/*
* login - create a new login session for a user
*
* login is typically called by getty as the second step of a
* new user session. getty is responsible for setting the line
* characteristics to a reasonable set of values and getting
* the name of the user to be logged in. login may also be
* called to create a new user session on a pty for a variety
* of reasons, such as X servers or network logins.
*
* the flags which login supports are
*
* -p - preserve the environment
* -r - perform autologin protocol for rlogin
* -f - do not perform authentication, user is preauthenticated
* -h - the name of the remote host
*/
int main (int argc, char **argv)
{
const char *tmptty;
char tty[BUFSIZ];
#ifdef RLOGIN
char term[128] = "";
#endif /* RLOGIN */
#if defined(HAVE_STRFTIME) && !defined(USE_PAM)
char ptime[80];
#endif
unsigned int delay;
unsigned int retries;
bool failed;
bool subroot = false;
#ifndef USE_PAM
bool is_console;
#endif
int err;
const char *cp;
char *tmp;
char fromhost[512];
struct passwd *pwd = NULL;
char **envp = environ;
const char *failent_user;
/*@null@*/struct utmp *utent;
#ifdef USE_PAM
int retcode;
pid_t child;
char *pam_user = NULL;
#else
struct spwd *spwd = NULL;
#endif
/*
* Some quick initialization.
*/
sanitize_env ();
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
initenv ();
amroot = (getuid () == 0);
Prog = Basename (argv[0]);
if (geteuid() != 0) {
fprintf (stderr, _("%s: Cannot possibly work without effective root\n"), Prog);
exit (1);
}
process_flags (argc, argv);
if ((isatty (0) == 0) || (isatty (1) == 0) || (isatty (2) == 0)) {
exit (1); /* must be a terminal */
}
utent = get_current_utmp ();
/*
* Be picky if run by normal users (possible if installed setuid
* root), but not if run by root. This way it still allows logins
* even if your getty is broken, or if something corrupts utmp,
* but users must "exec login" which will use the existing utmp
* entry (will not overwrite remote hostname). --marekm
*/
if (!amroot && (NULL == utent)) {
(void) puts (_("No utmp entry. You must exec \"login\" from the lowest level \"sh\""));
exit (1);
}
/* NOTE: utent might be NULL afterwards */
tmptty = ttyname (0);
if (NULL == tmptty) {
tmptty = "UNKNOWN";
}
STRFCPY (tty, tmptty);
#ifndef USE_PAM
is_console = console (tty);
#endif
if (rflg || hflg) {
/*
* Add remote hostname to the environment. I think
* (not sure) I saw it once on Irix. --marekm
*/
addenv ("REMOTEHOST", hostname);
}
if (fflg) {
preauth_flag = true;
}
if (hflg) {
reason = PW_RLOGIN;
}
#ifdef RLOGIN
if (rflg) {
assert (NULL == username);
username = xmalloc (USER_NAME_MAX_LENGTH + 1);
username[USER_NAME_MAX_LENGTH] = '\0';
if (do_rlogin (hostname, username, USER_NAME_MAX_LENGTH, term, sizeof term)) {
preauth_flag = true;
} else {
free (username);
username = NULL;
}
}
#endif /* RLOGIN */
OPENLOG ("login");
setup_tty ();
#ifndef USE_PAM
(void) umask (getdef_num ("UMASK", GETDEF_DEFAULT_UMASK));
{
/*
* Use the ULIMIT in the login.defs file, and if
* there isn't one, use the default value. The
* user may have one for themselves, but otherwise,
* just take what you get.
*/
long limit = getdef_long ("ULIMIT", -1L);
if (limit != -1) {
set_filesize_limit (limit);
}
}
#endif
/*
* The entire environment will be preserved if the -p flag
* is used.
