tendermint/lite/static_certifier.go

74 lines
1.8 KiB
Go

package lite
import (
"bytes"
"github.com/pkg/errors"
"github.com/tendermint/tendermint/types"
liteErr "github.com/tendermint/tendermint/lite/errors"
)
var _ Certifier = (*StaticCertifier)(nil)
// StaticCertifier assumes a static set of validators, set on
// initilization and checks against them.
// The signatures on every header is checked for > 2/3 votes
// against the known validator set upon Certify
//
// Good for testing or really simple chains. Building block
// to support real-world functionality.
type StaticCertifier struct {
chainID string
vSet *types.ValidatorSet
vhash []byte
}
// NewStaticCertifier returns a new certifier with a static validator set.
func NewStaticCertifier(chainID string, vals *types.ValidatorSet) *StaticCertifier {
return &StaticCertifier{
chainID: chainID,
vSet: vals,
}
}
// ChainID returns the chain id.
// Implements Certifier.
func (sc *StaticCertifier) ChainID() string {
return sc.chainID
}
// Validators returns the validator set.
func (sc *StaticCertifier) Validators() *types.ValidatorSet {
return sc.vSet
}
// Hash returns the hash of the validator set.
func (sc *StaticCertifier) Hash() []byte {
if len(sc.vhash) == 0 {
sc.vhash = sc.vSet.Hash()
}
return sc.vhash
}
// Certify makes sure that the commit is valid.
// Implements Certifier.
func (sc *StaticCertifier) Certify(commit Commit) error {
// do basic sanity checks
err := commit.ValidateBasic(sc.chainID)
if err != nil {
return err
}
// make sure it has the same validator set we have (static means static)
if !bytes.Equal(sc.Hash(), commit.Header.ValidatorsHash) {
return liteErr.ErrValidatorsChanged()
}
// then make sure we have the proper signatures for this
err = sc.vSet.VerifyCommit(sc.chainID, commit.Commit.BlockID,
commit.Header.Height, commit.Commit)
return errors.WithStack(err)
}