|
package types
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/binary"
|
|
"errors"
|
|
"fmt"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/tendermint/tendermint/crypto/merkle"
|
|
"github.com/tendermint/tendermint/crypto/tmhash"
|
|
tmjson "github.com/tendermint/tendermint/libs/json"
|
|
tmrand "github.com/tendermint/tendermint/libs/rand"
|
|
tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
|
|
)
|
|
|
|
// Evidence represents any provable malicious activity by a validator.
|
|
// Verification logic for each evidence is part of the evidence module.
|
|
type Evidence interface {
|
|
Height() int64 // height of the infraction
|
|
Bytes() []byte // bytes which comprise the evidence
|
|
Hash() []byte // hash of the evidence
|
|
ValidateBasic() error // basic consistency check
|
|
String() string // string format of the evidence
|
|
}
|
|
|
|
const (
|
|
// MaxEvidenceBytes is a maximum size of any evidence (including amino overhead).
|
|
MaxEvidenceBytes int64 = 444
|
|
)
|
|
|
|
//--------------------------------------------------------------------------------------
|
|
|
|
// 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, 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
|
|
}
|
|
|
|
// Bytes returns the proto-encoded evidence as a byte array.
|
|
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 {
|
|
return tmhash.Sum(dve.Bytes())
|
|
}
|
|
|
|
// 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
|
|
}
|
|
|
|
// ToProto encodes DuplicateVoteEvidence to protobuf
|
|
func (dve *DuplicateVoteEvidence) ToProto() *tmproto.DuplicateVoteEvidence {
|
|
voteB := dve.VoteB.ToProto()
|
|
voteA := dve.VoteA.ToProto()
|
|
tp := tmproto.DuplicateVoteEvidence{
|
|
VoteA: voteA,
|
|
VoteB: voteB,
|
|
}
|
|
return &tp
|
|
}
|
|
|
|
// DuplicateVoteEvidenceFromProto decodes protobuf into DuplicateVoteEvidence
|
|
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 := NewDuplicateVoteEvidence(vA, vB)
|
|
|
|
return dve, dve.ValidateBasic()
|
|
}
|
|
|
|
//------------------------------------ LIGHT EVIDENCE --------------------------------------
|
|
|
|
// LightClientAttackEvidence is a generalized evidence that captures all forms of known attacks on
|
|
// a light client such that a full node can verify, propose and commit the evidence on-chain for
|
|
// punishment of the malicious validators. There are three forms of attacks: Lunatic, Equivocation
|
|
// and Amnesia. These attacks are exhaustive. You can find a more detailed overview of this at
|
|
// tendermint/docs/architecture/adr-047-handling-evidence-from-light-client.md
|
|
type LightClientAttackEvidence struct {
|
|
ConflictingBlock *LightBlock
|
|
CommonHeight int64
|
|
}
|
|
|
|
var _ Evidence = &LightClientAttackEvidence{}
|
|
|
|
// Height returns the last height at which the primary provider and witness provider had the same header.
|
|
// We use this as the height of the infraction rather than the actual conflicting header because we know
|
|
// that the malicious validators were bonded at this height which is important for evidence expiry
|
|
func (l *LightClientAttackEvidence) Height() int64 {
|
|
return l.CommonHeight
|
|
}
|
|
|
|
// Bytes returns the proto-encoded evidence as a byte array
|
|
func (l *LightClientAttackEvidence) Bytes() []byte {
|
|
pbe, err := l.ToProto()
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
bz, err := pbe.Marshal()
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return bz
|
|
}
|
|
|
|
// Hash returns the hash of the header and the commonHeight. This is designed to cause hash collisions with evidence
|
|
// that have the same conflicting header and common height but different permutations of validator commit signatures.
|
|
// The reason for this is that we don't want to allow several permutations of the same evidence to be committed on
|
|
// chain. Ideally we commit the header with the most commit signatures but anything greater than 1/3 is sufficient.
|
|
func (l *LightClientAttackEvidence) Hash() []byte {
|
|
buf := make([]byte, binary.MaxVarintLen64)
|
|
n := binary.PutVarint(buf, l.CommonHeight)
|
|
bz := make([]byte, tmhash.Size+n)
|
|
copy(bz[:tmhash.Size-1], l.ConflictingBlock.Hash().Bytes())
|
|
copy(bz[tmhash.Size:], buf)
|
|
return tmhash.Sum(bz)
|
|
}
|
|
|
|
// ValidateBasic performs basic validation such that the evidence is consistent and can now be used for verification.
|
|
func (l *LightClientAttackEvidence) ValidateBasic() error {
|
|
if l.ConflictingBlock == nil {
|
|
return errors.New("conflicting block is nil")
|
|
}
|
|
|
|
// this check needs to be done before we can run validate basic
|
|
if l.ConflictingBlock.Header == nil {
|
|
return errors.New("conflicting block missing header")
|
|
}
|
|
|
|
if err := l.ConflictingBlock.ValidateBasic(l.ConflictingBlock.ChainID); err != nil {
|
|
return fmt.Errorf("invalid conflicting light block: %w", err)
|
|
}
|
|
|
|
if l.CommonHeight <= 0 {
|
|
return errors.New("negative or zero common height")
|
|
}
|
|
|
|
// check that common height isn't ahead of the height of the conflicting block. It
|
|
// is possible that they are the same height if the light node witnesses either an
|
|
// amnesia or a equivocation attack.
