I installed the libonion and followed the steps
i.e unzip the files on linux
sudo apt-get install gntls-dev
mkdir build
cd build
cmake ..
make
sudo make install
I made change port # to 9999 in webSocket.c under src/examples/websocket.c
issued make.
I get the following error on attempting to connect to server using chrome client running from
~/onion-master/build/examples/websockets$ ./websockets
[E02DE700] [2017-02-03 19:35:42] [ERROR codecs.c:389] Cant calculate SHA1 if gnutls is not compiled in! Aborting now