/* * Nice and simple code provided by Linus Torvalds 16-Feb-93. * Non-blocking stuff by Maciej W. Rozycki, [email protected], 1999. * * He writes: "Login performs open() on a tty in a blocking mode. * In some cases it may make login wait in open() for carrier infinitely, * for example if the line is a simplistic case of a three-wire serial * connection. I believe login should open the line in non-blocking mode, * leaving the decision to make a connection to getty (where it actually * belongs)." */ static void open_tty(const char *tty) { int i, fd, flags; fd = open(tty, O_RDWR | O_NONBLOCK); if (fd == -1) { syslog(LOG_ERR, _("FATAL: can't reopen tty: %m")); sleepexit(EXIT_FAILURE); } if (!isatty(fd)) { close(fd); syslog(LOG_ERR, _("FATAL: %s is not a terminal"), tty); sleepexit(EXIT_FAILURE); } flags = fcntl(fd, F_GETFL); flags &= ~O_NONBLOCK; fcntl(fd, F_SETFL, flags); for (i = 0; i < fd; i++) close(i); for (i = 0; i < 3; i++) if (fd != i) dup2(fd, i); if (fd >= 3) close(fd); }
static void loginpam_acct(struct login_context *cxt)
{
int rc;
pam_handle_t *pamh = cxt->pamh;
rc = pam_acct_mgmt(pamh, 0);
if (rc == PAM_NEW_AUTHTOK_REQD)
rc = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
if (is_pam_failure(rc))
loginpam_err(pamh, rc);
/*
* Grab the user information out of the password file for future use.
* First get the username that we are actually using, though.
*/
rc = loginpam_get_username(pamh, &cxt->username);
if (is_pam_failure(rc))
loginpam_err(pamh, rc);
if (!cxt->username || !*cxt->username) {
warnx(_("\nSession setup problem, abort."));
syslog(LOG_ERR, _("NULL user name in %s:%d. Abort."),
__FUNCTION__, __LINE__);
pam_end(pamh, PAM_SYSTEM_ERR);
sleepexit(EXIT_FAILURE);
}
}
static void loginpam_err(pam_handle_t *pamh, int retcode)
{
const char *msg = pam_strerror(pamh, retcode);
if (msg) {
fprintf(stderr, "\n%s\n", msg);
syslog(LOG_ERR, "%s", msg);
}
pam_end(pamh, retcode);
sleepexit(EXIT_FAILURE);
}
static void
checknologin(char *fname)
{
int fd, nchars;
char tbuf[8192];
if ((fd = open(fname ? fname : _PATH_NOLOGIN, O_RDONLY, 0)) >= 0) {
while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
(void)write(fileno(stdout), tbuf, nchars);
sleepexit(EXIT_SUCCESS);
}
}
void
checknologin(void) {
int fd, nchars;
char tbuf[8192];
if ((fd = open(_PATH_NOLOGIN, O_RDONLY, 0)) >= 0) {
while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
write(fileno(stdout), tbuf, nchars);
close(fd);
sleepexit(0);
}
}
static pam_handle_t *init_loginpam(struct login_context *cxt)
{
pam_handle_t *pamh = NULL;
int rc;
/*
* username is initialized to NULL and if specified on the command line
* it is set. Therefore, we are safe not setting it to anything
*/
rc = pam_start(cxt->remote ? "remote" : "login",
cxt->username, &cxt->conv, &pamh);
if (rc != PAM_SUCCESS) {
warnx(_("PAM failure, aborting: %s"), pam_strerror(pamh, rc));
syslog(LOG_ERR, _("Couldn't initialize PAM: %s"),
pam_strerror(pamh, rc));
sleepexit(EXIT_FAILURE);
}
/* hostname & tty are either set to NULL or their correct values,
* depending on how much we know
*/
rc = pam_set_item(pamh, PAM_RHOST, cxt->hostname);
if (is_pam_failure(rc))
loginpam_err(pamh, rc);
rc = pam_set_item(pamh, PAM_TTY, cxt->tty_name);
if (is_pam_failure(rc))
loginpam_err(pamh, rc);
/*
* [email protected]: Provide a user prompt to PAM so that
* the "login: "******"Password: " string (yet).
*/
rc = pam_set_item(pamh, PAM_USER_PROMPT, loginpam_get_prompt(cxt));
if (is_pam_failure(rc))
loginpam_err(pamh, rc);
/* we need't the original username. We have to follow PAM. */
free(cxt->username);
cxt->username = NULL;
cxt->pamh = pamh;
return pamh;
}
int
main(int argc, char *argv[])
{
struct group *gr;
struct stat st;
int ask, ch, cnt, fflag, hflag, pflag, sflag, quietlog, rootlogin, rval;
uid_t uid, saved_uid;
gid_t saved_gid, saved_gids[NGROUPS_MAX];
int nsaved_gids;
#ifdef notdef
char *domain;
#endif
char *p, *ttyn;
const char *pwprompt;
char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
char localhost[MAXHOSTNAMELEN + 1];
int need_chpass, require_chpass;
int login_retries = DEFAULT_RETRIES,
login_backoff = DEFAULT_BACKOFF;
time_t pw_warntime = _PASSWORD_WARNDAYS * SECSPERDAY;
char *loginname = NULL;
#ifdef KERBEROS5
int Fflag;
krb5_error_code kerror;
#endif
#if defined(KERBEROS5)
int got_tickets = 0;
#endif
#ifdef LOGIN_CAP
char *shell = NULL;
login_cap_t *lc = NULL;
#endif
tbuf[0] = '\0';
rval = 0;
pwprompt = NULL;
nested = NULL;
need_chpass = require_chpass = 0;
(void)signal(SIGALRM, timedout);
(void)alarm(timeout);
(void)signal(SIGQUIT, SIG_IGN);
(void)signal(SIGINT, SIG_IGN);
(void)setpriority(PRIO_PROCESS, 0, 0);
openlog("login", 0, LOG_AUTH);
/*
* -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/utmpx and wtmp/wtmpx
* -a in addition to -h, a server may supply -a to pass the actual
* server address.
* -s is used to force use of S/Key or equivalent.
*/
if (gethostname(localhost, sizeof(localhost)) < 0) {
syslog(LOG_ERR, "couldn't get local hostname: %m");
strcpy(hostname, "amnesiac");
}
#ifdef notdef
domain = strchr(localhost, '.');
#endif
localhost[sizeof(localhost) - 1] = '\0';
fflag = hflag = pflag = sflag = 0;
have_ss = 0;
#ifdef KERBEROS5
Fflag = 0;
have_forward = 0;
#endif
uid = getuid();
while ((ch = getopt(argc, argv, "a:Ffh:ps")) != -1)
switch (ch) {
case 'a':
if (uid)
errx(EXIT_FAILURE, "-a option: %s", strerror(EPERM));
decode_ss(optarg);
#ifdef notdef
(void)sockaddr_snprintf(optarg,
sizeof(struct sockaddr_storage), "%a", (void *)&ss);
#endif
break;
case 'F':
#ifdef KERBEROS5
Fflag = 1;
#endif
/* FALLTHROUGH */
case 'f':
fflag = 1;
break;
case 'h':
if (uid)
errx(EXIT_FAILURE, "-h option: %s", strerror(EPERM));
hflag = 1;
#ifdef notdef
if (domain && (p = strchr(optarg, '.')) != NULL &&
strcasecmp(p, domain) == 0)
*p = '\0';
#endif
hostname = optarg;
break;
case 'p':
pflag = 1;
break;
case 's':
sflag = 1;
break;
default:
case '?':
usage();
break;
}
setproctitle(NULL);
argc -= optind;
argv += optind;
if (*argv) {
username = loginname = *argv;
ask = 0;
} else
ask = 1;
#ifdef F_CLOSEM
(void)fcntl(3, F_CLOSEM, 0);
#else
for (cnt = getdtablesize(); cnt > 2; cnt--)
(void)close(cnt);
#endif
ttyn = ttyname(STDIN_FILENO);
if (ttyn == NULL || *ttyn == '\0') {
(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
ttyn = tname;
}
if ((tty = strstr(ttyn, "/pts/")) != NULL)
++tty;
else if ((tty = strrchr(ttyn, '/')) != NULL)
++tty;
else
tty = ttyn;
if (issetugid()) {
nested = strdup(user_from_uid(getuid(), 0));
if (nested == NULL) {
syslog(LOG_ERR, "strdup: %m");
sleepexit(EXIT_FAILURE);
}
}
#ifdef LOGIN_CAP
/* Get "login-retries" and "login-backoff" from default class */
if ((lc = login_getclass(NULL)) != NULL) {
login_retries = (int)login_getcapnum(lc, "login-retries",
DEFAULT_RETRIES, DEFAULT_RETRIES);
login_backoff = (int)login_getcapnum(lc, "login-backoff",
DEFAULT_BACKOFF, DEFAULT_BACKOFF);
login_close(lc);
lc = NULL;
}
#endif
#ifdef KERBEROS5
kerror = krb5_init_context(&kcontext);
if (kerror) {
/*
* If Kerberos is not configured, that is, we are
* not using Kerberos, do not log the error message.
