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