RE: UTF-8 and case-insensitivity

Linus Torvalds
2004-02-18T00:22:40Z

On Tue, 17 Feb 2004, Robert White wrote:
>
> OK, so I wrote the below, but then in the summary I realized that there was
> a significant factor that doesn't fit in with the rest of the post. Case
> insensitivity, and more generally locale equivalence rules, is a security
> nightmare. Consider the number of different file names that "su" could map
> to if you apply case insensitivity (4) and/or worse yet the various accents
> and umlats (?,etc) that sort-equivalent for "u" in some locales. The user
> types "su" and runs "S(u-umlat)" etc.

This is but one reason why I will _refuse_ to make case insensitivity
magically start happening on regular "open()" etc calls.

You'd literally have to use a _different_ system call to do a
case-insensitive file open. Exactly because anything else would be very
confusing to existing apps (and thus be potential security holes).

Linus