Belated update on stats 2017-09/2017-10

Viktor Dukhovni ietf-dane at dukhovni.org
Thu Oct 26 08:31:42 CEST 2017


[ Sorry about the delay, I was too busy rewriting major chunks
  of the underlying code to produce a report.  Better late than
  never so the below is the status for today, rather than the end
  of September. ]

Summary:  The number of DANE-enabled domains that have also been sighted
	  on Google's email transparency report has increased from 115 to
	  122, while the number of DNS zones with TLSA-enabled primary MX
	  hosts has increased from 2708 to 2999.  The total domain count
	  is largely unchanged from 172205 to 172120.

	  A new type of TLSA record mismatch has cropped up, so far on
	  just two MX hosts.  Their RSA certificate chains match their
	  TLSA records, but their ECDSA certificate chains do not:

	  https://mail.sys4.de/pipermail/dane-users/2017-August/000416.html
	  https://mail.sys4.de/pipermail/dane-users/2017-August/000417.html

As of today I count 172120 domains with correct SMTP DANE TLSA
records at every primary MX host that accepts connections[1].  As
expected the bulk of the DANE domains are hosted by the handful of
DNS/hosting providers who've enabled DANE support in bulk for the
domains they host.  The top 10 MX host providers by domain count
are:

   68399 domeneshop.no
   60915 transip.nl
   18354 udmedia.de
    6460 bhosted.nl
    1787 nederhost.net
    1294 yourdomainprovider.net
    1009 ec-elements.com
     505 core-networks.de
     384 omc-mail.com
     333 mailbox.org

The real numbers are surely larger, because I don't have access to the
full zone data for most ccTLDs, especially .no/.nl/.de.

[ The DANE domain counts for the large providers appear to have
  plateaued in the past couple of months.  Perhaps, absent new more
  comprehensive sources of live domain names, I've finally found
  as many domains I can reasonably expect to find for these providers,
  and there's not much growth in their "visible" domain portfolios. ]

There are 2999 unique zones in which the underlying MX hosts are found,
this counts each of the above providers as just one zone, so is a measure
of the breadth of adoption in terms of servers deployed.  Alternatively,
a similar number is seen in the count (2853) of distinct MX host server
certificates that support the same ~172000 domains.

The number of published MX host TLSA RRsets found is 3932.  These
cover 4004 distinct MX hosts (some MX hosts share the same TLSA
records through CNAMEs).

The number of domains that at some point were listed in Gmail's
email transparency report is 122 (this is my ad-hoc criterion for
a domain being a large-enough actively used email domain).  Of
these, 70 are in recent reports (spanning Sep and Oct):

   gmx.at                  posteo.de               overheid.nl
   travelbirdbelgie.be     ruhr-uni-bochum.de      pathe.nl
   nic.br                  tum.de                  uvt.nl
   registro.br             uni-erlangen.de         xs4all.nl
   gmx.ch                  unitybox.de             domeneshop.no
   open.ch                 unitymedia.de           webcruitermail.no
   anubisnetworks.com      web.de                  debian.org
   gmx.com                 egmontpublishing.dk     freebsd.org
   mail.com                tilburguniversity.edu   gentoo.org
   solvinity.com           enron.email             ietf.org
   t-2.com                 octopuce.fr             isc.org
   trashmail.com           comcast.net             lazarus-ide.org
   xfinity.com             dd24.net                netbsd.org
   xfinityhomesecurity.com gmx.net                 openssl.org
   xfinitymobile.com       hr-manager.net          samba.org
   nic.cz                  t-2.net                 torproject.org
   bayern.de               xs4all.net              asf.com.pt
   bund.de                 asp4all.nl              minmyndighetspost.se
   fau.de                  bhosted.nl              skatteverket.se
   freenet.de              bit.nl                  t-2.si
   gmx.de                  boozyshop.nl            mail.co.uk
   jpberlin.de             hierinloggen.nl         govtrack.us
   lrz.de                  otvi.nl
   mail.de                 ouderportaal.nl

Of the ~172000 domains, 545 have "partial" TLSA records, that cover
only a subset of the MX hosts.  While this protects traffic to some
of the MX hosts, such domains are still vulnerable to the usual
active attacks via the remaining MX hosts.

