xref: /freebsd/usr.bin/chpass/chpass.1 (revision 2ad872c5794e4c26fdf6ed219ad3f09ca0d5304a)
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32.\"     @(#)chpass.1	8.2 (Berkeley) 12/30/93
33.\"     $Id: chpass.1,v 1.13 1998/12/13 02:48:43 dillon Exp $
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 "Other Information:" -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 Class:
92user's general classification
93.It Change:
94password change time
95.It Expire:
96account expiration time
97.It Full Name:
98user's real name
99.It Location:
100user's normal location (1)
101.It Home Phone:
102user's home phone (1)
103.It Office Phone:
104user's office phone (1)
105.It Other Information:
106any locally defined parameters for user (1)
107.It Home Directory:
108user's home directory
109.It Shell:
110user's login shell
111.Pp
112.It NOTE(1) -
113In the actual master.passwd file, these fields are comma-delimited
114fields embedded in the FullName field.
115.El
116.Pp
117The
118.Ar login
119field is the user name used to access the computer account.
120.Pp
121The
122.Ar password
123field contains the encrypted form of the user's password.
124.Pp
125The
126.Ar uid
127field is the number associated with the
128.Ar login
129field.
130Both of these fields should be unique across the system (and often
131across a group of systems) as they control file access.
132.Pp
133While it is possible to have multiple entries with identical login names
134and/or identical user id's, it is usually a mistake to do so.  Routines
135that manipulate these files will often return only one of the multiple
136entries, and that one by random selection.
137.Pp
138The
139.Ar group
140field is the group that the user will be placed in at login.
141Since BSD supports multiple groups (see
142.Xr groups 1 )
143this field currently has little special meaning.
144This field may be filled in with either a number or a group name (see
145.Xr group 5 ) .
146.Pp
147The
148.Ar class
149field references class descriptions in
150.Ar /etc/login.conf
151and is typically used to initialize the user's system resource limits
152when they login.
153.Pp
154The
155.Ar change
156field is the date by which the password must be changed.
157.Pp
158The
159.Ar expire
160field is the date on which the account expires.
161.Pp
162Both the
163.Ar change
164and
165.Ar expire
166fields should be entered in the form ``month day year'' where
167.Ar month
168is the month name (the first three characters are sufficient),
169.Ar day
170is the day of the month, and
171.Ar year
172is the year.
173.Pp
174Five fields are available for storing the user's
175.Ar full name , office location ,
176.Ar work
177and
178.Ar home telephone
179numbers and finally
180.Ar other information
181which is a single comma delimited string to represent any additional
182gcos fields (typically used for site specific user information).
183.Pp
184The user's
185.Ar home directory
186is the full UNIX path name where the user
187will be placed at login.
188.Pp
189The
190.Ar shell
191field is the command interpreter the user prefers.
192If the
193.Ar shell
194field is empty, the Bourne shell,
195.Pa /bin/sh ,
196is assumed.
197When altering a login shell, and not the super-user, the user
198may not change from a non-standard shell or to a non-standard
199shell.
200Non-standard is defined as a shell not found in
201.Pa /etc/shells .
202.Pp
203Once the information has been verified,
204.Nm chpass
205uses
206.Xr pwd_mkdb 8
207to update the user database.
208.Sh ENVIRONMENT
209The
210.Xr vi 1
211editor will be used unless the environment variable EDITOR is set to
212an alternate editor.
213When the editor terminates, the information is re-read and used to
214update the user database itself.
215Only the user, or the super-user, may edit the information associated
216with the user.
217.Sh NIS INTERACTION
218.Nm Chpass
219can also be used in conjunction with NIS, however some restrictions
220apply.
221Currently,
222.Nm chpass
223can only make changes to the NIS passwd maps through
224.Xr rpc.yppasswdd 8 ,
225which normally only permits changes to a user's password, shell and GECOS
226fields. Except when invoked by the super-user on the NIS master server,
227.Nm chpass
228(and, similarly,
229.Xr passwd 1 )
230can not use the
231.Xr rpc.yppasswdd 8
232server to change other user information or
233add new records to the NIS passwd maps.
234Furthermore,
235.Xr rpc.yppasswdd 8
236requires password authentication before it will make any
237changes. The only user allowed to submit changes without supplying
238a password is the super-user on the NIS master server; all other users,
239including those with root privileges on NIS clients (and NIS slave
240servers) must enter a password.
241(The super-user on the NIS master is allowed to bypass these restrictions
242largely for convenience: a user with root access
243to the NIS master server already has the privileges required to make
244updates to the NIS maps, but editing the map source files by hand can
245be cumbersome.
246.Pp
247Note: these exceptions only apply when the NIS master server is a
248FreeBSD system.)
249.Pp
250Consequently, except where noted, the following restrictions apply when
251.Nm chpass
252is used with NIS:
253.Bl -enum -offset indent
254.It
255.Pa Only the shell and GECOS information may be changed.
256All other
257fields are restricted, even when
258.Nm chpass
259is invoked by the super-user.
260While support for
261changing other fields could be added, this would lead to
262compatibility problems with other NIS-capable systems.
