1 /*
2 * Simple DTLS server demonstration program
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 #include "mbedtls/build_info.h"
21
22 #include "mbedtls/platform.h"
23
24 /* Uncomment out the following line to default to IPv4 and disable IPv6 */
25 //#define FORCE_IPV4
26
27 #ifdef FORCE_IPV4
28 #define BIND_IP "0.0.0.0" /* Forces IPv4 */
29 #else
30 #define BIND_IP "::"
31 #endif
32
33 #if !defined(MBEDTLS_SSL_SRV_C) || !defined(MBEDTLS_SSL_PROTO_DTLS) || \
34 !defined(MBEDTLS_SSL_COOKIE_C) || !defined(MBEDTLS_NET_C) || \
35 !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
36 !defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_RSA_C) || \
37 !defined(MBEDTLS_PEM_PARSE_C) || !defined(MBEDTLS_TIMING_C)
38
main(void)39 int main(void)
40 {
41 printf("MBEDTLS_SSL_SRV_C and/or MBEDTLS_SSL_PROTO_DTLS and/or "
42 "MBEDTLS_SSL_COOKIE_C and/or MBEDTLS_NET_C and/or "
43 "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
44 "MBEDTLS_X509_CRT_PARSE_C and/or MBEDTLS_RSA_C and/or "
45 "MBEDTLS_PEM_PARSE_C and/or MBEDTLS_TIMING_C not defined.\n");
46 mbedtls_exit(0);
47 }
48 #else
49
50 #if defined(_WIN32)
51 #include <windows.h>
52 #endif
53
54 #include <string.h>
55 #include <stdlib.h>
56 #include <stdio.h>
57
58 #include "mbedtls/entropy.h"
59 #include "mbedtls/ctr_drbg.h"
60 #include "mbedtls/x509.h"
61 #include "mbedtls/ssl.h"
62 #include "mbedtls/ssl_cookie.h"
63 #include "mbedtls/net_sockets.h"
64 #include "mbedtls/error.h"
65 #include "mbedtls/debug.h"
66 #include "mbedtls/timing.h"
67
68 #include "test/certs.h"
69
70 #if defined(MBEDTLS_SSL_CACHE_C)
71 #include "mbedtls/ssl_cache.h"
72 #endif
73
74 #define READ_TIMEOUT_MS 10000 /* 10 seconds */
75 #define DEBUG_LEVEL 0
76
77
my_debug(void * ctx,int level,const char * file,int line,const char * str)78 static void my_debug(void *ctx, int level,
79 const char *file, int line,
80 const char *str)
81 {
82 ((void) level);
83
84 mbedtls_fprintf((FILE *) ctx, "%s:%04d: %s", file, line, str);
85 fflush((FILE *) ctx);
86 }
87
main(void)88 int main(void)
89 {
90 int ret, len;
91 mbedtls_net_context listen_fd, client_fd;
92 unsigned char buf[1024];
93 const char *pers = "dtls_server";
94 unsigned char client_ip[16] = { 0 };
95 size_t cliip_len;
96 mbedtls_ssl_cookie_ctx cookie_ctx;
97
98 mbedtls_entropy_context entropy;
99 mbedtls_ctr_drbg_context ctr_drbg;
100 mbedtls_ssl_context ssl;
101 mbedtls_ssl_config conf;
102 mbedtls_x509_crt srvcert;
103 mbedtls_pk_context pkey;
104 mbedtls_timing_delay_context timer;
105 #if defined(MBEDTLS_SSL_CACHE_C)
106 mbedtls_ssl_cache_context cache;
107 #endif
108
109 mbedtls_net_init(&listen_fd);
110 mbedtls_net_init(&client_fd);
111 mbedtls_ssl_init(&ssl);
112 mbedtls_ssl_config_init(&conf);
113 mbedtls_ssl_cookie_init(&cookie_ctx);
114 #if defined(MBEDTLS_SSL_CACHE_C)
115 mbedtls_ssl_cache_init(&cache);
116 #endif
117 mbedtls_x509_crt_init(&srvcert);
118 mbedtls_pk_init(&pkey);
119 mbedtls_entropy_init(&entropy);
120 mbedtls_ctr_drbg_init(&ctr_drbg);
121
122 #if defined(MBEDTLS_DEBUG_C)
123 mbedtls_debug_set_threshold(DEBUG_LEVEL);
124 #endif
125
126 /*
127 * 1. Seed the RNG
128 */
129 printf(" . Seeding the random number generator...");
130 fflush(stdout);
131
132 if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
133 (const unsigned char *) pers,
134 strlen(pers))) != 0) {
135 printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret);
136 goto exit;
137 }
138
139 printf(" ok\n");
140
141 /*
142 * 2. Load the certificates and private RSA key
143 */
144 printf("\n . Loading the server cert. and key...");
145 fflush(stdout);
146
147 /*
148 * This demonstration program uses embedded test certificates.
