/*
* check_perms - check if the caller is allowed to add a group
*
* Non-root users are only allowed to change their gecos field.
* (see also may_change_field())
*
* Non-root users must be authenticated.
*
* It will not return if the user is not allowed.
*/
static void check_perms (const struct passwd *pw)
{
#ifdef USE_PAM
pam_handle_t *pamh = NULL;
int retval;
struct passwd *pampw;
#endif
/*
* Non-privileged users are only allowed to change the gecos field
* if the UID of the user matches the current real UID.
*/
if (!amroot && pw->pw_uid != getuid ()) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
closelog ();
exit (E_NOPERM);
}
#ifdef WITH_SELINUX
/*
* If the UID of the user does not match the current real UID,
* check if the change is allowed by SELinux policy.
*/
if ((pw->pw_uid != getuid ())
&& (is_selinux_enabled () > 0)
&& (selinux_check_passwd_access (PASSWD__CHFN) != 0)) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
closelog ();
exit (E_NOPERM);
}
#endif
#ifndef USE_PAM
/*
* Non-privileged users are optionally authenticated (must enter the
* password of the user whose information is being changed) before
* any changes can be made. Idea from util-linux chfn/chsh.
* --marekm
*/
if (!amroot && getdef_bool ("CHFN_AUTH")) {
passwd_check (pw->pw_name, pw->pw_passwd, "chfn");
}
#else /* !USE_PAM */
pampw = getpwuid (getuid ()); /* local, no need for xgetpwuid */
if (NULL == pampw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
exit (E_NOPERM);
}
retval = pam_start ("chfn", 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 (E_NOPERM);
}
(void) pam_end (pamh, retval);
#endif /* USE_PAM */
}
/*
* chfn - change a user's password file information
*
* This command controls the GECOS field information in the password
* file entry.
*
* The valid options are
*
* -f full name
* -r room number
* -w work phone number
* -h home phone number
* -o other information (*)
*
* (*) requires root permission to execute.
*/
int main (int argc, char **argv)
{
char *cp; /* temporary character pointer */
const struct passwd *pw; /* password file entry */
struct passwd pwent; /* modified password file entry */
char old_gecos[BUFSIZ]; /* buffer for old GECOS fields */
char new_gecos[BUFSIZ]; /* buffer for new GECOS fields */
int flag; /* flag currently being processed */
int fflg = 0; /* -f - set full name */
int rflg = 0; /* -r - set room number */
int wflg = 0; /* -w - set work phone number */
int hflg = 0; /* -h - set home phone number */
int oflg = 0; /* -o - set other information */
char *user;
#ifdef USE_PAM
pam_handle_t *pamh = NULL;
struct passwd *pampw;
int retval;
#endif
sanitize_env ();
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
/*
* This command behaves different for root and non-root
* users.
*/
amroot = (getuid () == 0);
/*
* Get the program name. The program name is used as a
* prefix to most error messages.
*/
Prog = Basename (argv[0]);
OPENLOG ("chfn");
/*
* The remaining arguments will be processed one by one and executed
* by this command. The name is the last argument if it does not
* begin with a "-", otherwise the name is determined from the
* environment and must agree with the real UID. Also, the UID will
* be checked for any commands which are restricted to root only.
*/
while ((flag = getopt (argc, argv, "f:r:w:h:o:")) != EOF) {
switch (flag) {
case 'f':
if (!may_change_field ('f')) {
fprintf (stderr,
_("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
fflg++;
STRFCPY (fullnm, optarg);
break;
case 'h':
if (!may_change_field ('h')) {
fprintf (stderr,
_("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
hflg++;
STRFCPY (homeph, optarg);
break;
case 'r':
if (!may_change_field ('r')) {
fprintf (stderr,
_("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
rflg++;
STRFCPY (roomno, optarg);
break;
case 'o':
if (!amroot) {
fprintf (stderr,
_("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
oflg++;
STRFCPY (slop, optarg);
break;
case 'w':
if (!may_change_field ('w')) {
fprintf (stderr,
_("%s: Permission denied.\n"), Prog);
exit (E_NOPERM);
}
wflg++;
STRFCPY (workph, optarg);
break;
default:
usage ();
}
}
/*
* Get the name of the user to check. It is either the command line
* name, or the name getlogin() returns.
