotentialAmnesiaEvidence) ToProto() *tmproto.PotentialAmnesiaEvidence {
voteB := e.VoteB.ToProto()
voteA := e.VoteA.ToProto()
tp := &tmproto.PotentialAmnesiaEvidence{
VoteA: voteA,
VoteB: voteB,
HeightStamp: e.HeightStamp,
}
return tp
}
// ------------------
// 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 NewPOLCFromVoteSet(voteSet *VoteSet, pubKey crypto.PubKey, blockID BlockID) (*ProofOfLockChange, error) {
polc := newPOLCFromVoteSet(voteSet, pubKey, blockID)
return polc, polc.ValidateBasic()
}
func newPOLCFromVoteSet(voteSet *VoteSet, pubKey crypto.PubKey, blockID BlockID) *ProofOfLockChange {
if voteSet == nil {
return nil
}
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 NewPOLC(votes, pubKey)
}
// NewPOLC creates a POLC
func NewPOLC(votes []*Vote, pubKey crypto.PubKey) *ProofOfLockChange {
return &ProofOfLockChange{
Votes: votes,
PubKey: pubKey,
}
}
// EmptyPOLC returns an empty polc. This is used when no polc has been provided in the allocated trial period time
// and the node now needs to move to upgrading to AmnesiaEvidence and hence uses an empty polc
func NewEmptyPOLC() *ProofOfLockChange {
return &ProofOfLockChange{
nil,
nil,
}
}
func (e *ProofOfLockChange) Height() int64 {
return e.Votes[0].Height
}
// Time returns time of the latest 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
}
// ValidateVotes checks the polc against the validator set of that height. The function makes sure that the polc
// contains a majority of votes and that each
func (e *ProofOfLockChange) ValidateVotes(valSet *ValidatorSet, chainID string) error {
if e.IsAbsent() {
return errors.New("polc is empty")
}
talliedVotingPower := int64(0)
votingPowerNeeded := valSet.TotalVotingPower() * 2 / 3
for _, vote := range e.Votes {
exists := false
for _, validator := range valSet.Validators {
if bytes.Equal(validator.Address, vote.ValidatorAddress) {
exists = true
v := vote.ToProto()
if !validator.PubKey.VerifyBytes(VoteSignBytes(chainID, v), vote.Signature) {
return fmt.Errorf("cannot verify vote (from validator: %d) against signature: %v",
vote.ValidatorIndex, vote.Signature)
}
talliedVotingPower += validator.VotingPower
}
}
if !exists {
return fmt.Errorf("vote was not from a validator in this set: %v", vote.String())
}
}
if talliedVotingPower <= votingPowerNeeded {
return ErrNotEnoughVotingPowerSigned{
Got: talliedVotingPower,
Needed: votingPowerNeeded + 1,
}
}
return nil
}
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 == nil {
return errors.New("empty proof of lock change")
}
// first check if the polc is absent / empty
if e.IsAbsent() {
return nil
}
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 || len(e.Votes) == 0 {
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 vote == nil {
return fmt.Errorf("nil vote at index: %d", idx)
}
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.PubKey.Address().Bytes())
}
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 {
if e.IsAbsent() {
return "Empty ProofOfLockChange"
}
return fmt.Sprintf("ProofOfLockChange {Address: %X, Height: %d, Round: %d", e.Address(), e.Height(),
e.Votes[0].Round)
}
// IsAbsent checks if the polc is empty
func (e *ProofOfLockChange) IsAbsent() bool {
return e.Votes == nil && e.PubKey == nil
}
func (e *ProofOfLockChange) ToProto() (*tmproto.ProofOfLockChange, error) {
plc := new(tmproto.ProofOfLockChange)
vpb := make([]*tmproto.Vote, len(e.Votes))
// if absent create empty proto polc
if e.IsAbsent() {
return plc, nil
}
if e.Votes == nil {
return plc, errors.New("invalid proof of lock change (no votes), did you forget to validate?")
