xref: /freebsd/contrib/bearssl/tools/client.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*
2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sublicense, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <stdint.h>
29 #include <errno.h>
30 #include <signal.h>
31 
32 #ifdef _WIN32
33 #include <winsock2.h>
34 #include <ws2tcpip.h>
35 #else
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <netdb.h>
39 #include <netinet/in.h>
40 #include <arpa/inet.h>
41 #include <unistd.h>
42 #include <fcntl.h>
43 
44 #define SOCKET             int
45 #define INVALID_SOCKET     (-1)
46 #endif
47 
48 #include "brssl.h"
49 
50 static int
51 host_connect(const char *host, const char *port, int verbose)
52 {
53 	struct addrinfo hints, *si, *p;
54 	SOCKET fd;
55 	int err;
56 
57 	memset(&hints, 0, sizeof hints);
58 	hints.ai_family = PF_UNSPEC;
59 	hints.ai_socktype = SOCK_STREAM;
60 	err = getaddrinfo(host, port, &hints, &si);
61 	if (err != 0) {
62 		fprintf(stderr, "ERROR: getaddrinfo(): %s\n",
63 			gai_strerror(err));
64 		return INVALID_SOCKET;
65 	}
66 	fd = INVALID_SOCKET;
67 	for (p = si; p != NULL; p = p->ai_next) {
68 		if (verbose) {
69 			struct sockaddr *sa;
70 			void *addr;
71 			char tmp[INET6_ADDRSTRLEN + 50];
72 
73 			sa = (struct sockaddr *)p->ai_addr;
74 			if (sa->sa_family == AF_INET) {
75 				addr = &((struct sockaddr_in *)
76 					(void *)sa)->sin_addr;
77 			} else if (sa->sa_family == AF_INET6) {
78 				addr = &((struct sockaddr_in6 *)
79 					(void *)sa)->sin6_addr;
80 			} else {
81 				addr = NULL;
82 			}
83 			if (addr != NULL) {
84 				if (!inet_ntop(p->ai_family, addr,
85 					tmp, sizeof tmp))
86 				{
87 					strcpy(tmp, "<invalid>");
88 				}
89 			} else {
90 				sprintf(tmp, "<unknown family: %d>",
91 					(int)sa->sa_family);
92 			}
93 			fprintf(stderr, "connecting to: %s\n", tmp);
94 		}
95 		fd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
96 		if (fd == INVALID_SOCKET) {
97 			if (verbose) {
98 				perror("socket()");
99 			}
100 			continue;
101 		}
102 		if (connect(fd, p->ai_addr, p->ai_addrlen) == INVALID_SOCKET) {
103 			if (verbose) {
104 				perror("connect()");
105 			}
106 #ifdef _WIN32
107 			closesocket(fd);
108 #else
109 			close(fd);
110 #endif
111 			continue;
112 		}
113 		break;
114 	}
115 	if (p == NULL) {
116 		freeaddrinfo(si);
117 		fprintf(stderr, "ERROR: failed to connect\n");
118 		return INVALID_SOCKET;
119 	}
120 	freeaddrinfo(si);
121 	if (verbose) {
122 		fprintf(stderr, "connected.\n");
123 	}
124 
125 	/*
126 	 * We make the socket non-blocking, since we are going to use
127 	 * poll() or select() to organise I/O.
128 	 */
129 #ifdef _WIN32
130 	{
131 		u_long arg;
132 
133 		arg = 1;
134 		ioctlsocket(fd, FIONBIO, &arg);
135 	}
136 #else
137 	fcntl(fd, F_SETFL, O_NONBLOCK);
138 #endif
139 	return fd;
140 }
141 
142 typedef struct {
143 	const br_ssl_client_certificate_class *vtable;
144 	int verbose;
145 	br_x509_certificate *chain;
146 	size_t chain_len;
147 	private_key *sk;
148 	int issuer_key_type;
149 } ccert_context;
150 
151 static void
152 cc_start_name_list(const br_ssl_client_certificate_class **pctx)
153 {
154 	ccert_context *zc;
155 
156 	zc = (ccert_context *)pctx;
157 	if (zc->verbose) {
158 		fprintf(stderr, "Server requests a client certificate.\n");
159 		fprintf(stderr, "--- anchor DN list start ---\n");
160 	}
161 }
162 
163 static void
164 cc_start_name(const br_ssl_client_certificate_class **pctx, size_t len)
165 {
166 	ccert_context *zc;
167 
168 	zc = (ccert_context *)pctx;
169 	if (zc->verbose) {
170 		fprintf(stderr, "new anchor name, length = %u\n",
171 			(unsigned)len);
172 	}
173 }
174 
175 static void
176 cc_append_name(const br_ssl_client_certificate_class **pctx,
177 	const unsigned char *data, size_t len)
178 {
179 	ccert_context *zc;
180 
181 	zc = (ccert_context *)pctx;
182 	if (zc->verbose) {
183 		size_t u;
184 
185 		for (u = 0; u < len; u ++) {
186 			if (u == 0) {
187 				fprintf(stderr, "  ");
188 			} else if (u > 0 && u % 16 == 0) {
