Merge pull request #3346 from SomberNight/encrypt_watch_only_wallets

allow encrypting watch-only wallets

electrum

@@ -193,6 +193,8 @@ def init_daemon(config_options):
         print_msg("Type 'electrum create' to create a new wallet, or provide a path to a wallet with the -w option")
         sys.exit(0)
     if storage.is_encrypted():
+        if storage.is_encrypted_with_hw_device():
+            raise NotImplementedError("CLI functionality of encrypted hw wallets")
         if config.get('password'):
             password = config.get('password')
         else:
@@ -237,6 +239,8 @@ def init_cmdline(config_options, server):
     # commands needing password
     if (cmd.requires_wallet and storage.is_encrypted() and server is None)\
        or (cmd.requires_password and (storage.get('use_encryption') or storage.is_encrypted())):
+        if storage.is_encrypted_with_hw_device():
+            raise NotImplementedError("CLI functionality of encrypted hw wallets")
         if config.get('password'):
             password = config.get('password')
         else:
@@ -263,12 +267,14 @@ def run_offline_command(config, config_options):
     if cmd.requires_wallet:
         storage = WalletStorage(config.get_wallet_path())
         if storage.is_encrypted():
+            if storage.is_encrypted_with_hw_device():
+                raise NotImplementedError("CLI functionality of encrypted hw wallets")
             storage.decrypt(password)
         wallet = Wallet(storage)
     else:
         wallet = None
     # check password
-    if cmd.requires_password and storage.get('use_encryption'):
+    if cmd.requires_password and wallet.has_password():
         try:
             seed = wallet.check_password(password)
         except InvalidPassword:

gui/kivy/uix/dialogs/installwizard.py

@@ -807,7 +807,7 @@ class InstallWizard(BaseWizard, Widget):
         popup.init(message, callback)
         popup.open()
 
-    def request_password(self, run_next):
+    def request_password(self, run_next, force_disable_encrypt_cb=False):
         def callback(pin):
             if pin:
                 self.run('confirm_password', pin, run_next)

gui/qt/installwizard.py

@@ -10,13 +10,13 @@ from PyQt5.QtWidgets import *
 
 from electrum import Wallet, WalletStorage
 from electrum.util import UserCancelled, InvalidPassword
-from electrum.base_wizard import BaseWizard
+from electrum.base_wizard import BaseWizard, HWD_SETUP_DECRYPT_WALLET
 from electrum.i18n import _
 
 from .seed_dialog import SeedLayout, KeysLayout
 from .network_dialog import NetworkChoiceLayout
 from .util import *
-from .password_dialog import PasswordLayout, PW_NEW
+from .password_dialog import PasswordLayout, PasswordLayoutForHW, PW_NEW
 
 
 class GoBack(Exception):
@@ -29,6 +29,10 @@ MSG_ENTER_SEED_OR_MPK = _("Please enter a seed phrase or a master key (xpub or x
 MSG_COSIGNER = _("Please enter the master public key of cosigner #%d:")
 MSG_ENTER_PASSWORD = _("Choose a password to encrypt your wallet keys.") + '\n'\
                      + _("Leave this field empty if you want to disable encryption.")
+MSG_HW_STORAGE_ENCRYPTION = _("Set wallet file encryption.") + '\n'\
+                          + _("Your wallet file does not contain secrets, mostly just metadata. ") \
+                          + _("It also contains your master public key that allows watching your addresses.") + '\n\n'\
+                          + _("Note: If you enable this setting, you will need your hardware device to open your wallet.")
 MSG_RESTORE_PASSPHRASE = \
     _("Please enter your seed derivation passphrase. "
       "Note: this is NOT your encryption password. "
@@ -196,12 +200,18 @@ class InstallWizard(QDialog, MessageBoxMixin, BaseWizard):
                     msg =_("This file does not exist.") + '\n' \
                           + _("Press 'Next' to create this wallet, or choose another file.")
                     pw = False
-                elif self.storage.file_exists() and self.storage.is_encrypted():
-                    msg = _("This file is encrypted.") + '\n' + _('Enter your password or choose another file.')
-                    pw = True
                 else:
-                    msg = _("Press 'Next' to open this wallet.")
-                    pw = False
+                    if self.storage.is_encrypted_with_user_pw():
+                        msg = _("This file is encrypted with a password.") + '\n' \
+                              + _('Enter your password or choose another file.')
+                        pw = True
+                    elif self.storage.is_encrypted_with_hw_device():
+                        msg = _("This file is encrypted using a hardware device.") + '\n' \
+                              + _("Press 'Next' to choose device to decrypt.")
+                        pw = False
+                    else:
+                        msg = _("Press 'Next' to open this wallet.")
+                        pw = False
             else:
                 msg = _('Cannot read file')
                 pw = False
@@ -227,17 +237,40 @@ class InstallWizard(QDialog, MessageBoxMixin, BaseWizard):
             if not self.storage.file_exists():
                 break
             if self.storage.file_exists() and self.storage.is_encrypted():
-                password = self.pw_e.text()
-                try:
-                    self.storage.decrypt(password)
-                    break
-                except InvalidPassword as e:
-                    QMessageBox.information(None, _('Error'), str(e))
-                    continue
-                except BaseException as e:
-                    traceback.print_exc(file=sys.stdout)
-                    QMessageBox.information(None, _('Error'), str(e))
-                    return
+                if self.storage.is_encrypted_with_user_pw():
+                    password = self.pw_e.text()
+                    try:
+                        self.storage.decrypt(password)
+                        break
+                    except InvalidPassword as e:
+                        QMessageBox.information(None, _('Error'), str(e))
+                        continue
+                    except BaseException as e:
+                        traceback.print_exc(file=sys.stdout)
+                        QMessageBox.information(None, _('Error'), str(e))
+                        return
+                elif self.storage.is_encrypted_with_hw_device():
+                    try:
+                        self.run('choose_hw_device', HWD_SETUP_DECRYPT_WALLET)
+                    except InvalidPassword as e:
+                        # FIXME if we get here because of mistyped passphrase
+                        # then that passphrase gets "cached"
+                        QMessageBox.information(
+                            None, _('Error'),
+                            _('Failed to decrypt using this hardware device.') + '\n' +
+                            _('If you use a passphrase, make sure it is correct.'))
+                        self.stack = []
+                        return self.run_and_get_wallet()
+                    except BaseException as e:
+                        traceback.print_exc(file=sys.stdout)
+                        QMessageBox.information(None, _('Error'), str(e))
+                        return
+                    if self.storage.is_past_initial_decryption():
+                        break
+                    else:
+                        return
+                else:
+                    raise Exception('Unexpected encryption version')
 
         path = self.storage.path
         if self.storage.requires_split():
@@ -386,17 +419,25 @@ class InstallWizard(QDialog, MessageBoxMixin, BaseWizard):
         self.exec_layout(slayout)
         return slayout.is_ext
 
