[mythtv] [PATCH] Enable recording of encrypted channels withoutdecrypting them first.
dibblah.allan.stirling at googlemail.com
Fri Jul 16 14:34:50 UTC 2010
wf_myth_user at online.nl wrote:
> But when the file is stored encrypted only people who have access to a cam
> with smartcard can watch the file.
> So for legal reasons option(2) would be the better solution.
> When looking at it this way it would even make sense to move the cam and
> smartcard to the frontend.
I'm not quite sure why all of this started but it's
essentially impractical to do "offline" decrypting for a
number of reasons:
1. There are no interfaces to hardware CAMs that are
supported in Linux that allow arbitrary data to be passed to
them. DVB cards take data from the demodulator and switch it
either through the CAM or directly to the bridge chip. Very
few video bridge chips have outputs and none that I have
seen pass the output to the CAM, since it would have no
purpose in a "normal" system. The Hauppauge standalone USB
CAM is not supported under Linux.
2. Keys change. This means that your recordings are only
"valid" and decryptable at the time when they are recorded.
Manufacturer PVRs get over this in a number of ways which
are not possible for us since we do not have access to the
internals of the CAM.
There are other reasons why this should not be in the
frontend, but these are the primary ones.
An open interface on the backend for the Hauppauge CAM may
not be a terrible idea, though - It may even spur on
development of the Linux driver.
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