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/cdefs.h>
33 #include <sys/param.h>
34 #include <sys/socket.h>
35 #include <sys/time.h>
36 #include <sys/uio.h>
37
38 #include <netinet/in.h>
39
40 #include <ctype.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <inttypes.h>
44 #include <netdb.h>
45 #include <paths.h>
46 #include <poll.h>
47 #include <pwd.h>
48 #include <stdarg.h>
49 #include <stdlib.h>
50 #include <stdio.h>
51 #include <string.h>
52 #include <unistd.h>
53
54 #ifdef WITH_SSL
55 #include <openssl/x509v3.h>
56 #endif
57
58 #include "fetch.h"
59 #include "common.h"
60
61
62 /*** Local data **************************************************************/
63
64 /*
65 * Error messages for resolver errors
66 */
67 static struct fetcherr netdb_errlist[] = {
68 #ifdef EAI_ADDRFAMILY
69 { EAI_ADDRFAMILY, FETCH_RESOLV, "Address family for host not supported" },
70 #endif
71 #ifdef EAI_NODATA
72 { EAI_NODATA, FETCH_RESOLV, "No address for host" },
73 #endif
74 { EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" },
75 { EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" },
76 { EAI_NONAME, FETCH_RESOLV, "Host does not resolve" },
77 { -1, FETCH_UNKNOWN, "Unknown resolver error" }
78 };
79
80 /*
81 * SOCKS5 error enumerations
82 */
83 enum SOCKS5_ERR {
84 /* Protocol errors */
85 SOCKS5_ERR_SELECTION,
86 SOCKS5_ERR_READ_METHOD,
87 SOCKS5_ERR_VER5_ONLY,
88 SOCKS5_ERR_NOMETHODS,
89 SOCKS5_ERR_NOTIMPLEMENTED,
90 SOCKS5_ERR_HOSTNAME_SIZE,
91 SOCKS5_ERR_REQUEST,
92 SOCKS5_ERR_REPLY,
93 SOCKS5_ERR_NON_VER5_RESP,
94 SOCKS5_ERR_GENERAL,
95 SOCKS5_ERR_NOT_ALLOWED,
96 SOCKS5_ERR_NET_UNREACHABLE,
97 SOCKS5_ERR_HOST_UNREACHABLE,
98 SOCKS5_ERR_CONN_REFUSED,
99 SOCKS5_ERR_TTL_EXPIRED,
100 SOCKS5_ERR_COM_UNSUPPORTED,
101 SOCKS5_ERR_ADDR_UNSUPPORTED,
102 SOCKS5_ERR_UNSPECIFIED,
103 /* Configuration errors */
104 SOCKS5_ERR_BAD_HOST,
105 SOCKS5_ERR_BAD_PROXY_FORMAT,
106 SOCKS5_ERR_BAD_PORT
107 };
108
109 /*
110 * Error messages for SOCKS5 errors
111 */
112 static struct fetcherr socks5_errlist[] = {
113 /* SOCKS5 protocol errors */
114 { SOCKS5_ERR_SELECTION, FETCH_ABORT, "SOCKS5: Failed to send selection method" },
115 { SOCKS5_ERR_READ_METHOD, FETCH_ABORT, "SOCKS5: Failed to read method" },
116 { SOCKS5_ERR_VER5_ONLY, FETCH_PROTO, "SOCKS5: Only version 5 is implemented" },
117 { SOCKS5_ERR_NOMETHODS, FETCH_PROTO, "SOCKS5: No acceptable methods" },
118 { SOCKS5_ERR_NOTIMPLEMENTED, FETCH_PROTO, "SOCKS5: Method currently not implemented" },
119 { SOCKS5_ERR_HOSTNAME_SIZE, FETCH_PROTO, "SOCKS5: Hostname size is above 256 bytes" },
120 { SOCKS5_ERR_REQUEST, FETCH_PROTO, "SOCKS5: Failed to request" },
121 { SOCKS5_ERR_REPLY, FETCH_PROTO, "SOCKS5: Failed to receive reply" },
122 { SOCKS5_ERR_NON_VER5_RESP, FETCH_PROTO, "SOCKS5: Server responded with a non-version 5 response" },
123 { SOCKS5_ERR_GENERAL, FETCH_ABORT, "SOCKS5: General server failure" },
124 { SOCKS5_ERR_NOT_ALLOWED, FETCH_AUTH, "SOCKS5: Connection not allowed by ruleset" },
125 { SOCKS5_ERR_NET_UNREACHABLE, FETCH_NETWORK, "SOCKS5: Network unreachable" },
126 { SOCKS5_ERR_HOST_UNREACHABLE, FETCH_ABORT, "SOCKS5: Host unreachable" },
127 { SOCKS5_ERR_CONN_REFUSED, FETCH_ABORT, "SOCKS5: Connection refused" },
128 { SOCKS5_ERR_TTL_EXPIRED, FETCH_TIMEOUT, "SOCKS5: TTL expired" },
129 { SOCKS5_ERR_COM_UNSUPPORTED, FETCH_PROTO, "SOCKS5: Command not supported" },
130 { SOCKS5_ERR_ADDR_UNSUPPORTED, FETCH_ABORT, "SOCKS5: Address type not supported" },
131 { SOCKS5_ERR_UNSPECIFIED, FETCH_UNKNOWN, "SOCKS5: Unspecified error" },
132 /* Configuration error */
133 { SOCKS5_ERR_BAD_HOST, FETCH_ABORT, "SOCKS5: Bad proxy host" },
134 { SOCKS5_ERR_BAD_PROXY_FORMAT, FETCH_ABORT, "SOCKS5: Bad proxy format" },
135 { SOCKS5_ERR_BAD_PORT, FETCH_ABORT, "SOCKS5: Bad port" }
136 };
137
138 /* End-of-Line */
139 static const char ENDL[2] = "\r\n";
140
141
142 /*** Error-reporting functions ***********************************************/
143
144 /*
145 * Map error code to string
146 */
147 static struct fetcherr *
fetch_finderr(struct fetcherr * p,int e)148 fetch_finderr(struct fetcherr *p, int e)
149 {
150 while (p->num != -1 && p->num != e)
151 p++;
152 return (p);
153 }
154
155 /*
156 * Set error code
157 */
158 void
fetch_seterr(struct fetcherr * p,int e)159 fetch_seterr(struct fetcherr *p, int e)
160 {
161 p = fetch_finderr(p, e);
162 fetchLastErrCode = p->cat;
163 snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
164 }
165
166 /*
167 * Set error code according to errno
168 */
169 void
fetch_syserr(void)170 fetch_syserr(void)
171 {
172 switch (errno) {
173 case 0:
174 fetchLastErrCode = FETCH_OK;
175 break;
176 case EPERM:
177 case EACCES:
178 case EROFS:
179 case EAUTH:
180 case ENEEDAUTH:
181 fetchLastErrCode = FETCH_AUTH;
182 break;
183 case ENOENT:
184 case EISDIR: /* XXX */
185 fetchLastErrCode = FETCH_UNAVAIL;
186 break;
187 case ENOMEM:
188 fetchLastErrCode = FETCH_MEMORY;
189 break;
190 case EBUSY:
191 case EAGAIN:
192 fetchLastErrCode = FETCH_TEMP;
193 break;
194 case EEXIST:
195 fetchLastErrCode = FETCH_EXISTS;
196 break;
197 case ENOSPC:
198 fetchLastErrCode = FETCH_FULL;
199 break;
200 case EADDRINUSE:
201 case EADDRNOTAVAIL:
202 case ENETDOWN:
203 case ENETUNREACH:
204 case ENETRESET:
205 case EHOSTUNREACH:
206 fetchLastErrCode = FETCH_NETWORK;
207 break;
208 case ECONNABORTED:
209 case ECONNRESET:
210 fetchLastErrCode = FETCH_ABORT;
211 break;
212 case ETIMEDOUT:
213 fetchLastErrCode = FETCH_TIMEOUT;
214 break;
215 case ECONNREFUSED:
216 case EHOSTDOWN:
217 fetchLastErrCode = FETCH_DOWN;
218 break;
219 default:
220 fetchLastErrCode = FETCH_UNKNOWN;
221 }
222 snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
223 }
224
225
226 /*
227 * Emit status message
228 */
229 void
fetch_info(const char * fmt,...)230 fetch_info(const char *fmt, ...)
