The GOST engine file was "libgost_engine.so". Unfortunately, this
will fail to load with any OpenSSL version, as the derived engine ID
will be "gost_engine" (OpenSSL <1.1.0) or "libgost_engine" (OpenSSL
>=1.1.0), since the engine checks the ID internally against "gost".
To make the IDs compatible, make sure the file name will be "gost.so"
set_target_properties(gost PROPERTIES POSITION_INDEPENDENT_CODE ON)
add_library(gost_engine MODULE ${GOST_ENGINE_SOURCE_FILES})
+set_target_properties(gost_engine PROPERTIES PREFIX "" OUTPUT_NAME "gost")
target_link_libraries(gost_engine crypto gost)