Comment 53 for bug 708493

My cases of this bug (though it seems like there are different ones with similar symptoms) happen each time I reset a 14.04 VM to an older state from a hard shutdown. Localhost ssh connections fail as well with same output.

Workaround for me is regenerating the host keys (sudo rm /etc/ssh/host_* && sudo ssh-keygen -A) each time I revert the VM. Changing the cipher/kex does not seem to change the outcome.

I wonder if some junk gets written to the keys in bad shutdowns. I'll see If I can debug the output of the sshd.

Client log below:
$ ssh root@redacted -vvvv
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.56.101 [192.168.56.101] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "/home/sg/.ssh/id_rsa" as a RSA1 public key
debug1: identity file /home/sg/.ssh/id_rsa type 1
debug1: identity file /home/sg/.ssh/id_rsa-cert type -1
debug1: identity file /home/sg/.ssh/id_dsa type -1
debug1: identity file /home/sg/.ssh/id_dsa-cert type -1
debug1: identity file /home/sg/.ssh/id_ecdsa type -1
debug1: identity file /home/sg/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/sg/.ssh/id_ed25519 type -1
debug1: identity file /home/sg/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6p1 Ubuntu-2ubuntu1
debug1: match: OpenSSH_6.6p1 Ubuntu-2ubuntu1 pat OpenSSH_6.5*,OpenSSH_6.6* compat 0x14000000
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "192.168.56.101" from file "/home/sg/.ssh/known_hosts"
debug3: load_hostkeys: found key type ECDSA in file /home/sg/.ssh/known_hosts:87
debug3: load_hostkeys: loaded 1 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: <email address hidden>,<email address hidden>,<email address hidden>,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug2: compat_kex_proposal: original KEX proposal: <email address hidden>,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: Compat: skipping algorithm "<email address hidden>"
debug2: compat_kex_proposal: compat KEX proposal: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug1: SSH2_MSG_KEXINIT sent
Read from socket failed: Connection reset by peer