1 /*
2  * Copyright (c) 2021-2023 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "gmid.h"
18 
19 #include <sys/socket.h>
20 
21 #include <assert.h>
22 #include <ctype.h>
23 #include <errno.h>
24 #include <locale.h>
25 #include <string.h>
26 #include <wchar.h>
27 
28 enum debug {
29 	DEBUG_NONE,
30 	DEBUG_CODE,
31 	DEBUG_HEADER,
32 	DEBUG_META,
33 	DEBUG_ALL,
34 };
35 
36 /* flags */
37 int		 debug;
38 int		 dont_verify_name;
39 int		 flag2;
40 int		 flag3;
41 int		 nop;
42 int		 redirects = 5;
43 int		 timer;
44 const char	*cert;
45 const char	*key;
46 const char	*proxy_host;
47 const char	*proxy_port;
48 const char	*sni;
49 
50 /* state */
51 struct tls_config *tls_conf;
52 
53 static void
54 timeout(int signo)
55 {
56 	dprintf(2, "%s: timer expired\n", getprogname());
57 	exit(1);
58 }
59 
60 static void
61 load_tls_conf(void)
62 {
63 	if ((tls_conf = tls_config_new()) == NULL)
64 		err(1, "tls_config_new");
65 
66 	tls_config_insecure_noverifycert(tls_conf);
67 	if (dont_verify_name)
68 		tls_config_insecure_noverifyname(tls_conf);
69 
70 	if (flag2 &&
71 	    tls_config_set_protocols(tls_conf, TLS_PROTOCOL_TLSv1_2) == -1)
72 		errx(1, "can't set TLSv1.2");
73 	if (flag3 &&
74 	    tls_config_set_protocols(tls_conf, TLS_PROTOCOL_TLSv1_3) == -1)
75 		errx(1, "can't set TLSv1.3");
76 
77 	if (cert != NULL &&
78 	    tls_config_set_keypair_file(tls_conf, cert, key) == -1)
79 		errx(1, "can't load client certificate %s", cert);
80 }
81 
82 static void
83 connectto(struct tls *ctx, const char *host, const char *port)
84 {
85 	struct addrinfo hints, *res, *res0;
86 	int error;
87 	int saved_errno;
88 	int s;
89 	const char *cause = NULL;
90 	const char *sname;
91 
92 	if (proxy_host != NULL) {
93 		host = proxy_host;
94 		port = proxy_port;
95 	}
96 
97 	if ((sname = sni) == NULL)
98 		sname = host;
99 
100 	memset(&hints, 0, sizeof(hints));
101 	hints.ai_family = AF_UNSPEC;
102 	hints.ai_socktype = SOCK_STREAM;
103 	error = getaddrinfo(host, port, &hints, &res0);
104 	if (error)
105 		errx(1, "%s", gai_strerror(error));
106 
107 	s = -1;
108 	for (res = res0; res != NULL; res = res->ai_next) {
109 		s = socket(res->ai_family, res->ai_socktype,
110 		    res->ai_protocol);
111 		if (s == -1) {
112 			cause = "socket";
113 			continue;
114 		}
115 
116 		if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
117 			cause = "connect";
118 			saved_errno = errno;
119 			close(s);
120 			errno = saved_errno;
121 			s = -1;
122 			continue;
123 		}
124 
125 		break;
126 	}
127 
128 	if (s == -1)
129 		err(1, "%s: can't connect to %s:%s", cause,
130 		    host, port);
131 
132 	freeaddrinfo(res0);
133 
134 	if (tls_connect_socket(ctx, s, sname) == -1)
135 		errx(1, "tls_connect_socket: %s", tls_error(ctx));
136 }
137 
138 static void
139 doreq(struct tls *ctx, const char *buf)
140 {
141 	size_t	s;
142 	ssize_t	w;
143 
144 	s = strlen(buf);
145 	while (s != 0) {
146 		switch (w = tls_write(ctx, buf, s)) {
147 		case 0:
148 		case -1:
149 			errx(1, "tls_write: %s", tls_error(ctx));
150 		case TLS_WANT_POLLIN:
151 		case TLS_WANT_POLLOUT:
152 			continue;
153 		}
154 
155 		s -= w;
156 		buf += w;
157 	}
158 }
159 
160 static size_t
161 dorep(struct tls *ctx, uint8_t *buf, size_t len)
162 {
163 	ssize_t	w;
