Public bug reported: SSH was working fine for years, until I upgraded to Ubuntu 16.04. When I upgraded to Ubuntu 16.04, the openssh-server stopped accepting connections from Ubuntu 14.04 LTS clients, with the following error:
---- Disconnecting: Hash's MIC didn't verify ---- The error above shows up on the client side. In the server logs, I see the following: ---- Mar 17 10:01:49 falcon polkitd(authority=local): Unregistered Authentication Agent for unix-process:125110:294284 (system bus name :1.133, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus) Mar 17 10:02:06 falcon sshd[125126]: error: Received disconnect from MY.IP.ADDRESS.HERE port PORTNUMBER:2: Hash's MIC didn't verify [preauth] Mar 17 10:02:06 falcon sshd[125126]: Disconnected from MY.IP.ADDRESS.HERE port PORTNUMBER [preauth] ---- I am using GSSAPI Key Exchange, and GSSAPI authentication. So I am not using public keys or passwords or anything like that; everything is entirely Kerberos 5. The problem, also, is only one-way. In other words, if I upgrade the server to Ubuntu 16.04, it stops accepting connections from 14.04 clients, but if I go the other direction and upgrade the client to Ubuntu 16.04, then it can still authenticate successfully to an Ubuntu 14.04 machine. I am more than happy to help debug this, so please let me know what you suggest and I'll do whatever I can to help. Thanks, Brian ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: openssh-server 1:7.2p2-1 ProcVersionSignature: Ubuntu 4.4.0-13.29-generic 4.4.5 Uname: Linux 4.4.0-13-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 Date: Thu Mar 17 10:02:45 2016 InstallationDate: Installed on 2015-05-04 (317 days ago) InstallationMedia: Ubuntu-Server 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: openssh UpgradeStatus: Upgraded to xenial on 2016-03-16 (0 days ago) ** Affects: openssh (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug xenial -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1558576 Title: OpenSSH Error "Disconnecting: Hash's MIC didn't verify" after upgrading to Ubuntu 16.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1558576/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs