Enable ipfw and divert sockets, if you haven't already (reboot required):
echo 'firewall_enable="YES"' >> /etc/rc.conf
echo 'firewall_type="open"' >> /etc/rc.conf
echo 'ipfw_load="YES"' >> /boot/loader.conf
echo 'ipdivert_load="YES"' >> /boot/loader.conf
reboot
Tcpcrypt also requires OpenSSL >= 0.9.8, which is provided by the
security/openssl port.
cd tcpcrypt/user
./configure
make
Optional: running make install will install libtcpcrypt and tcpcrypt
headers, for building apps that use tcpcrypt's session ID.
The launch script (in tcpcrypt/user) starts tcpcryptd and sets up your firewall to send port 80 and 7777 packets through tcpcrypt:
./launch_tcpcryptd.sh
With tcpcryptd running, open http://tcpcrypt.org/test.php to try it out.
See contrib/freebsd for a FreeBSD rc script that loads tcpcryptd on system startup.
See the included README.markdown file for more ways to try out tcpcrypt and
for troubleshooting help.
The included launch_tcpcryptd.sh script sets up reasonable firewall rules, but for more complex setups, add your own divert rules.
For example, this will divert all TCP packets to tcpcryptd (on divert port 666), and it will be rule #1.
ipfw 01 add divert 666 tcp from any to any
It's important that tcpcrypt divert rules are high on the list since tcpcryptd modifies the packet quite a lot, including sequence numbers, so other items (e.g., natd) may get confused if tcpcryptd doesn't do its magic first.