Microsoft open-sources LiteBox, a security-focused library OS

by aktau • 6 months ago

390 202 6 months ago

aktau3• 6 months ago

From the GitHub page:

LiteBox is a sandboxing library OS that drastically cuts down the interface to the host, thereby reducing attack surface. It focuses on easy interop of various "North" shims and "South" platforms. LiteBox is designed for usage in both kernel and non-kernel scenarios.

LiteBox exposes a Rust-y nix/rustix-inspired "North" interface when it is provided a Platform interface at its "South". These interfaces allow for a wide variety of use-cases, easily allowing for connection between any of the North--South pairs.

Example use cases include:

  - Running unmodified Linux programs on Windows
  - Sandboxing Linux applications on Linux
  - Run programs on top of SEV SNP
  - Running OP-TEE programs on Linux
  - Running on LVBS

aktau3• 6 months ago

More links with discussion:

Reddit discussion: https://www.reddit.com/r/linux/comments/1qw4r71/microsofts_n...

Project lead James Morris announcing it on social.kernel.org: https://social.kernel.org/notice/B2xBkzWsBX0NerohSC

xjamesmorris• 6 months ago

FYI, I am not the project lead for Litebox. It is led by Microsoft Research.

a-dub• 6 months ago

is this wslv1.2 (wslv1 redux) in now a more general cross-platform library firewall type thing?

rbanffy2• 6 months ago

- Running unmodified Linux programs on Windows

This might actually be my favourite use: I always thought WSL2 was a kludge, and WSL1 to be somewhat the fulfilment of the "personality modules" promise of Windows NT.

dixie_land• 6 months ago

Yup WSL feels closer to the Services for Unix which has been around since NT 4/5.

It was sad to see WSL2 taking the path of least resistance, that decision has always felt TPM driven ("we got unexpected success with WSL and people are asking for more, deliver xxx by Q4! No I don't care _how_ you do it!")

unixhero• 6 months ago

Personality was an OS aphorism that went longer back than NT I believe. But my memory is fuzzy on this.

Edit! Memory unfuzzed: It was Workplace OS, https://en.wikipedia.org/wiki/Workplace_OS

oofbey• 6 months ago

The amount of techno jargon marketing speak in this readme is impressive. I’m pretty well versed in most things computers, but it took me a long time to figure out what the heck this thing is good for. Leave it to Microsoft to try to rename lots of existing ideas and try to claim they’ve invented something amazing when it’s IMHO not all that useful.

kvuj2• 6 months ago

The cargo.lock file is 2200+ lines long. Did they spend a reasonable amount of time auditing these dependencies?

Andrex• 6 months ago

They ran it through Copilot which gave it the all-clear.

shikon7• 6 months ago

What would be a reasonable amount of time to audit the dependencies?

kvuj2• 6 months ago

I would let them decide based on their security policy.

If Microsoft states that they don't have any for a project like this, I would be wary of taking it too seriously.

adolph2• 6 months ago

  grep 'name = ' ms-litebox-Cargo.lock | wc -l
     238

edit:

  grep 'name = ' ms-litebox-Cargo.lock | sort -u | wc -l
     221

dizhn• 6 months ago

I've always done 'sort | uniq'. Never bothered to check for the the unique flag to sort. Although 'uniq -c' is quite nice to have.

       -c, --count
              prefix lines by the number of occurrences

CodesInChaos• 6 months ago

That's 238 dependencies (counting multiple versions of the same crate).

* Many of them are part of families of crates maintained by the same people (e.g. rust-crypto, windows, rand or regex).

* Most of them are popular crates I'm familiar with.

* Several are only needed to support old compiler versions and can be removed once the MSRV is raised

So it's not as bad as it looks at first glance.

jrm4• 6 months ago

Given, you know, Microsoft, I'd demand proof even if they said they did.

anon2912• 6 months ago

A library os to me would typically mean it's aimed at hosting a single user program on bare hardware. I don't see that here, but maybe I'm just confused

richardlblair• 6 months ago

The reddit conversation seems to allude to you being correct.

bri3d3• 6 months ago

It's both; it's aimed at hosting a single user program on another userspace, but also seems to have its own kernel as well?