-    def pw_layout(self, msg, kind):
-        playout = PasswordLayout(None, msg, kind, self.next_button)
+    def pw_layout(self, msg, kind, force_disable_encrypt_cb):
+        playout = PasswordLayout(None, msg, kind, self.next_button,
+                                 force_disable_encrypt_cb=force_disable_encrypt_cb)
         playout.encrypt_cb.setChecked(True)
         self.exec_layout(playout.layout())
         return playout.new_password(), playout.encrypt_cb.isChecked()
 
     @wizard_dialog
-    def request_password(self, run_next):
+    def request_password(self, run_next, force_disable_encrypt_cb=False):
         """Request the user enter a new password and confirm it.  Return
         the password or None for no password."""
-        return self.pw_layout(MSG_ENTER_PASSWORD, PW_NEW)
+        return self.pw_layout(MSG_ENTER_PASSWORD, PW_NEW, force_disable_encrypt_cb)
+
+    @wizard_dialog
+    def request_storage_encryption(self, run_next):
+        playout = PasswordLayoutForHW(None, MSG_HW_STORAGE_ENCRYPTION, PW_NEW, self.next_button)
+        playout.encrypt_cb.setChecked(True)
+        self.exec_layout(playout.layout())
+        return playout.encrypt_cb.isChecked()
 
     def show_restore(self, wallet, network):
         # FIXME: these messages are shown after the install wizard is

gui/qt/main_window.py

@@ -383,7 +383,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             extra.append(_('watching only'))
         title += '  [%s]'% ', '.join(extra)
         self.setWindowTitle(title)
-        self.password_menu.setEnabled(self.wallet.can_change_password())
+        self.password_menu.setEnabled(self.wallet.may_have_password())
         self.import_privkey_menu.setVisible(self.wallet.can_import_privkey())
         self.import_address_menu.setVisible(self.wallet.can_import_address())
         self.export_menu.setEnabled(self.wallet.can_export())
@@ -888,14 +888,15 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             if alias_addr:
                 if self.wallet.is_mine(alias_addr):
                     msg = _('This payment request will be signed.') + '\n' + _('Please enter your password')
-                    password = self.password_dialog(msg)
-                    if password:
-                        try:
-                            self.wallet.sign_payment_request(addr, alias, alias_addr, password)
-                        except Exception as e:
-                            self.show_error(str(e))
+                    password = None
+                    if self.wallet.has_keystore_encryption():
+                        password = self.password_dialog(msg)
+                        if not password:
                             return
-                    else:
+                    try:
+                        self.wallet.sign_payment_request(addr, alias, alias_addr, password)
+                    except Exception as e:
+                        self.show_error(str(e))
                         return
                 else:
                     return
@@ -1383,7 +1384,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         def request_password(self, *args, **kwargs):
             parent = self.top_level_window()
             password = None
-            while self.wallet.has_password():
+            while self.wallet.has_keystore_encryption():
                 password = self.password_dialog(parent=parent)
                 if password is None:
                     # User cancelled password input
@@ -1518,7 +1519,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         if fee > confirm_rate * tx.estimated_size() / 1000:
             msg.append(_('Warning') + ': ' + _("The fee for this transaction seems unusually high."))
 
-        if self.wallet.has_password():
+        if self.wallet.has_keystore_encryption():
             msg.append("")
             msg.append(_("Enter your password to proceed"))
             password = self.password_dialog('\n'.join(msg))
@@ -1921,17 +1922,37 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
 
     def update_buttons_on_seed(self):
         self.seed_button.setVisible(self.wallet.has_seed())
-        self.password_button.setVisible(self.wallet.can_change_password())
+        self.password_button.setVisible(self.wallet.may_have_password())
         self.send_button.setVisible(not self.wallet.is_watching_only())
 
     def change_password_dialog(self):
-        from .password_dialog import ChangePasswordDialog
-        d = ChangePasswordDialog(self, self.wallet)
-        ok, password, new_password, encrypt_file = d.run()
+        from electrum.storage import STO_EV_XPUB_PW
+        if self.wallet.get_available_storage_encryption_version() == STO_EV_XPUB_PW:
+            from .password_dialog import ChangePasswordDialogForHW
+            d = ChangePasswordDialogForHW(self, self.wallet)
+            ok, encrypt_file = d.run()
+            if not ok:
+                return
+
+            try:
+                hw_dev_pw = self.wallet.keystore.get_password_for_storage_encryption()
+            except UserCancelled:
+                return
+            except BaseException as e:
+                traceback.print_exc(file=sys.stderr)
+                self.show_error(str(e))
+                return
+            old_password = hw_dev_pw if self.wallet.has_password() else None
+            new_password = hw_dev_pw if encrypt_file else None
+        else:
+            from .password_dialog import ChangePasswordDialogForSW
+            d = ChangePasswordDialogForSW(self, self.wallet)
+            ok, old_password, new_password, encrypt_file = d.run()
+
         if not ok:
             return
         try:
-            self.wallet.update_password(password, new_password, encrypt_file)
+            self.wallet.update_password(old_password, new_password, encrypt_file)
         except BaseException as e:
             self.show_error(str(e))
             return
@@ -1939,7 +1960,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             traceback.print_exc(file=sys.stdout)
             self.show_error(_('Failed to update password'))
             return
-        msg = _('Password was updated successfully') if new_password else _('Password is disabled, this wallet is not protected')
+        msg = _('Password was updated successfully') if self.wallet.has_password() else _('Password is disabled, this wallet is not protected')
         self.show_message(msg, title=_("Success"))
         self.update_lock_icon()
 

gui/qt/password_dialog.py

@@ -57,7 +57,7 @@ class PasswordLayout(object):
 
     titles = [_("Enter Password"), _("Change Password"), _("Enter Passphrase")]
 
