xref: /freebsd/lib/libfetch/common.c (revision 6d5a428056b52c7ce47b01d6af8aaaff6feecfdd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1998-2016 Dag-Erling Smørgrav
5  * Copyright (c) 2013 Michael Gmelin <freebsd@grem.de>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer
13  *    in this position and unchanged.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/socket.h>
34 #include <sys/time.h>
35 #include <sys/uio.h>
36 
37 #include <netinet/in.h>
38 
39 #include <ctype.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <inttypes.h>
43 #include <netdb.h>
44 #include <paths.h>
45 #include <poll.h>
46 #include <pwd.h>
47 #include <stdarg.h>
48 #include <stdlib.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #ifdef WITH_SSL
54 #include <openssl/x509v3.h>
55 #endif
56 
57 #include "fetch.h"
58 #include "common.h"
59 
60 
61 /*** Local data **************************************************************/
62 
63 /*
64  * Error messages for resolver errors
65  */
66 static struct fetcherr netdb_errlist[] = {
67 #ifdef EAI_ADDRFAMILY
68 	{ EAI_ADDRFAMILY, FETCH_RESOLV, "Address family for host not supported" },
69 #endif
70 #ifdef EAI_NODATA
71 	{ EAI_NODATA,	FETCH_RESOLV,	"No address for host" },
72 #endif
73 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
74 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
75 	{ EAI_NONAME,	FETCH_RESOLV,	"Host does not resolve" },
76 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
77 };
78 
79 /*
80  * SOCKS5 error enumerations
81  */
82 enum SOCKS5_ERR {
83 /* Protocol errors */
84 	SOCKS5_ERR_SELECTION,
85 	SOCKS5_ERR_READ_METHOD,
86 	SOCKS5_ERR_VER5_ONLY,
87 	SOCKS5_ERR_NOMETHODS,
88 	SOCKS5_ERR_NOTIMPLEMENTED,
89 	SOCKS5_ERR_HOSTNAME_SIZE,
90 	SOCKS5_ERR_REQUEST,
91 	SOCKS5_ERR_REPLY,
92 	SOCKS5_ERR_NON_VER5_RESP,
93 	SOCKS5_ERR_GENERAL,
94 	SOCKS5_ERR_NOT_ALLOWED,
95 	SOCKS5_ERR_NET_UNREACHABLE,
96 	SOCKS5_ERR_HOST_UNREACHABLE,
97 	SOCKS5_ERR_CONN_REFUSED,
98 	SOCKS5_ERR_TTL_EXPIRED,
99 	SOCKS5_ERR_COM_UNSUPPORTED,
100 	SOCKS5_ERR_ADDR_UNSUPPORTED,
101 	SOCKS5_ERR_UNSPECIFIED,
102 /* Configuration errors */
103 	SOCKS5_ERR_BAD_HOST,
104 	SOCKS5_ERR_BAD_PROXY_FORMAT,
105 	SOCKS5_ERR_BAD_PORT
106 };
107 
108 /*
109  * Error messages for SOCKS5 errors
110  */
111 static struct fetcherr socks5_errlist[] = {
112 /* SOCKS5 protocol errors */
113 	{ SOCKS5_ERR_SELECTION,		FETCH_ABORT,	"SOCKS5: Failed to send selection method" },
114 	{ SOCKS5_ERR_READ_METHOD,	FETCH_ABORT,	"SOCKS5: Failed to read method" },
115 	{ SOCKS5_ERR_VER5_ONLY,		FETCH_PROTO,	"SOCKS5: Only version 5 is implemented" },
116 	{ SOCKS5_ERR_NOMETHODS,		FETCH_PROTO,	"SOCKS5: No acceptable methods" },
117 	{ SOCKS5_ERR_NOTIMPLEMENTED,	FETCH_PROTO,	"SOCKS5: Method currently not implemented" },
118 	{ SOCKS5_ERR_HOSTNAME_SIZE,	FETCH_PROTO,	"SOCKS5: Hostname size is above 256 bytes" },
119 	{ SOCKS5_ERR_REQUEST,		FETCH_PROTO,	"SOCKS5: Failed to request" },
120 	{ SOCKS5_ERR_REPLY,		FETCH_PROTO,	"SOCKS5: Failed to receive reply" },
121 	{ SOCKS5_ERR_NON_VER5_RESP,	FETCH_PROTO,	"SOCKS5: Server responded with a non-version 5 response" },
122 	{ SOCKS5_ERR_GENERAL,		FETCH_ABORT,	"SOCKS5: General server failure" },
123 	{ SOCKS5_ERR_NOT_ALLOWED,	FETCH_AUTH,	"SOCKS5: Connection not allowed by ruleset" },
124 	{ SOCKS5_ERR_NET_UNREACHABLE,	FETCH_NETWORK,	"SOCKS5: Network unreachable" },
125 	{ SOCKS5_ERR_HOST_UNREACHABLE,	FETCH_ABORT,	"SOCKS5: Host unreachable" },
126 	{ SOCKS5_ERR_CONN_REFUSED,	FETCH_ABORT,	"SOCKS5: Connection refused" },
127 	{ SOCKS5_ERR_TTL_EXPIRED,	FETCH_TIMEOUT,	"SOCKS5: TTL expired" },
128 	{ SOCKS5_ERR_COM_UNSUPPORTED,	FETCH_PROTO,	"SOCKS5: Command not supported" },
129 	{ SOCKS5_ERR_ADDR_UNSUPPORTED,	FETCH_ABORT,	"SOCKS5: Address type not supported" },
130 	{ SOCKS5_ERR_UNSPECIFIED,	FETCH_UNKNOWN,	"SOCKS5: Unspecified error" },
131 /* Configuration error */
132 	{ SOCKS5_ERR_BAD_HOST,		FETCH_ABORT,	"SOCKS5: Bad proxy host" },
133 	{ SOCKS5_ERR_BAD_PROXY_FORMAT,	FETCH_ABORT,	"SOCKS5: Bad proxy format" },
134 	{ SOCKS5_ERR_BAD_PORT,		FETCH_ABORT,	"SOCKS5: Bad port" }
135 };
136 
137 /* End-of-Line */
138 static const char ENDL[2] = { '\r', '\n' };
139 
140 
141 /*** Error-reporting functions ***********************************************/
142 
143 /*
144  * Map error code to string
145  */
146 static struct fetcherr *
147 fetch_finderr(struct fetcherr *p, int e)
148 {
149 	while (p->num != -1 && p->num != e)
150 		p++;
151 	return (p);
152 }
153 
154 /*
155  * Set error code
156  */
157 void
158 fetch_seterr(struct fetcherr *p, int e)
159 {
160 	p = fetch_finderr(p, e);
161 	fetchLastErrCode = p->cat;
162 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
163 }
164 
165 /*
166  * Set error code according to errno
167  */
168 void
169 fetch_syserr(void)
170 {
171 	switch (errno) {
172 	case 0:
173 		fetchLastErrCode = FETCH_OK;
174 		break;
175 	case EPERM:
176 	case EACCES:
177 	case EROFS:
178 	case EAUTH:
179 	case ENEEDAUTH:
180 		fetchLastErrCode = FETCH_AUTH;
181 		break;
182 	case ENOENT:
183 	case EISDIR: /* XXX */
184 		fetchLastErrCode = FETCH_UNAVAIL;
185 		break;
186 	case ENOMEM:
187 		fetchLastErrCode = FETCH_MEMORY;
188 		break;
189 	case EBUSY:
190 	case EAGAIN:
191 		fetchLastErrCode = FETCH_TEMP;
192 		break;
193 	case EEXIST:
194 		fetchLastErrCode = FETCH_EXISTS;
195 		break;
196 	case ENOSPC:
197 		fetchLastErrCode = FETCH_FULL;
198 		break;
199 	case EADDRINUSE:
200 	case EADDRNOTAVAIL:
201 	case ENETDOWN:
202 	case ENETUNREACH:
203 	case ENETRESET:
204 	case EHOSTUNREACH:
205 		fetchLastErrCode = FETCH_NETWORK;
206 		break;
207 	case ECONNABORTED:
208 	case ECONNRESET:
209 		fetchLastErrCode = FETCH_ABORT;
210 		break;
211 	case ETIMEDOUT:
212 		fetchLastErrCode = FETCH_TIMEOUT;
213 		break;
214 	case ECONNREFUSED:
215 	case EHOSTDOWN:
216 		fetchLastErrCode = FETCH_DOWN;
217 		break;
218 	default:
219 		fetchLastErrCode = FETCH_UNKNOWN;
220 	}
221 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
222 }
223 
224 
225 /*
226  * Emit status message
227  */
228 void
229 fetch_info(const char *fmt, ...)
