Pkcs11Interop | Managed .NET wrapper for unmanaged PKCS # 11 libraries | Cryptography library

Pkcs11Interop returns slots received by calling C_GetSlotList function of unmanaged PKCS#11 library. So if you get 0 slots then C_GetSlotList returned 0 slots. You need to discuss this situation with the vendor of your PKCS#11 library who might know why their library does not see any slots.

> Is a DispatcherTimer ok for WaitForSlotEvent?

It should be OK in general. You might also consider using WaitForSlotEvent in blocking mode called from a separate thread.

> What should I do to avoid C_WaitForSlotEvent CKR_DEVICE_ERROR?

You need to ask the vendor of your unmanaged PKCS#11 library.

AFAIK C_WaitForSlotEvent was designed for token/card related events not for slot/reader related events. PKCS#11 specification states that when you add or remove slot/reader you might need to reload PKCS#11 library or even restart OS:

On some platforms, or earlier PKCS11 compliant libraries, it may be necessary to successfully call C_Initialize or to restart the entire system.

> Does pkcs11Interop handle the adding and removing of slots (ie. SmartCard Readers)?

Pkcs11Interop does nothing else but gives you access to unmanaged function C_WaitForSlotEvent described in PKCS#11 specification.

> If pkcs11Interop does not handle adding and removing slots is polling the only way and what would be the best to poll?

See answer to first question.

If type of the parameter is uint, you can only pass values that are assignable to the type uint (as stated in Spec: Calls). And the valid range of uint does not include negative numbers.

What you may do is convert your negative value to uint. Converting a negative int to uint is roughly equivalent to subtracting the absolute value from the max value of int plus 1. So if your other constants are small, this won't cause a collision.

For example:

PKCS#11 library is not driver for card reader (in your case Cherry SmartTerminal ST-1144). PKCS#11 library is driver for the card. So I highly doubt such library is installed as a part of package provided by Cherry. It should be installed as part of software you got with your smartcard.

I had the same problem with Luna HSM (but was given CKR_MECHANISM_PARAM_INVALID).

That version of HSM simply did not support OAEP with SHA-256 and firmware upgrade was needed. After firmware upgrade it worked without any problems. Check if your device supports this variant.

Your code seems ok, I used (in java):

I was doing everything right, just had forgot to send initialised rsaParams with the call.

RSA public key objects do not have CKA_VALUE attribute. Instead, there are two attributes called CKA_MODULUS and CKA_PUBLIC_EXPONENT that make up the key value.