#!/bin/bash
#
# Quick and dirty extracter to get the EC image out of the iso file
# Copyright (C) 2016 Hamish Coleman
#
# TODO:
# - a tool that is portable to Windows
# - should output dependancy information

INFOFILE="$1"
if [ ! -r "$INFOFILE" ]; then
    echo Need file with source and offset info
    exit 1
fi
shift

OUT="$1"
if [ -z "$OUT" ]; then
    echo Need output filename
    exit 1
fi

read SOURCE OFFSET LENGTH <"$INFOFILE"

# assume that output filename is blahdyblah.img.orig
OUT1=$(basename "$OUT" .orig).enc.orig

set -x

dd if=$SOURCE bs=$[$OFFSET] skip=1 | dd bs=$[$LENGTH] count=1 of="$OUT1" 
mec-tools/mec_encrypt -d "$OUT1" >"$OUT"