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;
94 * Initialize statics and set limits, signals & umask to try to avoid
95 * interruptions, crashes etc. that might expose passord data.
98 pw_init(const char *dir, const char *master)
105 strcpy(passwd_dir, _PATH_ETC);
107 if (strlen(dir) >= sizeof(passwd_dir)) {
108 errno = ENAMETOOLONG;
111 strcpy(passwd_dir, dir);
114 if (master == NULL) {
116 strcpy(masterpasswd, _PATH_MASTERPASSWD);
117 } else if (snprintf(masterpasswd, sizeof(masterpasswd), "%s/%s",
118 passwd_dir, _MASTERPASSWD) > (int)sizeof(masterpasswd)) {
119 errno = ENAMETOOLONG;
123 if (strlen(master) >= sizeof(masterpasswd)) {
124 errno = ENAMETOOLONG;
127 strcpy(masterpasswd, master);
131 * The code that follows is extremely disruptive to the calling
132 * process, and is therefore disabled until someone can conceive
133 * of a realistic scenario where it would fend off a compromise.
134 * Race conditions concerning the temporary files can be guarded
135 * against in other ways than masking signals (by checking stat(2)
136 * results after creation).
139 /* Unlimited resource limits. */
140 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
141 (void)setrlimit(RLIMIT_CPU, &rlim);
142 (void)setrlimit(RLIMIT_FSIZE, &rlim);
143 (void)setrlimit(RLIMIT_STACK, &rlim);
144 (void)setrlimit(RLIMIT_DATA, &rlim);
145 (void)setrlimit(RLIMIT_RSS, &rlim);
147 /* Don't drop core (not really necessary, but GP's). */
148 rlim.rlim_cur = rlim.rlim_max = 0;
149 (void)setrlimit(RLIMIT_CORE, &rlim);
151 /* Turn off signals. */
152 (void)signal(SIGALRM, SIG_IGN);
153 (void)signal(SIGHUP, SIG_IGN);
154 (void)signal(SIGINT, SIG_IGN);
155 (void)signal(SIGPIPE, SIG_IGN);
156 (void)signal(SIGQUIT, SIG_IGN);
157 (void)signal(SIGTERM, SIG_IGN);
158 (void)signal(SIGCONT, pw_cont);
160 /* Create with exact permissions. */
168 * Lock the master password file.
174 if (*masterpasswd == '\0')
178 * If the master password file doesn't exist, the system is hosed.
179 * Might as well try to build one. Set the close-on-exec bit so
180 * that users can't get at the encrypted passwords while editing.
181 * Open should allow flock'ing the file; see 4.4BSD. XXX
186 lockfd = open(masterpasswd, O_RDONLY, 0);
187 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
188 err(1, "%s", masterpasswd);
189 /* XXX vulnerable to race conditions */
190 if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
191 if (errno == EWOULDBLOCK) {
192 errx(1, "the password db file is busy");
194 err(1, "could not lock the passwd file: ");
199 * If the password file was replaced while we were trying to
200 * get the lock, our hardlink count will be 0 and we have to
203 if (fstat(lockfd, &st) == -1)
204 err(1, "fstat() failed: ");
205 if (st.st_nlink != 0)
214 * Create and open a presumably safe temp file for editing the password
215 * data, and copy the master password file into it.
225 if (*masterpasswd == '\0')
227 if ((p = strrchr(masterpasswd, '/')))
231 if (snprintf(tempname, sizeof(tempname), "%.*spw.XXXXXX",
232 (int)(p - masterpasswd), masterpasswd) >= (int)sizeof(tempname)) {
233 errno = ENAMETOOLONG;
236 if ((tfd = mkstemp(tempname)) == -1)
239 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
240 if (write(tfd, buf, (size_t)nr) != nr)
253 * Regenerate the password database.
256 pw_mkdb(const char *user)
261 (void)fflush(stderr);
262 switch ((pid = fork())) {
268 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
269 "-d", passwd_dir, tempname, (char *)NULL);
271 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
272 "-d", passwd_dir, "-u", user, tempname,
280 if (waitpid(pid, &pstat, 0) == -1)
282 if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
289 * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
293 pw_edit(int notsetuid)
295 struct sigaction sa, sa_int, sa_quit;
296 sigset_t oldsigset, sigset;
297 struct stat st1, st2;
301 if ((editor = getenv("EDITOR")) == NULL)
303 if (stat(tempname, &st1) == -1)
305 sa.sa_handler = SIG_IGN;
306 sigemptyset(&sa.sa_mask);
308 sigaction(SIGINT, &sa, &sa_int);
309 sigaction(SIGQUIT, &sa, &sa_quit);
310 sigemptyset(&sigset);
311 sigaddset(&sigset, SIGCHLD);
312 sigprocmask(SIG_BLOCK, &sigset, &oldsigset);
313 switch ((editpid = fork())) {
317 sigaction(SIGINT, &sa_int, NULL);
318 sigaction(SIGQUIT, &sa_quit, NULL);
319 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
321 (void)setgid(getgid());
322 (void)setuid(getuid());
325 execlp(editor, basename(editor), tempname, (char *)NULL);
332 if (waitpid(editpid, &pstat, WUNTRACED) == -1) {
338 } else if (WIFSTOPPED(pstat)) {
339 raise(WSTOPSIG(pstat));
340 } else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) {
349 sigaction(SIGINT, &sa_int, NULL);
350 sigaction(SIGQUIT, &sa_quit, NULL);
351 sigprocmask(SIG_SETMASK, &oldsigset, NULL);
352 if (stat(tempname, &st2) == -1)
354 return (st1.st_mtime != st2.st_mtime);
358 * Clean up. Preserve errno for the caller's convenience.
