chpass/chpass.1

   1 .\" Copyright (c) 1988, 1990, 1993
   2 .\"     The Regents of the University of California.  All rights reserved.
   3 .\"
   4 .\" Redistribution and use in source and binary forms, with or without
   5 .\" modification, are permitted provided that the following conditions
   6 .\" are met:
   7 .\" 1. Redistributions of source code must retain the above copyright
   8 .\"    notice, this list of conditions and the following disclaimer.
   9 .\" 2. Redistributions in binary form must reproduce the above copyright
  10 .\"    notice, this list of conditions and the following disclaimer in the
  11 .\"    documentation and/or other materials provided with the distribution.
  12 .\" 3. All advertising materials mentioning features or use of this software
  13 .\"    must display the following acknowledgement:
  14 .\"     This product includes software developed by the University of
  15 .\"     California, Berkeley and its contributors.
  16 .\" 4. Neither the name of the University nor the names of its contributors
  17 .\"    may be used to endorse or promote products derived from this software
  18 .\"    without specific prior written permission.
  19 .\"
  20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30 .\" SUCH DAMAGE.
  31 .\"
  32 .\"     @(#)chpass.1    8.2 (Berkeley) 12/30/93
  33 .\"     $Id: chpass.1,v 1.7.2.4 1998/08/14 03:38:01 thepish 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
  48 The
  49 .Nm chpass
  50 program
  51 allows editing of the user database information associated
  52 with
  53 .Ar user
  54 or, by default, the current user.
  55 The information is formatted and supplied to an editor for changes.
  56 .Pp
  57 Only the information that the user is allowed to change is displayed.
  58 .Pp
  59 The options are as follows:
  60 .Bl -tag -width flag
  61 .It Fl a
  62 The super-user is allowed to directly supply a user database
  63 entry, in the format specified by
  64 .Xr passwd 5 ,
  65 as an argument.
  66 This argument must be a colon (``:'') separated list of all the
  67 user database fields, although they may be empty.
  68 .It Fl p
  69 The super-user is allowed to directly supply an encrypted password field,
  70 in the format used by
  71 .Xr crypt 3 ,
  72 as an argument.
  73 .It Fl s
  74 The
  75 .Fl s
  76 option attempts to change the user's shell to
  77 .Ar newshell .
  78 .El
  79 .Pp
  80 Possible display items are as follows:
  81 .Pp
  82 .Bl -tag -width "Other Information:" -compact -offset indent
  83 .It Login:
  84 user's login name
  85 .It Password:
  86 user's encrypted password
  87 .It Uid:
  88 user's login
  89 .It Gid:
  90 user's login group
  91 .It Change:
  92 password change time
  93 .It Expire:
  94 account expiration time
  95 .It Class:
  96 user's general classification
  97 .It Home Directory:
  98 user's home directory
  99 .It Shell:
 100 user's login shell
 101 .It Full Name:
 102 user's real name
 103 .It Location:
 104 user's normal location
 105 .It Home Phone:
 106 user's home phone
 107 .It Office Phone:
 108 user's office phone
 109 .It Other Information:
 110 any locally defined parameters for user
 111 .El
 112 .Pp
 113 The
 114 .Ar login
 115 field is the user name used to access the computer account.
 116 .Pp
 117 The
 118 .Ar password
 119 field contains the encrypted form of the user's password.
 120 .Pp
 121 The
 122 .Ar uid
 123 field is the number associated with the
 124 .Ar login
 125 field.
 126 Both of these fields should be unique across the system (and often
 127 across a group of systems) as they control file access.
 128 .Pp
 129 While it is possible to have multiple entries with identical login names
 130 and/or identical user id's, it is usually a mistake to do so.  Routines
 131 that manipulate these files will often return only one of the multiple
 132 entries, and that one by random selection.
 133 .Pp
 134 The
 135 .Ar group
 136 field is the group that the user will be placed in at login.
 137 Since BSD supports multiple groups (see
 138 .Xr groups 1 )
 139 this field currently has little special meaning.
 140 This field may be filled in with either a number or a group name (see
 141 .Xr group 5 ) .
 142 .Pp
 143 The
 144 .Ar change
 145 field is the date by which the password must be changed.
 146 .Pp
 147 The
 148 .Ar expire
 149 field is the date on which the account expires.
 150 .Pp
 151 Both the
 152 .Ar change
 153 and
 154 .Ar expire
 155 fields should be entered in the form ``month day year'' where
 156 .Ar month
 157 is the month name (the first three characters are sufficient),
 158 .Ar day
 159 is the day of the month, and
 160 .Ar year
 161 is the year.
