refactor: VerifyMembership and VerifyNonMembership api (#391)

* refactor: remove  and

* chore: CHANGELOG

* lint

* chore: changelog

* refactor: remove CombineProofs

* refactor: VerifyMembership and VerifyNonMembership api

* refactor: reset api

* Update go/ics23.go

* refactor: remove unnecessary code

* lint: remove isLeft and isRight as they are unused now

Author: colin-axner

go/ics23.go

@@ -23,25 +23,23 @@ and determine neighbors
 */
 package ics23
 
-import (
-	"bytes"
-)
-
 // CommitmentRoot is a byte slice that represents the merkle root of a tree that can be used to validate proofs
 type CommitmentRoot []byte
 
 // VerifyMembership returns true iff
-// proof is (contains) an ExistenceProof for the given key and value AND
-// calculating the root for the ExistenceProof matches the provided CommitmentRoot
+// proof is an ExistenceProof for the given key and value AND
+// calculating the root for the ExistenceProof matches the provided CommitmentRoot.
 func VerifyMembership(spec *ProofSpec, root CommitmentRoot, proof *CommitmentProof, key []byte, value []byte) bool {
-	// decompress it before running code (no-op if not compressed)
-	proof = Decompress(proof)
-	ep := getExistProofForKey(proof, key)
+	if proof == nil {
+		return false
+	}
+
+	ep := proof.GetExist()
 	if ep == nil {
 		return false
 	}
-	err := ep.Verify(spec, root, key, value)
-	return err == nil
+
+	return ep.Verify(spec, root, key, value) == nil
 }
 
 // VerifyNonMembership returns true iff
@@ -50,58 +48,14 @@ func VerifyMembership(spec *ProofSpec, root CommitmentRoot, proof *CommitmentPro
 // left and right proofs are neighbors (or left/right most if one is nil)
 // provided key is between the keys of the two proofs
 func VerifyNonMembership(spec *ProofSpec, root CommitmentRoot, proof *CommitmentProof, key []byte) bool {
-	// decompress it before running code (no-op if not compressed)
-	proof = Decompress(proof)
-	np := getNonExistProofForKey(spec, proof, key)
-	if np == nil {
-		return false
-	}
-	err := np.Verify(spec, root, key)
-	return err == nil
-}
-
-func getExistProofForKey(proof *CommitmentProof, key []byte) *ExistenceProof {
 	if proof == nil {
-		return nil
-	}
-
-	switch p := proof.Proof.(type) {
-	case *CommitmentProof_Exist:
-		ep := p.Exist
-		if bytes.Equal(ep.Key, key) {
-			return ep
-		}
-	case *CommitmentProof_Batch:
-		for _, sub := range p.Batch.Entries {
-			if ep := sub.GetExist(); ep != nil && bytes.Equal(ep.Key, key) {
-				return ep
-			}
-		}
+		return false
 	}
-	return nil
-}
 
-func getNonExistProofForKey(spec *ProofSpec, proof *CommitmentProof, key []byte) *NonExistenceProof {
-	switch p := proof.Proof.(type) {
-	case *CommitmentProof_Nonexist:
-		np := p.Nonexist
-		if isLeft(spec, np.Left, key) && isRight(spec, np.Right, key) {
-			return np
-		}
-	case *CommitmentProof_Batch:
-		for _, sub := range p.Batch.Entries {
-			if np := sub.GetNonexist(); np != nil && isLeft(spec, np.Left, key) && isRight(spec, np.Right, key) {
-				return np
-			}
-		}
+	np := proof.GetNonexist()
+	if np == nil {
+		return false
 	}
-	return nil
-}
-
-func isLeft(spec *ProofSpec, left *ExistenceProof, key []byte) bool {
-	return left == nil || bytes.Compare(keyForComparison(spec, left.Key), keyForComparison(spec, key)) < 0
-}
 
-func isRight(spec *ProofSpec, right *ExistenceProof, key []byte) bool {
-	return right == nil || bytes.Compare(keyForComparison(spec, right.Key), keyForComparison(spec, key)) > 0
+	return np.Verify(spec, root, key) == nil
 }

go/vectors_test.go

@@ -13,6 +13,7 @@ func TestVectors(t *testing.T) {
 		name := fmt.Sprintf("%s/%s", tc.Dir, tc.Filename)
 		t.Run(name, func(t *testing.T) {
 			proof, ref := LoadFile(t, tc.Dir, tc.Filename)
+
 			// Test Calculate method
 			calculatedRoot, err := proof.Calculate()
 			if err != nil {
@@ -26,12 +27,12 @@ func TestVectors(t *testing.T) {
 				// non-existence
 				valid := VerifyNonMembership(tc.Spec, ref.RootHash, proof, ref.Key)
 				if !valid {
-					t.Fatal("Invalid proof")
+					t.Fatalf("Invalid proof: %v", err)
 				}
 			} else {
 				valid := VerifyMembership(tc.Spec, ref.RootHash, proof, ref.Key, ref.Value)
 				if !valid {
-					t.Fatal("Invalid proof")
+					t.Fatalf("Invalid proof: %v", err)
 				}
 			}
 		})