tendermint/state/validation.go

126 lines
4.2 KiB
Go

package state
import (
"bytes"
"errors"
"fmt"
"github.com/tendermint/tendermint/types"
dbm "github.com/tendermint/tendermint/libs/db"
)
//-----------------------------------------------------
// Validate block
func validateBlock(stateDB dbm.DB, state State, block *types.Block) error {
// validate internal consistency
if err := block.ValidateBasic(); err != nil {
return err
}
// validate basic info
if block.ChainID != state.ChainID {
return fmt.Errorf("Wrong Block.Header.ChainID. Expected %v, got %v", state.ChainID, block.ChainID)
}
if block.Height != state.LastBlockHeight+1 {
return fmt.Errorf("Wrong Block.Header.Height. Expected %v, got %v", state.LastBlockHeight+1, block.Height)
}
/* TODO: Determine bounds for Time
See blockchain/reactor "stopSyncingDurationMinutes"
if !block.Time.After(lastBlockTime) {
return errors.New("Invalid Block.Header.Time")
}
*/
// validate prev block info
if !block.LastBlockID.Equals(state.LastBlockID) {
return fmt.Errorf("Wrong Block.Header.LastBlockID. Expected %v, got %v", state.LastBlockID, block.LastBlockID)
}
newTxs := int64(len(block.Data.Txs))
if block.TotalTxs != state.LastBlockTotalTx+newTxs {
return fmt.Errorf("Wrong Block.Header.TotalTxs. Expected %v, got %v", state.LastBlockTotalTx+newTxs, block.TotalTxs)
}
// validate app info
if !bytes.Equal(block.AppHash, state.AppHash) {
return fmt.Errorf("Wrong Block.Header.AppHash. Expected %X, got %v", state.AppHash, block.AppHash)
}
if !bytes.Equal(block.ConsensusHash, state.ConsensusParams.Hash()) {
return fmt.Errorf("Wrong Block.Header.ConsensusHash. Expected %X, got %v", state.ConsensusParams.Hash(), block.ConsensusHash)
}
if !bytes.Equal(block.LastResultsHash, state.LastResultsHash) {
return fmt.Errorf("Wrong Block.Header.LastResultsHash. Expected %X, got %v", state.LastResultsHash, block.LastResultsHash)
}
if !bytes.Equal(block.ValidatorsHash, state.Validators.Hash()) {
return fmt.Errorf("Wrong Block.Header.ValidatorsHash. Expected %X, got %v", state.Validators.Hash(), block.ValidatorsHash)
}
// Validate block LastCommit.
if block.Height == 1 {
if len(block.LastCommit.Precommits) != 0 {
return errors.New("Block at height 1 (first block) should have no LastCommit precommits")
}
} else {
if len(block.LastCommit.Precommits) != state.LastValidators.Size() {
return fmt.Errorf("Invalid block commit size. Expected %v, got %v",
state.LastValidators.Size(), len(block.LastCommit.Precommits))
}
err := state.LastValidators.VerifyCommit(
state.ChainID, state.LastBlockID, block.Height-1, block.LastCommit)
if err != nil {
return err
}
}
// TODO: Each check requires loading an old validator set.
// We should cap the amount of evidence per block
// to prevent potential proposer DoS.
for _, ev := range block.Evidence.Evidence {
if err := VerifyEvidence(stateDB, state, ev); err != nil {
return types.NewEvidenceInvalidErr(ev, err)
}
}
return nil
}
// VerifyEvidence verifies the evidence fully by checking:
// - it is sufficiently recent (MaxAge)
// - it is from a key who was a validator at the given height
// - it is internally consistent
// - it was properly signed by the alleged equivocator
func VerifyEvidence(stateDB dbm.DB, state State, evidence types.Evidence) error {
height := state.LastBlockHeight
evidenceAge := height - evidence.Height()
maxAge := state.ConsensusParams.EvidenceParams.MaxAge
if evidenceAge > maxAge {
return fmt.Errorf("Evidence from height %d is too old. Min height is %d",
evidence.Height(), height-maxAge)
}
valset, err := LoadValidators(stateDB, evidence.Height())
if err != nil {
// TODO: if err is just that we cant find it cuz we pruned, ignore.
// TODO: if its actually bad evidence, punish peer
return err
}
// The address must have been an active validator at the height.
// NOTE: we will ignore evidence from H if the key was not a validator
// at H, even if it is a validator at some nearby H'
ev := evidence
height, addr := ev.Height(), ev.Address()
_, val := valset.GetByAddress(addr)
if val == nil {
return fmt.Errorf("Address %X was not a validator at height %d", addr, height)
}
if err := evidence.Verify(state.ChainID, val.PubKey); err != nil {
return err
}
return nil
}