go-ethereum/accounts/account_manager.go
Gustav Simonsson b296b36d2b Add automatic locking / unlocking of accounts
* Change account signing API to two sign functions;
  Sign without passphrase - works if account is unlocked
  Sign with passphrase - always works and unlocks the account
* Account stays unlocked for X ms and is then automatically locked
2015-02-25 17:37:12 +01:00

130 lines
3.5 KiB
Go

/*
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 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/>.
*/
/**
* @authors
* Gustav Simonsson <gustav.simonsson@gmail.com>
* @date 2015
*
*/
/*
This abstracts part of a user's interaction with an account she controls.
It's not an abstraction of core Ethereum accounts data type / logic -
for that see the core processing code of blocks / txs.
Currently this is pretty much a passthrough to the KeyStore2 interface,
and accounts persistence is derived from stored keys' addresses
*/
package accounts
import (
crand "crypto/rand"
"errors"
"github.com/ethereum/go-ethereum/crypto"
"sync"
"time"
)
var ErrLocked = errors.New("account is locked; please request passphrase")
// TODO: better name for this struct?
type Account struct {
Address []byte
}
type AccountManager struct {
keyStore crypto.KeyStore2
unlockedKeys map[string]crypto.Key
unlockedMilliSeconds int
mutex sync.Mutex
}
func NewAccountManager(keyStore crypto.KeyStore2, unlockMilliSeconds int) AccountManager {
keysMap := make(map[string]crypto.Key)
am := &AccountManager{
keyStore: keyStore,
unlockedKeys: keysMap,
unlockedMilliSeconds: unlockMilliSeconds,
mutex: sync.Mutex{}, // for accessing unlockedKeys map
}
return *am
}
func (am AccountManager) DeleteAccount(address []byte, auth string) error {
return am.keyStore.DeleteKey(address, auth)
}
func (am *AccountManager) Sign(fromAccount *Account, toSign []byte) (signature []byte, err error) {
am.mutex.Lock()
unlockedKey := am.unlockedKeys[string(fromAccount.Address)]
am.mutex.Unlock()
if unlockedKey.Address == nil {
return nil, ErrLocked
}
signature, err = crypto.Sign(toSign, unlockedKey.PrivateKey)
return signature, err
}
func (am *AccountManager) SignLocked(fromAccount *Account, keyAuth string, toSign []byte) (signature []byte, err error) {
key, err := am.keyStore.GetKey(fromAccount.Address, keyAuth)
if err != nil {
return nil, err
}
am.mutex.Lock()
am.unlockedKeys[string(fromAccount.Address)] = *key
am.mutex.Unlock()
go unlockLater(am, fromAccount.Address)
signature, err = crypto.Sign(toSign, key.PrivateKey)
return signature, err
}
func (am AccountManager) NewAccount(auth string) (*Account, error) {
key, err := am.keyStore.GenerateNewKey(crand.Reader, auth)
if err != nil {
return nil, err
}
ua := &Account{
Address: key.Address,
}
return ua, err
}
func (am *AccountManager) Accounts() ([]Account, error) {
addresses, err := am.keyStore.GetKeyAddresses()
if err != nil {
return nil, err
}
accounts := make([]Account, len(addresses))
for i, addr := range addresses {
accounts[i] = Account{
Address: addr,
}
}
return accounts, err
}
func unlockLater(am *AccountManager, addr []byte) {
time.Sleep(time.Millisecond * time.Duration(am.unlockedMilliSeconds))
am.mutex.Lock()
// TODO: how do we know the key is actually gone from memory?
delete(am.unlockedKeys, string(addr))
am.mutex.Unlock()
}