The "North" part seems to be what I think you'd traditionally think of as a library OS, and then the "South" part seems to be shims to use various userlands and TEEs as the host (rather than the bare hardware in your example).

I'm really confused by the complete lack of documentation and examples, though. I think the "runners" are the closest thing there is.

ukuina• 6 months ago

No deployment instructions?

CasualSuperman• 6 months ago

With how buggy their flagship OS has become, why would I trust anything else they release to be better? Or even if it does work well now, why should I expect it to stay that way? Microsoft has burned through all possible goodwill at this point, at least for me.

rafram• 6 months ago

This isn't supposed to replace Windows, and it isn't a GUI desktop operating system at all. I doubt anyone working on this has anything to do with the modern Windows desktop UX.

dspillett2• 6 months ago

This isn't supposed to replace Windows,

OP wasn't suggesting it was, just that the lack of quality in one significant area of the company's output leads to a lack of confidence in other products that they release.

Reddit_MLP2• 6 months ago

but if the host OS is already comprised, what is the point of sandbox inside of it?

hudo• 6 months ago

UI of Windows is buggy and inconsistent. Kernel and low level stuff are actually very stable and good.

joe_mamba4• 6 months ago

Kernel and low level stuff are actually very stable and good.

This. A while ago a build of Win 11 was shared/leaked that was tailored for the Chinese government called "Windows G" and it had all the ads, games, telemetry, anti-malware and other bullshit removed and it flew on 4GB RAM. So Microsoft CAN DO IT, if they actually want to, they just don't want to for users.

You can get something similar yourself at home running all the debloat tools out there but since they're not officially supported, either you'll break future windows updates, or the future windows updates will break your setup, so it's not worth it.

exceptione2• 6 months ago

NTFS, not so great.

mananaysiempre4• 6 months ago

Kernel and low level stuff are actually very stable and good.

In their intended applications, which might or might not be the ones you need.

The slowness of the filesystem that necessitated a whole custom caching layer in Git for Windows, or the slowness of process creation that necessitated adding “picoprocesses” to the kernel so that WSL1 would perform acceptably and still wasn’t enough for it to survive, those are entirely due to the kernel’s archtecture.

It’s not necessarily a huge deal that NT makes a bad substrate for Unix, even if POSIX support has been in the product requirements since before Win32 was conceived. I agree with the MSR paper[1] on fork(), for instance. But for a Unix-head, the “good” in your statement comes with important caveats. The filesystem is in particular so slow that Windows users will unironically claim that Ripgrep is slow and build their own NTFS parsers to sell as the fix[2].

[1] https://lwn.net/Articles/785430/

[2] https://nitter.net/CharlieMQV/status/1972647630653227054

autoexec• 6 months ago

Microsoft doesn't have a very good track record with security or privacy. Maybe it works, but yeah you'll probably get screwed over at some point.

Still, the fact that it's open source is a good thing. People can now take that code and make something better (ripping out the AI for example) or just use bits and pieces for their own totally unrelated projects. I can't see that as anything but a win. I have no problem giving shitty companies credit where its due and they've done a good thing here.

MatejKafka4• 5 months ago

Microsoft doesn't have a very good track record with security or privacy.

That's a very unfair assessment. In many areas, Microsoft services and Windows are better protected than most alternatives (e.g., disk encryption, virtualization-based isolation,...), and security is taken pretty seriously for new products.

simonw• 6 months ago

Microsoft employ over 100,000 engineers. I'd advise against assuming that everything produced by any of them is bad because of bugs in Windows.

lysace• 6 months ago

This is also still small/unimportant enough not to be poisoned by their broken corporate culture.

replooda3• 6 months ago

The criticism was directed at the company's product, not the employees...

workfromspace2• 6 months ago

Not op, and I generally agree with your assumption but not for Microsoft, as I don't think it's limited to Windows:

Teams, Office (especially online), One Drive, SharePoint, Azure, GitHub, LinkedIn, all became very shitty and partially unusable with increasing number of weird bugs or problems lately.

ddtaylor• 6 months ago

They seem to be alienating a lot of their users right now in a lot of different products. There's a significant surge in open source software right now and Linux and all the people that are coming over are a bit more than usual. Their customer base seems tired of the game.

dvfjsdhgfv• 6 months ago

The problems with Windows today have nothing to do with bugs but with the strategic vision of Nadella.

solarkraft2• 6 months ago

This is not about individual employees. It’s in the nature of being an employee to be beholden to what’s incentivized by their company’s management and structure.

petterroea• 6 months ago

Skilled engineers in an environment that doesn't care about quality may become dull, or simply be forced by the system they are in to not care. In practice they are just like us and so I assume they would find outlets in their free time.

I haven't spoken to a Microsoft developer in a while because there are few in the hacker communities I'm around (go figure?) so not entirely sure though. I want to understand.

LatencyKills• 6 months ago

I spent 15 years as a senior dev on the Visual Studio team followed by 5 years on the Xcode team at Apple.

Individual engineers can be talented, professional, and end-user focused. Most of that effort gets lost when PMs refuse to work with each other in a coherent manner. Most of the major issues we ran into weren’t engineering bugs per se, they were the result of management refusing to allow teams to communicate effectively.

When we were first building out the original C# functionality, the C# team refused to talk to the existing compiler teams. I spent more time acting as a go-between than I did solving actual technical problems.

Good people can produce crappy software in that environment.

necovek4• 6 months ago

Windows is ultimately a lot more complex, and not open source. This also builds on the Linux ecosystem, so even if it comes from Microsoft, I imagine engineering culture is different from that on Windows and especially their online platforms (that's even worse than Windows if you ask me!).

dooglius• 6 months ago

MSR is a somewhat independent org; you should be making predictions based on other MSR projects

BrouteMinou3• 6 months ago

Microsoft US a massive corporation with so many people, business units, departments.

A comment like yours is just like saying: "I know a buggy open-source software, why would I trust that other open-source project? The open-source community burned all possible goodwill".

CodeMage• 6 months ago

Except that a company, no matter how heterogenous, has an overarching organization, whereas the open-source community doesn't.

There is no CEO of open source, there are no open-source shareholders, there are no open-source quarterly earnings reports, there are no open-source P&G policies (with or without stack ranking), and so on.

b00ty4breakfast• 6 months ago

I'm not defending MS in any capacity, but this library is open for viewing if you were so inclined.

lemonish97• 6 months ago

I know windows 11 is super buggy and riddled with issues (and the copilot mess), but I'm starting to feel there's a weird echo chamber around these forums that don't even bother looking at what the product or repository is, and automatically assume it's bad 'cause it's from Microsoft.

zelphirkalt• 6 months ago

Once the amount of bad software coming out of a shop rises over 50% this becomes a sane assumption, since it is more likely than not, that it is trash coming out of that shop. So in case of MS it does seem a reasonable assumption to make.

Peanuts99• 6 months ago

I use Windows 11 all day and can't agree it's buggy at all, compared to Windows of the past it's very reliable. The worst I can say is they've made some poor decisions about the defaults around ads in the UI. But all of that is easy to turn off.

sscarduzio• 6 months ago

Can it replace Wine to run Windows apps on Linux?

marklar423• 6 months ago

IIUC, if you have the source you can recompile said Windows app with LiteBox to statically link in the Windows OS kernel dependencies, so it'll run on any compatible processor regardless of OS (since it won't be making syscalls anymore). It's a unikernel basically.

That's the theory, but I don't know how far LiteBox is along to supporting that workflow.

johannes1234321• 6 months ago

They say

It focuses on easy interop of various "North" shims and "South" platforms.

For replacing wine on Linux the "North" would be kernel32 API or similar, the "South" would be Linux sys all API.

