// Copyright 2015 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum 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.
//
// go-ethereum 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 go-ethereum. If not, see <http://www.gnu.org/licenses/>.
// Package implements a private key management facility.
//
// This abstracts part of a user's interaction with an account she controls.
package accounts
// Currently this is pretty much a passthrough to the KeyStore interface,
// and accounts persistence is derived from stored keys' addresses
import (
"crypto/ecdsa"
crand "crypto/rand"
"errors"
"fmt"
"os"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
)
var (
ErrLocked = errors.New("account is locked")
ErrNoKeys = errors.New("no keys in store")
)
type Account struct {
Address common.Address
}
type Manager struct {
keyStore crypto.KeyStore
unlocked map[common.Address]*unlocked
mutex sync.RWMutex
}
type unlocked struct {
*crypto.Key
abort chan struct{}
}
func NewManager(keyStore crypto.KeyStore) *Manager {
return &Manager{
keyStore: keyStore,
unlocked: make(map[common.Address]*unlocked),
}
}
func (am *Manager) HasAccount(addr common.Address) bool {
accounts, _ := am.Accounts()
for _, acct := range accounts {
if acct.Address == addr {
return true
}
}
return false
}
func (am *Manager) DeleteAccount(address common.Address, auth string) error {
return am.keyStore.DeleteKey(address, auth)
}
func (am *Manager) Sign(a Account, toSign []byte) (signature []byte, err error) {
am.mutex.RLock()
defer am.mutex.RUnlock()
unlockedKey, found := am.unlocked[a.Address]
if !found {
return nil, ErrLocked
}
signature, err = crypto.Sign(toSign, unlockedKey.PrivateKey)
return signature, err
}
// Unlock unlocks the given account indefinitely.
func (am *Manager) Unlock(addr common.Address, keyAuth string) error {
return am.TimedUnlock(addr, keyAuth, 0)
}
// TimedUnlock unlocks the account with the given address. The account
// stays unlocked for the duration of timeout. A timeout of 0 unlocks the account
// until the program exits.
//
// If the accout is already unlocked, TimedUnlock extends or shortens
// the active unlock timeout.
func (am *Manager) TimedUnlock(addr common.Address, keyAuth string, timeout time.Duration) error {
key, err := am.keyStore.GetKey(addr, keyAuth)
if err != nil {
return err
}
var u *unlocked
am.mutex.Lock()
defer am.mutex.Unlock()
var found bool
u, found = am.unlocked[addr]
if found {
// terminate dropLater for this key to avoid unexpected drops.
if u.abort != nil {
close(u.abort)
}
}
if timeout > 0 {
u = &unlocked{Key: key, abort: make(chan struct{})}
go am.expire(addr, u, timeout)
} else {
u = &unlocked{Key: key}
}
am.unlocked[addr] = u
return nil
}
func (am *Manager) expire(addr common.Address, u *unlocked, timeout time.Duration) {
t := time.NewTimer(timeout)
defer t.Stop()
select {
case <-u.abort:
// just quit
case <-t.C:
am.mutex.Lock()
// only drop if it's still the same key instance that dropLater
// was launched with. we can check that using pointer equality
// because the map stores a new pointer every time the key is
// unlocked.
if am.unlocked[addr] == u {
zeroKey(u.PrivateKey)
delete(am.unlocked, addr)
}
am.mutex.Unlock()
}
}
func (am *Manager) NewAccount(auth string) (Account, error) {
key, err := am.keyStore.GenerateNewKey(crand.Reader, auth)
if err != nil {
return Account{}, err
}
return Account{Address: key.Address}, nil
}
func (am *Manager) AddressByIndex(index int) (addr string, err error) {
var addrs []common.Address
addrs, err = am.keyStore.GetKeyAddresses()
if err != nil {
return
}
if index < 0 || index >= len(addrs) {
err = fmt.Errorf("index out of range: %d (should be 0-%d)", index, len(addrs)-1)
} else {
addr = addrs[index].Hex()
}
return
}
func (am *Manager) Accounts() ([]Account, error) {
addresses, err := am.keyStore.GetKeyAddresses()
if os.IsNotExist(err) {
return nil, ErrNoKeys
} else if err != nil {
return nil, err
}
accounts := make([]Account, len(addresses))
for i, addr := range addresses {
accounts[i] = Account{
Address: addr,
}
}
return accounts, err
}
// zeroKey zeroes a private key in memory.
func zeroKey(k *ecdsa.PrivateKey) {
b := k.D.Bits()
for i := range b {
b[i] = 0
}
}
// USE WITH CAUTION = this will save an unencrypted private key on disk
// no cli or js interface
func (am *Manager) Export(path string, addr common.Address, keyAuth string) error {
key, err := am.keyStore.GetKey(addr, keyAuth)
if err != nil {
return err
}
return crypto.SaveECDSA(path, key.PrivateKey)
}
func (am *Manager) Import(path string, keyAuth string) (Account, error) {
privateKeyECDSA, err := crypto.LoadECDSA(path)
if err != nil {
return Account{}, err
}
key := crypto.NewKeyFromECDSA(privateKeyECDSA)
if err = am.keyStore.StoreKey(key, keyAuth); err != nil {
return Account{}, err
}
return Account{Address: key.Address}, nil
}
func (am *Manager) Update(addr common.Address, authFrom, authTo string) (err error) {
var key *crypto.Key
key, err = am.keyStore.GetKey(addr, authFrom)
if err == nil {
err = am.keyStore.StoreKey(key, authTo)
if err == nil {
am.keyStore.Cleanup(addr)
}
}
return
}
func (am *Manager) ImportPreSaleKey(keyJSON []byte, password string) (acc Account, err error) {
var key *crypto.Key
key, err = crypto.ImportPreSaleKey(am.keyStore, keyJSON, password)
if err != nil {
return
}
return Account{Address: key.Address}, nil
}
