Comment by zamalek
8 hours ago
File formats are the buffer issue honeypot. You may be aware of how often video and audio codecs have vulnerabilities - it's nearly never the hand-tuned frame decode assembly (where you would think all the mistakes would be). It's nearly always the thing that reads the metadata and encoded frames to memory. Binary formats have things like offsets in them, and those can be trivially used to overrun.
Same thing applies here. Even Rust has a crate for dealing with binary data, despite its memory promises: https://crates.io/crates/untrusted
It's a fucking minefield, and this is one area where the Rust zealots are undeniably correct. It doesn't have to be Rust, any memory safe language will do, but Rust also happens to be performance competitive and that's usually also desirable.
The technology you want for this sort of work is WUFFS, for Wrangling Untrusted File Formats Safely.
Rust is a general purpose programming language, which is great if your problem might be something never imagined before, but this literally isn't our first rodeo, we have wrangled lots of file formats before, we should use a language purpose-built to do that safely.
> Rust is a general purpose programming language
I don't understand how I hit the anti-Rust tripwire here:
> My comment: any memory safe language will do
Not an anti-Rust tripwire. Just that WUFFS is the appropriate technology.
I like 4th edition D&D but if you're trying to make a story about nuanced inter-personal conflict in which there's no actual violence it's just not the right roleplaying system and so I'm not going to agree with your choice to recommend 4eD&D as the system for the story "Love and Jealousy in the Elven Forest"
I've written a whole bunch of Rust, and hardly any WUFFS - but, I wasn't writing code for Wrangling Untrusted File Formats and that's very much what you're doing in a PDF parser.
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