RE: UltraVNC Repeater over port 80 (http like)

For feature requests and bug reports RC15 RC16. Please use the forum at http://forum.ultravnc.net/

The purpose of using UltraVNC ver port 80 is to be able to support my
customers with sophisticated filewalls, by using "HTTP" over port 80
(which is always open).

Sophisticated firewalls and routers can analyze the TCP/IP packet and
investigate the destination port. I guess on situations like that, the
firewall "see" that the transmission is directed to destination port 80
but the contents is not the HTTP protocol - thus the package is
quarantined or discarded.

As I see the problem, there are two ways to try and solve it (and both
require development...):

1. Add support to real HTTP protocol over port 80 or 443 (SSL) to
communicate between the UltraVNC SC (installed with a single click on
the customer's machine) and the UltraVNC Repeater service (installed on
my server with static IP).

2. Add some kind of HTTP signature to the transmitted packets between
the WinVNC SC Server and the UltraVNC Repeater service,  making the
firewall think that the transmition is really a legitimate HTTP packet. 

Following is the HTTP specifications:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
Thread about fooling the firewall:
http://cert.uni-stuttgart.de/archive/bugtraq/1998/10/msg00044.html
Greate sniffer program to analyse packets:
http://www.snapfiles.com/download/dlipsniffer.html

Nir Kornfeld
CTO
Odcanit Ltd.
Email:[email protected]
Mobile: +972 (54) 4614228
Web: www.od.co.il



 

> -----Original Message-----
> From: [email protected] 
> [mailto:[email protected]] On Behalf 
> Of Jason Passow
> Sent: Wednesday, March 30, 2005 3:34 PM
> To: [email protected]
> Subject: Re: [Ultravnc-list] UltraVNC Repeater over port 80 
> (http like)
> 
> For feature requests and bug reports RC15 RC16. Please use 
> the forum at http://forum.ultravnc.net/
> 
> Nope.  There is really nothing you can do with this using the single 
> click version.  If you were to set up vnc on their computers using an 
> ssl wrapper (search the forum) then you may be able to get through 
> firewalls using ssl.  Afaik there is no way to use the sc 
> version with 
> an ssl implementation. 
> 
> Nir Kornfeld wrote:
> 
> >For feature requests and bug reports RC15 RC16. Please use 
> the forum at http://forum.ultravnc.net/
> >
> >Hello,
> > 
> >I'm trying to use UltraVNC with the Repeater server over port 80. The
> >configuration I used is: 
> >* Mode II enabled
> >* Accept on port 5901 
> >* Listen on port 80
> >
> >I reconfigured my router (with static IP) to forward all port 80
> >requests from the internet to the machine hosting the 
> repeater (I'm not
> >using any web server on that IP address), and setup the OneClick VNC
> >Server (SC version that can be built using the site) to access the
> >repeater at my IP address over port 80, with some kind of IDs in it.
> >
> >So far so good! It works like a charm and bypasses a lot of 
> firewalls on
> >my client machines.
> >BUT, with certain firewalls that actually inspect the contents of the
> >HTTP package (post 80 is used for HTTP) I can not get 
> through. I guess
> >the repeater and the UltraVNC viewer/servers does not actually send a
> >"normal" http request - resulting in disgarded package by 
> the firewalls.
> >
> >Any ideas?
> >
> >Thanks!
> >Nir Kornfeld
> >CTO
> >Odcanit Ltd.
> >
> >
> >
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> >
> 
> -- 
> Jason Passow
> Mississippi Welders Supply
> [email protected]
> ph: (507) 454-5231
> fax: (507) 454-8104
> 
> 
> 
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