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
41 static const char sccsid[] = "@(#)pw_util.c 8.3 (Berkeley) 4/2/94";
43 static const char rcsid[] =
48 * This file is used by all the "password" programs; vipw(8), chpass(1),
52 #include <sys/param.h>
53 #include <sys/errno.h>
55 #include <sys/resource.h>
73 static pid_t editpid = -1;
74 static int lockfd = -1;
75 static char masterpasswd[PATH_MAX];
76 static char passwd_dir[PATH_MAX];
77 static char tempname[PATH_MAX];
78 static int initialized;
91 * Initialize statics and set limits, signals & umask to try to avoid
92 * interruptions, crashes etc. that might expose passord data.
95 pw_init(const char *dir, const char *master)
102 strcpy(passwd_dir, _PATH_ETC);
104 if (strlen(dir) >= sizeof(passwd_dir)) {
105 errno = ENAMETOOLONG;
108 strcpy(passwd_dir, dir);
111 if (master == NULL) {
113 strcpy(masterpasswd, _PATH_MASTERPASSWD);
114 } else if (snprintf(masterpasswd, sizeof(masterpasswd), "%s/%s",
115 passwd_dir, _MASTERPASSWD) > (int)sizeof(masterpasswd)) {
116 errno = ENAMETOOLONG;
120 if (strlen(master) >= sizeof(masterpasswd)) {
121 errno = ENAMETOOLONG;
124 strcpy(masterpasswd, master);
128 * The code that follows is extremely disruptive to the calling
129 * process, and is therefore disabled until someone can conceive
130 * of a realistic scenario where it would fend off a compromise.
131 * Race conditions concerning the temporary files can be guarded
132 * against in other ways than masking signals (by checking stat(2)
133 * results after creation).
136 /* Unlimited resource limits. */
137 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
138 (void)setrlimit(RLIMIT_CPU, &rlim);
139 (void)setrlimit(RLIMIT_FSIZE, &rlim);
140 (void)setrlimit(RLIMIT_STACK, &rlim);
141 (void)setrlimit(RLIMIT_DATA, &rlim);
142 (void)setrlimit(RLIMIT_RSS, &rlim);
144 /* Don't drop core (not really necessary, but GP's). */
145 rlim.rlim_cur = rlim.rlim_max = 0;
146 (void)setrlimit(RLIMIT_CORE, &rlim);
148 /* Turn off signals. */
149 (void)signal(SIGALRM, SIG_IGN);
150 (void)signal(SIGHUP, SIG_IGN);
151 (void)signal(SIGINT, SIG_IGN);
152 (void)signal(SIGPIPE, SIG_IGN);
153 (void)signal(SIGQUIT, SIG_IGN);
154 (void)signal(SIGTERM, SIG_IGN);
155 (void)signal(SIGCONT, pw_cont);
157 /* Create with exact permissions. */
165 * Lock the master password file.
171 if (*masterpasswd == '\0')
175 * If the master password file doesn't exist, the system is hosed.
176 * Might as well try to build one. Set the close-on-exec bit so
177 * that users can't get at the encrypted passwords while editing.
178 * Open should allow flock'ing the file; see 4.4BSD. XXX
183 lockfd = flopen(masterpasswd, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0);
185 if (errno == EWOULDBLOCK) {
186 errx(1, "the password db file is busy");
188 err(1, "could not lock the passwd file: ");
193 * If the password file was replaced while we were trying to
194 * get the lock, our hardlink count will be 0 and we have to
197 if (fstat(lockfd, &st) == -1)
198 err(1, "fstat() failed: ");
199 if (st.st_nlink != 0)
208 * Create and open a presumably safe temp file for editing the password
209 * data, and copy the master password file into it.
219 if (*masterpasswd == '\0')
221 if ((p = strrchr(masterpasswd, '/')))
225 if (snprintf(tempname, sizeof(tempname), "%.*spw.XXXXXX",
226 (int)(p - masterpasswd), masterpasswd) >= (int)sizeof(tempname)) {
227 errno = ENAMETOOLONG;
230 if ((tfd = mkostemp(tempname, 0)) == -1)
233 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
234 if (write(tfd, buf, (size_t)nr) != nr)
247 * Regenerate the password database.
250 pw_mkdb(const char *user)
255 (void)fflush(stderr);
256 switch ((pid = fork())) {
262 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
263 "-d", passwd_dir, tempname, (char *)NULL);
265 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
266 "-d", passwd_dir, "-u", user, tempname,
274 if (waitpid(pid, &pstat, 0) == -1)
276 if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
283 * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
287 pw_edit(int notsetuid)
289 struct sigaction sa, sa_int, sa_quit;
290 sigset_t oldsigset, nsigset;
291 struct stat st1, st2;
295 if ((editor = getenv("EDITOR")) == NULL)
297 if (stat(tempname, &st1) == -1)
299 sa.sa_handler = SIG_IGN;
300 sigemptyset(&sa.sa_mask);
302 sigaction(SIGINT, &sa, &sa_int);
303 sigaction(SIGQUIT, &sa, &sa_quit);
304 sigemptyset(&nsigset);
305 sigaddset(&nsigset, SIGCHLD);
306 sigprocmask(SIG_BLOCK, &nsigset, &oldsigset);
307 switch ((editpid = fork())) {
311 sigaction(SIGINT, &sa_int, NULL);
312 sigaction(SIGQUIT, &sa_quit, NULL);
313 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
315 (void)setgid(getgid());
316 (void)setuid(getuid());
319 execlp(editor, editor, tempname, (char *)NULL);
326 if (waitpid(editpid, &pstat, WUNTRACED) == -1) {
332 } else if (WIFSTOPPED(pstat)) {
333 raise(WSTOPSIG(pstat));
334 } else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) {
343 sigaction(SIGINT, &sa_int, NULL);
344 sigaction(SIGQUIT, &sa_quit, NULL);
345 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
346 if (stat(tempname, &st2) == -1)
348 return (st1.st_mtim.tv_sec != st2.st_mtim.tv_sec ||
349 st1.st_mtim.tv_nsec != st2.st_mtim.tv_nsec);
353 * Clean up. Preserve errno for the caller's convenience.
