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
|
# 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 six
from cryptography import utils
def generate_parameters(key_size, backend):
return backend.generate_dsa_parameters(key_size)
def generate_private_key(key_size, backend):
return backend.generate_dsa_private_key_and_parameters(key_size)
def _check_dsa_parameters(parameters):
if (utils.bit_length(parameters.p),
utils.bit_length(parameters.q)) not in (
(1024, 160),
(2048, 256),
(3072, 256)):
raise ValueError(
"p and q's bit-lengths must be one of these pairs (1024, 160), "
"(2048, 256), or (3072, 256). Not ({0:d}, {1:d})".format(
utils.bit_length(parameters.p), utils.bit_length(parameters.q)
)
)
if not (1 < parameters.g < parameters.p):
raise ValueError("g, p don't satisfy 1 < g < p.")
def _check_dsa_private_numbers(numbers):
parameters = numbers.public_numbers.parameter_numbers
_check_dsa_parameters(parameters)
if numbers.x <= 0 or numbers.x >= parameters.q:
raise ValueError("x must be > 0 and < q.")
if numbers.public_numbers.y != pow(parameters.g, numbers.x, parameters.p):
raise ValueError("y must be equal to (g ** x % p).")
class DSAParameterNumbers(object):
def __init__(self, p, q, g):
if (
not isinstance(p, six.integer_types) or
not isinstance(q, six.integer_types) or
not isinstance(g, six.integer_types)
):
raise TypeError(
"DSAParameterNumbers p, q, and g arguments must be integers."
)
self._p = p
self._q = q
self._g = g
@property
def p(self):
return self._p
@property
def q(self):
return self._q
@property
def g(self):
return self._g
def parameters(self, backend):
return backend.load_dsa_parameter_numbers(self)
class DSAPublicNumbers(object):
def __init__(self, y, parameter_numbers):
if not isinstance(y, six.integer_types):
raise TypeError("DSAPublicNumbers y argument must be an integer.")
if not isinstance(parameter_numbers, DSAParameterNumbers):
raise TypeError(
"parameter_numbers must be a DSAParameterNumbers instance."
)
self._y = y
self._parameter_numbers = parameter_numbers
@property
def y(self):
return self._y
@property
def parameter_numbers(self):
return self._parameter_numbers
def public_key(self, backend):
return backend.load_dsa_public_numbers(self)
class DSAPrivateNumbers(object):
def __init__(self, x, public_numbers):
if not isinstance(x, six.integer_types):
raise TypeError("DSAPrivateNumbers x argument must be an integer.")
if not isinstance(public_numbers, DSAPublicNumbers):
raise TypeError(
"public_numbers must be a DSAPublicNumbers instance."
)
self._public_numbers = public_numbers
self._x = x
@property
def x(self):
return self._x
@property
def public_numbers(self):
return self._public_numbers
def private_key(self, backend):
return backend.load_dsa_private_numbers(self)
|
