I’d like to AES encrypt MPEG-DASH streams without the use of PlayReady and Widevine DRM systems. I just need Wowza to encrypt the streams using a given key. Is this possible? The player will have access to the key via a separate proprietary infrastructure. I think what I am asking for is called Clear Key DRM: http://www.html5rocks.com/en/tutorials/eme/basics/#clear-key
According to our Senior Engineer, you would have to create a class that would provide the data required to serve up the keys to Wowza. In that CENC article you linked to, the API required to receive the keys is outlined. You can use that as a guide to tailor for Clear Key.
I will also make sure to pass along your request to add Clear Key as an out-of-the-box supported key management provider.