189 				fprintf(stderr, "\n  ");
190 			}
191 			fprintf(stderr, " %02x", data[u]);
192 		}
193 		if (len > 0) {
194 			fprintf(stderr, "\n");
195 		}
196 	}
197 }
198 
199 static void
200 cc_end_name(const br_ssl_client_certificate_class **pctx)
201 {
202 	(void)pctx;
203 }
204 
205 static void
206 cc_end_name_list(const br_ssl_client_certificate_class **pctx)
207 {
208 	ccert_context *zc;
209 
210 	zc = (ccert_context *)pctx;
211 	if (zc->verbose) {
212 		fprintf(stderr, "--- anchor DN list end ---\n");
213 	}
214 }
215 
216 static void
217 print_hashes(unsigned hh, unsigned hh2)
218 {
219 	int i;
220 
221 	for (i = 0; i < 8; i ++) {
222 		const char *name;
223 
224 		name = hash_function_name(i);
225 		if (((hh >> i) & 1) != 0) {
226 			fprintf(stderr, " %s", name);
227 		} else if (((hh2 >> i) & 1) != 0) {
228 			fprintf(stderr, " (%s)", name);
229 		}
230 	}
231 }
232 
233 static int
234 choose_hash(unsigned hh)
235 {
236 	static const int f[] = {
237 		br_sha256_ID, br_sha224_ID, br_sha384_ID, br_sha512_ID,
238 		br_sha1_ID, br_md5sha1_ID, -1
239 	};
240 
241 	size_t u;
242 
243 	for (u = 0; f[u] >= 0; u ++) {
244 		if (((hh >> f[u]) & 1) != 0) {
245 			return f[u];
246 		}
247 	}
248 	return -1;
249 }
250 
251 static void
252 cc_choose(const br_ssl_client_certificate_class **pctx,
253 	const br_ssl_client_context *cc, uint32_t auth_types,
254 	br_ssl_client_certificate *choices)
255 {
256 	ccert_context *zc;
257 	int scurve;
258 
259 	zc = (ccert_context *)pctx;
260 	scurve = br_ssl_client_get_server_curve(cc);
261 	if (zc->verbose) {
262 		unsigned hashes;
263 
264 		hashes = br_ssl_client_get_server_hashes(cc);
265 		if ((auth_types & 0x00FF) != 0) {
266 			fprintf(stderr, "supported: RSA signatures:");
267 			print_hashes(auth_types, hashes);
268 			fprintf(stderr, "\n");
269 		}
270 		if ((auth_types & 0xFF00) != 0) {
271 			fprintf(stderr, "supported: ECDSA signatures:");
272 			print_hashes(auth_types >> 8, hashes >> 8);
273 			fprintf(stderr, "\n");
274 		}
275 		if ((auth_types & 0x010000) != 0) {
276 			fprintf(stderr, "supported:"
277 				" fixed ECDH (cert signed with RSA)\n");
278 		}
279 		if ((auth_types & 0x020000) != 0) {
280 			fprintf(stderr, "supported:"
281 				" fixed ECDH (cert signed with ECDSA)\n");
282 		}
283 		if (scurve) {
284 			fprintf(stderr, "server key curve: %s (%d)\n",
285 				ec_curve_name(scurve), scurve);
286 		} else {
287 			fprintf(stderr, "server key is not EC\n");
288 		}
289 	}
290 	switch (zc->sk->key_type) {
291 	case BR_KEYTYPE_RSA:
292 		if ((choices->hash_id = choose_hash(auth_types)) >= 0) {
293 			if (zc->verbose) {
294 				fprintf(stderr, "using RSA, hash = %d (%s)\n",
295 					choices->hash_id,
296 					hash_function_name(choices->hash_id));
297 			}
298 			choices->auth_type = BR_AUTH_RSA;
299 			choices->chain = zc->chain;
300 			choices->chain_len = zc->chain_len;
301 			return;
302 		}
303 		break;
304 	case BR_KEYTYPE_EC:
305 		if (zc->issuer_key_type != 0
306 			&& scurve == zc->sk->key.ec.curve)
307 		{
308 			int x;
309 
310 			x = (zc->issuer_key_type == BR_KEYTYPE_RSA) ? 16 : 17;
311 			if (((auth_types >> x) & 1) != 0) {
312 				if (zc->verbose) {
313 					fprintf(stderr, "using static ECDH\n");
314 				}
315 				choices->auth_type = BR_AUTH_ECDH;
316 				choices->hash_id = -1;
317 				choices->chain = zc->chain;
318 				choices->chain_len = zc->chain_len;
319 				return;
320 			}
321 		}
322 		if ((choices->hash_id = choose_hash(auth_types >> 8)) >= 0) {
323 			if (zc->verbose) {
324 				fprintf(stderr, "using ECDSA, hash = %d (%s)\n",
325 					choices->hash_id,
326 					hash_function_name(choices->hash_id));
327 			}
328 			choices->auth_type = BR_AUTH_ECDSA;
329 			choices->chain = zc->chain;
330 			choices->chain_len = zc->chain_len;
331 			return;
332 		}
333 		break;
334 	}
335 	if (zc->verbose) {
336 		fprintf(stderr, "no matching client certificate\n");
337 	}
338 	choices->chain = NULL;
339 	choices->chain_len = 0;
340 }
341 
342 static uint32_t
