2 * SPDX-License-Identifier: BSD-3-Clause
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.
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.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
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. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 #include <sys/cdefs.h>
40 __SCCSID("@(#)pw_util.c 8.3 (Berkeley) 4/2/94");
43 * This file is used by all the "password" programs; vipw(8), chpass(1),
47 #include <sys/param.h>
48 #include <sys/errno.h>
50 #include <sys/resource.h>
68 static pid_t editpid = -1;
69 static int lockfd = -1;
70 static char masterpasswd[PATH_MAX];
71 static char passwd_dir[PATH_MAX];
72 static char tempname[PATH_MAX];
73 static int initialized;
86 * Initialize statics and set limits, signals & umask to try to avoid
87 * interruptions, crashes etc. that might expose passord data.
90 pw_init(const char *dir, const char *master)
97 strcpy(passwd_dir, _PATH_ETC);
99 if (strlen(dir) >= sizeof(passwd_dir)) {
100 errno = ENAMETOOLONG;
103 strcpy(passwd_dir, dir);
106 if (master == NULL) {
108 strcpy(masterpasswd, _PATH_MASTERPASSWD);
109 } else if (snprintf(masterpasswd, sizeof(masterpasswd), "%s/%s",
110 passwd_dir, _MASTERPASSWD) > (int)sizeof(masterpasswd)) {
111 errno = ENAMETOOLONG;
115 if (strlen(master) >= sizeof(masterpasswd)) {
116 errno = ENAMETOOLONG;
119 strcpy(masterpasswd, master);
123 * The code that follows is extremely disruptive to the calling
124 * process, and is therefore disabled until someone can conceive
125 * of a realistic scenario where it would fend off a compromise.
126 * Race conditions concerning the temporary files can be guarded
127 * against in other ways than masking signals (by checking stat(2)
128 * results after creation).
131 /* Unlimited resource limits. */
132 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
133 (void)setrlimit(RLIMIT_CPU, &rlim);
134 (void)setrlimit(RLIMIT_FSIZE, &rlim);
135 (void)setrlimit(RLIMIT_STACK, &rlim);
136 (void)setrlimit(RLIMIT_DATA, &rlim);
137 (void)setrlimit(RLIMIT_RSS, &rlim);
139 /* Don't drop core (not really necessary, but GP's). */
140 rlim.rlim_cur = rlim.rlim_max = 0;
141 (void)setrlimit(RLIMIT_CORE, &rlim);
143 /* Turn off signals. */
144 (void)signal(SIGALRM, SIG_IGN);
145 (void)signal(SIGHUP, SIG_IGN);
146 (void)signal(SIGINT, SIG_IGN);
147 (void)signal(SIGPIPE, SIG_IGN);
148 (void)signal(SIGQUIT, SIG_IGN);
149 (void)signal(SIGTERM, SIG_IGN);
150 (void)signal(SIGCONT, pw_cont);
152 /* Create with exact permissions. */
160 * Lock the master password file.
166 if (*masterpasswd == '\0')
170 * If the master password file doesn't exist, the system is hosed.
171 * Might as well try to build one. Set the close-on-exec bit so
172 * that users can't get at the encrypted passwords while editing.
173 * Open should allow flock'ing the file; see 4.4BSD. XXX
178 lockfd = flopen(masterpasswd, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0);
180 if (errno == EWOULDBLOCK) {
181 errx(1, "the password db file is busy");
183 err(1, "could not lock the passwd file");
188 * If the password file was replaced while we were trying to
189 * get the lock, our hardlink count will be 0 and we have to
192 if (fstat(lockfd, &st) == -1)
193 err(1, "fstat() failed");
194 if (st.st_nlink != 0)
203 * Create and open a presumably safe temp file for editing the password
204 * data, and copy the master password file into it.
