script to get to the root shell

ust · 04-18-2013, 11:09 PM

I would like to have a script , once run this script , it will go to the root shell , I tried the below but it is not work, can advise how can I do it ? thanks

su - root < /tmp/password.txt where password.txt is the plaintext of root password

p.s. this is testing only , please ignore the security issue.

roger_heslop · 04-18-2013, 11:39 PM

I can't think of a script, but if you're willing to ssh to the localhost, that could work for passwordless access.
Make sure your user has an ssh key generated via:

Code:

ssh-keygen -t rsa

Press enter throughout the prompts, the key here is to not enter a password, rather, have a blank password. Once this is done, copy the ssh id to the root profile so it has the matching key for authentication

Code:

ssh-copy-id root@localhost

Then to escalate without a password - ssh root@localhost.
If that's too much typing, put it in a bash shell with a short name in your bin directory. I just tested and it works

(You'll need the openssh-clients package for commands such as ssh-copy-id, just fyi)

ust · 04-19-2013, 12:16 AM

thanks reply , is there any simpler method ? thanks

eklavya · 04-19-2013, 12:20 AM

You can use ssh to reach on root command prompt

Code:

$ ssh ip-of-your-server

It will ask for password and now you will be logged in as root
If you do not want that it should ask password, copy your .pub file which is in user/.ssh and save in /root/.ssh as authorized_keys
Now next time when you log in to root, it will not ask password.

But if you do not want to use ssh and use sudo for root log in, you can use

Code:

sudo -i

It asks for your (user) password and you shift to root command prompt.
But if you do not want that it should ask password.
open /etc/sudoers
and uncomment following line

Code:

%sudo ALL=NOPASSWD: ALL

Now if you run sudo -i
it does not ask password and you will shift on root command prompt.

chrism01 · 04-19-2013, 12:36 AM

1. ssh auth keys (can even be used for a local login)
2. sudo NOPASSWD
3. expect tool - probably worst as it means putting passwd in the file in plaintext

I'll, take your word for it not being a security issue in this particular case ...

ust · 04-19-2013, 01:08 AM

thank your for replies ,

No script can do that ?

chrism01 · 04-19-2013, 02:15 AM

Put those cmds in a script..... actually, expect is a scripting tool, but the result is the same; you end up with a script you can call when reqd.

eklavya · 04-19-2013, 02:16 AM

Ofcourse You can use script to reach on root command prompt.

Code:

#!/bin/bash
sudo -i

If you have uncommented 'NOPASSWD' line in /etc/sudoers and you run above script, it takes you on root command prompt without asking any password.
************************

Code:

#!/bin/bash
ssh ip-of-your-server

If you have created authorized_keys in /root/.ssh and run above script, it takes you on root command prompt without asking any password.

TB0ne · 04-19-2013, 09:01 AM

Quote:

Originally Posted by ust

thank your for replies ,

No script can do that ?

After being a member here for TEN YEARS, can you not write a very simple script by now? Especially after asking dozens of questions about scripting, and being handed answers (and directed to scripting tutorials), MANY times.