2 * Copyright (c) 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 2002 Networks Associates Technology, Inc.
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
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19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
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26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)pw_util.c 8.3 (Berkeley) 4/2/94
37 * $FreeBSD: head/lib/libutil/pw_util.c 244744 2012-12-27 20:24:44Z bapt $
41 * This file is used by all the "password" programs; vipw(8), chpass(1),
45 #include <sys/param.h>
46 #include <sys/errno.h>
48 #include <sys/resource.h>
66 static pid_t editpid = -1;
67 static int lockfd = -1;
68 static char masterpasswd[PATH_MAX];
69 static char passwd_dir[PATH_MAX];
70 static char tempname[PATH_MAX];
71 static int initialized;
84 * Initialize statics and set limits, signals & umask to try to avoid
85 * interruptions, crashes etc. that might expose passord data.
88 pw_init(const char *dir, const char *master)
95 strcpy(passwd_dir, _PATH_ETC);
97 if (strlen(dir) >= sizeof(passwd_dir)) {
101 strcpy(passwd_dir, dir);
104 if (master == NULL) {
106 strcpy(masterpasswd, _PATH_MASTERPASSWD);
107 } else if (snprintf(masterpasswd, sizeof(masterpasswd), "%s/%s",
108 passwd_dir, _MASTERPASSWD) > (int)sizeof(masterpasswd)) {
109 errno = ENAMETOOLONG;
113 if (strlen(master) >= sizeof(masterpasswd)) {
114 errno = ENAMETOOLONG;
117 strcpy(masterpasswd, master);
121 * The code that follows is extremely disruptive to the calling
122 * process, and is therefore disabled until someone can conceive
123 * of a realistic scenario where it would fend off a compromise.
124 * Race conditions concerning the temporary files can be guarded
125 * against in other ways than masking signals (by checking stat(2)
126 * results after creation).
129 /* Unlimited resource limits. */
130 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
131 (void)setrlimit(RLIMIT_CPU, &rlim);
132 (void)setrlimit(RLIMIT_FSIZE, &rlim);
133 (void)setrlimit(RLIMIT_STACK, &rlim);
134 (void)setrlimit(RLIMIT_DATA, &rlim);
135 (void)setrlimit(RLIMIT_RSS, &rlim);
137 /* Don't drop core (not really necessary, but GP's). */
138 rlim.rlim_cur = rlim.rlim_max = 0;
139 (void)setrlimit(RLIMIT_CORE, &rlim);
141 /* Turn off signals. */
142 (void)signal(SIGALRM, SIG_IGN);
143 (void)signal(SIGHUP, SIG_IGN);
144 (void)signal(SIGINT, SIG_IGN);
145 (void)signal(SIGPIPE, SIG_IGN);
146 (void)signal(SIGQUIT, SIG_IGN);
147 (void)signal(SIGTERM, SIG_IGN);
148 (void)signal(SIGCONT, pw_cont);
150 /* Create with exact permissions. */
158 * Lock the master password file.
164 if (*masterpasswd == '\0')
168 * If the master password file doesn't exist, the system is hosed.
169 * Might as well try to build one. Set the close-on-exec bit so
170 * that users can't get at the encrypted passwords while editing.
171 * Open should allow flock'ing the file; see 4.4BSD. XXX
176 lockfd = flopen(masterpasswd, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0);
178 if (errno == EWOULDBLOCK) {
179 errx(1, "the password db file is busy");
181 err(1, "could not lock the passwd file: ");
186 * If the password file was replaced while we were trying to
187 * get the lock, our hardlink count will be 0 and we have to
190 if (fstat(lockfd, &st) == -1)
191 err(1, "fstat() failed: ");
192 if (st.st_nlink != 0)
201 * Create and open a presumably safe temp file for editing the password
202 * data, and copy the master password file into it.
212 if (*masterpasswd == '\0')
214 if ((p = strrchr(masterpasswd, '/')))
218 if (snprintf(tempname, sizeof(tempname), "%.*spw.XXXXXX",
219 (int)(p - masterpasswd), masterpasswd) >= (int)sizeof(tempname)) {
220 errno = ENAMETOOLONG;
223 if ((tfd = mkstemp(tempname)) == -1)
226 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
227 if (write(tfd, buf, (size_t)nr) != nr)
240 * Regenerate the password database.
243 pw_mkdb(const char *user)
248 (void)fflush(stderr);
249 switch ((pid = fork())) {
255 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
256 "-d", passwd_dir, tempname, NULL);
258 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
259 "-d", passwd_dir, "-u", user, tempname,
267 if (waitpid(pid, &pstat, 0) == -1)
269 if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
276 * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
280 pw_edit(int notsetuid)
282 struct sigaction sa, sa_int, sa_quit;
283 sigset_t oldsigset, nsigset;
284 struct stat st1, st2;
288 if ((editor = getenv("EDITOR")) == NULL)
290 if (stat(tempname, &st1) == -1)
292 sa.sa_handler = SIG_IGN;
293 sigemptyset(&sa.sa_mask);
295 sigaction(SIGINT, &sa, &sa_int);
296 sigaction(SIGQUIT, &sa, &sa_quit);
297 sigemptyset(&nsigset);
298 sigaddset(&nsigset, SIGCHLD);
299 sigprocmask(SIG_BLOCK, &nsigset, &oldsigset);
300 switch ((editpid = fork())) {
304 sigaction(SIGINT, &sa_int, NULL);
305 sigaction(SIGQUIT, &sa_quit, NULL);
306 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
308 (void)setgid(getgid());
309 (void)setuid(getuid());
312 execlp(editor, basename(editor), tempname, NULL);
319 if (waitpid(editpid, &pstat, WUNTRACED) == -1) {
325 } else if (WIFSTOPPED(pstat)) {
326 raise(WSTOPSIG(pstat));
327 } else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) {
336 sigaction(SIGINT, &sa_int, NULL);
337 sigaction(SIGQUIT, &sa_quit, NULL);
338 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
339 if (stat(tempname, &st2) == -1)
341 return (st1.st_mtim.tv_sec != st2.st_mtim.tv_sec ||
342 st1.st_mtim.tv_nsec != st2.st_mtim.tv_nsec);
346 * Clean up. Preserve errno for the caller's convenience.
