SlackBuildsOrg/network/fwknop
..
doinst.sh
fwknop.info
fwknop.SlackBuild
README
slack-desc

fwknop implements an authorization scheme known as Single Packet
Authorization (SPA) for Linux systems running iptables.

This optionally uses gpg and libgpgme if they are available.  Using
gpg with fwknop is highly recommended.