However this is meant as a library, thus require linking the Windows program to it and eine is more than the system interface, it has all the GUI parts etc of win32 API

cbondurant• 6 months ago

at first I thought library OS might have meant an OS meant for use at a library.

Honestly far less interesting to know I was wrong.

KPGv2• 6 months ago

yeah, same here, I was like "wow what an interesting side to their business, a whole operating system intended to serve public and academic libraries!"

rendaw2• 6 months ago

Is it not? You link the "library os" and you no longer need an os (when running in a supervisor) IIUC.

stackghost• 6 months ago

I think parent poster was referring to an actual library, i.e. where you would borrow books.

That's also what I thought this was, and came to the comments expecting to see something neat about why libraries might need bespoke operating systems.

noumenon1111• 6 months ago

Me too. Honestly I was vibing on nostalgia for this: https://en.wikipedia.org/wiki/Dynix_(software)

loufe• 6 months ago

The lack of integrated sandboxing in windows compared to android/iphone is still frankly unacceptable. I've become increasingly paranoid about running any application on Windows (not that your average linux distro is even remotely better) and yet Apple and Google seem to be far, far ahead in user permissions (especially with GrapheneOS, god bless that team) and isolation of processes.

Consumers and businesses deserve better. It's crazy to me that in 2026 Notepad++ being compromised means as much potential damage as it does, still.

digiown• 6 months ago

The sandboxing on mobile platforms puts the OS vendor in a special position to enforce a monopoly on apps and features. Apple enforces it aggressively, while Google only reluctantly so far. It also prevents the user from exerting full control of the system. Apple does it by locking things down directly, while Google punishes you for owning your devices with attestation.

There has to be a better way. I think Linux's flatpak is a reasonable approach here, although the execution might be rather poor. I want a basic set of trusted tool that I can do anything with, and run less trusted tools like GUI programs in sandboxes with limited filesystem access.

wat10000• 6 months ago

Those are policy decisions not really connected to the sandboxing technology. They control what sort of signing the system will accept and make it so that it only runs things they approve, and they only approve things that are sandboxed a certain way. The exact same sandboxing could be used with a system where an admin user can decide what gets to run and what kind of sandboxing is required for each thing.

pjmlp4• 6 months ago

UWP, and MSIX on Win32 via Appstore.

There is also sandboxing configuration via Intune for enterprises.

malkia• 6 months ago

There are containers, and one of their users is the Windows Sandbox - https://learn.microsoft.com/en-us/windows/security/applicati...

newsoftheday• 6 months ago

I've become increasingly paranoid about running any application on Windows (not that your average linux distro is even remotely better)

Linux excels over Windows in the area of security by a wide margin, I have no qualms about running an app on Linux versus Windows, any day of the week.

madspindel• 6 months ago

Linux excels over Windows in the area of security by a wide margin

No, this is wrong but might be true if you are talking about Linux package manager vs. Random Windows .exe on internet. But if you are talking about Secure Boot, encrypted disk, sudo etc. Windows is more secure but it looks like https://amutable.com/ will make Linux more secure like Windows.

Edit: Some insecure things on Linux: Dbus (kwallet etc.), sudo, fprint, "secure boot".

9dev2• 6 months ago

And executable you run has access to any file in your home directory, including SSH private keys, secrets in config files, browser cookies, passkeys—all of it. That includes the thousands of npm modules installed as a transient dependency of at least one tool you use that brings node as a dependency.

Windows at least has a proper ACL system; on Linux it just takes a single compromised executable to loose everything.

aseipp• 6 months ago

No, Windows has consistently been ahead of Linux for many years in terms of average-user desktop security, from binary hardening to designs like secure desktop, because average Windows users do not typically have curated software selections, so you assume the worst. (When I wrote the original "binary hardening via compiler flags" RFC for NixOS over 10 years ago, almost everything in it was already done on Windows and had been for years.) It's still not ideal; macOS takes it even further and actually allows things like "storing secrets on disk in a way that can't be read by random programs" because it can e.g. make policy decisions based on code signatures, which are widely deployed. None of this exists in pretty much any Linux distro; you can literally just impersonate password prompts, simply override 'sudo' in a user's shell to capture their password silently, copy every file in $HOME/.config to your evil server, setuid by its very definition is an absolute atrocity, etc. Linux distros make it easy for people to live in their own chosen curated software set, but the security calculus changes when people want to run arbitrary and non-curated software.

