C daemon for reading and writing to a usb device

The program must be written in C and needs to be compiled with gcc to use with different architectures (intel/amd, x86, ARM, 32/64bit) to run on normal linux pcs as well as on embedded devices like Netgear ReadyNAS, Rasperry Pi, AVM FritzBox and alike. The daemon must have a config file, in which the following settings must be made: - usb device (eg. /dev/usb01) - api_key (some string of any length provided to each install of the daemon individually) - local port the daemon listens on (eg. 6055) The daemon does 3 things: 1. on startup and after that every 5 minutes, calls a remote url ([login to view URL]) to retrieve the public ip address of the computer it is running on. If the daemon just started or the ip address has changed compared to a previous check, it will call another remote url with the new ip address and the api_key over a SSL encrypted call ([login to view URL];api_key=xyz) 2. Establish a connection to the usb device (which basically behaves like a serial modem) and listens to it. Every time the usb device sends something, the data is pushed over an SSL encrypted call to a remote url (eg. [login to view URL];data=abc) 3. Listen on the configured port for incoming SSL encrypted socket connection which contains the valid api_key and data to be handed to the usb device. The code must be easy to maintain (eg. change the remote urls; not via the config!), well documented and follow best practices in c programming as well as design principles. The usb device uses this protocol: FHZ 1000 ([login to view URL])