package lite import ( "bytes" "github.com/pkg/errors" 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 verify 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 (bv *BaseVerifier) ChainID() string { return bv.chainID } // Implements Verifier. func (bv *BaseVerifier) Verify(signedHeader types.SignedHeader) error { // We can't verify commits for a different chain. if signedHeader.ChainID != bv.chainID { return cmn.NewError("BaseVerifier chainID is %v, cannot verify chainID %v", bv.chainID, signedHeader.ChainID) } // We can't verify commits older than bv.height. if signedHeader.Height < bv.height { return cmn.NewError("BaseVerifier height is %v, cannot verify height %v", bv.height, signedHeader.Height) } // We can't verify with the wrong validator set. if !bytes.Equal(signedHeader.ValidatorsHash, bv.valset.Hash()) { return lerr.ErrUnexpectedValidators(signedHeader.ValidatorsHash, bv.valset.Hash()) } // Do basic sanity checks. err := signedHeader.ValidateBasic(bv.chainID) if err != nil { return errors.Wrap(err, "in verify") } // Check commit signatures. err = bv.valset.VerifyCommit( bv.chainID, signedHeader.Commit.BlockID, signedHeader.Height, signedHeader.Commit) if err != nil { return errors.Wrap(err, "in verify") } return nil }