-
Notifications
You must be signed in to change notification settings - Fork 0
/
lfsr11.py
94 lines (76 loc) · 2.39 KB
/
lfsr11.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
import time
# 00000000000000000000000000000
# 10000000000000000000000000010 = [29,2] = 268435458
# 11010111111010111101011101110 = 452819694
# 11111111111111111111111111111 = 536870911
def bytes_from_file(filename, chunksize=8192):
with open(filename, "rb") as f:
while True:
chunk = f.read(chunksize)
if chunk:
for b in chunk:
yield b
else:
break
def Cipher(filename, int = 452819694):
print(filename)
register = int
# register = 536870911
mask = 268435458
mask_obr = 536870911
print(bin(mask), bin(register))
b_arr = bytearray()
b_arr_key = bytearray()
file_out = open(filename+'.cph', 'wb')
start_time = time.time()
for b in bytes_from_file(filename):
key_byte = 0
i = 7
while i >= 0:
check = register & mask
if register & 268435456 == 268435456:
key_byte = key_byte ^ 2 ** i
register = register << 1
if check == 268435456 or check == 2:
register = register ^ 1
register = register & mask_obr
i -= 1
b_arr.append(b ^ key_byte)
b_arr_key.append(key_byte)
print("--- %s seconds ---" % (time.time() - start_time))
file_out.write(b_arr)
file_out.close()
return b_arr_key
def DeCipher(filename, int=452819694 ):
filename = filename[:(len(filename)-4)]
print(filename)
register = int
# register = 536870911
mask = 268435458
mask_obr = 536870911
print(bin(mask), bin(register))
b_arr = bytearray()
b_arr_key = bytearray()
file_out = open(filename, 'wb')
start_time = time.time()
for b in bytes_from_file(filename+'.cph'):
key_byte = 0
i = 7
while i >= 0:
check = register & mask
if register & 268435456 == 268435456:
key_byte = key_byte ^ 2 ** i
register = register << 1
if check == 268435456 or check == 2:
register = register ^ 1
register = register & mask_obr
i -= 1
b_arr.append(b ^ key_byte)
b_arr_key.append(key_byte)
print("--- %s seconds ---" % (time.time() - start_time))
file_out.write(b_arr)
file_out.close()
return b_arr_key
#Cipher('delphi.gif',1,1)
#DeCipher('delphi.gif',1,1)
#print(check,' ',key_byte)