343 cc_do_keyx(const br_ssl_client_certificate_class **pctx,
344 	unsigned char *data, size_t *len)
345 {
346 	const br_ec_impl *iec;
347 	ccert_context *zc;
348 	size_t xoff, xlen;
349 	uint32_t r;
350 
351 	zc = (ccert_context *)pctx;
352 	iec = br_ec_get_default();
353 	r = iec->mul(data, *len, zc->sk->key.ec.x,
354 		zc->sk->key.ec.xlen, zc->sk->key.ec.curve);
355 	xoff = iec->xoff(zc->sk->key.ec.curve, &xlen);
356 	memmove(data, data + xoff, xlen);
357 	*len = xlen;
358 	return r;
359 }
360 
361 static size_t
362 cc_do_sign(const br_ssl_client_certificate_class **pctx,
363 	int hash_id, size_t hv_len, unsigned char *data, size_t len)
364 {
365 	ccert_context *zc;
366 	unsigned char hv[64];
367 
368 	zc = (ccert_context *)pctx;
369 	memcpy(hv, data, hv_len);
370 	switch (zc->sk->key_type) {
371 		const br_hash_class *hc;
372 		const unsigned char *hash_oid;
373 		uint32_t x;
374 		size_t sig_len;
375 
376 	case BR_KEYTYPE_RSA:
377 		hash_oid = get_hash_oid(hash_id);
378 		if (hash_oid == NULL && hash_id != 0) {
379 			if (zc->verbose) {
380 				fprintf(stderr, "ERROR: cannot RSA-sign with"
381 					" unknown hash function: %d\n",
382 					hash_id);
383 			}
384 			return 0;
385 		}
386 		sig_len = (zc->sk->key.rsa.n_bitlen + 7) >> 3;
387 		if (len < sig_len) {
388 			if (zc->verbose) {
389 				fprintf(stderr, "ERROR: cannot RSA-sign,"
390 					" buffer is too small"
391 					" (sig=%lu, buf=%lu)\n",
392 					(unsigned long)sig_len,
393 					(unsigned long)len);
394 			}
395 			return 0;
396 		}
397 		x = br_rsa_pkcs1_sign_get_default()(
398 			hash_oid, hv, hv_len, &zc->sk->key.rsa, data);
399 		if (!x) {
400 			if (zc->verbose) {
401 				fprintf(stderr, "ERROR: RSA-sign failure\n");
402 			}
403 			return 0;
404 		}
405 		return sig_len;
406 
407 	case BR_KEYTYPE_EC:
408 		hc = get_hash_impl(hash_id);
409 		if (hc == NULL) {
410 			if (zc->verbose) {
411 				fprintf(stderr, "ERROR: cannot ECDSA-sign with"
412 					" unknown hash function: %d\n",
413 					hash_id);
414 			}
415 			return 0;
416 		}
417 		if (len < 139) {
418 			if (zc->verbose) {
419 				fprintf(stderr, "ERROR: cannot ECDSA-sign"
420 					" (output buffer = %lu)\n",
421 					(unsigned long)len);
422 			}
423 			return 0;
424 		}
425 		sig_len = br_ecdsa_sign_asn1_get_default()(
426 			br_ec_get_default(), hc, hv, &zc->sk->key.ec, data);
427 		if (sig_len == 0) {
428 			if (zc->verbose) {
429 				fprintf(stderr, "ERROR: ECDSA-sign failure\n");
430 			}
431 			return 0;
432 		}
433 		return sig_len;
434 
435 	default:
436 		return 0;
437 	}
438 }
439 
440 static const br_ssl_client_certificate_class ccert_vtable = {
441 	sizeof(ccert_context),
442 	cc_start_name_list,
443 	cc_start_name,
444 	cc_append_name,
445 	cc_end_name,
446 	cc_end_name_list,
447 	cc_choose,
448 	cc_do_keyx,
449 	cc_do_sign
450 };
451 
452 static void
453 free_alpn(void *alpn)
454 {
455 	xfree(*(char **)alpn);
456 }
457 
458 static void
459 usage_client(void)
460 {
461 	fprintf(stderr,
462 "usage: brssl client server[:port] [ options ]\n");
463 	fprintf(stderr,
464 "options:\n");
465 	fprintf(stderr,
466 "   -q              suppress verbose messages\n");
467 	fprintf(stderr,
468 "   -trace          activate extra debug messages (dump of all packets)\n");
469 	fprintf(stderr,
470 "   -sni name       use this specific name for SNI\n");
471 	fprintf(stderr,
472 "   -nosni          do not send any SNI\n");
473 	fprintf(stderr,
474 "   -mono           use monodirectional buffering\n");
475 	fprintf(stderr,
476 "   -buf length     set the I/O buffer length (in bytes)\n");
477 	fprintf(stderr,
478 "   -CA file        add certificates in 'file' to trust anchors\n");
479 	fprintf(stderr,
480 "   -cert file      set client certificate chain\n");
481 	fprintf(stderr,
482 "   -key file       set client private key (for certificate authentication)\n");
483 	fprintf(stderr,
484 "   -nostaticecdh   prohibit full-static ECDH (client certificate)\n");
485 	fprintf(stderr,
486 "   -list           list supported names (protocols, algorithms...)\n");
