usr.bin/chpass/chpass.c

   1 /*-
   2  * Copyright (c) 1988, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1988, 1993, 1994 The Regents of the University of California.  All rights reserved.
  34  * @(#)chpass.c 8.4 (Berkeley) 4/2/94
  35  * $FreeBSD: src/usr.bin/chpass/chpass.c,v 1.16.2.4 2002/08/11 14:16:42 dwmalone Exp $
  36  * $DragonFly: src/usr.bin/chpass/chpass.c,v 1.4 2003/11/03 19:31:28 eirikn Exp $
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/stat.h>
  41 #include <sys/signal.h>
  42 #include <sys/time.h>
  43 #include <sys/resource.h>
  44
  45 #include <ctype.h>
  46 #include <err.h>
  47 #include <errno.h>
  48 #include <fcntl.h>
  49 #include <pwd.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54
  55 #include <pw_scan.h>
  56 #include <pw_util.h>
  57 #include "pw_copy.h"
  58 #ifdef YP
  59 #include <rpcsvc/yp.h>
  60 int yp_errno = YP_TRUE;
  61 #include "pw_yp.h"
  62 #endif
  63
  64 #include "chpass.h"
  65 #include "pathnames.h"
  66
  67 char *tempname;
  68 uid_t uid;
  69
  70 void    baduser(void);
  71 void    usage(void);
  72
  73 int
  74 main(int argc, char **argv)
  75 {
  76         enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW, NEWEXP } op;
  77         struct passwd *pw = NULL, lpw, old_pw, *pold_pw;
  78         char *username = NULL;
  79         int ch, pfd, tfd;
  80         char *arg = NULL;
  81 #ifdef YP
  82         int force_local = 0;
  83         int force_yp = 0;
  84 #endif
  85
  86         op = EDITENTRY;
  87 #ifdef YP
  88         while ((ch = getopt(argc, argv, "a:p:s:e:d:h:oly")) != -1)
  89 #else
  90         while ((ch = getopt(argc, argv, "a:p:s:e:")) != -1)
  91 #endif
  92                 switch(ch) {
  93                 case 'a':
  94                         op = LOADENTRY;
  95                         arg = optarg;
  96                         break;
  97                 case 's':
  98                         op = NEWSH;
  99                         arg = optarg;
 100                         break;
 101                 case 'p':
 102                         op = NEWPW;
 103                         arg = optarg;
 104                         break;
 105                 case 'e':
 106                         op = NEWEXP;
 107                         arg = optarg;
 108                         break;
 109 #ifdef YP
 110                 case 'h':
 111 #ifdef PARANOID
 112                         if (getuid()) {
 113                                 warnx("Only the superuser can use the -h flag");
 114                         } else {
 115 #endif
 116                                 yp_server = optarg;
 117 #ifdef PARANOID
 118                         }
 119 #endif
 120                         break;
 121                 case 'd':
 122 #ifdef PARANOID
 123                         if (getuid()) {
 124                                 warnx("Only the superuser can use the -d flag");
 125                         } else {
 126 #endif
 127                                 yp_domain = optarg;
 128                                 if (yp_server == NULL)
 129                                         yp_server = "localhost";
 130 #ifdef PARANOID
 131                         }
 132 #endif
 133                         break;
 134                 case 'l':
 135                         _use_yp = 0;
 136                         force_local = 1;
 137                         break;
 138                 case 'y':
 139                         _use_yp = force_yp = 1;
 140                         break;
 141                 case 'o':
 142                         force_old++;
 143                         break;
 144 #endif
 145                 case '?':
 146                 default:
 147                         usage();
 148                 }
 149         argc -= optind;
 150         argv += optind;
 151
 152         uid = getuid();
 153
 154         if (op == EDITENTRY || op == NEWSH || op == NEWPW || op == NEWEXP) {
 155                 switch(argc) {
 156 #ifdef YP
 157                 case 0:
 158                         GETPWUID(uid)
 159                         get_yp_master(1); /* XXX just to set the suser flag */
 160                         break;
 161                 case 1:
 162                         GETPWNAM(*argv)
 163                         get_yp_master(1); /* XXX just to set the suser flag */
 164 #else
 165                 case 0:
 166                         if (!(pw = getpwuid(uid)))
 167                                 errx(1, "unknown user: uid %lu",
 168                                     (unsigned long)uid);
 169                         break;
 170                 case 1:
 171                         if (!(pw = getpwnam(*argv)))
 172                                 errx(1, "unknown user: %s", *argv);
