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/*
* pam_unix account management
*
* Copyright Elliot Lee, 1996. All rights reserved.
* Copyright Jan Rękorajski, 1999. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, and the entire permission notice in its entirety,
* including the disclaimer of warranties.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <syslog.h>
#include <pwd.h>
#include <shadow.h>
#include <time.h> /* for time() */
#include <errno.h>
#include <sys/wait.h>
#include <security/_pam_macros.h>
#include <security/pam_modules.h>
#include <security/pam_ext.h>
#include <security/pam_modutil.h>
#include "pam_cc_compat.h"
#include "support.h"
#include "passverify.h"
int _unix_run_verify_binary(pam_handle_t *pamh, unsigned long long ctrl,
const char *user, int *daysleft)
{
int retval=0, child, fds[2];
struct sigaction newsa, oldsa;
D(("running verify_binary"));
/* create a pipe for the messages */
if (pipe(fds) != 0) {
D(("could not make pipe"));
pam_syslog(pamh, LOG_ERR, "Could not make pipe: %m");
return PAM_AUTH_ERR;
}
D(("called."));
if (off(UNIX_NOREAP, ctrl)) {
/*
* This code arranges that the demise of the child does not cause
* the application to receive a signal it is not expecting - which
* may kill the application or worse.
*
* The "noreap" module argument is provided so that the admin can
* override this behavior.
*/
memset(&newsa, '\0', sizeof(newsa));
newsa.sa_handler = SIG_DFL;
sigaction(SIGCHLD, &newsa, &oldsa);
}
/* fork */
child = fork();
if (child == 0) {
static char *envp[] = { NULL };
const char *args[] = { NULL, NULL, NULL, NULL };
/* XXX - should really tidy up PAM here too */
/* reopen stdout as pipe */
if (dup2(fds[1], STDOUT_FILENO) != STDOUT_FILENO) {
pam_syslog(pamh, LOG_ERR, "dup2 of %s failed: %m", "stdout");
_exit(PAM_AUTHINFO_UNAVAIL);
}
if (pam_modutil_sanitize_helper_fds(pamh, PAM_MODUTIL_PIPE_FD,
PAM_MODUTIL_IGNORE_FD,
PAM_MODUTIL_PIPE_FD) < 0) {
_exit(PAM_AUTHINFO_UNAVAIL);
}
if (geteuid() == 0) {
/* must set the real uid to 0 so the helper will not error
out if pam is called from setuid binary (su, sudo...) */
if (setuid(0) == -1) {
pam_syslog(pamh, LOG_ERR, "setuid failed: %m");
printf("-1\n");
fflush(stdout);
_exit(PAM_AUTHINFO_UNAVAIL);
}
}
/* exec binary helper */
args[0] = CHKPWD_HELPER;
args[1] = user;
args[2] = "chkexpiry";
DIAG_PUSH_IGNORE_CAST_QUAL;
execve(CHKPWD_HELPER, (char *const *) args, envp);
DIAG_POP_IGNORE_CAST_QUAL;
pam_syslog(pamh, LOG_ERR, "helper binary execve failed: %m");
/* should not get here: exit with error */
D(("helper binary is not available"));
printf("-1\n");
fflush(stdout);
_exit(PAM_AUTHINFO_UNAVAIL);
} else {
close(fds[1]);
if (child > 0) {
char buf[32];
int rc=0;
/* wait for helper to complete: */
while ((rc=waitpid(child, &retval, 0)) < 0 && errno == EINTR);
if (rc<0) {
pam_syslog(pamh, LOG_ERR, "unix_chkpwd waitpid returned %d: %m", rc);
retval = PAM_AUTH_ERR;
} else if (!WIFEXITED(retval)) {
pam_syslog(pamh, LOG_ERR, "unix_chkpwd abnormal exit: %d", retval);
retval = PAM_AUTH_ERR;
} else {
retval = WEXITSTATUS(retval);
rc = pam_modutil_read(fds[0], buf, sizeof(buf) - 1);
if(rc > 0) {
buf[rc] = '\0';
if (sscanf(buf,"%d", daysleft) != 1 )
retval = PAM_AUTH_ERR;
}
else {
pam_syslog(pamh, LOG_ERR, "read unix_chkpwd output error %d: %m", rc);
retval = PAM_AUTH_ERR;
}
}
} else {
pam_syslog(pamh, LOG_ERR, "Fork failed: %m");
D(("fork failed"));
retval = PAM_AUTH_ERR;
}
close(fds[0]);
}
if (off(UNIX_NOREAP, ctrl)) {
sigaction(SIGCHLD, &oldsa, NULL); /* restore old signal handler */
}
D(("Returning %d",retval));
return retval;
}
/*
* PAM framework looks for this entry-point to pass control to the
* account management module.
