Re: [Qemu-devel] QEMU: VNC

[Fabrice Bellard <fabrice@bellard.org>]

Daniel P. Berrange wrote:
> On Mon, Feb 19, 2007 at 12:41:53PM -0500, Christopher Olsen wrote:
>> On Monday 19 February 2007 12:30, Daniel P. Berrange wrote:
>>> On Mon, Feb 19, 2007 at 03:11:15AM +0100, Johannes Schindelin wrote:
>>>> Hi,
>>>>
>>>> On Sun, 18 Feb 2007, Anthony Liguori wrote:
>>>>> Christopher Olsen wrote:
>>>>>> Sorry I'll attempt to use the preferred patching method in the
>>>>>> future..
>>>>>>
>>>>>> Secure vnc auth method the default built in method from
>>>>> We can't take a password from a command line.  Supporting VNC auth is
>>>>> super easy otherwise.  I really think we need to have a config file
>>>>> before we can do VNC passwords.
>>>> No, you should not do VNC passwords. The default VNC password exchange is
>>>> insecure and you should not lure users into believing in that false
>>>> security.
>>> Sure it is insecure over an unencrypted network channel, but if you are
>>> tunnelling the VNC connection over SSH, or have restricted it to only
>>> bind to 127.0.0.1  then AFAIK it is just fine. So supporting VNC password
>>> auth would allow users on a shared machine to secure the console from
>>> other unprivileged users on the same box. Definitely useful over the
>>> current situation where there's no way to secure even the local-only
>>> case. For a serious general purpose authentication I'd like to see the
>>> TLS protocol extension for VNC (as implemented in VeNCrypt) supported
>>> allowing both secure auth & wire encryption.
>>>
>>> Dan.
>> I've Checked out the VeNCrypt.. Looks a little win32 oriented... 
> 
> Guess you missed the 'unix' directory - I have compiled both server & client
> of VeNCrypt on Linux no trouble.
> 
>> I'm gathering the problem here is that VNC is spinning off in many 
>> directions...  So any implementation on the QEMU side will of course marry it 
>> to a particular VNC branch or I had an alternative idea..
> 
> I think the crux of the matter is that RealVNC sell a commercial version
> of VNC which offers real encryption. So I'm guessing that's why they've
> never merged any of the patches to do TLS encryption in the open source
> codebase. All the patches for VNC + TLS i've seen posted are iterations
> of each other - VeNCrypt is the most complete implenentation of any of
> them, so the one I'd go for out of the all the choices. 

On the technical side, adding OpenSSL support in the current VNC 
implementation is QEMU seems easy (OpenSSL has a non blocking API which 
can be used with the current callback API).

Fabrice.