487 	fprintf(stderr,
488 "   -vmin name      set minimum supported version (default: TLS-1.0)\n");
489 	fprintf(stderr,
490 "   -vmax name      set maximum supported version (default: TLS-1.2)\n");
491 	fprintf(stderr,
492 "   -cs names       set list of supported cipher suites (comma-separated)\n");
493 	fprintf(stderr,
494 "   -hf names       add support for some hash functions (comma-separated)\n");
495 	fprintf(stderr,
496 "   -minhello len   set minimum ClientHello length (in bytes)\n");
497 	fprintf(stderr,
498 "   -fallback       send the TLS_FALLBACK_SCSV (i.e. claim a downgrade)\n");
499 	fprintf(stderr,
500 "   -noreneg        prohibit renegotiations\n");
501 	fprintf(stderr,
502 "   -alpn name      add protocol name to list of protocols (ALPN extension)\n");
503 	fprintf(stderr,
504 "   -strictalpn     fail on ALPN mismatch\n");
505 }
506 
507 /* see brssl.h */
508 int
509 do_client(int argc, char *argv[])
510 {
511 	int retcode;
512 	int verbose;
513 	int trace;
514 	int i, bidi;
515 	const char *server_name;
516 	char *host;
517 	char *port;
518 	const char *sni;
519 	anchor_list anchors = VEC_INIT;
520 	unsigned vmin, vmax;
521 	VECTOR(char *) alpn_names = VEC_INIT;
522 	cipher_suite *suites;
523 	size_t num_suites;
524 	uint16_t *suite_ids;
525 	unsigned hfuns;
526 	size_t u;
527 	br_ssl_client_context cc;
528 	br_x509_minimal_context xc;
529 	x509_noanchor_context xwc;
530 	const br_hash_class *dnhash;
531 	ccert_context zc;
532 	br_x509_certificate *chain;
533 	size_t chain_len;
534 	private_key *sk;
535 	int nostaticecdh;
536 	unsigned char *iobuf;
537 	size_t iobuf_len;
538 	size_t minhello_len;
539 	int fallback;
540 	uint32_t flags;
541 	SOCKET fd;
542 
543 	retcode = 0;
544 	verbose = 1;
545 	trace = 0;
546 	server_name = NULL;
547 	host = NULL;
548 	port = NULL;
549 	sni = NULL;
550 	bidi = 1;
551 	vmin = 0;
552 	vmax = 0;
553 	suites = NULL;
554 	num_suites = 0;
555 	hfuns = 0;
556 	suite_ids = NULL;
557 	chain = NULL;
558 	chain_len = 0;
559 	sk = NULL;
560 	nostaticecdh = 0;
561 	iobuf = NULL;
562 	iobuf_len = 0;
563 	minhello_len = (size_t)-1;
564 	fallback = 0;
565 	flags = 0;
566 	fd = INVALID_SOCKET;
567 	for (i = 0; i < argc; i ++) {
568 		const char *arg;
569 
570 		arg = argv[i];
571 		if (arg[0] != '-') {
572 			if (server_name != NULL) {
573 				fprintf(stderr,
574 					"ERROR: duplicate server name\n");
575 				usage_client();
576 				goto client_exit_error;
577 			}
578 			server_name = arg;
579 			continue;
580 		}
581 		if (eqstr(arg, "-v") || eqstr(arg, "-verbose")) {
582 			verbose = 1;
583 		} else if (eqstr(arg, "-q") || eqstr(arg, "-quiet")) {
584 			verbose = 0;
585 		} else if (eqstr(arg, "-trace")) {
586 			trace = 1;
587 		} else if (eqstr(arg, "-sni")) {
588 			if (++ i >= argc) {
589 				fprintf(stderr,
590 					"ERROR: no argument for '-sni'\n");
591 				usage_client();
592 				goto client_exit_error;
593 			}
594 			if (sni != NULL) {
595 				fprintf(stderr, "ERROR: duplicate SNI\n");
596 				usage_client();
597 				goto client_exit_error;
598 			}
599 			sni = argv[i];
600 		} else if (eqstr(arg, "-nosni")) {
601 			if (sni != NULL) {
602 				fprintf(stderr, "ERROR: duplicate SNI\n");
603 				usage_client();
604 				goto client_exit_error;
605 			}
606 			sni = "";
607 		} else if (eqstr(arg, "-mono")) {
608 			bidi = 0;
609 		} else if (eqstr(arg, "-buf")) {
610 			if (++ i >= argc) {
611 				fprintf(stderr,
612 					"ERROR: no argument for '-buf'\n");
613 				usage_client();
614 				goto client_exit_error;
615 			}
616 			arg = argv[i];
617 			if (iobuf_len != 0) {
618 				fprintf(stderr,
619 					"ERROR: duplicate I/O buffer length\n");
620 				usage_client();
621 				goto client_exit_error;
622 			}
623 			iobuf_len = parse_size(arg);
624 			if (iobuf_len == (size_t)-1) {
625 				usage_client();
626 				goto client_exit_error;
627 			}
628 		} else if (eqstr(arg, "-CA")) {
629 			if (++ i >= argc) {
630 				fprintf(stderr,
631 					"ERROR: no argument for '-CA'\n");
632 				usage_client();
