Linux change user password from root

How To Linux Set or Change User Password

Linux Set User Password

Type following passwd command to change your own password:
$ passwd
Sample Outputs:

The user is first prompted for his/her old password if one is present. This password is then encrypted and compared against the stored password. The user has only one chance to enter the correct password. The super user is permitted to bypass this step so that forgotten passwords may be changed. A new password is tested for complexity. As a general guideline, passwords should consist of 10 to 20 characters including one or more from each of following sets:

1. Lower case alphabetics
2. Upper case alphabetics
3. Digits 0 thru 9
4. Punctuation marks/spacial characters

Linux change password for other user account

You need to login as the root user, type the following command to change password for user vivek:
# passwd vivek
OR
$ sudo passwd vivek
Sample putput:

• vivek – is username or account name.

Passwords do not display to the screen when you enter them. For example:

Linux changing user password using passwd

Linux Change Group Password

When the -g option is used, the password for the named group is changed. In this example, change password for group sales:
# passwd -g sales
The current group password is not prompted for. The -r option is used with the -g option to remove the current password from the named group. This allows group access to all members. The -R option is used with the -g option to restrict the named group for all users.

Changing user passwords on Linux

As a Linux system administrator (sysadmin) you can change password for any users on your server. To change a password on behalf of a user:

1. First sign on or “su” or “sudo” to the “root” account on Linux, run: sudo -i
2. Then type, passwd tom to change a password for tom user
3. The system will prompt you to enter a password twice

To change or set a new root (superuser) password type:
$ sudo passwd

Forcing Linux user to change password at their next login

By default, Linux passwords never expire for users. However, we can force users to change their password the next time they log in via GUI or CLI methods. The syntax is straightforward:
$ sudo passwd -e
$ sudo passwd —expire
Let us immediately expire an account’s password:
$ sudo passwd -e marlena
The system will confirm it:

When user try to login via ssh command, they will see the following on screen:

Locking and Unlocking user password of the named account

Note that the following local command does not disable the account. The user may still be able to login using another authentication token, such as an SSH key. To disable the account, administrators should use either usermod —expiredate 1 or sudo passwd —expire command. Also, users with a locked password are not allowed to change their password to get around the security policy set by sysadmin.

We can lock the password as follows:
$ sudo passwd -l
This option disables a password by changing it to a value which matches no possible encrypted value (it adds a ! at the beginning of the password in the /etc/shadow file. Want to unlock the password, try:
$ sudo passwd -u
The above command option re-enables a password by changing the password back to its previous value. In other words, to the value before using the -l option.

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A note about setting up a secure Linux password

Compromises in password security typically result from careless password selection. Avoid common password such as:

1. Words which appears in a dictionary
2. Your first and last name
3. Pet names
4. Kids or spouses names
5. License number
6. Date of birth (DoB)
7. Home or office address

I strongly recommend that you generate a unique password for all user accounts using your chosen password manager.

Conclusion

The passwd command line utility is used to update or change user’s password. The encrypted password is stored in /etc/shadow file and account information is in /etc/passwd file. To see all user account try grep command or cat command as follows:
$ cat /etc/passwd
$ grep ‘^userNameHere’ /etc/passwd
$ grep ‘^tom’ /etc/passwd
The guidance given in this quick tutorial should work with any Linux distribution, including Alpine, Arch, Ubuntu, Debian, RHEL, Fedora, Oracle CentOS, SUSE/OpenSUSE and other popular Linux distros.

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How to change root password in Ubuntu Linux

I am a new Ubuntu Linux server admin. How can I change root password in Ubuntu Linux server using the bash shell over ssh based session?

By default, the root user account password is locked in Ubuntu Linux for security reasons. As a result, you can not login using root user or use a command such as ‘su -‘ to become a SuperUser.

Tutorial details
Difficulty level	Easy
Root privileges	Yes
Requirements	Ubuntu
Est. reading time	1m

You need to use the passwd command to change the password for user accounts on Ubuntu Linux. A typical user can only change the password for his/her account only. A SuperUser (root) can change the password for any user account. Your user account info stored in /etc/passswd and an encrypted password stored in /etc/shadow file.

