[原创]CTF2019-1-CTF对抗-看雪-安全社区|安全招聘|kanxue.com

[原创]CTF2019-1

发表于: 2020-7-17 18:30 5380

[原创]CTF2019-1

wx_Assassin 活跃值

2020-7-17 18:30

5380

算法求逆

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int main()
{
    char *code = "KanXueCTF2019JustForhappy";
    char *temp_table = "abcdefghiABCDEFGHIJKLMNjklmn0123456789opqrstuvwxyzOPQRSTUVWXYZ";
    char flag[30];
    int len = strlen(code);
    for(int i = 0;i < len; i++){
        int index = 0;
        while(code[i]!=temp_table[index])index++;
        flag[i] = index < 10 ? index + 48 : (index <= 35 ? index + 87 : index + 29);
    }
    flag[len] = '\0';
    printf("%s\n",flag);
    return 0;
}