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 * Copyright (c) 2015-2018 The University of Oslo
9 * All rights reserved.
10 *
11 * Portions of this software were developed for the FreeBSD Project by
12 * ThinkSec AS and NAI Labs, the Security Research Division of Network
13 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
14 * ("CBOSS"), as part of the DARPA CHATS research program.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 * 3. The name of the author may not be used to endorse or promote
25 * products derived from this software without specific prior written
26 * permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 */
40
41 #include <sys/param.h>
42 #include <sys/socket.h>
43 #include <netdb.h>
44 #include <pwd.h>
45 #include <radlib.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <syslog.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 #define PAM_OPT_NAS_ID "nas_id"
60 #define PAM_OPT_NAS_IPADDR "nas_ipaddr"
61 #define PAM_OPT_NO_REPLYMSG "no_reply_message"
62
63 #define MAX_CHALLENGE_MSGS 10
64 #define PASSWORD_PROMPT "RADIUS Password:"
65
66 static int build_access_request(struct rad_handle *, const char *,
67 const char *, const char *, const char *, const char *,
68 const void *, size_t);
69 static int do_accept(pam_handle_t *, struct rad_handle *);
70 static int do_challenge(pam_handle_t *, struct rad_handle *,
71 const char *, const char *, const char *, const char *);
72
73 /*
74 * Construct an access request, but don't send it. Returns 0 on success,
75 * -1 on failure.
76 */
77 static int
build_access_request(struct rad_handle * radh,const char * user,const char * pass,const char * nas_id,const char * nas_ipaddr,const char * rhost,const void * state,size_t state_len)78 build_access_request(struct rad_handle *radh, const char *user,
79 const char *pass, const char *nas_id, const char *nas_ipaddr,
80 const char *rhost, const void *state, size_t state_len)
81 {
82 int error;
83 char host[MAXHOSTNAMELEN];
84 struct sockaddr_in *haddr;
85 struct addrinfo hints;
86 struct addrinfo *res;
87
88 if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) {
89 syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh));
90 return (-1);
91 }
92 if (nas_id == NULL ||
93 (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) {
94 if (gethostname(host, sizeof host) != -1) {
95 if (nas_id == NULL)
96 nas_id = host;
97 if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)
98 nas_ipaddr = host;
99 }
100 }
101 if ((user != NULL &&
102 rad_put_string(radh, RAD_USER_NAME, user) == -1) ||
103 (pass != NULL &&
104 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) ||
105 (nas_id != NULL &&
106 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) {
107 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh));
108 return (-1);
109 }
110 if (nas_ipaddr != NULL) {
111 memset(&hints, 0, sizeof(hints));
112 hints.ai_family = AF_INET;
113 if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 &&
114 res != NULL && res->ai_family == AF_INET) {
115 haddr = (struct sockaddr_in *)res->ai_addr;
116 error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS,
117 haddr->sin_addr);
118 freeaddrinfo(res);
119 if (error == -1) {
120 syslog(LOG_CRIT, "rad_put_addr: %s",
121 rad_strerror(radh));
122 return (-1);
123 }
124 }
125 }
126 if (rhost != NULL &&
127 rad_put_string(radh, RAD_CALLING_STATION_ID, rhost) == -1) {
128 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh));
129 return (-1);
130 }
131 if (state != NULL &&
132 rad_put_attr(radh, RAD_STATE, state, state_len) == -1) {
133 syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh));
134 return (-1);
135 }
136 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) {
137 syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh));
138 return (-1);
