1/*
2 * lws-minimal-secure-streams-proxy
3 *
4 * Written in 2010-2020 by Andy Green <andy@warmcat.com>
5 *
6 * This file is made available under the Creative Commons CC0 1.0
7 * Universal Public Domain Dedication.
8 *
9 *
10 * This is the proxy part for examples built to use it to connect to... it has
11 * the policy and the core SS function, but it doesn't contain any of the user
12 * code "business logic"... that's in the clients.
13 *
14 * The proxy side has the policy and performs the onward connection proxying
15 * fulfilment.  The clients state the streamtype name they want and ask for the
16 * client to do the connection part.
17 *
18 * Rideshare information is being parsed out at the proxy side; the SSS RX part
19 * also brings with it rideshare names.
20 *
21 * Metadata is passed back over SSS from the client in the TX messages for the
22 * proxy to use per the policy.
23 */
24
25#include <libwebsockets.h>
26#include <string.h>
27#include <signal.h>
28
29#if defined(__APPLE__) || defined(__linux__)
30#include <execinfo.h>
31#include <assert.h>
32#endif
33
34static int interrupted, bad = 1, port = 0 /* unix domain socket */;
35static const char *ibind = NULL; /* default to unix domain skt "proxy.ss.lws" */
36static lws_state_notify_link_t nl;
37static struct lws_context *context;
38
39/*
40 * We just define enough policy so it can fetch the latest one securely
41 */
42
43static const char * const default_ss_policy =
44	"{"
45	  "\"release\":"			"\"01234567\","
46	  "\"product\":"			"\"myproduct\","
47	  "\"schema-version\":"			"1,"
48	  "\"retry\": ["	/* named backoff / retry strategies */
49		"{\"default\": {"
50			"\"backoff\": ["	 "1000,"
51						 "2000,"
52						 "3000,"
53						 "5000,"
54						"10000"
55				"],"
56			"\"conceal\":"		"5,"
57			"\"jitterpc\":"		"20,"
58			"\"svalidping\":"	"30,"
59			"\"svalidhup\":"	"35"
60		"}}"
61	  "],"
62	  "\"certs\": [" /* named individual certificates in BASE64 DER */
63		/*
64		 * Let's Encrypt certs for warmcat.com / libwebsockets.org
65		 *
66		 * We fetch the real policy from there using SS and switch to
67		 * using that.
68		 */
69		"{\"isrg_root_x1\": \""
70	"MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw"
71	"TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh"
72	"cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4"
73	"WhcNMzUwNjA0MTEwNDM4WjBPMQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJu"
74	"ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY"
75	"MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc"
76	"h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+"
77	"0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U"
78	"A5/TR5d8mUgjU+g4rk8Kb4Mu0UlXjIB0ttov0DiNewNwIRt18jA8+o+u3dpjq+sW"
79	"T8KOEUt+zwvo/7V3LvSye0rgTBIlDHCNAymg4VMk7BPZ7hm/ELNKjD+Jo2FR3qyH"
80	"B5T0Y3HsLuJvW5iB4YlcNHlsdu87kGJ55tukmi8mxdAQ4Q7e2RCOFvu396j3x+UC"
81	"B5iPNgiV5+I3lg02dZ77DnKxHZu8A/lJBdiB3QW0KtZB6awBdpUKD9jf1b0SHzUv"
82	"KBds0pjBqAlkd25HN7rOrFleaJ1/ctaJxQZBKT5ZPt0m9STJEadao0xAH0ahmbWn"
83	"OlFuhjuefXKnEgV4We0+UXgVCwOPjdAvBbI+e0ocS3MFEvzG6uBQE3xDk3SzynTn"
84	"jh8BCNAw1FtxNrQHusEwMFxIt4I7mKZ9YIqioymCzLq9gwQbooMDQaHWBfEbwrbw"
85	"qHyGO0aoSCqI3Haadr8faqU9GY/rOPNk3sgrDQoo//fb4hVC1CLQJ13hef4Y53CI"
