static void
reconnect_to_parent (MdmDisplay *to)
{
GError *error;
gchar *command_argv[10];
const gchar *proxyreconnect = mdm_daemon_config_get_value_string (MDM_KEY_XDMCP_PROXY_RECONNECT);
command_argv[0] = (char *)proxyreconnect;
command_argv[1] = "--display";
command_argv[2] = to->parent_disp;
command_argv[3] = "--display-authfile";
command_argv[4] = to->parent_auth_file;
command_argv[5] = "--to";
command_argv[6] = to->name;
command_argv[7] = "--to-authfile";
command_argv[8] = to->authfile;
command_argv[9] = NULL;
mdm_debug ("XDMCP: migrating display by running "
"'%s --display %s --display-authfile %s --to %s --to-authfile %s'",
proxyreconnect,
to->parent_disp, to->parent_auth_file,
to->name, to->authfile);
error = NULL;
if (!g_spawn_async (NULL, command_argv, NULL, 0, NULL, NULL, NULL, &error)) {
mdm_error (_("%s: Failed to run "
"'%s --display %s --display-authfile %s --to %s --to-authfile %s': %s"),
"mdm_xdmcp_migrate",
proxyreconnect,
to->parent_disp, to->parent_auth_file,
to->name, to->authfile,
error->message);
g_error_free (error);
}
}
gchar *
mdm_verify_user (MdmDisplay *d,
const char *username,
gboolean allow_retry)
{
gint pamerr = 0;
struct passwd *pwent = NULL;
char *login, *passreq;
char *pam_stack = NULL;
MDM_PAM_QUAL void *p;
int null_tok = 0;
gboolean credentials_set = FALSE;
gboolean error_msg_given = FALSE;
gboolean started_timer = FALSE;
verify_user_again:
pamerr = 0;
login = NULL;
error_msg_given = FALSE;
credentials_set = FALSE;
started_timer = FALSE;
null_tok = 0;
/* Don't start a timed login if we've already entered a username */
if (username != NULL) {
login = g_strdup (username);
mdm_slave_greeter_ctl_no_ret (MDM_SETLOGIN, login);
} else {
/* start the timer for timed logins */
if ( ! ve_string_empty (mdm_daemon_config_get_value_string (MDM_KEY_TIMED_LOGIN)) &&
d->timed_login_ok && (d->attached)) {
mdm_slave_greeter_ctl_no_ret (MDM_STARTTIMER, "");
started_timer = TRUE;
}
}
cur_mdm_disp = d;
authenticate_again:
if (prev_user && !login) {
login = g_strdup (prev_user);
} else if (login && !prev_user) {
prev_user = g_strdup (login);
auth_retries = 0;
} else if (login && prev_user && strcmp (login, prev_user)) {
g_free (prev_user);
prev_user = g_strdup (login);
auth_retries = 0;
}
/*
* Initialize a PAM session for the user...
* Get value per-display so different displays can use different
* PAM Stacks, in case one display should use a different
* authentication mechanism than another display.
*/
pam_stack = mdm_daemon_config_get_value_string_per_display (MDM_KEY_PAM_STACK,
(char *)d->name);
if ( ! create_pamh (d, pam_stack, login, &pamc, d->name, &pamerr)) {
if (started_timer)
mdm_slave_greeter_ctl_no_ret (MDM_STOPTIMER, "");
g_free (pam_stack);
goto pamerr;
}
g_free (pam_stack);
/*
* have to unset login otherwise there is no chance to ever enter
* a different user
*/
g_free (login);
login = NULL;
pam_set_item (pamh, PAM_USER_PROMPT, _("Username:"******"PASSREQ=");
if (mdm_daemon_config_get_value_bool (MDM_KEY_PASSWORD_REQUIRED) ||
((passreq != NULL) && g_ascii_strcasecmp (passreq, "YES") == 0))
null_tok |= PAM_DISALLOW_NULL_AUTHTOK;
mdm_verify_select_user (NULL);
/* Start authentication session */
did_we_ask_for_password = FALSE;
if ((pamerr = pam_authenticate (pamh, null_tok)) != PAM_SUCCESS) {
if ( ! ve_string_empty (selected_user)) {
pam_handle_t *tmp_pamh;
/* Face browser was used to select a user,
just completely rewhack everything since it
seems various PAM implementations are
having goats with just setting PAM_USER
and trying to pam_authenticate again */
g_free (login);
login = selected_user;
selected_user = NULL;
mdm_sigterm_block_push ();
mdm_sigchld_block_push ();
