IPT_PKD Iptables Port Knocking Detection 1.10 – ipt_pkd – is an iptables extension implementing port knock detection with SPA (single packet authorization).

ipt_pkd is an iptables extension implementing port knock detection with SPA (single packet authorization). This project provides 3 parts: the kernel module ipt_pkd, the iptables user space module libipt_pkd.so, and a user space client knock program. For the knock packet, it uses a UDP packet sent to a random port that contains a SHA-256 of a timestamp, small header, random bytes, and a shared key. ipt_pkd checks the time window of the packet and does the SHA-256 to verify the packet. The shared key is never sent.

 

You can download it from the following link: https://packetstormsecurity.com/files/download/108955/pkd-1.10.tgz

Source: https://packetstormsecurity.com/files/108955/IPT_PKD-Iptables-Port-Knocking-Detection-1.10.html