Editing John the Ripper Rules
To demonstrate JtR’s word mangling rules,
we have changed the password on our wifu AP to “Password123”.
Searching for “password” in the default wordlist displays the following output.
Our password is not included in the JtR wordlist
since JtR’s default mangling rules only append one digit to the end of each word.
We need three digits appended to our input.
Let’s add two additional rules that append two and three digits
to the end of each word in the wordlist.
The JtR mangling rules are located in a john configuration file.
With our new rules added,
let’s test their effectiveness.
We’ll run JtR in wordlist mode,
apply our newly edited rule,
and pipe the result to a grep command to search for our password.
We were able to find an exact match to our WPA passphrase,
so we know our new mangling rules are operating as intended.
Not only that, but we can see that JtR created more than four million strings
to try as a passphrase.