两台主机(服务器)秘钥登录流程图

我们从A主机(左边)秘钥登录到B服务器(右边)

A主机生成公钥

生成公钥私钥，一般不需要特殊设置一路回车默认下一步即可

> 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:+ims1qKnA9kAUbwuaGmGLdg+V4w1PMj7RO4gMHI7NCU root@JD
The key's randomart image is:
+---[RSA 2048]----+
|.+.              |
|. E .            |
|.  = o           |
|= = o *          |
|=%.o B oS        |
|O=O + =.         |
|+= o O.          |
|  + = *. .       |
|  oO.o .o        |
+----[SHA256]-----+

查看公钥

> ls -al ~/.ssh
-rw-------   1 root root  1675 May  7 21:39 id_rsa //私钥
-rw-r--r--   1 root root   389 May  7 21:39 id_rsa.pub //公钥

> cat id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDULg8kwT2rW8Z/r0h5lvO6KziZWV1roM/0eKVnkxeKOF9A0JAL46WF4ZA2XsNfG2camxTekC0ZwArB6uvFQTR8RZtDCwdsdsdsds6K3ytR/FOzira6z+7xbk6LvPylaCLfjfMmta04Q7dsdsdsdsdsds5MDr7oY73TWt2XToDA3FynMnl9MQjO4SoTU/Z1PiKsdOoCnbeP/O6KL+6sh9tbd5HoPPLm8LtDCeebZNhvZSulsbeTFZ5Z+HzPLostXJVhRFtiwUlaemAhXngVdIB5D9feXCYdQiP3NM0zAI94XUFCFyaSnZdv3+OTqHmxJ root@local

id_rsa.pub公钥要发送到B服务器。

B服务器添加A主机的公钥

在B服务器对应登录账号的家目录下的.ssh/authorized_keys文件添加A主机的公钥

比如我们要使用rumenz账号进行秘钥登录,就是配置
/home/rumenz/.ssh/authorized_keys

> cat /home/rumenz/.ssh/authorized_keys
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDULg8kwT2rW8Z/r0h5lvO6KziZWV1roM/0eKVnkxeKOF9A0JAL46WF4ZA2XsNfG2camxTekC0ZwArB6uvFQTR8RZtDCwdsdsdsds6K3ytR/FOzira6z+7xbk6LvPylaCLfjfMmta04Q7dsdsdsdsdsds5MDr7oY73TWt2XToDA3FynMnl9MQjO4SoTU/Z1PiKsdOoCnbeP/O6KL+6sh9tbd5HoPPLm8LtDCeebZNhvZSulsbeTFZ5Z+HzPLostXJVhRFtiwUlaemAhXngVdIB5D9feXCYdQiP3NM0zAI94XUFCFyaSnZdv3+OTqHmxJ root@local

给公钥及目录添加权限

> chmod 600 /home/rumenz//.ssh/authorized_keys
> chmod 700 /home/rumenz/.ssh

sshd服务安全配置

开启秘钥登录

> vim /etc/ssh/sshd_config
RSAAuthentication yes
PubkeyAuthentication yes

重启sshd服务

> service sshd restart

密钥方式登录成功后，再禁用密码登录

一定要秘钥登录成功后,再禁用密码登录。

> vim /etc/ssh/sshd_config
PasswordAuthentication no

> service sshd restart

秘钥登录测试

A主机的命令行输入

> ssh rumenz@B服务器ip
Last login: Tue Mar 23 22:23:22 2021

配置正确,直接就可以登录B服务器。