.\"	$OpenBSD: changelist.5,v 1.4 2007/09/06 07:01:34 jmc Exp $
.\"
.\" Copyright (c) 2003 Jason McIntyre <jmc@openbsd.org>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
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.Dd $Mdocdate: September 6 2007 $
.Dt CHANGELIST 5
.Os
.Sh NAME
.Nm changelist
.Nd list of backup files
.Sh SYNOPSIS
.Nm /etc/changelist
.Sh DESCRIPTION
The
.Pa /etc/changelist
file is a simple text file containing the names of files to be backed up
and checked for modification by the system security script,
.Xr security 8 .
It is checked daily by the
.Pa /etc/daily
script.
See
.Xr daily 8
for further details.
.Pp
Each line of the file contains the name of a file,
specified by its absolute pathname,
one per line.
By default, configuration files in
.Pa /etc ,
.Pa /root ,
and
.Pa /var
are added during system install.
Administrators may add additional files at their discretion.
.Pp
Backup files are held in the directory
.Pa /var/backups .
A backup of the current version of a file is kept in this directory, marked
.Qq current .
When the file is altered, the old version is marked as
.Qq backup
and the new version becomes
.Qq current .
.Pp
For example,
the system shell database,
.Pa /etc/shells ,
is held as
.Pa /var/backups/etc_shells.current .
When this file is modified, it is renamed to
.Pa /var/backups/etc_shells.backup
and the new version becomes
.Pa /var/backups/etc_shells.current .
Thereafter, these files are rotated.
.Pp
Diffs are mailed to the root administrator, in unified
.Xr diff 1
format, via
.Xr daily 8 ,
in the following format:
.Bd -unfilled -offset indent
=====
/etc/shells diffs (-OLD  +NEW)
=====
.Ed
.Pp
Files in
.Pa /etc/changelist
beginning with a
.Sq +
character
.Pq generally non-text files
are stored as
.Xr md5 1
checksums.
Results are mailed in the following format:
.Bd -unfilled -offset indent
======
/etc/ssh/ssh_host_key MD5 checksums
======
OLD:
NEW:
.Ed
.Pp
Lines beginning with the comment character
.Pq Sq # ,
blank lines,
and non-existent files are all silently ignored.
.\" .Sh ENVIRONMENT
.Sh FILES
.Bl -tag -width /etc/changelist -compact
.It Pa /etc/changelist
Default changelist.
.It Pa /etc/daily
Maintenance script which runs
.Xr security 8 .
.It Pa /etc/security
Shell script which reads
.Pa /etc/changelist .
.It /var/backups/
Directory containing file backups.
.El
.Sh SEE ALSO
.Xr diff 1 ,
.Xr md5 1 ,
.Xr daily 8 ,
.Xr security 8
.Sh HISTORY
The
.Nm
manual page first appeared in
.Ox 3.5 .
.Sh CAVEATS
Anyone with the privileges to alter system configuration files
could also alter the backup files in
.Pa /var/backups .
It is important that this directory be owned by root:wheel
and have permissions 0700 set.
.Pp
Removal of the
.Pa /etc/changelist
file itself could cause confusion.
.Pp
.Nm
cannot warn about files being added to the system, although
.Xr security 8
will pick up on any files listed in
.Pa /etc/changelist
being added or deleted.
.Pp
If you hose your system configuration files,
you just might be able to find the information you need in
.Pa /var/backups .
This is not a CAVEAT, but we had to let you know somehow!