Testing a static variable certificate_loaded is simply wrong.
If create 2 threads to connect server with different URL paths,
the fist thread test certificate_loaded and init tls identity, the second
thread will NOT init tls identity.
In additional, use strlen( dct_security->private_key ) and strlen( dct_security->certificate ) are also buggy.
How do you make sure the private_key and certificate read from DCT is NULL terminated?
Think about the case write a longer cert/key to DCT then override it with a shorter cert/key.
Then you got wrong length by strlen().
