XSF Discussion - 2014-03-17

  1. Ge0rG

    dwd: ping. are you still overloaded with work?

  2. simon

    Zash has DANE working for Prosody now. It looks like Tigase has something on the horizon: https://projects.tigase.org/issues/1626. Anyone know about Ejabberd or MongooseIM or Openfire?

  3. Zash

    Need to write a proper DANE+XMPP draft

  4. simon

    Zash: Do you have some setup instructions lurking anywhere?

  5. Zash

    simon: For the Prosody DANE plugin, DNS setup or bot?

  6. Zash


  7. m&m

    Zash: would be acceptable to put the XMPP-specific parts of DANE into draft-ietf-xmpp-dna, or does it really require a standalone draft?

  8. simon

    The plugin looks pretty straight forward. But for the DNS setup. All the guides I've read are quite complex and assume a massive rollout... Well it would be nice to have a simple setup guide. Does such a thing exist?

  9. Zash

    m&m: Would probably be fine to have it in DNA-DANE

  10. m&m

    Zash: patches welcome (-:

  11. Zash

    Maybe, once I recover from the meeting I had this entire weekend.

  12. m&m


  13. m&m

    working on that is third on my TODO

  14. fippo

    DNA-DANE-POSH maybe

  15. fippo

    we still need to define what DNA is actually ;-)

  16. m&m


  17. Zash

    My code is currently diverging from the DANE-SRV stuff

  18. simon

    Zash: how does it diverge?

  19. Zash

    It looks up _xmpp-server.example.com IN TLSA instead of _$port._tcp.your-srv-target.example.com

  20. m&m

    I doubt that TLSA for _xmpp-server.example.com would get published

  21. Zash


  22. simon

    what's your thinking on using xmpp-server instead of _$port._tcp.your-srv-target.example.com?

  23. Zash

    simon: https://www.zash.se/dane-s2s-client.html

  24. simon

    I love it when someone can point to a webpage to answer questions!

  25. m&m

    the problem here is that it assumes a level of micro-coordination between the owning domain and the hosting provider that is only really possible for stand-alone servers

  26. Zash

    Basically, it's easier, especially for validating incoming connections.

  27. Zash

    m&m: CNAME :P

  28. m&m


  29. m&m


  30. m&m

    requiring CNAME to deploy seems like a Really Bad Idea™.

  31. m&m

    and again requires the owning domain and hosting provider to be in sync on DNS updates

  32. simon

    It's bad enough getting people setting up SRV records... (SRV what?)

  33. ralphm

    also, is this format for TLSA even valid?

  34. m&m

    ralphm: it's not prohibited, but it's not documented anywhere

  35. ralphm

    simon: strongly disagree. I wish SRV was used more. Like in HTTP.

  36. m&m

    RFC 6698 documents using _$port._tcp.hosting.example.net

  37. Zash

    ralphm: The qname has nothing to do with the TLSA format, that's just an example convention.

  38. m&m

    ralphm: wishing something were so and reality are often in conflict (-:

  39. simon

    Ralphm: I agree- wish they were used more too. But I have to explain why they are awesome every single bloody time.

  40. m&m

    and how 5222 and 5269 are not "proprietary ports"

  41. ralphm

    simon: write a web page to point to.

  42. Zash

    m&m: Incoming s2s connection, I wanna validate the client cert without doing over 9000 lookups.

  43. m&m

    ralphm: at that point, I might as well use .well-known and host metadata d-:

  44. Zash

    And SRV records might not even point to servers doing outgoing connections.

  45. ralphm

    m&m: I mean a web page explaining SRV

  46. m&m

    Zash: I understand your desire, but I think you're going to have to suck it up and deal with the extra lookups

  47. intosi

    You're going to do a million lookups anyway, because of DNSSEC.

  48. ralphm

    +1 sucking it up

  49. intosi

    m&m: +1

  50. Zash

    intosi: The dns library handles that for me.

  51. m&m

    Zash: it's not a ton of lookups, but n*2 (n == count of SRV RRs)

  52. m&m

    well, 3*n if you do both A and AAAA and TLSA

  53. simon

    One million lookups http://img2.wikia.nocookie.net/__cb20090506185112/uncyclopedia/images/f/fa/Dr_evil_one_million_dollars.jpg

  54. intosi

    And you probably will want to look up / have looked up the SRV records for the domain in question.

  55. m&m

    but really, anything that relies on the source domain holding information on the keying material severely constrains hosting deployments

  56. Zash

    intosi: Not for incoming connections with bidi

  57. ralphm

    I don't want to promote any non-standard use of existing DNS RRs. There are a few to choose from for pointing to things, all with their own uses. TXT, CNAME, SRV, TLSA, PTR. Please, just use them appropriately.

  58. ralphm

    I remember a recent discussion with simon on this for BC.

  59. simon

    Go PTR!

  60. Zash

    I remember a recent discussion with DANE people at IETF that this made more sense than the _port way.

  61. m&m

    if it wasn't Viktor Dukonvni or Wes Hardraker, then it probably wasn't with people actually deploying things (-:

  62. Zash

    where's that email

  63. Zash


  64. simon

    m&m: that's one of the most pleasant to read RFCs. Nice job btw.

  65. m&m

    Zash: /sigh … this is after spending about 2 minutes trying explain XMPP S2S to someone unfamiliar with XMPP

  66. ralphm


  67. m&m

    for actual XMPP clients, this might be ok, although I still doubt the actual deployability of true client certs

  68. m&m

    for servers, I think you'll have to do the SRV and TLSA lookups, or you could be getting false negatives

  69. m&m

    particularly for hosting providers that have separate certs for each individual end-point

  70. m&m

    simon: we try (-:

  71. Zash

    false negatives?

