What is Crunch? Free 2024 Guide, Generating Passwords Using Crunch

In this article, I will teach you What is Crunch? how you can generate passwords using Crunch. After you complete going through this blog you will figure out how to make a wordlist of different kinds including words with numbers, alphabets, etc.Also don’t forget check other interesting hacking articles on Hackingblogs

What is Crunch?

Crunch is a tool that is used to generate and create word lists of various types. This tool is pretty handy and it comes with a lot of functionality

• from supporting both mechanisms of cracking permutation and combinations
• Using numbers and symbols provides a status report
• resume option available
• Unicode support

Prerequisite

1.Kali or a system where Crunch is installed or the package manager has Cruch available
2.A bit of how combinations and brute attacks work.
3.Basic Linux Command Line usage

Installing Crunch On your System:-

To Install Crunch on Kali use the below command

sudo apt-get install crunch

To Check is successfully installed type

crunch

Using Crunch

Crunch Switches

Crunch Comes With A variety of different switches these switches can be used to get the results you are looking for. The switches range from size limiting to duplicating and excluding certain words etc.

Here are the switches you would most probably need while using crunch

-b to set the max size of the wordlist
-c to set the number of lines to write
-d to limit the number of duplicate words
-e to stop generating words at a certain strings
-z to compress the output field
-t to set a pattern
-r to resume

You can use the manual page or the help [-h] command to check more detailed switches

 man crunch

crunch -h

Let’s Generate

Password Generation Using Crunch

Crunch supports the generation of a wordlist containing alphanumeric characters. To generate such a combination to use crunch we run the following command :

crunch min max character set -o output file

Min – the minimum length of the password
Max – the max length of passwords
Character Set – Set of Characters To generate passwords.
Output file -o to store the results

Alpha-numeric Password Generation

Let’s generate a wordlist that has the minimum character of words containing 4 Characters to a max of 7 Characters using the following character [qwe1234]. To Generate a wordlist you will go and type the following command

crunch 4 7 qwe1234 -o wordlist.txt

Crunch will return the size and the total possible combinations are created.

Permutation For Wordlist Generation

There can be situations in which you know there is a word or phrase that is present for example your friend’s ram has wifi and to crack it you generate a password containing the term ram in it.
The results will be like following:
Ram123
Ram123pass
Rampassword….etc
You can use the -p switch to specify it
For example, to generate passwords containing the term hacking blogs we will use the following command via crunch :

crunch 4 5 -p 123pass hackingblogs

Generate a wordlist With Limited Words

This feature of crunch will help in generating a Wordlist up to a specified number of lines. Suppose we want it to generate a password but only till 20 lines we can use this functionality via the -c switch.

crunch 4 4 hack123 -c 15 -o wordlist.txt

so what this command will do is it will use the character from hack123 and create a wordlist of words with a length of 4 to a max length of 4 under 20 lines.

Compresses wordlist Generation

When we make a wordlist of a lot of words it takes a lot of space so we need to zip it up or in case of file transfer we need to compress it so that it won’t take a lot of space. This is where we use the -z flag and specify the kind of zip file we want bzip2, gzip, 7z, and luma

here is the command to generate a wordlist and then compress it to 7z compression

crunch 4 7 pass1234 -z 7z -o START

Frequently Asked Questions