wuffs VS ikos

Maybe this is what you are looking for:

https://github.com/google/wuffs

"Wuffs is a memory-safe programming language (and a standard library written in that language) for Wrangling Untrusted File Formats Safely."

It could author its format parsers in https://github.com/google/wuffs, and make them BSD-like open source to maximize adoption.

An even bigger change: It could allow users to choose their iMessage client freely. Why not open up the protocol? I’m sure a security focused client would be popular and in the grand scheme of things easy to author.

Perhaps they could open up more of the OS and apps. Perhaps their claims about the security of users and the App Store is kind of BS.

This is one of the reasons I'm a big fan of wuffs[0] - it specifically targets dealing with formats like pictures, safely, and the result drops in to a C codebase to make the compat/migration story easy.

[0] https://github.com/google/wuffs

There are already huffman-decoding and some parts of webp algorithms in https://github.com/google/wuffs (language that finds missing bounds checks during compilations). In contrary, according to readme, this language allows to write more optimized code (compared to C). WEBP decoding is stated as a midterm target in the roadmap.

Specifically, since performance is crucial for this type of work, it should be written in WUFFS. WUFFS doesn't emit bounds checks (as Java does and as Rust would where it's unclear why something should be in bounds at runtime) it just rejects programs where it can't see why the indexes are in-bounds.

https://github.com/google/wuffs

You can explicitly write the same checks and meet this requirement, but chances are since you believe you're producing a high performance piece of software which doesn't need checks you'll instead be pulled up by the fact the WUFFS tooling won't accept your code and discover you got it wrong.

This is weaker than full blown formal verification, but not for the purpose we care about in program safety, thus a big improvement on humans writing LGTM.

> parsing encoded files tends to introduce vulnerabilities

If we are talking about binary formats, now there are systematic solutions like https://github.com/google/wuffs that protect against vulnerabilities. But SQLite is not just a format - it's an evolving ecosystem with constantly added features. And the most prominent issue was not even in core, it was in FTS3. What will SQLite add next? More json-related functions? Maybe BSON? It is useful, but does not help in this situation.

Regarding traces, there are many forensics tools and even books about forensic analysis of SQLite databases. In well-designed format such tools should not exist in the first place. This is hard requirement: if it requires rewriting the whole file - then so be it.

I agree that Wuffs [1] would have been a very good alternative! If it can be made more generally. AFAIK Wuffs is still very limited, in particular it never allows dynamic allocation. Many formats, including those supported by Wuffs the library, need dynamic allocation, so Wuffs code has to be glued with unverified non-Wuffs code [2]. This only works with simpler formats.

[1] https://github.com/google/wuffs/blob/main/doc/wuffs-the-lang...

[2] https://github.com/google/wuffs/blob/main/doc/note/memory-sa...

There are efforts to do that, notably https://github.com/google/wuffs

RLBox is another interesting option that lets you sandbox C/C++ code.

I think the main reason is that security is one of those things that people don't care about until it is too late to change. They get to the point of having a fast PDF library in C++ that has all the features. Then they realise that they should have written it in a safer language but by that point it means a complete rewrite.

The same reason not enough people use Bazel. By the time most people realise they need it, you've already implemented a huge build system using Make or whatever.

I finally have time to try out wuffs (https://github.com/google/wuffs), which I first heard about here on HN. I want to develop a low-level tokenizer for SDF files, a small-molecule structure file format which started in the 1970s, with lots of, let's call it 'heritage'. Wuffs' ability to process near the data, with a coroutine-like interface, seems like a good fit.

I got the "hello-wuffs-c" example to work, which took some tinkering (see wuffs issue #24). That reads a single string and returns an unsigned int. Despite looking at the example implementations for json parsing, I can't figure out how to go from that example to something which handles multiple input buffer blocks, with string tokens that might straddle two buffers.

Nor could I find third-party examples of people using wuffs-the-language beyond basic experimentation for simple binary data. The handful of non-trivial examples I found only used wuffs-the-library, as a vendored component in a larger project.

The lack of wuffs-the-language use after several years seems a strong sign that I shouldn't look to wuffs for my project. Given the 'workarounds' in #24 are still present after 3 years, it doesn't even seem that widely internally at Google.

Does anyone here have experience to share, or pointers to related projects?

Here's an off-topic answer.

Depends on what you want your toy language to do and what sort of runtime support you'd like to lean on.

JVM is pretty good for a lot of script-y languages, does impose overhead of having a JVM around. Provides GC, Threads, Reflection, consistent semantics. Tons of tools, libraries, support.

WebAssembly is constrained (for running-in-a-browser safety reasons) but then you get to run your code in a browser, or as a service, etc, and Other People are working hard on the problem of getting your WA to go fast. That used to be a big reason for using JVM, but it turns out that Security Is Darn Hard.

I have used C in the (distant) past as an IL, and that works up to a point, implementing garbage collection can be a pain if that's a thing that you want. C compilers have had a lot of work on them over the years, and you also have access to some low-level stuff, so if you were E.G. trying to come up with a little language that had super-good performance, C might be a good choice. (See also, [Wuffs](https://github.com/google/wuffs), by Nigel Tao et al at Google).

