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This shows you the differences between two versions of the page.

--- tools:fwknop [2022/08/28 15:18] – created darron
+++ tools:fwknop [2023/01/20 20:16] (current) – [Server] darron
@@ Line 1: / Line 1: @@
 ====FWKNOP====
+Single Packet Authorization (SPA) Port Knocking.
+Port knocking is used to alter packet filter rules on a host
+dependant upon a packet encrypted with a secret key delivered to that host.
+It can be used to open a normally closed port to an SSH server
+from a single host for a limited time duration.
+===Server===
+==IPtables==
+<code>
+iptables -t filter -A INPUT -i eth0 -p tcp --syn --destination-port 22 -j REJECT --reject-with icmp-port-unreachable
+</code>
+==FWKNOP==
+==Install==
+<code>
+apt install fwknop-server
+</code>
+==Run==
+<code>
+/usr/sbin/fwknopd
+</code>
+==access.conf==
+<code>
+SOURCE: ANY
+OPEN_PORTS: tcp/22
+KEY: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+FW_ACCESS_TIMEOUT: 60
+</code>
+==fwknop.conf==
+<code>
+PCAP_INTF eth0;
+</code>
+===Client===
+==Install==
+<code>
+apt install fwknop-client
+</code>
+==.fwknoprc==
+<code>
+[default]
+[hostname]
+SPA_SERVER      x.x.x.x
+ACCESS          tcp/22
+ALLOW_IP        resolve
+KEY             XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+</code>
+==.ssh/config==
+<code>
+Match host hostname exec "fwknop -n hostname && sleep 0.5"
+</code>
 ===Resources===
 [[https://www.cipherdyne.org/fwknop/|Home page]]