Python中实现的RC4算法

yipeiwu_com5年前Python基础

闲暇之时,用Python实现了一下RC4算法

编码 UTF-8

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]))

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)

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)

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)

相关文章

python基础教程之实现石头剪刀布游戏示例

下面是规则.你和你的对手,在同一时间做出特定的手势,必须是下面一种手势:石头,剪子,布.胜利者从下面的规则中产生,这个规则本身是个悖论.(a) 布包石头.(b)石头砸剪子,(c)剪子剪破...

python绘制双Y轴折线图以及单Y轴双变量柱状图的实例

python绘制双Y轴折线图以及单Y轴双变量柱状图的实例

近来实验室的师姐要发论文,由于论文交稿时间临近,有一些杂活儿需要处理,作为实验室资历最浅的一批,我这个实习生也就责无旁贷地帮忙当个下手。今天师姐派了一个小活,具体要求是: 给一些训练模型...

python利用高阶函数实现剪枝函数

本文为大家分享了python利用高阶函数实现剪枝函数的具体代码,供大家参考,具体内容如下 案例:        某些时候,我们...

Python查询Mysql时返回字典结构的代码

MySQLdb默认查询结果都是返回tuple,输出时候不是很方便,必须按照0,1这样读取,无意中在网上找到简单的修改方法,就是传递一个cursors.DictCursor就行。 默认程序...

PyCharm导入python项目并配置虚拟环境的教程详解

PyCharm导入python项目并配置虚拟环境的教程详解

进入PyCharm后,点击File→Open,然后在弹窗中选择需要导入项目的文件夹; 打开了python项目后,需要配置该项目对应的python才可以正常运行; 配置步骤:File→...