I am trying to display/create/modify data from an external database in CRM. To avoid duplicating the data in CRM, I have created a shell entity in CRM that only has the ID of the corresponding record in the external database. The data is then pulled from the external database and shown in an IFrame. I will have to do some server-side processing, hence I will have to use asp and aspx pages.
My problem is that from the asp/aspx page, which is in the IFrame, I can neither access the data in the parent window nor execute web services against the CRM database. I tried all kinds of things but always run into issues with security.
Please note that this needs to work both for CRM 2011/2013 on-premises and CRM Online. The later prevents me from hosting my asp(x) pages on the CRM server. I also tried the approach of putting some relevant scripts in web resources and then access them via window.parent.myfunction(...). However, this also gives me an error probably due to calling scripts across domains.
Any input is appreciated.