1 /*
2 * Copyright 2023-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * NB: Changes to this file should also be reflected in
12 * doc/man7/ossl-guide-quic-multi-stream.pod
13 */
14
15 #include <string.h>
16
17 /* Include the appropriate header file for SOCK_DGRAM */
18 #ifdef _WIN32 /* Windows */
19 #include <winsock2.h>
20 #else /* Linux/Unix */
21 #include <sys/socket.h>
22 #endif
23
24 #include <openssl/bio.h>
25 #include <openssl/ssl.h>
26 #include <openssl/err.h>
27
28 /* Helper function to create a BIO connected to the server */
create_socket_bio(const char * hostname,const char * port,int family,BIO_ADDR ** peer_addr)29 static BIO *create_socket_bio(const char *hostname, const char *port,
30 int family, BIO_ADDR **peer_addr)
31 {
32 int sock = -1;
33 BIO_ADDRINFO *res;
34 const BIO_ADDRINFO *ai = NULL;
35 BIO *bio;
36
37 /*
38 * Lookup IP address info for the server.
39 */
40 if (!BIO_lookup_ex(hostname, port, BIO_LOOKUP_CLIENT, family, SOCK_DGRAM, 0,
41 &res))
42 return NULL;
43
44 /*
45 * Loop through all the possible addresses for the server and find one
46 * we can connect to.
47 */
48 for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
49 /*
50 * Create a UDP socket. We could equally use non-OpenSSL calls such
51 * as "socket" here for this and the subsequent connect and close
52 * functions. But for portability reasons and also so that we get
53 * errors on the OpenSSL stack in the event of a failure we use
54 * OpenSSL's versions of these functions.
55 */
56 sock = BIO_socket(BIO_ADDRINFO_family(ai), SOCK_DGRAM, 0, 0);
57 if (sock == -1)
58 continue;
59
60 /* Connect the socket to the server's address */
61 if (!BIO_connect(sock, BIO_ADDRINFO_address(ai), 0)) {
62 BIO_closesocket(sock);
63 sock = -1;
64 continue;
65 }
66
67 /* Set to nonblocking mode */
68 if (!BIO_socket_nbio(sock, 1)) {
69 BIO_closesocket(sock);
70 sock = -1;
71 continue;
72 }
73
74 break;
75 }
76
77 if (sock != -1) {
78 *peer_addr = BIO_ADDR_dup(BIO_ADDRINFO_address(ai));
79 if (*peer_addr == NULL) {
80 BIO_closesocket(sock);
81 return NULL;
82 }
83 }
84
85 /* Free the address information resources we allocated earlier */
86 BIO_ADDRINFO_free(res);
87
88 /* If sock is -1 then we've been unable to connect to the server */
89 if (sock == -1)
90 return NULL;
91
92 /* Create a BIO to wrap the socket */
93 bio = BIO_new(BIO_s_datagram());
94 if (bio == NULL) {
95 BIO_closesocket(sock);
96 return NULL;
97 }
98
99 /*
100 * Associate the newly created BIO with the underlying socket. By
101 * passing BIO_CLOSE here the socket will be automatically closed when
102 * the BIO is freed. Alternatively you can use BIO_NOCLOSE, in which
103 * case you must close the socket explicitly when it is no longer
104 * needed.
105 */
106 BIO_set_fd(bio, sock, BIO_CLOSE);
107
108 return bio;
109 }
110
write_a_request(SSL * stream,const char * request_start,const char * hostname)111 static int write_a_request(SSL *stream, const char *request_start,
112 const char *hostname)
113 {
114 const char *request_end = "\r\n\r\n";
115 size_t written;
116
117 if (!SSL_write_ex(stream, request_start, strlen(request_start),
118 &written))
119 return 0;
120 if (!SSL_write_ex(stream, hostname, strlen(hostname), &written))
121 return 0;
122 if (!SSL_write_ex(stream, request_end, strlen(request_end), &written))
123 return 0;
124
125 return 1;
126 }
127
128 /*
129 * Simple application to send basic HTTP/1.0 requests to a server and print the
130 * response on the screen. Note that HTTP/1.0 over QUIC is not a real protocol
131 * and will not be supported by real world servers. This is for demonstration
132 * purposes only.
133 */
main(int argc,char * argv[])134 int main(int argc, char *argv[])
135 {
136 SSL_CTX *ctx = NULL;
137 SSL *ssl = NULL;
138 SSL *stream1 = NULL, *stream2 = NULL, *stream3 = NULL;
139 BIO *bio = NULL;
140 int res = EXIT_FAILURE;
141 int ret;
142 unsigned char alpn[] = { 8, 'h', 't', 't', 'p', '/', '1', '.', '0' };
143 const char *request1_start = "GET /request1.html HTTP/1.0\r\nConnection: close\r\nHost: ";
144 const char *request2_start = "GET /request2.html HTTP/1.0\r\nConnection: close\r\nHost: ";
145 size_t readbytes;
146 char buf[160];
147 BIO_ADDR *peer_addr = NULL;
148 char *hostname, *port;
149 int argnext = 1;
150 int ipv6 = 0;
151
152 if (argc < 3) {
153 printf("Usage: quic-client-non-block [-6] hostname port\n");
154 goto end;
155 }
156
157 if (!strcmp(argv[argnext], "-6")) {
158 if (argc < 4) {
159 printf("Usage: quic-client-non-block [-6] hostname port\n");
160 goto end;
161 }
162 ipv6 = 1;
163 argnext++;
164 }
165 hostname = argv[argnext++];
166 port = argv[argnext];
167
168 /*
169 * Create an SSL_CTX which we can use to create SSL objects from. We
170 * want an SSL_CTX for creating clients so we use
171 * OSSL_QUIC_client_method() here.
