Generally when you tried to access Ubuntu vm on AWS server as user ‘root‘. You will find a message like below. It means you can’t SSH to your server directly using root account, and first you have to login as user ‘ubuntu’ first and then use ‘sudo su –‘ to get root access.

     Please login as the user “ubuntu” rather than the user “root”.

Warning => One of bigger security hole you are going to create in your server by opening direct root access. We recommend to not to do this until a more specific reason.

Enable SSH as root on AWS Ubuntu:

Follow the below steps to enable ssh as root user on AWS ubuntu instances. The same steps you can follow for other Linux distributions AWS instances like CentOS, RHEL, LinuxMint, Debian etc.

  • SSH to Server – Login to your server with ubuntu user and then switch to root user with sudo command.
    $ ssh -i server.pem [email protected]
    

    After successful login to ubuntu account switch to root account.

    $ sudo su -
    
  • Edit authorized_keys File – Now edit /root/.ssh/authorized_keys file the private key of yours. You will get something like code with your key.
    no-port-forwarding,no-agent-forwarding,no-X11-forwarding,command="
    echo 'Please login as the user "ubuntu" rather than the user "root".';
    echo;sleep 10" ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCPqJ2U4gidqek
    4FPQJABENkrUiLVP61LObdFAZXvs2EpCf/nBQCRg4ykMNg+8TC9lb7jC65zfIrTUcNcwongDb4
    3k6miSKu1M8fdqXDpcb8CdDRaKpM2wP8l+hTaJ2aWycXmGJ7lZKQPiwNUOhbrOLNEtDmOI9eiV
    lz7See98LVLW+6AwfzNA8Cu4riDTvEMQr/WQ9NLrS3BZE1TAAswJi9lGDfTgEvfh4Ji+eI/xT
    Xrjkkwjerkjk3jrkwejrkjwe9wASXob4rbV12TXjQIcMKaRGQAGrwOHu0nM2ibfTdgqjrTAG
    03CXKzQhF09LdxKlT7GpYe0oVU2R1kjkejwQp tecadmin.net
    

    Remove the highlighted text from authorized_keys file and your key should be look like this. There are no space before ssh-rsa text.

    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCPqJ2U4gidqek4FPQJABENkrUiLVP61LObd
    FAZXvs2EpCf/nBQCRg4ykMNg+8TC9lb7jC65zfIrTUcNcwongDb43k6miSKu1M8fdqXDpcb8C
    dDRaKpM2wP8l+hTaJ2aWycXmGJ7lZKQPiwNUOhbrOLNEtDmOI9eiVlz7See98LVLW+6AwfzNA
    8Cu4riDTvEMQrWQ9NLrS3BZE1TAAswJi9lGDfTgEvfh4Ji+eIxTXrjkkwjerkjk3jrkwejrkj
    we9wASXob4rbV12TXjQIcMKaRGQAGrwOHu0nM2ibfTdgqjrTAG03CXKzQhF09LdxKlT7GpYe0
    oVU2R1kjkejwQp tecadmin.net
    

    authorized-key-file

  • Save File – After removing above highlighted text from authorized_keys file, save it and try to ssh with root account.
    $ ssh -i server.pem [email protected]
    

    You will find that you have successfully logged in to server with root user directly.