1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2001 Mark R V Murray 5 * All rights reserved. 6 * Copyright (c) 2001,2002 Networks Associates Technology, Inc. 7 * All rights reserved. 8 * 9 * Portions of this software were developed for the FreeBSD Project by 10 * ThinkSec AS and NAI Labs, the Security Research Division of Network 11 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 12 * ("CBOSS"), as part of the DARPA CHATS research program. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. The name of the author may not be used to endorse or promote 23 * products derived from this software without specific prior written 24 * permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 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