3d8c823b87ffa13349c0e0204f4e358e633af7bc
[strongswan.git] / src / libcharon / plugins / eap_radius / eap_radius.c
1 /*
2 * Copyright (C) 2009 Martin Willi
3 * Hochschule fuer Technik Rapperswil
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * for more details.
14 */
15
16 #include "eap_radius.h"
17
18 #include "radius_message.h"
19 #include "radius_client.h"
20
21 #include <daemon.h>
22
23 #define TUNNEL_TYPE_ESP 9
24
25 typedef struct private_eap_radius_t private_eap_radius_t;
26
27 /**
28 * Private data of an eap_radius_t object.
29 */
30 struct private_eap_radius_t {
31
32 /**
33 * Public authenticator_t interface.
34 */
35 eap_radius_t public;
36
37 /**
38 * ID of the server
39 */
40 identification_t *server;
41
42 /**
43 * ID of the peer
44 */
45 identification_t *peer;
46
47 /**
48 * EAP method type we are proxying
49 */
50 eap_type_t type;
51
52 /**
53 * EAP vendor, if any
54 */
55 u_int32_t vendor;
56
57 /**
58 * EAP message identifier
59 */
60 u_int8_t identifier;
61
62 /**
63 * RADIUS client instance
64 */
65 radius_client_t *client;
66
67 /**
68 * TRUE to use EAP-Start, FALSE to send EAP-Identity Response directly
69 */
70 bool eap_start;
71
72 /**
73 * Prefix to prepend to EAP identity
74 */
75 char *id_prefix;
76
77 /**
78 * Handle the Class attribute as group membership information?
79 */
80 bool class_group;
81
82 /**
83 * Handle the Filter-Id attribute as IPsec CHILD_SA name?
84 */
85 bool filter_id;
86 };
87
88 /**
89 * Add EAP-Identity to RADIUS message
90 */
91 static void add_eap_identity(private_eap_radius_t *this,
92 radius_message_t *request)
93 {
94 struct {
95 /** EAP code (REQUEST/RESPONSE) */
96 u_int8_t code;
97 /** unique message identifier */
98 u_int8_t identifier;
99 /** length of whole message */
100 u_int16_t length;
101 /** EAP type */
102 u_int8_t type;
103 /** identity data */
104 u_int8_t data[];
105 } __attribute__((__packed__)) *hdr;
106 chunk_t id, prefix;
107 size_t len;
108
109 id = this->peer->get_encoding(this->peer);
110 prefix = chunk_create(this->id_prefix, strlen(this->id_prefix));
111 len = sizeof(*hdr) + prefix.len + id.len;
112
113 hdr = alloca(len);
114 hdr->code = EAP_RESPONSE;
115 hdr->identifier = this->identifier;
116 hdr->length = htons(len);
117 hdr->type = EAP_IDENTITY;
118 memcpy(hdr->data, prefix.ptr, prefix.len);
119 memcpy(hdr->data + prefix.len, id.ptr, id.len);
120
121 request->add(request, RAT_EAP_MESSAGE, chunk_create((u_char*)hdr, len));
122 }
123
124 /**
125 * Copy EAP-Message attribute from RADIUS message to an new EAP payload
126 */
127 static bool radius2ike(private_eap_radius_t *this,
128 radius_message_t *msg, eap_payload_t **out)
129 {
130 enumerator_t *enumerator;
131 eap_payload_t *payload;
132 chunk_t data, message = chunk_empty;
133 int type;
134
135 enumerator = msg->create_enumerator(msg);
136 while (enumerator->enumerate(enumerator, &type, &data))
137 {
138 if (type == RAT_EAP_MESSAGE && data.len)
139 {
140 message = chunk_cat("mc", message, data);
141 }
142 }
143 enumerator->destroy(enumerator);
144 if (message.len)
145 {
146 *out = payload = eap_payload_create_data(message);
147
148 /* apply EAP method selected by RADIUS server */
149 this->type = payload->get_type(payload, &this->vendor);
150
151 DBG3(DBG_IKE, "%N payload %B", eap_type_names, this->type, &message);
152 free(message.ptr);
153 return TRUE;
154 }
155 return FALSE;
156 }
157
158 METHOD(eap_method_t, initiate, status_t,
159 private_eap_radius_t *this, eap_payload_t **out)
160 {
161 radius_message_t *request, *response;
162 status_t status = FAILED;
163 chunk_t username;
164
165 request = radius_message_create(RMC_ACCESS_REQUEST);
166 username = chunk_create(this->id_prefix, strlen(this->id_prefix));
