accounts, cmd, eth, internal, miner, node: wallets and HD APIs

7 files changed, 519 insertions, 66 deletions

diff --git a/accounts/keystore/address_cache.go b/accounts/keystore/account_cache.go
index eb3e3263b..cc8626afc 100644
--- a/accounts/keystore/address_cache.go
+++ b/accounts/keystore/account_cache.go
@@ -39,11 +39,11 @@ import (
 // exist yet, the code will attempt to create a watcher at most this often.
 const minReloadInterval = 2 * time.Second
 
-type accountsByFile []accounts.Account
+type accountsByURL []accounts.Account
 
-func (s accountsByFile) Len() int           { return len(s) }
-func (s accountsByFile) Less(i, j int) bool { return s[i].URL < s[j].URL }
-func (s accountsByFile) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s accountsByURL) Len() int           { return len(s) }
+func (s accountsByURL) Less(i, j int) bool { return s[i].URL < s[j].URL }
+func (s accountsByURL) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 
 // AmbiguousAddrError is returned when attempting to unlock
 // an address for which more than one file exists.
@@ -63,26 +63,28 @@ func (err *AmbiguousAddrError) Error() string {
 	return fmt.Sprintf("multiple keys match address (%s)", files)
 }
 
-// addressCache is a live index of all accounts in the keystore.
-type addressCache struct {
+// accountCache is a live index of all accounts in the keystore.
+type accountCache struct {
 	keydir   string
 	watcher  *watcher
 	mu       sync.Mutex
-	all      accountsByFile
+	all      accountsByURL
 	byAddr   map[common.Address][]accounts.Account
 	throttle *time.Timer
+	notify   chan struct{}
 }
 
-func newAddrCache(keydir string) *addressCache {
-	ac := &addressCache{
+func newAccountCache(keydir string) (*accountCache, chan struct{}) {
+	ac := &accountCache{
 		keydir: keydir,
 		byAddr: make(map[common.Address][]accounts.Account),
+		notify: make(chan struct{}, 1),
 	}
 	ac.watcher = newWatcher(ac)
-	return ac
+	return ac, ac.notify
 }
 
-func (ac *addressCache) accounts() []accounts.Account {
+func (ac *accountCache) accounts() []accounts.Account {
 	ac.maybeReload()
 	ac.mu.Lock()
 	defer ac.mu.Unlock()
@@ -91,14 +93,14 @@ func (ac *addressCache) accounts() []accounts.Account {
 	return cpy
 }
 
-func (ac *addressCache) hasAddress(addr common.Address) bool {
+func (ac *accountCache) hasAddress(addr common.Address) bool {
 	ac.maybeReload()
 	ac.mu.Lock()
 	defer ac.mu.Unlock()
 	return len(ac.byAddr[addr]) > 0
 }
 
-func (ac *addressCache) add(newAccount accounts.Account) {
+func (ac *accountCache) add(newAccount accounts.Account) {
 	ac.mu.Lock()
 	defer ac.mu.Unlock()
 
@@ -111,18 +113,28 @@ func (ac *addressCache) add(newAccount accounts.Account) {
 	copy(ac.all[i+1:], ac.all[i:])
 	ac.all[i] = newAccount
 	ac.byAddr[newAccount.Address] = append(ac.byAddr[newAccount.Address], newAccount)
+
+	select {
+	case ac.notify <- struct{}{}:
+	default:
+	}
 }
 
 // note: removed needs to be unique here (i.e. both File and Address must be set).
-func (ac *addressCache) delete(removed accounts.Account) {
+func (ac *accountCache) delete(removed accounts.Account) {
 	ac.mu.Lock()
 	defer ac.mu.Unlock()
+
 	ac.all = removeAccount(ac.all, removed)
 	if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
 		delete(ac.byAddr, removed.Address)
 	} else {
 		ac.byAddr[removed.Address] = ba
 	}
+	select {
+	case ac.notify <- struct{}{}:
+	default:
+	}
 }
 
