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/param.h>
40
41 #include <pwd.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <syslog.h>
45 #include <taclib.h>
46 #include <unistd.h>
47
48 #define PAM_SM_AUTH
49
50 #include <security/pam_appl.h>
51 #include <security/pam_modules.h>
52 #include <security/pam_mod_misc.h>
53
54 #define PAM_OPT_CONF "conf"
55 #define PAM_OPT_TEMPLATE_USER "template_user"
56
57 typedef int (*set_func)(struct tac_handle *, const char *);
58
59 static int do_item(pam_handle_t *, struct tac_handle *, int,
60 set_func, const char *);
61 static char *get_msg(struct tac_handle *);
62 static int set_msg(struct tac_handle *, const char *);
63
64 static int
do_item(pam_handle_t * pamh,struct tac_handle * tach,int item,set_func func,const char * funcname)65 do_item(pam_handle_t *pamh, struct tac_handle *tach, int item,
66 set_func func, const char *funcname)
67 {
68 int retval;
69 const void *value;
70
71 retval = pam_get_item(pamh, item, &value);
72 if (retval != PAM_SUCCESS)
73 return retval;
74 if (value != NULL && (*func)(tach, (const char *)value) == -1) {
75 syslog(LOG_CRIT, "%s: %s", funcname, tac_strerror(tach));
76 tac_close(tach);
77 return PAM_SERVICE_ERR;
78 }
79 return PAM_SUCCESS;
80 }
81
82 static char *
get_msg(struct tac_handle * tach)83 get_msg(struct tac_handle *tach)
84 {
85 char *msg;
86
87 msg = tac_get_msg(tach);
88 if (msg == NULL) {
89 syslog(LOG_CRIT, "tac_get_msg: %s", tac_strerror(tach));
90 tac_close(tach);
91 return NULL;
92 }
93 return msg;
94 }
95
96 static int
set_msg(struct tac_handle * tach,const char * msg)97 set_msg(struct tac_handle *tach, const char *msg)
98 {
99 if (tac_set_msg(tach, msg) == -1) {
100 syslog(LOG_CRIT, "tac_set_msg: %s", tac_strerror(tach));
101 tac_close(tach);
102 return -1;
103 }
104 return 0;
105 }
106
107 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)108 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
109 int argc __unused, const char *argv[] __unused)
110 {
111 int retval;
112 struct tac_handle *tach;
113 const char *conf_file, *template_user;
114
115 conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
116 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
117
118 tach = tac_open();
119 if (tach == NULL) {
120 syslog(LOG_CRIT, "tac_open failed");
121 return (PAM_SERVICE_ERR);
122 }
123 if (tac_config(tach, conf_file) == -1) {
124 syslog(LOG_ALERT, "tac_config: %s", tac_strerror(tach));
125 tac_close(tach);
126 return (PAM_SERVICE_ERR);
127 }
128 if (tac_create_authen(tach, TAC_AUTHEN_LOGIN, TAC_AUTHEN_TYPE_ASCII,
129 TAC_AUTHEN_SVC_LOGIN) == -1) {
130 syslog(LOG_CRIT, "tac_create_authen: %s", tac_strerror(tach));
131 tac_close(tach);
132 return (PAM_SERVICE_ERR);
133 }
134
135 PAM_LOG("Done tac_open() ... tac_close()");
136
137 retval = do_item(pamh, tach, PAM_USER, tac_set_user, "tac_set_user");
138 if (retval != PAM_SUCCESS)
139 return (retval);
140
141 PAM_LOG("Done user");
142
143 retval = do_item(pamh, tach, PAM_TTY, tac_set_port, "tac_set_port");
144 if (retval != PAM_SUCCESS)
145 return (retval);
146
147 PAM_LOG("Done tty");
148
149 retval = do_item(pamh, tach, PAM_RHOST, tac_set_rem_addr,
150 "tac_set_rem_addr");
151 if (retval != PAM_SUCCESS)
152 return (retval);
153
154 for (;;) {
155 char *srvr_msg;
156 size_t msg_len;
157 const char *user_msg;
158 char *data_msg;
159 int sflags;
160 int status;
161
162 sflags = tac_send_authen(tach);
163 if (sflags == -1) {
164 syslog(LOG_CRIT, "tac_send_authen: %s",
165 tac_strerror(tach));
166 tac_close(tach);
167 return (PAM_AUTHINFO_UNAVAIL);
168 }
169 status = TAC_AUTHEN_STATUS(sflags);
170 openpam_set_option(pamh, PAM_OPT_ECHO_PASS,
171 TAC_AUTHEN_NOECHO(sflags) ? NULL : "");
172 switch (status) {
173
174 case TAC_AUTHEN_STATUS_PASS:
175 tac_close(tach);
176 if (template_user != NULL) {
177 const void *item;
178 const char *user;
179
180 PAM_LOG("Trying template user: %s",
181 template_user);
182
183 /*
184 * If the given user name doesn't exist in
185 * the local password database, change it
186 * to the value given in the "template_user"
187 * option.
