/*
* Copyright (c) 1990 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 2000, Marek Michałkiewicz
* Copyright (c) 2000 - 2006, Tomasz Kłoczko
* Copyright (c) 2007 - 2011, Nicolas François
* 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. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*/
#include <config.h>
#ident "$Id: chpasswd.c 3652 2011-12-09 21:31:39Z nekral-guest $"
#include <fcntl.h>
#include <getopt.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef USE_PAM
#include "pam_defs.h"
#endif /* USE_PAM */
#include "defines.h"
#include "nscd.h"
#include "getdef.h"
#include "prototypes.h"
#include "pwio.h"
#include "shadowio.h"
/*@-exitarg@*/
#include "exitcodes.h"
/*
* Global variables
*/
const char *Prog;
static bool eflg = false;
static bool md5flg = false;
#ifdef USE_SHA_CRYPT
static bool sflg = false;
#endif /* USE_SHA_CRYPT */
static /*@null@*//*@observer@*/const char *crypt_method = NULL;
#define cflg (NULL != crypt_method)
#ifdef USE_SHA_CRYPT
static long sha_rounds = 5000;
#endif /* USE_SHA_CRYPT */
static bool is_shadow_pwd;
static bool pw_locked = false;
static bool spw_locked = false;
/* local function prototypes */
static void fail_exit (int code);
static /*@noreturn@*/void usage (int status);
static void process_flags (int argc, char **argv);
static void check_flags (void);
static void check_perms (void);
static void open_files (void);
static void close_files (void);
/*
* fail_exit - exit with a failure code after unlocking the files
*/
static void fail_exit (int code)
{
if (pw_locked) {
if (pw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
/* continue */
}
}
if (spw_locked) {
if (spw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
/* continue */
}
}
exit (code);
}
/*
* usage - display usage message and exit
*/
static /*@noreturn@*/void usage (int status)
{
FILE *usageout = (E_SUCCESS != status) ? stderr : stdout;
(void) fprintf (usageout,
_("Usage: %s [options]\n"
"\n"
"Options:\n"),
Prog);
(void) fprintf (usageout,
_(" -c, --crypt-method METHOD the crypt method (one of %s)\n"),
#ifndef USE_SHA_CRYPT
"NONE DES MD5"
#else /* USE_SHA_CRYPT */
"NONE DES MD5 SHA256 SHA512"
#endif /* USE_SHA_CRYPT */
);
(void) fputs (_(" -e, --encrypted supplied passwords are encrypted\n"), usageout);
(void) fputs (_(" -h, --help display this help message and exit\n"), usageout);
(void) fputs (_(" -m, --md5 encrypt the clear text password using\n"
" the MD5 algorithm\n"),
usageout);
(void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
#ifdef USE_SHA_CRYPT
(void) fputs (_(" -s, --sha-rounds number of SHA rounds for the SHA*\n"
" crypt algorithms\n"),
usageout);
#endif /* USE_SHA_CRYPT */
(void) fputs ("\n", usageout);
exit (status);
}
/*
* process_flags - parse the command line options
*
* It will not return if an error is encountered.
*/
static void process_flags (int argc, char **argv)
{
int c;
static struct option long_options[] = {
{"crypt-method", required_argument, NULL, 'c'},
{"encrypted", no_argument, NULL, 'e'},
{"help", no_argument, NULL, 'h'},
{"md5", no_argument, NULL, 'm'},
{"root", required_argument, NULL, 'R'},
#ifdef USE_SHA_CRYPT
{"sha-rounds", required_argument, NULL, 's'},
#endif /* USE_SHA_CRYPT */
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv,
#ifdef USE_SHA_CRYPT
"c:ehmR:s:",
#else /* !USE_SHA_CRYPT */
"c:ehmR:",
#endif /* !USE_SHA_CRYPT */
long_options, NULL)) != -1) {
switch (c) {
case 'c':
crypt_method = optarg;
break;
case 'e':
eflg = true;
break;
case 'h':
usage (E_SUCCESS);
/*@notreached@*/break;
case 'm':
md5flg = true;
break;
case 'R': /* no-op, handled in process_root_flag () */
break;
#ifdef USE_SHA_CRYPT
case 's':
sflg = true;
if (getlong(optarg, &sha_rounds) == 0) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
usage (E_USAGE);
}
break;
#endif /* USE_SHA_CRYPT */
default:
usage (E_USAGE);
/*@notreached@*/break;
}
}
/* validate options */
check_flags ();
}
/*
* check_flags - check flags and parameters consistency
*
* It will not return if an error is encountered.
