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shadow/contrib/adduser.c

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/****
** 04/21/96
** hacked even more, replaced gets() with something slightly harder to buffer
** overflow. Added support for setting a default quota on new account, with
** edquota -p. Other cleanups for security, I let some users run adduser suid
** root to add new accounts. (overflow checks, clobber environment, valid
** shell checks, restrictions on gid + home dir settings).
** Added max. username length. Used syslog() a bit for important events.
** Support to immediately expire account with passwd -e.
** Called it version 2.0! Because I felt like it!
** -- Chris, chris@ferret.lmh.ox.ac.uk
** 03/17/96
** hacked a bit more, removed unused code, cleaned up for gcc -Wall.
** --marekm
**
** 02/26/96
** modified to call shadow utils (useradd,chage,passwd) on shadowed
** systems - Cristian Gafton, gafton@sorosis.ro
**
** 6/27/95
** shadow-adduser 1.4:
**
** now it copies the /etc/skel dir into the person's dir,
** makes the mail folders, changed some defaults and made a 'make
** install' just for the hell of it.
**
** Greg Gallagher
** CIN.Net
**
** 1/28/95
** shadow-adduser 1.3:
**
** Basically a bug-fix on my additions in 1.2. Thanks to Terry Stewart
** (stew@texas.net) for pointing out one of the many idiotic bugs I introduced.
** It was such a stupid bug that I would have never seen it myself.
**
** Brandon
*****
** 01/27/95
**
** shadow-adduser 1.2:
** I took the C source from adduser-shadow (credits are below) and made
** it a little more worthwhile. Many small changes... Here's
** the ones I can remember:
**
** Removed support for non-shadowed systems (if you don't have shadow,
** use the original adduser, don't get this shadow version!)
** Added support for the correct /etc/shadow fields (Min days before
** password change, max days before password change, Warning days,
** and how many days from expiry date does the account go invalid)
** The previous version just left all of those fields blank.
** There is still one field left (expiry date for the account, period)
** which I have left blank because I do not use it and didn't want to
** spend any more time on this. I'm sure someone will put it in and
** tack another plethora of credits on here. :)
** Added in the password date field, which should always reflect the last
** date the password was changed, for expiry purposes. "passwd" always
** updates this field, so the adduser program should set it up right
** initially (or a user could keep their initial password forever ;)
** The number is in days since Jan 1st, 1970.
**
** Have fun with it, and someone please make
** a real version(this is still just a hack)
** for us all to use (and Email it to me???)
**
** Brandon
** photon@usis.com
**
*****
** adduser 1.0: add a new user account (For systems not using shadow)
** With a nice little interface and a will to do all the work for you.
**
** Craig Hagan
** hagan@opine.cs.umass.edu
**
** Modified to really work, look clean, and find unused uid by Chris Cappuccio
** chris@slinky.cs.umass.edu
**
*****
**
** 01/19/95
**
** FURTHER modifications to enable shadow passwd support (kludged, but
** no more so than the original) by Dan Crowson - dcrowson@mo.net
**
** Search on DAN for all changes...
**
*****
**
** cc -O -o adduser adduser.c
** Use gcc if you have it... (political reasons beyond my control) (chris)
**
** I've gotten this program to work with success under Linux (without
** shadow) and SunOS 4.1.3. I would assume it should work pretty well
** on any system that uses no shadow. (chris)
**
** If you have no crypt() then try
** cc -DNO_CRYPT -O -o adduser adduser.c xfdes.c
** I'm not sure how login operates with no crypt()... I guess
** the same way we're doing it here.
*/
#include <unistd.h>
#include <stdlib.h>
#include <pwd.h>
#include <grp.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/timeb.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <syslog.h>
#define IMMEDIATE_CHANGE /* Expire newly created password, must be changed
* immediately upon next login */
#define HAVE_QUOTAS /* Obvious */
#define EXPIRE_VALS_SET /* If defined, 'normal' users can't change
* password expiry values (if running suid root) */
#define HAVE_GETUSERSHELL /* FIXME: Isn't this defined in config.h too? */
#define LOGGING /* If we want to log various things to syslog */
#define MAX_USRNAME 8 /* Longer usernames seem to work on my system....
