Reverseme: Easy Windows

To get back into the groove, I decided to try a crackme. After searching far and wide, I can’t seem to find where I got this from, other than crackmes.de.  One of my favorite sites.

Crackme.zip <– here it is in case it’s deleted.

And the solution is, with no analysis:


#include <iostream>
#include <string>
using namespace std;

int add_name_chars(string name) {
  int total = 0;
  for (int i=0; i<name.length(); i++) {
    total += name[i];
  }
  return total;
}

int main() {
  string name;
  cout<<"Name: ";
  cin>>name;

  unsigned int ser1 = 31 * add_name_chars(name) / 629u + 44431400;
  while (ser1 > 0x3b9ac9ff) {
    ser1 /= 10;
  }
  cout<<"Serial 1: "<<ser1<<endl;

  unsigned int ser2 = 82 * ser1 - 3;
  while (ser2 > 0x1869f)  {
    ser2 /= 10;
  }

  cout<<"Serial 2: "<<ser2<<endl;
  return 0;
}

Ok, one hint. All the logic is at 004013BC. This was rated as 1, for newbies, but it still took me awhile to figure out. I thought it was fun.

One Response to Reverseme: Easy Windows

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