* However, if Kerberos is configured, and the
* context init fails for some other reason, we need
* to issue a no tickets warning to the user when the
* login succeeds.
*/
if (kerror != ENXIO) { /* XXX NetBSD-local Heimdal hack */
syslog(LOG_NOTICE,
"%s when initializing Kerberos context",
error_message(kerror));
krb5_configured = 1;
}
login_krb5_get_tickets = 0;
}
#endif /* KERBEROS5 */
for (cnt = 0;; ask = 1) {
#if defined(KERBEROS5)
if (login_krb5_get_tickets)
k5destroy();
#endif
if (ask) {
fflag = 0;
loginname = getloginname();
}
rootlogin = 0;
#ifdef KERBEROS5
if ((instance = strchr(loginname, '/')) != NULL)
*instance++ = '\0';
else
instance = __UNCONST("");
#endif
username = trimloginname(loginname);
/*
* 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));
pwd = getpwnam(username);
#ifdef LOGIN_CAP
/*
* Establish the class now, before we might goto
* within the next block. pwd can be NULL since it
* falls back to the "default" class if it is.
*/
lc = login_getclass(pwd ? pwd->pw_class : NULL);
#endif
/*
* if we have a valid account name, and it doesn't have a
* password, or the -f option was specified and the caller
* is root or the caller isn't changing their uid, don't
* authenticate.
*/
if (pwd) {
if (pwd->pw_uid == 0)
rootlogin = 1;
if (fflag && (uid == 0 || uid == pwd->pw_uid)) {
/* already authenticated */
#ifdef KERBEROS5
if (login_krb5_get_tickets && Fflag)
k5_read_creds(username);
#endif
break;
} else if (pwd->pw_passwd[0] == '\0') {
/* pretend password okay */
rval = 0;
goto ttycheck;
}
}
fflag = 0;
(void)setpriority(PRIO_PROCESS, 0, -4);
#ifdef SKEY
if (skey_haskey(username) == 0) {
static char skprompt[80];
const char *skinfo = skey_keyinfo(username);
(void)snprintf(skprompt, sizeof(skprompt),
"Password [ %s ]:",
skinfo ? skinfo : "error getting challenge");
pwprompt = skprompt;
} else
#endif
pwprompt = "Password:"******"Login incorrect or refused on this "
"terminal.\n");
if (hostname)
syslog(LOG_NOTICE,
"LOGIN %s REFUSED FROM %s ON TTY %s",
pwd->pw_name, hostname, tty);
else
syslog(LOG_NOTICE,
"LOGIN %s REFUSED ON TTY %s",
pwd->pw_name, tty);
continue;
}
if (pwd && !rval)
break;
(void)printf("Login incorrect or refused on this "
"terminal.\n");
failures++;
cnt++;
/*
* We allow login_retries tries, but after login_backoff
* we start backing off. These default to 10 and 3
* respectively.
*/
if (cnt > login_backoff) {
if (cnt >= login_retries) {
badlogin(username);
sleepexit(EXIT_FAILURE);
}
sleep((u_int)((cnt - login_backoff) * 5));
}
}
/* committed to login -- turn off timeout */
(void)alarm((u_int)0);
endpwent();
/* if user not super-user, check for disabled logins */
#ifdef LOGIN_CAP
if (!login_getcapbool(lc, "ignorenologin", rootlogin))
checknologin(login_getcapstr(lc, "nologin", NULL, NULL));
#else
if (!rootlogin)
checknologin(NULL);
#endif
#ifdef LOGIN_CAP
quietlog = login_getcapbool(lc, "hushlogin", 0);
#else
quietlog = 0;
#endif
/* Temporarily give up special privileges so we can change */
/* into NFS-mounted homes that are exported for non-root */
/* access and have mode 7x0 */
saved_uid = geteuid();
saved_gid = getegid();
nsaved_gids = getgroups(NGROUPS_MAX, saved_gids);
(void)setegid(pwd->pw_gid);
initgroups(username, pwd->pw_gid);
(void)seteuid(pwd->pw_uid);
if (chdir(pwd->pw_dir) < 0) {
#ifdef LOGIN_CAP
if (login_getcapbool(lc, "requirehome", 0)) {
(void)printf("Home directory %s required\n",
pwd->pw_dir);
sleepexit(EXIT_FAILURE);
}
#endif
(void)printf("No home directory %s!\n", pwd->pw_dir);
if (chdir("/") == -1)
exit(EXIT_FAILURE);
pwd->pw_dir = __UNCONST("/");
(void)printf("Logging in with home = \"/\".\n");
}
if (!quietlog)
quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
/* regain special privileges */
(void)seteuid(saved_uid);
setgroups(nsaved_gids, saved_gids);
(void)setegid(saved_gid);
#ifdef LOGIN_CAP
pw_warntime = login_getcaptime(lc, "password-warn",
_PASSWORD_WARNDAYS * SECSPERDAY,
_PASSWORD_WARNDAYS * SECSPERDAY);
#endif
(void)gettimeofday(&now, NULL);
if (pwd->pw_expire) {
if (now.tv_sec >= pwd->pw_expire) {
(void)printf("Sorry -- your account has expired.\n");
sleepexit(EXIT_FAILURE);
} else if (pwd->pw_expire - now.tv_sec < pw_warntime &&
!quietlog)
(void)printf("Warning: your account expires on %s",
ctime(&pwd->pw_expire));
}
if (pwd->pw_change) {
if (pwd->pw_change == _PASSWORD_CHGNOW)
need_chpass = 1;
else if (now.tv_sec >= pwd->pw_change) {
(void)printf("Sorry -- your password has expired.\n");
sleepexit(EXIT_FAILURE);
} else if (pwd->pw_change - now.tv_sec < pw_warntime &&
!quietlog)
(void)printf("Warning: your password expires on %s",
ctime(&pwd->pw_change));
}
/* Nothing else left to fail -- really log in. */
update_db(quietlog, rootlogin, fflag);
(void)chown(ttyn, pwd->pw_uid,
(gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid);
if (ttyaction(ttyn, "login", pwd->pw_name))
(void)printf("Warning: ttyaction failed.\n");
#if defined(KERBEROS5)
/* Fork so that we can call kdestroy */
if (! login_krb5_retain_ccache && has_ccache)
dofork();
#endif
/* Destroy environment unless user has requested its preservation. */
if (!pflag)
environ = envinit;
#ifdef LOGIN_CAP
if (nested == NULL && setusercontext(lc, pwd, pwd->pw_uid,
LOGIN_SETLOGIN) != 0) {
syslog(LOG_ERR, "setusercontext failed");
exit(EXIT_FAILURE);
}
if (setusercontext(lc, pwd, pwd->pw_uid,
(LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETLOGIN))) != 0) {
syslog(LOG_ERR, "setusercontext failed");
exit(EXIT_FAILURE);
}
#else
(void)setgid(pwd->pw_gid);
initgroups(username, pwd->pw_gid);
if (nested == NULL && setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failure: %m");
/* Discard permissions last so can't get killed and drop core. */
if (rootlogin)
(void)setuid(0);
else
(void)setuid(pwd->pw_uid);
#endif
if (*pwd->pw_shell == '\0')
pwd->pw_shell = __UNCONST(_PATH_BSHELL);
#ifdef LOGIN_CAP
if ((shell = login_getcapstr(lc, "shell", NULL, NULL)) != NULL) {
if ((shell = strdup(shell)) == NULL) {
syslog(LOG_ERR, "Cannot alloc mem");
sleepexit(EXIT_FAILURE);
}
pwd->pw_shell = shell;
}
#endif
(void)setenv("HOME", pwd->pw_dir, 1);
(void)setenv("SHELL", pwd->pw_shell, 1);
if (term[0] == '\0') {
const char *tt = stypeof(tty);
#ifdef LOGIN_CAP
if (tt == NULL)
tt = login_getcapstr(lc, "term", NULL, NULL);
#endif
/* unknown term -> "su" */
(void)strlcpy(term, tt != NULL ? tt : "su", sizeof(term));
}
(void)setenv("TERM", term, 0);
(void)setenv("LOGNAME", pwd->pw_name, 1);
(void)setenv("USER", pwd->pw_name, 1);
#ifdef LOGIN_CAP
setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETPATH);
#else
(void)setenv("PATH", _PATH_DEFPATH, 0);
#endif
#ifdef KERBEROS5
if (krb5tkfile_env)
(void)setenv("KRB5CCNAME", krb5tkfile_env, 1);
#endif
/* 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",
username, tty, hostname);
else
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s",
username, tty);
}
#if defined(KERBEROS5)
if (KERBEROS_CONFIGURED && !quietlog && notickets == 1)
(void)printf("Warning: no Kerberos tickets issued.\n");
#endif
if (!quietlog) {
const char *fname;
#ifdef LOGIN_CAP
fname = login_getcapstr(lc, "copyright", NULL, NULL);
if (fname != NULL && access(fname, F_OK) == 0)
motd(fname);
else
#endif
(void)printf("%s", copyrightstr);
#ifdef LOGIN_CAP
fname = login_getcapstr(lc, "welcome", NULL, NULL);
if (fname == NULL || access(fname, F_OK) != 0)
#endif
fname = _PATH_MOTDFILE;
motd(fname);
(void)snprintf(tbuf,
sizeof(tbuf), "%s/%s", _PATH_MAILDIR, pwd->pw_name);
if (stat(tbuf, &st) == 0 && st.st_size != 0)
(void)printf("You have %smail.\n",
(st.st_mtime > st.st_atime) ? "new " : "");
}
#ifdef LOGIN_CAP
login_close(lc);
#endif
(void)signal(SIGALRM, SIG_DFL);
(void)signal(SIGQUIT, SIG_DFL);
(void)signal(SIGINT, SIG_DFL);
(void)signal(SIGTSTP, SIG_IGN);
tbuf[0] = '-';
(void)strlcpy(tbuf + 1, (p = strrchr(pwd->pw_shell, '/')) ?
