Le 25/02/2020 à 09:05, Steve Litt a écrit :
> On Mon, 24 Feb 2020 12:21:16 +0000
> Daniel Abrecht via Dng <dng@???> wrote:
...
>> Without dbus, applications & daemons could do similar things using
>> unix sockets. However, then, every application would need their own
>> socket, permission management, configs, etc.
> The preceding is true only if every app needed to be in every other
> app's business. For the vast majority of them, this just isn't true.
> For the few that need this, there are sockets, fifos, and signals.

    Yep, socket, signals, fifos, inotify, netlink, semaphores,
shared-memory, what else?

    It's probably possible to build some well thought middleware with
these, but Dbus isn't that one.

    Dbus more complicated than the others, and cast against C++
concepts, which isn't  a sign of quality. It was designed to match the
needs of the two biggest integrated blobs ever written for Linux, Gnome
and KDE. The aim is to "facilitate" a few things for the user, but it's
a little gain for a huge cost.

>> This would have the same
>> security implications as just using dbus, which also just uses unix
>> sockets, but would leave a bigger attack surface, and a lot of
>> scattered security critical configs with different formats.
> If every app required it. In a client-server situation, the user of the
> server would need to be in a specific group. If it's even that
> important. I don't really care if somebody else gets into my mplayer
> fifo.
>
>> Now, there is also the approach of using a suid binary for the
>> privileged stuff. As a good and bad thing, just like sudo, this can't
>> escape a container, unlike a unix socket passed to one could.
>> However, it would leave the problem of a bigger attack surface, and a
>> lot of scattered security critical configs with different formats,
>> and is very difficult to get right.
> I think suid binaries have fallen out of favor, for the reasons you
> mention.
>
    Well, suid binaries are still the only way to obtain root
priviledge. pkexec is one more; it does the same thing as login, su, and
sudo, in a different way.

    Didier