You should see if there is a way to enable the timestamp at the
beginning on your netscreen. OSSEC doesn't seem to like it when that
bit's missing.

On Thu, Jul 21, 2011 at 5:10 AM, Jérémie Belmudes
<[email protected]> wrote:
> Here is what I receive with tcpdump:
> E....z..?..{........Rl....&.<133>FIREWALL: NetScreen
> device_id=0100000000000001  [Root]system-notification-00257(traffic):
> start_time="2011-07-21 10:16:20" duration=0 policy_id=1 service=http proto=6
> src zone=ALPHA dst zone=BETA action=Permit sent=0 rcvd=0 src=172.16.0.1
> dst=10.0.0.1 src_port=65341 dst_port=80 src-xlated ip=172.16.0.1 port=65341
> dst-xlated ip=10.0.0.1 port=80 session_id=46083 reason=Creation.
> Now what is written in logs/archives/archives.log file:
> 2011 Jul 21 10:16:23 OSSEC->192.168.0.1 FIREWALL: NetScreen
> device_id=0100000000000001  [Root]system-notification-00257(traffic):
> start_time="2011-07-21 10:16:20" duration=0 policy_id=1 service=http proto=6
> src zone=ALPHA dst zone=BETA action=Permit sent=0 rcvd=0 src=172.16.0.1
> dst=10.0.0.1 src_port=65341 dst_port=80 src-xlated ip=172.16.0.1 port=65341
> dst-xlated ip=10.0.0.1 port=80 session_id=46083 reason=Creation
> None of these ones passes bin/ossec-logtest.
> I tried to just remove the green header following decoder regex (see below),
> but it fails.
> It finally works when I replace the green header by the one as the following
> example given in decoder.xml
> Jan  1 10:02:11 xx ns5gt: NetScreen device_id=ns5gt  [No
> Name]system-notification-00257(traffic): start_time="2006-01-01 10:09:38"
> duration=0 policy_id=310101 service=tcp/port:1526 proto=6 src zone=Null dst
> zone=self action=Deny sent=0 rcvd=38 src=10.1.2.3 dst=10.1.1.1
> src_port=51350 dst_port=1426
>
> decoder.xml says netscreen logs begin with "Netscreen device_id" :
> <decoder name="netscreenfw">
>   <program_name />
>   <prematch>^NetScreen device_id</prematch>
> </decoder>
> I tried to modify decoder to accept any characters before "Netscreen
> device_id", not working.
> Now I don't understand why bin/ossec-logtest requires a date as a prefix
> whereas decoder.xml says the contrary.
> Assuming that header is needed, I'm wondering where it can be configured.
> Comparing logs/archives/archives.log and the working example from
> decoder.xml, the problem seems coming from the date format.
> The fact is logs received from the firewall are in standard format. Also
> date format can't be changed.
> Have an idea about it ?
>
> 2011/7/20 dan (ddp) <[email protected]>
>>
>> On Wed, Jul 20, 2011 at 11:56 AM, Jérémie Belmudes
>> <[email protected]> wrote:
>> > Hi,
>> > Thanks for your hints Dan, I make OSSEC starts without any error, but
>> > still
>> > have somes issues.
>> > Here is where I am :
>> >
>> > Starting with a clean setup of OSSEC 2.6 on a linux server. Choose
>> > "server
>> > mode" to enable syslog in OSSEC.
>> > Adding a fake agent to avoid errors with manage_agents tools.
>> > Adding <allowed-ips> for syslog in ossec.conf file
>> > Finally starting ossec.
>> >
>> > I can see that OSSEC listen on the port UDP514 (via netstat -navup), and
>> > also, that traffic still arrives on the server (via tcpdump).
>> > As you said when logall option is set up, I retrieve all my logs in
>> > logs/archives/archives.log.
>> > I tried as you recommanded to test my logs, but they don't pass the test
>> > (ossec-logtest -f).
>> > I found out the problem comes from the Date prefix of the log.
>> > The prefix generated by OSSEC isn't recognized, but it works when I
>> > replace
>> > the prefix by the one presented in decoder.xml as exemple.
>> >
>> > generated prefix = 2011 Jul 20 16:57:21 nameOf Server->@IP_firewall
>>
>> This is just a header that's added to the entries. You should remove
>> it before pushing it through ossec-logtest. ossec-analysisd does not
>> see this header when trying to decode the messages.
>>
>> > prefix from decoder.xml = Jan  1 10:02:11 xx
>> >
>> > First thing, I don't know where that prefix regex can be updated, surely
>> > not
>> > in decoder.xml.
>>
>> It may not have to be. Send a few example logs so I can see what's going
>> on.
