The Qt instructions for manually adding OpenSSL support (http://doc.qt.io/qt-5/opensslsupport.html) don't work on OSX (https://bugreports.qt.io/browse/QTBUG-59375). Watch that ticket, which references a third party solution that works perfectly well as of writing (https://github.com/ekke/android-openssl-qt).

Note: Qt 5.9.0