Arthur de Jong

Open Source / Free Software developer

summaryrefslogtreecommitdiffstats
path: root/tests/auth_tests/test_auth_backends.py
blob: 6ded9f2eb8504bffb82161224cffd9b162312a43 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
from __future__ import unicode_literals

from datetime import date

from django.contrib.auth import (
    BACKEND_SESSION_KEY, SESSION_KEY, authenticate, get_user,
)
from django.contrib.auth.backends import ModelBackend
from django.contrib.auth.hashers import MD5PasswordHasher
from django.contrib.auth.models import AnonymousUser, Group, Permission, User
from django.contrib.auth.tests.custom_user import CustomUser, ExtensionUser
from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import ImproperlyConfigured, PermissionDenied
from django.http import HttpRequest
from django.test import (
    SimpleTestCase, TestCase, modify_settings, override_settings,
)

from .models import CustomPermissionsUser, UUIDUser


class CountingMD5PasswordHasher(MD5PasswordHasher):
    """Hasher that counts how many times it computes a hash."""

    calls = 0

    def encode(self, *args, **kwargs):
        type(self).calls += 1
        return super(CountingMD5PasswordHasher, self).encode(*args, **kwargs)


class BaseModelBackendTest(object):
    """
    A base class for tests that need to validate the ModelBackend
    with different User models. Subclasses should define a class
    level UserModel attribute, and a create_users() method to
    construct two users for test purposes.
    """
    backend = 'django.contrib.auth.backends.ModelBackend'

    def setUp(self):
        self.patched_settings = modify_settings(
            AUTHENTICATION_BACKENDS={'append': self.backend},
        )
        self.patched_settings.enable()
        self.create_users()

    def tearDown(self):
        self.patched_settings.disable()
        # The custom_perms test messes with ContentTypes, which will
        # be cached; flush the cache to ensure there are no side effects
        # Refs #14975, #14925
        ContentType.objects.clear_cache()

    def test_has_perm(self):
        user = self.UserModel._default_manager.get(pk=self.user.pk)
        self.assertEqual(user.has_perm('auth.test'), False)

        user.is_staff = True
        user.save()
        self.assertEqual(user.has_perm('auth.test'), False)

        user.is_superuser = True
        user.save()
        self.assertEqual(user.has_perm('auth.test'), True)

        user.is_staff = True
        user.is_superuser = True
        user.is_active = False
        user.save()
        self.assertEqual(user.has_perm('auth.test'), False)

    def test_custom_perms(self):
        user = self.UserModel._default_manager.get(pk=self.user.pk)
        content_type = ContentType.objects.get_for_model(Group)
        perm = Permission.objects.create(name='test', content_type=content_type, codename='test')
        user.user_permissions.add(perm)

        # reloading user to purge the _perm_cache
        user = self.UserModel._default_manager.get(pk=self.user.pk)
        self.assertEqual(user.get_all_permissions() == {'auth.test'}, True)
        self.assertEqual(user.get_group_permissions(), set())
        self.assertEqual(user.has_module_perms('Group'), False)
        self.assertEqual(user.has_module_perms('auth'), True)

        perm = Permission.objects.create(name='test2', content_type=content_type, codename='test2')
        user.user_permissions.add(perm)
        perm = Permission.objects.create(name='test3', content_type=content_type, codename='test3')
        user.user_permissions.add(perm)
        user = self.UserModel._default_manager.get(pk=self.user.pk)
        self.assertEqual(user.get_all_permissions(), {'auth.test2', 'auth.test', 'auth.test3'})
        self.assertEqual(user.has_perm('test'), False)
        self.assertEqual(user.has_perm('auth.test'), True)
        self.assertEqual(user.has_perms(['auth.test2', 'auth.test3']), True)

        perm = Permission.objects.create(name='test_group', content_type=content_type, codename='test_group')
        group = Group.objects.create(name='test_group')
        group.permissions.add(perm)
        user.groups.add(group)
        user = self.UserModel._default_manager.get(pk=self.user.pk)
        exp = {'auth.test2', 'auth.test', 'auth.test3', 'auth.test_group'}
        self.assertEqual(user.get_all_permissions(), exp)
        self.assertEqual(user.get_group_permissions(), {'auth.test_group'})
        self.assertEqual(user.has_perms(['auth.test3', 'auth.test_group']), True)

        user = AnonymousUser()
        self.assertEqual(user.has_perm('test'), False)
        self.assertEqual(user.has_perms(['auth.test2', 'auth.test3']), False)