167 username = chunk_cata("cc", username, this->peer->get_encoding(this->peer));
168 request->add(request, RAT_USER_NAME, username);
169
170 if (this->eap_start)
171 {
172 request->add(request, RAT_EAP_MESSAGE, chunk_empty);
173 }
174 else
175 {
176 add_eap_identity(this, request);
177 }
178
179 response = this->client->request(this->client, request);
180 if (response)
181 {
182 if (radius2ike(this, response, out))
183 {
184 status = NEED_MORE;
185 }
186 response->destroy(response);
187 }
188 request->destroy(request);
189 return status;
190 }
191
192 /**
193 * Handle the Class attribute as group membership information
194 */
195 static void process_class(private_eap_radius_t *this, radius_message_t *msg)
196 {
197 enumerator_t *enumerator;
198 chunk_t data;
199 int type;
200
201 enumerator = msg->create_enumerator(msg);
202 while (enumerator->enumerate(enumerator, &type, &data))
203 {
204 if (type == RAT_CLASS)
205 {
206 identification_t *id;
207 ike_sa_t *ike_sa;
208 auth_cfg_t *auth;
209
210 if (data.len >= 44)
211 { /* quirk: ignore long class attributes, these are used for
212 * other purposes by some RADIUS servers (such as NPS). */
213 continue;
214 }
215
216 ike_sa = charon->bus->get_sa(charon->bus);
217 if (ike_sa)
218 {
219 auth = ike_sa->get_auth_cfg(ike_sa, FALSE);
220 id = identification_create_from_data(data);
221 DBG1(DBG_CFG, "received group membership '%Y' from RADIUS", id);
222 auth->add(auth, AUTH_RULE_GROUP, id);
223 }
224 }
225 }
226 enumerator->destroy(enumerator);
227 }
228
229 /**
230 * Handle the Filter-Id attribute as IPsec CHILD_SA name
231 */
232 static void process_filter_id(private_eap_radius_t *this, radius_message_t *msg)
233 {
234 enumerator_t *enumerator;
235 int type;
236 u_int8_t tunnel_tag;
237 u_int32_t tunnel_type;
238 chunk_t filter_id = chunk_empty, data;
239 bool is_esp_tunnel = FALSE;
240
241 enumerator = msg->create_enumerator(msg);
242 while (enumerator->enumerate(enumerator, &type, &data))
243 {
244 switch (type)
245 {
246 case RAT_TUNNEL_TYPE:
247 if (data.len != 4)
248 {
249 continue;
250 }
251 tunnel_tag = *data.ptr;
252 *data.ptr = 0x00;
253 tunnel_type = untoh32(data.ptr);
254 DBG1(DBG_IKE, "received RADIUS attribute Tunnel-Type: "
255 "tag = %u, value = %u", tunnel_tag, tunnel_type);
256 is_esp_tunnel = (tunnel_type == TUNNEL_TYPE_ESP);
257 break;
258 case RAT_FILTER_ID:
259 filter_id = data;
260 DBG1(DBG_IKE, "received RADIUS attribute Filter-Id: "
261 "'%.*s'", filter_id.len, filter_id.ptr);
262 break;
263 default:
264 break;
265 }
266 }
267 enumerator->destroy(enumerator);
268
269 if (is_esp_tunnel && filter_id.len)
270 {
271 identification_t *id;
272 ike_sa_t *ike_sa;
273 auth_cfg_t *auth;
274
275 ike_sa = charon->bus->get_sa(charon->bus);
276 if (ike_sa)
277 {
278 auth = ike_sa->get_auth_cfg(ike_sa, FALSE);
279 id = identification_create_from_data(filter_id);
280 auth->add(auth, AUTH_RULE_GROUP, id);
281 }
282 }
283 }
284
285 /**
286 * Handle Session-Timeout attribte
287 */
288 static void process_timeout(private_eap_radius_t *this, radius_message_t *msg)
289 {
290 enumerator_t *enumerator;
291 ike_sa_t *ike_sa;
292 chunk_t data;
293 int type;
294
295 enumerator = msg->create_enumerator(msg);
296 while (enumerator->enumerate(enumerator, &type, &data))
297 {
298 if (type == RAT_SESSION_TIMEOUT && data.len == 4)
299 {
300 ike_sa = charon->bus->get_sa(charon->bus);
301 if (ike_sa)
302 {
303 ike_sa->set_auth_lifetime(ike_sa, untoh32(data.ptr));
304 }
305 }
306 }
307 enumerator->destroy(enumerator);
308 }
309
310 METHOD(eap_method_t, process, status_t,
311 private_eap_radius_t *this, eap_payload_t *in, eap_payload_t **out)
312 {
313 radius_message_t *request, *response;
314 status_t status = FAILED;
315 chunk_t data;
316
