shadow/src/gpasswd.c

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/*
* Copyright 1990 - 1994, Julianne Frances Haugh
* 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. Neither the name of Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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>
#include "rcsid.h"
RCSID (PKG_VER "$Id: gpasswd.c,v 1.25 2005/06/20 09:36:27 kloczek Exp $")
#include <sys/types.h>
#include <stdio.h>
#include <pwd.h>
#include <grp.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#include "prototypes.h"
#include "defines.h"
#include "groupio.h"
#ifdef SHADOWGRP
#include "sgroupio.h"
#endif
static char *Prog;
#ifdef SHADOWGRP
static int is_shadowgrp;
#endif
static int
aflg = 0, Aflg = 0, dflg = 0, Mflg = 0, rflg = 0, Rflg = 0;
#ifndef RETRIES
#define RETRIES 3
#endif
/* local function prototypes */
static void usage (void);
static RETSIGTYPE die (int);
static int check_list (const char *);
/*
* usage - display usage message
*/
static void usage (void)
{
fprintf (stderr, _("Usage: %s [-r|-R] group\n"), Prog);
fprintf (stderr, _(" %s [-a user] group\n"), Prog);
fprintf (stderr, _(" %s [-d user] group\n"), Prog);
#ifdef SHADOWGRP
fprintf (stderr,
_(" %s [-A user,...] [-M user,...] group\n"), Prog);
#else
fprintf (stderr, _(" %s [-M user,...] group\n"), Prog);
#endif
exit (1);
}
/*
* die - set or reset termio modes.
*
* die() is called before processing begins. signal() is then called
* with die() as the signal handler. If signal later calls die() with a
* signal number, the terminal modes are then reset.
*/
static RETSIGTYPE die (int killed)
{
static TERMIO sgtty;
if (killed)
STTY (0, &sgtty);
else
GTTY (0, &sgtty);
if (killed) {
putchar ('\n');
fflush (stdout);
exit (killed);
}
}
/*
* check_list - check a comma-separated list of user names for validity
*
* check_list scans a comma-separated list of user names and checks
* that each listed name exists.
*/
static int check_list (const char *users)
{
const char *start, *end;
char username[32];
int errors = 0;
int len;
for (start = users; start && *start; start = end) {
if ((end = strchr (start, ','))) {
len = end - start;
end++;
} else {
len = strlen (start);
}
if (len > sizeof (username) - 1)
len = sizeof (username) - 1;
strncpy (username, start, len);
username[len] = '\0';
/*
* This user must exist.
*/
if (!getpwnam (username)) {
fprintf (stderr, _("%s: unknown user %s\n"),
Prog, username);
errors++;
}
}
return errors;
}
static void failure (void)
{
fprintf (stderr, _("%s: Permission denied.\n"), Prog);
exit (1);
/*NOTREACHED*/}
/*
* gpasswd - administer the /etc/group file
*
* -a user add user to the named group
* -d user remove user from the named group
* -r remove password from the named group
* -R restrict access to the named group
* -A user,... make list of users the administrative users
* -M user,... make list of users the group members
*/
int main (int argc, char **argv)
{
int flag;
char *cp;
int amroot;
int retries;
struct group *gr = NULL;
struct group grent;
static char pass[BUFSIZ];
#ifdef SHADOWGRP
struct sgrp *sg = NULL;
struct sgrp sgent;
char *admins = NULL;
#endif
struct passwd *pw = NULL;
char *myname;
char *user = NULL;
char *group = NULL;
char *members = NULL;
sanitize_env ();
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
/*
* Make a note of whether or not this command was invoked by root.
* This will be used to bypass certain checks later on. Also, set
* the real user ID to match the effective user ID. This will
* prevent the invoker from issuing signals which would interfer
* with this command.
*/
amroot = getuid () == 0;
Prog = Basename (argv[0]);
OPENLOG ("gpasswd");
setbuf (stdout, NULL);
setbuf (stderr, NULL);
#ifdef SHADOWGRP
is_shadowgrp = sgr_file_present ();
#endif
while ((flag = getopt (argc, argv, "a:d:grRA:M:")) != EOF) {
switch (flag) {
case 'a': /* add a user */
user = optarg;
if (!getpwnam (user)) {
fprintf (stderr,
_("%s: unknown user %s\n"), Prog,
user);
exit (1);
}
aflg++;
break;
#ifdef SHADOWGRP
case 'A':
if (!amroot)
failure ();
if (!is_shadowgrp) {
fprintf (stderr,
_
("%s: shadow group passwords required for -A\n"),
Prog);
exit (2);
}
admins = optarg;
if (check_list (admins))
exit (1);
Aflg++;
break;
#endif
case 'd': /* delete a user */
dflg++;
user = optarg;
break;
case 'g': /* no-op from normal password */
break;
case 'M':
if (!amroot)
failure ();
members = optarg;
if (check_list (members))
exit (1);
Mflg++;
break;
case 'r': /* remove group password */
rflg++;
break;
case 'R': /* restrict group password */
Rflg++;
break;
default:
usage ();
}
}
/*
* Make sure exclusive flags are exclusive
*/
if (aflg + dflg + rflg + Rflg + (Aflg || Mflg) > 1)
usage ();
/*
* Determine the name of the user that invoked this command. This
* is really hit or miss because there are so many ways that command
* can be executed and so many ways to trip up the routines that
* report the user name.
