xref: /freebsd/usr.sbin/pwd_mkdb/pwd_mkdb.c (revision c68159a6d8eede11766cf13896d0f7670dbd51aa)
1 /*-
2  * Copyright (c) 1991, 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 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1991, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)pwd_mkdb.c	8.5 (Berkeley) 4/20/94";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <sys/param.h>
49 #include <sys/stat.h>
50 
51 #include <db.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <limits.h>
56 #include <pwd.h>
57 #include <signal.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 
63 #include "pw_scan.h"
64 
65 #define	INSECURE	1
66 #define	SECURE		2
67 #define	PERM_INSECURE	(S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)
68 #define	PERM_SECURE	(S_IRUSR|S_IWUSR)
69 
70 HASHINFO openinfo = {
71 	4096,		/* bsize */
72 	32,		/* ffactor */
73 	256,		/* nelem */
74 	2048 * 1024,	/* cachesize */
75 	NULL,		/* hash() */
76 	0		/* lorder */
77 };
78 
79 static enum state { FILE_INSECURE, FILE_SECURE, FILE_ORIG } clean;
80 static struct passwd pwd;			/* password structure */
81 static char *pname;				/* password file name */
82 static char prefix[MAXPATHLEN];
83 
84 static int is_comment;	/* flag for comments */
85 static char line[LINE_MAX];
86 
87 void	cleanup __P((void));
88 void	error __P((char *));
89 void	cp __P((char *, char *, mode_t mode));
90 void	mv __P((char *, char *));
91 int	scan __P((FILE *, struct passwd *));
92 static void	usage __P((void));
93 
94 int
95 main(argc, argv)
96 	int argc;
97 	char *argv[];
98 {
99 	DB *dp, *sdp, *pw_db;
100 	DBT data, sdata, key;
101 	FILE *fp, *oldfp;
102 	sigset_t set;
103 	int ch, cnt, ypcnt, len, makeold, tfd, yp_enabled = 0;
104 	char *p, *t;
105 	char buf[MAX(MAXPATHLEN, LINE_MAX * 2)], tbuf[1024];
106 	char sbuf[MAX(MAXPATHLEN, LINE_MAX * 2)];
107 	char buf2[MAXPATHLEN];
108 	char sbuf2[MAXPATHLEN];
109 	char *username;
110 	u_int method, methoduid;
111 	int Cflag;
112 	int nblock = 0;
113 
114 	Cflag = 0;
115 	strcpy(prefix, _PATH_PWD);
116 	makeold = 0;
117 	username = NULL;
118 	while ((ch = getopt(argc, argv, "Cd:ps:u:vN")) != -1)
119 		switch(ch) {
120 		case 'C':                       /* verify only */
121 			Cflag = 1;
122 			break;
123 		case 'd':
124 			strncpy(prefix, optarg, sizeof prefix - 1);
125 			break;
126 		case 'p':			/* create V7 "file.orig" */
127 			makeold = 1;
128 			break;
129 		case 's':			/* change default cachesize */
130 			openinfo.cachesize = atoi(optarg) * 1024 * 1024;
131 			break;
132 		case 'u':			/* only update this record */
133 			username = optarg;
134 			break;
135 		case 'v':                       /* backward compatible */
136 			break;
137 		case 'N':			/* do not wait for lock	*/
138 			nblock = LOCK_NB;
139 			break;
140 		default:
141 			usage();
142 		}
143 	argc -= optind;
144 	argv += optind;
145 
146 	if (argc != 1 || (username && (*username == '+' || *username == '-')))
147 		usage();
148 
149 	/*
150 	 * This could be changed to allow the user to interrupt.
151 	 * Probably not worth the effort.
152 	 */
153 	sigemptyset(&set);
154 	sigaddset(&set, SIGTSTP);
155 	sigaddset(&set, SIGHUP);
156 	sigaddset(&set, SIGINT);
157 	sigaddset(&set, SIGQUIT);
158 	sigaddset(&set, SIGTERM);
159 	(void)sigprocmask(SIG_BLOCK, &set, (sigset_t *)NULL);
160 
161 	/* We don't care what the user wants. */
162 	(void)umask(0);
163 
164 	pname = *argv;
165 
166 	/*
167 	 * Open and lock the original password file.  We have to check
168 	 * the hardlink count after we get the lock to handle any potential
169 	 * unlink/rename race.
