1994-05-30 19:09:18 +00:00
|
|
|
.\" Copyright (c) 1988, 1991, 1993
|
|
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
|
|
.\"
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
.\" are met:
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
|
|
.\" must display the following acknowledgement:
|
|
|
|
.\" This product includes software developed by the University of
|
|
|
|
.\" California, Berkeley and its contributors.
|
|
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
|
|
.\" may be used to endorse or promote products derived from this software
|
|
|
|
.\" without specific prior written permission.
|
|
|
|
.\"
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
.\"
|
1994-09-20 22:44:37 +00:00
|
|
|
.\" From: @(#)passwd.5 8.1 (Berkeley) 6/5/93
|
1997-01-14 07:20:47 +00:00
|
|
|
.\" $FreeBSD$
|
1994-05-30 19:09:18 +00:00
|
|
|
.\"
|
1994-09-20 22:44:37 +00:00
|
|
|
.Dd September 29, 1994
|
1994-05-30 19:09:18 +00:00
|
|
|
.Dt PASSWD 5
|
|
|
|
.Os
|
|
|
|
.Sh NAME
|
|
|
|
.Nm passwd
|
|
|
|
.Nd format of the password file
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
The
|
|
|
|
.Nm passwd
|
|
|
|
files are files consisting of newline separated records, one per user,
|
|
|
|
containing ten colon (``:'') separated fields. These fields are as
|
|
|
|
follows:
|
|
|
|
.Pp
|
|
|
|
.Bl -tag -width password -offset indent
|
|
|
|
.It name
|
|
|
|
User's login name.
|
|
|
|
.It password
|
|
|
|
User's
|
|
|
|
.Em encrypted
|
|
|
|
password.
|
|
|
|
.It uid
|
|
|
|
User's id.
|
|
|
|
.It gid
|
|
|
|
User's login group id.
|
|
|
|
.It class
|
|
|
|
User's general classification (unused).
|
|
|
|
.It change
|
|
|
|
Password change time.
|
|
|
|
.It expire
|
|
|
|
Account expiration time.
|
|
|
|
.It gecos
|
|
|
|
General information about the user.
|
|
|
|
.It home_dir
|
|
|
|
User's home directory.
|
|
|
|
.It shell
|
|
|
|
User's login shell.
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Ar name
|
|
|
|
field is the login used to access the computer account, and the
|
|
|
|
.Ar uid
|
|
|
|
field is the number associated with it. They should both be unique
|
|
|
|
across the system (and often across a group of systems) since they
|
|
|
|
control file access.
|
|
|
|
.Pp
|
|
|
|
While it is possible to have multiple entries with identical login names
|
|
|
|
and/or identical user id's, it is usually a mistake to do so. Routines
|
|
|
|
that manipulate these files will often return only one of the multiple
|
|
|
|
entries, and that one by random selection.
|
|
|
|
.Pp
|
|
|
|
The login name must never begin with a hyphen (``-''); also, it is strongly
|
|
|
|
suggested that neither upper-case characters or dots (``.'') be part
|
|
|
|
of the name, as this tends to confuse mailers. No field may contain a
|
|
|
|
colon (``:'') as this has been used historically to separate the fields
|
|
|
|
in the user database.
|
|
|
|
.Pp
|
|
|
|
The password field is the
|
|
|
|
.Em encrypted
|
|
|
|
form of the password.
|
|
|
|
If the
|
|
|
|
.Ar password
|
|
|
|
field is empty, no password will be required to gain access to the
|
|
|
|
machine. This is almost invariably a mistake.
|
|
|
|
Because these files contain the encrypted user passwords, they should
|
|
|
|
not be readable by anyone without appropriate privileges.
|
|
|
|
.Pp
|
|
|
|
The group field is the group that the user will be placed in upon login.
|
|
|
|
Since this system supports multiple groups (see
|
|
|
|
.Xr groups 1 )
|
|
|
|
this field currently has little special meaning.
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Ar class
|
|
|
|
field is currently unused. In the near future it will be a key to
|
|
|
|
a
|
|
|
|
.Xr termcap 5
|
|
|
|
style database of user attributes.
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Ar change
|
|
|
|
field is the number in seconds,
|
|
|
|
.Dv GMT ,
|
|
|
|
from the epoch, until the
|
|
|
|
password for the account must be changed.
|
|
|
|
This field may be left empty to turn off the password aging feature.
