GateWay 3.0 Decryptor

#define _CRT_SECURE_NO_WARNINGS true

#include <cstdio>
#include <memory>

void main() {
    FILE *IFile = fopen("Launcher.dat", "rb+");
    int *buffer = (int*)malloc(0x4000);
    fseek(IFile, 0x00012000, SEEK_SET);
    fread(buffer, 1, 0x4000, IFile);
    fclose(IFile);
    int state = 0;
    for (auto i = 0; i < 0x4000 / 4; i++) {
        state += 0xD5828281;
        buffer[i] += state;
    }
    IFile = fopen("first_stage_launcher_dec.dat", "wb+");
    fwrite(buffer, 0x1, 0x4000, IFile);
    fclose(IFile);
}