tmp_pamh = pamh;
pamh = NULL;
mdm_sigchld_block_pop ();
mdm_sigterm_block_pop ();
/* FIXME: what about errors */
/* really this has been a sucess, not a failure */
pam_end (tmp_pamh, pamerr);
g_free (prev_user);
prev_user = NULL;
auth_retries = 0;
mdm_slave_greeter_ctl_no_ret (MDM_SETLOGIN, login);
goto authenticate_again;
}
if (started_timer)
mdm_slave_greeter_ctl_no_ret (MDM_STOPTIMER, "");
if (mdm_slave_action_pending ()) {
/* FIXME: see note above about PAM_FAIL_DELAY */
/* #ifndef PAM_FAIL_DELAY */
mdm_sleep_no_signal (mdm_daemon_config_get_value_int (MDM_KEY_RETRY_DELAY));
/* wait up to 100ms randomly */
usleep (g_random_int_range (0, 100000));
/* #endif */ /* PAM_FAIL_DELAY */
mdm_error ("Couldn't authenticate user");
if (prev_user) {
unsigned max_auth_retries = 3;
char *val = mdm_read_default ("LOGIN_RETRIES=");
if (val) {
max_auth_retries = atoi (val);
g_free (val);
}
if (allow_retry == FALSE || pamerr == PAM_MAXTRIES ||
++auth_retries >= max_auth_retries) {
g_free (prev_user);
prev_user = NULL;
auth_retries = 0;
}
}
} else {
/* cancel, configurator etc pressed */
g_free (prev_user);
prev_user = NULL;
auth_retries = 0;
}
goto pamerr;
}
/* stop the timer for timed logins */
if (started_timer)
mdm_slave_greeter_ctl_no_ret (MDM_STOPTIMER, "");
g_free (login);
login = NULL;
g_free (prev_user);
prev_user = NULL;
if ((pamerr = pam_get_item (pamh, PAM_USER, &p)) != PAM_SUCCESS) {
login = NULL;
/* is not really an auth problem, but it will
pretty much look as such, it shouldn't really
happen */
if (mdm_slave_action_pending ())
mdm_error ("Couldn't authenticate user");
goto pamerr;
}
login = g_strdup ((const char *)p);
/* kind of anal, the greeter likely already knows, but it could have
been changed */
mdm_slave_greeter_ctl_no_ret (MDM_SETLOGIN, login);
if ( ! mdm_slave_check_user_wants_to_log_in (login)) {
/* cleanup stuff */
mdm_slave_greeter_ctl_no_ret (MDM_SETLOGIN, "");
g_free (login);
login = NULL;
mdm_slave_greeter_ctl_no_ret (MDM_RESETOK, "");
mdm_verify_cleanup (d);
goto verify_user_again;
}
/* Check if user is root and is allowed to log in */
pwent = getpwnam (login);
if (( ! mdm_daemon_config_get_value_bool (MDM_KEY_ALLOW_ROOT) ||
( ! d->attached )) &&
(pwent != NULL && pwent->pw_uid == 0)) {
mdm_error ("Root login disallowed on display '%s'", d->name);
mdm_slave_greeter_ctl_no_ret (MDM_ERRBOX,
_("\nThe system administrator "
"is not allowed to login "
"from this screen"));
/*mdm_slave_greeter_ctl_no_ret (MDM_ERRDLG,
_("Root login disallowed"));*/
error_msg_given = TRUE;
goto pamerr;
}
if (mdm_daemon_config_get_value_bool (MDM_KEY_DISPLAY_LAST_LOGIN)) {
char *info = mdm_get_last_info (login);
mdm_slave_greeter_ctl_no_ret (MDM_MSG, info);
g_free (info);
}
/* Check if the user's account is healthy. */
pamerr = pam_acct_mgmt (pamh, null_tok);
switch (pamerr) {
case PAM_SUCCESS :
break;
case PAM_NEW_AUTHTOK_REQD :
if ((pamerr = pam_chauthtok (pamh, PAM_CHANGE_EXPIRED_AUTHTOK)) != PAM_SUCCESS) {
mdm_error ("Authentication token change failed for user %s", login);
mdm_slave_greeter_ctl_no_ret (MDM_ERRBOX,
_("\nThe change of the authentication token failed. "
"Please try again later or contact the system administrator."));
error_msg_given = TRUE;
goto pamerr;
}
break;
case PAM_ACCT_EXPIRED :
mdm_error ("User %s no longer permitted to access the system", login);
mdm_slave_greeter_ctl_no_ret (MDM_ERRBOX,
_("\nThe system administrator has disabled your account."));
error_msg_given = TRUE;
goto pamerr;
case PAM_PERM_DENIED :
mdm_error ("User %s not permitted to gain access at this time", login);
mdm_slave_greeter_ctl_no_ret (MDM_ERRBOX,
_("\nThe system administrator has disabled access to the system temporarily."));
