[Linux] Exercise---FTP server

Question 1. Anonymous users can upload, download, and delete files through the ftp service and the permission to upload directory files is 704. ( Umask=073 )

     experiment procedure:

1. View yum source status, install vsftpd package

[root@localhost xiaoming]# yum repolist

 2. Turn off the firewall and selinux

[root@localhost xiaoming]# systemctl stop firewalld    //关闭防火墙
[root@localhost xiaoming]# setenforce 0    //关闭selinux
[root@localhost xiaoming]# systemctl status firewalld //查看防火墙状态
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@localhost xiaoming]# getenforce   //查看selinux状态
Permissive

3. Edit the content of the configuration file /etc/vsftpd/vsftpd.conf

 ① Allow anonymous users to log in to the vsftpd host and download files: anonymous_enable=YES                 

②Allow anonymous users to upload files: anon_upload_enable=YES

③Allow anonymous users to have the authority to create directories: anon_mkdir_write_enable=YES

④Set the permissions of uploading directory files to 704: anon_umask=073

⑤Allow anonymous users to delete files: anon_other_write_enable=YES

4. Settings can upload files in the /var/ftp/pub/ directory

[root@localhost ~]# chmod o+w /var/ftp/pub/

5. Restart the ftp service

[root@localhost ~]# systemctl restart vsftpd

6. Test

    ①Anonymous user login: Enter ftp://192.168.74.130 on the file explorer or browser to enter the server, anonymous users can log in.

   ②Download: Enter the pub directory, originally created a file haha, drag the haha ​​file into the local desktop, the download is successful!

③Upload    : Create a folder ceshi on the local desktop. Drag the ceshi file into the pub directory and the upload is successful!

    ④Check the permission of uploading directory files: 704 (Permission mask: 073)

 

 

Question 2. When accessing the ftp server through a local user, all users except redhat users are restricted to their home directories. (Note to add allow_writeable_chroot=YES)

experiment procedure:

1. Turn off the firewall and selinux

[root@localhost xiaoming]# systemctl stop firewalld    //关闭防火墙
[root@localhost xiaoming]# setenforce 0    //关闭selinux
[root@localhost xiaoming]# systemctl status firewalld //查看防火墙状态
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@localhost xiaoming]# getenforce   //查看selinux状态
Permissive

2. Modify the content of the configuration file /var/vsftpd/vsftpd.conf

   ①Reject anonymous user login: anonymous_enable=NO

②Allow    local users to log in: local_enable=YES

③Enable    chroot option: allow_writeable_chroot=YES

   ④ chroot three control files:

      chroot_local_user=YES

      chroot_list_enable=YES

      chroot_list_file=/etc/vsftpd/chroot_list

3. Add the redhat user in the /etc/vsftpd/chroot_list file

[root@localhost xiaoming]# vim /etc/vsftpd/chroot_list

redhat

4. Add user xiaoming and set password

[root@localhost home]# useradd xiaoming    //创建用户
[root@localhost home]# passwd xiaoming     //设置密码
更改用户 xiaoming 的密码 。
新的 密码：                             
无效的密码： 密码包含用户名在某些地方
重新输入新的 密码：
抱歉，密码不匹配。
新的 密码：
无效的密码： 密码包含用户名在某些地方
重新输入新的 密码：
passwd：所有的身份验证令牌已经成功更新。

5. Add the file heihei in the home directory of Xiaoming user

[root@localhost home]# cd xiaoming
[root@localhost xiaoming]# echo this is xiaoming > heihei
[root@localhost xiaoming]# ll
总用量 4
-rw-r--r--. 1 root root 17 10月 21 14:27 heihei

 6. Restart the ftp service

[root@localhost xiaoming]# systemctl restart vsftpd

7. Test 

 ①Redhat users log in to the ftp service (not restricted to their home directory)

②Other users: xiaoming users log in to the ftp server (limited to their home directory)