Re: Re: PHP 8 is_file/is_dir input handling

On Tue, 1 Dec 2020 at 18:07, Paul Crovella <paul.crovella@gmail.com> wrote: > On Tue, Dec 1, 2020 at 9:43 AM Christoph M. Becker <cmbecker69@gmx.de> > wrote: > > > > On 01.12.2020 at 18:35, Aimeos | Norbert Sendetzky wrote: > > > > > Am 01.12.20 um 18:24 schrieb Christoph M. Becker: > > >> > > >>> In PHP 7, this returns FALSE: > > >>> > > >>> php -r 'var_dump(is_file("ab\0c"));' > > >>> > > >>> In PHP 8, the same code throws a ValueException. Problem is now that > > >>> it's not possible to check upfront if the passed argument is a valid > > >>> path to avoid the exception being thrown. > > >> > > >> This is only about the NUL byte in the filename. You can easily check > > >> for that yourself. :) > > > > > > There may be other checks that will throw a ValueException. I'm not > sure > > > how it's implemented in detail because the filestat.c file doesn't > > > thrown an exception at all: > > > > The exception is thrown from inside the parameter parsing routines > > (zend_parse_parameters() and friends). Internal function differenciate > > between string and path, whereas the latter is an arbitrary string which > > does not contain NUL bytes. > > > > It would likely make sense to document that. OTOH, it's probably a good > > idea to check (almost) all user input for NUL bytes. > > Would it not make more sense for something like is_file to have > obvious sane behavior and simply return false itself? I don't > understand the resistance to making it more difficult for a developer > to screw something up. > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php So why having is_file()/is_dir() throw a warning for the past 8 years (since PHP 5.4) a non-issue? Because by that logic it shouldn't have been emitting warnings either. Would it have been fine if this would have been a TypeError as it was originally intended? Is a warning fine because null bytes indicate a potential attack as in no sane context should null bytes be passed around? I don't personally *care* that it throws a ValueError, but why is this issue only brought up *now* when it should have been shouting for 8 years and is either an indication of a bug or of something larger at play. Best regards, George P. Banyard