安全密钥验证
1、在客户端主机中生成“密钥对”并把公钥传送到远程服务器中：
[root@linuxprobe ~]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):直接敲击回车或设置密钥的存储路径
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 直接敲击回车或设置密钥的密码
Enter same passphrase again: 再次敲击回车或设置密钥的密码
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:
40:32:48:18:e4:ac:c0:c3:c1:ba:7c:6c:3a:a8:b5:22 root@linuxprobe.com
The key's randomart image is:
+--[ RSA 2048]----+
|+*..o . |
|*.o + |
|o* . |
|+ . . |
|o.. S |
|.. + |
|. = |
|E+ . |
|+.o |
+-----------------+
2、把客户端主机中生成好的公钥文件传送至远程主机：
[root@linuxprobe ~]# ssh-copy-id 192.168.10.10
The authenticity of host '192.168.10.20 (192.168.10.10)' can't be established.
ECDSA key fingerprint is 4f:a7:91:9e:8d:6f:b9:48:02:32:61:95:48:ed:1e:3f.
Are you sure you want to continue connecting (yes/no)? 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@192.168.10.10's password:此处输入远程服务器主机密码
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '192.168.10.10'"
and check to make sure that only the key(s) you wanted were added.
3、设置服务器主机只允许密钥验证，拒绝传统口令验证方式，记得修改配置文件后保存并重启sshd服务程序哦~：
[root@linuxprobe ~]# vim /etc/ssh/sshd_config
………………省略部分输出信息………………
74
75 # To disable tunneled clear text passwords, change to no here!
76 #PasswordAuthentication yes
77 #PermitEmptyPasswords no
78 PasswordAuthentication no
79
………………省略部分输出信息………………
[root@linuxprobe ~]# systemctl restart sshd
4、在客户端主机尝试登陆到服务端主机，此时无需输入密码口令也可直接验证登陆成功：
[root@linuxprobe ~]# ssh 192.168.10.10
Last login: Mon Apr 13 19:34:13 2017