*/
if (optind < argc) {
user = argv[optind];
pw = getpwnam (user);
if (!pw) {
fprintf (stderr, _("%s: unknown user %s\n"), Prog,
user);
exit (E_NOPERM);
}
} else {
pw = get_my_pwent ();
if (!pw) {
fprintf (stderr,
_
("%s: Cannot determine your user name.\n"),
Prog);
exit (E_NOPERM);
}
user = xstrdup (pw->pw_name);
}
#ifdef USE_NIS
/*
* Now we make sure this is a LOCAL password entry for this user ...
*/
if (__ispwNIS ()) {
char *nis_domain;
char *nis_master;
fprintf (stderr,
_("%s: cannot change user `%s' on NIS client.\n"),
Prog, user);
if (!yp_get_default_domain (&nis_domain) &&
!yp_master (nis_domain, "passwd.byname", &nis_master)) {
fprintf (stderr,
_
("%s: `%s' is the NIS master for this client.\n"),
Prog, nis_master);
}
exit (E_NOPERM);
}
#endif
/*
* Non-privileged users are only allowed to change the gecos field
* if the UID of the user matches the current real UID.
*/
if (!amroot && pw->pw_uid != getuid ()) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
closelog ();
exit (E_NOPERM);
}
#ifdef WITH_SELINUX
/*
* If the UID of the user does not match the current real UID,
* check if the change is allowed by SELinux policy.
*/
if ((pw->pw_uid != getuid ())
&& (selinux_check_passwd_access (PASSWD__CHFN) != 0)) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
closelog ();
exit (E_NOPERM);
}
#endif
#ifndef USE_PAM
/*
* Non-privileged users are optionally authenticated (must enter the
* password of the user whose information is being changed) before
* any changes can be made. Idea from util-linux chfn/chsh.
* --marekm
*/
if (!amroot && getdef_bool ("CHFN_AUTH"))
passwd_check (pw->pw_name, pw->pw_passwd, "chfn");
#else /* !USE_PAM */
retval = PAM_SUCCESS;
pampw = getpwuid (getuid ());
if (pampw == NULL) {
retval = PAM_USER_UNKNOWN;
}
if (retval == PAM_SUCCESS) {
retval = pam_start ("chfn", pampw->pw_name, &conv, &pamh);
}
if (retval == PAM_SUCCESS) {
retval = pam_authenticate (pamh, 0);
if (retval != PAM_SUCCESS) {
pam_end (pamh, retval);
}
}
if (retval == PAM_SUCCESS) {
retval = pam_acct_mgmt (pamh, 0);
if (retval != PAM_SUCCESS) {
pam_end (pamh, retval);
}
}
if (retval != PAM_SUCCESS) {
fprintf (stderr, _("%s: PAM authentication failed\n"), Prog);
exit (E_NOPERM);
}
#endif /* USE_PAM */
/*
* Now get the full name. It is the first comma separated field in
* the GECOS field.
*/
STRFCPY (old_gecos, pw->pw_gecos);
cp = copy_field (old_gecos, fflg ? (char *) 0 : fullnm, slop);
/*
* Now get the room number. It is the next comma separated field,
* if there is indeed one.
*/
if (cp)
cp = copy_field (cp, rflg ? (char *) 0 : roomno, slop);
/*
* Now get the work phone number. It is the third field.
*/
if (cp)
cp = copy_field (cp, wflg ? (char *) 0 : workph, slop);
/*
* Now get the home phone number. It is the fourth field.
*/
if (cp)
cp = copy_field (cp, hflg ? (char *) 0 : homeph, slop);
/*
* Anything left over is "slop".
*/
if (cp && !oflg) {
if (slop[0])
strcat (slop, ",");
strcat (slop, cp);
}
/*
* If none of the fields were changed from the command line, let the
* user interactively change them.
