audispd audit-remote plugin and uid, gid, euid, suid, fsuid, egid, sgid, fsgid

audispd audit-remote plugin and uid, gid, euid, suid, fsuid, egid, sgid, fsgid

[Wojtczak Arkadiusz]

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Hello,
Lets assume that *id = uid or gid or euid or suid or fsuid or egid or sgid or fsgid.
Audispd audit-remote (au-remote.conf) plugin sends native (numeric) uid, gid, euid, suid, fsuid, egid, sgid, fsgid.
I want to correlate logs from many Linux boxes so I need to have *ids resolved to user/group names, similar to ausearch witch option "-interpret". Is there any way to enrich events with user/group names in au-remote or even earlier - in auditd or audit?
I've considered forking audit-remote to use auparse (injecting additional code somewhere near line 412 of audisp-remote.c) or doing something like "tail ... --follow audit.log | ausearch ... -i". Am I correct that to be 100% sure that user or group corresponds to appropriate *id the mapping process has to be done in the kernel? Otherwise there is low probability that during the time gap between actual event and "ausearch -i" someone could change *id or user/group name.
Any help would be appreciated.
Best regards,

Arkadiusz Wojtczak
Mainframe Security Expert

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Re: audispd audit-remote plugin and uid, gid, euid, suid, fsuid, egid, sgid, fsgid

[Steve Grubb]

On Thursday, November 13, 2014 02:51:28 PM Wojtczak Arkadiusz wrote:
> Hello,
> Lets assume that *id = uid or gid or euid or suid or fsuid or egid or sgid
> or fsgid. Audispd audit-remote (au-remote.conf) plugin sends native
> (numeric) uid, gid, euid, suid, fsuid, egid, sgid, fsgid. I want to
> correlate logs from many Linux boxes so I need to have *ids resolved to
> user/group names, similar to ausearch witch option "-interpret". Is there
> any way to enrich events with user/group names in au-remote or even earlier
> - in auditd or audit?

Not yet. I have been thinking about this and think I am settled on how to do 
this. (You can look at the auformat utility for some hints.) Just haven't 
tackled it yet due to other priorities. If you have a central uid database and 
use sssd or nscd rather than /etc/passwd, then you can probably achieve this.


> I've considered forking audit-remote to use auparse
> (injecting additional code somewhere near line 412 of audisp-remote.c) or
> doing something like "tail ... --follow audit.log | ausearch ... -i". Am I
> correct that to be 100% sure that user or group corresponds to appropriate
> *id the mapping process has to be done in the kernel?

No, but rather on the local machine. User name mappings is a user space 
phenomenon. The kernel only understands numbers. All interprettation is done 
in user space with trusted databases.


> Otherwise there is low probability that during the time gap between actual
> event and "ausearch -i" someone could change *id or user/group name. Any
> help would be appreciated.

They could unless use of those utilities are restricted. You could also setup 
a centralized user name management system to help things. But if you want to 
tackle this yourself, I think the uids, gids, and hostnames are the main 
things that need interpreting locally. Everything else can be done after the 
fact.

-Steve

Re: audispd audit-remote plugin and uid, gid, euid, suid, fsuid, egid, sgid, fsgid

[LC Bruzenak]

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On 11/13/2014 09:01 AM, Steve Grubb wrote:
> They could unless use of those utilities are restricted. You could also setup 
> a centralized user name management system to help things. But if you want to 
> tackle this yourself, I think the uids, gids, and hostnames are the main 
> things that need interpreting locally. Everything else can be done after the 
> fact.
This subject is one I I've griped before. I'm amazed that more people
haven't mentioned this.
From an assurance perspective, having the human-understandable names of
the accounts is important.
If auditing systems aggregate records from multiple sources, this is
pretty big.

Until we can easily do something like the following, this isn't dire:

machine:             local aggregator       enterprise aggregator
---------------          ---------------------       
-----------------------------
finance sys1 ->
finance sys2 ->  fin. aggr    \    
finance sys3 ->                     ->

engineering1 ->
engineering2 -> eng. aggr  ->          enterprise aggregator
engineering3 ->

marketing1 ->                      ->
marketing2 -> mark. aggr  /
marketing3 ->

In fact, to me, the ultimate assurance architecture would be to have the
username management system reside on the local auditing aggregator with
a very controlled/audited/secure interface.
Then I'd interpret the uids, gids and hns there.

My $0.02 FWIW,
LCB

-- 
LC (Lenny) Bruzenak
lenny@magitekltd.com



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