633 				goto client_exit_error;
634 			}
635 			arg = argv[i];
636 			if (read_trust_anchors(&anchors, arg) == 0) {
637 				usage_client();
638 				goto client_exit_error;
639 			}
640 		} else if (eqstr(arg, "-cert")) {
641 			if (++ i >= argc) {
642 				fprintf(stderr,
643 					"ERROR: no argument for '-cert'\n");
644 				usage_client();
645 				goto client_exit_error;
646 			}
647 			if (chain != NULL) {
648 				fprintf(stderr,
649 					"ERROR: duplicate certificate chain\n");
650 				usage_client();
651 				goto client_exit_error;
652 			}
653 			arg = argv[i];
654 			chain = read_certificates(arg, &chain_len);
655 			if (chain == NULL || chain_len == 0) {
656 				goto client_exit_error;
657 			}
658 		} else if (eqstr(arg, "-key")) {
659 			if (++ i >= argc) {
660 				fprintf(stderr,
661 					"ERROR: no argument for '-key'\n");
662 				usage_client();
663 				goto client_exit_error;
664 			}
665 			if (sk != NULL) {
666 				fprintf(stderr,
667 					"ERROR: duplicate private key\n");
668 				usage_client();
669 				goto client_exit_error;
670 			}
671 			arg = argv[i];
672 			sk = read_private_key(arg);
673 			if (sk == NULL) {
674 				goto client_exit_error;
675 			}
676 		} else if (eqstr(arg, "-nostaticecdh")) {
677 			nostaticecdh = 1;
678 		} else if (eqstr(arg, "-list")) {
679 			list_names();
680 			goto client_exit;
681 		} else if (eqstr(arg, "-vmin")) {
682 			if (++ i >= argc) {
683 				fprintf(stderr,
684 					"ERROR: no argument for '-vmin'\n");
685 				usage_client();
686 				goto client_exit_error;
687 			}
688 			arg = argv[i];
689 			if (vmin != 0) {
690 				fprintf(stderr,
691 					"ERROR: duplicate minimum version\n");
692 				usage_client();
693 				goto client_exit_error;
694 			}
695 			vmin = parse_version(arg, strlen(arg));
696 			if (vmin == 0) {
697 				fprintf(stderr,
698 					"ERROR: unrecognised version '%s'\n",
699 					arg);
700 				usage_client();
701 				goto client_exit_error;
702 			}
703 		} else if (eqstr(arg, "-vmax")) {
704 			if (++ i >= argc) {
705 				fprintf(stderr,
706 					"ERROR: no argument for '-vmax'\n");
707 				usage_client();
708 				goto client_exit_error;
709 			}
710 			arg = argv[i];
711 			if (vmax != 0) {
712 				fprintf(stderr,
713 					"ERROR: duplicate maximum version\n");
714 				usage_client();
715 				goto client_exit_error;
716 			}
717 			vmax = parse_version(arg, strlen(arg));
718 			if (vmax == 0) {
719 				fprintf(stderr,
720 					"ERROR: unrecognised version '%s'\n",
721 					arg);
722 				usage_client();
723 				goto client_exit_error;
724 			}
725 		} else if (eqstr(arg, "-cs")) {
726 			if (++ i >= argc) {
727 				fprintf(stderr,
728 					"ERROR: no argument for '-cs'\n");
729 				usage_client();
730 				goto client_exit_error;
731 			}
732 			arg = argv[i];
733 			if (suites != NULL) {
734 				fprintf(stderr, "ERROR: duplicate list"
735 					" of cipher suites\n");
736 				usage_client();
737 				goto client_exit_error;
738 			}
739 			suites = parse_suites(arg, &num_suites);
740 			if (suites == NULL) {
741 				usage_client();
742 				goto client_exit_error;
743 			}
744 		} else if (eqstr(arg, "-hf")) {
745 			unsigned x;
746 
747 			if (++ i >= argc) {
748 				fprintf(stderr,
749 					"ERROR: no argument for '-hf'\n");
750 				usage_client();
751 				goto client_exit_error;
752 			}
753 			arg = argv[i];
754 			x = parse_hash_functions(arg);
755 			if (x == 0) {
756 				usage_client();
757 				goto client_exit_error;
758 			}
759 			hfuns |= x;
760 		} else if (eqstr(arg, "-minhello")) {
761 			if (++ i >= argc) {
762 				fprintf(stderr,
763 					"ERROR: no argument for '-minhello'\n");
764 				usage_client();
765 				goto client_exit_error;
766 			}
767 			arg = argv[i];
768 			if (minhello_len != (size_t)-1) {
769 				fprintf(stderr, "ERROR: duplicate minimum"
770 					" ClientHello length\n");
771 				usage_client();
772 				goto client_exit_error;
773 			}
774 			minhello_len = parse_size(arg);
775 			/*
776 			 * Minimum ClientHello length must fit on 16 bits.
