des.cpp

des数据加密和解密算法

kn[11] = kwork[ 9]; 
kn[12] = kwork[22]; 
kn[13] = kwork[18]; 
kn[14] = kwork[11]; 
kn[15] = kwork[ 3]; 
kn[16] = kwork[25]; 
kn[17] = kwork[ 7]; 
kn[18] = kwork[15]; 
kn[19] = kwork[ 6]; 
kn[20] = kwork[26]; 
kn[21] = kwork[19]; 
kn[22] = kwork[12]; 
kn[23] = kwork[ 1]; 
kn[24] = kwork[40]; 
kn[25] = kwork[51]; 
kn[26] = kwork[30]; 
kn[27] = kwork[36]; 
kn[28] = kwork[46]; 
kn[29] = kwork[54]; 
kn[30] = kwork[29]; 
kn[31] = kwork[39]; 
kn[32] = kwork[50]; 
kn[33] = kwork[44]; 
kn[34] = kwork[32]; 
kn[35] = kwork[47]; 
kn[36] = kwork[43]; 
kn[37] = kwork[48]; 
kn[38] = kwork[38]; 
kn[39] = kwork[55]; 
kn[40] = kwork[33]; 
kn[41] = kwork[52]; 
kn[42] = kwork[45]; 
kn[43] = kwork[41]; 
kn[44] = kwork[49]; 
kn[45] = kwork[35]; 
kn[46] = kwork[28]; 
kn[47] = kwork[31]; 

for(j=0;j<48;j++)
{k2[m-1][j]=kn[j];
}
}
//右半部分48位与ki的异或
if(flg)
{for(i=0; i<48; i++) 
worka[i] = worka[i] ^ kn[i] ; 
}
else{
	for (i = 0; i < 48; i++) 
worka[i] = worka[i] ^ k2[16-m][i]; }
//查找s盒函数
valindex = s1[2*worka[ 0]+worka[ 5]]//找出对应的si的值
[2*(2*(2*worka[ 1]+worka[ 2])+ 
worka[ 3])+worka[ 4]]; 
kn[0] = (valindex / 8) % 2; 
kn[1] = (valindex / 4) % 2; 
kn[2] = (valindex / 2) % 2; 
kn[3] = valindex % 2; 
//printf("%d",kn[0]*8+kn[1]*4+kn[2]*2+kn[3]);
valindex = s2[2*worka[ 6]+worka[11]] 
[2*(2*(2*worka[ 7]+worka[ 8])+ 
worka[ 9])+worka[10]]; 
kn[4] = (valindex / 8) % 2; 
kn[5] = (valindex / 4) % 2; 
kn[6] = (valindex / 2) % 2; 
kn[7] = valindex % 2; 
//printf("%d",kn[4]*8+kn[5]*4+kn[6]*2+kn[7]);
valindex = s3[2*worka[12]+worka[17]] 
[2*(2*(2*worka[13]+worka[14])+ 
worka[15])+worka[16]]; 
kn[8] = (valindex / 8) % 2; 
kn[9] = (valindex / 4) % 2; 
kn[10] = (valindex / 2) % 2; 
kn[11] = valindex % 2; 
//printf("%d",kn[8]*8+kn[9]*4+kn[10]*2+kn[11]);
valindex = s4[2*worka[18]+worka[23]] 
[2*(2*(2*worka[19]+worka[20])+ 
worka[21])+worka[22]]; 
kn[12] = (valindex / 8) % 2; 
kn[13] = (valindex / 4) % 2; 
kn[14] = (valindex / 2) % 2; 
kn[15] = valindex % 2; 
//printf("%d",kn[12]*8+kn[13]*4+kn[14]*2+kn[15]);
valindex = s5[2*worka[24]+worka[29]] 
[2*(2*(2*worka[25]+worka[26])+ 
worka[27])+worka[28]]; 
kn[16] = (valindex / 8) % 2; 
kn[17] = (valindex / 4) % 2; 
kn[18] = (valindex / 2) % 2; 
kn[19] = valindex % 2; 
//printf("%d",kn[16]*8+kn[17]*4+kn[18]*2+kn[19]);
valindex = s6[2*worka[30]+worka[35]] 
[2*(2*(2*worka[31]+worka[32])+ 
worka[33])+worka[34]]; 
kn[20] = (valindex / 8) % 2; 
kn[21] = (valindex / 4) % 2; 
kn[22] = (valindex / 2) % 2; 
kn[23] = valindex % 2; 
//printf("%d",kn[20]*8+kn[21]*4+kn[22]*2+kn[23]);
valindex = s7[2*worka[36]+worka[41]] 
[2*(2*(2*worka[37]+worka[38])+ 
worka[39])+worka[40]]; 
kn[24] = (valindex / 8) % 2; 
kn[25] = (valindex / 4) % 2; 
kn[26] = (valindex / 2) % 2; 
kn[27] = valindex % 2; 
//printf("%d",kn[24]*8+kn[25]*4+kn[26]*2+kn[27]);
valindex = s8[2*worka[42]+worka[47]] 
[2*(2*(2*worka[43]+worka[44])+ 
worka[45])+worka[46]]; 
kn[28] = (valindex / 8) % 2; 
kn[29] = (valindex / 4) % 2; 
kn[30] = (valindex / 2) % 2; 
kn[31] = valindex % 2; 
//printf("%d",kn[28]*8+kn[29]*4+kn[30]*2+kn[31]);
//printf("\n");

