john-users - Re: 8-bit candidates (was: single mode)

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Thu, 24 Mar 2011 20:39:53 +0100
From: magnum <rawsmooth@...dband.net>
To: john-users@...ts.openwall.com
Subject: Re: 8-bit candidates (was: single mode)

On 2011-03-24 03:31, Solar Designer wrote:
>> Then how come a word with no 7-bit chars will be used, *and* paired?
>
> Not as the first word in a pair.  Maybe this needs to be changed or made
> configurable.
>
>> I know I
>> can crack foreign passwords completely lacking ascii, with single user
>> mode and the test words put in the GECOS field.
>
> Sure, without word pairing.

I see. This will be on my to-do list for the utf8 patch, if nothing 
else. Use them, but not truncated.

By the way, I have also tried a new character class for the utf8 patch 
and it may actually be equally useful without that patch:

  ?b  matches any character with 8th bit set

This lets you write rules that only affect 8-bit candidates, or the 
opposite. My experimental implementation is not very pretty but it works 
just fine. Not sure how to do it cleaner.

I also have plans for a few rules that are really utf-8 aware. Like 
case-shifting of *any* (applicable) UCS-2 character. That won't be near 
as quick as a bit flip, but hey, it will only do it if you ask for it.

thanks
magnum



diff --git a/src/rules.c b/src/rules.c
index 7ad95c0..8dfb1b4 100644
--- a/src/rules.c
+++ b/src/rules.c
@@ -185,6 +185,11 @@ static void rules_init_class(char name, char *valid)
 static void rules_init_classes(void)
 {
 	memset(rules_classes, 0, sizeof(rules_classes));
+	static unsigned char eightbitstring[129];
+	int i;
+	for(i=0;i<=128;i++)
+		eightbitstring[i] = i+128;
+	eightbitstring[128] = 0;
 
 	rules_init_class('?', "?");
 	rules_init_class('v', "aeiouAEIOU");
@@ -197,6 +202,7 @@ static void rules_init_classes(void)
 	rules_init_class('d', CHARS_DIGITS);
 	rules_init_class('a', CHARS_LOWER CHARS_UPPER);
 	rules_init_class('x', CHARS_LOWER CHARS_UPPER CHARS_DIGITS);
+	rules_init_class('b', &eightbitstring);
 	rules_init_class('Z', "");
 }