Liunx两台服务器实现相互SSH免密登录

一、首先准备两台Linux虚拟机当作此次实验的两台服务器

服务器1：server        IPV4：192.168.110.136

服务器2：client         IPV4： 192.168.110.134

二、准备阶段

[root@server ~]# systemctl disable firewalld          #关闭防火墙

[root@server ~]# setenforce  0                                   #关闭seLiunx

[root@server ~]# getenforce

Permissive

[root@client ~]# systemctl disable firewalld          #关闭防火墙

[root@client ~]# setenforce  0                                   #关闭seLiunx

[root@client ~]# getenforce

Permissive

三、配置

server免密访问client

[root@server ~]# ssh-keygen -t rsa                                #此处为rsa密钥对
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Created directory '/root/.ssh'.
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:EtRb4lrkGMtSaa+JoG3bL2AfzUlJPbx114ZZyOmOf04 root@server
The key's randomart image is:
+---[RSA 3072]----+
|              .=     . B.  |
|          .* B o . B o  |
|          =.X B . o .   |
|          . . *.B     .    |
|       o . *.*S    o    |
|.       = o B.    . .    |
|       o = .       .  E  |
|          . +         ...  |
|            o.        o.  |
+----[SHA256]-----+

[root@server ~]# ll /root/.ssh/                                 #查看密钥匙目录
总用量 8
-rw-------. 1 root root 2590 10月 26 22:40 id_rsa               #私钥文件
-rw-r--r--. 1 root root  565 10月 26 22:40 id_rsa.pub         #公钥文件

[root@server ~]# ssh-copy-id root@192.168.110.134  #复制该公钥文件到服务端的该目录下
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.110.134 (192.168.110.134)' can't be established.
ED25519 key fingerprint is SHA256:rFpTMCYeFtLw16vHvNCtD7f+AutcLz68mnrlopUfino.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.110.134's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@192.168.110.134'"
and check to make sure that only the key(s) you wanted were added.

在client端查看文件

[root@client ~]# ll /root/.ssh/
总用量 4
-rw-------. 1 root root 565 10月 26 22:46 authorized_keys

[root@server ~]# ssh 192.168.110.134                 #使用SSH远程登录client

Register this system with Red Hat Insights: insights-client --register
Create an account or view all your systems at https://red.ht/insights-dashboard
Last login: Thu Oct 26 22:33:54 2023 from 192.168.110.1
[root@client ~]# 

免密登陆成功！！！

client免密访问server

[root@client ~]# ssh-keygen -t rsa                #此处为rsa密钥对
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:mmA+3Ih66Ue7yv1TBdvjbcsmmTKeK7U9rBEuW1NWOiU root@client
The key's randomart image is:
+---[RSA 3072]----+
|                            |
|        .                   |
|         +E o           |
|        . +=             |
|    o   So=o         |
|   =.+ +o+..o       |
|  .o=.=o=+ = .     |
| oo.o.o+++B +    |
|.o+oooo+== +    |
+----[SHA256]-----+

[root@client ~]# ll /root/.ssh/                #查看密钥匙目录
总用量 20
-rw-------. 1 root root  565 10月 26 22:46 authorized_keys  #server免密访问client生成的密钥
-rw-------. 1 root root 2590 10月 26 22:57 id_rsa                      #私钥文件
-rw-r--r--. 1 root root  565 10月 26 22:57 id_rsa.pub                 #公钥文件
-rw-------. 1 root root  843 10月 26 22:57 known_hosts              #记录服务端发来的公钥信息
-rw-r--r--. 1 root root   97 10月 26 22:57 known_hosts.old    #储之前连接过的 SSH 服务器的公钥

[root@client ~]# ssh-copy-id root@192.168.110.136    #复制该公钥文件到服务端的该目录下
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.110.136's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@192.168.110.136'"
and check to make sure that only the key(s) you wanted were added.

在server端查看文件

[root@server ~]# ll /root/.ssh/
总用量 20
-rw-------. 1 root root  565 10月 26 23:01 authorized_keys
-rw-------. 1 root root 2590 10月 26 22:40 id_rsa
-rw-r--r--. 1 root root  565 10月 26 22:40 id_rsa.pub
-rw-------. 1 root root  843 10月 26 22:46 known_hosts
-rw-r--r--. 1 root root   97 10月 26 22:46 known_hosts.old

[root@client ~]# ssh 192.168.110.136         #使用SSH远程登录server
Activate the web console with: systemctl enable --now cockpit.socket

Register this system with Red Hat Insights: insights-client --register
Create an account or view all your systems at https://red.ht/insights-dashboard
Last login: Thu Oct 26 22:57:34 2023 from 192.168.110.134
[root@server ~]# 

登陆成功！！！

实验结束实现服务器1server和服务器2client相互免密登录！