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Assume your devices are compromised

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Assume your devices are compromised

April 16, 2022

For decades, we have assumed our local computing devices are a safe
place to store digital secrets. Most software, systems and security
protocols make this assumption. But lately, I have been having doubts
and I'm really not sure how to safely use a system that others may
compromise at any time.

Linux as an example

/home/user with 700 perms is mine and mine only, right? Root could
mess about there (obviously), but when I'm the only user with the
root password, that's no real concern.

And for ages, Linux software packages have assumed that /home/user is
a safe place to store secrets.

Folders in /home/user such as .ssh, .gnupg, .aws (and many others)
store plaintext or encrypted secrets. My .bashrc file contains
secrets such as DB connection strings, API keys and others that are
accessible as environmental variables (got to keep those secrets out
of git repositories).

But what if…

Say sophisticated cyber criminal gangs (or governments) can
compromise my systems and read my /home files whenever they like (due
to all the memory unsafe C programs my system runs on the Internet)?

What if this hasn't happened to me because I'm simply not an
interesting target? I don't own a lot of Bitcoin or sell guns or
launder drug money on a Tor Location Hidden website.

Could it happen to me? Yes, I think that's possible.

Has it happened? I'm not sure and I'm not sure how I would know if it
has.

What should a reasonable person do? Don't worry about it.

If you're not a cyber criminal or don't have a lot of crypto to
steal, this will probably never happen to you… unless you're a
Linux kernel developer (got to get those backdoors into the git
repository somehow).

Isolation

I suppose I could run QubesOS and try to isolate some parts of my
digital life. I could keep all of my passwords and secret keys in an
offline qube and paste those into other qubes when needed. But that
doesn't work for all scenarios.

I need an online qube to do software development. This involves git
commits. I PGP sign those and also use a SSH key for repository
access. The dev qube obviously needs access to those secrets and it
has to be online (at least sometimes) to push and pull from the
remote repositories.

All of my keys are password protected, so if a cyber criminal gang
obtained them, they'd have to crack those passwords in order to use
the keys. But if they can access my computer and copy the secrets,
then they can probably watch me type or paste in passwords and take
those too.

Isolation seems helpful, but does not fully address the issue.

Update from the comments: Qubes offers Split GPG to further isolate
PGP keys. Thanks for the tip qubelover!

Hardware Tokens

What about hardware tokens? Maybe I could buy a YubiKey and put all
of my secrets on that and use that key with Qubes? I may try that
approach, but haven't thought through the details. That seems like a
solution that may fully address the issue, but I'm not certain.

Your ideas

Have others thought about this? How have you addressed it?

Please share your thoughts in the comments.

  * encryption
  * passwords

Related

  * Age File Encryption
  * Cracking passwords with cheap hardware
  * Now they have 2FA problems
  * Padder
  * Types of passwords
  * The design flaws of password managers
  * They want us to be compliant, not secure

(c) Go350 2022
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