149 * Instead, you may want to use mbedtls_x509_crt_parse_file() to read the
150 * server and CA certificates, as well as mbedtls_pk_parse_keyfile().
151 */
152 ret = mbedtls_x509_crt_parse(&srvcert, (const unsigned char *) mbedtls_test_srv_crt,
153 mbedtls_test_srv_crt_len);
154 if (ret != 0) {
155 printf(" failed\n ! mbedtls_x509_crt_parse returned %d\n\n", ret);
156 goto exit;
157 }
158
159 ret = mbedtls_x509_crt_parse(&srvcert, (const unsigned char *) mbedtls_test_cas_pem,
160 mbedtls_test_cas_pem_len);
161 if (ret != 0) {
162 printf(" failed\n ! mbedtls_x509_crt_parse returned %d\n\n", ret);
163 goto exit;
164 }
165
166 ret = mbedtls_pk_parse_key(&pkey,
167 (const unsigned char *) mbedtls_test_srv_key,
168 mbedtls_test_srv_key_len,
169 NULL,
170 0,
171 mbedtls_ctr_drbg_random,
172 &ctr_drbg);
173 if (ret != 0) {
174 printf(" failed\n ! mbedtls_pk_parse_key returned %d\n\n", ret);
175 goto exit;
176 }
177
178 printf(" ok\n");
179
180 /*
181 * 3. Setup the "listening" UDP socket
182 */
183 printf(" . Bind on udp/*/4433 ...");
184 fflush(stdout);
185
186 if ((ret = mbedtls_net_bind(&listen_fd, BIND_IP, "4433", MBEDTLS_NET_PROTO_UDP)) != 0) {
187 printf(" failed\n ! mbedtls_net_bind returned %d\n\n", ret);
188 goto exit;
189 }
190
191 printf(" ok\n");
192
193 /*
194 * 4. Setup stuff
195 */
196 printf(" . Setting up the DTLS data...");
197 fflush(stdout);
198
199 if ((ret = mbedtls_ssl_config_defaults(&conf,
200 MBEDTLS_SSL_IS_SERVER,
201 MBEDTLS_SSL_TRANSPORT_DATAGRAM,
202 MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
203 mbedtls_printf(" failed\n ! mbedtls_ssl_config_defaults returned %d\n\n", ret);
204 goto exit;
205 }
206
207 mbedtls_ssl_conf_rng(&conf, mbedtls_ctr_drbg_random, &ctr_drbg);
208 mbedtls_ssl_conf_dbg(&conf, my_debug, stdout);
209 mbedtls_ssl_conf_read_timeout(&conf, READ_TIMEOUT_MS);
210
211 #if defined(MBEDTLS_SSL_CACHE_C)
212 mbedtls_ssl_conf_session_cache(&conf, &cache,
213 mbedtls_ssl_cache_get,
214 mbedtls_ssl_cache_set);
215 #endif
216
217 mbedtls_ssl_conf_ca_chain(&conf, srvcert.next, NULL);
218 if ((ret = mbedtls_ssl_conf_own_cert(&conf, &srvcert, &pkey)) != 0) {
219 printf(" failed\n ! mbedtls_ssl_conf_own_cert returned %d\n\n", ret);
220 goto exit;
221 }
222
223 if ((ret = mbedtls_ssl_cookie_setup(&cookie_ctx,
224 mbedtls_ctr_drbg_random, &ctr_drbg)) != 0) {
225 printf(" failed\n ! mbedtls_ssl_cookie_setup returned %d\n\n", ret);
226 goto exit;
227 }
228
229 mbedtls_ssl_conf_dtls_cookies(&conf, mbedtls_ssl_cookie_write, mbedtls_ssl_cookie_check,
230 &cookie_ctx);
231
232 if ((ret = mbedtls_ssl_setup(&ssl, &conf)) != 0) {
233 printf(" failed\n ! mbedtls_ssl_setup returned %d\n\n", ret);
234 goto exit;
235 }
236
237 mbedtls_ssl_set_timer_cb(&ssl, &timer, mbedtls_timing_set_delay,
238 mbedtls_timing_get_delay);
239
240 printf(" ok\n");
241
242 reset:
243 #ifdef MBEDTLS_ERROR_C
244 if (ret != 0) {
245 char error_buf[100];
246 mbedtls_strerror(ret, error_buf, 100);
247 printf("Last error was: %d - %s\n\n", ret, error_buf);
248 }
249 #endif
250
251 mbedtls_net_free(&client_fd);
252
253 mbedtls_ssl_session_reset(&ssl);
254
255 /*
256 * 3. Wait until a client connects
257 */
258 printf(" . Waiting for a remote connection ...");
259 fflush(stdout);
260
261 if ((ret = mbedtls_net_accept(&listen_fd, &client_fd,
262 client_ip, sizeof(client_ip), &cliip_len)) != 0) {
263 printf(" failed\n ! mbedtls_net_accept returned %d\n\n", ret);
264 goto exit;
265 }
266
267 /* For HelloVerifyRequest cookies */
268 if ((ret = mbedtls_ssl_set_client_transport_id(&ssl,
