apppublic/appPublic/rc4.py

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# -*- coding: utf-8 -*-
import random, base64
from hashlib import sha1
class RC4:
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def __init__(self,data_coding='utf8'):
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self.bcoding = 'iso-8859-1'
self.dcoding = data_coding
self.salt = b'AFUqx9WZuI32lnHk'
def _crypt(self,data,key):
"""RC4 algorithm return bytes"""
x = 0
box = [i for i in range(256) ]
for i in range(256):
x = (x + box[i] + key[i % len(key)]) % 256
box[i], box[x] = box[x], box[i]
x = y = 0
out = []
for char in data:
x = (x + 1) % 256
y = (y + box[x]) % 256
box[x], box[y] = box[y], box[x]
out.append(chr(char ^ box[(box[x] + box[y]) % 256]))
return ''.join(out).encode(self.bcoding)
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def encode_bytes(self, bdata, key):
a = sha1(key + self.salt)
k = a.digest()
data = self.salt + self._crypt(bdata, k)
return data
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def encode(self,data, key,encode=base64.b64encode, salt_length=16):
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"""RC4 encryption with random salt and final encoding"""
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if type(data)==type(''):
data = data.encode(self.dcoding)
key = key.encode(self.bcoding)
self.encode_bytes(data, key)
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if encode:
data = encode(data)
return data.decode(self.dcoding)
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def decode_bytes(self, data, key):
salt_length = 16
salt = data[:salt_length]
a = sha1(key + self.salt)
k = a.digest() #.decode('iso-8859-1')
r = self._crypt(data[salt_length:], k)
return r
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def decode(self,data, key,decode=base64.b64decode, salt_length=16):
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"""RC4 decryption of encoded data"""
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if type(data)==type(''):
data = data.encode(self.dcoding)
key = key.encode(self.bcoding)
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if decode:
data = decode(data)
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r = self.decode_bytes(data, key)
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return r.decode(self.dcoding)
if __name__=='__main__':
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# 需要加密的数据长度没有限制
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# 密钥
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data=b"231r3 feregrenerjk gkht324g8924gnfw k;ejkvwkjerv"
key = b'123456'
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rc4 = RC4()
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print(data)
# 加码
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encoded_data = rc4.encode_bytes(data,key)
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print(encoded_data,len(encoded_data) )
# 解码
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decoded_data = rc4.decode_bytes(encoded_data,key)
print(data, decoded_data, decoded_data==data)