/usr/share/pyshared/gdata/tlslite/utils/Python_RC4.py is in python-gdata 2.0.14-2.
This file is owned by root:root, with mode 0o644.
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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 | """Pure-Python RC4 implementation."""
from RC4 import RC4
from cryptomath import *
def new(key):
return Python_RC4(key)
class Python_RC4(RC4):
def __init__(self, key):
RC4.__init__(self, key, "python")
keyBytes = stringToBytes(key)
S = [i for i in range(256)]
j = 0
for i in range(256):
j = (j + S[i] + keyBytes[i % len(keyBytes)]) % 256
S[i], S[j] = S[j], S[i]
self.S = S
self.i = 0
self.j = 0
def encrypt(self, plaintext):
plaintextBytes = stringToBytes(plaintext)
S = self.S
i = self.i
j = self.j
for x in range(len(plaintextBytes)):
i = (i + 1) % 256
j = (j + S[i]) % 256
S[i], S[j] = S[j], S[i]
t = (S[i] + S[j]) % 256
plaintextBytes[x] ^= S[t]
self.i = i
self.j = j
return bytesToString(plaintextBytes)
def decrypt(self, ciphertext):
return self.encrypt(ciphertext)
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