Re: [Exim] Sender-/Return-Path-Rewriting

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David Woodhouse <dwmw2@???> [2004-02-23/00:48]:
> On Sun, 2004-02-22 at 18:17 +0100, Daniel Roethlisberger wrote:
> > Your ``only rewrite for SPF-enabled domains'' has one flaw: SPF is
> > not the only origin verification scheme in use today.
>
> But the multiple-hop rewrite is even more fatally flawed; implementers
> are turned into open relays _without_ any form of verification as long
> as you only want to relay to addresses matching 'SRS0+...' at the
> eventual target domain.

As a general statement about multihop return path rewriting schemes,
this is not true. As a statement about Shevek's specific scheme used by
his Mail::SRS at this time, this seems to be true, but you should
discuss this on srs-discuss with him and other SRS proponents, not on
exim-users.

> > > Also, you don't seem to be doing much quoting... how does it fare
> > > with addresses such as
> > > 'one-two=th$r\ee#fo\\ur##fi}v\e%six\@_seven@???'?
> >
> > Depending on the scheme, you don't need to quote anything specially,
> > as the address is unambigously parseable in any case, even in the
> > multi-hop different RPR schemes (`babuschka') case.
>
> Not on the _wire_ -- I mean in the Exim config. For much the same
> reason you're advised to use data =
> ${quote_local_part:$local_part}@$domain
> in a redirect router to preserve the original address. Otherwise it'll
> get 'interpreted' and not passed through as-is. Did you _try_ the
> address I gave you?

Please always specify whose implementation you are talking about.

I agree that proper handling of quoting is extremely important, and both
my rewriting schemes use the exim3 ${quote:...} mechanism, and seem to
handle all aspects of RFC282[12] quoting just fine. But if you do find a
specific problem with my implementation after all, please let me know.

Naturally, I cannot speak for the other implementations of return path
rewriting (MTvB, Shevek, others?), but you can easily check them before
supposing quoting problems that might or might not be there.

If you would take the time to skim through the spf-discuss archives I
pointed you to before, most if not all of these quoting issues have been
discussed before.

I don't think this discussion is appropriate here on exim-users -- feel
free to reply to me personally about my schemes, or take the discussion
to srs-discuss if you want to talk about SRS, Mail::SRS or libsrs. I'm
reasonably sure their authors and proponents don't read exim-users.

Cheers,
Dan


--
Daniel Roethlisberger <daniel@???>
GnuPG key ID 0x804A06B1 (DSA/ElGamal)
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