This is a largely untested, hopefully correct version of the SHA2 family of hashing algorithms defined by RFC-4634.
Cryptographic libraries should always go through rigorous review and testing by relevant experts before seeing practical use.
This library has received neither of those.
I have done my best to implement and test the algorithm to ensure correctness, but this library is purely to learn about how SHA2 actually works.
Please do not use this library for anything besides toy/educational purposes.