xref: /freebsd/usr.bin/chpass/chpass.1 (revision 817420dc8eac7df799c78f5309b75092b7f7cd40)
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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.Pp
54.Nm
55.Op Fl oly
56.Op Fl a Ar list
57.Op Fl p Ar encpass
58.Op Fl e Ar expiretime
59.Op Fl s Ar newshell
60.Op Fl d Ar domain
61.Op Fl h Ar host
62.Op user
63.Sh DESCRIPTION
64The
65.Nm
66program
67allows editing of the user database information associated
68with
69.Ar user
70or, by default, the current user.
71The information is formatted and supplied to an editor for changes.
72.Pp
73Only the information that the user is allowed to change is displayed.
74.Pp
75The options are as follows:
76.Bl -tag -width indent
77.It Fl a
78The super-user is allowed to directly supply a user database
79entry, in the format specified by
80.Xr passwd 5 ,
81as an argument.
82This argument must be a colon
83.Pq Dq \:
84separated list of all the
85user database fields, although they may be empty.
86.It Fl p
87The super-user is allowed to directly supply an encrypted password field,
88in the format used by
89.Xr crypt 3 ,
90as an argument.
91.It Fl e Ar expiretime
92Change the account expire time.
93This option is used to set the expire time
94from a script as if it was done in the interactive editor.
95.It Fl s Ar newshell
96Attempt to change the user's shell to
97.Ar newshell .
98.El
99.Pp
100Possible display items are as follows:
101.Pp
102.Bl -tag -width "Other Information:" -compact -offset indent
103.It Login:
104user's login name
105.It Password:
106user's encrypted password
107.It Uid:
108user's login
109.It Gid:
110user's login group
111.It Class:
112user's general classification
113.It Change:
114password change time
115.It Expire:
116account expiration time
117.It Full Name:
118user's real name
119.It Office Location:
120user's office location (1)
121.It Office Phone:
122user's office phone (1)
123.It Home Phone:
124user's home phone (1)
125.It Other Information:
126any locally defined parameters for user (1)
127.It Home Directory:
128user's home directory
129.It Shell:
130user's login shell
131.Pp
132.It NOTE(1) -
133In the actual master.passwd file, these fields are comma-delimited
134fields embedded in the FullName field.
135.El
136.Pp
137The
138.Ar login
139field is the user name used to access the computer account.
140.Pp
141The
142.Ar password
143field contains the encrypted form of the user's password.
144.Pp
145The
146.Ar uid
147field is the number associated with the
148.Ar login
149field.
150Both of these fields should be unique across the system (and often
151across a group of systems) as they control file access.
152.Pp
153While it is possible to have multiple entries with identical login names
154and/or identical user id's, it is usually a mistake to do so.  Routines
155that manipulate these files will often return only one of the multiple
156entries, and that one by random selection.
157.Pp
158The
159.Ar group
160field is the group that the user will be placed in at login.
161Since BSD supports multiple groups (see
162.Xr groups 1 )
163this field currently has little special meaning.
164This field may be filled in with either a number or a group name (see
165.Xr group 5 ) .
166.Pp
167The
168.Ar class
169field references class descriptions in
170.Pa /etc/login.conf
171and is typically used to initialize the user's system resource limits
172when they login.
173.Pp
174The
175.Ar change
176field is the date by which the password must be changed.
177.Pp
178The
179.Ar expire
180field is the date on which the account expires.
181.Pp
182Both the
183.Ar change
184and
185.Ar expire
186fields should be entered in the form
187.Dq month day year
188where
189.Ar month
190is the month name (the first three characters are sufficient),
191.Ar day
192is the day of the month, and
193.Ar year
194is the year.
195.Pp
196Five fields are available for storing the user's
197.Ar full name , office location ,
198.Ar work
199and
200.Ar home telephone
201numbers and finally
202.Ar other information
203which is a single comma delimited string to represent any additional
204gcos fields (typically used for site specific user information).