230 {
231 	va_list ap;
232 
233 	va_start(ap, fmt);
234 	vfprintf(stderr, fmt, ap);
235 	va_end(ap);
236 	fputc('\n', stderr);
237 }
238 
239 
240 /*** Network-related utility functions ***************************************/
241 
242 /*
243  * Return the default port for a scheme
244  */
245 int
246 fetch_default_port(const char *scheme)
247 {
248 	struct servent *se;
249 
250 	if ((se = getservbyname(scheme, "tcp")) != NULL)
251 		return (ntohs(se->s_port));
252 	if (strcmp(scheme, SCHEME_FTP) == 0)
253 		return (FTP_DEFAULT_PORT);
254 	if (strcmp(scheme, SCHEME_HTTP) == 0)
255 		return (HTTP_DEFAULT_PORT);
256 	return (0);
257 }
258 
259 /*
260  * Return the default proxy port for a scheme
261  */
262 int
263 fetch_default_proxy_port(const char *scheme)
264 {
265 	if (strcmp(scheme, SCHEME_FTP) == 0)
266 		return (FTP_DEFAULT_PROXY_PORT);
267 	if (strcmp(scheme, SCHEME_HTTP) == 0)
268 		return (HTTP_DEFAULT_PROXY_PORT);
269 	return (0);
270 }
271 
272 
273 /*
274  * Create a connection for an existing descriptor.
275  */
276 conn_t *
277 fetch_reopen(int sd)
278 {
279 	conn_t *conn;
280 	int flags;
281 	int opt = 1;
282 
283 	/* allocate and fill connection structure */
284 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
285 		return (NULL);
286 	flags = fcntl(sd, F_GETFD);
287 	if (flags != -1 && (flags & FD_CLOEXEC) == 0)
288 		(void)fcntl(sd, F_SETFD, flags | FD_CLOEXEC);
289 	flags = fcntl(sd, F_GETFL);
290 	if (flags != -1 && (flags & O_NONBLOCK) == 0)
291 		(void)fcntl(sd, F_SETFL, flags | O_NONBLOCK);
292 	(void)setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
293 	conn->sd = sd;
294 	++conn->ref;
295 	return (conn);
296 }
297 
298 
299 /*
300  * Bump a connection's reference count.
301  */
302 conn_t *
303 fetch_ref(conn_t *conn)
304 {
305 
306 	++conn->ref;
307 	return (conn);
308 }
309 
310 
311 /*
312  * Resolve an address
313  */
314 struct addrinfo *
315 fetch_resolve(const char *addr, int port, int af)
316 {
317 	char hbuf[256], sbuf[8];
318 	struct addrinfo hints, *res;
319 	const char *hb, *he, *sep;
320 	const char *host, *service;
321 	int err, len;
322 
323 	/* first, check for a bracketed IPv6 address */
324 	if (*addr == '[') {
325 		hb = addr + 1;
326 		if ((sep = strchr(hb, ']')) == NULL) {
327 			errno = EINVAL;
328 			goto syserr;
329 		}
330 		he = sep++;
331 	} else {
332 		hb = addr;
333 		sep = strchrnul(hb, ':');
334 		he = sep;
335 	}
336 
337 	/* see if we need to copy the host name */
338 	if (*he != '\0') {
339 		len = snprintf(hbuf, sizeof(hbuf),
340 		    "%.*s", (int)(he - hb), hb);
341 		if (len < 0)
342 			goto syserr;
343 		if (len >= (int)sizeof(hbuf)) {
344 			errno = ENAMETOOLONG;
345 			goto syserr;
346 		}
347 		host = hbuf;
348 	} else {
349 		host = hb;
350 	}
351 
352 	/* was it followed by a service name? */
353 	if (*sep == '\0' && port != 0) {
354 		if (port < 1 || port > 65535) {
355 			errno = EINVAL;
356 			goto syserr;
357 		}
358 		if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
359 			goto syserr;
360 		service = sbuf;
361 	} else if (*sep != '\0') {
362 		service = sep + 1;
363 	} else {
364 		service = NULL;
365 	}
366 
367 	/* resolve */
368 	memset(&hints, 0, sizeof(hints));
369 	hints.ai_family = af;
370 	hints.ai_socktype = SOCK_STREAM;
371 	hints.ai_flags = AI_ADDRCONFIG;
372 	if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
373 		netdb_seterr(err);
374 		return (NULL);
375 	}
376 	return (res);
377 syserr:
378 	fetch_syserr();
379 	return (NULL);
380 }
381 
382 
383 /*
384  * Bind a socket to a specific local address
385  */
386 int
387 fetch_bind(int sd, int af, const char *addr)
388 {
389 	struct addrinfo *cliai, *ai;
390 	int err;
391 
392 	if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
393 		return (-1);
394 	for (ai = cliai; ai != NULL; ai = ai->ai_next)
395 		if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
396 			break;
397 	if (err != 0)
398 		fetch_syserr();
399 	freeaddrinfo(cliai);
400 	return (err == 0 ? 0 : -1);
401 }
402 
403 
404 /*
405  * SOCKS5 connection initiation, based on RFC 1928
406  * Default DNS resolution over SOCKS5
407  */
408 int
409 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
410 {
411 	/*
412 	 * Size is based on largest packet prefix (4 bytes) +
413 	 * Largest FQDN (256) + one byte size (1) +
414 	 * Port (2)
415 	 */
416 	unsigned char buf[BUFF_SIZE];
417 	unsigned char *ptr;
418 	int ret = 1;
419 
420 	if (verbose)
421 		fetch_info("Initializing SOCKS5 connection: %s:%d", host, port);
422 
423 	/* Connection initialization */
424 	ptr = buf;
425 	*ptr++ = SOCKS_VERSION_5;
426 	*ptr++ = SOCKS_CONNECTION;
427 	*ptr++ = SOCKS_RSV;
