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deb-mbse/unix/mblogin.c

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/*****************************************************************************
*
* Purpose ...............: Login program for MBSE BBS.
* Shadow Suite (c) ......: Julianne Frances Haugh
*
*****************************************************************************
* Copyright (C) 1997-2012
*
* Michiel Broek FIDO: 2:280/2802
* Beekmansbos 10
* 1971 BV IJmuiden
* the Netherlands
*
* This file is part of MBSE BBS.
*
* This BBS is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* MBSE BBS is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MBSE BBS; see the file COPYING. If not, write to the Free
* Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*****************************************************************************/
#include "../config.h"
#include "mblogin.h"
#include "../lib/users.h"
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <syslog.h>
#include <pwd.h>
#include <grp.h>
#if defined(SHADOW_PASSWORD)
#include <shadow.h>
#endif
#if defined(__NetBSD__)
#undef HAVE_UTMPX_H
#endif
#if HAVE_UTMPX_H
#include <utmpx.h>
#endif
#include <utmp.h>
#include <signal.h>
#include <unistd.h>
#include <ctype.h>
#include "getdef.h"
#ifdef SVR4_SI86_EUA
#include <sys/proc.h>
#include <sys/sysi86.h>
#endif
#ifdef UT_ADDR
#include <netdb.h>
#endif
#include "env.h"
#include "chowntty.h"
#include "basename.h"
#include "shell.h"
#include "pwdcheck.h"
#include "pwauth.h"
#include "loginprompt.h"
#include "utmp.h"
#include "limits.h"
#include "setupenv.h"
#include "sub.h"
#include "log.h"
#include "setugid.h"
/*
* Login parameters
*/
#define LOGIN_DELAY 3
#define LOGIN_TIMEOUT 300
#define LOGIN_RETRIES 10
/*
* Needed for MkLinux DR1/2/2.1 - J.
*/
#ifndef LASTLOG_FILE
#define LASTLOG_FILE "/var/log/lastlog"
#endif
const char *hostname = "";
struct passwd pwent, *pw;
#if HAVE_UTMPX_H
struct utmpx utxent, failent;
struct utmp utent;
#else
struct utmp utent, failent;
#endif
struct lastlog lastlog;
static int preauth_flag = 0;
/*
* Global variables.
*/
static int hflg = 0;
static int pflg = 0;
static char *Prog;
static int amroot;
static int timeout;
/*
* External identifiers.
*/
extern char **newenvp;
extern size_t newenvc;
extern int optind;
extern char *optarg;
extern char **environ;
#ifndef ALARM
#define ALARM 60
#endif
#ifndef RETRIES
#define RETRIES 3
#endif
#define NO_SHADOW "no shadow password for `%s'%s\n"
#define BAD_PASSWD "invalid password for `%s'%s\n"
#define BAD_DIALUP "invalid dialup password for `%s' on `%s'\n"
#define BAD_ROOT_LOGIN "ILLEGAL ROOT LOGIN%s\n"
#define BAD_GROUP "user `%s' not in group bbs\n"
#define ROOT_LOGIN "ROOT LOGIN%s\n"
#define FAILURE_CNT "exceeded failure limit for `%s'%s\n"
#define REG_LOGIN "`%s' logged in%s\n"
#define LOGIN_REFUSED "LOGIN `%s' REFUSED%s\n"
#define REENABLED2 \
"login `%s' re-enabled after temporary lockout (%d failures).\n"
#define MANY_FAILS "REPEATED login failures%s\n"
/* local function prototypes */
static void usage(void);
static void setup_tty(void);
static void check_flags(int, char * const *);
static void check_nologin(void);
static void init_env(void);
static RETSIGTYPE alarm_handler(int);
int main(int, char **);
/*
* usage - print login command usage and exit
*
* login [ name ]
* login -a hostname (for NetBSD)
* 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);
exit(1);
}
static void setup_tty(void)
{
TERMIO termio;
GTTY(0, &termio); /* get terminal characteristics */
/*
* 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
#ifdef SUN4
/*
* Terminal setup for SunOS 4.1 courtesy of Steve Allen
* at UCO/Lick.
