DES加密解密算法C语言代码实现
代码：
1 #include<stdio.h> 2 #include<string.h> 3 #include<stdlib.h> 4 /*------------------------ 5 定义枚举型全局变量 6 ------------------------*/ 7 typedef enum 8 { 9 false = 0, 10 true = 1 11 } bool; 12 13 // 十六轮子密钥 14 static bool SubKey[16][48]={0}; 15 16 /*---------------------*/ 17 /*------------------------------------------------------------- 18 各种置换表 19 -------------------------------------------------------------*/ 20 // IP置换表 21 const char IP_Table[64]={ 22 58,50,42,34,26,18,10, 2,60,52,44,36,28,20,12, 4, 23 62,54,46,38,30,22,14, 6,64,56,48,40,32,24,16, 8, 24 57,49,41,33,25,17, 9, 1,59,51,43,35,27,19,11, 3, 25 61,53,45,37,29,21,13, 5,63,55,47,39,31,23,15, 7 26 }; 27 // IP-1置换表 28 const char IPR_Table[64]={ 29 40, 8,48,16,56,24,64,32,39, 7,47,15,55,23,63,31, 30 38, 6,46,14,54,22,62,30,37, 5,45,13,53,21,61,29, 31 36, 4,44,12,52,20,60,28,35, 3,43,11,51,19,59,27, 32 34, 2,42,10,50,18,58,26,33, 1,41, 9,49,17,57,25 33 }; 34 35 // E扩展表 36 static char E_Table[48]={ 37 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 38 8, 9,10,11,12,13,12,13,14,15,16,17, 39 16,17,18,19,20,21,20,21,22,23,24,25, 40 24,25,26,27,28,29,28,29,30,31,32, 1 41 }; 42 // PC1置换表 43 static char PC1_Table[56]={ 44 57,49,41,33,25,17, 9, 1,58,50,42,34,26,18, 45 10, 2,59,51,43,35,27,19,11, 3,60,52,44,36, 46 63,55,47,39,31,23,15, 7,62,54,46,38,30,22, 47 14, 6,61,53,45,37,29,21,13, 5,28,20,12, 4 48 }; 49 50 // pc2表 51 static char PC2_Table[48]={ 52 14,17,11,24, 1, 5, 3,28,15, 6,21,10, 53 23,19,12, 4,26, 8,16, 7,27,20,13, 2, 54 41,52,31,37,47,55,30,40,51,34,33,48, 55 44,49,39,56,34,53,46,42,50,36,29,32 56 }; 57 // 移位表 58 static char Move_Table[16]={ 59 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 60 }; 61 // S盒 62 static char S_Box[8][4][16]={ 63 //S1 64 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7, 65 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8, 66 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0, 67 15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13, 68 //S2 69 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10, 70 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5, 71 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15, 72 13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9, 73 //S3 74 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8, 75 13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1, 76 13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7, 77 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12, 78 //S4 79 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15, 80 13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9, 81 10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4, 82 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14, 83 //S5 84 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9, 85 14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6, 86 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14, 87 11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3, 88 //S6 89 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11, 90 10,15, 4, 2, 7,12, 0, 5, 6, 1,13,14, 0,11, 3, 8, 91 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6, 92 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13, 93 //S7 94 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1, 95 13, 0,11, 7, 4, 0, 1,10,14, 3, 5,12, 2,15, 8, 6, 96 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2, 97 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12, 98 //S8 99 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7, 100 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2, 101 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8, 102 