172 */
173 ctx = SSL_CTX_new(OSSL_QUIC_client_method());
174 if (ctx == NULL) {
175 printf("Failed to create the SSL_CTX\n");
176 goto end;
177 }
178
179 /*
180 * Configure the client to abort the handshake if certificate
181 * verification fails. Virtually all clients should do this unless you
182 * really know what you are doing.
183 */
184 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL);
185
186 /* Use the default trusted certificate store */
187 if (!SSL_CTX_set_default_verify_paths(ctx)) {
188 printf("Failed to set the default trusted certificate store\n");
189 goto end;
190 }
191
192 /* Create an SSL object to represent the TLS connection */
193 ssl = SSL_new(ctx);
194 if (ssl == NULL) {
195 printf("Failed to create the SSL object\n");
196 goto end;
197 }
198
199 /*
200 * We will use multiple streams so we will disable the default stream mode.
201 * This is not a requirement for using multiple streams but is recommended.
202 */
203 if (!SSL_set_default_stream_mode(ssl, SSL_DEFAULT_STREAM_MODE_NONE)) {
204 printf("Failed to disable the default stream mode\n");
205 goto end;
206 }
207
208 /*
209 * Create the underlying transport socket/BIO and associate it with the
210 * connection.
211 */
212 bio = create_socket_bio(hostname, port, ipv6 ? AF_INET6 : AF_INET, &peer_addr);
213 if (bio == NULL) {
214 printf("Failed to crete the BIO\n");
215 goto end;
216 }
217 SSL_set_bio(ssl, bio, bio);
218
219 /*
220 * Tell the server during the handshake which hostname we are attempting
221 * to connect to in case the server supports multiple hosts.
222 */
223 if (!SSL_set_tlsext_host_name(ssl, hostname)) {
224 printf("Failed to set the SNI hostname\n");
225 goto end;
226 }
227
228 /*
229 * Ensure we check during certificate verification that the server has
230 * supplied a certificate for the hostname that we were expecting.
231 * Virtually all clients should do this unless you really know what you
232 * are doing.
233 */
234 if (!SSL_set1_host(ssl, hostname)) {
235 printf("Failed to set the certificate verification hostname");
236 goto end;
237 }
238
239 /* SSL_set_alpn_protos returns 0 for success! */
240 if (SSL_set_alpn_protos(ssl, alpn, sizeof(alpn)) != 0) {
241 printf("Failed to set the ALPN for the connection\n");
242 goto end;
243 }
244
245 /* Set the IP address of the remote peer */
246 if (!SSL_set1_initial_peer_addr(ssl, peer_addr)) {
247 printf("Failed to set the initial peer address\n");
248 goto end;
249 }
250
251 /* Do the handshake with the server */
252 if (SSL_connect(ssl) < 1) {
253 printf("Failed to connect to the server\n");
254 /*
255 * If the failure is due to a verification error we can get more
256 * information about it from SSL_get_verify_result().
257 */
258 if (SSL_get_verify_result(ssl) != X509_V_OK)
259 printf("Verify error: %s\n",
260 X509_verify_cert_error_string(SSL_get_verify_result(ssl)));
261 goto end;
262 }
263
264 /*
265 * We create two new client initiated streams. The first will be
266 * bi-directional, and the second will be uni-directional.
267 */
268 stream1 = SSL_new_stream(ssl, 0);
269 stream2 = SSL_new_stream(ssl, SSL_STREAM_FLAG_UNI);
270 if (stream1 == NULL || stream2 == NULL) {
271 printf("Failed to create streams\n");
272 goto end;
273 }
274
275 /* Write an HTTP GET request on each of our streams to the peer */
276 if (!write_a_request(stream1, request1_start, hostname)) {
277 printf("Failed to write HTTP request on stream 1\n");
278 goto end;
279 }
280
281 if (!write_a_request(stream2, request2_start, hostname)) {
282 printf("Failed to write HTTP request on stream 2\n");
283 goto end;
284 }
285
286 /*
287 * In this demo we read all the data from one stream before reading all the
288 * data from the next stream for simplicity. In practice there is no need to
289 * do this. We can interleave IO on the different streams if we wish, or
290 * manage the streams entirely separately on different threads.
291 */
292
293 printf("Stream 1 data:\n");
294 /*
295 * Get up to sizeof(buf) bytes of the response from stream 1 (which is a
296 * bidirectional stream). We keep reading until the server closes the
297 * connection.