-    def __init__(self, wallet, msg, kind, OK_button):
+    def __init__(self, wallet, msg, kind, OK_button, force_disable_encrypt_cb=False):
         self.wallet = wallet
 
         self.pw = QLineEdit()
@@ -126,7 +126,8 @@ class PasswordLayout(object):
         def enable_OK():
             ok = self.new_pw.text() == self.conf_pw.text()
             OK_button.setEnabled(ok)
-            self.encrypt_cb.setEnabled(ok and bool(self.new_pw.text()))
+            self.encrypt_cb.setEnabled(ok and bool(self.new_pw.text())
+                                       and not force_disable_encrypt_cb)
         self.new_pw.textChanged.connect(enable_OK)
         self.conf_pw.textChanged.connect(enable_OK)
 
@@ -163,11 +164,84 @@ class PasswordLayout(object):
         return pw
 
 
-class ChangePasswordDialog(WindowModalDialog):
+class PasswordLayoutForHW(object):
+
+    def __init__(self, wallet, msg, kind, OK_button):
+        self.wallet = wallet
+
+        self.kind = kind
+        self.OK_button = OK_button
+
+        vbox = QVBoxLayout()
+        label = QLabel(msg + "\n")
+        label.setWordWrap(True)
+
+        grid = QGridLayout()
+        grid.setSpacing(8)
+        grid.setColumnMinimumWidth(0, 150)
+        grid.setColumnMinimumWidth(1, 100)
+        grid.setColumnStretch(1,1)
+
+        logo_grid = QGridLayout()
+        logo_grid.setSpacing(8)
+        logo_grid.setColumnMinimumWidth(0, 70)
+        logo_grid.setColumnStretch(1,1)
+
+        logo = QLabel()
+        logo.setAlignment(Qt.AlignCenter)
+
+        logo_grid.addWidget(logo,  0, 0)
+        logo_grid.addWidget(label, 0, 1, 1, 2)
+        vbox.addLayout(logo_grid)
+
+        if wallet and wallet.has_storage_encryption():
+            lockfile = ":icons/lock.png"
+        else:
+            lockfile = ":icons/unlock.png"
+        logo.setPixmap(QPixmap(lockfile).scaledToWidth(36))
+
+        vbox.addLayout(grid)
+
+        self.encrypt_cb = QCheckBox(_('Encrypt wallet file'))
+        grid.addWidget(self.encrypt_cb, 1, 0, 1, 2)
+
+        self.vbox = vbox
+
+    def title(self):
+        return _("Toggle Encryption")
+
+    def layout(self):
+        return self.vbox
+
+
+class ChangePasswordDialogBase(WindowModalDialog):
 
     def __init__(self, parent, wallet):
         WindowModalDialog.__init__(self, parent)
-        is_encrypted = wallet.storage.is_encrypted()
+        is_encrypted = wallet.has_storage_encryption()
+        OK_button = OkButton(self)
+
+        self.create_password_layout(wallet, is_encrypted, OK_button)
+
+        self.setWindowTitle(self.playout.title())
+        vbox = QVBoxLayout(self)
+        vbox.addLayout(self.playout.layout())
+        vbox.addStretch(1)
+        vbox.addLayout(Buttons(CancelButton(self), OK_button))
+        self.playout.encrypt_cb.setChecked(is_encrypted)
+
+    def create_password_layout(self, wallet, is_encrypted, OK_button):
+        raise NotImplementedError()
+
+
+class ChangePasswordDialogForSW(ChangePasswordDialogBase):
+
+    def __init__(self, parent, wallet):
+        ChangePasswordDialogBase.__init__(self, parent, wallet)
+        if not wallet.has_password():
+            self.playout.encrypt_cb.setChecked(True)
+
+    def create_password_layout(self, wallet, is_encrypted, OK_button):
         if not wallet.has_password():
             msg = _('Your wallet is not protected.')
             msg += ' ' + _('Use this dialog to add a password to your wallet.')
@@ -177,14 +251,9 @@ class ChangePasswordDialog(WindowModalDialog):
             else:
                 msg = _('Your wallet is password protected and encrypted.')
             msg += ' ' + _('Use this dialog to change your password.')
-        OK_button = OkButton(self)
-        self.playout = PasswordLayout(wallet, msg, PW_CHANGE, OK_button)
-        self.setWindowTitle(self.playout.title())
-        vbox = QVBoxLayout(self)
-        vbox.addLayout(self.playout.layout())
-        vbox.addStretch(1)
-        vbox.addLayout(Buttons(CancelButton(self), OK_button))
-        self.playout.encrypt_cb.setChecked(is_encrypted or not wallet.has_password())
+        self.playout = PasswordLayout(
+            wallet, msg, PW_CHANGE, OK_button,
+            force_disable_encrypt_cb=not wallet.can_have_keystore_encryption())
 
     def run(self):
         if not self.exec_():
@@ -192,6 +261,26 @@ class ChangePasswordDialog(WindowModalDialog):
         return True, self.playout.old_password(), self.playout.new_password(), self.playout.encrypt_cb.isChecked()
 
 
+class ChangePasswordDialogForHW(ChangePasswordDialogBase):
+
+    def __init__(self, parent, wallet):
+        ChangePasswordDialogBase.__init__(self, parent, wallet)
+
+    def create_password_layout(self, wallet, is_encrypted, OK_button):
+        if not is_encrypted:
+            msg = _('Your wallet file is NOT encrypted.')
+        else:
+            msg = _('Your wallet file is encrypted.')
+        msg += '\n' + _('Note: If you enable this setting, you will need your hardware device to open your wallet.')
+        msg += '\n' + _('Use this dialog to toggle encryption.')
+        self.playout = PasswordLayoutForHW(wallet, msg, PW_CHANGE, OK_button)
+
+    def run(self):
+        if not self.exec_():
+            return False, None
+        return True, self.playout.encrypt_cb.isChecked()
+
+
 class PasswordDialog(WindowModalDialog):
 
     def __init__(self, parent=None, msg=None):

lib/base_wizard.py

@@ -24,12 +24,19 @@
 # SOFTWARE.
 
