Update hashcat mode rules for character class support

[solardiz]

Once https://github.com/hashcat/hashcat/pull/4107 is merged, we'll need to enable our class support in the purge command also in hashcat mode. It is currently disabled with the check here:

#define CLASS_export_pos(start, true, false) { \
        char value, *class; \
        if (((value = RULE) == '?') && !hc_logic) { \

This may be a bit complicated because:

1. It looks like hashcat is currently only adding class support to this one command, whereas we use the same macro for many commands.
2. hashcat will likely add exceptions where @? followed by some characters found in existing rulesets is treated the same as @??. We'll likely want to mimic those exceptions when in hashcat mode (or we'll need to update our copies of hashcat style rulesets to use @?? where appropriate - it's just 3 places).

[solardiz]

The referenced hashcat pull request has changed a lot since I posted the original description of this issue. It isn't yet clear what will actually go into hashcat, and thus what changes we need to make here, but now it looks likely that hashcat will implement character classes not only for the purge command, but for most or all commands where we support character classes.

[solardiz]

The hashcat PR referenced here got merged 2 weeks ago, and a new hashcat release was made today. So we need to review what actually got into hashcat and adapt our "hashcat logic" accordingly. cc: @matrix

[fukc-gihtub]

A number of other rules have been added to hashcat in the meantime: h, H, S, B, v.

[magnumripper]

A number of other rules have been added to hashcat in the meantime: h, H, S, B, v.

Did they add others back in August or were those the ones?

Here's what they do:

Hashcat	Description	Comment	JtR (clash or not)
h	convert the entire password to lowercase hex	I assume it means hello -> 68656c6c6f	free
H	convert the entire password to uppercase hex		free
S	shift the case of each char, JtR-like		Like it says, we have this.
B	add byte value of X at pos N, bytewise. ex: hello0 -> hello`	BNX	free
v	insert char X every N chars	vNX	vVNM: "update l (length), then subtract M from N and assign to variable V"

[fukc-gihtub]

BNX and vNX.

[solardiz]

Thanks @fukc-gihtub and @magnumripper. I don't understand this description of B, but anyway I think we should open a separate issue for these additions. This issue is to figure out what happened to character class support and mimic that.