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trie: reject deletions when verifying range proofs
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karalabe committed Nov 23, 2021
1 parent d15e423 commit 743769f
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Showing 2 changed files with 85 additions and 1 deletion.
7 changes: 6 additions & 1 deletion trie/proof.go
Original file line number Diff line number Diff line change
Expand Up @@ -472,12 +472,17 @@ func VerifyRangeProof(rootHash common.Hash, firstKey []byte, lastKey []byte, key
if len(keys) != len(values) {
return false, fmt.Errorf("inconsistent proof data, keys: %d, values: %d", len(keys), len(values))
}
// Ensure the received batch is monotonic increasing.
// Ensure the received batch is monotonic increasing and contains no deletions
for i := 0; i < len(keys)-1; i++ {
if bytes.Compare(keys[i], keys[i+1]) >= 0 {
return false, errors.New("range is not monotonically increasing")
}
}
for _, value := range values {
if len(value) == 0 {
return false, errors.New("range contains deletion")
}
}
// Special case, there is no edge proof at all. The given range is expected
// to be the whole leaf-set in the trie.
if proof == nil {
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79 changes: 79 additions & 0 deletions trie/proof_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -813,6 +813,85 @@ func TestBloatedProof(t *testing.T) {
}
}

// TestEmptyValueRangeProof tests normal range proof with both edge proofs
// as the existent proof, but with an extra empty value included, which is a
// noop technically, but practically should be rejected.
func TestEmptyValueRangeProof(t *testing.T) {
trie, values := randomTrie(512)
var entries entrySlice
for _, kv := range values {
entries = append(entries, kv)
}
sort.Sort(entries)

// Create a new entry with a slightly modified key
mid := len(entries) / 2
key := common.CopyBytes(entries[mid-1].k)
for n := len(key) - 1; n >= 0; n-- {
if key[n] < 0xff {
key[n]++
break
}
}
noop := &kv{key, []byte{}, false}
entries = append(append(append([]*kv{}, entries[:mid]...), noop), entries[mid:]...)

start, end := 1, len(entries)-1

proof := memorydb.New()
if err := trie.Prove(entries[start].k, 0, proof); err != nil {
t.Fatalf("Failed to prove the first node %v", err)
}
if err := trie.Prove(entries[end-1].k, 0, proof); err != nil {
t.Fatalf("Failed to prove the last node %v", err)
}
var keys [][]byte
var vals [][]byte
for i := start; i < end; i++ {
keys = append(keys, entries[i].k)
vals = append(vals, entries[i].v)
}
_, err := VerifyRangeProof(trie.Hash(), keys[0], keys[len(keys)-1], keys, vals, proof)
if err == nil {
t.Fatalf("Expected failure on noop entry")
}
}

// TestAllElementsEmptyValueRangeProof tests the range proof with all elements,
// but with an extra empty value included, which is a noop technically, but
// practically should be rejected.
func TestAllElementsEmptyValueRangeProof(t *testing.T) {
trie, values := randomTrie(512)
var entries entrySlice
for _, kv := range values {
entries = append(entries, kv)
}
sort.Sort(entries)

// Create a new entry with a slightly modified key
mid := len(entries) / 2
key := common.CopyBytes(entries[mid-1].k)
for n := len(key) - 1; n >= 0; n-- {
if key[n] < 0xff {
key[n]++
break
}
}
noop := &kv{key, []byte{}, false}
entries = append(append(append([]*kv{}, entries[:mid]...), noop), entries[mid:]...)

var keys [][]byte
var vals [][]byte
for i := 0; i < len(entries); i++ {
keys = append(keys, entries[i].k)
vals = append(vals, entries[i].v)
}
_, err := VerifyRangeProof(trie.Hash(), nil, nil, keys, vals, nil)
if err == nil {
t.Fatalf("Expected failure on noop entry")
}
}

// mutateByte changes one byte in b.
func mutateByte(b []byte) {
for r := mrand.Intn(len(b)); ; {
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