S盒的計算過程簡介

代碼實現（C#）

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;namespace S_box {class Program{//S 盒的簡單實現,利用二維數組來存儲 每一個S 盒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 = ""; // 用來存儲經過一個S 盒后 輸出的結果；//將長度為48 的字符串分割為長度為6 的8 個子串int one = 0;string[] splitattr = new string[8];// splitattr 存儲8 個子串for (int i = 0; i < 48; i++){splitattr[one] = splitattr[one] + attr[i];if (i % 6 == 5){one = one + 1;}}// 經過一個S 盒所需要的變換for (int i = 0; i < 8; i++){string attrone = splitattr[i];string heng = attrone[0].ToString() + attrone[5]; //取子串的第一位和最后一位string zhong = attrone[1].ToString() + attrone[2] + attrone[3] + attrone[4]; // 取中間的四位int comeout = 0; // 通過S盒確定的十進制數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;}//將結果轉換為二進制字符串end_attr = end_attr + Convert.ToString(comeout, 2).PadLeft(4, '0');}return end_attr;}static void Main(string[] args){string attr = "";Console.Write("請輸入二進制字符串(48位)：");attr = Console.ReadLine();if (attr.Length != 48){Console.WriteLine("字符串長度有問題！！！");}else{string one = box(attr);Console.WriteLine(one);}Console.ReadKey();}} }

總結

以上是生活随笔為你收集整理的DES密码 中 S盒的代码实现的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。