NOTE: This applies to Downcast (Mac) 1.0.7+
Downcast (Mac) supports password protected podcast feeds. However, the Apple provided framework we're using to stream media files does not directly support providing it with credentials. We can indirectly provide it with credentials as long as you've authenticated against the podcast's server, using Downcast, at least once. There are two basic scenarios:
Scenario 1 - The podcast requires authentication to download its feed and to download its episodes. In this case, you should be able to stream the podcast's episodes.
Scenario 2 - The podcast does not require authentication to download its feed but does require authentication to download its episodes. In this case, you will not be able to stream the podcast's episodes until you've successfully started downloading one of it's episodes through Downcast. All you need to to is start downloading one episode, you don't need to complete the download. Once the download has started, it means you've successfully authenticated and we can now indirectly provide credentials to the Apple provided framework we're using.