1 /*
2  * lws-minimal-http-client-jit-trust
3  *
4  * Written in 2010-2021 by Andy Green <[email protected]>
5  *
6  * This file is made available under the Creative Commons CC0 1.0
7  * Universal Public Domain Dedication.
8  *
9  * This demonstrates the a minimal http client using lws.
10  *
11  * It visits https://warmcat.com/ and receives the html page there.  You
12  * can dump the page data by changing the #if 0 below.
13  */
14 
15 #include <libwebsockets.h>
16 #include <string.h>
17 #include <signal.h>
18 
19 static int interrupted, bad = 1, status, conmon;
20 #if defined(LWS_WITH_HTTP2)
21 static int long_poll;
22 #endif
23 static struct lws *client_wsi;
24 static const char *ba_user, *ba_password;
25 static int budget = 6;
26 
27 /*
28  * For this example, we import the C-formatted array version of the trust blob
29  * directly.  This is produced by running scripts/mozilla-trust-gen.sh and can
30  * be found in ./_trust after that.
31  */
32 
33 static uint8_t jit_trust_blob[] = {
34 #include "./trust_blob.h"
35 };
36 
37 static const lws_retry_bo_t retry = {
38 	.secs_since_valid_ping = 3,
39 	.secs_since_valid_hangup = 10,
40 };
41 
42 #if defined(LWS_WITH_CONMON)
43 void
dump_conmon_data(struct lws * wsi)44 dump_conmon_data(struct lws *wsi)
45 {
46 	const struct addrinfo *ai;
47 	struct lws_conmon cm;
48 	char ads[48];
49 
50 	lws_conmon_wsi_take(wsi, &cm);
51 
52 	lws_sa46_write_numeric_address(&cm.peer46, ads, sizeof(ads));
53 	lwsl_notice("%s: peer %s, dns: %uus, sockconn: %uus, "
54 		    "tls: %uus, txn_resp: %uus\n",
55 		    __func__, ads,
56 		    (unsigned int)cm.ciu_dns,
57 		    (unsigned int)cm.ciu_sockconn,
58 		    (unsigned int)cm.ciu_tls,
59 		    (unsigned int)cm.ciu_txn_resp);
60 
61 	ai = cm.dns_results_copy;
62 	while (ai) {
63 		lws_sa46_write_numeric_address((lws_sockaddr46 *)ai->ai_addr,
64 						ads, sizeof(ads));
65 		lwsl_notice("%s: DNS %s\n", __func__, ads);
66 		ai = ai->ai_next;
67 	}
68 
69 	/*
70 	 * This destroys the DNS list in the lws_conmon that we took
71 	 * responsibility for when we used lws_conmon_wsi_take()
72 	 */
73 
74 	lws_conmon_release(&cm);
75 }
76 #endif
77 
78 struct args {
79 	int argc;
80 	const char **argv;
81 };
82 
83 static const struct lws_protocols protocols[];
84 
85 static int
try_connect(struct lws_context * cx)86 try_connect(struct lws_context *cx)
87 {
88 	struct lws_client_connect_info i;
89 	struct args *a = lws_context_user(cx);
90 	const char *p;
91 
92 	memset(&i, 0, sizeof i); /* otherwise uninitialized garbage */
93 	i.context = cx;
94 	if (!lws_cmdline_option(a->argc, a->argv, "-n")) {
95 		i.ssl_connection = LCCSCF_USE_SSL;
96 #if defined(LWS_WITH_HTTP2)
97 		/* requires h2 */
98 		if (lws_cmdline_option(a->argc, a->argv, "--long-poll")) {
99 			lwsl_user("%s: long poll mode\n", __func__);
100 			long_poll = 1;
101 		}
102 #endif
103 	}
104 
105 	if (lws_cmdline_option(a->argc, a->argv, "-l")) {
106 		i.port = 7681;
107 		i.address = "localhost";
108 		i.ssl_connection |= LCCSCF_ALLOW_SELFSIGNED;
109 	} else {
110 		i.port = 443;
111 		i.address = "warmcat.com";
112 	}
113 
114 	if (lws_cmdline_option(a->argc, a->argv, "--nossl"))
115 		i.ssl_connection = 0;
116 
117 	i.ssl_connection |= LCCSCF_H2_QUIRK_OVERFLOWS_TXCR |
118 			    LCCSCF_H2_QUIRK_NGHTTP2_END_STREAM |
119 			    LCCSCF_ACCEPT_TLS_DOWNGRADE_REDIRECTS;
120 
121 	i.alpn = "h2,http/1.1";
122 	if (lws_cmdline_option(a->argc, a->argv, "--h1"))
123 		i.alpn = "http/1.1";
124 
125 	if (lws_cmdline_option(a->argc, a->argv, "--h2-prior-knowledge"))
126 		i.ssl_connection |= LCCSCF_H2_PRIOR_KNOWLEDGE;
127 
128 	if ((p = lws_cmdline_option(a->argc, a->argv, "-p")))
129 		i.port = atoi(p);
