xref: /freebsd/usr.bin/chpass/chpass.1 (revision ce834215a70ff69e7e222827437116eee2f9ac6f)
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32.\"     @(#)chpass.1	8.2 (Berkeley) 12/30/93
33.\"     $Id$
34.\"
35.Dd December 30, 1993
36.Dt CHPASS 1
37.Os
38.Sh NAME
39.Nm chpass, chfn, chsh, ypchpass, ypchfn, ypchsh
40.Nd add or change user database information
41.Sh SYNOPSIS
42.Nm chpass
43.Op Fl a Ar list
44.Op Fl p Ar encpass
45.Op Fl s Ar newshell
46.Op user
47.Sh DESCRIPTION
48The
49.Nm chpass
50program
51allows editing of the user database information associated
52with
53.Ar user
54or, by default, the current user.
55The information is formatted and supplied to an editor for changes.
56.Pp
57Only the information that the user is allowed to change is displayed.
58.Pp
59The options are as follows:
60.Bl -tag -width flag
61.It Fl a
62The super-user is allowed to directly supply a user database
63entry, in the format specified by
64.Xr passwd 5 ,
65as an argument.
66This argument must be a colon (``:'') separated list of all the
67user database fields, although they may be empty.
68.It Fl p
69The super-user is allowed to directly supply an encrypted password field,
70in the format used by
71.Xr crypt 3 ,
72as an argument.
73.It Fl s
74The
75.Fl s
76option attempts to change the user's shell to
77.Ar newshell .
78.El
79.Pp
80Possible display items are as follows:
81.Pp
82.Bl -tag -width "Home Directory:" -compact -offset indent
83.It Login:
84user's login name
85.It Password:
86user's encrypted password
87.It Uid:
88user's login
89.It Gid:
90user's login group
91.It Change:
92password change time
93.It Expire:
94account expiration time
95.It Class:
96user's general classification
97.It Home Directory:
98user's home directory
99.It Shell:
100user's login shell
101.It Full Name:
102user's real name
103.It Location:
104user's normal location
105.It Home Phone:
106user's home phone
107.It Office Phone:
108user's office phone
109.El
110.Pp
111The
112.Ar login
113field is the user name used to access the computer account.
114.Pp
115The
116.Ar password
117field contains the encrypted form of the user's password.
118.Pp
119The
120.Ar uid
121field is the number associated with the
122.Ar login
123field.
124Both of these fields should be unique across the system (and often
125across a group of systems) as they control file access.
126.Pp
127While it is possible to have multiple entries with identical login names
128and/or identical user id's, it is usually a mistake to do so.  Routines
129that manipulate these files will often return only one of the multiple
130entries, and that one by random selection.
131.Pp
132The
133.Ar group
134field is the group that the user will be placed in at login.
135Since BSD supports multiple groups (see
136.Xr groups 1 )
137this field currently has little special meaning.
138This field may be filled in with either a number or a group name (see
139.Xr group 5 ) .
140.Pp
141The
142.Ar change
143field is the date by which the password must be changed.
144.Pp
145The
146.Ar expire
147field is the date on which the account expires.
148.Pp
149Both the
150.Ar change
151and
152.Ar expire
153fields should be entered in the form ``month day year'' where
154.Ar month
155is the month name (the first three characters are sufficient),
156.Ar day
157is the day of the month, and
158.Ar year
159is the year.
160.Pp
161The
162.Ar class
163field is currently unused.  In the near future it will be a key to
164a
165.Xr termcap 5
166style database of user attributes.
167.Pp
168The user's
169.Ar home directory
170is the full UNIX path name where the user
171will be placed at login.
172.Pp
173The
174.Ar shell
175field is the command interpreter the user prefers.
176If the
177.Ar shell
178field is empty, the Bourne shell,
179.Pa /bin/sh ,
180is assumed.
181When altering a login shell, and not the super-user, the user
182may not change from a non-standard shell or to a non-standard
183shell.
184Non-standard is defined as a shell not found in
185.Pa /etc/shells .
186.Pp
187The last four fields are for storing the user's
188.Ar full name , office location ,
189and
190.Ar home
191and
192.Ar work telephone
193numbers.
194.Pp
195Once the information has been verified,
196.Nm chpass
197uses
198.Xr pwd_mkdb 8
199to update the user database.
200.Sh ENVIRONMENT
201The
202.Xr vi 1
203editor will be used unless the environment variable EDITOR is set to
204an alternate editor.
205When the editor terminates, the information is re-read and used to
206update the user database itself.
207Only the user, or the super-user, may edit the information associated
208with the user.
209.Sh NIS INTERACTION
210.Nm Chpass
211can also be used in conjunction with NIS, however some restrictions
212apply.
213Currently,
214.Nm chpass
215can only make changes to the NIS passwd maps through
216.Xr rpc.yppasswdd 8 ,
217which normally only permits changes to a user's password, shell and GECOS
218fields. Except when invoked by the super-user on the NIS master server,
219.Nm chpass
220(and, similarly,
221.Xr passwd 1 )
222can not use the
223.Xr rpc.yppasswdd 8
224server to change other user information or
225add new records to the NIS passwd maps.
226Furthermore,
227.Xr rpc.yppasswdd 8
228requires password authentication before it will make any
229changes. The only user allowed to submit changes without supplying
230a password is the super-user on the NIS master server; all other users,
231including those with root privileges on NIS clients (and NIS slave
232servers) must enter a password.
233(The super-user on the NIS master is allowed to bypass these restrictions
234largely for convenience: a user with root access
235to the NIS master server already has the privileges required to make
236updates to the NIS maps, but editing the map source files by hand can
237be cumbersome.
