OpenVPN integration with java application

[Jas20]

I used perl script to implement username and pasword based authentication between openvpn and java application and it worked.
But now I need to send back a random number generated by the java application to the openvpn client for signing purpose and again send that random number to the application in order to facilitate successfull authentication.
Is it possible??and how can it be done?

[janjust]

err , not sure I understand: you want to send data to the openvpn client that the client itself needs to sign? AFAIK this is not possible. You *may* be able to pull this off by adding a plugin to openvpn but there's no way to get the VPN client to sign a random piece of data for you.