Portkey

A Port-Knocking implementation for Linux.

Introduction Portkey is an implementation of a port-knocking daemon. It's simple, reliable and requires no special clients - telnet is fine. It supports knocks on any valid TCP port in the range 1-65535 and supports key sequences of arbitrary lengths.

Portkey runs only on Linux at the present time (though that may change), and is only compatible with iptables based firewalls. It is firewall friendly: all the permissions granted to portkeyd clients are encapsulated in a specific chain that is created as required. If you restart your firewall, all the existing rules will be lost, but knocking again will recreate them.

Portkey is Open Source Software, licensed under the Academic Free License v2.1.

Intended Use

Portkey is intended to supplement your existing security measures. It is not, and should not be used as, a replacement for your existing defenses. Port-knocking is like a combination lock, and as any teenager will tell you, all combination locks can be broken with enough time and effort, so make sure that what you're hiding with portkeyd is something that is itself secure.

The idea behind this implementation of port-knocking is to hide services from the casual intruder: port scanners for example. It's not a defence against a determined attacker.

Downloads

Contacts

Send email with comments, suggestions, etc. to port-knocking@smee.org