 func removeAccount(slice []accounts.Account, elem accounts.Account) []accounts.Account {
@@ -137,7 +149,7 @@ func removeAccount(slice []accounts.Account, elem accounts.Account) []accounts.A
 // find returns the cached account for address if there is a unique match.
 // The exact matching rules are explained by the documentation of accounts.Account.
 // Callers must hold ac.mu.
-func (ac *addressCache) find(a accounts.Account) (accounts.Account, error) {
+func (ac *accountCache) find(a accounts.Account) (accounts.Account, error) {
 	// Limit search to address candidates if possible.
 	matches := ac.all
 	if (a.Address != common.Address{}) {
@@ -169,9 +181,10 @@ func (ac *addressCache) find(a accounts.Account) (accounts.Account, error) {
 	}
 }
 
-func (ac *addressCache) maybeReload() {
+func (ac *accountCache) maybeReload() {
 	ac.mu.Lock()
 	defer ac.mu.Unlock()
+
 	if ac.watcher.running {
 		return // A watcher is running and will keep the cache up-to-date.
 	}
@@ -189,18 +202,22 @@ func (ac *addressCache) maybeReload() {
 	ac.throttle.Reset(minReloadInterval)
 }
 
-func (ac *addressCache) close() {
+func (ac *accountCache) close() {
 	ac.mu.Lock()
 	ac.watcher.close()
 	if ac.throttle != nil {
 		ac.throttle.Stop()
 	}
+	if ac.notify != nil {
+		close(ac.notify)
+		ac.notify = nil
+	}
 	ac.mu.Unlock()
 }
 
 // reload caches addresses of existing accounts.
 // Callers must hold ac.mu.
-func (ac *addressCache) reload() {
+func (ac *accountCache) reload() {
 	accounts, err := ac.scan()
 	if err != nil && glog.V(logger.Debug) {
 		glog.Errorf("can't load keys: %v", err)
@@ -213,10 +230,14 @@ func (ac *addressCache) reload() {
 	for _, a := range accounts {
 		ac.byAddr[a.Address] = append(ac.byAddr[a.Address], a)
 	}
+	select {
+	case ac.notify <- struct{}{}:
+	default:
+	}
 	glog.V(logger.Debug).Infof("reloaded keys, cache has %d accounts", len(ac.all))
 }
 
-func (ac *addressCache) scan() ([]accounts.Account, error) {
+func (ac *accountCache) scan() ([]accounts.Account, error) {
 	files, err := ioutil.ReadDir(ac.keydir)
 	if err != nil {
 		return nil, err
diff --git a/accounts/keystore/address_cache_test.go b/accounts/keystore/account_cache_test.go
index 68af74338..ea6f7d011 100644
--- a/accounts/keystore/address_cache_test.go
+++ b/accounts/keystore/account_cache_test.go
@@ -53,11 +53,11 @@ var (
 func TestWatchNewFile(t *testing.T) {
 	t.Parallel()
 
-	dir, am := tmpKeyStore(t, false)
+	dir, ks := tmpKeyStore(t, false)
 	defer os.RemoveAll(dir)
 
 	// Ensure the watcher is started before adding any files.
-	am.Accounts()
+	ks.Accounts()
 	time.Sleep(200 * time.Millisecond)
 
 	// Move in the files.
@@ -71,11 +71,17 @@ func TestWatchNewFile(t *testing.T) {
 		}
 	}
 
-	// am should see the accounts.
+	// ks should see the accounts.
 	var list []accounts.Account
 	for d := 200 * time.Millisecond; d < 5*time.Second; d *= 2 {
-		list = am.Accounts()
+		list = ks.Accounts()
 		if reflect.DeepEqual(list, wantAccounts) {
+			// ks should have also received change notifications
+			select {
+			case <-ks.changes:
+			default:
+				t.Fatalf("wasn't notified of new accounts")
+			}
 			return
 		}
 		time.Sleep(d)
@@ -86,12 +92,12 @@ func TestWatchNewFile(t *testing.T) {
 func TestWatchNoDir(t *testing.T) {
 	t.Parallel()
 
