python实现DES加密解密方法实例详解_编程语言综合--HTML5中文学习网

　　本文实例讲述了python实现DES加密解密方法。分享给大家供大家参考。具体分析如下：

　　实现功能：加密中文等字符串

　　密钥与明文可以不等长

　　这里只贴代码，加密过程可以自己百度，此处python代码没有优化

　　1. desstruct.py DES加密中要使用的结构体

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)

ip_1=(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=[ [[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],

[0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],

[4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],

[15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]],

[[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],

[3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],

[0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],

[13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]],

[[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],

[13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],

[13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],

[1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]],

[[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],

[13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14,9],

[10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],

[3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]],

[[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],

[14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],

[4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],

[11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]],

[[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],

[10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],

[9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],

[4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]],

[[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],

[13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],

[1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],

[6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]],

[[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],

[1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],

[7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],

[2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]]]

pc1=(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, 33, 15,

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

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

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

pc2= (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)

d = ( 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1)

　　2. des.py 加密文件

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

#_*_ coding:utf-8 _*_

#!/usr/bin/env python

#Filename:des.py

from desstruct import *

import re

__all__=['desencode']

class DES():

'''des 加密'''

def __init__(self):

pass

#加密

def code(self,from_code,key,code_len,key_len):

output=""

trun_len=0

#将密文和密钥转换为二进制

code_string=self._functionCharToA(from_code,code_len)

code_key=self._functionCharToA(key,key_len)

#如果密钥长度不是16的整数倍则以增加0的方式变为16的整数倍

if code_len%16!=0:

real_len=(code_len/16)*16+16

else:

real_len=code_len

if key_len%16!=0:

key_len=(key_len/16)*16+16

key_len*=4

#每个16进制占4位

trun_len=4*real_len

#对每64位进行一次加密

for i in range(0,trun_len,64):

run_code=code_string[i:i+64]

l=i%key_len

run_key=code_key[l:l+64]

#64位明文、密钥初始置换

run_code= self._codefirstchange(run_code)

run_key= self._keyfirstchange(run_key)

#16次迭代

for j in range(16):

#取出明文左右32位

code_r=run_code[32:64]

code_l=run_code[0:32]

#64左右交换

run_code=code_r

#右边32位扩展置换

code_r= self._functionE(code_r)

#获取本轮子密钥

key_l=run_key[0:28]

key_r=run_key[28:56]

key_l=key_l[d[j]:28]+key_l[0:d[j]]

key_r=key_r[d[j]:28]+key_r[0:d[j]]

run_key=key_l+key_r

key_y= self._functionKeySecondChange(run_key)

#异或

code_r= self._codeyihuo(code_r,key_y)

#S盒代替/选择

code_r= self._functionS(code_r)

#P转换

code_r= self._functionP(code_r)

#异或

code_r= self._codeyihuo(code_l,code_r)

run_code+=code_r

#32互换

code_r=run_code[32:64]

code_l=run_code[0:32]

run_code=code_r+code_l

#将二进制转换为16进制、逆初始置换

output+=self._functionCodeChange(run_code)

return output

#异或

def _codeyihuo(self,code,key):

code_len=len(key)

return_list=''

for i in range(code_len):

if code[i]==key[i]:

return_list+='0'

else:

return_list+='1'

return return_list

#密文或明文初始置换

def _codefirstchange(self,code):

changed_code=''

for i in range(64):

changed_code+=code[ip[i]-1]

return changed_code

#密钥初始置换

def _keyfirstchange (self,key):

changed_key=''

for i in range(56):

changed_key+=key[pc1[i]-1]

return changed_key

#逆初始置换

def _functionCodeChange(self, code):

lens=len(code)/4

return_list=''

for i in range(lens):

list=''

for j in range(4):

list+=code[ip_1[i*4+j]-1]

return_list+="%x" %int(list,2)

return return_list

#扩展置换

def _functionE(self,code):

return_list=''

for i in range(48):

return_list+=code[e[i]-1]

return return_list

#置换P

def _functionP(self,code):

return_list=''

for i in range(32):

return_list+=code[p[i]-1]

return return_list

#S盒代替选择置换

def _functionS(self, key):

return_list=''

for i in range(8):

row=int( str(key[i*6])+str(key[i*6+5]),2)

raw=int(str( key[i*6+1])+str(key[i*6+2])+str(key[i*6+3])+str(key[i*6+4]),2)

return_list+=self._functionTos(s[i][row][raw],4)

return return_list

#密钥置换选择2

def _functionKeySecondChange(self,key):

return_list=''

for i in range(48):

return_list+=key[pc2[i]-1]

return return_list

#将十六进制转换为二进制字符串

def _functionCharToA(self,code,lens):

return_code=''

lens=lens%16

for key in code:

code_ord=int(key,16)

return_code+=self._functionTos(code_ord,4)

if lens!=0:

return_code+='0'*(16-lens)*4

return return_code

#二进制转换

def _functionTos(self,o,lens):

return_code=''

for i in range(lens):

return_code=str(o>>i &1)+return_code

return return_code

#将unicode字符转换为16进制

def tohex(string):

return_string=''

for i in string:

return_string+="%02x"%ord(i)

return return_string

def tounicode(string):

return_string=''

string_len=len(string)

for i in range(0,string_len,2):

return_string+=chr(int(string[i:i+2],16))

return return_string

#入口函数

def desencode(from_code,key):

#转换为16进制

from_code=tohex(from_code)

key=tohex(key)

des=DES()

key_len=len(key)

string_len=len(from_code)

if string_len<1 or key_len<1:

print 'error input'

return False

key_code= des.code(from_code,key,string_len,key_len)

return key_code

#测试

if __name__ == '__main__':

print desencode('我是12345678刘就是我abcdwfd','0f1571c947刘')

