原创 DES算法的介绍和实现(下)

INT32 handle_data(ULONG32 *left , ULONG8 choice)
{
       INT32  number = 0 ,j = 0;   
       ULONG32 *right = &left[1] ;
       ULONG32 tmp = 0;       
       ULONG32 tmpbuf[2] = { 0 };             

       /*第一次调整wz_pc1[64]*/
       for ( j = 0 ; j < 64 ; j++)
       {
              if (j < 32 ) 
              {
                     if ( wz_pc1[j] > 32)/*属于right*/
                     {
                            if ( *right&wz_pc2[wz_pc1[j]-1] )
                            {
                                   tmpbuf[0] |= wz_pc2[j] ;
                            }
                     }
                     else
                     {
                            if ( *left&wz_pc2[wz_pc1[j]-1] )
                            {
                                   tmpbuf[0] |= wz_pc2[j] ;
                            }
                     }
              }
              else
              {
                     if ( wz_pc1[j] > 32)/*属于right*/
                     {
                            if ( *right&wz_pc2[wz_pc1[j]-1] )
                            {
                                   tmpbuf[1] |= wz_pc2[j] ;
                            }
                     }
                     else
                     {
                            if ( *left&wz_pc2[wz_pc1[j]-1] )
                            {
                                   tmpbuf[1] |= wz_pc2[j] ;
                            }
                     }
              }
       }
       *left  = tmpbuf[0] ;
       *right = tmpbuf[1];
       tmpbuf[0] = 0 ;
       tmpbuf[1] = 0 ;
    switch( choice )
       {
       case DESENCRY:
              for ( number = 0 ; number < 16 ; number++)
              {            
                     makedata( left , right , (ULONG32)number) ;
              }
              break;
       case DESDECRY:
                     for ( number = 15 ; number >= 0 ; number--)
                     {            
                            makedata( left , right ,(ULONG32)number) ;
                     }
              break;
       default:
              break;
       }

       /*最后一轮操作不交换左右值*/

       tmp = *left ;
       *left = *right ;
       *right = tmp ;        

       /*最后一次调整wz_pc4[64]*/

       for ( j = 0 ; j < 64 ; j++)
       {
              if (j < 32 ) 
              {
                     if ( wz_pc4[j] > 32)/*属于right*/
                     {
                            if ( *right&wz_pc2[wz_pc4[j]-1] )
                            {
                                   tmpbuf[0] |= wz_pc2[j] ;
                            }
                     }
                     else
                     {
                            if ( *left&wz_pc2[wz_pc4[j]-1] )
                            {
                                   tmpbuf[0] |= wz_pc2[j] ;
                            }
                     }
              }
              else
              {
                     if ( wz_pc4[j] > 32)/*属于right*/
                     {
                            if ( *right&wz_pc2[wz_pc4[j]-1] )
                            {
                                   tmpbuf[1] |= wz_pc2[j] ;
                            }
                     }
                     else
                     {
                            if ( *left&wz_pc2[wz_pc4[j]-1] )
                            {
                                   tmpbuf[1] |= wz_pc2[j] ;
                            }
                     }
              }
       }
  
       *left =  tmpbuf[0] ;
       *right = tmpbuf[1];

       return SUCCESS;
}


INT32 makedata(ULONG32  *left ,ULONG32  *right ,ULONG32 number) 
{
              INT32 j; 
              ULONG32 oldright = *right;         
              ULONG8 rexpbuf[8] = { 0} ;
              ULONG32 datatmp = 0;        
              ULONG32 exp[2] = { 0} ;                         
       //由32扩充至48位

       for ( j = 0 ; j < 48 ; j++)
       {
              /*两个32位，每个存放24位*/
              if ( j < 24 )
              {
                     if ( *right&wz_pc2[exptab3[j]-1] )
                     {
                            exp[0] |= wz_pc2[j] ;
                     }            
              }            
              else
              {
                     if ( *right&wz_pc2[exptab3[j]-1] )
                     {
                            exp[1] |= wz_pc2[j-24] ;
                     }
              }
       }

       for ( j = 0 ; j < 2 ; j++)
       {            
              exp[j] ^= g_outkey[number][j] ;
       }    

       /*由48－>32*/      

       exp[1] >>= 8 ;
       rexpbuf[7] = (ULONG8) (exp[1]&0x0000003fL) ;
       exp[1] >>= 6 ;
       rexpbuf[6] = (ULONG8) (exp[1]&0x0000003fL) ;
       exp[1] >>= 6 ;
       rexpbuf[5] = (ULONG8) (exp[1]&0x0000003fL) ;
       exp[1] >>= 6 ;
       rexpbuf[4] = (ULONG8) (exp[1]&0x0000003fL) ;
       exp[0]  >>=  8 ;
       rexpbuf[3] = (ULONG8) (exp[0]&0x0000003fL) ;     
       exp[0] >>= 6 ;
       rexpbuf[2] = (ULONG8) (exp[0]&0x0000003fL) ;
       exp[0] >>= 6 ;
       rexpbuf[1] = (ULONG8) (exp[0]&0x0000003fL) ;
       exp[0] >>= 6 ;
       rexpbuf[0] = (ULONG8) (exp[0]&0x0000003fL) ;     
       exp[0] = 0 ;
       exp[1] = 0 ;