*/
if (pflg) {
while (NULL != *envp) { /* add inherited environment, */
addenv (*envp, NULL); /* some variables change later */
envp++;
}
}
#ifdef RLOGIN
if (term[0] != '\0') {
addenv ("TERM", term);
} else
#endif /* RLOGIN */
{
/* preserve TERM from getty */
if (!pflg) {
tmp = getenv ("TERM");
if (NULL != tmp) {
addenv ("TERM", tmp);
}
}
}
init_env ();
if (optind < argc) { /* now set command line variables */
set_env (argc - optind, &argv[optind]);
}
if (rflg || hflg) {
cp = hostname;
#ifdef HAVE_STRUCT_UTMP_UT_HOST
} else if ((NULL != utent) && ('\0' != utent->ut_host[0])) {
cp = utent->ut_host;
#endif /* HAVE_STRUCT_UTMP_UT_HOST */
} else {
cp = "";
}
if ('\0' != *cp) {
snprintf (fromhost, sizeof fromhost,
" on '%.100s' from '%.200s'", tty, cp);
} else {
snprintf (fromhost, sizeof fromhost,
" on '%.100s'", tty);
}
top:
/* only allow ALARM sec. for login */
(void) signal (SIGALRM, alarm_handler);
timeout = getdef_unum ("LOGIN_TIMEOUT", ALARM);
if (timeout > 0) {
(void) alarm (timeout);
}
environ = newenvp; /* make new environment active */
delay = getdef_unum ("FAIL_DELAY", 1);
retries = getdef_unum ("LOGIN_RETRIES", RETRIES);
#ifdef USE_PAM
retcode = pam_start ("login", username, &conv, &pamh);
if (retcode != PAM_SUCCESS) {
fprintf (stderr,
_("login: PAM Failure, aborting: %s\n"),
pam_strerror (pamh, retcode));
SYSLOG ((LOG_ERR, "Couldn't initialize PAM: %s",
pam_strerror (pamh, retcode)));
exit (99);
}
/*
* hostname & tty are either set to NULL or their correct values,
* depending on how much we know. We also set PAM's fail delay to
* ours.
*
* PAM_RHOST and PAM_TTY are used for authentication, only use
* information coming from login or from the caller (e.g. no utmp)
*/
retcode = pam_set_item (pamh, PAM_RHOST, hostname);
PAM_FAIL_CHECK;
retcode = pam_set_item (pamh, PAM_TTY, tty);
PAM_FAIL_CHECK;
#ifdef HAS_PAM_FAIL_DELAY
retcode = pam_fail_delay (pamh, 1000000 * delay);
PAM_FAIL_CHECK;
#endif
/* if fflg, then the user has already been authenticated */
if (!fflg) {
unsigned int failcount = 0;
char hostn[256];
char loginprompt[256]; /* That's one hell of a prompt :) */
/* Make the login prompt look like we want it */
if (gethostname (hostn, sizeof (hostn)) == 0) {
snprintf (loginprompt,
sizeof (loginprompt),
_("%s login: "******"login: "******"TOO MANY LOGIN TRIES (%u)%s FOR '%s'",
failcount, fromhost, failent_user));
fprintf(stderr,
_("Maximum number of tries exceeded (%u)\n"),
failcount);
PAM_END;
exit(0);
} else if (retcode == PAM_ABORT) {
/* Serious problems, quit now */
(void) fputs (_("login: abort requested by PAM\n"), stderr);
SYSLOG ((LOG_ERR,"PAM_ABORT returned from pam_authenticate()"));
PAM_END;
exit(99);
} else if (retcode != PAM_SUCCESS) {
SYSLOG ((LOG_NOTICE,"FAILED LOGIN (%u)%s FOR '%s', %s",
failcount, fromhost, failent_user,
pam_strerror (pamh, retcode)));
failed = true;
}
if (!failed) {
break;
}
#ifdef WITH_AUDIT
audit_fd = audit_open ();
audit_log_acct_message (audit_fd,
AUDIT_USER_LOGIN,
NULL, /* Prog. name */
"login",
failent_user,
AUDIT_NO_ID,
hostname,
NULL, /* addr */
tty,
0); /* result */
close (audit_fd);
#endif /* WITH_AUDIT */
(void) puts ("");
(void) puts (_("Login incorrect"));
if (failcount >= retries) {
SYSLOG ((LOG_NOTICE,
"TOO MANY LOGIN TRIES (%u)%s FOR '%s'",
failcount, fromhost, failent_user));
fprintf(stderr,
_("Maximum number of tries exceeded (%u)\n"),
failcount);
PAM_END;
exit(0);
}
/*
* Let's give it another go around.
