xref: /freebsd/usr.bin/chpass/chpass.1 (revision 74bf4e164ba5851606a27d4feff27717452583e5)
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32.\"     @(#)chpass.1	8.2 (Berkeley) 12/30/93
33.\" $FreeBSD$
34.\"
35.Dd December 30, 1993
36.Dt CHPASS 1
37.Os
38.Sh NAME
39.Nm chpass ,
40.Nm chfn ,
41.Nm chsh ,
42.Nm ypchpass ,
43.Nm ypchfn ,
44.Nm ypchsh
45.Nd add or change user database information
46.Sh SYNOPSIS
47.Nm
48.Op Fl a Ar list
49.Op Fl p Ar encpass
50.Op Fl e Ar expiretime
51.Op Fl s Ar newshell
52.Op user
53.Nm
54.Op Fl oly
55.Op Fl a Ar list
56.Op Fl p Ar encpass
57.Op Fl e Ar expiretime
58.Op Fl s Ar newshell
59.Op Fl d Ar domain
60.Op Fl h Ar host
61.Op user
62.Sh DESCRIPTION
63The
64.Nm
65utility
66allows editing of the user database information associated
67with
68.Ar user
69or, by default, the current user.
70.Pp
71The
72.Nm chfn ,
73.Nm chsh ,
74.Nm ypchpass ,
75.Nm ypchfn
76and
77.Nm ypchsh
78utilities behave identically to
79.Nm .
80(There is only one program.)
81.Pp
82The information is formatted and supplied to an editor for changes.
83.Pp
84Only the information that the user is allowed to change is displayed.
85.Pp
86The options are as follows:
87.Bl -tag -width indent
88.It Fl a
89The super-user is allowed to directly supply a user database
90entry, in the format specified by
91.Xr passwd 5 ,
92as an argument.
93This argument must be a colon
94.Pq Dq \&:
95separated list of all the
96user database fields, although they may be empty.
97.It Fl p
98The super-user is allowed to directly supply an encrypted password field,
99in the format used by
100.Xr crypt 3 ,
101as an argument.
102.It Fl e Ar expiretime
103Change the account expire time.
104This option is used to set the expire time
105from a script as if it was done in the interactive editor.
106.It Fl s Ar newshell
107Attempt to change the user's shell to
108.Ar newshell .
109.El
110.Pp
111Possible display items are as follows:
112.Pp
113.Bl -tag -width "Other Information:" -compact -offset indent
114.It Login:
115user's login name
116.It Password:
117user's encrypted password
118.It Uid:
119user's login
120.It Gid:
121user's login group
122.It Class:
123user's general classification
124.It Change:
125password change time
126.It Expire:
127account expiration time
128.It Full Name:
129user's real name
130.It Office Location:
131user's office location (1)
132.It Office Phone:
133user's office phone (1)
134.It Home Phone:
135user's home phone (1)
136.It Other Information:
137any locally defined parameters for user (1)
138.It Home Directory:
139user's home directory
140.It Shell:
141user's login shell
142.Pp
143.It NOTE(1) -
144In the actual master.passwd file, these fields are comma-delimited
145fields embedded in the FullName field.
146.El
147.Pp
148The
149.Ar login
150field is the user name used to access the computer account.
151.Pp
152The
153.Ar password
154field contains the encrypted form of the user's password.
155.Pp
156The
157.Ar uid
158field is the number associated with the
159.Ar login
160field.
161Both of these fields should be unique across the system (and often
162across a group of systems) as they control file access.
163.Pp
164While it is possible to have multiple entries with identical login names
165and/or identical user id's, it is usually a mistake to do so.
166Routines
167that manipulate these files will often return only one of the multiple
168entries, and that one by random selection.
169.Pp
170The
171.Ar group
172field is the group that the user will be placed in at login.
173Since
174.Bx
175supports multiple groups (see
176.Xr groups 1 )
177this field currently has little special meaning.
178This field may be filled in with either a number or a group name (see
179.Xr group 5 ) .
180.Pp
181The
182.Ar class
183field references class descriptions in
184.Pa /etc/login.conf
185and is typically used to initialize the user's system resource limits
186when they login.
