Trezor: session timeout improvements

Move session timeout from wallet to config
Prevent timeouts whenever a device operation is in progress
Move timeout job from each plugin to device manager

lib/plugins.py

@@ -45,8 +45,9 @@ class Plugins(DaemonThread):
         self.plugins = {}
         self.gui_name = gui_name
         self.descriptions = {}
-        self.device_manager = DeviceMgr()
+        self.device_manager = DeviceMgr(config)
         self.load_plugins()
+        self.add_jobs(self.device_manager.thread_jobs())
         self.start()
 
     def load_plugins(self):
@@ -247,7 +248,7 @@ class DeviceUnpairableError(Exception):
 Device = namedtuple("Device", "path interface_number id_ product_key")
 DeviceInfo = namedtuple("DeviceInfo", "device description initialized")
 
-class DeviceMgr(PrintError):
+class DeviceMgr(ThreadJob, PrintError):
     '''Manages hardware clients.  A client communicates over a hardware
     channel with the device.
 
@@ -276,11 +277,9 @@ class DeviceMgr(PrintError):
     the HID IDs.
 
     This plugin is thread-safe.  Currently only devices supported by
-    hidapi are implemented.
+    hidapi are implemented.'''
 
-    '''
-
-    def __init__(self):
+    def __init__(self, config):
         super(DeviceMgr, self).__init__()
         # Keyed by wallet.  The value is the device id if the wallet
         # has been paired, and None otherwise.
@@ -293,6 +292,20 @@ class DeviceMgr(PrintError):
         self.recognised_hardware = set()
         # For synchronization
         self.lock = threading.RLock()
+        self.config = config
+
+    def thread_jobs(self):
+        # Thread job to handle device timeouts
+        return [self]
+
+    def run(self):
+        '''Handle device timeouts.  Runs in the context of the Plugins
+        thread.'''
+        with self.lock:
+            clients = list(self.clients.keys())
+        cutoff = time.time() - self.config.get_session_timeout()
+        for client in clients:
+            client.timeout(cutoff)
 
     def register_devices(self, device_pairs):
         for pair in device_pairs:
@@ -343,9 +356,6 @@ class DeviceMgr(PrintError):
             self.wallets[wallet] = id_
         wallet.paired()
 
-    def paired_wallets(self):
-        return list(self.wallets.keys())
-
     def client_lookup(self, id_):
         with self.lock:
             for client, (path, client_id) in self.clients.items():

lib/simple_config.py

@@ -4,7 +4,7 @@ import threading
 import os
 
 from copy import deepcopy
-from util import user_dir, print_error, print_msg, print_stderr
+from util import user_dir, print_error, print_msg, print_stderr, PrintError
 
 SYSTEM_CONFIG_PATH = "/etc/electrum.conf"
 
@@ -21,7 +21,7 @@ def set_config(c):
     config = c
 
 
-class SimpleConfig(object):
+class SimpleConfig(PrintError):
     """
     The SimpleConfig class is responsible for handling operations involving
     configuration files.
@@ -168,6 +168,13 @@ class SimpleConfig(object):
             recent.remove(filename)
             self.set_key('recently_open', recent)
 
+    def set_session_timeout(self, seconds):
+        self.print_error("session timeout -> %d seconds" % seconds)
+        self.set_key('session_timeout', seconds)
+
+    def get_session_timeout(self):
+        return self.get('session_timeout', 300)
+
 
 def read_system_config(path=SYSTEM_CONFIG_PATH):
     """Parse and return the system config settings in /etc/electrum.conf."""

plugins/hw_wallet/hw_wallet.py

@@ -33,18 +33,11 @@ class BIP44_HW_Wallet(BIP44_Wallet):
 
     def __init__(self, storage):
         BIP44_Wallet.__init__(self, storage)
-        # After timeout seconds we clear the device session
-        self.session_timeout = storage.get('session_timeout', 180)
         # Errors and other user interaction is done through the wallet's
         # handler.  The handler is per-window and preserved across
         # device reconnects
         self.handler = None
 
-    def set_session_timeout(self, seconds):
-        self.print_error("setting session timeout to %d seconds" % seconds)
-        self.session_timeout = seconds
-        self.storage.put('session_timeout', seconds)
-
     def unpaired(self):
         '''A device paired with the wallet was diconnected.  This can be
         called in any thread context.'''
@@ -55,14 +48,6 @@ class BIP44_HW_Wallet(BIP44_Wallet):
         called in any thread context.'''
         self.print_error("paired")
 
-    def timeout(self):
-        '''Called when the wallet session times out.  Note this is called from
-        the Plugins thread.'''
-        client = self.get_client(force_pair=False)
-        if client:
-            client.clear_session()
-        self.print_error("timed out")
-
     def get_action(self):
         pass
 

plugins/hw_wallet/plugin.py

@@ -17,14 +17,11 @@
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-import time
-
-from electrum.util import ThreadJob
 from electrum.plugins import BasePlugin, hook
 from electrum.i18n import _
 
 
-class HW_PluginBase(BasePlugin, ThreadJob):
+class HW_PluginBase(BasePlugin):
     # Derived classes provide:
     #
     #  class-static variables: client_class, firmware_URL, handler_class,
@@ -35,7 +32,6 @@ class HW_PluginBase(BasePlugin, ThreadJob):
         BasePlugin.__init__(self, parent, config, name)
         self.device = self.wallet_class.device
         self.wallet_class.plugin = self
-        self.prevent_timeout = time.time() + 3600 * 24 * 365
 
     def is_enabled(self):
         return self.libraries_available
@@ -43,21 +39,6 @@ class HW_PluginBase(BasePlugin, ThreadJob):
     def device_manager(self):
         return self.parent.device_manager
 
