The trouble with symbolic links

How is it hopelessly elitist to call out insecure code as being INSECURE!!!

My whole point is the same as yours fix it at the source. You seem to think hacking off the hands of some coders is safer (I may agree). But why not try to EDUCATE THEM?!?

Education costs 1000s of dollars at most rather than your hypothetical billion dollar APPLICATION LEVEL hack.

Why are you so elitist to assume people can't cope with these concepts?

My whole point is that they need to be tought they're running on a Unix server rather than an 1998 SD card. The rest of your complaining is either you don't understand this or are trying to excuse bad or insecure practice as acceptable. If this is your case. RUN THE CODE IN AN ENVIRONMENT WHERE THIS CAN'T HAPPEN. Seriously there are filesystems and options for this.

Calling for these features to be removed from extX, ZFS or other shows you don't understand storage technologies well enough.

Symlinks are great from a "just make it work!" point of view but they're absolutely terrible from a "make it robust, sane and secure" point of view.

All of the points in the article are valid but there's even simpler stuff like the fact that you can't canonicalise paths (resolve ..) without reading the filesystem.

This should be required reading: https://9p.io/sys/doc/lexnames.html

> How is it hopelessly elitist to call out insecure code as being INSECURE!!!

If a lot of code, written by a lot of different engineers, all ends up being insecure, it is worth asking, why is code dealing with this particular domain so often insecure?

> But why not try to EDUCATE THEM?!?

You can do that, and of course we should, but here is the thing about security:

The good guys have to write secure code every time, or else the attackers guys win.

Eternal vigilance is inhumanly hard to maintain. A better solution is to write higher level APIs or API wrappers that don't have these flaws.

> Why are you so elitist to assume people can't cope with these concepts?

Sure they can, but how many concepts can people cope with at once? Humans have a limit for how much they can juggle in their head. A huge part of software engineering is picking what abstraction layer to operate at. If I am writing code that deals with tons of string parsing and manipulation, I'd be a fool to write it in C or C++. Now I've done that when I needed the performance, but managing a massive number of strings in native code is easily 5x the work compared to using a GC language that also automatically tracks string length.

C is the wrong abstraction there. And indeed an obscene number of security holes have historically centered around string processing in C. That is because on top of managing all the business logic (which may be obscenely complicated by itself!) engineers now have to do so in a language that is really bad at dealing with strings and they have to do a lot of mental work to ensure the code is correct.

If I am manually flipping bits in hardware, well, JS can do it (I have seen it!) but honestly, that shouldn't be anyone's language of choice for directly interfacing with hardware.

(Doing that in C, really fun!)

> Calling for these features to be removed from extX, ZFS or other shows you don't understand storage technologies well enough.

I am not saying that. I am saying that the original POSIX APIs make writing secure code around symlinks hard, and I am saying that solely based on the fact that a bunch of security holes around POSIX APIs and symlinks exist!

This isn't some shocking statement. The original POSIX APIs make a lot of things hard.

I was copying a file today and thought: "Why is it duplicating the data? Why does it not just create a new second filename pointer in the filesystem?"

People being educated for a specialist job, I wonder how they will cope. Well we hire in enough others for less serious problems, sure why not hire less than competent people to slap a fixed badge on the side of it.

If you want this level of abstraction it should be built into the framework or language you're using. I'm not saying go away and rewrite chrome in C you'd be chasing segfaults for 5 years.

If you want to hire people who don't care again. Run this in an environment where this doesn't matter. If you're ultra paranoid insist in a layer to compensate for people's failings.

Again there is nothing wrong with the tried and tested API that can't be fixed with a modicum of effort. Calling it broken or insisting it change to fit problems caused by people so far removed they don't know what architecture they're working code for is not a reason to change the POSIX system. It's a reason to fix your abstraction.