238.Pp
239Note: these exceptions only apply when the NIS master server is a
240FreeBSD system.)
241.Pp
242Consequently, except where noted, the following restrictions apply when
243.Nm chpass
244is used with NIS:
245.Bl -enum -offset indent
246.It
247.Pa Only the shell and GECOS information may be changed.
248All other
249fields are restricted, even when
250.Nm chpass
251is invoked by the super-user.
252While support for
253changing other fields could be added, this would lead to
254compatibility problems with other NIS-capable systems.
255Even though the super-user may supply data for other fields
256while editing an entry, the extra information (other than the
257password -- see below) will be silently discarded.
258.Pp
259Exception: the super-user on the NIS master server is permitted to
260change any field.
261.Pp
262.It
263.Pa Password authentication is required.
264.Nm Chpass
265will prompt for the user's NIS password before effecting
266any changes. If the password is invalid, all changes will be
267discarded.
268.Pp
269Exception: the super-user on the NIS master server is allowed to
270submit changes without supplying a password. (The super-user may
271choose to turn off this feature using the
272.Fl o
273flag, described below.)
274.It
275.Pa Adding new records to the local
276.Pa password database is discouraged.
277.Nm Chpass
278will allow the administrator to add new records to the
279local password database while NIS is enabled, but this can lead to
280some confusion since the new records are appended to the end of
281the master password file, usually after the special NIS '+' entries.
282The administrator should use
283.Xr vipw 8
284to modify the local password
285file when NIS is running.
286.Pp
287The super-user on the NIS master server is permitted to add new records
288to the NIS password maps, provided the
289.Xr rpc.yppasswdd 8
290server has been started with the
291.Fl a
292flag to permitted additions (it refuses them by default).
293.Nm Chpass
294tries to update the local password database by default; to update the
295NIS maps instead, invoke chpass with the
296.Fl y
297flag.
298.It
299.Pa Password changes are not permitted.
300Users should use
301.Xr passwd 1
302or
303.Xr yppasswd 1
304to change their NIS passwords. The super-user is allowed to specify
305a new password (even though the ``Password:'' field does not show
306up in the editor template, the super-user may add it back by hand),
307but even the super-user must supply the user's original password
308otherwise
309.Xr rpc.yppasswdd 8
310will refuse to update the NIS maps.
311.Pp
312Exception: the super-user on the NIS master server is permitted to
313change a user's NIS password with
314.Nm chpass .
315.El
316.Pp
317There are also a few extra option flags that are available when
318.Nm chpass
319is compiled with NIS support:
320.Bl -tag -width flag
321.It Fl l
322The
323.Fl l
324flag forces
325.Nm chpass
326to modify the local copy of a user's password
327information in the even that a user exists in both
328the local and NIS databases.
329.It Fl y
330This flag has the opposite effect of
331.Fl l .
332This flag is largely redundant since
333.Nm chpass
334operates on NIS entries by default if NIS is enabled.
335.It Fl d Ar domain
336Specify a particular NIS domain.
337.Nm Chpass
338uses the system domain name by default, as set by the
339.Xr domainname 1
340command. The
341.Fl d
342option can be used to override a default, or to specify a domain
343when the system domain name is not set.
344.It Fl h Ar host
345Specify the name or address of an NIS server to query. Normally,
346.Nm chpass
347will communicate with the NIS master host specified in the
348.Pa master.passwd
349or
350.Pa passwd
351maps. On hosts that have not been configured as NIS clients, there is
352no way for the program to determine this information unless the user
353provides the hostname of a server. Note that the specified hostname need
354not be that of the NIS master server; the name of any server, master or
355slave, in a given NIS domain will do.
356.Pp
357When using the
358.Fl d
359option, the hostname defaults to ``localhost.'' The
360.Fl h
361option can be used in conjunction with the
362.Fl d
363option, in which case the user-specified hostname will override
364the default.
365.Pp
366.It Fl o
367Force the use of RPC-based updates when communicating with
368.Xr rpc.yppasswdd 8
369(``old-mode'').
370When invoked by the super-user on the NIS master server,
371.Nm chpass
372allows unrestricted changes to the NIS passwd maps using dedicated,
373non-RPC-based mechanism (in this case, a UNIX domain socket). The
374.Fl o
375flag can be used to force
376.Nm chpass
377to use the standard update mechanism instead. This option is provided
378mainly for testing purposes.
379.El
380.Pp
381.Sh FILES
382.Bl -tag -width /etc/master.passwd -compact
383.It Pa /etc/master.passwd
384The user database
385.It Pa /etc/passwd
386A Version 7 format password file
387.It Pa /etc/chpass.XXXXXX
388Temporary copy of the password file
389.It Pa /etc/shells
390The list of approved shells
391.El
392.Sh SEE ALSO
393.Xr finger 1 ,
394.Xr login 1 ,
395.Xr passwd 1 ,
396.Xr getusershell 3 ,
397.Xr passwd 5 ,
398.Xr pwd_mkdb 8 ,
399.Xr vipw 8
400.Rs
401.%A Robert Morris
402and
403.%A Ken Thompson
404.%T "UNIX Password security"
405.Re
406.Sh NOTES
407The
408.Xr chfn 1 ,
409.Xr chsh 1 ,
410.Xr ypchpass 1 ,
411.Xr ypchfn 1
412and
413.Xr ypchsh 1
414commands are really only links to
415.Nm chpass .
416.Sh BUGS
417User information should (and eventually will) be stored elsewhere.
418.Sh HISTORY
419The
420.Nm
421command appeared in
422.Bx 4.3 Reno .
423