Ubuntu设置使用SSH密钥远程登陆管理

$ ssh-keygen  <== 建立密钥对

Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): <== 按 Enter
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): <== 输入密钥锁码，或直接按 Enter 留空
Enter same passphrase again: <== 再输入一遍密钥锁码
Your identification has been saved in /root/.ssh/id_rsa. <== 私钥
Your public key has been saved in /root/.ssh/id_rsa.pub. <== 公钥
The key fingerprint is:
****************************

$ cd .ssh
$ cat id_rsa.pub >> authorized_keys
$ chmod 600 authorized_keys
$ chmod 700 ~/.ssh

$ vim /etc/ssh/sshd_config

RSAAuthentication yes
PubkeyAuthentication yes

PermitRootLogin yes              ####  允许以root身份登录
PasswordAuthentication no        ####  在SSH密钥登入测试完成后再修改此项！

$ service sshd restart