428 
429 	if (fetch_write(conn, buf, 3) != 3) {
430 		ret = SOCKS5_ERR_SELECTION;
431 		goto fail;
432 	}
433 
434 	/* Verify response from SOCKS5 server */
435 	if (fetch_read(conn, buf, 2) != 2) {
436 		ret = SOCKS5_ERR_READ_METHOD;
437 		goto fail;
438 	}
439 
440 	ptr = buf;
441 	if (ptr[0] != SOCKS_VERSION_5) {
442 		ret = SOCKS5_ERR_VER5_ONLY;
443 		goto fail;
444 	}
445 	if (ptr[1] == SOCKS_NOMETHODS) {
446 		ret = SOCKS5_ERR_NOMETHODS;
447 		goto fail;
448 	}
449 	else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
450 		ret = SOCKS5_ERR_NOTIMPLEMENTED;
451 		goto fail;
452 	}
453 
454 	/* Send Request */
455 	*ptr++ = SOCKS_VERSION_5;
456 	*ptr++ = SOCKS_CONNECTION;
457 	*ptr++ = SOCKS_RSV;
458 	/* Encode all targets as a hostname to avoid DNS leaks */
459 	*ptr++ = SOCKS_ATYP_DOMAINNAME;
460 	if (strlen(host) > FQDN_SIZE) {
461 		ret = SOCKS5_ERR_HOSTNAME_SIZE;
462 		goto fail;
463 	}
464 	*ptr++ = strlen(host);
465 	memcpy(ptr, host, strlen(host));
466 	ptr = ptr + strlen(host);
467 
468 	port = htons(port);
469 	*ptr++ = port & 0x00ff;
470 	*ptr++ = (port & 0xff00) >> 8;
471 
472 	if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
473 		ret = SOCKS5_ERR_REQUEST;
474 		goto fail;
475 	}
476 
477 	/* BND.ADDR is variable length, read the largest on non-blocking socket */
478 	if (!fetch_read(conn, buf, BUFF_SIZE)) {
479 		ret = SOCKS5_ERR_REPLY;
480 		goto fail;
481 	}
482 
483 	ptr = buf;
484 	if (*ptr++ != SOCKS_VERSION_5) {
485 		ret = SOCKS5_ERR_NON_VER5_RESP;
486 		goto fail;
487 	}
488 
489 	switch(*ptr++) {
490 	case SOCKS_SUCCESS:
491 		break;
492 	case SOCKS_GENERAL_FAILURE:
493 		ret = SOCKS5_ERR_GENERAL;
494 		goto fail;
495 	case SOCKS_CONNECTION_NOT_ALLOWED:
496 		ret = SOCKS5_ERR_NOT_ALLOWED;
497 		goto fail;
498 	case SOCKS_NETWORK_UNREACHABLE:
499 		ret = SOCKS5_ERR_NET_UNREACHABLE;
500 		goto fail;
501 	case SOCKS_HOST_UNREACHABLE:
502 		ret = SOCKS5_ERR_HOST_UNREACHABLE;
503 		goto fail;
504 	case SOCKS_CONNECTION_REFUSED:
505 		ret = SOCKS5_ERR_CONN_REFUSED;
506 		goto fail;
507 	case SOCKS_TTL_EXPIRED:
508 		ret = SOCKS5_ERR_TTL_EXPIRED;
509 		goto fail;
510 	case SOCKS_COMMAND_NOT_SUPPORTED:
511 		ret = SOCKS5_ERR_COM_UNSUPPORTED;
512 		goto fail;
513 	case SOCKS_ADDRESS_NOT_SUPPORTED:
514 		ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
515 		goto fail;
516 	default:
517 		ret = SOCKS5_ERR_UNSPECIFIED;
518 		goto fail;
519 	}
520 
521 	return (ret);
522 
523 fail:
524 	socks5_seterr(ret);
525 	return (0);
526 }
527 
528 /*
529  * Perform SOCKS5 initialization
530  */
531 int
532 fetch_socks5_getenv(char **host, int *port)
533 {
534 	char *socks5env, *endptr, *ext;
535 	const char *portDelim;
536 	size_t slen;
537 
538 	portDelim = ":";
539 	if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
540 		*host = NULL;
541 		*port = -1;
542 		return (-1);
543 	}
544 
545 	/*
546 	 * IPv6 addresses begin and end in brackets.  Set the port delimiter
547 	 * accordingly and search for it so we can do appropriate validation.
548 	 */
549 	if (socks5env[0] == '[')
550 		portDelim = "]:";
551 
552 	slen = strlen(socks5env);
553 	ext = strstr(socks5env, portDelim);
554 	if (socks5env[0] == '[') {
555 		if (socks5env[slen - 1] == ']') {
556 			*host = strndup(socks5env, slen);
557 		} else if (ext != NULL) {
558 			*host = strndup(socks5env, ext - socks5env + 1);
559 		} else {
560 			socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
561 			return (0);
562 		}
563 	} else {
564 		*host = strndup(socks5env, ext - socks5env);
565 	}
566 
567 	if (*host == NULL) {
568 		fprintf(stderr, "Failure to allocate memory, exiting.\n");
569 		return (-1);
570 	}
571 	if (ext == NULL) {
572 		*port = 1080; /* Default port as defined in RFC1928 */
573 	} else {
574 		ext += strlen(portDelim);
575 		errno = 0;
576 		*port = strtoimax(ext, (char **)&endptr, 10);
577 		if (*endptr != '\0' || errno != 0 || *port < 0 ||
578 		    *port > 65535) {
579 			free(*host);
580 			*host = NULL;
581 			socks5_seterr(SOCKS5_ERR_BAD_PORT);
582 			return (0);
583 		}
584 	}
585 
586 	return (2);
587 }
588 
589 
590 /*
591  * Establish a TCP connection to the specified port on the specified host.
592  */
593 conn_t *
594 fetch_connect(const char *host, int port, int af, int verbose)
595 {
596 	struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
597 	const char *bindaddr;
598 	conn_t *conn = NULL;
599 	int err = 0, sd = -1;
600 	char *sockshost;
601 	int socksport;
602 
603 	DEBUGF("---> %s:%d\n", host, port);
604 
605 	/*
606 	 * Check if SOCKS5_PROXY env variable is set.  fetch_socks5_getenv
607 	 * will either set sockshost = NULL or allocate memory in all cases.
