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DES的C语言实现

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DES的C语言实现#include<stdio.h>Intasciim[8],m_16[16],m[64],asciik[8],k_16[16],k[64],m_ip[64],l[32],r[32],k_pc1[56],c[28],d[28],cd[5 6],k_pc2[48],re[48],sh[32],tempr[32],m0[64],m00[64],res[8];int type;int ip[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};int ip_1[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};int pc_1[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};int pc_2[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};int exe[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};int p[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};int s[8][4][16]={{{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}}};int print(int *jg,int a,int b)// 输出函数，第一个参数是要输出的数组，第二个参数数组的长度，第三个参数是每行数的个数{int i;for(i=0;i<a;i++){if(i%b==0){printf("\n");}printf("%d",jg[i]);}return 1;}int ascii_to_erjinzhi(int *ascii,int *jg)//这是将8位的ascii矩阵转换成为64位二进制的jg矩阵{int i,j,tempb;for(i=0,j=7;i<8;i++){tempb=(int) ascii[i];while(tempb>1){jg[j]=(int) (tempb%2);tempb=(int) (tempb/2);j--;}switch(tempb){case 0:jg[j]=0;break;case 1:jg[j]=1;break;}while(j%8!=0){j--;jg[j]=0;}j=(i+1)*8+7;}return 1;}int input_16(int *ja,int *jb,int *jc)//以16进制的形式输入，ja是16进制的矩阵，jb是16进制矩阵转换成8位的十进制矩阵，//jc是再将它转换成64位的二进制矩阵{int i,j;for(i=0;i<16;i++){ja[i]=getchar();if(ja[i]==' '||ja[i]=='\n'){i--;}}for(i=0;i<16;i++){if(i%2==0&&i!=0){printf("H ");}printf("%c",ja[i]);}for(i=0;i<16;i++){if(ja[i]<='9'){ja[i]=ja[i]-48;}else if(ja[i]>='A'&&ja[i]<='F'){ja[i]=ja[i]-55;}else{ja[i]=ja[i]-87;}}for(i=0,j=0;i<8;i++,j=j+2){jb[i]=ja[j]*16+ja[j+1];}ascii_to_erjinzhi(jb,jc);//printf("\n二进制表示是:");//print(jc,64,8);return 1;}int shuziinput(int *ja,int *jb)//以ascii码的数字的形式输入{int i;for(i=0;i<8;i++){scanf("%d",&ja[i]);}ascii_to_erjinzhi(ja,jb);return 1;}int zifuinput(int *ja,int *jb)//以ascii码的字符形式输入{int i;for(i=0;i<8;i++){ja[i]=getchar();if(ja[i]==' '||ja[i]=='\n')//如果没有换行符在密钥输入的时候密钥初始值就是10{ //如果写的是换行时break是那么密钥不能输入，直接出结果。

