Re: Using ncat as a SSH proxycommand to connect trough proxy

[David Fifield <david () bamsoftware com>]

On Mon, Jul 12, 2010 at 04:37:41PM +0100, Nuno Gonçalves wrote:
> I believe I found the cause of the problem.
>
> Machine at 192.168.137.3 have a tinyproxy running at port 8888
> Machine at 192.168.137.5 have ncat listening at port 443 (sudo ncat -l 443)
>
> I tested 3 commands from another machine:
>
> nc -X connect -x 192.168.137.3:8888 192.168.137.5 443
> ncat 192.168.137.5 443
> ncat --proxy 192.168.137.3:8888 192.168.137.5 443
>
>
> All BUT THE LAST, worked as expected.
> With the last command, lines are only displayed at the remote
> computer(192.168.137.5) in multiples of two. I.e, the first text line
> is only displayed after the second is finished and return is pressed.
>
> nuno@ground2:~$ nc -X connect -x 192.168.137.3:8888 192.168.137.5 443
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> 8
> ^C
> nuno@ground2:~$ ncat --proxy 192.168.137.3:8888 192.168.137.5 443
> HTTP/1.0 200 Connection established
> Proxy-agent: tinyproxy/1.8.1
>
> 1 ******NOT DISPLAYED on remote host after return*******
> 2 ******after return this and previous line are displayed on remote host********
> 3 ******NOT DISPLAYED on remote host after return*******
> 4 ******after return this and previous line are displayed on remote host********
> 5 ******NOT DISPLAYED on remote host after return*******
> 6 ******after return this and previous line are displayed on remote host********
> 7 ******NOT DISPLAYED on remote host after return*******
> 8 ******after return this and previous line are displayed on remote host********
> ^C
> nuno@ground2:~$ ncat 192.168.137.5 443
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> 8
> ^C
> nuno@ground2:~$

Thanks for posting this. For some reason, this behavior of printing
lines in pairs is familiar to me, but I can't remember the exact reason.
It may have been a bug I worked on.

What version of Ncat do you use? Is it the same with the latest
5.30BETA1?

David Fifield
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