[Python-Dev] Remove tempfile.mktemp()

[Giampaolo Rodola']

On Tue, 19 Mar 2019 at 17:47, Sebastian Rittau <srittau at rittau.biz> wrote:

> Am 19.03.19 um 17:23 schrieb Giampaolo Rodola':
> > @Sebastian
> >> If there are valid use cases for mktemp(), I recommend renaming
> >> it to mkname_unsafe() or something equally obvious.
> > I'm -1 about adding an alias (there should be one and preferably only
> > one way to do it). Also mkstemp() and mkdtemp() are somewhat poorly
> > named IMO, but I wouldn't add an alias for them either.
> >
> Just to clarify: I was not suggesting creating an alias, I was suggesting
> renaming the function, but keeping the old name for a normal
> deprecation cycle.
>
> But I had another thought: If I understand correctly, the exploitability
> of mktemp() relies on the fact that between determining whether the
> file exists and creation an attacker can create the file themselves.
> Couldn't this problem be solved by generating a filename of sufficient
> length using the secrets module? This way the filename should be
> "unguessable" and safe.


Technically you cannot make it 100% safe, only less likely to occur. And on
a second thought (I retract :)) since this could be used in real apps other
than tests (I was too focused on that) I think this should be a doc warning
after all, not info. Doc may suggest to use mode=x when creating the file,
in order to remove the security implications.

-- 
Giampaolo - http://grodola.blogspot.com
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