-
Notifications
You must be signed in to change notification settings - Fork 22
/
des.py
executable file
·252 lines (221 loc) · 8.64 KB
/
des.py
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
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2019 frey <[email protected]>
# blog:https://www.vhcffh.com
#
# Distributed under terms of the MIT license.
IP = (58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7)
FP = (40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25)
E = (32, 1, 2, 3, 4, 5,
4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13,
12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21,
20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1)
P = (16, 7, 20, 21,
29, 12, 28, 17,
1, 15, 23, 26,
5, 18, 31, 10,
2, 8, 24, 14,
32, 27, 3, 9,
19, 13, 30, 6,
22, 11, 4, 25)
S = [[[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
[0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
[4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
[15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]],
[[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
[3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
[0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
[13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]],
[[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
[13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
[13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
[1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]],
[[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
[13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
[10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
[3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]],
[[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
[14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
[4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
[11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]],
[[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
[10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
[9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
[4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]],
[[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
[13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
[1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
[6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]],
[[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
[1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
[7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
[2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]]]
PC_1L = (57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36)
PC_1R = (63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4)
PC_2 = (14, 17, 11, 24, 1, 5,
3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8,
16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55,
30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53,
46, 42, 50, 36, 29, 32)
def Permute(block, b_len, PP):
# 通过置换矩阵PP对block进行置换,b_len是块长度(位，bit)
res = 0
for i in PP:
res = res << 1
# 第i-1的位置 即倒数第
res |= (block >> (b_len - i)) & 0x01
return res
def bytesToblocks(m):
# 字节序列转换位blocks b'\x00\x01\x02\x03\xff\xff\xff\xff' -> [0x00010203,0xffffffff]
while len(m) % 8 != 0:
m += b'\x00'
blocks = []
for i in range(len(m) // 4):
blocks.append((m[4 * i] << 24) | (m[4 * i + 1] << 16) |
(m[4 * i + 2] << 8) | (m[4 * i + 3]))
return blocks
def blocksTobytes(blocks):
# blocks转换为字节序列 [0x00010203,0xffffffff] -> b'\x00\x01\x02\x03\xff\xff\xff\xff'
res = b''
for i in blocks:
res += i.to_bytes(4, byteorder="big")
return res
L = lambda x, n: ((x << n) | (x >> (28 - n))) & 0x0fffffff
# 对一个28bits的数x进行循环左移n位
class DES(object):
def F(self, block, subKeyid):
"""
:param block: 32bits
:param subKeyid:
:return: res: 32bits
"""
temp = Permute(block, 32, E) ^ self.subKs[subKeyid]
res = 0
for i in range(8):
res = res << 4
yxxxxy = (temp >> 6 * (7 - i)) & 0x3f
xxxx = (yxxxxy & 0x1f) >> 1
yy = ((yxxxxy >> 5) << 1) | (yxxxxy & 0x01)
res |= S[i][yy][xxxx]
res = Permute(res, 32, P)
return res & 0xffffffff
def __init__(self, K: bytes):
# 通过密钥K生成实例
self.K = K
self.K_blocks = bytesToblocks(K)[:2]
# 生成字密钥self.subKs[16]
self.subKs = None
self.generate_subKs()
def Encrypt(self, m: bytes) -> bytes:
# 加密
blocks = bytesToblocks(m)
cblocks = []
for i in range(len(blocks) // 2):
# 每个64bits的高32bits，低32bits
high, low = blocks[2 * i], blocks[2 * i + 1]
# 第一步：初始置换IP
temp = Permute((high << 32) | low, 64, IP) & 0xffffffffffffffff
# 第二步：获取 Li 和 Ri
high, low = temp >> 32, temp & 0xffffffff
# 第三步：共16轮迭代
for j in range(16):
high, low = low, (high ^ self.F(low, j))
# 第四步：合并L16和R16，注意合并为 R16L16
high, low = low, high
# 第五步：末尾置换FP
temp = Permute((high << 32) | low, 64, FP) & 0xffffffffffffffff
high, low = temp >> 32, temp & 0xffffffff
cblocks.append(high)
cblocks.append(low)
return blocksTobytes(cblocks)
def Decrypt(self, e: bytes) -> bytes:
# 解密
blocks = bytesToblocks(e)
cblocks = []
for i in range(len(blocks) // 2):
# 每个64bits的高32bits，低32bits
high, low = blocks[2 * i], blocks[2 * i + 1]
# 第一步：初始置换IP
temp = Permute((high << 32) | low, 64, IP) & 0xffffffffffffffff
# 第二步：获取 Li 和 Ri
high, low = temp >> 32, temp & 0xffffffff
# 第三步：共16轮迭代, 子密钥逆序
for j in range(16):
high, low = low, (high ^ self.F(low, 15 - j))
# 第四步：合并L16和R16，注意合并为 R16L16
high, low = low, high
# 第五步：末尾置换FP
temp = Permute((high << 32) | low, 64, FP) & 0xffffffffffffffff
high, low = temp >> 32, temp & 0xffffffff
cblocks.append(high)
cblocks.append(low)
return blocksTobytes(cblocks)
def generate_subKs(self):
# print(bin((self.K_blocks[0] << 32) | self.K_blocks[1])[2:].rjust(32, '0'))
C = Permute((self.K_blocks[0] << 32) | self.K_blocks[1], 64, PC_1L) & 0x0fffffff
D = Permute((self.K_blocks[0] << 32) | self.K_blocks[1], 64, PC_1R) & 0x0fffffff
# print(bin(C)[2:].rjust(28, '0'))
# print(bin(D)[2:].rjust(28, '0'))
self.subKs = []
for i in range(16):
if i in (0, 1, 8, 15):
C, D = L(C, 1), L(D, 1)
else:
C, D = L(C, 2), L(D, 2)
self.subKs.append(Permute((C << 28) | D, 56, PC_2))
# print(hex(self.subKs[i]))
def getK(self) -> bytes:
# 返回密钥K
return self.K
def generateK(self) -> bytes:
# 随机产生密钥K
pass
def print_bytes_hex(m):
for i in m:
print(hex(i)[2:].rjust(2, '0'), end='')
print()
if __name__ == '__main__':
# 密钥不足64bits 添零，多于64bits 使用前64bits
# messages 不足64bits的倍数 补零
m = b'https://www.vhcffh.com' # 明文
k = b'123456' # 密钥
a = DES(k)
cc = a.Encrypt(m)
mm = a.Decrypt(cc)
print("明文:", end='')
print(m)
print("密钥:", end='')
print(a.K)
print("密文:", end='')
print_bytes_hex(cc) # 以bytes输出
print("解密:", end='')
print(mm)
# http://www.hankcs.com/security/des-algorithm-illustrated.html