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+++ b/src/login.c
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+/*
+ * Copyright (c) 1989 - 1994, Julianne Frances Haugh
+ * Copyright (c) 1996 - 2001, Marek Michałkiewicz
+ * Copyright (c) 2001 - 2006, Tomasz Kłoczko
+ * Copyright (c) 2007 - 2012, Nicolas François
+ * 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. The name of the copyright holders or contributors may not be used to
+ * endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT
+ * HOLDERS 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>
+
+#ident "$Id$"
+
+#include <errno.h>
+#include <grp.h>
+#ifndef USE_PAM
+#include <lastlog.h>
+#endif /* !USE_PAM */
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <assert.h>
+#include "defines.h"
+#include "faillog.h"
+#include "failure.h"
+#include "getdef.h"
+#include "prototypes.h"
+#include "pwauth.h"
+/*@-exitarg@*/
+#include "exitcodes.h"
+
+#ifdef USE_PAM
+#include "pam_defs.h"
+
+static pam_handle_t *pamh = NULL;
+
+#define PAM_FAIL_CHECK if (retcode != PAM_SUCCESS) { \
+ fprintf(stderr,"\n%s\n",pam_strerror(pamh, retcode)); \
+ SYSLOG((LOG_ERR,"%s",pam_strerror(pamh, retcode))); \
+ (void) pam_end(pamh, retcode); \
+ exit(1); \
+ }
+#define PAM_END { retcode = pam_close_session(pamh,0); \
+ (void) pam_end(pamh,retcode); }
+
+#endif /* USE_PAM */
+
+#ifndef USE_PAM
+/*
+ * Needed for MkLinux DR1/2/2.1 - J.
+ */
+#ifndef LASTLOG_FILE
+#define LASTLOG_FILE "/var/log/lastlog"
+#endif
+#endif /* !USE_PAM */
+
+/*
+ * Global variables
+ */
+const char *Prog;
+
+static const char *hostname = "";
+static /*@null@*/ /*@only@*/char *username = NULL;
+static int reason = PW_LOGIN;
+
+#ifndef USE_PAM
+static struct lastlog ll;
+#endif /* !USE_PAM */
+static bool pflg = false;
+static bool fflg = false;
+
+#ifdef RLOGIN
+static bool rflg = false;
+#else /* RLOGIN */
+#define rflg false
+#endif /* !RLOGIN */
+static bool hflg = false;
+static bool preauth_flag = false;
+
+static bool amroot;
+static char tmsg[256];
+
+/*
+ * External identifiers.
+ */
+
+extern char **newenvp;
+extern size_t newenvc;
+extern char **environ;
+
+#ifndef ALARM
+#define ALARM 60
+#endif
+
+#ifndef RETRIES
+#define RETRIES 3
+#endif
+
+/* local function prototypes */
+static void usage (void);
+static void setup_tty (void);
+static void process_flags (int argc, char *const *argv);
+static /*@observer@*/const char *get_failent_user (/*@returned@*/const char *user);
+static void update_utmp (const char *user,
+ const char *tty,
+ const char *host,
+#ifdef USE_UTMPX
+ /*@null@*/const struct utmpx *utent
+#else
+ /*@null@*/const struct utmp *utent
+#endif
+ );
+
+#ifndef USE_PAM
+static struct faillog faillog;
+
+static void bad_time_notify (void);
+static void check_nologin (bool login_to_root);
+#else
+static void get_pam_user (char **ptr_pam_user);
+#endif
+
+static void init_env (void);
+static RETSIGTYPE alarm_handler (int);
+
+/*
+ * usage - print login command usage and exit
+ *
+ * login [ name ]
+ * login -r hostname (for rlogind)
+ * login -h hostname (for telnetd, etc.)
+ * login -f name (for pre-authenticated login: datakit, xterm, etc.)
+ */
+static void usage (void)
+{
+ fprintf (stderr, _("Usage: %s [-p] [name]\n"), Prog);
+ if (!amroot) {
+ exit (1);
+ }
+ fprintf (stderr, _(" %s [-p] [-h host] [-f name]\n"), Prog);
+#ifdef RLOGIN
+ fprintf (stderr, _(" %s [-p] -r host\n"), Prog);
+#endif /* RLOGIN */
+ exit (1);
+}
+
+static void setup_tty (void)
+{
+ TERMIO termio;
+
+ if (GTTY (0, &termio) == 0) { /* get terminal characteristics */
+ int erasechar;
+ int killchar;
+
+ /*
+ * Add your favorite terminal modes here ...