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Ar expire
|
|
|
|
field is the number in seconds,
|
|
|
|
.Dv GMT ,
|
|
|
|
from the epoch, until the
|
|
|
|
account expires.
|
|
|
|
This field may be left empty to turn off the account aging feature.
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Ar gecos
|
|
|
|
field normally contains comma (``,'') separated subfields as follows:
|
|
|
|
.Pp
|
|
|
|
.Bd -unfilled -offset indent
|
|
|
|
name user's full name
|
|
|
|
office user's office number
|
|
|
|
wphone user's work phone number
|
|
|
|
hphone user's home phone number
|
|
|
|
.Ed
|
|
|
|
.Pp
|
|
|
|
This information is used by the
|
|
|
|
.Xr finger 1
|
|
|
|
program.
|
|
|
|
.Pp
|
|
|
|
The user's home directory is the full
|
|
|
|
.Tn UNIX
|
|
|
|
path name where the user
|
|
|
|
will be placed on login.
|
|
|
|
.Pp
|
|
|
|
The shell field is the command interpreter the user prefers.
|
|
|
|
If there is nothing in the
|
|
|
|
.Ar shell
|
|
|
|
field, the Bourne shell
|
|
|
|
.Pq Pa /bin/sh
|
|
|
|
is assumed.
|
1994-09-20 22:44:37 +00:00
|
|
|
.Sh YP/NIS INTERACTION
|
1995-09-02 04:25:24 +00:00
|
|
|
.Ss Enabling access to NIS passwd data
|
|
|
|
The system administrator can configure FreeBSD to use NIS/YP for
|
|
|
|
its password information by adding special records to the
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
file. These entries should be added with
|
|
|
|
.Xr vipw 8
|
|
|
|
so that the changes can be properly merged with the hashed
|
|
|
|
password databases and the
|
1994-09-20 22:44:37 +00:00
|
|
|
.Pa /etc/passwd
|
1995-09-02 04:25:24 +00:00
|
|
|
file (
|
|
|
|
.Pa /etc/passwd
|
|
|
|
should never be edited manually). Alternatively, the administrator
|
|
|
|
can modify
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
in some other way and then manually update the password databases with
|
|
|
|
.Xr pwd_mkdb 8 .
|
|
|
|
.Pp
|
|
|
|
The simplest way to activate NIS is to add an empty record
|
|
|
|
with only a plus sign (`+') in the name field, such as this:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
+:::::::::
|
|
|
|
|
|
|
|
.Ed
|
|
|
|
The `+' will tell the
|
|
|
|
.Xr getpwent 3
|
|
|
|
routines in FreeBSD's standard C library to begin using the NIS passwd maps
|
|
|
|
for lookups.
|
|
|
|
.Pp
|
|
|
|
Note that the entry shown above is known as a
|
|
|
|
.Pa wildcard
|
|
|
|
entry, because it matches all users (the `+' without any other information
|
|
|
|
matches everybody) and allows all NIS password data to be retrieved
|
|
|
|
unaltered. However, by
|
|
|
|
specifying a username or netgroup next to the `+' in the NIS
|
|
|
|
entry, the administrator can affect what data is extracted from the
|
|
|
|
NIS passwd maps and how it is interpreted. Here are a few example
|
|
|
|
records that illustrate this feature (note that you can have several
|
|
|
|
NIS entries in a single
|
|
|
|
.Pa master.passwd
|
|
|
|
file):
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
-mitnick:::::::::
|
|
|
|
+@staff:::::::::
|
|
|
|
+@permitted-users:::::::::
|
|
|
|
+dennis:::::::::
|
|
|
|
+ken:::::::::/bin/csh
|
|
|
|
+@rejected-users::32767:32767::::::/bin/false
|
|
|
|
|
|
|
|
.Ed
|
|
|
|
Specific usernames are listed explicitly while netgroups are signfied
|
1996-01-30 13:52:50 +00:00
|
|
|
by a preceding `@'. In the above example, users in the ``staff'' and
|
1995-09-02 04:25:24 +00:00
|
|
|
``permitted-users'' netgroups will have their password information
|
1996-01-30 13:52:50 +00:00
|
|
|
read from NIS and used unaltered. In other words, they will be allowed
|
1995-09-02 04:25:24 +00:00
|
|
|
normal access to the machine. Users ``ken'' and ``dennis,'' who have
|
1996-01-30 13:52:50 +00:00
|
|
|
been named explicitly rather than through a netgroup, will also have
|
1995-09-02 04:25:24 +00:00
|
|
|
their password data read from NIS, _except_ that user ``ken'' will
|
|
|
|
have his shell remapped to
|
|
|
|
.Pa /bin/csh .
