羊城杯re 复现

easyre

先base64加密，在换位，接着在进行了一些取余

#include<iostream>
#include<string>

std::string s1="EmBmP5Pmn7QcPU4gLYKv5QcMmB3PWHcP5YkPq3=cT6QckkPckoRG";

int main()
{
    int idx = 0;
    char a3;
    while (1) {
        for (int j = 0; j < 128; j++)
        {
            for (int i = 0; i < 39; ++i)
            {
                if (j <= 64 || j > 90)
                {
                    if (j <= 96 || j > 122)
                    {
                        if (j <= 47 || j > 57)
                            a3 = j;
                        else
                            a3 = (j - 48 + 3) % 10 + 48;
                    }
                    else
                    {
                        a3 = (j - 97 + 3) % 26 + 97;
                    }
                }
                else
                {
                    a3 = (j - 65 + 3) % 26 + 65;
                }
            }
            if (a3 == s1[idx])
            {
                std::cout << char(j);
                break;
            }
        }
        idx++;
        if (idx == s1.size())
            break;
    }
}

在换位和解base64即可

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