/usr/lib/initcpio/hooks/customcrypt

#!/usr/bin/ash
run_hook() {
    #######################
    KEYS="/keys"
    KEYSIMG="/etc/keys.img"
    #######################
    error=0
    mountcrypt() {
        NAME="$1"
        DEVICE="$2"
        KEYFILE="$3"

        if [ -b "$DEVICE" ]; then
            if [ -b "/dev/mapper/$NAME" ]; then
                echo "$NAME: DEVICE ALREADY MOUNTED"
            else
                echo "$NAME: mounting..."
                if [ "$KEYFILE" == "NO" ]; then
                    cryptsetup luksOpen "$DEVICE" "$NAME"
                else
                    cryptsetup luksOpen -d "$KEYFILE" "$DEVICE" "$NAME"
                fi

                if [ -b "/dev/mapper/$NAME" ];then
                    echo "$NAME: mounted."
                else
                    echo "$NAME: UNABLE TO MOUNT."
                    error=1
                fi
            fi
        else
            echo "$NAME: DEVICE NOT FOUND"
            error=1
        fi
    }
    #######################

    # Mount keyfiles
    if [ ! -f "$KEYS/.mounted" ];then
        if [ ! -b "/dev/mapper/keys" ];then
            cryptsetup luksOpen "$KEYSIMG" keys
        fi
        if [ ! -d "$KEYS" ];then
            mkdir -p "$KEYS"
        fi
        mount -t ext2 -o ro /dev/mapper/keys "$KEYS"
    fi

    if [ -f "$KEYS/.mounted" ];then
        # Parse crypttab and start mounting
        while read line; do
            if [ "${line:0:1}" != "#" ];then
                NAME="$(echo $line | awk -F' ' '{print $1}')"
                DEVICE="$(echo $line | awk -F' ' '{print $2}')"
                KEYFILE="$(echo $line | awk -F' ' '{print $3}')"
                if [ "$KEYFILE" == "NO" ]; then
                    mountcrypt $NAME $DEVICE $KEYFILE
                elif [ "$KEYFILE" == "YES" ]; then
                    KEYFILE="$KEYS/$NAME.key"
                    if [ -f "$KEYFILE" ]; then
                        mountcrypt $NAME $DEVICE $KEYFILE
                    else
                        echo "$NAME: KEYFILE NOT FOUND"
                        error=1
                    fi
                else
                    echo "$NAME: KEYFILE VALUE IS INCORRECT."
                    error=1
                fi
            fi
        done < /etc/earlycrypttab
    else
        echo COULD NOT MOUNT KEYFILES IMAGE
        error=1
    fi

    if [ -f "$KEYS/.mounted" ];then
        umount /keys
    fi
    if [ -b "/dev/mapper/keys" ];then
        #echo CLOSING KEYS IMAGE
        cryptsetup luksClose keys
    fi

    if [ $error != 0 ];then
        echo "ERROR. Press ENTER to continue, or restart the computer."
        read
    fi
}