The util/ folder is meant to house core utility classes and logic that can be used by everything else in the Open Screen repository.
Code here is permitted to include platform/api and platform/base -- same as the rest of the repository. However, platform/api and platform/base are not allowed to use code in util/ to avoid circular dependencies.
Includes things like string utils, JSON parsing and serialization, our std_util.h header, numeric helpers, additional container classes, URL handling, and the alarm.
crypto contains helper classes for working with cryptographic functions and X.509 certificates.