error_msg_given = TRUE;
goto pamerr;
default :
if (mdm_slave_action_pending ())
mdm_error ("Couldn't set acct. mgmt for %s", login);
goto pamerr;
}
pwent = getpwnam (login);
if (/* paranoia */ pwent == NULL ||
! mdm_setup_gids (login, pwent->pw_gid)) {
mdm_error ("Cannot set user group for %s", login);
mdm_slave_greeter_ctl_no_ret (MDM_ERRBOX,
_("\nCannot set your user group; "
"you will not be able to log in. "
"Please contact your system administrator."));
goto pamerr;
}
did_setcred = TRUE;
/* Set credentials */
pamerr = pam_setcred (pamh, PAM_ESTABLISH_CRED);
if (pamerr != PAM_SUCCESS) {
did_setcred = FALSE;
if (mdm_slave_action_pending ())
mdm_error ("Couldn't set credentials for %s", login);
goto pamerr;
}
credentials_set = TRUE;
opened_session = TRUE;
/* Register the session */
pamerr = pam_open_session (pamh, 0);
if (pamerr != PAM_SUCCESS) {
opened_session = FALSE;
/* we handle this above */
did_setcred = FALSE;
if (mdm_slave_action_pending ())
mdm_error ("Couldn't open session for %s", login);
goto pamerr;
}
/* Workaround to avoid mdm messages being logged as PAM_pwdb */
mdm_log_shutdown ();
mdm_log_init ();
cur_mdm_disp = NULL;
/*
* Login succeeded.
* This function is a no-op if libaudit is not present.
*/
log_to_audit_system(login, d->hostname, d->name, AU_SUCCESS);
return login;
pamerr:
/*
* Take care of situation where we get here before setting pwent.
* Since login can be passed in as NULL, get the actual value if
* possible.
*/
if ((pam_get_item (pamh, PAM_USER, &p)) == PAM_SUCCESS) {
g_free (login);
login = g_strdup ((const char *)p);
}
if (pwent == NULL && login != NULL) {
pwent = getpwnam (login);
}
/*
* Log the failed login attempt.
* This function is a no-op if libaudit is not present.
*/
log_to_audit_system(login, d->hostname, d->name, AU_FAILED);
/* The verbose authentication is turned on, output the error
* message from the PAM subsystem */
if ( ! error_msg_given &&
mdm_slave_action_pending ()) {
mdm_slave_write_utmp_wtmp_record (d,
MDM_SESSION_RECORD_TYPE_FAILED_ATTEMPT,
login, getpid ());
/*
* I'm not sure yet if I should display this message for any
* other issues - heeten
* Adding AUTHINFO_UNAVAIL to the list - its what an unknown
* user is.
*/
if (pamerr == PAM_AUTH_ERR ||
pamerr == PAM_USER_UNKNOWN ||
pamerr == PAM_AUTHINFO_UNAVAIL) {
gboolean is_capslock = FALSE;
const char *basemsg;
char *msg;
char *ret;
ret = mdm_slave_greeter_ctl (MDM_QUERY_CAPSLOCK, "");
if ( ! ve_string_empty (ret))
is_capslock = TRUE;
g_free (ret);
/* Only give this message if we actually asked for
password, otherwise it would be silly to say that
the password may have been wrong */
if (did_we_ask_for_password) {
basemsg = _("\nIncorrect username or password. "
"Letters must be typed in the correct "
"case.");
} else {
basemsg = _("\nAuthentication failed. "
"Letters must be typed in the correct "
"case.");
}
if (is_capslock) {
msg = g_strconcat (basemsg, " ",
_("Caps Lock is on."),
NULL);
} else {
msg = g_strdup (basemsg);
}
mdm_slave_greeter_ctl_no_ret (MDM_ERRBOX, msg);
g_free (msg);
} else {
mdm_slave_greeter_ctl_no_ret (MDM_ERRDLG, _("Authentication failed"));
}
}
did_setcred = FALSE;
opened_session = FALSE;
if (pamh != NULL) {
pam_handle_t *tmp_pamh;
mdm_sigterm_block_push ();
mdm_sigchld_block_push ();
tmp_pamh = pamh;
pamh = NULL;
mdm_sigchld_block_pop ();
mdm_sigterm_block_pop ();
/* Throw away the credentials */
if (credentials_set)
pam_setcred (tmp_pamh, PAM_DELETE_CRED);
pam_end (tmp_pamh, pamerr);
}
pamh = NULL;
/* Workaround to avoid mdm messages being logged as PAM_pwdb */
mdm_log_shutdown ();
mdm_log_init ();
g_free (login);
cur_mdm_disp = NULL;
return NULL;
}