 import os
+import sys
+import traceback
+
 from . import bitcoin
 from . import keystore
 from .keystore import bip44_derivation
 from .wallet import Imported_Wallet, Standard_Wallet, Multisig_Wallet, wallet_types
+from .storage import STO_EV_USER_PW, STO_EV_XPUB_PW, get_derivation_used_for_hw_device_encryption
 from .i18n import _
+from .util import UserCancelled
 
+# hardware device setup purpose
+HWD_SETUP_NEW_WALLET, HWD_SETUP_DECRYPT_WALLET = range(0, 2)
 
 class ScriptTypeNotSupported(Exception): pass
 
@@ -147,17 +154,22 @@ class BaseWizard(object):
                              is_valid=v, allow_multi=True)
 
     def on_import(self, text):
+        # create a temporary wallet and exploit that modifications
+        # will be reflected on self.storage
         if keystore.is_address_list(text):
-            self.wallet = Imported_Wallet(self.storage)
+            w = Imported_Wallet(self.storage)
             for x in text.split():
-                self.wallet.import_address(x)
+                w.import_address(x)
         elif keystore.is_private_key_list(text):
             k = keystore.Imported_KeyStore({})
             self.storage.put('keystore', k.dump())
-            self.wallet = Imported_Wallet(self.storage)
+            w = Imported_Wallet(self.storage)
             for x in text.split():
-                self.wallet.import_private_key(x, None)
-        self.terminate()
+                w.import_private_key(x, None)
+            self.keystores.append(w.keystore)
+        else:
+            return self.terminate()
+        return self.run('create_wallet')
 
     def restore_from_key(self):
         if self.wallet_type == 'standard':
@@ -176,7 +188,7 @@ class BaseWizard(object):
         k = keystore.from_master_key(text)
         self.on_keystore(k)
 
-    def choose_hw_device(self):
+    def choose_hw_device(self, purpose=HWD_SETUP_NEW_WALLET):
         title = _('Hardware Keystore')
         # check available plugins
         support = self.plugins.get_hardware_support()
@@ -185,7 +197,7 @@ class BaseWizard(object):
                 _('No hardware wallet support found on your system.'),
                 _('Please install the relevant libraries (eg python-trezor for Trezor).'),
             ])
-            self.confirm_dialog(title=title, message=msg, run_next= lambda x: self.choose_hw_device())
+            self.confirm_dialog(title=title, message=msg, run_next= lambda x: self.choose_hw_device(purpose))
             return
         # scan devices
         devices = []
@@ -205,7 +217,7 @@ class BaseWizard(object):
                 _('If your device is not detected on Windows, go to "Settings", "Devices", "Connected devices", and do "Remove device". Then, plug your device again.') + ' ',
                 _('On Linux, you might have to add a new permission to your udev rules.'),
             ])
-            self.confirm_dialog(title=title, message=msg, run_next= lambda x: self.choose_hw_device())
+            self.confirm_dialog(title=title, message=msg, run_next= lambda x: self.choose_hw_device(purpose))
             return
         # select device
         self.devices = devices
@@ -216,23 +228,31 @@ class BaseWizard(object):
             descr = "%s [%s, %s]" % (label, name, state)
             choices.append(((name, info), descr))
         msg = _('Select a device') + ':'
-        self.choice_dialog(title=title, message=msg, choices=choices, run_next=self.on_device)
+        self.choice_dialog(title=title, message=msg, choices=choices, run_next= lambda *args: self.on_device(*args, purpose=purpose))
 
-    def on_device(self, name, device_info):
+    def on_device(self, name, device_info, *, purpose):
         self.plugin = self.plugins.get_plugin(name)
         try:
-            self.plugin.setup_device(device_info, self)
+            self.plugin.setup_device(device_info, self, purpose)
         except BaseException as e:
             self.show_error(str(e))
-            self.choose_hw_device()
+            self.choose_hw_device(purpose)
             return
-        if self.wallet_type=='multisig':
-            # There is no general standard for HD multisig.
-            # This is partially compatible with BIP45; assumes index=0
-            self.on_hw_derivation(name, device_info, "m/45'/0")
+        if purpose == HWD_SETUP_NEW_WALLET:
+            if self.wallet_type=='multisig':
+                # There is no general standard for HD multisig.
+                # This is partially compatible with BIP45; assumes index=0
+                self.on_hw_derivation(name, device_info, "m/45'/0")
+            else:
+                f = lambda x: self.run('on_hw_derivation', name, device_info, str(x))
+                self.derivation_dialog(f)
+        elif purpose == HWD_SETUP_DECRYPT_WALLET:
+            derivation = get_derivation_used_for_hw_device_encryption()
+            xpub = self.plugin.get_xpub(device_info.device.id_, derivation, 'standard', self)
+            password = keystore.Xpub.get_pubkey_from_xpub(xpub, ())
+            self.storage.decrypt(password)
         else:
-            f = lambda x: self.run('on_hw_derivation', name, device_info, str(x))
-            self.derivation_dialog(f)
+            raise Exception('unknown purpose: %s' % purpose)
 
     def derivation_dialog(self, f):
         default = bip44_derivation(0, bip43_purpose=44)
@@ -365,13 +385,45 @@ class BaseWizard(object):
                 self.run('create_wallet')
 