* Even if a username was given on the command
* line, prompt again for the username.
*/
retcode = pam_set_item (pamh, PAM_USER, NULL);
PAM_FAIL_CHECK;
}
/* We don't get here unless they were authenticated above */
(void) alarm (0);
}
/* Check the account validity */
retcode = pam_acct_mgmt (pamh, 0);
if (retcode == PAM_NEW_AUTHTOK_REQD) {
retcode = pam_chauthtok (pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
}
PAM_FAIL_CHECK;
/* Open the PAM session */
get_pam_user (&pam_user);
retcode = pam_open_session (pamh, hushed (pam_user) ? PAM_SILENT : 0);
PAM_FAIL_CHECK;
/* Grab the user information out of the password file for future usage
* First get the username that we are actually using, though.
*
* From now on, we will discard changes of the user (PAM_USER) by
* PAM APIs.
*/
get_pam_user (&pam_user);
if (NULL != username) {
free (username);
}
username = pam_user;
failent_user = get_failent_user (username);
pwd = xgetpwnam (username);
if (NULL == pwd) {
SYSLOG ((LOG_ERR, "cannot find user %s", failent_user));
exit (1);
}
/* This set up the process credential (group) and initialize the
* supplementary group access list.
* This has to be done before pam_setcred
*/
if (setup_groups (pwd) != 0) {
exit (1);
}
retcode = pam_setcred (pamh, PAM_ESTABLISH_CRED);
PAM_FAIL_CHECK;
/* NOTE: If pam_setcred changes PAM_USER, this will not be taken
* into account.
*/
#else /* ! USE_PAM */
while (true) { /* repeatedly get login/password pairs */
/* user_passwd is always a pointer to this constant string
* or a passwd or shadow password that will be memzero by
* pw_free / spw_free.
* Do not free() user_passwd. */
const char *user_passwd = "!";
/* Do some cleanup to avoid keeping entries we do not need
* anymore. */
if (NULL != pwd) {
pw_free (pwd);
pwd = NULL;
}
if (NULL != spwd) {
spw_free (spwd);
spwd = NULL;
}
failed = false; /* haven't failed authentication yet */
if (NULL == username) { /* need to get a login id */
if (subroot) {
closelog ();
exit (1);
}
preauth_flag = false;
username = xmalloc (USER_NAME_MAX_LENGTH + 1);
username[USER_NAME_MAX_LENGTH] = '\0';
login_prompt (_("\n%s login: "******"!",
* the account is locked and the user cannot
* login, even if they have been
* "pre-authenticated."
*/
if ( ('!' == user_passwd[0])
|| ('*' == user_passwd[0])) {
failed = true;
}
}
if (strcmp (user_passwd, SHADOW_PASSWD_STRING) == 0) {
spwd = xgetspnam (username);
if (NULL != spwd) {
user_passwd = spwd->sp_pwdp;
} else {
/* The user exists in passwd, but not in
* shadow. SHADOW_PASSWD_STRING indicates
* that the password shall be in shadow.
*/
SYSLOG ((LOG_WARN,
"no shadow password for '%s'%s",
username, fromhost));
}
}
/*
* The -r and -f flags provide a name which has already
* been authenticated by some server.
*/
if (preauth_flag) {
goto auth_ok;
}
if (pw_auth (user_passwd, username, reason, (char *) 0) == 0) {
goto auth_ok;
}
SYSLOG ((LOG_WARN, "invalid password for '%s' %s",
failent_user, fromhost));
failed = true;
auth_ok:
/*
* This is the point where all authenticated users wind up.
* If you reach this far, your password has been
* authenticated and so on.
