55 lines
1.2 KiB
Python
55 lines
1.2 KiB
Python
#!/usr/bin/env python
|
|
|
|
""" Python implementation of Arcfour encryption algorithm.
|
|
|
|
This code is in the public domain.
|
|
|
|
"""
|
|
|
|
|
|
## Arcfour
|
|
##
|
|
class Arcfour:
|
|
|
|
"""
|
|
>>> Arcfour(b'Key').process(b'Plaintext').hex()
|
|
'bbf316e8d940af0ad3'
|
|
>>> Arcfour(b'Wiki').process(b'pedia').hex()
|
|
'1021bf0420'
|
|
>>> Arcfour(b'Secret').process(b'Attack at dawn').hex()
|
|
'45a01f645fc35b383552544b9bf5'
|
|
"""
|
|
|
|
def __init__(self, key):
|
|
s = list(range(256))
|
|
j = 0
|
|
klen = len(key)
|
|
for i in range(256):
|
|
j = (j + s[i] + key[i % klen]) % 256
|
|
(s[i], s[j]) = (s[j], s[i])
|
|
self.s = s
|
|
(self.i, self.j) = (0, 0)
|
|
return
|
|
|
|
def process(self, data):
|
|
(i, j) = (self.i, self.j)
|
|
s = self.s
|
|
r = []
|
|
for c in data:
|
|
i = (i+1) % 256
|
|
j = (j+s[i]) % 256
|
|
(s[i], s[j]) = (s[j], s[i])
|
|
k = s[(s[i]+s[j]) % 256]
|
|
r.append(c ^ k)
|
|
(self.i, self.j) = (i, j)
|
|
return bytes(r)
|
|
|
|
encrypt = decrypt = process
|
|
|
|
new = Arcfour
|
|
|
|
# test
|
|
if __name__ == '__main__':
|
|
import doctest
|
|
print('pdfminer.arcfour:', doctest.testmod())
|