170 	 *
171 	 * This lock is necessary when someone runs pwd_mkdb manually, directly
172 	 * on master.passwd, to handle the case where a user might try to
173 	 * change his password while pwd_mkdb is running.
174 	 */
175 	for (;;) {
176 		struct stat st;
177 
178 		if (!(fp = fopen(pname, "r")))
179 			error(pname);
180 		if (flock(fileno(fp), LOCK_EX|nblock) < 0)
181 			error("flock");
182 		if (fstat(fileno(fp), &st) < 0)
183 			error(pname);
184 		if (st.st_nlink != 0)
185 			break;
186 		fclose(fp);
187 		fp = NULL;
188 	}
189 
190 	/* check only if password database is valid */
191 	if (Cflag) {
192 		for (cnt = 1; scan(fp, &pwd); ++cnt);
193 		exit(0);
194 	}
195 
196 	/* Open the temporary insecure password database. */
197 	(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _MP_DB);
198 	(void)snprintf(sbuf, sizeof(sbuf), "%s/%s.tmp", prefix, _SMP_DB);
199 	if (username) {
200 		(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _MP_DB);
201 		(void)snprintf(sbuf2, sizeof(sbuf2), "%s/%s", prefix, _SMP_DB);
202 
203 		clean = FILE_INSECURE;
204 		cp(buf2, buf, PERM_INSECURE);
205 		dp = dbopen(buf,
206 		    O_RDWR|O_EXCL, PERM_INSECURE, DB_HASH, &openinfo);
207 		if (dp == NULL)
208 			error(buf);
209 
210 		clean = FILE_SECURE;
211 		cp(sbuf2, sbuf, PERM_SECURE);
212 		sdp = dbopen(sbuf,
213 		    O_RDWR|O_EXCL, PERM_SECURE, DB_HASH, &openinfo);
214 		if (sdp == NULL)
215 			error(sbuf);
216 
217 		/*
218 		 * Do some trouble to check if we should store this users
219 		 * uid. Don't use getpwnam/getpwuid as that interferes
220 		 * with NIS.
221 		 */
222 		pw_db = dbopen(_PATH_MP_DB, O_RDONLY, 0, DB_HASH, NULL);
223 		if (!pw_db)
224 			error(_MP_DB);
225 		buf[0] = _PW_KEYBYNAME;
226 		len = strlen(username);
227 
228 		/* Only check that username fits in buffer */
229 		memmove(buf + 1, username, MIN(len, sizeof(buf) - 1));
230 		key.data = (u_char *)buf;
231 		key.size = len + 1;
232 		if ((pw_db->get)(pw_db, &key, &data, 0) == 0) {
233 			p = (char *)data.data;
234 
235 			/* jump over pw_name and pw_passwd, to get to pw_uid */
236 			while (*p++)
237 				;
238 			while (*p++)
239 				;
240 
241 			buf[0] = _PW_KEYBYUID;
242 			memmove(buf + 1, p, sizeof(int));
243 			key.data = (u_char *)buf;
244 			key.size = sizeof(int) + 1;
245 
246 			if ((pw_db->get)(pw_db, &key, &data, 0) == 0) {
247 				/* First field of data.data holds pw_pwname */
248 				if (!strcmp(data.data, username))
249 					methoduid = 0;
250 				else
251 					methoduid = R_NOOVERWRITE;
252 			} else {
253 				methoduid = R_NOOVERWRITE;
254 			}
255 		} else {
256 			methoduid = R_NOOVERWRITE;
257 		}
258 		if ((pw_db->close)(pw_db))
259 			error("close pw_db");
260 		method = 0;
261 	} else {
262 		dp = dbopen(buf,
263 		    O_RDWR|O_CREAT|O_EXCL, PERM_INSECURE, DB_HASH, &openinfo);
264 		if (dp == NULL)
265 			error(buf);
266 		clean = FILE_INSECURE;
267 
268 		sdp = dbopen(sbuf,
269 		    O_RDWR|O_CREAT|O_EXCL, PERM_SECURE, DB_HASH, &openinfo);
270 		if (sdp == NULL)
271 			error(sbuf);
272 		clean = FILE_SECURE;
273 
274 		method = R_NOOVERWRITE;
275 		methoduid = R_NOOVERWRITE;
276 	}
277 
278 	/*
279 	 * Open file for old password file.  Minor trickiness -- don't want to
280 	 * chance the file already existing, since someone (stupidly) might
281 	 * still be using this for permission checking.  So, open it first and
282 	 * fdopen the resulting fd.  The resulting file should be readable by
283 	 * everyone.
