Python encryption and decryption instance based on DES algorithm

This article describes the Python based on DES algorithm encryption and decryption implementation method. Share to everyone for your reference. The implementation methods are as follows:

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26-27--28 29---30 31--32 33 34 35 36 37 38-39 40 41 42 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 5, 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 11 9 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148-149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179-18 0

#coding =utf-8 from functools import partial Import Base64 Class des (object): "" DES encryption algorithm 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,0x8,0x 3,0xa,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, 41,52,31,37,47,55,30,4 0, 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 (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 '. Join ('%2x '% ord (W) ) for W-s), __hex_bin) __db = partial (lambda s: '. Join (Chr (int (s[i:i+8), 2)) for I in range (0, Len (s), 8)) __s = P Artial (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 = P Artial (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, b ASE=10): if base = = 2:pass Elif Base = = 16:key = '. Join (Self.__class__.__hex_bin[w] for W key) Else:key = Self.__cl Ass__.__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: 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 ret Urn 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.__kA = = '%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)): Before = '. Join (Self.__class__.__hex_bin[s[j]] to J in range (I, i+16)) after = Self.__code (befo Re, self.__k[::-1]) A + + self.__class__.__db return A.rstrip (). Decode (' Utf-8 ') if __name__ = = ' __main__ ': D = DES () D.input_key (' 123456789 ') s = ' another Chinese ' a = D.encode (s) print a b = D.decode (a) Print B

I hope this article will help you with your Python programming.