usr.bin/chpass/edit.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  * Copyright (c) 2002 Networks Associates Technology, Inc.
   7  * All rights reserved.
   8  *
   9  * Portions of this software were developed for the FreeBSD Project by
  10  * ThinkSec AS and NAI Labs, the Security Research Division of Network
  11  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
  12  * ("CBOSS"), as part of the DARPA CHATS research program.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  * 3. All advertising materials mentioning features or use of this software
  23  *    must display the following acknowledgement:
  24  *      This product includes software developed by the University of
  25  *      California, Berkeley and its contributors.
  26  * 4. Neither the name of the University nor the names of its contributors
  27  *    may be used to endorse or promote products derived from this software
  28  *    without specific prior written permission.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  40  * SUCH DAMAGE.
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/stat.h>
  45
  46 #include <ctype.h>
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <paths.h>
  50 #include <pwd.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 #include <pw_scan.h>
  57 #include <libutil.h>
  58
  59 #include "chpass.h"
  60
  61 static int display(const char *tfn, struct passwd *pw);
  62 static struct passwd *verify(const char *tfn, struct passwd *pw);
  63
  64 struct passwd *
  65 edit(const char *tfn, struct passwd *pw)
  66 {
  67         struct passwd *npw;
  68         char *line;
  69         size_t len;
  70
  71         if (display(tfn, pw) == -1)
  72                 return (NULL);
  73         for (;;) {
  74                 switch (pw_edit(1)) {
  75                 case -1:
  76                         return (NULL);
  77                 case 0:
  78                         return (pw_dup(pw));
  79                 default:
  80                         break;
  81                 }
  82                 if ((npw = verify(tfn, pw)) != NULL)
  83                         return (npw);
  84                 free(npw);
  85                 printf("re-edit the password file? ");
  86                 fflush(stdout);
  87                 if ((line = fgetln(stdin, &len)) == NULL) {
  88                         warn("fgetln()");
  89                         return (NULL);
  90                 }
  91                 if (len > 0 && (*line == 'N' || *line == 'n'))
  92                         return (NULL);
  93         }
  94 }
  95
  96 /*
  97  * display --
  98  *      print out the file for the user to edit; strange side-effect:
  99  *      set conditional flag if the user gets to edit the shell.
 100  */
 101 static int
 102 display(const char *tfn, struct passwd *pw)
 103 {
 104         FILE *fp;
 105         char *bp, *gecos, *p;
 106
 107         if ((fp = fopen(tfn, "w")) == NULL) {
 108                 warn("%s", tfn);
 109                 return (-1);
 110         }
 111
 112         (void)fprintf(fp,
 113             "#Changing user information for %s.\n", pw->pw_name);
 114         if (master_mode) {
 115                 (void)fprintf(fp, "Login: %s\n", pw->pw_name);
 116                 (void)fprintf(fp, "Password: %s\n", pw->pw_passwd);
 117                 (void)fprintf(fp, "Uid [#]: %lu\n", (unsigned long)pw->pw_uid);
 118                 (void)fprintf(fp, "Gid [# or name]: %lu\n",
 119                     (unsigned long)pw->pw_gid);
 120                 (void)fprintf(fp, "Change [month day year]: %s\n",
 121                     ttoa(pw->pw_change));
 122                 (void)fprintf(fp, "Expire [month day year]: %s\n",
 123                     ttoa(pw->pw_expire));
 124                 (void)fprintf(fp, "Class: %s\n", pw->pw_class);
 125                 (void)fprintf(fp, "Home directory: %s\n", pw->pw_dir);
 126                 (void)fprintf(fp, "Shell: %s\n",
 127                     *pw->pw_shell ? pw->pw_shell : _PATH_BSHELL);
 128         }
 129         /* Only admin can change "restricted" shells. */
 130 #if 0
 131         else if (ok_shell(pw->pw_shell))
 132                 /*
 133                  * Make shell a restricted field.  Ugly with a
 134                  * necklace, but there's not much else to do.
 135                  */
 136 #else
 137         else if ((!list[E_SHELL].restricted && ok_shell(pw->pw_shell)) ||
 138             master_mode)
 139                 /*
 140                  * If change not restrict (table.c) and standard shell
 141                  *      OR if root, then allow editing of shell.