}
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 plc, fmt.Errorf("invalid proof of lock change (err: %w), did you forget to validate?", err)
}
plc.PubKey = &pk
plc.Votes = vpb
return plc, nil
}
// AmnesiaEvidence is the progression of PotentialAmnesiaEvidence and is used to prove an infringement of the
// Tendermint consensus when a validator incorrectly sends a vote in a later round without correctly changing the lock
type AmnesiaEvidence struct {
*PotentialAmnesiaEvidence
Polc *ProofOfLockChange
}
// Height, Time, Address, and Verify, and Hash functions are all inherited by the PotentialAmnesiaEvidence struct
var _ Evidence = &AmnesiaEvidence{}
func NewAmnesiaEvidence(pe *PotentialAmnesiaEvidence, proof *ProofOfLockChange) *AmnesiaEvidence {
return &AmnesiaEvidence{
pe,
proof,
}
}
// Note: Amnesia evidence with or without a polc are considered the same
func (e *AmnesiaEvidence) Equal(ev Evidence) bool {
if e2, ok := ev.(*AmnesiaEvidence); ok {
return e.PotentialAmnesiaEvidence.Equal(e2.PotentialAmnesiaEvidence)
}
return false
}
func (e *AmnesiaEvidence) Bytes() []byte {
pbe := e.ToProto()
bz, err := pbe.Marshal()
if err != nil {
panic(fmt.Errorf("converting amnesia evidence to bytes, err: %w", err))
}
return bz
}
func (e *AmnesiaEvidence) ValidateBasic() error {
if e == nil {
return errors.New("empty amnesia evidence")
}
if e.Polc == nil || e.PotentialAmnesiaEvidence == nil {
return errors.New("amnesia evidence is missing either the polc or the potential amnesia evidence")
}
if err := e.PotentialAmnesiaEvidence.ValidateBasic(); err != nil {
return fmt.Errorf("invalid potential amnesia evidence: %w", err)
}
if !e.Polc.IsAbsent() {
if err := e.Polc.ValidateBasic(); err != nil {
return fmt.Errorf("invalid proof of lock change: %w", err)
}
if !bytes.Equal(e.PotentialAmnesiaEvidence.Address(), e.Polc.Address()) {
return fmt.Errorf("validator addresses do not match (%X - %X)", e.PotentialAmnesiaEvidence.Address(),
e.Polc.Address())
}
if e.PotentialAmnesiaEvidence.Height() != e.Polc.Height() {
return fmt.Errorf("heights do not match (%d - %d)", e.PotentialAmnesiaEvidence.Height(),
e.Polc.Height())
}
if e.Polc.Round() <= e.VoteA.Round || e.Polc.Round() > e.VoteB.Round {
return fmt.Errorf("polc must be between %d and %d (inclusive)", e.VoteA.Round+1, e.VoteB.Round)
}
if !e.Polc.BlockID().Equals(e.PotentialAmnesiaEvidence.VoteB.BlockID) && !e.Polc.BlockID().IsZero() {
return fmt.Errorf("polc must be either for a nil block or for the same block as the second vote: %v != %v",
e.Polc.BlockID(), e.PotentialAmnesiaEvidence.VoteB.BlockID)
}
if e.Polc.Time().After(e.PotentialAmnesiaEvidence.VoteB.Timestamp) {
return fmt.Errorf("validator voted again before receiving a majority of votes for the new block: %v is after %v",
e.Polc.Time(), e.PotentialAmnesiaEvidence.VoteB.Timestamp)
}
}
return nil
}
// ViolatedConsensus assess on the basis of the AmnesiaEvidence whether the validator has violated the
// Tendermint consensus. Evidence must be validated first (see ValidateBasic).
// We are only interested in proving that the latter of the votes in terms of time was correctly done.
