Python

python实现DES加密

实现功能：加密中文等字符串,其中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
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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, 23, 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)
  1. des.py 加密文件
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#_*_ 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

  1. 解密文件
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#_*_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

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