ssh免密码登陆配置方法，（图示加命令）

首先，说明一下咱们要作的是，serverA 服务器的 usera 用户免密码登陆 serverB 服务器的 userb用户。

咱们先使用usera 登陆 serverA 服务器

[root@serverA ~]# su - usera
[usera@serverA ~]$ pwd
/home/usera

 

 

而后在serverA上生成密钥对

[usera@serverA ~]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/usera/.ssh/id_rsa): 
Created directory '/home/usera/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/usera/.ssh/id_rsa.
Your public key has been saved in /home/usera/.ssh/id_rsa.pub.
The key fingerprint is:
39:f2:fc:70:ef:e9:bd:05:40:6e:64:b0:99:56:6e:01 usera@serverA
The key's randomart image is:
+--[ RSA 2048]----+
|          Eo*    |
|           @ .   |
|          = *    |
|         o o .   |
|      . S     .  |
|       + .     . |
|        + .     .|
|         + . o . |
|          .o= o. |
+-----------------+

 

 

 

此时会在/home/usera/.ssh目录下生成密钥对

 

[usera@serverA ~]$ ls -la .ssh
总用量 16
drwx------  2 usera usera 4096  8月 24 09:22 .
drwxrwx--- 12 usera usera 4096  8月 24 09:22 ..
-rw-------  1 usera usera 1675  8月 24 09:22 id_rsa
-rw-r--r--  1 usera usera  399  8月 24 09:22 id_rsa.pub

 

而后将公钥上传到serverB 服务器的，并以userb用户登陆

[usera@portalweb1 ~]$ ssh-copy-id userb@10.124.84.20
The authenticity of host '10.124.84.20 (10.124.84.20)' can't be established.
RSA key fingerprint is f0:1c:05:40:d3:71:31:61:b6:ad:7c:c2:f0:85:3c:cf.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '10.124.84.20' (RSA) to the list of known hosts.
userb@10.124.84.29's password: 
Now try logging into the machine, with "ssh 'userb@10.124.84.20'", and check in:

  .ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

 

 

这个时候usera的公钥文件内容会追加写入到userb的 .ssh/authorized_keys 文件中

 

[usera@serverA ~]$ cat .ssh/id_rsa.pub 
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA2dpxfvifkpswsbusPCUWReD/mfTWpDEErHLWAxnixGiXLvHuS9QNavepZoCvpbZWHade88KLPkr5XEv6M5RscHXxmxJ1IE5vBLrrS0NDJf8AjCLQpTDguyerpLybONRFFTqGXAc/ximMbyHeCtI0vnuJlvET0pprj7bqmMXr/2lNlhIfxkZCxgZZQHgqyBQqk/RQweuYAiuMvuiM8Ssk/rdG8hL/n0eXjh9JV8H17od4htNfKv5+zRfbKi5vfsetfFN49Q4xa7SB9o7z6sCvrHjCMW3gbzZGYUPsj0WKQDTW2uN0nH4UgQo7JfyILRVZtwIm7P6YgsI7vma/vRP0aw== usera@serverA

 

查看serverB服务器userb用户下的 ~/.ssh/authorized_keys文件，内容是同样的，此处我就不粘贴图片了。

 

[userb@serverB ~]$ cat .ssh/authorized_keys 
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA2dpxfvifkpswsbusPCUWReD/mfTWpDEErHLWAxnixGiXLvHuS9QNavepZoCvpbZWHade88KLPkr5XEv6M5RscHXxmxJ1IE5vBLrrS0NDJf8AjCLQpTDguyerpLybONRFFTqGXAc/ximMbyHeCtI0vnuJlvET0pprj7bqmMXr/2lNlhIfxkZCxgZZQHgqyBQqk/RQweuYAiuMvuiM8Ssk/rdG8hL/n0eXjh9JV8H17od4htNfKv5+zRfbKi5vfsetfFN49Q4xa7SB9o7z6sCvrHjCMW3gbzZGYUPsj0WKQDTW2uN0nH4UgQo7JfyILRVZtwIm7P6YgsI7vma/vRP0aw== usera@serverA

 

另外咱们要注意，.ssh目录的权限为700，其下文件authorized_keys和私钥的权限为600。不然会由于权限问题致使没法免密码登陆。咱们能够看到登录后会有known_hosts文件生成。

 

[useb@serverB ~]$ ls -la .ssh
total 24
drwx------.  2 useb useb 4096 Jul 27 16:13 .
drwx------. 35 useb useb 4096 Aug 24 09:18 ..
-rw-------   1 useb useb  796 Aug 24 09:24 authorized_keys
-rw-------   1 useb useb 1675 Jul 27 16:09 id_rsa
-rw-r--r--   1 useb useb  397 Jul 27 16:09 id_rsa.pub
-rw-r--r--   1 useb useb 1183 Aug 11 13:57 known_hosts

这样作完以后咱们就能够免密码登陆了

 

[usera@serverA ~]$ ssh userb@10.124.84.20