360 lines
11 KiB
Go
360 lines
11 KiB
Go
// Copyright 2015 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package trie
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/ethdb"
|
|
"github.com/ethereum/go-ethereum/ethdb/memorydb"
|
|
"github.com/ethereum/go-ethereum/log"
|
|
"github.com/ethereum/go-ethereum/rlp"
|
|
)
|
|
|
|
// Prove constructs a merkle proof for key. The result contains all encoded nodes
|
|
// on the path to the value at key. The value itself is also included in the last
|
|
// node and can be retrieved by verifying the proof.
|
|
//
|
|
// If the trie does not contain a value for key, the returned proof contains all
|
|
// nodes of the longest existing prefix of the key (at least the root node), ending
|
|
// with the node that proves the absence of the key.
|
|
func (t *Trie) Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error {
|
|
// Collect all nodes on the path to key.
|
|
key = keybytesToHex(key)
|
|
var nodes []node
|
|
tn := t.root
|
|
for len(key) > 0 && tn != nil {
|
|
switch n := tn.(type) {
|
|
case *shortNode:
|
|
if len(key) < len(n.Key) || !bytes.Equal(n.Key, key[:len(n.Key)]) {
|
|
// The trie doesn't contain the key.
|
|
tn = nil
|
|
} else {
|
|
tn = n.Val
|
|
key = key[len(n.Key):]
|
|
}
|
|
nodes = append(nodes, n)
|
|
case *fullNode:
|
|
tn = n.Children[key[0]]
|
|
key = key[1:]
|
|
nodes = append(nodes, n)
|
|
case hashNode:
|
|
var err error
|
|
tn, err = t.resolveHash(n, nil)
|
|
if err != nil {
|
|
log.Error(fmt.Sprintf("Unhandled trie error: %v", err))
|
|
return err
|
|
}
|
|
default:
|
|
panic(fmt.Sprintf("%T: invalid node: %v", tn, tn))
|
|
}
|
|
}
|
|
hasher := newHasher(false)
|
|
defer returnHasherToPool(hasher)
|
|
|
|
for i, n := range nodes {
|
|
if fromLevel > 0 {
|
|
fromLevel--
|
|
continue
|
|
}
|
|
var hn node
|
|
n, hn = hasher.proofHash(n)
|
|
if hash, ok := hn.(hashNode); ok || i == 0 {
|
|
// If the node's database encoding is a hash (or is the
|
|
// root node), it becomes a proof element.
|
|
enc, _ := rlp.EncodeToBytes(n)
|
|
if !ok {
|
|
hash = hasher.hashData(enc)
|
|
}
|
|
proofDb.Put(hash, enc)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Prove constructs a merkle proof for key. The result contains all encoded nodes
|
|
// on the path to the value at key. The value itself is also included in the last
|
|
// node and can be retrieved by verifying the proof.
|
|
//
|
|
// If the trie does not contain a value for key, the returned proof contains all
|
|
// nodes of the longest existing prefix of the key (at least the root node), ending
|
|
// with the node that proves the absence of the key.
|
|
func (t *SecureTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error {
|
|
return t.trie.Prove(key, fromLevel, proofDb)
|
|
}
|
|
|
|
// 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
|
|
// proof contains invalid trie nodes or the wrong value.
|
|
func VerifyProof(rootHash common.Hash, key []byte, proofDb ethdb.KeyValueReader) (value []byte, err error) {
|
|
key = keybytesToHex(key)
|
|
wantHash := rootHash
|
|
for i := 0; ; i++ {
|
|
buf, _ := proofDb.Get(wantHash[:])
|
|
if buf == nil {
|
|
return nil, fmt.Errorf("proof node %d (hash %064x) missing", i, wantHash)
|
|
}
|
|
n, err := decodeNode(wantHash[:], buf)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("bad proof node %d: %v", i, err)
|
|
}
|
|
keyrest, cld := get(n, key, true)
|
|
switch cld := cld.(type) {
|
|
case nil:
|
|
// The trie doesn't contain the key.
|
|
return nil, nil
|
|
case hashNode:
|
|
key = keyrest
|
|
copy(wantHash[:], cld)
|
|
case valueNode:
|
|
return cld, nil
|
|
}
|
|
}
|
|
}
|
|
|
|
// proofToPath converts a merkle proof to trie node path.
|
|
// The main purpose of this function is recovering a node
|
|
// path from the merkle proof stream. All necessary nodes
|
|
// will be resolved and leave the remaining as hashnode.