86	"rU7m2Ys6xt0nUW7/vGT1M0NPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNV"
87	"HRMBAf8EBTADAQH/MB0GA1UdDgQWBBR5tFnme7bl5AFzgAiIyBpY9umbbjANBgkq"
88	"hkiG9w0BAQsFAAOCAgEAVR9YqbyyqFDQDLHYGmkgJykIrGF1XIpu+ILlaS/V9lZL"
89	"ubhzEFnTIZd+50xx+7LSYK05qAvqFyFWhfFQDlnrzuBZ6brJFe+GnY+EgPbk6ZGQ"
90	"3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK"
91	"NFtY2PwByVS5uCbMiogziUwthDyC3+6WVwW6LLv3xLfHTjuCvjHIInNzktHCgKQ5"
92	"ORAzI4JMPJ+GslWYHb4phowim57iaztXOoJwTdwJx4nLCgdNbOhdjsnvzqvHu7Ur"
93	"TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC"
94	"jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc"
95	"oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq"
96	"4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA"
97	"mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d"
98	"emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc="
99		"\"}"
100	  "],"
101	  "\"trust_stores\": [" /* named cert chains */
102		"{"
103			"\"name\": \"le_via_isrg\","
104			"\"stack\": ["
105				"\"isrg_root_x1\""
106			"]"
107		"}"
108	  "],"
109	  "\"s\": [{"
110		"\"captive_portal_detect\": {"
111			"\"endpoint\": \"connectivitycheck.android.com\","
112			"\"http_url\": \"generate_204\","
113			"\"port\": 80,"
114			"\"protocol\": \"h1\","
115			"\"http_method\": \"GET\","
116			"\"opportunistic\": true,"
117			"\"http_expect\": 204,"
118			"\"http_fail_redirect\": true"
119		"},"
120		"\"fetch_policy\": {"
121			"\"endpoint\":"		"\"warmcat.com\","
122			"\"port\":"		"443,"
123			"\"protocol\":"		"\"h1\","
124			"\"http_method\":"	"\"GET\","
125			"\"http_url\":"		"\"policy/minimal-proxy-v4.2-v2.json\","
126			"\"tls\":"		"true,"
127			"\"opportunistic\":"	"true,"
128			"\"retry\":"		"\"default\","
129			"\"tls_trust_store\":"	"\"le_via_isrg\""
130		"}}"
131	"}"
132;
133
134static const char *canned_root_token_payload =
135	"grant_type=refresh_token"
136	"&refresh_token=Atzr|IwEBIJedGXjDqsU_vMxykqOMg"
137	"SHfYe3CPcedueWEMWSDMaDnEmiW8RlR1Kns7Cb4B-TOSnqp7ifVsY4BMY2B8tpHfO39XP"
138	"zfu9HapGjTR458IyHX44FE71pWJkGZ79uVBpljP4sazJuk8XS3Oe_yLnm_DIO6fU1nU3Y"
139	"0flYmsOiOAQE_gRk_pdlmEtHnpMA-9rLw3mkY5L89Ty9kUygBsiFaYatouROhbsTn8-jW"
140	"k1zZLUDpT6ICtBXSnrCIg0pUbZevPFhTwdXd6eX-u4rq0W-XaDvPWFO7au-iPb4Zk5eZE"
141	"iX6sissYrtNmuEXc2uHu7MnQO1hHCaTdIO2CANVumf-PHSD8xseamyh04sLV5JgFzY45S"
142	"KvKMajiUZuLkMokOx86rjC2Hdkx5DO7G-dbG1ufBDG-N79pFMSs7Ck5pc283IdLoJkCQc"
143	"AGvTX8o8I29QqkcGou-9TKhOJmpX8As94T61ok0UqqEKPJ7RhfQHHYdCtsdwxgvfVr9qI"
144	"xL_hDCcTho8opCVX-6QhJHl6SQFlTw13"
145	"&client_id="
146		"amzn1.application-oa2-client.4823334c434b4190a2b5a42c07938a2d";
147
148#if defined(LWS_WITH_SECURE_STREAMS_AUTH_SIGV4)
149static char *aws_keyid = NULL,
150	    *aws_key = NULL;
151#endif
152
153static int
154app_system_state_nf(lws_state_manager_t *mgr, lws_state_notify_link_t *link,
155		    int current, int target)
156{
157	struct lws_context *context = lws_system_context_from_system_mgr(mgr);
158	lws_system_blob_t *ab = lws_system_get_blob(context,
159				LWS_SYSBLOB_TYPE_AUTH, 1 /* AUTH_IDX_ROOT */);
160	size_t size;
161
162	/*
163	 * For the things we care about, let's notice if we are trying to get
164	 * past them when we haven't solved them yet, and make the system
165	 * state wait while we trigger the dependent action.
