xref: /freebsd/usr.bin/chpass/chpass.1 (revision 4a0f765fbf09711e612e86fce8bb09ec43f482d9)
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32.\"     @(#)chpass.1	8.2 (Berkeley) 12/30/93
33.\"
34.Dd December 30, 1993
35.Dt CHPASS 1
36.Os
37.Sh NAME
38.Nm chpass, chfn, chsh, ypchpass, ypchfn, ypchsh
39.Nd add or change user database information
40.Sh SYNOPSIS
41chpass
42.Op Fl a Ar list
43.Op Fl p Ar encpass
44.Op Fl s Ar newshell
45.Op user
46.Sh DESCRIPTION
47The
48.Nm chpass
49program
50allows editing of the user database information associated
51with
52.Ar user
53or, by default, the current user.
54The information is formatted and supplied to an editor for changes.
55.Pp
56Only the information that the user is allowed to change is displayed.
57.Pp
58The options are as follows:
59.Bl -tag -width flag
60.It Fl a
61The super-user is allowed to directly supply a user database
62entry, in the format specified by
63.Xr passwd 5 ,
64as an argument.
65This argument must be a colon (``:'') separated list of all the
66user database fields, although they may be empty.
67.It Fl p
68The super-user is allowed to directly supply an encrypted password field,
69in the format used by
70.Xr crypt 3 ,
71as an argument.
72.It Fl s
73The
74.Fl s
75option attempts to change the user's shell to
76.Ar newshell .
77.El
78.Pp
79Possible display items are as follows:
80.Pp
81.Bl -tag -width "Home Directory:" -compact -offset indent
82.It Login:
83user's login name
84.It Password:
85user's encrypted password
86.It Uid:
87user's login
88.It Gid:
89user's login group
90.It Change:
91password change time
92.It Expire:
93account expiration time
94.It Class:
95user's general classification
96.It Home Directory:
97user's home directory
98.It Shell:
99user's login shell
100.It Full Name:
101user's real name
102.It Location:
103user's normal location
104.It Home Phone:
105user's home phone
106.It Office Phone:
107user's office phone
108.El
109.Pp
110The
111.Ar login
112field is the user name used to access the computer account.
113.Pp
114The
115.Ar password
116field contains the encrypted form of the user's password.
117.Pp
118The
119.Ar uid
120field is the number associated with the
121.Ar login
122field.
123Both of these fields should be unique across the system (and often
124across a group of systems) as they control file access.
125.Pp
126While it is possible to have multiple entries with identical login names
127and/or identical user id's, it is usually a mistake to do so.  Routines
128that manipulate these files will often return only one of the multiple
129entries, and that one by random selection.
130.Pp
131The
132.Ar group
133field is the group that the user will be placed in at login.
134Since BSD supports multiple groups (see
135.Xr groups 1 )
136this field currently has little special meaning.
137This field may be filled in with either a number or a group name (see
138.Xr group 5 ) .
139.Pp
140The
141.Ar change
142field is the date by which the password must be changed.
143.Pp
144The
145.Ar expire
146field is the date on which the account expires.
147.Pp
148Both the
149.Ar change
150and
151.Ar expire
152fields should be entered in the form ``month day year'' where
153.Ar month
154is the month name (the first three characters are sufficient),
155.Ar day
156is the day of the month, and
157.Ar year
158is the year.
159.Pp
160The
161.Ar class
162field is currently unused.  In the near future it will be a key to
163a
164.Xr termcap 5
165style database of user attributes.
166.Pp
167The user's
168.Ar home directory
169is the full UNIX path name where the user
170will be placed at login.
171.Pp
172The
173.Ar shell
174field is the command interpreter the user prefers.
175If the
176.Ar shell
177field is empty, the Bourne shell,
178.Pa /bin/sh ,
179is assumed.
180When altering a login shell, and not the super-user, the user
181may not change from a non-standard shell or to a non-standard
182shell.
183Non-standard is defined as a shell not found in
184.Pa /etc/shells .
185.Pp
186The last four fields are for storing the user's
187.Ar full name , office location ,
188and
189.Ar home
190and
191.Ar work telephone
192numbers.
193.Pp
194Once the information has been verified,
195.Nm chpass
196uses
197.Xr pwd_mkdb 8
198to update the user database.
199.Sh ENVIRONMENT
200The
201.Xr vi 1
202editor will be used unless the environment variable EDITOR is set to
203an alternate editor.
204When the editor terminates, the information is re-read and used to
205update the user database itself.
206Only the user, or the super-user, may edit the information associated
207with the user.
208.Sh NIS INTERACTION
209.Nm Chpass
210can also be used in conjunction with NIS, however some restrictions
211apply.
212Currently,
213.Nm chpass
214can only make changes to the NIS passwd maps through
215.Xr rpc.yppasswdd 8 ,
216which normally only permits changes to a user's password, shell and GECOS
217fields. Except when invoked by the super-user on the NIS master server,
218.Nm chpass
219(and, similarly,
220.Xr passwd 1 )
221can not use the
222.Xr rpc.yppasswdd 8
223server to change other user information or
224add new records to the NIS passwd maps.
225Furthermore,
226.Xr rpc.yppasswdd 8
227requires password authentication before it will make any
228changes. The only user allowed to submit changes without supplying
229a password is the super-user on the NIS master server; all other users,
230including those with root privileges on NIS clients (and NIS slave
231servers) must enter a password.
232(The super-user on the NIS master is allowed to bypass these restrictions
233largely for convenience: a user with root access
234to the NIS master server already has the privileges required to make
235updates to the NIS maps, but editing the map source files by hand can
236be cumbersome.
