TLS is one of the reasons I'm really hopeful for the ESP32 that's supposed to have a good bit of hardware help for doing TLS and such. http://esp32.net/
If you're looking for improved TLS support, have a peek at esp-open-rtos[1], which is a re-implementation of the Espressif provided rtos sdk and is aiming to be fully open source.
It ships with the mbed TLS implementation, which supports TLS 1.2.
It CAN do TLS but it leaves very little left over if you have any kind of real business logic.