*/
pw = get_my_pwent ();
if (!pw) {
fprintf (stderr, _("Who are you?\n"));
exit (1);
}
myname = xstrdup (pw->pw_name);
/*
* Get the name of the group that is being affected. The group entry
* will be completely replicated so it may be modified later on.
*/
/*
* XXX - should get the entry using gr_locate() and modify that,
* getgrnam() could give us a NIS group. --marekm
*/
if (!(group = argv[optind]))
usage ();
if (!(gr = getgrnam (group))) {
fprintf (stderr, _("unknown group: %s\n"), group);
exit (1);
}
grent = *gr;
grent.gr_name = xstrdup (gr->gr_name);
grent.gr_passwd = xstrdup (gr->gr_passwd);
grent.gr_mem = dup_list (gr->gr_mem);
#ifdef SHADOWGRP
if ((sg = getsgnam (group))) {
sgent = *sg;
sgent.sg_name = xstrdup (sg->sg_name);
sgent.sg_passwd = xstrdup (sg->sg_passwd);
sgent.sg_mem = dup_list (sg->sg_mem);
sgent.sg_adm = dup_list (sg->sg_adm);
} else {
sgent.sg_name = xstrdup (group);
sgent.sg_passwd = grent.gr_passwd;
grent.gr_passwd = "!"; /* XXX warning: const */
sgent.sg_mem = dup_list (grent.gr_mem);
sgent.sg_adm = (char **) xmalloc (sizeof (char *) * 2);
#ifdef FIRST_MEMBER_IS_ADMIN
if (sgent.sg_mem[0]) {
sgent.sg_adm[0] = xstrdup (sgent.sg_mem[0]);
sgent.sg_adm[1] = 0;
} else
#endif
sgent.sg_adm[0] = 0;
sg = &sgent;
}
/*
* The policy here for changing a group is that 1) you must be root
* or 2). you must be listed as an administrative member.
* Administrative members can do anything to a group that the root
* user can.
*/
if (!amroot && !is_on_list (sgent.sg_adm, myname))
failure ();
#else /* ! SHADOWGRP */
#ifdef FIRST_MEMBER_IS_ADMIN
/*
* The policy here for changing a group is that 1) you must bes root
* or 2) you must be the first listed member of the group. The
* first listed member of a group can do anything to that group that
* the root user can. The rationale for this hack is that the FIRST
* user is probably the most important user in this entire group.
*/
if (!amroot) {
if (grent.gr_mem[0] == (char *) 0)
failure ();
if (strcmp (grent.gr_mem[0], myname) != 0)
failure ();
}
#else
/*
* This feature enabled by default could be a security problem when
* installed on existing systems where the first group member might
* be just a normal user. --marekm
*/
if (!amroot)
failure ();
#endif
#endif /* SHADOWGRP */
/*
* Removing a password is straight forward. Just set the password
* field to a "".
*/
if (rflg) {
grent.gr_passwd = ""; /* XXX warning: const */
#ifdef SHADOWGRP
sgent.sg_passwd = ""; /* XXX warning: const */
#endif
SYSLOG ((LOG_INFO, "remove password from group %s by %s",
group, myname));
goto output;
} else if (Rflg) {
/*
* Same thing for restricting the group. Set the password
* field to "!".
*/
grent.gr_passwd = "!"; /* XXX warning: const */
#ifdef SHADOWGRP
sgent.sg_passwd = "!"; /* XXX warning: const */
#endif
SYSLOG ((LOG_INFO, "restrict access to group %s by %s",
group, myname));
goto output;
}
/*
* Adding a member to a member list is pretty straightforward as
* well. Call the appropriate routine and split.
*/
if (aflg) {
printf (_("Adding user %s to group %s\n"), user, group);
grent.gr_mem = add_list (grent.gr_mem, user);
#ifdef SHADOWGRP
sgent.sg_mem = add_list (sgent.sg_mem, user);
#endif
SYSLOG ((LOG_INFO, "add member %s to group %s by %s", user,
group, myname));
goto output;
}
/*
* Removing a member from the member list is the same deal as adding
* one, except the routine is different.
*/
if (dflg) {
int removed = 0;
printf (_("Removing user %s from group %s\n"), user, group);
if (is_on_list (grent.gr_mem, user)) {
removed = 1;
grent.gr_mem = del_list (grent.gr_mem, user);
}
#ifdef SHADOWGRP
if (is_on_list (sgent.sg_mem, user)) {
removed = 1;
sgent.sg_mem = del_list (sgent.sg_mem, user);
}
#endif
if (!removed) {
fprintf (stderr, _("%s: unknown member %s\n"),
Prog, user);
exit (1);
}
SYSLOG ((LOG_INFO, "remove member %s from group %s by %s",
user, group, myname));
goto output;
}
#ifdef SHADOWGRP
/*
* Replacing the entire list of administators is simple. Check the
* list to make sure everyone is a real user. Then slap the new list
* in place.
