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
|
# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
from __future__ import absolute_import, division, print_function
import base64
import calendar
import json
import os
import time
import iso8601
import pytest
import six
from cryptography.fernet import Fernet, InvalidToken, MultiFernet
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.backends.interfaces import CipherBackend, HMACBackend
from cryptography.hazmat.primitives.ciphers import algorithms, modes
import cryptography_vectors
def json_parametrize(keys, filename):
vector_file = cryptography_vectors.open_vector_file(
os.path.join('fernet', filename), "r"
)
with vector_file:
data = json.load(vector_file)
return pytest.mark.parametrize(keys, [
tuple([entry[k] for k in keys])
for entry in data
])
def test_default_backend():
f = Fernet(Fernet.generate_key())
assert f._backend is default_backend()
@pytest.mark.requires_backend_interface(interface=CipherBackend)
@pytest.mark.requires_backend_interface(interface=HMACBackend)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 32), modes.CBC(b"\x00" * 16)
),
skip_message="Does not support AES CBC",
)
class TestFernet(object):
@json_parametrize(
("secret", "now", "iv", "src", "token"), "generate.json",
)
def test_generate(self, secret, now, iv, src, token, backend):
f = Fernet(secret.encode("ascii"), backend=backend)
actual_token = f._encrypt_from_parts(
src.encode("ascii"),
calendar.timegm(iso8601.parse_date(now).utctimetuple()),
b"".join(map(six.int2byte, iv))
)
assert actual_token == token.encode("ascii")
@json_parametrize(
("secret", "now", "src", "ttl_sec", "token"), "verify.json",
)
def test_verify(self, secret, now, src, ttl_sec, token, backend,
monkeypatch):
f = Fernet(secret.encode("ascii"), backend=backend)
current_time = calendar.timegm(iso8601.parse_date(now).utctimetuple())
payload = f.decrypt_at_time(
token.encode("ascii"), ttl=ttl_sec, current_time=current_time,
)
assert payload == src.encode("ascii")
monkeypatch.setattr(time, "time", lambda: current_time)
payload = f.decrypt(token.encode("ascii"), ttl=ttl_sec)
assert payload == src.encode("ascii")
@json_parametrize(("secret", "token", "now", "ttl_sec"), "invalid.json")
def test_invalid(self, secret, token, now, ttl_sec, backend, monkeypatch):
f = Fernet(secret.encode("ascii"), backend=backend)
current_time = calendar.timegm(iso8601.parse_date(now).utctimetuple())
with pytest.raises(InvalidToken):
f.decrypt_at_time(
token.encode("ascii"), ttl=ttl_sec, current_time=current_time,
)
monkeypatch.setattr(time, "time", lambda: current_time)
with pytest.raises(InvalidToken):
f.decrypt(token.encode("ascii"), ttl=ttl_sec)
def test_invalid_start_byte(self, backend):
f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
with pytest.raises(InvalidToken):
f.decrypt(base64.urlsafe_b64encode(b"\x81"))
def test_timestamp_too_short(self, backend):
f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
with pytest.raises(InvalidToken):
f.decrypt(base64.urlsafe_b64encode(b"\x80abc"))
def test_non_base64_token(self, backend):
f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
with pytest.raises(InvalidToken):
f.decrypt(b"\x00")
def test_unicode(self, backend):
f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
with pytest.raises(TypeError):
f.encrypt(u"")
with pytest.raises(TypeError):
f.decrypt(u"")
def test_timestamp_ignored_no_ttl(self, monkeypatch, backend):
f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
pt = b"encrypt me"
token = f.encrypt(pt)
ts = "1985-10-26T01:20:01-07:00"
current_time = calendar.timegm(iso8601.parse_date(ts).utctimetuple())
assert f.decrypt_at_time(
token, ttl=None, current_time=current_time) == pt
monkeypatch.setattr(time, "time", lambda: current_time)
assert f.decrypt(token, ttl=None) == pt
@pytest.mark.parametrize("message", [b"", b"Abc!", b"\x00\xFF\x00\x80"])
def test_roundtrips(self, message, backend):
f = Fernet(Fernet.generate_key(), backend=backend)
assert f.decrypt(f.encrypt(message)) == message
def test_bad_key(self, backend):
with pytest.raises(ValueError):
Fernet(base64.urlsafe_b64encode(b"abc"), backend=backend)
def test_extract_timestamp(self, monkeypatch, backend):
f = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
current_time = 1526138327
token = f.encrypt_at_time(b'encrypt me', current_time)
assert f.extract_timestamp(token) == current_time
with pytest.raises(InvalidToken):
f.extract_timestamp(b"nonsensetoken")
@pytest.mark.requires_backend_interface(interface=CipherBackend)
@pytest.mark.requires_backend_interface(interface=HMACBackend)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 32), modes.CBC(b"\x00" * 16)
),
skip_message="Does not support AES CBC",
)
class TestMultiFernet(object):
def test_encrypt(self, backend):
f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend)
f = MultiFernet([f1, f2])
assert f1.decrypt(f.encrypt(b"abc")) == b"abc"
def test_decrypt(self, backend):
f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend)
f = MultiFernet([f1, f2])
assert f.decrypt(f1.encrypt(b"abc")) == b"abc"
assert f.decrypt(f2.encrypt(b"abc")) == b"abc"
with pytest.raises(InvalidToken):
f.decrypt(b"\x00" * 16)
def test_no_fernets(self, backend):
with pytest.raises(ValueError):
MultiFernet([])
def test_non_iterable_argument(self, backend):
with pytest.raises(TypeError):
MultiFernet(None)
def test_rotate(self, backend):
f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend)
mf1 = MultiFernet([f1])
mf2 = MultiFernet([f2, f1])
plaintext = b"abc"
mf1_ciphertext = mf1.encrypt(plaintext)
assert mf2.decrypt(mf1_ciphertext) == plaintext
rotated = mf2.rotate(mf1_ciphertext)
assert rotated != mf1_ciphertext
assert mf2.decrypt(rotated) == plaintext
with pytest.raises(InvalidToken):
mf1.decrypt(rotated)
def test_rotate_preserves_timestamp(self, backend, monkeypatch):
f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend)
mf1 = MultiFernet([f1])
mf2 = MultiFernet([f2, f1])
plaintext = b"abc"
original_time = int(time.time()) - 5 * 60
mf1_ciphertext = mf1.encrypt_at_time(plaintext, original_time)
rotated_time, _ = Fernet._get_unverified_token_data(
mf2.rotate(mf1_ciphertext)
)
assert int(time.time()) != rotated_time
assert original_time == rotated_time
def test_rotate_decrypt_no_shared_keys(self, backend):
f1 = Fernet(base64.urlsafe_b64encode(b"\x00" * 32), backend=backend)
f2 = Fernet(base64.urlsafe_b64encode(b"\x01" * 32), backend=backend)
mf1 = MultiFernet([f1])
mf2 = MultiFernet([f2])
with pytest.raises(InvalidToken):
mf2.rotate(mf1.encrypt(b"abc"))
|
