shadow/src/pwconv.c
Chris Lamb fe34a2a0e4 Make the sp_lstchg shadow field reproducible (re. #71)
From <https://github.com/shadow-maint/shadow/pull/71>:

```
The third field in the /etc/shadow file (sp_lstchg) contains the date of
the last password change expressed as the number of days since Jan 1, 1970.
As this is a relative time, creating a user today will result in:

username:17238:0:99999:7:::
whilst creating the same user tomorrow will result in:

username:17239:0:99999:7:::
This has an impact for the Reproducible Builds[0] project where we aim to
be independent of as many elements the build environment as possible,
including the current date.

This patch changes the behaviour to use the SOURCE_DATE_EPOCH[1]
environment variable (instead of Jan 1, 1970) if valid.
```

This updated PR adds some missing calls to gettime (). This was originally
filed by Johannes Schauer in Debian as #917773 [2].

[0] https://reproducible-builds.org/
[1] https://reproducible-builds.org/specs/source-date-epoch/
[2] https://bugs.debian.org/917773
2019-03-31 16:00:01 +01:00

337 lines
9.5 KiB
C

/*
* Copyright (c) 1996 - 2000, Marek Michałkiewicz
* Copyright (c) 2002 - 2006, Tomasz Kłoczko
* Copyright (c) 2009 - 2012, 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.
*/
/*
* pwconv - create or update /etc/shadow with information from
* /etc/passwd.
*
* It is more like SysV pwconv, slightly different from the original Shadow
* pwconv. Depends on "x" as password in /etc/passwd which means that the
* password has already been moved to /etc/shadow. There is no need to move
* /etc/npasswd to /etc/passwd, password files are updated using library
* routines with proper locking.
*
* Can be used to update /etc/shadow after adding/deleting users by editing
* /etc/passwd. There is no man page yet, but this program should be close
* to pwconv(1M) on Solaris 2.x.
*
* Warning: make sure that all users have "x" as the password in /etc/passwd
* before running this program for the first time on a system which already
* has shadow passwords. Anything else (like "*" from old versions of the
* shadow suite) will replace the user's encrypted password in /etc/shadow.
*
* Doesn't currently support pw_age information in /etc/passwd, and doesn't
* support DBM files. Add it if you need it...
*
*/
#include <config.h>
#ident "$Id$"
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <getopt.h>
#include "defines.h"
#include "getdef.h"
#include "prototypes.h"
#include "pwio.h"
#include "shadowio.h"
#include "nscd.h"
#include "sssd.h"
/*
* exit status values
*/
/*@-exitarg@*/
#define E_SUCCESS 0 /* success */
#define E_NOPERM 1 /* permission denied */
#define E_USAGE 2 /* invalid command syntax */
#define E_FAILURE 3 /* unexpected failure, nothing done */
#define E_MISSING 4 /* unexpected failure, passwd file missing */
#define E_PWDBUSY 5 /* passwd file(s) busy */
#define E_BADENTRY 6 /* bad shadow entry */
/*
* Global variables
*/
const char *Prog;
static bool spw_locked = false;
static bool pw_locked = false;
/* local function prototypes */
static void fail_exit (int status);
static void usage (int status);
static void process_flags (int argc, char **argv);
static void fail_exit (int status)
{
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 (status);
}
static void usage (int status)
{
FILE *usageout = (E_SUCCESS != status) ? stderr : stdout;
(void) fprintf (usageout,
_("Usage: %s [options]\n"
"\n"
"Options:\n"),
Prog);
(void) fputs (_(" -h, --help display this help message and exit\n"), usageout);
(void) fputs (_(" -R, --root CHROOT_DIR directory to chroot into\n"), usageout);
(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)
{
/*
* Parse the command line options.
*/
int c;
static struct option long_options[] = {
