Engine_pkcs11 is an implementation of an engine for OpenSSL.
It can be loaded using code, config file or command line and
will pass any function call by openssl to a PKCS#11 module.
Engine_pkcs11 is meant to be used with smart cards and software
for using smart cards in PKCS#11 format, such as OpenSC.

WWW: https://github.com/OpenSC/OpenSC/wiki/OpenSSL-engine-for-PKCS%2311-modules