Why does john force MinLen to 8 for wpapsk?

Question

I'm trying to use john to test wpa security. I want it to generate 10-character passwords, so I've added this to john.conf:

[Incremental:Test]
File = $JOHN/alnum.chr
MinLen = 10
MaxLen = 10
CharCount = 62

However, when I run john --format=wpapsk --session=mysession --incremental=Test data, it prints:

Note: minimum length forced to 8

and still generates 8-character passwords. What am I missing?

score 1 · Answer 1 · answered Oct 31 '16 at 13:58

1

and still generates 8-character passwords. What am I missing?

"incremental" mode is limited to lengths up to 8 by default, at compile time.

How to deal with this ?

Download JTR source code

define CHARSET_MIN ' '
define CHARSET_MAX 0x7E
define CHARSET_LENGTH 8

with:

define CHARSET_MIN ' '
define CHARSET_MAX  0x7E
define CHARSET_LENGTH 10

./john --make-charset=digits10.chr

Now you can define a new "incremental" mode:

[Incremental:Digits10] 
File = $JOHN/digits10.chr 
MinLen = 10 
MaxLen = 10 
CharCount = 64

hope this will work for you

answered Oct 31 '16 at 13:58

Arjun sharma

Alright , please check the output of *./john -i=alnumspace.chr --stdout | head -1000000 | tail* and *./john -i=alnum.chr --stdout | head -1000000 | tail* – Arjun sharma Oct 31 '16 at 14:15
provide it here too – Arjun sharma Oct 31 '16 at 14:16
`"incremental" mode is limited to lengths up to 8 by default, at compile time.` — this is no longer true since [1.8.0](http://www.openwall.com/lists/announce/2013/05/30/1) – Eugene Yarmash Oct 31 '16 at 15:43
`john -i=alnumspace.chr --stdout | head -1000000 | tail Unknown option: "-i=alnumspace.chr"` – Eugene Yarmash Oct 31 '16 at 15:44

1 Answers1