-	// Create am but not the directory that it watches.
+	// Create ks but not the directory that it watches.
 	rand.Seed(time.Now().UnixNano())
 	dir := filepath.Join(os.TempDir(), fmt.Sprintf("eth-keystore-watch-test-%d-%d", os.Getpid(), rand.Int()))
-	am := NewKeyStore(dir, LightScryptN, LightScryptP)
+	ks := NewKeyStore(dir, LightScryptN, LightScryptP)
 
-	list := am.Accounts()
+	list := ks.Accounts()
 	if len(list) > 0 {
 		t.Error("initial account list not empty:", list)
 	}
@@ -105,12 +111,18 @@ func TestWatchNoDir(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// am should see the account.
+	// ks should see the account.
 	wantAccounts := []accounts.Account{cachetestAccounts[0]}
 	wantAccounts[0].URL = file
 	for d := 200 * time.Millisecond; d < 8*time.Second; d *= 2 {
-		list = am.Accounts()
+		list = ks.Accounts()
 		if reflect.DeepEqual(list, wantAccounts) {
+			// ks should have also received change notifications
+			select {
+			case <-ks.changes:
+			default:
+				t.Fatalf("wasn't notified of new accounts")
+			}
 			return
 		}
 		time.Sleep(d)
@@ -119,7 +131,7 @@ func TestWatchNoDir(t *testing.T) {
 }
 
 func TestCacheInitialReload(t *testing.T) {
-	cache := newAddrCache(cachetestDir)
+	cache, _ := newAccountCache(cachetestDir)
 	accounts := cache.accounts()
 	if !reflect.DeepEqual(accounts, cachetestAccounts) {
 		t.Fatalf("got initial accounts: %swant %s", spew.Sdump(accounts), spew.Sdump(cachetestAccounts))
@@ -127,7 +139,7 @@ func TestCacheInitialReload(t *testing.T) {
 }
 
 func TestCacheAddDeleteOrder(t *testing.T) {
-	cache := newAddrCache("testdata/no-such-dir")
+	cache, notify := newAccountCache("testdata/no-such-dir")
 	cache.watcher.running = true // prevent unexpected reloads
 
 	accs := []accounts.Account{
@@ -163,14 +175,24 @@ func TestCacheAddDeleteOrder(t *testing.T) {
 	for _, a := range accs {
 		cache.add(a)
 	}
+	select {
+	case <-notify:
+	default:
+		t.Fatalf("notifications didn't fire for adding new accounts")
+	}
 	// Add some of them twice to check that they don't get reinserted.
 	cache.add(accs[0])
 	cache.add(accs[2])
 
+	select {
+	case <-notify:
+		t.Fatalf("notifications fired for adding existing accounts")
+	default:
+	}
 	// Check that the account list is sorted by filename.
 	wantAccounts := make([]accounts.Account, len(accs))
 	copy(wantAccounts, accs)
-	sort.Sort(accountsByFile(wantAccounts))
+	sort.Sort(accountsByURL(wantAccounts))
 	list := cache.accounts()
 	if !reflect.DeepEqual(list, wantAccounts) {
 		t.Fatalf("got accounts: %s\nwant %s", spew.Sdump(accs), spew.Sdump(wantAccounts))
@@ -190,6 +212,11 @@ func TestCacheAddDeleteOrder(t *testing.T) {
 	}
 	cache.delete(accounts.Account{Address: common.HexToAddress("fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e"), URL: "something"})
 
+	select {
+	case <-notify:
+	default:
+		t.Fatalf("notifications didn't fire for deleting accounts")
+	}
 	// Check content again after deletion.
 	wantAccountsAfterDelete := []accounts.Account{
 		wantAccounts[1],
@@ -212,7 +239,7 @@ func TestCacheAddDeleteOrder(t *testing.T) {
 
 func TestCacheFind(t *testing.T) {
 	dir := filepath.Join("testdata", "dir")
-	cache := newAddrCache(dir)
+	cache, _ := newAccountCache(dir)
 	cache.watcher.running = true // prevent unexpected reloads
 
 	accs := []accounts.Account{
diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go
index d125f7d62..ce4e87ce9 100644
--- a/accounts/keystore/keystore.go
+++ b/accounts/keystore/keystore.go
@@ -37,23 +37,34 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/event"
 )
 
 var (
-	ErrNeedPasswordOrUnlock = accounts.NewAuthNeededError("password or unlock")
-	ErrNoMatch              = errors.New("no key for given address or file")
-	ErrDecrypt              = errors.New("could not decrypt key with given passphrase")
+	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 passphrase")
 )
 