如果先调用密钥输入明文直接出结果i--;}else{continue;}}for(i=0;i<8;i++){printf("%d ",ja[i]);}ascii_to_erjinzhi(ja,jb);// printf("\n二进制表示是:");// print(jb,64,8);getchar();return 1;}int input(int signal)//输入明文或者密文函数{printf("请选择输入方式(ASCII码字符形式输入1，ASCII码数字形式输入2，十六进制形式输入3)");scanf("%d",&type);if(signal==1){printf("请输入明文:\n");}else if(signal==2){printf("请输入密文:\n");}if(type==1){zifuinput(asciim,m);}else if(type==2){shuziinput(asciim,m);//printf("chenggong");}else{input_16(m_16,asciim,m);}return 1;}int miyaoinput()//密钥的输入{printf("\n请输入密钥:\n");if(type==1){zifuinput(asciik,k);}else if(type==2){shuziinput(asciik,k);}else{input_16(k_16,asciik,k);}return 1;}int ipzhihuan()//IP置换{int i,j;for(i=0;i<64;i++){j=(ip[i]-1);m_ip[i]=m[j];}// printf("\nIP置换后:");// print(m_ip,64,8);return 1;}int ipnizhihuan()//IP逆置换{int i,j;//print(m0,64,8);for(i=0;i<64;i++){j=(ip_1[i]-1);m00[i]=m0[j];}// printf("\n nizhihuanhou\n");// print(m00,64,8);return 1;}int pc1zhihuan()//PC1置换{int i,j;for(i=0;i<56;i++){j=(pc_1[i]-1);k_pc1[i]=k[j];}// printf("\npc_1置换后的结果是:"); // print(k_pc1,56,7);return 1;}int pc2zhihuan(int *ja,int *jb)//PC2置换{int i,j;for(i=0;i<48;i++){j=(pc_2[i]-1);jb[i]=ja[j];}// printf("\npc_2置换后的结果是:"); // print(jb,48,6);return 1;}int pzhihuan(int *ja,int *jb)//P置换{int i,j;for(i=0;i<32;i++){j=(p[i]-1);jb[i]=ja[j];}//printf("\np置换后的结果是:"); // print(jb,32,8);return 1;}int initlr(int *ja)//初始化l和r{int i;for(i=0;i<32;i++){l[i]=ja[i];}for(i=32;i<64;i++){r[i-32]=ja[i];}//printf("\nl是:");// print(l,32,8);// printf("\nr是:");// print(r,32,8);return 1;}int initcd(int *ja)//初始化C D{int i;for(i=0;i<28;i++){c[i]=ja[i];}for(i=28;i<56;i++){d[i-28]=ja[i];}//printf("\nc是:");/////print(c,28,7);//printf("\nd是:");//print(d,28,7);return 1;}int zuoyi1(int *ja)//以下都是左移{int i,temp[28];//printf("\n左移一位前的结果:"); // print(ja,28,7);temp[27]=ja[0];for(i=1;i<28;i++){temp[i-1]=ja[i];}for(i=0;i<28;i++){ja[i]=temp[i];}//printf("\n左移一位后的结果:"); // print(ja,28,7);return 1;}int youyi1(int *ja){int i,temp[28];//printf("\n右移一位之前:\n");//print(ja,28,7);temp[0]=ja[27];for(i=1;i<28;i++){temp[i]=ja[i-1];}for(i=0;i<28;i++){ja[i]=temp[i];}//printf("\n右移一位后的结果:");//print(ja,28,7);return 1;}int zuoyi2(int *ja){int i,temp[28];//printf("\n左移两位前的结果:");//print(ja,28,7);temp[26]=ja[0];temp[27]=ja[1];for(i=0;i<26;i++){temp[i]=ja[i+2];}for(i=0;i<28;i++){ja[i]=temp[i];}//printf("\n左移两位后的结果:");//print(ja,28,7);return 1;}int youyi2(int *ja){int