Enforcing 128-bit SSL encryption

Hi all,

I would like to force clients to use a 128-bit browser when connecting to a site with a 128-bit Verisign cert.

I have found this iRule on the forums :

when HTTP_REQUEST {
   if { [SSL::cipher bits] < 128 }{
      HTTP::respond 402 content "This web site requires 128 bit encryption or higher.\
  Please update your browser and try again."
   }
}

which looks fine, but is there a way to permanently stop the F5 from even negotiating to a weaker encryption? I'm already running a number of balancing decisions based on the HTTP Request, so don't really want to add this to the mix too.

Looking on the VeriSign website, I see this is easy to do on a MS IIS server (just change an option in the properties), but they were unable to help with the F5.

Any ideas?

Thanks