I only pointed to that API after a brief search without looking at details (Swift? oops!). If there is one available from C that'd also make sense to consider.

The only things I expect, relevant to hashlib, that would be accelerated by OS native APIs most platforms are SHA2, maybe SHA1, and sometimes HMAC using those.

I'm in no position to judge if there is value in using them, I'm just assuming there might be.  The irony is that builds without OpenSSL are rare, so unless the OS native APIs provide tangible benefits it may not matter.

(ex: the Linux APIs may allow for an efficient zero-copy variant of the new `hashlib.file_digest()` function)