Re: Re: [PATCH v2] config: preserve config file permissions on edits

> Am Montag, den 19.05.2014, 11:59 +0200 schrieb Erik Faye-Lund:
>> On Mon, May 19, 2014 at 9:44 AM, Erik Faye-Lund <kusmabite@gmail.com> wrote:
>> > On Mon, May 19, 2014 at 9:13 AM, Johannes Sixt <j.sixt@viscovery.net> wrote:
>> >> Am 5/6/2014 2:17, schrieb Eric Wong:
>> >>> Users may already store sensitive data such as imap.pass in
>> >>> ..git/config; making the file world-readable when "git config"
>> >>> is called to edit means their password would be compromised
>> >>> on a shared system.
>> >>>
>> >>> [v2: updated for section renames, as noted by Junio]
>> >>>
>> >>> Signed-off-by: Eric Wong <normalperson@yhbt.net>
>> >>> ---
>> >>>  config.c               | 16 ++++++++++++++++
>> >>>  t/t1300-repo-config.sh | 10 ++++++++++
>> >>>  2 files changed, 26 insertions(+)
>> >>>
>> >>> diff --git a/config.c b/config.c
>> >>> index a30cb5c..c227aa8 100644
>> >>> --- a/config.c
>> >>> +++ b/config.c
>> >>> @@ -1636,6 +1636,13 @@ int git_config_set_multivar_in_file(const char *config_filename,
>> >>>                       MAP_PRIVATE, in_fd, 0);
>> >>>               close(in_fd);
>> >>>
>> >>> +             if (fchmod(fd, st.st_mode & 07777) < 0) {
>> >>> +                     error("fchmod on %s failed: %s",
>> >>> +                             lock->filename, strerror(errno));
>> >>> +                     ret = CONFIG_NO_WRITE;
>> >>> +                     goto out_free;
>> >>> +             }
>> >>
>> >> This introduces a severe failure in the Windows port because we do not
>> >> implement fchmod. Existing fchmod invocations do not check the return
>> >> value, and they are only interested in removing the write bits, and we
>> >> generally don't care a lot if files remain writable.
>> >>
>> >> I'm not proficient enough to add any ACL fiddling to fchmod that would be
>> >> required by the above change, whose purpose is to be strict about
>> >> permissions. Nor am I interested (who the heck is sharing a Windows box
>> >> anyway? ;-)
>> >>
>> >> Therefore, here's just a work-around patch to keep things going on
>> >> Windows. Any opinions from the Windows corner?
>> >>
>> >
>> > Since we use MSVCRT's chmod implementation directly which only checks
>> > for S_IWRITE,and Get/SetFileAttributes to simply set or clear the
>> > FILE_ATTRIBUTE_READONLY-flag, perhaps we could do the same except
>> > using Get/SetFileInformationByHandle instead? That takes us in a
>> > better direction, IMO. Adding full ACL support seems like a bigger
>> > project.
>> >
>> > If there's no objection, I'll sketch up a patch for that...
>>
>> OK, this turned out a bit more yucky than I assumed, because
>> SetFileInformationByHandle is only available on Windows Vista and up.
>> There's a static library (FileExtd.lib) that ships with MSVC that
>> emulates it for legacy support, I guess I should have a look at what
>> that does.
>
> Do we still want to fully support Windows XP?
> Adding a work around here for a EOL operating system sounds like a lot
> of effort.