A suggestion, if you do target C -- don't work too hard to find isomorphisms between C's data structures and YourToyLang's data structures. Back around 1990, I did my C-generating compiler for Modula-3, and a friend at Xerox PARC used C as a target for Cedar Mesa, and Hans used it in a lower-level way (so I was mapping between M-3 records and C structs, for example, Hans was not) and the lower-level way worked better -- i.e., I chose poorly. It worked, but lower-level worked better.

If you are targeting a higher-level language, Rust and Go both seem like interesting options to me. Both have the disadvantage that they are still changing slightly but you get interesting "services" from the underlying VM -- for Rust, the borrow checker, plus libraries, for Go, reflection, goroutines, and the GC, plus libraries.

Rust should get you slightly higher performance, but I'd worry that you couldn't hide the existence of the borrow checker from your toy language, especially if you wanted to interact with Rust libraries from YTL. If you wanted to learn something vaguely publishable/wider-interesting, that question right there ("can I compile a TL to Rust, touch the Rust libraries, and not expose the borrow checker? No+what-I-tried/Yes+this-worked") is not bad.

I have a minor conflict of interest suggesting Go; I work on Go, usually on the compiler, and machine-generated code makes great test data. But regarded as a VM, I am a little puzzled why it hasn't seen wider use, because the GC is great (for lower-allocation rates than Java however; JVM GC has higher throughout efficiency, but Go has tagless objects, interior pointer support, and tiny pause times. Go-the-language makes it pretty easy to allocate less.) Things Go-as-a-VM currently lacks:

- tail call elimination (JVM same)

I beg to differ: there are a few tools which are comparable.

Frama-C (https://www.frama-c.com) is an open source framework that has, among its analyzers, one based on abstract interpretation (https://www.frama-c.com/fc-plugins/eva.html) that is very similar in spirit to Astree.

MOPSA (https://mopsa.lip6.fr) is another open-source project (albeit more recent, and in a more "academic" stage) that also provides abstract interpretation to analyze C programs for flaws.

NASA also released IKOS (https://github.com/NASA-SW-VnV/ikos), on the same vein.

Of course they lack the polish of a product which costs tens of thousands of euros per license, but they are open source, and their purpose is the same: to ensure code safety via formal methods, in particular abstract interpretation.

It is possible to get these tools to analyze some code and generate no complaints, which ensures absence of several kinds of problems, such as memory safety issues.

Then again, it's hard to know exactly how much they differ from Astree, since you need a license to compare them, and I don't even know if you are allowed to publish such comparisons.

I've been playing around with running IKOS (https://github.com/NASA-SW-VnV/ikos), it sounds very cool but doesn't seem to be super well maintained. I've managed to compile my project to llvm bit-code and run the IKSO on it, but the actual analysis seems to be buggy. There are open issues for the problems I encountered, but the make the analysis pretty useless (it thinks most functions are unreachable).

> https://www.absint.com/astree/index.htm

This looks interesting. It's based on abstract interpretation which is more or less the most powerful approach for imperative code available. (Because the way it works it's likely slow as hell though, I guess).

But it's closed source. One of this kind of products where you need to asks for the price… I think we all know what this means: It'll be laughably expensive.

I don't see any offer for OpenSource projects frankly.

> https://github.com/NASA-SW-VnV/ikos

Also abstract interpretation based. Looks less polished than the first one at first glance.

It's under some questionable license. According to OSI it's OpenSource. According to the FSF it's not. (The FSF argument sounds strong. They're right in my opinion. This NASA license does not look like OpenSource).

But an OpenSource project could use it for free I assume.

> https://github.com/static-analysis-engineering/CodeHawk-C

Much more constrained in scope than the other ones. But looks a little bit "too academic" imho: Uses its own C parser and such.

At least it's OpenSource under MIT license.

Thanks for the links either way! Good to know about some tools in case one would need them at some point.

> I have planned to try using them on OpenZFS for a while, but I am still busy reviewing and fixing reports made by conventional static analyzers.

Stupid question about usual C development practices (as I don't have much contact with that):

Aren't analyzers today part of the build pipeline form the get go? Especially as C is known to be full of booby traps.

Imho it shouldn't be even possible to push anything that has issues discovered by tools.

This should be the lowest barrier as most code analyzers are at most able to spot quite obvious problems (the commercial one above is likely an exception to this "rule"). When even the usual "stupid analyzer" sees issues than the code is very likely in a very bad shape.

Adding such tools later on in the development is like activating warnings post factum: You'll get drowned in issues.

Especially in such critical domains as file-systems I would actually expect that the developers are using "the best tools money can buy" (or at least the best OpenSource tools available).

"Still fixing bugs found by some code analyzer" doesn't sound like someone should have much trust with their data in something like ZFS, to be honest… The statement sounds actually quite scary to me.

They have very unusual license which I have never seen before: https://github.com/NASA-SW-VnV/ikos/blob/master/LICENSE.txt

Is anyone familiar with it? Is it OSI certified? (it's not on the OSI's site).

Yeah there are tools that require adding contracts as comments. But again, there are also friction-less tools that don't require any changes (for example a NASA one).