     def create_wallet(self):
-        if any(k.may_have_password() for k in self.keystores):
-            self.request_password(run_next=self.on_password)
+        encrypt_keystore = any(k.may_have_password() for k in self.keystores)
+        # note: the following condition ("if") is duplicated logic from
+        # wallet.get_available_storage_encryption_version()
+        if self.wallet_type == 'standard' and isinstance(self.keystores[0], keystore.Hardware_KeyStore):
+            # offer encrypting with a pw derived from the hw device
+            k = self.keystores[0]
+            try:
+                k.handler = self.plugin.create_handler(self)
+                password = k.get_password_for_storage_encryption()
+            except UserCancelled:
+                devmgr = self.plugins.device_manager
+                devmgr.unpair_xpub(k.xpub)
+                self.choose_hw_device()
+                return
+            except BaseException as e:
+                traceback.print_exc(file=sys.stderr)
+                self.show_error(str(e))
+                return
+            self.request_storage_encryption(
+                run_next=lambda encrypt_storage: self.on_password(
+                    password,
+                    encrypt_storage=encrypt_storage,
+                    storage_enc_version=STO_EV_XPUB_PW,
+                    encrypt_keystore=False))
         else:
-            self.on_password(None, False)
-
-    def on_password(self, password, encrypt):
-        self.storage.set_password(password, encrypt)
+            # prompt the user to set an arbitrary password
+            self.request_password(
+                run_next=lambda password, encrypt_storage: self.on_password(
+                    password,
+                    encrypt_storage=encrypt_storage,
+                    storage_enc_version=STO_EV_USER_PW,
+                    encrypt_keystore=encrypt_keystore),
+                force_disable_encrypt_cb=not encrypt_keystore)
+
+    def on_password(self, password, *, encrypt_storage,
+                    storage_enc_version=STO_EV_USER_PW, encrypt_keystore):
+        self.storage.set_keystore_encryption(bool(password) and encrypt_keystore)
+        if encrypt_storage:
+            self.storage.set_password(password, enc_version=storage_enc_version)
         for k in self.keystores:
             if k.may_have_password():
                 k.update_password(None, password)
@@ -387,6 +439,13 @@ class BaseWizard(object):
             self.storage.write()
             self.wallet = Multisig_Wallet(self.storage)
             self.run('create_addresses')
+        elif self.wallet_type == 'imported':
+            if len(self.keystores) > 0:
+                keys = self.keystores[0].dump()
+                self.storage.put('keystore', keys)
+            self.wallet = Imported_Wallet(self.storage)
+            self.wallet.storage.write()
+            self.terminate()
 
     def show_xpub_and_add_cosigners(self, xpub):
         self.show_xpub_dialog(xpub=xpub, run_next=lambda x: self.run('choose_keystore'))

lib/bitcoin.py

@@ -643,8 +643,8 @@ def verify_message(address, sig, message):
         return False
 
 
-def encrypt_message(message, pubkey):
-    return EC_KEY.encrypt_message(message, bfh(pubkey))
+def encrypt_message(message, pubkey, magic=b'BIE1'):
+    return EC_KEY.encrypt_message(message, bfh(pubkey), magic)
 
 
 def chunks(l, n):
@@ -789,7 +789,7 @@ class EC_KEY(object):
     # ECIES encryption/decryption methods; AES-128-CBC with PKCS7 is used as the cipher; hmac-sha256 is used as the mac
 
     @classmethod
-    def encrypt_message(self, message, pubkey):
+    def encrypt_message(self, message, pubkey, magic=b'BIE1'):
         assert_bytes(message)
 
         pk = ser_to_point(pubkey)
@@ -803,20 +803,20 @@ class EC_KEY(object):
         iv, key_e, key_m = key[0:16], key[16:32], key[32:]
         ciphertext = aes_encrypt_with_iv(key_e, iv, message)
         ephemeral_pubkey = bfh(ephemeral.get_public_key(compressed=True))
-        encrypted = b'BIE1' + ephemeral_pubkey + ciphertext
+        encrypted = magic + ephemeral_pubkey + ciphertext
         mac = hmac.new(key_m, encrypted, hashlib.sha256).digest()
 
         return base64.b64encode(encrypted + mac)
 
-    def decrypt_message(self, encrypted):
+    def decrypt_message(self, encrypted, magic=b'BIE1'):
         encrypted = base64.b64decode(encrypted)
         if len(encrypted) < 85:
             raise Exception('invalid ciphertext: length')
-        magic = encrypted[:4]
+        magic_found = encrypted[:4]
         ephemeral_pubkey = encrypted[4:37]
         ciphertext = encrypted[37:-32]
         mac = encrypted[-32:]
-        if magic != b'BIE1':
+        if magic_found != magic:
             raise Exception('invalid ciphertext: invalid magic bytes')
         try:
             ephemeral_pubkey = ser_to_point(ephemeral_pubkey)

lib/commands.py

@@ -82,7 +82,7 @@ def command(s):
             password = kwargs.get('password')
             if c.requires_wallet and wallet is None:
                 raise BaseException("wallet not loaded. Use 'electrum daemon load_wallet'")
-            if c.requires_password and password is None and wallet.storage.get('use_encryption'):
+            if c.requires_password and password is None and wallet.has_password():
                 return {'error': 'Password required' }
             return func(*args, **kwargs)
         return func_wrapper

lib/keystore.py

@@ -45,6 +45,10 @@ class KeyStore(PrintError):
     def can_import(self):
         return False
 
+    def may_have_password(self):
+        """Returns whether the keystore can be encrypted with a password."""
+        raise NotImplementedError()
+
     def get_tx_derivations(self, tx):
         keypairs = {}
         for txin in tx.inputs():
@@ -116,9 +120,6 @@ class Imported_KeyStore(Software_KeyStore):
     def is_deterministic(self):
         return False
 
-    def can_change_password(self):
-        return True
-
     def get_master_public_key(self):
         return None
 
@@ -196,9 +197,6 @@ class Deterministic_KeyStore(Software_KeyStore):
     def is_watching_only(self):
         return not self.has_seed()
 
-    def can_change_password(self):
-        return not self.is_watching_only()
-
     def add_seed(self, seed):
         if self.seed:
             raise Exception("a seed exists")
@@ -522,9 +520,13 @@ class Hardware_KeyStore(KeyStore, Xpub):
         assert not self.has_seed()
         return False
 
