opnsense-src/usr.bin/chpass/chpass.c
Crist J. Clark 8c44e77923 It was possible for an unprivileged user to tie up the password
information (no one else can vipw(8), chpass(1), or even passwd(1)),
either on purpose or by accident, until an administrator manually
intervened. Instead, do not lock the master.passwd file while a user
is editing his information. But once we go to write the new
information, check that the modified user's information has not
changed in the password database since we started. Abort the changes
if it has.

Add a $FreeBSD$ to pw_copy.h.

PR:		i386/35816
Obtained from:	NetBSD
MFC after:	1 week
2002-03-18 02:22:53 +00:00

299 lines
7.3 KiB
C

/*-
* Copyright (c) 1988, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1988, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static const char sccsid[] = "From: @(#)chpass.c 8.4 (Berkeley) 4/2/94";
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pw_scan.h>
#include <pw_util.h>
#include "pw_copy.h"
#ifdef YP
#include <rpcsvc/yp.h>
int yp_errno = YP_TRUE;
#include "pw_yp.h"
#endif
#include "chpass.h"
#include "pathnames.h"
char *tempname;
uid_t uid;
void baduser __P((void));
void usage __P((void));
int
main(argc, argv)
int argc;
char **argv;
{
enum { NEWSH, LOADENTRY, EDITENTRY, NEWPW, NEWEXP } op;
struct passwd *pw = NULL, lpw, old_pw;
char *username = NULL;
int ch, pfd, tfd;
char *arg = NULL;
#ifdef YP
int force_local = 0;
int force_yp = 0;
#endif
op = EDITENTRY;
#ifdef YP
while ((ch = getopt(argc, argv, "a:p:s:e:d:h:oly")) != -1)
#else
while ((ch = getopt(argc, argv, "a:p:s:e:")) != -1)
#endif
switch(ch) {
case 'a':
op = LOADENTRY;
arg = optarg;
break;
case 's':
op = NEWSH;
arg = optarg;
break;
case 'p':
op = NEWPW;
arg = optarg;
break;
case 'e':
op = NEWEXP;
arg = optarg;
break;
#ifdef YP
case 'h':
#ifdef PARANOID
if (getuid()) {
warnx("Only the superuser can use the -h flag");
} else {
#endif
yp_server = optarg;
#ifdef PARANOID
}
#endif
break;
case 'd':
#ifdef PARANOID
if (getuid()) {
warnx("Only the superuser can use the -d flag");
} else {
#endif
yp_domain = optarg;
if (yp_server == NULL)
yp_server = "localhost";
#ifdef PARANOID
}
#endif
break;
case 'l':
_use_yp = 0;
force_local = 1;
break;
case 'y':
_use_yp = force_yp = 1;
break;
case 'o':
force_old++;
break;
#endif
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
uid = getuid();
if (op == EDITENTRY || op == NEWSH || op == NEWPW || op == NEWEXP) {
switch(argc) {
#ifdef YP
case 0:
GETPWUID(uid)
get_yp_master(1); /* XXX just to set the suser flag */
break;
case 1:
GETPWNAM(*argv)
get_yp_master(1); /* XXX just to set the suser flag */
#else
case 0:
if (!(pw = getpwuid(uid)))
errx(1, "unknown user: uid %lu",
(unsigned long)uid);
break;
case 1:
if (!(pw = getpwnam(*argv)))
errx(1, "unknown user: %s", *argv);
#endif
if (uid && uid != pw->pw_uid)
baduser();
break;
default:
usage();
}
/* Make a copy for later verification */
old_pw = *pw;
old_pw.pw_gecos = strdup(old_pw.pw_gecos);
}
if (op == NEWSH) {
/* protect p_shell -- it thinks NULL is /bin/sh */
if (!arg[0])
usage();
if (p_shell(arg, pw, (ENTRY *)NULL))
pw_error((char *)NULL, 0, 1);
}
if (op == NEWEXP) {
if (uid) /* only root can change expire */
baduser();
if (p_expire(arg, pw, (ENTRY *)NULL))
pw_error((char *)NULL, 0, 1);
}
if (op == LOADENTRY) {
if (uid)
baduser();
pw = &lpw;
if (!__pw_scan(arg, pw, _PWSCAN_WARN|_PWSCAN_MASTER))
exit(1);
}
username = pw->pw_name;
if (op == NEWPW) {
if (uid)
baduser();
if(strchr(arg, ':')) {
errx(1, "invalid format for password");
}
pw->pw_passwd = arg;
}
/*
* The temporary file/file descriptor usage is a little tricky here.
* 1: Create a temporary file called tempname, get descriptor tfd.
* 2: Display() gets an fp for the temporary file, and copies the
* user's information into it. It then gives the temporary file
* to the user and closes the fp, closing the underlying fd.
* 3: The user edits the temporary file some number of times.
* The results are stored in pw by edit().
* 4: Delete the temporary file.
* 5: Make a new temporary file, descriptor tfd.
* 6: Get a descriptor for the master.passwd file, pfd, and
* lock master.passwd.
* 7: Pw_copy() gets descriptors for master.passwd and the
* temporary file and copies the master password file into it,
* replacing the modified user's record with a new one. We can't
* use the first temporary file for this because it was owned
* by the user. Pass the new and old user info. Check the
* entry for our user has not been changed by someone else by
* while the user was editing by comparing the old info to
* the entry freshly read from master.passwd. Pw_copy() closes
* its fp, flushing the data and closing the underlying file
* descriptor. We can't close the master password fp, or we'd
* lose the lock.
* 8: Call pw_mkdb() (which renames the temporary file) and exit.
* The exit closes the master passwd fp/fd.
*/
pw_init();
tfd = pw_tmp();
if (op == EDITENTRY) {
display(tfd, pw);
edit(pw);
(void)unlink(tempname);
tfd = pw_tmp();
}
#ifdef YP
if (_use_yp) {
yp_submit(pw);
(void)unlink(tempname);
} else {
#endif /* YP */
pfd = pw_lock();
pw_copy(pfd, tfd, pw, (op == LOADENTRY) ? NULL : &old_pw);
if (!pw_mkdb(username))
pw_error((char *)NULL, 0, 1);
#ifdef YP
}
#endif /* YP */
exit(0);
}
void
baduser()
{
errx(1, "%s", strerror(EACCES));
}
void
usage()
{
(void)fprintf(stderr,
#ifdef YP
"usage: chpass [-l] [-y] [-d domain [-h host]] [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
#else
"usage: chpass [-a list] [-p encpass] [-s shell] [-e mmm dd yy] [user]\n");
#endif
exit(1);
}