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local_passwd.c revision 1.35 
      1 /*	$NetBSD: local_passwd.c,v 1.35 2011/08/31 16:24:58 plunky 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 1.35 2011/08/31 16:24:58 plunky 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(progname)
    234 	const char *progname;
    235 {
    236 	force_local = 0;
    237 	return (0);
    238 }
    239 
    240 int
    241 local_arg(char ch, const char *arg)
    242 {
    243 	switch (ch) {
    244 	case 'l':
    245 		force_local = 1;
    246 		break;
    247 	default:
    248 		return(0);
    249 	}
    250 	return(1);
    251 }
    252 
    253 int
    254 local_arg_end()
    255 {
    256 	if (force_local)
    257 		return(PW_USE_FORCE);
    258 	return(PW_USE);
    259 }
    260 
    261 void
    262 local_end()
    263 {
    264 	/* NOOP */
    265 }
    266 
    267 int
    268 local_chpw(uname)
    269 	const char *uname;
    270 {
    271 	struct passwd *pw;
    272 	struct passwd old_pw;
    273 	time_t old_change;
    274 	int pfd, tfd;
    275 	int min_pw_len = 0;
    276 	int pw_expiry  = 0;
    277 #ifdef LOGIN_CAP
    278 	login_cap_t *lc;
    279 #endif
    280 
    281 	if (!(pw = getpwnam(uname))) {
    282 		warnx("unknown user %s", uname);
    283 		return (1);
    284 	}
    285 
    286 	uid = getuid();
    287 	if (uid && uid != pw->pw_uid) {
    288 		warnx("%s", strerror(EACCES));
    289 		return (1);
    290 	}
    291 
    292 	/* Save the old pw information for comparing on pw_copy(). */
    293 	old_pw = *pw;
    294 
    295 	/*
    296 	 * Get class restrictions for this user, then get the new password.
    297 	 */
    298 #ifdef LOGIN_CAP
    299 	if((lc = login_getclass(pw->pw_class))) {
    300 		min_pw_len = (int) login_getcapnum(lc, "minpasswordlen", 0, 0);
    301 		pw_expiry  = (int) login_getcaptime(lc, "passwordtime", 0, 0);
    302 		login_close(lc);
    303 	}
    304 #endif
    305 
    306 	pw->pw_passwd = getnewpasswd(pw, min_pw_len);
    307 	old_change = pw->pw_change;
    308 	pw->pw_change = pw_expiry ? pw_expiry + time(NULL) : 0;
    309 
    310 	/*
    311 	 * Now that the user has given us a new password, let us
    312 	 * change the database.
    313 	 */
    314 	pw_init();
    315 	tfd = pw_lock(0);
    316 	if (tfd < 0) {
    317 		warnx ("The passwd file is busy, waiting...");
    318 		tfd = pw_lock(10);
    319 		if (tfd < 0)
    320 			errx(1, "The passwd file is still busy, "
    321 			     "try again later.");
    322 	}
    323 
    324 	pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0);
    325 	if (pfd < 0)
    326 		pw_error(_PATH_MASTERPASSWD, 1, 1);
    327 
    328 	pw_copy(pfd, tfd, pw, &old_pw);
    329 
    330 	if (pw_mkdb(uname, old_change == pw->pw_change) < 0)
    331 		pw_error(NULL, 0, 1);
    332 
    333 	syslog(LOG_AUTH | LOG_INFO,
    334 	       "user %s (UID %lu) successfully changed "
    335 	       "the local password of user %s",
    336 	       uid ? uname : "root", (unsigned long)uid, uname);
    337 
    338 	return (0);
    339 }
    340 
    341 #endif /* USE_PAM */
    342