164 	size_t	tot = 0;
165 
166 	while (len != 0) {
167 		switch (w = tls_read(ctx, buf, len)) {
168 		case 0:
169 			return tot;
170 		case -1:
171 			errx(1, "tls_write: %s", tls_error(ctx));
172 		case TLS_WANT_POLLIN:
173 		case TLS_WANT_POLLOUT:
174 			continue;
175 		}
176 
177 		len -= w;
178 		buf += w;
179 		tot += w;
180 	}
181 
182 	return tot;
183 }
184 
185 static void
186 safeprint(FILE *fp, const char *str)
187 {
188 	int		 len;
189 	wchar_t		 wc;
190 
191 	for (; *str != '\0'; str += len) {
192 		if ((len = mbtowc(&wc, str, MB_CUR_MAX)) == -1) {
193 			mbtowc(NULL, NULL, MB_CUR_MAX);
194 			fputc('?', fp);
195 			len = 1;
196 		} else if (wcwidth(wc) == -1) {
197 			fputc('?', fp);
198 		} else if (wc != L'\n')
199 			putwc(wc, fp);
200 	}
201 
202 	fputc('\n', fp);
203 }
204 
205 static int
206 get(const char *r)
207 {
208 	struct tls	*ctx;
209 	struct iri	 iri;
210 	int		 foundhdr = 0, code = -1, od;
211 	char		 iribuf[GEMINI_URL_LEN];
212 	char		 req[GEMINI_URL_LEN];
213 	uint8_t		 buf[2048];
214 	const char	*parse_err, *host, *port;
215 
216 	if (strlcpy(iribuf, r, sizeof(iribuf)) >= sizeof(iribuf))
217 		errx(1, "iri too long: %s", r);
218 
219 	if (strlcpy(req, r, sizeof(req)) >= sizeof(req))
220 		errx(1, "iri too long: %s", r);
221 
222 	if (strlcat(req, "\r\n", sizeof(req)) >= sizeof(req))
223 		errx(1, "iri too long: %s", r);
224 
225 	if (!parse_iri(iribuf, &iri, &parse_err))
226 		errx(1, "invalid IRI: %s", parse_err);
227 
228 	if (nop)
229 		errx(0, "IRI OK");
230 
231 	if ((ctx = tls_client()) == NULL)
232 		errx(1, "can't create tls context");
233 
234 	if (tls_configure(ctx, tls_conf) == -1)
235 		errx(1, "tls_configure: %s", tls_error(ctx));
236 
237 	host = iri.host;
238 	port = "1965";
239 	if (*iri.port != '\0')
240 		port = iri.port;
241 
242 	connectto(ctx, host, port);
243 
244 	od = 0;
245 	while (!od) {
246 		switch (tls_handshake(ctx)) {
247 		case 0:
248 			od = 1;
249 			break;
250 		case -1:
251 			errx(1, "handshake: %s", tls_error(ctx));
252 		}
253 	}
254 
255 	doreq(ctx, req);
256 
257 	for (;;) {
258 		uint8_t	*t;
259 		size_t	 len;
260 
261 		len = dorep(ctx, buf, sizeof(buf));
262 		if (len == 0)
263 			break;
264 
265 		if (foundhdr) {
266 			write(1, buf, len);
267 			continue;
268 		}
269 		foundhdr = 1;
270 
271 		if (memmem(buf, len, "\r\n", 2) == NULL)
272 			errx(1, "invalid reply: no \\r\\n");
273 		if (!isdigit((unsigned char)buf[0]) ||
274 		    !isdigit((unsigned char)buf[1]) ||
275 		    buf[2] != ' ')
276 			errx(1, "invalid reply: invalid response format");
277 
278 		code = (buf[0] - '0') * 10 + buf[1] - '0';
279 
280 		if (debug == DEBUG_CODE) {
281 			printf("%d\n", code);
282 			break;
283 		}
284 
285 		if (debug == DEBUG_HEADER) {
286 			t = memmem(buf, len, "\r\n", 2);
287 			assert(t != NULL);
288 			*t = '\0';
289 			printf("%s\n", buf);
290 			break;
291 		}
292 
293 		if (debug == DEBUG_META) {
294 			t = memmem(buf, len, "\r\n", 2);
295 			assert(t != NULL);
296 			*t = '\0';
297 			printf("%s\n", buf+3);
298 			break;
299 		}
300 
301 		if (debug == DEBUG_ALL) {
302 			write(1, buf, len);
303 			continue;
304 		}
305 
306 		/* skip the header */
307 		t = memmem(buf, len, "\r\n", 2);
308 		assert(t != NULL);