i,temp[28];//printf("\n右移两位前的结果:");//print(ja,28,7);temp[0]=ja[26];temp[1]=ja[27];for(i=2;i<28;i++){temp[i]=ja[i-2];}for(i=0;i<28;i++){ja[i]=temp[i];}//printf("\n右移两位后的结果:");//print(ja,28,7);return 1;}int exetent(int *ja,int *jb)//E膨胀{int i,k;for(i=0;i<48;i++){k=(exe[i]-1);jb[i]=ja[k];}// printf("\nE膨胀后的结果是:");//print(jb,48,6);return 1;}int yihuo48(int *ja,int *jb)//48位异或{int i;for(i=0;i<48;i++){ja[i]=(ja[i]^jb[i]);}// printf("\n异或后的结果是:");//print(ja,48,6);return 1;}int yihuo32(int *ja,int *jb){int i;for(i=0;i<32;i++){ja[i]=(ja[i]^jb[i]);}// printf("\n异或后的结果是:");//print(ja,32,8);return 1;}int shzhihuan(int *ja,int *jb)//S盒置换{int i,j,a,b,temp;for(j=0;j<8;j++){i=j*6;a=ja[i]*2+ja[i+5]*1;b=ja[i+1]*8+ja[i+2]*4+ja[i+3]*2+ja[i+4]*1;temp=s[j][a][b];i=j*4+3;while(temp>1){jb[i]=(int) (temp%2);temp=(int) (temp/2);i--;}switch(temp){case 0:jb[i]=0;break;case 1:jb[i]=1;break;}while(i%4!=0){i--;jb[i]=0;}}//printf("\n经过s盒置换后结果是:");//print(jb,32,8);return 1;}int zuhecd(int *ja,int *jb)//将C D组合{int i;for(i=0;i<28;i++){cd[i]=ja[i];cd[i+28]=jb[i];}//print(cd,56,7);return 1;}int zhuanhuan(int *ja,int *jb)//将32位的jb赋值给ja {int i;for(i=0;i<32;i++){ja[i]=jb[i];}return 1;}int zuhe64(int *ja,int *jb,int *jc){int i;for(i=0;i<32;i++){jc[i]=ja[i];jc[i+32]=jb[i];}return 1;}int erjinzhi_to_ascii(int *jz,int *jg)//二进制转换成ASCII码{int i,j;for(i=0;i<8;i++){j=i*8;jg[i]=(jz[j]*128+jz[j+1]*64+jz[j+2]*32+jz[j+3]*16+jz[j+4]*8+jz[j+5]*4+jz[j+6]*2+jz[j+7]*1);}return 1;}int main(){int i,signal;printf("DES 加密与解密\t (加密输入1，解密输入2)\n");scanf("%d",&signal);input(signal);miyaoinput();ipzhihuan();initlr(m_ip);pc1zhihuan();initcd(k_pc1);for(i=0;i<16;i++){if(i>0){initcd(cd);}if(signal==1){if(i==0||i==1||i==8||i==15){zuoyi1(c);zuoyi1(d);}else{zuoyi2(c);zuoyi2(d);}}else if(signal==2){if(i==1||i==8||i==15){youyi1(c);youyi1(d);}else if(i==0){zuhecd(c,d);pc2zhihuan(cd,k_pc2);zhuanhuan(tempr,r);exetent(r,re);yihuo48(re,k_pc2);shzhihuan(re,sh);pzhihuan(sh,r);yihuo32(r,l);zhuanhuan(l,tempr);continue;}else{youyi2(c);youyi2(d);}}zuhecd(c,d);pc2zhihuan(cd,k_pc2);zhuanhuan(tempr,r);exetent(r,re);yihuo48(re,k_pc2);shzhihuan(re,sh);pzhihuan(sh,r);yihuo32(r,l);zhuanhuan(l,tempr);}zhuanhuan(tempr,l);zhuanhuan(l,r);zhuanhuan(r,tempr);zuhe64(l,r,m0);ipnizhihuan();erjinzhi_to_ascii(m00,res);printf("\n结果是:\n");for(i=0;i<8;i++){printf("%d ",res[i]);}printf("\n");for(i=0;i<8;i++){printf("%c ",res[i]);} Retern 1;。