    def test_has_no_object_perm(self):
        """Regressiontest for #12462"""
        user = self.UserModel._default_manager.get(pk=self.user.pk)
        content_type = ContentType.objects.get_for_model(Group)
        perm = Permission.objects.create(name='test', content_type=content_type, codename='test')
        user.user_permissions.add(perm)

        self.assertEqual(user.has_perm('auth.test', 'object'), False)
        self.assertEqual(user.get_all_permissions('object'), set())
        self.assertEqual(user.has_perm('auth.test'), True)
        self.assertEqual(user.get_all_permissions(), {'auth.test'})

    def test_anonymous_has_no_permissions(self):
        """
        #17903 -- Anonymous users shouldn't have permissions in
        ModelBackend.get_(all|user|group)_permissions().
        """
        backend = ModelBackend()

        user = self.UserModel._default_manager.get(pk=self.user.pk)
        content_type = ContentType.objects.get_for_model(Group)
        user_perm = Permission.objects.create(name='test', content_type=content_type, codename='test_user')
        group_perm = Permission.objects.create(name='test2', content_type=content_type, codename='test_group')
        user.user_permissions.add(user_perm)

        group = Group.objects.create(name='test_group')
        user.groups.add(group)
        group.permissions.add(group_perm)

        self.assertEqual(backend.get_all_permissions(user), {'auth.test_user', 'auth.test_group'})
        self.assertEqual(backend.get_user_permissions(user), {'auth.test_user', 'auth.test_group'})
        self.assertEqual(backend.get_group_permissions(user), {'auth.test_group'})

        user.is_anonymous = lambda: True

        self.assertEqual(backend.get_all_permissions(user), set())
        self.assertEqual(backend.get_user_permissions(user), set())
        self.assertEqual(backend.get_group_permissions(user), set())

    def test_inactive_has_no_permissions(self):
        """
        #17903 -- Inactive users shouldn't have permissions in
        ModelBackend.get_(all|user|group)_permissions().
        """
        backend = ModelBackend()

        user = self.UserModel._default_manager.get(pk=self.user.pk)
        content_type = ContentType.objects.get_for_model(Group)
        user_perm = Permission.objects.create(name='test', content_type=content_type, codename='test_user')
        group_perm = Permission.objects.create(name='test2', content_type=content_type, codename='test_group')
        user.user_permissions.add(user_perm)

        group = Group.objects.create(name='test_group')
        user.groups.add(group)
        group.permissions.add(group_perm)

        self.assertEqual(backend.get_all_permissions(user), {'auth.test_user', 'auth.test_group'})
        self.assertEqual(backend.get_user_permissions(user), {'auth.test_user', 'auth.test_group'})
        self.assertEqual(backend.get_group_permissions(user), {'auth.test_group'})

        user.is_active = False
        user.save()

        self.assertEqual(backend.get_all_permissions(user), set())
        self.assertEqual(backend.get_user_permissions(user), set())
        self.assertEqual(backend.get_group_permissions(user), set())

    def test_get_all_superuser_permissions(self):
        """A superuser has all permissions. Refs #14795."""
        user = self.UserModel._default_manager.get(pk=self.superuser.pk)
        self.assertEqual(len(user.get_all_permissions()), len(Permission.objects.all()))

    @override_settings(PASSWORD_HASHERS=['auth_tests.test_auth_backends.CountingMD5PasswordHasher'])
    def test_authentication_timing(self):
        """Hasher is run once regardless of whether the user exists. Refs #20760."""
        # Re-set the password, because this tests overrides PASSWORD_HASHERS
        self.user.set_password('test')
        self.user.save()

        CountingMD5PasswordHasher.calls = 0
        username = getattr(self.user, self.UserModel.USERNAME_FIELD)
        authenticate(username=username, password='test')
        self.assertEqual(CountingMD5PasswordHasher.calls, 1)

        CountingMD5PasswordHasher.calls = 0
        authenticate(username='no_such_user', password='test')
        self.assertEqual(CountingMD5PasswordHasher.calls, 1)


class ModelBackendTest(BaseModelBackendTest, TestCase):
    """
    Tests for the ModelBackend using the default User model.
    """
    UserModel = User

    def create_users(self):
        self.user = User.objects.create_user(
            username='test',
            email='test@example.com',
            password='test',
        )
        self.superuser = User.objects.create_superuser(
            username='test2',
            email='test2@example.com',
            password='test',
        )


@override_settings(AUTH_USER_MODEL='auth.ExtensionUser')
class ExtensionUserModelBackendTest(BaseModelBackendTest, TestCase):
    """
    Tests for the ModelBackend using the custom ExtensionUser model.

