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
|
# key.py - module for handling keys from pskc files
# coding: utf-8
#
# Copyright (C) 2014 Arthur de Jong
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301 USA
import base64
from pskc.encryption import EncryptedValue
from pskc.mac import ValueMAC
from pskc.policy import Policy
class DataType(object):
def __init__(self, key, element=None):
self.key = key
self.plain_value = None
self.encrypted_value = EncryptedValue(self.key.pskc.encryption)
self.value_mac = ValueMAC(self.key.pskc.mac)
self.parse(element)
def parse(self, element):
from pskc.parse import g_e_v, namespaces
if element is None:
return
self.plain_value = g_e_v(element, 'pskc:PlainValue')
self.encrypted_value.parse(element.find(
'pskc:EncryptedValue', namespaces=namespaces))
self.value_mac.parse(element.find(
'pskc:ValueMAC', namespaces=namespaces))
def check(self):
"""Check whether the embedded MAC is correct."""
return self.value_mac.check(self.encrypted_value.cipher_value)
class BinaryDataType(DataType):
@property
def value(self):
# plain value is base64 encoded
value = self.plain_value
if value is not None:
return base64.b64decode(value)
# encrypted value is in correct format
value = self.encrypted_value.decrypt()
if value is not None:
return value
class IntegerDataType(DataType):
@property
def value(self):
# plain value is a string representation of the number
value = self.plain_value
if value:
return int(value)
# decrypted value is a
value = self.encrypted_value.decrypt()
if value is not None:
# Python3 has int.from_bytes(value, byteorder='big')
v = 0
for x in value:
v = (v << 8) + ord(x)
return v
class Key(object):
def __init__(self, pskc, key_package):
self.pskc = pskc
self.manufacturer = None
self.serial = None
self.model = None
self.issue_no = None
self.device_binding = None
self.start_date = None
self.expiry_date = None
self.device_userid = None
self.crypto_module = None
self.id = None
self.algorithm = None
self.issuer = None
self.key_profile = None
self.key_reference = None
self.friendly_name = None
self.userid = None
self.algorithm_suite = None
self.challenge_encoding = None
self.challenge_min_length = None
self.challenge_max_length = None
self.challenge_check = None
self.response_encoding = None
self.response_length = None
self.response_check = None
self._secret = BinaryDataType(self)
self._counter = IntegerDataType(self)
self._time_offset = IntegerDataType(self)
self._time_interval = IntegerDataType(self)
self._time_drift = IntegerDataType(self)
self.policy = Policy(self)
self.parse(key_package)
def parse(self, key_package):
from pskc.parse import g_e_v, g_e_d, namespaces
if key_package is None:
return
self.manufacturer = g_e_v(key_package, 'pskc:DeviceInfo/pskc:Manufacturer')
self.serial = g_e_v(key_package, 'pskc:DeviceInfo/pskc:SerialNo')
self.model = g_e_v(key_package, 'pskc:DeviceInfo/pskc:Model')
self.issue_no = g_e_v(key_package, 'pskc:DeviceInfo/pskc:IssueNo')
self.device_binding = g_e_v(key_package, 'pskc:DeviceInfo/pskc:DeviceBinding')
self.start_date = g_e_d(key_package, 'pskc:DeviceInfo/pskc:StartDate')
self.expiry_date = g_e_d(key_package, 'pskc:DeviceInfo/pskc:ExpiryDate')
self.device_userid = g_e_v(key_package, 'pskc:DeviceInfo/pskc:UserId')
self.crypto_module = g_e_v(key_package, 'pskc:CryptoModuleInfo/pskc:Id')
key = key_package.find('pskc:Key', namespaces=namespaces)
if key is not None:
self.id = key.attrib.get('Id')
self.algorithm = key.attrib.get('Algorithm')
self.issuer = g_e_v(key_package, 'pskc:Key/pskc:Issuer')
self.key_profile = g_e_v(key_package, 'pskc:Key/pskc:KeyProfileId')
self.key_reference = g_e_v(key_package, 'pskc:Key/pskc:KeyReference')
self.friendly_name = g_e_v(key_package, 'pskc:Key/pskc:FriendlyName')
# TODO: support multi-language values of <FriendlyName>
self.userid = g_e_v(key_package, 'pskc:Key/pskc:UserId')
self.algorithm_suite = g_e_v(key_package, 'pskc:Key/pskc:AlgorithmParameters/pskc:Suite')
challenge_format = key_package.find('pskc:Key/pskc:AlgorithmParameters/pskc:ChallengeFormat', namespaces=namespaces)
if challenge_format is not None:
self.challenge_encoding = challenge_format.attrib.get('Encoding')
v = challenge_format.attrib.get('Min')
if v:
self.challenge_min_length = int(v)
v = challenge_format.attrib.get('Max')
if v:
self.challenge_max_length = int(v)
v = challenge_format.attrib.get('CheckDigits')
if v:
self.challenge_check = v.lower() == 'true'
response_format = key_package.find('pskc:Key/pskc:AlgorithmParameters/pskc:ResponseFormat', namespaces=namespaces)
if response_format is not None:
self.response_encoding = response_format.attrib.get('Encoding')
v = response_format.attrib.get('Length')
if v:
self.response_length = int(v)
v = response_format.attrib.get('CheckDigits')
if v:
self.response_check = v.lower() == 'true'
data = key_package.find('pskc:Key/pskc:Data', namespaces=namespaces)
if data is not None:
self._secret.parse(data.find(
'pskc:Secret', namespaces=namespaces))
self._counter.parse(data.find(
'pskc:Counter', namespaces=namespaces))
self._time_offset.parse(data.find(
'pskc:Time', namespaces=namespaces))
self._time_interval.parse(data.find(
'pskc:TimeInterval', namespaces=namespaces))
self._time_drift.parse(data.find(
'pskc:TimeDrift', namespaces=namespaces))
self.policy.parse(key_package.find(
'pskc:Key/pskc:Policy', namespaces=namespaces))
@property
def secret(self):
"""The secret key itself."""
return self._secret.value
@property
def counter(self):
"""An event counter for event-based OTP."""
return self._counter.value
@property
def time_offset(self):
"""A time offset for time-based OTP (number of intervals)."""
return self._time_offset.value
@property
def time_interval(self):
"""A time interval in seconds."""
return self._time_interval.value
@property
def time_drift(self):
"""Device clock drift value (number of time intervals)."""
return self._time_drift.value
def check(self):
"""Check if all MACs in the message are valid."""
checks = (self._secret.check(), self._counter.check(),
self._time_offset.check(), self._time_interval.check(),
self._time_drift.check())
if all(x is None for x in checks):
return None
return all(x is not False for x in checks)
|