实现DES密码体制.doc

实验 1: 实现 DES 密码体制一、实验目的 1. 编写程序实现 DES 的加、解密: 1 )编程构造 DES 的密钥; 2 )应用上述获得的密钥将一段英文或文件进行加、解密。 DES 算法实现口令的安全二、实验内容#include <> #include <> typedef unsigned char bit; typedef unsigned char byte; // 初始置换表 IP byte IP_Table[64] ={ 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, 56,48,40,32,24,16,8,0, 58,50,42,34,26,18,10,2, 60,52,44,36,28,20,12,4, 62,54,46,38,30,22,14,6}; // 逆初始置换表 IP^-1 byte IP_1_Table[64] = {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, 32,0,40,8,48,16,56,24}; // 扩充置换表 E byte E_Table[48] = {31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8, 7, 8,9,10,11, 12, 11,12,13,14,15,16, 15,16,17,18,19,20, 19,20,21,22,23,24, 23,24,25,26,27,28, 27,28,29,30,31, 0}; // 置换选择 1 byte PC_1[56] = {56,48,40,32,24,16,8, 0,57,49,41,33,25,17, 9,1,58,50,42,34,26, 18,10,2,59,51,43,35, 62,54,46,38,30,22,14, 6,61,53,45,37,29,21, 13,5,60,52,44,36,28, 20,12,4,27,19,11,3}; // 置换选择 2 byte PC_2[48] = {13,16,10,23,0,4,2,27, 14,5,20,9,22,18,11,3, 25,7,15,6,26,19,12,1, 40,51,30,36,46,54,29,39, 50,44,32,47,43,48,38,55,/*change 46 yto 47 */ 33,52,45,41,49,35,28,31}; // 对左移次数的规定 byte MOVE_TIMES[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; //S 盒 byte S[8][4][16] =//S1 {{{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,