How to bind a privileged port without privileges?

Question

I have a piece of daemon code that is supposed to be invoked by jsvc. The code needs to bind to a privileged port below 1024. I do not have root access so I am thinking of authbind. I tried:

authbind --deep jsvc ...

but in jsvc.err, it still says:

java.net.SocketException: Permission denied

Am I doing anything wrong?

Answer 1

Yes, you probably forgot to configure authbind.

If you want to allow user jo to bind port 80 you have to run the following commands as root.

root@lappy:~# touch /etc/authbind/byport/80
root@lappy:~# chown jo:jo /etc/authbind/byport/80
root@lappy:~# chmod 755 /etc/authbind/byport/80

Read the Running network services as a non-root user from the Debian Administration Guide for more information.