205Note that
206.Xr finger 1
207will display the office location and office phone together under the
208heading
209.Ar Office: .
210.Pp
211The user's
212.Ar home directory
213is the full
214.Ux
215path name where the user
216will be placed at login.
217.Pp
218The
219.Ar shell
220field is the command interpreter the user prefers.
221If the
222.Ar shell
223field is empty, the Bourne shell,
224.Pa /bin/sh ,
225is assumed.
226When altering a login shell, and not the super-user, the user
227may not change from a non-standard shell or to a non-standard
228shell.
229Non-standard is defined as a shell not found in
230.Pa /etc/shells .
231.Pp
232Once the information has been verified,
233.Nm
234uses
235.Xr pwd_mkdb 8
236to update the user database.
237.Sh ENVIRONMENT
238The
239.Xr vi 1
240editor will be used unless the environment variable
241.Ev EDITOR
242is set to
243an alternate editor.
244When the editor terminates, the information is re-read and used to
245update the user database itself.
246Only the user, or the super-user, may edit the information associated
247with the user.
248.Pp
249See
250.Xr pwd_mkdb 8
251for an explanation of the impact of setting the
252.Ev PW_SCAN_BIG_IDS
253environment variable.
254.Sh NIS INTERACTION
255.Nm Chpass
256can also be used in conjunction with NIS, however some restrictions
257apply.
258Currently,
259.Nm
260can only make changes to the NIS passwd maps through
261.Xr rpc.yppasswdd 8 ,
262which normally only permits changes to a user's password, shell and GECOS
263fields.
264Except when invoked by the super-user on the NIS master server,
265.Nm
266(and, similarly,
267.Xr passwd 1 )
268can not use the
269.Xr rpc.yppasswdd 8
270server to change other user information or
271add new records to the NIS passwd maps.
272Furthermore,
273.Xr rpc.yppasswdd 8
274requires password authentication before it will make any
275changes.
276The only user allowed to submit changes without supplying
277a password is the super-user on the NIS master server; all other users,
278including those with root privileges on NIS clients (and NIS slave
279servers) must enter a password.
280(The super-user on the NIS master is allowed to bypass these restrictions
281largely for convenience: a user with root access
282to the NIS master server already has the privileges required to make
283updates to the NIS maps, but editing the map source files by hand can
284be cumbersome.
285.Pp
286Note: these exceptions only apply when the NIS master server is a
287.Fx
288system).
289.Pp
290Consequently, except where noted, the following restrictions apply when
291.Nm
292is used with NIS:
293.Bl -enum -offset indent
294.It
295.Em "Only the shell and GECOS information may be changed" .
296All other
297fields are restricted, even when
298.Nm
299is invoked by the super-user.
300While support for
301changing other fields could be added, this would lead to
302compatibility problems with other NIS-capable systems.
303Even though the super-user may supply data for other fields
304while editing an entry, the extra information (other than the
305password -- see below) will be silently discarded.
306.Pp
307Exception: the super-user on the NIS master server is permitted to
308change any field.
309.Pp
310.It
311.Em "Password authentication is required" .
312.Nm Chpass
313will prompt for the user's NIS password before effecting
314any changes.
315If the password is invalid, all changes will be
316discarded.
317.Pp
318Exception: the super-user on the NIS master server is allowed to
319submit changes without supplying a password.
320(The super-user may
321choose to turn off this feature using the
322.Fl o
323flag, described below.)
324.It
325.Em "Adding new records to the local password database is discouraged" .
326.Nm Chpass
327will allow the administrator to add new records to the
328local password database while NIS is enabled, but this can lead to
329some confusion since the new records are appended to the end of
330the master password file, usually after the special NIS '+' entries.
331The administrator should use
332.Xr vipw 8
333to modify the local password
334file when NIS is running.
335.Pp
336The super-user on the NIS master server is permitted to add new records
337to the NIS password maps, provided the
338.Xr rpc.yppasswdd 8
339server has been started with the
340.Fl a
341flag to permitted additions (it refuses them by default).
