One of the foreign data wrappers I included in the PostgreSQL 9.3 Windows FDW bag and PostgreSQL 9.4 Windows FDW bag is the www_fdw extension used for querying web services. Someone asked that since I didn't build curl with SSL support,
they are unable to use it with https connections. The main reason I didn't is that the EDB installs come with ssleay32.dll and libeay32.dll (even the 64-bit) which
are dependencies of curl when built with SSL support. I wanted to minimize the issue of distributing dlls that are packaged with Windows PostgreSQL installers already.
Though this article is specific to using www_fdw on Windows systems, many of the issues are equally applicable to other platforms, so may be worth a read if you are running into similar issues with using specialty SSL certificates on Linux/Unix/Mac.