*/
if ( !failed
&& (NULL != pwd)
&& (0 == pwd->pw_uid)
&& !is_console) {
SYSLOG ((LOG_CRIT, "ILLEGAL ROOT LOGIN %s", fromhost));
failed = true;
}
if ( !failed
&& !login_access (username, ('\0' != *hostname) ? hostname : tty)) {
SYSLOG ((LOG_WARN, "LOGIN '%s' REFUSED %s",
username, fromhost));
failed = true;
}
if ( (NULL != pwd)
&& getdef_bool ("FAILLOG_ENAB")
&& !failcheck (pwd->pw_uid, &faillog, failed)) {
SYSLOG ((LOG_CRIT,
"exceeded failure limit for '%s' %s",
username, fromhost));
failed = true;
}
if (!failed) {
break;
}
/* don't log non-existent users */
if ((NULL != pwd) && getdef_bool ("FAILLOG_ENAB")) {
failure (pwd->pw_uid, tty, &faillog);
}
if (getdef_str ("FTMP_FILE") != NULL) {
#ifdef USE_UTMPX
struct utmpx *failent =
prepare_utmpx (failent_user,
tty,
/* FIXME: or fromhost? */hostname,
utent);
#else /* !USE_UTMPX */
struct utmp *failent =
prepare_utmp (failent_user,
tty,
hostname,
utent);
#endif /* !USE_UTMPX */
failtmp (failent_user, failent);
free (failent);
}
retries--;
if (retries <= 0) {
SYSLOG ((LOG_CRIT, "REPEATED login failures%s",
fromhost));
}
/*
* If this was a passwordless account and we get here, login
* was denied (securetty, faillog, etc.). There was no
* password prompt, so do it now (will always fail - the bad
* guys won't see that the passwordless account exists at
* all). --marekm
*/
if (user_passwd[0] == '\0') {
pw_auth ("!", username, reason, (char *) 0);
}
/*
* Authentication of this user failed.
* The username must be confirmed in the next try.
*/
free (username);
username = NULL;
/*
* Wait a while (a la SVR4 /usr/bin/login) before attempting
* to login the user again. If the earlier alarm occurs
* before the sleep() below completes, login will exit.
*/
if (delay > 0) {
(void) sleep (delay);
}
(void) puts (_("Login incorrect"));
/* allow only one attempt with -r or -f */
if (rflg || fflg || (retries <= 0)) {
closelog ();
exit (1);
}
} /* while (true) */
#endif /* ! USE_PAM */
assert (NULL != username);
assert (NULL != pwd);
(void) alarm (0); /* turn off alarm clock */
#ifndef USE_PAM /* PAM does this */
/*
* porttime checks moved here, after the user has been
* authenticated. now prints a message, as suggested
* by Ivan Nejgebauer <*****@*****.**>. --marekm
*/
if ( getdef_bool ("PORTTIME_CHECKS_ENAB")
&& !isttytime (username, tty, time ((time_t *) 0))) {
SYSLOG ((LOG_WARN, "invalid login time for '%s'%s",
username, fromhost));
closelog ();
bad_time_notify ();
exit (1);
}
check_nologin (pwd->pw_uid == 0);
#endif
if (getenv ("IFS")) { /* don't export user IFS ... */
addenv ("IFS= \t\n", NULL); /* ... instead, set a safe IFS */
}
if (pwd->pw_shell[0] == '*') { /* subsystem root */
pwd->pw_shell++; /* skip the '*' */
subsystem (pwd); /* figure out what to execute */
subroot = true; /* say I was here again */
endpwent (); /* close all of the file which were */
endgrent (); /* open in the original rooted file */
endspent (); /* system. they will be re-opened */
#ifdef SHADOWGRP
endsgent (); /* in the new rooted file system */
#endif
goto top; /* go do all this all over again */
}
#ifdef WITH_AUDIT
audit_fd = audit_open ();
audit_log_acct_message (audit_fd,
AUDIT_USER_LOGIN,
NULL, /* Prog. name */
"login",
username,
AUDIT_NO_ID,
hostname,
NULL, /* addr */
tty,
1); /* result */
close (audit_fd);
#endif /* WITH_AUDIT */
#ifndef USE_PAM /* pam_lastlog handles this */
if (getdef_bool ("LASTLOG_ENAB")) { /* give last login and log this one */
dolastlog (&ll, pwd, tty, hostname);
}
#endif
#ifndef USE_PAM /* PAM handles this as well */
/*
* Have to do this while we still have root privileges, otherwise we
* don't have access to /etc/shadow.
*/
if (NULL != spwd) { /* check for age of password */
if (expire (pwd, spwd)) {
/* The user updated her password, get the new
* entries.
* Use the x variants because we need to keep the
* entry for a long time, and there might be other
* getxxyy in between.
