-MASTER_KEYRING=/usr/share/keyrings/ubuntu-master-keyring.gpg
-ARCHIVE_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
-REMOVED_KEYS=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg
-ARCHIVE_KEYRING_URI=http://archive.ubuntu.com/ubuntu/project/ubuntu-archive-keyring.gpg
+MASTER_KEYRING=""
+ARCHIVE_KEYRING_URI=""
+#MASTER_KEYRING=/usr/share/keyrings/debian-master-keyring.gpg
+#ARCHIVE_KEYRING_URI=http://ftp.debian.org/debian/debian-archive-keyring.gpg
+
+ARCHIVE_KEYRING=/usr/share/keyrings/debian-archive-keyring.gpg
+REMOVED_KEYS=/usr/share/keyrings/debian-archive-removed-keys.gpg
+
+requires_root() {
+ if [ "$(id -u)" -ne 0 ]; then
+ echo >&1 "ERROR: This command can only be used by root."
+ exit 1
+ fi
+}