I have no idea on the posted error, however the relative new password “habopen” does NOT work if you use the old call “ssh karaf@…”. This has to be changed to “ssh openhab@…”
I found a solution for “Unable to negotiate key exchange for kex algorithms”: I did not make any thoughts about the java I used, it was just the java my SuSe Leap 42.1 was installed with. In fact this is openjdk version “1.8.0_91”. But I saw some notes which said that OracleJDK should be used - so I installed the actual OracleJDK "java version “1.8.0_102”. Now the problem is gone.
Maybe this is useful for someone other facing this problem …