Unable to compile a c application that reads smartcard

Question

I am trying to compile an example c application that is using pkcs#11 to finds all the private keys on the token, and print their label and id, but getting following errors

/tmp/ccAqQ7UI.o: In function initialize':
pkcs11_example1.c:(.text+0x8e5): undefined reference to C_Initialize'
/tmp/ccAqQ7UI.o: In function `get_slot':

The example is taken from here

compilling by using following command;

 `gcc pkcs11_example1.c -o slots -L /usr/lib/opensc-pkcs11.so`

I am not sure which library i should link after -L. Can anyone guide how to compile this and are there some libraries required to link.

Answer 1

C_Initialize and other 60+ functions with "C_" prefix are cryptoki functions defined in PKCS#11 specification. They are usually implemented in standalone library provided by HSM vendor. Looking at your code samples I would say that you need to directly link also PKCS#11 library or you can modify the code to dynamically load PKCS#11 library in runtime with LoadLibrary or dlopen and then acquire pointers to all cryptoki functions via the C_GetFunctionList call. You can also take a look at pkcs11-logger the source code for an example on how to do that.