How to change root password in Ubuntu

The procedure to change the root user password on Ubuntu Linux:

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1. Type the following command to become root user and issue passwd:
   sudo -i
   passwd
2. OR set a password for root user in a single go:
   sudo passwd root
3. Test it your root password by typing the following command:
   su —

How to disable your root account on Ubuntu

One can disable the root account by typing the following command:
$ sudo passwd -dl root
OR
$ sudo passwd —delete —lock root
Sample session from the above commands:

Understanding passwd command option

• -d OR —delete : Delete a user’s password (make it empty for root user). This is a quick way to disable a password for an account. It will set the named account passwordless.
• -l OR —lock : Lock the password of the named account such as root. This option disables a password by changing it to a value which matches no possible encrypted value (it adds a ‘!’ at the beginning of the password)
• root : Lock and disble root account i.e. re-disabling your root account

A note about root password on an Ubuntu server/desktop

Enabling the root account by setting the password is not needed. Almost everything you need to do as SuperUser (root) of an Ubuntu server can be done using sudo command. For example, restart apache server:
$ sudo systemctl restart apache2
You can add additional user to sudo by typing the following command:
$ sudo adduser sudo
For example, add a user named tom to sudo:
$ sudo adduser tom sudo
You can in as another user say logging as tom from jerry account:
< jerry@nixcraft >$ sudo -i -u tom
When prompted enter jerry’s password i.e. the password being asked for is your own, not tom’s. For more info see “How to create a new sudo user on Ubuntu Linux server” and RootSudo.

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How do I change a user password in Ubuntu Linux?

W e recently switched from Windows server operating system to Ubuntu Linux operating system at work. I am a developer by profession and do not know much about Linux. I need to change the sftp/ssh user account password on Ubuntu. How do I change a user password in Ubuntu Linux?

Introduction – Your Ubuntu Linux account information stored in a file named /etc/passwd and encrypted password in /etc/shadow . This page explains to you how to change the Ubuntu Linux root and user account password using the passwd command line.

Tutorial details
Difficulty level	Easy
Root privileges	Yes
Requirements	Ubuntu Linux
Est. reading time	2 minutes

How to change a user password in Ubuntu

1. Open the terminal application by pressing Ctrl + Alt + T
2. To change a password for user named tom in Ubuntu, type:
   sudo passwd tom
3. To change a password for root user on Ubuntu Linux, run:
   sudo passwd root
4. And to change your own password for Ubuntu, execute:
   passwd

How to change a root (superuser) password in Ubuntu

Firstly, open a terminal window. If you want to change the password for remote Ubuntu server, log in using the ssh command:
ssh user@ubuntu-server-ip
ssh vivek@ubuntu-webserver-1
Type ‘sudo -i’ at the command prompt, and Enter key:
sudo -i
Type the current user password and press Enter key. Finally type NA command and press Enter to change password for root user:
passwd

Change password for root user on Ubuntu

How do I change the user account password on Ubuntu?

Again open a terminal window. Type the following command to change the password for regular Ubuntu user account named jerry:
sudo passwd < userNameHere >
sudo passwd jerry ## ##
sudo passwd vivek ## ##

How to change the user Password in Ubuntu Linux

Deleting a user password

Users will not be able to log in when the password is deleted or expired on Ubuntu Linux.

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The syntax is as follow to remove the password for the account called tom:
sudo passwd -d tom
## OR ##
sudo passwd —delete jerry
You will see confirmation on screen as follows:

To set up a new password when deleted, run:
sudo passwd -d tom
We can also force expire the password for the named account jerry. Open the terminal and then type the following command:
sudo passwd -e jerry
sudo passwd —expire jerry
When user login they will be forced to reset their credentials when you use the -e / —expire option:

Linux locking an account

sudo passwd -l
sudo passwd -l tom

Linux unlocking an account

sudo passwd -u
sudo passwd -u tom

Conclusion

This quick tutorial taught you how to change the Ubuntu Linux root user and other user account password using the passwd command. You must root user to change the password for all other users, however users can change their password without sudo access. For more info see the passwd command help page using the man command man passwd

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For your own password:
passwd
For root password:
sudo passwd root

FYI, we don’t set root password on Ubuntu for security reasons. One user will be added to the ‘sudo’ group and that will act as admin user. This ensures safety as root account without password is locked and cannot be used for ssh.

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