1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright 1998 Juniper Networks, Inc.
5 * All rights reserved.
6 * Copyright (c) 2001-2003 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 __FBSDID("$FreeBSD: stable/12/lib/libpam/modules/pam_tacplus/pam_tacplus.c 326219 2017-11-26 02:00:33Z pfg $");
41
42 #include <sys/param.h>
43
44 #include <pwd.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <syslog.h>
48 #include <taclib.h>
49 #include <unistd.h>
50
51 #define PAM_SM_AUTH
52
53 #include <security/pam_appl.h>
54 #include <security/pam_modules.h>
55 #include <security/pam_mod_misc.h>
56
57 #define PAM_OPT_CONF "conf"
58 #define PAM_OPT_TEMPLATE_USER "template_user"
59
60 typedef int (*set_func)(struct tac_handle *, const char *);
61
62 static int do_item(pam_handle_t *, struct tac_handle *, int,
63 set_func, const char *);
64 static char *get_msg(struct tac_handle *);
65 static int set_msg(struct tac_handle *, const char *);
66
67 static int
do_item(pam_handle_t * pamh,struct tac_handle * tach,int item,set_func func,const char * funcname)68 do_item(pam_handle_t *pamh, struct tac_handle *tach, int item,
69 set_func func, const char *funcname)
70 {
71 int retval;
72 const void *value;
73
74 retval = pam_get_item(pamh, item, &value);
75 if (retval != PAM_SUCCESS)
76 return retval;
77 if (value != NULL && (*func)(tach, (const char *)value) == -1) {
78 syslog(LOG_CRIT, "%s: %s", funcname, tac_strerror(tach));
79 tac_close(tach);
80 return PAM_SERVICE_ERR;
81 }
82 return PAM_SUCCESS;
83 }
84
85 static char *
get_msg(struct tac_handle * tach)86 get_msg(struct tac_handle *tach)
87 {
88 char *msg;
89
90 msg = tac_get_msg(tach);
91 if (msg == NULL) {
92 syslog(LOG_CRIT, "tac_get_msg: %s", tac_strerror(tach));
93 tac_close(tach);
94 return NULL;
95 }
96 return msg;
97 }
98
99 static int
set_msg(struct tac_handle * tach,const char * msg)100 set_msg(struct tac_handle *tach, const char *msg)
101 {
102 if (tac_set_msg(tach, msg) == -1) {
103 syslog(LOG_CRIT, "tac_set_msg: %s", tac_strerror(tach));
104 tac_close(tach);
105 return -1;
106 }
107 return 0;
108 }
109
110 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)111 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
112 int argc __unused, const char *argv[] __unused)
113 {
114 int retval;
115 struct tac_handle *tach;
116 const char *conf_file, *template_user;
117
118 conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
119 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
120
121 tach = tac_open();
122 if (tach == NULL) {
123 syslog(LOG_CRIT, "tac_open failed");
124 return (PAM_SERVICE_ERR);
125 }
126 if (tac_config(tach, conf_file) == -1) {
127 syslog(LOG_ALERT, "tac_config: %s", tac_strerror(tach));
128 tac_close(tach);
129 return (PAM_SERVICE_ERR);
130 }
131 if (tac_create_authen(tach, TAC_AUTHEN_LOGIN, TAC_AUTHEN_TYPE_ASCII,
132 TAC_AUTHEN_SVC_LOGIN) == -1) {
133 syslog(LOG_CRIT, "tac_create_authen: %s", tac_strerror(tach));
134 tac_close(tach);
135 return (PAM_SERVICE_ERR);
136 }
137
138 PAM_LOG("Done tac_open() ... tac_close()");
139
140 retval = do_item(pamh, tach, PAM_USER, tac_set_user, "tac_set_user");
141 if (retval != PAM_SUCCESS)
142 return (retval);
143
144 PAM_LOG("Done user");
145
146 retval = do_item(pamh, tach, PAM_TTY, tac_set_port, "tac_set_port");
147 if (retval != PAM_SUCCESS)
148 return (retval);
149
150 PAM_LOG("Done tty");
151
152 retval = do_item(pamh, tach, PAM_RHOST, tac_set_rem_addr,
153 "tac_set_rem_addr");
154 if (retval != PAM_SUCCESS)
155 return (retval);
156
157 for (;;) {
158 char *srvr_msg;
159 size_t msg_len;
160 const char *user_msg;
161 char *data_msg;
162 int sflags;
163 int status;
164
165 sflags = tac_send_authen(tach);
166 if (sflags == -1) {
167 syslog(LOG_CRIT, "tac_send_authen: %s",
168 tac_strerror(tach));
169 tac_close(tach);
170 return (PAM_AUTHINFO_UNAVAIL);
171 }
172 status = TAC_AUTHEN_STATUS(sflags);
173 openpam_set_option(pamh, PAM_OPT_ECHO_PASS,
174 TAC_AUTHEN_NOECHO(sflags) ? NULL : "");
175 switch (status) {
176
177 case TAC_AUTHEN_STATUS_PASS:
178 tac_close(tach);
179 if (template_user != NULL) {
180 const void *item;
181 const char *user;
182
183 PAM_LOG("Trying template user: %s",
184 template_user);
185
186 /*
187 * If the given user name doesn't exist in
188 * the local password database, change it
189 * to the value given in the "template_user"
190 * option.
