Let’s consider a situation where you need to configure a secure FTP service in your Linux server without installing any new packages to the system. Easy way of achieving this scenario is by configuring a SFTP CHROOT service in your Linux system. By Default all Linux systems are pre configured with SSH service. There for you only need to edit the existing configuration for this purpose.
1) Modify “/etc/ssh/sshd_config” file to reflect bellow changes
#Subsystem sftp /usr/lib/openssh/sftp-server
Subsystem sftp internal-sftp