1 /*
2 * Simple DTLS server demonstration program
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 */
7
8 #define MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS
9
10 #include "mbedtls/build_info.h"
11
12 #include "mbedtls/platform.h"
13
14 /* Uncomment out the following line to default to IPv4 and disable IPv6 */
15 //#define FORCE_IPV4
16
17 #ifdef FORCE_IPV4
18 #define BIND_IP "0.0.0.0" /* Forces IPv4 */
19 #else
20 #define BIND_IP "::"
21 #endif
22
23 #if !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
24 !defined(MBEDTLS_NET_C) || !defined(MBEDTLS_SSL_SRV_C) || \
25 !defined(MBEDTLS_TIMING_C) || !defined(MBEDTLS_SSL_PROTO_DTLS) || \
26 !defined(MBEDTLS_SSL_COOKIE_C) || \
27 !defined(MBEDTLS_PEM_PARSE_C) || !defined(MBEDTLS_X509_CRT_PARSE_C)
main(void)28 int main(void)
29 {
30 mbedtls_printf("MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
31 "MBEDTLS_NET_C and/or MBEDTLS_SSL_SRV_C and/or "
32 "MBEDTLS_TIMING_C and/or MBEDTLS_SSL_PROTO_DTLS and/or "
33 "MBEDTLS_SSL_COOKIE_C and/or "
34 "MBEDTLS_PEM_PARSE_C and/or MBEDTLS_X509_CRT_PARSE_C "
35 "not defined.\n");
36 mbedtls_exit(0);
37 }
38 #else
39
40 #if defined(_WIN32)
41 #include <windows.h>
42 #endif
43
44 #include <string.h>
45 #include <stdlib.h>
46 #include <stdio.h>
47
48 #include "mbedtls/entropy.h"
49 #include "mbedtls/ctr_drbg.h"
50 #include "mbedtls/x509.h"
51 #include "mbedtls/ssl.h"
52 #include "mbedtls/ssl_cookie.h"
53 #include "mbedtls/net_sockets.h"
54 #include "mbedtls/error.h"
55 #include "mbedtls/debug.h"
56 #include "mbedtls/timing.h"
57
58 #include "test/certs.h"
59
60 #if defined(MBEDTLS_SSL_CACHE_C)
61 #include "mbedtls/ssl_cache.h"
62 #endif
63
64 #define READ_TIMEOUT_MS 10000 /* 10 seconds */
65 #define DEBUG_LEVEL 0
66
67
my_debug(void * ctx,int level,const char * file,int line,const char * str)68 static void my_debug(void *ctx, int level,
69 const char *file, int line,
70 const char *str)
71 {
72 ((void) level);
73
74 mbedtls_fprintf((FILE *) ctx, "%s:%04d: %s", file, line, str);
75 fflush((FILE *) ctx);
76 }
77
main(void)78 int main(void)
79 {
80 int ret, len;
81 mbedtls_net_context listen_fd, client_fd;
82 unsigned char buf[1024];
83 const char *pers = "dtls_server";
84 unsigned char client_ip[16] = { 0 };
85 size_t cliip_len;
86 mbedtls_ssl_cookie_ctx cookie_ctx;
87
88 mbedtls_entropy_context entropy;
89 mbedtls_ctr_drbg_context ctr_drbg;
90 mbedtls_ssl_context ssl;
91 mbedtls_ssl_config conf;
92 mbedtls_x509_crt srvcert;
93 mbedtls_pk_context pkey;
94 mbedtls_timing_delay_context timer;
95 #if defined(MBEDTLS_SSL_CACHE_C)
96 mbedtls_ssl_cache_context cache;
97 #endif
98
99 mbedtls_net_init(&listen_fd);
100 mbedtls_net_init(&client_fd);
101 mbedtls_ssl_init(&ssl);
102 mbedtls_ssl_config_init(&conf);
103 mbedtls_ssl_cookie_init(&cookie_ctx);
104 #if defined(MBEDTLS_SSL_CACHE_C)
105 mbedtls_ssl_cache_init(&cache);
106 #endif
107 mbedtls_x509_crt_init(&srvcert);
108 mbedtls_pk_init(&pkey);
109 mbedtls_entropy_init(&entropy);
110 mbedtls_ctr_drbg_init(&ctr_drbg);
111
112 psa_status_t status = psa_crypto_init();
113 if (status != PSA_SUCCESS) {
114 mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
115 (int) status);
116 ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
117 goto exit;
118 }
119
120 #if defined(MBEDTLS_DEBUG_C)
121 mbedtls_debug_set_threshold(DEBUG_LEVEL);
122 #endif
123
124 /*
125 * 1. Seed the RNG
126 */
127 printf(" . Seeding the random number generator...");
128 fflush(stdout);
129
130 if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
131 (const unsigned char *) pers,
132 strlen(pers))) != 0) {
133 printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret);
134 goto exit;
135 }
136
137 printf(" ok\n");
138
139 /*
140 * 2. Load the certificates and private RSA key
141 */
142 printf("\n . Loading the server cert. and key...");
143 fflush(stdout);
144
145 /*
146 * This demonstration program uses embedded test certificates.
