FlexHub currently only support SSL/TLS for Linux, the lib used in Windows can cause the hub to freeze.
For FlexHub to be able to use SSL/TLS, you will need to generate a selfsigned certificate.
To generate a selfsigned certificate you need to follow these 3 steps:
Step 1: Generate a RSA private key: openssl genrsa -out key.pem 1024
(it's possible that this command needs su rights, then use: sudo openssl genrsa -out key.pem 1024)
Step 2: Generate a signing request: openssl req -new -key key.pem -out req.pem
Step 3: Generate the certificate: openssl req -x509 -key key.pem -in req.pem -out cert.pem -days 3650
Then place the files key.pem and cert.pem in the subfolder 'certificates' of the FlexHub folder
After that you can add secure ports with the hub gui, or use the startup option --sport=<portnumber>
Note that normal (unsecure) connections won't be allowed on secure ports.