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 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 static const char sccsid[] = "@(#)pw_util.c 8.3 (Berkeley) 4/2/94";
45 static const char rcsid[] =
50 * This file is used by all the "password" programs; vipw(8), chpass(1),
54 #include <sys/param.h>
55 #include <sys/errno.h>
57 #include <sys/resource.h>
76 static pid_t editpid = -1;
77 static int lockfd = -1;
78 static char masterpasswd[PATH_MAX];
79 static char passwd_dir[PATH_MAX];
80 static char tempname[PATH_MAX];
81 static int initialized;
92 * Initialize statics and set limits, signals & umask to try to avoid
93 * interruptions, crashes etc. that might expose passord data.
96 pw_init(const char *dir, const char *master)
103 strcpy(passwd_dir, _PATH_ETC);
105 if (strlen(dir) >= sizeof passwd_dir) {
106 errno = ENAMETOOLONG;
109 strcpy(passwd_dir, dir);
112 if (master == NULL) {
114 strcpy(masterpasswd, _PATH_MASTERPASSWD);
115 } else if (snprintf(masterpasswd, sizeof masterpasswd, "%s/%s",
116 passwd_dir, _MASTERPASSWD) > sizeof masterpasswd) {
117 errno = ENAMETOOLONG;
121 if (strlen(master) >= sizeof masterpasswd) {
122 errno = ENAMETOOLONG;
125 strcpy(masterpasswd, master);
129 * The code that follows is extremely disruptive to the calling
130 * process, and is therefore disabled until someone can conceive
131 * of a realistic scenario where it would fend off a compromise.
132 * Race conditions concerning the temporary files can be guarded
133 * against in other ways than masking signals (by checking stat(2)
134 * results after creation).
137 /* Unlimited resource limits. */
138 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
139 (void)setrlimit(RLIMIT_CPU, &rlim);
140 (void)setrlimit(RLIMIT_FSIZE, &rlim);
141 (void)setrlimit(RLIMIT_STACK, &rlim);
142 (void)setrlimit(RLIMIT_DATA, &rlim);
143 (void)setrlimit(RLIMIT_RSS, &rlim);
145 /* Don't drop core (not really necessary, but GP's). */
146 rlim.rlim_cur = rlim.rlim_max = 0;
147 (void)setrlimit(RLIMIT_CORE, &rlim);
149 /* Turn off signals. */
150 (void)signal(SIGALRM, SIG_IGN);
151 (void)signal(SIGHUP, SIG_IGN);
152 (void)signal(SIGINT, SIG_IGN);
153 (void)signal(SIGPIPE, SIG_IGN);
154 (void)signal(SIGQUIT, SIG_IGN);
155 (void)signal(SIGTERM, SIG_IGN);
156 (void)signal(SIGCONT, pw_cont);
158 /* Create with exact permissions. */
166 * Lock the master password file.
172 if (*masterpasswd == '\0')
176 * If the master password file doesn't exist, the system is hosed.
177 * Might as well try to build one. Set the close-on-exec bit so
178 * that users can't get at the encrypted passwords while editing.
179 * Open should allow flock'ing the file; see 4.4BSD. XXX
184 lockfd = open(masterpasswd, O_RDONLY, 0);
185 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
186 err(1, "%s", masterpasswd);
187 /* XXX vulnerable to race conditions */
188 if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
189 if (errno == EWOULDBLOCK) {
190 errx(1, "the password db file is busy");
192 err(1, "could not lock the passwd file: ");
197 * If the password file was replaced while we were trying to
198 * get the lock, our hardlink count will be 0 and we have to
201 if (fstat(lockfd, &st) == -1)
202 err(1, "fstat() failed: ");
203 if (st.st_nlink != 0)
212 * Create and open a presumably safe temp file for editing the password
213 * data, and copy the master password file into it.
223 if (*masterpasswd == '\0')
225 if ((p = strrchr(masterpasswd, '/')))
229 if (snprintf(tempname, sizeof tempname, "%.*spw.XXXXXX",
230 (int)(p - masterpasswd), masterpasswd) >= sizeof tempname) {
231 errno = ENAMETOOLONG;
234 if ((tfd = mkstemp(tempname)) == -1)
237 while ((nr = read(mfd, buf, sizeof buf)) > 0)
238 if ((nw = write(tfd, buf, nr)) != nr)
251 * Regenerate the password database.
