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

[Petr Vobornik]

On 01/13/2017 03:49 PM, Rob Crittenden wrote:
> Tomas Krizek wrote:
>> On 01/12/2017 04:17 PM, Rob Crittenden wrote:
>>> Tomas Krizek wrote:
>>>> 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.
>>>>
>>> You could set some value in the replicated tree on FIPS status and write
>>> a 389-ds plugin to refuse to start if the environment doesn't match.
>>> Given this is started first it should cause a cascade of failures so no
>>> services are available.
>>>
>>> rob
>> Based on an offline discussion, we might just omit this feature
>> entirely. Our goal is to enable FreeIPA installation of FIPS configured
>> systems. It should be up to the customer to make sure other FIPS
>> requirements are met, i.e. all servers are configured to use FIPS.
>>
> 
> Up to you but this is bound to be an RFE and seems like quite a weakness
> to me.
> 
> You'll want to be sure to enforce that any additional masters get FIPS
> by default if the initial master has it. In other words, they shouldn't
> need to remember to pass an option, it should be automatic.
> 
> rob
> 

+1 to Rob.

We could operate between the two extremes:
  * Extreme 1: Ensuring that FIPS will remain enabled on all existing
replica.
  * Extreme 2: Do not validate anything

I.e. we could only:
  * Note in LDAP that first server was installed with FIPS
  * Check it at install time
        - prevent from installation of non-FIPS
        - prevent from installation of FIPS replica in non-FIPS topology

It won't be bullet proof but it will check major mistakes which the
admin can do by accident.

-- 
Petr Vobornik