Start implementing key and certificate handling
So far it's fairly simple logic:
- Create new private key if not existing
- validate private key
- Check and load ca-certificates
- validate ca-certificates
- Start parsing X509 subjects from the pem files
Error handling is still a mess as I'm passing Strings around with error messages, and they should probably be consolidated to a set of Enum's and use a more proper error-handling crate.
thiserror seems to be a decent solution for that: