On my Community page, I'm trying to provide a download for a file that resides outside of Salesforce. I want the user to be authenticated prior to download and I don't want the user to know the URL of the file.
Currently, I have a link to a Visualforce page on the Community. An Apex controller checks for a PermissionSet and returns a PageReference with the URL of the file.
With this method, the URL of the file can be determined by any download manager.
Is there a way to accomplish this in Salesforce? Maybe I'm going about this the wrong way....
I did find this https://developer.salesforce.com/forums/ForumsMain?id=906F00000008w0oIAA , which lets me retrieve the file in Apex controller, but can I serve the Blob to the user as a file download?