263Even though the super-user may supply data for other fields
264while editing an entry, the extra information (other than the
265password -- see below) will be silently discarded.
266.Pp
267Exception: the super-user on the NIS master server is permitted to
268change any field.
269.Pp
270.It
271.Pa Password authentication is required.
272.Nm Chpass
273will prompt for the user's NIS password before effecting
274any changes. If the password is invalid, all changes will be
275discarded.
276.Pp
277Exception: the super-user on the NIS master server is allowed to
278submit changes without supplying a password. (The super-user may
279choose to turn off this feature using the
280.Fl o
281flag, described below.)
282.It
283.Pa Adding new records to the local
284.Pa password database is discouraged.
285.Nm Chpass
286will allow the administrator to add new records to the
287local password database while NIS is enabled, but this can lead to
288some confusion since the new records are appended to the end of
289the master password file, usually after the special NIS '+' entries.
290The administrator should use
291.Xr vipw 8
292to modify the local password
293file when NIS is running.
294.Pp
295The super-user on the NIS master server is permitted to add new records
296to the NIS password maps, provided the
297.Xr rpc.yppasswdd 8
298server has been started with the
299.Fl a
300flag to permitted additions (it refuses them by default).
301.Nm Chpass
302tries to update the local password database by default; to update the
303NIS maps instead, invoke chpass with the
304.Fl y
305flag.
306.It
307.Pa Password changes are not permitted.
308Users should use
309.Xr passwd 1
310or
311.Xr yppasswd 1
312to change their NIS passwords. The super-user is allowed to specify
313a new password (even though the ``Password:'' field does not show
314up in the editor template, the super-user may add it back by hand),
315but even the super-user must supply the user's original password
316otherwise
317.Xr rpc.yppasswdd 8
318will refuse to update the NIS maps.
319.Pp
320Exception: the super-user on the NIS master server is permitted to
321change a user's NIS password with
322.Nm chpass .
323.El
324.Pp
325There are also a few extra option flags that are available when
326.Nm chpass
327is compiled with NIS support:
328.Bl -tag -width flag
329.It Fl l
330The
331.Fl l
332flag forces
333.Nm chpass
334to modify the local copy of a user's password
335information in the even that a user exists in both
336the local and NIS databases.
337.It Fl y
338This flag has the opposite effect of
339.Fl l .
340This flag is largely redundant since
341.Nm chpass
342operates on NIS entries by default if NIS is enabled.
343.It Fl d Ar domain
344Specify a particular NIS domain.
345.Nm Chpass
346uses the system domain name by default, as set by the
347.Xr domainname 1
348command. The
349.Fl d
350option can be used to override a default, or to specify a domain
351when the system domain name is not set.
352.It Fl h Ar host
353Specify the name or address of an NIS server to query. Normally,
354.Nm chpass
355will communicate with the NIS master host specified in the
356.Pa master.passwd
357or
358.Pa passwd
359maps. On hosts that have not been configured as NIS clients, there is
360no way for the program to determine this information unless the user
361provides the hostname of a server. Note that the specified hostname need
362not be that of the NIS master server; the name of any server, master or
363slave, in a given NIS domain will do.
364.Pp
365When using the
366.Fl d
367option, the hostname defaults to ``localhost.'' The
368.Fl h
369option can be used in conjunction with the
370.Fl d
371option, in which case the user-specified hostname will override
372the default.
373.Pp
374.It Fl o
375Force the use of RPC-based updates when communicating with
376.Xr rpc.yppasswdd 8
377(``old-mode'').
378When invoked by the super-user on the NIS master server,
379.Nm chpass
380allows unrestricted changes to the NIS passwd maps using dedicated,
381non-RPC-based mechanism (in this case, a UNIX domain socket). The
382.Fl o
383flag can be used to force
384.Nm chpass
385to use the standard update mechanism instead. This option is provided
386mainly for testing purposes.
387.El
388.Pp
389.Sh FILES
390.Bl -tag -width /etc/master.passwd -compact
391.It Pa /etc/master.passwd
392The user database
393.It Pa /etc/passwd
394A Version 7 format password file
395.It Pa /etc/chpass.XXXXXX
396Temporary copy of the password file
397.It Pa /etc/shells
398The list of approved shells
399.El
400.Sh SEE ALSO
401.Xr finger 1 ,
402.Xr login 1 ,
403.Xr passwd 1 ,
404.Xr getusershell 3 ,
405.Xr login.conf 5,
406.Xr passwd 5 ,
407.Xr pwd_mkdb 8 ,
408.Xr vipw 8
409.Rs
410.%A Robert Morris
411and
412.%A Ken Thompson
413.%T "UNIX Password security"
414.Re
415.Sh NOTES
416The
417.Xr chfn 1 ,
418.Xr chsh 1 ,
419.Xr ypchpass 1 ,
420.Xr ypchfn 1
421and
422.Xr ypchsh 1
423commands are really only links to
424.Nm chpass .
425.Sh BUGS
426User information should (and eventually will) be stored elsewhere.
427.Sh HISTORY
428The
429.Nm
430command appeared in
431.Bx 4.3 Reno .
432