Store passwords of Linux users in plain text - on purpose

Question

I want to reset passwords temporarily to log in as root at least one time to change passwords. I have access to the hard drive and I can run a live distro to gain root access.

I did think it would be enough to change for each user the x in the second column of /etc/passwd, but this does not work.

basically you are asking how to reset a password - this is also already answered in Resetting password of another Linux — maxschlepzig, Aug 03 '14 at 20:14
Why do you think you need to store a password in plain text? You are almost certainly doing something complicated and useless. Tell us what you really want to do. — Gilles 'SO- stop being evil', Aug 03 '14 at 21:34
I would like to recover hosts I cannot log on anymore. I have access to the hard drive and I can run a live distro to gain root access. Isn't there a way to regain control? — user2964971, Aug 04 '14 at 14:17

Cristian Ciupitu · Answer 1 · 2014-08-03T19:05:00.133

2

The passwords are stored in the shadow file, not in /etc/passwd, so you need to delete the contents of the second column from /etc/shadow. An entry should look something like this:

root::16229:0:99999:7:::

edited Aug 03 '14 at 19:05

answered Aug 03 '14 at 18:48

Cristian Ciupitu

2,510

Did not work either. Neither an empty field nor any other record. – user2964971 Aug 03 '14 at 18:57
The second column records an encrypted password. How can I store a password in plain text there? Even if I remove a user from /etc/shadow at all, the second column in /etc/passwd is ignored. – user2964971 Aug 03 '14 at 19:04
No, there's no easy way to disable that, but you can generate a new "encrypted" one manually, for example by running openssl passwd -1 or the crypt function from C or some scripting language (e.g. Python, PHP, etc.). – Cristian Ciupitu Aug 03 '14 at 19:07
See also "How to make user passwords shown as a clear text in Linux?" here on the U&L SE. – Cristian Ciupitu Aug 03 '14 at 19:12

Store passwords of Linux users in plain text - on purpose

1 Answers1