1 files changed, 210 insertions, 0 deletions
diff --git a/accounts/account_manager.go b/accounts/account_manager.go
new file mode 100644
index 000000000..646dc8376
--- /dev/null
+++ b/accounts/account_manager.go
@@ -0,0 +1,210 @@
+/*
+	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 (
+	"bytes"
+	"crypto/ecdsa"
+	crand "crypto/rand"
+	"os"
+
+	"errors"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+var (
+	ErrLocked = errors.New("account is locked")
+	ErrNoKeys = errors.New("no keys in store")
+)
+
+type Account struct {
+	Address []byte
+}
+
+type Manager struct {
+	keyStore crypto.KeyStore2
+	unlocked map[string]*unlocked
+	mutex    sync.RWMutex
+}
+
+type unlocked struct {
+	*crypto.Key
+	abort chan struct{}
+}
+
+func NewManager(keyStore crypto.KeyStore2) *Manager {
+	return &Manager{
+		keyStore: keyStore,
+		unlocked: make(map[string]*unlocked),
+	}
+}
+
+func (am *Manager) HasAccount(addr []byte) bool {
+	accounts, _ := am.Accounts()
+	for _, acct := range accounts {
+		if bytes.Compare(acct.Address, addr) == 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// Coinbase returns the account address that mining rewards are sent to.
+func (am *Manager) Coinbase() (addr []byte, err error) {
+	// TODO: persist coinbase address on disk
+	return am.firstAddr()
+}
+
+func (am *Manager) firstAddr() ([]byte, error) {
+	addrs, err := am.keyStore.GetKeyAddresses()
+	if os.IsNotExist(err) {
+		return nil, ErrNoKeys
+	} else if err != nil {
+		return nil, err
+	}
+	if len(addrs) == 0 {
+		return nil, ErrNoKeys
+	}
+	return addrs[0], nil
+}
+
+func (am *Manager) DeleteAccount(address []byte, auth string) error {
+	return am.keyStore.DeleteKey(address, auth)
+}
+
+func (am *Manager) Sign(a Account, toSign []byte) (signature []byte, err error) {
+	am.mutex.RLock()
+	unlockedKey, found := am.unlocked[string(a.Address)]
+	am.mutex.RUnlock()
+	if !found {
+		return nil, ErrLocked
+	}
+	signature, err = crypto.Sign(toSign, unlockedKey.PrivateKey)
+	return signature, err
+}
+
+// TimedUnlock unlocks the account with the given address.
+// When timeout has passed, the account will be locked again.
+func (am *Manager) TimedUnlock(addr []byte, keyAuth string, timeout time.Duration) error {
+	key, err := am.keyStore.GetKey(addr, keyAuth)
+	if err != nil {
+		return err
+	}
+	u := am.addUnlocked(addr, key)
+	go am.dropLater(addr, u, timeout)
+	return nil
+}
+
+// Unlock unlocks the account with the given address. The account
+// stays unlocked until the program exits or until a TimedUnlock
+// timeout (started after the call to Unlock) expires.
+func (am *Manager) Unlock(addr []byte, keyAuth string) error {
+	key, err := am.keyStore.GetKey(addr, keyAuth)
+	if err != nil {
+		return err
+	}
+	am.addUnlocked(addr, key)
+	return nil
+}
+
+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) 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
+}
+
+func (am *Manager) addUnlocked(addr []byte, key *crypto.Key) *unlocked {
+	u := &unlocked{Key: key, abort: make(chan struct{})}
+	am.mutex.Lock()
+	prev, found := am.unlocked[string(addr)]
+	if found {
+		// terminate dropLater for this key to avoid unexpected drops.
+		close(prev.abort)
+		// the key is zeroed here instead of in dropLater because
+		// there might not actually be a dropLater running for this
+		// key, i.e. when Unlock was used.
+		zeroKey(prev.PrivateKey)
+	}
+	am.unlocked[string(addr)] = u
+	am.mutex.Unlock()
+	return u
+}
+
+func (am *Manager) dropLater(addr []byte, 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[string(addr)] == u {
+			zeroKey(u.PrivateKey)
+			delete(am.unlocked, string(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
+	}
+}