You can make a pretty reasonably secure Linux server by doing your homework, it's nowhere close to impossible. An extremely secure server also requires a bit of hardware homework. The Linux desktop, however, is woefully behind macOS and Windows in terms of security by a pretty large margin, and most of it is by design.

(In theory you can probably bolt a macOS-like system onto Linux using tools like SCM_RIGHTS/pidfds/code signatures, along with delegated privilege escalation, no setuid, signature-based policy mechanisms, etc. But there are a lot of cultural and software challenges to overcome to make it all widely usable.)

MatejKafka4• 5 months ago

Microsoft tried with UWP. Developers mostly refused, for various reasons.

gdevenyi• 6 months ago

What is a 'library OS'?

zamadatix• 6 months ago

https://en.wikipedia.org/wiki/Operating_system#Library

charles_f• 6 months ago

I think that's an OS in the form of a library, like Wine for example. From what I get from the description it allows you to run programs on your real OS and make it see a cut down API to your actual system to reduce the attack surface.

bri3d3• 6 months ago

It's a library that is linked to in place of an operating system - so whatever interface the OS provided (syscalls+ioctls, SMC methods, etc.) ends up linked / compiled into the application directly, and the "external interface" of the application becomes something different.

This is how most unikernels work; the "OS" is linked directly into the application's address space and the "external interface" becomes either hardware access or hypercalls.

Wine is also arguably a form of "library OS," for example (although it goes deeper than the most strict definition by also re-implementing a lot of the userland libraries).

So for example with this project, you could take a Linux application's codebase, recompile it linked to LiteBox, and run it on SEV-SNP. Or take an OP-TEE TA, link it to LiteBox, and run it on Linux.

The notable thing here is that it tries to cut the interface in the middle down to an intermediate representation that's supposed to be sandbox-able - ie, instead of auditing and limiting hundreds of POSIX syscalls like you might with a traditional kernel capabilities system, you're supposed to be able to control access to just a few primitives that they're condensed down to in the middle.

kccqzy3• 6 months ago

So for example with this project, you could take a Linux application's codebase, recompile it linked to LiteBox

If you have to recompile, you might as well choose to recompile to WASM+WASI. The sandboxing story here is excellent due to its web origins. I thought the point of LiteBox is that recompilation isn’t needed.

tombert• 6 months ago

I’m not sure I understand what a library OS is; can someone here elaborate?

greatgib• 6 months ago

My understanding of this is that it is a sandbox. Providing a common interface like if it was an OS for the program to run inside, but avoiding the program to use the OS directly.

What is unclear is if it uses its own common ABI or if you use the one of the host os. I don't know why but from the project description I have a little bit of feeling that this is another vibe coded project.

wrs• 6 months ago

A library OS is an OS that is linked directly to your program instead of being a separate program accessed through a syscall to kernel mode. About the same as a “unikernel”, but a more recent term.

Basically it lets your program run directly on a hypervisor VM, though this one will also run as a Linux/Windows/BSD process.

hypfer• 6 months ago

"We did not find any viable commercial use for it, but maybe you will."

burnermore• 6 months ago

Baaah! Microsoft, security-focused in a single sentence!

throwoutway• 6 months ago

No mention of starting with a design specification & then tied to formal verification the whole way?

It sounds interesting and a step forward (never heard of library Os itll now), but why won't this run into hundreds of the same security bugs that plague Windows if it's not spec'd and verified?

anon2912• 6 months ago

People seem to believe writing things in rust means it's correct.

