[Freeipa-devel] [DESIGN] FreeIPA on FIPS + NSS question

[Tomas Krizek]

On 12/19/2016 04:41 PM, Standa Laznicka wrote:
> On 12/19/2016 03:07 PM, John Dennis wrote:
>> On 12/19/2016 03:12 AM, Standa Laznicka wrote:
>>> On 12/16/2016 03:23 PM, Rob Crittenden wrote:
>>>> Standa Laznicka wrote:
>>>>> Hello,
>>>>>
>>>>> I started a design page for FreeIPA on FIPS-enabled systems:
>>>>> https://www.freeipa.org/page/V4/FreeIPA-on-FIPS
>>>>>
>>>>> Me and Tomáš are still investigating what of all things will need to
>>>>> change in order to have FreeIPA on FIPS-enabled RHEL. So far I
>>>>> managed
>>>>> to install and run patched FreeIPA server and client and connect them
>>>>> together.
>>>>>
>>>>> There are some issues with NSS when trying to create an HTTPS request
>>>>> (apparently, NSS requires an NSS database password to set up an SSL
>>>>> connection). I am actually thinking of removing NSSConnection from
>>>>> the
>>>>> client altogether.
>>>> Can you expand on this a bit? NSS should only need a pin when it needs
>>>> access to a private key. What connection(s) are you talking about, and
>>>> what would you replace NSSConnection with?
>>>>
>>>> rob
>>>
>>> Hello Rob,
>>>
>>> Thank you for this excellent question, in order to cut the email
>>> short I
>>> seem to have omitted quite a few information.
>>>
>>> One of the very first problems I had with FreeIPA with FIPS was that
>>> NSS
>>> was always asking for password/pin. I was discussing this with the NSS
>>> guys on their IRC chat last week and it turns out that NSS tries to
>>> create a private key every time you want to use it as a backend for an
>>> SSL connection on FIPS. I still don't think this is quite right so I
>>> may
>>> open a bugzilla for that.
>>
>> I don't understand, I thought the case you were having problems with
>> was the FreeIPA client, not the server. I assume when you use the
>> term "backend" you mean server, and yes when NSS is in server mode it
>> will access to keys. So isn't the problem NSS is not being
>> initialized correctly so that it recognizes it is in client mode and
>> not server mode?
>>
> What I meant was "a client backend for an SSL connection" - we're
> using NSS implementation of SSL (via python-nss) for HTTPS connections
> from client to server during which we're getting a CA cert from an NSS
> database but this eventually leads to a password prompt.
>>>
>>> Anyway, the guys suggested me that we could try to create the database
>>> with an empty password and everything will work. I don't quite like
>>> that, too, but it's at least something if you don't want the `ipa`
>>> command to always bug you for password you have no way knowing if
>>> you're
>>> just a regular user.
>>>
>>> What I think would be a better way to go is to use
>>> httplib.HTTPSConnection. We have the needed certificates in
>>> /etc/ipa/ca.crt anyway so why not use them instead. We had a discussion
>>> with Honza this morning and it seems that with this approach we may get
>>> rid of the NSSConnection class altogether (although I still need to
>>> check a few spots) and start the process of moving away from NSS which
>>> was discussed some year ago in an internal mailing list (for some
>>> reason).
>>>
>>> Will be happy to hear thoughts on this,
>>> Standa
>>
>> I'm not a big fan of NSS, it has it's issues. As the author of the
>> Python binding I'm quite aware of all the nasty behaviors NSS has and
>> needs to be worked around. I wouldn't be sad to see it go but OpenSSL
>> has it's own issues too. If you remove NSS you're also removing the
>> option to support smart cards, HSM's etc. Perhaps before removing
>> functionality it would be good to assess what the requirements are.
>>
> I'm sorry I generalized too much, the original topic was moving away
> from python-nss (of which I am even more sorry as you're the author).
>
We could use some ideas on how to handle replica installations in FIPS.

We might use some flag in LDAP to indicate that a topology is
FIPS-enabled. It seems like a good idea to force all servers in
FIPS-enabled topology to also be FIPS-enabled. At the start of replica
installation, a check could be performed to verify the FIPS topology
status is the same as the current system's FIPS status. However, this
proposal has a flaw. It is possible to simply install a FIPS-enabled
replica and then turn FIPS off. This would result in non-FIPS systems
being part of a FIPS-enabled topology.

So we have a couple questions:

Does it make sense to require all the servers in the topology to be
either FIPS-enabled or FIPS-disabled?
What would be a good approach to achieve this? Simply checking during
installation does not guarantee that FIPS will stay turned on.

-- 
Tomas Krizek