ietf-dkim
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[ietf-dkim] DKIMnomics

2011-05-28 07:08:58
Alessandro Vesely wrote:

On 25/May/11 20:23, Dave CROCKER wrote:
That's not likely to be the goal of this sort of exercise.  Rather, it 
will be to choose a set of particular types of breakage, ignoring others.  
For an effort like that, it is not meaningful to come up with additional 
types of breakage, since there is no attempt to cover such additional 
examples.

Of course, a signature cannot survive a deliberate attempt at breaking
it.  However, earlier analysis considered man-in-the-middle attacks
like changing, e.g., "Amoeba yeast" into "Amo ebay east" [Bryan
Costales, Thu, 04 Aug 2005].  We don't know how likely such kind of
attacks may be, since only tight canonicalizations were standardized.

By introducing a loose canonicalization we may learn whether signature
survivability affects DKIM adoption.  If wider usage introduces
attacks, we can switch back to current canonicalizations --in case
downgrades will have gone away-- or design yet another one,
approaching just the tightness we need.  My appeal is for not imposing
monotonicity to successive approximations, and allow erring on the
too-lose side as well.

It seems the DKIMnomics are proving not to be there. It's like beating 
a dead horse dealing with the inconsistent considerations.  With so 
much failure with your own domain usages, it has become a big concern.

Its not a big deal when your own domain failures come back into your 
own system (via list distribution) because you can make the 
exceptions. But that knowledge is not known by others seeing the same 
message.  Its not like the world has "SPF-like" exposed information or 
3rd party vouching information for DKIM receivers, or users to at 
least to get a clue.

The irony is the seeing a high validation success among the unknown 
spammers w/o using unknown list to distribute their junk.  Since we 
separated the "question" between the resigner and the purported 
author, where are the benefits?  Your own domains are lost on list 
that resign as well on those that don't resign.

Seeing the following does not give one much hope:

+-----------------------------------------------------------------------+
| LIST-ID                                   SIGNER               % FAIL |
|-----------------------------------------------------------------------|
| 6522.31.email.enviomasivoempresarial.com  esp2.it                 0   |
|-----------------------------------------------------------------------|
| 8388.19.h3h8.s05.it                       emailingtools.it        0   |
| 8388.23.h3h8.s05.it                       emailingtools.it        0   |
| 8388.40.h3h8.s05.it                       emailingtools.it        0   |
| 8388.51.h3h8.s05.it                       emailingtools.it        0   |
| 8974.19.h9g4.s06.it                       emailingtools.it        0   |
|-----------------------------------------------------------------------|
| Developers.winserver.com                  mapurdy.com.au        100   |
|-----------------------------------------------------------------------|
| dkim-ops.mipassoc.org                     mipassoc.org            0   |
|-----------------------------------------------------------------------|
| ietf-822.imc.org                          cybernothing.org      100   |
| ietf-822.imc.org                          tana.it               100   |
| ietf-822.imc.org                          mrochek.com           100   |
| ietf-822.imc.org                          isdg.net              100   |
| ietf-822.imc.org                          messagingengine.com   100   |
|-----------------------------------------------------------------------|
| ietf-dkim.mipassoc.org                    mipassoc.org          0.2   |
|-----------------------------------------------------------------------|
| ietf-pop3ext.imc.org                      gmail.com             100   |
|-----------------------------------------------------------------------|
| ietf-smtp.imc.org                         santronics.com        100   |
| ietf-smtp.imc.org                         tana.it               100   |
| ietf-smtp.imc.org                         gmail.com             100   |
| ietf-smtp.imc.org                         sonnection.nl         100   |
| ietf-smtp.imc.org                         taugh.com             100   |
| ietf-smtp.imc.org                         resistor.net          100   |
| ietf-smtp.imc.org                         mrochek.com           100   |
| ietf-smtp.imc.org                         messagingengine.com   100   |
|-----------------------------------------------------------------------|
| ietf.ietf.org                             resistor.net          100   |
| ietf.ietf.org                             cybernothing.org      100   |
| ietf.ietf.org                             cisco.com             100   |
| ietf.ietf.org                             mrochek.com           100   |
| ietf.ietf.org                             iecc.com              100   |
| ietf.ietf.org                             isdg.net              100   |
| ietf.ietf.org                             gmail.com             100   |
|-----------------------------------------------------------------------|
| pak-business-26.googlegroups.com          googlegroups.com        0   |
| pak-business-29.googlegroups.com          googlegroups.com        0   |
| pak-business-60.googlegroups.com          googlegroups.com        0   |
|-----------------------------------------------------------------------|
| rss-public.yahoogroups.com                yahoogroups.com         0   |
|-----------------------------------------------------------------------|
| spf-discuss(_at_)listbox(_dot_)com                   talamasca.ocis.net    
100   |
| spf-discuss(_at_)listbox(_dot_)com                   gmail.com             
100   |
| spf-discuss(_at_)listbox(_dot_)com                   listbox.com             
0   |
|-----------------------------------------------------------------------|
| spf-help(_at_)listbox(_dot_)com                      gmail.com             
100   |
| spf-help(_at_)listbox(_dot_)com                      listbox.com             
0   |
|-----------------------------------------------------------------------|
| WINServer.santronics.com                  megabytecoffee.com    100   |
| WINServer.santronics.com                  mapurdy.com.au        100   |
| WINServer.winserver.com                   megabytecoffee.com    100   |
| WINServer.winserver.com                   gmail.com             100   |
| WINServer.winserver.com                   mapurdy.com.au        100   |
+-----------------------------------------------------------------------+

All my signing domain, isdg.net, fails on all the above list and you 
can see others in the same list.   Its interesting to note, like on 
the spf-discuss and spf-help list, only its own signature survive, but 
not others. For our winserver.com and santronics.com list, everyone 
else signature fails.

Overall, its not about just how it all looks on your own system or 
MUA, but how it looks at other systems.

So what is DKIM for?  For the unknown?  Giving these Valid Signature 
SPAMMERS some sort of seal of approval?  I don't think so.

+-----------------------------------------------------------------------+
| LIST-ID                                   SIGNER               % FAIL |
|-----------------------------------------------------------------------|
| 6522.31.email.enviomasivoempresarial.com  esp2.it                 0   |
|-----------------------------------------------------------------------|
| 8388.19.h3h8.s05.it                       emailingtools.it        0   |
| 8388.23.h3h8.s05.it                       emailingtools.it        0   |
| 8388.40.h3h8.s05.it                       emailingtools.it        0   |
| 8388.51.h3h8.s05.it                       emailingtools.it        0   |
| 8974.19.h9g4.s06.it                       emailingtools.it        0   |
|-----------------------------------------------------------------------|
| pak-business-26.googlegroups.com          googlegroups.com        0   |
| pak-business-29.googlegroups.com          googlegroups.com        0   |
| pak-business-60.googlegroups.com          googlegroups.com        0   |
|-----------------------------------------------------------------------|
| rss-public.yahoogroups.com                yahoogroups.com         0   |
+-----------------------------------------------------------------------+

As far as I am concern the highest benefit DKIM can provide is an 
explicit POLICY of failure protection.  That is where the benefits 
comes - when there is a violation of a given practice. But MLM doesn't 
work with DKIM with or without policy.  So where is the DKIMnomics?

--
HLS


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