147 * Instead, you may want to use mbedtls_x509_crt_parse_file() to read the
148 * server and CA certificates, as well as mbedtls_pk_parse_keyfile().
149 */
150 ret = mbedtls_x509_crt_parse(&srvcert, (const unsigned char *) mbedtls_test_srv_crt,
151 mbedtls_test_srv_crt_len);
152 if (ret != 0) {
153 printf(" failed\n ! mbedtls_x509_crt_parse returned %d\n\n", ret);
154 goto exit;
155 }
156
157 ret = mbedtls_x509_crt_parse(&srvcert, (const unsigned char *) mbedtls_test_cas_pem,
158 mbedtls_test_cas_pem_len);
159 if (ret != 0) {
160 printf(" failed\n ! mbedtls_x509_crt_parse returned %d\n\n", ret);
161 goto exit;
162 }
163
164 ret = mbedtls_pk_parse_key(&pkey,
165 (const unsigned char *) mbedtls_test_srv_key,
166 mbedtls_test_srv_key_len,
167 NULL,
168 0);
169 if (ret != 0) {
170 printf(" failed\n ! mbedtls_pk_parse_key returned %d\n\n", ret);
171 goto exit;
172 }
173
174 printf(" ok\n");
175
176 /*
177 * 3. Setup the "listening" UDP socket
178 */
179 printf(" . Bind on udp/*/4433 ...");
180 fflush(stdout);
181
182 if ((ret = mbedtls_net_bind(&listen_fd, BIND_IP, "4433", MBEDTLS_NET_PROTO_UDP)) != 0) {
183 printf(" failed\n ! mbedtls_net_bind returned %d\n\n", ret);
184 goto exit;
185 }
186
187 printf(" ok\n");
188
189 /*
190 * 4. Setup stuff
191 */
192 printf(" . Setting up the DTLS data...");
193 fflush(stdout);
194
195 if ((ret = mbedtls_ssl_config_defaults(&conf,
196 MBEDTLS_SSL_IS_SERVER,
197 MBEDTLS_SSL_TRANSPORT_DATAGRAM,
198 MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
199 mbedtls_printf(" failed\n ! mbedtls_ssl_config_defaults returned %d\n\n", ret);
200 goto exit;
201 }
202
203 mbedtls_ssl_conf_dbg(&conf, my_debug, stdout);
204 mbedtls_ssl_conf_read_timeout(&conf, READ_TIMEOUT_MS);
205
206 #if defined(MBEDTLS_SSL_CACHE_C)
207 mbedtls_ssl_conf_session_cache(&conf, &cache,
208 mbedtls_ssl_cache_get,
209 mbedtls_ssl_cache_set);
210 #endif
211
212 mbedtls_ssl_conf_ca_chain(&conf, srvcert.next, NULL);
213 if ((ret = mbedtls_ssl_conf_own_cert(&conf, &srvcert, &pkey)) != 0) {
214 printf(" failed\n ! mbedtls_ssl_conf_own_cert returned %d\n\n", ret);
215 goto exit;
216 }
217
218 if ((ret = mbedtls_ssl_cookie_setup(&cookie_ctx)) != 0) {
219 printf(" failed\n ! mbedtls_ssl_cookie_setup returned %d\n\n", ret);
220 goto exit;
221 }
222
223 mbedtls_ssl_conf_dtls_cookies(&conf, mbedtls_ssl_cookie_write, mbedtls_ssl_cookie_check,
224 &cookie_ctx);
225
226 if ((ret = mbedtls_ssl_setup(&ssl, &conf)) != 0) {
227 printf(" failed\n ! mbedtls_ssl_setup returned %d\n\n", ret);
228 goto exit;
229 }
230
231 mbedtls_ssl_set_timer_cb(&ssl, &timer, mbedtls_timing_set_delay,
232 mbedtls_timing_get_delay);
233
234 printf(" ok\n");
235
236 reset:
237 #ifdef MBEDTLS_ERROR_C
238 if (ret != 0) {
239 char error_buf[100];
240 mbedtls_strerror(ret, error_buf, 100);