|
|
|
|
This means that value for his shell specified in the NIS password map
|
1996-01-30 13:52:50 +00:00
|
|
|
will be overridden by the value specified in the special NIS entry in
|
1995-09-02 04:25:24 +00:00
|
|
|
the local
|
|
|
|
.Pa master.passwd
|
|
|
|
file. User ``ken'' may have been assigned the csh shell because his
|
|
|
|
NIS password entry specified a different shell that may not be
|
|
|
|
installed on the client machine for political or technical reasons.
|
|
|
|
Meanwhile, users in the ``rejected-users'' netgroup are prevented
|
|
|
|
from logging in because their UIDs, GIDs and shells have been overridden
|
|
|
|
with invalid values.
|
|
|
|
.Pp
|
|
|
|
User ``mitnick'' will be be ignored entirely because his entry is
|
|
|
|
specified with a `-' instead of a `+'. A minus entry can be used
|
|
|
|
to block out certain NIS password entries completely; users who's
|
|
|
|
password data has been excluded in this way are not recognized by
|
|
|
|
the system at all. (Any overrides specified with minus entries are
|
|
|
|
also ignored since there is no point in processing override information
|
|
|
|
for a user that the system isn't going to recognize in the first place.)
|
|
|
|
In general, a minus entry is used to specifically exclude a user
|
|
|
|
who might otherwise be granted access because he happens to be a
|
|
|
|
member of an authorized netgroup. For example, if ``mitnick'' is
|
|
|
|
a member of the ``permitted-users'' netgroup and must, for whatever
|
|
|
|
the reason, be permitted to remain in that netgroup (possibly to
|
1996-01-30 13:52:50 +00:00
|
|
|
retain access to other machines within the domain), the administrator
|
1995-09-02 04:25:24 +00:00
|
|
|
can still deny him access to a particular system with a minus entry.
|
|
|
|
Also, it is sometimes easier to explicitly list those users who aren't
|
|
|
|
allowed access rather than generate a possibly complicated list of
|
|
|
|
users who are allowed access and omit the rest.
|
|
|
|
.Pp
|
|
|
|
Note that the plus and minus entries are evaluated in order from
|
|
|
|
first to last with the first match taking precedence. This means
|
|
|
|
that the system will only use the first entry which matches a particular user.
|
|
|
|
If, for instance, we have a user ``foo'' who is a member of both the ``staff''
|
|
|
|
netgroup and the ``rejected-users'' netgroup, he will be admitted to
|
|
|
|
the system because the above example lists the entry for ``staff''
|
|
|
|
before the entry for ``rejected-users.'' If we reversed the order,
|
|
|
|
user ``foo'' would be flagged as a ``rejected-user'' instead and
|
|
|
|
denied access.
|
|
|
|
.Pp
|
|
|
|
Lastly, any NIS password database records that do not match against
|
|
|
|
at least one of the users or netgroups specified by the NIS access
|
|
|
|
entries in the
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
file will be ignored (along with any users specified using minus
|
|
|
|
entries). In our example shown above, we do not have a wildcard
|
|
|
|
entry at the end of the list; therefore, the system will not recognize
|
|
|
|
anyone except
|
|
|
|
``ken,'' ``dennis,'' the ``staff'' netgroup and the ``permitted-users''
|
|
|
|
netgroup as authorized users. The ``rejected-users'' netgroup will
|
|
|
|
be recognized but all members will have their shells remapped and
|
|
|
|
therefore be denied access.
|
|
|
|
All other NIS password records
|
|
|
|
will be ignored. The administrator may add a wildcard entry to the
|
|
|
|
end of the list such as:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
+:::::::::/usr/local/bin/go_away
|
|
|
|
|
|
|
|
.Ed
|
|
|
|
This entry acts as a catch-all for all users that don't match against
|
|
|
|
any of the other entries.
|
|
|
|
.Pa /usr/local/bin/go_away
|
|
|
|
can be a short shell script or program
|
|
|
|
that prints a message telling the user that he is not allowed access
|
1996-01-30 13:52:50 +00:00
|
|
|
to the system. This technique is sometimes useful when it is
|
|
|
|
desirable to have the system be able to recognize all users in a
|
1995-09-02 04:25:24 +00:00
|
|
|
particular NIS domain without necessarily granting them login access.
