/*
* passwd - change a user's password file information
*
* This command controls the password file and commands which are used
* to modify it.
*
* The valid options are
*
* -d delete the password for the named account (*)
* -e expire the password for the named account (*)
* -f execute chfn command to interpret flags
* -g execute gpasswd command to interpret flags
* -i # set sp_inact to # days (*)
* -k change password only if expired
* -l lock the password of the named account (*)
* -n # set sp_min to # days (*)
* -r # change password in # repository
* -s execute chsh command to interpret flags
* -S show password status of named account
* -u unlock the password of the named account (*)
* -w # set sp_warn to # days (*)
* -x # set sp_max to # days (*)
*
* (*) requires root permission to execute.
*
* All of the time fields are entered in days and converted to the
* appropriate internal format. For finer resolute the chage
* command must be used.
*/
int main (int argc, char **argv)
{
const struct passwd *pw; /* Password file entry for user */
#ifndef USE_PAM
char *cp; /* Miscellaneous character pointing */
const struct spwd *sp; /* Shadow file entry for user */
#endif /* !USE_PAM */
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
/*
* The program behaves differently when executed by root than when
* executed by a normal user.
*/
amroot = (getuid () == 0);
/*
* Get the program name. The program name is used as a prefix to
* most error messages.
*/
Prog = Basename (argv[0]);
sanitize_env ();
OPENLOG ("passwd");
{
/*
* Parse the command line options.
*/
int option_index = 0;
int c;
static struct option long_options[] = {
{"all", no_argument, NULL, 'a'},
{"delete", no_argument, NULL, 'd'},
{"expire", no_argument, NULL, 'e'},
{"help", no_argument, NULL, 'h'},
{"inactive", required_argument, NULL, 'i'},
{"keep-tokens", no_argument, NULL, 'k'},
{"lock", no_argument, NULL, 'l'},
{"mindays", required_argument, NULL, 'n'},
{"quiet", no_argument, NULL, 'q'},
{"root", required_argument, NULL, 'R'},
{"repository", required_argument, NULL, 'r'},
{"status", no_argument, NULL, 'S'},
{"unlock", no_argument, NULL, 'u'},
{"warndays", required_argument, NULL, 'w'},
{"maxdays", required_argument, NULL, 'x'},
{NULL, 0, NULL, '\0'}
};
while ((c = getopt_long (argc, argv, "adei:kln:qR:r:Suw:x:",
long_options, &option_index)) != -1) {
switch (c) {
case 'a':
aflg = true;
break;
case 'd':
dflg = true;
anyflag = true;
break;
case 'e':
eflg = true;
anyflag = true;
break;
case 'i':
if ( (getlong (optarg, &inact) == 0)
|| (inact < -1)) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
usage (E_BAD_ARG);
}
iflg = true;
anyflag = true;
break;
case 'k':
/* change only if expired, like Linux-PAM passwd -k. */
kflg = true; /* ok for users */
break;
case 'l':
lflg = true;
anyflag = true;
break;
case 'n':
if ( (getlong (optarg, &age_min) == 0)
|| (age_min < -1)) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
usage (E_BAD_ARG);
}
nflg = true;
anyflag = true;
break;
case 'q':
qflg = true; /* ok for users */
break;
case 'R':
if ('/' != optarg[0]) {
fprintf (stderr,
_("%s: invalid chroot path '%s'\n"),
Prog, optarg);
exit (E_BAD_ARG);
}
newroot = optarg;
if (access (newroot, F_OK) != 0) {
fprintf(stderr,
_("%s: chroot directory %s does not exist\n"),
Prog, newroot);
exit (E_BAD_ARG);
}
if ( chroot(newroot) != 0 ) {
fprintf(stderr,
_("%s: unable to chroot to directory %s\n"),
Prog, newroot);
exit (E_BAD_ARG);
}
break;
case 'r':
/* -r repository (files|nis|nisplus) */
/* only "files" supported for now */
if (strcmp (optarg, "files") != 0) {
fprintf (stderr,
_("%s: repository %s not supported\n"),
Prog, optarg);
exit (E_BAD_ARG);
}
break;
case 'S':
Sflg = true; /* ok for users */
break;
case 'u':
uflg = true;
anyflag = true;
break;
case 'w':
if ( (getlong (optarg, &warn) == 0)
|| (warn < -1)) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
usage (E_BAD_ARG);
}
wflg = true;
anyflag = true;
break;
case 'x':
if ( (getlong (optarg, &age_max) == 0)
|| (age_max < -1)) {
fprintf (stderr,
_("%s: invalid numeric argument '%s'\n"),
Prog, optarg);
usage (E_BAD_ARG);
}
xflg = true;
anyflag = true;
break;
default:
usage (E_BAD_ARG);
}
}
}
/*
* Now I have to get the user name. The name will be gotten from the
* command line if possible. Otherwise it is figured out from the
* environment.
