xref: /freebsd/usr.bin/chpass/chpass.1 (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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32.\"     @(#)chpass.1	8.2 (Berkeley) 12/30/93
33.\"     $Id: chpass.1,v 1.14 1998/12/13 15:32:26 bde 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 Office Location:
100user's office location (1)
101.It Office Phone:
102user's office phone (1)
103.It Home Phone:
104user's home 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).
183Note that
184.Xr finger 1
185will display the office location and office phone together under the
186heading
187.Ar Office: .
188.Pp
189The user's
190.Ar home directory
191is the full UNIX path name where the user
192will be placed at login.
193.Pp
194The
195.Ar shell
196field is the command interpreter the user prefers.
197If the
198.Ar shell
199field is empty, the Bourne shell,
200.Pa /bin/sh ,
201is assumed.
202When altering a login shell, and not the super-user, the user
203may not change from a non-standard shell or to a non-standard
204shell.
205Non-standard is defined as a shell not found in
206.Pa /etc/shells .
207.Pp
208Once the information has been verified,
209.Nm chpass
210uses
211.Xr pwd_mkdb 8
212to update the user database.
213.Sh ENVIRONMENT
214The
215.Xr vi 1
216editor will be used unless the environment variable EDITOR is set to
217an alternate editor.
218When the editor terminates, the information is re-read and used to
219update the user database itself.
220Only the user, or the super-user, may edit the information associated
221with the user.
222.Sh NIS INTERACTION
223.Nm Chpass
224can also be used in conjunction with NIS, however some restrictions
225apply.
226Currently,
227.Nm chpass
228can only make changes to the NIS passwd maps through
229.Xr rpc.yppasswdd 8 ,
230which normally only permits changes to a user's password, shell and GECOS
231fields. Except when invoked by the super-user on the NIS master server,
232.Nm chpass
233(and, similarly,
234.Xr passwd 1 )
235can not use the
236.Xr rpc.yppasswdd 8
237server to change other user information or
238add new records to the NIS passwd maps.
239Furthermore,
240.Xr rpc.yppasswdd 8
241requires password authentication before it will make any
242changes. The only user allowed to submit changes without supplying
243a password is the super-user on the NIS master server; all other users,
244including those with root privileges on NIS clients (and NIS slave
245servers) must enter a password.
246(The super-user on the NIS master is allowed to bypass these restrictions
247largely for convenience: a user with root access
248to the NIS master server already has the privileges required to make
249updates to the NIS maps, but editing the map source files by hand can
250be cumbersome.
251.Pp
252Note: these exceptions only apply when the NIS master server is a
253FreeBSD system.)
254.Pp
255Consequently, except where noted, the following restrictions apply when
256.Nm chpass
257is used with NIS:
258.Bl -enum -offset indent
259.It
260.Pa Only the shell and GECOS information may be changed.
261All other
262fields are restricted, even when
263.Nm chpass
264is invoked by the super-user.
265While support for
266changing other fields could be added, this would lead to
267compatibility problems with other NIS-capable systems.
268Even though the super-user may supply data for other fields
269while editing an entry, the extra information (other than the
270password -- see below) will be silently discarded.
271.Pp
272Exception: the super-user on the NIS master server is permitted to
273change any field.
274.Pp
275.It
276.Pa Password authentication is required.
277.Nm Chpass
278will prompt for the user's NIS password before effecting
279any changes. If the password is invalid, all changes will be
280discarded.
281.Pp
282Exception: the super-user on the NIS master server is allowed to
283submit changes without supplying a password. (The super-user may
284choose to turn off this feature using the
285.Fl o
286flag, described below.)
287.It
288.Pa Adding new records to the local
289.Pa password database is discouraged.
290.Nm Chpass
291will allow the administrator to add new records to the
292local password database while NIS is enabled, but this can lead to
293some confusion since the new records are appended to the end of
294the master password file, usually after the special NIS '+' entries.
295The administrator should use
296.Xr vipw 8
297to modify the local password
298file when NIS is running.
