2-factor code via SMS iRule

We have a need for 2-factor auth on some of our external services, and are looking at alternatives to the current SecurID setup. Would it be possible to have an iiRule to generate a random code, send out via SMS provider, and wait for the user to receive the code on his mobile phone, enter as part of the APM login and compare the codes for accept/deny. Thanks for any feedback!

 

 

Jon Ole