//单纯置换
worka[ 0] = kn[15]; 
worka[ 1] = kn[ 6]; 
worka[ 2] = kn[19]; 
worka[ 3] = kn[20]; 
worka[ 4] = kn[28]; 
worka[ 5] = kn[11]; 
worka[ 6] = kn[27]; 
worka[ 7] = kn[16]; 
worka[ 8] = kn[ 0]; 
worka[ 9] = kn[14]; 
worka[10] = kn[22]; 
worka[11] = kn[25]; 
worka[12] = kn[ 4]; 
worka[13] = kn[17]; 
worka[14] = kn[30]; 
worka[15] = kn[ 9]; 
worka[16] = kn[ 1]; 
worka[17] = kn[ 7]; 
worka[18] = kn[23]; 
worka[19] = kn[13]; 
worka[20] = kn[31]; 
worka[21] = kn[26]; 
worka[22] = kn[ 2]; 
worka[23] = kn[ 8]; 
worka[24] = kn[18]; 
worka[25] = kn[12]; 
worka[26] = kn[29]; 
worka[27] = kn[ 5]; 
worka[28] = kn[21]; 
worka[29] = kn[10]; 
worka[30] = kn[ 3]; 
worka[31] = kn[24]; 

//左半部分f 输出的异或,左右换位
for (i = 0; i < 32; i++) { 
bufout[i+32] = bufout[i] ^ worka[i]; 
bufout[i]=buffer[i]; 
} 
//for(i=0;i<64;i++)
//printf("%d",bufout[i]);
//printf("\n");
}//循环结束
//最后一次换位逆运算，因为算法没有换 
for (i=0; i< 32; i++) { 
j = bufout[i]; 
bufout[i] = bufout[32+i]; 
bufout[32+i] = j; 
} 
//逆置换
buffer[ 0] = bufout[39]; 
buffer[ 1] = bufout[ 7]; 
buffer[ 2] = bufout[47]; 
buffer[ 3] = bufout[15]; 
buffer[ 4] = bufout[55]; 
buffer[ 5] = bufout[23]; 
buffer[ 6] = bufout[63]; 
buffer[ 7] = bufout[31]; 
buffer[ 8] = bufout[38]; 
buffer[ 9] = bufout[ 6]; 
buffer[10] = bufout[46]; 
buffer[11] = bufout[14]; 
buffer[12] = bufout[54]; 
buffer[13] = bufout[22]; 
buffer[14] = bufout[62]; 
buffer[15] = bufout[30]; 
buffer[16] = bufout[37]; 
buffer[17] = bufout[ 5]; 
buffer[18] = bufout[45]; 
buffer[19] = bufout[13]; 
buffer[20] = bufout[53]; 
buffer[21] = bufout[21]; 
buffer[22] = bufout[61]; 
buffer[23] = bufout[29]; 
buffer[24] = bufout[36]; 
buffer[25] = bufout[ 4]; 
buffer[26] = bufout[44]; 
buffer[27] = bufout[12]; 
buffer[28] = bufout[52]; 
buffer[29] = bufout[20]; 
buffer[30] = bufout[60]; 
buffer[31] = bufout[28]; 
buffer[32] = bufout[35]; 
buffer[33] = bufout[ 3]; 
buffer[34] = bufout[43]; 
buffer[35] = bufout[11]; 
buffer[36] = bufout[51]; 
buffer[37] = bufout[19]; 
buffer[38] = bufout[59]; 
buffer[39] = bufout[27]; 
buffer[40] = bufout[34]; 
buffer[41] = bufout[ 2]; 
buffer[42] = bufout[42]; 
buffer[43] = bufout[10]; 
buffer[44] = bufout[50]; 
buffer[45] = bufout[18]; 
buffer[46] = bufout[58]; 
buffer[47] = bufout[26]; 
buffer[48] = bufout[33]; 
buffer[49] = bufout[ 1]; 
buffer[50] = bufout[41]; 
buffer[51] = bufout[ 9]; 
buffer[52] = bufout[49]; 
buffer[53] = bufout[17]; 
buffer[54] = bufout[57]; 
buffer[55] = bufout[25]; 
buffer[56] = bufout[32]; 
buffer[57] = bufout[ 0]; 
buffer[58] = bufout[40]; 
buffer[59] = bufout[ 8]; 
buffer[60] = bufout[48]; 
buffer[61] = bufout[16]; 
buffer[62] = bufout[56]; 
buffer[63] = bufout[24]; 
if(flg)
{printf("密文是:");
for(j=0;j<64;j++)
printf("%d",buffer[j]);
printf("\n");
for(i=0;i<8;i++)
{source2[i]=buffer[0+i*8]*128+buffer[1+i*8]*64+buffer[2+i*8]*32+
	buffer[3+i*8]*16+buffer[4+i*8]*8+buffer[5+i*8]*4+buffer[6+i*8]*2+buffer[7+i*8]*1;
}
for(i=0;i<8;i++)
printf("%c",source2[i]);
printf("\n");
}
else 
{ 
printf("原文是:");
for(i=0;i<8;i++)
{dest[i]=buffer[0+i*8]*128+buffer[1+i*8]*64+buffer[2+i*8]*32+
	buffer[3+i*8]*16+buffer[4+i*8]*8+buffer[5+i*8]*4+buffer[6+i*8]*2+buffer[7+i*8]*1;
}
for(i=0;i<8;i++)
printf("%c",dest[i]);
printf("\n");
} 
}

void main()
{char c;unsigned char source[9], inkey[9]; int flg;
	printf("****************欢迎使用DES加密 ，解密算法*****************\n");
 while(1){
	printf("请选择:加密请输入 s;解密请输入d\n");
    scanf("%c",&c);
     if(c=='s')
	 {printf("请输入要加密的原文:");
      scanf("%s",source);
	   printf("请输入密钥:");
	  scanf("%s",inkey);
	   flg=1;
	   des(source,inkey, flg) ;
	 }
	 else if(c=='d')
	 {flg=0;
	 des(source2,'\0',flg);
	 }
}
}