p + 1 : pwd->pw_shell, sizeof(tbuf) - 1);
/* Wait to change password until we're unprivileged */
if (need_chpass) {
if (!require_chpass)
(void)printf(
"Warning: your password has expired. Please change it as soon as possible.\n");
else {
int status;
(void)printf(
"Your password has expired. Please choose a new one.\n");
switch (fork()) {
case -1:
warn("fork");
sleepexit(EXIT_FAILURE);
case 0:
execl(_PATH_BINPASSWD, "passwd", NULL);
_exit(EXIT_FAILURE);
default:
if (wait(&status) == -1 ||
WEXITSTATUS(status))
sleepexit(EXIT_FAILURE);
}
}
}
#ifdef KERBEROS5
if (login_krb5_get_tickets)
k5_write_creds();
#endif
execlp(pwd->pw_shell, tbuf, NULL);
err(EXIT_FAILURE, "%s", pwd->pw_shell);
}
int
main(int argc, char **argv)
{
extern int optind;
extern char *optarg, **environ;
register int ch;
register char *p;
int ask, fflag, hflag, pflag, cnt, errsv;
int quietlog, passwd_req;
char *domain, *ttyn;
char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
char *termenv;
char *childArgv[10];
char *buff;
int childArgc = 0;
char *salt, *pp;
pid = getpid();
signal(SIGALRM, timedout);
alarm((unsigned int)timeout);
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
setpriority(PRIO_PROCESS, 0, 0);
/*
* -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
*/
gethostname(tbuf, sizeof(tbuf));
xstrncpy(thishost, tbuf, sizeof(thishost));
domain = index(tbuf, '.');
username = tty_name = hostname = NULL;
fflag = hflag = pflag = 0;
passwd_req = 1;
while ((ch = getopt(argc, argv, "fh:p")) != -1)
switch (ch) {
case 'f':
fflag = 1;
break;
case 'h':
if (getuid()) {
fprintf(stderr,
"login: -h for super-user only.\n");
exit(1);
}
hflag = 1;
if (domain && (p = index(optarg, '.')) &&
strcasecmp(p, domain) == 0)
*p = 0;
hostname = strdup(optarg); /* strdup: Ambrose C. Li */
{
struct hostent *he = gethostbyname(hostname);
/* he points to static storage; copy the part we use */
hostaddress[0] = 0;
if (he && he->h_addr_list && he->h_addr_list[0])
memcpy(hostaddress, he->h_addr_list[0],
sizeof(hostaddress));
}
break;
case 'p':
pflag = 1;
break;
case '?':
default:
fprintf(stderr,
"usage: login [-fp] [username]\n");
exit(1);
}
argc -= optind;
argv += optind;
if (*argv) {
char *p = *argv;
username = strdup(p);
ask = 0;
/* wipe name - some people mistype their password here */
/* (of course we are too late, but perhaps this helps a little ..) */
while(*p)
*p++ = ' ';
} else
ask = 1;
for (cnt = getdtablesize(); cnt > 2; cnt--)
close(cnt);
ttyn = ttyname(0);
if (ttyn == NULL || *ttyn == '\0') {
/* no snprintf required - see definition of tname */
sprintf(tname, "%s??", _PATH_TTY);
ttyn = tname;
}
check_ttyname(ttyn);
if (strncmp(ttyn, "/dev/", 5) == 0)
tty_name = ttyn+5;
else
tty_name = ttyn;
if (strncmp(ttyn, "/dev/tty", 8) == 0)
tty_number = ttyn+8;
else {
char *p = ttyn;
while (*p && !isdigit(*p)) p++;
tty_number = p;
}
/* set pgid to pid */
setpgrp();
/* this means that setsid() will fail */
{
struct termios tt, ttt;
tcgetattr(0, &tt);
ttt = tt;
ttt.c_cflag &= ~HUPCL;
/* These can fail, e.g. with ttyn on a read-only filesystem */
chown(ttyn, 0, 0);
chmod(ttyn, TTY_MODE);
/* Kill processes left on this tty */
tcsetattr(0,TCSAFLUSH,&ttt);
signal(SIGHUP, SIG_IGN); /* so vhangup() wont kill us */
//vhangup();
signal(SIGHUP, SIG_DFL);
/* open stdin,stdout,stderr to the tty */
opentty(ttyn);
/* restore tty modes */
tcsetattr(0,TCSAFLUSH,&tt);
}
openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
#if 0
/* other than iso-8859-1 */
printf("\033(K");
fprintf(stderr,"\033(K");
#endif
for (cnt = 0;; ask = 1) {
if (ask) {
fflag = 0;
getloginname();
}
/* Dirty patch to fix a gigantic security hole when using
yellow pages. This problem should be solved by the
libraries, and not by programs, but this must be fixed
urgently! If the first char of the username is '+', we
avoid login success.
Feb 95 <*****@*****.**> */
if (username[0] == '+') {
puts("Illegal username");
badlogin(username);
sleepexit(1);
}
/* (void)strcpy(tbuf, username); why was this here? */
if ((pwd = getpwnam(username))) {
salt = pwd->pw_passwd;
} else
salt = (char *) "xx";
if (pwd) {
initgroups(username, pwd->pw_gid);
}
/* if user not super-user, check for disabled logins */
if (pwd == NULL || pwd->pw_uid)
checknologin();
/*
* Disallow automatic login to root; if not invoked by
* root, disallow if the uid's differ.
*/
if (fflag && pwd) {
int uid = getuid();
passwd_req = pwd->pw_uid == 0 ||
(uid && uid != pwd->pw_uid);
}
/*
* If no pre-authentication and a password exists
* for this user, prompt for one and verify it.
*/
if (!passwd_req || (pwd && !*pwd->pw_passwd))
break;
setpriority(PRIO_PROCESS, 0, -4);
pp = getpass("Password: "******"Login incorrect\n");
badlogin(username); /* log ALL bad logins */
failures++;
/* we allow 10 tries, but after 3 we start backing off */
if (++cnt > 3) {
if (cnt >= 10) {
sleepexit(1);
}
sleep((unsigned int)((cnt - 3) * 5));
}
}
/* committed to login -- turn off timeout */
alarm((unsigned int)0);
endpwent();
/* This requires some explanation: As root we may not be able to
read the directory of the user if it is on an NFS mounted
filesystem. We temporarily set our effective uid to the user-uid
making sure that we keep root privs. in the real uid.
