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
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 4. 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
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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
39 static const char sccsid[] = "@(#)pw_util.c 8.3 (Berkeley) 4/2/94";
41 static const char rcsid[] =
46 * This file is used by all the "password" programs; vipw(8), chpass(1),
50 #include <sys/param.h>
51 #include <sys/errno.h>
53 #include <sys/resource.h>
72 static pid_t editpid = -1;
73 static int lockfd = -1;
74 static char masterpasswd[PATH_MAX];
75 static char passwd_dir[PATH_MAX];
76 static char tempname[PATH_MAX];
77 static int initialized;
90 * Initialize statics and set limits, signals & umask to try to avoid
91 * interruptions, crashes etc. that might expose passord data.
94 pw_init(const char *dir, const char *master)
101 strcpy(passwd_dir, _PATH_ETC);
103 if (strlen(dir) >= sizeof(passwd_dir)) {
104 errno = ENAMETOOLONG;
107 strcpy(passwd_dir, dir);
110 if (master == NULL) {
112 strcpy(masterpasswd, _PATH_MASTERPASSWD);
113 } else if (snprintf(masterpasswd, sizeof(masterpasswd), "%s/%s",
114 passwd_dir, _MASTERPASSWD) > (int)sizeof(masterpasswd)) {
115 errno = ENAMETOOLONG;
119 if (strlen(master) >= sizeof(masterpasswd)) {
120 errno = ENAMETOOLONG;
123 strcpy(masterpasswd, master);
127 * The code that follows is extremely disruptive to the calling
128 * process, and is therefore disabled until someone can conceive
129 * of a realistic scenario where it would fend off a compromise.
130 * Race conditions concerning the temporary files can be guarded
131 * against in other ways than masking signals (by checking stat(2)
132 * results after creation).
135 /* Unlimited resource limits. */
136 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
137 (void)setrlimit(RLIMIT_CPU, &rlim);
138 (void)setrlimit(RLIMIT_FSIZE, &rlim);
139 (void)setrlimit(RLIMIT_STACK, &rlim);
140 (void)setrlimit(RLIMIT_DATA, &rlim);
141 (void)setrlimit(RLIMIT_RSS, &rlim);
143 /* Don't drop core (not really necessary, but GP's). */
144 rlim.rlim_cur = rlim.rlim_max = 0;
145 (void)setrlimit(RLIMIT_CORE, &rlim);
147 /* Turn off signals. */
148 (void)signal(SIGALRM, SIG_IGN);
149 (void)signal(SIGHUP, SIG_IGN);
150 (void)signal(SIGINT, SIG_IGN);
151 (void)signal(SIGPIPE, SIG_IGN);
152 (void)signal(SIGQUIT, SIG_IGN);
153 (void)signal(SIGTERM, SIG_IGN);
154 (void)signal(SIGCONT, pw_cont);
156 /* Create with exact permissions. */
164 * Lock the master password file.
170 if (*masterpasswd == '\0')
174 * If the master password file doesn't exist, the system is hosed.
175 * Might as well try to build one. Set the close-on-exec bit so
176 * that users can't get at the encrypted passwords while editing.
177 * Open should allow flock'ing the file; see 4.4BSD. XXX
182 lockfd = open(masterpasswd, O_RDONLY, 0);
183 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
184 err(1, "%s", masterpasswd);
185 /* XXX vulnerable to race conditions */
186 if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
187 if (errno == EWOULDBLOCK) {
188 errx(1, "the password db file is busy");
190 err(1, "could not lock the passwd file: ");
195 * If the password file was replaced while we were trying to
196 * get the lock, our hardlink count will be 0 and we have to
199 if (fstat(lockfd, &st) == -1)
200 err(1, "fstat() failed: ");
201 if (st.st_nlink != 0)
210 * Create and open a presumably safe temp file for editing the password
211 * data, and copy the master password file into it.
221 if (*masterpasswd == '\0')
223 if ((p = strrchr(masterpasswd, '/')))
227 if (snprintf(tempname, sizeof(tempname), "%.*spw.XXXXXX",
228 (int)(p - masterpasswd), masterpasswd) >= (int)sizeof(tempname)) {
229 errno = ENAMETOOLONG;
232 if ((tfd = mkstemp(tempname)) == -1)
235 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
236 if (write(tfd, buf, (size_t)nr) != nr)
249 * Regenerate the password database.
252 pw_mkdb(const char *user)
257 (void)fflush(stderr);
258 switch ((pid = fork())) {
264 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
265 "-d", passwd_dir, tempname, (char *)NULL);
267 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
268 "-d", passwd_dir, "-u", user, tempname,
276 if (waitpid(pid, &pstat, 0) == -1)
278 if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
285 * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
289 pw_edit(int notsetuid)
291 struct sigaction sa, sa_int, sa_quit;
292 sigset_t oldsigset, nsigset;
293 struct stat st1, st2;
297 if ((editor = getenv("EDITOR")) == NULL)
299 if (stat(tempname, &st1) == -1)
301 sa.sa_handler = SIG_IGN;
302 sigemptyset(&sa.sa_mask);
304 sigaction(SIGINT, &sa, &sa_int);
305 sigaction(SIGQUIT, &sa, &sa_quit);
306 sigemptyset(&nsigset);
307 sigaddset(&nsigset, SIGCHLD);
308 sigprocmask(SIG_BLOCK, &nsigset, &oldsigset);
309 switch ((editpid = fork())) {
313 sigaction(SIGINT, &sa_int, NULL);
314 sigaction(SIGQUIT, &sa_quit, NULL);
315 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
317 (void)setgid(getgid());
318 (void)setuid(getuid());
321 execlp(editor, basename(editor), tempname, (char *)NULL);
328 if (waitpid(editpid, &pstat, WUNTRACED) == -1) {
334 } else if (WIFSTOPPED(pstat)) {
335 raise(WSTOPSIG(pstat));
336 } else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) {
345 sigaction(SIGINT, &sa_int, NULL);
346 sigaction(SIGQUIT, &sa_quit, NULL);
347 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
348 if (stat(tempname, &st2) == -1)
350 return (st1.st_mtime != st2.st_mtime);
354 * Clean up. Preserve errno for the caller's convenience.