|
|
|
|
.Pp
|
|
|
|
The primary use of this
|
|
|
|
.Pa override
|
|
|
|
feature is to permit the administrator
|
|
|
|
to enforce access restrictions on NIS client systems. Users can be
|
|
|
|
granted access to one group of machines and denied access to other
|
|
|
|
machines simply by adding or removing them from a particular netgroup.
|
|
|
|
Since the netgroup database can also be accessed via NIS, this allows
|
|
|
|
access restrictions to be administered from a single location, namely
|
|
|
|
the NIS master server; once a host's access list has been set in
|
|
|
|
.Pa /etc/master.passwd ,
|
|
|
|
it need not be modified again unless new netgroups are created.
|
|
|
|
.Sh NOTES
|
|
|
|
.Ss Shadow passwords through NIS
|
|
|
|
FreeBSD uses a shadow password scheme: users' encrypted passwords
|
|
|
|
are stored only in
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
and
|
|
|
|
.Pa /etc/spwd.db ,
|
|
|
|
which are readable and writable only by the superuser. This is done
|
|
|
|
to prevent users from running the encrypted passwords through
|
|
|
|
password-guessing programs and gaining unauthorized access to
|
|
|
|
other users' accounts. NIS does not support a standard means of
|
|
|
|
password shadowing, which implies that placing your password data
|
|
|
|
into the NIS passwd maps totally defeats the security of FreeBSD's
|
|
|
|
password shadowing system.
|
|
|
|
.Pp
|
|
|
|
FreeBSD provides a few special features to help get around this
|
1996-01-30 13:52:50 +00:00
|
|
|
problem. It is possible to implement password shadowing between
|
1995-09-02 04:25:24 +00:00
|
|
|
FreeBSD NIS clients and FreeBSD NIS servers. The
|
|
|
|
.Xr getpwent 3
|
|
|
|
routines will search for a
|
|
|
|
.Pa master.passwd.byname
|
|
|
|
and
|
|
|
|
.Pa master.passwd.byuid
|
|
|
|
maps which should contain the same data found in the
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
file. If the maps exist, FreeBSD will attempt to use them for user
|
|
|
|
authentication instead of the standard
|
|
|
|
.Pa passwd.byname
|
|
|
|
and
|
|
|
|
.Pa passwd.byuid
|
|
|
|
maps. FreeBSD's
|
|
|
|
.Xr ypserv 8
|
|
|
|
will also check client requests to make sure they originate on a
|
|
|
|
privileged port. Since only the superuser is allowed to bind to
|
|
|
|
a privileged port, the server can tell if the requesting user
|
|
|
|
is the superuser; all requests from non-privileged users to access
|
|
|
|
the
|
|
|
|
.Pa master.passwd
|
|
|
|
maps will be refused. Since all user authentication programs run
|
|
|
|
with superuser privilege, they should have the required access to
|
|
|
|
users' encrypted password data while normal users will only
|
|
|
|
be allowed access to the standard
|
|
|
|
.Pa passwd
|
|
|
|
maps which contain no password information.
|
|
|
|
.Pp
|
|
|
|
Note that this feature cannot be used in an environment with
|
|
|
|
non-FreeBSD systems. Note also that a truly determined user with
|
|
|
|
unrestricted access to your network could still compromise the
|
|
|
|
.Pa master.passwd
|
|
|
|
maps.
|
|
|
|
.Ss UID and GID remapping with NIS overrides
|
|
|
|
Unlike SunOS and other operating systems that use Sun's NIS code,
|
|
|
|
FreeBSD allows the user to override
|
|
|
|
.Pa all
|
|
|
|
of the fields in a user's NIS
|
|
|
|
.Pa passwd
|
|
|
|
entry.