-// BackendType can be used to query the account manager for encrypted keystores.
-var BackendType = reflect.TypeOf(new(KeyStore))
+// KeyStoreType is the reflect type of a keystore backend.
+var KeyStoreType = reflect.TypeOf(&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 {
-	cache    *addressCache
-	keyStore keyStore
-	mu       sync.RWMutex
-	unlocked map[common.Address]*unlocked
+	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 {
@@ -64,7 +75,7 @@ type unlocked struct {
 // NewKeyStore creates a keystore for the given directory.
 func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
 	keydir, _ = filepath.Abs(keydir)
-	ks := &KeyStore{keyStore: &keyStorePassphrase{keydir, scryptN, scryptP}}
+	ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP}}
 	ks.init(keydir)
 	return ks
 }
@@ -73,20 +84,136 @@ func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
 // Deprecated: Use NewKeyStore.
 func NewPlaintextKeyStore(keydir string) *KeyStore {
 	keydir, _ = filepath.Abs(keydir)
-	ks := &KeyStore{keyStore: &keyStorePlain{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 = newAddrCache(keydir)
+	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
+	accs := ks.cache.accounts()
+
+	// Transform the current list of wallets into the new one
+	ks.mu.Lock()
+
+	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() < account.URL {
+			events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Arrive: false})
+			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() > account.URL {
+			wallet := &keystoreWallet{account: account, keystore: ks}
+
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Arrive: true})
+			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, Arrive: false})
+	}
+	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.
@@ -118,6 +245,7 @@ func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error {
 	err = os.Remove(a.URL)
 	if err == nil {
 		ks.cache.delete(a)
+		ks.refreshWallets()
 	}
 	return err
 }
@@ -131,7 +259,7 @@ func (ks *KeyStore) SignHash(a accounts.Account, hash []byte) ([]byte, error) {
 
 	unlockedKey, found := ks.unlocked[a.Address]
 	if !found {
-		return nil, ErrNeedPasswordOrUnlock
+		return nil, ErrLocked
 	}
 	// Sign the hash using plain ECDSA operations
 	return crypto.Sign(hash, unlockedKey.PrivateKey)
@@ -145,7 +273,7 @@ func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *b
 
 	unlockedKey, found := ks.unlocked[a.Address]
 	if !found {
-		return nil, ErrNeedPasswordOrUnlock
+		return nil, ErrLocked
 	}
 	// Depending on the presence of the chain ID, sign with EIP155 or homestead
 	if chainID != nil {
@@ -221,10 +349,9 @@ func (ks *KeyStore) TimedUnlock(a accounts.Account, passphrase string, timeout t
 			// it with a timeout would be confusing.
 			zeroKey(key.PrivateKey)
 			return nil
-		} else {
-			// Terminate the expire goroutine and replace it below.
-			close(u.abort)
 		}
+		// Terminate the expire goroutine and replace it below.
+		close(u.abort)
 	}
 	if timeout > 0 {
 		u = &unlocked{Key: key, abort: make(chan struct{})}
@@ -250,7 +377,7 @@ func (ks *KeyStore) getDecryptedKey(a accounts.Account, auth string) (accounts.A
 	if err != nil {
 		return a, nil, err
 	}
-	key, err := ks.keyStore.GetKey(a.Address, a.URL, auth)
+	key, err := ks.storage.GetKey(a.Address, a.URL, auth)
 	return a, key, err
 }
 
