go-ethereum/tests/fuzzers/stacktrie/trie_fuzzer.go

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// Copyright 2020 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 stacktrie
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"hash"
"io"
"sort"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/trie"
"golang.org/x/crypto/sha3"
)
type fuzzer struct {
input io.Reader
exhausted bool
debugging bool
}
func (f *fuzzer) read(size int) []byte {
out := make([]byte, size)
if _, err := f.input.Read(out); err != nil {
f.exhausted = true
}
return out
}
func (f *fuzzer) readSlice(min, max int) []byte {
var a uint16
binary.Read(f.input, binary.LittleEndian, &a)
size := min + int(a)%(max-min)
out := make([]byte, size)
if _, err := f.input.Read(out); err != nil {
f.exhausted = true
}
return out
}
// spongeDb is a dummy db backend which accumulates writes in a sponge
type spongeDb struct {
sponge hash.Hash
debug bool
}
func (s *spongeDb) Has(key []byte) (bool, error) { panic("implement me") }
func (s *spongeDb) Get(key []byte) ([]byte, error) { return nil, errors.New("no such elem") }
func (s *spongeDb) Delete(key []byte) error { panic("implement me") }
func (s *spongeDb) NewBatch() ethdb.Batch { return &spongeBatch{s} }
func (s *spongeDb) NewBatchWithSize(size int) ethdb.Batch { return &spongeBatch{s} }
func (s *spongeDb) NewSnapshot() (ethdb.Snapshot, error) { panic("implement me") }
func (s *spongeDb) Stat(property string) (string, error) { panic("implement me") }
func (s *spongeDb) Compact(start []byte, limit []byte) error { panic("implement me") }
func (s *spongeDb) Close() error { return nil }
func (s *spongeDb) Put(key []byte, value []byte) error {
if s.debug {
fmt.Printf("db.Put %x : %x\n", key, value)
}
s.sponge.Write(key)
s.sponge.Write(value)
return nil
}
func (s *spongeDb) NewIterator(prefix []byte, start []byte) ethdb.Iterator { panic("implement me") }
// spongeBatch is a dummy batch which immediately writes to the underlying spongedb
type spongeBatch struct {
db *spongeDb
}
func (b *spongeBatch) Put(key, value []byte) error {
b.db.Put(key, value)
return nil
}
func (b *spongeBatch) Delete(key []byte) error { panic("implement me") }
func (b *spongeBatch) ValueSize() int { return 100 }
func (b *spongeBatch) Write() error { return nil }
func (b *spongeBatch) Reset() {}
func (b *spongeBatch) Replay(w ethdb.KeyValueWriter) error { return nil }
type kv struct {
k, v []byte
}
type kvs []kv
func (k kvs) Len() int {
return len(k)
}
func (k kvs) Less(i, j int) bool {
return bytes.Compare(k[i].k, k[j].k) < 0
}
func (k kvs) Swap(i, j int) {
k[j], k[i] = k[i], k[j]
}
// The function must return
//
// - 1 if the fuzzer should increase priority of the
// given input during subsequent fuzzing (for example, the input is lexically
// correct and was parsed successfully);
// - -1 if the input must not be added to corpus even if gives new coverage; and
// - 0 otherwise
//
// other values are reserved for future use.
func Fuzz(data []byte) int {
f := fuzzer{
input: bytes.NewReader(data),
exhausted: false,
}
return f.fuzz()
}
func Debug(data []byte) int {
f := fuzzer{
input: bytes.NewReader(data),
exhausted: false,
debugging: true,
}
return f.fuzz()
}
func (f *fuzzer) fuzz() int {
// This spongeDb is used to check the sequence of disk-db-writes
var (
spongeA = &spongeDb{sponge: sha3.NewLegacyKeccak256()}
dbA = trie.NewDatabase(spongeA)
trieA = trie.NewEmpty(dbA)
spongeB = &spongeDb{sponge: sha3.NewLegacyKeccak256()}
trieB = trie.NewStackTrie(spongeB)
vals kvs
useful bool
maxElements = 10000
// operate on unique keys only
keys = make(map[string]struct{})
)
// Fill the trie with elements
for i := 0; !f.exhausted && i < maxElements; i++ {
k := f.read(32)
v := f.readSlice(1, 500)
if f.exhausted {
// If it was exhausted while reading, the value may be all zeroes,
// thus 'deletion' which is not supported on stacktrie
break
}
if _, present := keys[string(k)]; present {
// This key is a duplicate, ignore it
continue
}
keys[string(k)] = struct{}{}
vals = append(vals, kv{k: k, v: v})
trieA.Update(k, v)
useful = true
}
if !useful {
return 0
}
// Flush trie -> database
rootA, nodes, err := trieA.Commit(false)
if err != nil {
panic(err)
}
if nodes != nil {
dbA.Update(trie.NewWithNodeSet(nodes))
}
// Flush memdb -> disk (sponge)
dbA.Commit(rootA, false, nil)
// Stacktrie requires sorted insertion
sort.Sort(vals)
for _, kv := range vals {
if f.debugging {
fmt.Printf("{\"%#x\" , \"%#x\"} // stacktrie.Update\n", kv.k, kv.v)
}
trieB.Update(kv.k, kv.v)
}
rootB := trieB.Hash()
if _, err := trieB.Commit(); err != nil {
panic(err)
}
if rootA != rootB {
panic(fmt.Sprintf("roots differ: (trie) %x != %x (stacktrie)", rootA, rootB))
}
sumA := spongeA.sponge.Sum(nil)
sumB := spongeB.sponge.Sum(nil)
if !bytes.Equal(sumA, sumB) {
panic(fmt.Sprintf("sequence differ: (trie) %x != %x (stacktrie)", sumA, sumB))
}
return 1
}