View Single Post
  #223  
Old 03-10-2015, 10:11 AM
enrud enrud is offline
Member
 
Join Date: Jun 2014
Posts: 33
enrud is on a distinguished road
Default

Re: I downloaded Netflix videos in HD, I can play off line,need a little help W/.key


Quote:
Originally Posted by BlueCop View Post
For the the old playready HLS streams I think the decryption key is actually stored in the video itself in an encrypted envelope. I don't know the details of how that works though.
You are correct. The reason for this is because of incompatibility between playready and HLS. HLS requires an AES-CBC-128 key whereas playready uses an AES-CTR-128 key. Netflix worked around this by encoding the HLS key in the encrypted envelope and then using playready to decode that key. That was the whole weakness in the HLS mechanism. At some point the Netflix app had to decrypt that envelope, grab the key and pass it off to the iOS player. And it was that point where key extraction was occurring.

Now with Fairplay, the key is not passed in the clear and extracting the key would require breaking Fairplay.

I suspect Netflix will try and drop HLS streaming as soon as possible. I would if I were them. Doing so would require Apple to either support IOS 6 on all devices or backporting Fairplay/Dash support to IOS5.
Reply With Quote