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Crunch

Crunch Description

Crunch is a wordlist generator where you can specify a standard character set or a character set you specify. crunch can generate all possible combinations and permutations.

Features

  • crunch generates wordlists in both combination and permutation ways
  • it can breakup output by number of lines or file size
  • now has resume support
  • pattern now supports number and symbols
  • pattern now supports upper and lower case characters separately
  • adds a status report when generating multiple files
  • new -l option for literal support of @,%^
  • new -d option to limit duplicate characters see man file for details
  • now has unicode support

Homepage: https://sourceforge.net/projects/crunch-wordlist/

Author: bofh28

License: GPLv2

Crunch Help

Usage:

crunch <min> <max> [options]

where min and max are numbers

Crunch can create a wordlist based on criteria you specify. The outout from crunch can be sent to the screen, file, or to another program. The required parameters are:

min-len

The minimum length string you want crunch to start at. This option is required even for parameters that won't use the value.

max-len

The maximum length string you want crunch to end at. This option is required even for parameters that won't use the value.

charset string

You may specify character sets for crunch to use on the command line or if you leave it blank crunch will use the default character sets. The order MUST BE lower case characters, upper case characters, numbers, and then symbols. If you don't follow this order you will not get the results you want. You MUST specify either values for the character type or a plus sign. NOTE: If you want to include the space character in your character set you must escape it using the \ character or enclose your character set in quotes i.e. "abc ". See the examples 3, 11, 12, and 13 for examples.

Crunch Options

-b number[type]

Specifies the size of the output file, only works if -o START is used, i.e.: 60MB The output files will be in the format of starting letter-ending letter for example:

./crunch 4 5 -b 20mib -o START 

will generate 4 files: aaaa-gvfed.txt, gvfee-ombqy.txt, ombqz-wcydt.txt, wcydu-zzzzz.txt valid values for type are kb, mb, gb, kib, mib, and gib. The first three types are based on 1000 while the last three types are based on 1024. NOTE There is no space between the number and type. For example 500mb is correct 500 mb is NOT correct.

-c number

Specifies the number of lines to write to output file, only works if -o START is used, i.e.: 60 The output files will be in the format of starting letter-ending letter for example: 

./crunch 1 1 -f /pentest/password/crunch/charset.lst mixalpha-numeric-all-space -o START -c 60

will result in 2 files: a-7.txt and 8-\ .txt The reason for the slash in the second filename is the ending character is space and ls has to escape it to print it. Yes you will need to put in the \ when specifying the filename because the last character is a space.

-d numbersymbol

Limits the number of duplicate characters. -d 2@ limits the lower case alphabet to output like aab and aac. aaa would not be generated as that is 3 consecutive letters of a. The format is number then symbol where number is the maximum number of consecutive characters and symbol is the symbol of the the character set you want to limit i.e. @,%^ See examples 17-19.

-e string

Specifies when crunch should stop early

-f /path/to/charset.lst charset-name

Specifies a character set from the charset.lst

-i

Inverts the output so instead of aaa,aab,aac,aad, etc you get aaa,baa,caa,daa,aba,bba, etc

-l

When you use the -t option this option tells crunch which symbols should be treated as literals. This will allow you to use the placeholders as letters in the pattern. The -l option should be the same length as the -t option. See example 15.

-m

Merged with -p. Please use -p instead.

-o wordlist.txt

Specifies the file to write the output to, eg: wordlist.txt

-p charset OR -p word1 word2 …

Tells crunch to generate words that don't have repeating characters. By default crunch will generate a wordlist size of #of_chars_in_charset ^ max_length. This option will instead generate #of_chars_in_charset!. The ! stands for factorial. For example say the charset is abc and max length is 4. Crunch will by default generate 3^4 = 81 words. This option will instead generate 3! = 3x2x1 = 6 words (abc, acb, bac, bca, cab, cba). THIS MUST BE THE LAST OPTION! This option CANNOT be used with -s and it ignores min and max length however you must still specify two numbers.

-q filename.txt

Tells crunch to read filename.txt and permute what is read. This is like the -p option except it gets the input from filename.txt.

-r

Tells crunch to resume generate words from where it left off. -r only works if you use -o. You must use the same command as the original command used to generate the words. The only exception to this is the -s option. If your original command used the -s option you MUST remove it before you resume the session. Just add -r to the end of the original command.

-s startblock

Specifies a starting string, eg: 03god22fs

-t @,%^

Specifies a pattern, eg: @@god@@@@ where the only the @'s, ,'s, %'s, and ^'s will change.

  • @ will insert lower case characters
  • , will insert upper case characters
  • % will insert numbers
  • ^ will insert symbols

-u

The -u option disables the printpercentage thread. This should be the last option.