*/
static void check_flags (void)
{
#ifdef USE_SHA_CRYPT
if (sflg && !cflg) {
fprintf (stderr,
_("%s: %s flag is only allowed with the %s flag\n"),
Prog, "-s", "-c");
usage (E_USAGE);
}
#endif
if ((eflg && (md5flg || cflg)) ||
(md5flg && cflg)) {
fprintf (stderr,
_("%s: the -c, -e, and -m flags are exclusive\n"),
Prog);
usage (E_USAGE);
}
if (cflg) {
if ( (0 != strcmp (crypt_method, "DES"))
&& (0 != strcmp (crypt_method, "MD5"))
&& (0 != strcmp (crypt_method, "NONE"))
#ifdef USE_SHA_CRYPT
&& (0 != strcmp (crypt_method, "SHA256"))
&& (0 != strcmp (crypt_method, "SHA512"))
#endif /* USE_SHA_CRYPT */
) {
fprintf (stderr,
_("%s: unsupported crypt method: %s\n"),
Prog, crypt_method);
usage (E_USAGE);
}
}
}
/*
* check_perms - check if the caller is allowed to add a group
*
* With PAM support, the setuid bit can be set on chpasswd to allow
* non-root users to groups.
* Without PAM support, only users who can write in the group databases
* can add groups.
*
* It will not return if the user is not allowed.
*/
static void check_perms (void)
{
#ifdef USE_PAM
#ifdef ACCT_TOOLS_SETUID
/* If chpasswd uses PAM and is SUID, check the permissions,
* otherwise, the permissions are enforced by the access to the
* passwd and shadow files.
*/
pam_handle_t *pamh = NULL;
int retval;
struct passwd *pampw;
pampw = getpwuid (getuid ()); /* local, no need for xgetpwuid */
if (NULL == pampw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
exit (1);
}
retval = pam_start ("chpasswd", pampw->pw_name, &conv, &pamh);
if (PAM_SUCCESS == retval) {
retval = pam_authenticate (pamh, 0);
}
if (PAM_SUCCESS == retval) {
retval = pam_acct_mgmt (pamh, 0);
}
if (PAM_SUCCESS != retval) {
fprintf (stderr, _("%s: PAM: %s\n"),
Prog, pam_strerror (pamh, retval));
SYSLOG((LOG_ERR, "%s", pam_strerror (pamh, retval)));
if (NULL != pamh) {
(void) pam_end (pamh, retval);
}
exit (1);
}
(void) pam_end (pamh, retval);
#endif /* ACCT_TOOLS_SETUID */
#endif /* USE_PAM */
}
/*
* open_files - lock and open the password databases
*/
static void open_files (void)
{
/*
* Lock the password file and open it for reading and writing. This
* will bring all of the entries into memory where they may be updated.
*/
if (pw_lock () == 0) {
fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
Prog, pw_dbname ());
fail_exit (1);
}
pw_locked = true;
if (pw_open (O_RDWR) == 0) {
fprintf (stderr,
_("%s: cannot open %s\n"), Prog, pw_dbname ());
fail_exit (1);
}
/* Do the same for the shadowed database, if it exist */
if (is_shadow_pwd) {
if (spw_lock () == 0) {
fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
Prog, spw_dbname ());
fail_exit (1);
}
spw_locked = true;
if (spw_open (O_RDWR) == 0) {
fprintf (stderr,
_("%s: cannot open %s\n"),
Prog, spw_dbname ());
fail_exit (1);
}
}
}
/*
* close_files - close and unlock the password databases
*/
static void close_files (void)
{
if (is_shadow_pwd) {
if (spw_close () == 0) {
fprintf (stderr,
_("%s: failure while writing changes to %s\n"),
Prog, spw_dbname ());
SYSLOG ((LOG_ERR, "failure while writing changes to %s", spw_dbname ()));
fail_exit (1);
}
if (spw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
/* continue */
}
spw_locked = false;
}
if (pw_close () == 0) {
fprintf (stderr,
_("%s: failure while writing changes to %s\n"),
Prog, pw_dbname ());
SYSLOG ((LOG_ERR, "failure while writing changes to %s", pw_dbname ()));
fail_exit (1);
}
if (pw_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
/* continue */
}
pw_locked = false;
}
int main (int argc, char **argv)
{
char buf[BUFSIZ];
char *name;
char *newpwd;
char *cp;
#ifdef USE_PAM
bool use_pam = true;
#endif /* USE_PAM */
int errors = 0;
int line = 0;
Prog = Basename (argv[0]);
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
process_root_flag ("-R", argc, argv);
process_flags (argc, argv);
#ifdef USE_PAM
if (md5flg || eflg || cflg) {
use_pam = false;
}
#endif /* USE_PAM */
OPENLOG ("chpasswd");
check_perms ();
#ifdef USE_PAM
if (!use_pam)
#endif /* USE_PAM */
{
is_shadow_pwd = spw_file_present ();
open_files ();
}
/*
* Read each line, separating the user name from the password. The
* password entry for each user will be looked up in the appropriate
* file (shadow or passwd) and the password changed. For shadow
* files the last change date is set directly, for passwd files the
* last change date is set in the age only if aging information is
* present.
