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 __FBSDID("$FreeBSD$");
41 __SCCSID("@(#)pw_util.c 8.3 (Berkeley) 4/2/94");
44 * This file is used by all the "password" programs; vipw(8), chpass(1),
48 #include <sys/param.h>
49 #include <sys/errno.h>
51 #include <sys/resource.h>
69 static pid_t editpid = -1;
70 static int lockfd = -1;
71 static char masterpasswd[PATH_MAX];
72 static char passwd_dir[PATH_MAX];
73 static char tempname[PATH_MAX];
74 static int initialized;
87 * Initialize statics and set limits, signals & umask to try to avoid
88 * interruptions, crashes etc. that might expose passord data.
91 pw_init(const char *dir, const char *master)
98 strcpy(passwd_dir, _PATH_ETC);
100 if (strlen(dir) >= sizeof(passwd_dir)) {
101 errno = ENAMETOOLONG;
104 strcpy(passwd_dir, dir);
107 if (master == NULL) {
109 strcpy(masterpasswd, _PATH_MASTERPASSWD);
110 } else if (snprintf(masterpasswd, sizeof(masterpasswd), "%s/%s",
111 passwd_dir, _MASTERPASSWD) > (int)sizeof(masterpasswd)) {
112 errno = ENAMETOOLONG;
116 if (strlen(master) >= sizeof(masterpasswd)) {
117 errno = ENAMETOOLONG;
120 strcpy(masterpasswd, master);
124 * The code that follows is extremely disruptive to the calling
125 * process, and is therefore disabled until someone can conceive
126 * of a realistic scenario where it would fend off a compromise.
127 * Race conditions concerning the temporary files can be guarded
128 * against in other ways than masking signals (by checking stat(2)
129 * results after creation).
132 /* Unlimited resource limits. */
133 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
134 (void)setrlimit(RLIMIT_CPU, &rlim);
135 (void)setrlimit(RLIMIT_FSIZE, &rlim);
136 (void)setrlimit(RLIMIT_STACK, &rlim);
137 (void)setrlimit(RLIMIT_DATA, &rlim);
138 (void)setrlimit(RLIMIT_RSS, &rlim);
140 /* Don't drop core (not really necessary, but GP's). */
141 rlim.rlim_cur = rlim.rlim_max = 0;
142 (void)setrlimit(RLIMIT_CORE, &rlim);
144 /* Turn off signals. */
145 (void)signal(SIGALRM, SIG_IGN);
146 (void)signal(SIGHUP, SIG_IGN);
147 (void)signal(SIGINT, SIG_IGN);
148 (void)signal(SIGPIPE, SIG_IGN);
149 (void)signal(SIGQUIT, SIG_IGN);
150 (void)signal(SIGTERM, SIG_IGN);
151 (void)signal(SIGCONT, pw_cont);
153 /* Create with exact permissions. */
161 * Lock the master password file.
167 if (*masterpasswd == '\0')
171 * If the master password file doesn't exist, the system is hosed.
172 * Might as well try to build one. Set the close-on-exec bit so
173 * that users can't get at the encrypted passwords while editing.
174 * Open should allow flock'ing the file; see 4.4BSD. XXX
179 lockfd = flopen(masterpasswd, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0);
181 if (errno == EWOULDBLOCK) {
182 errx(1, "the password db file is busy");
184 err(1, "could not lock the passwd file");
189 * If the password file was replaced while we were trying to
190 * get the lock, our hardlink count will be 0 and we have to
193 if (fstat(lockfd, &st) == -1)
194 err(1, "fstat() failed");
195 if (st.st_nlink != 0)
204 * Create and open a presumably safe temp file for editing the password
205 * data, and copy the master password file into it.