608 	 */
609 	sockshost = NULL;
610 	if (!fetch_socks5_getenv(&sockshost, &socksport))
611 		goto fail;
612 
613 	/* Not using SOCKS5 proxy */
614 	if (sockshost == NULL) {
615 		/* resolve server address */
616 		if (verbose)
617 			fetch_info("resolving server address: %s:%d", host,
618 			    port);
619 		if ((sais = fetch_resolve(host, port, af)) == NULL)
620 			goto fail;
621 
622 		/* resolve client address */
623 		bindaddr = getenv("FETCH_BIND_ADDRESS");
624 		if (bindaddr != NULL && *bindaddr != '\0') {
625 			if (verbose)
626 				fetch_info("resolving client address: %s",
627 				    bindaddr);
628 			if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
629 				goto fail;
630 		}
631 	} else {
632 		/* resolve socks5 proxy address */
633 		if (verbose)
634 			fetch_info("resolving SOCKS5 server address: %s:%d",
635 			    sockshost, socksport);
636 		if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
637 			socks5_seterr(SOCKS5_ERR_BAD_HOST);
638 			goto fail;
639 		}
640 	}
641 
642 	/* try each server address in turn */
643 	for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
644 		/* open socket */
645 		if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0)
646 			goto syserr;
647 		/* attempt to bind to client address */
648 		for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
649 			if (cai->ai_family != sai->ai_family)
650 				continue;
651 			if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
652 				break;
653 		}
654 		if (err != 0) {
655 			if (verbose)
656 				fetch_info("failed to bind to %s", bindaddr);
657 			goto syserr;
658 		}
659 		/* attempt to connect to server address */
660 		if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
661 			break;
662 		/* clean up before next attempt */
663 		close(sd);
664 		sd = -1;
665 	}
666 	if (err != 0) {
667 		if (verbose && sockshost == NULL) {
668 			fetch_info("failed to connect to %s:%d", host, port);
669 			goto syserr;
670 		} else if (sockshost != NULL) {
671 			if (verbose)
672 				fetch_info(
673 				    "failed to connect to SOCKS5 server %s:%d",
674 				    sockshost, socksport);
675 			socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
676 			goto fail;
677 		}
678 		goto syserr;
679 	}
680 
681 	if ((conn = fetch_reopen(sd)) == NULL)
682 		goto syserr;
683 
684 	if (sockshost)
685 		if (!fetch_socks5_init(conn, host, port, verbose))
686 			goto fail;
687 	free(sockshost);
688 	if (cais != NULL)
689 		freeaddrinfo(cais);
690 	if (sais != NULL)
691 		freeaddrinfo(sais);
692 	return (conn);
693 syserr:
694 	fetch_syserr();
695 fail:
696 	free(sockshost);
697 	/* Fully close if it was opened; otherwise just don't leak the fd. */
698 	if (conn != NULL)
699 		fetch_close(conn);
700 	else if (sd >= 0)
701 		close(sd);
702 	if (cais != NULL)
703 		freeaddrinfo(cais);
704 	if (sais != NULL)
705 		freeaddrinfo(sais);
706 	return (NULL);
707 }
708 
709 #ifdef WITH_SSL
710 /*
711  * Convert characters A-Z to lowercase (intentionally avoid any locale
712  * specific conversions).
713  */
714 static char
715 fetch_ssl_tolower(char in)
716 {
717 	if (in >= 'A' && in <= 'Z')
718 		return (in + 32);
719 	else
720 		return (in);
721 }
722 
723 /*
724  * isalpha implementation that intentionally avoids any locale specific
725  * conversions.
726  */
727 static int
728 fetch_ssl_isalpha(char in)
729 {
730 	return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
731 }
732 
733 /*
734  * Check if passed hostnames a and b are equal.
735  */
736 static int
737 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
738     size_t blen)
739 {
740 	size_t i;
741 
742 	if (alen != blen)
743 		return (0);
744 	for (i = 0; i < alen; ++i) {
745 		if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
746 			return (0);
747 	}
748 	return (1);
749 }
750 
751 /*
752  * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
753  * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
754  * numeric characters. Double hyphens (like they're found in IDN a-labels
755  * 'xn--') are not allowed. Empty labels are invalid.
756  */
757 static int
758 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
759 {
760 	size_t i;
761 
762 	if (!len || l[0] == '-' || l[len-1] == '-')
763 		return (0);
764 	for (i = 0; i < len; ++i) {
765 		if (!isdigit(l[i]) &&
766 		    !fetch_ssl_isalpha(l[i]) &&
767 		    !(l[i] == '*' && wcok) &&
768 		    !(l[i] == '-' && l[i - 1] != '-'))
769 			return (0);
770 	}
771 	return (1);
772 }
773 
774 /*
775  * Check if host name consists only of numbers. This might indicate an IP
776  * address, which is not a good idea for CN wildcard comparison.
777  */
778 static int
779 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
780 {
781 	size_t i;
782 
783 	for (i = 0; i < len; ++i) {
784 		if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
785 		    hostname[i] == '.'))
786 			return (0);
787 	}
788 	return (1);
789 }
790 
791 /*
792  * Check if the host name h passed matches the pattern passed in m which
793  * is usually part of subjectAltName or CN of a certificate presented to
794  * the client. This includes wildcard matching. The algorithm is based on
795  * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
796  */
797 static int
798 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
799     size_t mlen)
800 {
801 	int delta, hdotidx, mdot1idx, wcidx;
802 	const char *hdot, *mdot1, *mdot2;
803 	const char *wc; /* wildcard */
804 
805 	if (!(h && *h && m && *m))
806 		return (0);
807 	if ((wc = strnstr(m, "*", mlen)) == NULL)
808 		return (fetch_ssl_hname_equal(h, hlen, m, mlen));
809 	wcidx = wc - m;
810 	/* hostname should not be just dots and numbers */
811 	if (fetch_ssl_hname_is_only_numbers(h, hlen))
812 		return (0);
813 	/* only one wildcard allowed in pattern */
814 	if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
815 		return (0);
816 	/*
817 	 * there must be at least two more domain labels and
818 	 * wildcard has to be in the leftmost label (RFC6125)
819 	 */
820 	mdot1 = strnstr(m, ".", mlen);
821 	if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
822 		return (0);
823 	mdot1idx = mdot1 - m;
824 	mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
825 	if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
826 		return (0);
827 	/* hostname must contain a dot and not be the 1st char */
828 	hdot = strnstr(h, ".", hlen);
829 	if (hdot == NULL || hdot == h)
830 		return (0);
831 	hdotidx = hdot - h;
832 	/*
833 	 * host part of hostname must be at least as long as
834 	 * pattern it's supposed to match
835 	 */
836 	if (hdotidx < mdot1idx)
837 		return (0);
838 	/*
839 	 * don't allow wildcards in non-traditional domain names
840 	 * (IDN, A-label, U-label...)
841 	 */
842 	if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
843 	    !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
844 		return (0);
845 	/* match domain part (part after first dot) */
846 	if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
847 	    mlen - mdot1idx))
848 		return (0);
849 	/* match part left of wildcard */
850 	if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
851 		return (0);
852 	/* match part right of wildcard */
853 	delta = mdot1idx - wcidx - 1;
854 	if (!fetch_ssl_hname_equal(hdot - delta, delta,
855 	    mdot1 - delta, delta))
856 		return (0);
857 	/* all tests succeeded, it's a match */
858 	return (1);
859 }
860 
861 /*
862  * Get numeric host address info - returns NULL if host was not an IP
863  * address. The caller is responsible for deallocation using
864  * freeaddrinfo(3).
865  */
866 static struct addrinfo *
867 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
868 {
869 	struct addrinfo hints, *res;
870 	char *host;
871 
872 	host = (char *)malloc(len + 1);
873 	memcpy(host, hostname, len);
874 	host[len] = '\0';
875 	memset(&hints, 0, sizeof(hints));
876 	hints.ai_family = PF_UNSPEC;
877 	hints.ai_socktype = SOCK_STREAM;
878 	hints.ai_protocol = 0;
879 	hints.ai_flags = AI_NUMERICHOST;
880 	/* port is not relevant for this purpose */
881 	if (getaddrinfo(host, "443", &hints, &res) != 0)
882 		res = NULL;
883 	free(host);
884 	return res;
885 }
886 
887 /*
888  * Compare ip address in addrinfo with address passes.
