Sample code for working with OpenSSL, LibP11, engine_pkcs11, and OpenSC

encrypt.c -- Software-based encryption.

sign.c -- Software-based signing.

tok-sign.c -- Signing with a hardware token.

OpenSSLWrappers.hpp -- While I still don't fully understand the lifecycle rules of the OpenSSL+Engine bits, these classes let me use some amount of RAII to help manage lifetimes.