-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathround.py
99 lines (79 loc) · 3.51 KB
/
round.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
import box
REGULAR = 0
INVERSE = 1
class Round:
def __init__(self, state, mode):
self.__state = state
self.__xtime = lambda a: (((a << 1) ^ 0x1B) & 0xFF) if (a & 0x80) else (a << 1)
self.__mode = mode
def __sub_bytes(self):
table = box.s_box if self.__mode == REGULAR else box.inverse_s_box
for i in range(4):
for j in range(4):
index = self.__state[i][j]
self.__state[i][j] = table[index]
def __shift_rows(self):
self.__state[1][0], self.__state[1][1], self.__state[1][2], self.__state[1][3] = \
self.__state[1][1], self.__state[1][2], self.__state[1][3], self.__state[1][0]
self.__state[2][0], self.__state[2][1], self.__state[2][2], self.__state[2][3] = \
self.__state[2][2], self.__state[2][3], self.__state[2][0], self.__state[2][1]
self.__state[3][0], self.__state[3][1], self.__state[3][2], self.__state[3][3] = \
self.__state[3][3], self.__state[3][0], self.__state[3][1], self.__state[3][2]
def __inverse_shift_rows(self):
self.__state[1][0], self.__state[1][1], self.__state[1][2], self.__state[1][3] = \
self.__state[1][3], self.__state[1][0], self.__state[1][1], self.__state[1][2]
self.__state[2][0], self.__state[2][1], self.__state[2][2], self.__state[2][3] = \
self.__state[2][2], self.__state[2][3], self.__state[2][0], self.__state[2][1]
self.__state[3][0], self.__state[3][1], self.__state[3][2], self.__state[3][3] = \
self.__state[3][1], self.__state[3][2], self.__state[3][3], self.__state[3][0]
def __mix_single_column(self, a):
t = a[0] ^ a[1] ^ a[2] ^ a[3]
u = a[0]
a[0] ^= t ^ self.__xtime(a[0] ^ a[1])
a[1] ^= t ^ self.__xtime(a[1] ^ a[2])
a[2] ^= t ^ self.__xtime(a[2] ^ a[3])
a[3] ^= t ^ self.__xtime(a[3] ^ u)
def __mix_columns(self):
for i in range(4):
self.__mix_single_column(self.__state[i])
def __inv_mix_columns(self):
for i in range(4):
u = self.__xtime(self.__xtime(self.__state[i][0] ^ self.__state[i][2]))
v = self.__xtime(self.__xtime(self.__state[i][1] ^ self.__state[i][3]))
self.__state[i][0] ^= u
self.__state[i][1] ^= v
self.__state[i][2] ^= u
self.__state[i][3] ^= v
self.__mix_columns()
def __add_round_key(self, cipher_key):
for i in range(4):
for j in range(4):
self.__state[i][j] = (self.__state[i][j] ^ (cipher_key[i][j]))
###################
# Round executions
###################
def initial_round(self, cipher_key):
self.__add_round_key(cipher_key)
return self.__state
def main_round(self, cipher_key):
if self.__mode == REGULAR:
self.__sub_bytes()
self.__shift_rows()
self.__mix_columns()
self.__add_round_key(cipher_key)
elif self.__mode == INVERSE:
self.__add_round_key(cipher_key)
self.__inv_mix_columns()
self.__inverse_shift_rows()
self.__sub_bytes()
return self.__state
def final_round(self, cipher_key):
if self.__mode == REGULAR:
self.__sub_bytes()
self.__shift_rows()
self.__add_round_key(cipher_key)
elif self.__mode == INVERSE:
self.__add_round_key(cipher_key)
self.__inverse_shift_rows()
self.__sub_bytes()
return self.__state