+ */
+ termio.c_lflag |= ISIG | ICANON | ECHO | ECHOE;
+ termio.c_iflag |= ICRNL;
+
+#if defined(ECHOKE) && defined(ECHOCTL)
+ termio.c_lflag |= ECHOKE | ECHOCTL;
+#endif
+#if defined(ECHOPRT) && defined(NOFLSH) && defined(TOSTOP)
+ termio.c_lflag &= ~(ECHOPRT | NOFLSH | TOSTOP);
+#endif
+#ifdef ONLCR
+ termio.c_oflag |= ONLCR;
+#endif
+
+ /* leave these values unchanged if not specified in login.defs */
+ erasechar = getdef_num ("ERASECHAR", (int) termio.c_cc[VERASE]);
+ killchar = getdef_num ("KILLCHAR", (int) termio.c_cc[VKILL]);
+ termio.c_cc[VERASE] = (cc_t) erasechar;
+ termio.c_cc[VKILL] = (cc_t) killchar;
+ /* Make sure the values were valid.
+ * getdef_num cannot validate this.
+ */
+ if (erasechar != (int) termio.c_cc[VERASE]) {
+ fprintf (stderr,
+ _("configuration error - cannot parse %s value: '%d'"),
+ "ERASECHAR", erasechar);
+ exit (1);
+ }
+ if (killchar != (int) termio.c_cc[VKILL]) {
+ fprintf (stderr,
+ _("configuration error - cannot parse %s value: '%d'"),
+ "KILLCHAR", killchar);
+ exit (1);
+ }
+
+ /*
+ * ttymon invocation prefers this, but these settings
+ * won't come into effect after the first username login
+ */
+ (void) STTY (0, &termio);
+ }
+}
+
+
+#ifndef USE_PAM
+/*
+ * Tell the user that this is not the right time to login at this tty
+ */
+static void bad_time_notify (void)
+{
+ (void) puts (_("Invalid login time"));
+ (void) fflush (stdout);
+}
+
+static void check_nologin (bool login_to_root)
+{
+ const char *fname;
+
+ /*
+ * Check to see if system is turned off for non-root users.
+ * This would be useful to prevent users from logging in
+ * during system maintenance. We make sure the message comes
+ * out for root so she knows to remove the file if she's
+ * forgotten about it ...
+ */
+ fname = getdef_str ("NOLOGINS_FILE");
+ if ((NULL != fname) && (access (fname, F_OK) == 0)) {
+ FILE *nlfp;
+
+ /*
+ * Cat the file if it can be opened, otherwise just
+ * print a default message
+ */
+ nlfp = fopen (fname, "r");
+ if (NULL != nlfp) {
+ int c;
+ while ((c = getc (nlfp)) != EOF) {
+ if (c == '\n') {
+ (void) putchar ('\r');
+ }
+
+ (void) putchar (c);
+ }
+ (void) fflush (stdout);
+ (void) fclose (nlfp);
+ } else {
+ (void) puts (_("\nSystem closed for routine maintenance"));
+ }
+ /*
+ * Non-root users must exit. Root gets the message, but
+ * gets to login.
+ */
+
+ if (!login_to_root) {
+ closelog ();
+ exit (0);
+ }
+ (void) puts (_("\n[Disconnect bypassed -- root login allowed.]"));
+ }
+}
+#endif /* !USE_PAM */
+
+static void process_flags (int argc, char *const *argv)
+{
+ int arg;
+ int flag;
+
+ /*
+ * Check the flags for proper form. Every argument starting with
+ * "-" must be exactly two characters long. This closes all the
+ * clever rlogin, telnet, and getty holes.
+ */
+ for (arg = 1; arg < argc; arg++) {
+ if (argv[arg][0] == '-' && strlen (argv[arg]) > 2) {
+ usage ();
+ }
+ if (strcmp(argv[arg], "--") == 0) {
+ break; /* stop checking on a "--" */
+ }
+ }
+
+ /*
+ * Process options.
+ */
+ while ((flag = getopt (argc, argv, "d:fh:pr:")) != EOF) {
+ switch (flag) {
+ case 'd':
+ /* "-d device" ignored for compatibility */
+ break;
+ case 'f':
+ fflg = true;
+ break;
+ case 'h':
+ hflg = true;
+ hostname = optarg;
+ reason = PW_TELNET;
+ break;
+#ifdef RLOGIN
+ case 'r':
+ rflg = true;
+ hostname = optarg;
+ reason = PW_RLOGIN;
+ break;
+#endif /* RLOGIN */
+ case 'p':
+ pflg = true;
+ break;
+ default:
+ usage ();
+ }
+ }
+
+#ifdef RLOGIN
+ /*
+ * Neither -h nor -f should be combined with -r.
