grub2-signing-extension/sbin/grub2-unsign

#!/bin/bash
# grub2-unsign
# Unsigns every file in /boot. Depends on grub2-verify
# Author: Bandie 
# Licence: GNU-GPLv3

# Check if something is wrong
grub2-verify
stat=$?
if (( $stat == 1 ))
then
  printf '%s\n' "grub2-verify has detected a one or more bad signatures." "Please check for malicious software before you're unsigning everything!" >&2
  exit 1
elif (( $stat == 2 ))
then
  printf 'Everything is unsigned already.\n'
  exit 0
elif (( $stat == 3 ))
then
  printf 'Ignoring missing signatures...\n'
else
  printf 'Something unknown happened!\n'
  exit 99
fi

# Then remove the signatures.
find /boot -name '*.sig' -exec rm -- '{}' +

echo "GRUB2 unsigned. WARNING: If you want to deactivate GRUB2's signature feature, change the check_signatures variable in the headers file!"
exit 0