 162 .Pp
 163 The
 164 .Ar class
 165 field is currently unused.  In the near future it will be a key to
 166 a
 167 .Xr termcap 5
 168 style database of user attributes.
 169 .Pp
 170 The user's
 171 .Ar home directory
 172 is the full UNIX path name where the user
 173 will be placed at login.
 174 .Pp
 175 The
 176 .Ar shell
 177 field is the command interpreter the user prefers.
 178 If the
 179 .Ar shell
 180 field is empty, the Bourne shell,
 181 .Pa /bin/sh ,
 182 is assumed.
 183 When altering a login shell, and not the super-user, the user
 184 may not change from a non-standard shell or to a non-standard
 185 shell.
 186 Non-standard is defined as a shell not found in
 187 .Pa /etc/shells .
 188 .Pp
 189 The last five fields are for storing the user's
 190 .Ar full name , office location ,
 191 .Ar work
 192 and
 193 .Ar home telephone
 194 numbers and finally
 195 .Ar other information
 196 which is a single comma delimited string to represent any additional
 197 gcos fields (typically used for site specific user information).
 198 .Pp
 199 Once the information has been verified,
 200 .Nm chpass
 201 uses
 202 .Xr pwd_mkdb 8
 203 to update the user database.
 204 .Sh ENVIRONMENT
 205 The
 206 .Xr vi 1
 207 editor will be used unless the environment variable EDITOR is set to
 208 an alternate editor.
 209 When the editor terminates, the information is re-read and used to
 210 update the user database itself.
 211 Only the user, or the super-user, may edit the information associated
 212 with the user.
 213 .Sh NIS INTERACTION
 214 .Nm Chpass
 215 can also be used in conjunction with NIS, however some restrictions
 216 apply.
 217 Currently,
 218 .Nm chpass
 219 can only make changes to the NIS passwd maps through
 220 .Xr rpc.yppasswdd 8 ,
 221 which normally only permits changes to a user's password, shell and GECOS
 222 fields. Except when invoked by the super-user on the NIS master server,
 223 .Nm chpass
 224 (and, similarly,
 225 .Xr passwd 1 )
 226 can not use the
 227 .Xr rpc.yppasswdd 8
 228 server to change other user information or
 229 add new records to the NIS passwd maps.
 230 Furthermore,
 231 .Xr rpc.yppasswdd 8
 232 requires password authentication before it will make any
 233 changes. The only user allowed to submit changes without supplying
 234 a password is the super-user on the NIS master server; all other users,
 235 including those with root privileges on NIS clients (and NIS slave
 236 servers) must enter a password.
 237 (The super-user on the NIS master is allowed to bypass these restrictions
 238 largely for convenience: a user with root access
 239 to the NIS master server already has the privileges required to make
 240 updates to the NIS maps, but editing the map source files by hand can
 241 be cumbersome.
 242 .Pp
 243 Note: these exceptions only apply when the NIS master server is a
 244 FreeBSD system.)
 245 .Pp
 246 Consequently, except where noted, the following restrictions apply when
 247 .Nm chpass
 248 is used with NIS:
 249 .Bl -enum -offset indent
 250 .It
 251 .Pa Only the shell and GECOS information may be changed.
 252 All other
 253 fields are restricted, even when
 254 .Nm chpass
 255 is invoked by the super-user.
 256 While support for
 257 changing other fields could be added, this would lead to
 258 compatibility problems with other NIS-capable systems.
 259 Even though the super-user may supply data for other fields
 260 while editing an entry, the extra information (other than the
 261 password -- see below) will be silently discarded.
 262 .Pp
 263 Exception: the super-user on the NIS master server is permitted to
 264 change any field.
 265 .Pp
 266 .It
 267 .Pa Password authentication is required.
 268 .Nm Chpass
 269 will prompt for the user's NIS password before effecting
 270 any changes. If the password is invalid, all changes will be
 271 discarded.
 272 .Pp
 273 Exception: the super-user on the NIS master server is allowed to
 274 submit changes without supplying a password. (The super-user may
 275 choose to turn off this feature using the
 276 .Fl o
 277 flag, described below.)
 278 .It
 279 .Pa Adding new records to the local
 280 .Pa password database is discouraged.
 281 .Nm Chpass
 282 will allow the administrator to add new records to the
 283 local password database while NIS is enabled, but this can lead to
 284 some confusion since the new records are appended to the end of
 285 the master password file, usually after the special NIS '+' entries.
 286 The administrator should use
 287 .Xr vipw 8
 288 to modify the local password
 289 file when NIS is running.
 290 .Pp
 291 The super-user on the NIS master server is permitted to add new records
 292 to the NIS password maps, provided the
 293 .Xr rpc.yppasswdd 8
 294 server has been started with the
 295 .Fl a
 296 flag to permitted additions (it refuses them by default).