365 kill(editpid, SIGTERM);
366 kill(editpid, SIGCONT);
367 waitpid(editpid, &status, 0);
370 if (*tempname != '\0') {
380 * Compares two struct pwds.
383 pw_equal(const struct passwd *pw1, const struct passwd *pw2)
385 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
386 pw1->pw_uid == pw2->pw_uid &&
387 pw1->pw_gid == pw2->pw_gid &&
388 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
389 pw1->pw_change == pw2->pw_change &&
390 pw1->pw_expire == pw2->pw_expire &&
391 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
392 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
393 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
397 * Make a passwd line out of a struct passwd.
400 pw_make(const struct passwd *pw)
404 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
405 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
406 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
407 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
412 * Make a passwd line (in v7 format) out of a struct passwd
415 pw_make_v7(const struct passwd *pw)
419 asprintf(&line, "%s:*:%ju:%ju:%s:%s:%s", pw->pw_name,
420 (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
421 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
426 * Copy password file from one descriptor to another, replacing, deleting
427 * or adding a single record on the way.
430 pw_copy(int ffd, int tfd, const struct passwd *pw, struct passwd *old_pw)
432 char *buf, *end, *line, *p, *q, *r, *tmp;
434 const struct passwd *spw;
439 if (old_pw == NULL && pw == NULL)
443 /* deleting a user */
447 if ((line = pw_make(pw)) == NULL)
455 /* initialize the buffer */
456 if ((buf = malloc(size = 1024)) == NULL)
463 /* find the end of the current line */
464 for (p = q; q < end && *q != '\0'; ++q)
468 /* if we don't have a complete line, fill up the buffer */
472 while ((size_t)(q - p) >= size) {
473 if ((tmp = reallocarray(buf, 2, size)) == NULL) {
474 warnx("passwd line too long");
479 end = tmp + (end - buf);
484 q = memmove(buf, p, end - p);
489 readlen = read(ffd, end, size - (end - buf));
493 len = (size_t)readlen;
494 if (len == 0 && p == buf)
500 if (len > 0 && buf[len - 1] != '\n')
501 ++len, *end++ = '\n';
506 /* is it a blank line or a comment? */
507 for (r = p; r < q && isspace(*r); ++r)
509 if (r == q || *r == '#') {
511 if (write(tfd, p, q - p + 1) != q - p + 1)
517 /* is it the one we're looking for? */
522 fpw = pw_scan(r, PWSCAN_MASTER);
525 * fpw is either the struct passwd for the current line,
526 * or NULL if the line is malformed.
530 if (fpw == NULL || strcmp(fpw->pw_name, spw->pw_name) != 0) {
534 if (write(tfd, p, q - p + 1) != q - p + 1)
539 if (old_pw && !pw_equal(fpw, old_pw)) {
540 warnx("entry inconsistent");
542 errno = EINVAL; /* hack */
547 /* it is, replace or remove it */
550 if (write(tfd, line, len) != (int)len)
553 /* when removed, avoid the \n */
556 /* we're done, just copy the rest over */
558 if (write(tfd, q, end - q) != end - q)
561 readlen = read(ffd, buf, size);
565 len = (size_t)readlen;
573 /* if we got here, we didn't find the old entry */
579 if ((size_t)write(tfd, line, len) != len ||
580 write(tfd, "\n", 1) != 1)
593 * Return the current value of tempname.
603 * Duplicate a struct passwd.
606 pw_dup(const struct passwd *pw)
613 if (pw->pw_name != NULL)
614 len += strlen(pw->pw_name) + 1;
615 if (pw->pw_passwd != NULL)
616 len += strlen(pw->pw_passwd) + 1;
617 if (pw->pw_class != NULL)
618 len += strlen(pw->pw_class) + 1;
619 if (pw->pw_gecos != NULL)
620 len += strlen(pw->pw_gecos) + 1;
621 if (pw->pw_dir != NULL)
622 len += strlen(pw->pw_dir) + 1;
623 if (pw->pw_shell != NULL)
624 len += strlen(pw->pw_shell) + 1;
625 if ((npw = malloc((size_t)len)) == NULL)
627 memcpy(npw, pw, sizeof(*npw));
628 dst = (char *)npw + sizeof(*npw);
629 if (pw->pw_name != NULL) {
631 dst = stpcpy(npw->pw_name, pw->pw_name) + 1;
633 if (pw->pw_passwd != NULL) {
634 npw->pw_passwd = dst;
635 dst = stpcpy(npw->pw_passwd, pw->pw_passwd) + 1;
637 if (pw->pw_class != NULL) {
639 dst = stpcpy(npw->pw_class, pw->pw_class) + 1;
641 if (pw->pw_gecos != NULL) {
643 dst = stpcpy(npw->pw_gecos, pw->pw_gecos) + 1;
645 if (pw->pw_dir != NULL) {
647 dst = stpcpy(npw->pw_dir, pw->pw_dir) + 1;
649 if (pw->pw_shell != NULL) {
651 dst = stpcpy(npw->pw_shell, pw->pw_shell) + 1;
659 * Wrapper around an internal libc function
662 pw_scan(const char *line, int flags)
664 struct passwd pw, *ret;
667 if ((bp = strdup(line)) == NULL)
669 if (!__pw_scan(bp, &pw, flags)) {