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Ask HN: How do you trust that your personal machine is not compromised?

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Re: Ask HN: How do you trust that your personal machine is not compromised?

#431

Earlier quoted context omitted.

MSIX doesn't implement sandboxing. Apps can opt in to being sandboxed via that tech, but you can also write totally unsandboxed apps. There's also a very light weight app container mode called (internally) Helium which just redirects some filesystem and registry stuff, but the goal is to make uninstalls clean, not security. The Windows kernel does offer an impressive number of options to lock down processes. Look at…

Is Helium mandatory for MSIX-packaged apps?

I think they recently added a way to opt out of it entirely. That said, it does very little and because it's not a sandbox it's easy to 'escape':

• Copy an EXE to %TEMP% and run it from there.

• Use a Win32 API flag to start a process (of any path) outside the app container.

There are only a few cases where Helium is an issue and they're all easy to work around. One example is writing a log file to your app private UserData directory and then opening Notepad on it. If you do it the 'naive' way then Notepad won't be able to find it, because you'll pass a redirected path which it can't see. The fix is simply to resolve the redirect before passing the argument to Notepad using a Win32 API call.

I know we talked about Conveyor a few days ago so I'll note here that if you package a JVM app with it then the %LOCALAPPDATA% and %APPDATA% environment variables are rewritten to their target locations automatically, so as long as you use them to decide where to write app private files then their paths will be visible to other apps, avoiding the Notepad issue. This doesn't apply to native or Electron apps though, at least not at this time.

Re: Ask HN: How do you trust that your personal machine is not compromised?

#432
post #315

Earlier quoted context omitted.

No other general-purpose OS that runs on my laptop has the track record of OpenBSD: only 2 remotely exploitable security holes in the default installation since ~1996. And then the other mitigations let you control carefully what more attack surface to expose--those mitigations dramatically reduce it. I appreciate the general lack of privilege escalation 0-day exploits, as seen over time.

Serious question: How big is OpenBSD as a target for malware, exploits, viruses, etc. ? OpenBSD's track record is impressive but is it a significant target compared to Windows, MacOS, and Linux? It is easy to say "only two bullets have ever penetrated my armor" when hardly anyone is shooting at you. I do not know if this is the case because I have never used OpenBSD and I do not know how widely it is used (headless s…

If that were true you might also expect FreeBSD and NetBSD to have similarly low levels of exploits, and my general impression (not research, just reading around) is that they have had more exploits in that timeframe (privilege escalation bugs, whatever).

You can read more about OBSD's security by going to https://openbsd.org then clicking the "Security" link near the top left.

ps: FreeBSD seems to have more users than OpenBSD, and NetBSD seems to have fewer users than OpenBSD.

Re: Ask HN: How do you trust that your personal machine is not compromised?

#433
post #315

Earlier quoted context omitted.

No other general-purpose OS that runs on my laptop has the track record of OpenBSD: only 2 remotely exploitable security holes in the default installation since ~1996. And then the other mitigations let you control carefully what more attack surface to expose--those mitigations dramatically reduce it. I appreciate the general lack of privilege escalation 0-day exploits, as seen over time.

On OpenBSD do you even need to compromise the kernel? Can't your normal user account install a backdoored browser, steal your ssh keys, DDOS people, start a VNC server, keylog, etc.

I guess that is possible if you try to do so -- compile your own stuff, or download and run it. But if you act normally instead, installing just what you actually need, from the package repository (where most things are "pledged" and "unveiled" which adds some impressive protections), I think the chances are much lower than with other OSes.

Also I separate things by user account, so I don't do my general browsing as the same user that does my programming, which is again separate from bank access, which is separate from .... So the kernel is providing a lot of protections.

(And I usually browse without images and javascript, which is not OS-specific but a suggestion. Many things I use don't require it, and I can flip it on or configure it specifically for those that do.)

Re: Ask HN: How do you trust that your personal machine is not compromised?

#434
post #401
post #170

Earlier quoted context omitted.

