bring in merkle from tmlibs

merkle/simple_tree_test.go

@@ -0,0 +1,87 @@
+package merkle
+
+import (
+	"bytes"
+
+	cmn "github.com/tendermint/tmlibs/common"
+	. "github.com/tendermint/tmlibs/test"
+
+	"testing"
+)
+
+type testItem []byte
+
+func (tI testItem) Hash() []byte {
+	return []byte(tI)
+}
+
+func TestSimpleProof(t *testing.T) {
+
+	total := 100
+
+	items := make([]Hasher, total)
+	for i := 0; i < total; i++ {
+		items[i] = testItem(cmn.RandBytes(32))
+	}
+
+	rootHash := SimpleHashFromHashers(items)
+
+	rootHash2, proofs := SimpleProofsFromHashers(items)
+
+	if !bytes.Equal(rootHash, rootHash2) {
+		t.Errorf("Unmatched root hashes: %X vs %X", rootHash, rootHash2)
+	}
+
+	// For each item, check the trail.
+	for i, item := range items {
+		itemHash := item.Hash()
+		proof := proofs[i]
+
+		// Verify success
+		ok := proof.Verify(i, total, itemHash, rootHash)
+		if !ok {
+			t.Errorf("Verification failed for index %v.", i)
+		}
+
+		// Wrong item index should make it fail
+		{
+			ok = proof.Verify((i+1)%total, total, itemHash, rootHash)
+			if ok {
+				t.Errorf("Expected verification to fail for wrong index %v.", i)
+			}
+		}
+
+		// Trail too long should make it fail
+		origAunts := proof.Aunts
+		proof.Aunts = append(proof.Aunts, cmn.RandBytes(32))
+		{
+			ok = proof.Verify(i, total, itemHash, rootHash)
+			if ok {
+				t.Errorf("Expected verification to fail for wrong trail length.")
+			}
+		}
+		proof.Aunts = origAunts
+
+		// Trail too short should make it fail
+		proof.Aunts = proof.Aunts[0 : len(proof.Aunts)-1]
+		{
+			ok = proof.Verify(i, total, itemHash, rootHash)
+			if ok {
+				t.Errorf("Expected verification to fail for wrong trail length.")
+			}
+		}
+		proof.Aunts = origAunts
+
+		// Mutating the itemHash should make it fail.
+		ok = proof.Verify(i, total, MutateByteSlice(itemHash), rootHash)
+		if ok {
+			t.Errorf("Expected verification to fail for mutated leaf hash")
+		}
+
+		// Mutating the rootHash should make it fail.
+		ok = proof.Verify(i, total, itemHash, MutateByteSlice(rootHash))
+		if ok {
+			t.Errorf("Expected verification to fail for mutated root hash")
+		}
+	}
+}