#返回密文为: 84148584371a6a1fe99e1da0ce1e34649b88ed15098e8aa4b8eb0bf24885c658

　　3. 解密文件

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

#_*_coding:utf-8_*_

#!/usr/bin/env python

#Filename:des.py

from desstruct import *

import re

__all__=['desdecode']

class DES():

'''解密函数，DES加密与解密的方法相差不大

只是在解密的时候所用的子密钥与加密的子密钥相反

'''

def __init__(self):

pass

def decode(self,string,key,key_len,string_len):

output=""

trun_len=0

num=0

#将密文转换为二进制

code_string=self._functionCharToA(string,string_len)

#获取字密钥

code_key=self._getkey(key,key_len)

#如果密钥长度不是16的整数倍则以增加0的方式变为16的整数倍

real_len=(key_len/16)+1 if key_len%16!=0 else key_len/16

trun_len=string_len*4

#对每64位进行一次加密

for i in range(0,trun_len,64):

run_code=code_string[i:i+64]

run_key=code_key[num%real_len]

#64位明文初始置换

run_code= self._codefirstchange(run_code)

#16次迭代

for j in range(16):

code_r=run_code[32:64]

code_l=run_code[0:32]

#64左右交换

run_code=code_r

#右边32位扩展置换

code_r= self._functionE(code_r)

#获取本轮子密钥

key_y=run_key[15-j]

#异或

code_r= self._codeyihuo(code_r,key_y)

#S盒代替/选择

code_r= self._functionS(code_r)

#P转换

code_r= self._functionP(code_r)

#异或

code_r= self._codeyihuo(code_l,code_r)

run_code+=code_r

num+=1

#32互换

code_r=run_code[32:64]

code_l=run_code[0:32]

run_code=code_r+code_l

#将二进制转换为16进制、逆初始置换

output+=self._functionCodeChange(run_code)

return output

#获取子密钥

def _getkey(self,key,key_len):

#将密钥转换为二进制

code_key=self._functionCharToA(key,key_len)

a=['']*16

real_len=(key_len/16)*16+16 if key_len%16!=0 else key_len

b=['']*(real_len/16)

for i in range(real_len/16):

b[i]=a[:]

num=0

trun_len=4*key_len

for i in range(0,trun_len,64):

run_key=code_key[i:i+64]

run_key= self._keyfirstchange(run_key)

for j in range(16):

key_l=run_key[0:28]

key_r=run_key[28:56]

key_l=key_l[d[j]:28]+key_l[0:d[j]]

key_r=key_r[d[j]:28]+key_r[0:d[j]]

run_key=key_l+key_r

key_y= self._functionKeySecondChange(run_key)

b[num][j]=key_y[:]

num+=1

return b

#异或

def _codeyihuo(self,code,key):

code_len=len(key)

return_list=''

for i in range(code_len):

if code[i]==key[i]:

return_list+='0'

else:

return_list+='1'

return return_list

#密文或明文初始置换

def _codefirstchange(self,code):

changed_code=''

for i in range(64):

changed_code+=code[ip[i]-1]

return changed_code

#密钥初始置换

def _keyfirstchange (self,key):

changed_key=''

for i in range(56):

changed_key+=key[pc1[i]-1]

return changed_key

#逆初始置换

def _functionCodeChange(self, code):

return_list=''

for i in range(16):

list=''

for j in range(4):

list+=code[ip_1[i*4+j]-1]

return_list+="%x" %int(list,2)

return return_list

#扩展置换

def _functionE(self,code):

return_list=''

for i in range(48):

return_list+=code[e[i]-1]

return return_list

#置换P

def _functionP(self,code):

return_list=''

for i in range(32):

return_list+=code[p[i]-1]

return return_list

#S盒代替选择置换

def _functionS(self, key):

return_list=''

for i in range(8):

row=int( str(key[i*6])+str(key[i*6+5]),2)

raw=int(str( key[i*6+1])+str(key[i*6+2])+str(key[i*6+3])+str(key[i*6+4]),2)

return_list+=self._functionTos(s[i][row][raw],4)

return return_list

#密钥置换选择2

def _functionKeySecondChange(self,key):

return_list=''

for i in range(48):

return_list+=key[pc2[i]-1]

return return_list

#将十六进制转换为二进制字符串

def _functionCharToA(self,code,lens):

return_code=''

lens=lens%16

for key in code:

code_ord=int(key,16)

return_code+=self._functionTos(code_ord,4)

if lens!=0:

return_code+='0'*(16-lens)*4

return return_code

#二进制转换

def _functionTos(self,o,lens):

return_code=''

for i in range(lens):

return_code=str(o>>i &1)+return_code

return return_code

#将unicode字符转换为16进制

def tohex(string):

return_string=''

for i in string:

return_string+="%02x"%ord(i)

return return_string

def tounicode(string):

return_string=''

string_len=len(string)

for i in range(0,string_len,2):

return_string+=chr(int(string[i:i+2],16))

return return_string

#入口函数

def desdecode(from_code,key):

key=tohex(key)

des=DES()

key_len=len(key)

string_len=len(from_code)

if string_len%16!=0:

return False

if string_len<1 or key_len<1:

return False

key_code= des.decode(from_code,key,key_len,string_len)

return tounicode(key_code)

#测试

if __name__ == '__main__':

print desdecode('84148584371a6a1fe99e1da0ce1e34649b88ed15098e8aa4b8eb0bf24885c658','0f1571c947刘'

　　解密后为: 我是12345678刘就是我abcdwfd

　　希望本文所述对大家的Python程序设计有所帮助。