Author: Bill Hacker Date: To: exim Subject: Re: [exim] Running exim as a user with no username
Mike Cardwell wrote:
> Bill Hacker wrote:
> *trim*
> ... The answer I was hoping for would have been
> something along the lines of:
>
> "You need to take a look at the section of code starting at line xxx of
> the file foo.c. You can probably set the return-path by setting the
> variable xx to it at this point."
>
Just because you *can* hack other folk's 'C' code doesn't mean you
should have made, for example, the change where you claim to
have Exim run with no fixed UID of its own...
Aside from being bizarre, perhaps dangerous from a security standpoint,
it is not at all necessary.
Exim happily shifts effective UID:GID as directed, within a running process,
from settings in the ~/configure file. Those ID's can be fed to it in
the usual
variety of ways from external information, derived from a number of internal
variables - or 'generated' by algorithms, even.
Further, the *process* UID:GID has SQRT Fine Abalone to do with what goes
into a message header - unless you choose it to be so.
Those can be 'defaulted', fed from macros, derived from variables, lookups,
written, re-written, and/or stripped independently in acl's and
router/transport sets.
You need to step a bit further back from the 'problem' - far enough back to
look about and take note that there have been many other simpler means
used to handle this very sort of issue. Most are already 'built-in' to
Exim.
More research into ~/configure options, and what, and why, you think
you need to accomplish - not more coding in source...
Innovation, elegant solutions, and clever use of tools are welcome.
Extensive and highly expert help is readily available - and has been
provided (Google 'Tony Finch +Exim').
You should expect to find much less support for approaches that ignore
available standard tools to solve 'perceived' problems that seem to arise
purely from contrarianism of application.
That you have this "problem" *at all* indicates to me that you are
mis-applying
the MTA - Exim or otherwise. That can bite. Bigtime.