|
|
func proofToPath(rootHash common.Hash, root node, key []byte, proofDb ethdb.KeyValueReader) (node, error) {
|
|
// resolveNode retrieves and resolves trie node from merkle proof stream
|
|
resolveNode := func(hash common.Hash) (node, error) {
|
|
buf, _ := proofDb.Get(hash[:])
|
|
if buf == nil {
|
|
return nil, fmt.Errorf("proof node (hash %064x) missing", hash)
|
|
}
|
|
n, err := decodeNode(hash[:], buf)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("bad proof node %v", err)
|
|
}
|
|
return n, err
|
|
}
|
|
// If the root node is empty, resolve it first
|
|
if root == nil {
|
|
n, err := resolveNode(rootHash)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
root = n
|
|
}
|
|
var (
|
|
err error
|
|
child, parent node
|
|
keyrest []byte
|
|
terminate bool
|
|
)
|
|
key, parent = keybytesToHex(key), root
|
|
for {
|
|
keyrest, child = get(parent, key, false)
|
|
switch cld := child.(type) {
|
|
case nil:
|
|
// The trie doesn't contain the key.
|
|
return nil, errors.New("the node is not contained in trie")
|
|
case *shortNode:
|
|
key, parent = keyrest, child // Already resolved
|
|
continue
|
|
case *fullNode:
|
|
key, parent = keyrest, child // Already resolved
|
|
continue
|
|
case hashNode:
|
|
child, err = resolveNode(common.BytesToHash(cld))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
case valueNode:
|
|
terminate = true
|
|
}
|
|
// Link the parent and child.
|
|
switch pnode := parent.(type) {
|
|
case *shortNode:
|
|
pnode.Val = child
|
|
case *fullNode:
|
|
pnode.Children[key[0]] = child
|
|
default:
|
|
panic(fmt.Sprintf("%T: invalid node: %v", pnode, pnode))
|
|
}
|
|
if terminate {
|
|
return root, nil // The whole path is resolved
|
|
}
|
|
key, parent = keyrest, child
|
|
}
|
|
}
|
|
|
|
// unsetInternal removes all internal node references(hashnode, embedded node).
|
|
// It should be called after a trie is constructed with two edge proofs. Also
|
|
// the given boundary keys must be the one used to construct the edge proofs.
|
|
//
|
|
// It's the key step for range proof. All visited nodes should be marked dirty
|
|
// since the node content might be modified. Besides it can happen that some
|
|
// fullnodes only have one child which is disallowed. But if the proof is valid,
|
|
// the missing children will be filled, otherwise it will be thrown anyway.
|
|
func unsetInternal(node node, left []byte, right []byte) error {
|
|
left, right = keybytesToHex(left), keybytesToHex(right)
|
|
|
|
// todo(rjl493456442) different length edge keys should be supported
|
|
if len(left) != len(right) {
|
|
return errors.New("inconsistent edge path")
|
|
}
|
|
// Step down to the fork point
|
|
prefix, pos := prefixLen(left, right), 0
|
|
for {
|
|
if pos >= prefix {
|
|
break
|
|
}
|
|
switch n := (node).(type) {
|
|
case *shortNode:
|
|
if len(left)-pos < len(n.Key) || !bytes.Equal(n.Key, left[pos:pos+len(n.Key)]) {
|
|
return errors.New("invalid edge path")
|
|
}
|
|
n.flags = nodeFlag{dirty: true}
|
|
node, pos = n.Val, pos+len(n.Key)
|
|
case *fullNode:
|
|
n.flags = nodeFlag{dirty: true}
|
|
node, pos = n.Children[left[pos]], pos+1
|
|
default:
|
|
panic(fmt.Sprintf("%T: invalid node: %v", node, node))
|
|
}
|
|
}
|
|
fn, ok := node.(*fullNode)
|
|
if !ok {
|
|
return errors.New("the fork point must be a fullnode")
|
|
}
|
|
// Find the fork point! Unset all intermediate references
|
|
for i := left[prefix] + 1; i < right[prefix]; i++ {
|
|
fn.Children[i] = nil
|
|
}
|
|
fn.flags = nodeFlag{dirty: true}
|
|
unset(fn.Children[left[prefix]], left[prefix+1:], false)
|
|
unset(fn.Children[right[prefix]], right[prefix+1:], true)
|
|
return nil
|
|
}
|
|
|
|
// unset removes all internal node references either the left most or right most.
