9.openssh-serve (linux)

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9.openssh-serve (linux)

余二五 2017-11-14 17:18:00 浏览745
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1.openssh-server

功能:让远程主机可以通过网络访问sshd服务,开始一个安全shell

2.客户端连接方式
ssh 远程主机用户@远程主机ip
操作过程

[root@desktop0 ~]# ssh root@172.25.0.11
The authenticity of host '172.25.0.11 (172.25.0.11)' can't beestablished.
ECDSA key fingerprint is eb:24:0e:07:96:26:b1:04:c2:37:0c:78:2d:bc:b0:08.
Are you sure you want to continue connecting (yes/no)? yes  ##连接陌生主机时需要建立认证关xi
Warning: Permanently added '172.25.0.11' (ECDSA) to the list of known hosts.
root@172.25.0.11's password:                ##远程用户密码
Last login: Mon Oct  3 03:13:472016
[root@server0 ~]#                   ##登陆成功


ssh 远程主机用户@远程主机ip -X              ##调用远程主机图形工具
ssh     远程主机用户@远程主机ip     command     ##直接在远程主机运行某条命令

操作截图
wKiom1jsZ6rRVyhtAAHfmH-KXBw768.png-wh_50

3.sshkey加密
1).生成公钥私钥

操作过程
[root@server0 ~]# ssh-keygen        ##生成公钥私钥工具
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):[enter]     ##加密字符保存文件(建议用默认)
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):         [enter]     ##密钥密码,必须>4个字符
Enter same passphrase again:                [enter]     ##确认密码
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:                     
ab:3c:73:2e:c8:0b:75:c8:39:3a:46:a2:22:34:84:81 root@server0.example.com
The key's randomart image is:
+--[ RSA 2048]----+
|o                |
|E.               |
|..               |
|.  . o           |
|.o. * . S        |
|oo.o o   .       |
|+ =. .  .        |
|o. oo.+..        |
|    ..o*.        |
+-----------------+
[root@server0 ~]# ls /root/.ssh/
id_rsa  id_rsa.pub
id_rsa      ##私钥,就是钥匙
id_rsa.pub  ##公钥,就是锁
操作后截图

wKiom1jsaN7hCozYAADylUNNQ44541.png-wh_50

wKiom1jsaN6QTrXAAACEKDAmliQ003.png-wh_50


2.添加key认证方式

操作过程
[root@server0 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub  root@172.25.254.244
ssh-copy-id     ##添加key认证方式的工具
-i          ##指定加密key文件
/root/.ssh/id_rsa.pub   ##加密key
root            ##加密用户为root
172.25.254.244    ##被加密主机ip

wKioL1jsac7g_UCAAAHq_r6Gzrw044.png-wh_50
3.分发钥匙给client主机
[root@server0 ~]# scp /root/.ssh/id_rsa root@172.25.254.144:/root/.ssh/

wKiom1jsamPAX-E_AAJT_B4JfpY822.png-wh_50

4.测试

[root@desktop0 ~]# ssh root@172.25.254.244     ##通过id_rsa直接连接不需要输入用户密码
Last login: Mon Oct  3 03:58:10 2016 from172.25.0.250
[root@server0 ~]# 
wKioL1jsavCwMbZpAADlF6BupZs023.png-wh_50

4.提升openssh的安全级别

1.openssh-server配置文件

/etc/ssh/sshd_config

78 PasswordAuthentication yes|no        ##是否开启用户密码认证,yes为支持no为关闭

wKioL1jsbIKDCj9DAAE9uLSI1UM078.png-wh_50

48 PermitRootLogin yes|no           ##是否允许超级用户登陆

wKiom1jsbIKwXMdcAABY8otgWy0351.png-wh_50

49 AllowUsers student westos            ##用户白名单,只有在名单中出现的用户可以使用sshd建立shell
50 DenyUsers westos             ##用户黑名单

wKioL1jsbIPzGGz5AABfkOMC-kg713.png-wh_50

截图

wKiom1jsbIWg7sMDAAFKJY-eJts919.png-wh_50










本文转自 如何何如  51CTO博客,原文链接:http://blog.51cto.com/12778805/1915712,如需转载请自行联系原作者

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