889  */
890 static int
891 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
892     size_t rhostlen)
893 {
894 	const void *left;
895 
896 	if (lhost->ai_family == AF_INET && rhostlen == 4) {
897 		left = (void *)&((struct sockaddr_in*)(void *)
898 		    lhost->ai_addr)->sin_addr.s_addr;
899 #ifdef INET6
900 	} else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
901 		left = (void *)&((struct sockaddr_in6 *)(void *)
902 		    lhost->ai_addr)->sin6_addr;
903 #endif
904 	} else
905 		return (0);
906 	return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
907 }
908 
909 /*
910  * Compare ip address in addrinfo with host passed. If host is not an IP
911  * address, comparison will fail.
912  */
913 static int
914 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
915     size_t rlen)
916 {
917 	struct addrinfo *raddr;
918 	int ret;
919 	char *rip;
920 
921 	ret = 0;
922 	if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
923 		return 0; /* not a numeric host */
924 
925 	if (laddr->ai_family == raddr->ai_family) {
926 		if (laddr->ai_family == AF_INET) {
927 			rip = (char *)&((struct sockaddr_in *)(void *)
928 			    raddr->ai_addr)->sin_addr.s_addr;
929 			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
930 #ifdef INET6
931 		} else if (laddr->ai_family == AF_INET6) {
932 			rip = (char *)&((struct sockaddr_in6 *)(void *)
933 			    raddr->ai_addr)->sin6_addr;
934 			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
935 #endif
936 		}
937 
938 	}
939 	freeaddrinfo(raddr);
940 	return (ret);
941 }
942 
943 /*
944  * Verify server certificate by subjectAltName.
945  */
946 static int
947 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
948     const char *host, struct addrinfo *ip)
949 {
950 	const GENERAL_NAME *name;
951 	size_t nslen;
952 	int i;
953 	const char *ns;
954 
955 	for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
956 		name = sk_GENERAL_NAME_value(altnames, i);
957 		ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
958 		nslen = (size_t)ASN1_STRING_length(name->d.ia5);
959 
960 		if (name->type == GEN_DNS && ip == NULL &&
961 		    fetch_ssl_hname_match(host, strlen(host), ns, nslen))
962 			return (1);
963 		else if (name->type == GEN_IPADD && ip != NULL &&
964 		    fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
965 			return (1);
966 	}
967 	return (0);
968 }
969 
970 /*
971  * Verify server certificate by CN.
972  */
973 static int
974 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
975     struct addrinfo *ip)
976 {
977 	ASN1_STRING *namedata;
978 	X509_NAME_ENTRY *nameentry;
979 	int cnlen, lastpos, loc, ret;
980 	unsigned char *cn;
981 
982 	ret = 0;
983 	lastpos = -1;
984 	loc = -1;
985 	cn = NULL;
986 	/* get most specific CN (last entry in list) and compare */
987 	while ((lastpos = X509_NAME_get_index_by_NID(subject,
988 	    NID_commonName, lastpos)) != -1)
989 		loc = lastpos;
990 
991 	if (loc > -1) {
992 		nameentry = X509_NAME_get_entry(subject, loc);
993 		namedata = X509_NAME_ENTRY_get_data(nameentry);
994 		cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
995 		if (ip == NULL &&
996 		    fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
997 			ret = 1;
998 		else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
999 			ret = 1;
1000 		OPENSSL_free(cn);
1001 	}
1002 	return (ret);
1003 }
1004 
1005 /*
1006  * Verify that server certificate subjectAltName/CN matches
1007  * hostname. First check, if there are alternative subject names. If yes,
1008  * those have to match. Only if those don't exist it falls back to
1009  * checking the subject's CN.
1010  */
1011 static int
1012 fetch_ssl_verify_hname(X509 *cert, const char *host)
1013 {
1014 	struct addrinfo *ip;
1015 	STACK_OF(GENERAL_NAME) *altnames;
1016 	X509_NAME *subject;
1017 	int ret;
1018 
1019 	ret = 0;
1020 	ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1021 	altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1022 	    NULL, NULL);
1023 
1024 	if (altnames != NULL) {
1025 		ret = fetch_ssl_verify_altname(altnames, host, ip);
1026 	} else {
1027 		subject = X509_get_subject_name(cert);
1028 		if (subject != NULL)
1029 			ret = fetch_ssl_verify_cn(subject, host, ip);
1030 	}
1031 
1032 	if (ip != NULL)
1033 		freeaddrinfo(ip);
1034 	if (altnames != NULL)
1035 		GENERAL_NAMES_free(altnames);
1036 	return (ret);
1037 }
1038 
1039 /*
1040  * Configure transport security layer based on environment.
1041  */
1042 static void
1043 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1044 {
1045 	long ssl_ctx_options;
1046 
1047 	ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1048 	if (getenv("SSL_NO_TLS1") != NULL)
1049 		ssl_ctx_options |= SSL_OP_NO_TLSv1;
1050 	if (getenv("SSL_NO_TLS1_1") != NULL)
1051 		ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1052 	if (getenv("SSL_NO_TLS1_2") != NULL)
1053 		ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1054 	if (getenv("SSL_NO_TLS1_3") != NULL)
1055 		ssl_ctx_options |= SSL_OP_NO_TLSv1_3;
1056 	if (verbose)
1057 		fetch_info("SSL options: %lx", ssl_ctx_options);
1058 	SSL_CTX_set_options(ctx, ssl_ctx_options);
1059 }
1060 
1061 
1062 /*
1063  * Configure peer verification based on environment.
1064  */
1065 static int
1066 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1067 {
1068 	X509_LOOKUP *crl_lookup;
1069 	X509_STORE *crl_store;
1070 	const char *ca_cert_file, *ca_cert_path, *crl_file;
1071 
1072 	if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1073 		ca_cert_file = getenv("SSL_CA_CERT_FILE");
1074 		ca_cert_path = getenv("SSL_CA_CERT_PATH");
1075 		if (verbose) {
1076 			fetch_info("Peer verification enabled");
1077 			if (ca_cert_file != NULL)
1078 				fetch_info("Using CA cert file: %s",
1079 				    ca_cert_file);
1080 			if (ca_cert_path != NULL)
1081 				fetch_info("Using CA cert path: %s",
1082 				    ca_cert_path);
1083 			if (ca_cert_file == NULL && ca_cert_path == NULL)
1084 				fetch_info("Using OpenSSL default "
1085 				    "CA cert file and path");
1086 		}
1087 		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1088 		    fetch_ssl_cb_verify_crt);
1089 		if (ca_cert_file != NULL || ca_cert_path != NULL)
1090 			SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1091 			    ca_cert_path);
1092 		else
1093 			SSL_CTX_set_default_verify_paths(ctx);
1094 		if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1095 			if (verbose)
1096 				fetch_info("Using CRL file: %s", crl_file);
1097 			crl_store = SSL_CTX_get_cert_store(ctx);
1098 			crl_lookup = X509_STORE_add_lookup(crl_store,
1099 			    X509_LOOKUP_file());
1100 			if (crl_lookup == NULL ||
1101 			    !X509_load_crl_file(crl_lookup, crl_file,
1102 				X509_FILETYPE_PEM)) {
1103 				fprintf(stderr,
1104 				    "Could not load CRL file %s\n",
1105 				    crl_file);
1106 				return (0);
1107 			}
1108 			X509_STORE_set_flags(crl_store,
1109 			    X509_V_FLAG_CRL_CHECK |
1110 			    X509_V_FLAG_CRL_CHECK_ALL);
1111 		}
1112 	}
1113 	return (1);
1114 }
1115 
1116 /*
1117  * Configure client certificate based on environment.
