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 * $FreeBSD: head/lib/libpam/modules/pam_guest/pam_guest.c 326219 2017-11-26 02:00:33Z pfg $ 37 */ 38 39 #include <string.h> 40 41 #define PAM_SM_AUTH 42 43 #include <security/pam_appl.h> 44 #include <security/pam_modules.h> 45 #include <security/openpam.h> 46 47 #define DEFAULT_GUESTS "guest" 48 49 static int 50 lookup(const char *str, const char *list) 51 { 52 const char *next; 53 size_t len; 54 55 len = strlen(str); 56 while (*list != '\0') { 57 while (*list == ',') 58 ++list; 59 if ((next = strchr(list, ',')) == NULL) 60 next = strchr(list, '\0'); 61 if (next - list == (ptrdiff_t)len && 62 strncmp(list, str, len) == 0) 63 return (1); 64 list = next; 65 } 66 return (0); 67 } 68 69 PAM_EXTERN int 70 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 71 int argc __unused, const char *argv[] __unused) 72 { 73 const char *authtok, *guests, *user; 74 int err, is_guest; 75 76 /* get target account */ 77 if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL) 78 return (PAM_AUTH_ERR); 79 80 /* get list of guest logins */ 81 if ((guests = openpam_get_option(pamh, "guests")) == NULL) 82 guests = DEFAULT_GUESTS; 83 84 /* check if the target account is on the list */ 85 is_guest = lookup(user, guests); 86 87 /* check password */ 88 if (!openpam_get_option(pamh, "nopass")) { 89 err = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL); 90 if (err != PAM_SUCCESS) 91 return (err); 92 if (openpam_get_option(pamh, "pass_is_user") && 93 strcmp(user, authtok) != 0) 94 return (PAM_AUTH_ERR); 95 if (openpam_get_option(pamh, "pass_as_ruser")) 96 pam_set_item(pamh, PAM_RUSER, authtok); 97 } 98 99 /* done */ 100 if (is_guest) { 101 pam_setenv(pamh, "GUEST", user, 1); 102 return (PAM_SUCCESS); 103 } 104 return (PAM_AUTH_ERR); 105 } 106 107 PAM_EXTERN int 108 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused, 109 int argc __unused, const char *argv[] __unused) 110 { 111 112 return (PAM_SUCCESS); 113 } 114 115 PAM_MODULE_ENTRY("pam_guest"); 116