Add hyper proof tests

Co-authored-by: Gabriel Díaz <g.diaz.lopezllave@bbva.com>

balloon/hyper2/proof.go

@@ -17,7 +17,10 @@
 package hyper2
 
 import (
+	"bytes"
+
 	"github.com/bbva/qed/balloon/hyper2/navigation"
+	"github.com/bbva/qed/balloon/hyper2/pruning2"
 	"github.com/bbva/qed/hashing"
 	"github.com/bbva/qed/log"
 )
@@ -44,11 +47,19 @@ func (p QueryProof) Verify(key []byte, expectedRootHash hashing.Digest) (valid b
 
 	log.Debugf("Verifying query proof for key %d", p.Key)
 
-	// build a visitable pruned tree and the visit it to recompute the root hash
-	// visitor := pruning.NewComputeHashVisitor(p)
-	// recomputed := pruning.PruneToVerify(key, p.Value, p.hasher.Len()-len(p.AuditPath)).Accept(visitor)
+	if len(p.AuditPath) == 0 {
+		// an empty audit path (empty tree) shows non-membersip for any key
+		return false
+	}
+
+	// build a stack of operations and then interpret it to recompute the root hash
+	ops := pruning2.PruneToVerify(key, p.Value, p.hasher.Len()-uint16(len(p.AuditPath)))
+	ctx := &pruning2.Context{
+		Hasher:    p.hasher,
+		AuditPath: p.AuditPath,
+	}
+	recomputed := ops.Pop().Interpret(ops, ctx)
 
-	// return bytes.Equal(key, p.Key) && bytes.Equal(recomputed, expectedRootHash)
-	return true
+	return bytes.Equal(key, p.Key) && bytes.Equal(recomputed, expectedRootHash)
 
 }

balloon/hyper2/proof_test.go

@@ -0,0 +1,78 @@
+/*
+   Copyright 2018 Banco Bilbao Vizcaya Argentaria, S.A.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package hyper2
+
+import (
+	"testing"
+
+	"github.com/bbva/qed/hashing"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/bbva/qed/balloon/hyper2/navigation"
+)
+
+func TestProofVerify(t *testing.T) {
+
+	testCases := []struct {
+		key, value   []byte
+		auditPath    navigation.AuditPath
+		rootHash     hashing.Digest
+		verifyResult bool
+	}{
+		{
+			// verify key=0 with empty audit path
+			key:          []byte{0},
+			value:        []byte{0},
+			auditPath:    navigation.AuditPath{},
+			rootHash:     hashing.Digest{0x0},
+			verifyResult: false,
+		},
+		{
+			// verify key=0 with empty audit path
+			key:   []byte{0},
+			value: []byte{0},
+			auditPath: navigation.AuditPath{
+				"0x80|7": hashing.Digest{0x0},
+				"0x40|6": hashing.Digest{0x0},
+				"0x20|5": hashing.Digest{0x0},
+				"0x10|4": hashing.Digest{0x0},
+			},
+			rootHash:     hashing.Digest{0x0},
+			verifyResult: true,
+		},
+		{
+			// verify key=0 with empty audit path
+			key:   []byte{0},
+			value: []byte{0},
+			auditPath: navigation.AuditPath{
+				"0x80|7": hashing.Digest{0x0},
+				"0x40|6": hashing.Digest{0x0},
+				"0x20|5": hashing.Digest{0x0},
+				"0x10|4": hashing.Digest{0x0},
+			},
+			rootHash:     hashing.Digest{0x1},
+			verifyResult: false,
+		},
+	}
+
+	for i, c := range testCases {
+		proof := NewQueryProof(c.key, c.value, c.auditPath, hashing.NewFakeXorHasher())
+		correct := proof.Verify(c.key, c.rootHash)
+		assert.Equalf(t, c.verifyResult, correct, "The verification result should match for test case %d", i)
+	}
+
+}