RADIUS message constructor accepts a message code parameter
[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_request(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 METHOD(eap_method_t, process, status_t,
286 private_eap_radius_t *this, eap_payload_t *in, eap_payload_t **out)
287 {
288 radius_message_t *request, *response;
289 status_t status = FAILED;
290 chunk_t data;
291
292 request = radius_message_create_request(RMC_ACCESS_REQUEST);
293 request->add(request, RAT_USER_NAME, this->peer->get_encoding(this->peer));
294 data = in->get_data(in);
295 DBG3(DBG_IKE, "%N payload %B", eap_type_names, this->type, &data);
296
297 /* fragment data suitable for RADIUS (not more than 253 bytes) */
298 while (data.len > 253)
299 {
300 request->add(request, RAT_EAP_MESSAGE, chunk_create(data.ptr, 253));
301 data = chunk_skip(data, 253);
302 }
303 request->add(request, RAT_EAP_MESSAGE, data);
304
305 response = this->client->request(this->client, request);
306 if (response)
307 {
308 switch (response->get_code(response))
309 {
310 case RMC_ACCESS_CHALLENGE:
311 if (radius2ike(this, response, out))
312 {
313 status = NEED_MORE;
314 break;
315 }
316 status = FAILED;
317 break;
318 case RMC_ACCESS_ACCEPT:
319 if (this->class_group)
320 {
321 process_class(this, response);
322 }
323 if (this->filter_id)
324 {
325 process_filter_id(this, response);
326 }
327 DBG1(DBG_IKE, "RADIUS authentication of '%Y' successful",
328 this->peer);
329 status = SUCCESS;
330 break;
331 case RMC_ACCESS_REJECT:
332 default:
333 DBG1(DBG_IKE, "RADIUS authentication of '%Y' failed", this->peer);
334 status = FAILED;
335 break;
336 }
337 response->destroy(response);
338 }
339 request->destroy(request);
340 return status;
341 }
342
343 METHOD(eap_method_t, get_type, eap_type_t,
344 private_eap_radius_t *this, u_int32_t *vendor)
345 {
346 *vendor = this->vendor;
347 return this->type;
348 }
349
350 METHOD(eap_method_t, get_msk, status_t,
351 private_eap_radius_t *this, chunk_t *out)
352 {
353 chunk_t msk;
354
355 msk = this->client->get_msk(this->client);
356 if (msk.len)
357 {
358 *out = msk;
359 return SUCCESS;
360 }
361 return FAILED;
362 }
363
364 METHOD(eap_method_t, get_identifier, u_int8_t,
365 private_eap_radius_t *this)
366 {
367 return this->identifier;
368 }
369
370 METHOD(eap_method_t, set_identifier, void,
371 private_eap_radius_t *this, u_int8_t identifier)
372 {
373 this->identifier = identifier;
374 }
375
376 METHOD(eap_method_t, is_mutual, bool,
377 private_eap_radius_t *this)
378 {
379 switch (this->type)
380 {
381 case EAP_AKA:
382 case EAP_SIM:
383 return TRUE;
384 default:
385 return FALSE;
386 }
387 }
388
389 METHOD(eap_method_t, destroy, void,
390 private_eap_radius_t *this)
391 {
392 this->peer->destroy(this->peer);
393 this->server->destroy(this->server);
394 this->client->destroy(this->client);
395 free(this);
396 }
397
398 /**
399 * Generic constructor
400 */
401 eap_radius_t *eap_radius_create(identification_t *server, identification_t *peer)
402 {
403 private_eap_radius_t *this;
404
405 INIT(this,
406 .public = {
407 .eap_method = {
408 .initiate = _initiate,
409 .process = _process,
410 .get_type = _get_type,
411 .is_mutual = _is_mutual,
412 .get_msk = _get_msk,
413 .get_identifier = _get_identifier,
414 .set_identifier = _set_identifier,
415 .destroy = _destroy,
416 },
417 },
418 /* initially EAP_RADIUS, but is set to the method selected by RADIUS */
419 .type = EAP_RADIUS,
420 .eap_start = lib->settings->get_bool(lib->settings,
421 "charon.plugins.eap-radius.eap_start", FALSE),
422 .id_prefix = lib->settings->get_str(lib->settings,
423 "charon.plugins.eap-radius.id_prefix", ""),
424 .class_group = lib->settings->get_bool(lib->settings,
425 "charon.plugins.eap-radius.class_group", FALSE),
426 .filter_id = lib->settings->get_bool(lib->settings,
427 "charon.plugins.eap-radius.filter_id", FALSE),
428
429 );
430 this->client = radius_client_create();
431 if (!this->client)
432 {
433 free(this);
434 return NULL;
435 }
436 this->peer = peer->clone(peer);
437 this->server = server->clone(server);
438 return &this->public;
439 }
440