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 /* Maximum length of a line, newline included, for fetch_getln() */
61 #define FETCH_LINE_MAX 65536
62
63 /*** Local data **************************************************************/
64
65 /*
66 * Error messages for resolver errors
67 */
68 static struct fetcherr netdb_errlist[] = {
69 #ifdef EAI_ADDRFAMILY
70 { EAI_ADDRFAMILY, FETCH_RESOLV, "Address family for host not supported" },
71 #endif
72 #ifdef EAI_NODATA
73 { EAI_NODATA, FETCH_RESOLV, "No address for host" },
74 #endif
75 { EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" },
76 { EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" },
77 { EAI_NONAME, FETCH_RESOLV, "Host does not resolve" },
78 { -1, FETCH_UNKNOWN, "Unknown resolver error" }
79 };
80
81 /*
82 * SOCKS5 error enumerations
83 */
84 enum SOCKS5_ERR {
85 /* Protocol errors */
86 SOCKS5_ERR_SELECTION,
87 SOCKS5_ERR_READ_METHOD,
88 SOCKS5_ERR_VER5_ONLY,
89 SOCKS5_ERR_NOMETHODS,
90 SOCKS5_ERR_NOTIMPLEMENTED,
91 SOCKS5_ERR_HOSTNAME_SIZE,
92 SOCKS5_ERR_REQUEST,
93 SOCKS5_ERR_REPLY,
94 SOCKS5_ERR_NON_VER5_RESP,
95 SOCKS5_ERR_GENERAL,
96 SOCKS5_ERR_NOT_ALLOWED,
97 SOCKS5_ERR_NET_UNREACHABLE,
98 SOCKS5_ERR_HOST_UNREACHABLE,
99 SOCKS5_ERR_CONN_REFUSED,
100 SOCKS5_ERR_TTL_EXPIRED,
101 SOCKS5_ERR_COM_UNSUPPORTED,
102 SOCKS5_ERR_ADDR_UNSUPPORTED,
103 SOCKS5_ERR_UNSPECIFIED,
104 /* Configuration errors */
105 SOCKS5_ERR_BAD_HOST,
106 SOCKS5_ERR_BAD_PROXY_FORMAT,
107 SOCKS5_ERR_BAD_PORT
108 };
109
110 /*
111 * Error messages for SOCKS5 errors
112 */
113 static struct fetcherr socks5_errlist[] = {
114 /* SOCKS5 protocol errors */
115 { SOCKS5_ERR_SELECTION, FETCH_ABORT, "SOCKS5: Failed to send selection method" },
116 { SOCKS5_ERR_READ_METHOD, FETCH_ABORT, "SOCKS5: Failed to read method" },
117 { SOCKS5_ERR_VER5_ONLY, FETCH_PROTO, "SOCKS5: Only version 5 is implemented" },
118 { SOCKS5_ERR_NOMETHODS, FETCH_PROTO, "SOCKS5: No acceptable methods" },
119 { SOCKS5_ERR_NOTIMPLEMENTED, FETCH_PROTO, "SOCKS5: Method currently not implemented" },
120 { SOCKS5_ERR_HOSTNAME_SIZE, FETCH_PROTO, "SOCKS5: Hostname size is above 256 bytes" },
121 { SOCKS5_ERR_REQUEST, FETCH_PROTO, "SOCKS5: Failed to request" },
122 { SOCKS5_ERR_REPLY, FETCH_PROTO, "SOCKS5: Failed to receive reply" },
123 { SOCKS5_ERR_NON_VER5_RESP, FETCH_PROTO, "SOCKS5: Server responded with a non-version 5 response" },
124 { SOCKS5_ERR_GENERAL, FETCH_ABORT, "SOCKS5: General server failure" },
125 { SOCKS5_ERR_NOT_ALLOWED, FETCH_AUTH, "SOCKS5: Connection not allowed by ruleset" },
126 { SOCKS5_ERR_NET_UNREACHABLE, FETCH_NETWORK, "SOCKS5: Network unreachable" },
127 { SOCKS5_ERR_HOST_UNREACHABLE, FETCH_ABORT, "SOCKS5: Host unreachable" },
128 { SOCKS5_ERR_CONN_REFUSED, FETCH_ABORT, "SOCKS5: Connection refused" },
129 { SOCKS5_ERR_TTL_EXPIRED, FETCH_TIMEOUT, "SOCKS5: TTL expired" },
130 { SOCKS5_ERR_COM_UNSUPPORTED, FETCH_PROTO, "SOCKS5: Command not supported" },
131 { SOCKS5_ERR_ADDR_UNSUPPORTED, FETCH_ABORT, "SOCKS5: Address type not supported" },
132 { SOCKS5_ERR_UNSPECIFIED, FETCH_UNKNOWN, "SOCKS5: Unspecified error" },
133 /* Configuration error */
134 { SOCKS5_ERR_BAD_HOST, FETCH_ABORT, "SOCKS5: Bad proxy host" },
135 { SOCKS5_ERR_BAD_PROXY_FORMAT, FETCH_ABORT, "SOCKS5: Bad proxy format" },
136 { SOCKS5_ERR_BAD_PORT, FETCH_ABORT, "SOCKS5: Bad port" }
137 };
138
139 /* End-of-Line */
140 static const char ENDL[2] = { '\r', '\n' };
141
142
143 /*** Error-reporting functions ***********************************************/
144
145 /*
146 * Map error code to string
147 */
148 static struct fetcherr *
fetch_finderr(struct fetcherr * p,int e)149 fetch_finderr(struct fetcherr *p, int e)
150 {
151 while (p->num != -1 && p->num != e)
152 p++;
153 return (p);
154 }
155
156 /*
157 * Set error code
158 */
159 void
fetch_seterr(struct fetcherr * p,int e)160 fetch_seterr(struct fetcherr *p, int e)
161 {
162 p = fetch_finderr(p, e);
163 fetchLastErrCode = p->cat;
164 snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
165 }
166
167 /*
168 * Set error code according to errno
169 */
170 void
fetch_syserr(void)171 fetch_syserr(void)
172 {
173 switch (errno) {
174 case 0:
175 fetchLastErrCode = FETCH_OK;
176 break;
177 case EPERM:
178 case EACCES:
179 case EROFS:
180 case EAUTH:
181 case ENEEDAUTH:
182 fetchLastErrCode = FETCH_AUTH;
183 break;
184 case ENOENT:
185 case EISDIR: /* XXX */
186 fetchLastErrCode = FETCH_UNAVAIL;
187 break;
188 case ENOMEM:
189 fetchLastErrCode = FETCH_MEMORY;
190 break;
191 case EBUSY:
192 case EAGAIN:
193 fetchLastErrCode = FETCH_TEMP;
194 break;
195 case EEXIST:
196 fetchLastErrCode = FETCH_EXISTS;
197 break;
198 case ENOSPC:
199 fetchLastErrCode = FETCH_FULL;
200 break;
201 case EADDRINUSE:
202 case EADDRNOTAVAIL:
203 case ENETDOWN:
204 case ENETUNREACH:
205 case ENETRESET:
206 case EHOSTUNREACH:
207 fetchLastErrCode = FETCH_NETWORK;
208 break;
209 case ECONNABORTED:
210 case ECONNRESET:
211 fetchLastErrCode = FETCH_ABORT;
212 break;
213 case ETIMEDOUT:
214 fetchLastErrCode = FETCH_TIMEOUT;
215 break;
216 case ECONNREFUSED:
217 case EHOSTDOWN:
218 fetchLastErrCode = FETCH_DOWN;
219 break;
220 default:
221 fetchLastErrCode = FETCH_UNKNOWN;
222 }
223 snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
224 }
225
226
227 /*
228 * Emit status message
229 */
230 void
fetch_info(const char * fmt,...)231 fetch_info(const char *fmt, ...)