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11 103 }; 104 //P置换表 105 static char P_Table[32]={ 106 16, 7,20,21,29,12,28,17, 1,15,23,26, 5,18,31,10, 107 2, 8,24,14,32,27, 3, 9,19,13,30, 6,22,11, 4,25 108 }; 109 /*-------------------------------------------------------------------*/ 110 111 /*-----------------------------自定义函数-----------------------------*/ 112 void SetKey(char My_key[8]); //生成16轮的子密钥； 113 void ByteToBit(bool * Data_out,char * Data_in,int Num); //字节转换成位； 114 void Change_bit(bool * Data_out,int Num);//二进制的位置进行转换； 115 void BitToByte(char My_message[8],bool * Message_in,int Num); //位转换成字节； 116 void TableReplace(bool *Data_out,bool *Data_in,const char *Table,int Num); //各种表的置换算法； 117 void Bitcopy(bool * Data_out,bool * Data_in,int Num); //二进制数组的拷贝 118 void Loop_bit(bool * Data_out,int movstep,int len); //左移位； 119 void Run_Des(char My_message[8],char HexMssage[16]);//des的轮加密算法 120 void Xor(bool * Message_out, bool * Message_in,int Num); //执行异或 121 void S_change(bool * Data_out, bool * Data_in); // S盒变换； 122 void HexToBit(bool * Data_out,char * Data_in,int Num); // 十六进制转二进制 123 void BitToHex(char * Data_out,bool * Data_in,int Num); //二进制转换成十六进制； 124 void Run_desDes(char My_message[8],char HexMessage[16]);// DES轮解密算法； 125 126 /*--------------------------*/ 127 128 /*--------------------------主函数----------------------------------*/ 129 int main() 130 { 131 int i=0,j; 132 char My_key[8]={0}; //记录加密密钥； 133 char You_key[8]={0}; //解密密钥 134 char My_message[8]={0}; //明文 135 char Message_hex[16]={0};//16进制的密文 136 printf("请输入你要加密的内容(8 Byte):\n"); 137 gets(My_message); 138 printf("请输入你的加密密钥:\n"); 139 gets(My_key); 140 i=strlen(My_key); 141 while(i!=8) 142 { 143 printf("请输入加密密钥(8 Byte)\n"); 144 gets(My_key); 145 i=0; 146 i=strlen(My_key); 147 } 148 SetKey(My_key); //生成16轮的加密子密钥； 149 Run_Des(My_message,Message_hex); //des的轮加密过程 150 printf("经过加密的密文为:\n"); 151 for(i=0;i<16;i++) 152 { 153 printf("%c ",Message_hex[i]); 154 } 155 printf("\n"); 156 printf("请输入你的解密密钥(8 Byte):\n"); 157 gets(You_key); 158 i=strlen(You_key); 159 while(i!=8) 160 { 161 printf("请输入解密密钥(8 Byte)\n"); 162 gets(You_key); 163 i=0; 164 i=strlen(You_key); 165 } 166 SetKey(You_key); //生成16轮的解密子密钥； 167 Run_desDes(My_message,Message_hex);//解密; 168 printf("解密结果为:\n"); 169 for(i=0;i<8;i++) 170 { 171 printf("%c ",My_message[i]); 172 } 173 printf("\n"); 174 return 0; 175 } 176 177 /*--------------------具体函数定义----------------------*/ 178 void Bitcopy(bool * Data_out, bool * Data_in,int Num) //二进制数组拷贝 179 { 180 int i=0; 181 for(i=0;i<Num;i++) 182 { 183 Data_out[i]=Data_in[i]; 184 } 185 186 } 187 void Change_bit(bool * Data_out,int Num) //二进制的位置进行转换； 188 { 189 int i,j; 190 static bool Temp[8]={0}; 191 for(i=0;i<Num/8;i++) 192 { 193 Bitcopy(Temp,Data_out,Num/8); 194 for(j=0;j<Num/8;j++) 195 { 196 Data_out[j]=Temp[Num/8-1-j]; 197 } 198 Data_out+=Num/8; 199 } 200 } 201 void ByteToBit( bool * Data_out,char * Data_in,int Num) //字节转位 202 { 203 int i,j; 204 for(i=0;i<Num;i++) 205 { 206 Data_out[i]=(Data_in[i/8]>>(i%8))&0x01; 207 } 208 //Change_bit(Data_out,Num); 209 } 210 void BitToHex(char * Data_out, bool * Data_in,int Num) //二进制转十六进制 211 { 212 int i; 213 for(i=0;i<Num/4;i++) 214 { 215 Data_out[i]=0; 216 } 217 for(i=0;i<Num/4;i++) 218 { 219 Data_out[i]=Data_in[4*i]+Data_in[4*i+1]*2+Data_in[4*i+2]*4+Data_in[4*i+3]*8; 220 if(Data_out[i]%16>9) 221 { 222 Data_out[i]=Data_out[i]%16+'7'; 223 } 224 else 225 Data_out[i]=Data_out[i]%16+'0'; 226 } 227 } 228 void HexToBit(bool * Data_out,char * Data_in,int Num) //十六进制转二进制 229 { 230 int i; 231 for(i=0;i<Num;i++) 232 { 233 if(Data_in[i/4]<='9') 234 { 235 Data_out[i]=((Data_in[i/4]-'0')>>(i%4))&0x01; 236 } 237 else 238 { 239 Data_out[i]=((Data_in[i/4]-'7')>>(i%4))&0x01; 