Adding PCFGs to Hashcat's Brain

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1) Just like there are many types of Markov attacks, (Hashcat Markov, JtR/Narayanan Markov, JtR Incremental, OMEN, etc), there are many ways to generate guesses with PCFGs. These different ways have pluses and minuses.

2) There is no single "best" way to generate guesses with PCFGs

3) In my previous guess generators, I prioritized probability order since I was approaching it mostly from a research/academic standpoint. I wanted to have the most "accurate" password guess generator, at the expense of many other things such as performance. With this approach there is no good index function.

I don't see a reason why not to stick to prioritized probability. That's what we want actually. Again I understood that you can not have a index function, but by calling the next function N times, that is a way to seek. It's slow, but it will work.

4) If you don't care about probability order, there are other methods that have indexing functions of various speeds. Heck, I wrote a proof of concept PCFG rainbow table back in the day when rainbow tables were still relevant. What this means is that a PCFG based approach could support sc_pcfg_seek

I care, that's the most important part.

6) I'd also like a new name for this approach so that it doesn't get confused with the probability order version.

Sure, but keep in mind that this is not what we're looking for.

7) If there is yet another version of an interface of hashcat's slow guess framework that doesn't require a "seek" function, I think that would be valuable for future work. My gut feeling though is that the Hashcat user-base would be more interested in an index version that has better support for restarting sessions, is faster with less memory usage, etc, even though it is significantly less accurate/precise. What that means is I'll probably focus on providing you a version of a pcfg guess generator that supports the five functions you requested.

Maybe I'll add princeprocessor as an example.