  72. m&m

    for instance, let's say hobbiton.example is hosted at a large provider with 6 s2s end-points(im1.middle-earth.example, im2.middle-earth.example, im3.middle-earth.example, im4.middle-earth.example, im5.middle-earth.example, im6.middle-earth.example)

  73. m&m

    you get an incoming connection from one of these, and you do a IN TLSA _xmpp-server.hobbiton.example

  74. Zash

    I get 6 records back, find at least one matching and then I'm happy.

  75. m&m

    if that resulted in 6 different TLSA RRs, then you'll probably be fine unless im3.middle-eath.example had to rotate keys

  76. m&m

    but if you relied on your CNAME, well things get a lot messier

  77. Zash


  78. m&m

    if you did the SRV then TLSA lookups, you'd get a whole lot closer to reality

  79. m&m

    CNAME to multiple records are messy

  80. Zash

    Is it?

  81. m&m

    that's what I've been told at least (-:

  82. m&m

    plus, you're requiring the owning domain and possibly hosting provider to make sure extra records are in sync, which increases the likelihood of failure

  83. m&m

    doing the same SRV + TLSA dance for incoming connections as outgoing minimizes the number of records operators have to publish (reducing the bugs)

  84. ralphm

    also, you can't point to CNAMEs with SRV

  85. m&m

    ralphm: you can have CNAME _xmpp-server._tcp.example.com

  86. ralphm

    I'm sure that goes for other record types, too

  87. ralphm cries

  88. Zash

    ralphm: Not relevant.

  89. m&m

    ralphm: it also turns out the vast majority of resolvers don't really care where the CNAME/DNAME records are in the chain )-:

  90. ralphm

    CNAMEs only exist because there wasn't anything better

  91. m&m

    the other thing with doing the SRV + TLSA dance on incoming is that you'll almost always have cached records for the outgoing (or almost always have cached on your outgoing before you got the incoming)

  92. simon

    Ralphm: kinda like MX too?

  93. ralphm

    simon: well, yeah, MX is just e-mail specific SRV

  94. m&m

    ralphm: kind of (-: It turns out to be more complicated than that, mixing MSA (Mail Submission Agents) and MTA (Mail Transfer Agents)

  95. simon

    I'm still watching this bug: https://bugzilla.mozilla.org/show_bug.cgi?id=14328

  96. simon

    one can have hope...

  97. ralphm

    m&m: arguably, e-mail now has different services for submission and transfer

  98. ralphm

    the fact that people still submit on 25 is, well, backwards

  99. ralphm

    (so _smtp vs. _submission)

  100. fippo

    m&m: almost always, unless you're the receiving server. but then you need to outgoing dance soon anyway ;-)

  101. m&m

    fippo: that's my point (-:

  102. m&m goes back to cooking jose

  103. Zash

    I thougt people agreed with this already..

  104. Simon

    Quick question before send out an email to the list about the <potential> DNSSEC grant: Who is it from?

  105. stpeter


  106. stpeter

    the Internet Society are the folks we'd ask to fund this

  107. Simon

    Thanks. That's what I needed.

  108. Simon

    Doing my board task from last week - email about how we get most bang-for-buck from it.

  109. stpeter

    Simon: thanks!

  110. Neustradamus

    Have you planned an article for the next Security Test Day? "March 22, 2014 - third test day"

  111. Simon

    Neustradamus: I'm working on that.

  112. Santiago26

    I'm going to write an article for Russian speaking audience. You may know, we have a pretty large community, including ejabberd developers, but still no one takes part in the test days. I'll try to fix this. Just FYI:)

  113. Simon

    Hi Santiago26. Which are the big XMPP servers in Russia?

  114. Neustradamus

    Simon: :)

  115. Santiago26

    Hi. Ya.ru (by yandex.ru search engine), qip.ru (QIP IM) — millions of users, hundreds of thousands online daily …and jabber.ru is the godfather, but it has not so many users

  116. Simon

    Santiago26. Thanks. Do you have any way to track down the admins for those servers? It would be great to shoot them a private message from either you or myself with a quick heads-up.

  117. Tobias

    also wondering why qip.ru runs a quite old version of ejabberd

  118. Santiago26

    I think that yandex.ru admins are not accessible for me (us), qip.ru have some problems with their bosses, but we are discussing this idea, and i've tried to discuss Manifesto with zinid and ermine from jabber.ru and have no answer.

  119. Santiago26

    Tobias: It is custom version of ejabberd, forked at 2.0.3, I think.

  120. Tobias

    Santiago26, ahh..i hope it's well maintained :)

  121. fippo

    http://blogs.adobe.com/standards/2014/03/18/the-business-of-standards-part-1/ -- true, true

  122. Tobias

    fippo, nice read

  123. ralphm

    Tobias, fippo, yes, but I can't see it separate from the context this is posted on

  124. ralphm

    Adobe isn't necessarily on the forefront of standards development.

  125. Tobias

    ralphm, wasn't it behind standardizing PDF at ISO?

  126. Tobias

    but yeah..that's an old one

  127. Tobias

    ralphm, what context are you referring to exactly?

  128. ralphm

    Tobias: well, mostly that it is posted by Adobe

  129. Tobias


  130. ralphm

    and also that the context is a bit missing, I suppose

  131. ralphm

    why it he talking about standards, really?

  132. Tobias

    right...that i wondered about too..i first thought i missed some WebRTC news or so :)

  133. Tobias

    i mean while HTML5 and WebRTC are taking the biggest chunk out of flash over time, are they active in the WebRTC development or mostly just HTML5?

  134. ralphm

    About that, couldn't do our weekly hangout because Hangouts is having issues. Used talky this time. Nice.

  135. ralphm

    I haven't conciously noticed Adobe being active in WebRTC, but I am not following in minute detail.