241 printf("Last error was: %d - %s\n\n", ret, error_buf);
242 }
243 #endif
244
245 mbedtls_net_free(&client_fd);
246
247 mbedtls_ssl_session_reset(&ssl);
248
249 /*
250 * 5. Wait until a client connects
251 */
252 printf(" . Waiting for a remote connection ...");
253 fflush(stdout);
254
255 if ((ret = mbedtls_net_accept(&listen_fd, &client_fd,
256 client_ip, sizeof(client_ip), &cliip_len)) != 0) {
257 printf(" failed\n ! mbedtls_net_accept returned %d\n\n", ret);
258 goto exit;
259 }
260
261 /* For HelloVerifyRequest cookies */
262 if ((ret = mbedtls_ssl_set_client_transport_id(&ssl,
263 client_ip, cliip_len)) != 0) {
264 printf(" failed\n ! "
265 "mbedtls_ssl_set_client_transport_id() returned -0x%x\n\n", (unsigned int) -ret);
266 goto exit;
267 }
268
269 mbedtls_ssl_set_bio(&ssl, &client_fd,
270 mbedtls_net_send, mbedtls_net_recv, mbedtls_net_recv_timeout);
271
272 printf(" ok\n");
273
274 /*
275 * 6. Handshake
276 */
277 printf(" . Performing the DTLS handshake...");
278 fflush(stdout);
279
280 do {
281 ret = mbedtls_ssl_handshake(&ssl);
282 } while (ret == MBEDTLS_ERR_SSL_WANT_READ ||
283 ret == MBEDTLS_ERR_SSL_WANT_WRITE);
284
285 if (ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED) {
286 printf(" hello verification requested\n");
287 ret = 0;
288 goto reset;
289 } else if (ret != 0) {
290 printf(" failed\n ! mbedtls_ssl_handshake returned -0x%x\n", (unsigned int) -ret);
291 if (ret == MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE) {
292 printf(" An unexpected message was received from our peer. If this happened at\n");
293 printf(" the beginning of the handshake, this is likely a duplicated packet or\n");
294 printf(" a close_notify alert from the previous connection, which is harmless.\n");
295 ret = 0;
296 }
297 printf("\n");
298 goto reset;
299 }
300
301 printf(" ok\n");
302
303 /*
304 * 7. Read the echo Request
305 */
306 printf(" < Read from client:");
307 fflush(stdout);
308
309 len = sizeof(buf) - 1;
310 memset(buf, 0, sizeof(buf));
311
312 do {
313 ret = mbedtls_ssl_read(&ssl, buf, len);
314 } while (ret == MBEDTLS_ERR_SSL_WANT_READ ||
315 ret == MBEDTLS_ERR_SSL_WANT_WRITE);
316
317 if (ret <= 0) {
318 switch (ret) {
319 case MBEDTLS_ERR_SSL_TIMEOUT:
320 printf(" timeout\n\n");
321 goto reset;
322
323 case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY:
324 printf(" connection was closed gracefully\n");
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 * 8. 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 * 9. 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 mbedtls_psa_crypto_free();
398
399 /* Shell can not handle large exit numbers -> 1 for errors */
400 if (ret < 0) {
401 ret = 1;
402 }
403
404 mbedtls_exit(ret);
405 }
406
407 #endif /* configuration allows running this program */
408