+ */
+
+ if (rflg && (hflg || fflg)) {
+ usage ();
+ }
+#endif /* RLOGIN */
+
+ /*
+ * Allow authentication bypass only if real UID is zero.
+ */
+
+ if ((rflg || fflg || hflg) && !amroot) {
+ fprintf (stderr, _("%s: Permission denied.\n"), Prog);
+ exit (1);
+ }
+
+ /*
+ * Get the user name.
+ */
+ if (optind < argc) {
+ assert (NULL == username);
+ username = xstrdup (argv[optind]);
+ strzero (argv[optind]);
+ ++optind;
+ }
+
+#ifdef RLOGIN
+ if (rflg && (NULL != username)) {
+ usage ();
+ }
+#endif /* RLOGIN */
+ if (fflg && (NULL == username)) {
+ usage ();
+ }
+
+}
+
+
+static void init_env (void)
+{
+#ifndef USE_PAM
+ const char *cp;
+#endif
+ char *tmp;
+
+ tmp = getenv ("LANG");
+ if (NULL != tmp) {
+ addenv ("LANG", tmp);
+ }
+
+ /*
+ * Add the timezone environmental variable so that time functions
+ * work correctly.
+ */
+ tmp = getenv ("TZ");
+ if (NULL != tmp) {
+ addenv ("TZ", tmp);
+ }
+#ifndef USE_PAM
+ else {
+ cp = getdef_str ("ENV_TZ");
+ if (NULL != cp) {
+ addenv (('/' == *cp) ? tz (cp) : cp, NULL);
+ }
+ }
+#endif /* !USE_PAM */
+ /*
+ * Add the clock frequency so that profiling commands work
+ * correctly.
+ */
+ tmp = getenv ("HZ");
+ if (NULL != tmp) {
+ addenv ("HZ", tmp);
+ }
+#ifndef USE_PAM
+ else {
+ cp = getdef_str ("ENV_HZ");
+ if (NULL != cp) {
+ addenv (cp, NULL);
+ }
+ }
+#endif /* !USE_PAM */
+}
+
+
+static RETSIGTYPE alarm_handler (unused int sig)
+{
+ write (STDERR_FILENO, tmsg, strlen (tmsg));
+ _exit (0);
+}
+
+#ifdef USE_PAM
+/*
+ * get_pam_user - Get the username according to PAM
+ *
+ * ptr_pam_user shall point to a malloc'ed string (or NULL).
+ */
+static void get_pam_user (char **ptr_pam_user)
+{
+ int retcode;
+ void *ptr_user;
+
+ assert (NULL != ptr_pam_user);
+
+ retcode = pam_get_item (pamh, PAM_USER, (const void **)&ptr_user);
+ PAM_FAIL_CHECK;
+
+ if (NULL != *ptr_pam_user) {
+ free (*ptr_pam_user);
+ }
+ if (NULL != ptr_user) {
+ *ptr_pam_user = xstrdup ((const char *)ptr_user);
+ } else {
+ *ptr_pam_user = NULL;
+ }
+}
+#endif
+
+/*
+ * get_failent_user - Return a string that can be used to log failure
+ * from an user.
+ *
+ * This will be either the user argument, or "UNKNOWN".
+ *
+ * It is quite common to mistyped the password for username, and passwords
+ * should not be logged.
+ */
+static /*@observer@*/const char *get_failent_user (/*@returned@*/const char *user)
+{
+ const char *failent_user = "UNKNOWN";
+ bool log_unkfail_enab = getdef_bool("LOG_UNKFAIL_ENAB");
+
+ if ((NULL != user) && ('\0' != user[0])) {
+ if ( log_unkfail_enab
+ || (getpwnam (user) != NULL)) {
+ failent_user = user;
+ }
+ }
+
+ return failent_user;
+}
+
+/*
+ * update_utmp - Update or create an utmp entry in utmp, wtmp, utmpw, and
+ * wtmpx
+ *
+ * utent should be the utmp entry returned by get_current_utmp (or
+ * NULL).
