5 ms·

There's always a big issue with systems like this: Any sophisticated attacker will have an image of the machine he's trying to get into at hand to stop exactly

There's always a big issue with systems like this: Any sophisticated attacker will have an image of the machine he's trying to get into at hand to stop exactly what this pam module is trying to achieve from happening. All this would do is make you appear in a worse light to the deciding judge when it comes to trial or get your other kneecap shattered in a not so civil situation.

t0mas88 5y ago
Lawenforcement yes, but I'm not sure most criminals are digital enough. Especially if it all looks just normal logged in, but in the background deletes some hidden files.
- f1refly 5y ago
  People who would want the data of someone knowledgable enough to install a custom pam module and write a script to utilize it are most likely also sophisticated and informed enough to know what to look for. This is not some street thug, it's most likely either law enforcement or organized crime who know very well what they want and that it's supposed to be on your machine.
intellix 5y ago
So you're saying if I'm held at gunpoint or forced to surrender my password at the US airport that a password to clear my account of anything would be useless? Neither of them know anything about me. It reminds me of the Trezor hardware wallet that allows you to have multiple passwords into your account. If your forced to give access you can log into the version with little in it. Nobody knows that you have secondary accounts with more in it...
- jeroenhd 5y ago
  If you're held under gunpoint, that script that wipes your entire hard drive will only make your day worse. AFAIK if you actually get detained and questioned at airports, your drive will already get imaged before any password is even tried. You may be able to get away with this on a mobile device where this feature isn't generally expected (because who uses Linux on a smartphone in the first place). I always wonder at what scenarios like these are supposed to be about. If saying no is not an option, pissing off your captors by giving them fake info probably isn't either. I don't know what law enforcement would be looking for on my work drive, but if saying no is no longer an option, my encryption password isn't worth getting shot over.
  - varjag 5y ago
    It doesn't have to wipe your drive, just do reasonable things like kill your sensitive messenger accounts and clean up the history.
  - shawnz 5y ago
    What does it matter if your drive is imaged if you are using full disk encryption?
    - dailyanchovy 5y ago
      They can try their luck again at having you give access.
      - shawnz 5y ago
        The duress login shouldn't reveal that anything is happening, so they have no reason to suspect you're using such a feature at all. Thus there would be no reason to ask you to log in again, and even if they do, you can simply use the duress credentials a second time.
        eurasiantiger 5y ago
        If they can monitor network connections, they can see the duress connections, too.
        shawnz 5y ago
        You don't need to make it take any network actions, but even if you wanted to do that you could just use TLS. It would easily blend in with all the other services that use TLS as part of their normal operation.
        o-__-o 5y ago
        https://serverfault.com/questions/574405/tcpdump-server-hello-certificate-filter https://serverfault.com/questions/574405/tcpdump-server-hell...
- tedunangst 5y ago
  Without knowing what your captor already knows about your device, deleting data they may expect to find is a pretty high risk gambit.
  - Sebb767 5y ago
    If you think that them finding your data is the better option, you can always revert to using your normal login credentials.
EamonnMR 5y ago
If your attacker has a full image of your system why are they bothering with duress?
- deleted 5y ago
  [deleted]
- dogma1138 5y ago
  Also depending on the jurisdiction depending on the circumstances triggering it can be a felony the same as destroying evidence or tampering with an investigation, if a court compelled you congrats you’ve just earned yourself a contempt of court charge that can last pretty indefinitely. In a jurisdiction that doesn’t adhere to the rule of law you are already screwed. What people often don’t seem to comprehend is that if you get picked up by a “secret police” in the middle of the night it’s pretty much game over already.
  - trothamel 5y ago
    Deleting data, if someone can prove it, also opens you up to Adverse Inference, which means the jury can consider the plaintiff's reasonable inference as to what the destroyed documents contained. https://en.wikipedia.org/wiki/Adverse_inference https://en.wikipedia.org/wiki/Adverse_inference
  - atok1 5y ago
    But at this point, we are not caring about 'law' are we? This is used when you are fear for your life because of law enforcement entities.
    - dogma1138 5y ago
      If you have an actual reason to fear for your life it’s game over, the “Stasi” doesn’t care if they find evidence or not. If it’s the FBI then fearing for your life isn’t exactly part of the equation really.
- bigiain 5y ago
  Because it’s encrypted? And these days, it’s common for the decryption keys to exist only in a Secure Enclave type thing that makes extracting those keys many orders of magnitude more difficult that asking you for your password while they hit you with a wrench.
moonchild 5y ago
My understanding is that, with veracrypt (which implements something similar to the linked system), if you enter the duress password, the hidden areas appear to simply be unallocated disc space.