-    def thread_jobs(self):
-        # Thread job to handle device timeouts
-        return [self] if self.libraries_available else []
-
-    def run(self):
-        '''Handle device timeouts.  Runs in the context of the Plugins
-        thread.'''
-        now = time.time()
-        for wallet in self.device_manager().paired_wallets():
-            if (isinstance(wallet, self.wallet_class)
-                    and hasattr(wallet, 'last_operation')
-                    and now > wallet.last_operation + wallet.session_timeout):
-                wallet.timeout()
-                wallet.last_operation = self.prevent_timeout
-
     @hook
     def close_wallet(self, wallet):
         if isinstance(wallet, self.wallet_class):

plugins/ledger/ledger.py

@@ -392,8 +392,4 @@ class LedgerPlugin(HW_PluginBase):
             wallet.proper_device = False
             self.client = client
 
-        if client:
-            self.print_error("set last_operation")
-            wallet.last_operation = time.time()
-
         return self.client

plugins/trezor/clientbase.py

@@ -1,4 +1,4 @@
-from sys import stderr
+import time
 
 from electrum.i18n import _
 from electrum.util import PrintError, UserCancelled
@@ -82,6 +82,7 @@ class TrezorClientBase(GuiMixin, PrintError):
         self.tx_api = plugin
         self.types = plugin.types
         self.msg_code_override = None
+        self.used()
 
     def __str__(self):
         return "%s/%s" % (self.label(), self.features.device_id)
@@ -97,6 +98,20 @@ class TrezorClientBase(GuiMixin, PrintError):
     def is_pairable(self):
         return not self.features.bootloader_mode
 
+    def used(self):
+        self.print_error("used")
+        self.last_operation = time.time()
+
+    def prevent_timeouts(self):
+        self.print_error("prevent timeouts")
+        self.last_operation = float('inf')
+
+    def timeout(self, cutoff):
+        '''Time out the client if the last operation was before cutoff.'''
+        if self.last_operation < cutoff:
+            self.print_error("timed out")
+            self.clear_session()
+
     @staticmethod
     def expand_path(n):
         '''Convert bip32 path to list of uint32 integers with prime flags
@@ -158,6 +173,7 @@ class TrezorClientBase(GuiMixin, PrintError):
         '''Clear the session to force pin (and passphrase if enabled)
         re-entry.  Does not leak exceptions.'''
         self.print_error("clear session:", self)
+        self.prevent_timeouts()
         try:
             super(TrezorClientBase, self).clear_session()
         except BaseException as e:
@@ -185,8 +201,10 @@ class TrezorClientBase(GuiMixin, PrintError):
 
         def wrapped(self, *args, **kwargs):
             try:
+                self.prevent_timeouts()
                 return func(self, *args, **kwargs)
             finally:
+                self.used()
                 self.handler.finished()
 
         return wrapped

plugins/trezor/plugin.py

@@ -1,7 +1,6 @@
 import base64
 import re
 import threading
-import time
 
 from binascii import unhexlify
 from functools import partial
@@ -136,8 +135,7 @@ class TrezorCompatiblePlugin(HW_PluginBase):
         devmgr = self.device_manager()
         client = devmgr.client_for_wallet(self, wallet, force_pair)
         if client:
-            self.print_error("set last_operation")
-            wallet.last_operation = time.time()
+            client.used()
 
         return client
 
@@ -147,9 +145,6 @@ class TrezorCompatiblePlugin(HW_PluginBase):
             self.device_manager().unpair_wallet(wallet)
 
     def initialize_device(self, wallet):
-        # Prevent timeouts during initialization
-        wallet.last_operation = self.prevent_timeout
-
         # Initialization method
         msg = _("Choose how you want to initialize your %s.\n\n"
                 "The first two methods are secure as no secret information "

plugins/trezor/qt_generic.py

@@ -345,6 +345,7 @@ class SettingsDialog(WindowModalDialog):
         self.setMaximumWidth(540)
 
         devmgr = plugin.device_manager()
+        config = devmgr.config
         handler = window.wallet.handler
         thread = window.wallet.thread
         # wallet can be None, needn't be window.wallet
@@ -459,8 +460,7 @@ class SettingsDialog(WindowModalDialog):
             timeout_minutes.setText(_("%2d minutes") % mins)
 
         def slider_released():
-            seconds = timeout_slider.sliderPosition() * 60
-            wallet.set_session_timeout(seconds)
+            config.set_session_timeout(timeout_slider.sliderPosition() * 60)
 
         # Information tab
         info_tab = QWidget()
@@ -549,7 +549,6 @@ class SettingsDialog(WindowModalDialog):
             settings_glayout.addWidget(homescreen_msg, 5, 1, 1, -1)
 
         # Settings tab - Session Timeout
-        if wallet:
         timeout_label = QLabel(_("Session Timeout"))
         timeout_minutes = QLabel()
         timeout_slider = QSlider(Qt.Horizontal)
@@ -564,7 +563,7 @@ class SettingsDialog(WindowModalDialog):
               "your PIN and passphrase (if enabled) must be "
               "re-entered to use the device."))
         timeout_msg.setWordWrap(True)
-            timeout_slider.setSliderPosition(wallet.session_timeout // 60)
+        timeout_slider.setSliderPosition(config.get_session_timeout() // 60)
         slider_moved()
         timeout_slider.valueChanged.connect(slider_moved)
         timeout_slider.sliderReleased.connect(slider_released)