Home | History | Annotate | Line # | Download | only in pam_self
pam_self.c revision 1.1 
      1 /*-
      2  * Copyright (c) 2001 Mark R V Murray
      3  * All rights reserved.
      4  * Copyright (c) 2001,2002 Networks Associates Technology, Inc.
      5  * All rights reserved.
      6  *
      7  * Portions of this software were developed for the FreeBSD Project by
      8  * ThinkSec AS and NAI Labs, the Security Research Division of Network
      9  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
     10  * ("CBOSS"), as part of the DARPA CHATS research program.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. The name of the author may not be used to endorse or promote
     21  *    products derived from this software without specific prior written
     22  *    permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_self/pam_self.c,v 1.9 2002/04/12 22:27:24 des Exp $");
     39 
     40 #define _BSD_SOURCE
     41 
     42 #include <pwd.h>
     43 #include <unistd.h>
     44 #include <syslog.h>
     45 
     46 #define PAM_SM_AUTH
     47 
     48 #include <security/pam_appl.h>
     49 #include <security/pam_modules.h>
     50 #include <security/pam_mod_misc.h>
     51 
     52 #define OPT_ALLOW_ROOT "allow_root"
     53 
     54 PAM_EXTERN int
     55 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
     56     int argc __unused, const char *argv[] __unused)
     57 {
     58 	struct passwd *pwd;
     59 	const char *luser;
     60 	int pam_err;
     61 	uid_t uid;
     62 
     63 	pam_err = pam_get_user(pamh, &luser, NULL);
     64 	if (pam_err != PAM_SUCCESS)
     65 		return (pam_err);
     66 	if (luser == NULL || (pwd = getpwnam(luser)) == NULL)
     67 		return (PAM_AUTH_ERR);
     68 
     69 	uid = getuid();
     70 	if (uid == 0 && !openpam_get_option(pamh, OPT_ALLOW_ROOT))
     71 		return (PAM_AUTH_ERR);
     72 
     73 	if (uid == (uid_t)pwd->pw_uid)
     74 		return (PAM_SUCCESS);
     75 
     76 	PAM_VERBOSE_ERROR("Refused; source and target users differ");
     77 
     78 	return (PAM_AUTH_ERR);
     79 }
     80 
     81 PAM_EXTERN int
     82 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
     83     int argc __unused, const char *argv[] __unused)
     84 {
     85 
     86 	return (PAM_SUCCESS);
     87 }
     88 
     89 PAM_MODULE_ENTRY("pam_self");
     90