231 {
232 va_list ap;
233
234 va_start(ap, fmt);
235 vfprintf(stderr, fmt, ap);
236 va_end(ap);
237 fputc('\n', stderr);
238 }
239
240
241 /*** Network-related utility functions ***************************************/
242
243 /*
244 * Return the default port for a scheme
245 */
246 int
fetch_default_port(const char * scheme)247 fetch_default_port(const char *scheme)
248 {
249 struct servent *se;
250
251 if ((se = getservbyname(scheme, "tcp")) != NULL)
252 return (ntohs(se->s_port));
253 if (strcmp(scheme, SCHEME_FTP) == 0)
254 return (FTP_DEFAULT_PORT);
255 if (strcmp(scheme, SCHEME_HTTP) == 0)
256 return (HTTP_DEFAULT_PORT);
257 return (0);
258 }
259
260 /*
261 * Return the default proxy port for a scheme
262 */
263 int
fetch_default_proxy_port(const char * scheme)264 fetch_default_proxy_port(const char *scheme)
265 {
266 if (strcmp(scheme, SCHEME_FTP) == 0)
267 return (FTP_DEFAULT_PROXY_PORT);
268 if (strcmp(scheme, SCHEME_HTTP) == 0)
269 return (HTTP_DEFAULT_PROXY_PORT);
270 return (0);
271 }
272
273
274 /*
275 * Create a connection for an existing descriptor.
276 */
277 conn_t *
fetch_reopen(int sd)278 fetch_reopen(int sd)
279 {
280 conn_t *conn;
281 int opt = 1;
282
283 /* allocate and fill connection structure */
284 if ((conn = calloc(1, sizeof(*conn))) == NULL)
285 return (NULL);
286 fcntl(sd, F_SETFD, FD_CLOEXEC);
287 setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt);
288 conn->sd = sd;
289 ++conn->ref;
290 return (conn);
291 }
292
293
294 /*
295 * Bump a connection's reference count.
296 */
297 conn_t *
fetch_ref(conn_t * conn)298 fetch_ref(conn_t *conn)
299 {
300
301 ++conn->ref;
302 return (conn);
303 }
304
305
306 /*
307 * Resolve an address
308 */
309 struct addrinfo *
fetch_resolve(const char * addr,int port,int af)310 fetch_resolve(const char *addr, int port, int af)
311 {
312 char hbuf[256], sbuf[8];
313 struct addrinfo hints, *res;
314 const char *hb, *he, *sep;
315 const char *host, *service;
316 int err, len;
317
318 /* first, check for a bracketed IPv6 address */
319 if (*addr == '[') {
320 hb = addr + 1;
321 if ((sep = strchr(hb, ']')) == NULL) {
322 errno = EINVAL;
323 goto syserr;
324 }
325 he = sep++;
326 } else {
327 hb = addr;
328 sep = strchrnul(hb, ':');
329 he = sep;
330 }
331
332 /* see if we need to copy the host name */
333 if (*he != '\0') {
334 len = snprintf(hbuf, sizeof(hbuf),
335 "%.*s", (int)(he - hb), hb);
336 if (len < 0)
337 goto syserr;
338 if (len >= (int)sizeof(hbuf)) {
339 errno = ENAMETOOLONG;
340 goto syserr;
341 }
342 host = hbuf;
343 } else {
344 host = hb;
345 }
346
347 /* was it followed by a service name? */
348 if (*sep == '\0' && port != 0) {
349 if (port < 1 || port > 65535) {
350 errno = EINVAL;
351 goto syserr;
352 }
353 if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
354 goto syserr;
355 service = sbuf;
356 } else if (*sep != '\0') {
357 service = sep + 1;
358 } else {
359 service = NULL;
360 }
361
362 /* resolve */
363 memset(&hints, 0, sizeof(hints));
364 hints.ai_family = af;
365 hints.ai_socktype = SOCK_STREAM;
366 hints.ai_flags = AI_ADDRCONFIG;
367 if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
368 netdb_seterr(err);
369 return (NULL);
370 }
371 return (res);
372 syserr:
373 fetch_syserr();
374 return (NULL);
375 }
376
377
378 /*
379 * Bind a socket to a specific local address
380 */
381 int
fetch_bind(int sd,int af,const char * addr)382 fetch_bind(int sd, int af, const char *addr)
383 {
384 struct addrinfo *cliai, *ai;
385 int err;
386
387 if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
388 return (-1);
389 for (ai = cliai; ai != NULL; ai = ai->ai_next)
390 if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
391 break;
392 if (err != 0)
393 fetch_syserr();
394 freeaddrinfo(cliai);
395 return (err == 0 ? 0 : -1);
396 }
397
398
399 /*
400 * SOCKS5 connection initiation, based on RFC 1928
401 * Default DNS resolution over SOCKS5
402 */
403 int
fetch_socks5_init(conn_t * conn,const char * host,int port,int verbose)404 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
405 {
406 /*
407 * Size is based on largest packet prefix (4 bytes) +
408 * Largest FQDN (256) + one byte size (1) +
409 * Port (2)
410 */
411 unsigned char buf[BUFF_SIZE];
412 unsigned char *ptr;
413 int ret = 1;
414
415 if (verbose)
416 fetch_info("Initializing SOCKS5 connection: %s:%d", host, port);
417
418 /* Connection initialization */
419 ptr = buf;
420 *ptr++ = SOCKS_VERSION_5;
421 *ptr++ = SOCKS_CONNECTION;
422 *ptr++ = SOCKS_RSV;
423
424 if (fetch_write(conn, buf, 3) != 3) {
425 ret = SOCKS5_ERR_SELECTION;
426 goto fail;
427 }
428
429 /* Verify response from SOCKS5 server */
430 if (fetch_read(conn, buf, 2) != 2) {
431 ret = SOCKS5_ERR_READ_METHOD;
432 goto fail;
433 }
434
435 ptr = buf;
436 if (ptr[0] != SOCKS_VERSION_5) {
437 ret = SOCKS5_ERR_VER5_ONLY;
438 goto fail;
439 }
440 if (ptr[1] == SOCKS_NOMETHODS) {
441 ret = SOCKS5_ERR_NOMETHODS;
442 goto fail;
443 }
444 else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
445 ret = SOCKS5_ERR_NOTIMPLEMENTED;
446 goto fail;
447 }
448
449 /* Send Request */
450 *ptr++ = SOCKS_VERSION_5;
451 *ptr++ = SOCKS_CONNECTION;
452 *ptr++ = SOCKS_RSV;
453 /* Encode all targets as a hostname to avoid DNS leaks */
454 *ptr++ = SOCKS_ATYP_DOMAINNAME;
455 if (strlen(host) > FQDN_SIZE) {
456 ret = SOCKS5_ERR_HOSTNAME_SIZE;
457 goto fail;
458 }
459 *ptr++ = strlen(host);
460 memcpy(ptr, host, strlen(host));
461 ptr = ptr + strlen(host);
462
463 port = htons(port);
464 *ptr++ = port & 0x00ff;
465 *ptr++ = (port & 0xff00) >> 8;
466
467 if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
468 ret = SOCKS5_ERR_REQUEST;
469 goto fail;
470 }
471
472 /* BND.ADDR is variable length, read the largest on non-blocking socket */
473 if (!fetch_read(conn, buf, BUFF_SIZE)) {
474 ret = SOCKS5_ERR_REPLY;
475 goto fail;
476 }
477
478 ptr = buf;
479 if (*ptr++ != SOCKS_VERSION_5) {
480 ret = SOCKS5_ERR_NON_VER5_RESP;