|
|
if l.CommonHeight > l.ConflictingBlock.Height {
|
|
return fmt.Errorf("common height is ahead of the conflicting block height (%d > %d)",
|
|
l.CommonHeight, l.ConflictingBlock.Height)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// String returns a string representation of LightClientAttackEvidence
|
|
func (l *LightClientAttackEvidence) String() string {
|
|
return fmt.Sprintf("LightClientAttackEvidence{ConflictingBlock: %v, CommonHeight: %d}",
|
|
l.ConflictingBlock.String(), l.CommonHeight)
|
|
}
|
|
|
|
// ToProto encodes LightClientAttackEvidence to protobuf
|
|
func (l *LightClientAttackEvidence) ToProto() (*tmproto.LightClientAttackEvidence, error) {
|
|
conflictingBlock, err := l.ConflictingBlock.ToProto()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &tmproto.LightClientAttackEvidence{
|
|
ConflictingBlock: conflictingBlock,
|
|
CommonHeight: l.CommonHeight,
|
|
}, nil
|
|
}
|
|
|
|
// LightClientAttackEvidenceFromProto decodes protobuf
|
|
func LightClientAttackEvidenceFromProto(l *tmproto.LightClientAttackEvidence) (*LightClientAttackEvidence, error) {
|
|
if l == nil {
|
|
return nil, errors.New("empty light client attack evidence")
|
|
}
|
|
|
|
conflictingBlock, err := LightBlockFromProto(l.ConflictingBlock)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
le := &LightClientAttackEvidence{
|
|
ConflictingBlock: conflictingBlock,
|
|
CommonHeight: l.CommonHeight,
|
|
}
|
|
|
|
return le, le.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 bytes.Equal(evidence.Hash(), ev.Hash()) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
//------------------------------------------ PROTO --------------------------------------
|
|
|
|
// EvidenceToProto is a generalized function for encoding evidence that conforms to the
|
|
// evidence interface to protobuf
|
|
func EvidenceToProto(evidence Evidence) (*tmproto.Evidence, error) {
|
|
if evidence == nil {
|
|
return nil, errors.New("nil evidence")
|
|
}
|
|
|
|
switch evi := evidence.(type) {
|
|
case *DuplicateVoteEvidence:
|
|
pbev := evi.ToProto()
|
|
return &tmproto.Evidence{
|
|
Sum: &tmproto.Evidence_DuplicateVoteEvidence{
|
|
DuplicateVoteEvidence: pbev,
|
|
},
|
|
}, nil
|
|
|
|
case *LightClientAttackEvidence:
|
|
pbev, err := evi.ToProto()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &tmproto.Evidence{
|
|
Sum: &tmproto.Evidence_LightClientAttackEvidence{
|
|
LightClientAttackEvidence: pbev,
|
|
},
|
|
}, nil
|
|
|
|
default:
|
|
return nil, fmt.Errorf("toproto: evidence is not recognized: %T", evi)
|
|
}
|
|
}
|
|
|
|
// EvidenceFromProto is a generalized function for decoding protobuf into the
|
|
// evidence interface
|
|
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_LightClientAttackEvidence:
|
|
return LightClientAttackEvidenceFromProto(evi.LightClientAttackEvidence)
|
|
default:
|
|
return nil, errors.New("evidence is not recognized")
|
|
}
|
|
}
|
|
|
|
func init() {
|
|
tmjson.RegisterType(&DuplicateVoteEvidence{}, "tendermint/DuplicateVoteEvidence")
|
|
tmjson.RegisterType(&LightClientAttackEvidence{}, "tendermint/LightClientAttackEvidence")
|
|
}
|
|
|
|
//-------------------------------------------- ERRORS --------------------------------------
|
|
|
|
// ErrInvalidEvidence wraps a piece of evidence and the error denoting how or why it is invalid.
|
|
type ErrInvalidEvidence struct {
|
|
Evidence Evidence
|
|
Reason error
|
|
}
|
|
|
|
// NewErrInvalidEvidence returns a new EvidenceInvalid with the given err.
|
|
func NewErrInvalidEvidence(ev Evidence, err error) *ErrInvalidEvidence {
|
|
return &ErrInvalidEvidence{ev, err}
|
|
}
|
|
|
|
// Error returns a string representation of the error.
|
|
func (err *ErrInvalidEvidence) Error() string {
|
|
return fmt.Sprintf("Invalid evidence: %v. Evidence: %v", err.Reason, 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)
|
|
}
|
|
|
|
//-------------------------------------------- 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),
|
|
},
|
|
}
|
|
}
|