366 kill(editpid, SIGTERM);
367 kill(editpid, SIGCONT);
368 waitpid(editpid, &status, 0);
371 if (*tempname != '\0') {
381 * Compares two struct pwds.
384 pw_equal(const struct passwd *pw1, const struct passwd *pw2)
386 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
387 pw1->pw_uid == pw2->pw_uid &&
388 pw1->pw_gid == pw2->pw_gid &&
389 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
390 pw1->pw_change == pw2->pw_change &&
391 pw1->pw_expire == pw2->pw_expire &&
392 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
393 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
394 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
398 * Make a passwd line out of a struct passwd.
401 pw_make(const struct passwd *pw)
405 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
406 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
407 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
408 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
413 * Make a passwd line (in v7 format) out of a struct passwd
416 pw_make_v7(const struct passwd *pw)
420 asprintf(&line, "%s:*:%ju:%ju:%s:%s:%s", pw->pw_name,
421 (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
422 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
427 * Copy password file from one descriptor to another, replacing, deleting
428 * or adding a single record on the way.
431 pw_copy(int ffd, int tfd, const struct passwd *pw, struct passwd *old_pw)
433 char buf[8192], *end, *line, *p, *q, *r, t;
435 const struct passwd *spw;
439 if (old_pw == NULL && pw == NULL)
443 /* deleting a user */
447 if ((line = pw_make(pw)) == NULL)
459 /* find the end of the current line */
460 for (p = q; q < end && *q != '\0'; ++q)
464 /* if we don't have a complete line, fill up the buffer */
468 if ((size_t)(q - p) >= sizeof(buf)) {
469 warnx("passwd line too long");
470 errno = EINVAL; /* hack */
474 q = memmove(buf, p, end - p);
479 readlen = read(ffd, end, sizeof(buf) - (end - buf));
483 len = (size_t)readlen;
484 if (len == 0 && p == buf)
488 if (len < (ssize_t)sizeof(buf)) {
490 if (len > 0 && buf[len - 1] != '\n')
491 ++len, *end++ = '\n';
496 /* is it a blank line or a comment? */
497 for (r = p; r < q && isspace(*r); ++r)
499 if (r == q || *r == '#') {
501 if (write(tfd, p, q - p + 1) != q - p + 1)
507 /* is it the one we're looking for? */
512 fpw = pw_scan(r, PWSCAN_MASTER);
515 * fpw is either the struct passwd for the current line,
516 * or NULL if the line is malformed.
520 if (fpw == NULL || strcmp(fpw->pw_name, spw->pw_name) != 0) {
524 if (write(tfd, p, q - p + 1) != q - p + 1)
529 if (old_pw && !pw_equal(fpw, old_pw)) {
530 warnx("entry inconsistent");
532 errno = EINVAL; /* hack */
537 /* it is, replace or remove it */
540 if (write(tfd, line, len) != (int)len)
543 /* when removed, avoid the \n */
546 /* we're done, just copy the rest over */
548 if (write(tfd, q, end - q) != end - q)
551 readlen = read(ffd, buf, sizeof(buf));
555 len = (size_t)readlen;
563 /* if we got here, we didn't find the old entry */
569 if ((size_t)write(tfd, line, len) != len ||
570 write(tfd, "\n", 1) != 1)
583 * Return the current value of tempname.
593 * Duplicate a struct passwd.
596 pw_dup(const struct passwd *pw)
603 if (pw->pw_name != NULL)
604 len += strlen(pw->pw_name) + 1;
605 if (pw->pw_passwd != NULL)
606 len += strlen(pw->pw_passwd) + 1;
607 if (pw->pw_class != NULL)
608 len += strlen(pw->pw_class) + 1;
609 if (pw->pw_gecos != NULL)
610 len += strlen(pw->pw_gecos) + 1;
611 if (pw->pw_dir != NULL)
612 len += strlen(pw->pw_dir) + 1;
613 if (pw->pw_shell != NULL)
614 len += strlen(pw->pw_shell) + 1;
615 if ((npw = malloc((size_t)len)) == NULL)
617 memcpy(npw, pw, sizeof(*npw));
618 dst = (char *)npw + sizeof(*npw);
619 if (pw->pw_name != NULL) {
621 dst = stpcpy(npw->pw_name, pw->pw_name) + 1;
623 if (pw->pw_passwd != NULL) {
624 npw->pw_passwd = dst;
625 dst = stpcpy(npw->pw_passwd, pw->pw_passwd) + 1;
627 if (pw->pw_class != NULL) {
629 dst = stpcpy(npw->pw_class, pw->pw_class) + 1;
631 if (pw->pw_gecos != NULL) {
633 dst = stpcpy(npw->pw_gecos, pw->pw_gecos) + 1;
635 if (pw->pw_dir != NULL) {
637 dst = stpcpy(npw->pw_dir, pw->pw_dir) + 1;
639 if (pw->pw_shell != NULL) {
641 dst = stpcpy(npw->pw_shell, pw->pw_shell) + 1;
649 * Wrapper around an internal libc function
652 pw_scan(const char *line, int flags)
654 struct passwd pw, *ret;
657 if ((bp = strdup(line)) == NULL)
659 if (!__pw_scan(bp, &pw, flags)) {