481 goto fail;
482 }
483
484 switch(*ptr++) {
485 case SOCKS_SUCCESS:
486 break;
487 case SOCKS_GENERAL_FAILURE:
488 ret = SOCKS5_ERR_GENERAL;
489 goto fail;
490 case SOCKS_CONNECTION_NOT_ALLOWED:
491 ret = SOCKS5_ERR_NOT_ALLOWED;
492 goto fail;
493 case SOCKS_NETWORK_UNREACHABLE:
494 ret = SOCKS5_ERR_NET_UNREACHABLE;
495 goto fail;
496 case SOCKS_HOST_UNREACHABLE:
497 ret = SOCKS5_ERR_HOST_UNREACHABLE;
498 goto fail;
499 case SOCKS_CONNECTION_REFUSED:
500 ret = SOCKS5_ERR_CONN_REFUSED;
501 goto fail;
502 case SOCKS_TTL_EXPIRED:
503 ret = SOCKS5_ERR_TTL_EXPIRED;
504 goto fail;
505 case SOCKS_COMMAND_NOT_SUPPORTED:
506 ret = SOCKS5_ERR_COM_UNSUPPORTED;
507 goto fail;
508 case SOCKS_ADDRESS_NOT_SUPPORTED:
509 ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
510 goto fail;
511 default:
512 ret = SOCKS5_ERR_UNSPECIFIED;
513 goto fail;
514 }
515
516 return (ret);
517
518 fail:
519 socks5_seterr(ret);
520 return (0);
521 }
522
523 /*
524 * Perform SOCKS5 initialization
525 */
526 int
fetch_socks5_getenv(char ** host,int * port)527 fetch_socks5_getenv(char **host, int *port)
528 {
529 char *socks5env, *endptr, *ext;
530 const char *portDelim;
531 size_t slen;
532
533 portDelim = ":";
534 if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
535 *host = NULL;
536 *port = -1;
537 return (-1);
538 }
539
540 /*
541 * IPv6 addresses begin and end in brackets. Set the port delimiter
542 * accordingly and search for it so we can do appropriate validation.
543 */
544 if (socks5env[0] == '[')
545 portDelim = "]:";
546
547 slen = strlen(socks5env);
548 ext = strstr(socks5env, portDelim);
549 if (socks5env[0] == '[') {
550 if (socks5env[slen - 1] == ']') {
551 *host = strndup(socks5env, slen);
552 } else if (ext != NULL) {
553 *host = strndup(socks5env, ext - socks5env + 1);
554 } else {
555 socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
556 return (0);
557 }
558 } else {
559 *host = strndup(socks5env, ext - socks5env);
560 }
561
562 if (*host == NULL) {
563 fprintf(stderr, "Failure to allocate memory, exiting.\n");
564 return (-1);
565 }
566 if (ext == NULL) {
567 *port = 1080; /* Default port as defined in RFC1928 */
568 } else {
569 ext += strlen(portDelim);
570 errno = 0;
571 *port = strtoimax(ext, (char **)&endptr, 10);
572 if (*endptr != '\0' || errno != 0 || *port < 0 ||
573 *port > 65535) {
574 free(*host);
575 *host = NULL;
576 socks5_seterr(SOCKS5_ERR_BAD_PORT);
577 return (0);
578 }
579 }
580
581 return (2);
582 }
583
584
585 /*
586 * Establish a TCP connection to the specified port on the specified host.
587 */
588 conn_t *
fetch_connect(const char * host,int port,int af,int verbose)589 fetch_connect(const char *host, int port, int af, int verbose)
590 {
591 struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
592 const char *bindaddr;
593 conn_t *conn = NULL;
594 int err = 0, sd = -1;
595 char *sockshost;
596 int socksport;
597
598 DEBUGF("---> %s:%d\n", host, port);
599
600 /*
601 * Check if SOCKS5_PROXY env variable is set. fetch_socks5_getenv
602 * will either set sockshost = NULL or allocate memory in all cases.
603 */
604 sockshost = NULL;
605 if (!fetch_socks5_getenv(&sockshost, &socksport))
606 goto fail;
607
608 /* Not using SOCKS5 proxy */
609 if (sockshost == NULL) {
610 /* resolve server address */
611 if (verbose)
612 fetch_info("resolving server address: %s:%d", host,
613 port);
614 if ((sais = fetch_resolve(host, port, af)) == NULL)
615 goto fail;
616
617 /* resolve client address */
618 bindaddr = getenv("FETCH_BIND_ADDRESS");
619 if (bindaddr != NULL && *bindaddr != '\0') {
620 if (verbose)
621 fetch_info("resolving client address: %s",
622 bindaddr);
623 if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
624 goto fail;
625 }
626 } else {
627 /* resolve socks5 proxy address */
628 if (verbose)
629 fetch_info("resolving SOCKS5 server address: %s:%d",
630 sockshost, socksport);
631 if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
632 socks5_seterr(SOCKS5_ERR_BAD_HOST);
633 goto fail;
634 }
635 }
636
637 /* try each server address in turn */
638 for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
639 /* open socket */
640 if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0)
641 goto syserr;
642 /* attempt to bind to client address */
643 for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
644 if (cai->ai_family != sai->ai_family)
645 continue;
646 if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
647 break;
648 }
649 if (err != 0) {
650 if (verbose)
651 fetch_info("failed to bind to %s", bindaddr);
652 goto syserr;
653 }
654 /* attempt to connect to server address */
655 if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
656 break;
657 /* clean up before next attempt */
658 close(sd);
659 sd = -1;
660 }
661 if (err != 0) {
662 if (verbose && sockshost == NULL) {
663 fetch_info("failed to connect to %s:%d", host, port);
664 goto syserr;
665 } else if (sockshost != NULL) {
666 if (verbose)
667 fetch_info(
668 "failed to connect to SOCKS5 server %s:%d",
669 sockshost, socksport);
670 socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
671 goto fail;
672 }
673 goto syserr;
674 }
675
676 if ((conn = fetch_reopen(sd)) == NULL)
677 goto syserr;
678
679 if (sockshost)
680 if (!fetch_socks5_init(conn, host, port, verbose))
681 goto fail;
682 free(sockshost);
683 if (cais != NULL)
684 freeaddrinfo(cais);
685 if (sais != NULL)
686 freeaddrinfo(sais);
687 return (conn);
688 syserr:
689 fetch_syserr();
690 fail:
691 free(sockshost);
692 /* Fully close if it was opened; otherwise just don't leak the fd. */
693 if (conn != NULL)
694 fetch_close(conn);
695 else if (sd >= 0)
696 close(sd);
697 if (cais != NULL)
698 freeaddrinfo(cais);
699 if (sais != NULL)
700 freeaddrinfo(sais);
701 return (NULL);
702 }
703
704 #ifdef WITH_SSL
705 /*
706 * Convert characters A-Z to lowercase (intentionally avoid any locale
707 * specific conversions).