* But they're probably a poor idea */
#define DEFAULT_SHELL "/bin/bash" /* because BASH is your friend */
#define DEFAULT_HOME "/home"
#define USERADD_PATH "/usr/sbin/useradd"
#define CHAGE_PATH "/usr/bin/chage"
#define PASSWD_PATH "/usr/bin/passwd"
#define EDQUOTA_PATH "/usr/sbin/edquota"
#define QUOTA_DEFAULT "defuser"
#define DEFAULT_GROUP 100
#define DEFAULT_MIN_PASS 0
#define DEFAULT_MAX_PASS 100
#define DEFAULT_WARN_PASS 14
#define DEFAULT_USER_DIE 366
void safeget (char *, int);
void
main (void)
{
char foo[32];
char usrname[32], person[32], dir[32], shell[32];
unsigned int group, min_pass, max_pass, warn_pass, user_die;
/* the group and uid of the new user */
int bad = 0, done = 0, correct = 0, olduid;
char cmd[255];
struct group *grp;
/* flags, in order:
* bad to see if the username is in /etc/passwd, or if strange stuff has
* been typed if the user might be put in group 0
* done allows the program to exit when a user has been added
* correct loops until a username is found that isn't in /etc/passwd
*/
/* The real program starts HERE! */
if (geteuid () != 0)
{
printf ("It seems you don't have access to add a new user. Try\n");
printf ("logging in as root or su root to gain superuser access.\n");
exit (1);
}
/* Sanity checks
*/
#ifdef LOGGING
openlog ("adduser", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
syslog (LOG_INFO, "invoked by user %s\n", getpwuid (getuid ())->pw_name);
#endif
if (!(grp = getgrgid (DEFAULT_GROUP)))
{
printf ("Error: the default group %d does not exist on this system!\n",
DEFAULT_GROUP);
printf ("adduser must be recompiled.\n");
#ifdef LOGGING
syslog (LOG_ERR, "warning: failed. no such default group\n");
closelog ();
#endif
exit (1);
};
while (!correct)
{ /* loop until a "good" usrname is chosen */
while (!done)
{
printf ("\nLogin to add (^C to quit): ");
fflush (stdout);
safeget (usrname, sizeof (usrname));
if (!strlen (usrname))
{
printf ("Empty input.\n");
done = 0;
continue;
};
/* what I saw here before made me think maybe I was running DOS */
/* might this be a solution? (chris) */
if (strlen (usrname) > MAX_USRNAME)
{
printf ("That name is longer than the maximum of %d characters. Choose another.\n", MAX_USRNAME);
done = 0;
}
else if (getpwnam (usrname) != NULL)
{
printf ("That name is in use, choose another.\n");
done = 0;
}
else if (strchr (usrname, ' ') != NULL)
{
printf ("No spaces in username!!\n");
done = 0;
}
else
done = 1;
}; /* done, we have a valid new user name */
/* all set, get the rest of the stuff */
printf ("\nEditing information for new user [%s]\n", usrname);
printf ("\nFull Name [%s]: ", usrname);
fflush (stdout);
safeget (person, sizeof (person));
if (!strlen (person))
{
bzero (person, sizeof (person));
strcpy (person, usrname);
};
if (getuid () == 0)
{
do
{
bad = 0;
printf ("GID [%d]: ", DEFAULT_GROUP);
fflush (stdout);
safeget (foo, sizeof (foo));
if (!strlen (foo))
group = DEFAULT_GROUP;
else if (isdigit (*foo))
{
group = atoi (foo);
if (!(grp = getgrgid (group)))
{
printf ("unknown gid %s\n", foo);
group = DEFAULT_GROUP;
bad = 1;
};
}
else if ((grp = getgrnam (foo)))
group = grp->gr_gid;
else
{
printf ("unknown group %s\n", foo);
group = DEFAULT_GROUP;
bad = 1;
}
if (group == 0)
{ /* You're not allowed to make root group users! */
printf ("Creation of root group users not allowed (must be done by hand)\n");
group = DEFAULT_GROUP;
bad = 1;
};
}
while (bad);
}
else
{
printf ("Group will be default of: %d\n", DEFAULT_GROUP);
group = DEFAULT_GROUP;
}
if (getuid () == 0)
{
printf ("\nIf home dir ends with a / then '%s' will be appended to it\n", usrname);
printf ("Home Directory [%s/%s]: ", DEFAULT_HOME, usrname);
fflush (stdout);
safeget (dir, sizeof (dir));
if (!strlen (dir))
{ /* hit return */
sprintf (dir, "%s/%s", DEFAULT_HOME, usrname);
}
else if (dir[strlen (dir) - 1] == '/')
sprintf (dir+strlen(dir), "%s", usrname);
}
else
{
printf ("\nHome directory will be %s/%s\n", DEFAULT_HOME, usrname);
sprintf (dir, "%s/%s", DEFAULT_HOME, usrname);
}
printf ("\nShell [%s]: ", DEFAULT_SHELL);
fflush (stdout);
safeget (shell, sizeof (shell));
if (!strlen (shell))
sprintf (shell, "%s", DEFAULT_SHELL);
else
{
char *sh;
int ok = 0;
#ifdef HAVE_GETUSERSHELL
setusershell ();
