模拟场景：192.168..5服务器上配置，通过ssh远程免密登录192.168.1.

1、安装SSH，此处省略
2、生成公钥和私钥，生成的秘钥默认在/root/.ssh/文件夹里面

[root@localhost ~ ::&&]# ssh-keygen #默认按enter直至结束

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/.ssh/id_rsa.pub.

The key fingerprint is:

SHA256:2GM5hi5CJhi+6JbmYkHfbbnNzYB3FoFUr+D50gGt9KQ root@localhost.localdomain

The key's randomart image is:

+---[RSA ]----+

|        ..o.     |

|         ....    |

|.        + o..   |

|oo     +o.O..    |

|+.+ . + SE +.    |

|.=.. o B =oo.    |

|..+ . o =.*o     |

|o= . . . o.o     |

|*o               |

+----[SHA256]-----+

3、把生成的公钥发送到对方的主机上去，用ssh-copy-id命令，自动保存在对方主机的/root/.ssh/authorized_keys文件中去

[root@localhost ~ ::&&]# ssh 192.168.1.160 #需要登录密码

[root@localhost ~ ::&&]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.1.160

[root@localhost ~ ::&&]# ssh 192.168.1.160 #免密登录