When importing a certificate, the private key is passed to the
import/upload process from the UI as a str object. In Python3 this
raises two issues when processing the private key - the private key
validation fails and database insert of the certificate fails.
The fix in both cases is to correctly encode the private key as a bytes
object.
Lemur's documentation already mentions LEMUR_RESTRICTED_DOMAINS, a list
of regular expressions matching domains only administrators can issue
certificates for. An option to mark domains as sensitive existed in the
API, however the configuration option was not implemented.
Now both ways of sensitivity are checked in the same place.