while ((sh = getusershell ()) != NULL)
if (!strcmp (shell, sh))
ok = 1;
endusershell ();
#endif
if (!ok)
{
if (getuid () == 0)
printf ("Warning: root allowed non standard shell\n");
else
{
printf ("Shell NOT in /etc/shells, DEFAULT used\n");
sprintf (shell, "%s", DEFAULT_SHELL);
}
}
}
#ifdef EXPIRE_VALS_SET
if (getuid () == 0)
{
#endif
printf ("\nMin. Password Change Days [%d]: ", DEFAULT_MIN_PASS);
fflush (stdout);
safeget (foo, sizeof (foo));
if (strlen (foo) > 1)
min_pass = DEFAULT_MIN_PASS;
else
min_pass = atoi (foo);
printf ("Max. Password Change Days [%d]: ", DEFAULT_MAX_PASS);
fflush (stdout);
safeget (foo, sizeof (foo));
if (strlen (foo) > 1)
max_pass = atoi (foo);
else
max_pass = DEFAULT_MAX_PASS;
printf ("Password Warning Days [%d]: ", DEFAULT_WARN_PASS);
fflush (stdout);
safeget (foo, sizeof (foo));
warn_pass = atoi (foo);
if (warn_pass == 0)
warn_pass = DEFAULT_WARN_PASS;
printf ("Days after Password Expiry for Account Locking [%d]: ", DEFAULT_USER_DIE);
fflush (stdout);
safeget (foo, sizeof (foo));
user_die = atoi (foo);
if (user_die == 0)
user_die = DEFAULT_USER_DIE;
#ifdef EXPIRE_VALS_SET
}
else
{
printf ("\nSorry, account expiry values are set.\n");
user_die = DEFAULT_USER_DIE;
warn_pass = DEFAULT_WARN_PASS;
max_pass = DEFAULT_MAX_PASS;
min_pass = DEFAULT_MIN_PASS;
}
#endif
printf ("\nInformation for new user [%s] [%s]:\n", usrname, person);
printf ("Home directory: [%s] Shell: [%s]\n", dir, shell);
printf ("GID: [%d]\n", group);
printf ("MinPass: [%d] MaxPass: [%d] WarnPass: [%d] UserExpire: [%d]\n",
min_pass, max_pass, warn_pass, user_die);
printf ("\nIs this correct? [y/N]: ");
fflush (stdout);
safeget (foo, sizeof (foo));
done = bad = correct = (foo[0] == 'y' || foo[0] == 'Y');
if (bad != 1)
printf ("\nUser [%s] not added\n", usrname);
}
/* Clobber the environment, I run this suid root sometimes to let
* non root privileged accounts add users --chris */
*environ = NULL;
bzero (cmd, sizeof (cmd));
sprintf (cmd, "%s -g %d -d %s -s %s -c \"%s\" -m -k /etc/skel %s",
USERADD_PATH, group, dir, shell, person, usrname);
printf ("Calling useradd to add new user:\n%s\n", cmd);
if (system (cmd))
{
printf ("User add failed!\n");
#ifdef LOGGING
syslog (LOG_ERR, "could not add new user\n");
closelog ();
#endif
exit (errno);
};
olduid = getuid (); /* chage, passwd, edquota etc. require ruid = root
*/
setuid (0);
bzero (cmd, sizeof (cmd));
/* Chage runs suid root. => we need ruid root to run it with
* anything other than chage -l
*/
sprintf (cmd, "%s -m %d -M %d -W %d -I %d %s", CHAGE_PATH,
min_pass, max_pass, warn_pass, user_die, usrname);
printf ("%s\n", cmd);
if (system (cmd))
{
printf ("There was an error setting password expire values\n");
#ifdef LOGGING
syslog (LOG_ERR, "password expire values could not be set\n");
#endif
};
/* I want to add a user completely with one easy command --chris */
#ifdef HAVE_QUOTAS
bzero (cmd, sizeof (cmd));
sprintf (cmd, "%s -p %s -u %s", EDQUOTA_PATH, QUOTA_DEFAULT, usrname);
printf ("%s\n", cmd);
if (system (cmd))
{
printf ("\nWarning: error setting quota\n");
#ifdef LOGGING
syslog (LOG_ERR, "warning: account created but NO quotas set!\n");
#endif /* LOGGING */
}
else
printf ("\nDefault quota set.\n");
#endif /* HAVE_QUOTAS */
bzero (cmd, sizeof (cmd));
sprintf (cmd, "%s %s", PASSWD_PATH, usrname);
if (system (cmd))
{
printf ("\nWarning: error setting password\n");
#ifdef LOGGING
syslog (LOG_ERR, "warning: password set failed!\n");
#endif
}
#ifdef IMMEDIATE_CHANGE
bzero (cmd, sizeof (cmd));
sprintf (cmd, "%s -e %s", PASSWD_PATH, usrname);
if (system (cmd))
{
printf ("\nWarning: error expiring password\n");
#ifdef LOGGING
syslog (LOG_ERR, "warning: password expire failed!\n");
#endif /* LOGGING */
}
#endif /* IMMEDIATE_CHANGE */
setuid (olduid);
#ifdef LOGGING
closelog ();
#endif
printf ("\nDone.\n");
}
void
safeget (char *buf, int maxlen)
{
int c, i = 0, bad = 0;
char *bstart = buf;
while ((c = getc (stdin)) != EOF && (c != '\n') && (++i < maxlen))
{
bad = (!isalnum (c) && (c != '_') && (c != ' '));
*(buf++) = c;
}
*buf = '\0';
if (bad)
{
printf ("\nString contained banned character. Please stick to alphanumerics.\n");
*bstart = '\0';
}
}
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