 142                  */
 143 #endif
 144                 (void)fprintf(fp, "Shell: %s\n",
 145                     *pw->pw_shell ? pw->pw_shell : _PATH_BSHELL);
 146         else
 147                 list[E_SHELL].restricted = 1;
 148
 149         if ((bp = gecos = strdup(pw->pw_gecos)) == NULL) {
 150                 warn(NULL);
 151                 fclose(fp);
 152                 return (-1);
 153         }
 154
 155         p = strsep(&bp, ",");
 156         p = strdup(p ? p : "");
 157         list[E_NAME].save = p;
 158         if (!list[E_NAME].restricted || master_mode)
 159           (void)fprintf(fp, "Full Name: %s\n", p);
 160
 161         p = strsep(&bp, ",");
 162         p = strdup(p ? p : "");
 163         list[E_LOCATE].save = p;
 164         if (!list[E_LOCATE].restricted || master_mode)
 165           (void)fprintf(fp, "Office Location: %s\n", p);
 166
 167         p = strsep(&bp, ",");
 168         p = strdup(p ? p : "");
 169         list[E_BPHONE].save = p;
 170         if (!list[E_BPHONE].restricted || master_mode)
 171           (void)fprintf(fp, "Office Phone: %s\n", p);
 172
 173         p = strsep(&bp, ",");
 174         p = strdup(p ? p : "");
 175         list[E_HPHONE].save = p;
 176         if (!list[E_HPHONE].restricted || master_mode)
 177           (void)fprintf(fp, "Home Phone: %s\n", p);
 178
 179         bp = strdup(bp ? bp : "");
 180         list[E_OTHER].save = bp;
 181         if (!list[E_OTHER].restricted || master_mode)
 182           (void)fprintf(fp, "Other information: %s\n", bp);
 183
 184         free(gecos);
 185
 186         (void)fchown(fileno(fp), getuid(), getgid());
 187         (void)fclose(fp);
 188         return (0);
 189 }
 190
 191 static struct passwd *
 192 verify(const char *tfn, struct passwd *pw)
 193 {
 194         struct passwd *npw;
 195         ENTRY *ep;
 196         char *buf, *p, *val;
 197         struct stat sb;
 198         FILE *fp;
 199         int line;
 200         size_t len;
 201
 202         if ((pw = pw_dup(pw)) == NULL)
 203                 return (NULL);
 204         if ((fp = fopen(tfn, "r")) == NULL ||
 205             fstat(fileno(fp), &sb) == -1) {
 206                 warn("%s", tfn);
 207                 free(pw);
 208                 return (NULL);
 209         }
 210         if (sb.st_size == 0) {
 211                 warnx("corrupted temporary file");
 212                 fclose(fp);
 213                 free(pw);
 214                 return (NULL);
 215         }
 216         val = NULL;
 217         for (line = 1; (buf = fgetln(fp, &len)) != NULL; ++line) {
 218                 if (*buf == '\0' || *buf == '#')
 219                         continue;
 220                 while (len > 0 && isspace(buf[len - 1]))
 221                         --len;
 222                 for (ep = list;; ++ep) {
 223                         if (!ep->prompt) {
 224                                 warnx("%s: unrecognized field on line %d",
 225                                     tfn, line);
 226                                 goto bad;
 227                         }
 228                         if (ep->len > len)
 229                                 continue;
 230                         if (strncasecmp(buf, ep->prompt, ep->len) != 0)
 231                                 continue;
 232                         if (ep->restricted && !master_mode) {
 233                                 warnx("%s: you may not change the %s field",
 234                                     tfn, ep->prompt);
 235                                 goto bad;
 236                         }
 237                         for (p = buf; p < buf + len && *p != ':'; ++p)
 238                                 /* nothing */ ;
 239                         if (*p != ':') {
 240                                 warnx("%s: line %d corrupted", tfn, line);
 241                                 goto bad;
 242                         }
 243                         while (++p < buf + len && isspace(*p))
 244                                 /* nothing */ ;
 245                         free(val);
 246                         asprintf(&val, "%.*s", (int)(buf + len - p), p);
 247                         if (val == NULL)
 248                                 goto bad;
 249                         if (ep->except && strpbrk(val, ep->except)) {
 250                                 warnx("%s: invalid character in \"%s\" field '%s'",
 251                                     tfn, ep->prompt, val);
 252                                 goto bad;
 253                         }
 254                         if ((ep->func)(val, pw, ep))
 255                                 goto bad;
 256                         break;
 257                 }
 258         }
 259         free(val);
 260         fclose(fp);
 261
 262         /* Build the gecos field. */
 263         len = asprintf(&p, "%s,%s,%s,%s,%s", list[E_NAME].save,
 264             list[E_LOCATE].save, list[E_BPHONE].save,
 265             list[E_HPHONE].save, list[E_OTHER].save);
 266         if (p == NULL) {
 267                 warn("asprintf()");
 268                 free(pw);
 269                 return (NULL);
 270         }
 271         while (len > 0 && p[len - 1] == ',')
 272                 p[--len] = '\0';
 273         pw->pw_gecos = p;
 274         buf = pw_make(pw);
 275         free(pw);
 276         free(p);
 277         if (buf == NULL) {
 278                 warn("pw_make()");
 279                 return (NULL);
 280         }
 281         npw = pw_scan(buf, PWSCAN_WARN|PWSCAN_MASTER);
 282         free(buf);
 283         return (npw);
 284 bad:
 285         free(pw);
 286         free(val);
 287         fclose(fp);
 288         return (NULL);
 289 }