214 if (*masterpasswd == '\0')
216 if ((p = strrchr(masterpasswd, '/')))
220 if (snprintf(tempname, sizeof(tempname), "%.*spw.XXXXXX",
221 (int)(p - masterpasswd), masterpasswd) >= (int)sizeof(tempname)) {
222 errno = ENAMETOOLONG;
225 if ((tfd = mkostemp(tempname, 0)) == -1)
228 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
229 if (write(tfd, buf, (size_t)nr) != nr)
242 * Regenerate the password database.
245 pw_mkdb(const char *user)
250 (void)fflush(stderr);
251 switch ((pid = fork())) {
257 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
258 "-d", passwd_dir, tempname, (char *)NULL);
260 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
261 "-d", passwd_dir, "-u", user, tempname,
269 if (waitpid(pid, &pstat, 0) == -1)
271 if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
278 * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
282 pw_edit(int notsetuid)
284 struct sigaction sa, sa_int, sa_quit;
285 sigset_t oldsigset, nsigset;
286 struct stat st1, st2;
290 if ((editor = getenv("EDITOR")) == NULL)
292 if (stat(tempname, &st1) == -1)
294 sa.sa_handler = SIG_IGN;
295 sigemptyset(&sa.sa_mask);
297 sigaction(SIGINT, &sa, &sa_int);
298 sigaction(SIGQUIT, &sa, &sa_quit);
299 sigemptyset(&nsigset);
300 sigaddset(&nsigset, SIGCHLD);
301 sigprocmask(SIG_BLOCK, &nsigset, &oldsigset);
302 switch ((editpid = fork())) {
306 sigaction(SIGINT, &sa_int, NULL);
307 sigaction(SIGQUIT, &sa_quit, NULL);
308 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
310 if (setgid(getgid()) == -1)
312 if (setuid(getuid()) == -1)
315 execlp(editor, editor, tempname, (char *)NULL);
316 err(1, "%s", editor);
322 if (waitpid(editpid, &pstat, WUNTRACED) == -1) {
328 } else if (WIFSTOPPED(pstat)) {
329 raise(WSTOPSIG(pstat));
330 } else if (WIFEXITED(pstat)) {
331 if (WEXITSTATUS(pstat) != 0)
332 errx(1, "\"%s\" exited with status %d", editor, WEXITSTATUS(pstat));
341 sigaction(SIGINT, &sa_int, NULL);
342 sigaction(SIGQUIT, &sa_quit, NULL);
343 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
344 if (stat(tempname, &st2) == -1)
346 return (st1.st_mtim.tv_sec != st2.st_mtim.tv_sec ||
347 st1.st_mtim.tv_nsec != st2.st_mtim.tv_nsec);
351 * Clean up. Preserve errno for the caller's convenience.
363 kill(editpid, SIGTERM);
364 kill(editpid, SIGCONT);
365 waitpid(editpid, &status, 0);
368 if (*tempname != '\0') {
378 * Compares two struct pwds.
381 pw_equal(const struct passwd *pw1, const struct passwd *pw2)
383 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
384 pw1->pw_uid == pw2->pw_uid &&
385 pw1->pw_gid == pw2->pw_gid &&
386 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
387 pw1->pw_change == pw2->pw_change &&
388 pw1->pw_expire == pw2->pw_expire &&
389 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
390 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
391 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
395 * Make a passwd line out of a struct passwd.
398 pw_make(const struct passwd *pw)
402 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
403 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
404 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
405 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
410 * Make a passwd line (in v7 format) out of a struct passwd
413 pw_make_v7(const struct passwd *pw)
417 asprintf(&line, "%s:*:%ju:%ju:%s:%s:%s", pw->pw_name,
418 (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
419 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
424 * Copy password file from one descriptor to another, replacing, deleting
425 * or adding a single record on the way.
