Add option to clear LUKS key from card

usr/bin/setupcard.sh

@@ -675,6 +675,16 @@ function loadlukskey {
 	fi
 }
 
+function clearlukskey {
+	echo "Clearing LUKS key..."
+	authenticatecard "AUT1"
+	if [[ $authenticated = "1" ]]; then
+		dd if=/dev/zero of=$SECURE_DIRECTORY/smart.key.blank bs=255 count=1
+		update_file "10 01" "$SECURE_DIRECTORY/smart.key.blank"
+		rm -f $SECURE_DIRECTORY/smart.key.blank
+	fi
+}
+
 function loadusername {
 	echo "Loading username..."
 	authenticatecard "AUT1"
@@ -744,6 +754,7 @@ while [[ 1 -eq 1 ]]; do
 				FALSE "Import LUKS encryption key from file to system" \
 				FALSE "Get LUKS encryption key from Smart Card [File 1001]" \
 				FALSE "Load LUKS encryption key into Smart Card [File 1001]" \
+				FALSE "Clear LUKS encryption key from Smart Card [File 1001]" \
 				FALSE "Load username into Smart Card [File 1002]" \
 				FALSE "Load password into Smart Card [File 1003]" \
 				FALSE "Update Smart Card Transport Keys [AUT1-AUT3]" \
@@ -759,6 +770,7 @@ while [[ 1 -eq 1 ]]; do
 				FALSE "Import LUKS encryption key from file to system" \
 				FALSE "Get LUKS encryption key from Smart Card [File 1001]" \
 				FALSE "Load LUKS encryption key into Smart Card [File 1001]" \
+				FALSE "Clear LUKS encryption key from Smart Card [File 1001]" \
 				FALSE "Load username into Smart Card [File 1002]" \
 				FALSE "Load password into Smart Card [File 1003]" \
 				FALSE "Update Smart Card Transport Keys [AUT1-AUT3]" \
@@ -822,6 +834,10 @@ while [[ 1 -eq 1 ]]; do
 		loadlukskey
 	fi
 
+	if [[ $selection = "Clear LUKS encryption key from Smart Card [File 1001]" ]]; then
+		clearlukskey
+	fi
+
 	if [[ $selection = "Load username into Smart Card [File 1002]" ]]; then
 		loadusername
 	fi