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OSSEC: building an OpenBSD package

by : Johnny Morano

OSSEC is an Open Source Host-based Intrusion Detection System that performs log analysis, file integrity checking, policy monitoring, rootkit detection, real-time alerting and active response.

It runs on most operating systems, including Linux, MacOS, Solaris, HP-UX, AIX and OpenBSD.

There is no OSSEC package available on the OSSEC website or in the OpenBSDs ports repositry, so I’ve decided to create an OpenBSD on my own.
OpenBSD packages are pretty easy to create and are very useful when installing, upgrading or deleting software on a server.

One of the disadvantages when creating an OpenBSD package, is that you will need to have X11 installed on your OpenBSD system.
In the following example I have used OpenBSD 5.8 to create a package for OSSEC 2.8.2 (OSSEC 2.8.3 doesn’t compile on OpenBSD 5.8)

Step 1: Prerequisites

cd /tmp
wget http://ftp.eu.openbsd.org/pub/OpenBSD/5.8/amd64/xbase58.tgz 
wget http://ftp.eu.openbsd.org/pub/OpenBSD/5.8/amd64/xshare58.tgz
wget http://ftp.eu.openbsd.org/pub/OpenBSD/5.8/amd64/comp58.tgz
tar -C / -xzvphf xbase58.tgz
tar -C / -xzvphf xshare58.tgz
tar -C / -xzvphf comp58.tgz

cd /tmp
ftp http://ftp.eu.openbsd.org/pub/OpenBSD/$(uname -r)/ports.tar.gz
ftp http://ftp.eu.openbsd.org/pub/OpenBSD/$(uname -r)/SHA256.sig
signify -Cp /etc/signify/openbsd-$(uname -r | cut -c 1,3)-base.pub -x SHA256.sig ports.tar.gz

cd /usr
tar xzf /tmp/ports.tar.gz

You will also need a compiler:

pkg_add gcc

Step 2: Download and repack the source

ossec_version="2.8.2"
cd /usr/src
wget https://github.com/ossec/ossec-hids/archive/${ossec_version}.tar.gz 
mv ${ossec_version}.tar.gz ossec-hids-${ossec_version}.tar.gz 
tar xfz ossec-hids-${ossec_version}.tar.gz
cd ossec-hids-${ossec_version}

Since the Makefile for OSSEC is in the src/ sub directory, we will create a proxy Makefile in /usr/src/ossec-hids-2.8.2

cd ossec-hids-2.8.2
vim Makefile

I have actually taken the original Makefile from src/ and narrowed it down to the following:

# Makefile
# http://www.ossec.net/hids/

none:
 @echo "Nothing selected ..."
 @echo "\"make all\" to compile everything."
 @echo "\"make server\" to build the server."
 @echo "\"make local\" to build the local."
 @echo "\"make agent\" to build the agent."
 @echo "\"make clean\" to clean anything built."

clean:
 cd src/ ; $(MAKE) clean

all:
 cd src/ ; $(MAKE) all
 
test:
 cd src/ ; $(MAKE) test

server:
 cd src/ ; $(MAKE) server

local:
 cd src/ ; $(MAKE) local

agent:
 cd src/ ; $(MAKE) agent

We will also edit the ‘ossec-clients.sh‘ script, because we will use this script as a start/stop script. We will have to set the path name in this script.

vim src/init/ossec-client.sh
# LOCAL=/var/ossec
# cd ${LOCAL}
# PWD=`pwd`
DIR=/var/ossec
cd ${DIR}

And that’s the only thing we will need to change in the sources, we can now repackage it.

cd ..
tar czf /usr/ports/distfiles/ossec-hids-2.8.2.tar.gz ossec-hids-2.8.2/

Step 3: Prepare the ports directory

The following steps explain how to set up a ports directory in /usr/ports for OSSEC, in order to build the package.
Custom made packages are built in /usr/ports/mystuff. In there, we will have to one sub directory for the package category (we will use security) and in there the package name, which in our case will be ossec-hids.

cd /usr/ports/mystuff
mkdir -p security/ossec-hids

The configuration file for building an OpenBSD package is a Makefile. There is a template file in /usr/ports/infrastructure/templates/Makefile.template which can be used.

cd security/ossec-hids
cp /usr/ports/infrastructure/templates/Makefile.template Makefile

This file of course needs editing. Not everything is required in this file, so I have narrowed the Makefile down to what I need it for:

# $OpenBSD: Makefile.template,v 1.68 2013/10/02 07:34:45 ajacoutot Exp $
# $FreeBSD/NetBSD: credit FreeBSD/NetBSD if thats where the port came from $
# Original from: credit the original author here
COMMENT =               OSSEC is an Open Source HIDS
DISTNAME =              ossec-hids-2.8.2
CATEGORIES =            security
HOMEPAGE =              http://www.ossec.net/
MAINTAINER =            Johnny Morano <jmorano@moretrix.com>;
MASTER_SITES =          https://github.com/ossec/ossec-hids/

