Centos实现SSH证书登录

出于安全考虑，我们建议使用SSH证书登录，这样被人破解的可能性会大大降低，秘钥方式不容易破解，秘钥传输数据是加密过的，而且一定程度上可以“防止中间人攻击”。
1.执行命令ssh-keygen -t rsa 生成密钥对

ssh-keygen -t rsa

按提示输入密码并确认

# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
\Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root