342.Nm Chpass
343tries to update the local password database by default; to update the
344NIS maps instead, invoke chpass with the
345.Fl y
346flag.
347.It
348.Em "Password changes are not permitted".
349Users should use
350.Xr passwd 1
351or
352.Xr yppasswd 1
353to change their NIS passwords.
354The super-user is allowed to specify
355a new password (even though the
356.Dq Password:
357field does not show
358up in the editor template, the super-user may add it back by hand),
359but even the super-user must supply the user's original password
360otherwise
361.Xr rpc.yppasswdd 8
362will refuse to update the NIS maps.
363.Pp
364Exception: the super-user on the NIS master server is permitted to
365change a user's NIS password with
366.Nm .
367.El
368.Pp
369There are also a few extra option flags that are available when
370.Nm
371is compiled with NIS support:
372.Bl -tag -width indent
373.It Fl l
374Force
375.Nm
376to modify the local copy of a user's password
377information in the even that a user exists in both
378the local and NIS databases.
379.It Fl y
380Opposite effect of
381.Fl l .
382This flag is largely redundant since
383.Nm
384operates on NIS entries by default if NIS is enabled.
385.It Fl d Ar domain
386Specify a particular NIS domain.
387.Nm Chpass
388uses the system domain name by default, as set by the
389.Xr domainname 1
390command.
391The
392.Fl d
393option can be used to override a default, or to specify a domain
394when the system domain name is not set.
395.It Fl h Ar host
396Specify the name or address of an NIS server to query.
397Normally,
398.Nm
399will communicate with the NIS master host specified in the
400.Pa master.passwd
401or
402.Pa passwd
403maps.
404On hosts that have not been configured as NIS clients, there is
405no way for the program to determine this information unless the user
406provides the hostname of a server.
407Note that the specified hostname need
408not be that of the NIS master server; the name of any server, master or
409slave, in a given NIS domain will do.
410.Pp
411When using the
412.Fl d
413option, the hostname defaults to
414.Dq localhost .
415The
416.Fl h
417option can be used in conjunction with the
418.Fl d
419option, in which case the user-specified hostname will override
420the default.
421.Pp
422.It Fl o
423Force the use of RPC-based updates when communicating with
424.Xr rpc.yppasswdd 8
425.Pq Dq old-mode .
426When invoked by the super-user on the NIS master server,
427.Nm
428allows unrestricted changes to the NIS passwd maps using dedicated,
429non-RPC-based mechanism (in this case, a
430.Ux
431domain socket). The
432.Fl o
433flag can be used to force
434.Nm
435to use the standard update mechanism instead.
436This option is provided
437mainly for testing purposes.
438.El
439.Pp
440.Sh FILES
441.Bl -tag -width /etc/master.passwd -compact
442.It Pa /etc/master.passwd
443the user database
444.It Pa /etc/passwd
445a Version 7 format password file
446.It Pa /etc/chpass.XXXXXX
447temporary copy of the password file
448.It Pa /etc/shells
449the list of approved shells
450.El
451.Sh SEE ALSO
452.Xr finger 1 ,
453.Xr login 1 ,
454.Xr passwd 1 ,
455.Xr getusershell 3 ,
456.Xr login.conf 5 ,
457.Xr passwd 5 ,
458.Xr pwd_mkdb 8 ,
459.Xr vipw 8
460.Rs
461.%A Robert Morris
462and
463.%A Ken Thompson
464.%T "UNIX Password security"
465.Re
466.Sh NOTES
467The
468.Xr chfn 1 ,
469.Xr chsh 1 ,
470.Xr ypchpass 1 ,
471.Xr ypchfn 1
472and
473.Xr ypchsh 1
474commands are really only links to
475.Nm .
476.Sh BUGS
477User information should (and eventually will) be stored elsewhere.
478.Sh HISTORY
479The
480.Nm
481command appeared in
482.Bx 4.3 Reno .
483