@mito,
The files you list are identical to those found on E(S) / F- models and later TV?s ..
We basically know what we need to know about what is inside each file.
The SRF file contain the encrypted .ts stream. This is what we want to decode.
The INF file contain PUBLIC information about the recording.
This is the information that the PVRDecoder use to display all sort of stuff about each recording.
The MTA file contain 5 thumbs encoded in jpg, encoded in Base64, wrapped as XML. The PVRDecoder use this (like the TV) to
display a 5-image-rotating preview
I have no idea about what is inside the CIP file or the MDB file really, because the PVRDecoder process does NOT require their presents.
The key (that we need to decode the SRF file) is locked inside the SS file (Secure Storage).
This SS file is encrypted .. We need to decrypt THIS file before anything else, - and
ONLY the TV knows
about the PRIVATE key that is needed to do so.
And this is why you
MUST have access to rooted TV. At decode-time the PVRDecoder needs to launch a tool directly on the TV.
This tool (keydumper (c)sectroyer) "tricks" the TV into thinking we are right about to start a playback of EVERY recording currently stored on the TV external storage, and all keys are intercepted into KEY files on the TV?s external storage (where the PVRDecoder can access it),
and those key-files can then be used by the PVRDecoder to launch another tool that can do the actual decoding of the SRF file(s).
So, in reality we never reach a point where
WE can decode the SS files, but we
CAN call on the TV?s internal crypto-engine to do it
for us (when we have root, and can "reach" deeply into the TV?s kernel system and memory), and force it to provide cleartext KEY files for us.
The above is not a perfect description of the process, but a working mental model, if you will ..
In other words, - as long as we cannot access TV internal crypto-engine for a given model, we cannot decode its SS files,
and thusly not retrieve the key(s) needed to decode the SRF file(s).
If you want to know more about whats going on, I suggest you read this:
https://wikileaks.org/sony/docs/05/docs ... 202010.pdf
Its a little outdated now, but I suspect much of the information is still valid,
when it comes down to the "construct" of the secutity-implementation .. sort of .. go figure