       /*由48－> 32*/

       *right = 0 ;
       for ( j = 0 ; j < 7 ; j++)
       {
              *right |= SP[j][rexpbuf[j]] ;
              *right <<= 4 ;
       }
       *right |= SP[j][rexpbuf[j]] ;

       /*又要换位了*/

       datatmp = 0;
       for ( j = 0 ; j < 32 ; j++)
       {
              if ( *right&wz_pc2[wz_pc3[j]-1] )
              {
                     datatmp |= wz_pc2[j] ;
              }
       }
       *right = datatmp ;

       /*一轮结束收尾操作*/                

       *right ^= *left;       
       *left = oldright;

       return SUCCESS;
}

INT32 makefirstkey( ULONG32 *keyP )
{
       ULONG32 key[2] = {0};
       ULONG32 *Pkey ;
       ULONG32 *Pbufkey ;
       INT32 j; 
       Pbufkey = (ULONG32*)g_bufkey ;
       Pkey = (ULONG32*)key;
              
       memset((ULONG8*)g_bufkey,0,sizeof(g_bufkey));    
       memcpy((ULONG8*)&key,(ULONG8*)keyP ,8) ;      
       memset((ULONG8*)g_outkey,0,sizeof(g_outkey));
       for(  j = 0 ; j < 28 ; j++)
       {
              if ( wz_keyleft[j] > 32 ) 
              {
                     if ( Pkey[1]&wz_pc2[wz_keyleft][j]-1] )
                     {
                            Pbufkey[0] |= wz_pc2[j] ;
                     }
              }
              else
              {
                     if ( Pkey[0]&wz_pc2[wz_keyleft][j]-1] )
                     {
                            Pbufkey[0] |= wz_pc2[j] ;
                     }
              }
              
              if ( wz_keyright[j] > 32 ) 
              {
                     if ( Pkey[1]&wz_pc2[wz_keyright][j]-1] )
                     {
                            Pbufkey[1] |= wz_pc2[j];
                     }
              }
              else
              {
                     if ( Pkey[0]&wz_pc2[wz_keyright][j]-1] )
                     {
                            Pbufkey[1] |= wz_pc2[j];
                     }
              }
       }
       for (j = 0 ; j < 16 ; j++)
       {
              makekey(&Pbufkey[0],&Pbufkey[1] , j ) ;
       }
       return SUCCESS;
}


INT32 makekey(  ULONG32 *keyleft,ULONG32 *keyright ,ULONG32 number)/*输入密钥的地址，一个32位的*/
{
       ULONG32 tmpkey[2] ={0};
       ULONG32 *Ptmpkey = (ULONG32*)tmpkey;     
       ULONG32 *Poutkey = (ULONG32*)&g_outkey[number]; 
       INT32 j;        
       memset((ULONG8*)tmpkey,0,sizeof(tmpkey));          
              /*要最高的一位或两位*/
              *Ptmpkey = *keyleft&wz_leftandtab[wz_lefttable][number]] ;           
              Ptmpkey[1] = *keyright&wz_leftandtab[wz_lefttable][number]] ;              
              if ( wz_lefttable[number] == 1)
              {
                     *Ptmpkey >>= 27;
                     Ptmpkey[1] >>= 27;
              }
              else
              {
                     *Ptmpkey >>= 26;
                     Ptmpkey[1] >>= 26;                    
              }
              Ptmpkey[0] &= 0xfffffff0;
              Ptmpkey[1] &= 0xfffffff0;
              /*得到高位的值*/
              *keyleft <<= wz_lefttable[number] ;
              *keyright <<= wz_lefttable[number] ;
              *keyleft |= Ptmpkey[0] ;
              *keyright |= Ptmpkey[1] ;            
              Ptmpkey[0] = 0;
              Ptmpkey[1] = 0;
    
       /*从56位中选出48位,3个16位*/
       for ( j = 0 ; j < 48 ; j++)
       {
              if ( j < 24 )
              {
              
                            if ( *keyleft&wz_pc2[wz_keychoose][j]-1])
                            {
                                   Poutkey[0] |= wz_pc2[j] ;
                            }                   
              }            
              
              else /*j>=24*/
              {                   
                            if ( *keyright&wz_pc2[(wz_keychoose][j]-28)])
                            {
                                   Poutkey[1] | = wz_pc2[j-24] ;
                            }                   
              }
       }
       return SUCCESS;
}