Linux...第九章作业

<<<第九单元练习>>>
1.在desktop主机中建立用户westos，并设定其密码为westoslinux
2.配置desktop中的sshd服务要求如下：
*）设定sshd服务只允许westos用户可以被访问使用
*）创建westos用户的key认证方式
*）设定westos用户只允许使用key认证方式，屏蔽其系统密码认证方式
实验过程如下：
在服务器端的虚拟机下，创建用户westos 并设置密码



添加用户白名单，
#vim /etc/ssh/sshd_config
在100行位置更改系统文件



切换到客户端的虚拟机登录



重启sshd.service
#systemctl restart sshd.service
结果：
root登录失败，westos登录成功。

# ssh-keygen
生成公钥和私钥




查看文件



发送密钥给客户端






进入#vim /ect/ssh/sshd_config



重启sshd
删除authorzied_keys
再在客户端中登录，

1.ssh的key认证

#######生成key###########
[test@foundation0 ~]$ ssh-keygen ###生成公钥和私钥的工具
Generating public/private rsa key pair.
Enter file in which to save the key (/home/test/.ssh/id_rsa):『enter』 ###指定加密字符保存文件，使用默认
Created directory '/home/test/.ssh'.
Enter passphrase (empty for no passphrase): ###密码，必须大于4位
Enter same passphrase again:
Your identification has been saved in /home/test/.ssh/id_rsa.
Your public key has been saved in /home/test/.ssh/id_rsa.pub.
The key fingerprint is:###确认密码
a5:4f:02:51:68:59:f4:e8:e3:c5:91:1f:6f:86:99:06 test@foundation0.ilt.example.com
The key's randomart image is:
+--[ RSA 2048]----+
| .*+ |
| +. o . |
| .. . E . |
| o + + * |
| S + * + |
| . * . o |
| . . |
| |
| |
+-----------------+
[test@foundation0 .ssh]$ pwd
/home/test/.ssh###生成密钥存放位置
[test@foundation0 .ssh]$ ls
id_rsa id_rsa.pub####id_rsa位私钥，id_rsa.pub位公钥

#####################使用key加密目标主机的目标用户############
[test@foundation0 ~]$ ssh-copy-id -i /home/test/.ssh/id_rsa.pub westos@172.25.254.100

The authenticity of host '172.25.254.100 (172.25.254.100)' can't be established.
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
/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
westos@172.25.254.100's password:

Number of key(s) added: 1

Now try logging into the machine, with: "ssh 'westos@172.25.254.100'"
and check to make sure that only the key(s) you wanted were added.

ssh-copy-id####上传key的工具
-i####指定使用的公钥
/home/test/.ssh/id_rsa.pub#####使用公钥的名称
westos####被管理的目标用户
172.25.254.100####被管理用户所在主机的ip

authorized_keys###此文件在目标用户加目录的.ssh中，这个文件就是目标用户被加密的标识，文件内容位公钥内容。

2.sshd服务的简单配置
vim /etc/ssh/sshd_config###sshd服务的配置文件

48 PermitRootLogin yes|no###是否允许root用户通过sshd的认证
78 PasswordAuthentication yes|no###开启或关闭用户密码认证
AllowUsers student westos###用户白名单，只允许在名单中出现的用户使用sshd服务
systemctl restart sshd###从新加载配置