191 */
192 retval = pam_get_item(pamh, PAM_USER, &item);
193 if (retval != PAM_SUCCESS)
194 return (retval);
195 user = (const char *)item;
196 if (getpwnam(user) == NULL) {
197 pam_set_item(pamh, PAM_USER,
198 template_user);
199 PAM_LOG("Using template user");
200 }
201 }
202 return (PAM_SUCCESS);
203
204 case TAC_AUTHEN_STATUS_FAIL:
205 tac_close(tach);
206 PAM_VERBOSE_ERROR("TACACS+ authentication failed");
207 return (PAM_AUTH_ERR);
208
209 case TAC_AUTHEN_STATUS_GETUSER:
210 case TAC_AUTHEN_STATUS_GETPASS:
211 if ((srvr_msg = get_msg(tach)) == NULL)
212 return (PAM_SERVICE_ERR);
213 if (status == TAC_AUTHEN_STATUS_GETUSER)
214 retval = pam_get_user(pamh, &user_msg,
215 *srvr_msg ? srvr_msg : NULL);
216 else if (status == TAC_AUTHEN_STATUS_GETPASS)
217 retval = pam_get_authtok(pamh,
218 PAM_AUTHTOK, &user_msg,
219 *srvr_msg ? srvr_msg : "Password:");
220 free(srvr_msg);
221 if (retval != PAM_SUCCESS) {
222 /* XXX - send a TACACS+ abort packet */
223 tac_close(tach);
224 return (retval);
225 }
226 if (set_msg(tach, user_msg) == -1)
227 return (PAM_SERVICE_ERR);
228 break;
229
230 case TAC_AUTHEN_STATUS_GETDATA:
231 if ((srvr_msg = get_msg(tach)) == NULL)
232 return (PAM_SERVICE_ERR);
233 retval = pam_prompt(pamh,
234 openpam_get_option(pamh, PAM_OPT_ECHO_PASS) ?
235 PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF,
236 &data_msg, "%s", *srvr_msg ? srvr_msg : "Data:");
237 free(srvr_msg);
238 if (retval != PAM_SUCCESS) {
239 /* XXX - send a TACACS+ abort packet */
240 tac_close(tach);
241 return (retval);
242 }
243 retval = set_msg(tach, data_msg);
244 memset(data_msg, 0, strlen(data_msg));
245 free(data_msg);
246 if (retval == -1)
247 return (PAM_SERVICE_ERR);
248 break;
249
250 case TAC_AUTHEN_STATUS_ERROR:
251 srvr_msg = (char *)tac_get_data(tach, &msg_len);
252 if (srvr_msg != NULL && msg_len != 0) {
253 syslog(LOG_CRIT, "tac_send_authen:"
254 " server detected error: %s", srvr_msg);
255 free(srvr_msg);
256 }
257 else
258 syslog(LOG_CRIT,
259 "tac_send_authen: server detected error");
260 tac_close(tach);
261 return (PAM_AUTHINFO_UNAVAIL);
262 break;
263
264 case TAC_AUTHEN_STATUS_RESTART:
265 case TAC_AUTHEN_STATUS_FOLLOW:
266 default:
267 syslog(LOG_CRIT,
268 "tac_send_authen: unexpected status %#x", status);
269 tac_close(tach);
270 return (PAM_AUTHINFO_UNAVAIL);
271 }
272 }
273 }
274
275 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)276 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
277 int argc __unused, const char *argv[] __unused)
278 {
279
280 return (PAM_IGNORE);
281 }
282
283 PAM_MODULE_ENTRY("pam_tacplus");
284