How test in a LTM policy if traffic is coming from HTTPS?

We are at version: BIG-IP 12.1.2 Build 1.0.271 Hotfix HF1

For almost all applications we have HTTP and HTTPS functions. We are terminating the HTTPS on the F5. Both VS (HTTP and HTTPS) share the same policy for redirecting the flow to the destination pool.

Now there is an application that only wants HTTPS. So the policy should only accept (and redirect) the HTTPS flow.

So I need to test in my policy if the origin of the flow is HTTPS. How do I do this.

We try not to use iRules since iRule errors can affect the whole system.

Thanks