 297 .Nm Chpass
 298 tries to update the local password database by default; to update the
 299 NIS maps instead, invoke chpass with the
 300 .Fl y
 301 flag.
 302 .It
 303 .Pa Password changes are not permitted.
 304 Users should use
 305 .Xr passwd 1
 306 or
 307 .Xr yppasswd 1
 308 to change their NIS passwords. The super-user is allowed to specify
 309 a new password (even though the ``Password:'' field does not show
 310 up in the editor template, the super-user may add it back by hand),
 311 but even the super-user must supply the user's original password
 312 otherwise
 313 .Xr rpc.yppasswdd 8
 314 will refuse to update the NIS maps.
 315 .Pp
 316 Exception: the super-user on the NIS master server is permitted to
 317 change a user's NIS password with
 318 .Nm chpass .
 319 .El
 320 .Pp
 321 There are also a few extra option flags that are available when
 322 .Nm chpass
 323 is compiled with NIS support:
 324 .Bl -tag -width flag
 325 .It Fl l
 326 The
 327 .Fl l
 328 flag forces
 329 .Nm chpass
 330 to modify the local copy of a user's password
 331 information in the even that a user exists in both
 332 the local and NIS databases.
 333 .It Fl y
 334 This flag has the opposite effect of
 335 .Fl l .
 336 This flag is largely redundant since
 337 .Nm chpass
 338 operates on NIS entries by default if NIS is enabled.
 339 .It Fl d Ar domain
 340 Specify a particular NIS domain.
 341 .Nm Chpass
 342 uses the system domain name by default, as set by the
 343 .Xr domainname 1
 344 command. The
 345 .Fl d
 346 option can be used to override a default, or to specify a domain
 347 when the system domain name is not set.
 348 .It Fl h Ar host
 349 Specify the name or address of an NIS server to query. Normally,
 350 .Nm chpass
 351 will communicate with the NIS master host specified in the
 352 .Pa master.passwd
 353 or
 354 .Pa passwd
 355 maps. On hosts that have not been configured as NIS clients, there is
 356 no way for the program to determine this information unless the user
 357 provides the hostname of a server. Note that the specified hostname need
 358 not be that of the NIS master server; the name of any server, master or
 359 slave, in a given NIS domain will do.
 360 .Pp
 361 When using the
 362 .Fl d
 363 option, the hostname defaults to ``localhost.'' The
 364 .Fl h
 365 option can be used in conjunction with the
 366 .Fl d
 367 option, in which case the user-specified hostname will override
 368 the default.
 369 .Pp
 370 .It Fl o
 371 Force the use of RPC-based updates when communicating with
 372 .Xr rpc.yppasswdd 8
 373 (``old-mode'').
 374 When invoked by the super-user on the NIS master server,
 375 .Nm chpass
 376 allows unrestricted changes to the NIS passwd maps using dedicated,
 377 non-RPC-based mechanism (in this case, a UNIX domain socket). The
 378 .Fl o
 379 flag can be used to force
 380 .Nm chpass
 381 to use the standard update mechanism instead. This option is provided
 382 mainly for testing purposes.
 383 .El
 384 .Pp
 385 .Sh FILES
 386 .Bl -tag -width /etc/master.passwd -compact
 387 .It Pa /etc/master.passwd
 388 The user database
 389 .It Pa /etc/passwd
 390 A Version 7 format password file
 391 .It Pa /etc/chpass.XXXXXX
 392 Temporary copy of the password file
 393 .It Pa /etc/shells
 394 The list of approved shells
 395 .El
 396 .Sh SEE ALSO
 397 .Xr finger 1 ,
 398 .Xr login 1 ,
 399 .Xr passwd 1 ,
 400 .Xr getusershell 3 ,
 401 .Xr passwd 5 ,
 402 .Xr pwd_mkdb 8 ,
 403 .Xr vipw 8
 404 .Rs
 405 .%A Robert Morris
 406 and
 407 .%A Ken Thompson
 408 .%T "UNIX Password security"
 409 .Re
 410 .Sh NOTES
 411 The
 412 .Xr chfn 1 ,
 413 .Xr chsh 1 ,
 414 .Xr ypchpass 1 ,
 415 .Xr ypchfn 1
 416 and
 417 .Xr ypchsh 1
 418 commands are really only links to
 419 .Nm chpass .
 420 .Sh BUGS
 421 User information should (and eventually will) be stored elsewhere.
 422 .Sh HISTORY
 423 The
 424 .Nm
 425 command appeared in
 426 .Bx 4.3 Reno .