The number of domains with incorrect TLSA records or failure to advertise
STARTTLS (even though TLSA records are published) stands today at 160.
Below is a list of the 100 underlying MX hosts that serve these domains
and whose TLSA records don't match reality:

  Hall of Shame:

  white.agoracon.at             mail.manima.de         mx2.wfbrace.net
  mail.dipietro.id.au           mail.ocmenzel.de       mx3.wfbrace.net
  asp-mxa.belnet.be             supersahnetorten.de    wfbrace.net
  asp-mxb.belnet.be             mx.thorko.de           mx2.cbrace.nl
  asp-mxtest.belnet.be          mail.0pc.eu            mx3.cbrace.nl
  eufront.stansoft.bg           relay.antoineducret.eu mail.lajetee.nl
  eumembers.stansoft.bg         mail2.cesidianroot.eu  smtp1.lococensus.nl
  fazendeiro.ifba.edu.br        gamepixel.eu           smtp2.lococensus.nl
  mail.gna.ch                   webmail.kassoft.eu     mail.myzt.nl
  andbraiz.com                  smtp.skolovi.eu        mx2.nuj-netherlands.nl
  mx1.cloudfiltering.com        mail2.subse.eu         nuj-netherlands.nl
  mx2.cloudfiltering.com        smtp.vdlaken.eu        mail.solarisinternetgroep.nl
  mail.digitalwebpros.com       mx.quentindavid.fr     bounder.steelyard.nl
  mail.itsmine.com              servmail.fr            mail.abanto-zierbena.org
  demo.liveconfig.com           mail.demongeot.info    freebox.crans.org
  mx04.mykolab.com              mail.nonoserver.info   soyouz.crans.org
  intranet.nctechcenter.com     node1.mxbackup.io      eumembers.datacentrix.org
  mta1-em1.orleans.occnc.com    mail.rapidfuse.io      genius.konundrum.org
  mta3-em1.somerville.occnc.com mail.lsd.is            smtp2.amadigi.ovh
  lon-do.pieterpottie.com       mail.laukas.lt         smtp3.amadigi.ovh
  ny-do.pieterpottie.com        mx.datenknoten.me      itaskmanager.ovh
  ma.qbitnet.com                mx.giesen.me           mail.bacrau.ro
  stmics01.smia-automotive.com  rootbox.me             club3d.ro
  stmics02.smia-automotive.com  lima.ahrain.net        mail.itconnect.ro
  mail.zx.com                   avarty.net             mx.itconnect.ro
  mx.bels.cz                    mail.castleturing.net  mail.pasion.ro
  mail.davidbodnar.cz           mail.d3fy.net          mail.familie-sander.rocks
  gaia.nfx.cz                   mail.efflam.net        mx1.shevaldin.ru
  petg.cz                       mail.luyckx.net        mail.labbrack.se
  mail.seslost.cz               mail.misbegotten.net   mail2.puggan.se
  mail.zionbit.cz               mx2.oostergo.net       mail.rostit.se
  mail.jo8.de                   oostergo.net           mail.muthai.in.th
  mail.lanasoft.de              mail.qusign.net
  mutt.lsexperts.de             mail.roeller.net

Some just notified, so I expect this to be a local peak.

After eliminating parked domains that do not accept email of any
kind, The number of "real" email domains with bad DNSSEC support
stands at 175.  (The accenture.com domains from the previous
report were all parked).  The top 10 name server operators with
problem domains are:

  63 jsr-it.nl
  17 firstfind.nl
   7 active24.cz
   5 tse.jus.br
   4 glbns.com
   3 cas-com.net
   2 tiscomhosting.nl
   2 sylconia.net
   2 psyclonecontacts.net
   2 ns01.nl

Only 7 of the DNS-broken domains appear in historical Google Email
transparency reports:

  tiviths.com.br
  tre-ce.jus.br
  trtrj.jus.br
  tse.jus.br
  idaho.gov
  nsysu.edu.tw

The problem DNS queries are:

  _25._tcp.mx.tiviths.com.br. IN TLSA ?
  _25._tcp.dexter.tse.jus.br. IN TLSA ?
  _25._tcp.lalavava.tse.jus.br. IN TLSA ?
  _25._tcp.mandark.tse.jus.br. IN TLSA ?
  _25._tcp.inbound.idaho.gov. IN TLSA ?
  _25._tcp.mx1.trtrj.jus.br. IN TLSA ?
  _25._tcp.barracuda.nsysu.edu.tw. IN TLSA ?

  [ See <https://tools.ietf.org/html/draft-ietf-dnsop-no-response-issue-08>,
    Much of the TLSA non-response issue seems to be related to a
    "feature" of some firewalls, that enables droping of DNS requests
    for all but the most common RRtypes.  Do not make the mistake
    of enabling this firewall "feature". ]

The oldest outstanding DNS issue is an SOA signature issue at
truman.edu dating back to Nov/2014:

  http://dnsviz.net/d/_25._tcp.barracuda.truman.edu/VGzORw/dnssec/

I hope some day soon they'll start missing email they care about
and take the time to resolve the problem.

-- 
	Viktor.

[1] Some domains deliberately include MX hosts that are always
down, presumably as a hurdle to botnet SMTP code that gives up
where real MTAs might persist.  I am not a fan of this type of
defence (it can also impose undue latency on legitimate email).
However, provided the dead hosts still have TLSA records, (which
don't need to match anything, just need to exist and be well-formed)
there's no loss of security.


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