void
auth_checknologin(login_cap_t *lc)
{
const char *file;
/* Do we ignore a nologin file? */
if (login_getcapbool(lc, "ignorenologin", 0))
return;
/* Note that <file> will be "" if there is no nologin capability */
if ((file = login_getcapstr(lc, "nologin", "", NULL)) == NULL)
exit(1);
/*
* *file is true IFF there was a "nologin" capability
* Note that auth_cat() returns 1 only if the specified
* file exists, and is readable. E.g., /.nologin exists.
*/
if ((*file && auth_cat(file)) || auth_cat(_PATH_NOLOGIN))
exit(1);
}
int
main(int argc, char *argv[])
{
char *domain, *p, *ttyn, *shell, *fullname, *instance;
char *lipaddr, *script, *ripaddr, *style, *type, *fqdn;
char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
char localhost[MAXHOSTNAMELEN], *copyright;
char mail[sizeof(_PATH_MAILDIR) + 1 + NAME_MAX];
int ask, ch, cnt, fflag, pflag, quietlog, rootlogin, lastchance;
int error, homeless, needto, authok, tries, backoff;
struct addrinfo *ai, hints;
struct rlimit cds, scds;
quad_t expire, warning;
struct utmp utmp;
struct group *gr;
struct stat st;
uid_t uid;
openlog("login", LOG_ODELAY, LOG_AUTH);
fqdn = lipaddr = ripaddr = fullname = type = NULL;
authok = 0;
tries = 10;
backoff = 3;
domain = NULL;
if (gethostname(localhost, sizeof(localhost)) < 0) {
syslog(LOG_ERR, "couldn't get local hostname: %m");
strlcpy(localhost, "localhost", sizeof(localhost));
} else if ((domain = strchr(localhost, '.'))) {
domain++;
if (*domain && strchr(domain, '.') == NULL)
domain = localhost;
}
if ((as = auth_open()) == NULL) {
syslog(LOG_ERR, "auth_open: %m");
err(1, "unable to initialize BSD authentication");
}
auth_setoption(as, "login", "yes");
/*
* -p is used by getty to tell login not to destroy the environment
* -f is used to skip a second login authentication
* -h is used by other servers to pass the name of the remote
* host to login so that it may be placed in utmp and wtmp
*/
fflag = pflag = 0;
uid = getuid();
while ((ch = getopt(argc, argv, "fh:pu:L:R:")) != -1)
switch (ch) {
case 'f':
fflag = 1;
break;
case 'h':
if (uid) {
warnc(EPERM, "-h option");
quickexit(1);
}
free(fqdn);
if ((fqdn = strdup(optarg)) == NULL) {
warn(NULL);
quickexit(1);
}
auth_setoption(as, "fqdn", fqdn);
if (domain && (p = strchr(optarg, '.')) &&
strcasecmp(p+1, domain) == 0)
*p = 0;
hostname = optarg;
auth_setoption(as, "hostname", hostname);
break;
case 'L':
if (uid) {
warnc(EPERM, "-L option");
quickexit(1);
}
if (lipaddr) {
warnx("duplicate -L option");
quickexit(1);
}
lipaddr = optarg;
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_flags = AI_CANONNAME;
error = getaddrinfo(lipaddr, NULL, &hints, &ai);
if (!error) {
strlcpy(localhost, ai->ai_canonname,
sizeof(localhost));
freeaddrinfo(ai);
} else
strlcpy(localhost, lipaddr, sizeof(localhost));
auth_setoption(as, "local_addr", lipaddr);
break;
case 'p':
pflag = 1;
break;
case 'R':
if (uid) {
warnc(EPERM, "-R option");
quickexit(1);
}
if (ripaddr) {
warnx("duplicate -R option");
quickexit(1);
}
ripaddr = optarg;
auth_setoption(as, "remote_addr", ripaddr);
break;
case 'u':
if (uid) {
warnc(EPERM, "-u option");
quickexit(1);
}
rusername = optarg;
break;
default:
if (!uid)
syslog(LOG_ERR, "invalid flag %c", ch);
(void)fprintf(stderr,
"usage: login [-fp] [-h hostname] [-L local-addr] "
"[-R remote-addr] [-u username]\n\t[user]\n");
quickexit(1);
}
argc -= optind;
argv += optind;
if (*argv) {
username = *argv;
ask = 0;
} else
ask = 1;
/*
* If effective user is not root, just run su(1) to emulate login(1).