240 } 241 } 242 } 243 void BitToByte(char My_message[8],bool * Message_in,int Num) //位转换成字节 244 { 245 int i=0; 246 for(i=0;i<(Num/8);i++) 247 { 248 My_message[i]=0; 249 } 250 for(i=0;i<Num;i++) 251 { 252 My_message[i/8]|=Message_in[i]<<(i%8); 253 } 254 } 255 void TableReplace( bool *Data_out, bool * Data_in,const char *Table ,int Num) // 置换算法 256 { 257 int i=0; 258 static bool Temp[256]={0}; 259 for(i=0;i<Num;i++) 260 { 261 Temp[i]=Data_in[Table[i]-1]; 262 } 263 Bitcopy(Data_out,Temp,Num); 264 } 265 void Loop_bit(bool * Data_out,int movstep,int len) 266 { 267 static bool Temp[256]={0}; 268 Bitcopy(Temp,Data_out,movstep); 269 Bitcopy(Data_out,Data_out+movstep,len-movstep); 270 Bitcopy(Data_out+len-movstep,Temp,movstep); 271 /*Temp=Data_out; 272 Temp[movstep]='\0'; 273 Data_out=Data_out+movstep; 274 Data_out+(len-movstep)=Temp;*/ 275 } 276 void Xor(bool * Message_out,bool * Message_in,int Num)//执行异或 277 { 278 int i; 279 for(i=0;i<Num;i++) 280 { 281 Message_out[i]=Message_out[i]^Message_in[i]; 282 } 283 } 284 void SetKey(char My_key[8]) 285 { 286 int i,j; 287 static bool Key_bit[64]={0}; //Key的二进制缓存； 288 static bool *Key_bit_L,*Key_bit_R; 289 Key_bit_L=&Key_bit[0]; //key的左边28位； 290 Key_bit_R=&Key_bit[28]; //key的右边28位； 291 ByteToBit(Key_bit,My_key,64); 292 /* Change_bit(Key_bit,64) ;//二进制的位置进行转换； 293 for(i=0;i<64;i++) 294 { 295 printf("%d ",Key_bit[i]); 296 } 297 printf("\n"); 298 printf("\n");*/ 299 TableReplace(Key_bit,Key_bit,PC1_Table,56);//pc-1 置换 300 for(i=0;i<16;i++) 301 { 302 Loop_bit(Key_bit_L,Move_Table[i],28); 303 Loop_bit(Key_bit_R,Move_Table[i],28); 304 TableReplace(SubKey[i],Key_bit,PC2_Table,48);//pc-2置换 305 } 306 } 307 void S_change(bool * Data_out, bool * Data_in) //S盒变换 308 { 309 int i; 310 int r=0,c=0;//S盒的行和列； 311 for(i=0;i<8;i++,Data_in=Data_in+6,Data_out=Data_out+4) 312 { 313 r=Data_in[0]*2+Data_in[5]*1; 314 c=Data_in[1]*8+Data_in[2]*4+Data_in[3]*2+Data_in[4]*1; 315 ByteToBit(Data_out,&S_Box[i][r][c],4); 316 } 317 } 318 void F_change(bool Data_out[32],bool Data_in[48]) // f函数； 319 { 320 int i; 321 static bool Message_E[48]={0}; //存放E置换的结果； 322 TableReplace(Message_E,Data_out,E_Table,48);//E表置换 323 Xor(Message_E,Data_in,48); 324 S_change(Data_out,Message_E); // S盒变换 325 TableReplace(Data_out,Data_out,P_Table,32); //P置换 326 } 327 void Run_Des(char My_message[8],char HexMssage[16])//des轮加密算法； 328 { 329 int i; 330 static bool Message_bit[64]={0}; 331 static bool *Message_bit_L=&Message_bit[0],*Message_bit_R=&Message_bit[32]; 332 static bool Temp[32]={0}; 333 ByteToBit(Message_bit,My_message,64); 334 /*Change_bit(Message_bit,64) ;//二进制的位置进行转换； 335 for(i=0;i<64;i++) 336 { 337 printf("%d ",Message_bit[i]); 338 } 339 printf("\n"); 340 printf("\n");*/ 341 TableReplace(Message_bit,Message_bit,IP_Table,64); 342 for(i=0;i<16;i++) 343 { 344 Bitcopy(Temp,Message_bit_R,32); 345 F_change(Message_bit_R,SubKey[i]); 346 Xor(Message_bit_R,Message_bit_L,32); 347 Bitcopy(Message_bit_L,Temp,32); 348 } 349 TableReplace(Message_bit,Message_bit,IPR_Table,64); 350 BitToHex(HexMssage,Message_bit,64);//二进制转换成十六进制； 351 } 352 void Run_desDes(char My_message[8],char HexMessage[16])// DES轮解密算法； 353 { 354 int i=0; 355 static bool Message_bit[64]={0}; 356 static bool * Message_bit_L=&Message_bit[0], * Message_bit_R=&Message_bit[32]; 357 static bool Temp[32]={0}; 358 HexToBit(Message_bit,HexMessage,64); 359 TableReplace(Message_bit,Message_bit,IP_Table,64); 360 for(i=15;i>=0;i--) 361 { 362 Bitcopy(Temp,Message_bit_L,32); 363 F_change(Message_bit_L,SubKey[i]); 364 Xor(Message_bit_L,Message_bit_R,32); 365 Bitcopy(Message_bit_R,Temp,32); 366 } 367 TableReplace(Message_bit,Message_bit,IPR_Table,64); 368 BitToByte(My_message,Message_bit,64); 369 }