777 			 */
778 			if (minhello_len == (size_t)-1
779 				|| (((minhello_len >> 12) >> 4) != 0))
780 			{
781 				usage_client();
782 				goto client_exit_error;
783 			}
784 		} else if (eqstr(arg, "-fallback")) {
785 			fallback = 1;
786 		} else if (eqstr(arg, "-noreneg")) {
787 			flags |= BR_OPT_NO_RENEGOTIATION;
788 		} else if (eqstr(arg, "-alpn")) {
789 			if (++ i >= argc) {
790 				fprintf(stderr,
791 					"ERROR: no argument for '-alpn'\n");
792 				usage_client();
793 				goto client_exit_error;
794 			}
795 			VEC_ADD(alpn_names, xstrdup(argv[i]));
796 		} else if (eqstr(arg, "-strictalpn")) {
797 			flags |= BR_OPT_FAIL_ON_ALPN_MISMATCH;
798 		} else {
799 			fprintf(stderr, "ERROR: unknown option: '%s'\n", arg);
800 			usage_client();
801 			goto client_exit_error;
802 		}
803 	}
804 	if (server_name == NULL) {
805 		fprintf(stderr, "ERROR: no server name/address provided\n");
806 		usage_client();
807 		goto client_exit_error;
808 	}
809 	for (u = strlen(server_name); u > 0; u --) {
810 		int c = server_name[u - 1];
811 		if (c == ':') {
812 			break;
813 		}
814 		if (c < '0' || c > '9') {
815 			u = 0;
816 			break;
817 		}
818 	}
819 	if (u == 0) {
820 		host = xstrdup(server_name);
821 		port = xstrdup("443");
822 	} else {
823 		port = xstrdup(server_name + u);
824 		host = xmalloc(u);
825 		memcpy(host, server_name, u - 1);
826 		host[u - 1] = 0;
827 	}
828 	if (sni == NULL) {
829 		sni = host;
830 	}
831 
832 	if (chain == NULL && sk != NULL) {
833 		fprintf(stderr, "ERROR: private key specified, but"
834 			" no certificate chain\n");
835 		usage_client();
836 		goto client_exit_error;
837 	}
838 	if (chain != NULL && sk == NULL) {
839 		fprintf(stderr, "ERROR: certificate chain specified, but"
840 			" no private key\n");
841 		usage_client();
842 		goto client_exit_error;
843 	}
844 
845 	if (vmin == 0) {
846 		vmin = BR_TLS10;
847 	}
848 	if (vmax == 0) {
849 		vmax = BR_TLS12;
850 	}
851 	if (vmax < vmin) {
852 		fprintf(stderr, "ERROR: impossible minimum/maximum protocol"
853 			" version combination\n");
854 		usage_client();
855 		goto client_exit_error;
856 	}
857 	if (suites == NULL) {
858 		num_suites = 0;
859 
860 		for (u = 0; cipher_suites[u].name; u ++) {
861 			if ((cipher_suites[u].req & REQ_TLS12) == 0
862 				|| vmax >= BR_TLS12)
863 			{
864 				num_suites ++;
865 			}
866 		}
867 		suites = xmalloc(num_suites * sizeof *suites);
868 		num_suites = 0;
869 		for (u = 0; cipher_suites[u].name; u ++) {
870 			if ((cipher_suites[u].req & REQ_TLS12) == 0
871 				|| vmax >= BR_TLS12)
872 			{
873 				suites[num_suites ++] = cipher_suites[u];
874 			}
875 		}
876 	}
877 	if (hfuns == 0) {
878 		hfuns = (unsigned)-1;
879 	}
880 	if (iobuf_len == 0) {
881 		if (bidi) {
882 			iobuf_len = BR_SSL_BUFSIZE_BIDI;
883 		} else {
884 			iobuf_len = BR_SSL_BUFSIZE_MONO;
885 		}
886 	}
887 	iobuf = xmalloc(iobuf_len);
888 
889 	/*
890 	 * Compute implementation requirements and inject implementations.