232 {
233 va_list ap;
234 int serrno = errno;
235
236 va_start(ap, fmt);
237 vfprintf(stderr, fmt, ap);
238 va_end(ap);
239 fputc('\n', stderr);
240 errno = serrno;
241 }
242 #define fetch_verbose(...) \
243 do { if (verbose) fetch_info(__VA_ARGS__); } while (0)
244
245
246 /*** Network-related utility functions ***************************************/
247
248 /*
249 * Return the default port for a scheme
250 */
251 int
fetch_default_port(const char * scheme)252 fetch_default_port(const char *scheme)
253 {
254 struct servent *se;
255
256 if ((se = getservbyname(scheme, "tcp")) != NULL)
257 return (ntohs(se->s_port));
258 if (strcmp(scheme, SCHEME_FTP) == 0)
259 return (FTP_DEFAULT_PORT);
260 if (strcmp(scheme, SCHEME_HTTP) == 0)
261 return (HTTP_DEFAULT_PORT);
262 return (0);
263 }
264
265 /*
266 * Return the default proxy port for a scheme
267 */
268 int
fetch_default_proxy_port(const char * scheme)269 fetch_default_proxy_port(const char *scheme)
270 {
271 if (strcmp(scheme, SCHEME_FTP) == 0)
272 return (FTP_DEFAULT_PROXY_PORT);
273 if (strcmp(scheme, SCHEME_HTTP) == 0)
274 return (HTTP_DEFAULT_PROXY_PORT);
275 return (0);
276 }
277
278
279 /*
280 * Create a connection for an existing descriptor.
281 */
282 conn_t *
fetch_reopen(int sd)283 fetch_reopen(int sd)
284 {
285 conn_t *conn;
286 int flags;
287 int opt = 1;
288
289 /* allocate and fill connection structure */
290 if ((conn = calloc(1, sizeof(*conn))) == NULL)
291 return (NULL);
292 flags = fcntl(sd, F_GETFD);
293 if (flags != -1 && (flags & FD_CLOEXEC) == 0)
294 (void)fcntl(sd, F_SETFD, flags | FD_CLOEXEC);
295 flags = fcntl(sd, F_GETFL);
296 if (flags != -1 && (flags & O_NONBLOCK) == 0)
297 (void)fcntl(sd, F_SETFL, flags | O_NONBLOCK);
298 (void)setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
299 conn->sd = sd;
300 ++conn->ref;
301 return (conn);
302 }
303
304
305 /*
306 * Resolve an address
307 */
308 struct addrinfo *
fetch_resolve(const char * addr,int port,int af)309 fetch_resolve(const char *addr, int port, int af)
310 {
311 char hbuf[256], sbuf[8];
312 struct addrinfo hints, *res;
313 const char *hb, *he, *sep;
314 const char *host, *service;
315 int err, len;
316
317 /* first, check for a bracketed IPv6 address */
318 if (*addr == '[') {
319 hb = addr + 1;
320 if ((sep = strchr(hb, ']')) == NULL) {
321 errno = EINVAL;
322 goto syserr;
323 }
324 he = sep++;
325 } else {
326 hb = addr;
327 sep = strchrnul(hb, ':');
328 he = sep;
329 }
330
331 /* see if we need to copy the host name */
332 if (*he != '\0') {
333 len = snprintf(hbuf, sizeof(hbuf),
334 "%.*s", (int)(he - hb), hb);
335 if (len < 0)
336 goto syserr;
337 if (len >= (int)sizeof(hbuf)) {
338 errno = ENAMETOOLONG;
339 goto syserr;
340 }
341 host = hbuf;
342 } else {
343 host = hb;
344 }
345
346 /* was it followed by a service name? */
347 if (*sep == '\0' && port != 0) {
348 if (port < 1 || port > 65535) {
349 errno = EINVAL;
350 goto syserr;
351 }
352 if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
353 goto syserr;
354 service = sbuf;
355 } else if (*sep != '\0') {
356 service = sep + 1;
357 } else {
358 service = NULL;
359 }
360
361 /* resolve */
362 memset(&hints, 0, sizeof(hints));
363 hints.ai_family = af;
364 hints.ai_socktype = SOCK_STREAM;
365 hints.ai_flags = AI_ADDRCONFIG;
366 if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
367 netdb_seterr(err);
368 return (NULL);
369 }
370 return (res);
371 syserr:
372 fetch_syserr();
373 return (NULL);
374 }
375
376
377 /*
378 * Bind a socket to a specific local address
379 */
380 int
fetch_bind(int sd,int af,const char * addr)381 fetch_bind(int sd, int af, const char *addr)
382 {
383 struct addrinfo *cliai, *ai;
384 int err;
385
386 if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
387 return (-1);
388 for (ai = cliai; ai != NULL; ai = ai->ai_next)
389 if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
390 break;
391 if (err != 0)
392 fetch_syserr();
393 freeaddrinfo(cliai);
394 return (err == 0 ? 0 : -1);
395 }
396
397
398 /*
399 * SOCKS5 connection initiation, based on RFC 1928
400 * Default DNS resolution over SOCKS5
401 */
402 int
fetch_socks5_init(conn_t * conn,const char * host,int port,int verbose)403 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
404 {
405 /*
406 * Size is based on largest packet prefix (4 bytes) +
407 * Largest FQDN (256) + one byte size (1) +
408 * Port (2)
409 */
410 unsigned char buf[BUFF_SIZE];
411 unsigned char *ptr;
412 int ret = 1;
413
414 fetch_verbose("Initializing SOCKS5 connection: %s:%d", host, port);
415
416 /* Connection initialization */
417 ptr = buf;
418 *ptr++ = SOCKS_VERSION_5;
419 *ptr++ = SOCKS_CONNECTION;
420 *ptr++ = SOCKS_RSV;
421
422 if (fetch_write(conn, buf, 3) != 3) {
423 ret = SOCKS5_ERR_SELECTION;
424 goto fail;
425 }
426
427 /* Verify response from SOCKS5 server */
428 if (fetch_read(conn, buf, 2) != 2) {
429 ret = SOCKS5_ERR_READ_METHOD;
430 goto fail;
431 }
432
433 ptr = buf;
434 if (ptr[0] != SOCKS_VERSION_5) {
435 ret = SOCKS5_ERR_VER5_ONLY;
436 goto fail;
437 }
438 if (ptr[1] == SOCKS_NOMETHODS) {
439 ret = SOCKS5_ERR_NOMETHODS;
440 goto fail;
441 }
442 else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
443 ret = SOCKS5_ERR_NOTIMPLEMENTED;
444 goto fail;
445 }
446
447 /* Send Request */
448 *ptr++ = SOCKS_VERSION_5;
449 *ptr++ = SOCKS_CONNECTION;
450 *ptr++ = SOCKS_RSV;
451 /* Encode all targets as a hostname to avoid DNS leaks */
452 *ptr++ = SOCKS_ATYP_DOMAINNAME;
453 if (strlen(host) > FQDN_SIZE) {
454 ret = SOCKS5_ERR_HOSTNAME_SIZE;
455 goto fail;
456 }
457 *ptr++ = strlen(host);
458 memcpy(ptr, host, strlen(host));
459 ptr = ptr + strlen(host);
460
461 port = htons(port);
462 *ptr++ = port & 0x00ff;
463 *ptr++ = (port & 0xff00) >> 8;
464
465 if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
466 ret = SOCKS5_ERR_REQUEST;
467 goto fail;
468 }
469
470 /* BND.ADDR is variable length, read the largest on non-blocking socket */
471 if (!fetch_read(conn, buf, BUFF_SIZE)) {
472 ret = SOCKS5_ERR_REPLY;
473 goto fail;
474 }
475
476 ptr = buf;
477 if (*ptr++ != SOCKS_VERSION_5) {
478 ret = SOCKS5_ERR_NON_VER5_RESP;
479 goto fail;
480 }
481
482 switch (*ptr++) {
483 case SOCKS_SUCCESS:
484 break;
485 case SOCKS_GENERAL_FAILURE:
486 ret = SOCKS5_ERR_GENERAL;
487 goto fail;
488 case SOCKS_CONNECTION_NOT_ALLOWED:
489 ret = SOCKS5_ERR_NOT_ALLOWED;
490 goto fail;
491 case SOCKS_NETWORK_UNREACHABLE:
492 ret = SOCKS5_ERR_NET_UNREACHABLE;
493 goto fail;
494 case SOCKS_HOST_UNREACHABLE:
495 ret = SOCKS5_ERR_HOST_UNREACHABLE;
496 goto fail;
497 case SOCKS_CONNECTION_REFUSED:
498 ret = SOCKS5_ERR_CONN_REFUSED;
499 goto fail;
500 case SOCKS_TTL_EXPIRED:
501 ret = SOCKS5_ERR_TTL_EXPIRED;
502 goto fail;
503 case SOCKS_COMMAND_NOT_SUPPORTED:
504 ret = SOCKS5_ERR_COM_UNSUPPORTED;
505 goto fail;
506 case SOCKS_ADDRESS_NOT_SUPPORTED:
507 ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
508 goto fail;
509 default:
510 ret = SOCKS5_ERR_UNSPECIFIED;
511 goto fail;
512 }
513
514 return (ret);
515
516 fail:
517 socks5_seterr(ret);
518 return (0);
519 }
520
521 /*
522 * Perform SOCKS5 initialization
523 */
524 int
fetch_socks5_getenv(char ** host,int * port)525 fetch_socks5_getenv(char **host, int *port)
526 {
527 char *socks5env, *endptr, *ext;
528 const char *portDelim;
529 size_t slen;
530
531 portDelim = ":";
532 if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
533 *host = NULL;
534 *port = -1;
535 return (-1);
536 }
537
538 /*
539 * IPv6 addresses begin and end in brackets. Set the port delimiter
540 * accordingly and search for it so we can do appropriate validation.
