usr.bin/passwd/local_passwd.c

   1 /*      $NetBSD: local_passwd.c,v 1.36 2012/03/25 05:55:07 dholland Exp $       */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "from: @(#)local_passwd.c    8.3 (Berkeley) 4/2/94";
  36 #else
  37 __RCSID("$NetBSD: local_passwd.c,v 1.36 2012/03/25 05:55:07 dholland Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <ctype.h>
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <pwd.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <limits.h>
  52 #include <time.h>
  53 #include <unistd.h>
  54 #include <util.h>
  55 #include <login_cap.h>
  56 #include <syslog.h>
  57
  58 #include "extern.h"
  59
  60 static uid_t uid;
  61
  62 static char *
  63 getnewpasswd(struct passwd *pw, int min_pw_len)
  64 {
  65         int tries;
  66         char *p, *t;
  67         char buf[_PASSWORD_LEN+1], salt[_PASSWORD_LEN+1];
  68         char option[LINE_MAX], *key, *opt;
  69
  70         (void)printf("Changing local password for %s.\n", pw->pw_name);
  71
  72         if (uid && pw->pw_passwd[0] &&
  73             strcmp(crypt(getpass("Old password:"), pw->pw_passwd),
  74             pw->pw_passwd)) {
  75                 errno = EACCES;
  76                 syslog(LOG_AUTH | LOG_NOTICE,
  77                        "user %s (UID %lu) failed to change the "
  78                        "local password of user %s: %m",
  79                        pw->pw_name, (unsigned long)uid, pw->pw_name);
  80                 pw_error(NULL, 1, 1);
  81         }
  82
  83         for (buf[0] = '\0', tries = 0;;) {
  84                 p = getpass("New password:");
  85                 if (!*p) {
  86                         (void)printf("Password unchanged.\n");
  87                         pw_error(NULL, 0, 0);
  88                 }
  89                 if (min_pw_len > 0 && (int)strlen(p) < min_pw_len) {
  90                         (void) printf("Password is too short.\n");
  91                         continue;
  92                 }
  93                 if (strlen(p) <= 5 && ++tries < 2) {
  94                         (void)printf("Please enter a longer password.\n");
  95                         continue;
  96                 }
  97                 for (t = p; *t && islower((unsigned char)*t); ++t);
  98                 if (!*t && ++tries < 2) {
  99                         (void)printf("Please don't use an all-lower case "
 100                                      "password.\nUnusual capitalization, "
 101                                      "control characters or digits are "
 102                                      "suggested.\n");
 103                         continue;
 104                 }
 105                 (void)strlcpy(buf, p, sizeof(buf));
 106                 if (!strcmp(buf, getpass("Retype new password:")))
 107                         break;
 108                 (void)printf("Mismatch; try again, EOF to quit.\n");
 109         }
 110
 111         pw_getpwconf(option, sizeof(option), pw, "localcipher");
 112         opt = option;
 113         key = strsep(&opt, ",");
 114         if(pw_gensalt(salt, _PASSWORD_LEN, key, opt) == -1) {
 115                 warn("Couldn't generate salt");
 116                 pw_error(NULL, 0, 0);
 117         }
 118         return(crypt(buf, salt));
 119 }
 120
 121 #ifdef USE_PAM
 122
 123 void
 124 pwlocal_usage(const char *prefix)
 125 {
 126
 127         (void) fprintf(stderr, "%s %s [-d files | -l] [user]\n",
 128             prefix, getprogname());
 129 }
 130
 131 void
 132 pwlocal_process(const char *username, int argc, char **argv)
 133 {
 134         struct passwd *pw;
 135         struct passwd old_pw;
 136         time_t old_change;
 137         int pfd, tfd;
 138         int min_pw_len = 0;
 139         int pw_expiry  = 0;
 140         int ch;
 141 #ifdef LOGIN_CAP
 142         login_cap_t *lc;
 143 #endif
 144
 145         while ((ch = getopt(argc, argv, "l")) != -1) {
 146                 switch (ch) {
 147                 case 'l':
 148                         /*
 149                          * Aborb the -l that may have gotten us here.
 150                          */
 151                         break;
 152
 153                 default:
 154                         usage();
 155                         /* NOTREACHED */
 156                 }
 157         }
 158
 159         argc -= optind;
 160         argv += optind;
 161
 162         switch (argc) {
 163         case 0:
 164                 /* username already provided */
 165                 break;
 166         case 1:
 167                 username = argv[0];
 168                 break;
 169         default:
 170                 usage();
 171                 /* NOTREACHED */
 172         }
 173
 174         if (!(pw = getpwnam(username)))
 175                 errx(1, "unknown user %s", username);
 176
 177         uid = getuid();
 178         if (uid && uid != pw->pw_uid)
 179                 errx(1, "%s", strerror(EACCES));
 180
 181         /* Save the old pw information for comparing on pw_copy(). */
 182         old_pw = *pw;
 183
 184         /*
 185          * Get class restrictions for this user, then get the new password.
