--- encrypt	2017-12-25 11:30:54.000000000 -0800
+++ encrypt-custom	2018-01-17 15:38:17.878734369 -0800
@@ -60,6 +60,13 @@
             allow-discards)
                 cryptargs="${cryptargs} --allow-discards"
                 ;;
+            shutdown-after*)
+                IFS='=' read opt timeo <<EOF
+$cryptopt
+EOF
+                cryptargs="${cryptargs} --timeout ${timeo}"
+                shutdown_after=1
+                ;;
             *)
                 echo "Encryption option '${cryptopt}' not known, ignoring." >&2
                 ;;
@@ -85,7 +92,11 @@
 
                 #loop until we get a real password
                 while ! eval cryptsetup open --type luks ${resolved} ${cryptname} ${cryptargs} ${CSQUIET}; do
-                    sleep 2;
+                    if [ -n "$shutdown_after" ]; then
+                        echo "Input timeout. Shutting down."
+                        for x in u s o; do echo $x > /proc/sysrq-trigger; sleep 2; done
+                    fi
+                    sleep 2
                 done
             fi
             if [ -e "/dev/mapper/${cryptname}" ]; then