708 */
709 static char
fetch_ssl_tolower(char in)710 fetch_ssl_tolower(char in)
711 {
712 if (in >= 'A' && in <= 'Z')
713 return (in + 32);
714 else
715 return (in);
716 }
717
718 /*
719 * isalpha implementation that intentionally avoids any locale specific
720 * conversions.
721 */
722 static int
fetch_ssl_isalpha(char in)723 fetch_ssl_isalpha(char in)
724 {
725 return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
726 }
727
728 /*
729 * Check if passed hostnames a and b are equal.
730 */
731 static int
fetch_ssl_hname_equal(const char * a,size_t alen,const char * b,size_t blen)732 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
733 size_t blen)
734 {
735 size_t i;
736
737 if (alen != blen)
738 return (0);
739 for (i = 0; i < alen; ++i) {
740 if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
741 return (0);
742 }
743 return (1);
744 }
745
746 /*
747 * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
748 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
749 * numeric characters. Double hyphens (like they're found in IDN a-labels
750 * 'xn--') are not allowed. Empty labels are invalid.
751 */
752 static int
fetch_ssl_is_trad_domain_label(const char * l,size_t len,int wcok)753 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
754 {
755 size_t i;
756
757 if (!len || l[0] == '-' || l[len-1] == '-')
758 return (0);
759 for (i = 0; i < len; ++i) {
760 if (!isdigit(l[i]) &&
761 !fetch_ssl_isalpha(l[i]) &&
762 !(l[i] == '*' && wcok) &&
763 !(l[i] == '-' && l[i - 1] != '-'))
764 return (0);
765 }
766 return (1);
767 }
768
769 /*
770 * Check if host name consists only of numbers. This might indicate an IP
771 * address, which is not a good idea for CN wildcard comparison.
772 */
773 static int
fetch_ssl_hname_is_only_numbers(const char * hostname,size_t len)774 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
775 {
776 size_t i;
777
778 for (i = 0; i < len; ++i) {
779 if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
780 hostname[i] == '.'))
781 return (0);
782 }
783 return (1);
784 }
785
786 /*
787 * Check if the host name h passed matches the pattern passed in m which
788 * is usually part of subjectAltName or CN of a certificate presented to
789 * the client. This includes wildcard matching. The algorithm is based on
790 * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
791 */
792 static int
fetch_ssl_hname_match(const char * h,size_t hlen,const char * m,size_t mlen)793 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
794 size_t mlen)
795 {
796 int delta, hdotidx, mdot1idx, wcidx;
797 const char *hdot, *mdot1, *mdot2;
798 const char *wc; /* wildcard */
799
800 if (!(h && *h && m && *m))
801 return (0);
802 if ((wc = strnstr(m, "*", mlen)) == NULL)
803 return (fetch_ssl_hname_equal(h, hlen, m, mlen));
804 wcidx = wc - m;
805 /* hostname should not be just dots and numbers */
806 if (fetch_ssl_hname_is_only_numbers(h, hlen))
807 return (0);
808 /* only one wildcard allowed in pattern */
809 if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
810 return (0);
811 /*
812 * there must be at least two more domain labels and
813 * wildcard has to be in the leftmost label (RFC6125)
814 */
815 mdot1 = strnstr(m, ".", mlen);
816 if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
817 return (0);
818 mdot1idx = mdot1 - m;
819 mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
820 if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
821 return (0);
822 /* hostname must contain a dot and not be the 1st char */
823 hdot = strnstr(h, ".", hlen);
824 if (hdot == NULL || hdot == h)
825 return (0);
826 hdotidx = hdot - h;
827 /*
828 * host part of hostname must be at least as long as
829 * pattern it's supposed to match
830 */
831 if (hdotidx < mdot1idx)
832 return (0);
833 /*
834 * don't allow wildcards in non-traditional domain names
835 * (IDN, A-label, U-label...)
836 */
837 if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
838 !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
839 return (0);
840 /* match domain part (part after first dot) */
841 if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
842 mlen - mdot1idx))
843 return (0);
844 /* match part left of wildcard */
845 if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
846 return (0);
847 /* match part right of wildcard */
848 delta = mdot1idx - wcidx - 1;
849 if (!fetch_ssl_hname_equal(hdot - delta, delta,
850 mdot1 - delta, delta))
851 return (0);
852 /* all tests succeeded, it's a match */
853 return (1);
854 }
855
856 /*
857 * Get numeric host address info - returns NULL if host was not an IP
858 * address. The caller is responsible for deallocation using
859 * freeaddrinfo(3).
860 */
861 static struct addrinfo *
fetch_ssl_get_numeric_addrinfo(const char * hostname,size_t len)862 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
863 {
864 struct addrinfo hints, *res;
865 char *host;
866
867 host = (char *)malloc(len + 1);
868 memcpy(host, hostname, len);
869 host[len] = '\0';
870 memset(&hints, 0, sizeof(hints));
871 hints.ai_family = PF_UNSPEC;
872 hints.ai_socktype = SOCK_STREAM;
873 hints.ai_protocol = 0;
874 hints.ai_flags = AI_NUMERICHOST;
875 /* port is not relevant for this purpose */
876 if (getaddrinfo(host, "443", &hints, &res) != 0)
877 res = NULL;
878 free(host);
879 return res;
880 }
881
882 /*
883 * Compare ip address in addrinfo with address passes.
884 */
885 static int
fetch_ssl_ipaddr_match_bin(const struct addrinfo * lhost,const char * rhost,size_t rhostlen)886 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
887 size_t rhostlen)
888 {
889 const void *left;
890
891 if (lhost->ai_family == AF_INET && rhostlen == 4) {
892 left = (void *)&((struct sockaddr_in*)(void *)
893 lhost->ai_addr)->sin_addr.s_addr;
894 #ifdef INET6
895 } else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
896 left = (void *)&((struct sockaddr_in6 *)(void *)
897 lhost->ai_addr)->sin6_addr;
898 #endif
899 } else
900 return (0);
901 return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
902 }
903
904 /*
905 * Compare ip address in addrinfo with host passed. If host is not an IP
906 * address, comparison will fail.