+ */
+static void update_utmp (const char *user,
+ const char *tty,
+ const char *host,
+#ifdef USE_UTMPX
+ /*@null@*/const struct utmpx *utent
+#else
+ /*@null@*/const struct utmp *utent
+#endif
+ )
+{
+#ifdef USE_UTMPX
+ struct utmpx *utx = prepare_utmpx (user, tty, host, utent);
+#else
+ struct utmp *ut = prepare_utmp (user, tty, host, utent);
+#endif /* USE_UTMPX */
+
+#ifndef USE_UTMPX
+ (void) setutmp (ut); /* make entry in the utmp & wtmp files */
+ free (ut);
+#else
+ (void) setutmpx (utx); /* make entry in the utmpx & wtmpx files */
+ free (utx);
+#endif /* USE_UTMPX */
+}
+
+/*
+ * 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 subroot = false;
+#ifndef USE_PAM
+ bool is_console;
+#endif
+ int err;
+ unsigned int timeout;
+ const char *cp;
+ const char *tmp;
+ char fromhost[512];
+ struct passwd *pwd = NULL;
+ char **envp = environ;
+ const char *failent_user;
+#ifdef USE_UTMPX
+ /*@null@*/struct utmpx *utent;
+#else
+ /*@null@*/struct utmp *utent;
+#endif
+
+#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;
+#if defined(HAVE_STRUCT_UTMP_UT_HOST) || defined(USE_UTMPX)
+ } 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 */
+ timeout = getdef_unum ("LOGIN_TIMEOUT", ALARM);
+ snprintf (tmsg, sizeof tmsg,
+ _("\nLogin timed out after %u seconds.\n"), timeout);
+ (void) signal (SIGALRM, alarm_handler);
+ 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: "), hostn);
+ } else {
+ strncpy (loginprompt, _("login: "),
+ sizeof (loginprompt));
+ }
+
+ retcode = pam_set_item (pamh, PAM_USER_PROMPT, loginprompt);
+ PAM_FAIL_CHECK;
+
+ /* if we didn't get a user on the command line,
+ set it to NULL */
+ get_pam_user (&pam_user);
+ if ((NULL != pam_user) && ('\0' == pam_user[0])) {
+ retcode = pam_set_item (pamh, PAM_USER, NULL);
+ PAM_FAIL_CHECK;
+ }
+
+ /*
+ * There may be better ways to deal with some of
+ * these conditions, but at least this way I don't
+ * think we'll be giving away information. Perhaps
+ * someday we can trust that all PAM modules will
+ * pay attention to failure count and get rid of
+ * MAX_LOGIN_TRIES?
+ */
+ failcount = 0;
+ while (true) {
+ bool failed = false;
+
+ failcount++;
+#ifdef HAS_PAM_FAIL_DELAY
+ if (delay > 0) {
+ retcode = pam_fail_delay(pamh, 1000000*delay);
+ PAM_FAIL_CHECK;
+ }
+#endif
+
+ retcode = pam_authenticate (pamh, 0);
+
+ get_pam_user (&pam_user);
+ failent_user = get_failent_user (pam_user);
+
+ if (retcode == PAM_MAXTRIES) {
+ 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);
+ } 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 = xstrdup (pam_user);
+ failent_user = get_failent_user (username);
+
+ pwd = xgetpwnam (username);
+ if (NULL == pwd) {
+ SYSLOG ((LOG_ERR, "cannot find user %s", failent_user));
+ fprintf (stderr,
+ _("Cannot find user (%s)\n"),
+ username);
+ 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 */
+ bool failed;
+ /* 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: "), username, USER_NAME_MAX_LENGTH);
+
+ if ('\0' == username[0]) {
+ /* Prompt for a new login */
+ free (username);
+ username = NULL;
+ continue;
+ }
+ }
+ /* Get the username to be used to log failures */
+ failent_user = get_failent_user (username);
+
+ pwd = xgetpwnam (username);
+ if (NULL == pwd) {
+ preauth_flag = false;
+ failed = true;
+ } else {
+ user_passwd = pwd->pw_passwd;
+ /*
+ * If the encrypted password begins with a "!",
+ * 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 <ian@unsux.ns.ac.yu>. --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")
+ && pwd->pw_uid <= (uid_t) getdef_ulong ("LASTLOG_UID_MAX", 0xFFFFFFFFUL)) {
+ /* 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
+ * getxxyyy 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")
+ && pwd->pw_uid <= (uid_t) getdef_ulong ("LASTLOG_UID_MAX", 0xFFFFFFFFUL)
+ && (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);
+}
+