284 	 */
285 	if (makeold) {
286 		(void)snprintf(buf, sizeof(buf), "%s.orig", pname);
287 		if ((tfd = open(buf,
288 		    O_WRONLY|O_CREAT|O_EXCL, PERM_INSECURE)) < 0)
289 			error(buf);
290 		if ((oldfp = fdopen(tfd, "w")) == NULL)
291 			error(buf);
292 		clean = FILE_ORIG;
293 	}
294 
295 	/*
296 	 * The databases actually contain three copies of the original data.
297 	 * Each password file entry is converted into a rough approximation
298 	 * of a ``struct passwd'', with the strings placed inline.  This
299 	 * object is then stored as the data for three separate keys.  The
300 	 * first key * is the pw_name field prepended by the _PW_KEYBYNAME
301 	 * character.  The second key is the pw_uid field prepended by the
302 	 * _PW_KEYBYUID character.  The third key is the line number in the
303 	 * original file prepended by the _PW_KEYBYNUM character.  (The special
304 	 * characters are prepended to ensure that the keys do not collide.)
305 	 */
306 	ypcnt = 1;
307 	data.data = (u_char *)buf;
308 	sdata.data = (u_char *)sbuf;
309 	key.data = (u_char *)tbuf;
310 	for (cnt = 1; scan(fp, &pwd); ++cnt) {
311 		if (!is_comment &&
312 		    (pwd.pw_name[0] == '+' || pwd.pw_name[0] == '-'))
313 			yp_enabled = 1;
314 		if (is_comment)
315 			--cnt;
316 #define	COMPACT(e)	t = e; while ((*p++ = *t++));
317 		if (!is_comment &&
318 		    (!username || (strcmp(username, pwd.pw_name) == 0))) {
319 			/* Create insecure data. */
320 			p = buf;
321 			COMPACT(pwd.pw_name);
322 			COMPACT("*");
323 			memmove(p, &pwd.pw_uid, sizeof(pwd.pw_uid));
324 			p += sizeof(int);
325 			memmove(p, &pwd.pw_gid, sizeof(pwd.pw_gid));
326 			p += sizeof(int);
327 			memmove(p, &pwd.pw_change, sizeof(time_t));
328 			p += sizeof(time_t);
329 			COMPACT(pwd.pw_class);
330 			COMPACT(pwd.pw_gecos);
331 			COMPACT(pwd.pw_dir);
332 			COMPACT(pwd.pw_shell);
333 			memmove(p, &pwd.pw_expire, sizeof(time_t));
334 			p += sizeof(time_t);
335 			memmove(p, &pwd.pw_fields, sizeof pwd.pw_fields);
336 			p += sizeof pwd.pw_fields;
337 			data.size = p - buf;
338 
339 			/* Create secure data. */
340 			p = sbuf;
341 			COMPACT(pwd.pw_name);
342 			COMPACT(pwd.pw_passwd);
343 			memmove(p, &pwd.pw_uid, sizeof(pwd.pw_uid));
344 			p += sizeof(int);
345 			memmove(p, &pwd.pw_gid, sizeof(pwd.pw_gid));
346 			p += sizeof(int);
347 			memmove(p, &pwd.pw_change, sizeof(time_t));
348 			p += sizeof(time_t);
349 			COMPACT(pwd.pw_class);
350 			COMPACT(pwd.pw_gecos);
351 			COMPACT(pwd.pw_dir);
352 			COMPACT(pwd.pw_shell);
353 			memmove(p, &pwd.pw_expire, sizeof(time_t));
354 			p += sizeof(time_t);
355 			memmove(p, &pwd.pw_fields, sizeof pwd.pw_fields);
356 			p += sizeof pwd.pw_fields;
357 			sdata.size = p - sbuf;
358 
359 			/* Store insecure by name. */
360 			tbuf[0] = _PW_KEYBYNAME;
361 			len = strlen(pwd.pw_name);
362 			memmove(tbuf + 1, pwd.pw_name, len);
363 			key.size = len + 1;
364 			if ((dp->put)(dp, &key, &data, method) == -1)
365 				error("put");
366 
367 			/* Store insecure by number. */
368 			tbuf[0] = _PW_KEYBYNUM;
369 			memmove(tbuf + 1, &cnt, sizeof(cnt));
370 			key.size = sizeof(cnt) + 1;
371 			if ((dp->put)(dp, &key, &data, method) == -1)
372 				error("put");
373 
374 			/* Store insecure by uid. */
375 			tbuf[0] = _PW_KEYBYUID;
376 			memmove(tbuf + 1, &pwd.pw_uid, sizeof(pwd.pw_uid));