-    def can_change_password(self):
-        return False
-
+    def get_password_for_storage_encryption(self):
+        from .storage import get_derivation_used_for_hw_device_encryption
+        client = self.plugin.get_client(self)
+        derivation = get_derivation_used_for_hw_device_encryption()
+        xpub = client.get_xpub(derivation, "standard")
+        password = self.get_pubkey_from_xpub(xpub, ())
+        return password
 
 
 def bip39_normalize_passphrase(passphrase):

lib/storage.py

@@ -33,7 +33,7 @@ import pbkdf2, hmac, hashlib
 import base64
 import zlib
 
-from .util import PrintError, profiler
+from .util import PrintError, profiler, InvalidPassword
 from .plugins import run_hook, plugin_loaders
 from .keystore import bip44_derivation
 from . import bitcoin
@@ -56,6 +56,13 @@ def multisig_type(wallet_type):
         match = [int(x) for x in match.group(1, 2)]
     return match
 
+def get_derivation_used_for_hw_device_encryption():
+    return ("m"
+            "/4541509'"      # ascii 'ELE'  as decimal ("BIP43 purpose")
+            "/1112098098'")  # ascii 'BIE2' as decimal
+
+# storage encryption version
+STO_EV_PLAINTEXT, STO_EV_USER_PW, STO_EV_XPUB_PW = range(0, 3)
 
 class WalletStorage(PrintError):
 
@@ -70,9 +77,11 @@ class WalletStorage(PrintError):
         if self.file_exists():
             with open(self.path, "r") as f:
                 self.raw = f.read()
+            self._encryption_version = self._init_encryption_version()
             if not self.is_encrypted():
                 self.load_data(self.raw)
         else:
+            self._encryption_version = STO_EV_PLAINTEXT
             # avoid new wallets getting 'upgraded'
             self.put('seed_version', FINAL_SEED_VERSION)
 
@@ -106,11 +115,47 @@ class WalletStorage(PrintError):
             if self.requires_upgrade():
                 self.upgrade()
 
+    def is_past_initial_decryption(self):
+        """Return if storage is in a usable state for normal operations.
+
+        The value is True exactly
+            if encryption is disabled completely (self.is_encrypted() == False),
+            or if encryption is enabled but the contents have already been decrypted.
+        """
+        return bool(self.data)
+
     def is_encrypted(self):
+        """Return if storage encryption is currently enabled."""
+        return self.get_encryption_version() != STO_EV_PLAINTEXT
+
+    def is_encrypted_with_user_pw(self):
+        return self.get_encryption_version() == STO_EV_USER_PW
+
+    def is_encrypted_with_hw_device(self):
+        return self.get_encryption_version() == STO_EV_XPUB_PW
+
+    def get_encryption_version(self):
+        """Return the version of encryption used for this storage.
+
+        0: plaintext / no encryption
+
+        ECIES, private key derived from a password,
+        1: password is provided by user
+        2: password is derived from an xpub; used with hw wallets
+        """
+        return self._encryption_version
+
+    def _init_encryption_version(self):
         try:
-            return base64.b64decode(self.raw)[0:4] == b'BIE1'
+            magic = base64.b64decode(self.raw)[0:4]
+            if magic == b'BIE1':
+                return STO_EV_USER_PW
+            elif magic == b'BIE2':
+                return STO_EV_XPUB_PW
+            else:
+                return STO_EV_PLAINTEXT
         except:
-            return False
+            return STO_EV_PLAINTEXT
 
     def file_exists(self):
         return self.path and os.path.exists(self.path)
@@ -120,20 +165,50 @@ class WalletStorage(PrintError):
         ec_key = bitcoin.EC_KEY(secret)
         return ec_key
 
+    def _get_encryption_magic(self):
+        v = self._encryption_version
+        if v == STO_EV_USER_PW:
+            return b'BIE1'
+        elif v == STO_EV_XPUB_PW:
+            return b'BIE2'
+        else:
+            raise Exception('no encryption magic for version: %s' % v)
+
     def decrypt(self, password):
         ec_key = self.get_key(password)
-        s = zlib.decompress(ec_key.decrypt_message(self.raw)) if self.raw else None
+        if self.raw:
+            enc_magic = self._get_encryption_magic()
+            s = zlib.decompress(ec_key.decrypt_message(self.raw, enc_magic))
+        else:
+            s = None
         self.pubkey = ec_key.get_public_key()
         s = s.decode('utf8')
         self.load_data(s)
 
-    def set_password(self, password, encrypt):
-        self.put('use_encryption', bool(password))
-        if encrypt and password:
+    def check_password(self, password):
+        """Raises an InvalidPassword exception on invalid password"""
+        if not self.is_encrypted():
+            return
+        if self.pubkey and self.pubkey != self.get_key(password).get_public_key():
+            raise InvalidPassword()
+
+    def set_keystore_encryption(self, enable):
+        self.put('use_encryption', enable)
+
+    def set_password(self, password, enc_version=None):
+        """Set a password to be used for encrypting this storage."""
+        if enc_version is None:
+            enc_version = self._encryption_version
+        if password and enc_version != STO_EV_PLAINTEXT:
             ec_key = self.get_key(password)
             self.pubkey = ec_key.get_public_key()
+            self._encryption_version = enc_version
         else:
             self.pubkey = None
+            self._encryption_version = STO_EV_PLAINTEXT
+        # make sure next storage.write() saves changes
+        with self.lock:
+            self.modified = True
 
     def get(self, key, default=None):
         with self.lock:
@@ -175,7 +250,8 @@ class WalletStorage(PrintError):
         if self.pubkey:
             s = bytes(s, 'utf8')
             c = zlib.compress(s)
-            s = bitcoin.encrypt_message(c, self.pubkey)
+            enc_magic = self._get_encryption_magic()
+            s = bitcoin.encrypt_message(c, self.pubkey, enc_magic)
             s = s.decode('utf8')
 
         temp_path = "%s.tmp.%s" % (self.path, os.getpid())

lib/wallet.py

@@ -48,7 +48,7 @@ from .util import (NotEnoughFunds, PrintError, UserCancelled, profiler,
 from .bitcoin import *
 from .version import *
 from .keystore import load_keystore, Hardware_KeyStore
-from .storage import multisig_type
+from .storage import multisig_type, STO_EV_PLAINTEXT, STO_EV_USER_PW, STO_EV_XPUB_PW
 