A portable solution would require a fork(), but we rely on Linux
having the BSD setreuid() */
quietlog = 0;
dolastlog(quietlog);
chown(ttyn, pwd->pw_uid, pwd->pw_gid);
chmod(ttyn, TTY_MODE);
setgid(pwd->pw_gid);
if (*pwd->pw_shell == '\0')
pwd->pw_shell = (char *)_PATH_BSHELL;
/* preserve TERM even without -p flag */
{
char *ep;
if(!((ep = getenv("TERM")) && (termenv = strdup(ep))))
termenv = (char *) "dumb";
}
/* destroy environment unless user has requested preservation */
if (!pflag)
{
environ = (char**)malloc(sizeof(char*));
memset(environ, 0, sizeof(char*));
}
setenv("HOME", pwd->pw_dir, 0); /* legal to override */
if(pwd->pw_uid)
setenv("PATH", _PATH_DEFPATH, 1);
else
setenv("PATH", _PATH_DEFPATH_ROOT, 1);
setenv("SHELL", pwd->pw_shell, 1);
setenv("TERM", termenv, 1);
/* mailx will give a funny error msg if you forget this one */
{
char tmp[MAXPATHLEN];
/* avoid snprintf */
if (sizeof(_PATH_MAILDIR) + strlen(pwd->pw_name) + 1 < MAXPATHLEN) {
sprintf(tmp, "%s/%s", _PATH_MAILDIR, pwd->pw_name);
setenv("MAIL",tmp,0);
}
}
/* LOGNAME is not documented in login(1) but
HP-UX 6.5 does it. We'll not allow modifying it.
*/
setenv("LOGNAME", pwd->pw_name, 1);
if (!strncmp(tty_name, "ttyS", 4))
syslog(LOG_INFO, "DIALUP AT %s BY %s", tty_name, pwd->pw_name);
/* allow tracking of good logins.
-steve philp ([email protected]) */
if (pwd->pw_uid == 0) {
if (hostname)
syslog(LOG_NOTICE, "ROOT LOGIN ON %s FROM %s",
tty_name, hostname);
else
syslog(LOG_NOTICE, "ROOT LOGIN ON %s", tty_name);
} else {
if (hostname)
syslog(LOG_INFO, "LOGIN ON %s BY %s FROM %s", tty_name,
pwd->pw_name, hostname);
else
syslog(LOG_INFO, "LOGIN ON %s BY %s", tty_name,
pwd->pw_name);
}
if (!quietlog) {
struct stat st;
char *mail;
mail = getenv("MAIL");
if (mail && stat(mail, &st) == 0 && st.st_size != 0) {
if (st.st_mtime > st.st_atime)
printf("You have new mail.\n");
else
printf("You have mail.\n");
}
}
signal(SIGALRM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGTSTP, SIG_IGN);
signal(SIGINT, SIG_DFL);
/* discard permissions last so can't get killed and drop core */
if(setuid(pwd->pw_uid) < 0 && pwd->pw_uid) {
syslog(LOG_ALERT, "setuid() failed");
exit(1);
}
/* wait until here to change directory! */
if (chdir(pwd->pw_dir) < 0) {
printf("No directory %s!\n", pwd->pw_dir);
if (chdir("/"))
exit(0);
pwd->pw_dir = (char *) "/";
printf("Logging in with home = \"/\".\n");
}
/* if the shell field has a space: treat it like a shell script */
if (strchr(pwd->pw_shell, ' ')) {
buff = malloc(strlen(pwd->pw_shell) + 6);
if (!buff) {
fprintf(stderr, "login: no memory for shell script.\n");
exit(0);
}
strcpy(buff, "exec ");
strcat(buff, pwd->pw_shell);
childArgv[childArgc++] = (char *) "/bin/sh";
childArgv[childArgc++] = (char *) "-sh";
childArgv[childArgc++] = (char *) "-c";
childArgv[childArgc++] = buff;
} else {
tbuf[0] = '-';
xstrncpy(tbuf + 1, ((p = rindex(pwd->pw_shell, '/')) ?
p + 1 : pwd->pw_shell),
sizeof(tbuf)-1);
childArgv[childArgc++] = pwd->pw_shell;
childArgv[childArgc++] = tbuf;
}
childArgv[childArgc++] = NULL;
execvp(childArgv[0], childArgv + 1);
errsv = errno;
if (!strcmp(childArgv[0], "/bin/sh"))
fprintf(stderr, "login: couldn't exec shell script: %s.\n",
strerror(errsv));
else
fprintf(stderr, "login: no shell: %s.\n", strerror(errsv));
exit(0);
}
/*
* Detach the controlling terminal, fork, restore syslog stuff, and create
* a new session.
*/
static void fork_session(struct login_context *cxt)
{
struct sigaction sa, oldsa_hup, oldsa_term;
signal(SIGALRM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGTSTP, SIG_IGN);
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_IGN;
sigaction(SIGINT, &sa, NULL);
sigaction(SIGHUP, &sa, &oldsa_hup); /* ignore when TIOCNOTTY */
/*
* Detach the controlling tty.
* We don't need the tty in a parent who only waits for a child.
* The child calls setsid() that detaches from the tty as well.
*/
ioctl(0, TIOCNOTTY, NULL);
/*
* We have to beware of SIGTERM, because leaving a PAM session
* without pam_close_session() is a pretty bad thing.
*/
sa.sa_handler = sig_handler;
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGTERM, &sa, &oldsa_term);
closelog();
/*
* We must fork before setuid(), because we need to call
* pam_close_session() as root.
*/
child_pid = fork();
if (child_pid < 0) {
warn(_("fork failed"));
pam_setcred(cxt->pamh, PAM_DELETE_CRED);
pam_end(cxt->pamh, pam_close_session(cxt->pamh, 0));
sleepexit(EXIT_FAILURE);
}
if (child_pid) {
/*
* parent - wait for child to finish, then clean up session
*/
close(0);
close(1);
close(2);
sa.sa_handler = SIG_IGN;
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
/* wait as long as any child is there */
while (wait(NULL) == -1 && errno == EINTR) ;
openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
pam_setcred(cxt->pamh, PAM_DELETE_CRED);
pam_end(cxt->pamh, pam_close_session(cxt->pamh, 0));
exit(EXIT_SUCCESS);
}
/*
* child
*/
sigaction(SIGHUP, &oldsa_hup, NULL); /* restore old state */
sigaction(SIGTERM, &oldsa_term, NULL);
if (got_sig)
exit(EXIT_FAILURE);
/*
* Problem: if the user's shell is a shell like ash that doesn't do
* setsid() or setpgrp(), then a ctrl-\, sending SIGQUIT to every
* process in the pgrp, will kill us.
*/
/* start new session */
setsid();
/* make sure we have a controlling tty */
open_tty(cxt->tty_path);
openlog("login", LOG_ODELAY, LOG_AUTHPRIV); /* reopen */
/*
* TIOCSCTTY: steal tty from other process group.
*/
if (ioctl(0, TIOCSCTTY, 1))
syslog(LOG_ERR, _("TIOCSCTTY failed: %m"));
signal(SIGINT, SIG_DFL);
}
static void loginpam_auth(struct login_context *cxt)
{
int rc, show_unknown;
unsigned int retries, failcount = 0;
const char *hostname = cxt->hostname ? cxt->hostname :
cxt->tty_name ? cxt->tty_name : "<unknown>";
pam_handle_t *pamh = cxt->pamh;
/* if we didn't get a user on the command line, set it to NULL */
loginpam_get_username(pamh, &cxt->username);
show_unknown = getlogindefs_bool("LOG_UNKFAIL_ENAB", 0);
retries = getlogindefs_num("LOGIN_RETRIES", LOGIN_MAX_TRIES);
/*
* 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 LOGIN_MAX_TRIES?
*/
rc = pam_authenticate(pamh, 0);
while ((++failcount < retries) &&
((rc == PAM_AUTH_ERR) ||
(rc == PAM_USER_UNKNOWN) ||
(rc == PAM_CRED_INSUFFICIENT) ||
(rc == PAM_AUTHINFO_UNAVAIL))) {
if (rc == PAM_USER_UNKNOWN && !show_unknown)
/*
* Logging unknown usernames may be a security issue if
* a user enters her password instead of her login name.