@@ -277,13 +404,14 @@ func (ks *KeyStore) expire(addr common.Address, u *unlocked, timeout time.Durati
 // NewAccount generates a new key and stores it into the key directory,
 // encrypting it with the passphrase.
 func (ks *KeyStore) NewAccount(passphrase string) (accounts.Account, error) {
-	_, account, err := storeNewKey(ks.keyStore, crand.Reader, passphrase)
+	_, account, err := storeNewKey(ks.storage, crand.Reader, passphrase)
 	if err != nil {
 		return accounts.Account{}, err
 	}
 	// Add the account to the cache immediately rather
 	// than waiting for file system notifications to pick it up.
 	ks.cache.add(account)
+	ks.refreshWallets()
 	return account, nil
 }
 
@@ -294,7 +422,7 @@ func (ks *KeyStore) Export(a accounts.Account, passphrase, newPassphrase string)
 		return nil, err
 	}
 	var N, P int
-	if store, ok := ks.keyStore.(*keyStorePassphrase); ok {
+	if store, ok := ks.storage.(*keyStorePassphrase); ok {
 		N, P = store.scryptN, store.scryptP
 	} else {
 		N, P = StandardScryptN, StandardScryptP
@@ -325,11 +453,12 @@ func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (acco
 }
 
 func (ks *KeyStore) importKey(key *Key, passphrase string) (accounts.Account, error) {
-	a := accounts.Account{Address: key.Address, URL: ks.keyStore.JoinPath(keyFileName(key.Address))}
-	if err := ks.keyStore.StoreKey(a.URL, key, passphrase); err != nil {
+	a := accounts.Account{Address: key.Address, URL: ks.storage.JoinPath(keyFileName(key.Address))}
+	if err := ks.storage.StoreKey(a.URL, key, passphrase); err != nil {
 		return accounts.Account{}, err
 	}
 	ks.cache.add(a)
+	ks.refreshWallets()
 	return a, nil
 }
 
@@ -339,17 +468,18 @@ func (ks *KeyStore) Update(a accounts.Account, passphrase, newPassphrase string)
 	if err != nil {
 		return err
 	}
-	return ks.keyStore.StoreKey(a.URL, key, newPassphrase)
+	return ks.storage.StoreKey(a.URL, key, newPassphrase)
 }
 
 // ImportPreSaleKey decrypts the given Ethereum presale wallet and stores
 // a key file in the key directory. The key file is encrypted with the same passphrase.
 func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (accounts.Account, error) {
-	a, _, err := importPreSaleKey(ks.keyStore, keyJSON, passphrase)
+	a, _, err := importPreSaleKey(ks.storage, keyJSON, passphrase)
 	if err != nil {
 		return a, err
 	}
 	ks.cache.add(a)
+	ks.refreshWallets()
 	return a, nil
 }
 
diff --git a/accounts/keystore/keystore_test.go b/accounts/keystore/keystore_test.go
index af2140c31..6b7170a2f 100644
--- a/accounts/keystore/keystore_test.go
+++ b/accounts/keystore/keystore_test.go
@@ -18,14 +18,17 @@ package keystore
 
 import (
 	"io/ioutil"
+	"math/rand"
 	"os"
 	"runtime"
+	"sort"
 	"strings"
 	"testing"
 	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/event"
 )
 
 var testSigData = make([]byte, 32)
@@ -122,8 +125,8 @@ func TestTimedUnlock(t *testing.T) {
 
 	// Signing without passphrase fails because account is locked
 	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
-	if err != ErrNeedPasswordOrUnlock {
-		t.Fatal("Signing should've failed with ErrNeedPasswordOrUnlock before unlocking, got ", err)
+	if err != ErrLocked {
+		t.Fatal("Signing should've failed with ErrLocked before unlocking, got ", err)
 	}
 
 	// Signing with passphrase works
@@ -140,8 +143,8 @@ func TestTimedUnlock(t *testing.T) {
 	// Signing fails again after automatic locking
 	time.Sleep(250 * time.Millisecond)
 	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
-	if err != ErrNeedPasswordOrUnlock {
-		t.Fatal("Signing should've failed with ErrNeedPasswordOrUnlock timeout expired, got ", err)
+	if err != ErrLocked {
+		t.Fatal("Signing should've failed with ErrLocked timeout expired, got ", err)
 	}
 }
 