*/
termio.c_cc[VEOF] = '\04';
termio.c_cflag &= ~CSIZE;
termio.c_cflag |= (PARENB|CS7);
termio.c_lflag |= (ISIG|ICANON|ECHO|IEXTEN);
termio.c_iflag |= (BRKINT|IGNPAR|ISTRIP|IMAXBEL|ICRNL|IXON);
termio.c_iflag &= ~IXANY;
termio.c_oflag |= (XTABS|OPOST|ONLCR);
#endif
/* leave these values unchanged if not specified in login.defs */
termio.c_cc[VERASE] = getdef_num("ERASECHAR", termio.c_cc[VERASE]);
termio.c_cc[VKILL] = getdef_num("KILLCHAR", termio.c_cc[VKILL]);
/*
* ttymon invocation prefers this, but these settings won't come into
* effect after the first username login
*/
STTY(0, &termio);
}
static void check_flags(int argc, char * const *argv)
{
int arg;
/*
* 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();
}
}
static void check_nologin(void)
{
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 (access(fname, F_OK) == 0) {
FILE *nlfp;
int c;
/*
* Cat the file if it can be opened, otherwise just
* print a default message
*/
if ((nlfp = fopen (fname, "r"))) {
while ((c = getc (nlfp)) != EOF) {
if (c == '\n')
putchar ('\r');
putchar (c);
}
fflush (stdout);
fclose (nlfp);
} else
printf("\nSystem closed for routine maintenance\n");
free(fname);
closelog();
exit(0);
}
free(fname);
}
static void init_env(void)
{
char *cp, *tmp;
if ((tmp = getenv("LANG"))) {
addenv("LANG", tmp);
}
/*
* Add the timezone environmental variable so that time functions
* work correctly.
*/
if ((tmp = getenv("TZ"))) {
addenv("TZ", tmp);
}
/*
* Add the clock frequency so that profiling commands work
* correctly.
*/
if ((tmp = getenv("HZ"))) {
addenv("HZ", tmp);
} else if ((cp = getdef_str("ENV_HZ"))) {
addenv(cp, NULL);
}
}
static RETSIGTYPE alarm_handler(int sig)
{
fprintf(stderr, "\nLogin timed out after %d seconds.\n", timeout);
exit(0);
}
/*
* 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.
*/
int main(int argc, char **argv)
{
char username[37];
char tty[BUFSIZ];
char userfile[PATH_MAX];
FILE *ufp;
int reason = PW_LOGIN;
int delay;
int retries;
int failed;
int flag;
int subroot = 0;
int is_console = 0;
int FoundName;
const char *cp;
char *tmp;
char fromhost[512];
struct passwd *pwd;
char **envp = environ;
static char temp_pw[2];
static char temp_shell[] = "/bin/sh";
#ifdef SHADOW_PASSWORD
struct spwd *spwd=NULL;
#endif
#if defined(DES_RPC) || defined(KERBEROS)
/* from pwauth.c */
extern char *clear_pass;
extern int wipe_clear_pass;
/*
* We may need the password later, don't want pw_auth() to wipe it
* (we do it ourselves when it is no longer needed). --marekm
*/
wipe_clear_pass = 0;
#endif
/*
* Some quick initialization.
*/
sanitize_env();
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
initenv();
username[0] = '\0';
amroot = (getuid() == 0);
Prog = Basename(argv[0]);
check_flags(argc, argv);
while ((flag = getopt(argc, argv, "a:d:h:p")) != EOF) {
switch (flag) {
case 'p':
pflg++;
break;
#ifdef __NetBSD__
case 'a':
#endif
case 'h':
hflg++;
hostname = optarg;
reason = PW_TELNET;
break;
case 'd':
/* "-d device" ignored for compatibility */
break;
default:
usage();
}
}
/*
* Allow authentication bypass only if real UID is zero.
*/
if (hflg && !amroot) {
fprintf(stderr, _("%s: permission denied\n"), Prog);
exit(1);
}
if (!isatty(0) || !isatty(1) || !isatty(2))
exit(1); /* must be a terminal */
if (hflg) {
/*
* Only show this before a prompt from telnetd
*/
printf("\nMBSE BBS v%s (Release: %s)\n", VERSION, ReleaseDate);
printf("%s\n\n", COPYRIGHT);
}
/*
* 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
*/
checkutmp(!amroot);
STRFCPY(tty, utent.ut_line);
if (hflg) {
/*
* Add remote hostname to the environment. I think
* (not sure) I saw it once on Irix. --marekm
*/
addenv("REMOTEHOST", hostname);
}
#ifdef __linux__
/* workaround for init/getty leaving junk in ut_host at least in some
version of RedHat. --marekm */
else if (amroot)
memzero(utent.ut_host, sizeof utent.ut_host);
#endif
openlog("mblogin", LOG_PID|LOG_CONS|LOG_NOWAIT, LOG_AUTHPRIV);
setup_tty();
umask(getdef_num("UMASK", 007));
if (pflg)
while (*envp) /* add inherited environment, */
addenv(*envp++, NULL); /* some variables change later */
/* preserve TERM from getty */
if (!pflg && (tmp = getenv("TERM")))
addenv("TERM", tmp);
/* preserver CONNECT messages from mgetty */
if ((tmp = getenv("CONNECT")))
addenv("CONNECT", tmp);
if ((tmp = getenv("CALLER_ID")))
addenv("CALLER_ID", tmp);
/* get the mbse environment */
pw = getpwnam("mbse");
addenv("MBSE_ROOT", pw->pw_dir);
snprintf(userfile, PATH_MAX, "%s/etc/users.data", pw->pw_dir);
check_nologin();
init_env();
if (optind < argc) { /* get the user name */
#ifdef SVR4
/*
* The "-h" option can't be used with a command-line username,
* because telnetd invokes us as: login -h host TERM=...