|
|
|
|
For example, consider the following
|
1994-09-20 22:44:37 +00:00
|
|
|
.Pa /etc/master.passwd
|
1995-09-02 04:25:24 +00:00
|
|
|
entry:
|
1994-09-20 22:44:37 +00:00
|
|
|
.Bd -literal -offset indent
|
1995-09-02 04:25:24 +00:00
|
|
|
+@foo-users:???:666:666:0:0:0:Bogus user:/home/bogus:/bin/bogus
|
1994-09-20 22:44:37 +00:00
|
|
|
|
|
|
|
.Ed
|
1995-09-02 04:25:24 +00:00
|
|
|
This entry will cause all users in the `foo-users' netgroup to
|
|
|
|
have
|
|
|
|
.Pa all
|
1996-01-30 13:52:50 +00:00
|
|
|
of their password information overridden, including UIDs,
|
1995-09-02 04:25:24 +00:00
|
|
|
GIDs and passwords. The result is that all `foo-users' will be
|
|
|
|
locked out of the system, since their passwords will be remapped
|
|
|
|
to invalid values.
|
|
|
|
.Pp
|
|
|
|
This is important to remember because most people are accustomed to
|
|
|
|
using an NIS wildcard entry that looks like this:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
+:*:0:0:::
|
|
|
|
|
|
|
|
.Ed
|
1996-01-30 13:52:50 +00:00
|
|
|
This often leads to new FreeBSD administrators choosing NIS entries for their
|
1995-09-02 04:25:24 +00:00
|
|
|
.Pa master.passwd
|
|
|
|
files that look like this:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
+:*:0:0::::::
|
|
|
|
|
|
|
|
.Ed
|
|
|
|
Or worse, this
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
+::0:0::::::
|
|
|
|
|
|
|
|
.Ed
|
|
|
|
.Pa DO _NOT_ PUT ENTRIES LIKE THIS IN YOUR
|
|
|
|
.Nm master.passwd
|
|
|
|
.Pa FILE!!
|
|
|
|
The first tells FreeBSD to remap all passwords to `*' (which
|
|
|
|
will prevent anybody from logging in) and to remap all UIDs and GIDs
|
|
|
|
to 0 (which will make everybody appear to be the superuser). The
|
|
|
|
second case just maps all UIDs and GIDs to 0, which means that
|
|
|
|
.Pa all users will appear to be root!
|
|
|
|
.Pp
|
|
|
|
.Ss Compatibility of NIS override evaluation
|
|
|
|
When Sun originally added NIS support to their
|
|
|
|
.Xr getpwent 3
|
|
|
|
routines, they took into account the fact that the SunOS password
|
|
|
|
.Pa /etc/passwd
|
|
|
|
file is in plain ASCII format. The SunOS documentation claims that
|
|
|
|
adding a '+' entry to the password file causes the contents of
|
|
|
|
the NIS password database to be 'inserted' at the position in
|
|
|
|
the file where the '+' entry appears. If, for example, the
|
|
|
|
administrator places the +:::::: entry in the middle of
|
|
|
|
.Pa /etc/passwd,
|
|
|
|
then the entire contents of the NIS password map would appear
|
|
|
|
as though it had been copied into the middle of the password
|
|
|
|
file. If the administrator places the +:::::: entry at both the
|
|
|
|
middle and the end of
|
|
|
|
.Pa /etc/passwd ,
|
|
|
|
then the NIS password map would appear twice: once in the middle
|
|
|
|
of the file and once at the end. (By using override entries
|
|
|
|
instead of simple wildcards, other combinations could be achieved.)
|
|
|
|
.Pp
|
|
|
|
By contrast, FreeBSD does not have a single ASCII password file: it
|
|
|
|
has a hashed password database. This database does not have an
|
|
|
|
easily-defined beginning, middle or end, which makes it very hard
|
|
|
|
to design a scheme that is 100% compatible with SunOS. For example,
|
|
|
|
the
|
|
|
|
.Fn getpwnam
|
|
|
|
and
|
|
|
|
.Fn getpwuid
|
|
|
|
functions in FreeBSD are designed to do direct queries to the
|
|
|
|
hash database rather than a linear search. This approach is faster
|
|
|
|
on systems where the password database is large. However, when
|
|
|
|
using direct database queries, the system does not know or care
|
|
|
|
about the order of the original password file, and therefore
|
|
|
|
it cannot easily apply the same override logic used by SunOS.
|
|
|
|
.Pp
|
|
|
|
Instead, FreeBSD groups all the NIS override entries together
|
|
|
|
and constructs a filter out of them. Each NIS password entry
|
|
|
|
is compared against the override filter exactly once and
|
|
|
|
treated accordingly: if the filter allows the entry through
|
|
|
|
unaltered, it's treated unaltered; if the filter calls for remapping
|
|
|
|
of fields, then fields are remapped; if the filter calls for
|
|
|
|
explicit exclusion (i.e. the entry matches a '-' override),
|
|
|
|
the entry is ignored; if the entry doesn't match against any
|
|
|
|
of the filter specifications, it's discarded.
