Python基于DES算法加密解密实例

2020-01-04 18:07:44

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这篇文章主要介绍了Python基于DES算法加密解密实现方法,以实例形式分析了DES算法实现加密解密的相关技巧,需要的朋友可以参考下

本文实例讲述了Python基于DES算法加密解密实现方法。分享给大家供大家参考。具体实现方法如下：

#coding=utf-8

from functools import partial

import base64

class DES(object):

"""

DES加密算法

interface: input_key(s, base=10), encode(s), decode(s)

"""

__ip = [

58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,

62,54,46,38,30,22,14,6,64,56,48,40,32,24,16,8,

57,49,41,33,25,17, 9,1,59,51,43,35,27,19,11,3,

61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7,

]

__ip1 = [

40,8,48,16,56,24,64,32,39,7,47,15,55,23,63,31,

38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,

36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,

34,2,42,10,50,18,58,26,33,1,41, 9,49,17,57,25,

]

__e = [

32, 1, 2, 3, 4, 5,

4 , 5, 6, 7, 8, 9,

8 , 9,10,11,12,13,

12,13,14,15,16,17,

16,17,18,19,20,21,

20,21,22,23,24,25,

24,25,26,27,28,29,

28,29,30,31,32, 1,

]

__p = [

16, 7,20,21,29,12,28,17,

1 ,15,23,26, 5,18,31,10,

2 ,8 ,24,14,32,27, 3, 9,

19,13,30, 6,22,11, 4,25,

]