*/
if (!fflg && !rflg && !wflg && !hflg && !oflg) {
printf (_("Changing the user information for %s\n"), user);
new_fields ();
}
/*
* Check all of the fields for valid information
*/
if (valid_field (fullnm, ":,=")) {
fprintf (stderr, _("%s: invalid name: \"%s\"\n"), Prog, fullnm);
closelog ();
exit (E_NOPERM);
}
if (valid_field (roomno, ":,=")) {
fprintf (stderr, _("%s: invalid room number: \"%s\"\n"),
Prog, roomno);
closelog ();
exit (E_NOPERM);
}
if (valid_field (workph, ":,=")) {
fprintf (stderr, _("%s: invalid work phone: \"%s\"\n"),
Prog, workph);
closelog ();
exit (E_NOPERM);
}
if (valid_field (homeph, ":,=")) {
fprintf (stderr, _("%s: invalid home phone: \"%s\"\n"),
Prog, homeph);
closelog ();
exit (E_NOPERM);
}
if (valid_field (slop, ":")) {
fprintf (stderr,
_("%s: \"%s\" contains illegal characters\n"),
Prog, slop);
closelog ();
exit (E_NOPERM);
}
/*
* Build the new GECOS field by plastering all the pieces together,
* if they will fit ...
*/
if (strlen (fullnm) + strlen (roomno) + strlen (workph) +
strlen (homeph) + strlen (slop) > (unsigned int) 80) {
fprintf (stderr, _("%s: fields too long\n"), Prog);
closelog ();
exit (E_NOPERM);
}
snprintf (new_gecos, sizeof new_gecos, "%s,%s,%s,%s%s%s",
fullnm, roomno, workph, homeph, slop[0] ? "," : "", slop);
/*
* 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.
*/
if (setuid (0)) {
fprintf (stderr, _("Cannot change ID to root.\n"));
SYSLOG ((LOG_ERR, "can't setuid(0)"));
closelog ();
exit (E_NOPERM);
}
pwd_init ();
/*
* The passwd entry is now ready to be committed back to the
* password file. Get a lock on the file and open it.
*/
if (!pw_lock ()) {
fprintf (stderr,
_
("Cannot lock the password file; try again later.\n"));
SYSLOG ((LOG_WARN, "can't lock /etc/passwd"));
closelog ();
exit (E_NOPERM);
}
if (!pw_open (O_RDWR)) {
fprintf (stderr, _("Cannot open the password file.\n"));
pw_unlock ();
SYSLOG ((LOG_ERR, "can't open /etc/passwd"));
closelog ();
exit (E_NOPERM);
}
/*
* Get the entry to update using pw_locate() - we want the real one
* from /etc/passwd, not the one from getpwnam() which could contain
* the shadow password if (despite the warnings) someone enables
* AUTOSHADOW (or SHADOW_COMPAT in libc). --marekm
*/
pw = pw_locate (user);
if (!pw) {
pw_unlock ();
fprintf (stderr,
_("%s: %s not found in /etc/passwd\n"), Prog, user);
exit (E_NOPERM);
}
/*
* Make a copy of the entry, then change the gecos field. The other
* fields remain unchanged.
*/
pwent = *pw;
pwent.pw_gecos = new_gecos;
/*
* Update the passwd file entry. If there is a DBM file, update that
* entry as well.
*/
if (!pw_update (&pwent)) {
fprintf (stderr, _("Error updating the password entry.\n"));
pw_unlock ();
SYSLOG ((LOG_ERR, "error updating passwd entry"));
closelog ();
exit (E_NOPERM);
}
/*
* Changes have all been made, so commit them and unlock the file.