func (e *AmnesiaEvidence) ViolatedConsensus() (bool, string) {
// a validator having voted cannot go back and vote on an earlier round
if e.PotentialAmnesiaEvidence.VoteA.Round > e.PotentialAmnesiaEvidence.VoteB.Round {
return true, "validator went back and voted on a previous round"
}
// if empty, then no proof was provided to defend the validators actions
if e.Polc.IsAbsent() {
return true, "no proof of lock was provided"
}
return false, ""
}
func (e *AmnesiaEvidence) String() string {
return fmt.Sprintf("AmnesiaEvidence{ %v, polc: %v }", e.PotentialAmnesiaEvidence, e.Polc)
}
func (e *AmnesiaEvidence) ToProto() *tmproto.AmnesiaEvidence {
paepb := e.PotentialAmnesiaEvidence.ToProto()
polc, err := e.Polc.ToProto()
if err != nil {
polc, _ = NewEmptyPOLC().ToProto()
}
return &tmproto.AmnesiaEvidence{
PotentialAmnesiaEvidence: paepb,
Polc: polc,
}
}
func ProofOfLockChangeFromProto(pb *tmproto.ProofOfLockChange) (*ProofOfLockChange, error) {
if pb == nil {
return nil, errors.New("nil proof of lock change")
}
plc := new(ProofOfLockChange)
// check if it is an empty polc
if pb.PubKey == nil && pb.Votes == nil {
return plc, nil
}
if pb.Votes == nil {
return nil, errors.New("proofOfLockChange: is not absent but has no votes")
}
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: is not absent but has nil PubKey")
}
pk, err := cryptoenc.PubKeyFromProto(*pb.PubKey)
if err != nil {
return nil, err
}
plc.PubKey = pk
plc.Votes = vpb
return plc, plc.ValidateBasic()
}
func PotentialAmnesiaEvidenceFromProto(pb *tmproto.PotentialAmnesiaEvidence) (*PotentialAmnesiaEvidence, error) {
voteA, err := VoteFromProto(pb.GetVoteA())
if err != nil {
return nil, err
}
voteB, err := VoteFromProto(pb.GetVoteB())
if err != nil {
return nil, err
}
tp := PotentialAmnesiaEvidence{
VoteA: voteA,
VoteB: voteB,
HeightStamp: pb.GetHeightStamp(),
}
return &tp, tp.ValidateBasic()
}
func AmnesiaEvidenceFromProto(pb *tmproto.AmnesiaEvidence) (*AmnesiaEvidence, error) {
if pb == nil {
return nil, errors.New("nil amnesia evidence")
}
pae, err := PotentialAmnesiaEvidenceFromProto(pb.PotentialAmnesiaEvidence)
if err != nil {
return nil, fmt.Errorf("decoding to amnesia evidence, err: %w", err)
}
polc, err := ProofOfLockChangeFromProto(pb.Polc)
if err != nil {
return nil, fmt.Errorf("decoding to amnesia evidence, err: %w", err)
}
tp := &AmnesiaEvidence{
PotentialAmnesiaEvidence: pae,
Polc: polc,
}
return tp, tp.ValidateBasic()
}
//--------------------------------------------------
// 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.HashFromByteSlices(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
}
//-------------------------------------------- MOCKING --------------------------------------
// unstable - use only for testing
// assumes the round to be 0 and the validator index to be 0
func NewMockDuplicateVoteEvidence(height int64, time time.Time, chainID string) *DuplicateVoteEvidence {
val := NewMockPV()
return NewMockDuplicateVoteEvidenceWithValidator(height, time, val, chainID)
}
func NewMockDuplicateVoteEvidenceWithValidator(height int64, time time.Time,
pv PrivValidator, chainID string) *DuplicateVoteEvidence {
pubKey, _ := pv.GetPubKey()
voteA := makeMockVote(height, 0, 0, pubKey.Address(), randBlockID(), time)
vA := voteA.ToProto()
_ = pv.SignVote(chainID, vA)
voteA.Signature = vA.Signature
voteB := makeMockVote(height, 0, 0, pubKey.Address(), randBlockID(), time)
vB := voteB.ToProto()
_ = pv.SignVote(chainID, vB)
voteB.Signature = vB.Signature
return NewDuplicateVoteEvidence(voteA, voteB)
}
func makeMockVote(height int64, round, index int32, addr Address,
blockID BlockID, time time.Time) *Vote {
return &Vote{
Type: tmproto.SignedMsgType(2),
Height: height,
Round: round,
BlockID: blockID,
Timestamp: time,
ValidatorAddress: addr,
ValidatorIndex: index,
}
}
func randBlockID() BlockID {
return BlockID{
Hash: tmrand.Bytes(tmhash.Size),
PartSetHeader: PartSetHeader{
Total: 1,
Hash: tmrand.Bytes(tmhash.Size),
},
}
}
// 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{}}
v := vote.ToProto()
if err := voteVal.SignVote("mock-chain-id", v); err != nil {
panic(err)
}
vote.Signature = v.Signature
return ProofOfLockChange{
Votes: []*Vote{&vote},
PubKey: pubKey,
}
}
func maxTime(t1 time.Time, t2 time.Time) time.Time {
if t1.After(t2) {
return t1
}
return t2
}