std.file functions and embedded NUL characters [CWE-158]

[H. S. Teoh]

On Thu, Jul 31, 2025 at 09:25:44PM +0000, Doigt via Digitalmars-d wrote:
> On Thursday, 31 July 2025 at 20:45:14 UTC, kdevel wrote:
[...]
> > Other languages like D, perl or even Ada seem to let the embedded
> > NUL character silently truncate the filename. This poses a
> > considerable risk when the input to std.file functions is not
> > controlled by the program author [1]. E.g.
> > 
> >    rmdirRecurse ("/\0/home/user/subdir");
> > 
> > [1] https://cwe.mitre.org/data/definitions/158.html
> 
> Do you actually have a source or an example program that D actually does
> anything with the null terminator or are you talking out of your ass? D
> doesn't care about the null terminator and doesn't do anything with it.

This tone is uncalled for.  OP is specifically pointing the issue with
passing NUL-containing strings to underlying OS calls.  For example:

```
void main() {
	auto fp = File("/tmp/x\0reallynow", "w");
	// What's the filename of the created file?
}
```


T

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