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DES算法的C语言实现

DES算法的C语言实现

DES算法的C语⾔实现利⽤C语⾔实现DES算法，分组密码原理过程很简单，但是在写的过程中检查了好久才发现错误原因，主要有两点：1.在加密过程16轮迭代过程中，最后⼀轮迭代运算后的结果并没有进⾏交换，即C=IP-1（R16，L16），这样做的⽬的是为了加密解密使⽤同⼀个算法2.在S盒的过程中，移位后应该加括号，否则+的优先级⾼于<<,会出错，下⾯是算法源码：1 #include "des.h"2 #include <stdio.h>3 #include <stdlib.h>45const unsigned char IP_table[64] = {658, 50, 42, 34, 26, 18, 10, 2,760, 52, 44, 36, 28, 20, 12, 4,862, 54, 46, 38, 30, 22, 14, 6,964, 56, 48, 40, 32, 24, 16, 8,1057, 49, 41, 33, 25, 17, 9, 1,1159, 51, 43, 35, 27, 19, 11, 3,1261, 53, 45, 37, 29, 21, 13, 5,1363, 55, 47, 39, 31, 23, 15, 714 };1516const unsigned char IPR_table[64] = {1740, 8, 48, 16, 56, 24, 64, 32,1839, 7, 47, 15, 55, 23, 63, 31,1938, 6, 46, 14, 54, 22, 62, 30,2037, 5, 45, 13, 53, 21, 61, 29,2136, 4, 44, 12, 52, 20, 60, 28,2235, 3, 43, 11, 51, 19, 59, 27,2334, 2, 42, 10, 50, 18, 58, 26,2433, 1, 41, 9, 49, 17, 57, 2525 };2627const unsigned char E_table[48] = {2832, 1, 2, 3, 4, 5,294, 5, 6, 7, 8, 9,308, 9, 10, 11, 12, 13,3112, 13, 14, 15, 16, 17,3216, 17, 18, 19, 20, 21,3320, 21, 22, 23, 24, 25,3424, 25, 26, 27, 28, 29,3528, 29, 30, 31, 32, 136 };3738const unsigned char P_table[32] = {3916, 7, 20, 21, 29, 12, 28, 17,401, 15, 23, 26, 5, 18, 31, 10,412, 8, 24, 14, 32, 27, 3, 9,4219, 13, 30, 6, 22, 11, 4, 2543 };4445const unsigned char PC1_table[56] = {4657, 49, 41, 33, 25, 17, 9,471, 58, 50, 42, 34, 26, 18,4810, 2, 59, 51, 43, 35, 27,4919, 11, 3, 60, 52, 44, 36,5063, 55, 47, 39, 31, 23, 15,517, 62, 54, 46, 38, 30, 22,5214, 6, 61, 53, 45, 37, 29,5321, 13, 5, 28, 20, 12, 454 };5556const unsigned char LOOP_table[16] = {571, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 158 };5960const unsigned char PC2_table[48] = {6114, 17, 11, 24, 1, 5,623, 28, 15, 6, 21, 10,6323, 19, 12, 4, 26, 8,6416, 7, 27, 20, 13, 2,6541, 52, 31, 37, 47, 55,6630, 40, 51, 45, 33, 48,6744, 49, 39, 56, 34, 53,6846, 42, 50, 36, 29, 3269 };7071const unsigned char sbox[8][4][16] = {72// S17314, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,740, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,754, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,7615, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13,77//S27815, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,793, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,800, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,8113, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9,82//S38310, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,8413, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,8513, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,861, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12,87//S4887, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,8913, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,9010, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,913, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14,92//S5932, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,9414, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,954, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,9611, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3,97//S69812, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,9910, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,1009, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,1014, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13,102//S71034, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,10413, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,1051, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,1066, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12,107//S810813, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,1091, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,1107, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,1112, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11112 };113114void ByteToBit(unsigned char* out, const unsigned char* in, const int bits){115for(int i=0;i<bits;i++)116out[i]=(in[i/8]>>(7-i%8))&1;117 }118119void BitToByte(unsigned char* out, const unsigned char* in, const int bits){120 memset(out, 0, (bits + 7) / 8);121for(int i=0;i<bits;i++)122out[i/8]|=in[i]<<(7-i%8);123 }124125void Transform(unsigned char* out,const unsigned char* in, const unsigned char* table, const int len){ 126 unsigned char tmp[64] = {0};127for (int i = 0; i < len; i++)128 tmp[i] = in[table[i] - 1];129 memcpy(out, tmp, len);130 }131132void RotateL(unsigned char* in, const int len, int loop){133static unsigned char tmp[64];134 memcpy(tmp, in, len);135 memcpy(in, in + loop, len - loop);136 memcpy(in + len - loop, tmp, loop);137 }138139static unsigned char subKey[16][48] = { 0 };140void setKey(const unsigned char* in){141char key[64] = { 0 };142 ByteToBit(key, in, 64);143char temp[56]={0};144 Transform(temp, key, PC1_table, 56);145for(int i=0;i<16;i++){146 RotateL(temp, 28, LOOP_table[i]);147 RotateL(temp + 28, 28, LOOP_table[i]);148 Transform(subKey[i], temp, PC2_table, 48);149 }150 }151152void xor(unsigned char* in1,const unsigned char* in2,int len){153for(int i=0;i<len;i++)154 in1[i]^=in2[i];155 }156157void sbox_exchange(unsigned char* out,const unsigned char* in){158char row, column;159for (int i = 0; i < 8; i++){160char num = 0;161 row = (in[6 * i]<<1)+ in[6 * i + 5];162 column = (in[6 * i + 1] << 3) + (in[6 * i + 2] << 2) + (in[6 * i + 3] << 1) + in[6 * i + 4]; 163 num = sbox[i][row][column];164for (int j = 0; j < 4; j++)165 {166out[4 * i + j] = (num >> (3 - j)) & 1;167 }168 }169 }170171void F_func(unsigned char* out,const unsigned char* in,unsigned char* subKey){172 unsigned char temp[48]={0};173 unsigned char res[32]={0};174 Transform(temp, in, E_table, 48);175 xor(temp,subKey,48);176 sbox_exchange(res,temp);177 Transform(out, res, P_table, 32);178 }179180void encryptDES(unsigned char* out,const unsigned char* in, const unsigned char* key){ 181 unsigned char input[64] = { 0 };182 unsigned char output[64] = { 0 };183 unsigned char tmp[64] = { 0 };184 ByteToBit(input, in, 64);185 Transform(tmp, input, IP_table, 64);186char* Li = &tmp[0], *Ri = &tmp[32];187 setKey(key);188for(int i=0;i<16;i++){189char temp[32]={0};190 memcpy(temp,Ri,32);191 F_func(Ri, Ri,subKey[i]);192 xor(Ri, Li, 32);193 memcpy(Li,temp,32);194 }195 RotateL(tmp, 64, 32);//the input is LR,output is RL196 Transform(output, tmp, IPR_table, 64);197 BitToByte(out, output,64);198 }199200void decryptDES(unsigned char* out,const unsigned char* in, const unsigned char* key){ 201 unsigned char input[64] = { 0 };202 unsigned char output[64] = { 0 };203 unsigned char tmp[64] = { 0 };204 ByteToBit(input, in, 64);205 Transform(tmp, input, IP_table, 64);206char* Li = &tmp[0], *Ri = &tmp[32];207 setKey(key);208 RotateL(tmp, 64, 32);209for (int i = 0; i < 16; i++){210char temp[32] = { 0 };211 memcpy(temp, Li, 32);212 F_func(Li, Li,subKey[15 - i]);213 xor(Li, Ri, 32);214 memcpy(Ri, temp, 32);215 }216 Transform(output, tmp, IPR_table, 64);217 BitToByte(out, output, 64);218 }。