*/
if (Aflg) {
SYSLOG ((LOG_INFO, "set administrators of %s to %s",
group, admins));
sgent.sg_adm = comma_to_list (admins);
if (!Mflg)
goto output;
}
#endif
/*
* Replacing the entire list of members is simple. Check the list to
* make sure everyone is a real user. Then slap the new list in
* place.
*/
if (Mflg) {
SYSLOG ((LOG_INFO, "set members of %s to %s", group, members));
#ifdef SHADOWGRP
sgent.sg_mem = comma_to_list (members);
#endif
grent.gr_mem = comma_to_list (members);
goto output;
}
/*
* If the password is being changed, the input and output must both
* be a tty. The typical keyboard signals are caught so the termio
* modes can be restored.
*/
if (!isatty (0) || !isatty (1)) {
fprintf (stderr, _("%s: Not a tty\n"), Prog);
exit (1);
}
die (0); /* save tty modes */
signal (SIGHUP, die);
signal (SIGINT, die);
signal (SIGQUIT, die);
signal (SIGTERM, die);
#ifdef SIGTSTP
signal (SIGTSTP, die);
#endif
/*
* A new password is to be entered and it must be encrypted, etc.
* The password will be prompted for twice, and both entries must be
* identical. There is no need to validate the old password since
* the invoker is either the group owner, or root.
*/
printf (_("Changing the password for group %s\n"), group);
for (retries = 0; retries < RETRIES; retries++) {
if (!(cp = getpass (_("New Password: "))))
exit (1);
STRFCPY (pass, cp);
strzero (cp);
if (!(cp = getpass (_("Re-enter new password: "))))
exit (1);
if (strcmp (pass, cp) == 0) {
strzero (cp);
break;
}
strzero (cp);
memzero (pass, sizeof pass);
if (retries + 1 < RETRIES)
puts (_("They don't match; try again"));
}
if (retries == RETRIES) {
fprintf (stderr, _("%s: Try again later\n"), Prog);
exit (1);
}
cp = pw_encrypt (pass, crypt_make_salt ());
memzero (pass, sizeof pass);
#ifdef SHADOWGRP
if (is_shadowgrp)
sgent.sg_passwd = cp;
else
#endif
grent.gr_passwd = cp;
SYSLOG ((LOG_INFO, "change the password for group %s by %s", group,
myname));
/*
* This is the common arrival point to output the new group file.
* The freshly crafted entry is in allocated space. The group file
* will be locked and opened for writing. The new entry will be
* output, etc.
*/
output:
if (setuid (0)) {
fprintf (stderr, _("Cannot change ID to root.\n"));
SYSLOG ((LOG_ERR, "can't setuid(0)"));
closelog ();
exit (1);
}
pwd_init ();
if (!gr_lock ()) {
fprintf (stderr, _("%s: can't get lock\n"), Prog);
SYSLOG ((LOG_WARN, "failed to get lock for /etc/group"));
exit (1);
}
#ifdef SHADOWGRP
if (is_shadowgrp && !sgr_lock ()) {
fprintf (stderr, _("%s: can't get shadow lock\n"), Prog);
SYSLOG ((LOG_WARN, "failed to get lock for /etc/gshadow"));
exit (1);
}
#endif
if (!gr_open (O_RDWR)) {
fprintf (stderr, _("%s: can't open file\n"), Prog);
SYSLOG ((LOG_WARN, "cannot open /etc/group"));
exit (1);
}
#ifdef SHADOWGRP
if (is_shadowgrp && !sgr_open (O_RDWR)) {
fprintf (stderr, _("%s: can't open shadow file\n"), Prog);
SYSLOG ((LOG_WARN, "cannot open /etc/gshadow"));
exit (1);
}
#endif
if (!gr_update (&grent)) {
fprintf (stderr, _("%s: can't update entry\n"), Prog);
SYSLOG ((LOG_WARN, "cannot update /etc/group"));
exit (1);
}
#ifdef SHADOWGRP
if (is_shadowgrp && !sgr_update (&sgent)) {
fprintf (stderr, _("%s: can't update shadow entry\n"), Prog);
SYSLOG ((LOG_WARN, "cannot update /etc/gshadow"));
exit (1);
}
#endif
if (!gr_close ()) {
fprintf (stderr, _("%s: can't re-write file\n"), Prog);
SYSLOG ((LOG_WARN, "cannot re-write /etc/group"));
exit (1);
}
#ifdef SHADOWGRP
if (is_shadowgrp && !sgr_close ()) {
fprintf (stderr, _("%s: can't re-write shadow file\n"), Prog);
SYSLOG ((LOG_WARN, "cannot re-write /etc/gshadow"));
exit (1);
}
if (is_shadowgrp)
sgr_unlock ();
#endif
if (!gr_unlock ()) {
fprintf (stderr, _("%s: can't unlock file\n"), Prog);
exit (1);
}
exit (0);
/* NOT REACHED */
}