358 kill(editpid, SIGTERM);
359 kill(editpid, SIGCONT);
360 waitpid(editpid, &status, 0);
363 if (*tempname != '\0') {
373 * Compares two struct pwds.
376 pw_equal(const struct passwd *pw1, const struct passwd *pw2)
378 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
379 pw1->pw_uid == pw2->pw_uid &&
380 pw1->pw_gid == pw2->pw_gid &&
381 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
382 pw1->pw_change == pw2->pw_change &&
383 pw1->pw_expire == pw2->pw_expire &&
384 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
385 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
386 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
390 * Make a passwd line out of a struct passwd.
393 pw_make(const struct passwd *pw)
397 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
398 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
399 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
400 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
405 * Make a passwd line (in v7 format) out of a struct passwd
408 pw_make_v7(const struct passwd *pw)
412 asprintf(&line, "%s:*:%ju:%ju:%s:%s:%s", pw->pw_name,
413 (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
414 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
419 * Copy password file from one descriptor to another, replacing, deleting
420 * or adding a single record on the way.
423 pw_copy(int ffd, int tfd, const struct passwd *pw, struct passwd *old_pw)
425 char buf[8192], *end, *line, *p, *q, *r, t;
427 const struct passwd *spw;
431 if (old_pw == NULL && pw == NULL)
435 /* deleting a user */
439 if ((line = pw_make(pw)) == NULL)
451 /* find the end of the current line */
452 for (p = q; q < end && *q != '\0'; ++q)
456 /* if we don't have a complete line, fill up the buffer */
460 if ((size_t)(q - p) >= sizeof(buf)) {
461 warnx("passwd line too long");
462 errno = EINVAL; /* hack */
466 q = memmove(buf, p, end - p);
471 readlen = read(ffd, end, sizeof(buf) - (end - buf));
475 len = (size_t)readlen;
476 if (len == 0 && p == buf)
480 if (len < (ssize_t)sizeof(buf)) {
482 if (len > 0 && buf[len - 1] != '\n')
483 ++len, *end++ = '\n';
488 /* is it a blank line or a comment? */
489 for (r = p; r < q && isspace(*r); ++r)
491 if (r == q || *r == '#') {
493 if (write(tfd, p, q - p + 1) != q - p + 1)
499 /* is it the one we're looking for? */
504 fpw = pw_scan(r, PWSCAN_MASTER);
507 * fpw is either the struct passwd for the current line,
508 * or NULL if the line is malformed.
512 if (fpw == NULL || strcmp(fpw->pw_name, spw->pw_name) != 0) {
516 if (write(tfd, p, q - p + 1) != q - p + 1)
521 if (old_pw && !pw_equal(fpw, old_pw)) {
522 warnx("entry inconsistent");
524 errno = EINVAL; /* hack */
529 /* it is, replace or remove it */
532 if (write(tfd, line, len) != (int)len)
535 /* when removed, avoid the \n */
538 /* we're done, just copy the rest over */
540 if (write(tfd, q, end - q) != end - q)
543 readlen = read(ffd, buf, sizeof(buf));
547 len = (size_t)readlen;
555 /* if we got here, we didn't find the old entry */
561 if ((size_t)write(tfd, line, len) != len ||
562 write(tfd, "\n", 1) != 1)
575 * Return the current value of tempname.
585 * Duplicate a struct passwd.
588 pw_dup(const struct passwd *pw)
595 if (pw->pw_name != NULL)
596 len += strlen(pw->pw_name) + 1;
597 if (pw->pw_passwd != NULL)
598 len += strlen(pw->pw_passwd) + 1;
599 if (pw->pw_class != NULL)
600 len += strlen(pw->pw_class) + 1;
601 if (pw->pw_gecos != NULL)
602 len += strlen(pw->pw_gecos) + 1;
603 if (pw->pw_dir != NULL)
604 len += strlen(pw->pw_dir) + 1;
605 if (pw->pw_shell != NULL)
606 len += strlen(pw->pw_shell) + 1;
607 if ((npw = malloc((size_t)len)) == NULL)
609 memcpy(npw, pw, sizeof(*npw));
610 dst = (char *)npw + sizeof(*npw);
611 if (pw->pw_name != NULL) {
613 dst = stpcpy(npw->pw_name, pw->pw_name) + 1;
615 if (pw->pw_passwd != NULL) {
616 npw->pw_passwd = dst;
617 dst = stpcpy(npw->pw_passwd, pw->pw_passwd) + 1;
619 if (pw->pw_class != NULL) {
621 dst = stpcpy(npw->pw_class, pw->pw_class) + 1;
623 if (pw->pw_gecos != NULL) {
625 dst = stpcpy(npw->pw_gecos, pw->pw_gecos) + 1;
627 if (pw->pw_dir != NULL) {
629 dst = stpcpy(npw->pw_dir, pw->pw_dir) + 1;
631 if (pw->pw_shell != NULL) {
633 dst = stpcpy(npw->pw_shell, pw->pw_shell) + 1;
641 * Wrapper around an internal libc function
644 pw_scan(const char *line, int flags)
646 struct passwd pw, *ret;
649 if ((bp = strdup(line)) == NULL)
651 if (!__pw_scan(bp, &pw, flags)) {