小巧玲珑的des加密解密算法 C语言 （dll形式）附送原代码

#include<memory.h> #include<stdio.h> _declspec(dllexport) enum {ENCRYPT,DECRYPT};//ENCRYPT 加密 DECRYPT 解密 _declspec(dllexport) void Des_run(char Out[8],char In[8],bool Type=ENCRYPT); //Des加密 _declspec(dllexport) void Des_SetKey(const char Key[8]);//设置密钥 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 static void Transform(bool *Out,bool *In,const char *Table,int len);//变换 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 static void ByteToBit(bool *Out,const char *In,int bits);//字节转换成组 static void BitToByte(char *Out,const bool *In, int bits);//位组转换成字节 const static 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, //check 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 };//置换IP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, //check 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 };//逆置换IPR表 const static 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, //check 24,25,26,27,28,29,28,29,30,31,32,1 };//E位选择表 const static char P_Table[32]={ 16,7,20,21,29,12,28,17,1,15,23,26,5,18,31,10, //check 2,8,24,14,32,27,3,9,19,13,30,6,22,11,4,25 };//P换位表 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, //check 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 };//PC1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, //check 44,49,39,56,34,53,46,42,50,36,29,32 };//PC2选位表 const static char LOOP_Table[16]={ 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 // };//左移位数表 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, //check 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, //check 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, //check 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, //check 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, //check 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, //check 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, //check 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, //check 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 };//S盒 static bool SubKey[16][48];//16圈子密钥 //////////////////////////////////////函数实现 void ByteToBit(bool *Out,const char *In,int bits) { for(int i=0;i<bits;i++) Out[i]=(In[i/8]>>(i%8))&1; //把每一个字符转为二进制 低位在前高位在后 } void BitToByte(char *Out,const bool *In,int bits) { memset(Out,0,(bits+7)/8); //Out 空间全部置0; for(int i=0;i<bits;i++) Out[i/8] |= In[i]<<(i%8); //二进制串八个一组 转为字节 高位在前 低位在后, 牛X算法 } void Transform(bool *Out,bool *In,const char *Table,int len) { static bool Tmp[256]; for(int i=0;i<len;i++) Tmp[i]=In[Table[i]-1];//数组从0开始存储 memcpy(Out,Tmp,len); } void Xor(bool *InA,const bool *InB,int len) { for(int i=0;i<len;i++) InA[i] ^=InB[i]; } void RotateL(bool *In,int len,int loop) { static bool Tmp[256]; memcpy(Tmp,In,loop); memcpy(In,In+loop,len-loop); //值得深究 memcpy(In+len-loop,Tmp,loop); } 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 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); } _declspec(dllexport) 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); } } _declspec(dllexport) 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); }