EXT :Re: Adding enterprise capability - an includeConfig directive for audit.rules?

[Boyce, Kevin P. (AS)]

I think this is a worthwhile effort. You might have a look at how the 
Canonical folks do things like this, in particular the update-grub 
script, uses a bunch of files in a ".d" directory and build the actual 
config file (/boot/grub/grub.cfg).

On another note I will take the opportunity to introduce some feature 
creep.  At one point I had written a cron script for my environment that 
rebuilt the snare.conf file every week and restart the audit daemon.  
Additionally, this script would take in a list of the names of packages 
you were interested in auditing. For example passwd-0.77-4.el6_2.2 (by 
name passwd) and wireshark-1.2.15-2.el6_2.1 (by name wireshark).  The 
script would then query the package manager to see if it was installed.  
If it is, it would list all files provided by the package, filter out 
the executables from the libraries from the config files from the 
documentation.  Then it would generate a rule for each type of file.  
Config files and libraries were added to the rule list looking for 
failure to write or change the file.  Executables would be added to the 
rule list looking for success or failure to execute the file.

The reason for all of this was that in a large environment with many 
users with root privilege you don't always know what software would be 
installed on a system.  If at some point someone had added wireshark 
(via rpm) to a system you know it will get audited after that.  The 
other benefit is that it make the generation of rules sort of agnostic 
with regard to the architecture of the system; the package manager 
handles telling you the location of the files you are interested in for 
any given package.

I don't know if this sort of thing has value to anyone else, but I 
thought I'd throw it out there as a suggestion anyway.

Kevin

On 04/03/2013 07:42 AM, Steve Grubb wrote:
> On Wednesday, April 03, 2013 09:37:23 PM Burn Alting wrote:
>> Thanks for these comments Steve.
>>
>> I will come up with a solution based on option one. Perhaps along the
>> line of a script (to suit both auditd.init and auditd.service) that
>> 	a. Looks for a known directory, say /etc/audit/auditd.rules
> I was thinking something like /etc/audit/rules.d/  or something ending in '.d'
> under the audit directory so that selinux labels are the same.
>
>> 	b. If not empty, it will concatenate all files of the form xxx.rules,
>> stripping comments and blank lines. The xxx will determine sort.
> Sure. I think some people prefix numbers to the name to help guide the ordering
> like udev.
>
>
>> 	c. If the resultant file is not empty, it can
>> replace /etc/audit/audit.rules.
> Sure. The question is should it do that always on start? What about reload?
> Should it replace it only if its changed? (writing to /etc/audit/audit.rules
> is an auditable event...we probably want to minimize that.)
>
> Thanks,
> -Steve
>
>
>> On Tue, 2013-04-02 at 14:03 -0400, Steve Grubb wrote:
>>> On Wednesday, March 27, 2013 08:38:07 PM Burn Alting wrote:
>>>> All,
>>>>
>>>> Has anyone considered allowing an includeConfig statement for
>>>> audit.rules (or auditd.conf if need be)?
>>>>
>>>> The action would be to, at that point in the parse (or the end of the
>>>> file, if auditd.conf holds the directive), open the nominated directory
>>>> and any files within, and parse them.
>>>>
>>>> The idea is to allow for localization of audit. At an enterprise level
>>>> one would deploy the common, corporate set of rules
>>>> in /etc/audit/audit.rules. Should a local system need additional rules
>>>> such as tailored file watches, workstation or capability specific
>>>> monitoring, these could appear in files in the includeConfig directory.
>>>> That way, distribution mechanisms such as puppet, rpm satellite server,
>>>> apt repositories, etc can maintain the corporate set of rules without
>>>> changing localized configurations on updates.
>>> Sorry for the late reply, been out a bit and am trying to catch up on
>>> email.
>>>
>>> Well...have you heard of SCAP? Its a whole framework for assessing the
>>> security posture of a system based on open standards to prevent vendor
>>> lockin. It can also allow for continuous monitoring, boot up attestation
>>> via TNC, patch management, and we are working on some basic level of
>>> remediation.
>>>
>>> More info about SCAP can be found at these sites:
>>> http://scap.nist.gov/
>>> http://makingsecuritymeasurable.mitre.org/
>>>
>>> We have an openscap project
>>> http://www.open-scap.org/
>>>
>>> There is an SCAP Security Guide which will become a STIG:
>>> https://fedorahosted.org/scap-security-guide/
>>>
>>> And its being integrated into various systems management tools. The reason
>>> I mention this is that currently there is no way that you could evaluate
>>> audit rules from an SCAP based tool with a decomposed set of audit rules.
>>> The OVAL interpreter is the limitation. It does not have any method of
>>> being able to smartly assemble the collective audit rules to assess if
>>> the system is in compliance. In the audit system, the order of rules
>>> matters and that is one of the problems OVAL would have to be specified
>>> and coded to understand.
>>>
>>> So with SCAP in mind, the options seem to be:
>>>
>>> 1) Build a rule compiler that assembles a master audit.rules file from
>>> sources but only 1 set of rules are loaded.
>>> 2) Request a change in OVAL 5.11 to support this kind of setup. Sometime
>>> around 2014 NIST should have it approved and content developers can use
>>> it.
>>> This means holding off the functionality a bit because we can't allow
>>> audit
>>> configurations that cannot be monitored.
>>> 3) ??  (Any other ideas)
>>>
>>> OVAL has limited capability for reading file formats. Changes in
>>> capability
>>> have a long lead time. Audit configuration is very important to be able to
>>> assess from SCAP. For example, the DISA STIG and USGCB would mandate it. I
>>> think someone is working on a DSS-PCI profile which would also include
>>> some
>>> form of audit rule tests.
>>>
>>> In my opinion, the ability to assess the audit system's compliance has to
>>> take SCAP into account and solutions to allow drop in audit rule
>>> additions ought to fit within those limitations. I would imagine the same
>>> set of people that care about audit rules are nearly the same set of
>>> people that care about SCAP.
>>>
>>> -Steve
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