|
|
|
|
.Pp
|
|
|
|
Again, note that the NIS '+' and '-' entries
|
|
|
|
themselves are handled in the order in which they were specified
|
|
|
|
in the
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
file since doing otherwise would lead to unpredicable behavior.
|
|
|
|
.Pp
|
|
|
|
The end result is that FreeBSD's provides a very close approximation
|
|
|
|
of SunOS's behavior while maintaining the database paradigm, though the
|
|
|
|
.Xr getpwent 3
|
|
|
|
functions do behave somewhat differently that their SunOS counterparts.
|
|
|
|
The primary differences are:
|
|
|
|
.Bl -bullet -offset indent
|
|
|
|
.It
|
|
|
|
Each NIS password map record can be mapped into the password
|
|
|
|
local password space only once.
|
|
|
|
.It
|
|
|
|
The placement of the NIS '+' and '-' entries does not necessarily
|
|
|
|
affect where NIS password records will be mapped into
|
|
|
|
the password space.
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
In %99 of all FreeBSD configurations, NIS client behavior will be
|
|
|
|
indistinguishable from that of SunOS or other similar systems. Even
|
1996-01-30 13:52:50 +00:00
|
|
|
so, users should be aware of these architectural differences.
|
1995-09-02 04:25:24 +00:00
|
|
|
.Pp
|
|
|
|
.Ss Using groups instead of netgroups for NIS overrides
|
|
|
|
FreeBSD offers the capability to do override matching based on
|
|
|
|
user groups rather than netgroups. If, for example, an NIS entry
|
|
|
|
is specified as:
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
+@operator:::::::::
|
|
|
|
|
|
|
|
.Ed
|
|
|
|
the system will first try to match users against a netgroup called
|
|
|
|
`operator.' If an `operator' netgroup doesn't exist, the system
|
|
|
|
will try to match users against the normal `operator' group
|
|
|
|
instead.
|
|
|
|
.Ss Changes in behavior from older versions of FreeBSD
|
|
|
|
There have been several bug fixes and improvements in FreeBSD's
|
|
|
|
NIS/YP handling, some of which have caused changes in behavior.
|
|
|
|
While the behavior changes are generally positive, it is important
|
|
|
|
that users and system administrators be aware of them:
|
|
|
|
.Bl -enum -offset indent
|
|
|
|
.It
|
|
|
|
In versions prior to 2.0.5, reverse lookups (i.e. using
|
1994-09-20 22:44:37 +00:00
|
|
|
.Fn getpwuid )
|
1995-09-02 04:25:24 +00:00
|
|
|
would not have overrides applied, which is to say that it
|
|
|
|
was possible for
|
1994-09-20 22:44:37 +00:00
|
|
|
.Fn getpwuid
|
1995-09-02 04:25:24 +00:00
|
|
|
to return a login name that
|
|
|
|
.Fn getpwnam
|
|
|
|
would not recognize. This has been fixed: overrides specified
|
|
|
|
in
|
|
|
|
.Pa /etc/master.passwd
|
|
|
|
now apply to all
|
|
|
|
.Xr getpwent 3
|
|
|
|
functions.
|
|
|
|
.It
|
|
|
|
Prior to FreeBSD 2.0.5, netgroup overrides did not work at
|
|
|
|
all, largely because FreeBSD did not have support for reading
|
|
|
|
netgroups through NIS. Again, this has been fixed, and
|
|
|
|
netgroups can be specified just as in SunOS and similar NIS-capable
|
|
|
|
systems.
|
|
|
|
.It
|
|
|
|
FreeBSD now has NIS server capabilities and supports the use
|
|
|
|
of
|
|
|
|
.Pa master.passwd
|
|
|
|
NIS maps in addition to the standard Sixth Edition format
|
|
|
|
.Pa passwd
|
|
|
|
maps.
|
|
|
|
This means that you can specify change, expiration and class
|
|
|
|
information through NIS, provided you use a FreeBSD system as
|
|
|
|
the NIS server.