1118  */
1119 static int
1120 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1121 {
1122 	const char *client_cert_file, *client_key_file;
1123 
1124 	if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1125 		client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1126 		    getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1127 		if (verbose) {
1128 			fetch_info("Using client cert file: %s",
1129 			    client_cert_file);
1130 			fetch_info("Using client key file: %s",
1131 			    client_key_file);
1132 		}
1133 		if (SSL_CTX_use_certificate_chain_file(ctx,
1134 			client_cert_file) != 1) {
1135 			fprintf(stderr,
1136 			    "Could not load client certificate %s\n",
1137 			    client_cert_file);
1138 			return (0);
1139 		}
1140 		if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1141 			SSL_FILETYPE_PEM) != 1) {
1142 			fprintf(stderr,
1143 			    "Could not load client key %s\n",
1144 			    client_key_file);
1145 			return (0);
1146 		}
1147 	}
1148 	return (1);
1149 }
1150 
1151 /*
1152  * Callback for SSL certificate verification, this is called on server
1153  * cert verification. It takes no decision, but informs the user in case
1154  * verification failed.
1155  */
1156 int
1157 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1158 {
1159 	X509 *crt;
1160 	X509_NAME *name;
1161 	char *str;
1162 
1163 	str = NULL;
1164 	if (!verified) {
1165 		if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1166 		    (name = X509_get_subject_name(crt)) != NULL)
1167 			str = X509_NAME_oneline(name, 0, 0);
1168 		fprintf(stderr, "Certificate verification failed for %s\n",
1169 		    str != NULL ? str : "no relevant certificate");
1170 		OPENSSL_free(str);
1171 	}
1172 	return (verified);
1173 }
1174 
1175 #endif
1176 
1177 /*
1178  * Enable SSL on a connection.
1179  */
1180 int
1181 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1182 {
1183 #ifdef WITH_SSL
1184 	int ret, ssl_err;
1185 	X509_NAME *name;
1186 	char *str;
1187 
1188 	if ((conn->ssl_ctx = SSL_CTX_new(TLS_client_method())) == NULL) {
1189 		fprintf(stderr, "SSL context creation failed\n");
1190 		ERR_print_errors_fp(stderr);
1191 		return (-1);
1192 	}
1193 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1194 
1195 	fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1196 	if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1197 		return (-1);
1198 	if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1199 		return (-1);
1200 
1201 	conn->ssl = SSL_new(conn->ssl_ctx);
1202 	if (conn->ssl == NULL) {
1203 		fprintf(stderr, "SSL connection creation failed\n");
1204 		ERR_print_errors_fp(stderr);
1205 		return (-1);
1206 	}
1207 	SSL_set_fd(conn->ssl, conn->sd);
1208 
1209 #if !defined(OPENSSL_NO_TLSEXT)
1210 	if (!SSL_set_tlsext_host_name(conn->ssl,
1211 	    __DECONST(struct url *, URL)->host)) {
1212 		fprintf(stderr,
1213 		    "TLS server name indication extension failed for host %s\n",
1214 		    URL->host);
1215 		return (-1);
1216 	}
1217 #endif
1218 	while ((ret = SSL_connect(conn->ssl)) == -1) {
1219 		ssl_err = SSL_get_error(conn->ssl, ret);
1220 		if (ssl_err != SSL_ERROR_WANT_READ &&
1221 		    ssl_err != SSL_ERROR_WANT_WRITE) {
1222 			ERR_print_errors_fp(stderr);
1223 			return (-1);
1224 		}
1225 	}
1226 	conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1227 
1228 	if (conn->ssl_cert == NULL) {
1229 		fprintf(stderr, "No server SSL certificate\n");
1230 		return (-1);
1231 	}
1232 
1233 	if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1234 		if (verbose)
1235 			fetch_info("Verify hostname");
1236 		if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1237 			fprintf(stderr,
1238 			    "SSL certificate subject doesn't match host %s\n",
1239 			    URL->host);
1240 			return (-1);
1241 		}
1242 	}
1243 
1244 	if (verbose) {
1245 		fetch_info("%s connection established using %s",
1246 		    SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1247 		name = X509_get_subject_name(conn->ssl_cert);
1248 		str = X509_NAME_oneline(name, 0, 0);
1249 		fetch_info("Certificate subject: %s", str);
1250 		OPENSSL_free(str);
1251 		name = X509_get_issuer_name(conn->ssl_cert);
1252 		str = X509_NAME_oneline(name, 0, 0);
1253 		fetch_info("Certificate issuer: %s", str);
1254 		OPENSSL_free(str);
1255 	}
1256 
1257 	return (0);
1258 #else
1259 	(void)conn;
1260 	(void)verbose;
1261 	(void)URL;
1262 	fprintf(stderr, "SSL support disabled\n");
1263 	return (-1);
1264 #endif
1265 }
1266 
1267 #define FETCH_READ_WAIT		-2
1268 #define FETCH_READ_ERROR	-1
1269 #define FETCH_READ_DONE		 0
1270 
1271 #ifdef WITH_SSL
1272 static ssize_t
1273 fetch_ssl_read(SSL *ssl, char *buf, size_t len)
1274 {
1275 	ssize_t rlen;
1276 	int ssl_err;
1277 
1278 	rlen = SSL_read(ssl, buf, len);
1279 	if (rlen < 0) {
1280 		ssl_err = SSL_get_error(ssl, rlen);
1281 		if (ssl_err == SSL_ERROR_WANT_READ ||
1282 		    ssl_err == SSL_ERROR_WANT_WRITE) {
1283 			return (FETCH_READ_WAIT);
1284 		} else {
1285 			ERR_print_errors_fp(stderr);
1286 			return (FETCH_READ_ERROR);
1287 		}
1288 	}
1289 	return (rlen);
1290 }
1291 #endif
1292 
1293 static ssize_t
1294 fetch_socket_read(int sd, char *buf, size_t len)
1295 {
1296 	ssize_t rlen;
1297 
1298 	rlen = read(sd, buf, len);
1299 	if (rlen < 0) {
1300 		if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
1301 			return (FETCH_READ_WAIT);
1302 		else
1303 			return (FETCH_READ_ERROR);
1304 	}
1305 	return (rlen);
1306 }
1307 
1308 /*
1309  * Read a character from a connection w/ timeout
1310  */
1311 ssize_t
1312 fetch_read(conn_t *conn, char *buf, size_t len)
1313 {
1314 	struct timeval now, timeout, delta;
1315 	struct pollfd pfd;
1316 	ssize_t rlen;
1317 	int deltams;
1318 
1319 	if (fetchTimeout > 0) {
1320 		gettimeofday(&timeout, NULL);
1321 		timeout.tv_sec += fetchTimeout;
1322 	}
1323 
1324 	deltams = INFTIM;
1325 	memset(&pfd, 0, sizeof pfd);
1326 	pfd.fd = conn->sd;
1327 	pfd.events = POLLIN | POLLERR;
1328 
1329 	for (;;) {
1330 		/*
1331 		 * The socket is non-blocking.  Instead of the canonical
1332 		 * poll() -> read(), we do the following:
1333 		 *
1334 		 * 1) call read() or SSL_read().
1335 		 * 2) if we received some data, return it.
1336 		 * 3) if an error occurred, return -1.
1337 		 * 4) if read() or SSL_read() signaled EOF, return.
