tendermint/lite/base_verifier.go

73 lines
1.9 KiB
Go

package lite
import (
"bytes"
cmn "github.com/tendermint/tendermint/libs/common"
lerr "github.com/tendermint/tendermint/lite/errors"
"github.com/tendermint/tendermint/types"
)
var _ Verifier = (*BaseVerifier)(nil)
// BaseVerifier lets us check the validity of SignedHeaders at height or
// later, requiring sufficient votes (> 2/3) from the given valset.
// To certify blocks produced by a blockchain with mutable validator sets,
// use the DynamicVerifier.
// TODO: Handle unbonding time.
type BaseVerifier struct {
chainID string
height int64
valset *types.ValidatorSet
}
// NewBaseVerifier returns a new Verifier initialized with a validator set at
// some height.
func NewBaseVerifier(chainID string, height int64, valset *types.ValidatorSet) *BaseVerifier {
if valset.IsNilOrEmpty() {
panic("NewBaseVerifier requires a valid valset")
}
return &BaseVerifier{
chainID: chainID,
height: height,
valset: valset,
}
}
// Implements Verifier.
func (bc *BaseVerifier) ChainID() string {
return bc.chainID
}
// Implements Verifier.
func (bc *BaseVerifier) Certify(signedHeader types.SignedHeader) error {
// We can't certify commits older than bc.height.
if signedHeader.Height < bc.height {
return cmn.NewError("BaseVerifier height is %v, cannot certify height %v",
bc.height, signedHeader.Height)
}
// We can't certify with the wrong validator set.
if !bytes.Equal(signedHeader.ValidatorsHash,
bc.valset.Hash()) {
return lerr.ErrUnexpectedValidators(signedHeader.ValidatorsHash, bc.valset.Hash())
}
// Do basic sanity checks.
err := signedHeader.ValidateBasic(bc.chainID)
if err != nil {
return cmn.ErrorWrap(err, "in certify")
}
// Check commit signatures.
err = bc.valset.VerifyCommit(
bc.chainID, signedHeader.Commit.BlockID,
signedHeader.Height, signedHeader.Commit)
if err != nil {
return cmn.ErrorWrap(err, "in certify")
}
return nil
}