Sftp

Sometimes crappy old sftp is required. Always prefer scp for copying and web hosting on bitpost.com for sharing.

• Ensure you installed openssh-server (of course you did)
• Set up an ftp group

sudo addgroup ftpusergroup

• Edit /etc/ssh/sshd_config

Subsystem sftp internal-sftp
Match group ftpusergroup
ChrootDirectory %h
X11Forwarding no
AllowTcpForwarding no
ForceCommand internal-sftp

• Restart sshd service

sudo service ssh restart

• Add user with correct permissions

sudo adduser lemmeftp --ingroup ftpusergroup --shell /usr/sbin/nologin
# set the password
# if the user exists, to change pw: sudo -u lemmeftp passwd
sudo chown root:root /home/lemmeftp
sudo mkdir /home/lemmeftp/files
sudo chown lemmeftp:ftpusergroup /home/lemmeftp/files

Reference 1, and 2