travis: Enable caching for sonarcloud scan
[strongswan.git] / src / libradius / radius_socket.c
1 /*
2 * Copyright (C) 2010 Martin Willi
3 * Copyright (C) 2010 revosec AG
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 /*
17 * Copyright (C) 2015 Thom Troy
18 *
19 * Permission is hereby granted, free of charge, to any person obtaining a copy
20 * of this software and associated documentation files (the "Software"), to deal
21 * in the Software without restriction, including without limitation the rights
22 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
23 * copies of the Software, and to permit persons to whom the Software is
24 * furnished to do so, subject to the following conditions:
25 *
26 * The above copyright notice and this permission notice shall be included in
27 * all copies or substantial portions of the Software.
28 *
29 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
30 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
31 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
32 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
33 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
34 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
35 * THE SOFTWARE.
36 */
37
38 #include "radius_socket.h"
39 #include "radius_mppe.h"
40
41 #include <errno.h>
42 #include <unistd.h>
43 #include <math.h>
44
45 #include <pen/pen.h>
46 #include <utils/debug.h>
47
48 typedef struct private_radius_socket_t private_radius_socket_t;
49
50 /**
51 * Private data of an radius_socket_t object.
52 */
53 struct private_radius_socket_t {
54
55 /**
56 * Public radius_socket_t interface.
57 */
58 radius_socket_t public;
59
60 /**
61 * Server port for authentication
62 */
63 uint16_t auth_port;
64
65 /**
66 * socket file descriptor for authentication
67 */
68 int auth_fd;
69
70 /**
71 * Server port for accounting
72 */
73 uint16_t acct_port;
74
75 /**
76 * socket file descriptor for accounting
77 */
78 int acct_fd;
79
80 /**
81 * Server address
82 */
83 char *address;
84
85 /**
86 * current RADIUS identifier
87 */
88 uint8_t identifier;
89
90 /**
91 * hasher to use for response verification
92 */
93 hasher_t *hasher;
94
95 /**
96 * HMAC-MD5 signer to build Message-Authenticator attribute
97 */
98 signer_t *signer;
99
100 /**
101 * random number generator for RADIUS request authenticator
102 */
103 rng_t *rng;
104
105 /**
106 * RADIUS secret
107 */
108 chunk_t secret;
109
110 /**
111 * Number of times we retransmit messages before giving up
112 */
113 u_int retransmit_tries;
114
115 /**
116 * Retransmission timeout
117 */
118 double retransmit_timeout;
119
120 /**
121 * Base to calculate retransmission timeout
122 */
123 double retransmit_base;
124 };
125
126 /**
127 * Check or establish RADIUS connection
128 */
129 static bool check_connection(private_radius_socket_t *this,
130 int *fd, uint16_t port)
131 {
132 if (*fd == -1)
133 {
134 host_t *server;
135
136 server = host_create_from_dns(this->address, AF_UNSPEC, port);
137 if (!server)
138 {
139 DBG1(DBG_CFG, "resolving RADIUS server address '%s' failed",
140 this->address);
141 return FALSE;
142 }
143 *fd = socket(server->get_family(server), SOCK_DGRAM, IPPROTO_UDP);
144 if (*fd == -1)
145 {
146 DBG1(DBG_CFG, "opening RADIUS socket for %#H failed: %s",
147 server, strerror(errno));
148 server->destroy(server);
149 return FALSE;
150 }
151 if (connect(*fd, server->get_sockaddr(server),
152 *server->get_sockaddr_len(server)) < 0)
153 {
154 DBG1(DBG_CFG, "connecting RADIUS socket to %#H failed: %s",
