This is an absolutely new machine and my current situation is I don't have root's password. I have a user (A) that has sudo privilege. I would like to create a user (B) which needs no password to log in. And I can only manipulate the machine through ssh.
$ whoami
A
$ sudo adduser -m B
$ sudo passwd -d B
passwd: password expiry information changed.
$ su - B
Password:
su: Authentication failure
$ sudo su - B
$ whoami
B
$ passwd -d B
passwd: Permission denied.
The above shows I cannot delete the password.
Why does this happen, and how can I fix it?