Wiki : ./Security/Password_Operations/Brute-Force.md

As soon as we have an understanding what the policy dictates we can create a mask or configure the right settings for brute-forcing.

Example

[Capital Letter]  [2 x lower case letters]  [2 x special chars]  [3 x numeric]

Crunch

Crunch is a [[Wordlists]] generator that can be used with a certain set of rules. It uses placeholders which translate to different characters for generating the list.

Placeholder character translation
@ Lower case alpha characters
, Upper case alpha characters
% Numeric characters
^ Special characters including space

To generate a list with a minimum and maximum of 8 characters in length and the example set we can use the following command:

  • Be aware that it will take up a lot of space.
$ crunch 8 8 -t ,@@^^%%%
Crunch will now generate the following amount of data: 172262376000 bytes
164282 MB
160 GB
0 TB
0 PB
Crunch will now generate the following number of lines: 19140264000 

To define a specific character set we can use the following syntax:

$ crunch 4 6 0123456789ABCDEF -o Upper_Number.txt

Crunch can also use a charset defined in a file

  • Check /usr/share/crunch/charset.lst for different options
$ crunch 4 6 -f /usr/share/crunch/charset.lst mixalpha -o output.txt

Tools