Date: Sun, 21 Aug 2011 15:41:37 +0200 From: "madfran" <madfran@...-ezine.org> To: john-users@...ts.openwall.com Subject: Re: Some problems to build chr Hi, > Well, this is definitely becoming a FAQ. :-( We can't bring the same > topic up every 3 days, can we?.. It's like the third time this week. Perhaps the explanation is not very clear,... or perhaps the students are not so intelligent :-) > > # ./john --make-charset=lanman.chr > > Self test failed (pow64of32() overflow) > > This means that you set the params.h settings too high, beyond what's > supported. Please read the lengthy comment right before your edits. > Also, see this older posting for sample valid settings: > > http://www.openwall.com/lists/john-users/2007/07/04/6 > In my poor opinion, the referenced posting not give a so clear explanation. Perhaps better information is in the comments of params.h * Please note that certain intermediate values computed in charset.c while * generating a new charset file should fit in 64 bits. As long as * ((SIZE ** LENGTH) * SCALE) fits in 64 bits you're definitely safe, although * the exact requirement, which you can see in charset.c: charset_self_test(), * is a bit less strict. John will refuse to generate a charset file if the * values would overflow, so rather than do the math yourself you can simply * let John test the values for you. You can reduce the SCALE if required. If I understood well, to avoid a overflow: ((SIZE ** LENGTH) * SCALE) must fit in 64 bits. That means ((SIZE ** LENGTH) * SCALE) < 2**64 So, if I want to cover the complete range of characters (FF) the max. size must be 8 and the scale 1. 256**8*1 = 2**64 I am right?
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.