This mirrors `crypto+` protocol from ffmpeg, which is used in HLS demuxer. Unfortunatelly ffmpeg doesn't use custom io_open in their crypto.c, so we spin our own decryption.
This mirrors `crypto+` protocol from ffmpeg, which is used in HLS demuxer. Unfortunatelly ffmpeg doesn't use custom io_open in their crypto.c, so we spin our own decryption.