trie: clarify why verifyProof doesn't check hashes (#19530)

* trie: fix merkle proof

* trie: use hasher instead of allocate keccack256 every time

* trie: add comments
This commit is contained in:
gary rong 2019-05-07 20:06:07 +08:00 committed by Péter Szilágyi
parent abeba0a1de
commit 14868a37fb

@ -21,7 +21,6 @@ import (
"fmt" "fmt"
"github.com/ethereum/go-ethereum/common" "github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb" "github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log" "github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rlp" "github.com/ethereum/go-ethereum/rlp"
@ -81,7 +80,7 @@ func (t *Trie) Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) error {
} else { } else {
enc, _ := rlp.EncodeToBytes(n) enc, _ := rlp.EncodeToBytes(n)
if !ok { if !ok {
hash = crypto.Keccak256(enc) hash = hasher.makeHashNode(enc)
} }
proofDb.Put(hash, enc) proofDb.Put(hash, enc)
} }
@ -104,6 +103,8 @@ func (t *SecureTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) err
// VerifyProof checks merkle proofs. The given proof must contain the value for // VerifyProof checks merkle proofs. The given proof must contain the value for
// key in a trie with the given root hash. VerifyProof returns an error if the // key in a trie with the given root hash. VerifyProof returns an error if the
// proof contains invalid trie nodes or the wrong value. // proof contains invalid trie nodes or the wrong value.
//
// Note, the method assumes that all key-values in proofDb satisfy key = hash(value).
func VerifyProof(rootHash common.Hash, key []byte, proofDb ethdb.Reader) (value []byte, nodes int, err error) { func VerifyProof(rootHash common.Hash, key []byte, proofDb ethdb.Reader) (value []byte, nodes int, err error) {
key = keybytesToHex(key) key = keybytesToHex(key)
wantHash := rootHash wantHash := rootHash