加载OpenSSL Engine时，SO_PATH和MODULE_PATH有什么区别？

Question

当尝试使用以下命令将引擎加载到openssl时

openSSL> engine -t dynamic -pre\ SO_PATH:/usr/lib/engines/engine_pkcs11.so \
-pre ID:pkcs11 -pre\ LIST_ADD:1 -pre LOAD -pre \
MODULE_PATH:/usr/lib/libcs_pkcs11_R2.so

我们必须指定两个共享对象的路径，即引擎和模块，谁能告诉我有什么区别？

Answer 1

SO_PATH tells OpenSSL where to find the engine.

MODULE_PATH is an engine-specific control that tells some engines where to find the module that they depend on. Basically, it's up to the engine to either execute the commands given it directly, or, in the case where third-party software is involved, pass them onto the third-party software, in which case the engine acts as a wrapper for the third-party module. It's up to the engine to figure out where this module is and load it, but some, like libp11，使其可以通过MODULE_PATH控件进行配置。