t0mas88 5y ago

Lawenforcement yes, but I'm not sure most criminals are digital enough. Especially if it all looks just normal logged in, but in the background deletes some hidden files.

f1refly 5y ago
People who would want the data of someone knowledgable enough to install a custom pam module and write a script to utilize it are most likely also sophisticated and informed enough to know what to look for. This is not some street thug, it's most likely either law enforcement or organized crime who know very well what they want and that it's supposed to be on your machine.

intellix 5y ago

So you're saying if I'm held at gunpoint or forced to surrender my password at the US airport that a password to clear my account of anything would be useless? Neither of them know anything about me. It reminds me of the Trezor hardware wallet that allows you to have multiple passwords into your account. If your forced to give access you can log into the version with little in it. Nobody knows that you have secondary accounts with more in it...

jeroenhd 5y ago
If you're held under gunpoint, that script that wipes your entire hard drive will only make your day worse. AFAIK if you actually get detained and questioned at airports, your drive will already get imaged before any password is even tried. You may be able to get away with this on a mobile device where this feature isn't generally expected (because who uses Linux on a smartphone in the first place). I always wonder at what scenarios like these are supposed to be about. If saying no is not an option, pissing off your captors by giving them fake info probably isn't either. I don't know what law enforcement would be looking for on my work drive, but if saying no is no longer an option, my encryption password isn't worth getting shot over.
- varjag 5y ago
  It doesn't have to wipe your drive, just do reasonable things like kill your sensitive messenger accounts and clean up the history.
- shawnz 5y ago
  What does it matter if your drive is imaged if you are using full disk encryption?
  - dailyanchovy 5y ago
    They can try their luck again at having you give access.
    - shawnz 5y ago
      The duress login shouldn't reveal that anything is happening, so they have no reason to suspect you're using such a feature at all. Thus there would be no reason to ask you to log in again, and even if they do, you can simply use the duress credentials a second time.
      - eurasiantiger 5y ago
        If they can monitor network connections, they can see the duress connections, too.
        shawnz 5y ago
        You don't need to make it take any network actions, but even if you wanted to do that you could just use TLS. It would easily blend in with all the other services that use TLS as part of their normal operation.
        o-__-o 5y ago
        https://serverfault.com/questions/574405/tcpdump-server-hello-certificate-filter https://serverfault.com/questions/574405/tcpdump-server-hell...
tedunangst 5y ago
Without knowing what your captor already knows about your device, deleting data they may expect to find is a pretty high risk gambit.
- Sebb767 5y ago
  If you think that them finding your data is the better option, you can always revert to using your normal login credentials.

EamonnMR 5y ago

If your attacker has a full image of your system why are they bothering with duress?

deleted 5y ago
[deleted]
dogma1138 5y ago
Also depending on the jurisdiction depending on the circumstances triggering it can be a felony the same as destroying evidence or tampering with an investigation, if a court compelled you congrats you’ve just earned yourself a contempt of court charge that can last pretty indefinitely. In a jurisdiction that doesn’t adhere to the rule of law you are already screwed. What people often don’t seem to comprehend is that if you get picked up by a “secret police” in the middle of the night it’s pretty much game over already.
- trothamel 5y ago
  Deleting data, if someone can prove it, also opens you up to Adverse Inference, which means the jury can consider the plaintiff's reasonable inference as to what the destroyed documents contained. https://en.wikipedia.org/wiki/Adverse_inference https://en.wikipedia.org/wiki/Adverse_inference
- atok1 5y ago
  But at this point, we are not caring about 'law' are we? This is used when you are fear for your life because of law enforcement entities.
  - dogma1138 5y ago
    If you have an actual reason to fear for your life it’s game over, the “Stasi” doesn’t care if they find evidence or not. If it’s the FBI then fearing for your life isn’t exactly part of the equation really.
bigiain 5y ago
Because it’s encrypted? And these days, it’s common for the decryption keys to exist only in a Secure Enclave type thing that makes extracting those keys many orders of magnitude more difficult that asking you for your password while they hit you with a wrench.

moonchild 5y ago

My understanding is that, with veracrypt (which implements something similar to the linked system), if you enter the duress password, the hidden areas appear to simply be unallocated disc space.