-z gzip, bzip2, lzma, and 7z

Compresses the output from the -o option. Valid parameters are gzip, bzip2, lzma, and 7z. gzip is the fastest but the compression is minimal. bzip2 is a little slower than gzip but has better compression. 7z is slowest but has the best compression.

Crunch Usage Example

Example 1. crunch will display a wordlist that starts at a and ends at zzzzzzzz:

crunch 1 8

Example 2. crunch will display a wordlist using the character set abcdefg that starts at a and ends at gggggg:

crunch 1 6 abcdefg

Example 3. there is a space at the end of the character string. In order for crunch to use the space you will need to escape it using the \ character. In this example you could also put quotes around the letters and not need the \, i.e. "abcdefg ". Crunch will display a wordlist using the character set abcdefg that starts at a and ends at (6 spaces):

crunch 1 6 abcdefg\

Example 4. crunch will use the mixalpha-numeric-all-space character set from charset.lst and will write the wordlist to a file named wordlist.txt. The file will start with a and end with "        ":

crunch 1 8 -f charset.lst mixalpha-numeric-all-space -o wordlist.txt

Example 5. crunch should generate a 8 character wordlist using the mixalpha-number-all-space character set from charset.lst and will write the wordlist to a file named wordlist.txt. The file will start at cbdogaaa and end at "  dog   ":

crunch 8 8 -f charset.lst mixalpha-numeric-all-space -o wordlist.txt -t @@dog@@@ -s cbdogaaa

Example 6. crunch with start generating a wordlist at BB and end with ZZZ. This is useful if you have to stop generating a wordlist in the middle. Just do a tail wordlist.txt and set the -s parameter to the next word in the sequence. Be sure to rename the original wordlist BEFORE you begin as crunch will overwrite the existing wordlist:

crunch 2 3 -f charset.lst ualpha -s BB

Example 7. The numbers aren't processed but are needed:

crunch 4 5 -p abc

crunch will generate abc, acb, bac, bca, cab, cba.

Example 8. The numbers aren't processed but are needed. crunch will generate birdcatdog, birddogcat, catbirddog, catdogbird, dogbirdcat, dogcatbird.

crunch 4 5 -p dog cat bird

Example 9. crunch will generate bzip2 compressed files with each file containing 6000 words. The filenames of the compressed files will be first_word-last_word.txt.bz2:

crunch 1 5 -o START -c 6000 -z bzip2

time ./crunch 1 4 -o START -c 6000 -z gzip
real    0m2.729s
user    0m2.216s
sys     0m0.360s

time ./crunch 1 4 -o START -c 6000 -z bzip2
real    0m3.414s
user    0m2.620s
sys     0m0.580s

time ./crunch 1 4 -o START -c 6000 -z lzma
real    0m43.060s
user    0m9.965s
sys     0m32.634s

size  filename
30K   aaaa-aiwt.txt
12K   aaaa-aiwt.txt.gz
3.8K  aaaa-aiwt.txt.bz2
1.1K  aaaa-aiwt.txt.lzma

Example 10. will generate 4 files: aaaa-gvfed.txt, gvfee-ombqy.txt, ombqz-wcydt.txt, wcydu-zzzzz.txt the first three files are 20MBs (real power of 2 MegaBytes) and the last file is 11MB.

crunch 4 5 -b 20mib -o START

Example 11. will generate a 3 character long word with a character as the first character, and number as the second character, and a symbol for the third character. The order in which you specify the characters you want is important. You must specify the order as lower case character, upper case character, number, and symbol. If you aren't going to use a particular character set you use a plus sign as a placeholder. As you can see I am not using the upper case character set so I am using the plus sign placeholder. The above will start at a1! and end at c3#

crunch 3 3 abc + 123 !@# -t @%^

Example 12. will generate 3 character words starting with !1a and ending with #3c

crunch 3 3 abc + 123 !@# -t ^%@

Example 13

crunch 4 4 + + 123 + -t %%@^

the plus sign (+) is a place holder so you can specify a character set for the character type. crunch will use the default character set for the character type when crunch encounters a + (plus sign) on the command line. You must either specify values for each character type or use the plus sign. I.E. if you have two characters types you MUST either specify values for each type or use a plus sign. So in this example the character sets will be:

  • abcdefghijklmnopqrstuvwxyz
  • ABCDEFGHIJKLMNOPQRSTUVWXYZ
  • 123
  • !@#$%^&*()-_+=~`[]{}|\:;"'<>,.?/

there is a space at the end of the above string the output will start at 11a! and end at "33z ". The quotes show the space at the end of the string.

