Watching over non-existent folder to maintain a generic audit.rules file

[Florian Crouzat]

On 07/29/2015 12:39 AM, Burn Alting wrote:
> On Tue, 2015-07-28 at 15:23 -0400, Steve Grubb wrote:
>> On Tuesday, July 28, 2015 05:26:18 PM Florian Crouzat wrote:
>>> Unfortunately, I do not only watch over system-related files and folders
>>> but also applicative ones (eg custom path where some private keys are
>>> stored, etc) ..
>>> My problem is that these folders do not exists on all hosts thus making
>>> it impossible to write a generic audit.rules files.
>>
>> What kernel are you using? And user space package?
>>
>>
>>> As I said, I have thousands of hosts and I can't imagine deploying
>>> different files on every hosts depending on the profile of the host.
>>> I know puppet could help me for this kind of stuff but I don't have it
>>> yet and even though, it would be difficult to configure.
>>
>> As of the 2.3 user space release, there is a utility, augenrules which takes 
>> files in /etc/audit/rules.d/ and compiles them into an audit.rules file. So, it 
>> would be possible for you to package up some rules for bind and install them 
>> when you install bind and have your package install a 
>> /etc/audit/rules.d/bind.rules file. You can have a base config, and then one for 
>> each kind of daemon or role that the machine serves.
>>
>>
>>> How do you guys usually workaround this issue ? I'm pretty sure I'm not
>>> the first one wanting to deploy a generic hardening across many hosts
>>> (but maybe I'm the only one using auditd to watch over something else
>>> than pure system-related stuff?
>>
>> Others can chime in here.
> 
> As Steve suggests, you should base you efforts around augenrules ...
> that why it was written. If you have a project that delivers a new
> capability, then part of the security element of it's transition to
> operations would be to have the project identify the sensitive files and
> have the system administrators deploy project specific .rules files
> in /etc/audit/rules.d to monitor them.
> 
> If you have pre 2.3 audit user space deployments, then it is not
> difficult to deploy your own augenrules setup, but don't deploy it in
> the 'production' locations ... it's a bitch to remove when a 2.3 audit
> user space upgrade comes ... lots of rpm clashes.
> 
> A word to the wise on file watches. If you have a capability who's
> 'service/process' continually accesses configuration files you will
> typically mask this out by having the service start under the init.d
> regime at boot time and configure auditd to not monitor the 'unset'
> auid. The problem comes when a sustainment staff member, elevates
> privilege, and restarts the service. At this, all file accesses by the
> service/process will be attributed to the sustainment staff members uid,
> not the 'unset' user. This appears to have been addressed by systemd, so
> if your Linux release supports systemd, and you configure your
> application to use it appropriately, it will not have the problem.
> There are workarounds for the init.d based service regime, but that will
> have to be a separate post if ane are interested.
> 

Hey,

Thanks for the answers.

I have both up-to-date EL6 and EL7 hosts with latests kernel available
in base channel so I think it means I have >=2.3 auditd package.
I'll definitely have a look into augenrules and how to use it.
I'll probably come back at you with mores questions after that.

Florian