blog/data/2020-05-08-zoom-jami-client.txt

   1 Title: Jami as a Zoom client, a trick for password protected rooms...
   2 Tags: english, debian, sikkerhet, surveillance
   3 Date: 2020-05-08 13:30
   4
   5 <p>Half a year ago,
   6 <a href="http://people.skolelinux.org/pere/blog/Jami_Ring__finally_functioning_peer_to_peer_communication_client.html">I
   7 wrote</a> about <a href="https://jami.net/">the Jami communication
   8 client</a>, capable of peer-to-peer encrypted communication.  It
   9 handle both messages, audio and video.  It uses distributed hash
  10 tables instead of central infrastructure to connect its users to each
  11 other, which in my book is a plus.  I mentioned briefly that it could
  12 also work as a SIP client, which came in handy when the higher
  13 educational sector in Norway started to promote Zoom as its video
  14 conferencing solution.  I am reluctant to use the official Zoom client
  15 software, due to their <a href="https://zoom.us/terms">copyright
  16 license clauses</a> prohibiting users to reverse engineer (for example
  17 to check the security) and benchmark it, and thus prefer to connect to
  18 Zoom meetings with free software clients.</p>
  19
  20 <p>Jami worked OK as a SIP client to Zoom as long as there was no
  21 password set on the room.  The Jami daemon leak memory like crazy
  22 (approximately 1 GiB a minute) when I am connected to the video
  23 conference, so I had to restart the client every 7-10 minutes, which
  24 is not a great.  I tried to get other SIP Linux clients to work
  25 without success, so I decided I would have to live with this wart
  26 until someone managed to fix the leak in the dring code base.  But
  27 another problem showed up once the rooms were password protected.  I
  28 could not get my dial tone signaling through from Jami to Zoom, and
  29 dial tone signaling is used to enter the password when connecting to
  30 Zoom.  I tried a lot of different permutations with my Jami and
  31 Asterisk setup to try to figure out why the signaling did not get
  32 through, only to finally discover that the fundamental problem seem to
  33 be that Zoom is simply not able to receive dial tone signaling when
  34 connecting via SIP.  There seem to be nothing wrong with the Jami and
  35 Asterisk end, it is simply broken in the Zoom end.  I got help from a
  36 very skilled VoIP engineer figuring out this last part.  And being a
  37 very skilled engineer, he was also able to locate a solution for me.
  38 Or to be exact, a workaround that solve my initial problem of
  39 connecting to password protected Zoom rooms using Jami.</p>
  40
  41 <p>So, how do you do this, I am sure you are wondering by now.  The
  42 trick is already
  43 <a href="https://support.zoom.us/hc/en-us/articles/202405539-H-323-SIP-Room-Connector-Dial-Strings#sip">documented
  44 from Zoom</a>, and it is to modify the SIP address to include the room
  45 password.  What is most surprising about this is that the
  46 automatically generated email from Zoom with instructions on how to
  47 connect via SIP do not mention this.  The SIP address to use normally
  48 consist of the room ID (a number), an @ character and the IP address
  49 of the Zoom SIP gateway.  But Zoom understand a lot more than just the
  50 room ID in front of the at sign.  The format is "<tt>[Meeting
  51 ID].[Password].[Layout].[Host Key]</tt>", and you can hear see how you
  52 can both enter password, control the layout (full screen, active
  53 presence and gallery) and specify the host key to start the meeting.
  54 The full SIP address entered into Jami to provide the password will
  55 then look like this (all using made up numbers):</p>
  56
  57 <p><blockquote>
  58 <tt>sip:657837644.522827@192.168.169.170</tt>
  59 </blockquote></p>
  60
  61 <p>Now if only jami would reduce its memory usage, I could even
  62 recommend this setup to others. :)</p>
  63
  64 <p>As usual, if you use Bitcoin and want to show your support of my
  65 activities, please send Bitcoin donations to my address
  66 <b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>