state.VerifyEvidence enforces EvidenceParams.MaxAge

state/state.go

@@ -389,6 +389,13 @@ func (s *State) GetValidators() (last *types.ValidatorSet, current *types.Valida
 // NOTE: return error may be ErrNoValSetForHeight, in which case the validator set
 // for the evidence height could not be loaded.
 func (s *State) VerifyEvidence(evidence types.Evidence) (priority int, err error) {
+	evidenceAge := s.LastBlockHeight - evidence.Height()
+	maxAge := s.Params.EvidenceParams.MaxAge
+	if evidenceAge > maxAge {
+		return priority, fmt.Errorf("Evidence from height %d is too old. Min height is %d",
+			evidence.Height(), s.LastBlockHeight-maxAge)
+	}
+
 	if err := evidence.Verify(s.ChainID); err != nil {
 		return priority, err
 	}

types/params.go

@@ -40,7 +40,7 @@ type BlockGossip struct {
 
 // EvidenceParams determine how we handle evidence of malfeasance
 type EvidenceParams struct {
-	MaxHeightDiff int `json:"max_height_diff"` // only accept new evidence more recent than this
+	MaxAge int `json:"max_age"` // only accept new evidence more recent than this
 }
 
 // DefaultConsensusParams returns a default ConsensusParams.
@@ -80,7 +80,7 @@ func DefaultBlockGossip() BlockGossip {
 // DefaultEvidence Params returns a default EvidenceParams.
 func DefaultEvidenceParams() EvidenceParams {
 	return EvidenceParams{
-		MaxHeightDiff: 100000, // 27.8 hrs at 1block/s
+		MaxAge: 100000, // 27.8 hrs at 1block/s
 	}
 }