{"help", no_argument, NULL, 'h'},
{"root", required_argument, NULL, 'R'},
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv, "hR:",
long_options, NULL)) != -1) {
switch (c) {
case 'h':
usage (E_SUCCESS);
/*@notreached@*/break;
case 'R': /* no-op, handled in process_root_flag () */
break;
default:
usage (E_USAGE);
}
}
if (optind != argc) {
usage (E_USAGE);
}
}
int main (int argc, char **argv)
{
const struct passwd *pw;
struct passwd pwent;
const struct spwd *sp;
struct spwd spent;
Prog = Basename (argv[0]);
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
process_root_flag ("-R", argc, argv);
OPENLOG ("pwconv");
process_flags (argc, argv);
#ifdef WITH_TCB
if (getdef_bool("USE_TCB")) {
fprintf (stderr, _("%s: can't work with tcb enabled\n"), Prog);
exit (E_FAILURE);
}
#endif /* WITH_TCB */
if (pw_lock () == 0) {
fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
Prog, pw_dbname ());
fail_exit (E_PWDBUSY);
}
pw_locked = true;
if (pw_open (O_CREAT | O_RDWR) == 0) {
fprintf (stderr,
_("%s: cannot open %s\n"), Prog, pw_dbname ());
fail_exit (E_MISSING);
}
if (spw_lock () == 0) {
fprintf (stderr,
_("%s: cannot lock %s; try again later.\n"),
Prog, spw_dbname ());
fail_exit (E_PWDBUSY);
}
spw_locked = true;
if (spw_open (O_CREAT | O_RDWR) == 0) {
fprintf (stderr,
_("%s: cannot open %s\n"), Prog, spw_dbname ());
fail_exit (E_FAILURE);
}
/*
* Remove /etc/shadow entries for users not in /etc/passwd.
*/
(void) spw_rewind ();
while ((sp = spw_next ()) != NULL) {
if (pw_locate (sp->sp_namp) != NULL) {
continue;
}
if (spw_remove (sp->sp_namp) == 0) {
/*
* This shouldn't happen (the entry exists) but...
*/
fprintf (stderr,
_("%s: cannot remove entry '%s' from %s\n"),
Prog, sp->sp_namp, spw_dbname ());
fail_exit (E_FAILURE);
}
(void) spw_rewind();
}
/*
* Update shadow entries which don't have "x" as pw_passwd. Add any
* missing shadow entries.
*/
(void) pw_rewind ();
while ((pw = pw_next ()) != NULL) {
sp = spw_locate (pw->pw_name);
if (NULL != sp) {
/* do we need to update this entry? */
if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
continue;
}
/* update existing shadow entry */
spent = *sp;
} else {
/* add new shadow entry */
memset (&spent, 0, sizeof spent);
spent.sp_namp = pw->pw_name;
spent.sp_min = getdef_num ("PASS_MIN_DAYS", -1);
spent.sp_max = getdef_num ("PASS_MAX_DAYS", -1);
spent.sp_warn = getdef_num ("PASS_WARN_AGE", -1);
spent.sp_inact = -1;
spent.sp_expire = -1;
spent.sp_flag = SHADOW_SP_FLAG_UNSET;
}
spent.sp_pwdp = pw->pw_passwd;
spent.sp_lstchg = (long) gettime () / SCALE;
if (0 == spent.sp_lstchg) {
/* Better disable aging than requiring a password
* change */
spent.sp_lstchg = -1;
}
if (spw_update (&spent) == 0) {
fprintf (stderr,
_("%s: failed to prepare the new %s entry '%s'\n"),
Prog, spw_dbname (), spent.sp_namp);
fail_exit (E_FAILURE);
}
/* remove password from /etc/passwd */
pwent = *pw;
pwent.pw_passwd = SHADOW_PASSWD_STRING; /* XXX warning: const */
if (pw_update (&pwent) == 0) {
fprintf (stderr,
_("%s: failed to prepare the new %s entry '%s'\n"),
Prog, pw_dbname (), pwent.pw_name);
fail_exit (E_FAILURE);
}
}
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 (E_FAILURE);
}
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 (E_FAILURE);
}
/* /etc/passwd- (backup file) */
errno = 0;
if ((chmod (PASSWD_FILE "-", 0600) != 0) && (errno != ENOENT)) {
fprintf (stderr,
_("%s: failed to change the mode of %s to 0600\n"),
Prog, PASSWD_FILE "-");
SYSLOG ((LOG_ERR, "failed to change the mode of %s to 0600", PASSWD_FILE "-"));
/* continue */
}
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_unlock () == 0) {
fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
/* continue */
}
nscd_flush_cache ("passwd");
sssd_flush_cache (SSSD_DB_PASSWD);
return E_SUCCESS;
}