155 server, strerror(errno));
156 server->destroy(server);
157 close(*fd);
158 *fd = -1;
159 return FALSE;
160 }
161 server->destroy(server);
162 }
163 return TRUE;
164 }
165
166 /**
167 * Receive the response to the message with the given ID
168 */
169 static status_t receive_response(int fd, int timeout, uint8_t id,
170 radius_message_t **response)
171 {
172 radius_message_t *msg;
173 char buf[4096];
174 int res;
175 struct pollfd pfd = {
176 .fd = fd,
177 .events = POLLIN,
178 };
179
180 while (TRUE)
181 {
182 res = poll(&pfd, 1, timeout);
183 if (res < 0)
184 {
185 DBG1(DBG_CFG, "waiting for RADIUS message failed: %s",
186 strerror(errno));
187 return FAILED;
188 }
189 if (res == 0)
190 { /* timeout */
191 return OUT_OF_RES;
192 }
193 res = recv(fd, buf, sizeof(buf), MSG_DONTWAIT);
194 if (res <= 0)
195 {
196 DBG1(DBG_CFG, "receiving RADIUS message failed: %s",
197 strerror(errno));
198 return FAILED;
199 }
200 msg = radius_message_parse(chunk_create(buf, res));
201 if (!msg)
202 {
203 DBG1(DBG_CFG, "received invalid RADIUS message, ignored");
204 return FAILED;
205 }
206 if (id != msg->get_identifier(msg))
207 {
208 /* we haven't received the response to our current request, but
209 * perhaps one for an earlier request for which we didn't wait
210 * long enough */
211 DBG1(DBG_CFG, "received RADIUS message with unexpected ID %d "
212 "[%d expected], ignored", msg->get_identifier(msg), id);
213 msg->destroy(msg);
214 continue;
215 }
216 *response = msg;
217 return SUCCESS;
218 }
219 }
220
221 METHOD(radius_socket_t, request, radius_message_t*,
222 private_radius_socket_t *this, radius_message_t *request)
223 {
224 radius_message_t *response;
225 chunk_t data;
226 int *fd, retransmit = 0, timeout;
227 uint16_t port;
228 rng_t *rng = NULL;
229
230 if (request->get_code(request) == RMC_ACCOUNTING_REQUEST)
231 {
232 fd = &this->acct_fd;
233 port = this->acct_port;
234 }
235 else
236 {
237 fd = &this->auth_fd;
238 port = this->auth_port;
239 rng = this->rng;
240 }
241
242 /* set Message Identifier */
243 request->set_identifier(request, this->identifier++);
244 /* sign the request */
245 if (!request->sign(request, NULL, this->secret, this->hasher, this->signer,
246 rng, rng != NULL))
247 {
248 return NULL;
249 }
250
251 if (!check_connection(this, fd, port))
252 {
253 return NULL;
254 }
255
256 data = request->get_encoding(request);
257 DBG3(DBG_CFG, "%B", &data);
258
259 while (retransmit < this->retransmit_tries)
260 {
261 timeout = (int)(this->retransmit_timeout * 1000.0 *
262 pow(this->retransmit_base, retransmit));
263 if (retransmit)
264 {
265 DBG1(DBG_CFG, "retransmit %d of RADIUS %N (timeout: %.1fs)",
266 retransmit, radius_message_code_names,
267 request->get_code(request), timeout/1000.0);
268 }
269 if (send(*fd, data.ptr, data.len, 0) != data.len)
270 {
271 DBG1(DBG_CFG, "sending RADIUS message failed: %s", strerror(errno));
272 return NULL;
273 }
274 switch (receive_response(*fd, timeout, request->get_identifier(request),
275 &response))
276 {
277 case SUCCESS:
278 break;
279 case OUT_OF_RES:
280 retransmit++;
281 continue;
282 default:
283 return NULL;
284 }
285 if (response->verify(response, request->get_authenticator(request),
286 this->secret, this->hasher, this->signer))
287 {
288 return response;
289 }
290 response->destroy(response);
291 return NULL;
292 }
293
294 DBG1(DBG_CFG, "RADIUS %N timed out after %d attempts",
295 radius_message_code_names, request->get_code(request), retransmit);