891 	 */
892 	suite_ids = xmalloc((num_suites + 1) * sizeof *suite_ids);
893 	br_ssl_client_zero(&cc);
894 	br_ssl_engine_set_versions(&cc.eng, vmin, vmax);
895 	dnhash = NULL;
896 	for (u = 0; hash_functions[u].name; u ++) {
897 		const br_hash_class *hc;
898 		int id;
899 
900 		hc = hash_functions[u].hclass;
901 		id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
902 		if ((hfuns & ((unsigned)1 << id)) != 0) {
903 			dnhash = hc;
904 		}
905 	}
906 	if (dnhash == NULL) {
907 		fprintf(stderr, "ERROR: no supported hash function\n");
908 		goto client_exit_error;
909 	}
910 	br_x509_minimal_init(&xc, dnhash,
911 		&VEC_ELT(anchors, 0), VEC_LEN(anchors));
912 	if (vmin <= BR_TLS11) {
913 		if (!(hfuns & (1 << br_md5_ID))) {
914 			fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need MD5\n");
915 			goto client_exit_error;
916 		}
917 		if (!(hfuns & (1 << br_sha1_ID))) {
918 			fprintf(stderr, "ERROR: TLS 1.0 and 1.1 need SHA-1\n");
919 			goto client_exit_error;
920 		}
921 	}
922 	for (u = 0; u < num_suites; u ++) {
923 		unsigned req;
924 
925 		req = suites[u].req;
926 		suite_ids[u] = suites[u].suite;
927 		if ((req & REQ_TLS12) != 0 && vmax < BR_TLS12) {
928 			fprintf(stderr,
929 				"ERROR: cipher suite %s requires TLS 1.2\n",
930 				suites[u].name);
931 			goto client_exit_error;
932 		}
933 		if ((req & REQ_SHA1) != 0 && !(hfuns & (1 << br_sha1_ID))) {
934 			fprintf(stderr,
935 				"ERROR: cipher suite %s requires SHA-1\n",
936 				suites[u].name);
937 			goto client_exit_error;
938 		}
939 		if ((req & REQ_SHA256) != 0 && !(hfuns & (1 << br_sha256_ID))) {
940 			fprintf(stderr,
941 				"ERROR: cipher suite %s requires SHA-256\n",
942 				suites[u].name);
943 			goto client_exit_error;
944 		}
945 		if ((req & REQ_SHA384) != 0 && !(hfuns & (1 << br_sha384_ID))) {
946 			fprintf(stderr,
947 				"ERROR: cipher suite %s requires SHA-384\n",
948 				suites[u].name);
949 			goto client_exit_error;
950 		}
951 		/* TODO: algorithm implementation selection */
952 		if ((req & REQ_AESCBC) != 0) {
953 			br_ssl_engine_set_default_aes_cbc(&cc.eng);
954 		}
955 		if ((req & REQ_AESCCM) != 0) {
956 			br_ssl_engine_set_default_aes_ccm(&cc.eng);
957 		}
958 		if ((req & REQ_AESGCM) != 0) {
959 			br_ssl_engine_set_default_aes_gcm(&cc.eng);
960 		}
961 		if ((req & REQ_CHAPOL) != 0) {
962 			br_ssl_engine_set_default_chapol(&cc.eng);
963 		}
964 		if ((req & REQ_3DESCBC) != 0) {
965 			br_ssl_engine_set_default_des_cbc(&cc.eng);
966 		}
967 		if ((req & REQ_RSAKEYX) != 0) {
968 			br_ssl_client_set_default_rsapub(&cc);
969 		}
970 		if ((req & REQ_ECDHE_RSA) != 0) {
971 			br_ssl_engine_set_default_ec(&cc.eng);
972 			br_ssl_engine_set_default_rsavrfy(&cc.eng);
973 		}
974 		if ((req & REQ_ECDHE_ECDSA) != 0) {
975 			br_ssl_engine_set_default_ecdsa(&cc.eng);
976 		}
977 		if ((req & REQ_ECDH) != 0) {
978 			br_ssl_engine_set_default_ec(&cc.eng);
979 		}
980 	}
981 	if (fallback) {
982 		suite_ids[num_suites ++] = 0x5600;
983 	}
984 	br_ssl_engine_set_suites(&cc.eng, suite_ids, num_suites);
985 
986 	for (u = 0; hash_functions[u].name; u ++) {
987 		const br_hash_class *hc;
988 		int id;
989 
990 		hc = hash_functions[u].hclass;
991 		id = (hc->desc >> BR_HASHDESC_ID_OFF) & BR_HASHDESC_ID_MASK;
992 		if ((hfuns & ((unsigned)1 << id)) != 0) {
993 			br_ssl_engine_set_hash(&cc.eng, id, hc);
994 			br_x509_minimal_set_hash(&xc, id, hc);
995 		}
996 	}
997 	if (vmin <= BR_TLS11) {
998 		br_ssl_engine_set_prf10(&cc.eng, &br_tls10_prf);
999 	}
1000 	if (vmax >= BR_TLS12) {
1001 		if ((hfuns & ((unsigned)1 << br_sha256_ID)) != 0) {
1002 			br_ssl_engine_set_prf_sha256(&cc.eng,
1003 				&br_tls12_sha256_prf);
1004 		}
1005 		if ((hfuns & ((unsigned)1 << br_sha384_ID)) != 0) {
1006 			br_ssl_engine_set_prf_sha384(&cc.eng,
1007 				&br_tls12_sha384_prf);
1008 		}
1009 	}
1010 	br_x509_minimal_set_rsa(&xc, br_rsa_pkcs1_vrfy_get_default());
1011 	br_x509_minimal_set_ecdsa(&xc,
1012 		br_ec_get_default(), br_ecdsa_vrfy_asn1_get_default());
1013 
1014 	/*
1015 	 * If there is no provided trust anchor, then certificate validation
1016 	 * will always fail. In that situation, we use our custom wrapper
1017 	 * that tolerates unknown anchors.