139 }
140 return (0);
141 }
142
143 static int
do_accept(pam_handle_t * pamh,struct rad_handle * radh)144 do_accept(pam_handle_t *pamh, struct rad_handle *radh)
145 {
146 int attrtype;
147 const void *attrval;
148 size_t attrlen;
149 char *s;
150
151 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
152 switch (attrtype) {
153 case RAD_USER_NAME:
154 if ((s = rad_cvt_string(attrval, attrlen)) == NULL)
155 goto enomem;
156 pam_set_item(pamh, PAM_USER, s);
157 free(s);
158 break;
159 case RAD_REPLY_MESSAGE:
160 if ((s = rad_cvt_string(attrval, attrlen)) == NULL)
161 goto enomem;
162 if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG))
163 pam_info(pamh, "%s", s);
164 free(s);
165 break;
166 default:
167 PAM_LOG("%s(): ignoring RADIUS attribute %d",
168 __func__, attrtype);
169 }
170 }
171 if (attrtype == -1) {
172 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
173 return (-1);
174 }
175 return (0);
176 enomem:
177 syslog(LOG_CRIT, "%s(): out of memory", __func__);
178 return (-1);
179 }
180
181 static int
do_reject(pam_handle_t * pamh,struct rad_handle * radh)182 do_reject(pam_handle_t *pamh, struct rad_handle *radh)
183 {
184 int attrtype;
185 const void *attrval;
186 size_t attrlen;
187 char *s;
188
189 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
190 switch (attrtype) {
191 case RAD_REPLY_MESSAGE:
192 if ((s = rad_cvt_string(attrval, attrlen)) == NULL)
193 goto enomem;
194 if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG))
195 pam_error(pamh, "%s", s);
196 free(s);
197 break;
198 default:
199 PAM_LOG("%s(): ignoring RADIUS attribute %d",
200 __func__, attrtype);
201 }
202 }
203 if (attrtype < 0) {
204 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
205 return (-1);
206 }
207 return (0);
208 enomem:
209 syslog(LOG_CRIT, "%s(): out of memory", __func__);
210 return (-1);
211 }
212
213 static int
do_challenge(pam_handle_t * pamh,struct rad_handle * radh,const char * user,const char * nas_id,const char * nas_ipaddr,const char * rhost)214 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user,
215 const char *nas_id, const char *nas_ipaddr, const char *rhost)
216 {
217 int retval;
218 int attrtype;
219 const void *attrval;
220 size_t attrlen;
221 const void *state;
222 size_t statelen;
223 struct pam_message msgs[MAX_CHALLENGE_MSGS];
224 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS];
225 struct pam_response *resp;
226 int num_msgs;
227 const void *item;
228 const struct pam_conv *conv;
229
230 state = NULL;
231 statelen = 0;
232 num_msgs = 0;
233 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
234 switch (attrtype) {
235
236 case RAD_STATE:
237 state = attrval;
238 statelen = attrlen;
239 break;
240
241 case RAD_REPLY_MESSAGE:
242 if (num_msgs >= MAX_CHALLENGE_MSGS) {
243 syslog(LOG_CRIT,
244 "Too many RADIUS challenge messages");
245 return (PAM_SERVICE_ERR);
246 }
247 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen);
248 if (msgs[num_msgs].msg == NULL) {
249 syslog(LOG_CRIT,
250 "rad_cvt_string: out of memory");
251 return (PAM_SERVICE_ERR);
252 }
253 msgs[num_msgs].msg_style = PAM_TEXT_INFO;
254 msg_ptrs[num_msgs] = &msgs[num_msgs];
255 num_msgs++;
256 break;
257 }
258 }
259 if (attrtype == -1) {
260 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
261 return (PAM_SERVICE_ERR);
262 }
263 if (num_msgs == 0) {
264 msgs[num_msgs].msg = strdup("(null RADIUS challenge): ");
265 if (msgs[num_msgs].msg == NULL) {
266 syslog(LOG_CRIT, "Out of memory");
267 return (PAM_SERVICE_ERR);
268 }
269 msgs[num_msgs].msg_style = PAM_TEXT_INFO;
270 msg_ptrs[num_msgs] = &msgs[num_msgs];
271 num_msgs++;
272 }
273 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON;
274 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) {
275 syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV");
