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I need to ssh to localhost using root account, by ssh root@localhost. When it prompts for passwords, I can not login with all possible passwords. On setting of localhost machine, regular user xxx and root user share the same password (the password that works for sudo -s), but it does not works for ssh root@localhost. So where to look at the password for ssh root@localhost

PS: with the password, I can login to regular account on ssh xxx@localhost.

PPS: to answer further questions on motivation of doing so, localhost is just a computer in a private network and setting up ssh root@localhost is just to relieve some manual management in a prototype system.

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    Are you doing this in a script, or is this for interactive use? If interactive, why not just log in as some other user and then use sudo as needed? If for a script, then you really shouldn't be using password authentication anyway, since it means you have to put the password in plaintext in the script.
    – Daniel Pryden
    Aug 3, 2012 at 15:46
  • I am doing this in a script, but a passphraseless ssh based on public/private key is intended to setup, so password is not really stored in plaintext. Good comments, though
    – Richard
    Aug 4, 2012 at 14:50

6 Answers 6

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ssh root@localhost uses the same password for root. It looks like you have not set root password. To do that log in as root using sudo -s then use passwd command to set root password.

After that you must be able to ssh as root

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    this works. just out of curiosity, is there any difference between the root account when doing sudo -s and when doing ssh root@localhost ?
    – Richard
    Aug 3, 2012 at 12:20
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    you should never do that, if you set a password for the user root you will enable the user root and this is a really bad move for the system's security.
    – user827992
    Aug 3, 2012 at 13:53
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    @user827992 it is necessary to enable the user root to take advantage of ehealth-aussie.blogspot.com/2012/01/…. However, you can mitigate the security damage by disabling root login for openssh. dropbear will allow root login but only with a key and only for the brief time between power on and decryption.
    – emory
    Aug 3, 2012 at 14:56
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If you decide to use the root account.

Disable the ability to log in over ssh with root if ssh is exposed to internet. Instead login as a user, and su to root.

This will make sure to prevent brute force attacks against your computer. Since its harder to guess both the user and password. Knowing the username one would only have to brute force the password

changing the line:

PermitRootLogin yes

under /etc/ssh/sshd_config

to

PermitRootLogin no

and run:

service sshd restart

to reload the configuration.

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Login as a normal user and use sudo -i to drop to a root shell.

You should not use the root account or change it's password for the matter.

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The user root is not enabled and is not capable of doing a log in, you can see that doing so:

sudo grep root /etc/shadow

the field that usually contains an encrypted password is filled with a !.

If you read the shadow(5) manpage you will get this

If the password field contains some string that is not a valid result of crypt(3), for instance ! or *, the user will not be able to use a unix password to log in (but the user may log in the system by other means).

You should not enable the user root for security reasons.

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set root password using following command

sudo passwd
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  • Your answer while possible may be a bit late as the OP already accepted the other answer. Your help is of course appreciated, however you might be better served by focusing your efforts on the unanswered questions
    – Wayne_Yux
    Jun 17, 2016 at 7:59
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They answered your question about login to ssh with non super user (say [email protected] -p 22).

First create another account without su privleges. After you log into ssh as a non super user you can enter this command to switch to root (escalate your privileges):

su

And enter password.

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    they scripted it that way for security reasons. dont enter root as your username enter a non super user and the enter password for non superuser and the su to superuser (su stands for substitute user) its less safe letting you ssh directly into root than it is ssh-ing into average user and Substituting user or escalating privledges sudo stands for super user Do so while in a normal user account you can always type sudo before your actual command and it will grant superuser privleges for That command. <3 happy Linux-ing <3
    – Sean KaliLinux Calcagni
    Nov 22, 2016 at 18:32

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