215 if (*masterpasswd == '\0')
217 if ((p = strrchr(masterpasswd, '/')))
221 if (snprintf(tempname, sizeof(tempname), "%.*spw.XXXXXX",
222 (int)(p - masterpasswd), masterpasswd) >= (int)sizeof(tempname)) {
223 errno = ENAMETOOLONG;
226 if ((tfd = mkostemp(tempname, 0)) == -1)
229 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
230 if (write(tfd, buf, (size_t)nr) != nr)
243 * Regenerate the password database.
246 pw_mkdb(const char *user)
251 (void)fflush(stderr);
252 switch ((pid = fork())) {
258 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
259 "-d", passwd_dir, tempname, (char *)NULL);
261 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
262 "-d", passwd_dir, "-u", user, tempname,
270 if (waitpid(pid, &pstat, 0) == -1)
272 if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
279 * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
283 pw_edit(int notsetuid)
285 struct sigaction sa, sa_int, sa_quit;
286 sigset_t oldsigset, nsigset;
287 struct stat st1, st2;
291 if ((editor = getenv("EDITOR")) == NULL)
293 if (stat(tempname, &st1) == -1)
295 sa.sa_handler = SIG_IGN;
296 sigemptyset(&sa.sa_mask);
298 sigaction(SIGINT, &sa, &sa_int);
299 sigaction(SIGQUIT, &sa, &sa_quit);
300 sigemptyset(&nsigset);
301 sigaddset(&nsigset, SIGCHLD);
302 sigprocmask(SIG_BLOCK, &nsigset, &oldsigset);
303 switch ((editpid = fork())) {
307 sigaction(SIGINT, &sa_int, NULL);
308 sigaction(SIGQUIT, &sa_quit, NULL);
309 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
311 if (setgid(getgid()) == -1)
313 if (setuid(getuid()) == -1)
316 execlp(editor, editor, tempname, (char *)NULL);
317 err(1, "%s", editor);
323 if (waitpid(editpid, &pstat, WUNTRACED) == -1) {
329 } else if (WIFSTOPPED(pstat)) {
330 raise(WSTOPSIG(pstat));
331 } else if (WIFEXITED(pstat)) {
332 if (WEXITSTATUS(pstat) != 0)
333 errx(1, "\"%s\" exited with status %d", editor, WEXITSTATUS(pstat));
342 sigaction(SIGINT, &sa_int, NULL);
343 sigaction(SIGQUIT, &sa_quit, NULL);
344 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
345 if (stat(tempname, &st2) == -1)
347 return (st1.st_mtim.tv_sec != st2.st_mtim.tv_sec ||
348 st1.st_mtim.tv_nsec != st2.st_mtim.tv_nsec);
352 * Clean up. Preserve errno for the caller's convenience.
364 kill(editpid, SIGTERM);
365 kill(editpid, SIGCONT);
366 waitpid(editpid, &status, 0);
369 if (*tempname != '\0') {
379 * Compares two struct pwds.
382 pw_equal(const struct passwd *pw1, const struct passwd *pw2)
384 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
385 pw1->pw_uid == pw2->pw_uid &&
386 pw1->pw_gid == pw2->pw_gid &&
387 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
388 pw1->pw_change == pw2->pw_change &&
389 pw1->pw_expire == pw2->pw_expire &&
390 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
391 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
392 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
396 * Make a passwd line out of a struct passwd.
399 pw_make(const struct passwd *pw)
403 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
404 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
405 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
406 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
411 * Make a passwd line (in v7 format) out of a struct passwd
414 pw_make_v7(const struct passwd *pw)
418 asprintf(&line, "%s:*:%ju:%ju:%s:%s:%s", pw->pw_name,
419 (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
420 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
425 * Copy password file from one descriptor to another, replacing, deleting
426 * or adding a single record on the way.