187.Pp
188The
189.Ar change
190field is the date by which the password must be changed.
191.Pp
192The
193.Ar expire
194field is the date on which the account expires.
195.Pp
196Both the
197.Ar change
198and
199.Ar expire
200fields should be entered in the form
201.Dq month day year
202where
203.Ar month
204is the month name (the first three characters are sufficient),
205.Ar day
206is the day of the month, and
207.Ar year
208is the year.
209.Pp
210Five fields are available for storing the user's
211.Ar full name , office location ,
212.Ar work
213and
214.Ar home telephone
215numbers and finally
216.Ar other information
217which is a single comma delimited string to represent any additional
218gecos fields (typically used for site specific user information).
219Note that
220.Xr finger 1
221will display the office location and office phone together under the
222heading
223.Ar Office: .
224.Pp
225The user's
226.Ar home directory
227is the full
228.Ux
229path name where the user
230will be placed at login.
231.Pp
232The
233.Ar shell
234field is the command interpreter the user prefers.
235If the
236.Ar shell
237field is empty, the Bourne shell,
238.Pa /bin/sh ,
239is assumed.
240When altering a login shell, and not the super-user, the user
241may not change from a non-standard shell or to a non-standard
242shell.
243Non-standard is defined as a shell not found in
244.Pa /etc/shells .
245.Pp
246Once the information has been verified,
247.Nm
248uses
249.Xr pwd_mkdb 8
250to update the user database.
251.Sh ENVIRONMENT
252The
253.Xr vi 1
254editor will be used unless the environment variable
255.Ev EDITOR
256is set to
257an alternate editor.
258When the editor terminates, the information is re-read and used to
259update the user database itself.
260Only the user, or the super-user, may edit the information associated
261with the user.
262.Pp
263See
264.Xr pwd_mkdb 8
265for an explanation of the impact of setting the
266.Ev PW_SCAN_BIG_IDS
267environment variable.
268.Sh NIS INTERACTION
269The
270.Nm
271utility can also be used in conjunction with NIS, however some restrictions
272apply.
273Currently,
274.Nm
275can only make changes to the NIS passwd maps through
276.Xr rpc.yppasswdd 8 ,
277which normally only permits changes to a user's password, shell and GECOS
278fields.
279Except when invoked by the super-user on the NIS master server,
280.Nm
281(and, similarly,
282.Xr passwd 1 )
283cannot use the
284.Xr rpc.yppasswdd 8
285server to change other user information or
286add new records to the NIS passwd maps.
287Furthermore,
288.Xr rpc.yppasswdd 8
289requires password authentication before it will make any
290changes.
291The only user allowed to submit changes without supplying
292a password is the super-user on the NIS master server; all other users,
293including those with root privileges on NIS clients (and NIS slave
294servers) must enter a password.
295(The super-user on the NIS master is allowed to bypass these restrictions
296largely for convenience: a user with root access
297to the NIS master server already has the privileges required to make
298updates to the NIS maps, but editing the map source files by hand can
299be cumbersome.
300.Pp
301Note: these exceptions only apply when the NIS master server is a
302.Fx
303system).
304.Pp
305Consequently, except where noted, the following restrictions apply when
306.Nm
307is used with NIS:
308.Bl -enum -offset indent
309.It
310.Em "Only the shell and GECOS information may be changed" .
311All other
312fields are restricted, even when
313.Nm
314is invoked by the super-user.
315While support for
316changing other fields could be added, this would lead to
317compatibility problems with other NIS-capable systems.
318Even though the super-user may supply data for other fields
319while editing an entry, the extra information (other than the
320password -- see below) will be silently discarded.
321.Pp
322Exception: the super-user on the NIS master server is permitted to
323change any field.
324.Pp
325.It
326.Em "Password authentication is required" .
327The
328.Nm
329utility will prompt for the user's NIS password before effecting
330any changes.
331If the password is invalid, all changes will be
332discarded.
333.Pp
334Exception: the super-user on the NIS master server is allowed to
335submit changes without supplying a password.
336(The super-user may
337choose to turn off this feature using the
338.Fl o
339flag, described below.)
340.It
341.Em "Adding new records to the local password database is discouraged" .
