Can't send peripherals controls on ACS ACR1252U

[SomaticIT]

Hello,

Thank you for your amazing work porting PCSC on ChromeOS.
We are working on a project which require us to communicate directly with the reader internal chip.

However when we try to send SCardControl with a control code of SCARD_CTL_CODE(3500) as indicated in the ACR ACS1252U API docs (chapter 5.4. Peripherals Control), we receive a SCARD_E_UNSUPPORTED_FEATURE error code from ifdwrapper.c.

It seems to happen because SCARD_CTL_CODE(3500) is not known by the port.
Can we help improving the PCSC implementation to support custom CTL CODES?

Thanks,

PS: here is an pseudo code implementation:

const api_context = GoogleSmartCard.PcscLiteClient.Context("myapp");

api_context.addOnInitializedCallback(async (api) => {
  const context_result = await api.SCardEstablishContext(GoogleSmartCard.PcscLiteClient.API.SCARD_SCOPE_SYSTEM); //also tried USER
  const context = await get_async(context_result);

  const connect_result = await api.SCardConnect(context, reader, GoogleSmartCard.PcscLiteClient.API.SCARD_SHARE_DIRECT, GoogleSmartCard.PcscLiteClient.API.SCARD_PROTOCOL_UNDEFINED); // also tried RAW
  const [card, protocol] = await get_all_async(connect_result);
  if (protocol !== 4) throw "bad protocol";

  const firmware_result = await api.SCardControl(
    card,
    GoogleSmartCard.PcscLiteClient.API.SCARD_CTL_CODE(3500),
    [0xe0, 0x00, 0x00, 0x18, 0x00]
  );

  const firmware = await get_async(firmware_res); // respond with GoogleSmartCard.PcscLiteClient.API.SCARD_E_UNSUPPORTED_FEATURE
});

api_context.initialize();

[SomaticIT]

Ok after little investigations, I found that IFDHControl is not implemented at all on the driver...

Would it be feasible to implement this method (at least partially) for a subset of devices?

[emaxx-google]

We use the CCID free software driver mostly as-is; so for feature requests you might want to start from asking upstream: https://github.com/LudovicRousseau/CCID .

Also it'll be a question of how/when new releases of Smart Card Connector could be made. There has never been a fixed release cadence, and whether the team plans new releases anytime soon is unknown (I'm on a different team now so I don't have such information).

[Fabian-Sommer]

Like Maksim said, please direct the feature request to CCID. Once it is implemented there, you can let us know and we should be able to push an update within a few weeks.

[emaxx-google]

Alternatively, it might be that the functionality you need is already present in the acsccid driver (https://github.com/acshk/acsccid/). In that case, the work here would be to integrate this new driver into Smart Card Connector (in addition to the CCID Free Software Driver and the HID5021 driver).