@@ -180,8 +183,8 @@ func TestOverrideUnlock(t *testing.T) {
 	// Signing fails again after automatic locking
 	time.Sleep(250 * time.Millisecond)
 	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
-	if err != ErrNeedPasswordOrUnlock {
-		t.Fatal("Signing should've failed with ErrNeedPasswordOrUnlock timeout expired, got ", err)
+	if err != ErrLocked {
+		t.Fatal("Signing should've failed with ErrLocked timeout expired, got ", err)
 	}
 }
 
@@ -201,7 +204,7 @@ func TestSignRace(t *testing.T) {
 	}
 	end := time.Now().Add(500 * time.Millisecond)
 	for time.Now().Before(end) {
-		if _, err := ks.SignHash(accounts.Account{Address: a1.Address}, testSigData); err == ErrNeedPasswordOrUnlock {
+		if _, err := ks.SignHash(accounts.Account{Address: a1.Address}, testSigData); err == ErrLocked {
 			return
 		} else if err != nil {
 			t.Errorf("Sign error: %v", err)
@@ -212,6 +215,145 @@ func TestSignRace(t *testing.T) {
 	t.Errorf("Account did not lock within the timeout")
 }
 
+// Tests that the wallet notifier loop starts and stops correctly based on the
+// addition and removal of wallet event subscriptions.
+func TestWalletNotifierLifecycle(t *testing.T) {
+	// Create a temporary kesytore to test with
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	// Ensure that the notification updater is not running yet
+	time.Sleep(250 * time.Millisecond)
+	ks.mu.RLock()
+	updating := ks.updating
+	ks.mu.RUnlock()
+
+	if updating {
+		t.Errorf("wallet notifier running without subscribers")
+	}
+	// Subscribe to the wallet feed and ensure the updater boots up
+	updates := make(chan accounts.WalletEvent)
+
+	subs := make([]event.Subscription, 2)
+	for i := 0; i < len(subs); i++ {
+		// Create a new subscription
+		subs[i] = ks.Subscribe(updates)
+
+		// Ensure the notifier comes online
+		time.Sleep(250 * time.Millisecond)
+		ks.mu.RLock()
+		updating = ks.updating
+		ks.mu.RUnlock()
+
+		if !updating {
+			t.Errorf("sub %d: wallet notifier not running after subscription", i)
+		}
+	}
+	// Unsubscribe and ensure the updater terminates eventually
+	for i := 0; i < len(subs); i++ {
+		// Close an existing subscription
+		subs[i].Unsubscribe()
+
+		// Ensure the notifier shuts down at and only at the last close
+		for k := 0; k < int(walletRefreshCycle/(250*time.Millisecond))+2; k++ {
+			ks.mu.RLock()
+			updating = ks.updating
+			ks.mu.RUnlock()
+
+			if i < len(subs)-1 && !updating {
+				t.Fatalf("sub %d: event notifier stopped prematurely", i)
+			}
+			if i == len(subs)-1 && !updating {
+				return
+			}
+			time.Sleep(250 * time.Millisecond)
+		}
+	}
+	t.Errorf("wallet notifier didn't terminate after unsubscribe")
+}
+
+// Tests that wallet notifications and correctly fired when accounts are added
+// or deleted from the keystore.
+func TestWalletNotifications(t *testing.T) {
+	// Create a temporary kesytore to test with
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	// Subscribe to the wallet feed
+	updates := make(chan accounts.WalletEvent, 1)
+	sub := ks.Subscribe(updates)
+	defer sub.Unsubscribe()
+
+	// Randomly add and remove account and make sure events and wallets are in sync
+	live := make(map[common.Address]accounts.Account)
+	for i := 0; i < 1024; i++ {
+		// Execute a creation or deletion and ensure event arrival
+		if create := len(live) == 0 || rand.Int()%4 > 0; create {
+			// Add a new account and ensure wallet notifications arrives
+			account, err := ks.NewAccount("")
+			if err != nil {
+				t.Fatalf("failed to create test account: %v", err)
+			}
+			select {
+			case event := <-updates:
+				if !event.Arrive {
+					t.Errorf("departure event on account creation")
+				}
+				if event.Wallet.Accounts()[0] != account {
+					t.Errorf("account mismatch on created wallet: have %v, want %v", event.Wallet.Accounts()[0], account)
+				}
+			default:
+				t.Errorf("wallet arrival event not fired on account creation")
+			}
+			live[account.Address] = account
+		} else {
+			// Select a random account to delete (crude, but works)
+			var account accounts.Account
+			for _, a := range live {
+				account = a
+				break
+			}
+			// Remove an account and ensure wallet notifiaction arrives
+			if err := ks.Delete(account, ""); err != nil {
+				t.Fatalf("failed to delete test account: %v", err)
+			}
+			select {
+			case event := <-updates:
+				if event.Arrive {
+					t.Errorf("arrival event on account deletion")
+				}
+				if event.Wallet.Accounts()[0] != account {
+					t.Errorf("account mismatch on deleted wallet: have %v, want %v", event.Wallet.Accounts()[0], account)
+				}
+			default:
+				t.Errorf("wallet departure event not fired on account creation")
+			}
+			delete(live, account.Address)
+		}
+		// Retrieve the list of wallets and ensure it matches with our required live set
+		liveList := make([]accounts.Account, 0, len(live))
+		for _, account := range live {
+			liveList = append(liveList, account)
+		}
+		sort.Sort(accountsByURL(liveList))
+
+		wallets := ks.Wallets()
+		if len(liveList) != len(wallets) {
+			t.Errorf("wallet list doesn't match required accounts: have %v, want %v", wallets, liveList)
+		} else {
+			for j, wallet := range wallets {
+				if accs := wallet.Accounts(); len(accs) != 1 {
+					t.Errorf("wallet %d: contains invalid number of accounts: have %d, want 1", j, len(accs))
+				} else if accs[0] != liveList[j] {
+					t.Errorf("wallet %d: account mismatch: have %v, want %v", j, accs[0], liveList[j])
+				}
+			}
+		}
+		// Sleep a bit to avoid same-timestamp keyfiles
+		time.Sleep(10 * time.Millisecond)
+	}
+}
+
 func tmpKeyStore(t *testing.T, encrypted bool) (string, *KeyStore) {
 	d, err := ioutil.TempDir("", "eth-keystore-test")
 	if err != nil {
diff --git a/accounts/keystore/keystore_wallet.go b/accounts/keystore/keystore_wallet.go
new file mode 100644
index 000000000..d92926478
--- /dev/null
+++ b/accounts/keystore/keystore_wallet.go
@@ -0,0 +1,133 @@
+// 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
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// keystoreWallet implements the accounts.Wallet interface for the original
+// keystore.
+type keystoreWallet struct {
+	account  accounts.Account // Single account contained in this wallet
+	keystore *KeyStore        // Keystore where the account originates from
+}
+
+// Type implements accounts.Wallet, returning the textual type of the wallet.
+func (w *keystoreWallet) Type() string {
+	return "secret-storage"
+}
+
+// URL implements accounts.Wallet, returning the URL of the account within.
+func (w *keystoreWallet) URL() string {
+	return w.account.URL
+}
+
+// Status implements accounts.Wallet, always returning "open", since there is no
+// concept of open/close for plain keystore accounts.
+func (w *keystoreWallet) Status() string {
+	return "Open"
+}
+
+// Open implements accounts.Wallet, but is a noop for plain wallets since there
+// is no connection or decryption step necessary to access the list of accounts.
+func (w *keystoreWallet) Open(passphrase string) error { return nil }
+
+// Close implements accounts.Wallet, but is a noop for plain wallets since is no
+// meaningful open operation.
+func (w *keystoreWallet) Close() error { return nil }
+
+// Accounts implements accounts.Wallet, returning an account list consisting of
+// a single account that the plain kestore wallet contains.
+func (w *keystoreWallet) Accounts() []accounts.Account {
+	return []accounts.Account{w.account}
+}
+
+// Contains implements accounts.Wallet, returning whether a particular account is
+// or is not wrapped by this wallet instance.
+func (w *keystoreWallet) Contains(account accounts.Account) bool {
