https://www.digitalocean.com/community/tutorials/how-to-set-up-vsftpd-for-a-user-s-directory-on-ubuntu-16-04#step-6-—-securing-transactionshttps://www.ostechnix.com/install-vsftpd-server-ubuntu-16-04-lts/https://help.ubuntu.com/lts/serverg…