370 kill(editpid, SIGTERM);
371 kill(editpid, SIGCONT);
372 waitpid(editpid, &status, 0);
375 if (*tempname != '\0') {
385 * Compares two struct pwds.
388 pw_equal(const struct passwd *pw1, const struct passwd *pw2)
390 return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
391 pw1->pw_uid == pw2->pw_uid &&
392 pw1->pw_gid == pw2->pw_gid &&
393 strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
394 pw1->pw_change == pw2->pw_change &&
395 pw1->pw_expire == pw2->pw_expire &&
396 strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
397 strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
398 strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
402 * Make a passwd line out of a struct passwd.
405 pw_make(const struct passwd *pw)
409 asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
410 pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
411 pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
412 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
417 * Copy password file from one descriptor to another, replacing or adding
418 * a single record on the way.
421 pw_copy(int ffd, int tfd, const struct passwd *pw, struct passwd *old_pw)
423 char buf[8192], *end, *line, *p, *q, *r, t;
428 if ((line = pw_make(pw)) == NULL)
435 /* find the end of the current line */
436 for (p = q; q < end && *q != '\0'; ++q)
440 /* if we don't have a complete line, fill up the buffer */
444 if ((size_t)(q - p) >= sizeof(buf)) {
445 warnx("passwd line too long");
446 errno = EINVAL; /* hack */
450 q = memmove(buf, p, end - p);
455 readlen = read(ffd, end, sizeof(buf) - (end - buf));
459 len = (size_t)readlen;
460 if (len == 0 && p == buf)
464 if (len < (ssize_t)sizeof(buf)) {
466 if (len > 0 && buf[len - 1] != '\n')
467 ++len, *end++ = '\n';
472 /* is it a blank line or a comment? */
473 for (r = p; r < q && isspace(*r); ++r)
475 if (r == q || *r == '#') {
477 if (write(tfd, p, q - p + 1) != q - p + 1)
483 /* is it the one we're looking for? */
486 fpw = pw_scan(r, PWSCAN_MASTER);
488 if (strcmp(fpw->pw_name, pw->pw_name) != 0) {
491 if (write(tfd, p, q - p + 1) != q - p + 1)
496 if (old_pw && !pw_equal(fpw, old_pw)) {
497 warnx("entry inconsistent");
499 errno = EINVAL; /* hack */
504 /* it is, replace it */
506 if (write(tfd, line, len) != (int)len)
509 /* we're done, just copy the rest over */
511 if (write(tfd, q, end - q) != end - q)
514 readlen = read(ffd, buf, sizeof(buf));
518 len = (size_t)readlen;
526 /* if we got here, we have a new entry */
528 if ((size_t)write(tfd, line, len) != len ||
529 write(tfd, "\n", 1) != 1)
540 * Return the current value of tempname.
550 * Duplicate a struct passwd.
553 pw_dup(const struct passwd *pw)
559 (pw->pw_name ? strlen(pw->pw_name) + 1 : 0) +
560 (pw->pw_passwd ? strlen(pw->pw_passwd) + 1 : 0) +
561 (pw->pw_class ? strlen(pw->pw_class) + 1 : 0) +
562 (pw->pw_gecos ? strlen(pw->pw_gecos) + 1 : 0) +
563 (pw->pw_dir ? strlen(pw->pw_dir) + 1 : 0) +
564 (pw->pw_shell ? strlen(pw->pw_shell) + 1 : 0);
565 if ((npw = malloc((size_t)len)) == NULL)
567 memcpy(npw, pw, sizeof(*npw));
570 npw->pw_name = ((char *)npw) + len;
571 len += sprintf(npw->pw_name, "%s", pw->pw_name) + 1;
574 npw->pw_passwd = ((char *)npw) + len;
575 len += sprintf(npw->pw_passwd, "%s", pw->pw_passwd) + 1;
578 npw->pw_class = ((char *)npw) + len;
579 len += sprintf(npw->pw_class, "%s", pw->pw_class) + 1;
582 npw->pw_gecos = ((char *)npw) + len;
583 len += sprintf(npw->pw_gecos, "%s", pw->pw_gecos) + 1;
586 npw->pw_dir = ((char *)npw) + len;
587 len += sprintf(npw->pw_dir, "%s", pw->pw_dir) + 1;
590 npw->pw_shell = ((char *)npw) + len;
591 len += sprintf(npw->pw_shell, "%s", pw->pw_shell) + 1;
599 * Wrapper around an internal libc function
602 pw_scan(const char *line, int flags)
604 struct passwd pw, *ret;
607 if ((bp = strdup(line)) == NULL)
609 if (!__pw_scan(bp, &pw, flags)) {