*/
if (geteuid() != 0) {
char *av[5], **ap;
auth_close(as);
closelog();
closefrom(STDERR_FILENO + 1);
ap = av;
*ap++ = _PATH_SU;
*ap++ = "-L";
if (!pflag)
*ap++ = "-l";
if (!ask)
*ap++ = username;
*ap = NULL;
execv(_PATH_SU, av);
warn("unable to exec %s", _PATH_SU);
_exit(1);
}
ttyn = ttyname(STDIN_FILENO);
if (ttyn == NULL || *ttyn == '\0') {
(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
ttyn = tname;
}
if ((tty = strrchr(ttyn, '/')))
++tty;
else
tty = ttyn;
/*
* Since login deals with sensitive information, turn off coredumps.
*/
if (getrlimit(RLIMIT_CORE, &scds) < 0) {
syslog(LOG_ERR, "couldn't get core dump size: %m");
scds.rlim_cur = scds.rlim_max = QUAD_MIN;
}
cds.rlim_cur = cds.rlim_max = 0;
if (setrlimit(RLIMIT_CORE, &cds) < 0) {
syslog(LOG_ERR, "couldn't set core dump size to 0: %m");
scds.rlim_cur = scds.rlim_max = QUAD_MIN;
}
(void)signal(SIGALRM, timedout);
if (argc > 1) {
needto = 0;
(void)alarm(timeout);
} else
needto = 1;
(void)signal(SIGQUIT, SIG_IGN);
(void)signal(SIGINT, SIG_IGN);
(void)signal(SIGHUP, SIG_IGN);
(void)setpriority(PRIO_PROCESS, 0, 0);
#ifdef notyet
/* XXX - we don't (yet) support per-tty auth stuff */
/* BSDi uses a ttys.conf file but we could just overload /etc/ttys */
/*
* Classify the attempt.
* By default we use the value in the ttys file.
* If there is a classify script we run that as
*
* classify [-f] [username]
*/
if (type = getttyauth(tty))
auth_setoption(as, "auth_type", type);
#endif
/* get the default login class */
if ((lc = login_getclass(0)) == NULL) { /* get the default class */
warnx("Failure to retrieve default class");
quickexit(1);
}
timeout = (u_int)login_getcapnum(lc, "login-timeout", 300, 300);
if ((script = login_getcapstr(lc, "classify", NULL, NULL)) != NULL) {
unsetenv("AUTH_TYPE");
unsetenv("REMOTE_NAME");
if (script[0] != '/') {
syslog(LOG_ERR, "Invalid classify script: %s", script);
warnx("Classification failure");
quickexit(1);
}
shell = strrchr(script, '/') + 1;
auth_setstate(as, AUTH_OKAY);
auth_call(as, script, shell,
fflag ? "-f" : username, fflag ? username : 0, (char *)0);
if (!(auth_getstate(as) & AUTH_ALLOW))
quickexit(1);
auth_setenv(as);
if ((p = getenv("AUTH_TYPE")) != NULL &&
strncmp(p, "auth-", 5) == 0)
type = p;
if ((p = getenv("REMOTE_NAME")) != NULL)
hostname = p;
/*
* we may have changed some values, reset them
*/
auth_clroptions(as);
if (type)
auth_setoption(as, "auth_type", type);
if (fqdn)
auth_setoption(as, "fqdn", fqdn);
if (hostname)
auth_setoption(as, "hostname", hostname);
if (lipaddr)
auth_setoption(as, "local_addr", lipaddr);
if (ripaddr)
auth_setoption(as, "remote_addr", ripaddr);
}
/*
* Request the things like the approval script print things
* to stdout (in particular, the nologins files)
*/
auth_setitem(as, AUTHV_INTERACTIVE, "True");
for (cnt = 0;; ask = 1) {
/*
* Clean up our current authentication session.
* Options are not cleared so we need to clear any
* we might set below.
*/
auth_clean(as);
auth_clroption(as, "style");
auth_clroption(as, "lastchance");
lastchance = 0;
if (ask) {
fflag = 0;
getloginname();
}
if (needto) {
needto = 0;
alarm(timeout);
}
if ((style = strchr(username, ':')) != NULL)
*style++ = '\0';
if (fullname)
free(fullname);
if (auth_setitem(as, AUTHV_NAME, username) < 0 ||
(fullname = strdup(username)) == NULL) {
syslog(LOG_ERR, "%m");
warn(NULL);
quickexit(1);
}
rootlogin = 0;
if ((instance = strchr(username, '/')) != NULL) {
if (strncmp(instance + 1, "root", 4) == 0)
rootlogin = 1;
*instance++ = '\0';
} else
instance = "";
if (strlen(username) > UT_NAMESIZE)
username[UT_NAMESIZE] = '\0';
/*
* Note if trying multiple user names; log failures for
* previous user name, but don't bother logging one failure
* for nonexistent name (mistyped username).
