Update on stats 2017-12
Viktor Dukhovni
ietf-dane at dukhovni.org
Mon Jan 1 22:49:00 CET 2018
[ Happy New Year! May 2018 see major advances in DANE adoption and
even fewer operational issues. ]
Summary: The number of DANE-enabled domains that have also been sighted
on Google's email transparency report has increased from 125 to 127
The total domain count has increased from 173857 to 176079.
The number DNSSEC domains in the survey stands at 5096318,
thus DANE TLSA is deployed on 3.46% of domains with DNSSEC.
Many DNSSEC domains use third-party MX hosts, that don't
have DNSSEC, so they can't benefit from DANE until their
providers secure the MX hosts. Please ask your provider
to enable DNSSEC and DANE on their MX hosts. [ It would
be especially significant if "redirect.ovh.net" were to
implement DNSSEC+DANE, if someone personally knows the
right people to gently nudge at ovh.net, please do. ]
As of today I count 176079 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:
68824 domeneshop.no
63076 transip.nl
18510 udmedia.de
6318 bhosted.nl
1767 nederhost.nl
1265 yourdomainprovider.net
1003 ec-elements.com
516 core-networks.de
395 omc-mail.com
370 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. Speaking
of countries, the IPv4 GeoIP distribution of DANE-enabled MX hosts
shows the below top 10 countries (each unique IP address is counted,
so multi-homed MX hosts are perhaps somewhat over-represented):
1277 GeoIP Country Edition: DE, Germany
770 GeoIP Country Edition: US, United States
450 GeoIP Country Edition: NL, Netherlands
321 GeoIP Country Edition: FR, France
149 GeoIP Country Edition: GB, United Kingdom
102 GeoIP Country Edition: CZ, Czech Republic
74 GeoIP Country Edition: CA, Canada
62 GeoIP Country Edition: CH, Switzerland
60 GeoIP Country Edition: SE, Sweden
58 GeoIP Country Edition: BR, Brazil
IPv6 is still comparatively rare for MX hosts, and the top 11
countries by DANE MX host IPv6 GeoIP are:
212 GeoIP Country V6 Edition: DE, Germany
103 GeoIP Country V6 Edition: US, United States
100 GeoIP Country V6 Edition: NL, Netherlands
56 GeoIP Country V6 Edition: FR, France
29 GeoIP Country V6 Edition: GB, United Kingdom
23 GeoIP Country V6 Edition: CZ, Czech Republic
8 GeoIP Country V6 Edition: SE, Sweden
7 GeoIP Country V6 Edition: SG, Singapore
7 GeoIP Country V6 Edition: NO, Norway
7 GeoIP Country V6 Edition: ID, Indonesia
7 GeoIP Country V6 Edition: CH, Switzerland
There are 3018 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.
The number of published MX host TLSA RRsets found is 4652. These
cover 4742 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 128 (this is my ad-hoc criterion for
a domain being a large-enough actively used email domain). Of
these, 73 are in recent reports:
gmx.at lrz.de ouderportaal.nl
travelbirdbelgie.be mail.de overheid.nl
travelbirdbelgique.be posteo.de pathe.nl
nic.br ruhr-uni-bochum.de uvt.nl
registro.br tum.de xs4all.nl
gmx.ch uni-erlangen.de domeneshop.no
open.ch unitybox.de handelsbanken.no
switch.ch unitymedia.de webcruitermail.no
anubisnetworks.com web.de aegee.org
gmx.com egmontpublishing.dk debian.org
isavedialogue.com netic.dk freebsd.org
mail.com tilburguniversity.edu gentoo.org
solvinity.com octopuce.fr ietf.org
t-2.com comcast.net isc.org
trashmail.com dd24.net netbsd.org
xfinity.com dns-oarc.net openssl.org
xfinityhomesecurity.com gmx.net samba.org
xfinitymobile.com hr-manager.net torproject.org
nic.cz mpssec.net asf.com.pt
bayern.de t-2.net handelsbanken.se
bund.de xs4all.net t-2.si
fau.de bhosted.nl mail.co.uk
freenet.de boozyshop.nl govtrack.us
gmx.de hierinloggen.nl
jpberlin.de otvi.nl
Of the ~176000 domains, 785 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 192.