130 
131 	if ((p = lws_cmdline_option(a->argc, a->argv, "--user")))
132 		ba_user = p;
133 	if ((p = lws_cmdline_option(a->argc, a->argv, "--password")))
134 		ba_password = p;
135 
136 	if (lws_cmdline_option(a->argc, a->argv, "-j"))
137 		i.ssl_connection |= LCCSCF_ALLOW_SELFSIGNED;
138 
139 	if (lws_cmdline_option(a->argc, a->argv, "-k"))
140 		i.ssl_connection |= LCCSCF_ALLOW_INSECURE;
141 
142 	if (lws_cmdline_option(a->argc, a->argv, "-m"))
143 		i.ssl_connection |= LCCSCF_SKIP_SERVER_CERT_HOSTNAME_CHECK;
144 
145 	if (lws_cmdline_option(a->argc, a->argv, "-e"))
146 		i.ssl_connection |= LCCSCF_ALLOW_EXPIRED;
147 
148 	if ((p = lws_cmdline_option(a->argc, a->argv, "-f"))) {
149 		i.ssl_connection |= LCCSCF_H2_MANUAL_RXFLOW;
150 		i.manual_initial_tx_credit = atoi(p);
151 		lwsl_notice("%s: manual peer tx credit %d\n", __func__,
152 				i.manual_initial_tx_credit);
153 	}
154 
155 #if defined(LWS_WITH_CONMON)
156 	if (lws_cmdline_option(a->argc, a->argv, "--conmon")) {
157 		i.ssl_connection |= LCCSCF_CONMON;
158 		conmon = 1;
159 	}
160 #endif
161 
162 	/* the default validity check is 5m / 5m10s... -v = 3s / 10s */
163 
164 	if (lws_cmdline_option(a->argc, a->argv, "-v"))
165 		i.retry_and_idle_policy = &retry;
166 
167 	if ((p = lws_cmdline_option(a->argc, a->argv, "--server")))
168 		i.address = p;
169 
170 	if ((p = lws_cmdline_option(a->argc, a->argv, "--path")))
171 		i.path = p;
172 	else
173 		i.path = "/";
174 
175 	i.host = i.address;
176 	i.origin = i.address;
177 	i.method = "GET";
178 
179 	i.protocol = protocols[0].name;
180 	i.pwsi = &client_wsi;
181 	i.fi_wsi_name = "user";
182 
183 	if (!lws_client_connect_via_info(&i)) {
184 		lwsl_err("Client creation failed\n");
185 		interrupted = 1;
186 		bad = 2; /* could not even start client connection */
187 		lws_cancel_service(cx);
188 
189 		return 1;
190 	}
191 
192 	return 0;
193 }
194 
195 static const char *ua = "Mozilla/5.0 (X11; Linux x86_64) "
196 			"AppleWebKit/537.36 (KHTML, like Gecko) "
197 			"Chrome/51.0.2704.103 Safari/537.36",
198 		  *acc = "*/*";
199 
200 static int
callback_http(struct lws * wsi,enum lws_callback_reasons reason,void * user,void * in,size_t len)201 callback_http(struct lws *wsi, enum lws_callback_reasons reason,
202 	      void *user, void *in, size_t len)
203 {
204 	switch (reason) {
205 
206 	/* because we are protocols[0] ... */
207 	case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
208 		lwsl_err("CLIENT_CONNECTION_ERROR: %s\n",
209 			 in ? (char *)in : "(null)");
210 
211 		if (budget--) {
212 			try_connect(lws_get_context(wsi));
213 			break;
214 		}
215 
216 		interrupted = 1;
217 		bad = 3; /* connection failed before we could make connection */
218 		lws_cancel_service(lws_get_context(wsi));
219 
220 #if defined(LWS_WITH_CONMON)
221 	if (conmon)
222 		dump_conmon_data(wsi);
223 #endif
224 		break;
225 
226 	case LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP:
227 		{
228 			char buf[128];
229 
230 			lws_get_peer_simple(wsi, buf, sizeof(buf));
231 			status = (int)lws_http_client_http_response(wsi);
232 
233 			lwsl_user("Connected to %s, http response: %d\n",
234 					buf, status);
235 		}
236 #if defined(LWS_WITH_HTTP2)
237 		if (long_poll) {
238 			lwsl_user("%s: Client entering long poll mode\n", __func__);
239 			lws_h2_client_stream_long_poll_rxonly(wsi);
240 		}
241 #endif
242 
243 		if (lws_fi_user_wsi_fi(wsi, "user_reject_at_est"))
244 			return -1;
245 
246 		break;
247 
248 
249 	case LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER:
250 	{
251 		unsigned char **p = (unsigned char **)in, *end = (*p) + len;
252 
253 		if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_USER_AGENT,