907 */
908 static int
fetch_ssl_ipaddr_match(const struct addrinfo * laddr,const char * r,size_t rlen)909 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
910 size_t rlen)
911 {
912 struct addrinfo *raddr;
913 int ret;
914 char *rip;
915
916 ret = 0;
917 if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
918 return 0; /* not a numeric host */
919
920 if (laddr->ai_family == raddr->ai_family) {
921 if (laddr->ai_family == AF_INET) {
922 rip = (char *)&((struct sockaddr_in *)(void *)
923 raddr->ai_addr)->sin_addr.s_addr;
924 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
925 #ifdef INET6
926 } else if (laddr->ai_family == AF_INET6) {
927 rip = (char *)&((struct sockaddr_in6 *)(void *)
928 raddr->ai_addr)->sin6_addr;
929 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
930 #endif
931 }
932
933 }
934 freeaddrinfo(raddr);
935 return (ret);
936 }
937
938 /*
939 * Verify server certificate by subjectAltName.
940 */
941 static int
fetch_ssl_verify_altname(STACK_OF (GENERAL_NAME)* altnames,const char * host,struct addrinfo * ip)942 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
943 const char *host, struct addrinfo *ip)
944 {
945 const GENERAL_NAME *name;
946 size_t nslen;
947 int i;
948 const char *ns;
949
950 for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
951 #if OPENSSL_VERSION_NUMBER < 0x10000000L
952 /*
953 * This is a workaround, since the following line causes
954 * alignment issues in clang:
955 * name = sk_GENERAL_NAME_value(altnames, i);
956 * OpenSSL explicitly warns not to use those macros
957 * directly, but there isn't much choice (and there
958 * shouldn't be any ill side effects)
959 */
960 name = (GENERAL_NAME *)SKM_sk_value(void, altnames, i);
961 #else
962 name = sk_GENERAL_NAME_value(altnames, i);
963 #endif
964 #if OPENSSL_VERSION_NUMBER < 0x10100000L
965 ns = (const char *)ASN1_STRING_data(name->d.ia5);
966 #else
967 ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
968 #endif
969 nslen = (size_t)ASN1_STRING_length(name->d.ia5);
970
971 if (name->type == GEN_DNS && ip == NULL &&
972 fetch_ssl_hname_match(host, strlen(host), ns, nslen))
973 return (1);
974 else if (name->type == GEN_IPADD && ip != NULL &&
975 fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
976 return (1);
977 }
978 return (0);
979 }
980
981 /*
982 * Verify server certificate by CN.
983 */
984 static int
fetch_ssl_verify_cn(X509_NAME * subject,const char * host,struct addrinfo * ip)985 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
986 struct addrinfo *ip)
987 {
988 ASN1_STRING *namedata;
989 X509_NAME_ENTRY *nameentry;
990 int cnlen, lastpos, loc, ret;
991 unsigned char *cn;
992
993 ret = 0;
994 lastpos = -1;
995 loc = -1;
996 cn = NULL;
997 /* get most specific CN (last entry in list) and compare */
998 while ((lastpos = X509_NAME_get_index_by_NID(subject,
999 NID_commonName, lastpos)) != -1)
1000 loc = lastpos;
1001
1002 if (loc > -1) {
1003 nameentry = X509_NAME_get_entry(subject, loc);
1004 namedata = X509_NAME_ENTRY_get_data(nameentry);
1005 cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
1006 if (ip == NULL &&
1007 fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
1008 ret = 1;
1009 else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
1010 ret = 1;
1011 OPENSSL_free(cn);
1012 }
1013 return (ret);
1014 }
1015
1016 /*
1017 * Verify that server certificate subjectAltName/CN matches
1018 * hostname. First check, if there are alternative subject names. If yes,
1019 * those have to match. Only if those don't exist it falls back to
1020 * checking the subject's CN.
1021 */
1022 static int
fetch_ssl_verify_hname(X509 * cert,const char * host)1023 fetch_ssl_verify_hname(X509 *cert, const char *host)
1024 {
1025 struct addrinfo *ip;
1026 STACK_OF(GENERAL_NAME) *altnames;
1027 X509_NAME *subject;
1028 int ret;
1029
1030 ret = 0;
1031 ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1032 altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1033 NULL, NULL);
1034
1035 if (altnames != NULL) {
1036 ret = fetch_ssl_verify_altname(altnames, host, ip);
1037 } else {
1038 subject = X509_get_subject_name(cert);
1039 if (subject != NULL)
1040 ret = fetch_ssl_verify_cn(subject, host, ip);
1041 }
1042
1043 if (ip != NULL)
1044 freeaddrinfo(ip);
1045 if (altnames != NULL)
1046 GENERAL_NAMES_free(altnames);
1047 return (ret);
1048 }
1049
1050 /*
1051 * Configure transport security layer based on environment.
1052 */
1053 static void
fetch_ssl_setup_transport_layer(SSL_CTX * ctx,int verbose)1054 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1055 {
1056 long ssl_ctx_options;
1057
1058 ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1059 if (getenv("SSL_NO_TLS1") != NULL)
1060 ssl_ctx_options |= SSL_OP_NO_TLSv1;
1061 if (getenv("SSL_NO_TLS1_1") != NULL)
1062 ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1063 if (getenv("SSL_NO_TLS1_2") != NULL)
1064 ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1065 if (verbose)
1066 fetch_info("SSL options: %lx", ssl_ctx_options);
1067 SSL_CTX_set_options(ctx, ssl_ctx_options);
1068 }
1069
1070
1071 /*
1072 * Configure peer verification based on environment.
1073 */
1074 static int
fetch_ssl_setup_peer_verification(SSL_CTX * ctx,int verbose)1075 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1076 {
1077 X509_LOOKUP *crl_lookup;
1078 X509_STORE *crl_store;
1079 const char *ca_cert_file, *ca_cert_path, *crl_file;
1080
1081 if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1082 ca_cert_file = getenv("SSL_CA_CERT_FILE");
1083 ca_cert_path = getenv("SSL_CA_CERT_PATH");
1084 if (verbose) {
1085 fetch_info("Peer verification enabled");
1086 if (ca_cert_file != NULL)
1087 fetch_info("Using CA cert file: %s",
1088 ca_cert_file);
1089 if (ca_cert_path != NULL)
1090 fetch_info("Using CA cert path: %s",
1091 ca_cert_path);
1092 if (ca_cert_file == NULL && ca_cert_path == NULL)
1093 fetch_info("Using OpenSSL default "
1094 "CA cert file and path");
1095 }
1096 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1097 fetch_ssl_cb_verify_crt);
1098 if (ca_cert_file != NULL || ca_cert_path != NULL)
1099 SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1100 ca_cert_path);
1101 else
1102 SSL_CTX_set_default_verify_paths(ctx);
1103 if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1104 if (verbose)
1105 fetch_info("Using CRL file: %s", crl_file);
1106 crl_store = SSL_CTX_get_cert_store(ctx);
1107 crl_lookup = X509_STORE_add_lookup(crl_store,
1108 X509_LOOKUP_file());
1109 if (crl_lookup == NULL ||
1110 !X509_load_crl_file(crl_lookup, crl_file,
1111 X509_FILETYPE_PEM)) {
1112 fprintf(stderr,
1113 "Could not load CRL file %s\n",
1114 crl_file);
1115 return (0);
1116 }
1117 X509_STORE_set_flags(crl_store,
1118 X509_V_FLAG_CRL_CHECK |
1119 X509_V_FLAG_CRL_CHECK_ALL);
1120 }
1121 }
1122 return (1);
1123 }
1124
1125 /*
1126 * Configure client certificate based on environment.