342The
343.Nm
344utility will allow the administrator to add new records to the
345local password database while NIS is enabled, but this can lead to
346some confusion since the new records are appended to the end of
347the master password file, usually after the special NIS '+' entries.
348The administrator should use
349.Xr vipw 8
350to modify the local password
351file when NIS is running.
352.Pp
353The super-user on the NIS master server is permitted to add new records
354to the NIS password maps, provided the
355.Xr rpc.yppasswdd 8
356server has been started with the
357.Fl a
358flag to permitted additions (it refuses them by default).
359The
360.Nm
361utility tries to update the local password database by default; to update the
362NIS maps instead, invoke chpass with the
363.Fl y
364flag.
365.It
366.Em "Password changes are not permitted".
367Users should use
368.Xr passwd 1
369or
370.Xr yppasswd 1
371to change their NIS passwords.
372The super-user is allowed to specify
373a new password (even though the
374.Dq Password:
375field does not show
376up in the editor template, the super-user may add it back by hand),
377but even the super-user must supply the user's original password
378otherwise
379.Xr rpc.yppasswdd 8
380will refuse to update the NIS maps.
381.Pp
382Exception: the super-user on the NIS master server is permitted to
383change a user's NIS password with
384.Nm .
385.El
386.Pp
387There are also a few extra option flags that are available when
388.Nm
389is compiled with NIS support:
390.Bl -tag -width indent
391.It Fl l
392Force
393.Nm
394to modify the local copy of a user's password
395information in the event that a user exists in both
396the local and NIS databases.
397.It Fl y
398Opposite effect of
399.Fl l .
400This flag is largely redundant since
401.Nm
402operates on NIS entries by default if NIS is enabled.
403.It Fl d Ar domain
404Specify a particular NIS domain.
405The
406.Nm
407utility uses the system domain name by default, as set by the
408.Xr domainname 1
409utility.
410The
411.Fl d
412option can be used to override a default, or to specify a domain
413when the system domain name is not set.
414.It Fl h Ar host
415Specify the name or address of an NIS server to query.
416Normally,
417.Nm
418will communicate with the NIS master host specified in the
419.Pa master.passwd
420or
421.Pa passwd
422maps.
423On hosts that have not been configured as NIS clients, there is
424no way for the program to determine this information unless the user
425provides the hostname of a server.
426Note that the specified hostname need
427not be that of the NIS master server; the name of any server, master or
428slave, in a given NIS domain will do.
429.Pp
430When using the
431.Fl d
432option, the hostname defaults to
433.Dq localhost .
434The
435.Fl h
436option can be used in conjunction with the
437.Fl d
438option, in which case the user-specified hostname will override
439the default.
440.Pp
441.It Fl o
442Force the use of RPC-based updates when communicating with
443.Xr rpc.yppasswdd 8
444.Pq Dq old-mode .
445When invoked by the super-user on the NIS master server,
446.Nm
447allows unrestricted changes to the NIS passwd maps using dedicated,
448non-RPC-based mechanism (in this case, a
449.Ux
450domain socket).
451The
452.Fl o
453flag can be used to force
454.Nm
455to use the standard update mechanism instead.
456This option is provided
457mainly for testing purposes.
458.El
459.Sh FILES
460.Bl -tag -width /etc/master.passwd -compact
461.It Pa /etc/master.passwd
462the user database
463.It Pa /etc/passwd
464a Version 7 format password file
465.It Pa /etc/chpass.XXXXXX
466temporary copy of the password file
467.It Pa /etc/shells
468the list of approved shells
469.El
470.Sh SEE ALSO
471.Xr finger 1 ,
472.Xr login 1 ,
473.Xr passwd 1 ,
474.Xr getusershell 3 ,
475.Xr login.conf 5 ,
476.Xr passwd 5 ,
477.Xr pwd_mkdb 8 ,
478.Xr vipw 8
479.Rs
480.%A Robert Morris
481and
482.%A Ken Thompson
483.%T "UNIX Password security"
484.Re
485.Sh BUGS
486User information should (and eventually will) be stored elsewhere.
487.Sh HISTORY
488The
489.Nm
490utility appeared in
491.Bx 4.3 Reno .
492