317 request = radius_message_create(RMC_ACCESS_REQUEST);
318 request->add(request, RAT_USER_NAME, this->peer->get_encoding(this->peer));
319 data = in->get_data(in);
320 DBG3(DBG_IKE, "%N payload %B", eap_type_names, this->type, &data);
321
322 /* fragment data suitable for RADIUS (not more than 253 bytes) */
323 while (data.len > 253)
324 {
325 request->add(request, RAT_EAP_MESSAGE, chunk_create(data.ptr, 253));
326 data = chunk_skip(data, 253);
327 }
328 request->add(request, RAT_EAP_MESSAGE, data);
329
330 response = this->client->request(this->client, request);
331 if (response)
332 {
333 switch (response->get_code(response))
334 {
335 case RMC_ACCESS_CHALLENGE:
336 if (radius2ike(this, response, out))
337 {
338 status = NEED_MORE;
339 break;
340 }
341 status = FAILED;
342 break;
343 case RMC_ACCESS_ACCEPT:
344 if (this->class_group)
345 {
346 process_class(this, response);
347 }
348 if (this->filter_id)
349 {
350 process_filter_id(this, response);
351 }
352 process_timeout(this, response);
353 DBG1(DBG_IKE, "RADIUS authentication of '%Y' successful",
354 this->peer);
355 status = SUCCESS;
356 break;
357 case RMC_ACCESS_REJECT:
358 default:
359 DBG1(DBG_IKE, "RADIUS authentication of '%Y' failed", this->peer);
360 status = FAILED;
361 break;
362 }
363 response->destroy(response);
364 }
365 request->destroy(request);
366 return status;
367 }
368
369 METHOD(eap_method_t, get_type, eap_type_t,
370 private_eap_radius_t *this, u_int32_t *vendor)
371 {
372 *vendor = this->vendor;
373 return this->type;
374 }
375
376 METHOD(eap_method_t, get_msk, status_t,
377 private_eap_radius_t *this, chunk_t *out)
378 {
379 chunk_t msk;
380
381 msk = this->client->get_msk(this->client);
382 if (msk.len)
383 {
384 *out = msk;
385 return SUCCESS;
386 }
387 return FAILED;
388 }
389
390 METHOD(eap_method_t, get_identifier, u_int8_t,
391 private_eap_radius_t *this)
392 {
393 return this->identifier;
394 }
395
396 METHOD(eap_method_t, set_identifier, void,
397 private_eap_radius_t *this, u_int8_t identifier)
398 {
399 this->identifier = identifier;
400 }
401
402 METHOD(eap_method_t, is_mutual, bool,
403 private_eap_radius_t *this)
404 {
405 switch (this->type)
406 {
407 case EAP_AKA:
408 case EAP_SIM:
409 return TRUE;
410 default:
411 return FALSE;
412 }
413 }
414
415 METHOD(eap_method_t, destroy, void,
416 private_eap_radius_t *this)
417 {
418 this->peer->destroy(this->peer);
419 this->server->destroy(this->server);
420 this->client->destroy(this->client);
421 free(this);
422 }
423
424 /**
425 * Generic constructor
426 */
427 eap_radius_t *eap_radius_create(identification_t *server, identification_t *peer)
428 {
429 private_eap_radius_t *this;
430
431 INIT(this,
432 .public = {
433 .eap_method = {
434 .initiate = _initiate,
435 .process = _process,
436 .get_type = _get_type,
437 .is_mutual = _is_mutual,
438 .get_msk = _get_msk,
439 .get_identifier = _get_identifier,
440 .set_identifier = _set_identifier,
441 .destroy = _destroy,
442 },
443 },
444 /* initially EAP_RADIUS, but is set to the method selected by RADIUS */
445 .type = EAP_RADIUS,
446 .eap_start = lib->settings->get_bool(lib->settings,
447 "charon.plugins.eap-radius.eap_start", FALSE),
448 .id_prefix = lib->settings->get_str(lib->settings,
449 "charon.plugins.eap-radius.id_prefix", ""),
450 .class_group = lib->settings->get_bool(lib->settings,
451 "charon.plugins.eap-radius.class_group", FALSE),
452 .filter_id = lib->settings->get_bool(lib->settings,
453 "charon.plugins.eap-radius.filter_id", FALSE),
454
455 );
456 this->client = radius_client_create();
457 if (!this->client)
458 {
459 free(this);
460 return NULL;
461 }
462 this->peer = peer->clone(peer);
463 this->server = server->clone(server);
464 return &this->public;
465 }
466