SSH秘钥生成和使用

1. 生成秘钥对
[root@localhost ~]# ssh-keygen -t rsa       #生成密钥对，-t代表类型，有RSA和DSA两种
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):   #密钥文件默认存放位置，按Enter即可
Created directory ‘/root/.ssh‘.
Enter passphrase (empty for no passphrase):     #输入密钥锁码，或直接按 Enter 留空
Enter same passphrase again:     
Your identification has been saved in /root/.ssh/id_rsa.    #生成的私钥
Your public key has been saved in /root/.ssh/id_rsa.pub.    #生成的公钥
The key fingerprint is:
SHA256:K1qy928tkk1FUuzQtsdfsdf6dfdfPvHw9lQ+KNuZ4 root@localhost.localdomain
The key‘s randomart image is:
+---[RSA 2048]----+
|           +.    |
|          o * .  |
|        . .O +   |
|       . *. *    |
|        S =3+     |
|    .    =...    |
|    .oo =+ov+     |
|     ==o+B*3o.    |
|    oo.3=EXO.     |
+----[SHA256]-----+

2. 分发公钥
ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.1.2
#修改权限
chmod 600 /root/.ssh/authorized_keys

3. 锁定秘钥文件,不能被更改
chattr +i /root/.ssh/id_rsa.pub
chattr +i /root/.ssh/authorized_keys