[Pcsclite-muscle] Changes to pcscd for XSpice support

[Jeremy White]

>> Yes, exactly.  (Except that, afaict, we also need to do the same thing for
>> the pubshm file, pid file, events dir, and the ipc dir in general).
>
> pubshm is no more used.
> events dir is no more used.
>
> PCSCLITE_IPC_DIR should now contains only 2 files: pcscd.pid and pcscd.comm

My apologies; I'll need to eventually back port this to 1.5.2, so that's 
the code I've been studying.

> pcscd is running on the side with the smart card reader. So you would
> have N-pcscd on N-client machine.
>
> You then need to connect N-libpcsclite running on the application
> server to the N-pcscd.
> You should be able to use the PCSCLITE_CSOCK_NAME environment variable
> to connect the libpcsclite part to the pcscd part through Spice (if
> Spice can redirect a socket).

That would be an elegant solution.  Unfortunately, Spice doesn't really 
have a socket redirection capability.  (In fact, it's even more awkward 
than that; the Spice client uses libnss to get certs, and then simulates 
a particular model of reader by sending simulated APDUs with the 
relevant cert info).

The alternate I can imagine would be instead of having a spiceccid 
driver, to have a spice-simulated-pcscd interface, where the XSpice 
server would simulate pcscd.  I haven't (yet) looked into the level of 
difficulty in doing that; my instinct was that it was better to use the 
real pcscd than to try to emulate it.

Cheers,

Jeremy