188 */
189 retval = pam_get_item(pamh, PAM_USER, &item);
190 if (retval != PAM_SUCCESS)
191 return (retval);
192 user = (const char *)item;
193 if (getpwnam(user) == NULL) {
194 pam_set_item(pamh, PAM_USER,
195 template_user);
196 PAM_LOG("Using template user");
197 }
198 }
199 return (PAM_SUCCESS);
200
201 case TAC_AUTHEN_STATUS_FAIL:
202 tac_close(tach);
203 PAM_VERBOSE_ERROR("TACACS+ authentication failed");
204 return (PAM_AUTH_ERR);
205
206 case TAC_AUTHEN_STATUS_GETUSER:
207 case TAC_AUTHEN_STATUS_GETPASS:
208 if ((srvr_msg = get_msg(tach)) == NULL)
209 return (PAM_SERVICE_ERR);
210 if (status == TAC_AUTHEN_STATUS_GETUSER)
211 retval = pam_get_user(pamh, &user_msg,
212 *srvr_msg ? srvr_msg : NULL);
213 else if (status == TAC_AUTHEN_STATUS_GETPASS)
214 retval = pam_get_authtok(pamh,
215 PAM_AUTHTOK, &user_msg,
216 *srvr_msg ? srvr_msg : "Password:");
217 free(srvr_msg);
218 if (retval != PAM_SUCCESS) {
219 /* XXX - send a TACACS+ abort packet */
220 tac_close(tach);
221 return (retval);
222 }
223 if (set_msg(tach, user_msg) == -1)
224 return (PAM_SERVICE_ERR);
225 break;
226
227 case TAC_AUTHEN_STATUS_GETDATA:
228 if ((srvr_msg = get_msg(tach)) == NULL)
229 return (PAM_SERVICE_ERR);
230 retval = pam_prompt(pamh,
231 openpam_get_option(pamh, PAM_OPT_ECHO_PASS) ?
232 PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF,
233 &data_msg, "%s", *srvr_msg ? srvr_msg : "Data:");
234 free(srvr_msg);
235 if (retval != PAM_SUCCESS) {
236 /* XXX - send a TACACS+ abort packet */
237 tac_close(tach);
238 return (retval);
239 }
240 retval = set_msg(tach, data_msg);
241 memset(data_msg, 0, strlen(data_msg));
242 free(data_msg);
243 if (retval == -1)
244 return (PAM_SERVICE_ERR);
245 break;
246
247 case TAC_AUTHEN_STATUS_ERROR:
248 srvr_msg = (char *)tac_get_data(tach, &msg_len);
249 if (srvr_msg != NULL && msg_len != 0) {
250 syslog(LOG_CRIT, "tac_send_authen:"
251 " server detected error: %s", srvr_msg);
252 free(srvr_msg);
253 }
254 else
255 syslog(LOG_CRIT,
256 "tac_send_authen: server detected error");
257 tac_close(tach);
258 return (PAM_AUTHINFO_UNAVAIL);
259 break;
260
261 case TAC_AUTHEN_STATUS_RESTART:
262 case TAC_AUTHEN_STATUS_FOLLOW:
263 default:
264 syslog(LOG_CRIT,
265 "tac_send_authen: unexpected status %#x", status);
266 tac_close(tach);
267 return (PAM_AUTHINFO_UNAVAIL);
268 }
269 }
270 }
271
272 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)273 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
274 int argc __unused, const char *argv[] __unused)
275 {
276
277 return (PAM_IGNORE);
278 }
279
280 PAM_MODULE_ENTRY("pam_tacplus");
281