Re: [gmime-devel] [PATCH 5/6] Use pinentry-mode loopback in test suite when using "modern" GnuPG

[Jeffrey Stedfast <fejj gnome org>]

On 12/2/2016 11:21 AM, Daniel Kahn Gillmor wrote:
> On Fri 2016-12-02 11:05:59 -0500, Daniel Kahn Gillmor wrote:
> > > > +       if (strncmp (vstring, vheader, sizeof (vheader) - 1))
> > > > +               return 0;
> > > Same. In fact, I'd probably recommend pclose()ing vpipe as soon as you
> > > finish reading the output of gpg --version (no reason to keep it open
> > > after reading it).
> > >
> > > > +       ret = (vstring[sizeof (vheader) - 1] > '2') ||
> > > > +               (vstring[sizeof (vheader) - 1] == '2' &&
> > > > +                vstring[sizeof (vheader)] == '.' &&
> > > > +                vstring[sizeof (vheader) + 1] >= '1');
> > > This has the potential of reading past the end of the buffer.
> > ah, right.  maybe we should first assert that vlen >= sizeof (vheader) ?
> hm, i take it back -- how can this read past the end of the buffer if
> the strncmp test above already succeeded?  the first thing it reads is
> at sizeof (vheader - 1), and we already know that the first vheader-1
> octets match.  So in the event that the buffer is too short,
> vstring[sizeof (vheader) - 1] will be NULL, which is < '2', so "ret"
> will be set to 0 and will never test vstring[sizeof (vheader)] or later.
>
>       --dkg

Hmmm, yea, you're right. I blame it on my lack of coffee before replying :)


Jeff