[SSHD-930] Send the client version string after receiving the version string of the server

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.0
• Fix Version/s: 2.4.0
• Assignee: Lyor Goldstein
• Reporter: Zhenliang Su
• Created: 03/Jul/19 02:44
• Updated: 08/Jun/20 13:33
• Resolved: 18/Jul/19 11:24

Description

The rfc4253 does not indicate whether the ssh client must send its own version number right after receiving the version number of the server.
I have encountered a situation where mina-sshd is used to connect to cisco's sshd service, sometimes it can be connected, sometimes not connected.
Some rules are found by capturing packets. If the client sends its own version number after receiving the version number of the server, it can be connected. If the client sends its own version number before receiving the version number of the server, then it will not be connected.
I think, a better way is to change the SshClient code to send the version number of the client right after receiving the version number of the server.

Issue Links

• is related to: SSHD-941 mina ssh client times out connecting with IOS 15.2
• is related to: SSHD-969 compatibility problem with cisco-2.0 ssh on ios-xr
• is related to: SSHD-947 Use separate configuration to control sending client session identity and KEX-INIT
• links to: GitHub Pull Request #105