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Attempt to open SSH shell produces "invalid server's version string" [message #12041]

Thu, 05 July 2007 22:42

Thomas D. Johnson

Messages: 72
Registered: July 2009

Member

Using RSE 2.0 with Eclipse 3.3.0 on Windows, when I attempt to open a
shell on one machine with SSH, it succeeds, but with another machine,
the attempt fails, and generates the following error log/traceback:

com.jcraft.jsch.JSchException: invalid server's version string
at com.jcraft.jsch.Session.connect(Session.java:253)
at
org.eclipse.rse.internal.connectorservice.ssh.SshConnectorSe rvice.internalConnect(SshConnectorService.java:121)
at
org.eclipse.rse.core.subsystems.AbstractConnectorService.con nect(AbstractConnectorService.java:412)
at
org.eclipse.rse.internal.shells.ui.actions.SystemCommandActi on.connect(SystemCommandAction.java:611)
at
org.eclipse.rse.internal.shells.ui.actions.SystemCommandActi on.access$0(SystemCommandAction.java:604)
at
org.eclipse.rse.internal.shells.ui.actions.SystemCommandActi on$RunShellJob.run(SystemCommandAction.java:113)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

What puzzles me is that on the (server) machine where I succeed, I see:

v > ssh -V
OpenSSH_3.8p1, SSH protocols 1.5/2.0, OpenSSL 0.9.7g 11 Apr 2005

but on the (server) machine where I fail, I see:

j > ssh -V
OpenSSH_3.8p1, SSH protocols 1.5/2.0, OpenSSL 0.9.7g 11 Apr 2005

Are there some additional traces that I can enable so I can actually see
the "invalid server's version string"?

By the way, I can use SSH (on the native command line) to reach "j" from
"v", and I can reach both "j" and "v" using PuTTY from the Windows
machine that I'm using to run Eclipse 3.3.0 and RSE 2.0

Thanks in advance for any hints,

Tom Johnson

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Re: Attempt to open SSH shell produces "invalid server's version string" [message #12055 is a reply to message #12041]

Mon, 09 July 2007 14:23

Martin Oberhuber

Messages: 1007
Registered: July 2009

Senior Member

Hi Tom,

by running ssh -V you just check the ssh client version on your
machines. But what we'd like to know is the sshd server version. You can
check this by logging in to the remote hosts with verbose logging enabled:

482 mober@parser~>ssh -v osgiliath
OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003
[...]
debug1: Remote protocol version 1.99, remote software version OpenSSH_4.4
debug1: match: OpenSSH_4.4 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_3.9p1

As you see, on my local machine I have OpenSSH_3.9p1 but on the remote
machine I have OpenSSH_4.4. Try this on you two machines and look at the
differences. Another option to try on your servers is
ps -ef | grep sshd
and you'll see where the sshd is actually running from. If still unclear
after these checks, you may want to contact the Jsch-users mailing list
at https://lists.sourceforge.net/lists/listinfo/jsch-users

Thanks,
--
Martin Oberhuber
Target Management Project Lead, DSDP PMC Member
http://www.eclipse.org/dsdp/tm

Tom Johnson wrote:
> Using RSE 2.0 with Eclipse 3.3.0 on Windows, when I attempt to open a
> shell on one machine with SSH, it succeeds, but with another machine,
> the attempt fails, and generates the following error log/traceback:
>
> com.jcraft.jsch.JSchException: invalid server's version string
> at com.jcraft.jsch.Session.connect(Session.java:253)
> at
> org.eclipse.rse.internal.connectorservice.ssh.SshConnectorSe rvice.internalConnect(SshConnectorService.java:121)
>
> at
> org.eclipse.rse.core.subsystems.AbstractConnectorService.con nect(AbstractConnectorService.java:412)
>
> at
> org.eclipse.rse.internal.shells.ui.actions.SystemCommandActi on.connect(SystemCommandAction.java:611)
>
> at
> org.eclipse.rse.internal.shells.ui.actions.SystemCommandActi on.access$0(SystemCommandAction.java:604)
>
> at
> org.eclipse.rse.internal.shells.ui.actions.SystemCommandActi on$RunShellJob.run(SystemCommandAction.java:113)
>
> at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
>
> What puzzles me is that on the (server) machine where I succeed, I see:
>
> v > ssh -V
> OpenSSH_3.8p1, SSH protocols 1.5/2.0, OpenSSL 0.9.7g 11 Apr 2005
>
> but on the (server) machine where I fail, I see:
>
> j > ssh -V
> OpenSSH_3.8p1, SSH protocols 1.5/2.0, OpenSSL 0.9.7g 11 Apr 2005
>
> Are there some additional traces that I can enable so I can actually see
> the "invalid server's version string"?
>
> By the way, I can use SSH (on the native command line) to reach "j" from
> "v", and I can reach both "j" and "v" using PuTTY from the Windows
> machine that I'm using to run Eclipse 3.3.0 and RSE 2.0
>
> Thanks in advance for any hints,
>
> Tom Johnson
>

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Re: Attempt to open SSH shell produces "invalid server's version string" [message #12079 is a reply to message #12055]

Mon, 09 July 2007 15:33

Thomas D. Johnson

Messages: 72
Registered: July 2009

Member

Martin Oberhuber wrote:
> Hi Tom,
>
> by running ssh -V you just check the ssh client version on your
> machines. But what we'd like to know is the sshd server version. You can
> check this by logging in to the remote hosts with verbose logging enabled:

<snip>

> As you see, on my local machine I have OpenSSH_3.9p1 but on the remote
> machine I have OpenSSH_4.4. Try this on you two machines and look at the
> differences. Another option to try on your servers is
> ps -ef | grep sshd
> and you'll see where the sshd is actually running from. If still unclear
> after these checks, you may want to contact the Jsch-users mailing list
> at https://lists.sourceforge.net/lists/listinfo/jsch-users

Sorry about being so sketchy with my description but I had already
looked at the logging:

(host names and IPs sanitized)

Event Log: Writing new session log (SSH packets mode) to file: putty.log
Event Log: Looking up host "j.d.r.c"
Event Log: Connecting to 192.168.0.11 port 22
Event Log: Server version: SSH-1.99-OpenSSH_3.8p1
Event Log: We claim version: SSH-2.0-PuTTY-Release-0.55
Event Log: Using SSH protocol version 2

Event Log: Writing new session log (SSH packets mode) to file: putty.log
Event Log: Looking up host "v"
Event Log: Connecting to 192.168.1.12 port 22
Event Log: Server version: SSH-1.99-OpenSSH_3.8p1
Event Log: We claim version: SSH-2.0-PuTTY-Release-0.55
Event Log: Using SSH protocol version 2

Both hosts seem to be claiming the same server version.

Note that one is on a different internal subnet, so I had to qualify the
domain name.

I'll probably try to reduce this further and trace into the Jsch source
code to find out what is going on.

Thanks for the advice on the Jsch group, I'll check that also.

Tom J.

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