__s = [

[

0xe,0x4,0xd,0x1,0x2,0xf,0xb,0x8,0x3,0xa,0x6,0xc,0x5,0x9,0x0,0x7,

0x0,0xf,0x7,0x4,0xe,0x2,0xd,0x1,0xa,0x6,0xc,0xb,0x9,0x5,0x3,0x8,

0x4,0x1,0xe,0x8,0xd,0x6,0x2,0xb,0xf,0xc,0x9,0x7,0x3,0xa,0x5,0x0,

0xf,0xc,0x8,0x2,0x4,0x9,0x1,0x7,0x5,0xb,0x3,0xe,0xa,0x0,0x6,0xd,

],

[

0xf,0x1,0x8,0xe,0x6,0xb,0x3,0x4,0x9,0x7,0x2,0xd,0xc,0x0,0x5,0xa,

0x3,0xd,0x4,0x7,0xf,0x2,0x8,0xe,0xc,0x0,0x1,0xa,0x6,0x9,0xb,0x5,

0x0,0xe,0x7,0xb,0xa,0x4,0xd,0x1,0x5,0x8,0xc,0x6,0x9,0x3,0x2,0xf,

0xd,0x8,0xa,0x1,0x3,0xf,0x4,0x2,0xb,0x6,0x7,0xc,0x0,0x5,0xe,0x9,

],

[

0xa,0x0,0x9,0xe,0x6,0x3,0xf,0x5,0x1,0xd,0xc,0x7,0xb,0x4,0x2,0x8,

0xd,0x7,0x0,0x9,0x3,0x4,0x6,0xa,0x2,0x8,0x5,0xe,0xc,0xb,0xf,0x1,

0xd,0x6,0x4,0x9,0x8,0xf,0x3,0x0,0xb,0x1,0x2,0xc,0x5,0xa,0xe,0x7,

0x1,0xa,0xd,0x0,0x6,0x9,0x8,0x7,0x4,0xf,0xe,0x3,0xb,0x5,0x2,0xc,

],

[

0x7,0xd,0xe,0x3,0x0,0x6,0x9,0xa,0x1,0x2,0x8,0x5,0xb,0xc,0x4,0xf,

0xd,0x8,0xb,0x5,0x6,0xf,0x0,0x3,0x4,0x7,0x2,0xc,0x1,0xa,0xe,0x9,

0xa,0x6,0x9,0x0,0xc,0xb,0x7,0xd,0xf,0x1,0x3,0xe,0x5,0x2,0x8,0x4,

0x3,0xf,0x0,0x6,0xa,0x1,0xd,0x8,0x9,0x4,0x5,0xb,0xc,0x7,0x2,0xe,

],

[

0x2,0xc,0x4,0x1,0x7,0xa,0xb,0x6,0x8,0x5,0x3,0xf,0xd,0x0,0xe,0x9,

0xe,0xb,0x2,0xc,0x4,0x7,0xd,0x1,0x5,0x0,0xf,0xa,0x3,0x9,0x8,0x6,

0x4,0x2,0x1,0xb,0xa,0xd,0x7,0x8,0xf,0x9,0xc,0x5,0x6,0x3,0x0,0xe,

0xb,0x8,0xc,0x7,0x1,0xe,0x2,0xd,0x6,0xf,0x0,0x9,0xa,0x4,0x5,0x3,

],

[

0xc,0x1,0xa,0xf,0x9,0x2,0x6,0x8,0x0,0xd,0x3,0x4,0xe,0x7,0x5,0xb,

0xa,0xf,0x4,0x2,0x7,0xc,0x9,0x5,0x6,0x1,0xd,0xe,0x0,0xb,0x3,0x8,

0x9,0xe,0xf,0x5,0x2,0x8,0xc,0x3,0x7,0x0,0x4,0xa,0x1,0xd,0xb,0x6,

0x4,0x3,0x2,0xc,0x9,0x5,0xf,0xa,0xb,0xe,0x1,0x7,0x6,0x0,0x8,0xd,

],

[

0x4,0xb,0x2,0xe,0xf,0x0,0x8,0xd,0x3,0xc,0x9,0x7,0x5,0xa,0x6,0x1,

0xd,0x0,0xb,0x7,0x4,0x9,0x1,0xa,0xe,0x3,0x5,0xc,0x2,0xf,0x8,0x6,

0x1,0x4,0xb,0xd,0xc,0x3,0x7,0xe,0xa,0xf,0x6,0x8,0x0,0x5,0x9,0x2,

0x6,0xb,0xd,0x8,0x1,0x4,0xa,0x7,0x9,0x5,0x0,0xf,0xe,0x2,0x3,0xc,

],

[

0xd,0x2,0x8,0x4,0x6,0xf,0xb,0x1,0xa,0x9,0x3,0xe,0x5,0x0,0xc,0x7,

0x1,0xf,0xd,0x8,0xa,0x3,0x7,0x4,0xc,0x5,0x6,0xb,0x0,0xe,0x9,0x2,

0x7,0xb,0x4,0x1,0x9,0xc,0xe,0x2,0x0,0x6,0xa,0xd,0xf,0x3,0x5,0x8,

0x2,0x1,0xe,0x7,0x4,0xa,0x8,0xd,0xf,0xc,0x9,0x0,0x3,0x5,0x6,0xb,

],

]

__k1 = [

57,49,41,33,25,17, 9,

1 ,58,50,42,34,26,18,

10, 2,59,51,43,35,27,

19,11, 3,60,52,44,36,

63,55,47,39,31,23,15,

7 ,62,54,46,38,30,22,

14, 6,61,53,45,37,29,

21,13, 5,28,20,12, 4,

]

__k2 = [

14,17,11,24, 1, 5, 3,28,

15, 6,21,10,23,19,12, 4,

26, 8,16, 7,27,20,13, 2,

41,52,31,37,47,55,30,40,

51,45,33,48,44,49,39,56,

34,53,46,42,50,36,29,32,

]

__k0 = [

1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,

]

__hex_bin = {

'0':'0000','1':'0001','2':'0010','3':'0011',

'4':'0100','5':'0101','6':'0110','7':'0111',

'8':'1000','9':'1001','a':'1010','b':'1011',

'c':'1100','d':'1101','e':'1110','f':'1111',

' ':'0000'

}

__re = lambda t, s: ''.join(s[i-1] for i in t)

__IP = partial(__re, __ip)

__IP1 = partial(__re, __ip1)

__E = partial(__re, __e)

__P = partial(__re, __p)

__K1 = partial(__re, __k1)

__K2 = partial(__re, __k2)

__B = partial( lambda hex_bin, s: ''.join(hex_bin[w]

for w in ''.join('%2x' % ord(w) for w in s))

, __hex_bin)

__DB = partial( lambda s: ''.join(chr(int(s[i:i+8], 2)) for i in range(0, len(s), 8)))

__S = partial( lambda hex_bin, __s, s: ''.join(hex_bin['%x' % __s[i][

int(s[i*6]+s[i*6+5], 2)*16 + int(s[i*6+1:i*6+5], 2)]] for i in range(8))

, __hex_bin, __s)

__F = partial( lambda s, k: ''.join('0' if s[i]==k[i] else '1' for i in range(len(s))))

__K0 = partial( lambda k0, K2, k: map(K2,

(k[k0[i]:28]+k[0:k0[i]] + k[k0[i]+28:56]+k[28:k0[i]+28] for i in range(16)))

, __k0, __K2)

__K = partial( lambda K1, K0, k: K0(K1(k))

, __K1, __K0)

def __init__(self):

pass

def input_key(self, key, base=10):

if base == 2:

pass

elif base == 16:

key = ''.join(self.__class__.__hex_bin[w] for w in key)

else:

key = self.__class__.__B(key)

self.__k = self.__class__.__K(key)

def __code(self, s, k):

s = self.__IP(s)

l, r = s[0:32], s[32:64]

for i in range(16):

r_t = r

r = self.__E(r)

r = self.__F(r, k[i])

r = self.__S(r)

r = self.__P(r)

r = self.__F(r, l)

l = r_t

return self.__class__.__IP1(r+l)

def encode(self, s):

a = ''

s += ' ' * ((8-len(s)%8)%8)

for i in range(0, len(s), 8):

before = self.__class__.__B(s[i:i+8])

after = self.__code(before, self.__k)

a += '%16x' % int(after, 2)

return ''.join(w if w!=' ' else '0' for w in a)

def decode(self, s):

a = ''

s.lower()

for i in range(0, len(s), 16):

before = ''.join(self.__class__.__hex_bin[s[j]] for j in range(i, i+16))

after = self.__code(before, self.__k[::-1])

a += self.__class__.__DB(after)

return a.rstrip().decode('utf-8')

if __name__ == '__main__':

d = DES()

d.input_key('123456789')

s = '再来一段中文'

a = d.encode(s)

print a

b = d.decode(a)

print b