<IfModule mod_sftp.c>
#  SFTPEngine on
#  Port 2222
#  SFTPLog /var/log/proftpd/sftp.log
#  SFTPHostKey /etc/ssh/ssh_host_rsa_key
#  SFTPHostKey /etc/ssh/ssh_host_dsa_key
#  SFTPAuthMethods publickey
#  SFTPAuthorizedUserKeys file:/etc/proftpd/authorized_keys/%u
#  SFTPCompression delayed
</IfModule>