254 				(unsigned char *)ua, (int)strlen(ua), p, end))
255 			return -1;
256 
257 		if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_ACCEPT,
258 				(unsigned char *)acc, (int)strlen(acc), p, end))
259 			return -1;
260 
261 #if defined(LWS_WITH_HTTP_BASIC_AUTH)
262 		{
263 		char b[128];
264 
265 	/* you only need this if you need to do Basic Auth */
266 
267 		if (!ba_user || !ba_password)
268 			break;
269 
270 		if (lws_http_basic_auth_gen(ba_user, ba_password, b, sizeof(b)))
271 			break;
272 		if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_AUTHORIZATION,
273 				(unsigned char *)b, (int)strlen(b), p, end))
274 			return -1;
275 		}
276 #endif
277 
278 		break;
279 	}
280 
281 	/* chunks of chunked content, with header removed */
282 	case LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ:
283 		lwsl_user("RECEIVE_CLIENT_HTTP_READ: read %d\n", (int)len);
284 #if defined(LWS_WITH_HTTP2)
285 		if (long_poll) {
286 			char dotstar[128];
287 			lws_strnncpy(dotstar, (const char *)in, len,
288 				     sizeof(dotstar));
289 			lwsl_notice("long poll rx: %d '%s'\n", (int)len,
290 					dotstar);
291 		}
292 #endif
293 #if 0
294 		lwsl_hexdump_notice(in, len);
295 #endif
296 
297 		return 0; /* don't passthru */
298 
299 	/* uninterpreted http content */
300 	case LWS_CALLBACK_RECEIVE_CLIENT_HTTP:
301 		{
302 			char buffer[1024 + LWS_PRE];
303 			char *px = buffer + LWS_PRE;
304 			int lenx = sizeof(buffer) - LWS_PRE;
305 
306 			if (lws_fi_user_wsi_fi(wsi, "user_reject_at_rx"))
307 				return -1;
308 
309 			if (lws_http_client_read(wsi, &px, &lenx) < 0)
310 				return -1;
311 		}
312 		return 0; /* don't passthru */
313 
314 	case LWS_CALLBACK_COMPLETED_CLIENT_HTTP:
315 		lwsl_user("LWS_CALLBACK_COMPLETED_CLIENT_HTTP\n");
316 		interrupted = 1;
317 		bad = 0; // we accept 403 or whatever for this test status != 200;
318 		lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
319 		break;
320 
321 	case LWS_CALLBACK_CLOSED_CLIENT_HTTP:
322 		lwsl_notice("%s: LWS_CALLBACK_CLOSED_CLIENT_HTTP\n", __func__);
323 		interrupted = 1;
324 		bad = 0; // status != 200;
325 		lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */
326 #if defined(LWS_WITH_CONMON)
327 		if (conmon)
328 			dump_conmon_data(wsi);
329 #endif
330 		break;
331 
332 	default:
333 		break;
334 	}
335 
336 	return lws_callback_http_dummy(wsi, reason, user, in, len);
337 }
338 
339 static const struct lws_protocols protocols[] = {
340 	{
341 		"http",
342 		callback_http,
343 		0, 0, 0, NULL, 0
344 	},
345 	LWS_PROTOCOL_LIST_TERM
346 };
347 
348 static void
sigint_handler(int sig)349 sigint_handler(int sig)
350 {
351 	interrupted = 1;
352 }
353 
354 static int
system_notify_cb(lws_state_manager_t * mgr,lws_state_notify_link_t * link,int current,int target)355 system_notify_cb(lws_state_manager_t *mgr, lws_state_notify_link_t *link,
356 		   int current, int target)
357 {
358 	struct lws_context *cx = mgr->parent;
359 
360 	if (current != LWS_SYSTATE_OPERATIONAL ||
361 	    target != LWS_SYSTATE_OPERATIONAL)
362 		return 0;
363 
364 	lwsl_info("%s: operational\n", __func__);
365 
366 	try_connect(cx);
367 
368 	return 0;
369 }
370 
371 static int
jit_trust_query(struct lws_context * cx,const uint8_t * skid,size_t skid_len,void * got_opaque)372 jit_trust_query(struct lws_context *cx, const uint8_t *skid,
373 		size_t skid_len, void *got_opaque)
374 {
375 	const uint8_t *der = NULL;
376 	size_t der_len = 0;
377 
378 	lwsl_info("%s\n", __func__);
379 	lwsl_hexdump_info(skid, skid_len);
380 
381 	/*
382 	 * For this example, we look up SKIDs using a trust table that's
383 	 * compiled in, synchronously.  Lws provides the necessary helper.
