The most likely cause would be that Twisted doesn't handle firstPacketFollows properly, which seems to be the case looking at https://github.com/twisted/twisted/blob/trunk/src/twisted/conch/ssh/transport.py#L869 Can you add that to the Twisted bug report?
Cheers, Matt > On Tue 5/6/2018, at 1:12 am, Michael Ducharme <mducha...@gobcn.ca> wrote: > > I recently upgraded our Zenoss system to 6.1.2 which includes a newer version > of Twisted python framework. This new version of Twisted no longer connects > to dropbear on our Ubiquiti radios. > > When Twisted tries to connect, the connection is lost while authenticating, > and dropbear logs the error: > > Jun 4 10:29:02 dropbear[28183]: Child connection from 206.red.ac.ted:60338 > Jun 4 10:29:04 dropbear[28183]: Exit before auth: Integrity error > Jun 4 10:29:07 dropbear[28195]: Child connection from 206.red.ac.ted:60342 > Jun 4 10:29:09 dropbear[28195]: Exit before auth: Integrity error > > I've been able to reproduce this issue with the latest release of twisted, > 18.4.0, which I installed on another server by itself. This issue did not > happen on the 2 or 3 year old version of Zenoss we were upgrading from, which > presumably used an older version of Twisted. > > I submitted a bug report with twisted > (https://twistedmatrix.com/trac/ticket/9464 > <https://twistedmatrix.com/trac/ticket/9464>) but thought I would ask here on > the off chance that it is due to a dropbear bug.
