diff --git a/README b/README
new file mode 100644
index 0000000..02f6835
--- /dev/null
+++ b/README
@@ -0,0 +1,15 @@
+Yubikey login:
+^^^^^^^^^^^^^^
+
+-please create /etc/udev/rules.d/92-yubikey.rules with the following content:
+   ACTION=="add", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0010", RUN+="/etc/door/door.sh"
+
+
+
+SSH login:
+^^^^^^^^^^
+
+-in ~/.ssh/authorized_keys add to the first line:
+   no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty
+
+-in /etc/passwd change the the default shell to door_ssh_login.sh
diff --git a/door.sh b/door.sh
index f28c4c1..b24fc29 100755
--- a/door.sh
+++ b/door.sh
@@ -4,6 +4,8 @@ export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
 
 OPEN_INDICATOR=/tmp/door_status_open
 CLOSED_INDICATOR=/tmp/door_status_closed
+GPIO_SWITCH=21
+WATCHDOG_PID=/tmp/door_watchdog_pid
 
 DELAY=10
 DATE_STRING="$(date +%s)#$(date +"%F %X")"
@@ -53,6 +55,28 @@ cd $(dirname $0) || {
     exit 1
 }
 
+if ! kill -0 $(cat $WATCHDOG_PID 2> /dev/null) > /dev/null 2>&1; then
+{
+	( while true; do
+		{
+		if [ $(cat /sys/class/gpio/gpio${GPIO_SWITCH}/value) -ne 1 -a -f $CLOSED_INDICATOR ]; then
+			{
+			lock_file $OPEN_INDICATOR
+			lock_file $CLOSED_INDICATOR
+			touch $OPEN_INDICATOR
+			rm -f $CLOSED_INDICATOR >> /dev/null 2>&1
+			unlock_file $OPEN_INDICATOR
+                        unlock_file $CLOSED_INDICATOR
+			}
+		fi
+		sleep .5
+		}
+	done ) &
+	echo $! > $WATCHDOG_PID
+	cat $WATCHDOG_PID
+}
+fi
+
 lock_file $OPEN_INDICATOR
 lock_file $CLOSED_INDICATOR
 if [ -f $OPEN_INDICATOR ]; then
diff --git a/door_lock.sh b/door_lock.sh
index 4884e5b..48d02d3 100755
--- a/door_lock.sh
+++ b/door_lock.sh
@@ -3,13 +3,18 @@
 GPIO_OPEN=23
 GPIO_CLOSE=24
 GPIO_CLIP=22
-SLEEP=2
+GPIO_SWITCH=21
+SLEEP=4
+CLOSE_TIMEOUT=15
 
 for i in $GPIO_OPEN $GPIO_CLOSE $GPIO_CLIP; do
 	echo "$i" > /sys/class/gpio/export
 	echo "out" > /sys/class/gpio/gpio${i}/direction
 done
 
+echo "$GPIO_SWITCH" > /sys/class/gpio/export
+echo "in" > /sys/class/gpio/gpio${GPIO_SWITCH}/direction
+
 case $1 in
 	open)
 		echo "1" > /sys/class/gpio/gpio${GPIO_OPEN}/value
@@ -17,9 +22,22 @@ case $1 in
 		echo "0" > /sys/class/gpio/gpio${GPIO_OPEN}/value
 		;;
 	close)
-		echo "1" > /sys/class/gpio/gpio${GPIO_CLOSE}/value
-		sleep $SLEEP
-		echo "0" > /sys/class/gpio/gpio${GPIO_CLOSE}/value
+		TIMER=$(($CLOSE_TIMEOUT*10))
+		while [ $TIMER -ge 0 ]; do
+		{
+			SWITCH=$(cat /sys/class/gpio/gpio${GPIO_SWITCH}/value)
+			if [ $SWITCH -eq 1 ]; then
+			{
+				echo "1" > /sys/class/gpio/gpio${GPIO_CLOSE}/value
+				sleep $SLEEP
+				echo "0" > /sys/class/gpio/gpio${GPIO_CLOSE}/value
+				break
+			}
+			fi
+			sleep .1
+			TIMER=$(($TIMER-1))
+		}
+		done
 		;;
 	clip)
 		echo "1" > /sys/class/gpio/gpio${GPIO_CLIP}/value
diff --git a/door_ssh_login.sh b/door_ssh_login.sh
new file mode 100755
index 0000000..5761eed
--- /dev/null
+++ b/door_ssh_login.sh
@@ -0,0 +1,10 @@
+#! /bin/bash --
+
+ping -c1 -t3  $(echo $SSH_CONNECTION | cut -d" " -f 1) >> /dev/null 2>&1
+STATUS=$?
+if [ $STATUS -ne 0 ]; then
+	echo "come closer... ;-)"
+	exit 1
+fi
+
+sudo $(dirname $0)/door.sh noverify
diff --git a/etc_udev_rules.d_92-yubikey.rules b/etc_udev_rules.d_92-yubikey.rules
deleted file mode 100644
index 812f95a..0000000
--- a/etc_udev_rules.d_92-yubikey.rules
+++ /dev/null
@@ -1 +0,0 @@
-ACTION=="add", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0010", RUN+="/etc/door/door.sh"