*/
cxt->username = NULL;
else
loginpam_get_username(pamh, &cxt->username);
syslog(LOG_NOTICE,
_("FAILED LOGIN %u FROM %s FOR %s, %s"),
failcount, hostname,
cxt->username ? cxt->username : "******",
pam_strerror(pamh, rc));
log_btmp(cxt);
log_audit(cxt, 0);
fprintf(stderr, _("Login incorrect\n\n"));
pam_set_item(pamh, PAM_USER, NULL);
rc = pam_authenticate(pamh, 0);
}
if (is_pam_failure(rc)) {
if (rc == PAM_USER_UNKNOWN && !show_unknown)
cxt->username = NULL;
else
loginpam_get_username(pamh, &cxt->username);
if (rc == PAM_MAXTRIES)
syslog(LOG_NOTICE,
_("TOO MANY LOGIN TRIES (%u) FROM %s FOR %s, %s"),
failcount, hostname,
cxt->username ? cxt->username : "******",
pam_strerror(pamh, rc));
else
syslog(LOG_NOTICE,
_("FAILED LOGIN SESSION FROM %s FOR %s, %s"),
hostname,
cxt->username ? cxt->username : "******",
pam_strerror(pamh, rc));
log_btmp(cxt);
log_audit(cxt, 0);
fprintf(stderr, _("\nLogin incorrect\n"));
pam_end(pamh, rc);
sleepexit(EXIT_SUCCESS);
}
}
/*
* Reads the currect terminal path and initializes cxt->tty_* variables.
*/
static void init_tty(struct login_context *cxt)
{
struct stat st;
struct termios tt, ttt;
cxt->tty_mode = (mode_t) getlogindefs_num("TTYPERM", TTY_MODE);
get_terminal_name(0, &cxt->tty_path, &cxt->tty_name, &cxt->tty_number);
/*
* In case login is suid it was possible to use a hardlink as stdin
* and exploit races for a local root exploit. (Wojciech Purczynski).
*
* More precisely, the problem is ttyn := ttyname(0); ...; chown(ttyn);
* here ttyname() might return "/tmp/x", a hardlink to a pseudotty.
* All of this is a problem only when login is suid, which it isn't.
*/
if (!cxt->tty_path || !*cxt->tty_path ||
lstat(cxt->tty_path, &st) != 0 || !S_ISCHR(st.st_mode) ||
(st.st_nlink > 1 && strncmp(cxt->tty_path, "/dev/", 5)) ||
access(cxt->tty_path, R_OK | W_OK) != 0) {
syslog(LOG_ERR, _("FATAL: bad tty"));
sleepexit(EXIT_FAILURE);
}
#ifdef LOGIN_CHOWN_VCS
if (cxt->tty_number) {
/* find names of Virtual Console devices, for later mode change */
snprintf(cxt->vcsn, sizeof(cxt->vcsn), "/dev/vcs%s", cxt->tty_number);
snprintf(cxt->vcsan, sizeof(cxt->vcsan), "/dev/vcsa%s", cxt->tty_number);
}
#endif
tcgetattr(0, &tt);
ttt = tt;
ttt.c_cflag &= ~HUPCL;
if ((fchown(0, 0, 0) || fchmod(0, cxt->tty_mode)) && errno != EROFS) {
syslog(LOG_ERR, _("FATAL: %s: change permissions failed: %m"),
cxt->tty_path);
sleepexit(EXIT_FAILURE);
}
/* Kill processes left on this tty */
tcsetattr(0, TCSANOW, &ttt);
/*
* Let's close file decriptors before vhangup
* https://lkml.org/lkml/2012/6/5/145
*/
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
signal(SIGHUP, SIG_IGN); /* so vhangup() wont kill us */
vhangup();
signal(SIGHUP, SIG_DFL);
/* open stdin,stdout,stderr to the tty */
open_tty(cxt->tty_path);
/* restore tty modes */
tcsetattr(0, TCSAFLUSH, &tt);
}
int
main(int argc, char **argv)
{
extern int optind;
extern char *optarg, **environ;
struct group *gr;
register int ch;
register char *p;
int ask, fflag, hflag, pflag, cnt, errsv;
int quietlog, passwd_req;
char *domain, *ttyn;
char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
char *termenv;
char *childArgv[10];
char *buff;
int childArgc = 0;
#ifdef HAVE_SECURITY_PAM_MISC_H
int retcode;
pam_handle_t *pamh = NULL;
struct pam_conv conv = { misc_conv, NULL };
pid_t childPid;
#else
char *salt, *pp;
#endif
#ifdef LOGIN_CHOWN_VCS
char vcsn[20], vcsan[20];
#endif
pid = getpid();
signal(SIGALRM, timedout);
alarm((unsigned int)timeout);
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
setpriority(PRIO_PROCESS, 0, 0);
initproctitle(argc, argv);
/*
* -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
*/
gethostname(tbuf, sizeof(tbuf));
xstrncpy(thishost, tbuf, sizeof(thishost));
domain = index(tbuf, '.');
username = tty_name = hostname = NULL;
fflag = hflag = pflag = 0;
passwd_req = 1;
while ((ch = getopt(argc, argv, "fh:p")) != -1)
switch (ch) {
case 'f':
fflag = 1;
break;
case 'h':
if (getuid()) {
fprintf(stderr,
_("login: -h for super-user only.\n"));
exit(1);
}
hflag = 1;
if (domain && (p = index(optarg, '.')) &&
strcasecmp(p, domain) == 0)
*p = 0;
hostname = strdup(optarg); /* strdup: Ambrose C. Li */
{
struct hostent *he = gethostbyname(hostname);
/* he points to static storage; copy the part we use */
hostaddress[0] = 0;
if (he && he->h_addr_list && he->h_addr_list[0])
memcpy(hostaddress, he->h_addr_list[0],
sizeof(hostaddress));
}
break;
case 'p':
pflag = 1;
break;
case '?':
default:
fprintf(stderr,
_("usage: login [-fp] [username]\n"));
exit(1);
}
argc -= optind;
argv += optind;
if (*argv) {
char *p = *argv;
username = strdup(p);
ask = 0;
/* wipe name - some people mistype their password here */
/* (of course we are too late, but perhaps this helps a little ..) */
while(*p)
*p++ = ' ';
} else
ask = 1;
for (cnt = getdtablesize(); cnt > 2; cnt--)
close(cnt);
ttyn = ttyname(0);
if (ttyn == NULL || *ttyn == '\0') {
/* no snprintf required - see definition of tname */
sprintf(tname, "%s??", _PATH_TTY);
ttyn = tname;
}
check_ttyname(ttyn);
if (strncmp(ttyn, "/dev/", 5) == 0)
tty_name = ttyn+5;
else
tty_name = ttyn;
if (strncmp(ttyn, "/dev/tty", 8) == 0)
tty_number = ttyn+8;
else {
char *p = ttyn;
while (*p && !isdigit(*p)) p++;
tty_number = p;
}
#ifdef LOGIN_CHOWN_VCS
/* find names of Virtual Console devices, for later mode change */
snprintf(vcsn, sizeof(vcsn), "/dev/vcs%s", tty_number);
snprintf(vcsan, sizeof(vcsan), "/dev/vcsa%s", tty_number);
#endif
/* set pgid to pid */
setpgrp();
/* this means that setsid() will fail */
{
struct termios tt, ttt;
tcgetattr(0, &tt);
ttt = tt;
ttt.c_cflag &= ~HUPCL;
/* These can fail, e.g. with ttyn on a read-only filesystem */
chown(ttyn, 0, 0);
chmod(ttyn, TTY_MODE);
/* Kill processes left on this tty */
tcsetattr(0,TCSAFLUSH,&ttt);
signal(SIGHUP, SIG_IGN); /* so vhangup() wont kill us */
vhangup();
signal(SIGHUP, SIG_DFL);
/* open stdin,stdout,stderr to the tty */
opentty(ttyn);
/* restore tty modes */
tcsetattr(0,TCSAFLUSH,&tt);
}
openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
#if 0
/* other than iso-8859-1 */
printf("\033(K");
fprintf(stderr,"\033(K");
#endif
#ifdef HAVE_SECURITY_PAM_MISC_H
/*
* username is initialized to NULL
* and if specified on the command line it is set.
