oscrypto: oscrypto segfaults on catalina

I’ve come here after an all-day debugging session. tl;dr I think oscrypto is picking up the wrong SSL backend for catalina (OS X 10.15.1) which causes a crash.

There’s some workarounds as documented here: https://forums.developer.apple.com/thread/119429 Though that seems pretty gnarly.

Specifically I’m finding it failing in _libcrypto_cffi:

libcrypto_path = _backend_config().get('libcrypto_path')
if libcrypto_path is None:
    libcrypto_path = find_library('crypto')
if not libcrypto_path:
    raise LibraryNotFoundError('The library libcrypto could not be found')

try:
    vffi = FFI()
    vffi.cdef("const char *SSLeay_version(int type);")
    version_string = vffi.string(vffi.dlopen(libcrypto_path).SSLeay_version(0)).decode('utf-8') #### fails here
except (AttributeError):
    vffi = FFI()
    vffi.cdef("const char *OpenSSL_version(int type);")
    version_string = vffi.string(vffi.dlopen(libcrypto_path).OpenSSL_version(0)).decode('utf-8')

I suspect we are just picking a version that makes Catalina extremely upset, and so if we can pick a pinned version that would be better.

I posted something similar here: https://github.com/snowflakedb/snowflake-connector-python/issues/235