Tripwire-portable-0.9

Introduction to Tripwire

The Tripwire package contains programs used to verify the integrity of the files on a given system.

Package Information

Tripwire Dependencies

Optional

MTA (See Chapter 22, Mail Server Software)

Installation of Tripwire

Compile Tripwire by running the following commands:

sed -i -e 's@TWDB="${prefix}@TWDB="/var@' install/install.cfg &&
./configure --prefix=/usr --sysconfdir=/etc/tripwire &&
make

Now, as the root user:

make install &&
cp -v policy/*.txt /usr/share/doc/tripwire

The default configuration is to use a local MTA. If you don't have an MTA installed and have no wish to install one, modify install.cfg to use an SMTP server instead.

Command Explanations

sed -i -e 's@TWDB="${prefix}@TWDB="/var@' install/install.cfg: This command tells the package to install the program database and reports in /var/lib/tripwire.

make install: This command creates the Tripwire security keys as well as installing the binaries. There are two keys: a site key and a local key which are stored in /etc/tripwire/.

cp -v policy/*.txt /usr/share/doc/tripwire: This command installs the documentation.

Configuring Tripwire

Config Files

/etc/tripwire/*

Configuration Information

Tripwire uses a policy file to determine which files are integrity checked. The default policy file (/etc/tripwire/twpol.txt) is for a default Redhat installation and will need to be updated for your system.

Policy files should be tailored to each individual distribution and/or installation. Some custom policy files can be found below:

http://home.iprimus.com.au/glombowski/blfs/twpol-all.txt
Checks integrity of all files
http://home.iprimus.com.au/glombowski/blfs/twpol-lfs.txt
Custom policy file for Base LFS 3.0 system
http://home.iprimus.com.au/glombowski/blfs/twpol-suse7.2.txt
Custom policy file for SuSE 7.2 system

Download the custom policy file you'd like to try, copy it into /etc/tripwire/, and use it instead of twpol.txt. It is, however, recommended that you make your own policy file. Get ideas from the examples above and read /usr/share/doc/tripwire/policyguide.txt for additional information. twpol.txt is a good policy file for beginners as it will note any changes to the file system and can even be used as an annoying way of keeping track of changes for uninstallation of software.

After your policy file has been transferred to /etc/tripwire/ you may begin the configuration steps (perform as the root):

twadmin --create-polfile --site-keyfile /etc/tripwire/site.key \
    /etc/tripwire/twpol.txt &&
tripwire --init

Usage Information

To use Tripwire after creating a policy file to run a report, use the following command:

tripwire --check > /etc/tripwire/report.txt

View the output to check the integrity of your files. An automatic integrity report can be produced by using a cron facility to schedule the runs.

Please note that after you run an integrity check, you must examine the report (or email) and then modify the Tripwire database to reflect the changed files on your system. This is so that Tripwire will not continually notify you that files you intentionally changed are a security violation. To do this you must first ls -l /var/lib/tripwire/report/ and note the name of the newest file which starts with linux- and ends in .twr. This encrypted file was created during the last report creation and is needed to update the Tripwire database of your system. Then, as the root user, type in the following command making the appropriate substitutions for [?]:

tripwire --update -twrfile \
    /var/lib/tripwire/report/linux-[???????]-[??????].twr

You will be placed into vim with a copy of the report in front of you. If all the changes were good, then just type :x and after entering your local key, the database will be updated. If there are files which you still want to be warned about, remove the 'x' before the filename in the report and type :x.

Changing the Policy File

If you are unhappy with your policy file and would like to modify it or use a new one, modify the policy file and then execute the following commands as the root user:

twadmin --create-polfile /etc/tripwire/twpol.txt &&
tripwire --init

Contents

Installed Programs: siggen, tripwire, twadmin, and twprint.
Installed Libraries: None
Installed Directories: /etc/tripwire, /usr/share/doc/tripwire, and /var/lib/tripwire

Short Descriptions

siggen

is a signature gathering utility that displays the hash function values for the specified files.

tripwire

is the main file integrity checking program.

twadmin

administrative and utility tool used to perform certain administrative functions related to Tripwire files and configuration options.

twprint

prints Tripwire database and report files in clear text format.

Last updated on 2005-08-01 13:29:19 -0600