|
|
func unset(root node, rest []byte, removeLeft bool) {
|
|
switch rn := root.(type) {
|
|
case *fullNode:
|
|
if removeLeft {
|
|
for i := 0; i < int(rest[0]); i++ {
|
|
rn.Children[i] = nil
|
|
}
|
|
rn.flags = nodeFlag{dirty: true}
|
|
} else {
|
|
for i := rest[0] + 1; i < 16; i++ {
|
|
rn.Children[i] = nil
|
|
}
|
|
rn.flags = nodeFlag{dirty: true}
|
|
}
|
|
unset(rn.Children[rest[0]], rest[1:], removeLeft)
|
|
case *shortNode:
|
|
rn.flags = nodeFlag{dirty: true}
|
|
if _, ok := rn.Val.(valueNode); ok {
|
|
rn.Val = nilValueNode
|
|
return
|
|
}
|
|
unset(rn.Val, rest[len(rn.Key):], removeLeft)
|
|
case hashNode, nil, valueNode:
|
|
panic("it shouldn't happen")
|
|
}
|
|
}
|
|
|
|
// VerifyRangeProof checks whether the given leave nodes and edge proofs
|
|
// can prove the given trie leaves range is matched with given root hash
|
|
// and the range is consecutive(no gap inside).
|
|
func VerifyRangeProof(rootHash common.Hash, keys [][]byte, values [][]byte, firstProof ethdb.KeyValueReader, lastProof ethdb.KeyValueReader) error {
|
|
if len(keys) != len(values) {
|
|
return fmt.Errorf("inconsistent proof data, keys: %d, values: %d", len(keys), len(values))
|
|
}
|
|
if len(keys) == 0 {
|
|
return fmt.Errorf("nothing to verify")
|
|
}
|
|
if len(keys) == 1 {
|
|
value, err := VerifyProof(rootHash, keys[0], firstProof)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if !bytes.Equal(value, values[0]) {
|
|
return fmt.Errorf("correct proof but invalid data")
|
|
}
|
|
return nil
|
|
}
|
|
// Convert the edge proofs to edge trie paths. Then we can
|
|
// have the same tree architecture with the original one.
|
|
root, err := proofToPath(rootHash, nil, keys[0], firstProof)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
// Pass the root node here, the second path will be merged
|
|
// with the first one.
|
|
root, err = proofToPath(rootHash, root, keys[len(keys)-1], lastProof)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
// Remove all internal references. All the removed parts should
|
|
// be re-filled(or re-constructed) by the given leaves range.
|
|
if err := unsetInternal(root, keys[0], keys[len(keys)-1]); err != nil {
|
|
return err
|
|
}
|
|
// Rebuild the trie with the leave stream, the shape of trie
|
|
// should be same with the original one.
|
|
newtrie := &Trie{root: root, db: NewDatabase(memorydb.New())}
|
|
for index, key := range keys {
|
|
newtrie.TryUpdate(key, values[index])
|
|
}
|
|
if newtrie.Hash() != rootHash {
|
|
return fmt.Errorf("invalid proof, wanthash %x, got %x", rootHash, newtrie.Hash())
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// get returns the child of the given node. Return nil if the
|
|
// node with specified key doesn't exist at all.
|
|
//
|
|
// There is an additional flag `skipResolved`. If it's set then
|
|
// all resolved nodes won't be returned.
|
|
func get(tn node, key []byte, skipResolved bool) ([]byte, node) {
|
|
for {
|
|
switch n := tn.(type) {
|
|
case *shortNode:
|
|
if len(key) < len(n.Key) || !bytes.Equal(n.Key, key[:len(n.Key)]) {
|
|
return nil, nil
|
|
}
|
|
tn = n.Val
|
|
key = key[len(n.Key):]
|
|
if !skipResolved {
|
|
return key, tn
|
|
}
|
|
case *fullNode:
|
|
tn = n.Children[key[0]]
|
|
key = key[1:]
|
|
if !skipResolved {
|
|
return key, tn
|
|
}
|
|
case hashNode:
|
|
return key, n
|
|
case nil:
|
|
return key, nil
|
|
case valueNode:
|
|
return nil, n
|
|
default:
|
|
panic(fmt.Sprintf("%T: invalid node: %v", tn, tn))
|
|
}
|
|
}
|
|
}
|