428 pw_copy(int ffd, int tfd, const struct passwd *pw, struct passwd *old_pw)
430 char *buf, *end, *line, *p, *q, *r, *tmp;
432 const struct passwd *spw;
437 if (old_pw == NULL && pw == NULL)
441 /* deleting a user */
445 if ((line = pw_make(pw)) == NULL)
453 /* initialize the buffer */
454 if ((buf = malloc(size = 1024)) == NULL)
461 /* find the end of the current line */
462 for (p = q; q < end && *q != '\0'; ++q)
466 /* if we don't have a complete line, fill up the buffer */
470 while ((size_t)(q - p) >= size) {
471 if ((tmp = reallocarray(buf, 2, size)) == NULL) {
472 warnx("passwd line too long");
477 end = tmp + (end - buf);
482 q = memmove(buf, p, end - p);
487 readlen = read(ffd, end, size - (end - buf));
491 len = (size_t)readlen;
492 if (len == 0 && p == buf)
498 if (len > 0 && buf[len - 1] != '\n')
499 ++len, *end++ = '\n';
504 /* is it a blank line or a comment? */
505 for (r = p; r < q && isspace(*r); ++r)
507 if (r == q || *r == '#') {
509 if (write(tfd, p, q - p + 1) != q - p + 1)
515 /* is it the one we're looking for? */
520 fpw = pw_scan(r, PWSCAN_MASTER);
523 * fpw is either the struct passwd for the current line,
524 * or NULL if the line is malformed.
528 if (fpw == NULL || strcmp(fpw->pw_name, spw->pw_name) != 0) {
532 if (write(tfd, p, q - p + 1) != q - p + 1)
537 if (old_pw && !pw_equal(fpw, old_pw)) {
538 warnx("entry inconsistent");
540 errno = EINVAL; /* hack */
545 /* it is, replace or remove it */
548 if (write(tfd, line, len) != (int)len)
551 /* when removed, avoid the \n */
554 /* we're done, just copy the rest over */
556 if (write(tfd, q, end - q) != end - q)
559 readlen = read(ffd, buf, size);
563 len = (size_t)readlen;
571 /* if we got here, we didn't find the old entry */
577 if ((size_t)write(tfd, line, len) != len ||
578 write(tfd, "\n", 1) != 1)
591 * Return the current value of tempname.
601 * Duplicate a struct passwd.
604 pw_dup(const struct passwd *pw)
611 if (pw->pw_name != NULL)
612 len += strlen(pw->pw_name) + 1;
613 if (pw->pw_passwd != NULL)
614 len += strlen(pw->pw_passwd) + 1;
615 if (pw->pw_class != NULL)
616 len += strlen(pw->pw_class) + 1;
617 if (pw->pw_gecos != NULL)
618 len += strlen(pw->pw_gecos) + 1;
619 if (pw->pw_dir != NULL)
620 len += strlen(pw->pw_dir) + 1;
621 if (pw->pw_shell != NULL)
622 len += strlen(pw->pw_shell) + 1;
623 if ((npw = malloc((size_t)len)) == NULL)
625 memcpy(npw, pw, sizeof(*npw));
626 dst = (char *)npw + sizeof(*npw);
627 if (pw->pw_name != NULL) {
629 dst = stpcpy(npw->pw_name, pw->pw_name) + 1;
631 if (pw->pw_passwd != NULL) {
632 npw->pw_passwd = dst;
633 dst = stpcpy(npw->pw_passwd, pw->pw_passwd) + 1;
635 if (pw->pw_class != NULL) {
637 dst = stpcpy(npw->pw_class, pw->pw_class) + 1;
639 if (pw->pw_gecos != NULL) {
641 dst = stpcpy(npw->pw_gecos, pw->pw_gecos) + 1;
643 if (pw->pw_dir != NULL) {
645 dst = stpcpy(npw->pw_dir, pw->pw_dir) + 1;
647 if (pw->pw_shell != NULL) {
649 dst = stpcpy(npw->pw_shell, pw->pw_shell) + 1;
657 * Wrapper around some internal libc functions.
661 pw_initpwd(struct passwd *pw)
668 pw_scan(const char *line, int flags)
670 struct passwd pw, *ret;
673 if ((bp = strdup(line)) == NULL)
676 if (!__pw_scan(bp, &pw, flags)) {