Reject signatures with empty encapsulated content. Enforce SHA-1 in the first pass. Change-Id: I42b5f90d02d2abc0c250497d6cc64df4fa798d5d Reviewed-on: https://gerrit.libreoffice.org/c/core/+/185207 Tested-by: Jenkins Reviewed-by: Miklos Vajna <vmiklos@collabora.com>