* Therefore, we are safe not setting it to anything
*/
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 */
retcode = pam_set_item(pamh, PAM_RHOST, hostname);
PAM_FAIL_CHECK;
retcode = pam_set_item(pamh, PAM_TTY, tty_name);
PAM_FAIL_CHECK;
/*
* [email protected]: Provide a user prompt to PAM
* so that the "login: "******"Password: "******"login: "******"\033(K");
fprintf(stderr,"\033(K");
#endif
/* if fflag == 1, then the user has already been authenticated */
if (fflag && (getuid() == 0))
passwd_req = 0;
else
passwd_req = 1;
if(passwd_req == 1) {
int failcount=0;
/* if we didn't get a user on the command line, set it to NULL */
pam_get_item(pamh, PAM_USER, (const void **) &username);
if (!username)
pam_set_item(pamh, PAM_USER, NULL);
/* 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? */
retcode = pam_authenticate(pamh, 0);
while((failcount++ < PAM_MAX_LOGIN_TRIES) &&
((retcode == PAM_AUTH_ERR) ||
(retcode == PAM_USER_UNKNOWN) ||
(retcode == PAM_CRED_INSUFFICIENT) ||
(retcode == PAM_AUTHINFO_UNAVAIL))) {
pam_get_item(pamh, PAM_USER, (const void **) &username);
syslog(LOG_NOTICE,_("FAILED LOGIN %d FROM %s FOR %s, %s"),
failcount, hostname, username, pam_strerror(pamh, retcode));
logbtmp(tty_name, username, hostname);
fprintf(stderr,_("Login incorrect\n\n"));
pam_set_item(pamh,PAM_USER,NULL);
retcode = pam_authenticate(pamh, 0);
}
if (retcode != PAM_SUCCESS) {
pam_get_item(pamh, PAM_USER, (const void **) &username);
if (retcode == PAM_MAXTRIES)
syslog(LOG_NOTICE,_("TOO MANY LOGIN TRIES (%d) FROM %s FOR "
"%s, %s"), failcount, hostname, username,
pam_strerror(pamh, retcode));
else
syslog(LOG_NOTICE,_("FAILED LOGIN SESSION FROM %s FOR %s, %s"),
hostname, username, pam_strerror(pamh, retcode));
logbtmp(tty_name, username, hostname);
fprintf(stderr,_("\nLogin incorrect\n"));
pam_end(pamh, retcode);
exit(0);
}
retcode = pam_acct_mgmt(pamh, 0);
if(retcode == PAM_NEW_AUTHTOK_REQD) {
retcode = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
}
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.
*/
retcode = pam_get_item(pamh, PAM_USER, (const void **) &username);
PAM_FAIL_CHECK;
if (!username || !*username) {
fprintf(stderr, _("\nSession setup problem, abort.\n"));
syslog(LOG_ERR, _("NULL user name in %s:%d. Abort."),
__FUNCTION__, __LINE__);
pam_end(pamh, PAM_SYSTEM_ERR);
exit(1);
}
if (!(pwd = getpwnam(username))) {
fprintf(stderr, _("\nSession setup problem, abort.\n"));
syslog(LOG_ERR, _("Invalid user name \"%s\" in %s:%d. Abort."),
username, __FUNCTION__, __LINE__);
pam_end(pamh, PAM_SYSTEM_ERR);
exit(1);
}
/*
* Create a copy of the pwd struct - otherwise it may get
* clobbered by PAM
*/
memcpy(&pwdcopy, pwd, sizeof(*pwd));
pwd = &pwdcopy;
pwd->pw_name = strdup(pwd->pw_name);
pwd->pw_passwd = strdup(pwd->pw_passwd);
pwd->pw_gecos = strdup(pwd->pw_gecos);
pwd->pw_dir = strdup(pwd->pw_dir);
pwd->pw_shell = strdup(pwd->pw_shell);
if (!pwd->pw_name || !pwd->pw_passwd || !pwd->pw_gecos ||
!pwd->pw_dir || !pwd->pw_shell) {
fprintf(stderr, _("login: Out of memory\n"));
syslog(LOG_ERR, "Out of memory");
pam_end(pamh, PAM_SYSTEM_ERR);
exit(1);
}
username = pwd->pw_name;
/*
* Initialize the supplementary group list.
* This should be done before pam_setcred because
* the PAM modules might add groups during pam_setcred.
*/
if (initgroups(username, pwd->pw_gid) < 0) {
syslog(LOG_ERR, "initgroups: %m");
fprintf(stderr, _("\nSession setup problem, abort.\n"));
pam_end(pamh, PAM_SYSTEM_ERR);
exit(1);
}
retcode = pam_open_session(pamh, 0);
PAM_FAIL_CHECK;
retcode = pam_setcred(pamh, PAM_ESTABLISH_CRED);
PAM_FAIL_CHECK;
#else /* ! HAVE_SECURITY_PAM_MISC_H */
for (cnt = 0;; ask = 1) {
if (ask) {
fflag = 0;
getloginname();
}
/* Dirty patch to fix a gigantic security hole when using
yellow pages. This problem should be solved by the
libraries, and not by programs, but this must be fixed
urgently! If the first char of the username is '+', we
avoid login success.
Feb 95 <*****@*****.**> */
if (username[0] == '+') {
puts(_("Illegal username"));
badlogin(username);
sleepexit(1);
}
/* (void)strcpy(tbuf, username); why was this here? */
if ((pwd = getpwnam(username))) {
# ifdef SHADOW_PWD
struct spwd *sp;
if ((sp = getspnam(username)))
pwd->pw_passwd = sp->sp_pwdp;
# endif
salt = pwd->pw_passwd;
} else
salt = "xx";
if (pwd) {
initgroups(username, pwd->pw_gid);
checktty(username, tty_name, pwd); /* in checktty.c */
}
/* if user not super-user, check for disabled logins */
if (pwd == NULL || pwd->pw_uid)
checknologin();
/*
* Disallow automatic login to root; if not invoked by
* root, disallow if the uid's differ.
*/
if (fflag && pwd) {
int uid = getuid();
passwd_req = pwd->pw_uid == 0 ||
(uid && uid != pwd->pw_uid);
}
/*
* If trying to log in as root, but with insecure terminal,
* refuse the login attempt.
*/
if (pwd && pwd->pw_uid == 0 && !rootterm(tty_name)) {
fprintf(stderr,
_("%s login refused on this terminal.\n"),
pwd->pw_name);
if (hostname)
syslog(LOG_NOTICE,
_("LOGIN %s REFUSED FROM %s ON TTY %s"),
pwd->pw_name, hostname, tty_name);
else
syslog(LOG_NOTICE,
_("LOGIN %s REFUSED ON TTY %s"),
pwd->pw_name, tty_name);
continue;
}
/*
* If no pre-authentication and a password exists
* for this user, prompt for one and verify it.
*/
if (!passwd_req || (pwd && !*pwd->pw_passwd))
break;
setpriority(PRIO_PROCESS, 0, -4);
pp = getpass(_("Password: "******"CRYPTO", 6) == 0) {
if (pwd && cryptocard()) break;
}
# endif /* CRYPTOCARD */
p = crypt(pp, salt);
setpriority(PRIO_PROCESS, 0, 0);
# ifdef KERBEROS
/*
* If not present in pw file, act as we normally would.
* If we aren't Kerberos-authenticated, try the normal
* pw file for a password. If that's ok, log the user
* in without issueing any tickets.
*/
if (pwd && !krb_get_lrealm(realm,1)) {
/*
* get TGT for local realm; be careful about uid's
* here for ticket file ownership
*/
setreuid(geteuid(),pwd->pw_uid);
kerror = krb_get_pw_in_tkt(pwd->pw_name, "", realm,
"krbtgt", realm, DEFAULT_TKT_LIFE, pp);
setuid(0);
if (kerror == INTK_OK) {
memset(pp, 0, strlen(pp));
notickets = 0; /* user got ticket */
break;
}
}
# endif /* KERBEROS */
memset(pp, 0, strlen(pp));
if (pwd && !strcmp(p, pwd->pw_passwd))
break;
printf(_("Login incorrect\n"));
badlogin(username); /* log ALL bad logins */
failures++;
/* we allow 10 tries, but after 3 we start backing off */
if (++cnt > 3) {
if (cnt >= 10) {
sleepexit(1);
}
sleep((unsigned int)((cnt - 3) * 5));
}
}
#endif /* !HAVE_SECURITY_PAM_MISC_H */
/* committed to login -- turn off timeout */
alarm((unsigned int)0);
endpwent();
/* This requires some explanation: As root we may not be able to
read the directory of the user if it is on an NFS mounted
filesystem. We temporarily set our effective uid to the user-uid
making sure that we keep root privs. in the real uid.
