DES.rar_Des加密解密_des 密码算法

/* *This program is about the DES algorithm. *Author : Ting *E-mail:kilvdn@yahoo.com.cn *Addr: China University of Geosciences ( WuHan ) */ #include <stdio.h> #include <string.h> int key[64] , tempkey[56] , subkey[16][48] ; int choose ; //置换选择1的矩阵 int zhxz1[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 }; //置换选择2的矩阵 int zhxz2[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 }; //循环左移位数表 int shiftleft[16]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; //置换选择1 void ChooseI(){ for (int i=0; i<56; i++) tempkey[i] = key[zhxz1[i]-1]; } //置换选择2,找出一个48位的子密钥 void ChooseSubKey( int n ){ for (int i=0; i<48; i++) subkey[n][i]=tempkey[zhxz2[i]-1]; } //循环左移n位 void ShiftL( int n ){ int temp ; temp = tempkey[0]; for ( int i=0; i<27; i++ ) tempkey[i]=tempkey[i+1]; tempkey[27]=temp; temp = tempkey[28] ; for ( int i=28; i<55; i++ ) tempkey[i]=tempkey[i+1]; tempkey[55]=temp; if (shiftleft[n]==2){ temp = tempkey[0]; for ( int i=0; i<27; i++ ) tempkey[i]=tempkey[i+1]; tempkey[27]=temp; temp = tempkey[28] ; for ( int i=28; i<55; i++ ) tempkey[i]=tempkey[i+1]; tempkey[55]=temp; } } //生成子密钥 void MakeSubKey(){ ChooseI(); for ( int i=0; i<16; i++){ ShiftL( i ) ; ChooseSubKey( i ) ; } } //plaintext:明文 //ciphertext: 密文 int plaintext[64] , ciphertext[64] , ans[64]; //初始置换IP的矩阵 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 }; typedef struct{ int num[32]; }PlainNum ; PlainNum l[17],r[17]; int temp[48],s_temp[32]; //选择运算用的扩展矩阵 int expanper[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 }; //8个S盒 int 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 }; //置换运算p所用的矩阵 int permuted[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 }; /*初始置换IP*/ void Init_Per(){ for ( int i=0;i<32;i++) l[0].num[i]=plaintext[ip[i]-1]; for ( int i=0;i<32;i++) r[0].num[i]=plaintext[ip[i+32]-1]; } /*解密的初始置换*/ void De_Per(){ for ( int i=0;i<32;i++) r[0].num[i]=plaintext[ip[i]-1]; for ( int i=0;i<32;i++) l[0].num[i]=plaintext[ip[i+32]-1]; } /*选择运算E(Expansion Permutation)*/ void ExpanPer( int n ){ for ( int i=0;i<48;i++) temp[i]=r[n-1].num[expanper[i]-1]; } /*置换运算P*/ void Permute(){ for ( int i=0;i<32;i++) temp[i]=s_temp[permuted[i]-1]; } /*S盒运算SBOX*/ void SBOX(){ int row , col , svalue; for ( int i=0;i<8;i++){ row=temp[i*6]*2+temp[i*6+5]; col=temp[i*6+1]*8+temp[i*6+2]*4+temp[i*6+3]*2+temp[i*6+4]; svalue=s_box[i][row][col]; s_temp[i*4]=svalue/8 ; svalue %= 8; s_temp[i*4+1]=svalue/4; svalue %= 4; s_temp[i*4+2]=svalue/2; svalue %= 2; s_temp[i*4+3]=svalue ; } } /*加密函数*/ void EncryFunc( int n ){ for ( int i=0;i<32;i++) l[n].num[i]=r[n-1].num[i]; for ( int i=0;i<48;i++) temp[i]=r[n-1].num[expanper[i]-1]; for ( int i=0;i<48;i++) temp[i] = temp[i]^subkey[n-1][i]; SBOX(); Permute(); for ( int i=0;i<32;i++) r[n].num[i] = temp[i]^l[n-1].num[i]; } /*解密函数*/ void DecryFunc( int n ){ for ( int i=0;i<48;i++) temp[i]=l[n-1].num[expanper[i]-1]; for ( int i=0;i<48;i++) temp[i] = temp[i]^subkey[16-n][i]; SBOX(); for ( int i=0;i<32;i++) temp[i]=s_temp[permuted[i]-1]; for ( int i=0;i<32;i++) r[n].num[i]=l[n-1].num[i]; for ( int i=0;i<32;i++) l[n].num[i] = temp[i]^r[n-1].num[i]; } /*逆初始置换IP-1*/ void IP_r(){ for ( int i=0;i<32;i++) ans[i]=r[16].num[i]; for ( int i=0;i<32;i++) ans[32+i]=l[16].num[i]; for ( int i=0;i<64;i++) ciphertext[ip[i]-1]=ans[i]; } /*解密的逆初始置换IP-1*/ void DIP_r(){ for ( int i=0;i<32;i++) ans[i]=l[16].num[i]; for ( int i=0;i<32;i++) ans[32+i]=r[16].num[i]; for ( int i=0;i<64;i++) ciphertext[ip[i]-1]=ans[i]; } /*加密过程*/ void Encryption(){ Init_Per( ) ; for (int i=1;i<=16;i++) EncryFunc( i ) ; IP_r(); printf("得出的密文为: "); for ( int i=0;i<64;i++) printf("%d",ciphertext[i]); printf(" "); } /*解密过程*/ void Decryption(){ De_Per(); for (int i=1;i<=16;i++) DecryFunc( i ) ; DIP_r(); printf("得出的明文为: "); for ( int i=0;i<64;i++) printf("%d",ciphertext[i]); printf(" "); } char plain[100] , des_key[100]; int len_plain , len_key ; int main(){ while (1){ printf("请选择 1 加密 2 解密: "); scanf("%d",&choose); switch (choose){ case 1 : printf("请输入明文: ");break; case 2 : printf("请输入密文: ");break; } scanf("%s",plain); printf("请输入密钥: ");