1127 */
1128 static int
fetch_ssl_setup_client_certificate(SSL_CTX * ctx,int verbose)1129 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1130 {
1131 const char *client_cert_file, *client_key_file;
1132
1133 if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1134 client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1135 getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1136 if (verbose) {
1137 fetch_info("Using client cert file: %s",
1138 client_cert_file);
1139 fetch_info("Using client key file: %s",
1140 client_key_file);
1141 }
1142 if (SSL_CTX_use_certificate_chain_file(ctx,
1143 client_cert_file) != 1) {
1144 fprintf(stderr,
1145 "Could not load client certificate %s\n",
1146 client_cert_file);
1147 return (0);
1148 }
1149 if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1150 SSL_FILETYPE_PEM) != 1) {
1151 fprintf(stderr,
1152 "Could not load client key %s\n",
1153 client_key_file);
1154 return (0);
1155 }
1156 }
1157 return (1);
1158 }
1159
1160 /*
1161 * Callback for SSL certificate verification, this is called on server
1162 * cert verification. It takes no decision, but informs the user in case
1163 * verification failed.
1164 */
1165 int
fetch_ssl_cb_verify_crt(int verified,X509_STORE_CTX * ctx)1166 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1167 {
1168 X509 *crt;
1169 X509_NAME *name;
1170 char *str;
1171
1172 str = NULL;
1173 if (!verified) {
1174 if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1175 (name = X509_get_subject_name(crt)) != NULL)
1176 str = X509_NAME_oneline(name, 0, 0);
1177 fprintf(stderr, "Certificate verification failed for %s\n",
1178 str != NULL ? str : "no relevant certificate");
1179 OPENSSL_free(str);
1180 }
1181 return (verified);
1182 }
1183
1184 #endif
1185
1186 /*
1187 * Enable SSL on a connection.
1188 */
1189 int
fetch_ssl(conn_t * conn,const struct url * URL,int verbose)1190 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1191 {
1192 #ifdef WITH_SSL
1193 int ret, ssl_err;
1194 X509_NAME *name;
1195 char *str;
1196
1197 /* Init the SSL library and context */
1198 if (!SSL_library_init()){
1199 fprintf(stderr, "SSL library init failed\n");
1200 return (-1);
1201 }
1202
1203 SSL_load_error_strings();
1204
1205 conn->ssl_meth = SSLv23_client_method();
1206 conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
1207 SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1208
1209 fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1210 if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1211 return (-1);
1212 if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1213 return (-1);
1214
1215 conn->ssl = SSL_new(conn->ssl_ctx);
1216 if (conn->ssl == NULL) {
1217 fprintf(stderr, "SSL context creation failed\n");
1218 return (-1);
1219 }
1220 SSL_set_fd(conn->ssl, conn->sd);
1221
1222 #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
1223 if (!SSL_set_tlsext_host_name(conn->ssl,
1224 __DECONST(struct url *, URL)->host)) {
1225 fprintf(stderr,
1226 "TLS server name indication extension failed for host %s\n",
1227 URL->host);
1228 return (-1);
1229 }
1230 #endif
1231 while ((ret = SSL_connect(conn->ssl)) == -1) {
1232 ssl_err = SSL_get_error(conn->ssl, ret);
1233 if (ssl_err != SSL_ERROR_WANT_READ &&
1234 ssl_err != SSL_ERROR_WANT_WRITE) {
1235 ERR_print_errors_fp(stderr);
1236 return (-1);
1237 }
1238 }
1239 conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1240
1241 if (conn->ssl_cert == NULL) {
1242 fprintf(stderr, "No server SSL certificate\n");
1243 return (-1);
1244 }
1245
1246 if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1247 if (verbose)
1248 fetch_info("Verify hostname");
1249 if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1250 fprintf(stderr,
1251 "SSL certificate subject doesn't match host %s\n",
1252 URL->host);
1253 return (-1);
1254 }
1255 }
1256
1257 if (verbose) {
1258 fetch_info("%s connection established using %s",
1259 SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1260 name = X509_get_subject_name(conn->ssl_cert);
1261 str = X509_NAME_oneline(name, 0, 0);
1262 fetch_info("Certificate subject: %s", str);
1263 OPENSSL_free(str);
1264 name = X509_get_issuer_name(conn->ssl_cert);
1265 str = X509_NAME_oneline(name, 0, 0);
1266 fetch_info("Certificate issuer: %s", str);
1267 OPENSSL_free(str);
1268 }
1269
1270 return (0);
1271 #else
1272 (void)conn;
1273 (void)verbose;
1274 (void)URL;
1275 fprintf(stderr, "SSL support disabled\n");
1276 return (-1);
1277 #endif
1278 }
1279
1280 #define FETCH_READ_WAIT -2
1281 #define FETCH_READ_ERROR -1
1282 #define FETCH_READ_DONE 0
1283
1284 #ifdef WITH_SSL
1285 static ssize_t
fetch_ssl_read(SSL * ssl,char * buf,size_t len)1286 fetch_ssl_read(SSL *ssl, char *buf, size_t len)
1287 {
1288 ssize_t rlen;
1289 int ssl_err;
1290
1291 rlen = SSL_read(ssl, buf, len);
1292 if (rlen < 0) {
1293 ssl_err = SSL_get_error(ssl, rlen);
1294 if (ssl_err == SSL_ERROR_WANT_READ ||
1295 ssl_err == SSL_ERROR_WANT_WRITE) {
1296 return (FETCH_READ_WAIT);
1297 } else {
1298 ERR_print_errors_fp(stderr);
1299 return (FETCH_READ_ERROR);
1300 }
1301 }
1302 return (rlen);
1303 }
1304 #endif
1305
1306 static ssize_t
fetch_socket_read(int sd,char * buf,size_t len)1307 fetch_socket_read(int sd, char *buf, size_t len)
1308 {
1309 ssize_t rlen;
1310
1311 rlen = read(sd, buf, len);
1312 if (rlen < 0) {
1313 if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
1314 return (FETCH_READ_WAIT);
1315 else
1316 return (FETCH_READ_ERROR);
1317 }
1318 return (rlen);
1319 }
1320
1321 /*
1322 * Read a character from a connection w/ timeout
1323 */
1324 ssize_t
fetch_read(conn_t * conn,char * buf,size_t len)1325 fetch_read(conn_t *conn, char *buf, size_t len)
1326 {
1327 struct timeval now, timeout, delta;
1328 struct pollfd pfd;
1329 ssize_t rlen;
1330 int deltams;
1331
1332 if (fetchTimeout > 0) {
1333 gettimeofday(&timeout, NULL);
1334 timeout.tv_sec += fetchTimeout;
1335 }
1336
1337 deltams = INFTIM;
1338 memset(&pfd, 0, sizeof pfd);
1339 pfd.fd = conn->sd;
1340 pfd.events = POLLIN | POLLERR;
1341
1342 for (;;) {
1343 /*
1344 * The socket is non-blocking. Instead of the canonical
1345 * poll() -> read(), we do the following:
1346 *
1347 * 1) call read() or SSL_read().