296 return NULL;
297 }
298
299 /**
300 * Decrypt a MS-MPPE-Send/Recv-Key
301 */
302 static chunk_t decrypt_mppe_key(private_radius_socket_t *this, uint16_t salt,
303 chunk_t C, radius_message_t *request)
304 {
305 chunk_t decrypted;
306
307 decrypted = chunk_alloca(C.len);
308 if (!request->crypt(request, chunk_from_thing(salt), C, decrypted,
309 this->secret, this->hasher) ||
310 decrypted.ptr[0] >= decrypted.len)
311 { /* decryption failed? */
312 return chunk_empty;
313 }
314 /* remove truncation, first byte is key length */
315 return chunk_clone(chunk_create(decrypted.ptr + 1, decrypted.ptr[0]));
316 }
317
318 METHOD(radius_socket_t, decrypt_msk, chunk_t,
319 private_radius_socket_t *this, radius_message_t *request,
320 radius_message_t *response)
321 {
322 mppe_key_t *mppe_key;
323 enumerator_t *enumerator;
324 chunk_t data, send = chunk_empty, recv = chunk_empty;
325 int type;
326
327 enumerator = response->create_enumerator(response);
328 while (enumerator->enumerate(enumerator, &type, &data))
329 {
330 if (type == RAT_VENDOR_SPECIFIC && data.len > sizeof(mppe_key_t))
331 {
332 mppe_key = (mppe_key_t*)data.ptr;
333 if (ntohl(mppe_key->id) == PEN_MICROSOFT &&
334 mppe_key->length == data.len - sizeof(mppe_key->id))
335 {
336 data = chunk_create(mppe_key->key, data.len - sizeof(mppe_key_t));
337 if (mppe_key->type == MS_MPPE_SEND_KEY)
338 {
339 send = decrypt_mppe_key(this, mppe_key->salt, data, request);
340 }
341 if (mppe_key->type == MS_MPPE_RECV_KEY)
342 {
343 recv = decrypt_mppe_key(this, mppe_key->salt, data, request);
344 }
345 }
346 }
347 }
348 enumerator->destroy(enumerator);
349 if (send.ptr && recv.ptr)
350 {
351 chunk_t pad = chunk_empty;
352
353 if ((send.len + recv.len) < 64)
354 { /* zero-pad MSK to at least 64 bytes */
355 pad = chunk_alloca(64 - send.len - recv.len);
356 memset(pad.ptr, 0, pad.len);
357 }
358 return chunk_cat("mmc", recv, send, pad);
359 }
360 chunk_clear(&send);
361 chunk_clear(&recv);
362 return chunk_empty;
363 }
364
365 METHOD(radius_socket_t, destroy, void,
366 private_radius_socket_t *this)
367 {
368 DESTROY_IF(this->hasher);
369 DESTROY_IF(this->signer);
370 DESTROY_IF(this->rng);
371 if (this->auth_fd != -1)
372 {
373 close(this->auth_fd);
374 };
375 if (this->acct_fd != -1)
376 {
377 close(this->acct_fd);
378 }
379 free(this);
380 }
381
382 /**
383 * See header
384 */
385 radius_socket_t *radius_socket_create(char *address, uint16_t auth_port,
386 uint16_t acct_port, chunk_t secret,
387 u_int tries, double timeout, double base)
388 {
389 private_radius_socket_t *this;
390
391 INIT(this,
392 .public = {
393 .request = _request,
394 .decrypt_msk = _decrypt_msk,
395 .destroy = _destroy,
396 },
397 .address = address,
398 .auth_port = auth_port,
399 .auth_fd = -1,
400 .acct_port = acct_port,
401 .acct_fd = -1,
402 .hasher = lib->crypto->create_hasher(lib->crypto, HASH_MD5),
403 .signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_MD5_128),
404 .rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK),
405 .retransmit_tries = tries,
406 .retransmit_timeout = timeout,
407 .retransmit_base = base,
408 );
409
410 if (!this->hasher || !this->signer || !this->rng ||
411 !this->signer->set_key(this->signer, secret))
412 {
413 DBG1(DBG_CFG, "RADIUS initialization failed, HMAC/MD5/RNG required");
414 destroy(this);
415 return NULL;
416 }
417 this->secret = secret;
418 /* we use a random identifier, helps if we restart often */
419 this->identifier = random();
420
421 return &this->public;
422 }