hw wallet encryption unlock: clear session on incorrect passphrase

gui/qt/installwizard.py

@@ -246,8 +246,6 @@ class InstallWizard(QDialog, MessageBoxMixin, BaseWizard):
                     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' +

lib/base_wizard.py

@@ -33,7 +33,7 @@ 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
+from .util import UserCancelled, InvalidPassword
 
 # hardware device setup purpose
 HWD_SETUP_NEW_WALLET, HWD_SETUP_DECRYPT_WALLET = range(0, 2)
@@ -259,7 +259,15 @@ class BaseWizard(object):
             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)
+            try:
+                self.storage.decrypt(password)
+            except InvalidPassword:
+                # try to clear session so that user can type another passphrase
+                devmgr = self.plugins.device_manager
+                client = devmgr.client_by_id(device_info.device.id_)
+                if hasattr(client, 'clear_session'):  # FIXME not all hw wallet plugins have this
+                    client.clear_session()
+                raise
         else:
             raise Exception('unknown purpose: %s' % purpose)