Suppose you want to add another public key (
id_rsa.pub) on an existing non-sudoer user, e.g.
ftpuser for your teammate or another machine that you'll
sshing often and you want this user to have access to a specific dir. In this example we'll use
/var/www/html as the specific dir, also I'm using ubuntu as an example server.
1. (optional) where's the home dir of
If for some odd reason your non-sudoer user has a different home directory like
/var/www/html, you may want to move it back to its default dir and symlinking it instead:
# server sudo usermod -m -d /home/userA userA
.ssh dir and
authorized_keys file if not exists
# server mkdir /home/userA/.ssh && chmod 700 $_ touch authorized_keys && chmod 600 $_
3. symlink a directory (e.g.
# server # ln -s /var/www/html /home/userA/link_name ln -s /var/www/html /home/userA/www
authorized_keys file in
This is where we read keys that are authorized to log in:
# server # add/update this line accordingly AuthorizedKeysFile /home/old_user/.ssh/authorized_keys /home/userA/.ssh/authorized_keys
then restart it with
sudo service sshd restart
5. add client's public key (
id_rsa file) to server:
let's check if we have keys:
# client # check if there's any keys exists ls -al ~/.ssh # otherwise create one # for the rsa file you could # name it like userA_id_rsa ssh-keygen -t rsa -b 4096 -C "your comment" # start in background eval "$(ssh-agent -s)" # adds key to ssh-agent, it'll ask for passphrase ssh-add ~/.ssh/userA_id_rsa # copy public key to authorized_keys in server cat ~/.ssh/userA_id_rsa | ssh email@example.com -vvv "cat - >> /home/userA/.ssh/authorized_keys" # or if the sudo user uses key for loggin in cat ~/.ssh/userA_id_rsa | ssh firstname.lastname@example.org -vvv -i ~/.ssh/sudouser_id_rsa "cat - >> /home/userA/.ssh/authorized_keys"
6. then log in:
userA@host.domain -vvv -i ~/.ssh/userA_id_rsa # remember step 3 symlink? # once logged in successfully, confirm if # you can see /var/www/html in your home dir: # ls -la ~/home/userA/link_name ls -la ~/home/userA/www
saving ssh config
have some ssh config handy (
Host userA.domain HostName host.domain User userA PreferredAuthentications publickey IdentityFile ~/.ssh/userA_id_rsa IdentitiesOnly yes RemoteForward 52698 localhost: 52698
then log in
ssh userA.domain -vvv