OpenSSL supports 78 ciphers but the UWP SSL implementation only supports 4.

These 4 are not explicitly named when you get QSslConfiguration::supportedCiphers(), however I know that it doesn't support the ECDHE-RSA-AES256-GCM-SHA384 cipher in protocol TLS 1.2. The attempt to connect to a webservice with an ssl certificate (recently acquired, issued by COMODO) using this cipher fails with a network error code of 99 - "Permission denied".

This basically renders a client app useless.