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
|
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import absolute_import, division, print_function
import binascii
import pytest
from cryptography import utils
from cryptography.exceptions import (
AlreadyFinalized, _Reasons
)
from cryptography.hazmat.primitives import interfaces
from cryptography.hazmat.primitives.ciphers import (
Cipher, algorithms, modes
)
from .utils import (
generate_aead_exception_test, generate_aead_tag_exception_test
)
from ...utils import raises_unsupported_algorithm
@utils.register_interface(interfaces.Mode)
class DummyMode(object):
name = "dummy-mode"
def validate_for_algorithm(self, algorithm):
pass
@utils.register_interface(interfaces.CipherAlgorithm)
class DummyCipher(object):
name = "dummy-cipher"
key_size = 128
@pytest.mark.cipher
class TestCipher(object):
def test_creates_encryptor(self, backend):
cipher = Cipher(
algorithms.AES(binascii.unhexlify(b"0" * 32)),
modes.CBC(binascii.unhexlify(b"0" * 32)),
backend
)
assert isinstance(cipher.encryptor(), interfaces.CipherContext)
def test_creates_decryptor(self, backend):
cipher = Cipher(
algorithms.AES(binascii.unhexlify(b"0" * 32)),
modes.CBC(binascii.unhexlify(b"0" * 32)),
backend
)
assert isinstance(cipher.decryptor(), interfaces.CipherContext)
def test_instantiate_with_non_algorithm(self, backend):
algorithm = object()
with pytest.raises(TypeError):
Cipher(algorithm, mode=None, backend=backend)
@pytest.mark.cipher
class TestCipherContext(object):
def test_use_after_finalize(self, backend):
cipher = Cipher(
algorithms.AES(binascii.unhexlify(b"0" * 32)),
modes.CBC(binascii.unhexlify(b"0" * 32)),
backend
)
encryptor = cipher.encryptor()
encryptor.update(b"a" * 16)
encryptor.finalize()
with pytest.raises(AlreadyFinalized):
encryptor.update(b"b" * 16)
with pytest.raises(AlreadyFinalized):
encryptor.finalize()
decryptor = cipher.decryptor()
decryptor.update(b"a" * 16)
decryptor.finalize()
with pytest.raises(AlreadyFinalized):
decryptor.update(b"b" * 16)
with pytest.raises(AlreadyFinalized):
decryptor.finalize()
def test_unaligned_block_encryption(self, backend):
cipher = Cipher(
algorithms.AES(binascii.unhexlify(b"0" * 32)),
modes.ECB(),
backend
)
encryptor = cipher.encryptor()
ct = encryptor.update(b"a" * 15)
assert ct == b""
ct += encryptor.update(b"a" * 65)
assert len(ct) == 80
ct += encryptor.finalize()
decryptor = cipher.decryptor()
pt = decryptor.update(ct[:3])
assert pt == b""
pt += decryptor.update(ct[3:])
assert len(pt) == 80
assert pt == b"a" * 80
decryptor.finalize()
@pytest.mark.parametrize("mode", [DummyMode(), None])
def test_nonexistent_cipher(self, backend, mode):
cipher = Cipher(
DummyCipher(), mode, backend
)
with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_CIPHER):
cipher.encryptor()
with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_CIPHER):
cipher.decryptor()
def test_incorrectly_padded(self, backend):
cipher = Cipher(
algorithms.AES(b"\x00" * 16),
modes.CBC(b"\x00" * 16),
backend
)
encryptor = cipher.encryptor()
encryptor.update(b"1")
with pytest.raises(ValueError):
encryptor.finalize()
decryptor = cipher.decryptor()
decryptor.update(b"1")
with pytest.raises(ValueError):
decryptor.finalize()
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES("\x00" * 16), modes.GCM("\x00" * 12)
),
skip_message="Does not support AES GCM",
)
@pytest.mark.cipher
class TestAEADCipherContext(object):
test_aead_exceptions = generate_aead_exception_test(
algorithms.AES,
modes.GCM,
)
test_aead_tag_exceptions = generate_aead_tag_exception_test(
algorithms.AES,
modes.GCM,
)
@pytest.mark.cipher
class TestModeValidation(object):
def test_cbc(self, backend):
with pytest.raises(ValueError):
Cipher(
algorithms.AES(b"\x00" * 16),
modes.CBC(b"abc"),
backend,
)
def test_ofb(self, backend):
with pytest.raises(ValueError):
Cipher(
algorithms.AES(b"\x00" * 16),
modes.OFB(b"abc"),
backend,
)
def test_cfb(self, backend):
with pytest.raises(ValueError):
Cipher(
algorithms.AES(b"\x00" * 16),
modes.CFB(b"abc"),
backend,
)
def test_cfb8(self, backend):
with pytest.raises(ValueError):
Cipher(
algorithms.AES(b"\x00" * 16),
modes.CFB8(b"abc"),
backend,
)
def test_ctr(self, backend):
with pytest.raises(ValueError):
Cipher(
algorithms.AES(b"\x00" * 16),
modes.CTR(b"abc"),
backend,
)
|
