Microsoft proves backdoor keys are a bad idea • Hacker News Board

Re: Microsoft proves backdoor keys are a bad idea

#41

Post by jewel » Wed, Aug 10, 2016, 7:14 PM UTC

TheSpiceIsLife wrote: post #37

bradford wrote: post #5

(disclaimer, MS employee, non-security expert here). I've read through the article, here, and in other places, and I'm seeing sentiment that this is a big fuck up on Microsoft's part. I might be completely misunderstanding, but I just don't see it. In order to use the backdoor, you've got to flash firmware, so, you've got to have physical access to the device. If an attacker has physical access to your device, you're…

If an attacker has physical access to your device, you're already screwed. I'm no security expert, but is this true? Say I use full drive encryption, with whatever the popular Linux distros are offering at install time, and Say I use a strong password of 30 random characters. Is it feasible to break this encryption in a reasonable time frame?

There's a lot that can go wrong if an attacker has physical access to your device.

As far as is publicly known, you're not directly vulnerable to having the password broken as long as the device is powered off when it falls into the wrong hands, but there are a lot of caveats. If it's powered on they can possibly extract the password from RAM using a "cold boot attack". They can also freeze the RAM to get its contents to last longer and then moving it to another computer and dump it, recovering your full-disk encryption key.

If the attacker has temporary physical access, they have a number of ways that they can tamper with the device. For example, they can replace the BIOS, the bootloader, the firmware on your keyboard, etc. The new code can record your passwords or send your data to the attacker over the internet.

One other way that you're physically vulnerable is that the attacker can possibly infect your hardware before it even arrives at your home, by replacing hardware while it's shipping. This is probably only available to nation-states.

Re: Microsoft proves backdoor keys are a bad idea

#42

Post by allendoerfer » Wed, Aug 10, 2016, 7:14 PM UTC

I think people should be able to sue companies that do this. They surely did not advertise it as "secure unless we lose the key". Having a backdoor in the first place could be counted as negligent (should be counted as outright fraud).

Re: Microsoft proves backdoor keys are a bad idea

#43

Post by IBM » Wed, Aug 10, 2016, 7:17 PM UTC

bradford wrote: post #5

(disclaimer, MS employee, non-security expert here). I've read through the article, here, and in other places, and I'm seeing sentiment that this is a big fuck up on Microsoft's part. I might be completely misunderstanding, but I just don't see it. In order to use the backdoor, you've got to flash firmware, so, you've got to have physical access to the device. If an attacker has physical access to your device, you're…

>If an attacker has physical access to your device, you're already screwed.

The FBI had physical access to the San Bernardino iPhone. If this were true, what was the point of the public fight with Apple and eventual purchase of a zero day exploit to get into it?

Re: Microsoft proves backdoor keys are a bad idea

#44

Post by contextfree » Wed, Aug 10, 2016, 7:21 PM UTC

I'm actually a bit confused about how this is a "golden key" problem (if I understand what that means).

As far as I can tell, the problem here is that there's a signed policy that was intended for newer versions of Windows, but is also interpreted by older versions of Windows as a valid policy with a different meaning. On Win10 1607 it means "under such-and-such conditions, merge these additional rules into the already applied policy" and on older Windows it just means "apply this policy".

But the only key here in both cases is Microsoft's regular signing key. Which I guess could be considered a kind of golden key/backdoor/whatever in itself - just as in the recent Apple vs. FBI standoff you could say the fact that Apple had the technical ability to sign and install a hacked OS was a backdoor to begin with - but that doesn't seem to be what people mean.

Re: Microsoft proves backdoor keys are a bad idea

#45

Post by noenpnqnoen » Wed, Aug 10, 2016, 7:22 PM UTC

bradford wrote: post #27

sp332 wrote: post #16

Earlier quoted context omitted.

You need admin rights, but not physical access.

requiring admin rights for an exploit is certainly a lower barrier to entry than is requiring physical access, but I think my point still stands: if someone has those rights, you're already screwed.

...which means secure boot doesn't provide security.

