linux基于key验证

第一步:在主机A上生成公钥私钥对

#查看/root/.ssh/目录中是否有公钥私钥对
[root@localhost ~]# ll /root/.ssh/
total 4
-rw-r--r-- 1 root root 512 Sep  8 17:32 known_hosts

#创建公钥私钥对(一直回车即可,创建的私钥会按照默认的格式创建)
[root@localhost ~]# ssh-keygen 
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:
SHA256:7wpX+TirC3Bbbl/O+x1znXI3DEQ3A8BMRqwYbp0LuDY root@localhost.localdomain
The key's randomart image is:
+---[RSA 2048]----+
|          *=.o.+ |
|       .  .+. . o|
|      o + o  .   |
|     . = + ..    |
|    . + S +  .   |
|     E + + o  o o|
|    . = + + o. B+|
|       = o *  o.*|
|        +++ +o. .|
+----[SHA256]-----+
#看到/root/.ssh/目录中已生成公钥私钥对

　　[root@localhost ~]# ll /root/.ssh/
　　total 12
　　-rw------- 1 root root 1831 Sep 8 18:19 id_rsa
　　-rw-r--r-- 1 root root 408 Sep 8 18:19 id_rsa.pub
　　-rw-r--r-- 1 root root 512 Sep 8 17:32 known_hosts

第二步:通过ssh-copy-id命令将主机A公钥传给需要key验证的主机B

[root@localhost ~]# ssh-copy-id root@10.0.0.50
/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@10.0.0.50's password:     (输入50主机的root密码)

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@10.0.0.50'"
and check to make sure that only the key(s) you wanted were added.

第三步:尝试基于key验证是否成功

[root@localhost ~]# ssh 10.0.0.50
Last login: Tue Sep  8 10:13:30 2020 from 10.0.0.8
操作系统注意事项:
1.不能随意使用root用户,如需使用请申请
2.操作前需对文件进行备份
3.请谨慎使用rm命令删除数据
[root@centos7 ~]#