Revert "delete everything" (includes everything non-go-crypto)

This reverts commit 96a3502

lite/static_certifier.go

@@ -0,0 +1,73 @@
+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)
+}