John the Ripper

https://www.openwall.com/john/doc/

Installer et lancer

Installer John

$sudo apt-get install john

Préparer le fichier

$sudo unshadow /etc/passwd /etc/shadow > mypasswd

Lancer la recherche de mots de passe

$sudo john mypasswd

Afficher les résultats

$sudo john –show mypasswd

Optimiser la recherche pour Ubuntu

Remplacer sha512 par md5 dans common-password: <licode file=/etc/pam.d/common-password>

1. here are the per-package modules (the "Primary" block)

password [success=1 default=ignore] pam_unix.so obscure sha512 </licode>

<licode file=/etc/pam.d/common-password>

1. here are the per-package modules (the "Primary" block)

password [success=1 default=ignore] pam_unix.so obscure md5 </licode>

Il faut recréer le fichier de mot de passe avec les commandes du paragraphe précédent.

Ajouter des dictionnaires

• https://crackstation.net/crackstation-wordlist-password-cracking-dictionary.htm
• http://contest-2012.korelogic.com/ (Download the password hash file bundle)
• http://contest.korelogic.com/wordlists/Feb-10-2011/final-fr-wikipedia.dic.gz
• http://downloads.skullsecurity.org/passwords/rockyou.txt.bz2

Lancer john en choississant un dictionnaire:

$sudo john -w:dictionnaire.txt mypasswd

Afficher l'avancement

$sudo john --status

While John the Ripper is running, press any key (like enter) to see a status output. Or to check from another terminal you can run john --status. The output looks like this:

DES cracking speed: 94g 0:01:08:34 74% 2/3 0.02284g/s 2784p/s 97648c/s 269491C/s day?..Hal?
1                   2   3          4   5   6          7       8        9         10

Here is what each section means:

1. Type of encryption it is trying to crack with
2. Number of successful password guesses
3. Time elapsed since started
4. Percent completed for that pass
5. Current pass / number of passes total
6. g/s = successful guesses per second
7. p/s = passwords tested per second
8. c/s = crypts (password hashes) computed per second
9. C/s = crypts tested per second (in versions below 1.8.0 this was “c/s”)
10. The current word it’s trying.