>>
>> > At first I thought the remote syslog would be automatically analyzed. If
>> > it's not the case I would like to retrieve them in a specific file. I
>> > think
>> > that archives.log file shouldn't be analyzed (<localfile> in
>> > ossec.conf).
>>
>> The log messages coming in via syslog are being looked at. They may
>> not be triggering anything, or they may not be decoded properly. It's
>> tough to tell without a log sample.
>>
>> > Thanks,
>> > J
>> >
>> >
>> >
>> > 2011/7/18 dan (ddp) <[email protected]>
>> >>
>> >> Hi Jérémie,
>> >>
>> >> On Mon, Jul 18, 2011 at 10:22 AM, Jérémie Belmudes
>> >> <[email protected]> wrote:
>> >> > Hi,
>> >> >
>> >> > First thing, I’m new with OSSEC and didn’t find any clue in archives.
>> >> >
>> >> >
>> >> >
>> >> > I would like an OSSEC server to receive logs from a Juniper firewall,
>> >> > in
>> >> > order to analyse them. Note there is nothing else than OSSEC on the
>> >> > server.
>> >> >
>> >>
>> >> If you are not planning on adding some real clients, you should
>> >> probably use a local installation.
>> >>
>> >> >
>> >> >
>> >> > Here is the issue:
>> >> >
>> >> > Firewall side: everything is fine, logs are received on OSSEC server
>> >> > on
>> >> > default port 514(checked via tcpdump).
>> >> > OSSEC side:
>> >> >
>> >> >  remote syslog was enabled during setup
>> >> >  I change ossec.conf file :
>> >> >
>> >> > <remote>
>> >> >   <connection>syslog</connection>
>> >> >   <allowed-ips>firewall IP</allowed-ips>
>> >> > </remote>
>> >> >
>> >> > OSSEC was restarted
>> >> >  I get error “2011/07/18 15:06:56 ossec-remoted(1402): ERROR:
>> >> > Authentication
>> >> > key file '/etc/client.keys' not found. 2011/07/18 15:06:56
>> >>
>> >> Either setup a local install or add an agent (even a fake agent should
>> >> be
>> >> ok).
>> >>
>> >> > ossec-remoted(1750): ERROR: No remote connection configured.
>> >> > Exiting.”
>> >> >
>> >>
>> >> You can check to see if an ossec-remoted is still alive listening on
>> >> 514/UDP with "netstat -pan | grep 514" (I'm assuming your manager is
>> >> Linux).
>> >>
>> >> > Here is what I tried, to make it works, but still fails :
>> >> >
>> >> > I added firewall IP via manage agents ; restart ; configuring logs on
>> >> > firewall to be sent on port 1514 ; getting error for each log
>> >> > received
>> >> > from
>> >> > the firewall “2011/07/18 14:47:44 ossec-remoted(1403): ERROR:
>> >> > Incorrectly
>> >> > formated message from 'IP adress'.”
>> >>
>> >> 1514 is for OSSEC's secure messaging, not syslog. The error is correct.
>> >>
>> >> > Tried to receive logs on another port, assigning in ossec.conf file
>> >> > <port>port_number</port> in <remote>…</remote> ; OSSEC restarted ; no
>> >> > error,
>> >> > but can’t find firewall logs in any log file (/var/log/* &
>> >> > /var/ossec/logs/*)
>> >> >
>> >>
>> >> You won't find the firewall logs in any of these files, unless an
>> >> alert is triggered.
>> >> OSSEC does not log to /var/log at all, so nothing should go from it to
>> >> any file there.
>> >> /var/ossec/logs/alerts/alerts.log will contain the alerts.
>> >> By default OSSEC does not log all log messages, but you can force it
>> >> to do so by adding <logall>yes</logall> to the <global> section.
>> >> After restarting OSSEC you can find all logs received by OSSEC in
>> >> /var/ossec/logs/archives/archive.log. I think this is really helpful
>> >> to figure out what is happening on an OSSEC system, and I generally
>> >> turn it on. If you have a few copies of various logs you can even use
>> >> ossec-logtest to see how they are being decoded.
>> >>
>> >> > Now, I’m wondering what I’m missing.
>> >> >
>> >> > Can OSSEC receive logs from device with syslog ? I read many articles
>> >> > answering yes, but can’t make it works.
>> >> >
>> >>
>> >> Yes, it can. I do it, as do many others daily. :)
>> >>
>> >> > If you have any idea…
>> >> >
>> >> > Thanks,
>> >> >
>> >> > J
>> >
>> >
>> >
>> > --
>> > Cordialement,
>> >
>> > Jérémie BELMUDES
>> > [email protected]
>> >
>
>
>
> --
> Cordialement,
>
> Jérémie BELMUDES
> [email protected]
>

Reply via email to