OpenSC is an open-source package that provides the pkcs11-tool command-line utility. It is not required for the Kron PAM integration itself, but it is extremely useful for verifying HSM connectivity and key availability independent of the Kron PAM application. Being able to confirm that the library can reach the HSM and list the key before attempting the Kron PAM configuration significantly reduces diagnostic complexity.
[pamuser@KronPAM_Instance]# dnf install opensc -y
Once installed, you can use pkcs11-tool to verify the integration at any point. The command from Verify the AES Key on the Utimaco u.trust GP HSM - listing objects on slot 0 - is the primary verification test. If this command returns the expected key listing, all network and library configuration is correct.