Solution for challenge GDBug at the Insomni'hack 2022 CTF

gdbug.py

from string import ascii_uppercase
import itertools

def iter():
    for s in itertools.product(ascii_uppercase, repeat=24):
        s = list(s)
        s[4] = "-"
        s[9] = "-"
        s[14] = "-"
        s[19] = "-"
        yield "".join(s)

def solve():
    while True:
        for serial in iter():
            x = 0x539 # Setup the variables
            i = 0
            while (True):
                if (i >= len(serial)): # Go over the length of the string
                    break
                x += ord(serial[i]) # Append the hexadecimal value of the current character to 'x'
                i += 1
            print(f"Trying {serial}", end="\r")
            if (hex(0xb38)==hex(x)): # Check if the serial is a valid serial or not
                print(f"Found: INS{{{serial}}}")
                return # Remove this to see all possible flags

solve()