*/
pw = get_my_pwent ();
if (NULL == pw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"), Prog);
SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
(unsigned long) getuid ()));
exit (E_NOPERM);
}
myname = xstrdup (pw->pw_name);
if (optind < argc) {
name = argv[optind];
} else {
name = myname;
}
/*
* Make sure that at most one username was specified.
*/
if (argc > (optind+1)) {
usage (E_USAGE);
}
/*
* The -a flag requires -S, no other flags, no username, and
* you must be root. --marekm
*/
if (aflg) {
if (anyflag || !Sflg || (optind < argc)) {
usage (E_USAGE);
}
if (!amroot) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
setpwent ();
while ( (pw = getpwent ()) != NULL ) {
print_status (pw);
}
endpwent ();
exit (E_SUCCESS);
}
#if 0
/*
* Allow certain users (administrators) to change passwords of
* certain users. Not implemented yet. --marekm
*/
if (may_change_passwd (myname, name))
amroot = 1;
#endif
/*
* If any of the flags were given, a user name must be supplied on
* the command line. Only an unadorned command line doesn't require
* the user's name be given. Also, -x, -n, -w, -i, -e, -d,
* -l, -u may appear with each other. -S, -k must appear alone.
*/
/*
* -S now ok for normal users (check status of my own account), and
* doesn't require username. --marekm
*/
if (anyflag && optind >= argc) {
usage (E_USAGE);
}
if ( (Sflg && kflg)
|| (anyflag && (Sflg || kflg))) {
usage (E_USAGE);
}
if (anyflag && !amroot) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
pw = xgetpwnam (name);
if (NULL == pw) {
fprintf (stderr, _("%s: user '%s' does not exist\n"), Prog, name);
exit (E_NOPERM);
}
#ifdef WITH_SELINUX
/* only do this check when getuid()==0 because it's a pre-condition for
changing a password without entering the old one */
if ((is_selinux_enabled() > 0) && (getuid() == 0) &&
(check_selinux_access (name, pw->pw_uid, PASSWD__PASSWD) != 0)) {
security_context_t user_context = NULL;
const char *user = "******";
if (getprevcon (&user_context) == 0) {
user = user_context;
}
SYSLOG ((LOG_ALERT,
"%s is not authorized to change the password of %s",
user, name));
fprintf(stderr,
_("%s: %s is not authorized to change the password of %s\n"),
Prog, user, name);
if (NULL != user_context) {
freecon (user_context);
}
exit (E_NOPERM);
}
#endif /* WITH_SELINUX */
/*
* If the UID of the user does not match the current real UID,
* check if I'm root.
*/
if (!amroot && (pw->pw_uid != getuid ())) {
fprintf (stderr,
_("%s: You may not view or modify password information for %s.\n"),
Prog, name);
SYSLOG ((LOG_WARN,
"%s: can't view or modify password information for %s",
Prog, name));
closelog ();
exit (E_NOPERM);
}
if (Sflg) {
print_status (pw);
exit (E_SUCCESS);
}
#ifndef USE_PAM
/*
* The user name is valid, so let's get the shadow file entry.
*/
sp = getspnam (name); /* !USE_PAM, no need for xgetspnam */
if (NULL == sp) {
sp = pwd_to_spwd (pw);
}
cp = sp->sp_pwdp;
/*
* If there are no other flags, just change the password.
*/
if (!anyflag) {
STRFCPY (crypt_passwd, cp);
/*
* See if the user is permitted to change the password.
* Otherwise, go ahead and set a new password.
*/
check_password (pw, sp);
/*
* Let the user know whose password is being changed.
*/
if (!qflg) {
printf (_("Changing password for %s\n"), name);
}
if (new_password (pw)) {
fprintf (stderr,
_("The password for %s is unchanged.\n"),
name);
closelog ();
exit (E_NOPERM);
}
do_update_pwd = true;
do_update_age = true;
}
#endif /* !USE_PAM */
/*
* Before going any further, raise the ulimit to prevent colliding
* into a lowered ulimit, and set the real UID to root to protect
* against unexpected signals. Any keyboard signals are set to be
* ignored.
*/
pwd_init ();
#ifdef USE_PAM
/*
* Don't set the real UID for PAM...
