Any advice to secure a homemade ftp server? : programming | Torhoo darknet markets

What OS? Listening on a public IP address?

An FTP server doesn't have anything to do with JS, PHP, HTML or CSS. Using something like ProFTPd on Linux you can lock it down pretty creatively, use a cron job to start and stop it so its only listening when you need or when you trigger it, etc. Or use SFTP through SSH and use an ssh key, stuff like that. Treat it like a refrigerator; you only open the door when you need something, reach in and grab/put it, and close the door. Logging in hooked to mac address is a pain in the ass and means you can only access your stuff from one specific net adapter or you have to munge your mac for each session. Easier to just use SFTP with ssh keys and turn SSH on/off as needed.

To secure the server the first thing I would do is have your OS encrypt your home folder. Next I'd set up SSH keys AND a password. Then use the UFW firewall to block all traffic to unneeded ports. As /u/Grazelda suggested you can get creative with cron. Maybe block your SSH port except for a specific time during the day if you want to be extra careful? Let me know what you do.