 186          */
 187 #ifdef LOGIN_CAP
 188         if((lc = login_getclass(pw->pw_class)) != NULL) {
 189                 min_pw_len = (int) login_getcapnum(lc, "minpasswordlen", 0, 0);
 190                 pw_expiry  = (int) login_getcaptime(lc, "passwordtime", 0, 0);
 191                 login_close(lc);
 192         }
 193 #endif
 194
 195         pw->pw_passwd = getnewpasswd(pw, min_pw_len);
 196         old_change = pw->pw_change;
 197         pw->pw_change = pw_expiry ? pw_expiry + time(NULL) : 0;
 198
 199         /*
 200          * Now that the user has given us a new password, let us
 201          * change the database.
 202          */
 203         pw_init();
 204         tfd = pw_lock(0);
 205         if (tfd < 0) {
 206                 warnx ("The passwd file is busy, waiting...");
 207                 tfd = pw_lock(10);
 208                 if (tfd < 0)
 209                         errx(1, "The passwd file is still busy, "
 210                              "try again later.");
 211         }
 212
 213         pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0);
 214         if (pfd < 0)
 215                 pw_error(_PATH_MASTERPASSWD, 1, 1);
 216
 217         pw_copy(pfd, tfd, pw, &old_pw);
 218
 219         if (pw_mkdb(username, old_change == pw->pw_change) < 0)
 220                 pw_error(NULL, 0, 1);
 221
 222         syslog(LOG_AUTH | LOG_INFO,
 223                "user %s (UID %lu) successfully changed "
 224                "the local password of user %s",
 225                uid ? username : "root", (unsigned long)uid, username);
 226 }
 227
 228 #else /* ! USE_PAM */
 229
 230 static int force_local;
 231
 232 int
 233 local_init(const char *progname)
 234 {
 235         force_local = 0;
 236         return (0);
 237 }
 238
 239 int
 240 local_arg(char ch, const char *arg)
 241 {
 242         switch (ch) {
 243         case 'l':
 244                 force_local = 1;
 245                 break;
 246         default:
 247                 return(0);
 248         }
 249         return(1);
 250 }
 251
 252 int
 253 local_arg_end(void)
 254 {
 255         if (force_local)
 256                 return(PW_USE_FORCE);
 257         return(PW_USE);
 258 }
 259
 260 void
 261 local_end(void)
 262 {
 263         /* NOOP */
 264 }
 265
 266 int
 267 local_chpw(const char *uname)
 268 {
 269         struct passwd *pw;
 270         struct passwd old_pw;
 271         time_t old_change;
 272         int pfd, tfd;
 273         int min_pw_len = 0;
 274         int pw_expiry  = 0;
 275 #ifdef LOGIN_CAP
 276         login_cap_t *lc;
 277 #endif
 278
 279         if (!(pw = getpwnam(uname))) {
 280                 warnx("unknown user %s", uname);
 281                 return (1);
 282         }
 283
 284         uid = getuid();
 285         if (uid && uid != pw->pw_uid) {
 286                 warnx("%s", strerror(EACCES));
 287                 return (1);
 288         }
 289
 290         /* Save the old pw information for comparing on pw_copy(). */
 291         old_pw = *pw;
 292
 293         /*
 294          * Get class restrictions for this user, then get the new password.
 295          */
 296 #ifdef LOGIN_CAP
 297         if((lc = login_getclass(pw->pw_class))) {
 298                 min_pw_len = (int) login_getcapnum(lc, "minpasswordlen", 0, 0);
 299                 pw_expiry  = (int) login_getcaptime(lc, "passwordtime", 0, 0);
 300                 login_close(lc);
 301         }
 302 #endif
 303
 304         pw->pw_passwd = getnewpasswd(pw, min_pw_len);
 305         old_change = pw->pw_change;
 306         pw->pw_change = pw_expiry ? pw_expiry + time(NULL) : 0;
 307
 308         /*
 309          * Now that the user has given us a new password, let us
 310          * change the database.
 311          */
 312         pw_init();
 313         tfd = pw_lock(0);
 314         if (tfd < 0) {
 315                 warnx ("The passwd file is busy, waiting...");
 316                 tfd = pw_lock(10);
 317                 if (tfd < 0)
 318                         errx(1, "The passwd file is still busy, "
 319                              "try again later.");
 320         }
 321
 322         pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0);
 323         if (pfd < 0)
 324                 pw_error(_PATH_MASTERPASSWD, 1, 1);
 325
 326         pw_copy(pfd, tfd, pw, &old_pw);
 327
 328         if (pw_mkdb(uname, old_change == pw->pw_change) < 0)
 329                 pw_error(NULL, 0, 1);
 330
 331         syslog(LOG_AUTH | LOG_INFO,
 332                "user %s (UID %lu) successfully changed "
 333                "the local password of user %s",
 334                uid ? uname : "root", (unsigned long)uid, uname);
 335
 336         return (0);
 337 }
 338
 339 #endif /* USE_PAM */