1338 		 * 5) if we did not receive any data but we're not at EOF,
1339 		 *    call poll().
1340 		 *
1341 		 * In the SSL case, this is necessary because if we
1342 		 * receive a close notification, we have to call
1343 		 * SSL_read() one additional time after we've read
1344 		 * everything we received.
1345 		 *
1346 		 * In the non-SSL case, it may improve performance (very
1347 		 * slightly) when reading small amounts of data.
1348 		 */
1349 #ifdef WITH_SSL
1350 		if (conn->ssl != NULL)
1351 			rlen = fetch_ssl_read(conn->ssl, buf, len);
1352 		else
1353 #endif
1354 			rlen = fetch_socket_read(conn->sd, buf, len);
1355 		if (rlen >= 0) {
1356 			break;
1357 		} else if (rlen == FETCH_READ_ERROR) {
1358 			fetch_syserr();
1359 			return (-1);
1360 		}
1361 		// assert(rlen == FETCH_READ_WAIT);
1362 		if (fetchTimeout > 0) {
1363 			gettimeofday(&now, NULL);
1364 			if (!timercmp(&timeout, &now, >)) {
1365 				errno = ETIMEDOUT;
1366 				fetch_syserr();
1367 				return (-1);
1368 			}
1369 			timersub(&timeout, &now, &delta);
1370 			deltams = delta.tv_sec * 1000 +
1371 			    delta.tv_usec / 1000;
1372 		}
1373 		errno = 0;
1374 		pfd.revents = 0;
1375 		if (poll(&pfd, 1, deltams) < 0) {
1376 			if (errno == EINTR && fetchRestartCalls)
1377 				continue;
1378 			fetch_syserr();
1379 			return (-1);
1380 		}
1381 	}
1382 	return (rlen);
1383 }
1384 
1385 
1386 /*
1387  * Read a line of text from a connection w/ timeout
1388  */
1389 #define MIN_BUF_SIZE 1024
1390 
1391 int
1392 fetch_getln(conn_t *conn)
1393 {
1394 	char *tmp;
1395 	size_t tmpsize;
1396 	ssize_t len;
1397 	char c;
1398 
1399 	if (conn->buf == NULL) {
1400 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
1401 			errno = ENOMEM;
1402 			return (-1);
1403 		}
1404 		conn->bufsize = MIN_BUF_SIZE;
1405 	}
1406 
1407 	conn->buf[0] = '\0';
1408 	conn->buflen = 0;
1409 
1410 	do {
1411 		len = fetch_read(conn, &c, 1);
1412 		if (len == -1)
1413 			return (-1);
1414 		if (len == 0)
1415 			break;
1416 		conn->buf[conn->buflen++] = c;
1417 		if (conn->buflen == conn->bufsize) {
1418 			tmp = conn->buf;
1419 			tmpsize = conn->bufsize * 2 + 1;
1420 			if ((tmp = realloc(tmp, tmpsize)) == NULL) {
1421 				errno = ENOMEM;
1422 				return (-1);
1423 			}
1424 			conn->buf = tmp;
1425 			conn->bufsize = tmpsize;
1426 		}
1427 	} while (c != '\n');
1428 
1429 	conn->buf[conn->buflen] = '\0';
1430 	DEBUGF("<<< %s", conn->buf);
1431 	return (0);
1432 }
1433 
1434 
1435 /*
1436  * Write to a connection w/ timeout
1437  */
1438 ssize_t
1439 fetch_write(conn_t *conn, const char *buf, size_t len)
1440 {
1441 	struct iovec iov;
1442 
1443 	iov.iov_base = __DECONST(char *, buf);
1444 	iov.iov_len = len;
1445 	return fetch_writev(conn, &iov, 1);
1446 }
1447 
1448 /*
1449  * Write a vector to a connection w/ timeout
1450  * Note: can modify the iovec.
1451  */
1452 ssize_t
1453 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1454 {
1455 	struct timeval now, timeout, delta;
1456 	struct pollfd pfd;
1457 	ssize_t wlen, total;
1458 	int deltams;
1459 
1460 	memset(&pfd, 0, sizeof pfd);
1461 	if (fetchTimeout) {
1462 		pfd.fd = conn->sd;
1463 		pfd.events = POLLOUT | POLLERR;
1464 		gettimeofday(&timeout, NULL);
1465 		timeout.tv_sec += fetchTimeout;
1466 	}
1467 
1468 	total = 0;
1469 	while (iovcnt > 0) {
1470 		while (fetchTimeout && pfd.revents == 0) {
1471 			gettimeofday(&now, NULL);
1472 			if (!timercmp(&timeout, &now, >)) {
1473 				errno = ETIMEDOUT;
1474 				fetch_syserr();
1475 				return (-1);
1476 			}
1477 			timersub(&timeout, &now, &delta);
1478 			deltams = delta.tv_sec * 1000 +
1479 			    delta.tv_usec / 1000;
1480 			errno = 0;
1481 			pfd.revents = 0;
1482 			if (poll(&pfd, 1, deltams) < 0) {
1483 				/* POSIX compliance */
1484 				if (errno == EAGAIN)
1485 					continue;
1486 				if (errno == EINTR && fetchRestartCalls)
1487 					continue;
1488 				return (-1);
1489 			}
1490 		}
1491 		errno = 0;
1492 #ifdef WITH_SSL
1493 		if (conn->ssl != NULL)
1494 			wlen = SSL_write(conn->ssl,
1495 			    iov->iov_base, iov->iov_len);
1496 		else
1497 #endif
1498 			wlen = writev(conn->sd, iov, iovcnt);
1499 		if (wlen == 0) {
1500 			/* we consider a short write a failure */
1501 			/* XXX perhaps we shouldn't in the SSL case */
1502 			errno = EPIPE;
1503 			fetch_syserr();
1504 			return (-1);
1505 		}
1506 		if (wlen < 0) {
1507 			if (errno == EINTR && fetchRestartCalls)
1508 				continue;
1509 			return (-1);
1510 		}
1511 		total += wlen;
1512 		while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1513 			wlen -= iov->iov_len;
1514 			iov++;
1515 			iovcnt--;
1516 		}
1517 		if (iovcnt > 0) {
1518 			iov->iov_len -= wlen;
1519 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1520 		}
1521 	}
1522 	return (total);
1523 }
1524 
1525 
1526 /*
1527  * Write a line of text to a connection w/ timeout
1528  */
1529 int
1530 fetch_putln(conn_t *conn, const char *str, size_t len)
1531 {
1532 	struct iovec iov[2];
1533 	int ret;
1534 
1535 	DEBUGF(">>> %s\n", str);
1536 	iov[0].iov_base = __DECONST(char *, str);
1537 	iov[0].iov_len = len;
1538 	iov[1].iov_base = __DECONST(char *, ENDL);
1539 	iov[1].iov_len = sizeof(ENDL);
1540 	if (len == 0)
1541 		ret = fetch_writev(conn, &iov[1], 1);
1542 	else
1543 		ret = fetch_writev(conn, iov, 2);
1544 	if (ret == -1)
1545 		return (-1);
1546 	return (0);
1547 }
1548 
1549 
1550 /*
1551  * Close connection
1552  */
1553 int
1554 fetch_close(conn_t *conn)
1555 {
1556 	int ret;
1557 
1558 	if (--conn->ref > 0)
1559 		return (0);
1560 #ifdef WITH_SSL
1561 	if (conn->ssl) {
1562 		SSL_shutdown(conn->ssl);
1563 		SSL_set_connect_state(conn->ssl);
1564 		SSL_free(conn->ssl);
1565 		conn->ssl = NULL;
1566 	}
1567 	if (conn->ssl_ctx) {
1568 		SSL_CTX_free(conn->ssl_ctx);