429 pw_copy(int ffd, int tfd, const struct passwd *pw, struct passwd *old_pw)
431 char *buf, *end, *line, *p, *q, *r, *tmp;
433 const struct passwd *spw;
438 if (old_pw == NULL && pw == NULL)
442 /* deleting a user */
446 if ((line = pw_make(pw)) == NULL)
454 /* initialize the buffer */
455 if ((buf = malloc(size = 1024)) == NULL)
462 /* find the end of the current line */
463 for (p = q; q < end && *q != '\0'; ++q)
467 /* if we don't have a complete line, fill up the buffer */
471 while ((size_t)(q - p) >= size) {
472 if ((tmp = reallocarray(buf, 2, size)) == NULL) {
473 warnx("passwd line too long");
478 end = tmp + (end - buf);
483 q = memmove(buf, p, end - p);
488 readlen = read(ffd, end, size - (end - buf));
492 len = (size_t)readlen;
493 if (len == 0 && p == buf)
499 if (len > 0 && buf[len - 1] != '\n')
500 ++len, *end++ = '\n';
505 /* is it a blank line or a comment? */
506 for (r = p; r < q && isspace(*r); ++r)
508 if (r == q || *r == '#') {
510 if (write(tfd, p, q - p + 1) != q - p + 1)
516 /* is it the one we're looking for? */
521 fpw = pw_scan(r, PWSCAN_MASTER);
524 * fpw is either the struct passwd for the current line,
525 * or NULL if the line is malformed.
529 if (fpw == NULL || strcmp(fpw->pw_name, spw->pw_name) != 0) {
533 if (write(tfd, p, q - p + 1) != q - p + 1)
538 if (old_pw && !pw_equal(fpw, old_pw)) {
539 warnx("entry inconsistent");
541 errno = EINVAL; /* hack */
546 /* it is, replace or remove it */
549 if (write(tfd, line, len) != (int)len)
552 /* when removed, avoid the \n */
555 /* we're done, just copy the rest over */
557 if (write(tfd, q, end - q) != end - q)
560 readlen = read(ffd, buf, size);
564 len = (size_t)readlen;
572 /* if we got here, we didn't find the old entry */
578 if ((size_t)write(tfd, line, len) != len ||
579 write(tfd, "\n", 1) != 1)
592 * Return the current value of tempname.
602 * Duplicate a struct passwd.
605 pw_dup(const struct passwd *pw)
612 if (pw->pw_name != NULL)
613 len += strlen(pw->pw_name) + 1;
614 if (pw->pw_passwd != NULL)
615 len += strlen(pw->pw_passwd) + 1;
616 if (pw->pw_class != NULL)
617 len += strlen(pw->pw_class) + 1;
618 if (pw->pw_gecos != NULL)
619 len += strlen(pw->pw_gecos) + 1;
620 if (pw->pw_dir != NULL)
621 len += strlen(pw->pw_dir) + 1;
622 if (pw->pw_shell != NULL)
623 len += strlen(pw->pw_shell) + 1;
624 if ((npw = malloc((size_t)len)) == NULL)
626 memcpy(npw, pw, sizeof(*npw));
627 dst = (char *)npw + sizeof(*npw);
628 if (pw->pw_name != NULL) {
630 dst = stpcpy(npw->pw_name, pw->pw_name) + 1;
632 if (pw->pw_passwd != NULL) {
633 npw->pw_passwd = dst;
634 dst = stpcpy(npw->pw_passwd, pw->pw_passwd) + 1;
636 if (pw->pw_class != NULL) {
638 dst = stpcpy(npw->pw_class, pw->pw_class) + 1;
640 if (pw->pw_gecos != NULL) {
642 dst = stpcpy(npw->pw_gecos, pw->pw_gecos) + 1;
644 if (pw->pw_dir != NULL) {
646 dst = stpcpy(npw->pw_dir, pw->pw_dir) + 1;
648 if (pw->pw_shell != NULL) {
650 dst = stpcpy(npw->pw_shell, pw->pw_shell) + 1;
658 * Wrapper around some internal libc functions.
662 pw_initpwd(struct passwd *pw)
669 pw_scan(const char *line, int flags)
671 struct passwd pw, *ret;
674 if ((bp = strdup(line)) == NULL)
677 if (!__pw_scan(bp, &pw, flags)) {