541 */
542 if (socks5env[0] == '[')
543 portDelim = "]:";
544
545 slen = strlen(socks5env);
546 ext = strstr(socks5env, portDelim);
547 if (socks5env[0] == '[') {
548 if (socks5env[slen - 1] == ']') {
549 *host = strndup(socks5env, slen);
550 } else if (ext != NULL) {
551 *host = strndup(socks5env, ext - socks5env + 1);
552 } else {
553 socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
554 return (0);
555 }
556 } else {
557 *host = strndup(socks5env, ext - socks5env);
558 }
559
560 if (*host == NULL)
561 return (-1);
562 if (ext == NULL) {
563 *port = 1080; /* Default port as defined in RFC1928 */
564 } else {
565 ext += strlen(portDelim);
566 errno = 0;
567 *port = strtoimax(ext, (char **)&endptr, 10);
568 if (*endptr != '\0' || errno != 0 || *port < 0 ||
569 *port > 65535) {
570 free(*host);
571 *host = NULL;
572 socks5_seterr(SOCKS5_ERR_BAD_PORT);
573 return (0);
574 }
575 }
576
577 return (2);
578 }
579
580
581 /*
582 * Establish a TCP connection to the specified port on the specified host.
583 */
584 conn_t *
fetch_connect(const char * host,int port,int af,int verbose)585 fetch_connect(const char *host, int port, int af, int verbose)
586 {
587 struct timeval now, timeout, delta;
588 struct pollfd pfd;
589 struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
590 const char *bindaddr;
591 conn_t *conn = NULL;
592 int deltams, err = 0, serrno, sd = -1;
593 char *sockshost;
594 int socksport;
595
596 DEBUGF("---> %s:%d\n", host, port);
597
598 /*
599 * Check if SOCKS5_PROXY env variable is set. fetch_socks5_getenv
600 * will either set sockshost = NULL or allocate memory in all cases.
601 */
602 sockshost = NULL;
603 if (!fetch_socks5_getenv(&sockshost, &socksport))
604 goto fail;
605
606 /* Not using SOCKS5 proxy */
607 if (sockshost == NULL) {
608 /* resolve server address */
609 fetch_verbose("resolving server address: %s:%d", host, port);
610 if ((sais = fetch_resolve(host, port, af)) == NULL)
611 goto fail;
612
613 /* resolve client address */
614 bindaddr = getenv("FETCH_BIND_ADDRESS");
615 if (bindaddr != NULL && *bindaddr != '\0') {
616 fetch_verbose("resolving client address: %s", bindaddr);
617 if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
618 goto fail;
619 }
620 } else {
621 /* resolve socks5 proxy address */
622 fetch_verbose("resolving SOCKS5 server address: %s:%d",
623 sockshost, socksport);
624 if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
625 socks5_seterr(SOCKS5_ERR_BAD_HOST);
626 goto fail;
627 }
628 }
629
630 /* try each server address in turn */
631 for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
632 /* start the clock */
633 if (fetchTimeout > 0) {
634 gettimeofday(&timeout, NULL);
635 timeout.tv_sec += fetchTimeout;
636 }
637
638 /* open socket */
639 if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0) {
640 err = -1;
641 if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT)
642 continue;
643 goto syserr;
644 }
645
646 /* attempt to bind to client address */
647 for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
648 if (cai->ai_family != sai->ai_family)
649 continue;
650 if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
651 break;
652 }
653 if (err != 0) {
654 fetch_verbose("failed to bind to %s", bindaddr);
655 goto syserr;
656 }
657
658 /* make the socket non-blocking */
659 (void)fcntl(sd, F_SETFL, O_NONBLOCK);
660
661 /* attempt to connect to server address */
662 if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
663 break;
664 if (errno != EINPROGRESS)
665 goto next;
666
667 /* wait for connection */
668 for (;;) {
669 deltams = INFTIM;
670 pfd.fd = sd;
671 pfd.events = POLLOUT;
672
673 /* check the clock */
674 if (fetchTimeout > 0) {
675 gettimeofday(&now, NULL);
676 if (!timercmp(&timeout, &now, >)) {
677 errno = ETIMEDOUT;
678 err = -1;
679 goto next;
680 }
681 timersub(&timeout, &now, &delta);
682 deltams = delta.tv_sec * 1000 +
683 delta.tv_usec / 1000;
684 }
685 /* wait for something to happen */
686 if ((err = poll(&pfd, 1, deltams)) > 0)
687 break;
688 if (err == 0)
689 continue;
690 if (errno != EINTR)
691 goto syserr;
692 if (!fetchRestartCalls)
693 break;
694 }
695
696 /* check the outcome */
697 if (err > 0) {
698 if (pfd.revents == POLLOUT) {
699 /* connection established */
700 err = 0;
701 break;
702 }
703 /* we don't know the actual reason */
704 errno = ECONNREFUSED;
705 }
706 next:
707 /* clean up before next attempt */
708 serrno = errno;
709 close(sd);
710 sd = -1;
711 errno = serrno;
712 }
713
714 /* all attempts failed */
715 if (err != 0) {
716 if (sockshost != NULL) {
717 fetch_verbose("failed to connect to SOCKS5 server %s:%d",
718 sockshost, socksport);
719 socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
720 goto fail;
721 }
722 fetch_verbose("failed to connect to %s:%d", host, port);
723 goto syserr;
724 }
725
726 if ((conn = fetch_reopen(sd)) == NULL)
727 goto syserr;
728
729 if (sockshost != NULL) {
730 if (!fetch_socks5_init(conn, host, port, verbose))
731 goto fail;
732 free(sockshost);
733 }
734 if (cais != NULL)
735 freeaddrinfo(cais);
736 if (sais != NULL)
737 freeaddrinfo(sais);
738 return (conn);
739 syserr:
740 fetch_syserr();
741 fail:
742 if (sockshost != NULL)
743 free(sockshost);
744 /* Fully close if it was opened; otherwise just don't leak the fd. */
745 if (conn != NULL)
746 fetch_close(conn);
747 else if (sd >= 0)
748 close(sd);
749 if (cais != NULL)
750 freeaddrinfo(cais);
751 if (sais != NULL)
752 freeaddrinfo(sais);
753 return (NULL);
754 }
755
756 #ifdef WITH_SSL
757 /*
758 * Convert characters A-Z to lowercase (intentionally avoid any locale
759 * specific conversions).
