add ClearSession message with unit test

cmdtr.py

@@ -108,6 +108,9 @@ class Commands(object):
     def set_label(self, args):
         return self.client.apply_settings(label=args.label)
 
+    def clear_session(self, args):
+        return self.client.clear_session()
+
     def change_pin(self, args):
         return self.client.change_pin(args.remove)
 
@@ -187,6 +190,7 @@ class Commands(object):
     get_features.help = 'Retrieve device features and settings'
     get_public_node.help = 'Get public node of given path'
     set_label.help = 'Set new wallet label'
+    clear_session.help = 'Clear session (remove cached PIN, passphrase, etc.)'
     change_pin.help = 'Change new PIN or remove existing'
     list_coins.help = 'List all supported coin types by the device'
     wipe_device.help = 'Reset device to factory defaults and remove all private data.'

tests/test_msg_clearsession.py

@@ -0,0 +1,39 @@
+import time
+import unittest
+import common
+
+from trezorlib import messages_pb2 as proto
+from trezorlib import types_pb2 as proto_types
+
+class TestMsgClearsession(common.TrezorTest):
+
+    def test_clearsession(self):
+        self.setup_mnemonic_pin_passphrase()
+
+        with self.client:
+            self.client.set_expected_responses([proto.ButtonRequest(code=proto_types.ButtonRequest_ProtectCall), proto.PinMatrixRequest(), proto.PassphraseRequest(), proto.Success()])
+            res = self.client.ping('random data', button_protection=True, pin_protection=True, passphrase_protection=True)
+            self.assertEqual(res, 'random data')
+
+        with self.client:
+            # pin and passphrase are cached
+            self.client.set_expected_responses([proto.ButtonRequest(code=proto_types.ButtonRequest_ProtectCall), proto.Success()])
+            res = self.client.ping('random data', button_protection=True, pin_protection=True, passphrase_protection=True)
+            self.assertEqual(res, 'random data')
+
+        self.client.clear_session()
+
+        # session cache is cleared
+        with self.client:
+            self.client.set_expected_responses([proto.ButtonRequest(code=proto_types.ButtonRequest_ProtectCall), proto.PinMatrixRequest(), proto.PassphraseRequest(), proto.Success()])
+            res = self.client.ping('random data', button_protection=True, pin_protection=True, passphrase_protection=True)
+            self.assertEqual(res, 'random data')
+
+        with self.client:
+            # pin and passphrase are cached
+            self.client.set_expected_responses([proto.ButtonRequest(code=proto_types.ButtonRequest_ProtectCall), proto.Success()])
+            res = self.client.ping('random data', button_protection=True, pin_protection=True, passphrase_protection=True)
+            self.assertEqual(res, 'random data')
+
+if __name__ == '__main__':
+    unittest.main()

trezorlib/client.py

@@ -378,6 +378,11 @@ class ProtocolMixin(object):
         self.init_device()  # Reload Features
         return out
 
+    @field('message')
+    @expect(proto.Success)
+    def clear_session(self):
+        return self.call(proto.ClearSession())
+
     @field('message')
     @expect(proto.Success)
     def change_pin(self, remove=False):