           SPELL=knock
         VERSION=0.7
          SOURCE=$SPELL-$VERSION.tar.gz
SOURCE_DIRECTORY="$BUILD_DIRECTORY/$SPELL-$VERSION"
   SOURCE_URL[0]=http://www.zeroflux.org/proj/$SPELL/files/$SOURCE
        WEB_SITE=http://www.zeroflux.org/projects/knock
         ENTERED=20060529
     SOURCE_HASH=sha512:eab5d855f7111d9411e84a56a15e8ea74f41c5bd9dee27ab49f0d8d509eeeb96a60c508928c92916dc0ec9b737c447ca8ca5ed4db6479b389549d60e76a85aa7
      LICENSE[0]=GPL
     GATHER_DOCS=off
           SHORT="port-knocking server and client"
cat << EOF
Port knocking is a stealthy system for network authentication across closed
ports.

knockd is a port-knock server. It listens to all traffic on an ethernet (or PPP)
interface, looking for special "knock" sequences of port-hits. A client makes
these port-hits by sending a TCP (or UDP) packet to a port on the server.

This port need not be open -- since knockd listens at the link-layer level,
it sees all traffic even if it's destined for a closed port. When the server
detects a specific sequence of port-hits, it runs a command defined in its
configuration file.

This can be used to open up holes in a firewall for quick access.
EOF
