How to detect smartcard insertion or removal event in linux

Question

Folks, I'm working on a certificate authentication app that will authenticate user based on CAC inserted. How do I know when the CAC is inserted / removed? I'll be "catching" that event in C++ or Java. Thanks.

Answer 1

You have two options:

1. If you go for "low level" (which you apparently want to do) is to use PC/SC level (pcsc-lite) and the SCardGetStatusChange function (or the equivalent in Java, what is javax.smartcardio.CardTerminal.waitForCardPresent())
2. If you're working with higher level abstractions and go for PKCS#11 (and if your PKCS#11 provider implements it correctly), C_WaitForSlotEvent can be used.

Answer 2

You might see if it is reported through udev.