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

This reverts commit 96a3502

lite/proxy/block.go

@@ -0,0 +1,49 @@
+package proxy
+
+import (
+	"bytes"
+
+	"github.com/pkg/errors"
+
+	"github.com/tendermint/tendermint/lite"
+	certerr "github.com/tendermint/tendermint/lite/errors"
+	"github.com/tendermint/tendermint/types"
+)
+
+func ValidateBlockMeta(meta *types.BlockMeta, check lite.Commit) error {
+	if meta == nil {
+		return errors.New("expecting a non-nil BlockMeta")
+	}
+	// TODO: check the BlockID??
+	return ValidateHeader(meta.Header, check)
+}
+
+func ValidateBlock(meta *types.Block, check lite.Commit) error {
+	if meta == nil {
+		return errors.New("expecting a non-nil Block")
+	}
+	err := ValidateHeader(meta.Header, check)
+	if err != nil {
+		return err
+	}
+	if !bytes.Equal(meta.Data.Hash(), meta.Header.DataHash) {
+		return errors.New("Data hash doesn't match header")
+	}
+	return nil
+}
+
+func ValidateHeader(head *types.Header, check lite.Commit) error {
+	if head == nil {
+		return errors.New("expecting a non-nil Header")
+	}
+	// make sure they are for the same height (obvious fail)
+	if head.Height != check.Height() {
+		return certerr.ErrHeightMismatch(head.Height, check.Height())
+	}
+	// check if they are equal by using hashes
+	chead := check.Header
+	if !bytes.Equal(head.Hash(), chead.Hash()) {
+		return errors.New("Headers don't match")
+	}
+	return nil
+}