ESP8266 Community Forum

I am new to esp8266. I am trying to grasp my head around ESP8266 programming model, and have learnt a lot in last few days.
I am trying to start a socket server on ESP8266 and connect from browser using websockets.
I was referring the websocket specification https://tools.ietf.org/html/rfc6455
It Says for handshake we would need SHA1 and base64 algorithms (to send keys back to client, method is not relevant).
I looked up if any library available for cryptography but most are arduino based(although we could use it easily)
But
http://hackaday.com/2015/03/18/how-to-directly-program-an-inexpensive-esp8266-wifi-module/
Here CnLohr says there is a ROM for that too(SHA1 and base64).
How can i access those functionalities(or other ROM functions) from my code in C?
Any pointers would be helpful!
Thanks.

Update:
As of now i figured out a way to access SHA1 functions using header files from some project(unable to find the link will post it soon.)

But the question remains. How do i access ROM functions? from eagle.app.addrs file i know the list of functions. How would i know the parameters and return types?