Hi nastymatt,
Actually what Kevin is telling you is a good thing and not that difficult at all.
1. Export SSL Certificate from Server.
2. Import SSL Certificate into the LTM Certificate Store (Local Traffic -> SSL Certificates -> Import)
3. Create new SSL Profile (Local Traffic -> Profiles -> SSL -> Client) and assign the Certificate and Key that you imported.
4. Apply SSL Profile (Client) made in Step 3 to the Virtual Server, Apply SSL Profile (Server) to be the default "serverssl".
5. Apply an HTTP Profile (you could use the default if you wish)
6. Assign iRule to the Virtual Server.
This should solve your entire problem and allow your HTTPS Virtual Server to behave just like your HTTP Virtual Server with no SSL Certificate mismatch errors.
The biggest things to remember are:
1. You cannot use an iRule that uses HTTP Methods (when HTTP_REQUEST or when HTTP_RESPONSE) without an HTTP Profile assigned to the Virtual Server.
2. You cannot use an HTTP Profile on encrypted traffic, so if you need an iRule you need to at least Decrypt the traffic (SSL Profile (Client)).
3. If the downstream servers are expecting an secure session then you will need to apply a SSL Profile (Server). This tells the LTM that the downstream server wants to talk securely, so expect it.