Linux Tutorials - Herong's Tutorial Examples

∟vsftpd - Very Secure FTP Daemon

∟Disable SSH Access for FTP Users

This section provides a tutorial example on how to disable SSH login access of a user on CentOS systems and allow his/her to use FTP service only for upload and download files.

Some times, you may want to create a user and allow him/her to use the FTP service only, not allow him/her to use the SSH (Secure Shell) service to login to your CentOS system. This can be done by disabling his/her access in the sshd (SSH Daemon) configuration.

Here is what I did to create "john" as FTP user and disable his access in the sshd configuration.

1. Create "john" as a user: 

herong$ sudo useradd john

herong$ sudo passwd john
Changing password for user john.

2. Enable FTP access for John: 

herong$ sudo vi /etc/vsftpd/user_list
...
herong
john

herong$ sudo systemctl restart vsftpd

3. Create FTP home directory for John: 

sudo mkdir /home/john/ftp
sudo chown nobody:nobody /home/john/ftp
sudo mkdir /home/john/ftp/private
sudo chown john:john /home/john/ftp/private

4. Disable SSH access for John: 

herong$ sudo vi /etc/ssh/sshd_config
...
#  ForceCommand cvs server

UseDNS no
AddressFamily inet
SyslogFacility AUTHPRIV
PermitRootLogin yes
PasswordAuthentication yes
DenyUsers guest john

herong$ sudo systemctl restart sshd

5. Verify SSH access. It should be denied. 

herong$ ssh john@192.168.1.3
  john@192.168.1.3's password:
  Permission denied, please try again.
  john@192.168.1.3's password:

Now John can upload and download files remotely on my CentOS computer. But he can not SSH login remotely.

Table of Contents

 About This Book

 Introduction to Linux Systems

 Cockpit - Web Portal for Administrator

 Process Management

 Files and Directories

 Users and Groups

 File Systems

 Block Devices and Partitions

 LVM (Logical Volume Manager)

 Installing CentOS

 SELinux - Security-Enhanced Linux

 Network Connection on CentOS

 Internet Networking Tools

 SSH Protocol and ssh/scp Commands

 Software Package Manager on CentOS - DNF and YUM

►vsftpd - Very Secure FTP Daemon

 Install vsftpd on CentOS

 vsftpd Server Configuration

 Setup FTP Sub-Directory for Local Users

 Test FTP Access Locally on CentOS

 Test FTP Access Remotely on CentOS

 Support FTP Over TLS on CentOS

►Disable SSH Access for FTP Users

 LDAP (Lightweight Directory Access Protocol)

 Administrative Tasks

 References

 Full Version in PDF/EPUB