*/
if (!pw_close ()) {
fprintf (stderr, _("Cannot commit password file changes.\n"));
pw_unlock ();
SYSLOG ((LOG_ERR, "can't rewrite /etc/passwd"));
closelog ();
exit (E_NOPERM);
}
if (!pw_unlock ()) {
fprintf (stderr, _("Cannot unlock the password file.\n"));
SYSLOG ((LOG_ERR, "can't unlock /etc/passwd"));
closelog ();
exit (E_NOPERM);
}
SYSLOG ((LOG_INFO, "changed user `%s' information", user));
nscd_flush_cache ("passwd");
#ifdef USE_PAM
if (retval == PAM_SUCCESS)
pam_end (pamh, PAM_SUCCESS);
#endif /* USE_PAM */
closelog ();
exit (E_SUCCESS);
}
int main (int argc, char **argv)
{
const struct spwd *sp;
uid_t ruid;
gid_t rgid;
const struct passwd *pw;
/*
* Get the program name so that error messages can use it.
*/
Prog = Basename (argv[0]);
sanitize_env ();
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
process_root_flag ("-R", argc, argv);
#ifdef WITH_AUDIT
audit_help_open ();
#endif
OPENLOG ("chage");
ruid = getuid ();
rgid = getgid ();
amroot = (ruid == 0);
#ifdef WITH_SELINUX
if (amroot && (is_selinux_enabled () > 0)) {
amroot = (selinux_check_passwd_access (PASSWD__ROOTOK) == 0);
}
#endif
process_flags (argc, argv);
check_perms ();
if (!spw_file_present ()) {
fprintf (stderr,
_("%s: the shadow password file is not present\n"),
Prog);
SYSLOG ((LOG_WARN, "can't find the shadow password file"));
closelog ();
exit (E_SHADOW_NOTFOUND);
}
open_files (lflg);
/* Drop privileges */
if (lflg && ( (setregid (rgid, rgid) != 0)
|| (setreuid (ruid, ruid) != 0))) {
fprintf (stderr, _("%s: failed to drop privileges (%s)\n"),
Prog, strerror (errno));
fail_exit (E_NOPERM);
}
pw = pw_locate (argv[optind]);
if (NULL == pw) {
fprintf (stderr, _("%s: user '%s' does not exist in %s\n"),
Prog, argv[optind], pw_dbname ());
closelog ();
fail_exit (E_NOPERM);
}
STRFCPY (user_name, pw->pw_name);
#ifdef WITH_TCB
if (shadowtcb_set_user (pw->pw_name) == SHADOWTCB_FAILURE) {
fail_exit (E_NOPERM);
}
#endif
user_uid = pw->pw_uid;
sp = spw_locate (argv[optind]);
get_defaults (sp);
/*
* Print out the expiration fields if the user has requested the
* list option.
*/
if (lflg) {
if (!amroot && (ruid != user_uid)) {
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
fail_exit (E_NOPERM);
}
#ifdef WITH_AUDIT
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"display aging info",
user_name, (unsigned int) user_uid, 1);
#endif
list_fields ();
fail_exit (E_SUCCESS);
}
/*
* If none of the fields were changed from the command line, let the
* user interactively change them.
*/
if (!mflg && !Mflg && !dflg && !Wflg && !Iflg && !Eflg) {
printf (_("Changing the aging information for %s\n"),
user_name);
if (new_fields () == 0) {
fprintf (stderr, _("%s: error changing fields\n"),
Prog);
fail_exit (E_NOPERM);
}
#ifdef WITH_AUDIT
else {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change all aging information",
user_name, (unsigned int) user_uid, 1);
}
#endif
} else {
#ifdef WITH_AUDIT
if (Mflg) {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change max age",
user_name, (unsigned int) user_uid, 1);
}
if (mflg) {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change min age",
user_name, (unsigned int) user_uid, 1);
}
if (dflg) {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change last change date",
user_name, (unsigned int) user_uid, 1);
}
if (Wflg) {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change passwd warning",
user_name, (unsigned int) user_uid, 1);
}
if (Iflg) {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change inactive days",
user_name, (unsigned int) user_uid, 1);
}
if (Eflg) {
audit_logger (AUDIT_USER_CHAUTHTOK, Prog,
"change passwd expiration",
user_name, (unsigned int) user_uid, 1);
}
#endif
}
update_age (sp, pw);
close_files ();
SYSLOG ((LOG_INFO, "changed password expiry for %s", user_name));
closelog ();
exit (E_SUCCESS);
}
