_vvhw

11 ms·

61.
by _vvhw 4y ago
PDF is also a minefield, for how many ways there are to mess with the format: https://blog.didierstevens.com/2008/04/29/pdf-let-me-count-t...
62.
by _vvhw 4y ago
Thanks for the link to that comment of mine. Wow, that's a blast from the past! Here's also a recent HN discussion about Pure, in the context of buffer bleeds and memory safe languages, with tptacek: https://news.ycombi
63.
by _vvhw 4y ago
Exactly, although, at present, Pure will also do dynamic analysis on the compressed stream once the metadata checks out, to verify that the compressed stream checks out with the metadata, i.e. that there's no semantic gap between the d
64.
by _vvhw 4y ago
I wanted to do this for those formats in particular, as well as Office files. Fastmail were going to sponsor some of this work to extend Pure, and I was chatting with the folks at Hey, but I couldn't get enough other sponsors to fund t
65.
by _vvhw 4y ago
> I’m a little confused by this statement. I assume by “address” you mean indexing, and the size of an index is related to the number of entries, not the amount of data being indexed. Thanks for the question! What's in view here is
66.
by _vvhw 4y ago
Thanks for the question. "I would consider that type of logic error more or less impossible to defend at the language level, but I can see how analysis tools can be helpful." This is how I see it too, as a logic error that exposes
67.
by _vvhw 4y ago
Thanks for these!
68.
by _vvhw 4y ago
Thanks! Yes, I did mention WUFFS before the edit, but then figured I could make it a bit more detailed. WUFFS is great. The SafeDocs program and approach looks incredible. Installing tools like this at border gateways for SMTP servers, or a
69.
by _vvhw 4y ago
Yes, exactly. That's what I was driving at. It's just a logic error, that leaks sensitive information, by virtue of leaking the wrong information. File formats in particular can make this difficult to get right. For example, the Z
70.
by _vvhw 4y ago
Hackers exploit any avenue (and usually come in through the basement!), regardless of how skeptical we might be that they won't. They don't need the details, they'll figure it out. You give them a scrap and they'll get t
71.
by _vvhw 4y ago
Wow, that's saying something! The tool is called Pure [1]. It was originally written in JavaScript and open-sourced, then rewritten for Microsoft in C at their request for performance (running sandboxed) after it also detected David Fi
72.
by _vvhw 4y ago
I worked on a static analysis tool to detect bleeds in outgoing email attachments, looking for non-zero padding in the ZIP file format. It caught different banking/investment systems written in memory safe languages leaking server RAM.
73.
by _vvhw 4y ago
I see your UAF and raise you a bleed! As you know, buffer bleeds like Heartbleed and Cloudbleed can happen even in a memory safe language, they're hard to defend against (padding is everywhere in most formats!), easier to pull off than
74.
by _vvhw 4y ago
This is almost what we do for TigerBeetle, a new distributed database being written in Zig. All memory is statically allocated at startup [1]. Thereafter, there are zero calls to malloc() or free(). We run a single-threaded control plane fo
75.
by _vvhw 4y ago
And coined the term “killer heuristic” for chess algorithms.
76.
by _vvhw 4y ago
The founders of Convex are some of the most talented developers I know. The CTO worked with Turing-award winner Barbara Liskov on Viewstamped Replication Revisited [1], the revision of the pioneering consensus protocol, and later the foundi
77.
Let's remix distributed database design(youtube.com)
2 points by _vvhw 4y ago|0 comments
78.
by _vvhw 4y ago
Wow, this is high praise coming from Derek Sivers. This should immediately be on Mercury's landing page. :)
79.
Let's Remix Distributed Database Design — TigerBeetle, Recurse Center [video](youtube.com)
2 points by _vvhw 4y ago|0 comments
80.
by _vvhw 4y ago
No, I don't believe that the phrase “based solely” would be a fair assessment. That there's a $1,024 bounty being awarded should be reason enough to suggest more than “10 minutes” went into this. While the issue was first reported
81.
by _vvhw 4y ago
Details and verification are in the quoted thread (you need to click through). TLDR: https://twitter.com/jorandirkgreef/status/153231416960472678... You can see that, for those block sizes, the throughput of O_DSY
82.
by _vvhw 4y ago
We discovered this through our use of O_DSYNC, and O_SYNC also has the same problem. I think that for macOS so far, the focus has been on ordering guarantees, i.e. write barriers to reset the disk back to some atomic point in time after a c
83.
by _vvhw 4y ago
Yes, we were counting on O_DSYNC to set the FUA bit on the write syscall so that we could avoid an extra F_FULLFSYNC fcntl syscall.
84.
O_DSYNC on Darwin is completely broken for the last 15 years(twitter.com)
20 points by _vvhw 4y ago|9 comments
85.
TigerStyle – TigerBeetle's coding style guide(github.com)
5 points by _vvhw 4y ago|0 comments
86.
O_DSYNC on macOS is also broken(twitter.com)
4 points by _vvhw 4y ago|0 comments
87.
by _vvhw 4y ago
Technical debt has the second order effect of crippling morale.
88.
by _vvhw 4y ago
We've been designing TigerBeetle [1], a distributed financial accounting database, from the beginning with the ultimate goal that the whole architecture of: * global consensus layer (Viewstamped Replication) [2], and the * local
89.
TigerBeetle's LSM-Forest (HYTRADBOI '22)(youtube.com)
1 points by _vvhw 4y ago|0 comments
90.
How to Write Cross-Platform Software for Different Filesystems(nodejs.org)
2 points by _vvhw 4y ago|0 comments

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