用c语言实现des算法

用c语言实现des算法

用c语言实现des算法由于DES算法被广泛应用于加密和数据安全方面，因此在计算机科学领域，了解和实现DES算法是非常重要的。

C语言是一种强大的编程语言，其通用性和高效性使其成为实现DES算法的理想选择。

以下是使用C语言实现DES算法的步骤和方法：1.将明文和密钥转换为二进制格式在DES算法中，明文和密钥必须先转换为二进制格式才能进行加密或解密操作。

可以使用一个字符串数组来存储明文和密钥，然后使用C 语言的位运算符将每个字符转换为二进制格式。

2.对明文进行初始置换DES算法的第一步是对明文进行初始置换。

可以使用一个int型数据来存储初始置换后的结果。

3.密钥生成使用密钥生成算法来生成16个48位的子密钥。

可以使用一个二维数组来存储每个子密钥。

4.将初始置换后的明文分为左右两个部分将初始置换后的明文分为左右两个部分，每个部分32位。

5.进行16轮迭代在每轮迭代中，右半部分32位的明文和48位的子密钥进行异或运算，然后使用S盒置换和P盒置换来处理数据。

最后将结果与左半部分32位的明文异或，以更新下一轮迭代所需的数据。

6.合并左右两个部分在进行最后一轮迭代后，将左右两个部分合并成一段64位的二进制数据。

7.进行最后的逆置换使用逆置换来处理上一步生成的64位二进制数据，以生成最终的密文。

实现DES算法需要一定的数学知识和编程技能，因此建议有一定编程基础的人才尝试实现此算法。

列表：1.使用C语言实现DES算法步骤2.将明文和密钥转换为二进制格式的方法3.对明文进行初始置换的具体过程4.密钥生成算法的原理和实现方法5.如何将初始置换后的明文分为左右两个部分6.DES算法16轮迭代的详细过程7.如何合并左右两个部分的数据8.DES算法中的最后一步逆置换的作用和过程9.DES算法的应用场景和重要性10.如何使用C语言实现DES算法的具体步骤和技巧。

DES加密算法的C语言实现

DES加密算法的C语言实现

//密钥置换 unsigned char Key[]= {
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 };
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 };
FILE *input = fopen( argv[1], "r"); if(ferror( input ))
return 0 ; //创建文件 用于输出密文 FILE *encyption = fopen(argv[2],"w"); if(ferror( encyption ))
return 0 ; //创建文件 用于输出解密后的明文 FILE *decyption = fopen(argv[3],"w"); if(ferror( decyption ))
};
//S-盒置换 unsigned char S_Box[8][64] = {
/* S1 */
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DES对称加密算法详解和c++代码实现（带样例和详细的中间数据）

