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Raspberry Pi Pico cracks BitLocker in under a minute

theregister.com

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Re: Raspberry Pi Pico cracks BitLocker in under a minute

#11

Post by p_l »

nullindividual wrote: post #8
buran77 wrote: post #7

Am I missing something or is this the same TPM bus sniffing for the key exchange attack (from @marcan maybe?) that was detailed some years back but using a cheap Pi? Is this attack BitLocker specific somehow? It looks like it would affect LUKS or others just as well. Just trying to understand the novelty of this particular method or if it's tied to BitLocker in particular. Anyway, not to detract from the nice work of…

This impacts any encryption scheme using dTPM, which today should be uncommon as fTPM has been in AMD and Intel chips for many years.

It also impacts only dTPM use that does not set up encrypted session first. No idea why Bitlocker doesn't use encrypted session.

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#12

Post by iLoveOncall »

I'm not familiar at all with this kind of low-level knowledge so probably a stupid question but: does that require the device to be connected when the user types their password to actually retrieve the key, or is it an actual "crack" as in it can unlock BitLocker without key nor password ever being inputted on the device?

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#13

Post by buran77 »

soraminazuki wrote: post #9
buran77 wrote: post #7

Am I missing something or is this the same TPM bus sniffing for the key exchange attack (from @marcan maybe?) that was detailed some years back but using a cheap Pi? Is this attack BitLocker specific somehow? It looks like it would affect LUKS or others just as well. Just trying to understand the novelty of this particular method or if it's tied to BitLocker in particular. Anyway, not to detract from the nice work of…

> It looks like it would affect LUKS or others just as well. Except you can use good old password protected FDE on any major desktop operating system other than Windows Home Edition. > I can hack a lot of encryptions in seconds with a simple keylogger. A thief can't use your keylogger to decrypt a stolen laptop that's properly encrypted. A rogue recycling shop can't do that either. And kids won't be able to use, uh,…

> Except you can use good old password

But one could not do that and be just as vulnerable. Same as you can use a PIN on BitLocker and be safe in this case. Which answers my question that this is not something BitLocker specific, just a bit of name dropping to garner more attention. Which is fine from the original author, not so fine from the journalists that picked it up.

> So yes, it's kind of a big deal.

You're not wrong but also this is not new. On close read this is indeed the same attack detailed as far back as 2019, says the internet. Presumably a few dollars cheaper now.

Use an additional factor if you care about that data staying encrypted, it only takes a few seconds and could save you quite the headache.

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#14

Post by realo »

This particular bus sniffing attack is easily prevented... it's just that Microsoft _chose_ to avoid implementing the protection.

Mission critical embedded devices are not designed by Microsoft, and would normally have tpm parameter encryption...

https://security.stackexchange.com/questions/253776/why-does...

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#15

Post by bri3d »

iLoveOncall wrote: post #12

I'm not familiar at all with this kind of low-level knowledge so probably a stupid question but: does that require the device to be connected when the user types their password to actually retrieve the key, or is it an actual "crack" as in it can unlock BitLocker without key nor password ever being inputted on the device?

It only works with Bitlocker which relies only on external/discrete (dTPM) key material and no configured PIN or password, so there is nothing to input. It’s just sniffing key material off of the external TPM bus after the bootloader asks for it. This is an ancient attack and not very technically interesting, but it comes up every few years because Microsoft still don’t switch to using TPM encrypted sessions.

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#16

Post by vel0city »

iLoveOncall wrote: post #12

I'm not familiar at all with this kind of low-level knowledge so probably a stupid question but: does that require the device to be connected when the user types their password to actually retrieve the key, or is it an actual "crack" as in it can unlock BitLocker without key nor password ever being inputted on the device?

This is for non-password Bitlocker with discrete TPMs that aren't configured to encrypt their exchange.

There's a mode of Bitlocker where it boots into a basic boot environment, asks the TPM for the key, the TPM validates the environment, and then gives the decryption key. For some discrete TPMs, this last step of the TPM giving the key to the boot environment is done in the clear and can be sniffed.

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#17

Post by orev »

Impressive technical feat, even if not completely new.

However, as tech people we need to stop downplaying our accomplishments. “43 seconds” (plus the lifetime of learning that allowed them to figure out how to do all these things: decoding the wire signals, writing a custom firmware, knowing how to probe the motherboard for the correct signals, etc.)

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#18

Post by darkclouds »

soraminazuki wrote: post #9
buran77 wrote: post #7

Am I missing something or is this the same TPM bus sniffing for the key exchange attack (from @marcan maybe?) that was detailed some years back but using a cheap Pi? Is this attack BitLocker specific somehow? It looks like it would affect LUKS or others just as well. Just trying to understand the novelty of this particular method or if it's tied to BitLocker in particular. Anyway, not to detract from the nice work of…

> It looks like it would affect LUKS or others just as well. Except you can use good old password protected FDE on any major desktop operating system other than Windows Home Edition. > I can hack a lot of encryptions in seconds with a simple keylogger. A thief can't use your keylogger to decrypt a stolen laptop that's properly encrypted. A rogue recycling shop can't do that either. And kids won't be able to use, uh,…

[dead]

Re: Raspberry Pi Pico cracks BitLocker in under a minute

#19

Post by woodrowbarlow »

orev wrote: post #17

Impressive technical feat, even if not completely new. However, as tech people we need to stop downplaying our accomplishments. “43 seconds” (plus the lifetime of learning that allowed them to figure out how to do all these things: decoding the wire signals, writing a custom firmware, knowing how to probe the motherboard for the correct signals, etc.)

43 seconds is the time taken to deploy the exploit, not to develop it. the short time window communicates the severity of the exploit.
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