Re: Microsoft proves backdoor keys are a bad idea

#46

Post by l3m0ndr0p » Wed, Aug 10, 2016, 7:30 PM UTC

mtgx wrote: post #34

bradford wrote: post #26

Earlier quoted context omitted.

Ok, I get it. The message is "don't use backdoors, because they'll inevitably get leaked", which I agree with. Unfortunately, I don't think that's the message that's being interpreted by the vast majority of readers. I'm delving into opinion territory now, but when the word 'backdoor' is used, aren't most people going to assume that it's an FBI backdoor, instead of a test/development backdoor? This seems like the kin…

A backdoor is a backdoor = unauthorized access to a user's device. What does it matter if it's Microsoft, FBI, or the Chinese government using it? By definition, it can't be "just Microsoft" anyway, as the people who discovered this pointed out, whether it's up to Microsoft or not. > and no one seems to be doing anything to correct the record. Maybe Microsoft feels guilty about it? It reminds me of when a journalist…

The US government is enforcing implied consent on all citizens by forcing corporations to have these "backdoors" in place. I can see now why there are many of these backdoors or issues with the MS Windows. I think these issues exist to provide that backdoor opportunity for our government.

No government will respect your privacy and will always claim ownership over everything you do.

It's a corrupt system and it needs to end. Peacefully.

Re: Microsoft proves backdoor keys are a bad idea

#47

Post by rdtsc » Wed, Aug 10, 2016, 7:34 PM UTC

bradford wrote: post #5

(disclaimer, MS employee, non-security expert here). I've read through the article, here, and in other places, and I'm seeing sentiment that this is a big fuck up on Microsoft's part. I might be completely misunderstanding, but I just don't see it. In order to use the backdoor, you've got to flash firmware, so, you've got to have physical access to the device. If an attacker has physical access to your device, you're…

Ok but then why bother with whole key thing then? That's a whole lot of code, API crap and other junk why not just force user to hold a key to specifically reboot to reflash / upgrade boot loader. So have to hold the devices in hand to do it.

It seems to me the mechanism was created exactly not allow even an owner to boot a non-approved OS image.

Re: Microsoft proves backdoor keys are a bad idea

#48

Post by ge0rg » Wed, Aug 10, 2016, 7:34 PM UTC

rocky1138 wrote: post #25

> The Register understands that this debug-mode policy was accidentally shipped on retail devices, and discovered by curious minds including Slip and MY123. > The policy was effectively inert and deactivated on these products but present nonetheless. Whenever I read things like this, I always envision that it's not a cock-up at all, but instead a deliberate effort by righteous free software-minded people who happen t…

a deliberate effort by righteous free software-minded people who happen to work at Microsoft

Or maybe a deliberate effort by developers who are paid by a three letter agency to sneak in a backdoor that looks like an accidental bug.

In this case you might be right, but the last time a similar issue was widely circulated (Heartbleed in OpenSSL), it also looked like an accident (or rather gross negligence), but its effect was much more beneficial to agencies and not usable to increase FOSS domination.

Re: Microsoft proves backdoor keys are a bad idea

#49

Post by ruste » Wed, Aug 10, 2016, 7:39 PM UTC

Is this code also used for the Xbox? It would be really cool if we could run linux/bsd easily on one of those.

Re: Microsoft proves backdoor keys are a bad idea

#50

Post by cptskippy » Wed, Aug 10, 2016, 7:39 PM UTC

Nullabillity wrote: post #39

bradford wrote: post #36

Earlier quoted context omitted.

I think you're missing my point (and my poor wording probably didn't help). A backdoor that requires physical access isn't a backdoor. If an attacker has such access, you're already screwed. A backdoor that requires administrative privileges isn't a backdoor. If an attacker has such access, you're already screwed. The so-called dev/test 'backdoor' really isn't a backdoor. It's a 'unlock' tool that's required for anyo…

> A backdoor that requires physical access isn't a backdoor. If an attacker has such access, you're already screwed. > A backdoor that requires administrative privileges isn't a backdoor. If an attacker has such access, you're already screwed. Then why bother trying to lock it down in the first place?

Service providers that wish to provide subsidized devices as part of service contracts usually require that said devices can't be repurposed for the duration of the service contracts. Thus a means is needed to lock a device.