Avoid duplicate attempts caused by the collision of different masks

[royce]

I'm not aware of anything that will easily pre-process a set of masks and do intersection / difference / etc.. And in this case, even if there were, depending on how much you had previously exhausted, it might produce quite a few more-specific masks. And there's a little autotuning overhead for each mask, so it might not even be worth the trade-off (faster to re-run the entire attack). You'd basically have to do the math and benchmark both options to see if it's worth the trade-off.

You could write something that would expand all possible ?l vs ?d variants, and then simply remove the ones you'd already exhausted.