*/
if (failures && strcmp(tbuf, username)) {
if (failures > (pwd ? 0 : 1))
badlogin(tbuf);
failures = 0;
}
(void)strlcpy(tbuf, username, sizeof(tbuf));
if ((pwd = getpwnam(username)) != NULL &&
auth_setpwd(as, pwd) < 0) {
syslog(LOG_ERR, "%m");
warn(NULL);
quickexit(1);
}
lc = login_getclass(pwd ? pwd->pw_class : NULL);
if (!lc)
goto failed;
style = login_getstyle(lc, style, type);
if (!style)
goto failed;
/*
* We allow "login-tries" attempts to login but start
* slowing down after "login-backoff" attempts.
*/
tries = (int)login_getcapnum(lc, "login-tries", 10, 10);
backoff = (int)login_getcapnum(lc, "login-backoff", 3, 3);
/*
* Turn off the fflag if we have an invalid user
* or we are not root and we are trying to change uids.
*/
if (!pwd || (uid && uid != pwd->pw_uid))
fflag = 0;
if (pwd && pwd->pw_uid == 0)
rootlogin = 1;
/*
* If we do not have the force flag authenticate the user
*/
if (!fflag) {
lastchance =
login_getcaptime(lc, "password-dead", 0, 0) != 0;
if (lastchance)
auth_setoption(as, "lastchance", "yes");
/*
* Once we start asking for a password
* we want to log a failure on a hup.
*/
signal(SIGHUP, sighup);
auth_verify(as, style, NULL, lc->lc_class, NULL);
authok = auth_getstate(as);
/*
* If their password expired and it has not been
* too long since then, give the user one last
* chance to change their password
*/
if ((authok & AUTH_PWEXPIRED) && lastchance) {
authok = AUTH_OKAY;
} else
lastchance = 0;
if ((authok & AUTH_ALLOW) == 0)
goto failed;
if (auth_setoption(as, "style", style) < 0) {
syslog(LOG_ERR, "%m");
warn(NULL);
quickexit(1);
}
}
/*
* explicitly reject users without password file entries
*/
if (pwd == NULL)
goto failed;
/*
* If trying to log in as root on an insecure terminal,
* refuse the login attempt unless the authentication
* style explicitly says a root login is okay.
*/
if (pwd && rootlogin && !rootterm(tty))
goto failed;
if (fflag) {
type = 0;
style = "forced";
}
break;
failed:
if (authok & AUTH_SILENT)
quickexit(0);
if (rootlogin && !rootterm(tty)) {
warnx("%s login refused on this terminal.",
fullname);
if (hostname)
syslog(LOG_NOTICE,
"LOGIN %s REFUSED FROM %s%s%s ON TTY %s",
fullname, rusername ? rusername : "",
rusername ? "@" : "", hostname, tty);
else
syslog(LOG_NOTICE,
"LOGIN %s REFUSED ON TTY %s",
fullname, tty);
} else {
if (!as || (p = auth_getvalue(as, "errormsg")) == NULL)
p = "Login incorrect";
(void)printf("%s\n", p);
}
failures++;
if (pwd)
log_failedlogin(pwd->pw_uid, hostname, rusername, tty);
/*
* By default, we allow 10 tries, but after 3 we start
* backing off to slow down password guessers.
*/
if (++cnt > backoff) {
if (cnt >= tries) {
badlogin(username);
sleepexit(1);
}
sleep((u_int)((cnt - backoff) * tries / 2));
}
}
/* committed to login -- turn off timeout */
(void)alarm(0);
endpwent();
shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
if (*shell == '\0')
shell = _PATH_BSHELL;
else if (strlen(shell) >= MAXPATHLEN) {
syslog(LOG_ERR, "shell path too long: %s", shell);
warnx("invalid shell");
quickexit(1);
}
/* Destroy environment unless user has requested its preservation. */
if (!pflag) {
if ((environ = calloc(1, sizeof (char *))) == NULL)
err(1, "calloc");
} else {
char **cpp, **cpp2;
for (cpp2 = cpp = environ; *cpp; cpp++) {
if (strncmp(*cpp, "LD_", 3) &&
strncmp(*cpp, "ENV=", 4) &&
strncmp(*cpp, "BASH_ENV=", 9) &&
strncmp(*cpp, "IFS=", 4))
*cpp2++ = *cpp;
}
*cpp2 = 0;
}
/* Note: setusercontext(3) will set PATH */
if (setenv("HOME", pwd->pw_dir, 1) == -1 ||
setenv("SHELL", pwd->pw_shell, 1) == -1) {
warn("unable to setenv()");
quickexit(1);
}
if (term[0] == '\0')
(void)strlcpy(term, stypeof(tty), sizeof(term));
(void)snprintf(mail, sizeof(mail), "%s/%s", _PATH_MAILDIR,
pwd->pw_name);
if (setenv("TERM", term, 0) == -1 ||
setenv("LOGNAME", pwd->pw_name, 1) == -1 ||
setenv("USER", pwd->pw_name, 1) == -1 ||
