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<p>Hi Chris,</p>
<p>Thanks for the input.<br>
</p>
<p>I looked at STIX/TAXII 2 some while ago and also have been in
contact with the creators back then. IIRC and according to what
the creators said, STIX/TAXII cannot be used for some/most of the
data we are processing in IntelMQ. For example, how do you
represent an open port (vulnerable service), an infected device or
a malicious website? I don't see any STIX Object listed on the
page linked by you, that could match for that kind of data.</p>
<p>kind regards<br>
Sebastian<br>
</p>
<div class="moz-cite-prefix">On 3/31/21 5:43 AM, Chris Horsley
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:0656c609-af33-f6eb-2459-c93fc7a8ecc1@csirtfoundry.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Before going too far down this road, I'd be looking at the
suitability or adaptability of STIX / TAXII 2.1 (<a
class="moz-txt-link-freetext"
href="https://oasis-open.github.io/cti-documentation/stix/intro"
moz-do-not-send="true">https://oasis-open.github.io/cti-documentation/stix/intro</a>).<br>
</p>
<p>The STIX steering committee has spent years iterating and
debating the data model for STIX. They've already done a lot of
the hard work on how entities should reference one another, how
TLP is implemented, consistent taxonomies, appropriate metadata
and so on. There's also Python libs available, so it's more a
case of working out how to integrate rather than reinvent.<br>
</p>
<p> TAXII provides a HTTP-based transport layer for STIX (or other
data formats) which you can operate via push, pull, or otherwise
relay via some sort of chained series of TAXII servers.</p>
<p>As a bonus, it would give sharing inter-operation between
IntelMQ and other platforms which also implement STIX / TAXII.
MISP is one of those (<a class="moz-txt-link-freetext"
href="https://www.misp-project.org/2020/06/24/MISP.2.4.128.released.html"
moz-do-not-send="true">https://www.misp-project.org/2020/06/24/MISP.2.4.128.released.html</a>)
so there'd be some good experiences to draw from their
developers I feel.</p>
<p>Best regards,</p>
<p>Chris<br>
</p>
<div class="moz-cite-prefix">On 31/03/2021 2:56 am, Sebastian
Waldbauer wrote:<br>
</div>
<blockquote type="cite"
cite="mid:692d6097-d968-5942-6231-e17abcccc53e@cert.at">Dear
IntelMQ Developers and Users, <br>
<br>
nowadays security incidents are more important than 10 years
ago. As IntelMQ can be used as core element for automated
security incident handling, we would like to provide a way to
share information with other intelmq instances. This proposal is
also an alternative to IEP03 insofar as solving the "multiple
values" is possible by using UUIDs so "link" related events in a
backwards-compatible manner. <br>
<br>
If you're interested, please let us know, so we could organize a
hackathon for further discussions about the specification of the
meta-information. <br>
Previously this idea was discussed in [0] and [1]. <br>
<br>
[0]
<a class="moz-txt-link-freetext"
href="https://github.com/certtools/intelmq/blob/version-3.0-ideas/docs/architecture-3.0.md#user-content-general-requirements"
moz-do-not-send="true">https://github.com/certtools/intelmq/blob/version-3.0-ideas/docs/architecture-3.0.md#user-content-general-requirements</a><br>
[1] <a class="moz-txt-link-freetext"
href="https://github.com/certtools/intelmq/issues/1521"
moz-do-not-send="true">https://github.com/certtools/intelmq/issues/1521</a>
<br>
# IEP04: Internal Data Format: Meta Information and Data
Exchange <br>
To ease data exchange between two or more IntelMQ instances,
adding some meta-information to the events can make this sharing
easier in certain regards. <br>
"Linking" events could be based on the same theory as `git`
using it - with parent hashes ( we would call it UUID ). <br>
<br>
### TL;DR <br>
Communication between one or more IntelMQ instances &
exchange data with a backwards-compatible format. P2P or
centralized architecture is a big topic, which has to be
discussed after the format is being set. <br>
<br>
### Why is metadata important? <br>
Short and simple. To avoid race conditions & being able to
discard/drop already processed events from other instances. <br>
<br>
### Meta information <br>
Metadata is used to transfer some general data, which is not
likely related to the event itself. It's more or less just an
information to keep events clear & sortable. <br>
<br>
A message could look like: <br>
<br>
{ <br>
"meta": { <br>
"version": 1, # protocol version, so we are allowed to
fallback to old versions too <br>
"uuid": { <br>
current: "cert_at:aaaa-bbbb-cccc-dddd" # format to be
decided <br>
parent: "cert_at:xxxx-yyyy-zzzz-ffff" # format to be
discussed, if not set -> current is the parent uuid <br>
}, <br>
"type": "event", <br>
"format": "intelmq", # i. e. this field could contain
"n6" or "idea", so the receiving component can decode on demand.
<br>
}, <br>
"payload": { # normal intelmq data <br>
"source.ip": "127.0.0.1", <br>
"source.fqdn": "example.com", <br>
"raw": base64-blob <br>
} <br>
} <br>
<br>
Tell us your opinion about adding non-standardized
meta-information fields ( i. e. RTIR ticket number, origin,
other local contact informationen ... and so on ) <br>
<br>
#### The UUID <br>
For the UUID there are multiple options: <br>
1. Generate a random 128 bit UUID <br>
2. A list of entities, which dealt with this event already. For
example if an event was passed on from cert-at to cert-ee, the
field could look like `!cert-at!cert-ee`. A message sending loop
can be detected if the own name is already in this field upon
reception. <br>
3. Using CyCat: `publisher-short-name:project-short-name:UUID`.
For example:
`cert-at:intelmq:72ddb00c-2d0a-4eea-b7ac-ae122b8e6c3b`, or
`cert-pl:n6:f60c9fb9-81f9-4e0b-8a44-ea41326a15b3`. Some more
research and discussion is required before the implementation of
this option. Have a look at <a class="moz-txt-link-freetext"
href="https://www.cycat.org/services/concept/"
moz-do-not-send="true">https://www.cycat.org/services/concept/</a>
for more details. <br>
4. A hash: A benefit using a hash is that we're able to
recalculate them on every intelmq instance. <br>
<br>
### Exporting events to other systems <br>
In IntelMQ 2.x the events only comprise of the "payload" and no
meta information. For local storages like file output or
databases, the meta information may not be relevant in some
use-cases. So it needs to be possible to export events *without*
meta information, which is also the backwards-compatible
behaviour. <br>
<br>
The "type" field exists in the current format as "__type" in the
flat payload structure. In the output bots there's currently a
boolean parameter `message_with_type` to include the field
`__type` in the "export". <br>
For optionally exporting meta-information like uuid or format, a
similar logic could be used. <br>
<br>
### How can data exchange work? <br>
This now depends on how IntelMQ instances can communicate,
either Peer-to-peer or via a central data hub. Both of them do
have pro's and con's. <br>
<br>
#### P2P ( Peer 2 Peer ) <br>
Decentralized network <br>
+ Less downtimes: A downtime of one instance, does not affect
the whole network <br>
+ Better privacy: data is not shared to an unrelated instance <br>
+ More secure: data can optionally be encrypted (key-exchange
between instances?) <br>
+ Decentralized and local maintenance <br>
~ Network latency depends on server locations <br>
- Networking issues may occur <br>
<br>
How would data exchange looks like between two instances: <br>
1) Instance A has events which should be relayed to Instance B
& C, because they're not sure who the actually receiver
should be <br>
2) Instance A ensures all messages have a UUID <br>
3) Instance A sends the data to Instance B & Instance C <br>
4) Instance B checks the data & they're sure that the data
should be for Instance C <br>
5) Instance C receives data from Instance A & Instance B <br>
6) Instance C checks the UUID, which is the same & drops the
package from Instance B <br>
<br>
#### (Central) Data hub <br>
+ Less maintenance: Is maintained by the hub administrator <br>
+ Central data storage (reports can optionally be cached to be
downloaded later) <br>
~ Central data analysis (e.g. statistics) is possible <br>
~ Network latency depends on server locations <br>
- point of failure: if network problems occur, no exchange is
possible <br>
<br>
As already seen above, data exchange here would be less
complicated. The sending may look like: <br>
1) Instance A has events which should be relayed to Instance B
(e.g. different country) <br>
2) Instance A ensures all messages have a UUID <br>
3) Instance A sends these messages to the data hub <br>
<br>
The reception side can look like: <br>
1) Instance B connects to central instance <br>
2) Instance B queries and downloads all available messages <br>
3) Upon reception, all messages are de-duplicated based on the
UUID: <br>
a) If the UUID is already known, discard the message <br>
b) If the UUID has not been seen before, continue with
processing <br>
<br>
To sum up, both exchange variants are useful. More research is
needed, i. e. a mixed infrastructure with centralized parts but
can be decentralized too. However, this shall not be neither the
purpose nor the aim of this IEP. <br>
<br>
<br>
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<pre class="moz-signature" cols="72">--
// Sebastian Wagner <a class="moz-txt-link-rfc2396E" href="mailto:wagner@cert.at"><wagner@cert.at></a> - T: +43 1 5056416 7201
// CERT Austria - <a class="moz-txt-link-freetext" href="https://www.cert.at/">https://www.cert.at/</a>
// Eine Initiative der nic.at GmbH - <a class="moz-txt-link-freetext" href="https://www.nic.at/">https://www.nic.at/</a>
// Firmenbuchnummer 172568b, LG Salzburg</pre>
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