309 		if (code < 20 || code >= 30) {
310 			*t = '\0';
311 			fprintf(stderr, "Server says: ");
312 			safeprint(stderr, buf + 3); /* skip return code */
313 		}
314 		t += 2; /* skip \r\n */
315 		len -= t - buf;
316 		write(1, t, len);
317 	}
318 
319 	for (;;) {
320 		switch (tls_close(ctx)) {
321 		case TLS_WANT_POLLIN:
322 		case TLS_WANT_POLLOUT:
323 			continue;
324 		case -1:
325 			warnx("tls_close: %s", tls_error(ctx));
326 			/* fallthrough */
327 		default:
328 			tls_free(ctx);
329 			return code;
330 		}
331 	}
332 }
333 
334 static void __attribute__((noreturn))
335 usage(void)
336 {
337 	fprintf(stderr, "version: " GG_STRING "\n");
338 	fprintf(stderr, "usage: %s [-23Nn] [-C cert] [-d mode] [-H sni] "
339 	    "[-K key] [-P host[:port]]\n",
340 	    getprogname());
341 	fprintf(stderr, "          [-T seconds] gemini://...\n");
342 	exit(1);
343 }
344 
345 static int
346 parse_debug(const char *arg)
347 {
348 	if (!strcmp(arg, "none"))
349 		return DEBUG_NONE;
350 	if (!strcmp(arg, "code"))
351 		return DEBUG_CODE;
352 	if (!strcmp(arg, "header"))
353 		return DEBUG_HEADER;
354 	if (!strcmp(arg, "meta"))
355 		return DEBUG_META;
356 	if (!strcmp(arg, "all"))
357 		return DEBUG_ALL;
358 	usage();
359 }
360 
361 static void
362 parse_proxy(const char *arg)
363 {
364 	char *at;
365 
366 	if ((proxy_host = strdup(arg)) == NULL)
367 		err(1, "strdup");
368 
369 	proxy_port = "1965";
370 
371 	if ((at = strchr(proxy_host, ':')) == NULL)
372 		return;
373 	*at = '\0';
374 	proxy_port = ++at;
375 
376 	if (strchr(proxy_port, ':') != NULL)
377 		errx(1, "invalid port %s", proxy_port);
378 }
379 
380 int
381 main(int argc, char **argv)
382 {
383 	int		 ch, code;
384 	const char	*errstr;
385 
386 	setlocale(LC_CTYPE, "");
387 
388 	while ((ch = getopt(argc, argv, "23C:d:H:K:NP:T:")) != -1) {
389 		switch (ch) {
390 		case '2':
391 			flag2 = 1;
392 			break;
393 		case '3':
394 			flag3 = 1;
395 			break;
396 		case 'C':
397 			cert = optarg;
398 			break;
399 		case 'd':
400 			debug = parse_debug(optarg);
401 			break;
402 		case 'H':
403 			sni = optarg;
404 			break;
405 		case 'K':
406 			key = optarg;
407 			break;
408 		case 'N':
409 			dont_verify_name = 1;
410 			break;
411 		case 'n':
412 			nop = 1;
413 			break;
414 		case 'P':
415 			parse_proxy(optarg);
416 			dont_verify_name = 1;
417 			break;
418 		case 'T':
419 			timer = strtonum(optarg, 1, 1000, &errstr);
420 			if (errstr != NULL)
421 				errx(1, "timeout is %s: %s",
422 				    errstr, optarg);
423 			signal(SIGALRM, timeout);
424 			alarm(timer);
425 			break;
426 		default:
427 			usage();
428 		}
429 	}
430 	argc -= optind;
431 	argv += optind;
432 
433 	if (flag2 + flag3 > 1) {
434 		warnx("only -2 or -3 can be specified at the same time");
435 		usage();
436 	}
437 
438 	if ((cert != NULL && key == NULL) ||
439 	    (cert == NULL && key != NULL)) {
440 		warnx("cert or key is missing");
441 		usage();
442 	}
443 
444 	if (argc != 1)
445 		usage();
446 
447 	load_tls_conf();
448 
449 	signal(SIGPIPE, SIG_IGN);
450 
451 #ifdef __OpenBSD__
452 	if (pledge("stdio inet dns", NULL) == -1)
453 		err(1, "pledge");
454 #endif
455 
456 	code = get(*argv);
457 	if (code >= 20 && code < 30)
458 		return 0;
459 	return code;
460 }