Open SSH not support DSA default

Open SSH installed in Ubuntu 16.04, is not support DSA default.
If you would login SSH without password by using DSA pub-key, you may receive: root@localhost: Permission Denied.

Solutions below:
Solution I:
using RSA pub-key.

Solution II (support DSA):

1. Add the line of "PubkeyAcceptedKeyTypes=+ssh-dss" into /etc/ssh/sshd_config. Then restart the service of SSHD.
2. Create the file named config at /root/.ssh, then add the line of "PubkeyAcceptedKeyTypes=+ssh-dss" into it.