Re: fix mktemp (remove mktemp ;)

From: Paul Jackson <pj@sgi.com>
Date: Apr 17, 2005, 00:44 UTC
Message-ID: <20050416174409.59f94c26.pj@sgi.com>
In-Reply-To: <20050417003325.GA15608@redhat.com>

Dave wrote:

> mktemp is being used here to provide randomness in the filename,
> not just a uniqueness.

Ok - useful point.

How about:

	t=${TMPDIR:-/usr/tmp}/gitdiff.$$.$RANDOM

> all an attacker has to do is create 65535 symlinks in /usr/tmp

And how about if I removed the tmp files at the top:

	t=${TMPDIR:-/usr/tmp}/gitdiff.$$.$RANDOM
	trap 'rm -fr $t.?; trap 0; exit 0' 0 1 2 3 15
	rm -fr $t.?

	... rest of script ...

How close does that come to providing the same level of safety, while remaining portable over a wider range of systems, and not requiring that a separate command be forked?

> I'd suggest fixing your distributions ...

It's not just my distro; it's the distros of all git users.

If apps can avoid depending on inessential details of their environment, that's friendlier to all concerned.

And actually my distro is fine - it's just that I am running an old version of it on one of my systems. Newer versions of the mktemp -t option.

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@engr.sgi.com> 1.650.933.1373, 1.925.600.0401