1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 __FBSDID("$FreeBSD$"); 39 40 #include <string.h> 41 42 #define PAM_SM_AUTH 43 44 #include <security/pam_appl.h> 45 #include <security/pam_modules.h> 46 #include <security/openpam.h> 47 48 #define DEFAULT_GUESTS "guest" 49 50 static int 51 lookup(const char *str, const char *list) 52 { 53 const char *next; 54 size_t len; 55 56 len = strlen(str); 57 while (*list != '\0') { 58 while (*list == ',') 59 ++list; 60 if ((next = strchr(list, ',')) == NULL) 61 next = strchr(list, '\0'); 62 if (next - list == (ptrdiff_t)len && 63 strncmp(list, str, len) == 0) 64 return (1); 65 list = next; 66 } 67 return (0); 68 } 69 70 PAM_EXTERN int 71 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 72 int argc __unused, const char *argv[] __unused) 73 { 74 const char *authtok, *guests, *user; 75 int err, is_guest; 76 77 /* get target account */ 78 if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL) 79 return (PAM_AUTH_ERR); 80 81 /* get list of guest logins */ 82 if ((guests = openpam_get_option(pamh, "guests")) == NULL) 83 guests = DEFAULT_GUESTS; 84 85 /* check if the target account is on the list */ 86 is_guest = lookup(user, guests); 87 88 /* check password */ 89 if (!openpam_get_option(pamh, "nopass")) { 90 err = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL); 91 if (err != PAM_SUCCESS) 92 return (err); 93 if (openpam_get_option(pamh, "pass_is_user") && 94 strcmp(user, authtok) != 0) 95 return (PAM_AUTH_ERR); 96 if (openpam_get_option(pamh, "pass_as_ruser")) 97 pam_set_item(pamh, PAM_RUSER, authtok); 98 } 99 100 /* done */ 101 if (is_guest) { 102 pam_setenv(pamh, "GUEST", user, 1); 103 return (PAM_SUCCESS); 104 } 105 return (PAM_AUTH_ERR); 106 } 107 108 PAM_EXTERN int 109 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused, 110 int argc __unused, const char *argv[] __unused) 111 { 112 113 return (PAM_SUCCESS); 114 } 115 116 PAM_MODULE_ENTRY("pam_guest"); 117