Gets an encoded public key from user's DID doc and wraps it in some OpenSSL nonsense so it can be fed to the `jwt` gem which verifies the token. The OpenSSL part is what I have no idea why it is this way, because it's much more than just OpenSSL::Key.new(file)…

OpenSSL is infamous for being complicated to use. It's not meant to be maneuvered by people who aren't experts.