PERMIT_PACKAGE_CDROM =  Yes
PERMIT_PACKAGE_FTP =    Yes
PERMIT_DISTFILES_FTP =  Yes

PKG_ARCH =              *
PREFIX = /var/ossec

do-install:
        mkdir -p ${PREFIX}/bin
        mkdir -p ${PREFIX}/logs
        mkdir -p ${PREFIX}/var/run
        mkdir -p ${PREFIX}/queue
        mkdir -p ${PREFIX}/active-response/bin
        mkdir -p ${PREFIX}/agentless
        mkdir -p ${PREFIX}/etc/orig/shared
        mkdir -p ${PREFIX}/doc
        ${INSTALL_SCRIPT} ${WRKSRC}/active-response/firewalls/pf.sh ${PREFIX}/active-response/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/agentlessd/scripts/* ${PREFIX}/agentless
        ${INSTALL_SCRIPT} ${WRKSRC}/src/os_execd/ossec-execd ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/logcollector/ossec-logcollector ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/client-agent/ossec-agentd ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/addagent/manage_agents ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/syscheckd/ossec-syscheckd ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/os_auth/agent-auth ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/init/ossec-client.sh ${PREFIX}/bin/
        ${INSTALL_SCRIPT} ${WRKSRC}/doc/*.txt ${PREFIX}/doc/
        ${INSTALL_SCRIPT} ${WRKSRC}/doc/README.config ${PREFIX}/doc/
        ${INSTALL_SCRIPT} ${WRKSRC}/etc/*.conf ${PREFIX}/etc/orig/
        ${INSTALL_SCRIPT} ${WRKSRC}/etc/*.xml ${PREFIX}/etc/orig/
        ${INSTALL_SCRIPT} ${WRKSRC}/src/rootcheck/db/* ${PREFIX}/etc/orig/shared/

.include <bsd.port.mk>;

The above Makefile will install OSSEC in /var/ossec and will only install the agent files. It does not install the server files.

Step 4: Test the settings

First we will make a checksum and then we will start a fake compile run, to see if everything compiles nicely.

make makesum 
===>  Checking files for ossec-hids-2.8.2
`/usr/ports/distfiles/ossec-hids-2.8.2.tar.gz' is up to date.

make fake
===>  Checking files for ossec-hids-2.8.2
`/usr/ports/distfiles/ossec-hids-2.8.2.tar.gz' is up to date.
>> (SHA256) ossec-hids-2.8.2.tar.gz: OK
===>  Extracting for ossec-hids-2.8.2
===>  Patching for ossec-hids-2.8.2
===>  Configuring for ossec-hids-2.8.2
===>  Building for ossec-hids-2.8.2
***snip***

If there were no errors, then we are ready to create the actual package.

Step 5: Create the OpenBSD package

mkdir pkg
echo "OSSEC is an Open Source HIDS" &gt; pkg/DESCR
make plist
vim pkg/PLIST

Normally we do not need to edit the PLIST file, but I wanted to create an ossec user upon installation and chown the /var/ossec directory to that user.
So I have added the following lines to the top of pkg/PLIST:

@comment $OpenBSD$
@newgroup ossec:1002
@newuser ossec:1005:ossec:daemon:OSSEC User:/var/ossec:/bin/sh

And these to the bottom:

@exec-add mkdir -p /var/ossec
@exec-add chown -R ossec.ossec /var/ossec
@exec-add cp %D/bin/ossec-client.sh /etc/rc.d/ossec

Afterwards you will need to run:

make plist

Now we are ready to build the package:

make package
`/usr/ports/pobj/ossec-hids-2.8.2/fake-amd64/.fake_done' is up to date.
===>  Building package for ossec-hids-2.8.2
Create /usr/ports/packages/amd64/no-arch/ossec-hids-2.8.2.tgz
Link to /usr/ports/packages/amd64/all/ossec-hids-2.8.2.tgz
Link to /usr/ports/packages/amd64/ftp/ossec-hids-2.8.2.tgz
Link to /usr/ports/packages/amd64/cdrom/ossec-hids-2.8.2.tgz

That’s it! This package can now be installed with the ‘pkg_add‘ command.

pkg_add ./ossec-hids-2.8.2.tgz 
quirks-2.114 signed on 2015-08-09T11:57:52Z
UNSIGNED PACKAGE file:./ossec-hids-2.8.2.tgz: install anyway ? [y/N/a] y
ossec-hids-2.8.2: ok
UNSIGNED PACKAGES: ossec-hids-2.8.2

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