298 */
299 while (SSL_read_ex(stream1, buf, sizeof(buf), &readbytes)) {
300 /*
301 * OpenSSL does not guarantee that the returned data is a string or
302 * that it is NUL terminated so we use fwrite() to write the exact
303 * number of bytes that we read. The data could be non-printable or
304 * have NUL characters in the middle of it. For this simple example
305 * we're going to print it to stdout anyway.
306 */
307 fwrite(buf, 1, readbytes, stdout);
308 }
309 /* In case the response didn't finish with a newline we add one now */
310 printf("\n");
311
312 /*
313 * Check whether we finished the while loop above normally or as the
314 * result of an error. The 0 argument to SSL_get_error() is the return
315 * code we received from the SSL_read_ex() call. It must be 0 in order
316 * to get here. Normal completion is indicated by SSL_ERROR_ZERO_RETURN. In
317 * QUIC terms this means that the peer has sent FIN on the stream to
318 * indicate that no further data will be sent.
319 */
320 switch (SSL_get_error(stream1, 0)) {
321 case SSL_ERROR_ZERO_RETURN:
322 /* Normal completion of the stream */
323 break;
324
325 case SSL_ERROR_SSL:
326 /*
327 * Some stream fatal error occurred. This could be because of a stream
328 * reset - or some failure occurred on the underlying connection.
329 */
330 switch (SSL_get_stream_read_state(stream1)) {
331 case SSL_STREAM_STATE_RESET_REMOTE:
332 printf("Stream reset occurred\n");
333 /* The stream has been reset but the connection is still healthy. */
334 break;
335
336 case SSL_STREAM_STATE_CONN_CLOSED:
337 printf("Connection closed\n");
338 /* Connection is already closed. Skip SSL_shutdown() */
339 goto end;
340
341 default:
342 printf("Unknown stream failure\n");
343 break;
344 }
345 break;
346
347 default:
348 /* Some other unexpected error occurred */
349 printf("Failed reading remaining data\n");
350 break;
351 }
352
353 /*
354 * In our hypothetical HTTP/1.0 over QUIC protocol that we are using we
355 * assume that the server will respond with a server initiated stream
356 * containing the data requested in our uni-directional stream. This doesn't
357 * really make sense to do in a real protocol, but its just for
358 * demonstration purposes.
359 *
360 * We're using blocking mode so this will block until a stream becomes
361 * available. We could override this behaviour if we wanted to by setting
362 * the SSL_ACCEPT_STREAM_NO_BLOCK flag in the second argument below.
363 */
364 stream3 = SSL_accept_stream(ssl, 0);
365 if (stream3 == NULL) {
366 printf("Failed to accept a new stream\n");
367 goto end;
368 }
369
370 printf("Stream 3 data:\n");
371 /*
372 * Read the data from stream 3 like we did for stream 1 above. Note that
373 * stream 2 was uni-directional so there is no data to be read from that
374 * one.
375 */
376 while (SSL_read_ex(stream3, buf, sizeof(buf), &readbytes))
377 fwrite(buf, 1, readbytes, stdout);
378 printf("\n");
379
380 /* Check for errors on the stream */
381 switch (SSL_get_error(stream3, 0)) {
382 case SSL_ERROR_ZERO_RETURN:
383 /* Normal completion of the stream */
384 break;
385
386 case SSL_ERROR_SSL:
387 switch (SSL_get_stream_read_state(stream3)) {
388 case SSL_STREAM_STATE_RESET_REMOTE:
389 printf("Stream reset occurred\n");
390 break;
391
392 case SSL_STREAM_STATE_CONN_CLOSED:
393 printf("Connection closed\n");
394 goto end;
395
396 default:
397 printf("Unknown stream failure\n");
398 break;
399 }
400 break;
401
402 default:
403 printf("Failed reading remaining data\n");
404 break;
405 }
406
407 /*
408 * Repeatedly call SSL_shutdown() until the connection is fully
409 * closed.
410 */
411 do {
412 ret = SSL_shutdown(ssl);
413 if (ret < 0) {
414 printf("Error shutting down: %d\n", ret);
415 goto end;
416 }
417 } while (ret != 1);
418
419 /* Success! */
420 res = EXIT_SUCCESS;
421 end:
422 /*
423 * If something bad happened then we will dump the contents of the
424 * OpenSSL error stack to stderr. There might be some useful diagnostic
425 * information there.
426 */
427 if (res == EXIT_FAILURE)
428 ERR_print_errors_fp(stderr);
429
430 /*
431 * Free the resources we allocated. We do not free the BIO object here
432 * because ownership of it was immediately transferred to the SSL object
433 * via SSL_set_bio(). The BIO will be freed when we free the SSL object.
434 */
435 SSL_free(ssl);
436 SSL_free(stream1);
437 SSL_free(stream2);
438 SSL_free(stream3);
439 SSL_CTX_free(ctx);
440 BIO_ADDR_free(peer_addr);
441 return res;
442 }
443