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/* pam_rootok module */
/*
* $Id$
*
* Written by Andrew Morgan <morgan@linux.kernel.org> 1996/3/11
*/
#include "config.h"
#include <stdio.h>
#include <unistd.h>
#include <syslog.h>
#include <stdarg.h>
#include <string.h>
/*
* here, we make a definition for the externally accessible function
* in this file (this definition is required for static a module
* but strongly encouraged generally) it is used to instruct the
* modules include file to define the function prototypes.
*/
#define PAM_SM_AUTH
#include <security/pam_modules.h>
#include <security/pam_ext.h>
#ifdef WITH_SELINUX
#include <selinux/selinux.h>
#include <selinux/avc.h>
#endif
#ifdef HAVE_LIBAUDIT
#include <libaudit.h>
#endif
/* argument parsing */
#define PAM_DEBUG_ARG 01
static int
_pam_parse (const pam_handle_t *pamh, int argc, const char **argv)
{
int ctrl=0;
/* step through arguments */
for (ctrl=0; argc-- > 0; ++argv) {
/* generic options */
if (!strcmp(*argv,"debug"))
ctrl |= PAM_DEBUG_ARG;
else {
pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv);
}
}
return ctrl;
}
#ifdef WITH_SELINUX
static int
log_callback (int type, const char *fmt, ...)
{
int audit_fd;
va_list ap;
va_start(ap, fmt);
#ifdef HAVE_LIBAUDIT
audit_fd = audit_open();
if (audit_fd >= 0) {
char *buf;
if (vasprintf (&buf, fmt, ap) < 0)
return 0;
audit_log_user_avc_message(audit_fd, AUDIT_USER_AVC, buf, NULL, NULL,
NULL, 0);
audit_close(audit_fd);
free(buf);
return 0;
}
#endif
vsyslog (LOG_USER | LOG_INFO, fmt, ap);
va_end(ap);
return 0;
}
static int
selinux_check_root (void)
{
int status = -1;
security_context_t user_context;
union selinux_callback old_callback;
if (is_selinux_enabled() < 1)
return 0;
old_callback = selinux_get_callback(SELINUX_CB_LOG);
/* setup callbacks */
selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) &log_callback);
if ((status = getprevcon(&user_context)) < 0) {
selinux_set_callback(SELINUX_CB_LOG, old_callback);
return status;
}
status = selinux_check_access(user_context, user_context, "passwd", "passwd", NULL);
selinux_set_callback(SELINUX_CB_LOG, old_callback);
freecon(user_context);
return status;
}
#endif
static int
check_for_root (pam_handle_t *pamh, int ctrl)
{
int retval = PAM_AUTH_ERR;
if (getuid() == 0)
#ifdef WITH_SELINUX
if (selinux_check_root() == 0 || security_getenforce() == 0)
#endif
retval = PAM_SUCCESS;
if (ctrl & PAM_DEBUG_ARG) {
pam_syslog(pamh, LOG_DEBUG, "root check %s",
(retval==PAM_SUCCESS) ? "succeeded" : "failed");
}
return retval;
}
/* --- management functions --- */
PAM_EXTERN int
pam_sm_authenticate (pam_handle_t *pamh, int flags UNUSED,
int argc, const char **argv)
{
int ctrl;
ctrl = _pam_parse(pamh, argc, argv);
return check_for_root (pamh, ctrl);
}
PAM_EXTERN int
pam_sm_setcred (pam_handle_t *pamh UNUSED, int flags UNUSED,
int argc UNUSED, const char **argv UNUSED)
{
return PAM_SUCCESS;
}
PAM_EXTERN int
pam_sm_acct_mgmt (pam_handle_t *pamh, int flags UNUSED,
int argc, const char **argv)
{
int ctrl;
ctrl = _pam_parse(pamh, argc, argv);
return check_for_root (pamh, ctrl);
}
PAM_EXTERN int
pam_sm_chauthtok (pam_handle_t *pamh, int flags UNUSED,
int argc, const char **argv)
{
int ctrl;
ctrl = _pam_parse(pamh, argc, argv);
return check_for_root (pamh, ctrl);
}
#ifdef PAM_STATIC
/* static module data */
struct pam_module _pam_rootok_modstruct = {
"pam_rootok",
pam_sm_authenticate,
pam_sm_setcred,
pam_sm_acct_mgmt,
NULL,
NULL,
pam_sm_chauthtok,
};
#endif
/* end of module definition */
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