299.Pp
300The super-user on the NIS master server is permitted to add new records
301to the NIS password maps, provided the
302.Xr rpc.yppasswdd 8
303server has been started with the
304.Fl a
305flag to permitted additions (it refuses them by default).
306.Nm Chpass
307tries to update the local password database by default; to update the
308NIS maps instead, invoke chpass with the
309.Fl y
310flag.
311.It
312.Pa Password changes are not permitted.
313Users should use
314.Xr passwd 1
315or
316.Xr yppasswd 1
317to change their NIS passwords. The super-user is allowed to specify
318a new password (even though the ``Password:'' field does not show
319up in the editor template, the super-user may add it back by hand),
320but even the super-user must supply the user's original password
321otherwise
322.Xr rpc.yppasswdd 8
323will refuse to update the NIS maps.
324.Pp
325Exception: the super-user on the NIS master server is permitted to
326change a user's NIS password with
327.Nm chpass .
328.El
329.Pp
330There are also a few extra option flags that are available when
331.Nm chpass
332is compiled with NIS support:
333.Bl -tag -width flag
334.It Fl l
335The
336.Fl l
337flag forces
338.Nm chpass
339to modify the local copy of a user's password
340information in the even that a user exists in both
341the local and NIS databases.
342.It Fl y
343This flag has the opposite effect of
344.Fl l .
345This flag is largely redundant since
346.Nm chpass
347operates on NIS entries by default if NIS is enabled.
348.It Fl d Ar domain
349Specify a particular NIS domain.
350.Nm Chpass
351uses the system domain name by default, as set by the
352.Xr domainname 1
353command. The
354.Fl d
355option can be used to override a default, or to specify a domain
356when the system domain name is not set.
357.It Fl h Ar host
358Specify the name or address of an NIS server to query. Normally,
359.Nm chpass
360will communicate with the NIS master host specified in the
361.Pa master.passwd
362or
363.Pa passwd
364maps. On hosts that have not been configured as NIS clients, there is
365no way for the program to determine this information unless the user
366provides the hostname of a server. Note that the specified hostname need
367not be that of the NIS master server; the name of any server, master or
368slave, in a given NIS domain will do.
369.Pp
370When using the
371.Fl d
372option, the hostname defaults to ``localhost.'' The
373.Fl h
374option can be used in conjunction with the
375.Fl d
376option, in which case the user-specified hostname will override
377the default.
378.Pp
379.It Fl o
380Force the use of RPC-based updates when communicating with
381.Xr rpc.yppasswdd 8
382(``old-mode'').
383When invoked by the super-user on the NIS master server,
384.Nm chpass
385allows unrestricted changes to the NIS passwd maps using dedicated,
386non-RPC-based mechanism (in this case, a UNIX domain socket). The
387.Fl o
388flag can be used to force
389.Nm chpass
390to use the standard update mechanism instead. This option is provided
391mainly for testing purposes.
392.El
393.Pp
394.Sh FILES
395.Bl -tag -width /etc/master.passwd -compact
396.It Pa /etc/master.passwd
397The user database
398.It Pa /etc/passwd
399A Version 7 format password file
400.It Pa /etc/chpass.XXXXXX
401Temporary copy of the password file
402.It Pa /etc/shells
403The list of approved shells
404.El
405.Sh SEE ALSO
406.Xr finger 1 ,
407.Xr login 1 ,
408.Xr passwd 1 ,
409.Xr getusershell 3 ,
410.Xr login.conf 5,
411.Xr passwd 5 ,
412.Xr pwd_mkdb 8 ,
413.Xr vipw 8
414.Rs
415.%A Robert Morris
416and
417.%A Ken Thompson
418.%T "UNIX Password security"
419.Re
420.Sh NOTES
421The
422.Xr chfn 1 ,
423.Xr chsh 1 ,
424.Xr ypchpass 1 ,
425.Xr ypchfn 1
426and
427.Xr ypchsh 1
428commands are really only links to
429.Nm chpass .
430.Sh BUGS
431User information should (and eventually will) be stored elsewhere.
432.Sh HISTORY
433The
434.Nm
435command appeared in
436.Bx 4.3 Reno .
437