设置无密码登陆Linux
生成公钥和私钥
root登录后运行如下命令
ssh-keygen -t rsa Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): ##直接回车默认路径
Created directory '/root/.ssh'.
Enter passphrase (empty for no 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.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
04:e1:93:92:95:ba:55:21:58:05:7d:57:58:92:32:d3 root@vpn
The key's randomart image is:
+--[ RSA 2048]----+
| oB*o. ..=o |
| .+.+o = E. |
| o.+... = |
| ...o |
| o S |
| . |
| |
| |
| |
+-----------------+
在/root/.ssh/目录下生成了2个文件，id_rsa为私钥，id_rsa.pub为公钥。私钥自己下载到本地电脑妥善保存，公钥则可任意公开
导入公钥
cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys更改SSH配置文件
修改SSH的配置文件
vi /etc/ssh/sshd_config #RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys将前面的#去掉后保存 Centos7无RSAAuthentication选项 忽略
重启SSH服务，运行命令：
service sshd restart制作用于putty的私钥
将VPS上的/root/.ssh/id_rsa下载到本地，利用PUTTYGEN.EXE转换为putty用的ppk文件 (Save Private Key)
关闭SSH密码登陆
修改SSH的配置文件
vi /etc/ssh/sshd_config PasswordAuthentication no重启SSH服务
service sshd restart文章来源
https://teddysun.com/237.html