[SOLVED] Tool to check user passwords

linuxguy7820 · 02-25-2013, 09:37 AM

Hello:

I am looking for a tool that will try to crack user passwords on the system or determine how strong their password is. I would prefer just having a tool that could determine a users password weakness though.

_thanks

shivaa · 02-25-2013, 09:45 AM

Look, there is no defined criteria for password strength. But for online as well as personal security reasons, it's always recommended to use a password that is a combinations of uppercase, lowercase, special characters and numbers. Such a password will call a 'strong' password.

In the meantime, you can use following link from Microsoft for password strength checker. (Check here). Just type in any password, and it will show you it's strength.

linuxguy7820 · 02-25-2013, 10:04 AM

I'm doing auditing of linux builds, part of that is to determine how strong service account passwords are. I don't know what the passwords are set to on the box which is why I'm looking for a tool that can scan the /etc/password and shawdow files to determine how secure they are.

TobiSGD · 02-25-2013, 10:08 AM

You can't read out the password from /etc/passwd or /etc/shadow, only the hashes of those passwords, so it is impossible to say if a password is strong or not. You can try to crack the passwords, for example with John the Ripper, but it can literally take years to do so.

linosaurusroot · 02-25-2013, 10:11 AM

Quote:

Originally Posted by shivaa

it's always recommended to use a password that is a combinations of uppercase, lowercase, special characters and numbers. Such a password will call a 'strong' password.

false - long passwords can be equally strong and more memorable

http://xkcd.com/936/

https://www.usenix.org/publications/...tter-passwords

linosaurusroot · 02-25-2013, 10:15 AM

Quote:

Originally Posted by TobiSGD

try to crack the passwords, for example with John the Ripper, but it can literally take years to do so.

But for audit purposes you might accept anything not cracked in a week as adequate. My experience is when weak passwords are in use some of them are very weak.

Quote:

I don't understand why I have to change my password.
It was cracked in 2 seconds ... let me do that again ... "record1", ok?
But it's not a dictionary word!

shivaa · 02-25-2013, 10:15 AM

Quote:

Originally Posted by linuxguy7820

I'm doing auditing of linux builds, part of that is to determine how strong service account passwords are. I don't know what the passwords are set to on the box which is why I'm looking for a tool that can scan the /etc/password and shawdow files to determine how secure they are.

In that case, you should better define some rules or policy for using a strong password.

Check following files, where such rules can be defined:

Code:

~$ cat /etc/default/useradd
~$ cat /etc/pam.d/common-auth