*/
if (! hflg)
#endif
{
STRFCPY(username, argv[optind]);
strzero(argv[optind]);
++optind;
}
}
#ifdef SVR4
/*
* check whether ttymon has done the prompt for us already
*/
{
char *ttymon_prompt;
if ((ttymon_prompt = getenv("TTYPROMPT")) != NULL && (*ttymon_prompt != 0)) {
/* read name, without prompt */
login_prompt((char *)0, username, sizeof username);
}
}
#endif /* SVR4 */
if (optind < argc) /* now set command line variables */
set_env(argc - optind, &argv[optind]);
if (hflg)
cp = hostname;
else
#ifdef UT_HOST
if (utent.ut_host[0])
cp = utent.ut_host;
else
#endif
#if HAVE_UTMPX_H
if (utxent.ut_host[0])
cp = utxent.ut_host;
else
#endif
cp = "";
if (*cp)
snprintf(fromhost, sizeof fromhost, _(" on `%s' from `%s'"), tty, cp);
else
snprintf(fromhost, sizeof fromhost, _(" on `%s'"), tty);
top:
/* only allow ALARM sec. for login */
signal(SIGALRM, alarm_handler);
timeout = getdef_num("LOGIN_TIMEOUT", ALARM);
if (timeout > 0)
alarm(timeout);
environ = newenvp; /* make new environment active */
delay = getdef_num("FAIL_DELAY", 1);
retries = getdef_num("LOGIN_RETRIES", RETRIES);
while (1) { /* repeatedly get login/password pairs */
failed = 0; /* haven't failed authentication yet */
if (! username[0]) { /* need to get a login id */
if (subroot) {
closelog ();
exit (1);
}
preauth_flag = 0;
login_prompt(_("login: "), username, sizeof username);
continue;
}
/*
* Here we try usernames on unix names and Fidonet style
* names that are stored in the bbs userdatabase.
* The name "bbs" is for new users, don't check the bbs userfile.
* If allowed from login.defs accept the name "mbse".
*/
FoundName = 0;
if (strcmp(username, getdef_str("NEWUSER_ACCOUNT")) == 0) {
FoundName = 1;
}
if ((getdef_bool("ALLOW_MBSE") != 0) && (strcmp(username, "mbse") == 0)) {
FoundName = 1;
}
if (! FoundName) {
if ((ufp = fopen(userfile, "r"))) {
fread(&usrconfighdr, sizeof(usrconfighdr), 1, ufp);
while (fread(&usrconfig, usrconfighdr.recsize, 1, ufp) == 1) {
if ((strcasecmp(usrconfig.sUserName, username) == 0) ||
(strcasecmp(usrconfig.sHandle, username) == 0) ||
(strcmp(usrconfig.Name, username) == 0)) {
FoundName = 1;
STRFCPY(username, usrconfig.Name);
break;
}
}
fclose(ufp);
}
}
if (!FoundName) {
if (getdef_bool("ASK_NEWUSER") != 0) {
/*
* User entered none excisting name, offer him/her the choice
* to register as a new user.
*/
login_prompt(_("Do you want to register as new user? [y/N]: "), username, sizeof username);
if ((username[0] && (toupper(username[0]) == 'Y'))) {
FoundName = 1;
preauth_flag = 0;
STRFCPY(username, getdef_str("NEWUSER_ACCOUNT"));
syslog(LOG_WARNING, "unknown user wants to register");
}
}
}
if ((! (pwd = getpwnam(username))) || (FoundName == 0)) {
pwent.pw_name = username;
strcpy(temp_pw, "!");
pwent.pw_passwd = temp_pw;
pwent.pw_shell = temp_shell;
preauth_flag = 0;
failed = 1;
} else {
pwent = *pwd;
}
#ifdef SHADOW_PASSWORD
spwd = NULL;
if (pwd && strcmp(pwd->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
spwd = getspnam(username);
if (spwd)
pwent.pw_passwd = spwd->sp_pwdp;
else
syslog(LOG_WARNING, NO_SHADOW, username, fromhost);
}
#endif /* SHADOWPWD */
/*
* If the encrypted password begins with a "!", the account
* is locked and the user cannot login, even if they have
* been "pre-authenticated."