276 return (retval);
277 }
278 conv = (const struct pam_conv *)item;
279 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp,
280 conv->appdata_ptr)) != PAM_SUCCESS)
281 return (retval);
282 if (build_access_request(radh, user, resp[num_msgs-1].resp, nas_id,
283 nas_ipaddr, rhost, state, statelen) == -1)
284 return (PAM_SERVICE_ERR);
285 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp));
286 free(resp[num_msgs-1].resp);
287 free(resp);
288 while (num_msgs > 0)
289 free(msgs[--num_msgs].msg);
290 return (PAM_SUCCESS);
291 }
292
293 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)294 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
295 int argc __unused, const char *argv[] __unused)
296 {
297 struct rad_handle *radh;
298 const char *user, *pass;
299 const void *rhost, *tmpuser;
300 const char *conf_file, *template_user, *nas_id, *nas_ipaddr;
301 int retval;
302 int e;
303
304 conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
305 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
306 nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID);
307 nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR);
308 pam_get_item(pamh, PAM_RHOST, &rhost);
309
310 retval = pam_get_user(pamh, &user, NULL);
311 if (retval != PAM_SUCCESS)
312 return (retval);
313
314 PAM_LOG("Got user: %s", user);
315
316 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT);
317 if (retval != PAM_SUCCESS)
318 return (retval);
319
320 PAM_LOG("Got password");
321
322 radh = rad_open();
323 if (radh == NULL) {
324 syslog(LOG_CRIT, "rad_open failed");
325 return (PAM_SERVICE_ERR);
326 }
327
328 PAM_LOG("Radius opened");
329
330 if (rad_config(radh, conf_file) == -1) {
331 syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh));
332 rad_close(radh);
333 return (PAM_SERVICE_ERR);
334 }
335
336 PAM_LOG("Radius config file read");
337
338 if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, rhost,
339 NULL, 0) == -1) {
340 rad_close(radh);
341 return (PAM_SERVICE_ERR);
342 }
343
344 PAM_LOG("Radius build access done");
345
346 for (;;) {
347 switch (rad_send_request(radh)) {
348
349 case RAD_ACCESS_ACCEPT:
350 e = do_accept(pamh, radh);
351 rad_close(radh);
352 if (e == -1)
353 return (PAM_SERVICE_ERR);
354 if (template_user != NULL) {
355
356 PAM_LOG("Trying template user: %s",
357 template_user);
358
359 /*
360 * If the given user name doesn't exist in
361 * the local password database, change it
362 * to the value given in the "template_user"
363 * option.
364 */
365 retval = pam_get_item(pamh, PAM_USER, &tmpuser);
366 if (retval != PAM_SUCCESS)
367 return (retval);
368 if (getpwnam(tmpuser) == NULL) {
369 pam_set_item(pamh, PAM_USER,
370 template_user);
371 PAM_LOG("Using template user");
372 }
373
374 }
375 return (PAM_SUCCESS);
376
377 case RAD_ACCESS_REJECT:
378 retval = do_reject(pamh, radh);
379 rad_close(radh);
380 PAM_VERBOSE_ERROR("Radius rejection");
381 return (PAM_AUTH_ERR);
382
383 case RAD_ACCESS_CHALLENGE:
384 retval = do_challenge(pamh, radh, user, nas_id,
385 nas_ipaddr, rhost);
386 if (retval != PAM_SUCCESS) {
387 rad_close(radh);
388 return (retval);
389 }
390 break;
391
392 case -1:
393 syslog(LOG_CRIT, "rad_send_request: %s",
394 rad_strerror(radh));
395 rad_close(radh);
396 PAM_VERBOSE_ERROR("Radius failure");
397 return (PAM_AUTHINFO_UNAVAIL);
398
399 default:
400 syslog(LOG_CRIT,
401 "rad_send_request: unexpected return value");
402 rad_close(radh);
403 PAM_VERBOSE_ERROR("Radius error");
404 return (PAM_SERVICE_ERR);
405 }
406 }
407 }
408
409 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)410 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
411 int argc __unused, const char *argv[] __unused)
412 {
413
414 return (PAM_SUCCESS);
415 }
416
417 PAM_MODULE_ENTRY("pam_radius");
418