diff --git a/trie/iterator.go b/trie/iterator.go
index 64110c6d96a9645288a7b334939e43fd50b0afa0..00b890eb896fade08b70c47b4928af1b73449f46 100644
--- a/trie/iterator.go
+++ b/trie/iterator.go
@@ -22,6 +22,7 @@ import (
"errors"
"github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/rlp"
)
// Iterator is a key-value trie iterator that traverses a Trie.
@@ -55,31 +56,50 @@ func (it *Iterator) Next() bool {
return false
}
+// Prove generates the Merkle proof for the leaf node the iterator is currently
+// positioned on.
+func (it *Iterator) Prove() [][]byte {
+ return it.nodeIt.LeafProof()
+}
+
// NodeIterator is an iterator to traverse the trie pre-order.
type NodeIterator interface {
// Next moves the iterator to the next node. If the parameter is false, any child
// nodes will be skipped.
Next(bool) bool
+
// Error returns the error status of the iterator.
Error() error
// Hash returns the hash of the current node.
Hash() common.Hash
+
// Parent returns the hash of the parent of the current node. The hash may be the one
// grandparent if the immediate parent is an internal node with no hash.
Parent() common.Hash
+
// Path returns the hex-encoded path to the current node.
// Callers must not retain references to the return value after calling Next.
// For leaf nodes, the last element of the path is the 'terminator symbol' 0x10.
Path() []byte
// Leaf returns true iff the current node is a leaf node.
- // LeafBlob, LeafKey return the contents and key of the leaf node. These
- // method panic if the iterator is not positioned at a leaf.
- // Callers must not retain references to their return value after calling Next
Leaf() bool
- LeafBlob() []byte
+
+ // LeafKey returns the key of the leaf. The method panics if the iterator is not
+ // positioned at a leaf. Callers must not retain references to the value after
+ // calling Next.
LeafKey() []byte
+
+ // LeafBlob returns the content of the leaf. The method panics if the iterator
+ // is not positioned at a leaf. Callers must not retain references to the value
+ // after calling Next.
+ LeafBlob() []byte
+
+ // LeafProof returns the Merkle proof of the leaf. The method panics if the
+ // iterator is not positioned at a leaf. Callers must not retain references
+ // to the value after calling Next.
+ LeafProof() [][]byte
}
// nodeIteratorState represents the iteration state at one particular node of the
@@ -139,6 +159,15 @@ func (it *nodeIterator) Leaf() bool {
return hasTerm(it.path)
}
+func (it *nodeIterator) LeafKey() []byte {
+ if len(it.stack) > 0 {
+ if _, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
+ return hexToKeybytes(it.path)
+ }
+ }
+ panic("not at leaf")
+}
+
func (it *nodeIterator) LeafBlob() []byte {
if len(it.stack) > 0 {
if node, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
@@ -148,10 +177,22 @@ func (it *nodeIterator) LeafBlob() []byte {
panic("not at leaf")
}
-func (it *nodeIterator) LeafKey() []byte {
+func (it *nodeIterator) LeafProof() [][]byte {
if len(it.stack) > 0 {
if _, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
- return hexToKeybytes(it.path)
+ hasher := newHasher(0, 0, nil)
+ proofs := make([][]byte, 0, len(it.stack))
+
