# Functions
CheckRootKeyIsEncrypted makes sure the root key is encrypted.
GenerateCertificate generates an X509 Certificate from a template, given a GUN and validity interval.
NewCryptoService returns an instance of CryptoService.
# Variables
ErrNoKeysFoundForGUN is returned if no keys are found for the specified GUN during export.
ErrNoValidPrivateKey is returned if a key being imported doesn't look like a private key.
ErrRootKeyNotEncrypted is returned if a root key being imported is unencrypted.
# Structs
CryptoService implements Sign and Create, holding a specific GUN and keystore to operate on.