Yep the libraries I've used can generate a hash byte by byte luckily without loading everything in memory. Here's an example of how I call Amazon services and

Yep the libraries I've used can generate a hash byte by byte luckily without loading everything in memory. Here's an example of how I call Amazon services and generate a signature on an Arduino: https://github.com/tdicola/CloudThermometer https://github.com/tdicola/CloudThermometer