src/libopensc/sc-ossl-compat.h uses defines, macros and inline code for backward compatibility with older versions of OpenSSL. It only implements backward compatibility for functions currently used by
OpenSC and may need additional changes.
PR 861 changed a lot of code and only partially tested. Please test the https://github.com/OpenSC/OpenSC master branch with any of your devices or proposed changes. You can test with whatever OpenSSL
version you need. But you may need to change your code to use the OPenSSL-1.1.0 API.