linux配置免密登陆

[root@VM-11-6-centos .ssh]# 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/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:z8OjvmpTfFsSN1+CIpMun3BvDE/YgO/ZoVU0g+j0wjk root@VM-11-6-centos
The key's randomart image is:
+---[RSA 2048]----+
|         . .     |
|        o . +    |
|       = + . +   |
|      . E + = . .|
|       +SO = o o |
|      o O+B . .  |
|       B &*=     |
|      o *.Bo     |
|     ..++o       |
+----[SHA256]-----+
[root@VM-11-6-centos .ssh]# ls
authorized_keys  id_rsa  id_rsa.pub

id_rsa.pub公钥传至authorized_keys或者手动复制

[root@VM-11-6-centos .ssh]# chmod 600 authorized_keys
[root@VM-11-6-centos ~]# chmod 700 .ssh/
[root@VM-11-6-centos .ssh]# scp id_rsa id_rsa.pub root@172.16.11.16:/root/.ssh/
The authenticity of host '172.16.11.16 (172.16.11.16)' can't be established.
ECDSA key fingerprint is SHA256:WKCT+eDW17GPtADwTCIxTnEssoynlYB/eIUly1D0y9w.
ECDSA key fingerprint is MD5:fd:16:cd:5a:d3:e9:bc:2b:67:27:97:aa:66:93:a5:33.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.16.11.16' (ECDSA) to the list of known hosts.
root@172.16.11.16's password: 
id_rsa                                       100% 1675     5.3MB/s   00:00    
id_rsa.pub                                   100%  401     1.6MB/s   00:00
[root@VM-11-6-centos .ssh]# exit
logout
Connection to 172.16.11.6 closed.
[root@VM-11-16-centos ~]# cd .
./       ../      .cache/  .config/ .pip/    .ssh/    
[root@VM-11-16-centos ~]# cd .ssh/
[root@VM-11-16-centos .ssh]# ls
authorized_keys  id_rsa  id_rsa.pub  known_hosts
[root@VM-11-16-centos .ssh]# ssh root@172.16.11.6
Last login: Tue Aug 16 17:26:28 2022 from 172.16.11.16
[root@VM-11-6-centos ~]# ^C