ietf-mxcomp
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SPF/FROM-HDR (was: IPR Disclosure for Sender-ID)

2004-08-04 06:48:12

wayne wrote in mxcomp (MARID):

http://www.ietf.org/internet-drafts/draft-schlitt-marid-spf-from-hdr-00.txt

That's the first time I see this.  It's not on the page with
the MARID drafts (see <http://purl.net/xyzzy/-ietf/marid>),
it's not on <http://spf.pobox.com/rfcs.html>, IIRC it was not
published on the SPF announce list, and if it was mentioned on
the SPF-discuss list I must have missed it:

| Comments on this draft are welcome.  In the interests of
| openness, before contacting the authors directly, please
| post to the spf-discuss mailing list.

The date says July 12 2004.  The algorithm is incompatible with
SPF classic, therefore it cannot be used with existing v=spf1
sender policies.

| There are no changes in semantics to existing protocols

That's not true.

IP okay for xyzzy:        SPF classic  SPF/FROM-HDR
MAIL FROM:<valid(_at_)xyzzy>   PASS         PASS only if whitelisted
2822 From:<some(_at_)example>  don't care   (FAIL => test MAIL FROM)

IP not okay for xyzzy:    SPF classic  SPF/FROM-HDR
MAIL FROM:<user(_at_)MSA(_dot_)test> UNKNOWN      (UNKNOWN in step 3)
2822 From:<valid(_at_)xyzzy>   don't care   FAIL (step 5)

IP okay for spam(_at_)test:    SPF classic  SPF/FROM-HDR
MAIL FROM:<forged(_at_)xyzzy>  FAIL         don't care
2622 From:<spam(_at_)test>     don't care   PASS (step 1)

I'm not really interested in the 1st example, because I don't
use arbitrary 2822 From headers with a SPF-protected MAIL FROM.

But the 2nd example is real and almost the same problem as with
Sender-Id.  In fact it's even worse because Sender-Id at least
allowed to use a matching Sender:<user(_at_)MSA(_dot_)test> to bypass its
2822 From:-test.

And the 3rd example is evil, SPF/FROM-HDR results in a PASS,
but the bounce for this spam is later sent to a 3rd party (?)

What's the purpose of step 2 spf_test(To:,IP) ?  Bye, Frank