Smart Cards Hurt - 1

So here's the new toy I've got to play with - the DataCard CP40 Plus card printer with the SCM SCR331-DI Smart Card reader.

Datacard CP40 Plus

Developing the application for the printer consists mostly of two parts - communicating with the printer and communicating with the smart card reader. You tell the printer to pick up the card, you tell the printer to position the card for smart card processing, you tell the smart card reader to write data to the smart card, you tell the printer to encode the magstripe and print something on the card, you tell the printer to finish with the print job.

It does not look so easy when you read the manual. This is how the programming flow looks like:

In reality, though, the whole printer communication is mostly done by the following code:

printer.Hdc = PrintDoc.PrinterSettings.CreateMeasurementGraphics().GetHdc().ToInt32();

/* Set Interactive mode */
if (ICE_API.SetInteractiveMode(printer.Hdc, true) > 0)
{
 ICE_API.DOCINFO di = new ICE_API.DOCINFO();
 /* Initialize DOCINFO */
 di.cbSize = 16;
 di.lpszDocName = "Card Printer SDK Test";
 di.lpszDataType = string.Empty;
 di.lpszOutput = string.Empty;

 /* Start document and page */
 if (ICE_API.StartDoc(printer.Hdc, ref di) > 0)
 {
  if (ICE_API.StartPage(printer.Hdc) > 0)
  {
   /* Set card rotation on */
   ICE_API.RotateCardSide(printer.Hdc, 1);
   /* Feed the card into the smart card reader */
   if (ICE_API.FeedCard(printer.Hdc, ICE_API.ICE_SMARTCARD_FRONT + ICE_API.ICE_GRAPHICS_FRONT) > 0)
   {
    /* Put any SmartCard processing/communication here */
    TalkToSmartCard();
   }
   /* Remove the card from the reader and continue printing */
   ICE_API.SmartCardContinue(printer.Hdc, ICE_API.ICE_SMART_CARD_GOOD);
   /* End the page */
   ICE_API.EndPage(printer.Hdc);
  }
  /* End job */
  ICE_API.EndDoc(printer.Hdc);
 }
}

The ICE_API mostly contains wrappings for the functions from the ICE_API.dll which comes with the printer and defines some constants and data structures, like this

[StructLayout(LayoutKind.Sequential)]
public struct DOCINFO
{ 
 public int cbSize;
 public string lpszDocName;
 public string lpszOutput;
 public string lpszDataType;
}

........

[DllImport("ICE_API.dll")]
public static extern int FeedCard(int hdc, int dwCardData);

[DllImport("ICE_API.dll")]
public static extern int GetCardId(int hdc, CARDIDTYPE pCardId);

[DllImport("ICE_API.dll")]
public static extern int SmartCardContinue(int hdc, int dwCommand);

.........

public const int ICE_SMARTCARD_FRONT = 0x10;
public const int ICE_GRAPHICS_FRONT = 0x1;

public const int ICE_SMART_CARD_GOOD = 0;
public const int ICE_SMART_CARD_ABORT = 1;

Now that was the easy part.

by Evgeny. Also posted on my website