237.Pp
238Note: these exceptions only apply when the NIS master server is a
239FreeBSD system.)
240.Pp
241Consequently, except where noted, the following restrictions apply when
242.Nm chpass
243is used with NIS:
244.Bl -enum -offset indent
245.It
246.Pa Only the shell and GECOS information may be changed.
247All other
248fields are restricted, even when
249.Nm chpass
250is invoked by the super-user.
251While support for
252changing other fields could be added, this would lead to
253compatibility problems with other NIS-capable systems.
254Even though the super-user may supply data for other fields
255while editing an entry, the extra information (other than the
256password -- see below) will be silently discarded.
257.Pp
258Exception: the super-user on the NIS master server is permitted to
259change any field.
260.Pp
261.It
262.Pa Password authentication is required.
263.Nm Chpass
264will prompt for the user's NIS password before effecting
265any changes. If the password is invalid, all changes will be
266discarded.
267.Pp
268Exception: the super-user on the NIS master server is allowed to
269submit changes without supplying a password. (The super-user may
270choose to turn off this feature using the
271.Fl o
272flag, described below.)
273.It
274.Pa Adding new records to the local
275.Pa password database is discouraged.
276.Nm Chpass
277will allow the administrator to add new records to the
278local password database while NIS is enabled, but this can lead to
279some confusion since the new records are appended to the end of
280the master password file, usually after the special NIS '+' entries.
281The administrator should use
282.Xr vipw 8
283to modify the local password
284file when NIS is running.
285.Pp
286The super-user on the NIS master server is permitted to add new records
287to the NIS password maps, provided the
288.Xr rpc.yppasswdd 8
289server has been started with the
290.Fl a
291flag to permitted additions (it refuses them by default).
292.Nm Chpass
293tries to update the local password database by default; to update the
294NIS maps instead, invoke chpass with the
295.Fl y
296flag.
297.It
298.Pa Password changes are not permitted.
299Users should use
300.Xr passwd 1
301or
302.Xr yppasswd 1
303to change their NIS passwords. The super-user is allowed to specify
304a new password (even though the ``Password:'' field does not show
305up in the editor template, the super-user may add it back by hand),
306but even the super-user must supply the user's original password
307otherwise
308.Xr rpc.yppasswdd 8
309will refuse to update the NIS maps.
310.Pp
311Exception: the super-user on the NIS master server is permitted to
312change a user's NIS password with
313.Nm chpass .
314.El
315.Pp
316There are also a few extra option flags that are available when
317.Nm chpass
318is compiled with NIS support:
319.Bl -tag -width flag
320.It Fl l
321The
322.Fl l
323flag forces
324.Nm chpass
325to modify the local copy of a user's password
326information in the even that a user exists in both
327the local and NIS databases.
328.It Fl y
329This flag has the opposite effect of
330.Fl l .
331This flag is largely redundant since
332.Nm chpass
333operates on NIS entries by default if NIS is enabled.
334.It Fl d Ar domain
335Specify a particular NIS domain.
336.Nm Chpass
337uses the system domain name by default, as set by the
338.Xr domainname 1
339command. The
340.Fl d
341option can be used to override a default, or to specify a domain
342when the system domain name is not set.
343.It Fl h Ar host
344Specify the name or address of an NIS server to query. Normally,
345.Nm chpass
346will communicate with the NIS master host specified in the
347.Pa master.passwd
348or
349.Pa passwd
350maps. On hosts that have not been configured as NIS clients, there is
351no way for the program to determine this information unless the user
352provides the hostname of a server. Note that the specified hostname need
353not be that of the NIS master server; the name of any server, master or
354slave, in a given NIS domain will do.
355.Pp
356When using the
357.Fl d
358option, the hostname defaults to ``localhost.'' The
359.Fl h
360option can be used in conjunction with the
361.Fl d
362option, in which case the user-specified hostname will override
363the default.
364.Pp
365.It Fl o
366Force the use of RPC-based updates when communicating with
367.Xr rpc.yppasswdd 8
368(``old-mode'').
369When invoked by the super-user on the NIS master server,
370.Nm chpass
371allows unrestricted changes to the NIS passwd maps using dedicated,
372non-RPC-based mechanism (in this case, a UNIX domain socket). The
373.Fl o
374flag can be used to force
375.Nm chpass
376to use the standard update mechanism instead. This option is provided
377mainly for testing purposes.
378.El
379.Pp
380.Sh FILES
381.Bl -tag -width /etc/master.passwd -compact
382.It Pa /etc/master.passwd
383The user database
384.It Pa /etc/passwd
385A Version 7 format password file
386.It Pa /etc/chpass.XXXXXX
387Temporary copy of the password file
388.It Pa /etc/shells
389The list of approved shells
390.El
391.Sh SEE ALSO
392.Xr finger 1 ,
393.Xr login 1 ,
394.Xr passwd 1 ,
395.Xr getusershell 3 ,
396.Xr passwd 5 ,
397.Xr pwd_mkdb 8 ,
398.Xr vipw 8
399.Rs
400.%A Robert Morris
401and
402.%A Ken Thompson
403.%T "UNIX Password security"
404.Re
405.Sh NOTES
406The
407.Xr chfn 1 ,
408.Xr chsh 1 ,
409.Xr ypchpass 1 ,
410.Xr ypchfn 1
411and
412.Xr ypchsh 1
413commands are really only links to
414.Nm chpass .
415.Sh BUGS
416User information should (and eventually will) be stored elsewhere.
417.Sh HISTORY
418The
419.Nm
420command appeared in
421.Bx 4.3 Reno .
422