You could make a wrapper class for the SSL Connection in C++ then simply add the metatype of your wrapper class to the QML engine with
qmlRegisterMetaType<SSLWrapper>("com.your.app", 1, 0, "SSLWrapper");
from C++
and
import com.your.app 1.0
from qml
This would allow you to create an instance of your C++ class using:
SSLWrapper { id: my_wrapper }
and then grab the image from your remote server using a native C++ method that has been prefixed by Q_INVOKABLE in order to access it from QML, then convert it into bytes and send it over a signal/slot setup to pass the bytes and then set the Image URL that you want to import to use data string for the image which you would get from the SSLWrapper's signal
Also check out
Qt/QML : Send QImage From C++ to QML and Display The QImage On GUI