R_Spaghetti• 6 months ago

I'm not sure whether Microsoft, the makers of Windows 95 (after which I stopped taking them seriously), are the sharpest tool in the box when it comes to security.

ementally• 6 months ago

Copilot

https://github.com/microsoft/litebox/blob/main/.github/copil...

pjmlp4• 6 months ago

To be expected, given how many organisations now require employees to use AI if they want to meet their OKRs, especially all that sell AI tools.

outofpaper• 6 months ago

What's dumb, on top of everything, is needing to store non special standard operating procedures in specific AI folders and files when wanting to work with AI tooling.

embedding-shape• 6 months ago

Extremely simple changes do not require explicit unit tests.

I haven't used Copilot much, because people keep saying how bad it is, but generally if you add escape hatches like this without hard requirements of when the LLM can take them, they won't follow that rule in a intuitive way most of the time.

sandos• 6 months ago

Yeah, I tried various very sane-looking instrucions file when starting to use copilot 6 months ago. Turned out it was not really useful. It mostly follows the rules anyway, but it also often forgot to. So turns out, especially with the fast turnaround with models today, it was better to just forego these instructions files.

pjmlp4• 6 months ago

It is kind of alright, I use mostly on VS when coding C# or C++, for code completions, error analysis, check code quality and such.

As agent, or writing everything for me, not yet.

viraptor2• 6 months ago

It doesn't say much really. At this point we can assume almost every project has some generated code in it. Unless you're sure that every single author hates the idea and there are no external contributions. Agent configuration just makes it clear.

ho_schi• 6 months ago

Another layer (ouch) to abstract away Windows (ouch * ouch).

Use Linux or BSD and ignore that approach for Vendor Lock-in* into their “library OS”.

runjake• 6 months ago

For others as lost as I am and want the tl;dr:

A library OS is an operating system design where traditional OS services are provided as application-linked libraries, rather than a single, shared kernel serving all the programs.

cmrdporcupine• 6 months ago

I know we're not supposed to complain about comment quality, but -- I came here to look for interesting technical analysis but instead it's Slashdot level snipes about Microsoft the company. And yes, I also dislike Windows and Microsoft generally but this looks like a very interesting project and I'm frankly frustrated at the level of discussion here, it's juvenile. This has nothing to do with Windows, and it looks like most people didn't even read past the title.

I'll play with this later today after work and see how mature it is and hopefully have something concrete and constructive to say. Hopefully others will, too.

BrouteMinou3• 6 months ago

I am with you on that. HN is becoming a "14 years old edgy mini-tech" Facebook.

"Microsoft bad, Linux good" kind of comments are all over the place. There is no more in depth discussions about projects anymore. Add the people linking their blogs only to sell you thier services for an imaginary problem, and you get HN 2026.

It's maybe the time to find another tech media. If you know one, I would be glad to know.

MatejKafka4• 5 months ago

Lobste.rs mostly are what HN used to be, with less focus on startup culture and more focus on hacking.

bg24• 6 months ago

Would be nice to see an OCI runtime and if it can give high-performant I/O as opposed to other we have today (eg. Gvisor).

dzonga• 6 months ago

Microsoft gonna release a windows flavored Linux Distro soon ;)

Brian_K_White• 6 months ago

Aliens come to visit. I have to tell one the difference between an app linked against a "library os" running on a hypervisor, and an app running on a kernel. I couldn't do it with a straight face.

perbu• 6 months ago

A proper library OS doesn't have syscalls. Everything operates in the same space, no user/kernel split.

palata• 6 months ago

First time I hear the concept of "library OS".

Is it similar to e.g. gVisor? Like would gVisor count as a library OS, too?

zx80802• 6 months ago

Microsoft? No, thank you.

hulitu2• 6 months ago

Seeing Microsoft and security-focused in the same semtence makes me suspicious.

tnodir• 6 months ago

It'll be interesting if MS allows to write e.g. WFP callout drivers via LiteBox and not requiring attestation signing. It'll still work in kernel mode, unlike NetworkExtensions in MacOS.

Microsoft open-sources LiteBox, a security-focused library OS

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