diff options
| -rw-r--r-- | accounts/account_manager.go | 69 |
1 files changed, 50 insertions, 19 deletions
diff --git a/accounts/account_manager.go b/accounts/account_manager.go index c0f2953bd..bb6d970b2 100644 --- a/accounts/account_manager.go +++ b/accounts/account_manager.go @@ -53,17 +53,24 @@ type Account struct { } type AccountManager struct { - keyStore crypto.KeyStore2 - unlockedKeys map[string]crypto.Key - unlockTime time.Duration - mutex sync.RWMutex + keyStore crypto.KeyStore2 + unlocked map[string]*unlocked + unlockTime time.Duration + mutex sync.RWMutex +} + +type unlocked struct { + addr []byte + abort chan struct{} + + *crypto.Key } func NewAccountManager(keyStore crypto.KeyStore2, unlockTime time.Duration) *AccountManager { return &AccountManager{ - keyStore: keyStore, - unlockedKeys: make(map[string]crypto.Key), - unlockTime: unlockTime, + keyStore: keyStore, + unlocked: make(map[string]*unlocked), + unlockTime: unlockTime, } } @@ -97,9 +104,9 @@ func (am *AccountManager) DeleteAccount(address []byte, auth string) error { func (am *AccountManager) Sign(a Account, toSign []byte) (signature []byte, err error) { am.mutex.RLock() - unlockedKey := am.unlockedKeys[string(a.Address)] + unlockedKey, found := am.unlocked[string(a.Address)] am.mutex.RUnlock() - if unlockedKey.Address == nil { + if !found { return nil, ErrLocked } signature, err = crypto.Sign(toSign, unlockedKey.PrivateKey) @@ -111,10 +118,8 @@ func (am *AccountManager) SignLocked(a Account, keyAuth string, toSign []byte) ( if err != nil { return nil, err } - am.mutex.Lock() - am.unlockedKeys[string(a.Address)] = *key - am.mutex.Unlock() - go unlockLater(am, a.Address) + u := am.addUnlocked(a.Address, key) + go am.dropLater(u) signature, err = crypto.Sign(toSign, key.PrivateKey) return signature, err } @@ -143,14 +148,40 @@ func (am *AccountManager) Accounts() ([]Account, error) { return accounts, err } -func unlockLater(am *AccountManager, addr []byte) { - select { - case <-time.After(am.unlockTime): - } +func (am *AccountManager) addUnlocked(addr []byte, key *crypto.Key) *unlocked { + u := &unlocked{addr: addr, abort: make(chan struct{}), Key: key} am.mutex.Lock() - // TODO: how do we know the key is actually gone from memory? - delete(am.unlockedKeys, string(addr)) + prev, found := am.unlocked[string(addr)] + if found { + // terminate dropLater for this key to avoid unexpected drops. + close(prev.abort) + zeroKey(prev.PrivateKey) + } + am.unlocked[string(addr)] = u am.mutex.Unlock() + return u } +func (am *AccountManager) dropLater(u *unlocked) { + t := time.NewTimer(am.unlockTime) + defer t.Stop() + select { + case <-u.abort: + // just quit + case <-t.C: + am.mutex.Lock() + if am.unlocked[string(u.addr)] == u { + zeroKey(u.PrivateKey) + delete(am.unlocked, string(u.addr)) + } + am.mutex.Unlock() + } +} + +// zeroKey zeroes a private key in memory. +func zeroKey(k *ecdsa.PrivateKey) { + b := k.D.Bits() + for i := range b { + b[i] = 0 + } } |