269 client_ip, cliip_len)) != 0) {
270 printf(" failed\n ! "
271 "mbedtls_ssl_set_client_transport_id() returned -0x%x\n\n", (unsigned int) -ret);
272 goto exit;
273 }
274
275 mbedtls_ssl_set_bio(&ssl, &client_fd,
276 mbedtls_net_send, mbedtls_net_recv, mbedtls_net_recv_timeout);
277
278 printf(" ok\n");
279
280 /*
281 * 5. Handshake
282 */
283 printf(" . Performing the DTLS handshake...");
284 fflush(stdout);
285
286 do {
287 ret = mbedtls_ssl_handshake(&ssl);
288 } while (ret == MBEDTLS_ERR_SSL_WANT_READ ||
289 ret == MBEDTLS_ERR_SSL_WANT_WRITE);
290
291 if (ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED) {
292 printf(" hello verification requested\n");
293 ret = 0;
294 goto reset;
295 } else if (ret != 0) {
296 printf(" failed\n ! mbedtls_ssl_handshake returned -0x%x\n\n", (unsigned int) -ret);
297 goto reset;
298 }
299
300 printf(" ok\n");
301
302 /*
303 * 6. Read the echo Request
304 */
305 printf(" < Read from client:");
306 fflush(stdout);
307
308 len = sizeof(buf) - 1;
309 memset(buf, 0, sizeof(buf));
310
311 do {
312 ret = mbedtls_ssl_read(&ssl, buf, len);
313 } while (ret == MBEDTLS_ERR_SSL_WANT_READ ||
314 ret == MBEDTLS_ERR_SSL_WANT_WRITE);
315
316 if (ret <= 0) {
317 switch (ret) {
318 case MBEDTLS_ERR_SSL_TIMEOUT:
319 printf(" timeout\n\n");
320 goto reset;
321
322 case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY:
323 printf(" connection was closed gracefully\n");
324 ret = 0;
325 goto close_notify;
326
327 default:
328 printf(" mbedtls_ssl_read returned -0x%x\n\n", (unsigned int) -ret);
329 goto reset;
330 }
331 }
332
333 len = ret;
334 printf(" %d bytes read\n\n%s\n\n", len, buf);
335
336 /*
337 * 7. Write the 200 Response
338 */
339 printf(" > Write to client:");
340 fflush(stdout);
341
342 do {
343 ret = mbedtls_ssl_write(&ssl, buf, len);
344 } while (ret == MBEDTLS_ERR_SSL_WANT_READ ||
345 ret == MBEDTLS_ERR_SSL_WANT_WRITE);
346
347 if (ret < 0) {
348 printf(" failed\n ! mbedtls_ssl_write returned %d\n\n", ret);
349 goto exit;
350 }
351
352 len = ret;
353 printf(" %d bytes written\n\n%s\n\n", len, buf);
354
355 /*
356 * 8. Done, cleanly close the connection
357 */
358 close_notify:
359 printf(" . Closing the connection...");
360
361 /* No error checking, the connection might be closed already */
362 do {
363 ret = mbedtls_ssl_close_notify(&ssl);
364 } while (ret == MBEDTLS_ERR_SSL_WANT_WRITE);
365 ret = 0;
366
367 printf(" done\n");
368
369 goto reset;
370
371 /*
372 * Final clean-ups and exit
373 */
374 exit:
375
376 #ifdef MBEDTLS_ERROR_C
377 if (ret != 0) {
378 char error_buf[100];
379 mbedtls_strerror(ret, error_buf, 100);
380 printf("Last error was: %d - %s\n\n", ret, error_buf);
381 }
382 #endif
383
384 mbedtls_net_free(&client_fd);
385 mbedtls_net_free(&listen_fd);
386
387 mbedtls_x509_crt_free(&srvcert);
388 mbedtls_pk_free(&pkey);
389 mbedtls_ssl_free(&ssl);
390 mbedtls_ssl_config_free(&conf);
391 mbedtls_ssl_cookie_free(&cookie_ctx);
392 #if defined(MBEDTLS_SSL_CACHE_C)
393 mbedtls_ssl_cache_free(&cache);
394 #endif
395 mbedtls_ctr_drbg_free(&ctr_drbg);
396 mbedtls_entropy_free(&entropy);
397
398 /* Shell can not handle large exit numbers -> 1 for errors */
399 if (ret < 0) {
400 ret = 1;
401 }
402
403 mbedtls_exit(ret);
404 }
405 #endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_PROTO_DTLS &&
406 MBEDTLS_SSL_COOKIE_C && MBEDTLS_NET_C && MBEDTLS_ENTROPY_C &&
407 MBEDTLS_CTR_DRBG_C && MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_RSA_C
408 && MBEDTLS_PEM_PARSE_C && MBEDTLS_TIMING_C */
409