[SSHD-840] Unknown commands cause IllegalStateException instead of being correctly handled

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.14.0, 1.6.0, 2.0.0
• Fix Version/s: 2.1.0
• Assignee: Unassigned
• Reporter: Robert Varga
• Created: 10/Aug/18 20:20
• Updated: 08/Jun/20 13:35
• Resolved: 11/Aug/18 08:12

Description

As https://github.com/CESNET/libnetconf2/issues/68 shows, MINA SSHD has a different behavior than OpenSSH when faced unknowns – in this case coming from a buggy server.

While OpenSSH was able to establish a session, OpenDaylight (using SSHD 1.6.0) was not – throwing an IllegalStateException.

Rather than throwing an exception, send an SSH_MSG_UNIMPLEMENTED as specified by https://tools.ietf.org/html/rfc4253#section-11.4 .

Issue Links

• links to: GitHub Pull Request #66