+	return account.Address == w.account.Address && (account.URL == "" || account.URL == w.account.URL)
+}
+
+// Derive implements accounts.Wallet, but is a noop for plain wallets since there
+// is no notion of hierarchical account derivation for plain keystore accounts.
+func (w *keystoreWallet) Derive(path string, pin bool) (accounts.Account, error) {
+	return accounts.Account{}, accounts.ErrNotSupported
+}
+
+// SignHash implements accounts.Wallet, attempting to sign the given hash with
+// the given account. If the wallet does not wrap this particular account, an
+// error is returned to avoid account leakage (even though in theory we may be
+// able to sign via our shared keystore backend).
+func (w *keystoreWallet) SignHash(account accounts.Account, hash []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if account.Address != w.account.Address {
+		return nil, accounts.ErrUnknownAccount
+	}
+	if account.URL != "" && account.URL != w.account.URL {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHash(account, hash)
+}
+
+// SignTx implements accounts.Wallet, attempting to sign the given transaction
+// with the given account. If the wallet does not wrap this particular account,
+// an error is returned to avoid account leakage (even though in theory we may
+// be able to sign via our shared keystore backend).
+func (w *keystoreWallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Make sure the requested account is contained within
+	if account.Address != w.account.Address {
+		return nil, accounts.ErrUnknownAccount
+	}
+	if account.URL != "" && account.URL != w.account.URL {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignTx(account, tx, chainID)
+}
+
+// SignHashWithPassphrase implements accounts.Wallet, attempting to sign the
+// given hash with the given account using passphrase as extra authentication.
+func (w *keystoreWallet) SignHashWithPassphrase(account accounts.Account, passphrase string, hash []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if account.Address != w.account.Address {
+		return nil, accounts.ErrUnknownAccount
+	}
+	if account.URL != "" && account.URL != w.account.URL {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHashWithPassphrase(account, passphrase, hash)
+}
+
+// SignTxWithPassphrase implements accounts.Wallet, attempting to sign the given
+// transaction with the given account using passphrase as extra authentication.
+func (w *keystoreWallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Make sure the requested account is contained within
+	if account.Address != w.account.Address {
+		return nil, accounts.ErrUnknownAccount
+	}
+	if account.URL != "" && account.URL != w.account.URL {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignTxWithPassphrase(account, passphrase, tx, chainID)
+}
diff --git a/accounts/keystore/watch.go b/accounts/keystore/watch.go
index 04a87b12e..0b4401255 100644
--- a/accounts/keystore/watch.go
+++ b/accounts/keystore/watch.go
@@ -27,14 +27,14 @@ import (
 )
 
 type watcher struct {
-	ac       *addressCache
+	ac       *accountCache
 	starting bool
 	running  bool
 	ev       chan notify.EventInfo
 	quit     chan struct{}
 }
 
-func newWatcher(ac *addressCache) *watcher {
+func newWatcher(ac *accountCache) *watcher {
 	return &watcher{
 		ac:   ac,
 		ev:   make(chan notify.EventInfo, 10),
diff --git a/accounts/keystore/watch_fallback.go b/accounts/keystore/watch_fallback.go
index 6412f3b33..7c5e9cb2e 100644
--- a/accounts/keystore/watch_fallback.go
+++ b/accounts/keystore/watch_fallback.go
@@ -23,6 +23,6 @@ package keystore
 
 type watcher struct{ running bool }
 
-func newWatcher(*addressCache) *watcher { return new(watcher) }
+func newWatcher(*accountCache) *watcher { return new(watcher) }
 func (*watcher) start()                 {}
 func (*watcher) close()                 {}