760 */
761 static char
fetch_ssl_tolower(char in)762 fetch_ssl_tolower(char in)
763 {
764 if (in >= 'A' && in <= 'Z')
765 return (in + 32);
766 else
767 return (in);
768 }
769
770 /*
771 * isalpha implementation that intentionally avoids any locale specific
772 * conversions.
773 */
774 static int
fetch_ssl_isalpha(char in)775 fetch_ssl_isalpha(char in)
776 {
777 return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
778 }
779
780 /*
781 * Check if passed hostnames a and b are equal.
782 */
783 static int
fetch_ssl_hname_equal(const char * a,size_t alen,const char * b,size_t blen)784 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
785 size_t blen)
786 {
787 size_t i;
788
789 if (alen != blen)
790 return (0);
791 for (i = 0; i < alen; ++i) {
792 if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
793 return (0);
794 }
795 return (1);
796 }
797
798 /*
799 * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
800 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
801 * numeric characters. Double hyphens (like they're found in IDN a-labels
802 * 'xn--') are not allowed. Empty labels are invalid.
803 */
804 static int
fetch_ssl_is_trad_domain_label(const char * l,size_t len,int wcok)805 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
806 {
807 size_t i;
808
809 if (!len || l[0] == '-' || l[len-1] == '-')
810 return (0);
811 for (i = 0; i < len; ++i) {
812 if (!isdigit(l[i]) &&
813 !fetch_ssl_isalpha(l[i]) &&
814 !(l[i] == '*' && wcok) &&
815 !(l[i] == '-' && l[i - 1] != '-'))
816 return (0);
817 }
818 return (1);
819 }
820
821 /*
822 * Check if host name consists only of numbers. This might indicate an IP
823 * address, which is not a good idea for CN wildcard comparison.
824 */
825 static int
fetch_ssl_hname_is_only_numbers(const char * hostname,size_t len)826 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
827 {
828 size_t i;
829
830 for (i = 0; i < len; ++i) {
831 if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
832 hostname[i] == '.'))
833 return (0);
834 }
835 return (1);
836 }
837
838 /*
839 * Check if the host name h passed matches the pattern passed in m which
840 * is usually part of subjectAltName or CN of a certificate presented to
841 * the client. This includes wildcard matching. The algorithm is based on
842 * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
843 */
844 static int
fetch_ssl_hname_match(const char * h,size_t hlen,const char * m,size_t mlen)845 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
846 size_t mlen)
847 {
848 int delta, hdotidx, mdot1idx, wcidx;
849 const char *hdot, *mdot1, *mdot2;
850 const char *wc; /* wildcard */
851
852 if (!(h && *h && m && *m))
853 return (0);
854 if ((wc = strnstr(m, "*", mlen)) == NULL)
855 return (fetch_ssl_hname_equal(h, hlen, m, mlen));
856 wcidx = wc - m;
857 /* hostname should not be just dots and numbers */
858 if (fetch_ssl_hname_is_only_numbers(h, hlen))
859 return (0);
860 /* only one wildcard allowed in pattern */
861 if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
862 return (0);
863 /*
864 * there must be at least two more domain labels and
865 * wildcard has to be in the leftmost label (RFC6125)
866 */
867 mdot1 = strnstr(m, ".", mlen);
868 if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
869 return (0);
870 mdot1idx = mdot1 - m;
871 mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
872 if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
873 return (0);
874 /* hostname must contain a dot and not be the 1st char */
875 hdot = strnstr(h, ".", hlen);
876 if (hdot == NULL || hdot == h)
877 return (0);
878 hdotidx = hdot - h;
879 /*
880 * host part of hostname must be at least as long as
881 * pattern it's supposed to match
882 */
883 if (hdotidx < mdot1idx)
884 return (0);
885 /*
886 * don't allow wildcards in non-traditional domain names
887 * (IDN, A-label, U-label...)
888 */
889 if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
890 !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
891 return (0);
892 /* match domain part (part after first dot) */
893 if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
894 mlen - mdot1idx))
895 return (0);
896 /* match part left of wildcard */
897 if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
898 return (0);
899 /* match part right of wildcard */
900 delta = mdot1idx - wcidx - 1;
901 if (!fetch_ssl_hname_equal(hdot - delta, delta,
902 mdot1 - delta, delta))
903 return (0);
904 /* all tests succeeded, it's a match */
905 return (1);
906 }
907
908 /*
909 * Get numeric host address info - returns NULL if host was not an IP
910 * address. The caller is responsible for deallocation using
911 * freeaddrinfo(3).
912 */
913 static struct addrinfo *
fetch_ssl_get_numeric_addrinfo(const char * hostname,size_t len)914 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
915 {
916 struct addrinfo hints, *res;
917 char *host;
918
919 host = (char *)malloc(len + 1);
920 memcpy(host, hostname, len);
921 host[len] = '\0';
922 memset(&hints, 0, sizeof(hints));
923 hints.ai_family = PF_UNSPEC;
924 hints.ai_socktype = SOCK_STREAM;
925 hints.ai_protocol = 0;
926 hints.ai_flags = AI_NUMERICHOST;
927 /* port is not relevant for this purpose */
928 if (getaddrinfo(host, "443", &hints, &res) != 0)
929 res = NULL;
930 free(host);
931 return res;
932 }
933
934 /*
935 * Compare ip address in addrinfo with address passes.
936 */
937 static int
fetch_ssl_ipaddr_match_bin(const struct addrinfo * lhost,const char * rhost,size_t rhostlen)938 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
939 size_t rhostlen)
940 {
941 const void *left;
942
943 if (lhost->ai_family == AF_INET && rhostlen == 4) {
944 left = (void *)&((struct sockaddr_in*)(void *)
945 lhost->ai_addr)->sin_addr.s_addr;
946 #ifdef INET6
947 } else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
948 left = (void *)&((struct sockaddr_in6 *)(void *)
949 lhost->ai_addr)->sin6_addr;
950 #endif
951 } else
952 return (0);
953 return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
954 }
955
956 /*
957 * Compare ip address in addrinfo with host passed. If host is not an IP
958 * address, comparison will fail.
959 */
960 static int
fetch_ssl_ipaddr_match(const struct addrinfo * laddr,const char * r,size_t rlen)961 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
962 size_t rlen)
963 {
964 struct addrinfo *raddr;
965 int ret;
966 char *rip;
967
968 ret = 0;
969 if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
970 return 0; /* not a numeric host */
971
972 if (laddr->ai_family == raddr->ai_family) {
973 if (laddr->ai_family == AF_INET) {
974 rip = (char *)&((struct sockaddr_in *)(void *)
975 raddr->ai_addr)->sin_addr.s_addr;
976 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
977 #ifdef INET6
978 } else if (laddr->ai_family == AF_INET6) {
979 rip = (char *)&((struct sockaddr_in6 *)(void *)
980 raddr->ai_addr)->sin6_addr;
981 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
982 #endif
983 }
984
985 }
986 freeaddrinfo(raddr);
987 return (ret);
988 }
989
990 /*
991 * Verify server certificate by subjectAltName.
992 */
993 static int
fetch_ssl_verify_altname(STACK_OF (GENERAL_NAME)* altnames,const char * host,struct addrinfo * ip)994 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
995 const char *host, struct addrinfo *ip)
996 {
997 const GENERAL_NAME *name;
998 size_t nslen;
999 int i;
1000 const char *ns;
1001
1002 for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
1003 name = sk_GENERAL_NAME_value(altnames, i);
1004 ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
1005 nslen = (size_t)ASN1_STRING_length(name->d.ia5);
1006
1007 if (name->type == GEN_DNS && ip == NULL &&
1008 fetch_ssl_hname_match(host, strlen(host), ns, nslen))
1009 return (1);
1010 else if (name->type == GEN_IPADD && ip != NULL &&
1011 fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
1012 return (1);
1013 }
1014 return (0);
1015 }
1016
1017 /*
1018 * Verify server certificate by CN.