    This isn't a perfect test, because both the User and ExtensionUser are
    synchronized to the database, which wouldn't ordinary happen in
    production. As a result, it doesn't catch errors caused by the non-
    existence of the User table.

    The specific problem is queries on .filter(groups__user) et al, which
    makes an implicit assumption that the user model is called 'User'. In
    production, the auth.User table won't exist, so the requested join
    won't exist either; in testing, the auth.User *does* exist, and
    so does the join. However, the join table won't contain any useful
    data; for testing, we check that the data we expect actually does exist.
    """

    UserModel = ExtensionUser

    def create_users(self):
        self.user = ExtensionUser._default_manager.create_user(
            username='test',
            email='test@example.com',
            password='test',
            date_of_birth=date(2006, 4, 25)
        )
        self.superuser = ExtensionUser._default_manager.create_superuser(
            username='test2',
            email='test2@example.com',
            password='test',
            date_of_birth=date(1976, 11, 8)
        )


@override_settings(AUTH_USER_MODEL='auth_tests.CustomPermissionsUser')
class CustomPermissionsUserModelBackendTest(BaseModelBackendTest, TestCase):
    """
    Tests for the ModelBackend using the CustomPermissionsUser model.

    As with the ExtensionUser test, this isn't a perfect test, because both
    the User and CustomPermissionsUser are synchronized to the database,
    which wouldn't ordinary happen in production.
    """

    UserModel = CustomPermissionsUser

    def create_users(self):
        self.user = CustomPermissionsUser._default_manager.create_user(
            email='test@example.com',
            password='test',
            date_of_birth=date(2006, 4, 25)
        )
        self.superuser = CustomPermissionsUser._default_manager.create_superuser(
            email='test2@example.com',
            password='test',
            date_of_birth=date(1976, 11, 8)
        )


@override_settings(AUTH_USER_MODEL='auth.CustomUser')
class CustomUserModelBackendAuthenticateTest(TestCase):
    """
    Tests that the model backend can accept a credentials kwarg labeled with
    custom user model's USERNAME_FIELD.
    """

    def test_authenticate(self):
        test_user = CustomUser._default_manager.create_user(
            email='test@example.com',
            password='test',
            date_of_birth=date(2006, 4, 25)
        )
        authenticated_user = authenticate(email='test@example.com', password='test')
        self.assertEqual(test_user, authenticated_user)


@override_settings(AUTH_USER_MODEL='auth_tests.UUIDUser')
class UUIDUserTests(TestCase):

    def test_login(self):
        """
        A custom user with a UUID primary key should be able to login.
        """
        user = UUIDUser.objects.create_user(username='uuid', password='test')
        self.assertTrue(self.client.login(username='uuid', password='test'))
        self.assertEqual(UUIDUser.objects.get(pk=self.client.session[SESSION_KEY]), user)


class TestObj(object):
    pass


class SimpleRowlevelBackend(object):
    def has_perm(self, user, perm, obj=None):
        if not obj:
            return  # We only support row level perms

        if isinstance(obj, TestObj):
            if user.username == 'test2':
                return True
            elif user.is_anonymous() and perm == 'anon':
                return True
            elif not user.is_active and perm == 'inactive':
                return True
        return False

    def has_module_perms(self, user, app_label):
        if not user.is_anonymous() and not user.is_active:
            return False
        return app_label == "app1"

    def get_all_permissions(self, user, obj=None):
        if not obj:
            return []  # We only support row level perms

        if not isinstance(obj, TestObj):
            return ['none']

        if user.is_anonymous():
            return ['anon']
        if user.username == 'test2':
            return ['simple', 'advanced']
        else:
            return ['simple']

    def get_group_permissions(self, user, obj=None):
        if not obj:
            return  # We only support row level perms

        if not isinstance(obj, TestObj):
            return ['none']

        if 'test_group' in [group.name for group in user.groups.all()]:
            return ['group_perm']
        else:
            return ['none']


