man debsums (1): check the MD5 sums of installed Debian packages

SYNOPSIS

debsums [options] [package|deb] ...

DESCRIPTION

Verify installed Debian package files against MD5 checksum lists from /var/lib/dpkg/info/*.md5sums.

debsums can generate checksum lists from deb archives for packages that don't include one.

OPTIONS

-a, --all

Also check configuration files (normally excluded).

-e, --config

Only check configuration files.

-c, --changed

Report changed file list to stdout (implies -s).

-l, --list-missing

List packages (or debs) which don't have an MD5 sums file.

-s, --silent

Only report errors.

-m, --md5sums=file

Read list of deb checksums from file.

-r, --root=dir

Root directory to check (default /).

-d, --admindir=dir

dpkg admin directory (default /var/lib/dpkg).

-p, --deb-path=dir[:dir...]

Directories in which to look for debs derived from the package name (default is the current directory).

A useful value is /var/cache/apt/archives when using apt-get autoclean or not clearing the cache at all. The command:

: apt-get --reinstall -d install `debsums -l`

may be used to populate the cache with any debs not already in the cache.

Note: This doesn't work for CD-ROM and other local sources as packages are not copied to /var/cache. Simple file sources (all debs in a single directory) should be added to the -p list.

-g, --generate=[missing|all][,keep[,nocheck]]

Generate MD5 sums from deb contents. If the argument is a package name rather than a deb archive, the program will look for a deb named package_version_arch.deb in the directories given by the -p option.

missing: Generate MD5 sums from the deb for packages which don't provide one.
all: Ignore the on disk sums and use the one supplied in the deb, or generated from it if none exists.
keep: Write the extracted/generated sums to /var/lib/dpkg/info/package.md5sums.
nocheck: Implies keep; the extracted/generated sums are not checked against the installed package.

For backward compatibility, the short option -g is equivalent to --generate=missing.

--no-locale-purge

Report missing locale files even if localepurge is configured.

--no-prelink

Report changed ELF files even if prelink is configured.

--ignore-permissions

Treat permission errors as warnings when running as non-root.

--help

--version

Print help and version information.

EXIT STATUS

debsums returns 0 on success, or a combination* of the following values on error:

1: A specified package or archive name was not installed, invalid or the installed version did not match the given archive.
2: Changed or missing package files, or checksum mismatch on an archive.
255: Invalid option.

*If both of the first two conditions are true, the exit status will be 3.

EXAMPLES

debsums foo bar: Check the sums for installed packages foo and bar.
debsums foo.deb bar.deb: As above, using checksums from (or generated from) the archives.
debsums -l: List installed packages with no checksums.
debsums -ca: List changed package files from all installed packages with checksums.
debsums -ce: List changed configuration files.
debsums -cagp /var/cache/apt/archives: As above, using sums from cached debs where available.
apt-get install --reinstall $(dpkg -S $(debsums -c) | cut -d : -f 1 | sort -u): Reinstalls packages with changed files.

RESULTS

OK: The file's MD5 sum is good.
FAILED: The file's MD5 sum does not match.
REPLACED: The file has been replaced by a file from a different package.

NOTES

In order to create md5sums files for the already installed packages which don't have them, you must run debsums_init once after the installation of debsums package.

ENVIRONMENT

TMPDIR: Directory for extracting information and contents from package archives (/tmp by default).

CAVEATS

While in general the program may be run as a normal user, some packages contain files which are not globally readable so cannot be checked. Privileges are of course also required when generating sums with the keep option set.

Files which have been replaced by another package may be erroneously reported as changed.

debsums is intended primarily as a way of determining what installed files have been locally modified by the administrator or damaged by media errors and is of limited use as a security tool.

If you are looking for an integrity checker that can run from safe media, do integrity checks on checksum databases and can be easily configured to run periodically to warn the admin of changes see other tools such as: aide, integrit, samhain, or tripwire.

AUTHOR

Written by Brendan O'Dea <[email protected]>.
Based on a program by Christoph Lameter <[email protected]> and Petr Cech <[email protected]>.

COPYRIGHT

Copyright © 2002 Brendan O'Dea <[email protected]>
This is free software, licensed under the terms of the GNU General Public License. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.