*/
if (!anyflag) {
do_pam_passwd (name, qflg, kflg);
exit (E_SUCCESS);
}
#endif /* USE_PAM */
if (setuid (0) != 0) {
fputs (_("Cannot change ID to root.\n"), stderr);
SYSLOG ((LOG_ERR, "can't setuid(0)"));
closelog ();
exit (E_NOPERM);
}
if (spw_file_present ()) {
update_shadow ();
} else {
update_noshadow ();
}
nscd_flush_cache ("passwd");
nscd_flush_cache ("group");
SYSLOG ((LOG_INFO, "password for '%s' changed by '%s'", name, myname));
closelog ();
if (!qflg) {
if (!anyflag) {
#ifndef USE_PAM
printf (_("%s: password changed.\n"), Prog);
#endif /* USE_PAM */
} else {
printf (_("%s: password expiry information changed.\n"), Prog);
}
}
return E_SUCCESS;
}
int passwd_main(int argc UNUSED_PARAM, char **argv)
{
enum {
OPT_algo = (1 << 0), /* -a - password algorithm */
OPT_lock = (1 << 1), /* -l - lock account */
OPT_unlock = (1 << 2), /* -u - unlock account */
OPT_delete = (1 << 3), /* -d - delete password */
OPT_lud = OPT_lock | OPT_unlock | OPT_delete,
};
unsigned opt;
int rc;
const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
const char *filename;
char *myname;
char *name;
char *newp;
struct passwd *pw;
uid_t myuid;
struct rlimit rlimit_fsize;
char c;
#if ENABLE_FEATURE_SHADOWPASSWDS
/* Using _r function to avoid pulling in static buffers */
struct spwd spw;
char buffer[256];
#endif
logmode = LOGMODE_BOTH;
openlog(applet_name, 0, LOG_AUTH);
opt = getopt32(argv, "a:lud", &opt_a);
//argc -= optind;
argv += optind;
myuid = getuid();
/* -l, -u, -d require root priv and username argument */
if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
bb_show_usage();
/* Will complain and die if username not found */
myname = xstrdup(xuid2uname(myuid));
name = argv[0] ? argv[0] : myname;
pw = xgetpwnam(name);
if (myuid != 0 && pw->pw_uid != myuid) {
/* LOGMODE_BOTH */
bb_error_msg_and_die("%s can't change password for %s", myname, name);
}
#if ENABLE_FEATURE_SHADOWPASSWDS
{
/* getspnam_r may return 0 yet set result to NULL.
* At least glibc 2.4 does this. Be extra paranoid here. */
struct spwd *result = NULL;
errno = 0;
if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) != 0
|| !result /* no error, but no record found either */
|| strcmp(result->sp_namp, pw->pw_name) != 0 /* paranoia */
) {
if (errno != ENOENT) {
/* LOGMODE_BOTH */
bb_perror_msg("no record of %s in %s, using %s",
name, bb_path_shadow_file,
bb_path_passwd_file);
}
/* else: /etc/shadow does not exist,
* apparently we are on a shadow-less system,
* no surprise there */
} else {
pw->pw_passwd = result->sp_pwdp;
}
}
#endif
/* Decide what the new password will be */
newp = NULL;
c = pw->pw_passwd[0] - '!';
if (!(opt & OPT_lud)) {
if (myuid != 0 && !c) { /* passwd starts with '!' */
/* LOGMODE_BOTH */
bb_error_msg_and_die("can't change "
"locked password for %s", name);
}
printf("Changing password for %s\n", name);
newp = new_password(pw, myuid, opt_a);
if (!newp) {
logmode = LOGMODE_STDIO;
bb_error_msg_and_die("password for %s is unchanged", name);
}
} else if (opt & OPT_lock) {
if (!c)
goto skip; /* passwd starts with '!' */
newp = xasprintf("!%s", pw->pw_passwd);
} else if (opt & OPT_unlock) {
if (c)
goto skip; /* not '!' */
/* pw->pw_passwd points to static storage,
* strdup'ing to avoid nasty surprizes */
newp = xstrdup(&pw->pw_passwd[1]);
} else if (opt & OPT_delete) {
newp = (char*)"";
}
rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
bb_signals(0
+ (1 << SIGHUP)
+ (1 << SIGINT)
+ (1 << SIGQUIT)
, SIG_IGN);
umask(077);
xsetuid(0);
#if ENABLE_FEATURE_SHADOWPASSWDS
filename = bb_path_shadow_file;
rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
if (rc > 0)
/* password in /etc/shadow was updated */
newp = (char*) "x";
if (rc >= 0)
/* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
#endif
{
filename = bb_path_passwd_file;
rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
}
/* LOGMODE_BOTH */
if (rc < 0)
bb_error_msg_and_die("can't update password file %s", filename);
bb_error_msg("password for %s changed by %s", name, myname);
/*if (ENABLE_FEATURE_CLEAN_UP) free(newp); - can't, it may be non-malloced */
skip:
if (!newp) {
bb_error_msg_and_die("password for %s is already %slocked",
name, (opt & OPT_unlock) ? "un" : "");
}
if (ENABLE_FEATURE_CLEAN_UP)
free(myname);
return 0;
}