@modify_settings(AUTHENTICATION_BACKENDS={
    'append': 'auth_tests.test_auth_backends.SimpleRowlevelBackend',
})
class RowlevelBackendTest(TestCase):
    """
    Tests for auth backend that supports object level permissions
    """

    def setUp(self):
        self.user1 = User.objects.create_user('test', 'test@example.com', 'test')
        self.user2 = User.objects.create_user('test2', 'test2@example.com', 'test')
        self.user3 = User.objects.create_user('test3', 'test3@example.com', 'test')

    def tearDown(self):
        # The get_group_permissions test messes with ContentTypes, which will
        # be cached; flush the cache to ensure there are no side effects
        # Refs #14975, #14925
        ContentType.objects.clear_cache()

    def test_has_perm(self):
        self.assertEqual(self.user1.has_perm('perm', TestObj()), False)
        self.assertEqual(self.user2.has_perm('perm', TestObj()), True)
        self.assertEqual(self.user2.has_perm('perm'), False)
        self.assertEqual(self.user2.has_perms(['simple', 'advanced'], TestObj()), True)
        self.assertEqual(self.user3.has_perm('perm', TestObj()), False)
        self.assertEqual(self.user3.has_perm('anon', TestObj()), False)
        self.assertEqual(self.user3.has_perms(['simple', 'advanced'], TestObj()), False)

    def test_get_all_permissions(self):
        self.assertEqual(self.user1.get_all_permissions(TestObj()), {'simple'})
        self.assertEqual(self.user2.get_all_permissions(TestObj()), {'simple', 'advanced'})
        self.assertEqual(self.user2.get_all_permissions(), set())

    def test_get_group_permissions(self):
        group = Group.objects.create(name='test_group')
        self.user3.groups.add(group)
        self.assertEqual(self.user3.get_group_permissions(TestObj()), {'group_perm'})


@override_settings(
    AUTHENTICATION_BACKENDS=['auth_tests.test_auth_backends.SimpleRowlevelBackend'],
)
class AnonymousUserBackendTest(SimpleTestCase):
    """
    Tests for AnonymousUser delegating to backend.
    """

    def setUp(self):
        self.user1 = AnonymousUser()

    def test_has_perm(self):
        self.assertEqual(self.user1.has_perm('perm', TestObj()), False)
        self.assertEqual(self.user1.has_perm('anon', TestObj()), True)

    def test_has_perms(self):
        self.assertEqual(self.user1.has_perms(['anon'], TestObj()), True)
        self.assertEqual(self.user1.has_perms(['anon', 'perm'], TestObj()), False)

    def test_has_module_perms(self):
        self.assertEqual(self.user1.has_module_perms("app1"), True)
        self.assertEqual(self.user1.has_module_perms("app2"), False)

    def test_get_all_permissions(self):
        self.assertEqual(self.user1.get_all_permissions(TestObj()), {'anon'})


@override_settings(AUTHENTICATION_BACKENDS=[])
class NoBackendsTest(TestCase):
    """
    Tests that an appropriate error is raised if no auth backends are provided.
    """
    def setUp(self):
        self.user = User.objects.create_user('test', 'test@example.com', 'test')

    def test_raises_exception(self):
        self.assertRaises(ImproperlyConfigured, self.user.has_perm, ('perm', TestObj(),))


@override_settings(AUTHENTICATION_BACKENDS=['auth_tests.test_auth_backends.SimpleRowlevelBackend'])
class InActiveUserBackendTest(TestCase):
    """
    Tests for an inactive user
    """

    def setUp(self):
        self.user1 = User.objects.create_user('test', 'test@example.com', 'test')
        self.user1.is_active = False
        self.user1.save()

    def test_has_perm(self):
        self.assertEqual(self.user1.has_perm('perm', TestObj()), False)
        self.assertEqual(self.user1.has_perm('inactive', TestObj()), True)

    def test_has_module_perms(self):
        self.assertEqual(self.user1.has_module_perms("app1"), False)
        self.assertEqual(self.user1.has_module_perms("app2"), False)


class PermissionDeniedBackend(object):
    """
    Always raises PermissionDenied in `authenticate`, `has_perm` and `has_module_perms`.
    """

    def authenticate(self, username=None, password=None):
        raise PermissionDenied

    def has_perm(self, user_obj, perm, obj=None):
        raise PermissionDenied

    def has_module_perms(self, user_obj, app_label):
        raise PermissionDenied


class PermissionDeniedBackendTest(TestCase):
    """
    Tests that other backends are not checked once a backend raises PermissionDenied
    """
    backend = 'auth_tests.test_auth_backends.PermissionDeniedBackend'

    def setUp(self):
        self.user1 = User.objects.create_user('test', 'test@example.com', 'test')
        self.user1.save()

    @modify_settings(AUTHENTICATION_BACKENDS={'prepend': backend})
    def test_permission_denied(self):
        "user is not authenticated after a backend raises permission denied #2550"
        self.assertEqual(authenticate(username='test', password='test'), None)

