# DES算法用C++实现的源代码

opend7y8 贡献于2012-12-24

﻿DES算法用C++实现的源代码   用C++实现的源代码 #include "memory.h" #include "stdio.h" enum  {encrypt,decrypt};//ENCRYPT:加密，DECRYPT：解密 void des_run(char out[8],char in[8],bool type=encrypt); //设置密钥 void des_setkey(const char key[8]); static void f_func(bool in[32],const bool ki[48]);//f函数 static void s_func(bool out[32],const bool in[48]);//s盒代替 //变换 static void transform(bool *out, bool *in, const char *table, int len); static void xor(bool *ina, const bool *inb, int len);//异或 static void rotatel(bool *in, int len, int loop);//循环左移  //字节组转换成位组 static void bytetobit(bool *out,const char *in, int bits); //位组转换成字节组 static void bittobyte(char *out, const bool *in, int bits); //置换IP表 conststatic char ip_table[64]={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}; //逆置换IP-1表 const static char ipr_table[64]={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 位选择表 static const char e_table[48]={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换位表 const static char p_table[32]={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}; //pc1选位表 const static char pc1_table[56]={                              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选位表 const static char pc2_table[48]={                                     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 }; //左移位数表 const static char loop_table[16]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; //S盒 const static char s_box[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, 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,        //s2        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,        //s3        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,        //s4        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,        //s5        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,        //s6        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,        //s7        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,        //s8        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 }; static bool subkey[16][48];//16圈子密钥 void des_run(char out[8],char in[8], bool type) {        static bool m[64],tmp[32],*li=&m[0], *ri=&m[32];        bytetobit(m,in,64);        transform(m,m,ip_table,64);        if(type==encrypt){               for(int i=0;i<16;i++){                      memcpy(tmp,ri,32);                      f_func(ri,subkey[i]);                      xor(ri,li,32);                      memcpy(li,tmp,32);               }        }else{               for(int i=15;i>=0;i--){                      memcpy(tmp,li,32);                      f_func(li,subkey[i]);                      xor(li,ri,32);                      memcpy(ri,tmp,32);               }        }        transform(m,m,ipr_table,64);        bittobyte(out,m,64); } void des_setkey(const char key[8]) {        static bool k[64], *kl=&k[0], *kr=&k[28];        bytetobit(k,key,64);        transform(k,k,pc1_table,56);        for(int i=0;i<16;i++)        {               rotatel(kl,28,loop_table[i]);               rotatel(kr,28,loop_table[i]);               transform(subkey[i],k,pc2_table,48);        } } void f_func(bool in[32],const bool ki[48]) {        static bool mr[48];        transform(mr,in,e_table,48);        xor(mr,ki,48);        s_func(in,mr);        transform(in,in,p_table,32); } void s_func(bool out[32],const bool in[48]) {        for(char i=0,j,k;i<8;i++,in+=6,out+=4)        {               j=(in[0]<<1)+in[5];               k=(in[1]<<3)+(in[2]<<2)+(in[3]<<1)+in[4];               bytetobit(out,&s_box[i][j][k],4);        } } void transform(bool *out,bool *in,const char *table,int len) {        static bool tmp[256];        for(int i=0;i>(i%8)) &1; } void bittobyte(char *out,const bool *in,int bits) {        memset(out,0,(bits+7)/8);        for(int i=0;i