 173 #endif
 174                         if (uid && uid != pw->pw_uid)
 175                                 baduser();
 176                         break;
 177                 default:
 178                         usage();
 179                 }
 180
 181                 /* Make a copy for later verification */
 182                 old_pw = *pw;
 183                 old_pw.pw_gecos = strdup(old_pw.pw_gecos);
 184                 pold_pw = &old_pw;
 185         }
 186
 187         if (op == NEWSH) {
 188                 /* protect p_shell -- it thinks NULL is /bin/sh */
 189                 if (!arg[0])
 190                         usage();
 191                 if (p_shell(arg, pw, (ENTRY *)NULL))
 192                         pw_error((char *)NULL, 0, 1);
 193         }
 194
 195         if (op == NEWEXP) {
 196                 if (uid)        /* only root can change expire */
 197                         baduser();
 198                 if (p_expire(arg, pw, (ENTRY *)NULL))
 199                         pw_error((char *)NULL, 0, 1);
 200         }
 201
 202         if (op == LOADENTRY) {
 203                 if (uid)
 204                         baduser();
 205                 pw = &lpw;
 206                 if (!pw_scan(arg, pw))
 207                         exit(1);
 208                 if ((pold_pw = getpwnam(pw->pw_name)) != NULL) {
 209                         old_pw = *pold_pw;
 210                         old_pw.pw_gecos = strdup(old_pw.pw_gecos);
 211                 }
 212         }
 213         username = pw->pw_name;
 214
 215         if (op == NEWPW) {
 216                 if (uid)
 217                         baduser();
 218
 219                 if(strchr(arg, ':')) {
 220                         errx(1, "invalid format for password");
 221                 }
 222                 pw->pw_passwd = arg;
 223         }
 224
 225         /*
 226          * The temporary file/file descriptor usage is a little tricky here.
 227          * 1:   We start off with two fd's, one for the master password
 228          *      file (used to lock everything), and one for a temporary file.
 229          * 2:   Display() gets an fp for the temporary file, and copies the
 230          *      user's information into it.  It then gives the temporary file
 231          *      to the user and closes the fp, closing the underlying fd.
 232          * 3:   The user edits the temporary file some number of times.
 233          * 4:   Verify() gets an fp for the temporary file, and verifies the
 234          *      contents.  It can't use an fp derived from the step #2 fd,
 235          *      because the user's editor may have created a new instance of
 236          *      the file.  Once the file is verified, its contents are stored
 237          *      in a password structure.  The verify routine closes the fp,
 238          *      closing the underlying fd.
 239          * 5:   Delete the temporary file.
 240          * 6:   Get a new temporary file/fd.  Pw_copy() gets an fp for it
 241          *      file and copies the master password file into it, replacing
 242          *      the user record with a new one.  We can't use the first
 243          *      temporary file for this because it was owned by the user.
 244          *      Pw_copy() closes its fp, flushing the data and closing the
 245          *      underlying file descriptor.  We can't close the master
 246          *      password fp, or we'd lose the lock.
 247          * 7:   Call pw_mkdb() (which renames the temporary file) and exit.
 248          *      The exit closes the master passwd fp/fd.
 249          */
 250         pw_init();
 251         tfd = pw_tmp();
 252
 253         if (op == EDITENTRY) {
 254                 display(tfd, pw);
 255                 edit(pw);
 256                 (void)unlink(tempname);
 257                 tfd = pw_tmp();
 258         }
 259
 260 #ifdef YP
 261         if (_use_yp) {
 262                 yp_submit(pw);
 263                 (void)unlink(tempname);
 264         } else {
 265 #endif /* YP */
 266         pfd = pw_lock();
 267         pw_copy(pfd, tfd, pw, pold_pw);
 268
 269         if (!pw_mkdb(username))
 270                 pw_error((char *)NULL, 0, 1);
 271 #ifdef YP
 272         }
 273 #endif /* YP */
 274         exit(0);
 275 }
 276
 277 void
 278 baduser(void)
 279 {
 280         errx(1, "%s", strerror(EACCES));
 281 }
 282
 283 void
 284 usage(void)
 285 {
 286
 287         (void)fprintf(stderr,
 288 #ifdef YP
 289                 "usage: chpass [-o] [-l] [-y] [-d domain] [-h host] [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
 290 #else
 291                 "usage: chpass [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
 292 #endif
 293         exit(1);
 294 }