+ for i, item := range it.stack[:len(it.stack)-1] {
+ // Gather nodes that end up as hash nodes (or the root)
+ node, _, _ := hasher.hashChildren(item.node, nil)
+ hashed, _ := hasher.store(node, nil, false)
+ if _, ok := hashed.(hashNode); ok || i == 0 {
+ enc, _ := rlp.EncodeToBytes(node)
+ proofs = append(proofs, enc)
+ }
+ }
+ return proofs
}
}
panic("not at leaf")
@@ -361,12 +402,16 @@ func (it *differenceIterator) Leaf() bool {
return it.b.Leaf()
}
+func (it *differenceIterator) LeafKey() []byte {
+ return it.b.LeafKey()
+}
+
func (it *differenceIterator) LeafBlob() []byte {
return it.b.LeafBlob()
}
-func (it *differenceIterator) LeafKey() []byte {
- return it.b.LeafKey()
+func (it *differenceIterator) LeafProof() [][]byte {
+ return it.b.LeafProof()
}
func (it *differenceIterator) Path() []byte {
@@ -464,12 +509,16 @@ func (it *unionIterator) Leaf() bool {
return (*it.items)[0].Leaf()
}
+func (it *unionIterator) LeafKey() []byte {
+ return (*it.items)[0].LeafKey()
+}
+
func (it *unionIterator) LeafBlob() []byte {
return (*it.items)[0].LeafBlob()
}
-func (it *unionIterator) LeafKey() []byte {
- return (*it.items)[0].LeafKey()
+func (it *unionIterator) LeafProof() [][]byte {
+ return (*it.items)[0].LeafProof()
}
func (it *unionIterator) Path() []byte {
@@ -509,12 +558,10 @@ func (it *unionIterator) Next(descend bool) bool {
heap.Push(it.items, skipped)
}
}
-
if least.Next(descend) {
it.count++
heap.Push(it.items, least)
}
-
return len(*it.items) > 0
}
diff --git a/trie/proof_test.go b/trie/proof_test.go
index dee6f7d8593110fcfecdfa2364af5eb27e1fa6ae..996f8747814382d18835da382781d4becdb5df49 100644
--- a/trie/proof_test.go
+++ b/trie/proof_test.go
@@ -32,20 +32,46 @@ func init() {
mrand.Seed(time.Now().Unix())
}
+// makeProvers creates Merkle trie provers based on different implementations to
+// test all variations.
+func makeProvers(trie *Trie) []func(key []byte) *ethdb.MemDatabase {
+ var provers []func(key []byte) *ethdb.MemDatabase
+
+ // Create a direct trie based Merkle prover
+ provers = append(provers, func(key []byte) *ethdb.MemDatabase {
+ proof := ethdb.NewMemDatabase()
+ trie.Prove(key, 0, proof)
+ return proof
+ })
+ // Create a leaf iterator based Merkle prover
+ provers = append(provers, func(key []byte) *ethdb.MemDatabase {
+ proof := ethdb.NewMemDatabase()
+ if it := NewIterator(trie.NodeIterator(key)); it.Next() && bytes.Equal(key, it.Key) {
+ for _, p := range it.Prove() {
+ proof.Put(crypto.Keccak256(p), p)
+ }
+ }
+ return proof
+ })
+ return provers
+}
+
func TestProof(t *testing.T) {
trie, vals := randomTrie(500)
root := trie.Hash()
- for _, kv := range vals {
- proofs := ethdb.NewMemDatabase()
- if trie.Prove(kv.k, 0, proofs) != nil {
- t.Fatalf("missing key %x while constructing proof", kv.k)
- }
- val, _, err := VerifyProof(root, kv.k, proofs)
- if err != nil {
- t.Fatalf("VerifyProof error for key %x: %v\nraw proof: %v", kv.k, err, proofs)
- }
- if !bytes.Equal(val, kv.v) {
- t.Fatalf("VerifyProof returned wrong value for key %x: got %x, want %x", kv.k, val, kv.v)
+ for i, prover := range makeProvers(trie) {
+ for _, kv := range vals {
+ proof := prover(kv.k)
+ if proof == nil {
