Can Not Add SSH Key To Ubuntu

4/17/16 – Fixed formatting.

I wanted to add an SSH key to a new minimal Debian VM install, but attempting to add the key resulted in a No such file or directory error.

sudo cat id_rsa.pub >> .ssh/authorized_keys
cat: id_rsa.pub: No such file or directory

The error was the result of the non-existent authorized_keys file which is where SSH key happens to be stored.

If we look inside the ~/.ssh directory you will notice the missing authorized_keys file.

ls ~/.ssh
known_hosts

To be able to store the SSH key create the missing authorized_keys in the right location and with the right permission.

Move to the directory where key files are stored for the user.

cd ~/.ssh

Create necessary file.

touch authorized_keys

Assign permission to file.

chmod 600 authorized_keys

Copy SSH key to authorized_keys file.

cat id_rsa.pub >> .ssh/authorized_keys

Optional, but I recommend removing the key since it’s no longer needed.

rm id_rsa.pub

Restart the service.

sudo service ssh restart