*/
if (pwent.pw_passwd[0] == '!' || pwent.pw_passwd[0] == '*')
failed = 1;
/*
* 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(pwent.pw_passwd, username, reason, (char *) 0) == 0)
goto auth_ok;
/*
* Don't log unknown usernames - I mistyped the password for
* username at least once... Should probably use LOG_AUTHPRIV
* for those who really want to log them. --marekm
*/
syslog(LOG_WARNING, BAD_PASSWD, (pwd || getdef_bool("LOG_UNKFAIL_ENAB")) ? username : "UNKNOWN", fromhost);
failed = 1;
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 defined(RADIUS) && !(defined(DES_RPC) || defined(KERBEROS))
if (clear_pass) {
strzero(clear_pass);
clear_pass = NULL;
}
#endif
if (! failed && pwent.pw_name && pwent.pw_uid == 0 && ! is_console) {
syslog(LOG_CRIT, BAD_ROOT_LOGIN, fromhost);
failed = 1;
}
#ifdef LOGIN_ACCESS
if (!failed && !login_access(username, *hostname ? hostname : tty)) {
syslog(LOG_WARNING, LOGIN_REFUSED, username, fromhost);
failed = 1;
}
#endif
if (! failed)
break;
memzero(username, sizeof username);
if (--retries <= 0)
syslog(LOG_CRIT, MANY_FAILS, fromhost);
#if 1
/*
* 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 (pwent.pw_passwd[0] == '\0')
pw_auth("!", username, reason, (char *) 0);
#endif
/*
* 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)
sleep(delay);
puts(_("Login incorrect"));
} /* while (1) */
(void) alarm (0); /* turn off alarm clock */
if (getenv("IFS")) /* don't export user IFS ... */
addenv("IFS= \t\n", NULL); /* ... instead, set a safe IFS */
setutmp(username, tty, hostname); /* make entry in utmp & wtmp files */
if (pwent.pw_shell[0] == '*') { /* subsystem root */
subsystem (&pwent); /* figure out what to execute */
subroot++; /* say i was here again */
endpwent (); /* close all of the file which were */
endgrent (); /* open in the original rooted file */
#ifdef SHADOW_PASSWORD
endspent (); /* system. they will be re-opened */
#endif
#ifdef SHADOWGRP
endsgent (); /* in the new rooted file system */
#endif
goto top; /* go do all this all over again */
}
if (getdef_bool("LASTLOG_ENAB")) /* give last login and log this one */
dolastlog(&lastlog, &pwent, utent.ut_line, hostname);
#ifdef SVR4_SI86_EUA
sysi86(SI86LIMUSER, EUA_ADD_USER); /* how do we test for fail? */
#endif
#ifdef AGING
/*
* Have to do this while we still have root privileges, otherwise
* we don't have access to /etc/shadow. expire() closes password
* files, and changes to the user in the child before executing
* the passwd program. --marekm
*/
#ifdef SHADOW_PASSWORD
if (spwd) { /* check for age of password */
if (expire (&pwent, spwd)) {
pwd = getpwnam(username);
spwd = getspnam(username);
if (pwd)
pwent = *pwd;
}
}
#else
#ifdef ATT_AGE
if (pwent.pw_age && pwent.pw_age[0]) {
if (expire (&pwent)) {
pwd = getpwnam(username);
if (pwd)
pwent = *pwd;
}
}
#endif /* ATT_AGE */
#endif /* SHADOWPWD */
#endif /* AGING */
setup_limits(&pwent); /* nice, ulimit etc. */
chown_tty(tty, &pwent);
if (setup_uid_gid(&pwent, is_console))
exit(1);
#ifdef KERBEROS
if (clear_pass)
login_kerberos(username, clear_pass);
#endif
#ifdef DES_RPC
if (clear_pass)
login_desrpc(clear_pass);
#endif
#if defined(DES_RPC) || defined(KERBEROS)
if (clear_pass)
strzero(clear_pass);
#endif
setup_env(&pwent); /* set env vars, cd to the home dir */
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
addenv("HUSHLOGIN=TRUE", NULL);
signal(SIGQUIT, SIG_DFL); /* default quit signal */
signal(SIGTERM, SIG_DFL); /* default terminate signal */
signal(SIGALRM, SIG_DFL); /* default alarm signal */
signal(SIGHUP, SIG_DFL); /* added this. --marekm */
signal(SIGINT, SIG_DFL); /* default interrupt signal */
endpwent(); /* stop access to password file */
endgrent(); /* stop access to group file */
#ifdef SHADOW_PASSWORD
endspent(); /* stop access to shadow passwd file */
#endif
#ifdef SHADOWGRP
endsgent(); /* stop access to shadow group file */
#endif
if (pwent.pw_uid == 0)
syslog(LOG_WARNING, ROOT_LOGIN, fromhost);
else
syslog(LOG_WARNING, REG_LOGIN, username, fromhost);
closelog();
shell (pwent.pw_shell, (char *) 0); /* exec the shell finally. */
/*NOTREACHED*/
return 0;
}
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