1348 * 2) if we received some data, return it.
1349 * 3) if an error occurred, return -1.
1350 * 4) if read() or SSL_read() signaled EOF, return.
1351 * 5) if we did not receive any data but we're not at EOF,
1352 * call poll().
1353 *
1354 * In the SSL case, this is necessary because if we
1355 * receive a close notification, we have to call
1356 * SSL_read() one additional time after we've read
1357 * everything we received.
1358 *
1359 * In the non-SSL case, it may improve performance (very
1360 * slightly) when reading small amounts of data.
1361 */
1362 #ifdef WITH_SSL
1363 if (conn->ssl != NULL)
1364 rlen = fetch_ssl_read(conn->ssl, buf, len);
1365 else
1366 #endif
1367 rlen = fetch_socket_read(conn->sd, buf, len);
1368 if (rlen >= 0) {
1369 break;
1370 } else if (rlen == FETCH_READ_ERROR) {
1371 fetch_syserr();
1372 return (-1);
1373 }
1374 // assert(rlen == FETCH_READ_WAIT);
1375 if (fetchTimeout > 0) {
1376 gettimeofday(&now, NULL);
1377 if (!timercmp(&timeout, &now, >)) {
1378 errno = ETIMEDOUT;
1379 fetch_syserr();
1380 return (-1);
1381 }
1382 timersub(&timeout, &now, &delta);
1383 deltams = delta.tv_sec * 1000 +
1384 delta.tv_usec / 1000;;
1385 }
1386 errno = 0;
1387 pfd.revents = 0;
1388 if (poll(&pfd, 1, deltams) < 0) {
1389 if (errno == EINTR && fetchRestartCalls)
1390 continue;
1391 fetch_syserr();
1392 return (-1);
1393 }
1394 }
1395 return (rlen);
1396 }
1397
1398
1399 /*
1400 * Read a line of text from a connection w/ timeout
1401 */
1402 #define MIN_BUF_SIZE 1024
1403
1404 int
fetch_getln(conn_t * conn)1405 fetch_getln(conn_t *conn)
1406 {
1407 char *tmp;
1408 size_t tmpsize;
1409 ssize_t len;
1410 char c;
1411
1412 if (conn->buf == NULL) {
1413 if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
1414 errno = ENOMEM;
1415 return (-1);
1416 }
1417 conn->bufsize = MIN_BUF_SIZE;
1418 }
1419
1420 conn->buf[0] = '\0';
1421 conn->buflen = 0;
1422
1423 do {
1424 len = fetch_read(conn, &c, 1);
1425 if (len == -1)
1426 return (-1);
1427 if (len == 0)
1428 break;
1429 conn->buf[conn->buflen++] = c;
1430 if (conn->buflen == conn->bufsize) {
1431 tmp = conn->buf;
1432 tmpsize = conn->bufsize * 2 + 1;
1433 if ((tmp = realloc(tmp, tmpsize)) == NULL) {
1434 errno = ENOMEM;
1435 return (-1);
1436 }
1437 conn->buf = tmp;
1438 conn->bufsize = tmpsize;
1439 }
1440 } while (c != '\n');
1441
1442 conn->buf[conn->buflen] = '\0';
1443 DEBUGF("<<< %s", conn->buf);
1444 return (0);
1445 }
1446
1447
1448 /*
1449 * Write to a connection w/ timeout
1450 */
1451 ssize_t
fetch_write(conn_t * conn,const char * buf,size_t len)1452 fetch_write(conn_t *conn, const char *buf, size_t len)
1453 {
1454 struct iovec iov;
1455
1456 iov.iov_base = __DECONST(char *, buf);
1457 iov.iov_len = len;
1458 return fetch_writev(conn, &iov, 1);
1459 }
1460
1461 /*
1462 * Write a vector to a connection w/ timeout
1463 * Note: can modify the iovec.
1464 */
1465 ssize_t
fetch_writev(conn_t * conn,struct iovec * iov,int iovcnt)1466 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1467 {
1468 struct timeval now, timeout, delta;
1469 struct pollfd pfd;
1470 ssize_t wlen, total;
1471 int deltams;
1472
1473 memset(&pfd, 0, sizeof pfd);
1474 if (fetchTimeout) {
1475 pfd.fd = conn->sd;
1476 pfd.events = POLLOUT | POLLERR;
1477 gettimeofday(&timeout, NULL);
1478 timeout.tv_sec += fetchTimeout;
1479 }
1480
1481 total = 0;
1482 while (iovcnt > 0) {
1483 while (fetchTimeout && pfd.revents == 0) {
1484 gettimeofday(&now, NULL);
1485 if (!timercmp(&timeout, &now, >)) {
1486 errno = ETIMEDOUT;
1487 fetch_syserr();
1488 return (-1);
1489 }
1490 timersub(&timeout, &now, &delta);
1491 deltams = delta.tv_sec * 1000 +
1492 delta.tv_usec / 1000;
1493 errno = 0;
1494 pfd.revents = 0;
1495 if (poll(&pfd, 1, deltams) < 0) {
1496 /* POSIX compliance */
1497 if (errno == EAGAIN)
1498 continue;
1499 if (errno == EINTR && fetchRestartCalls)
1500 continue;
1501 return (-1);
1502 }
1503 }
1504 errno = 0;
1505 #ifdef WITH_SSL
1506 if (conn->ssl != NULL)
1507 wlen = SSL_write(conn->ssl,
1508 iov->iov_base, iov->iov_len);
1509 else
1510 #endif
1511 wlen = writev(conn->sd, iov, iovcnt);
1512 if (wlen == 0) {
1513 /* we consider a short write a failure */
1514 /* XXX perhaps we shouldn't in the SSL case */
1515 errno = EPIPE;
1516 fetch_syserr();
1517 return (-1);
1518 }
1519 if (wlen < 0) {
1520 if (errno == EINTR && fetchRestartCalls)
1521 continue;
1522 return (-1);
1523 }
1524 total += wlen;
1525 while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1526 wlen -= iov->iov_len;
1527 iov++;
1528 iovcnt--;
1529 }
1530 if (iovcnt > 0) {
1531 iov->iov_len -= wlen;
1532 iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1533 }
1534 }
1535 return (total);
1536 }
1537
1538
1539 /*
1540 * Write a line of text to a connection w/ timeout
1541 */
1542 int
fetch_putln(conn_t * conn,const char * str,size_t len)1543 fetch_putln(conn_t *conn, const char *str, size_t len)
1544 {
1545 struct iovec iov[2];
1546 int ret;
1547
1548 DEBUGF(">>> %s\n", str);
1549 iov[0].iov_base = __DECONST(char *, str);
1550 iov[0].iov_len = len;
1551 iov[1].iov_base = __DECONST(char *, ENDL);
1552 iov[1].iov_len = sizeof(ENDL);
1553 if (len == 0)
1554 ret = fetch_writev(conn, &iov[1], 1);
1555 else
1556 ret = fetch_writev(conn, iov, 2);
1557 if (ret == -1)
1558 return (-1);
1559 return (0);
1560 }
1561
1562
1563 /*
1564 * Close connection
1565 */
1566 int
fetch_close(conn_t * conn)1567 fetch_close(conn_t *conn)
1568 {
1569 int ret;
1570
1571 if (--conn->ref > 0)
1572 return (0);
1573 #ifdef WITH_SSL
1574 if (conn->ssl) {
1575 SSL_shutdown(conn->ssl);
1576 SSL_set_connect_state(conn->ssl);
1577 SSL_free(conn->ssl);
1578 conn->ssl = NULL;
1579 }