DES对称加密算法详解和c++代码实现（带样例和详细的中间数据）

DES对称加密算法详解和c++代码实现（带样例和详细的中间数据）特点：1.DES是对称性加密算法，即加密和解密是对称的，⽤的是同⼀个密钥2.DES只处理⼆进制数据，所以需要将明⽂转换成为2进制数据3.DES每次处理64位的数据，所以应该将明⽂切割成64位的分组，当最后⼀组数据不⾜64位的时候，⾼位补04.DES使⽤64位的密钥，但因为密钥中的每8位会被忽略，所以有效的密钥长度是56位，从⽽产⽣16个48位的⼦密钥（变换过程后⾯会说明）5.每64位数据⼀个块，是DES的永恒组织⽅式具体样例分析：（仅以⼀组64位数据为例分析加密过程）明⽂M是：8787878787878787密钥K是：0E329232EA6D0D73上⾯的信息都是16进制的，转换为2进制明⽂M是：0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111密钥K是：00010011 00110100 01010111 01111001 10011011 10111100 11011111 11110001第⼀步：根据密钥⽣成16个⼦密钥1.根据密钥初始置换表将64位的密钥转化为58位的密钥57 49 41 33 25 17 91 58 50 42 34 26 1810 2 59 51 43 35 2719 11 3 60 52 44 3663 55 47 39 31 23 157 62 54 46 38 30 2214 6 61 53 45 37 2921 13 5 28 20 12 4由于上表中第⼀个元素为57，这将使原秘钥的第57位变换为新秘钥K+的第1位。

同理，原秘钥的第49位变换为新秘钥的第2位……原秘钥的第4位变换为新秘钥的最后⼀位。

注意原秘钥中只有56位会进⼊新秘钥，上表也只有56个元素。

原密钥K：00010011 00110100 01010111 01111001 10011011 10111100 11011111 11110001新密钥K：1111000 0110011 0010101 0101111 0101010 1011001 1001111 00011112.将新密钥拆分成C0和D0，每组都有28位⽐如新密钥C0：1111000 0110011 0010101 0101111D0：0101010 1011001 1001111 00011113.根据密钥轮次左移表，左移特定的位数1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 161 12 2 2 2 2 2 1 2 2 2 2 2 2 1⽐如第⼀轮是左移1位，第⼆轮也是左移1位，第三轮是左移两位所以C1：1110000110011001010101011111D1：1010101011001100111100011110下⾯给出C1,D1到C16，D16的数据：C1 = 1110000110011001010101011111D1 = 1010101011001100111100011110C2 = 1100001100110010101010111111D2 = 0101010110011001111000111101C3 = 0000110011001010101011111111D3 = 0101011001100111100011110101C4 = 0011001100101010101111111100D4 = 0101100110011110001111010101C5 = 1100110010101010111111110000D5 = 0110011001111000111101010101C6 = 0011001010101011111111000011D6 = 1001100111100011110101010101C7 = 1100101010101111111100001100D7 = 0110011110001111010101010110C8 = 0010101010111111110000110011D8 = 1001111000111101010101011001C9 = 0101010101111111100001100110D9 = 0011110001111010101010110011C10 = 0101010111111110000110011001D10 = 1111000111101010101011001100C11 = 0101011111111000011001100101D11 = 1100011110101010101100110011C12 = 0101111111100001100110010101D12 = 0001111010101010110011001111C13 = 0111111110000110011001010101D13 = 0111101010101011001100111100C14 = 1111111000011001100101010101D14 = 1110101010101100110011110001C15 = 1111100001100110010101010111D15 = 1010101010110011001111000111C16 = 1111000011001100101010101111D16 = 0101010101100110011110001111需要记住的是：每⼀对Cn 和 Dn都是由前⼀对Cn-1 和 Dn-1移位⽽来！4.得到Cn，Dn后合并CnDn，然后根据密钥压缩置换表将56位密钥压缩成48位的⼦密钥密钥压缩置换表：14 17 11 24 1 53 28 15 6 21 1023 19 12 4 26 816 7 27 20 13 241 52 31 37 47 5530 40 51 45 33 4844 49 39 56 34 5346 42 50 36 29 32每对⼦秘钥有56位，但PC-2仅仅使⽤其中的48位。