377 			key.size = sizeof(pwd.pw_uid) + 1;
378 			if ((dp->put)(dp, &key, &data, methoduid) == -1)
379 				error("put");
380 
381 			/* Store secure by name. */
382 			tbuf[0] = _PW_KEYBYNAME;
383 			len = strlen(pwd.pw_name);
384 			memmove(tbuf + 1, pwd.pw_name, len);
385 			key.size = len + 1;
386 			if ((sdp->put)(sdp, &key, &sdata, method) == -1)
387 				error("put");
388 
389 			/* Store secure by number. */
390 			tbuf[0] = _PW_KEYBYNUM;
391 			memmove(tbuf + 1, &cnt, sizeof(cnt));
392 			key.size = sizeof(cnt) + 1;
393 			if ((sdp->put)(sdp, &key, &sdata, method) == -1)
394 				error("put");
395 
396 			/* Store secure by uid. */
397 			tbuf[0] = _PW_KEYBYUID;
398 			memmove(tbuf + 1, &pwd.pw_uid, sizeof(pwd.pw_uid));
399 			key.size = sizeof(pwd.pw_uid) + 1;
400 			if ((sdp->put)(sdp, &key, &sdata, methoduid) == -1)
401 				error("put");
402 
403 			/* Store insecure and secure special plus and special minus */
404 			if (pwd.pw_name[0] == '+' || pwd.pw_name[0] == '-') {
405 				tbuf[0] = _PW_KEYYPBYNUM;
406 				memmove(tbuf + 1, &ypcnt, sizeof(cnt));
407 				ypcnt++;
408 				key.size = sizeof(cnt) + 1;
409 				if ((dp->put)(dp, &key, &data, method) == -1)
410 					error("put");
411 				if ((sdp->put)(sdp, &key, &sdata, method) == -1)
412 					error("put");
413 			}
414 		}
415 		/* Create original format password file entry */
416 		if (is_comment && makeold){	/* copy comments */
417 			if (fprintf(oldfp, "%s\n", line) < 0)
418 				error("write old");
419 		} else if (makeold) {
420 			char uidstr[20];
421 			char gidstr[20];
422 
423 			snprintf(uidstr, sizeof(uidstr), "%u", pwd.pw_uid);
424 			snprintf(gidstr, sizeof(gidstr), "%u", pwd.pw_gid);
425 
426 			if (fprintf(oldfp, "%s:*:%s:%s:%s:%s:%s\n",
427 			    pwd.pw_name, pwd.pw_fields & _PWF_UID ? uidstr : "",
428 			    pwd.pw_fields & _PWF_GID ? gidstr : "",
429 			    pwd.pw_gecos, pwd.pw_dir, pwd.pw_shell) < 0)
430 				error("write old");
431 		}
432 	}
433 	/* If YP enabled, set flag. */
434 	if (yp_enabled) {
435 		buf[0] = yp_enabled + 2;
436 		data.size = 1;
437 		tbuf[0] = _PW_KEYYPENABLED;
438 		key.size = 1;
439 		if ((dp->put)(dp, &key, &data, method) == -1)
440 			error("put");
441 		if ((sdp->put)(sdp, &key, &data, method) == -1)
442 			error("put");
443 	}
444 
445 	if ((dp->close)(dp) == -1)
446 		error("close");
447 	if ((sdp->close)(sdp) == -1)
448 		error("close");
449 	if (makeold) {
450 		(void)fflush(oldfp);
451 		if (fclose(oldfp) == EOF)
452 			error("close old");
453 	}
454 
455 	/* Set master.passwd permissions, in case caller forgot. */
456 	(void)fchmod(fileno(fp), S_IRUSR|S_IWUSR);
457 
458 	/* Install as the real password files. */
459 	(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _MP_DB);
460 	(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _MP_DB);
461 	mv(buf, buf2);
462 	(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _SMP_DB);
463 	(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _SMP_DB);
464 	mv(buf, buf2);
465 	if (makeold) {
466 		(void)snprintf(buf2, sizeof(buf2), "%s/%s", prefix, _PASSWD);
467 		(void)snprintf(buf, sizeof(buf), "%s.orig", pname);
468 		mv(buf, buf2);
469 	}
470 	/*
471 	 * Move the master password LAST -- chpass(1), passwd(1) and vipw(8)
472 	 * all use flock(2) on it to block other incarnations of themselves.
