update_password() {
    USER=$1
    GENERATE_RANDOM=$2

    if [ "$GENERATE_RANDOM" == "y" ]; then
        PASSWORD=`chroot . usr/bin/hashpass`
    else
        PASSWORD=`usr/bin/get-mac-address`
        PASSWORD=`chroot . usr/bin/hashpass -p $PASSWORD`
    fi

    NEWLINE="$USER:$PASSWORD:14076:0:99999:7:::"
    update_line "^$USER:" etc/shadow "$NEWLINE"
    return 0
}