Using hashcat Brain with slow hash and specific password length

[Toetje]

I am trying to attack a slow hash which I know has a length of 12 or more characters.

Since I want to use a rule based attack I am wondering how I can easily limit the amount of password candidates for cracking combined with the hashcat brain.

If I use the example wordlist:

Code:

123456789abcd
123456789abc
12345678
1234

combined with the example ruleset:

Code:

:
$1 $2 $3 $4
]

My desired output would be:

Code:

123456789abcd
123456789abcd1234
123456789abc
123456789abc
123456789abc1234
123456781234

Thereby skipping:

Code:

123456789ab
12345678
1234567
1234
12341234
123

When using an inline filter, it seems to only look at the length of the word before rules are applied:

Code:

hashcat64.bin -a 0 example.dic -r example.rule -j '>C' --stdout
123456789abcd
123456789abcd1234
123456789abc
123456789abc
123456789abc1234
123456789ab

This way I will miss the password 123456781234 while it will try the 11 character password 123456789ab.

I can pipe the output from hashcat to hashcat to remedy this:

Code:

hashcat64.bin -a 0 example.dic -r example.rule —session output --stdout | hashcat64.bin -j '>C' --stdout
123456789abcd
123456789abcd1234
123456789abc
123456789abc
123456789abc1234
123456781234

This works fine (especially because it is a slow hash), however I want to use the hashcat brain which does not accept stdin mode.

So this leaves me with 4 undesirable options:

-Don’t use hashcat brain
-Accept a large set of password candidates are just a waste of computational power since they will never find the correct password
-Create a (insanely large) dictionary file from all password candidates generated by the wordlist and rule that are 12 characters or longer and then start the attack.
-Create a (insanely large) dictionary file from all password candidates generated by the wordlist and rule that are 11 characters or shorter and feed this file to the hashcat brain with a faster hash, afterwards running the normal attack with brain active.

Am I skipping a nice feature of hashcat that I am unaware of and would solve my problem, or is there no better solution than already mentioned above?