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pam_group.c revision 1.3 
      1 /*	$NetBSD: pam_group.c,v 1.3 2005/02/01 22:55:11 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003 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 #ifdef __FreeBSD__
     39 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_group/pam_group.c,v 1.4 2003/12/11 13:55:15 des Exp $");
     40 #else
     41 __RCSID("$NetBSD: pam_group.c,v 1.3 2005/02/01 22:55:11 christos Exp $");
     42 #endif
     43 
     44 #include <sys/types.h>
     45 
     46 #include <grp.h>
     47 #include <pwd.h>
     48 #include <stdarg.h>
     49 #include <stdio.h>
     50 #include <string.h>
     51 #include <syslog.h>
     52 #include <unistd.h>
     53 #include <login_cap.h>
     54 
     55 #define PAM_SM_AUTH
     56 
     57 #include <security/pam_appl.h>
     58 #include <security/pam_modules.h>
     59 #include <security/pam_mod_misc.h>
     60 #include <security/openpam.h>
     61 
     62 static int authenticate(pam_handle_t *, struct passwd *, int);
     63 
     64 PAM_EXTERN int
     65 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
     66     int argc __unused, const char *argv[] __unused)
     67 {
     68 	const char *group, *user;
     69 	const void *ruser;
     70 	char *const *list;
     71 	struct passwd *pwd;
     72 	struct group *grp;
     73 	int pam_err;
     74 
     75 	/* get target account */
     76 	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
     77 	    user == NULL || (pwd = getpwnam(user)) == NULL)
     78 		return (PAM_AUTH_ERR);
     79 	if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
     80 		return (PAM_IGNORE);
     81 
     82 	/* get applicant */
     83 	if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS
     84 	    || ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
     85 		return (PAM_AUTH_ERR);
     86 
     87 	/* get regulating group */
     88 	if ((group = openpam_get_option(pamh, "group")) == NULL)
     89 		group = "wheel";
     90 	if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
     91 		goto failed;
     92 
     93 	/* check if the group is empty */
     94 	if (*grp->gr_mem == NULL)
     95 		goto failed;
     96 
     97 	/* check membership */
     98 	if (pwd->pw_gid == grp->gr_gid)
     99 		goto found;
    100 	for (list = grp->gr_mem; *list != NULL; ++list)
    101 		if (strcmp(*list, pwd->pw_name) == 0)
    102 			goto found;
    103 
    104  not_found:
    105 	if (openpam_get_option(pamh, "deny"))
    106 		return (PAM_SUCCESS);
    107 	return (PAM_AUTH_ERR);
    108  found:
    109 	if (openpam_get_option(pamh, "authenticate"))
    110 		if ((pam_err = authenticate(pamh, pwd, flags)) != PAM_SUCCESS)
    111 			return pam_err;
    112 
    113 	if (openpam_get_option(pamh, "deny"))
    114 		return (PAM_AUTH_ERR);
    115 	return (PAM_SUCCESS);
    116  failed:
    117 	if (openpam_get_option(pamh, "fail_safe"))
    118 		goto found;
    119 	else
    120 		goto not_found;
    121 }
    122 
    123 PAM_EXTERN int
    124 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
    125     int argc __unused, const char *argv[] __unused)
    126 {
    127 
    128 	return (PAM_SUCCESS);
    129 }
    130 
    131 static int
    132 authenticate(pam_handle_t *pamh, struct passwd *pwd, int flags)
    133 {
    134 	int retval;
    135 	login_cap_t *lc;
    136 	const char *pass;
    137 
    138 	lc = login_getpwclass(pwd);
    139 	retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, NULL);
    140 	login_close(lc);
    141 
    142 	if (retval != PAM_SUCCESS)
    143 		return retval;
    144         PAM_LOG("Got password");
    145         if (strcmp(crypt(pass, pwd->pw_passwd), pwd->pw_passwd) == 0)
    146                 return PAM_SUCCESS;
    147 
    148         PAM_VERBOSE_ERROR("UNIX authentication refused");
    149         return PAM_AUTH_ERR;
    150 }
    151 
    152 
    153 PAM_MODULE_ENTRY("pam_group");
    154