Example 14. any character other than one of the following: @,%^ is the placeholder for the words to permute. The @,%^ symbols have the same function as -t. If you want to use @,%^ in your output you can use the -l option to specify which character you want crunch to treat as a literal. So the results are:

crunch 5 5 -t ddd@@ -o j -p dog cat bird
birdcatdogaa
birdcatdogab
birdcatdogac
<skipped>
dogcatbirdzy
dogcatbirdzz

Example 15. crunch will now treat the @ symbol as a literal character and not replace the character with a uppercase letter. this will generate

crunch 7 7 -t p@ss,%^ -l a@aaaaa
p@ssA0!
p@ssA0@
p@ssA0#
p@ssA0$
<skipped>
p@ssZ9

Example 16. crunch will generate 5 character strings starting with @4#S2 and ending at @8 Q2. The output will be broken into 10KB sized files named for the files starting and ending strings.

crunch 5 5 -s @4#S2 -t @%^,2 -e @8 Q2 -l @dddd -b 10KB -o START

Example 17. crunch will generate 5 character strings staring with aab00 and ending at zzy99. Notice that aaa and zzz are not present.

crunch 5 5 -d 2@ -t @@@%%

Example 18. crunch will generate 10 character strings starting with aab!0001!! and ending at zzy 9998 The output will be written to 20mb files.

crunch 10 10 -t @@@^%%%%^^ -d 2@ -d 3% -b 20mb -o START

Example 19. crunch will gernerate 8 characters that limit the same number of lower case characters to 2. Crunch will start at aabaabaa and end at zzyzzyzz.

crunch 8 8 -d 2@

Example 20. crunch will load some japanese characters from the unicode_test character set file. The output will start at @日00 and end at @語99.

crunch 4 4 -f unicode_test.lst japanese -t @@%% -l @xdd

Crunch Redirection 

You can use crunch's output and pipe it into other programs. The two most popular programs to pipe crunch into are: aircrack-ng and airolib-ng. The syntax is as follows:

crunch 2 4 abcdefghijklmnopqrstuvwxyz | aircrack-ng /root/Mycapfile.cap -e MyESSID -w-
crunch 10 10 12345 --stdout | airolib-ng testdb -import passwd -

Crunch Notes

1. Starting in version 2.6 crunch will display how much data is about to be generated. In 2.7 it will also display how many lines will be generated. Crunch will now wait 3 seconds BEFORE it begins generating data to give you time to press Ctrl-C to abort crunch if you find the values are too large for your application.

2. I have added hex-lower (0123456789abcdef) and hex-upper (0123456789ABCDEF) to charset.lst.

3. Several people have requested that I add support for the space character to crunch. crunch has always supported the space character on the command line and in the charset.lst. To add a space on the command line you must escape it using the / character. See example 3 for the syntax. You may need to escape other characters like ! or # depending on your operating system.

4. Starting in 2.7 if you are generating a file then every 10 seconds you will receive the % done.

5. Starting in 3.0 I had to change the -t * character to a , as the * is a reserved character. You could still use it if you put a \ in front of the *. Yes it breaks crunch's syntax and I do my best to avoid doing that, but in this instance it is easier to make the change for long term support.

6. Some output is missing. A file didn't get generated. The mostly explaination is you ran out of disk space. If you have verified you have plenty of disk space then the problem is most likely the filename begins with a period. In Linux filenames that begin with a period are hidden. To view them do a ls -l .*

7. Crunch says The maximum and minimum length should be the same size as the pattern you specified, however the length is set correctly.

This usually means your pattern contains a character that needs to be escaped. In bash you need to escape the followings: &, *, space, \, (, ), |, ', ", ;, <, >.

The escape character in bash is a \. So a pattern that has a & and a * in it would look like this:

crunch 4 4 -t \&\*d@

An alternative to escaping characters is to wrap your string with quotes. For example:

crunch 4 4 -t "&*d@"

If you want to use the " in your pattern you will need to escape it like this: crunch 4 4 -t "&*\"@"

Please note that different terminals have different escape characters and probably have different characters that will need escaping. Please check the manpage of your terminal for the escape characters and characters that need escaping.

8. When using the -z 7z option, 7z does not delete the original file. You will have to delete those files by hand.

How to install Crunch

The program is pre-installed on Kali Linux.

Installation on Linux (Debian, Mint, Ubuntu)

Download the program source:

wget https://sourceforge.net/projects/crunch-wordlist/files/latest/download -O crunch-.tgz

Unpack

tar xvzf crunch-*.tgz

Compile:

cd crunch-*/
sudo make PREFIX=/usr INSTALL_OPTIONS=geninstall

Run it (portable):

./crunch

Installation:

sudo make install

After installation:

crunch

Crunch Screenshots

31

Crunch Tutorials

Coming soon…

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