The installation of fwknop is handled by the perl script "install.pl" that
is bundled with the fwknop sources.  Just run:

./install.pl

This will result in a functioning fwknop installation on your Linux system.
If you run the installer as a non-root user, fwknop will be installed in your
home directory (specifically in ~/bin and a few perl modules in ~/lib).  In
this case fwknop can only be used as an authentication client against an
fwknop server on a different system.

DEPENDENCIES:
    fwknop requires several perl modules that may or may not already be
installed on your Linux system.  These modules are included in the deps/
directory in the fwknop sources (unless you have installed one of the -nodeps
tarballs), and the list of modules is:

Class-MethodMaker
Crypt-CBC
Crypt-Rijndael
Digest-SHA
GnuPG-Interface
IPTables-ChainMgr
IPTables-Parse
Net-IPv4Addr
Net-Pcap
Net-RawIP
Net-Ping-External
TermReadKey
Unix-Syslog