254 pw_mkdb(const char *user)
259 (void)fflush(stderr);
260 switch ((pid = fork())) {
266 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
267 "-d", passwd_dir, tempname, NULL);
269 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
270 "-d", passwd_dir, "-u", user, tempname, NULL);
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 stat st1, st2;
295 if ((editor = getenv("EDITOR")) == NULL)
297 if (stat(tempname, &st1) == -1)
299 switch ((editpid = fork())) {
305 (void)setgid(getgid());
306 (void)setuid(getuid());
309 execlp(editor, basename(editor), tempname, NULL);
316 editpid = waitpid(editpid, &pstat, WUNTRACED);
320 } else if (WIFSTOPPED(pstat)) {
321 raise(WSTOPSIG(pstat));
322 } else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) {
332 if (stat(tempname, &st2) == -1)
334 return (st1.st_mtime != st2.st_mtime);
338 * Clean up. Preserve errno for the caller's convenience.
350 kill(editpid, SIGTERM);
351 kill(editpid, SIGCONT);
352 waitpid(editpid, &status, 0);
355 if (*tempname != '\0') {
365 * Compares two struct pwds.
368 pw_equal(struct passwd *pw1, struct passwd *pw2)
370 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
371 pw1->pw_uid == pw2->pw_uid &&
372 pw1->pw_gid == pw2->pw_gid &&
373 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
374 pw1->pw_change == pw2->pw_change &&
375 pw1->pw_expire == pw2->pw_expire &&
376 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
377 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
378 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
382 * Make a passwd line out of a struct passwd.
385 pw_make(struct passwd *pw)
389 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
390 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
391 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
392 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
397 * Copy password file from one descriptor to another, replacing or adding
398 * a single record on the way.
401 pw_copy(int ffd, int tfd, struct passwd *pw, struct passwd *old_pw)
403 char buf[8192], *end, *line, *p, *q, *r, t;
408 if ((line = pw_make(pw)) == NULL)
415 /* find the end of the current line */
416 for (p = q; q < end && *q != '\0'; ++q)
420 /* if we don't have a complete line, fill up the buffer */
424 if (q - p >= sizeof buf) {
425 warnx("passwd line too long");
426 errno = EINVAL; /* hack */
430 q = memmove(buf, p, end - p);
435 len = read(ffd, end, sizeof buf - (end - buf));
438 if (len == 0 && p == buf)
442 if (len < sizeof buf) {
444 if (len > 0 && buf[len - 1] != '\n')
445 ++len, *end++ = '\n';
450 /* is it a blank line or a comment? */
451 for (r = p; r < q && isspace(*r); ++r)
453 if (r == q || *r == '#') {
455 if (write(tfd, p, q - p + 1) != q - p + 1)
461 /* is it the one we're looking for? */
464 fpw = pw_scan(r, PWSCAN_MASTER);
466 if ((old_pw && !pw_equal(fpw, old_pw)) ||
467 (!old_pw && strcmp(fpw->pw_name, pw->pw_name))) {
470 if (write(tfd, p, q - p + 1) != q - p + 1)
477 /* it is, replace it */
479 if (write(tfd, line, len) != len)
482 /* we're done, just copy the rest over */
484 if (write(tfd, q, end - q) != end - q)
487 len = read(ffd, buf, sizeof buf);
497 /* if we got here, we have a new entry */
499 if (write(tfd, line, len) != len)
510 * Return the current value of tempname.
520 * Duplicate a struct passwd.
523 pw_dup(struct passwd *pw)
529 (pw->pw_name ? strlen(pw->pw_name) + 1 : 0) +
530 (pw->pw_passwd ? strlen(pw->pw_passwd) + 1 : 0) +
531 (pw->pw_class ? strlen(pw->pw_class) + 1 : 0) +
532 (pw->pw_gecos ? strlen(pw->pw_gecos) + 1 : 0) +
533 (pw->pw_dir ? strlen(pw->pw_dir) + 1 : 0) +
534 (pw->pw_shell ? strlen(pw->pw_shell) + 1 : 0);
535 if ((npw = malloc(len)) == NULL)
537 memcpy(npw, pw, sizeof *npw);
540 npw->pw_name = ((char *)npw) + len;
541 len += sprintf(npw->pw_name, "%s", pw->pw_name) + 1;
544 npw->pw_passwd = ((char *)npw) + len;
545 len += sprintf(npw->pw_passwd, "%s", pw->pw_passwd) + 1;
548 npw->pw_class = ((char *)npw) + len;
549 len += sprintf(npw->pw_class, "%s", pw->pw_class) + 1;
552 npw->pw_gecos = ((char *)npw) + len;
553 len += sprintf(npw->pw_gecos, "%s", pw->pw_gecos) + 1;
556 npw->pw_dir = ((char *)npw) + len;
557 len += sprintf(npw->pw_dir, "%s", pw->pw_dir) + 1;
560 npw->pw_shell = ((char *)npw) + len;
561 len += sprintf(npw->pw_shell, "%s", pw->pw_shell) + 1;
569 * Wrapper around an internal libc function
572 pw_scan(const char *line, int flags)
574 struct passwd pw, *ret;
577 if ((bp = strdup(line)) == NULL)
579 if (!__pw_scan(bp, &pw, flags)) {