1019 */
1020 static int
fetch_ssl_verify_cn(X509_NAME * subject,const char * host,struct addrinfo * ip)1021 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
1022 struct addrinfo *ip)
1023 {
1024 ASN1_STRING *namedata;
1025 X509_NAME_ENTRY *nameentry;
1026 int cnlen, lastpos, loc, ret;
1027 unsigned char *cn;
1028
1029 ret = 0;
1030 lastpos = -1;
1031 loc = -1;
1032 cn = NULL;
1033 /* get most specific CN (last entry in list) and compare */
1034 while ((lastpos = X509_NAME_get_index_by_NID(subject,
1035 NID_commonName, lastpos)) != -1)
1036 loc = lastpos;
1037
1038 if (loc > -1) {
1039 nameentry = X509_NAME_get_entry(subject, loc);
1040 namedata = X509_NAME_ENTRY_get_data(nameentry);
1041 cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
1042 if (ip == NULL &&
1043 fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
1044 ret = 1;
1045 else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
1046 ret = 1;
1047 OPENSSL_free(cn);
1048 }
1049 return (ret);
1050 }
1051
1052 /*
1053 * Verify that server certificate subjectAltName/CN matches
1054 * hostname. First check, if there are alternative subject names. If yes,
1055 * those have to match. Only if those don't exist it falls back to
1056 * checking the subject's CN.
1057 */
1058 static int
fetch_ssl_verify_hname(X509 * cert,const char * host)1059 fetch_ssl_verify_hname(X509 *cert, const char *host)
1060 {
1061 struct addrinfo *ip;
1062 STACK_OF(GENERAL_NAME) *altnames;
1063 X509_NAME *subject;
1064 int ret;
1065
1066 ret = 0;
1067 ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1068 altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1069 NULL, NULL);
1070
1071 if (altnames != NULL) {
1072 ret = fetch_ssl_verify_altname(altnames, host, ip);
1073 } else {
1074 subject = X509_get_subject_name(cert);
1075 if (subject != NULL)
1076 ret = fetch_ssl_verify_cn(subject, host, ip);
1077 }
1078
1079 if (ip != NULL)
1080 freeaddrinfo(ip);
1081 if (altnames != NULL)
1082 GENERAL_NAMES_free(altnames);
1083 return (ret);
1084 }
1085
1086 /*
1087 * Configure transport security layer based on environment.
1088 */
1089 static void
fetch_ssl_setup_transport_layer(SSL_CTX * ctx,int verbose)1090 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1091 {
1092 long ssl_ctx_options;
1093
1094 ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1095 if (getenv("SSL_NO_TLS1") != NULL)
1096 ssl_ctx_options |= SSL_OP_NO_TLSv1;
1097 if (getenv("SSL_NO_TLS1_1") != NULL)
1098 ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1099 if (getenv("SSL_NO_TLS1_2") != NULL)
1100 ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1101 if (getenv("SSL_NO_TLS1_3") != NULL)
1102 ssl_ctx_options |= SSL_OP_NO_TLSv1_3;
1103 fetch_verbose("SSL options: %lx", ssl_ctx_options);
1104 SSL_CTX_set_options(ctx, ssl_ctx_options);
1105 }
1106
1107
1108 /*
1109 * Configure peer verification based on environment.
1110 */
1111 static int
fetch_ssl_setup_peer_verification(SSL_CTX * ctx,int verbose)1112 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1113 {
1114 X509_LOOKUP *crl_lookup;
1115 X509_STORE *crl_store;
1116 const char *ca_cert_file, *ca_cert_path, *crl_file;
1117
1118 if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1119 ca_cert_file = getenv("SSL_CA_CERT_FILE");
1120 ca_cert_path = getenv("SSL_CA_CERT_PATH");
1121 if (verbose) {
1122 fetch_info("Peer verification enabled");
1123 if (ca_cert_file != NULL)
1124 fetch_info("Using CA cert file: %s",
1125 ca_cert_file);
1126 if (ca_cert_path != NULL)
1127 fetch_info("Using CA cert path: %s",
1128 ca_cert_path);
1129 if (ca_cert_file == NULL && ca_cert_path == NULL)
1130 fetch_info("Using OpenSSL default "
1131 "CA cert file and path");
1132 }
1133 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1134 fetch_ssl_cb_verify_crt);
1135 if (ca_cert_file != NULL || ca_cert_path != NULL)
1136 SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1137 ca_cert_path);
1138 else
1139 SSL_CTX_set_default_verify_paths(ctx);
1140 if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1141 fetch_verbose("Using CRL file: %s", crl_file);
1142 crl_store = SSL_CTX_get_cert_store(ctx);
1143 crl_lookup = X509_STORE_add_lookup(crl_store,
1144 X509_LOOKUP_file());
1145 if (crl_lookup == NULL ||
1146 !X509_load_crl_file(crl_lookup, crl_file,
1147 X509_FILETYPE_PEM)) {
1148 fetch_info("Could not load CRL file %s",
1149 crl_file);
1150 return (0);
1151 }
1152 X509_STORE_set_flags(crl_store,
1153 X509_V_FLAG_CRL_CHECK |
1154 X509_V_FLAG_CRL_CHECK_ALL);
1155 }
1156 }
1157 return (1);
1158 }
1159
1160 /*
1161 * Configure client certificate based on environment.
1162 */
1163 static int
fetch_ssl_setup_client_certificate(SSL_CTX * ctx,int verbose)1164 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1165 {
1166 const char *client_cert_file, *client_key_file;
1167
1168 if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1169 client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1170 getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1171 fetch_verbose("Using client cert file: %s", client_cert_file);
1172 fetch_verbose("Using client key file: %s", client_key_file);
1173 if (SSL_CTX_use_certificate_chain_file(ctx,
1174 client_cert_file) != 1) {
1175 fetch_info("Could not load client certificate %s",
1176 client_cert_file);
1177 return (0);
1178 }
1179 if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1180 SSL_FILETYPE_PEM) != 1) {
1181 fetch_info("Could not load client key %s",
1182 client_key_file);
1183 return (0);
1184 }
1185 }
1186 return (1);
1187 }
1188
1189 /*
1190 * Callback for SSL certificate verification, this is called on server
1191 * cert verification. It takes no decision, but informs the user in case
1192 * verification failed.
1193 */
1194 int
fetch_ssl_cb_verify_crt(int verified,X509_STORE_CTX * ctx)1195 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1196 {
1197 X509 *crt;
1198 X509_NAME *name;
1199 char *str;
1200
1201 str = NULL;
1202 if (!verified) {
1203 if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1204 (name = X509_get_subject_name(crt)) != NULL)
1205 str = X509_NAME_oneline(name, 0, 0);
1206 fetch_info("Certificate verification failed for %s",
1207 str != NULL ? str : "no relevant certificate");
1208 OPENSSL_free(str);
1209 }
1210 return (verified);
1211 }
1212
1213 #endif
1214
1215 /*
1216 * Enable SSL on a connection.
