S盒的计算过程简介
代码实现（C#）
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace S_box
{
class Program
{
static string box(string attr)
{
int[,] s1 = new int[4, 16] {
{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}
};
int[,] s2 = new int[4, 16] {
{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}
};
int[,] s3 = new int[4, 16] {
{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}
};
int[,] s4 = new int[4, 16] {
{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}
};
int[,] s5 = new int[4, 16] {
{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}
};
int[,] s6 = new int[4, 16] {
{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}
};
int[,] s7 = new int[4, 16] {
{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}
};
int[,] s8 = new int[4, 16] {
{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}
};
string end_attr = "";
int one = 0;
string[] splitattr = new string[8];
for (int i = 0; i < 48; i++)
{
splitattr[one] = splitattr[one] + attr[i];
if (i % 6 == 5)
{
one = one + 1;
}
}
for (int i = 0; i < 8; i++)
{
string attrone = splitattr[i];
string heng = attrone[0].ToString() + attrone[5];
string zhong = attrone[1].ToString() + attrone[2] + attrone[3] + attrone[4];
int comeout = 0;
switch (i)
{
case 0:
comeout = s1[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 1:
comeout = s2[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 2:
comeout = s3[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 3:
comeout = s4[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 4:
comeout = s5[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 5:
comeout = s6[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 6:
comeout = s7[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
case 7:
comeout = s8[Convert.ToInt32(heng, 2), Convert.ToInt32(zhong, 2)];
break;
}
end_attr = end_attr + Convert.ToString(comeout, 2).PadLeft(4, '0');
}
return end_attr;
}
static void Main(string[] args)
{
string attr = "";
Console.Write("请输入二进制字符串(48位)：");
attr = Console.ReadLine();
if (attr.Length != 48)
{
Console.WriteLine("字符串长度有问题！！！");
}
else
{
string one = box(attr);
Console.WriteLine(one);
}
Console.ReadKey();
}
}
}
