Python中实现的RC4算法

闲暇之时，用Python实现了一下RC4算法

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class 方式

#/usr/bin/python #coding=utf-8 import sys,os,hashlib,time,base64 class rc4: def __init__(self,public_key = None,ckey_lenth = 16): self.ckey_lenth = ckey_lenth self.public_key = public_key or 'none_public_key' key = hashlib.md5(self.public_key).hexdigest() self.keya = hashlib.md5(key[0:16]).hexdigest() self.keyb = hashlib.md5(key[16:32]).hexdigest() self.keyc = '' def encode(self,string): self.keyc = hashlib.md5(str(time.time())).hexdigest()[32 - self.ckey_lenth:32] string = '0000000000' + hashlib.md5(string + self.keyb).hexdigest()[0:16] + string self.result = '' self.docrypt(string) return self.keyc + base64.b64encode(self.result) def decode(self,string): self.keyc = string[0:self.ckey_lenth] string = base64.b64decode(string[self.ckey_lenth:]) self.result = '' self.docrypt(string) result = self.result if (result[0:10] == '0000000000' or int(result[0:10]) - int(time.time()) > 0) and result[10:26] == hashlib.md5(result[26:] + self.keyb).hexdigest()[0:16]: return result[26:] else: return None def docrypt(self,string): string_lenth = len(string) result = '' box = list(range(256)) randkey = [] cryptkey = self.keya + hashlib.md5(self.keya + self.keyc).hexdigest() key_lenth = len(cryptkey) for i in xrange(255): randkey.append(ord(cryptkey[i % key_lenth])) for i in xrange(255): j = 0 j = (j + box[i] + randkey[i]) % 256 tmp = box[i] box[i] = box[j] box[j] = tmp for i in xrange(string_lenth): a = j = 0 a = (a + 1) % 256 j = (j + box[a]) % 256 tmp = box[a] box[a] = box[j] box[j] = tmp self.result += chr(ord(string[i]) ^ (box[(box[a] + box[j]) % 256])) 登录后复制

测试：

rc = rc4('nishidahuaidan') string = '我在这里呢，你在那里呢' print(string) str = rc.encode(string) print(str) str = rc.decode(str) print(str) 登录后复制

function方式

#/usr/bin/python #coding=utf-8 import sys,os,hashlib,time,base64 def rc4(string, op = 'encode', public_key = 'ddd', expirytime = 0): ckey_lenth = 4 public_key = public_key and public_key or '' key = hashlib.md5(public_key).hexdigest() keya = hashlib.md5(key[0:16]).hexdigest() keyb = hashlib.md5(key[16:32]).hexdigest() keyc = ckey_lenth and (op == 'decode' and string[0:ckey_lenth] or hashlib.md5(str(time.time())).hexdigest()[32 - ckey_lenth:32]) or '' cryptkey = keya + hashlib.md5(keya + keyc).hexdigest() key_lenth = len(cryptkey) string = op == 'decode' and base64.b64decode(string[4:]) or '0000000000' + hashlib.md5(string + keyb).hexdigest()[0:16] + string string_lenth = len(string) result = '' box = list(range(256)) randkey = [] for i in xrange(255): randkey.append(ord(cryptkey[i % key_lenth])) for i in xrange(255): j = 0 j = (j + box[i] + randkey[i]) % 256 tmp = box[i] box[i] = box[j] box[j] = tmp for i in xrange(string_lenth): a = j = 0 a = (a + 1) % 256 j = (j + box[a]) % 256 tmp = box[a] box[a] = box[j] box[j] = tmp result += chr(ord(string[i]) ^ (box[(box[a] + box[j]) % 256])) if op == 'decode': if (result[0:10] == '0000000000' or int(result[0:10]) - int(time.time()) > 0) and result[10:26] == hashlib.md5(result[26:] + keyb).hexdigest()[0:16]: return result[26:] else: return None else: return keyc + base64.b64encode(result) 登录后复制

测试：

string = '我在这里呢，你在那里呢' print(string) str = rc4(string,'encode') print(str) rc = rc4(str,'decode') print(rc) 登录后复制