A portable solution would require a fork(), but we rely on Linux
having the BSD setreuid() */
{
char tmpstr[MAXPATHLEN];
uid_t ruid = getuid();
gid_t egid = getegid();
/* avoid snprintf - old systems do not have it, or worse,
have a libc in which snprintf is the same as sprintf */
if (strlen(pwd->pw_dir) + sizeof(_PATH_HUSHLOGIN) + 2 > MAXPATHLEN)
quietlog = 0;
else {
sprintf(tmpstr, "%s/%s", pwd->pw_dir, _PATH_HUSHLOGIN);
setregid(-1, pwd->pw_gid);
setreuid(0, pwd->pw_uid);
quietlog = (access(tmpstr, R_OK) == 0);
setuid(0); /* setreuid doesn't do it alone! */
setreuid(ruid, 0);
setregid(-1, egid);
}
}
/* for linux, write entries in utmp and wtmp */
{
struct utmp ut;
struct utmp *utp;
utmpname(_PATH_UTMP);
setutent();
/* Find pid in utmp.
login sometimes overwrites the runlevel entry in /var/run/utmp,
confusing sysvinit. I added a test for the entry type, and the problem
was gone. (In a runlevel entry, st_pid is not really a pid but some number
calculated from the previous and current runlevel).
Michael Riepe <*****@*****.**>
*/
while ((utp = getutent()))
if (utp->ut_pid == pid
&& utp->ut_type >= INIT_PROCESS
&& utp->ut_type <= DEAD_PROCESS)
break;
/* If we can't find a pre-existing entry by pid, try by line.
BSD network daemons may rely on this. (anonymous) */
if (utp == NULL) {
setutent();
ut.ut_type = LOGIN_PROCESS;
strncpy(ut.ut_line, tty_name, sizeof(ut.ut_line));
utp = getutline(&ut);
}
if (utp) {
memcpy(&ut, utp, sizeof(ut));
} else {
/* some gettys/telnetds don't initialize utmp... */
memset(&ut, 0, sizeof(ut));
}
if (ut.ut_id[0] == 0)
strncpy(ut.ut_id, tty_number, sizeof(ut.ut_id));
strncpy(ut.ut_user, username, sizeof(ut.ut_user));
xstrncpy(ut.ut_line, tty_name, sizeof(ut.ut_line));
#ifdef _HAVE_UT_TV /* in <utmpbits.h> included by <utmp.h> */
gettimeofday(&ut.ut_tv, NULL);
#else
{
time_t t;
time(&t);
ut.ut_time = t; /* ut_time is not always a time_t */
/* glibc2 #defines it as ut_tv.tv_sec */
}
#endif
ut.ut_type = USER_PROCESS;
ut.ut_pid = pid;
if (hostname) {
xstrncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
if (hostaddress[0])
memcpy(&ut.ut_addr, hostaddress, sizeof(ut.ut_addr));
}
pututline(&ut);
endutent();
#if HAVE_UPDWTMP
updwtmp(_PATH_WTMP, &ut);
#else
#if 0
/* The O_APPEND open() flag should be enough to guarantee
atomic writes at end of file. */
{
int wtmp;
if((wtmp = open(_PATH_WTMP, O_APPEND|O_WRONLY)) >= 0) {
write(wtmp, (char *)&ut, sizeof(ut));
close(wtmp);
}
}
#else
/* Probably all this locking below is just nonsense,
and the short version is OK as well. */
{
int lf, wtmp;
if ((lf = open(_PATH_WTMPLOCK, O_CREAT|O_WRONLY, 0660)) >= 0) {
flock(lf, LOCK_EX);
if ((wtmp = open(_PATH_WTMP, O_APPEND|O_WRONLY)) >= 0) {
write(wtmp, (char *)&ut, sizeof(ut));
close(wtmp);
}
flock(lf, LOCK_UN);
close(lf);
}
}
#endif
#endif
}
dolastlog(quietlog);
chown(ttyn, pwd->pw_uid,
(gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid);
chmod(ttyn, TTY_MODE);
#ifdef LOGIN_CHOWN_VCS
/* if tty is one of the VC's then change owner and mode of the
special /dev/vcs devices as well */
if (consoletty(0)) {
chown(vcsn, pwd->pw_uid, (gr ? gr->gr_gid : pwd->pw_gid));
chown(vcsan, pwd->pw_uid, (gr ? gr->gr_gid : pwd->pw_gid));
chmod(vcsn, TTY_MODE);
chmod(vcsan, TTY_MODE);
}
#endif
setgid(pwd->pw_gid);
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
/* preserve TERM even without -p flag */
{
char *ep;
if(!((ep = getenv("TERM")) && (termenv = strdup(ep))))
termenv = "dumb";
}
/* destroy environment unless user has requested preservation */
if (!pflag)
{
environ = (char**)malloc(sizeof(char*));
memset(environ, 0, sizeof(char*));
}
setenv("HOME", pwd->pw_dir, 0); /* legal to override */
if(pwd->pw_uid)
setenv("PATH", _PATH_DEFPATH, 1);
else
setenv("PATH", _PATH_DEFPATH_ROOT, 1);
setenv("SHELL", pwd->pw_shell, 1);
setenv("TERM", termenv, 1);
/* mailx will give a funny error msg if you forget this one */
{
char tmp[MAXPATHLEN];
/* avoid snprintf */
if (sizeof(_PATH_MAILDIR) + strlen(pwd->pw_name) + 1 < MAXPATHLEN) {
sprintf(tmp, "%s/%s", _PATH_MAILDIR, pwd->pw_name);
setenv("MAIL",tmp,0);
}
}
/* LOGNAME is not documented in login(1) but
HP-UX 6.5 does it. We'll not allow modifying it.
*/
setenv("LOGNAME", pwd->pw_name, 1);
#ifdef HAVE_SECURITY_PAM_MISC_H
{
int i;
char ** env = pam_getenvlist(pamh);
if (env != NULL) {
for (i=0; env[i]; i++) {
putenv(env[i]);
/* D(("env[%d] = %s", i,env[i])); */
}
}
}
#endif
setproctitle("login", username);
if (!strncmp(tty_name, "ttyS", 4))
syslog(LOG_INFO, _("DIALUP AT %s BY %s"), tty_name, pwd->pw_name);
/* allow tracking of good logins.
-steve philp ([email protected]) */
if (pwd->pw_uid == 0) {
if (hostname)
syslog(LOG_NOTICE, _("ROOT LOGIN ON %s FROM %s"),
tty_name, hostname);
else
syslog(LOG_NOTICE, _("ROOT LOGIN ON %s"), tty_name);
} else {
if (hostname)
syslog(LOG_INFO, _("LOGIN ON %s BY %s FROM %s"), tty_name,
pwd->pw_name, hostname);
else
syslog(LOG_INFO, _("LOGIN ON %s BY %s"), tty_name,
pwd->pw_name);
}
if (!quietlog) {
motd();
#ifdef LOGIN_STAT_MAIL
/*
* This turns out to be a bad idea: when the mail spool
* is NFS mounted, and the NFS connection hangs, the
* login hangs, even root cannot login.
* Checking for mail should be done from the shell.
*/
{
struct stat st;
char *mail;
mail = getenv("MAIL");
if (mail && stat(mail, &st) == 0 && st.st_size != 0) {
if (st.st_mtime > st.st_atime)
printf(_("You have new mail.\n"));
else
printf(_("You have mail.\n"));
}
}
#endif
}
signal(SIGALRM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGTSTP, SIG_IGN);
#ifdef HAVE_SECURITY_PAM_MISC_H
/*
* We must fork before setuid() because we need to call
* pam_close_session() as root.
*/
childPid = fork();
if (childPid < 0) {
int errsv = errno;
/* error in fork() */
fprintf(stderr, _("login: failure forking: %s"), strerror(errsv));
PAM_END;
exit(0);
}
if (childPid) {
/* parent - wait for child to finish, then cleanup session */
signal(SIGHUP, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
wait(NULL);
PAM_END;
exit(0);
}
/* child */
/*
* Problem: if the user's shell is a shell like ash that doesnt do
* setsid() or setpgrp(), then a ctrl-\, sending SIGQUIT to every
* process in the pgrp, will kill us.
*/
/* start new session */
setsid();
/* make sure we have a controlling tty */
opentty(ttyn);
openlog("login", LOG_ODELAY, LOG_AUTHPRIV); /* reopen */
/*
* TIOCSCTTY: steal tty from other process group.
