Re: [naviserver-devel] ns_mktemp

[Wolfgang W. <wol...@di...>]

I like the solution suggested by Andrew as well. This should allow an 
easy transition of existing code without sacrificing security.

Am 07.10.24 um 17:59 schrieb Andrew Piskorski:
> On Mon, Oct 07, 2024 at 12:54:32PM +0200, Gustaf Neumann (sslmail) wrote:
>
>> However, there are many cases, where existing programs use "ns_mkstemp", which cannot be replaced easily. When looking at OpenACS, I see 33 cases like
>>
>> - the temporary name is passed to an external program (e.g. "tar", "zip", image creation), or
>> - the temporary name is passed to a Tcl function expecting a filename (e.g. "file copy").
> Interesting.  It sounds like are no 100% good solutions for this, and
> in fact there CAN'T be.
>
>> - Call the safe function (e.g. mkstemp()) and delete the file, while
>>    producing a depreciation message? This could also be done on the Tcl-level.
> I guess so.  Probably with a switch to control whether the file is
> created and remains (new-style behavior), or gets quickly deleted
> (more fully backward compatible).
>
> I'd lean towards turning ns_mktemp into a wrapper around Tcl's "file
> tempfile".  That calls TclUnixOpenTemporaryFile() and thus mkstemp()
> or mkstemps(), but it looks like Tcl has already done the necessary
> work to easily make the wrapper backwards compatible with the
> old-style ns_mktemp.  And having the compatibility wrapper in Tcl
> instead of C makes it a lot easier for NaviServer users to adjust it
> to their own needs if necessary.
>