I'm experiencing particular issues when i try to deliver an audio MP4 content (Original extension of the file not encrypted: ".MP4" with either Content-Type: "audio/mp4" or "audio/aac") protected with DRM OMA 2.0 to a Nokia N95 phone (V 10.0.018 - 15-03-07).
I'm actually able to download the encrypted content to the phone (through HTTP) and correctly get the RO (Separate Delivery, ROAP over HTTP), but when i try to play the file the handset pops up an "Damaged file. Step aside" message (the real message could be different...i'm working on an italian version...but that's the sense ).
The behavior is pretty different when I perform the same test with MP3s (Original extension of the file not encrypted: ".MP3" and Content-Type: "audio/mp3") or AACs (Original extension of the file not encrypted: ".AAC" and Content-Type: "audio/aac") files: the phone is in this case able to play the protected content with no issues.
Moreover, the same MP4 file not encrypted is actually playable from the same phone.
My guess is that this problem could be related to the DRM Agent on the phone. My perception is that when it receives an ".MP4" content, it is actually managing it as a video content (even if an "audio/mp4" content type is present).
The entire PKI authentication infrastructure (RI, CA...) is pretty the same for every content. As a further test, I copied on my laptop (through Bluetooth) the DCF not playable by the phone, decrypted it with the same RO previously delivered to the phone and was able to play back the decrypted content...
At least, the issue seems to be strictly related to the phone...
Can you please give me some feedback on this case?
Thanks and regards,