473 	 * The rename means that everything is unlocked, as the original file
474 	 * can no longer be accessed.
475 	 */
476 	(void)snprintf(buf, sizeof(buf), "%s/%s", prefix, _MASTERPASSWD);
477 	mv(pname, buf);
478 
479 	/*
480 	 * Close locked password file after rename()
481 	 */
482 	if (fclose(fp) == EOF)
483 		error("close fp");
484 
485 	exit(0);
486 }
487 
488 int
489 scan(fp, pw)
490 	FILE *fp;
491 	struct passwd *pw;
492 {
493 	static int lcnt;
494 	char *p;
495 
496 	if (!fgets(line, sizeof(line), fp))
497 		return (0);
498 	++lcnt;
499 	/*
500 	 * ``... if I swallow anything evil, put your fingers down my
501 	 * throat...''
502 	 *	-- The Who
503 	 */
504 	if (!(p = strchr(line, '\n'))) {
505 		warnx("line too long");
506 		goto fmt;
507 
508 	}
509 	*p = '\0';
510 
511 	/*
512 	 * Ignore comments: ^[ \t]*#
513 	 */
514 	for (p = line; *p != '\0'; p++)
515 		if (*p != ' ' && *p != '\t')
516 			break;
517 	if (*p == '#' || *p == '\0') {
518 		is_comment = 1;
519 		return(1);
520 	} else
521 		is_comment = 0;
522 
523 	if (!__pw_scan(line, pw, _PWSCAN_WARN|_PWSCAN_MASTER)) {
524 		warnx("at line #%d", lcnt);
525 fmt:		errno = EFTYPE;	/* XXX */
526 		error(pname);
527 	}
528 
529 	return (1);
530 }
531 
532 void
533 cp(from, to, mode)
534 	char *from, *to;
535 	mode_t mode;
536 {
537 	static char buf[MAXBSIZE];
538 	int from_fd, rcount, to_fd, wcount;
539 
540 	if ((from_fd = open(from, O_RDONLY, 0)) < 0)
541 		error(from);
542 	if ((to_fd = open(to, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)
543 		error(to);
544 	while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
545 		wcount = write(to_fd, buf, rcount);
546 		if (rcount != wcount || wcount == -1) {
547 			int sverrno = errno;
548 
549 			(void)snprintf(buf, sizeof(buf), "%s to %s", from, to);
550 			errno = sverrno;
551 			error(buf);
552 		}
553 	}
554 	if (rcount < 0) {
555 		int sverrno = errno;
556 
557 		(void)snprintf(buf, sizeof(buf), "%s to %s", from, to);
558 		errno = sverrno;
559 		error(buf);
560 	}
561 }
562 
563 
564 void
565 mv(from, to)
566 	char *from, *to;
567 {
568 	char buf[MAXPATHLEN];
569 
570 	if (rename(from, to)) {
571 		int sverrno = errno;
572 		(void)snprintf(buf, sizeof(buf), "%s to %s", from, to);
573 		errno = sverrno;
574 		error(buf);
575 	}
576 }
577 
578 void
579 error(name)
580 	char *name;
581 {
582 
583 	warn("%s", name);
584 	cleanup();
585 	exit(1);
586 }
587 
588 void
589 cleanup()
590 {
591 	char buf[MAXPATHLEN];
592 
593 	switch(clean) {
594 	case FILE_ORIG:
595 		(void)snprintf(buf, sizeof(buf), "%s.orig", pname);
596 		(void)unlink(buf);
597 		/* FALLTHROUGH */
598 	case FILE_SECURE:
599 		(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _SMP_DB);
600 		(void)unlink(buf);
601 		/* FALLTHROUGH */
602 	case FILE_INSECURE:
603 		(void)snprintf(buf, sizeof(buf), "%s/%s.tmp", prefix, _MP_DB);
604 		(void)unlink(buf);
605 	}
606 }
607 
608 static void
609 usage()
610 {
611 
612 	(void)fprintf(stderr,
613 "usage: pwd_mkdb [-C] [-N] [-p] [-d <dest dir>] [-s <cachesize>] [-u <local username>] file\n");
614 	exit(1);
615 }
616