384 	 *
385 	 * DER will remain NULL if no match.
386 	 */
387 
388 	lws_tls_jit_trust_blob_queury_skid(jit_trust_blob,
389 					   sizeof(jit_trust_blob), skid,
390 					   skid_len, &der, &der_len);
391 
392 	if (der)
393 		lwsl_info("%s: found len %d\n", __func__, (int)der_len);
394 	else
395 		lwsl_info("%s: not trusted\n", __func__);
396 
397 	/* Once we have a result, pass it to the completion helper */
398 
399 	return lws_tls_jit_trust_got_cert_cb(cx, got_opaque, skid, skid_len,
400 					     der, der_len);
401 }
402 
403 static lws_system_ops_t system_ops = {
404 	.jit_trust_query		= jit_trust_query
405 };
406 
main(int argc,const char ** argv)407 int main(int argc, const char **argv)
408 {
409 	lws_state_notify_link_t notifier = { { NULL, NULL, NULL },
410 						system_notify_cb, "app" };
411 	lws_state_notify_link_t *na[] = { &notifier, NULL };
412 	struct lws_context_creation_info info;
413 	struct lws_context *context;
414 	int n = 0, expected = 0;
415 	struct args args;
416 	const char *p;
417 
418 	args.argc = argc;
419 	args.argv = argv;
420 
421 	signal(SIGINT, sigint_handler);
422 
423 	memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
424 	lws_cmdline_option_handle_builtin(argc, argv, &info);
425 
426 	lwsl_user("LWS minimal http client JIT Trust [-d<verbosity>] [-l] [--h1]\n");
427 
428 	info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT |
429 		       /* we start off not trusting anything */
430 		       LWS_SERVER_OPTION_DISABLE_OS_CA_CERTS |
431 		       LWS_SERVER_OPTION_H2_JUST_FIX_WINDOW_UPDATE_OVERFLOW;
432 	info.port = CONTEXT_PORT_NO_LISTEN; /* we do not run any server */
433 	info.protocols = protocols;
434 	info.user = &args;
435 	info.register_notifier_list = na;
436 	info.connect_timeout_secs = 30;
437 	info.system_ops = &system_ops;
438 	info.fd_limit_per_thread = 1 + 6 + 1;
439 	info.max_http_header_data = 8192;
440 
441 	context = lws_create_context(&info);
442 	if (!context) {
443 		lwsl_err("lws init failed\n");
444 		bad = 5;
445 		goto bail;
446 	}
447 
448 	while (n >= 0 && !interrupted)
449 		n = lws_service(context, 0);
450 
451 	lwsl_err("%s: destroying context, interrupted = %d\n", __func__,
452 			interrupted);
453 
454 	lws_context_destroy(context);
455 
456 bail:
457 	if ((p = lws_cmdline_option(argc, argv, "--expected-exit")))
458 		expected = atoi(p);
459 
460 	if (bad == expected) {
461 		lwsl_user("Completed: OK (seen expected %d)\n", expected);
462 		return 0;
463 	}
464 
465 	lwsl_err("Completed: failed: exit %d, expected %d\n", bad, expected);
466 
467 	return 1;
468 }
469