生成PublicKey
建议设置并牢记passphrase密码短语，以Linux生成为例
Linux：ssh-keygen -t rsa
[私钥 (id_rsa) 与公钥 (id_rsa.pub)]
Windows：SecurCRT/Xshell/PuTTY
[SSH-2 RSA 2048]
生成SSH密钥对
ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): //建议直接回车使用默认路径
Enter passphrase (empty forno passphrase): //输入密码短语（留空则直接回车）
Enter same passphrase again: //重复密码短语
Your identification has been saved in/root/.ssh/id_rsa.
Yourpublic key has been saved in/root/.ssh/id_rsa.pub.
The key fingerprint is:
aa:8b:61:13:38:ad:b5:49:ca:51:45:b9:77:e1:97:e1 root@localhost.localdomain
The key's randomart image is:
+--[ RSA 2048]----+
| .o. |
| .. . . |
| . . . o o |
| o. . . o E |
|o.= . S . |
|.*.+ . |
|o.* . |
| . + . |
| . o. |
+-----------------+
在 /root/.ssh/... 下创建 <strong> authorized_keys </strong> 文件，然后执行：
cat id_rsa.pub >> authorized_keys
修改SSH配置文件
编辑sshd_config文件
vim /etc/ssh/sshd_config
禁用密码验证
PasswordAuthentication no
启用密钥验证
RSAAuthentication yes
PubkeyAuthentication yes
指定公钥数据库文件
AuthorsizedKeysFile.ssh/authorized_keys
重启SSH服务前建议多保留一个会话以防不测
RHEL/CentOS系统
service sshd restart
Ubuntu系统
service ssh restart
debian系统
/etc/init.d/ssh restart
手动增加管理用户
可以在== 后加入用户注释标识方便管理
echo 'ssh-rsa XXXX'>>/root/.ssh/authorized_keys
复查
cat /root/.ssh/authorized_keys
