m3u8 encrypted - how is the key stored?

Dev Community Dev/API Corner
1

I came across a couple of m3u8 files, showing...

#EXT-X-KEY:METHOD=AES-128,URI="https:...

 

But then the given key file seemed fishy. AFAIK it should hold 16bytes, but the content was everything but 16bytes...

Does it get encoded for the HTML transfer? How? It's not utf-8, is it?

2

So... if I see something like "Y�" which backwards equates to 59 EF BF BD... what was this before the HTML conversion? Who is changing that data in transfer? And why?

3

Answer a) The "EF BF BD" (or converted FFFD) seems to be the "unicode replacement character". It is inserted to indicate a non-printable char has been exchanged/removed. Yes... removed - the previously unsupported byte is gone for good.