1217 */
1218 int
fetch_ssl(conn_t * conn,const struct url * URL,int verbose)1219 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1220 {
1221 #ifdef WITH_SSL
1222 int ret, ssl_err;
1223 X509_NAME *name;
1224 char *str;
1225
1226 if ((conn->ssl_ctx = SSL_CTX_new(TLS_client_method())) == NULL) {
1227 fetch_info("SSL context creation failed");
1228 ERR_print_errors_fp(stderr);
1229 return (-1);
1230 }
1231 SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1232
1233 fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1234 if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1235 return (-1);
1236 if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1237 return (-1);
1238
1239 conn->ssl = SSL_new(conn->ssl_ctx);
1240 if (conn->ssl == NULL) {
1241 fetch_info("SSL connection creation failed");
1242 ERR_print_errors_fp(stderr);
1243 return (-1);
1244 }
1245 SSL_set_fd(conn->ssl, conn->sd);
1246
1247 #if !defined(OPENSSL_NO_TLSEXT)
1248 if (!SSL_set_tlsext_host_name(conn->ssl, __DECONST(char *, URL->host))) {
1249 fetch_info("Failed to set TLS server name indication for host %s",
1250 URL->host);
1251 return (-1);
1252 }
1253 #endif
1254 while ((ret = SSL_connect(conn->ssl)) == -1) {
1255 ssl_err = SSL_get_error(conn->ssl, ret);
1256 if (ssl_err != SSL_ERROR_WANT_READ &&
1257 ssl_err != SSL_ERROR_WANT_WRITE) {
1258 ERR_print_errors_fp(stderr);
1259 return (-1);
1260 }
1261 }
1262 conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1263
1264 if (conn->ssl_cert == NULL) {
1265 fetch_info("No server SSL certificate");
1266 return (-1);
1267 }
1268
1269 if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1270 fetch_verbose("Verify hostname");
1271 if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1272 fetch_info("SSL certificate subject does not match host %s",
1273 URL->host);
1274 return (-1);
1275 }
1276 }
1277
1278 if (verbose) {
1279 fetch_info("%s connection established using %s",
1280 SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1281 name = X509_get_subject_name(conn->ssl_cert);
1282 str = X509_NAME_oneline(name, 0, 0);
1283 fetch_info("Certificate subject: %s", str);
1284 OPENSSL_free(str);
1285 name = X509_get_issuer_name(conn->ssl_cert);
1286 str = X509_NAME_oneline(name, 0, 0);
1287 fetch_info("Certificate issuer: %s", str);
1288 OPENSSL_free(str);
1289 }
1290
1291 return (0);
1292 #else
1293 (void)conn;
1294 (void)verbose;
1295 (void)URL;
1296 fetch_info("SSL support disabled");
1297 return (-1);
1298 #endif
1299 }
1300
1301 #ifdef WITH_SSL
1302 static ssize_t
fetch_ssl_read(SSL * ssl,void * buf,size_t len)1303 fetch_ssl_read(SSL *ssl, void *buf, size_t len)
1304 {
1305 ssize_t rlen;
1306 int ssl_err;
1307
1308 rlen = SSL_read(ssl, buf, len);
1309 if (rlen < 0) {
1310 ssl_err = SSL_get_error(ssl, rlen);
1311 switch (ssl_err) {
1312 case SSL_ERROR_ZERO_RETURN:
1313 return (0);
1314 case SSL_ERROR_WANT_READ:
1315 errno = EAGAIN;
1316 return (-1);
1317 case SSL_ERROR_SYSCALL:
1318 return (-1);
1319 default:
1320 errno = EPROTO;
1321 return (-1);
1322 }
1323 }
1324 return (rlen);
1325 }
1326
1327 static ssize_t
fetch_ssl_write(SSL * ssl,void * buf,size_t len)1328 fetch_ssl_write(SSL *ssl, void *buf, size_t len)
1329 {
1330 ssize_t wlen;
1331 int ssl_err;
1332
1333 wlen = SSL_write(ssl, buf, len);
1334 if (wlen < 0) {
1335 ssl_err = SSL_get_error(ssl, wlen);
1336 switch (ssl_err) {
1337 case SSL_ERROR_ZERO_RETURN:
1338 return (0);
1339 case SSL_ERROR_WANT_WRITE:
1340 errno = EAGAIN;
1341 return (-1);
1342 case SSL_ERROR_SYSCALL:
1343 return (-1);
1344 default:
1345 errno = EPROTO;
1346 return (-1);
1347 }
1348 }
1349 return (wlen);
1350 }
1351 #endif
1352
1353 /*
1354 * Read from a connection w/ timeout
1355 */
1356 ssize_t
fetch_read(conn_t * conn,void * buf,size_t len)1357 fetch_read(conn_t *conn, void *buf, size_t len)
1358 {
1359 struct timeval now, timeout, delta;
1360 struct pollfd pfd;
1361 ssize_t rlen, total;
1362 int deltams;
1363
1364 if (fetchTimeout > 0) {
1365 gettimeofday(&timeout, NULL);
1366 timeout.tv_sec += fetchTimeout;
1367 }
1368
1369 deltams = INFTIM;
1370 pfd.fd = conn->sd;
1371 pfd.events = POLLIN;
1372
1373 total = 0;
1374 for (;;) {
1375 /*
1376 * The socket is non-blocking. Instead of the canonical
1377 * poll() -> read(), we do the following:
1378 *
1379 * 1) call read() or SSL_read().
1380 * 2) if we received some data, return it.
1381 * 3) if read() or SSL_read() signaled EOF, return.
1382 * 4) if an error occurred, return -1.
1383 * 5) if we did not receive any data but we're not at EOF,
1384 * call poll().
1385 *
1386 * In the SSL case, this is necessary because if we
1387 * receive a close notification, we have to call
1388 * SSL_read() one additional time after we've read
1389 * everything we received.
1390 *
1391 * In the non-SSL case, it may improve performance (very
1392 * slightly) when reading small amounts of data.
1393 */
1394 #ifdef WITH_SSL
1395 if (conn->ssl != NULL)
1396 rlen = fetch_ssl_read(conn->ssl, buf, len);
1397 else
1398 #endif
1399 rlen = read(conn->sd, buf, len);
1400 if (rlen > 0) {
1401 /* something was read */
1402 total += rlen;
1403 len -= rlen;
1404 if (len == 0)
1405 break;
1406 /* a partial read is success */
1407 break;
1408 } else if (rlen == 0) {
1409 /* connection closed */
1410 break;
1411 } else if (errno != EAGAIN) {
1412 /* error */
1413 if (errno == EINTR && fetchRestartCalls)
1414 continue;
1415 fetch_syserr();
1416 break;
1417 }
1418 /* check what's left of our timeout */
1419 if (fetchTimeout > 0) {
1420 gettimeofday(&now, NULL);