*/
pw_free (pwd);
pwd = xgetpwnam (username);
if (NULL == pwd) {
SYSLOG ((LOG_ERR,
"cannot find user %s after update of expired password",
username));
exit (1);
}
spw_free (spwd);
spwd = xgetspnam (username);
}
}
setup_limits (pwd); /* nice, ulimit etc. */
#endif /* ! USE_PAM */
chown_tty (pwd);
#ifdef USE_PAM
/*
* We must fork before setuid() because we need to call
* pam_close_session() as root.
*/
(void) signal (SIGINT, SIG_IGN);
child = fork ();
if (child < 0) {
/* error in fork() */
fprintf (stderr, _("%s: failure forking: %s"),
Prog, strerror (errno));
PAM_END;
exit (0);
} else if (child != 0) {
/*
* parent - wait for child to finish, then cleanup
* session
*/
wait (NULL);
PAM_END;
exit (0);
}
/* child */
#endif
/* If we were init, we need to start a new session */
if (getppid() == 1) {
setsid();
if (ioctl(0, TIOCSCTTY, 1) != 0) {
fprintf (stderr, _("TIOCSCTTY failed on %s"), tty);
}
}
/*
* The utmp entry needs to be updated to indicate the new status
* of the session, the new PID and SID.
*/
update_utmp (username, tty, hostname, utent);
/* The pwd and spwd entries for the user have been copied.
*
* Close all the files so that unauthorized access won't occur.
*/
endpwent (); /* stop access to password file */
endgrent (); /* stop access to group file */
endspent (); /* stop access to shadow passwd file */
#ifdef SHADOWGRP
endsgent (); /* stop access to shadow group file */
#endif
/* Drop root privileges */
#ifndef USE_PAM
if (setup_uid_gid (pwd, is_console))
#else
/* The group privileges were already dropped.
* See setup_groups() above.
*/
if (change_uid (pwd))
#endif
{
exit (1);
}
setup_env (pwd); /* set env vars, cd to the home dir */
#ifdef USE_PAM
{
const char *const *env;
env = (const char *const *) pam_getenvlist (pamh);
while ((NULL != env) && (NULL != *env)) {
addenv (*env, NULL);
env++;
}
}
#endif
(void) setlocale (LC_ALL, "");
(void) bindtextdomain (PACKAGE, LOCALEDIR);
(void) textdomain (PACKAGE);
if (!hushed (username)) {
addenv ("HUSHLOGIN=FALSE", NULL);
/*
* pam_unix, pam_mail and pam_lastlog should take care of
* this
*/
#ifndef USE_PAM
motd (); /* print the message of the day */
if ( getdef_bool ("FAILLOG_ENAB")
&& (0 != faillog.fail_cnt)) {
failprint (&faillog);
/* Reset the lockout times if logged in */
if ( (0 != faillog.fail_max)
&& (faillog.fail_cnt >= faillog.fail_max)) {
(void) puts (_("Warning: login re-enabled after temporary lockout."));
SYSLOG ((LOG_WARN,
"login '%s' re-enabled after temporary lockout (%d failures)",
username, (int) faillog.fail_cnt));
}
}
if ( getdef_bool ("LASTLOG_ENAB")
&& (ll.ll_time != 0)) {
time_t ll_time = ll.ll_time;
#ifdef HAVE_STRFTIME
(void) strftime (ptime, sizeof (ptime),
"%a %b %e %H:%M:%S %z %Y",
localtime (&ll_time));
printf (_("Last login: %s on %s"),
ptime, ll.ll_line);
#else
printf (_("Last login: %.19s on %s"),
ctime (&ll_time), ll.ll_line);
#endif
#ifdef HAVE_LL_HOST /* __linux__ || SUN4 */
if ('\0' != ll.ll_host[0]) {
printf (_(" from %.*s"),
(int) sizeof ll.ll_host, ll.ll_host);
}
#endif
printf (".\n");
}
agecheck (spwd);
mailcheck (); /* report on the status of mail */
#endif /* !USE_PAM */
