Skip to main content

unified2 IDS binary log format parser

Project description

unified2: pure-python parser for IDS (think [Snort]( unified2 binary log format

Module allows to process IDS logs in binary "unified2" format into python

It does not resolve rule ids and is not meant to be a replacement for
[barnyard2]( or Snort itself in that role.

In fact, I've found that snort-produced text logs are enough for my purposes, so
**this module isn't really maintained or updated** (at least by me), so if you
really find it useful, I encourage you to fork the module, and contact me to
transfer pypi package ownership to you.

Main purpose is to extract a packet data from the log, associated with some
particular triggered (and resolved/logged separately via other means,
e.g. alert_syslog or alert_csv snort modules) rule, so I haven't paid much
attention to processing event metadata.

Module doesn't have C components and doesn't use ctypes, so should be fairly
portable to non-cPython language implementations.


Format definition is derived from Snort headers (src/sfutil/Unified2_common.h)
via [pyclibrary]( module
and are cached in unified2/ file.

Newer definitions (say, if new data types were added) can be generated by
running the same script on the Snort's Unified2_common.h:

bzr branch lp:pyclibrary
cd pyclibrary
python .../unified2/ .../snort-2.X.Y.Z/src/sfutil/Unified2_common.h


It's a regular package for Python 2.7 (not 3.X).

Using [pip]( is the best way:

% pip install unified2

If you don't have it, use:

% easy_install pip
% pip install unified2

Alternatively ([see

% curl | python
% pip install unified2

Or, if you absolutely must:

% easy_install unified2

But, you really shouldn't do that.

Current-git version can be installed like this:

% pip install -e 'git://'


Simple example:

import unified2.parser
for ev, ev_tail in unified2.parser.parse('/var/log/snort/snort.u2.1337060186'):
print 'Event:', ev
if ev_tail: print 'Event tail:', ev_tail

Event object here is a dict of metadata and a "tail", which can either be a blob
or a similar recursively-parsed tuple of metadata-dict and "tail" (e.g. for

unified2.parser.Parser interface is best illustrated by the

parser, buff_agg = Parser(), ''
while True:
buff =
if not buff: break # EOF
buff_agg += buff
while True:
buff_agg, ev = parser.process(buff_agg)
if ev is None: break
yield ev

Idea here is that method should be called with a stream (e.g. a file
object), returning however many bytes parser needs to get the next parseable
chunk of data (one packet, in case of u2 log) or whatever can be read at the
moment, empty string is usually an indication of EOF or maybe non-blocking read

Parser.process then should be called with accumulated (by calls)
buffer, returning the first packet that can be parsed from there (or None, if
buffer isn't large enough) and remaining (non-parsed) buffer data.

Related stuff


Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

unified2-12.06.1.tar.gz (5.5 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page