setenv("MAIL", mail, 1) == -1) {
warn("unable to setenv()");
quickexit(1);
}
if (hostname) {
if (setenv("REMOTEHOST", hostname, 1) == -1) {
warn("unable to setenv()");
quickexit(1);
}
}
if (rusername) {
if (setenv("REMOTEUSER", rusername, 1) == -1) {
warn("unable to setenv()");
quickexit(1);
}
}
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETPATH)) {
warn("unable to set user context");
quickexit(1);
}
auth_setenv(as);
/* if user not super-user, check for disabled logins */
if (!rootlogin)
auth_checknologin(lc);
setegid(pwd->pw_gid);
seteuid(pwd->pw_uid);
homeless = chdir(pwd->pw_dir);
if (homeless) {
if (login_getcapbool(lc, "requirehome", 0)) {
(void)printf("No home directory %s!\n", pwd->pw_dir);
quickexit(1);
}
if (chdir("/"))
quickexit(0);
}
quietlog = ((strcmp(pwd->pw_shell, "/sbin/nologin") == 0) ||
login_getcapbool(lc, "hushlogin", 0) ||
(access(_PATH_HUSHLOGIN, F_OK) == 0));
seteuid(0);
setegid(0); /* XXX use a saved gid instead? */
if ((p = auth_getvalue(as, "warnmsg")) != NULL)
(void)printf("WARNING: %s\n\n", p);
expire = auth_check_expire(as);
if (expire < 0) {
(void)printf("Sorry -- your account has expired.\n");
quickexit(1);
} else if (expire > 0 && !quietlog) {
warning = login_getcaptime(lc, "expire-warn",
2 * DAYSPERWEEK * SECSPERDAY, 2 * DAYSPERWEEK * SECSPERDAY);
if (expire < warning)
(void)printf("Warning: your account expires on %s",
ctime(&pwd->pw_expire));
}
/* Nothing else left to fail -- really log in. */
(void)signal(SIGHUP, SIG_DFL);
memset(&utmp, 0, sizeof(utmp));
(void)time(&utmp.ut_time);
(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
if (hostname)
(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
login(&utmp);
if (!quietlog)
(void)check_failedlogin(pwd->pw_uid);
dolastlog(quietlog);
login_fbtab(tty, pwd->pw_uid, pwd->pw_gid);
(void)chown(ttyn, pwd->pw_uid,
(gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid);
/* If fflag is on, assume caller/authenticator has logged root login. */
if (rootlogin && fflag == 0) {
if (hostname)
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s%s%s",
username, tty, rusername ? rusername : "",
rusername ? "@" : "", hostname);
else
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", username, tty);
}
if (!quietlog) {
if ((copyright =
login_getcapstr(lc, "copyright", NULL, NULL)) != NULL)
auth_cat(copyright);
motd();
if (stat(mail, &st) == 0 && st.st_size != 0)
(void)printf("You have %smail.\n",
(st.st_mtime > st.st_atime) ? "new " : "");
}
(void)signal(SIGALRM, SIG_DFL);
(void)signal(SIGQUIT, SIG_DFL);
(void)signal(SIGHUP, SIG_DFL);
(void)signal(SIGINT, SIG_DFL);
(void)signal(SIGTSTP, SIG_IGN);
tbuf[0] = '-';
(void)strlcpy(tbuf + 1, (p = strrchr(shell, '/')) ?
p + 1 : shell, sizeof(tbuf) - 1);
if ((scds.rlim_cur != QUAD_MIN || scds.rlim_max != QUAD_MIN) &&
setrlimit(RLIMIT_CORE, &scds) < 0)
syslog(LOG_ERR, "couldn't reset core dump size: %m");
if (lastchance)
(void)printf("WARNING: Your password has expired."
" You must change your password, now!\n");
if (setusercontext(lc, pwd, rootlogin ? 0 : pwd->pw_uid,
LOGIN_SETALL & ~LOGIN_SETPATH) < 0) {
warn("unable to set user context");
quickexit(1);
}
if (homeless) {
(void)printf("No home directory %s!\n", pwd->pw_dir);
(void)printf("Logging in with home = \"/\".\n");
(void)setenv("HOME", "/", 1);
}
if (auth_approval(as, lc, NULL, "login") == 0) {
if (auth_getstate(as) & AUTH_EXPIRED)
(void)printf("Sorry -- your account has expired.\n");
else
(void)printf("approval failure\n");
quickexit(1);
}
/*
* The last thing we do is discard all of the open file descriptors.
* Last because the C library may have some open.
*/
closefrom(STDERR_FILENO + 1);
/*
* Close the authentication session, make sure it is marked
* as okay so no files are removed.
*/
auth_setstate(as, AUTH_OKAY);
auth_close(as);
execlp(shell, tbuf, (char *)NULL);
err(1, "%s", shell);
}
