From the documentation


Maximum password length to try. The default is 8 (or CHARSET_LENGTH as defined in src/params.h at compile time).

I've compiled it to support up to 62 characters, modified john.conf, but when running john it returns:

Incompatible charset file: $JOHN/alnum.chr

That's when using --incremental=alnum, but happens with any method. Why does this happens? Which are the exact modifications or parameters to support 62 characters?

Thanks in advance.


The included charset files are based on the default maximum length. You'll need to generate charsets for your target length:

john --pot=rockyou.txt --make-charset=alnum62.chr

Existing files will be overwritten, so you'll probably want to choose a different filename from the default.

More in this thread.

| improve this answer | |
  • and .... when I run the custom charset, it will use the words in rockyou.txt? Or the characters? – Megver83 Sep 13 '17 at 22:33
  • Well, it's generating Markov stats by analyzing the combinations of characters in the list. So it's a little of both. :) – Royce Williams Sep 14 '17 at 0:13
  • and what if I do john --stdout --incremental=MODE | john --pot=- --make-charset=alnum62.chr I put --pot=- but how would it be? – Megver83 Sep 14 '17 at 0:27

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