1018 	 */
1019 	if (VEC_LEN(anchors) == 0) {
1020 		if (verbose) {
1021 			fprintf(stderr,
1022 				"WARNING: no configured trust anchor\n");
1023 		}
1024 		x509_noanchor_init(&xwc, &xc.vtable);
1025 		br_ssl_engine_set_x509(&cc.eng, &xwc.vtable);
1026 	} else {
1027 		br_ssl_engine_set_x509(&cc.eng, &xc.vtable);
1028 	}
1029 
1030 	if (minhello_len != (size_t)-1) {
1031 		br_ssl_client_set_min_clienthello_len(&cc, minhello_len);
1032 	}
1033 	br_ssl_engine_set_all_flags(&cc.eng, flags);
1034 	if (VEC_LEN(alpn_names) != 0) {
1035 		br_ssl_engine_set_protocol_names(&cc.eng,
1036 			(const char **)&VEC_ELT(alpn_names, 0),
1037 			VEC_LEN(alpn_names));
1038 	}
1039 
1040 	if (chain != NULL) {
1041 		zc.vtable = &ccert_vtable;
1042 		zc.verbose = verbose;
1043 		zc.chain = chain;
1044 		zc.chain_len = chain_len;
1045 		zc.sk = sk;
1046 		if (nostaticecdh || sk->key_type != BR_KEYTYPE_EC) {
1047 			zc.issuer_key_type = 0;
1048 		} else {
1049 			zc.issuer_key_type = get_cert_signer_algo(&chain[0]);
1050 			if (zc.issuer_key_type == 0) {
1051 				goto client_exit_error;
1052 			}
1053 		}
1054 		br_ssl_client_set_client_certificate(&cc, &zc.vtable);
1055 	}
1056 
1057 	br_ssl_engine_set_buffer(&cc.eng, iobuf, iobuf_len, bidi);
1058 	br_ssl_client_reset(&cc, sni, 0);
1059 
1060 	/*
1061 	 * On Unix systems, we need to avoid SIGPIPE.
1062 	 */
1063 #ifndef _WIN32
1064 	signal(SIGPIPE, SIG_IGN);
1065 #endif
1066 
1067 	/*
1068 	 * Connect to the peer.
1069 	 */
1070 	fd = host_connect(host, port, verbose);
1071 	if (fd == INVALID_SOCKET) {
1072 		goto client_exit_error;
1073 	}
1074 
1075 	/*
1076 	 * Run the engine until completion.
1077 	 */
1078 	if (run_ssl_engine(&cc.eng, fd,
1079 		(verbose ? RUN_ENGINE_VERBOSE : 0)
1080 		| (trace ? RUN_ENGINE_TRACE : 0)) != 0)
1081 	{
1082 		goto client_exit_error;
1083 	} else {
1084 		goto client_exit;
1085 	}
1086 
1087 	/*
1088 	 * Release allocated structures.
1089 	 */
1090 client_exit:
1091 	xfree(host);
1092 	xfree(port);
1093 	xfree(suites);
1094 	xfree(suite_ids);
1095 	VEC_CLEAREXT(anchors, &free_ta_contents);
1096 	VEC_CLEAREXT(alpn_names, &free_alpn);
1097 	free_certificates(chain, chain_len);
1098 	free_private_key(sk);
1099 	xfree(iobuf);
1100 	if (fd != INVALID_SOCKET) {
1101 #ifdef _WIN32
1102 		closesocket(fd);
1103 #else
1104 		close(fd);
1105 #endif
1106 	}
1107 	return retcode;
1108 
1109 client_exit_error:
1110 	retcode = -1;
1111 	goto client_exit;
1112 }
1113