|
|
|
|
.El
|
1994-09-20 22:44:37 +00:00
|
|
|
.Sh FILES
|
|
|
|
.Bl -tag -width /etc/master.passwd -compact
|
|
|
|
.It Pa /etc/passwd
|
|
|
|
ASCII password file, with passwords removed
|
|
|
|
.It Pa /etc/pwd.db
|
|
|
|
.Xr db 3 -format
|
|
|
|
password database, with passwords removed
|
|
|
|
.It Pa /etc/master.passwd
|
|
|
|
ASCII password file, with passwords intact
|
|
|
|
.It Pa /etc/spwd.db
|
|
|
|
.Xr db 3 -format
|
|
|
|
password database, with passwords intact
|
|
|
|
.El
|
1994-05-30 19:09:18 +00:00
|
|
|
.Sh SEE ALSO
|
|
|
|
.Xr chpass 1 ,
|
|
|
|
.Xr login 1 ,
|
|
|
|
.Xr passwd 1 ,
|
1996-12-26 02:02:31 +00:00
|
|
|
.Xr getpwent 3 ,
|
|
|
|
.Xr yp 4 ,
|
|
|
|
.Xr adduser 8 ,
|
1994-05-30 19:09:18 +00:00
|
|
|
.Xr pwd_mkdb 8 ,
|
1996-12-26 02:02:31 +00:00
|
|
|
.Xr vipw 8
|
1994-05-30 19:09:18 +00:00
|
|
|
.Sh BUGS
|
|
|
|
User information should (and eventually will) be stored elsewhere.
|
1994-09-20 22:44:37 +00:00
|
|
|
.Pp
|
|
|
|
The YP/NIS password database makes encrypted passwords visible to
|
1995-09-02 04:25:24 +00:00
|
|
|
ordinary users, thus making password cracking easier unless you use
|
|
|
|
shadow passwords with the
|
|
|
|
.Pa master.passwd
|
|
|
|
maps and FreeBSD's
|
|
|
|
.Xr ypserv 8
|
|
|
|
server.
|
1994-09-20 22:44:37 +00:00
|
|
|
.Pp
|
1995-09-02 04:25:24 +00:00
|
|
|
Unless you're using FreeBSD's
|
|
|
|
.Xr ypserv 8 ,
|
|
|
|
which supports the use of
|
|
|
|
.Pa master.passwd
|
1996-01-30 13:52:50 +00:00
|
|
|
type maps,
|
1995-09-02 04:25:24 +00:00
|
|
|
the YP/NIS password database will be in old-style (Sixth Edition) format,
|
|
|
|
which means that site-wide values for user login class, password
|
|
|
|
expiration date, and other fields present in the current format
|
|
|
|
will not be available when a FreeBSD system is used as a client with
|
|
|
|
a standard NIS server.
|
1994-05-30 19:09:18 +00:00
|
|
|
.Sh COMPATIBILITY
|
1996-08-22 23:39:32 +00:00
|
|
|
The password file format has changed since
|
|
|
|
.Bx 4.3 .
|
1994-05-30 19:09:18 +00:00
|
|
|
The following awk script can be used to convert your old-style password
|
|
|
|
file into a new style password file.
|
|
|
|
The additional fields
|
|
|
|
.Dq class ,
|
|
|
|
.Dq change
|
|
|
|
and
|
|
|
|
.Dq expire
|
|
|
|
are added, but are turned off by default.
|
|
|
|
Class is currently not implemented, but change and expire are; to set them,
|
|
|
|
use the current day in seconds from the epoch + whatever number of seconds
|
|
|
|
of offset you want.
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
BEGIN { FS = ":"}
|
|
|
|
{ print $1 ":" $2 ":" $3 ":" $4 "::0:0:" $5 ":" $6 ":" $7 }
|
|
|
|
.Ed
|
|
|
|
.Sh HISTORY
|
|
|
|
A
|
|
|
|
.Nm
|
|
|
|
file format appeared in
|
|
|
|
.At v6 .
|
1994-09-20 22:44:37 +00:00
|
|
|
The YP/NIS functionality is modeled after
|
|
|
|
.Tn SunOS
|
|
|
|
and first appeared in
|
|
|
|
.Tn FreeBSD
|
|
|
|
1.1. The override capability is new in
|
1996-08-22 23:51:58 +00:00
|
|
|
.Fx 2.0 .
|
|
|
|
The override capability was updated to properly support netgroups
|
1995-09-02 04:25:24 +00:00
|
|
|
in
|
1996-08-22 23:51:58 +00:00
|
|
|
.Fx 2.0.5 .
|