[coreboot] 3 Chip Open BIOS + ESP: Backup/Secure BIOS with Redundancy

[Corey Osgood]

I'd just like to point out some flaws in your proposal:

1. If Chip 1 is read only, and something happens, chips 2 and 3 are
restored to whatever version they were originally, leaving chips 2 and
3 open to the same vulnerability, should it not be eradicated from the
hard drive or fixed by an update.
2. Without some sort of extremely efficient compression algorithm,
Chip 1 would have to be as large as Chip 2 + 3. I'm guessing it would
probably end up being 4 chips, all the same size.
3. How is Chip 3 to determine what network to connect to? Can you
really fit a networking stack, dhcp client, and secure ftp client into
1 or 2MB or less? How much time would be added to the boot time for
Chip 3 to identify a network, connect to it, get an IP, and then check
the versioning and potentially download an update and apply it?
4. What happens if the download server is compromised? Or if the
download location is forced to move? Do you really like the idea of
writing down 75 character web addresses so you can type them in to a
BIOS (or rather, payload) configuration menu, to change an update
path? What happens if Chip 3 needs to get restored?
5. How does this protect against malicious/infected PCI roms?
6. Do you honestly believe your brother's type of ignorance can be
fixed by a more secure BIOS? Seriously, the type of people who have
those kinds of problems, viruses and malware running amuck, would
never realize their BIOS had a problem, wouldn't open their case to
realize there's a switch on the board, and probably wouldn't even read
the manual to find out it was there or what it did. Proper antivirus
software, malware protection, and a decent firewall, combined with
reflashing the BIOS every once in a while, can give exactly the same
result. I know several people who had me work on their computers, back
when windows 98 and ME were the current versions, they were having
horrible problems with their computers running slow, this file or that
was missing/damaged, etc. Come to find out, in at least half a dozen
cases, they were canceling scandisk every time the computer started.
Let it run, and in every case, problem solved. What happens when your
rootkit detection program realizes the BIOS is messed up, and asks the
user to get down on their hands and knees, dig the computer out of the
desk they so lovingly hid it in, open the case, flip a switch, get it
all back together so they can restart it, wait 5 minutes, and repeat?

I'm not an engineer either, yet, working on my degree, I'm just trying
to give you some things to consider. You should also consider that
vendors don't like spending any more money then they absolutely have
to, so adding 2 or 3 redundant chips is not cool. Also, most current
hardware only supports one flash chip, or else 2 flash chips but on 2
different interfaces (SPI and LPC, for example).

-Corey

On Thu, Jun 12, 2008 at 2:42 AM, Nathaniel Dube <njdube at gmail.com> wrote:
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> First off, I'm by no means a engineer.  This message is going out to real
> engineers that might have interest in bringing the idea I'm about to share
> with you to reality.  This idea came to me after some light reading about
> rootkits on wikipedia and playing around with the program "rkhunter".
>
> Malware designers are writing code that can infect a system via rootkits.
> I've even read about the possibility of malware that can infect ROM chips on
> mother boards as well as ROM chips on PCI cards.  Meaning, anything that is
> rewritable isn't safe from malware.  Then it dawned on me that most of these
> security issues could be minimized at the hardware level at preboot, meaning
> before the operating system loads.
>
> My brother brought his laptop to me complaning the internet wont work and that
> it's slow as a whale turd.  When I looked at it I found it swarming with
> viruses.  I asked him what happened to the firewall and antivirus that In
> installed for him and he said he turned them off because the firewall was
> messing with his internet and he didn't know how to turn it off with out also
> turning off the antivirus.  I think it was Eset Internet Security.  I use
> Linux on my system so I don't touch Windows software all that often.  I've
> come to the conclusion that it doesn't matter what software you put on there
> or what you do, stupid users (and most users are stupid) will fsck up there
> system.
>
> That's when I decided that mother boards need to be dramatically redesigned
> from the ground up with a proactive role in security.  Now here's where I
> will start with my wonderful idea that will save the world.  You will either
> see that world with me or you wont.
>
> I'm sure most of you are aware of the history of the BIOS and the ROM's
> they're on.  Back in the day they really where ROM in every sense of the term
> that they where READ only.  They where embed on the board so you would need a
> solder iron to remove them.  Then they came out with the removable kind with
> sockets that you can replace with a new chip.  Then comes the kind you can
> flash with software but are embedded.  I'm sorry but impeded un-removeable ROM
> chips are completely asinine.  Now on to my idea.
>
> Instead of one ROM chip for the BIOS there should be 3 and use "coreboot" as
> the BIOS.  All 3 will utilize sockets to be removeable for easy replacement.
> The first chip will have the purpose as a backup of the default BIOS and the
> chip will be read only.  The second chip will house a copy of the primary
> BIOS which will be rewritable and allow for updates.  The third chip I will
> call the ESP (Emergency Security Protocols) ROM which may or may not be read
> only, I haven't decided yet.  The third chip will have the open source
> programs rkhunter, clamav and perhaps other programs that might be useful for
> a preboot.
>
> In the event the other two are corrupted for what ever reason you need only
> flip a jumper, turn on the computer and the backup BIOS takes control and
> allows you to wipe the other two chips and restore a rewritable copy of the
> BIOS to chip 2 and the ESP BIOS to chip 3.  The backup BIOS will also have
> the Linux program "wipe" so in the unlikeliness a rootkit takes control of
> chips 2 and 3 chip 1 will wipe it out and start from scratch.
>
> This board will also have integrated wifi as well as lan making it easy to get
> a internet connection.  The goal being to be able to update the signatures of
> rkhunter and clamav as well as update both firmware by direct download before
> the OS even loads.  This entire process will have a liberal use of checksums
> to make sure at no time is any malware being installed during the preboot
> process.
>
> I'm still trying to work out the finer details in my head.  So my idea may
> make sense or it may not.  Ultimately what I'm trying to do is build a mother
> board with BIOS backup/security redundancy.  The 3 chips act as a triad that
> protect one another.  The board should be designed so it tries to load the
> second chip with the rewritable BIOS and use the third chip to do a quick
> self scan for rootkits.  If for some reason the first BIOS wont load it will
> fall back on the backup BIOS restoring the primary.  Perhaps some one can
> share a better way of implimenting my idea.  The goal is to make it damn near
> impossible for malware to alter or change the BIOS or load at preboot.  These
> security meause could also be used to protect rewritable ROM on other
> hardware.
>
> Please share your thoughts.  I would really like to see a board like this see
> the light of reality.
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