// Copyright 2017 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 keystore implements encrypted storage of secp256k1 private keys.
//
// Keys are stored as encrypted JSON files according to the Web3 Secret Storage specification.
// See https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition for more information.
package keystore
import (
"crypto/ecdsa"
crand "crypto/rand"
"errors"
"fmt"
"math/big"
"os"
"path/filepath"
"reflect"
"runtime"
"sync"
"time"
"github.com/ava-labs/coreth/accounts"
"github.com/ava-labs/coreth/core/types"
"github.com/ava-labs/go-ethereum/common"
"github.com/ava-labs/go-ethereum/crypto"
"github.com/ava-labs/go-ethereum/event"
)
var (
ErrLocked = accounts.NewAuthNeededError("password or unlock")
ErrNoMatch = errors.New("no key for given address or file")
ErrDecrypt = errors.New("could not decrypt key with given password")
)
// KeyStoreType is the reflect type of a keystore backend.
var KeyStoreType = reflect.TypeOf(&KeyStore{})
// KeyStoreScheme is the protocol scheme prefixing account and wallet URLs.
const KeyStoreScheme = "keystore"
// Maximum time between wallet refreshes (if filesystem notifications don't work).
const walletRefreshCycle = 3 * time.Second
// KeyStore manages a key storage directory on disk.
type KeyStore struct {
storage keyStore // Storage backend, might be cleartext or encrypted
cache *accountCache // In-memory account cache over the filesystem storage
changes chan struct{} // Channel receiving change notifications from the cache
unlocked map[common.Address]*unlocked // Currently unlocked account (decrypted private keys)
wallets []accounts.Wallet // Wallet wrappers around the individual key files
updateFeed event.Feed // Event feed to notify wallet additions/removals
updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
updating bool // Whether the event notification loop is running
mu sync.RWMutex
}
type unlocked struct {
*Key
abort chan struct{}
}
// NewKeyStore creates a keystore for the given directory.
func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
keydir, _ = filepath.Abs(keydir)
ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP, false}}
ks.init(keydir)
return ks
}
// NewPlaintextKeyStore creates a keystore for the given directory.
// Deprecated: Use NewKeyStore.
func NewPlaintextKeyStore(keydir string) *KeyStore {
keydir, _ = filepath.Abs(keydir)
ks := &KeyStore{storage: &keyStorePlain{keydir}}
ks.init(keydir)
return ks
}
func (ks *KeyStore) init(keydir string) {
// Lock the mutex since the account cache might call back with events
ks.mu.Lock()
defer ks.mu.Unlock()
// Initialize the set of unlocked keys and the account cache
ks.unlocked = make(map[common.Address]*unlocked)
ks.cache, ks.changes = newAccountCache(keydir)
// TODO: In order for this finalizer to work, there must be no references
// to ks. addressCache doesn't keep a reference but unlocked keys do,
// so the finalizer will not trigger until all timed unlocks have expired.
runtime.SetFinalizer(ks, func(m *KeyStore) {
m.cache.close()
})
// Create the initial list of wallets from the cache
accs := ks.cache.accounts()
ks.wallets = make([]accounts.Wallet, len(accs))
for i := 0; i < len(accs); i++ {
ks.wallets[i] = &keystoreWallet{account: accs[i], keystore: ks}
}
}
// Wallets implements accounts.Backend, returning all single-key wallets from the
// keystore directory.
func (ks *KeyStore) Wallets() []accounts.Wallet {
// Make sure the list of wallets is in sync with the account cache
ks.refreshWallets()
ks.mu.RLock()
defer ks.mu.RUnlock()
cpy := make([]accounts.Wallet, len(ks.wallets))
copy(cpy, ks.wallets)
return cpy
}
// refreshWallets retrieves the current account list and based on that does any
// necessary wallet refreshes.
func (ks *KeyStore) refreshWallets() {
// Retrieve the current list of accounts
ks.mu.Lock()
accs := ks.cache.accounts()
// Transform the current list of wallets into the new one
var (
wallets = make([]accounts.Wallet, 0, len(accs))
events []accounts.WalletEvent
)
for _, account := range accs {
// Drop wallets while they were in front of the next account
for len(ks.wallets) > 0 && ks.wallets[0].URL().Cmp(account.URL) < 0 {
events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Kind: accounts.WalletDropped})
ks.wallets = ks.wallets[1:]
}
// If there are no more wallets or the account is before the next, wrap new wallet
if len(ks.wallets) == 0 || ks.wallets[0].URL().Cmp(account.URL) > 0 {
wallet := &keystoreWallet{account: account, keystore: ks}
events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
wallets = append(wallets, wallet)
continue
}
// If the account is the same as the first wallet, keep it
if ks.wallets[0].Accounts()[0] == account {
wallets = append(wallets, ks.wallets[0])
ks.wallets = ks.wallets[1:]
continue
}
}
// Drop any leftover wallets and set the new batch
for _, wallet := range ks.wallets {
events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
}
ks.wallets = wallets
ks.mu.Unlock()
// Fire all wallet events and return
for _, event := range events {
ks.updateFeed.Send(event)
}
}
// Subscribe implements accounts.Backend, creating an async subscription to
// receive notifications on the addition or removal of keystore wallets.
func (ks *KeyStore) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
// We need the mutex to reliably start/stop the update loop
ks.mu.Lock()
defer ks.mu.Unlock()
// Subscribe the caller and track the subscriber count
sub := ks.updateScope.Track(ks.updateFeed.Subscribe(sink))
// Subscribers require an active notification loop, start it
if !ks.updating {
ks.updating = true
go ks.updater()
}
return sub
}
// updater is responsible for maintaining an up-to-date list of wallets stored in
// the keystore, and for firing wallet addition/removal events. It listens for
// account change events from the underlying account cache, and also periodically
// forces a manual refresh (only triggers for systems where the filesystem notifier
// is not running).
func (ks *KeyStore) updater() {
for {
// Wait for an account update or a refresh timeout
select {
case <-ks.changes:
case <-time.After(walletRefreshCycle):
}
// Run the wallet refresher
ks.refreshWallets()
// If all our subscribers left, stop the updater
ks.mu.Lock()
if ks.updateScope.Count() == 0 {
ks.updating = false
ks.mu.Unlock()
return
}
ks.mu.Unlock()
}
}
// HasAddress reports whether a key with the given address is present.
func (ks *KeyStore) HasAddress(addr common.Address) bool {
return ks.cache.hasAddress(addr)
}
// Accounts returns all key files present in the directory.
func (ks *KeyStore) Accounts() []accounts.Account {
return ks.cache.accounts()
}
// Delete deletes the key matched by account if the passphrase is correct.
// If the account contains no filename, the address must match a unique key.
func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error {
// Decrypting the key isn't really necessary, but we do
// it anyway to check the password and zero out the key
// immediately afterwards.
a, key, err := ks.getDecryptedKey(a, passphrase)
if key != nil {
zeroKey(key.PrivateKey)
}
if err != nil {
return err
}
// The order is crucial here. The key is dropped from the
// cache after the file is gone so that a rel