blob: 56ce5fb2fc24db514ecc1c225c7015f51302e771 [file] [log] [blame]
"""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)