On Thursday, November 13, 2014 02:20:02 PM Wojtczak Arkadiusz wrote:
I've been searching for Audit documentation and stumbled upon
following
conversation:
http://www.redhat.com/archives/linux-audit/2006-September/msg00081.html
Has anything changed since 2006?
Yes, there is a little more documentation and sample code.
I need to write set of rules to correlate audit events from many
systems.
Following information would be very useful:
1) Event formats - What fields will be generated for particular event
type?
Doesn't exist. What I have been doing is using ausearch-test to collect
events. From that you can look through them.
Which fields are common to all event types?
The audit events have to meet common criteria requirements which asks for
date, time, subject, object, action, outcome. Each event has that somewhere.
Generally the events have auid as the subject, the object varies based on what
kind of event it is, the action is generally the type of event except syscalls
- which the key that may be added serves as the action, the outcome is either
sucess, res, or results.
What type of data will be in those fields
(binary/encoded/ASCII/UNICODE)?
What do those fields describe?
I have created a mapping here:
http://people.redhat.com/sgrubb/audit/audit-events.txt
This document describes all known fields.
2) For all event types - description when (in what
circumstances) are
generated events of this type
Doesn't exist. There are over 150 kinds of events. Some are deprecated, some
are not. The best description for what they are is in the header file for the
kernel and libaudit.
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/incl...
https://fedorahosted.org/audit/browser/trunk/lib/libaudit.h#L40
Also, I have been writing some specifications around when and why certain
events are created:
http://people.redhat.com/sgrubb/audit/user-account-lifecycle.txt
http://people.redhat.com/sgrubb/audit/audit-state-diagram.png
I have another around logins that is in development and have another around
virt/containers in works.
3) How do DAC event types relate to AVC (which fields are
common,
which are not)
The AVCs are created by a whole different community for their own needs. They
more or less conform to the recommended style. If you have auditing enabled,
you should also get a syscall record with the AVC. But if auditing is not
enabled, then you won't.
For DAC events, you get a syscall record. You have to specify what events you
are interested in by the rules. I'd recommend the stig.rules as the best
starting point
-Steve