+ t.Fatalf("prover %d: missing key %x while constructing proof", i, kv.k)
+ }
+ val, _, err := VerifyProof(root, kv.k, proof)
+ if err != nil {
+ t.Fatalf("prover %d: failed to verify proof for key %x: %v\nraw proof: %x", i, kv.k, err, proof)
+ }
+ if !bytes.Equal(val, kv.v) {
+ t.Fatalf("prover %d: verified value mismatch for key %x: have %x, want %x", i, kv.k, val, kv.v)
+ }
}
}
}
@@ -53,37 +79,66 @@ func TestProof(t *testing.T) {
func TestOneElementProof(t *testing.T) {
trie := new(Trie)
updateString(trie, "k", "v")
- proofs := ethdb.NewMemDatabase()
- trie.Prove([]byte("k"), 0, proofs)
- if len(proofs.Keys()) != 1 {
- t.Error("proof should have one element")
- }
- val, _, err := VerifyProof(trie.Hash(), []byte("k"), proofs)
- if err != nil {
- t.Fatalf("VerifyProof error: %v\nproof hashes: %v", err, proofs.Keys())
- }
- if !bytes.Equal(val, []byte("v")) {
- t.Fatalf("VerifyProof returned wrong value: got %x, want 'k'", val)
+ for i, prover := range makeProvers(trie) {
+ proof := prover([]byte("k"))
+ if proof == nil {
+ t.Fatalf("prover %d: nil proof", i)
+ }
+ if proof.Len() != 1 {
+ t.Errorf("prover %d: proof should have one element", i)
+ }
+ val, _, err := VerifyProof(trie.Hash(), []byte("k"), proof)
+ if err != nil {
+ t.Fatalf("prover %d: failed to verify proof: %v\nraw proof: %x", i, err, proof)
+ }
+ if !bytes.Equal(val, []byte("v")) {
+ t.Fatalf("prover %d: verified value mismatch: have %x, want 'k'", i, val)
+ }
}
}
-func TestVerifyBadProof(t *testing.T) {
+func TestBadProof(t *testing.T) {
trie, vals := randomTrie(800)
root := trie.Hash()
- for _, kv := range vals {
- proofs := ethdb.NewMemDatabase()
- trie.Prove(kv.k, 0, proofs)
- if len(proofs.Keys()) == 0 {
- t.Fatal("zero length proof")
+ for i, prover := range makeProvers(trie) {
+ for _, kv := range vals {
+ proof := prover(kv.k)
+ if proof == nil {
+ t.Fatalf("prover %d: nil proof", i)
+ }
+ key := proof.Keys()[mrand.Intn(proof.Len())]
+ val, _ := proof.Get(key)
+ proof.Delete(key)
+
+ mutateByte(val)
+ proof.Put(crypto.Keccak256(val), val)
+
+ if _, _, err := VerifyProof(root, kv.k, proof); err == nil {
+ t.Fatalf("prover %d: expected proof to fail for key %x", i, kv.k)
+ }
+ }
+ }
+}
+
+// Tests that missing keys can also be proven. The test explicitly uses a single
+// entry trie and checks for missing keys both before and after the single entry.
+func TestMissingKeyProof(t *testing.T) {
+ trie := new(Trie)
+ updateString(trie, "k", "v")
+
+ for i, key := range []string{"a", "j", "l", "z"} {
+ proof := ethdb.NewMemDatabase()
+ trie.Prove([]byte(key), 0, proof)
+
+ if proof.Len() != 1 {
+ t.Errorf("test %d: proof should have one element", i)
+ }
+ val, _, err := VerifyProof(trie.Hash(), []byte(key), proof)
+ if err != nil {
+ t.Fatalf("test %d: failed to verify proof: %v\nraw proof: %x", i, err, proof)
}
- keys := proofs.Keys()
- key := keys[mrand.Intn(len(keys))]
- node, _ := proofs.Get(key)
- proofs.Delete(key)
- mutateByte(node)
- proofs.Put(crypto.Keccak256(node), node)
- if _, _, err := VerifyProof(root, kv.k, proofs); err == nil {
- t.Fatalf("expected proof to fail for key %x", kv.k)
+ if val != nil {
+ t.Fatalf("test %d: verified value mismatch: have %x, want nil", i, val)
}
}
}