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

[Alexander Graf]

On 06.06.2012, at 01:07, Anthony Liguori wrote:

> On 06/06/2012 06:06 AM, Paul Moore wrote:
>> On Tuesday, June 05, 2012 11:51:40 PM Alexander Graf wrote:
>>> On 05.06.2012, at 23:45, Paul Moore wrote:
>>>> On Tuesday, June 05, 2012 03:08:26 AM Alexander Graf wrote:
>>>>> Which gets me to a new idea. Why not exit(1) when we detect FIPS and a
>>>>> password is set? I agree with the assessment that we should never
>>>>> silently drop features. So the best way to make sure that the user knows
>>>>> he did something stupid (enable FIPS, but require a non-FIPS compliant
>>>>> authentication method) would be to just quit, no?
>>>> 
>>>> That is basically what the patch does now.  In vnc_display_open() if it
>>>> detects that the user has supplied a VNC password it prints an error to
>>>> stderr and returns an error which causes QEMU to exit.
>>>> 
>>>> The error message displayed is shown below:
>>>> 
>>>> "VNC password auth disabled due to FIPS mode, consider using the VeNCrypt
>>>>  or SASL authentication methods as an alernative"
>>>> 
>>>> ... which seems pretty obvious to me.  If anyone would prefer something
>>>> different, let me know.
>>> 
>>> No, as long as the spelling is actually correct and not the one above,
>>> that's perfectly fine.
>> 
>> What, not a fan of my "alernative" spelling?  Fixed in the next version of 
>> the
>> patch :)
>> 
>>> I just have a habit of not reading the patches I comment on :).
>> 
>> If nothing else, it makes the discussions much more interesting :)
>> 
>>>> On Tuesday, June 05, 2012 09:23:04 AM Anthony Liguori wrote:
>>>>> I think my primary requirement is: allow a user to use vnc authentication
>>>>> even when fips mode is active by using some command line option.
>>>> 
>>>> I'll agree that FIPS mode can be a bit silly in the case of QEMU and VNC
>>>> but to be honest, that requirement above seems just as silly to me, if
>>>> not more so.  However, if making this behavior optional is what it takes
>>>> to get the patch accepted, so be it.
>>>> 
>>>> I'll start working on v4 of the patch tomorrow.
>>> 
>>> Let's just wait for Anthony to reply ...
>> 
>> Fine with me, I've got plenty else to do in the meantime and I don't think
>> this is 1.1 material anyway.
> 
> What's the actual requirement from FIPS for applications?

If I understood Roman correctly, there are 2 puzzle pieces to this. One (whose 
name I forgot) is responsible for making sure you use encryption at all, which 
authentication methods (retina scan, fingerprint, etc) are allowed and so forth.

The other one (FIPS) is basically a list of encryption algorithms that are 
deemed OK and not crackable within seconds by anyone.

Only one of the 2 doesn't help much. In combination they actually enhance 
security. This patch is only about FIPS though.


Alex