How to create new user with ssh access – Ubuntu 16.04

Log into your remote server as a root user or with an account with sudo privileges

Create Home and .ssh Directory

mkdir -p /home/yournewuser/.ssh

Create Authorized Keys File

touch /home/yournewuser/.ssh/authorized_keys

Create User and Set Home Directory for New User

useradd -d /home/yournewuser yournewuser

Add User to sudo Group for sudo privileges

usermod -aG sudo yournewuser

Set Password for User – Optional

This will allow access into the server without the need for your private key in as much as PasswordAuthentication is enabled in /etc/ssh/sshd_config.

passwd yournewuser

Disable Password Authentication on Your Server – Optional

This is optional but should only be done to improve security

nano /etc/ssh/sshd_config

This will disable your ability to log in via SSH using usernames and passwords. Inside the file, search for the line containing PasswordAuthentication. This may be commented out. Uncomment the line and set the value to “no”.

/etc/ssh/sshd_config
 
.
.
.
# Change to no to disable tunnelled clear text passwords
#PasswordAuthentication yes
.
.
.

Press CTRL X to save and close the file then Y to confirm, followed by ENTER to exit the editor

Restart SSH Server

systemctl restart ssh

Set Permissions

chown -R yournewuser:yournewuser /home/yournewuser/

chown root:root /home/yournewuser

chmod 700 /home/yournewuser/.ssh

chmod 644 /home/yournewuser/.ssh/authorized_keys

Generate SSH Key

Log into the new user to create SSH (Priv/Pub Keys)

su yournewuser

ssh-keygen -a 1000 -b 4096 -C "" -E sha256 -o -t rsa

Specify the location of ssh files as requested

/home/yournewuser/.ssh/authorized_keys

Final Steps – Optional

Covert generated private key to ppk for use with Putty

apt-get install putty-tools

puttygen authorized_keys -o authorized_keys.ppk