[SOLVED] What encryption does the /etc/shadow file use for passwords?

Karas · 11-26-2009, 01:29 PM

I am just wondering what encryption method the shadow file uses, so that I may be able to manually change it. I ask this because I am trying to make a web page that will allow people to change their linux password via a browser.

Or if anyone has any better ideas I am open to suggestions.

Thanks again.

TB0ne · 11-26-2009, 01:34 PM

Quote:

Originally Posted by Karas

I am just wondering what encryption method the shadow file uses, so that I may be able to manually change it. I ask this because I am trying to make a web page that will allow people to change their linux password via a browser.

Or if anyone has any better ideas I am open to suggestions.

Thanks again.

There are several that can be used, and what your options are, depends on your system and how you set it up. openSUSE uses Blowfish by default, others use MDx, etc.

And I would *NEVER* allow password changes via web page....so many security holes, it's not even funny. That said, it's your call...I'd use the default "passwd" program, and just pass it a string from the web form, and not code your own.

r3sistance · 11-26-2009, 01:44 PM

If you want to supply more information on what your intending to achieve might be able to give a better answer to this question. Are the customer's not able to use SSH for any particular reason?

I would advise that if you have a page that does anything around passwords that you ensure it's using an SSL certificate (ie an https:// page instead of a normal http://).

Karas · 11-26-2009, 02:34 PM

Customers can use SSH if they choose, but this is for a uni project, and I am meant to add extra value, one such value being web stuff, file upload, password changing and blog software etc.

How would I pass a string to passwd from a web page?

Would it be purely just: -

Quote:

<?php
exec ('echo "$userpass:$userpass" | passwd', $data, $ret)
?>

chrism01 · 11-26-2009, 07:01 PM

There is a non-interactive mode for the passwd cmd

echo password | passwd --stdin $USER