166	 */
167	switch (target) {
168	case LWS_SYSTATE_REGISTERED:
169		size = lws_system_blob_get_size(ab);
170		if (size)
171			break;
172
173		/* let's register our canned root token so auth can use it */
174		lws_system_blob_direct_set(ab,
175				(const uint8_t *)canned_root_token_payload,
176				strlen(canned_root_token_payload));
177		break;
178	case LWS_SYSTATE_OPERATIONAL:
179		if (current == LWS_SYSTATE_OPERATIONAL) {
180#if defined(LWS_WITH_SECURE_STREAMS_AUTH_SIGV4)
181
182			if (lws_aws_filesystem_credentials_helper(
183						  "~/.aws/credentials",
184						  "aws_access_key_id",
185						  "aws_secret_access_key",
186						  &aws_keyid, &aws_key))
187				return -1;
188
189			lws_ss_sigv4_set_aws_key(context, 0, aws_keyid, aws_key);
190#endif
191			/*
192			 * At this point we have DHCP, ntp, system auth token
193			 * and we can reasonably create the proxy
194			 */
195			if (lws_ss_proxy_create(context, ibind, port)) {
196				lwsl_err("%s: failed to create ss proxy\n",
197						__func__);
198				return -1;
199			}
200		}
201		break;
202	case LWS_SYSTATE_POLICY_INVALID:
203		/*
204		 * This is a NOP since we used direct set... but in a real
205		 * system this could easily change to be done on the heap, then
206		 * this would be important
207		 */
208		lws_system_blob_destroy(lws_system_get_blob(context,
209					LWS_SYSBLOB_TYPE_AUTH,
210					1 /* AUTH_IDX_ROOT */));
211		break;
212	}
213
214	return 0;
215}
216
217static lws_state_notify_link_t * const app_notifier_list[] = {
218	&nl, NULL
219};
220
221#if defined(LWS_WITH_SYS_METRICS)
222
223static int
224my_metric_report(lws_metric_pub_t *mp)
225{
226	lws_metric_bucket_t *sub = mp->u.hist.head;
227	char buf[192];
228
229	do {
230		if (lws_metrics_format(mp, &sub, buf, sizeof(buf)))
231			lwsl_user("%s: %s\n", __func__, buf);
232	} while ((mp->flags & LWSMTFL_REPORT_HIST) && sub);
233
234	/* 0 = leave metric to accumulate, 1 = reset the metric */
235
236	return 1;
237}
238
239static const lws_system_ops_t system_ops = {
240	.metric_report = my_metric_report,
241};
242
243#endif
244
245static void
246sigint_handler(int sig)
247{
248	lwsl_notice("%s\n", __func__);
249	interrupted = 1;
250	lws_cancel_service(context);
251}
252
253int main(int argc, const char **argv)
254{
255	struct lws_context_creation_info info;
256	const char *p;
257	int n = 0;
258
259	memset(&info, 0, sizeof info);
260	lws_cmdline_option_handle_builtin(argc, argv, &info);
261
262	signal(SIGINT, sigint_handler);
263
264	/* connect to ssproxy via UDS by default, else via tcp with this port */
265	if ((p = lws_cmdline_option(argc, argv, "-p")))
266		port = atoi(p);
267
268	/* UDS "proxy.ss.lws" in abstract namespace, else this socket path;
269	 * when -p given this can specify the network interface to bind to */
270	if ((p = lws_cmdline_option(argc, argv, "-i")))
271		ibind = p;
272
273	lwsl_user("LWS secure streams Proxy [-d<verb>]\n");
274
275	info.options = LWS_SERVER_OPTION_EXPLICIT_VHOSTS |
276		       LWS_SERVER_OPTION_H2_JUST_FIX_WINDOW_UPDATE_OVERFLOW |
277		       LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;
278	info.fd_limit_per_thread = 1 + 26 + 1;
279	info.pss_policies_json = default_ss_policy;
280	info.port = CONTEXT_PORT_NO_LISTEN;
281
282	/* integrate us with lws system state management when context created */
283	nl.name = "app";
284	nl.notify_cb = app_system_state_nf;
285	info.register_notifier_list = app_notifier_list;
286
287	info.pt_serv_buf_size = (unsigned int)((6144 * 2) + 2048);
288	info.max_http_header_data = (unsigned short)(6144 + 2048);
289
290#if defined(LWS_WITH_SYS_METRICS)
291	info.system_ops = &system_ops;
292	info.metrics_prefix = "ssproxy";
293#endif
294
295	context = lws_create_context(&info);
296	if (!context) {
297		lwsl_err("lws init failed\n");
298		return 1;
299	}
300
301	/* the event loop */
302
303	do {
304		n = lws_service(context, 0);
305	} while (n >= 0 && !interrupted);
306
307	bad = 0;
308
309#if defined(LWS_WITH_SECURE_STREAMS_AUTH_SIGV4)
310	if (aws_keyid)
311		free(aws_keyid);
312	if (aws_key)
313		free(aws_key);
314#endif
315
316	lws_context_destroy(context);
317	lwsl_user("Completed: %s\n", bad ? "failed" : "OK");
318
319	return bad;
320}
321