freebsd-dev/usr.bin/chpass/chpass.c
Mike Barcroft f458f48b02 Prevent chpass(1) from writing -1 in the UID or GID fields
in the password file by properly casting integers.

PR:		27757
Reviewed by:	des
Approved by:	des
MFC after:	4 days
2001-07-26 23:27:10 +00:00

293 lines
7.2 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;
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();
}
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: We start off with two fd's, one for the master password
* file (used to lock everything), and one for a temporary file.
* 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.
* 4: Verify() gets an fp for the temporary file, and verifies the
* contents. It can't use an fp derived from the step #2 fd,
* because the user's editor may have created a new instance of
* the file. Once the file is verified, its contents are stored
* in a password structure. The verify routine closes the fp,
* closing the underlying fd.
* 5: Delete the temporary file.
* 6: Get a new temporary file/fd. Pw_copy() gets an fp for it
* file and copies the master password file into it, replacing
* the user record with a new one. We can't use the first
* temporary file for this because it was owned by the user.
* 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.
* 7: Call pw_mkdb() (which renames the temporary file) and exit.
* The exit closes the master passwd fp/fd.
*/
pw_init();
pfd = pw_lock();
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 */
pw_copy(pfd, tfd, 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);
}