    @modify_settings(AUTHENTICATION_BACKENDS={'append': backend})
    def test_authenticates(self):
        self.assertEqual(authenticate(username='test', password='test'), self.user1)

    @modify_settings(AUTHENTICATION_BACKENDS={'prepend': backend})
    def test_has_perm_denied(self):
        content_type = ContentType.objects.get_for_model(Group)
        perm = Permission.objects.create(name='test', content_type=content_type, codename='test')
        self.user1.user_permissions.add(perm)

        self.assertIs(self.user1.has_perm('auth.test'), False)
        self.assertIs(self.user1.has_module_perms('auth'), False)

    @modify_settings(AUTHENTICATION_BACKENDS={'append': backend})
    def test_has_perm(self):
        content_type = ContentType.objects.get_for_model(Group)
        perm = Permission.objects.create(name='test', content_type=content_type, codename='test')
        self.user1.user_permissions.add(perm)

        self.assertIs(self.user1.has_perm('auth.test'), True)
        self.assertIs(self.user1.has_module_perms('auth'), True)


class NewModelBackend(ModelBackend):
    pass


class ChangedBackendSettingsTest(TestCase):
    """
    Tests for changes in the settings.AUTHENTICATION_BACKENDS
    """
    backend = 'auth_tests.test_auth_backends.NewModelBackend'

    TEST_USERNAME = 'test_user'
    TEST_PASSWORD = 'test_password'
    TEST_EMAIL = 'test@example.com'

    def setUp(self):
        User.objects.create_user(self.TEST_USERNAME,
                                 self.TEST_EMAIL,
                                 self.TEST_PASSWORD)

    @override_settings(AUTHENTICATION_BACKENDS=[backend])
    def test_changed_backend_settings(self):
        """
        Tests that removing a backend configured in AUTHENTICATION_BACKENDS
        make already logged-in users disconnect.
        """

        # Get a session for the test user
        self.assertTrue(self.client.login(
            username=self.TEST_USERNAME,
            password=self.TEST_PASSWORD)
        )

        # Prepare a request object
        request = HttpRequest()
        request.session = self.client.session

        # Remove NewModelBackend
        with self.settings(AUTHENTICATION_BACKENDS=[
                'django.contrib.auth.backends.ModelBackend']):
            # Get the user from the request
            user = get_user(request)

            # Assert that the user retrieval is successful and the user is
            # anonymous as the backend is not longer available.
            self.assertIsNotNone(user)
            self.assertTrue(user.is_anonymous())


class TypeErrorBackend(object):
    """
    Always raises TypeError.
    """

    def authenticate(self, username=None, password=None):
        raise TypeError


class TypeErrorBackendTest(TestCase):
    """
    Tests that a TypeError within a backend is propagated properly.

    Regression test for ticket #18171
    """
    backend = 'auth_tests.test_auth_backends.TypeErrorBackend'

    def setUp(self):
        self.user1 = User.objects.create_user('test', 'test@example.com', 'test')

    @override_settings(AUTHENTICATION_BACKENDS=[backend])
    def test_type_error_raised(self):
        self.assertRaises(TypeError, authenticate, username='test', password='test')


class ImproperlyConfiguredUserModelTest(TestCase):
    """
    Tests that an exception from within get_user_model is propagated and doesn't
    raise an UnboundLocalError.

    Regression test for ticket #21439
    """
    def setUp(self):
        self.user1 = User.objects.create_user('test', 'test@example.com', 'test')
        self.client.login(
            username='test',
            password='test'
        )

    @override_settings(AUTH_USER_MODEL='thismodel.doesntexist')
    def test_does_not_shadow_exception(self):
        # Prepare a request object
        request = HttpRequest()
        request.session = self.client.session

        self.assertRaises(ImproperlyConfigured, get_user, request)


class ImportedModelBackend(ModelBackend):
    pass


class ImportedBackendTests(TestCase):
    """
    #23925 - The backend path added to the session should be the same
    as the one defined in AUTHENTICATION_BACKENDS setting.
    """

    backend = 'auth_tests.backend_alias.ImportedModelBackend'

    @override_settings(AUTHENTICATION_BACKENDS=[backend])
    def test_backend_path(self):
        username = 'username'
        password = 'password'
        User.objects.create_user(username, 'email', password)
        self.assertTrue(self.client.login(username=username, password=password))
        request = HttpRequest()
        request.session = self.client.session
        self.assertEqual(request.session[BACKEND_SESSION_KEY], self.backend)