*/
int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
unsigned long long ctrl;
const void *void_uname;
const char *uname;
int retval, daysleft = -1;
char buf[256];
D(("called."));
ctrl = _set_ctrl(pamh, flags, NULL, NULL, NULL, argc, argv);
retval = pam_get_item(pamh, PAM_USER, &void_uname);
uname = void_uname;
D(("user = `%s'", uname));
if (retval != PAM_SUCCESS || uname == NULL) {
pam_syslog(pamh, LOG_ERR,
"could not identify user (from uid=%lu)",
(unsigned long int)getuid());
return PAM_USER_UNKNOWN;
}
retval = _unix_verify_user(pamh, ctrl, uname, &daysleft);
if (on(UNIX_NO_PASS_EXPIRY, ctrl)) {
const void *pretval = NULL;
int authrv = PAM_AUTHINFO_UNAVAIL; /* authentication not called */
if (pam_get_data(pamh, "unix_setcred_return", &pretval) == PAM_SUCCESS
&& pretval)
authrv = *(const int *)pretval;
if (authrv != PAM_SUCCESS
&& (retval == PAM_NEW_AUTHTOK_REQD || retval == PAM_AUTHTOK_EXPIRED))
retval = PAM_SUCCESS;
}
switch (retval) {
case PAM_ACCT_EXPIRED:
pam_syslog(pamh, LOG_NOTICE,
"account %s has expired (account expired)",
uname);
_make_remark(pamh, ctrl, PAM_ERROR_MSG,
_("Your account has expired; please contact your system administrator."));
break;
case PAM_NEW_AUTHTOK_REQD:
if (daysleft == 0) {
pam_syslog(pamh, LOG_NOTICE,
"expired password for user %s (root enforced)",
uname);
_make_remark(pamh, ctrl, PAM_ERROR_MSG,
_("You are required to change your password immediately (administrator enforced)."));
} else {
pam_syslog(pamh, LOG_DEBUG,
"expired password for user %s (password aged)",
uname);
_make_remark(pamh, ctrl, PAM_ERROR_MSG,
_("You are required to change your password immediately (password expired)."));
}
break;
case PAM_AUTHTOK_EXPIRED:
pam_syslog(pamh, LOG_NOTICE,
"account %s has expired (failed to change password)",
uname);
_make_remark(pamh, ctrl, PAM_ERROR_MSG,
_("Your account has expired; please contact your system administrator."));
break;
case PAM_AUTHTOK_ERR:
/*
* We ignore "password changed too early" error
* as it is relevant only for password change.
*/
retval = PAM_SUCCESS;
/* fallthrough */
case PAM_SUCCESS:
if (daysleft >= 0) {
pam_syslog(pamh, LOG_DEBUG,
"password for user %s will expire in %d days",
uname, daysleft);
#if defined HAVE_DNGETTEXT && defined ENABLE_NLS
snprintf (buf, sizeof (buf),
dngettext(PACKAGE,
"Warning: your password will expire in %d day.",
"Warning: your password will expire in %d days.",
daysleft),
daysleft);
#else
if (daysleft == 1)
snprintf(buf, sizeof (buf),
_("Warning: your password will expire in %d day."),
daysleft);
else
snprintf(buf, sizeof (buf),
/* TRANSLATORS: only used if dngettext is not supported */
_("Warning: your password will expire in %d days."),
daysleft);
#endif
_make_remark(pamh, ctrl, PAM_TEXT_INFO, buf);
}
}
D(("all done"));
return retval;
}
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