[coreboot] 3 Chip Open BIOS + ESP: Backup/Secure BIOS with Redundancy
njdube at gmail.com
Thu Jun 12 12:43:46 CEST 2008
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On Thursday 12 June 2008 02:46:19 am you wrote:
> 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.
Having the read only Backup-BIOS wipe the writable BIOS is simply a last case
scenario. It's a last line of defense incase your primary BIOS becomes
foobar. Keep in mind you would also have a software antivirus and firewall
running on your operating system. So if the malware happens to get through
that it would then have to deal with the hardware rootkit protection in the
mother board. When ever you boot, the BIOS would use a checksum to check it
self for modifications. I could be wrong but I believe there are similar
security protocols in SELinux and similar technologies to detect if the Linux
kernel has been screwed with.
> 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.
I suppose I could make it little more simple and just have 2 chips. One would
be a backup and one for primary use. I have a little flash drive in my
pocket right now, it's 8 GB. I'm sure we can design a sufficiently big
enough chip to store the necessary software.
> 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?
Sure, why not. If you want 100% guarantee, then don't ever use the internet.
If we can figure out how to buy stuff offline with strong enough encryption
with a big enough margin of safety, I'm sure we can figure out something on
how to download updates.
> 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?
I really don't see that happening. I don't remember ever having any issues
with download patches for openSUSE. Now that I mention it, the people at
Novell have their main update domain bounce you to random mirrors. So when
you download updates, you're not allways getting them from the same system.
Just incase one goes down it'll bounce you to a different mirror. Which
means you don't have to waste time changing URLs for your updates. Also, the
RPM packages are signed with GPG keys from the people who manage the
repositories you're downloading from. It's to help protect you incase the
servers are compromised. ;-)
> 5. How does this protect against malicious/infected PCI roms?
It would be possible in theory that when you install new hardware that have
writable ROMs (video card maybe I'm not sure there are any that are writable)
that your mother board makes a checksum of that ROM's firmware. So on a next
reboot your mother board does a quick check to see if there where any changes
and alert you if there is. Now if we could make this board really clever we
could give it enough room to make backups as well as checksums of all the
firmware off all your hardware. Then if something is changed it could either
ask you if you want to restore from backup or incase of stupid users have it
set to do it automatically.
> 6. Do you honestly believe your brother's type of ignorance can be
> fixed by a more secure BIOS?
There is no simple fix for stupidity but to go for a car metaphore for a
moment. You have locks and keys for your house and car. Sure, if some
people wanted to bad enough they can just break the window hot wire your car
and drive off or pick the lock on your house and steal your TV. Then you can
install a car alarm and a GPS for the cops and install a security system in
your house. It's a cat and mouse game. Persistant people will find ways
around almost any locked door. But that's no excuse not to lock your door.
While security may not keep every one out, it'll keep more people out then if
you use nothing at all. ;-)
> 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.
Instead of a jumper I suppose you can design it to be automatic in the
instance the writable BIOS failed a cheksum. The system would then reboot it
self, restore from backups after wiping the infected BIOS, download updates
for rkhunter and clamav. Then the BIOS would force clamav to scan the system
for infection. Most of this can be done automatically in a clever way in the
same way scandisk runs on windows if you shut it down wrong. Something
similar hapens on Linux.
Now I'm not suggesting a really long boot process every time you turn on the
system. On every boot it would only check the BIOS for modification and
maybe the MBR then continue on it's marry way. All this it meant to do is
help protect against rootkits. This could also help serve as a protection
measure against failed BIOS flashes to update the BIOS. Which has happened
to me before. I ordered a board for my dad and noticed the BIOS was out of
date. I followed the directions to the letter. Downloaded the updates from
the companies site attempted to flash the system. Everything appeared to
work. But when I rebooted the damn thing all I got was a black screen.
Now if mother boards had been built with a second read only chip as a backup
to restore from I wouldn't have waisted days sending it back in the mail
telling them it was DOA so I can get another one.
> Proper antivirus software, malware protection, and a decent firewall,
combined with reflashing the BIOS every once in a while, can give exactly the
This might work for people like you and me but this wont work for the average
> 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.
I find most people do that with everything that seems to be a boundary between
them and what they really feal like doing on the computer. If it comes to
taking maybe 10 seconds to read a security alert from their antivirus or
firewall or spending that 10 seconds on myspace they'll choose myspace every
time and just click what every to make the window go away. Which is what my
brother did with his firewall and ended up blocking all traffic. He couldn't
figure out what magical beast broke his internet so he managed to uninstall
the firwall all together which took the antivirus with it. Which is how he
ended up infected with more viruses then a Nigerian hooker. I had to tell
him to stop using limewire and if he insisted on downloading stuff to learn
how to use bittorrent.
> 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?
As I said above, a more clever system will do it all automatically. If you
shut down most operating systems improperly they're smart enough to run
software to scan the file system for damage on the next reboot. Perhaps my
idea is overly complicated, but the point I was trying to make still stands.
This is the 21st century, mother boards need to be taking a more active role
in protecting them selves from the crap that's out there. Because stupid
users isn't going to do it for them.
> 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).
Hardware manufactories need to get off their lazy a$$es and start innovating.
Oh well, there's always the technological singularity to look forward to.
Then machines can fix them selves and not rely on stupid users. Some times I
wish the Matrix was reality. A lot of people out there deserve to be turned
into batteries. ;-)
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