 from . import transaction
 from .transaction import Transaction
@@ -1383,10 +1383,65 @@ class Abstract_Wallet(PrintError):
             self.synchronizer.add(address)
 
     def has_password(self):
-        return self.storage.get('use_encryption', False)
+        return self.has_keystore_encryption() or self.has_storage_encryption()
+
+    def can_have_keystore_encryption(self):
+        return self.keystore and self.keystore.may_have_password()
+
+    def get_available_storage_encryption_version(self):
+        """Returns the type of storage encryption offered to the user.
+
+        A wallet file (storage) is either encrypted with this version
+        or is stored in plaintext.
+        """
+        if isinstance(self.keystore, Hardware_KeyStore):
+            return STO_EV_XPUB_PW
+        else:
+            return STO_EV_USER_PW
+
+    def has_keystore_encryption(self):
+        """Returns whether encryption is enabled for the keystore.
+
+        If True, e.g. signing a transaction will require a password.
+        """
+        if self.can_have_keystore_encryption():
+            return self.storage.get('use_encryption', False)
+        return False
+
+    def has_storage_encryption(self):
+        """Returns whether encryption is enabled for the wallet file on disk."""
+        return self.storage.is_encrypted()
+
+    @classmethod
+    def may_have_password(cls):
+        return True
 
     def check_password(self, password):
-        self.keystore.check_password(password)
+        if self.has_keystore_encryption():
+            self.keystore.check_password(password)
+        self.storage.check_password(password)
+
+    def update_password(self, old_pw, new_pw, encrypt_storage=False):
+        if old_pw is None and self.has_password():
+            raise InvalidPassword()
+        self.check_password(old_pw)
+
+        if encrypt_storage:
+            enc_version = self.get_available_storage_encryption_version()
+        else:
+            enc_version = STO_EV_PLAINTEXT
+        self.storage.set_password(new_pw, enc_version)
+
+        # note: Encrypting storage with a hw device is currently only
+        #       allowed for non-multisig wallets. Further,
+        #       Hardware_KeyStore.may_have_password() == False.
+        #       If these were not the case,
+        #       extra care would need to be taken when encrypting keystores.
+        self._update_password_for_keystore(old_pw, new_pw)
+        encrypt_keystore = self.can_have_keystore_encryption()
+        self.storage.set_keystore_encryption(bool(new_pw) and encrypt_keystore)
+
+        self.storage.write()
 
     def sign_message(self, address, message, password):
         index = self.get_address_index(address)
@@ -1420,16 +1475,10 @@ class Simple_Wallet(Abstract_Wallet):
     def is_watching_only(self):
         return self.keystore.is_watching_only()
 
-    def can_change_password(self):
-        return self.keystore.can_change_password()
-
-    def update_password(self, old_pw, new_pw, encrypt=False):
-        if old_pw is None and self.has_password():
-            raise InvalidPassword()
-        self.keystore.update_password(old_pw, new_pw)
-        self.save_keystore()
-        self.storage.set_password(new_pw, encrypt)
-        self.storage.write()
+    def _update_password_for_keystore(self, old_pw, new_pw):
+        if self.keystore and self.keystore.may_have_password():
+            self.keystore.update_password(old_pw, new_pw)
+            self.save_keystore()
 
     def save_keystore(self):
         self.storage.put('keystore', self.keystore.dump())
@@ -1468,9 +1517,6 @@ class Imported_Wallet(Simple_Wallet):
     def save_addresses(self):
         self.storage.put('addresses', self.addresses)
 
-    def can_change_password(self):
-        return not self.is_watching_only()
-
     def can_import_address(self):
         return self.is_watching_only()
 
@@ -1849,22 +1895,28 @@ class Multisig_Wallet(Deterministic_Wallet):
     def get_keystores(self):
         return [self.keystores[i] for i in sorted(self.keystores.keys())]
 
-    def update_password(self, old_pw, new_pw, encrypt=False):
-        if old_pw is None and self.has_password():
-            raise InvalidPassword()
+    def can_have_keystore_encryption(self):
+        return any([k.may_have_password() for k in self.get_keystores()])
+
+    def _update_password_for_keystore(self, old_pw, new_pw):
         for name, keystore in self.keystores.items():
-            if keystore.can_change_password():
+            if keystore.may_have_password():
                 keystore.update_password(old_pw, new_pw)
                 self.storage.put(name, keystore.dump())
-        self.storage.set_password(new_pw, encrypt)
-        self.storage.write()
+
+    def check_password(self, password):
+        for name, keystore in self.keystores.items():
+            if keystore.may_have_password():
+                keystore.check_password(password)
+        self.storage.check_password(password)
+
+    def get_available_storage_encryption_version(self):
+        # multisig wallets are not offered hw device encryption
+        return STO_EV_USER_PW
 
     def has_seed(self):
         return self.keystore.has_seed()
 
-    def can_change_password(self):
-        return self.keystore.can_change_password()
-
     def is_watching_only(self):
         return not any([not k.is_watching_only() for k in self.get_keystores()])
 

plugins/cosigner_pool/qt.py

@@ -194,7 +194,7 @@ class Plugin(BasePlugin):
             return
 
         wallet = window.wallet
-        if wallet.has_password():
+        if wallet.has_keystore_encryption():
             password = window.password_dialog('An encrypted transaction was retrieved from cosigning pool.\nPlease enter your password to decrypt it.')
             if not password:
                 return

plugins/digitalbitbox/digitalbitbox.py

@@ -12,7 +12,7 @@ try:
     from electrum.keystore import Hardware_KeyStore
     from ..hw_wallet import HW_PluginBase
     from electrum.util import print_error, to_string, UserCancelled
-    from electrum.base_wizard import ScriptTypeNotSupported
+    from electrum.base_wizard import ScriptTypeNotSupported, HWD_SETUP_NEW_WALLET
 
     import time
     import hid
@@ -670,12 +670,13 @@ class DigitalBitboxPlugin(HW_PluginBase):
             return None
 
