Context free grammar masks

[Kelob]

Hello all,
i'm curious, is there any way to use generative context free grammar for generating passwords? 

There are many patterns in the passwords that stem from some root and then are being embellished in a recursive manner, at the same  time, using word-lists, mutators or masks is not that far, so i guess some small recurcive grammar could be viable?

Thanks

[royce]

There is indeed some work in this space, by lakiw:

https://github.com/lakiw/pcfg_cracker

Not CFG per se IIRC, but this may also be of interest:

https://github.com/brannondorsey/PassGAN

[Kelob]

Thank you Royce,
as far as i understand, the both works work by pre-generating data into wordlists, which makes sense, however, it would be pretty great to have opportunity to specify such a grammar directly in Hashcat like the possibiilty for the masks,

also, i'm thinking about the following:
as in /Why not stick to regular expressions/ (https://hashcat.net/wiki/doku.php?id=rule_based_attack), are the masks generated on the GPU or CPU (when GPU is available)? Just thinking about where is the bottleneck and if creating CFG would make sense in the time/bottle-neck problem