1569 		conn->ssl_ctx = NULL;
1570 	}
1571 	if (conn->ssl_cert) {
1572 		X509_free(conn->ssl_cert);
1573 		conn->ssl_cert = NULL;
1574 	}
1575 #endif
1576 	ret = close(conn->sd);
1577 	free(conn->buf);
1578 	free(conn);
1579 	return (ret);
1580 }
1581 
1582 
1583 /*** Directory-related utility functions *************************************/
1584 
1585 int
1586 fetch_add_entry(struct url_ent **p, int *size, int *len,
1587     const char *name, struct url_stat *us)
1588 {
1589 	struct url_ent *tmp;
1590 
1591 	if (*p == NULL) {
1592 		*size = 0;
1593 		*len = 0;
1594 	}
1595 
1596 	if (*len >= *size - 1) {
1597 		tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1598 		if (tmp == NULL) {
1599 			errno = ENOMEM;
1600 			fetch_syserr();
1601 			return (-1);
1602 		}
1603 		*size = (*size * 2 + 1);
1604 		*p = tmp;
1605 	}
1606 
1607 	tmp = *p + *len;
1608 	snprintf(tmp->name, PATH_MAX, "%s", name);
1609 	memcpy(&tmp->stat, us, sizeof(*us));
1610 
1611 	(*len)++;
1612 	(++tmp)->name[0] = 0;
1613 
1614 	return (0);
1615 }
1616 
1617 
1618 /*** Authentication-related utility functions ********************************/
1619 
1620 static const char *
1621 fetch_read_word(FILE *f)
1622 {
1623 	static char word[1024];
1624 
1625 	if (fscanf(f, " %1023s ", word) != 1)
1626 		return (NULL);
1627 	return (word);
1628 }
1629 
1630 static int
1631 fetch_netrc_open(void)
1632 {
1633 	struct passwd *pwd;
1634 	char fn[PATH_MAX];
1635 	const char *p;
1636 	int fd, serrno;
1637 
1638 	if ((p = getenv("NETRC")) != NULL) {
1639 		DEBUGF("NETRC=%s\n", p);
1640 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1641 			fetch_info("$NETRC specifies a file name "
1642 			    "longer than PATH_MAX");
1643 			return (-1);
1644 		}
1645 	} else {
1646 		if ((p = getenv("HOME")) == NULL) {
1647 			if ((pwd = getpwuid(getuid())) == NULL ||
1648 			    (p = pwd->pw_dir) == NULL)
1649 				return (-1);
1650 		}
1651 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1652 			return (-1);
1653 	}
1654 
1655 	if ((fd = open(fn, O_RDONLY)) < 0) {
1656 		serrno = errno;
1657 		DEBUGF("%s: %s\n", fn, strerror(serrno));
1658 		errno = serrno;
1659 	}
1660 	return (fd);
1661 }
1662 
1663 /*
1664  * Get authentication data for a URL from .netrc
1665  */
1666 int
1667 fetch_netrc_auth(struct url *url)
1668 {
1669 	const char *word;
1670 	int serrno;
1671 	FILE *f;
1672 
1673 	if (url->netrcfd < 0)
1674 		url->netrcfd = fetch_netrc_open();
1675 	if (url->netrcfd < 0)
1676 		return (-1);
1677 	if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1678 		serrno = errno;
1679 		DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1680 		close(url->netrcfd);
1681 		url->netrcfd = -1;
1682 		errno = serrno;
1683 		return (-1);
1684 	}
1685 	rewind(f);
1686 	DEBUGF("searching netrc for %s\n", url->host);
1687 	while ((word = fetch_read_word(f)) != NULL) {
1688 		if (strcmp(word, "default") == 0) {
1689 			DEBUGF("using default netrc settings\n");
1690 			break;
1691 		}
1692 		if (strcmp(word, "machine") == 0 &&
1693 		    (word = fetch_read_word(f)) != NULL &&
1694 		    strcasecmp(word, url->host) == 0) {
1695 			DEBUGF("using netrc settings for %s\n", word);
1696 			break;
1697 		}
1698 	}
1699 	if (word == NULL)
1700 		goto ferr;
1701 	while ((word = fetch_read_word(f)) != NULL) {
1702 		if (strcmp(word, "login") == 0) {
1703 			if ((word = fetch_read_word(f)) == NULL)
1704 				goto ferr;
1705 			if (snprintf(url->user, sizeof(url->user),
1706 				"%s", word) > (int)sizeof(url->user)) {
1707 				fetch_info("login name in .netrc is too long");
1708 				url->user[0] = '\0';
1709 			}
1710 		} else if (strcmp(word, "password") == 0) {
1711 			if ((word = fetch_read_word(f)) == NULL)
1712 				goto ferr;
1713 			if (snprintf(url->pwd, sizeof(url->pwd),
1714 				"%s", word) > (int)sizeof(url->pwd)) {
1715 				fetch_info("password in .netrc is too long");
1716 				url->pwd[0] = '\0';
1717 			}
1718 		} else if (strcmp(word, "account") == 0) {
1719 			if ((word = fetch_read_word(f)) == NULL)
1720 				goto ferr;
1721 			/* XXX not supported! */
1722 		} else {
1723 			break;
1724 		}
1725 	}
1726 	fclose(f);
1727 	url->netrcfd = -1;
1728 	return (0);
1729 ferr:
1730 	serrno = errno;
1731 	fclose(f);
1732 	url->netrcfd = -1;
1733 	errno = serrno;
1734 	return (-1);
1735 }
1736 
1737 /*
1738  * The no_proxy environment variable specifies a set of domains for
1739  * which the proxy should not be consulted; the contents is a comma-,
1740  * or space-separated list of domain names.  A single asterisk will
1741  * override all proxy variables and no transactions will be proxied
1742  * (for compatibility with lynx and curl, see the discussion at
1743  * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1744  */
1745 int
1746 fetch_no_proxy_match(const char *host)
1747 {
1748 	const char *no_proxy, *p, *q;
1749 	size_t h_len, d_len;
1750 
1751 	if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1752 	    (no_proxy = getenv("no_proxy")) == NULL)
1753 		return (0);
1754 
1755 	/* asterisk matches any hostname */
1756 	if (strcmp(no_proxy, "*") == 0)
1757 		return (1);
1758 
1759 	h_len = strlen(host);
1760 	p = no_proxy;
1761 	do {
1762 		/* position p at the beginning of a domain suffix */
1763 		while (*p == ',' || isspace((unsigned char)*p))
1764 			p++;
1765 
1766 		/* position q at the first separator character */
1767 		for (q = p; *q; ++q)
1768 			if (*q == ',' || isspace((unsigned char)*q))
1769 				break;
1770 
1771 		d_len = q - p;
1772 		if (d_len > 0 && h_len >= d_len &&
1773 		    strncasecmp(host + h_len - d_len,
1774 			p, d_len) == 0) {
1775 			/* domain name matches */
1776 			return (1);
1777 		}
1778 
1779 		p = q + 1;
1780 	} while (*q);
1781 
1782 	return (0);
1783 }
1784