 
-    def setup_device(self, device_info, wizard):
+    def setup_device(self, device_info, wizard, purpose):
         devmgr = self.device_manager()
         device_id = device_info.device.id_
         client = devmgr.client_by_id(device_id)
         client.handler = self.create_handler(wizard)
-        client.setupRunning = True
+        if purpose == HWD_SETUP_NEW_WALLET:
+            client.setupRunning = True
         client.get_xpub("m/44'/0'", 'standard')
 
 

plugins/greenaddress_instant/qt.py

@@ -65,9 +65,14 @@ class Plugin(BasePlugin):
         tx = d.tx
         wallet = d.wallet
         window = d.main_window
+
+        if wallet.is_watching_only():
+            d.show_critical(_('This feature is not available for watch-only wallets.'))
+            return
+
         # 1. get the password and sign the verification request
         password = None
-        if wallet.has_password():
+        if wallet.has_keystore_encryption():
             msg = _('GreenAddress requires your signature \n'
                     'to verify that transaction is instant.\n'
                     'Please enter your password to sign a\n'

plugins/hw_wallet/plugin.py

@@ -51,3 +51,10 @@ class HW_PluginBase(BasePlugin):
         for keystore in wallet.get_keystores():
             if isinstance(keystore, self.keystore_class):
                 self.device_manager().unpair_xpub(keystore.xpub)
+
+    def setup_device(self, device_info, wizard, purpose):
+        """Called when creating a new wallet or when using the device to decrypt
+        an existing wallet. Select the device to use.  If the device is
+        uninitialized, go through the initialization process.
+        """
+        raise NotImplementedError()

plugins/hw_wallet/qt.py

@@ -70,9 +70,10 @@ class QtHandlerBase(QObject, PrintError):
         self.status_signal.emit(paired)
 
     def _update_status(self, paired):
-        button = self.button
-        icon = button.icon_paired if paired else button.icon_unpaired
-        button.setIcon(QIcon(icon))
+        if hasattr(self, 'button'):
+            button = self.button
+            icon = button.icon_paired if paired else button.icon_unpaired
+            button.setIcon(QIcon(icon))
 
     def query_choice(self, msg, labels):
         self.done.clear()

plugins/keepkey/plugin.py

@@ -194,10 +194,7 @@ class KeepKeyCompatiblePlugin(HW_PluginBase):
                                        label, language)
         wizard.loop.exit(0)
 
-    def setup_device(self, device_info, wizard):
-        '''Called when creating a new wallet.  Select the device to use.  If
-        the device is uninitialized, go through the intialization
-        process.'''
+    def setup_device(self, device_info, wizard, purpose):
         devmgr = self.device_manager()
         device_id = device_info.device.id_
         client = devmgr.client_by_id(device_id)

plugins/ledger/ledger.py

@@ -522,7 +522,7 @@ class LedgerPlugin(HW_PluginBase):
             client = Ledger_Client(client)
         return client
 
-    def setup_device(self, device_info, wizard):
+    def setup_device(self, device_info, wizard, purpose):
         devmgr = self.device_manager()
         device_id = device_info.device.id_
         client = devmgr.client_by_id(device_id)

plugins/trezor/plugin.py

@@ -214,10 +214,7 @@ class TrezorCompatiblePlugin(HW_PluginBase):
                                        label, language)
         wizard.loop.exit(0)
 
-    def setup_device(self, device_info, wizard):
-        '''Called when creating a new wallet.  Select the device to use.  If
-        the device is uninitialized, go through the intialization
-        process.'''
+    def setup_device(self, device_info, wizard, purpose):
         devmgr = self.device_manager()
         device_id = device_info.device.id_
         client = devmgr.client_by_id(device_id)

plugins/trustedcoin/trustedcoin.py

@@ -40,6 +40,7 @@ from electrum.wallet import Multisig_Wallet, Deterministic_Wallet
 from electrum.i18n import _
 from electrum.plugins import BasePlugin, hook
 from electrum.util import NotEnoughFunds
+from electrum.storage import STO_EV_USER_PW
 
 # signing_xpub is hardcoded so that the wallet can be restored from seed, without TrustedCoin's server
 signing_xpub = "xpub661MyMwAqRbcGnMkaTx2594P9EDuiEqMq25PM2aeG6UmwzaohgA6uDmNsvSUV8ubqwA3Wpste1hg69XHgjUuCD5HLcEp2QPzyV1HMrPppsL"
@@ -420,9 +421,11 @@ class TrustedCoinPlugin(BasePlugin):
         k2 = keystore.from_xpub(xpub2)
         wizard.request_password(run_next=lambda pw, encrypt: self.on_password(wizard, pw, encrypt, k1, k2))
 
-    def on_password(self, wizard, password, encrypt, k1, k2):
+    def on_password(self, wizard, password, encrypt_storage, k1, k2):
         k1.update_password(None, password)
-        wizard.storage.set_password(password, encrypt)
+        wizard.storage.set_keystore_encryption(bool(password))
+        if encrypt_storage:
+            wizard.storage.set_password(password, enc_version=STO_EV_USER_PW)
         wizard.storage.put('x1/', k1.dump())
         wizard.storage.put('x2/', k2.dump())
         wizard.storage.write()
@@ -470,7 +473,7 @@ class TrustedCoinPlugin(BasePlugin):
         else:
             self.create_keystore(wizard, seed, passphrase)
 
-    def on_restore_pw(self, wizard, seed, passphrase, password, encrypt):
+    def on_restore_pw(self, wizard, seed, passphrase, password, encrypt_storage):
         storage = wizard.storage
         xprv1, xpub1, xprv2, xpub2 = self.xkeys_from_seed(seed, passphrase)
         k1 = keystore.from_xprv(xprv1)
@@ -484,7 +487,11 @@ class TrustedCoinPlugin(BasePlugin):
         xpub3 = make_xpub(signing_xpub, long_user_id)
         k3 = keystore.from_xpub(xpub3)
         storage.put('x3/', k3.dump())
-        storage.set_password(password, encrypt)
+
+        storage.set_keystore_encryption(bool(password))
+        if encrypt_storage:
+            storage.set_password(password, enc_version=STO_EV_USER_PW)
+
         wizard.wallet = Wallet_2fa(storage)
         wizard.create_addresses()