commit bb45c1fbac8c2a0491a9b20c5fa686abd4b0e9de
Author: Leho Kraav <leho@kraav.com>
Date:   Thu Jun 16 14:06:37 2011 -0400

    working pipe system
    
    Example key created with a pipe. This ensures that a certain token has
    to be present in the system for sha512 to generate a correct password
    for unlocking the volume.
    
    /etc/conf.d/dmcrypt:
    target=c3
    source=/dev/sda3
    pipe='ls /dev/disk/by-uuid | sha512sum'

diff --git a/1.1.3-dm-crypt-start.sh b/1.1.3-dm-crypt-start.sh
index bc60ba0..027ff4a 100644
--- a/1.1.3-dm-crypt-start.sh
+++ b/1.1.3-dm-crypt-start.sh
@@ -176,7 +176,11 @@ dm_crypt_execute_dmcrypt() {
 			ret="$?"
 			eend "${ret}" "failure running cryptsetup"
 		else
-			cryptsetup ${options} ${arg1} ${arg2} ${arg3}
+			if [ -n "${pipe}" ]; then
+				eval "${pipe}" | cryptsetup ${options} ${arg1} ${arg2} ${arg3}
+			else
+				cryptsetup ${options} ${arg1} ${arg2} ${arg3}
+			fi
 			ret="$?"
 			eend "${ret}" "failure running cryptsetup"
 		fi
@@ -249,7 +253,7 @@ parse_opt() {
 }
 
 local cryptfs_status=0
-local gpg_options key loop_file target targetline options pre_mount post_mount source swap remdev
+local gpg_options key loop_file target targetline options pre_mount post_mount source swap remdev pipe
 
 CMDLINE="`cat /proc/cmdline`"
 for x in ${CMDLINE}
@@ -278,10 +282,10 @@ if [[ -f ${conf_file} ]] && [[ -x /sbin/cryptsetup ]] ; then
 				${execute_hook}
 
 				# Prepare for the next target/swap by resetting variables
-				unset gpg_options key loop_file target options pre_mount post_mount source swap remdev
+				unset gpg_options key loop_file target options pre_mount post_mount source swap remdev pipe
 				;;
 
-			gpg_options=*|remdev=*|key=*|loop_file=*|options=*|pre_mount=*|post_mount=*|source=*)
+			gpg_options=*|remdev=*|key=*|loop_file=*|options=*|pre_mount=*|post_mount=*|source=*|pipe=*)
 				if [[ -z ${target} && -z ${swap} ]] ; then
 					ewarn "Ignoring setting outside target/swap section: ${targetline}"
 					continue