Below is a list of the 102 underlying MX hosts that serve these domains
and whose TLSA records don't match reality:
Hall of Shame:
white.agoracon.at mx2.pfp.de mail.diejanssens.net
mail.dipietro.id.au mail.rleh.de mail.efflam.net
mx.krb.srv.pique.net.au mail.schwaho.de mail.lnaze.net
zebulon.pique.net.au mx1.spam-sponge.de mail.misbegotten.net
eufront.stansoft.bg mx2.spam-sponge.de wfbrace.net
eumembers.stansoft.bg mx3.spam-sponge.de mx2.wfbrace.net
mail.advokatur4a.ch mx1.spamsponge.de mx2.cbrace.nl
andbraiz.com mx2.spamsponge.de mx3.cbrace.nl
mail.digitalwebpros.com mx3.spamsponge.de mail.fscker.nl
mail.dnsmadefree.com mx10.timotoups.de smtp1.lococensus.nl
smtp-1.httrack.com fsck.email smtp2.lococensus.nl
mail.i-bible.com mail.0pc.eu mail.myzt.nl
demo.liveconfig.com mail2.cesidianroot.eu nuj-netherlands.nl
mx01.mykolab.com gamepixel.eu mx2.nuj-netherlands.nl
mx02.mykolab.com webmail.kassoft.eu bounder.steelyard.nl
mx04.mykolab.com smtp.skolovi.eu mail.abanto-zierbena.org
srv2.noneuclideanconcepts.com mail2.subse.eu smtp2.briaeros007.org
ma.qbitnet.com smtp.vdlaken.eu eumembers.datacentrix.org
stmics01.smia-automotive.com mx.quentindavid.fr genius.konundrum.org
stmics02.smia-automotive.com servmail.fr smtps.planchon.org
romulus.wittsend.com mail.demongeot.info smtp2.amadigi.ovh
mail.zx.com mail.nonoserver.info smtp3.amadigi.ovh
mx.bels.cz mx1.email.youwerehere.info mail.bacrau.ro
mail.davidbodnar.cz mx2.email.youwerehere.info mail.itconnect.ro
mail1.dolnipodluzi.cz mail.rapidfuse.io mx.itconnect.ro
mail.machkovi.cz mail2.galax.is mail.pasion.ro
gaia.nfx.cz mail.lsd.is mail.familie-sander.rocks
petg.cz mx.datenknoten.me mx1.shevaldin.ru
mail.zionbit.cz mx.giesen.me halon.gislaved.se
mail.absynth.de rootbox.me halon02.gislaved.se
mail.all4.de mail.amsx.net mail.labbrack.se
mx2.mindrun.de mail.castleturing.net mail1.puggan.se
www.mtg.de mail.culm.net mail.rostit.se
mail.ocmenzel.de anubis.delphij.net mail.xn----ymcadjpj1at5o.xn--wgbh
Some recently notified, but the number of long-term problem MX
hosts has been slowly creeping up... Please make sure to monitor
the validity of your TLSA records, and implement a reliable key
rotation procedure. Let's Encrypt users in particular tend to
forget that by default Let's Encrypt certificate renewal replaces
both the key and certificate, please read:
http://postfix.1071664.n5.nabble.com/WoSign-StartCom-CA-in-the-news-td86436.html#a86444
https://community.letsencrypt.org/t/new-certbot-client-and-csr-option/15766
https://www.internetsociety.org/deploy360/blog/2016/03/lets-encrypt-certificates-for-mail-servers-and-dane-part-2-of-2/
https://community.letsencrypt.org/t/please-avoid-3-0-1-and-3-0-2-dane-tlsa-records-with-le-certificates/7022
http://tools.ietf.org/html/rfc7671#section-8.1
http://tools.ietf.org/html/rfc7671#section-8.4
When updating the certificate chain you need to temporarily
pre-publish multiple TLSA records matching the current and future
certificate:
https://dane.sys4.de/common_mistakes#3
However, with "3 1 1" + "2 1 1", the rollover process can be
substantially simplified:
http://postfix.1071664.n5.nabble.com/WoSign-StartCom-CA-in-the-news-td86436.html#a86444
https://www.ietf.org/mail-archive/web/uta/current/msg01498.html
After eliminating parked domains that do not accept email of any
kind, the number of "real" email domains with bad DNSSEC support
stands at 116. The top 6 (the rest have too few domains to include
in a top 10) name server operators with problem domains
are:
24 firstfind.nl
7 active24.cz
5 tse.jus.br
4 ignum.com
4 glbns.com
4 army.mil
Only 2 DNS-broken domains have no working nameservers and also
appear in historical Google Email transparency reports:
tiviths.com.br
trtrj.jus.br
The problem DNS queries are:
_25._tcp.mx.tiviths.com.br
_25._tcp.mx1.trtrj.jus.br
[ 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.
More information about the dane-users
mailing list