1421 if (!timercmp(&timeout, &now, >)) {
1422 errno = ETIMEDOUT;
1423 fetch_syserr();
1424 return (-1);
1425 }
1426 timersub(&timeout, &now, &delta);
1427 deltams = delta.tv_sec * 1000 +
1428 delta.tv_usec / 1000;
1429 }
1430 /* wait for the socket to become readable */
1431 if (poll(&pfd, 1, deltams) < 0) {
1432 if (errno == EAGAIN)
1433 continue;
1434 if (errno == EINTR && fetchRestartCalls)
1435 continue;
1436 break;
1437 }
1438 }
1439 /* a partial read is success */
1440 if (rlen < 0 && total == 0)
1441 return (-1);
1442 return (total);
1443 }
1444
1445
1446 /*
1447 * Read a line of text from a connection w/ timeout
1448 */
1449 #define MIN_BUF_SIZE 1024
1450
1451 ssize_t
fetch_getln(conn_t * conn)1452 fetch_getln(conn_t *conn)
1453 {
1454 char *tmp;
1455 size_t tmpsize;
1456 ssize_t rlen;
1457
1458 /* allocate initial buffer */
1459 if (conn->buf == NULL) {
1460 if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL)
1461 goto fail;
1462 conn->line = conn->buf;
1463 conn->bufsize = MIN_BUF_SIZE;
1464 conn->buflen = 0;
1465 conn->pos = 0;
1466 }
1467
1468 /* look at the data we already have */
1469 if (conn->pos < conn->buflen) {
1470 conn->line = conn->buf + conn->pos;
1471 while (conn->pos < conn->buflen) {
1472 if (conn->buf[conn->pos++] == '\n')
1473 goto found;
1474 if (conn->buf + conn->pos - conn->line >=
1475 FETCH_LINE_MAX) {
1476 errno = EPROTO;
1477 goto fail;
1478 }
1479 }
1480 /* reset for the upcoming memmove() */
1481 conn->pos = conn->line - conn->buf;
1482 }
1483
1484 /* move residual data up */
1485 if (conn->buflen > 0) {
1486 if (conn->pos < conn->buflen) {
1487 memmove(conn->buf, conn->buf + conn->pos,
1488 conn->buflen - conn->pos);
1489 }
1490 conn->buflen -= conn->pos;
1491 conn->pos -= conn->pos;
1492 conn->line = conn->buf;
1493 }
1494
1495 for (;;) {
1496 /* read as much as we can right now */
1497 rlen = fetch_read(conn, conn->buf + conn->buflen,
1498 conn->bufsize - conn->buflen - 1);
1499 /* error */
1500 if (rlen < 0)
1501 goto fail;
1502 /* advance and terminate */
1503 conn->buflen += rlen;
1504 conn->buf[conn->buflen] = '\0';
1505 /* connection closed */
1506 if (rlen == 0)
1507 break;
1508 /* look for a newline */
1509 while (conn->pos < conn->buflen) {
1510 if (conn->buf[conn->pos++] == '\n')
1511 goto found;
1512 if (conn->pos >= FETCH_LINE_MAX) {
1513 errno = EPROTO;
1514 goto fail;
1515 }
1516 }
1517 /* do we need a bigger buffer? */
1518 if (conn->buflen > conn->bufsize / 2) {
1519 tmp = conn->buf;
1520 tmpsize = conn->bufsize * 2;
1521 if ((tmp = realloc(tmp, tmpsize)) == NULL)
1522 goto fail;
1523 conn->line = conn->buf = tmp;
1524 conn->bufsize = tmpsize;
1525 }
1526 }
1527 /* connection closed, return what's left */
1528 conn->pos = conn->buflen;
1529 found:
1530 conn->linelen = (conn->buf + conn->pos) - conn->line;
1531 if (conn->linelen > 0 && conn->line[conn->linelen - 1] == '\n')
1532 conn->line[--conn->linelen] = '\0';
1533 if (conn->linelen > 0 && conn->line[conn->linelen - 1] == '\r')
1534 conn->line[--conn->linelen] = '\0';
1535 DEBUGF("<<< %.*s\n", (int)conn->linelen, conn->line);
1536 return (conn->linelen);
1537 fail:
1538 conn->line = NULL;
1539 conn->linelen = 0;
1540 return (-1);
1541 }
1542
1543
1544 /*
1545 * Read from a connection, taking previously buffered data into account.
1546 */
1547 ssize_t
fetch_bufread(conn_t * conn,void * buf,size_t len)1548 fetch_bufread(conn_t *conn, void *buf, size_t len)
1549 {
1550 ssize_t rlen;
1551
1552 /* avoid overflow */
1553 if (len > SSIZE_MAX)
1554 len = SSIZE_MAX;
1555
1556 /* allocate initial buffer */
1557 if (conn->buf == NULL) {
1558 conn->bufsize = MIN_BUF_SIZE;
1559 while (conn->bufsize < len)
1560 conn->bufsize *= 2;
1561 if ((conn->buf = malloc(conn->bufsize)) == NULL)
1562 return (-1);
1563 conn->buflen = 0;
1564 conn->pos = 0;
1565 }
1566 conn->line = NULL;
1567 conn->linelen = 0;
1568
1569 /* return residual data first */
1570 if (conn->buflen > conn->pos) {
1571 if (len > conn->buflen - conn->pos)
1572 rlen = conn->buflen - conn->pos;
1573 else
1574 rlen = len;
1575 memcpy(buf, conn->buf + conn->pos, rlen);
1576 conn->pos += rlen;
1577 return (rlen);
1578 }
1579
1580 return (fetch_read(conn, buf, len));
1581 }
1582
1583
1584 /*
1585 * Write to a connection w/ timeout
1586 */
1587 ssize_t
fetch_write(conn_t * conn,const void * buf,size_t len)1588 fetch_write(conn_t *conn, const void *buf, size_t len)
1589 {
1590 struct iovec iov;
1591
1592 iov.iov_base = __DECONST(char *, buf);
1593 iov.iov_len = len;
1594 return (fetch_writev(conn, &iov, 1));
1595 }
1596
1597 /*
1598 * Write a vector to a connection w/ timeout
1599 * Note: can modify the iovec.
1600 */
1601 ssize_t
fetch_writev(conn_t * conn,struct iovec * iov,int iovcnt)1602 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1603 {
1604 struct timeval now, timeout, delta;
1605 struct pollfd pfd;
1606 ssize_t wlen, total;
1607 int deltams;
1608
1609 if (fetchTimeout > 0) {
1610 gettimeofday(&timeout, NULL);
1611 timeout.tv_sec += fetchTimeout;
1612 }
1613
1614 deltams = INFTIM;
1615 pfd.fd = conn->sd;
1616 pfd.events = POLLOUT;
1617
1618 total = 0;
1619 for (;;) {
1620 /*
1621 * The socket is non-blocking. Instead of the canonical
1622 * poll() -> write(), we do the following:
1623 *
1624 * 1) call write() or SSL_write().
1625 * 2) if we wrote everything, return success.
1626 * 3) if write() or SSL_write() signaled EOF before we
1627 * wrote everything, return -1.
1628 * 4) if an error occurred, return -1.
1629 * 5) if we did not write everything but we're not at EOF,
1630 * call poll().
1631 */
1632 #ifdef WITH_SSL
1633 if (conn->ssl != NULL) {
1634 wlen = fetch_ssl_write(conn->ssl,
1635 iov->iov_base, iov->iov_len);
1636 } else
1637 #endif
1638 wlen = writev(conn->sd, iov, iovcnt);
1639 if (wlen > 0) {
1640 /* something was written */
1641 total += wlen;
1642 /* skip iovs which were completely written */
1643 while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1644 wlen -= iov->iov_len;
1645 iov++;
1646 iovcnt--;
1647 }
1648 /* are we done? */
1649 if (iovcnt == 0)
1650 break;
1651 /* skip written portion of current iov */
1652 iov->iov_len -= wlen;
1653 iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1654 /* a partial write is incomplete */
1655 continue;
1656 } else if (wlen == 0) {
1657 /* connection closed */
1658 break;
1659 } else if (errno != EAGAIN) {
1660 /* error */
1661 if (errno == EINTR && fetchRestartCalls)
1662 continue;
1663 fetch_syserr();
1664 break;
1665 }
1666 /* check what's left of our timeout */
1667 if (fetchTimeout > 0) {
1668 gettimeofday(&now, NULL);
1669 if (!timercmp(&timeout, &now, >)) {
1670 errno = ETIMEDOUT;
1671 fetch_syserr();
1672 return (-1);
1673 }
1674 timersub(&timeout, &now, &delta);
1675 deltams = delta.tv_sec * 1000 +
1676 delta.tv_usec / 1000;
1677 }
1678 /* wait for the socket to become writeable */
1679 if (poll(&pfd, 1, deltams) < 0) {
1680 if (errno == EAGAIN)
1681 continue;
1682 if (errno == EINTR && fetchRestartCalls)
1683 continue;
1684 return (-1);
1685 }
1686 }
1687 /* a partial write is failure */
1688 if (iovcnt > 0)
1689 return (-1);
1690 return (total);
1691 }
1692
1693
1694 /*
1695 * Write a line of text to a connection w/ timeout
1696 */
1697 int
fetch_putln(conn_t * conn,const char * str,size_t len)1698 fetch_putln(conn_t *conn, const char *str, size_t len)
1699 {
1700 struct iovec iov[2];
1701 int ret;
1702
1703 DEBUGF(">>> %s\n", str);
1704 iov[0].iov_base = __DECONST(char *, str);
1705 iov[0].iov_len = len;
1706 iov[1].iov_base = __DECONST(char *, ENDL);
1707 iov[1].iov_len = sizeof(ENDL);
1708 if (len == 0)
1709 ret = fetch_writev(conn, &iov[1], 1);
1710 else
1711 ret = fetch_writev(conn, iov, 2);
1712 if (ret == -1)
1713 return (-1);
1714 return (0);
1715 }
1716
1717
1718 /*
1719 * Close connection
1720 */
1721 int
fetch_close(conn_t * conn)1722 fetch_close(conn_t *conn)
1723 {
1724 int ret;
1725
1726 if (--conn->ref > 0)
1727 return (0);
1728 #ifdef WITH_SSL
1729 if (conn->ssl) {
1730 SSL_shutdown(conn->ssl);
1731 SSL_set_connect_state(conn->ssl);
1732 SSL_free(conn->ssl);
1733 conn->ssl = NULL;
1734 }
1735 if (conn->ssl_ctx) {
1736 SSL_CTX_free(conn->ssl_ctx);
1737 conn->ssl_ctx = NULL;
1738 }
1739 if (conn->ssl_cert) {
1740 X509_free(conn->ssl_cert);
1741 conn->ssl_cert = NULL;
1742 }
1743 #endif
1744 ret = close(conn->sd);
1745 free(conn->buf);
1746 free(conn);
1747 return (ret);
1748 }
1749
1750
1751 /*** Directory-related utility functions *************************************/
1752
1753 int
fetch_add_entry(struct url_ent ** p,int * size,int * len,const char * name,struct url_stat * us)1754 fetch_add_entry(struct url_ent **p, int *size, int *len,
1755 const char *name, struct url_stat *us)
1756 {
1757 struct url_ent *tmp;
1758
1759 if (*p == NULL) {
1760 *size = 0;
1761 *len = 0;
1762 }
1763
1764 if (*len >= *size - 1) {
1765 tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1766 if (tmp == NULL) {
1767 errno = ENOMEM;
1768 fetch_syserr();
1769 return (-1);
1770 }
1771 *size = (*size * 2 + 1);
1772 *p = tmp;
1773 }
1774
1775 tmp = *p + *len;
1776 snprintf(tmp->name, PATH_MAX, "%s", name);
1777 memcpy(&tmp->stat, us, sizeof(*us));
1778
1779 (*len)++;
1780 (++tmp)->name[0] = 0;
1781
1782 return (0);
1783 }
1784
1785
1786 /*** Authentication-related utility functions ********************************/
1787
1788 static const char *
fetch_read_word(FILE * f)1789 fetch_read_word(FILE *f)
1790 {
1791 static char word[1024];
1792
1793 if (fscanf(f, " %1023s ", word) != 1)
1794 return (NULL);
1795 return (word);
1796 }
1797
1798 static int
fetch_netrc_open(void)1799 fetch_netrc_open(void)
1800 {
1801 struct passwd *pwd;
1802 char fn[PATH_MAX];
1803 const char *p;
1804 int fd, serrno;
1805
1806 if ((p = getenv("NETRC")) != NULL) {
1807 DEBUGF("NETRC=%s\n", p);
1808 if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1809 fetch_info("$NETRC specifies a file name "
1810 "longer than PATH_MAX");
1811 return (-1);
1812 }
1813 } else {
1814 if ((p = getenv("HOME")) == NULL) {
1815 if ((pwd = getpwuid(getuid())) == NULL ||
1816 (p = pwd->pw_dir) == NULL)
1817 return (-1);
1818 }
1819 if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1820 return (-1);
1821 }
1822
1823 if ((fd = open(fn, O_RDONLY)) < 0) {
1824 serrno = errno;
1825 DEBUGF("%s: %s\n", fn, strerror(serrno));
1826 errno = serrno;
1827 }
1828 return (fd);
1829 }
1830
1831 /*
1832 * Get authentication data for a URL from .netrc
1833 */
1834 int
fetch_netrc_auth(struct url * url)1835 fetch_netrc_auth(struct url *url)
1836 {
1837 const char *word;
1838 int serrno;
1839 FILE *f;
1840
1841 if (url->netrcfd < 0)
1842 url->netrcfd = fetch_netrc_open();
1843 if (url->netrcfd < 0)
1844 return (-1);
1845 if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1846 serrno = errno;
1847 DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1848 close(url->netrcfd);
1849 url->netrcfd = -1;
1850 errno = serrno;
1851 return (-1);
1852 }
1853 rewind(f);
1854 DEBUGF("searching netrc for %s\n", url->host);
1855 while ((word = fetch_read_word(f)) != NULL) {
1856 if (strcmp(word, "default") == 0) {
1857 DEBUGF("using default netrc settings\n");
1858 break;
1859 }
1860 if (strcmp(word, "machine") == 0 &&
1861 (word = fetch_read_word(f)) != NULL &&
1862 strcasecmp(word, url->host) == 0) {
1863 DEBUGF("using netrc settings for %s\n", word);
1864 break;
1865 }
1866 }
1867 if (word == NULL)
1868 goto ferr;
1869 while ((word = fetch_read_word(f)) != NULL) {
1870 if (strcmp(word, "login") == 0) {
1871 if ((word = fetch_read_word(f)) == NULL)
1872 goto ferr;
1873 if (snprintf(url->user, sizeof(url->user),
1874 "%s", word) > (int)sizeof(url->user)) {
1875 fetch_info("login name in .netrc is too long");
1876 url->user[0] = '\0';
1877 }
1878 } else if (strcmp(word, "password") == 0) {
1879 if ((word = fetch_read_word(f)) == NULL)
1880 goto ferr;
1881 if (snprintf(url->pwd, sizeof(url->pwd),
1882 "%s", word) > (int)sizeof(url->pwd)) {
1883 fetch_info("password in .netrc is too long");
1884 url->pwd[0] = '\0';
1885 }
1886 } else if (strcmp(word, "account") == 0) {
1887 if ((word = fetch_read_word(f)) == NULL)
1888 goto ferr;
1889 /* XXX not supported! */
1890 } else {
1891 break;
1892 }
1893 }
1894 fclose(f);
1895 url->netrcfd = -1;
1896 return (0);
1897 ferr:
1898 serrno = errno;
1899 fclose(f);
1900 url->netrcfd = -1;
1901 errno = serrno;
1902 return (-1);
1903 }
1904
1905 /*
1906 * The no_proxy environment variable specifies a set of domains for
1907 * which the proxy should not be consulted; the contents is a comma-,
1908 * or space-separated list of domain names. A single asterisk will
1909 * override all proxy variables and no transactions will be proxied
1910 * (for compatibility with lynx and curl, see the discussion at
1911 * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1912 */
1913 int
fetch_no_proxy_match(const char * host)1914 fetch_no_proxy_match(const char *host)
1915 {
1916 const char *no_proxy, *p, *q;
1917 size_t h_len, d_len;
1918
1919 if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1920 (no_proxy = getenv("no_proxy")) == NULL)
1921 return (0);
1922
1923 /* asterisk matches any hostname */
1924 if (strcmp(no_proxy, "*") == 0)
1925 return (1);
1926
1927 h_len = strlen(host);
1928 p = no_proxy;
1929 do {
1930 /* position p at the beginning of a domain suffix */
1931 while (*p == ',' || isspace((unsigned char)*p))
1932 p++;
1933
1934 /* position q at the first separator character */
1935 for (q = p; *q; ++q)
1936 if (*q == ',' || isspace((unsigned char)*q))
1937 break;
1938
1939 d_len = q - p;
1940 if (d_len > 0 && h_len >= d_len &&
1941 strncasecmp(host + h_len - d_len,
1942 p, d_len) == 0) {
1943 /* domain name matches */
1944 return (1);
1945 }
1946
1947 p = q + 1;
1948 } while (*q);
1949
1950 return (0);
1951 }
1952