I am using Amazon's AWS insances running CentOS. I was trying to create a user with SUDO privilege and then disable the Root login to secure the systems. I have already done the required to bring this into effect but am now stuck with a problem I failed to understand.
When I created a User (say ABC) I did not set a password for it. Instead I use RSA Keys for authentication purpose.
Then I used
visudo command and added
ABC ALL=(ALL) ALL to the bottom of the file to give sudo privilege to this user.
Then I opened
vi and turned
no and restart sshd. this is to disable root access.
I was expecting this to be it, i.e. disabling root login and having ABC do all the required administrative task. But am badly stuck now.
My Problem is when I login a ABC and try to
sudo any command, it is asking for user passsword. This user does not have a password but a RSA Key with it, which i dont think can be used with SUDO.
I tried setting a password for this user using
passwd command. Thats does not work either. Am getting following error.
$ passwd Changing password for user kagzisa. Changing password for kagzisa (current) UNIX password: passwd: Authentication token manipulation error
I am just pressing enter key when it prompts for current password as there is no current password specified.
Now I am stuck as I have got the Root login disabled and am not able to sudo any commands from ABC. I cant loose this system as there are some important process running on it.
Is there a way through which I can fix this. Either by reactivating root or by able to sudo commands?