> Android and ChromiumOS are likely the most trustable computing platforms out there I talked to a security researcher specializing on Android at a conference and he didn't sound like he'd agree. While I personally think ChromiumOS does a good job, I think a huge problem is that the issue is in how liberally complexity is added. And complexity is typically where security issues lurk. This has been seen again and agai…

Is openbsd not made to look more secure by the fact that it's so niche? Who gives a shit about it enough to attack it a la (say) Windows?

I replied to a similar question just above, for what it may be worth.

Re: Ask HN: How do you trust that your personal machine is not compromised?

#435

I assume it is, per Intel ME / AMD PSP's ability to read everything - memory, CPU registers, disk, inspect all network traffic, directly utilize onboard GbE for bidirectional communication. For adversaries below the level of the US intelligence agencies, I run everything virtualized and compartmentalized with Qubes, the installation image for which I verified the dev-provided cryptographic signature matches. I try to…

Did I misunderstand or do you really have a baseband hardware killswitch? That's some dedication.

Re: Ask HN: How do you trust that your personal machine is not compromised?

#436
post #170

Earlier quoted context omitted.

> Android and ChromiumOS are likely the most trustable computing platforms out there I talked to a security researcher specializing on Android at a conference and he didn't sound like he'd agree. While I personally think ChromiumOS does a good job, I think a huge problem is that the issue is in how liberally complexity is added. And complexity is typically where security issues lurk. This has been seen again and agai…

OpenBSD doesn't have proper sandboxing. If you download malware it can easily steal and upload your ssh keys.

There is a package repository where many of the packages have been "pledged" and "unveiled", meaning that they execute with fewer unneeded privileges. And a general lack of privilege escalation exploits in base. And privilege separate by running things as distinct users. So jails might be less needed or less helpful by comparison, overall. There are chroot jails though, not sure why anyone would think they are not available in OBSD.

Re: Ask HN: How do you trust that your personal machine is not compromised?

#437

Earlier quoted context omitted.

> proper sandboxing Do jails not fulfill this?

OpenBSD doesn't have jails. Jails take effort to setup. It's much easier to just run the malware instead of going through the effort of making a jail for it.

It certainly has chroot jails, and many other protections. You might find interesting: https://www.openbsd.org/security.html .

ps: see also: https://man.openbsd.org/?query=chroot&apropos=1&sec=0&arch=d...

Re: Ask HN: How do you trust that your personal machine is not compromised?

#438

Earlier quoted context omitted.

OpenBSD doesn't have proper sandboxing. If you download malware it can easily steal and upload your ssh keys.

> proper sandboxing Do jails not fulfill this?

Yes, among other protections that are even more convenient or built in. https://www.openbsd.org/security.html

Re: Ask HN: How do you trust that your personal machine is not compromised?

#439
post #427

Earlier quoted context omitted.

I find it hard to believe that the Linux codebase being auditable makes Linux more secure by default than MacOS, iOS, and Windows. I doubt it is humanly feasible to fully read and grok the several million LOC running within Linux. I would, however, trust a default MacOS/iOS/Windows system over a default Linux system. The Linux community has a track record of being hostile to the security community - for their own goo…

I regret my poor description of seL4. It has proofs for how it functions, and how code execution is isolated, etc. That is not -every- security issue by any means but reviewing a spec is easier than reviewing code, and a small code footprint that forces things out of the kernel that do not need to be there is a major win. I hope more projects follow their lead. As for Linux, piles of companies pay for Linux kernel se…

> QubesOS is the Linux distro

QubesOS is a Xen distro that happens to use Fedora by default as dom0 vm.

Re: Ask HN: How do you trust that your personal machine is not compromised?

#440

ex-AOSP dev here Android and ChromiumOS are likely the most trustable computing platforms out there; doubly so for Android running on Pixels. If you don't prefer the ROM Google ships with, you can flash GrapheneOS or CalyxOS and relock the bootloader. Pixels have several protections in place: - Hardware root of trust: This is the anchor on which the entire TCB (trusted computing base) is built. - Cryptographic verifi…

I didn't know that pixels allowed custom ROMs to re-lock bootloader with custom keys, Digging into it I found that even OnePlus & FairPhone might have that feature.
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