*/
if (ioctl(0, TIOCSCTTY, 1))
syslog(LOG_ERR, _("TIOCSCTTY failed: %m"));
#endif
signal(SIGINT, SIG_DFL);
/* discard permissions last so can't get killed and drop core */
if(setuid(pwd->pw_uid) < 0 && pwd->pw_uid) {
syslog(LOG_ALERT, _("setuid() failed"));
exit(1);
}
/* wait until here to change directory! */
if (chdir(pwd->pw_dir) < 0) {
printf(_("No directory %s!\n"), pwd->pw_dir);
if (chdir("/"))
exit(0);
pwd->pw_dir = "/";
printf(_("Logging in with home = \"/\".\n"));
}
/* if the shell field has a space: treat it like a shell script */
if (strchr(pwd->pw_shell, ' ')) {
buff = malloc(strlen(pwd->pw_shell) + 6);
if (!buff) {
fprintf(stderr, _("login: no memory for shell script.\n"));
exit(0);
}
strcpy(buff, "exec ");
strcat(buff, pwd->pw_shell);
childArgv[childArgc++] = "/bin/sh";
childArgv[childArgc++] = "-sh";
childArgv[childArgc++] = "-c";
childArgv[childArgc++] = buff;
} else {
tbuf[0] = '-';
xstrncpy(tbuf + 1, ((p = rindex(pwd->pw_shell, '/')) ?
p + 1 : pwd->pw_shell),
sizeof(tbuf)-1);
childArgv[childArgc++] = pwd->pw_shell;
childArgv[childArgc++] = tbuf;
}
childArgv[childArgc++] = NULL;
execvp(childArgv[0], childArgv + 1);
errsv = errno;
if (!strcmp(childArgv[0], "/bin/sh"))
fprintf(stderr, _("login: couldn't exec shell script: %s.\n"),
strerror(errsv));
else
fprintf(stderr, _("login: no shell: %s.\n"), strerror(errsv));
exit(0);
}
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);
}
int main(int argc, char **argv)
{
int c;
int cnt;
char *childArgv[10];
char *buff;
int childArgc = 0;
int retcode;
char *pwdbuf = NULL;
struct passwd *pwd = NULL, _pwd;
struct login_context cxt = {
.tty_mode = TTY_MODE, /* tty chmod() */
.pid = getpid(), /* PID */
.conv = { misc_conv, NULL } /* PAM conversation function */
};
timeout = getlogindefs_num("LOGIN_TIMEOUT", LOGIN_TIMEOUT);
signal(SIGALRM, timedout);
siginterrupt(SIGALRM, 1); /* we have to interrupt syscalls like ioclt() */
alarm((unsigned int)timeout);
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
setpriority(PRIO_PROCESS, 0, 0);
initproctitle(argc, argv);
/*
* -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
*/
while ((c = getopt(argc, argv, "fHh:pV")) != -1)
switch (c) {
case 'f':
cxt.noauth = 1;
break;
case 'H':
cxt.nohost = 1;
break;
case 'h':
if (getuid()) {
fprintf(stderr,
_("login: -h for super-user only.\n"));
exit(EXIT_FAILURE);
}
init_remote_info(&cxt, optarg);
break;
case 'p':
cxt.keep_env = 1;
break;
case 'V':
printf(UTIL_LINUX_VERSION);
return EXIT_SUCCESS;
case '?':
default:
fprintf(stderr, _("usage: login [ -p ] [ -h host ] [ -H ] [ -f username | username ]\n"));
exit(EXIT_FAILURE);
}
argc -= optind;
argv += optind;
if (*argv) {
char *p = *argv;
cxt.username = xstrdup(p);
/* wipe name - some people mistype their password here */
/* (of course we are too late, but perhaps this helps a little ..) */
while (*p)
*p++ = ' ';
}
for (cnt = get_fd_tabsize() - 1; cnt > 2; cnt--)
close(cnt);
setpgrp(); /* set pgid to pid this means that setsid() will fail */
openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
init_tty(&cxt);
init_loginpam(&cxt);
/* login -f, then the user has already been authenticated */
cxt.noauth = cxt.noauth && getuid() == 0 ? 1 : 0;
if (!cxt.noauth)
loginpam_auth(&cxt);
/*
* Authentication may be skipped (for example, during krlogin, rlogin,
* etc...), but it doesn't mean that we can skip other account checks.
* The account could be disabled or password expired (althought
* kerberos ticket is valid). -- [email protected] (22-Feb-2006)
*/
loginpam_acct(&cxt);
if (!(cxt.pwd = get_passwd_entry(cxt.username, &pwdbuf, &_pwd))) {
warnx(_("\nSession setup problem, abort."));
syslog(LOG_ERR, _("Invalid user name \"%s\" in %s:%d. Abort."),
cxt.username, __FUNCTION__, __LINE__);
pam_end(cxt.pamh, PAM_SYSTEM_ERR);
sleepexit(EXIT_FAILURE);
}
pwd = cxt.pwd;
cxt.username = pwd->pw_name;
/*
* Initialize the supplementary group list. This should be done before
* pam_setcred because the PAM modules might add groups during
* pam_setcred.
*
* For root we don't call initgroups, instead we call setgroups with
* group 0. This avoids the need to step through the whole group file,
* which can cause problems if NIS, NIS+, LDAP or something similar
* is used and the machine has network problems.
*/
retcode = pwd->pw_uid ? initgroups(cxt.username, pwd->pw_gid) : /* user */
setgroups(0, NULL); /* root */
if (retcode < 0) {
syslog(LOG_ERR, _("groups initialization failed: %m"));
warnx(_("\nSession setup problem, abort."));
pam_end(cxt.pamh, PAM_SYSTEM_ERR);
sleepexit(EXIT_FAILURE);
}
/*
* Open PAM session (after successful authentication and account check)
*/
loginpam_session(&cxt);
/* committed to login -- turn off timeout */
alarm((unsigned int)0);
endpwent();
cxt.quiet = get_hushlogin_status(pwd);
log_utmp(&cxt);
log_audit(&cxt, 1);
log_lastlog(&cxt);
chown_tty(&cxt);
if (setgid(pwd->pw_gid) < 0 && pwd->pw_gid) {
syslog(LOG_ALERT, _("setgid() failed"));
exit(EXIT_FAILURE);
}
if (pwd->pw_shell == NULL || *pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
init_environ(&cxt); /* init $HOME, $TERM ... */
setproctitle("login", cxt.username);
log_syslog(&cxt);
if (!cxt.quiet) {
motd();
#ifdef LOGIN_STAT_MAIL
/*
* This turns out to be a bad idea: when the mail spool
* is NFS mounted, and the NFS connection hangs, the
* login hangs, even root cannot login.
* Checking for mail should be done from the shell.
*/
{
struct stat st;
char *mail;
mail = getenv("MAIL");
if (mail && stat(mail, &st) == 0 && st.st_size != 0) {
if (st.st_mtime > st.st_atime)
printf(_("You have new mail.\n"));
else
printf(_("You have mail.\n"));
}
}
#endif
}
/*
* Detach the controlling terminal, fork() and create, new session
* and reinilizalize syslog stuff.
*/
fork_session(&cxt);
/* discard permissions last so can't get killed and drop core */
if (setuid(pwd->pw_uid) < 0 && pwd->pw_uid) {
syslog(LOG_ALERT, _("setuid() failed"));
exit(EXIT_FAILURE);
}
/* wait until here to change directory! */
if (chdir(pwd->pw_dir) < 0) {
warn(_("%s: change directory failed"), pwd->pw_dir);
if (!getlogindefs_bool("DEFAULT_HOME", 1))
exit(0);
if (chdir("/"))
exit(EXIT_FAILURE);
pwd->pw_dir = "/";
printf(_("Logging in with home = \"/\".\n"));
}
/* if the shell field has a space: treat it like a shell script */
if (strchr(pwd->pw_shell, ' ')) {
buff = xmalloc(strlen(pwd->pw_shell) + 6);
strcpy(buff, "exec ");
strcat(buff, pwd->pw_shell);
childArgv[childArgc++] = "/bin/sh";
childArgv[childArgc++] = "-sh";
childArgv[childArgc++] = "-c";
childArgv[childArgc++] = buff;
} else {
char tbuf[PATH_MAX + 2], *p;
tbuf[0] = '-';
xstrncpy(tbuf + 1, ((p = strrchr(pwd->pw_shell, '/')) ?
p + 1 : pwd->pw_shell), sizeof(tbuf) - 1);
childArgv[childArgc++] = pwd->pw_shell;
childArgv[childArgc++] = xstrdup(tbuf);
}
childArgv[childArgc++] = NULL;
execvp(childArgv[0], childArgv + 1);
if (!strcmp(childArgv[0], "/bin/sh"))
warn(_("couldn't exec shell script"));
else
warn(_("no shell"));
exit(EXIT_SUCCESS);
}