Rating:
# problem
[Re_Sign.zip](./Re_Sign.zip)
# exp
```
int main()
{
int int32_41E3D0[] = { 8, 59, 1, 32, 7, 52, 9, 31, 24, 36, 19, 3, 16, 56, 9, 27, 8, 52, 19, 2, 8, 34, 18, 3, 5, 6, 18, 3, 15, 34, 18, 23, 8, 1, 41, 34, 6, 36, 50, 36, 15, 31, 43, 36, 3, 21, 65, 65 };
char str_41E499[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
char base64_C[49] = {0};
for (int i = 0; i < 48; i++)
{
int temp_index = int32_41E3D0[i];
base64_C[i] = str_41E499[temp_index - 1];
}
cout <<"base64_C:"<< base64_C << endl;
char psss_list[65] = { 0 };
char list_41E380[] = { 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 91, 92, 73, 95, 90, 86, 69, 88, 93, 67, 85, 70, 82, 81, 95, 81, 80, 80, 80, 71, 70, 92, 118, 99, 108, 110, 85, 82, 67, 85, 92, 80, 95, 66, 67, 93, 79, 92, 84, 87, 85, 91, 94, 94, 90, 77, 64, 90, 76, 89, 82, 80, 21, 16 };
for (int i = 0; i <64; i++)
{
psss_list[i] = list_41E380[i] ^ i;
}
cout << "psss_list:" << psss_list << endl;
char str_re[100] = {0};
Base64_decode(base64_C, psss_list, str_re);
cout << "flag:" << str_re << endl;
getchar();
return 0;
}
```
# output
```
base64_C:H6AfGzIeXjSCP3IaHzSBHhRCEFRCOhRWHAohFjxjOeqjCU==
psss_list:0123456789QWERTYUIOPASDFGHJKLZXCVBNMqwertyuiopasdfghjklzxcvbnm+/
flag:de1ctf{E_L4nguag3_1s_K3KeK3_N4Ji4}
```
