Connection issue in OpenBMC image

[Patrick Williams]

Hello Jayashree,

I saw an output `ssh -v` from you earlier, but there really wasn't any
useful information there.  It looked like the connection was being made
and keys were exchanged and then the log just stopped abruptly.  This
tells me it likely isn't a networking issue but an issue in the
handshake between the ssh-client (your computer) and ssh-server
(dropbear).  You can continue to add '-v' parameters up to `ssh -vvv`
and you'll get increasingly more information.

Joseph Reynolds recently posted a reminder about dropbear disabling weak
ciphers[1].  Is it possible that your client is using an old cipher?

On Wed, Sep 16, 2020 at 11:35:28AM +0000, Jayashree D wrote:
> root at tiogapass:~# journalctl | grep drop
...
> Jan 01 00:15:28 tiogapass systemd[1]: dropbear at 0-10.0.128.108:22-10.0.0.1:51810.service: Succeeded.
> Jan 01 00:15:44 tiogapass dropbear[2753]: Child connection from ::ffff:10.0.0.1:51944
> Jan 01 00:15:50 tiogapass dropbear[2753]: PAM password auth succeeded for 'root' from ::ffff:10.0.0.1:51944

This looks like a valid connection was established.

> 15.09.2020, 16:12, "Jayashree D" <jayashree-d at hcl.com<mailto:jayashree-d at hcl.com>>:
> 
> OpenSSH_7.4p1, OpenSSL 1.0.2k-fips  26 Jan 2017
> debug1: Reading configuration data /etc/ssh/ssh_config
> debug1: /etc/ssh/ssh_config line 58: Applying options for *
> debug1: Connecting to 10.0.128.108 [10.0.128.108] port 22.
> debug1: Connection established.
> debug1: permanently_set_uid: 0/0
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_rsa type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_rsa-cert type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_dsa type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_dsa-cert type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_ecdsa type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_ecdsa-cert type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_ed25519 type -1
> debug1: key_load_public: No such file or directory
> debug1: identity file /root/.ssh/id_ed25519-cert type -1
> debug1: Enabling compatibility mode for protocol 2.0
> debug1: Local version string SSH-2.0-OpenSSH_7.4

This is the log that also looks like a good connection.  Identity files
were attempted to be exchanged.  Version strings were exchanged.  And
then the log just abruptly stops.  Was the connection dropped?  Is it
hung?

1. https://lists.ozlabs.org/pipermail/openbmc/2020-September/023071.html

-- 
Patrick Williams
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/openbmc/attachments/20200917/c9567e4f/attachment.sig>