1580 if (conn->ssl_ctx) {
1581 SSL_CTX_free(conn->ssl_ctx);
1582 conn->ssl_ctx = NULL;
1583 }
1584 if (conn->ssl_cert) {
1585 X509_free(conn->ssl_cert);
1586 conn->ssl_cert = NULL;
1587 }
1588 #endif
1589 ret = close(conn->sd);
1590 free(conn->buf);
1591 free(conn);
1592 return (ret);
1593 }
1594
1595
1596 /*** Directory-related utility functions *************************************/
1597
1598 int
fetch_add_entry(struct url_ent ** p,int * size,int * len,const char * name,struct url_stat * us)1599 fetch_add_entry(struct url_ent **p, int *size, int *len,
1600 const char *name, struct url_stat *us)
1601 {
1602 struct url_ent *tmp;
1603
1604 if (*p == NULL) {
1605 *size = 0;
1606 *len = 0;
1607 }
1608
1609 if (*len >= *size - 1) {
1610 tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1611 if (tmp == NULL) {
1612 errno = ENOMEM;
1613 fetch_syserr();
1614 return (-1);
1615 }
1616 *size = (*size * 2 + 1);
1617 *p = tmp;
1618 }
1619
1620 tmp = *p + *len;
1621 snprintf(tmp->name, PATH_MAX, "%s", name);
1622 memcpy(&tmp->stat, us, sizeof(*us));
1623
1624 (*len)++;
1625 (++tmp)->name[0] = 0;
1626
1627 return (0);
1628 }
1629
1630
1631 /*** Authentication-related utility functions ********************************/
1632
1633 static const char *
fetch_read_word(FILE * f)1634 fetch_read_word(FILE *f)
1635 {
1636 static char word[1024];
1637
1638 if (fscanf(f, " %1023s ", word) != 1)
1639 return (NULL);
1640 return (word);
1641 }
1642
1643 static int
fetch_netrc_open(void)1644 fetch_netrc_open(void)
1645 {
1646 struct passwd *pwd;
1647 char fn[PATH_MAX];
1648 const char *p;
1649 int fd, serrno;
1650
1651 if ((p = getenv("NETRC")) != NULL) {
1652 DEBUGF("NETRC=%s\n", p);
1653 if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1654 fetch_info("$NETRC specifies a file name "
1655 "longer than PATH_MAX");
1656 return (-1);
1657 }
1658 } else {
1659 if ((p = getenv("HOME")) == NULL) {
1660 if ((pwd = getpwuid(getuid())) == NULL ||
1661 (p = pwd->pw_dir) == NULL)
1662 return (-1);
1663 }
1664 if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1665 return (-1);
1666 }
1667
1668 if ((fd = open(fn, O_RDONLY)) < 0) {
1669 serrno = errno;
1670 DEBUGF("%s: %s\n", fn, strerror(serrno));
1671 errno = serrno;
1672 }
1673 return (fd);
1674 }
1675
1676 /*
1677 * Get authentication data for a URL from .netrc
1678 */
1679 int
fetch_netrc_auth(struct url * url)1680 fetch_netrc_auth(struct url *url)
1681 {
1682 const char *word;
1683 int serrno;
1684 FILE *f;
1685
1686 if (url->netrcfd < 0)
1687 url->netrcfd = fetch_netrc_open();
1688 if (url->netrcfd < 0)
1689 return (-1);
1690 if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1691 serrno = errno;
1692 DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1693 close(url->netrcfd);
1694 url->netrcfd = -1;
1695 errno = serrno;
1696 return (-1);
1697 }
1698 rewind(f);
1699 DEBUGF("searching netrc for %s\n", url->host);
1700 while ((word = fetch_read_word(f)) != NULL) {
1701 if (strcmp(word, "default") == 0) {
1702 DEBUGF("using default netrc settings\n");
1703 break;
1704 }
1705 if (strcmp(word, "machine") == 0 &&
1706 (word = fetch_read_word(f)) != NULL &&
1707 strcasecmp(word, url->host) == 0) {
1708 DEBUGF("using netrc settings for %s\n", word);
1709 break;
1710 }
1711 }
1712 if (word == NULL)
1713 goto ferr;
1714 while ((word = fetch_read_word(f)) != NULL) {
1715 if (strcmp(word, "login") == 0) {
1716 if ((word = fetch_read_word(f)) == NULL)
1717 goto ferr;
1718 if (snprintf(url->user, sizeof(url->user),
1719 "%s", word) > (int)sizeof(url->user)) {
1720 fetch_info("login name in .netrc is too long");
1721 url->user[0] = '\0';
1722 }
1723 } else if (strcmp(word, "password") == 0) {
1724 if ((word = fetch_read_word(f)) == NULL)
1725 goto ferr;
1726 if (snprintf(url->pwd, sizeof(url->pwd),
1727 "%s", word) > (int)sizeof(url->pwd)) {
1728 fetch_info("password in .netrc is too long");
1729 url->pwd[0] = '\0';
1730 }
1731 } else if (strcmp(word, "account") == 0) {
1732 if ((word = fetch_read_word(f)) == NULL)
1733 goto ferr;
1734 /* XXX not supported! */
1735 } else {
1736 break;
1737 }
1738 }
1739 fclose(f);
1740 url->netrcfd = -1;
1741 return (0);
1742 ferr:
1743 serrno = errno;
1744 fclose(f);
1745 url->netrcfd = -1;
1746 errno = serrno;
1747 return (-1);
1748 }
1749
1750 /*
1751 * The no_proxy environment variable specifies a set of domains for
1752 * which the proxy should not be consulted; the contents is a comma-,
1753 * or space-separated list of domain names. A single asterisk will
1754 * override all proxy variables and no transactions will be proxied
1755 * (for compatibility with lynx and curl, see the discussion at
1756 * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1757 */
1758 int
fetch_no_proxy_match(const char * host)1759 fetch_no_proxy_match(const char *host)
1760 {
1761 const char *no_proxy, *p, *q;
1762 size_t h_len, d_len;
1763
1764 if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1765 (no_proxy = getenv("no_proxy")) == NULL)
1766 return (0);
1767
1768 /* asterisk matches any hostname */
1769 if (strcmp(no_proxy, "*") == 0)
1770 return (1);
1771
1772 h_len = strlen(host);
1773 p = no_proxy;
1774 do {
1775 /* position p at the beginning of a domain suffix */
1776 while (*p == ',' || isspace((unsigned char)*p))
1777 p++;
1778
1779 /* position q at the first separator character */
1780 for (q = p; *q; ++q)
1781 if (*q == ',' || isspace((unsigned char)*q))
1782 break;
1783
1784 d_len = q - p;
1785 if (d_len > 0 && h_len >= d_len &&
1786 strncasecmp(host + h_len - d_len,
1787 p, d_len) == 0) {
1788 /* domain name matches */
1789 return (1);
1790 }
1791
1792 p = q + 1;
1793 } while (*q);
1794
1795 return (0);
1796 }
1797