*/
while (fgets (buf, (int) sizeof buf, stdin) != (char *) 0) {
line++;
cp = strrchr (buf, '\n');
if (NULL != cp) {
*cp = '\0';
} else {
if (feof (stdin) == 0) {
fprintf (stderr,
_("%s: line %d: line too long\n"),
Prog, line);
errors++;
continue;
}
}
/*
* The username is the first field. It is separated from the
* password with a ":" character which is replaced with a
* NUL to give the new password. The new password will then
* be encrypted in the normal fashion with a new salt
* generated, unless the '-e' is given, in which case it is
* assumed to already be encrypted.
*/
name = buf;
cp = strchr (name, ':');
if (NULL != cp) {
*cp = '\0';
cp++;
} else {
fprintf (stderr,
_("%s: line %d: missing new password\n"),
Prog, line);
errors++;
continue;
}
newpwd = cp;
#ifdef USE_PAM
if (use_pam){
if (do_pam_passwd_non_interractive ("chpasswd", name, newpwd) != 0) {
fprintf (stderr,
_("%s: (line %d, user %s) password not changed\n"),
Prog, line, name);
errors++;
}
} else
#endif /* USE_PAM */
{
const struct spwd *sp;
struct spwd newsp;
const struct passwd *pw;
struct passwd newpw;
if ( !eflg
&& ( (NULL == crypt_method)
|| (0 != strcmp (crypt_method, "NONE")))) {
void *arg = NULL;
if (md5flg) {
crypt_method = "MD5";
}
#ifdef USE_SHA_CRYPT
if (sflg) {
arg = &sha_rounds;
}
#endif
cp = pw_encrypt (newpwd,
crypt_make_salt(crypt_method, arg));
}
/*
* Get the password file entry for this user. The user must
* already exist.
*/
pw = pw_locate (name);
if (NULL == pw) {
fprintf (stderr,
_("%s: line %d: user '%s' does not exist\n"), Prog,
line, name);
errors++;
continue;
}
if (is_shadow_pwd) {
/* The shadow entry should be updated if the
* passwd entry has a password set to 'x'.
* But on the other hand, if there is already both
* a passwd and a shadow password, it's preferable
* to update both.
*/
sp = spw_locate (name);
if ( (NULL == sp)
&& (strcmp (pw->pw_passwd,
SHADOW_PASSWD_STRING) == 0)) {
/* If the password is set to 'x' in
* passwd, but there are no entries in
* shadow, create one.
*/
newsp.sp_namp = name;
/* newsp.sp_pwdp = NULL; will be set later */
/* newsp.sp_lstchg= 0; will be set later */
newsp.sp_min = getdef_num ("PASS_MIN_DAYS", -1);
newsp.sp_max = getdef_num ("PASS_MAX_DAYS", -1);
newsp.sp_warn = getdef_num ("PASS_WARN_AGE", -1);
newsp.sp_inact = -1;
newsp.sp_expire= -1;
newsp.sp_flag = SHADOW_SP_FLAG_UNSET;
sp = &newsp;
}
} else {
sp = NULL;
}
/*
* The freshly encrypted new password is merged into the
* user's password file entry and the last password change
* date is set to the current date.
*/
if (NULL != sp) {
newsp = *sp;
newsp.sp_pwdp = cp;
newsp.sp_lstchg = (long) time ((time_t *)NULL) / SCALE;
if (0 == newsp.sp_lstchg) {
/* Better disable aging than requiring a
* password change */
newsp.sp_lstchg = -1;
}
}
if ( (NULL == sp)
|| (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) != 0)) {
newpw = *pw;
newpw.pw_passwd = cp;
}
/*
* The updated password file entry is then put back and will
* be written to the password file later, after all the
* other entries have been updated as well.
*/
if (NULL != sp) {
if (spw_update (&newsp) == 0) {
fprintf (stderr,
_("%s: line %d: failed to prepare the new %s entry '%s'\n"),
Prog, line, spw_dbname (), newsp.sp_namp);
errors++;
continue;
}
}
if ( (NULL == sp)
|| (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) != 0)) {
if (pw_update (&newpw) == 0) {
fprintf (stderr,
_("%s: line %d: failed to prepare the new %s entry '%s'\n"),
Prog, line, pw_dbname (), newpw.pw_name);
errors++;
continue;
}
}
}
}
/*
* Any detected errors will cause the entire set of changes to be
* aborted. Unlocking the password file will cause all of the
* changes to be ignored. Otherwise the file is closed, causing the
* changes to be written out all at once, and then unlocked
* afterwards.
*
* With PAM, it is not possible to delay the update of the
* password database.
*/
if (0 != errors) {
#ifdef USE_PAM
if (!use_pam)
#endif /* USE_PAM */
{
fprintf (stderr,
_("%s: error detected, changes ignored\n"),
Prog);
}
fail_exit (1);
}
#ifdef USE_PAM
if (!use_pam)
#endif /* USE_PAM */
{
/* Save the changes */
close_files ();
}
nscd_flush_cache ("passwd");
return (0);
}