} else {
addenv ("HUSHLOGIN=TRUE", NULL);
}
ttytype (tty);
(void) signal (SIGQUIT, SIG_DFL); /* default quit signal */
(void) signal (SIGTERM, SIG_DFL); /* default terminate signal */
(void) signal (SIGALRM, SIG_DFL); /* default alarm signal */
(void) signal (SIGHUP, SIG_DFL); /* added this. --marekm */
(void) signal (SIGINT, SIG_DFL); /* default interrupt signal */
if (0 == pwd->pw_uid) {
SYSLOG ((LOG_NOTICE, "ROOT LOGIN %s", fromhost));
} else if (getdef_bool ("LOG_OK_LOGINS")) {
SYSLOG ((LOG_INFO, "'%s' logged in %s", username, fromhost));
}
closelog ();
tmp = getdef_str ("FAKE_SHELL");
if (NULL != tmp) {
err = shell (tmp, pwd->pw_shell, newenvp); /* fake shell */
} else {
/* exec the shell finally */
err = shell (pwd->pw_shell, (char *) 0, newenvp);
}
return ((err == ENOENT) ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
}
static void
update_user(void)
{
#if defined(AUTH_METHODS) || defined(NDBM)
struct passwd *pwd;
#endif
#ifdef AUTH_METHODS
#ifdef SHADOWPWD
struct spwd *spwd;
if (is_shadow_pwd && (spwd = spw_locate (user_name)) &&
spwd->sp_pwdp[0] == '@') {
if (pw_auth (spwd->sp_pwdp + 1, user_name, PW_DELETE, (char *) 0)) {
SYSLOG((LOG_ERR,
"failed deleting auth `%s' for user `%s'\n",
spwd->sp_pwdp + 1, user_name));
fprintf(stderr,
_("%s: error deleting authentication\n"),
Prog);
} else {
SYSLOG((LOG_INFO,
"delete auth `%s' for user `%s'\n",
spwd->sp_pwdp + 1, user_name));
}
}
#endif /* SHADOWPWD */
if ((pwd = pw_locate(user_name)) && pwd->pw_passwd[0] == '@') {
if (pw_auth(pwd->pw_passwd + 1, user_name, PW_DELETE, (char *) 0)) {
SYSLOG((LOG_ERR,
"failed deleting auth `%s' for user `%s'\n",
pwd->pw_passwd + 1, user_name));
fprintf(stderr,
_("%s: error deleting authentication\n"),
Prog);
} else {
SYSLOG((LOG_INFO, "delete auth `%s' for user `%s'\n",
pwd->pw_passwd + 1, user_name);
}
}
#endif /* AUTH_METHODS */
if (!pw_remove(user_name))
fprintf(stderr, _("%s: error deleting password entry\n"), Prog);
#ifdef SHADOWPWD
if (is_shadow_pwd && ! spw_remove (user_name))
fprintf(stderr, _("%s: error deleting shadow password entry\n"),
Prog);
#endif
#ifdef HAVE_TCFS
if (tcfs_locate (user_name)) {
if (!tcfs_remove (user_name)) {
SYSLOG((LOG_ERR,
"failed deleting TCFS entry for user `%s'\n",
user_name));
fprintf(stderr, _("%s: error deleting TCFS entry\n"),
Prog);
} else {
SYSLOG((LOG_INFO,
"delete TCFS entry for user `%s'\n",
user_name));
}
}
#endif /* HAVE_TCFS */
#ifdef NDBM
if (pw_dbm_present()) {
if ((pwd = getpwnam (user_name)) && ! pw_dbm_remove (pwd))
fprintf(stderr,
_("%s: error deleting password dbm entry\n"),
Prog);
}
/*
* If the user's UID is a duplicate the duplicated entry needs
* to be updated so that a UID match can be found in the DBM
* files.
*/
for (pw_rewind (), pwd = pw_next ();pwd;pwd = pw_next ()) {
if (pwd->pw_uid == user_id) {
pw_dbm_update (pwd);
break;
}
}
#ifdef SHADOWPWD
if (is_shadow_pwd && sp_dbm_present() && !sp_dbm_remove(user_name))
fprintf(stderr,
_("%s: error deleting shadow passwd dbm entry\n"),
Prog);
endspent ();
#endif
endpwent ();
#endif /* NDBM */
SYSLOG((LOG_INFO, "delete user `%s'\n", user_name));
}