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/*-
* Copyright (c) 2001 Mark R V Murray
* 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, this list of conditions and the following disclaimer.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define _BSD_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <stdarg.h>
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
#define PAM_SM_AUTH
#include <security/pam_modules.h>
#include <pam_mod_misc.h>
enum { PAM_OPT_DENY=PAM_OPT_STD_MAX, PAM_OPT_GROUP, PAM_OPT_TRUST,
PAM_OPT_AUTH_AS_SELF, PAM_OPT_NOROOT_OK };
static struct opttab other_options[] = {
{ "deny", PAM_OPT_DENY },
{ "group", PAM_OPT_GROUP },
{ "trust", PAM_OPT_TRUST },
{ "auth_as_self", PAM_OPT_AUTH_AS_SELF },
{ "noroot_ok", PAM_OPT_NOROOT_OK },
{ NULL, 0 }
};
/* Is member in list? */
static int
in_list(char *const *list, const char *member)
{
for (; *list; list++)
if (strcmp(*list, member) == 0)
return 1;
return 0;
}
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh, int flags, int argc, const char **argv)
{
struct options options;
struct passwd *pwd;
struct group *grp;
int retval;
uid_t tuid;
const char *user, *targetuser;
char *use_group;
pam_std_option(&options, other_options, argc, argv);
PAM_LOG("Options processed");
retval = pam_get_user(pamh, &targetuser, NULL);
if (retval != PAM_SUCCESS)
PAM_RETURN(retval);
pwd = getpwnam(targetuser);
if (pwd != NULL)
tuid = pwd->pw_uid;
else
PAM_RETURN(PAM_AUTH_ERR);
PAM_LOG("Got target user: %s uid: %d", targetuser, tuid);
if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) {
pwd = getpwnam(getlogin());
user = strdup(pwd->pw_name);
}
else {
user = targetuser;
pwd = getpwnam(user);
}
if (pwd == NULL)
PAM_RETURN(PAM_AUTH_ERR);
PAM_LOG("Got user: %s", user);
PAM_LOG("User's primary uid, gid: %d, %d", pwd->pw_uid, pwd->pw_gid);
/* Ignore if already uid 0 */
if (pwd->pw_uid == 0)
PAM_RETURN(PAM_IGNORE);
PAM_LOG("Not superuser");
/* If authenticating as something non-superuser, return OK */
if (pam_test_option(&options, PAM_OPT_NOROOT_OK, NULL))
if (tuid != 0)
PAM_RETURN(PAM_SUCCESS);
PAM_LOG("Checking group");
if (!pam_test_option(&options, PAM_OPT_GROUP, &use_group)) {
if ((grp = getgrnam("wheel")) == NULL)
grp = getgrgid(0);
}
else
grp = getgrnam(use_group);
if (grp == NULL || grp->gr_mem == NULL) {
if (pam_test_option(&options, PAM_OPT_DENY, NULL))
PAM_RETURN(PAM_IGNORE);
else {
PAM_VERBOSE_ERROR("Permission denied");
PAM_RETURN(PAM_AUTH_ERR);
}
}
PAM_LOG("Got group: %s", grp->gr_name);
if (pwd->pw_gid == grp->gr_gid || in_list(grp->gr_mem, pwd->pw_name)) {
if (pam_test_option(&options, PAM_OPT_DENY, NULL)) {
PAM_VERBOSE_ERROR("Member of group %s; denied",
grp->gr_name);
PAM_RETURN(PAM_PERM_DENIED);
}
if (pam_test_option(&options, PAM_OPT_TRUST, NULL))
PAM_RETURN(PAM_SUCCESS);
PAM_RETURN(PAM_IGNORE);
}
if (pam_test_option(&options, PAM_OPT_DENY, NULL))
PAM_RETURN(PAM_SUCCESS);
PAM_VERBOSE_ERROR("Not member of group %s; denied", grp->gr_name);
PAM_RETURN(PAM_PERM_DENIED);
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh, int flags, int argc, const char **argv)
{
struct options options;
pam_std_option(&options, other_options, argc, argv);
PAM_LOG("Options processed");
PAM_RETURN(PAM_SUCCESS);
}
PAM_MODULE_ENTRY("pam_wheel");
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