Re: [Qemu-devel] [PATCH v2] vnc: disable VNC password authentication (security type 2) when in FIPS mode

[Alexander Graf]

On 03.05.2012, at 11:01, Alexander Graf wrote:

> 
> On 03.05.2012, at 10:57, Daniel P. Berrange wrote:
> 
>> On Thu, May 03, 2012 at 10:51:15AM +0200, Alexander Graf wrote:
>>> 
>>> On 03.05.2012, at 10:29, Daniel P. Berrange wrote:
>>> 
>>>> On Wed, May 02, 2012 at 03:32:56PM -0400, Paul Moore wrote:
>>>>> FIPS 140-2 requires disabling certain ciphers, including DES, which is 
>>>>> used
>>>>> by VNC to obscure passwords when they are sent over the network.  The
>>>>> solution for FIPS users is to disable the use of VNC password auth when 
>>>>> the
>>>>> host system is operating in FIPS mode.
>>> 
>>> So that means "no password" is more secure according to FIPS than
>>> "DES encrypted password"?
>> 
>> No, FIPS is not making statements about the choice of auth methods.
>> FIPS is concerned with what encryption algorithms an application uses.
>> The requirements about whether authentication is required & what sort,
>> is upto other specifications (eg Common Criteria) to decide.
> 
> Hrm, so short-term this fixes things. But long-term, I think the better 
> solution would be to implement the tight security model and use a real cipher:
> 
>  http://www.tigervnc.org/cgi-bin/rfbproto#tight-security-type

In fact, there were even patches to get AES encryption into the tight auth:

  http://old.nabble.com/adding-AES-encryption-to-TightVNC-td14235009.html

Not sure what became of that though :).


Alex