如何禁止掉root登录，使用key密钥登录

 在Linux系统下执行命令：

ssh-keygen -t rsa
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

vim /etc/ssh/sshd_config

AuthorizedKeysFile      .ssh/authorized_keys
RSAAuthentication       yes
PubkeyAuthentication yes
PasswordAuthentication no

service sshd restart