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
233 va_start(ap, fmt);
234 vfprintf(stderr, fmt, ap);
235 va_end(ap);
236 fputc('\n', stderr);
237 }
238
239
240 /*** Network-related utility functions ***************************************/
241
242 /*
243 * Return the default port for a scheme
244 */
245 int
fetch_default_port(const char * scheme)246 fetch_default_port(const char *scheme)
247 {
248 struct servent *se;
249
250 if ((se = getservbyname(scheme, "tcp")) != NULL)
251 return (ntohs(se->s_port));
252 if (strcmp(scheme, SCHEME_FTP) == 0)
253 return (FTP_DEFAULT_PORT);
254 if (strcmp(scheme, SCHEME_HTTP) == 0)
255 return (HTTP_DEFAULT_PORT);
256 return (0);
257 }
258
259 /*
260 * Return the default proxy port for a scheme
261 */
262 int
fetch_default_proxy_port(const char * scheme)263 fetch_default_proxy_port(const char *scheme)
264 {
265 if (strcmp(scheme, SCHEME_FTP) == 0)
266 return (FTP_DEFAULT_PROXY_PORT);
267 if (strcmp(scheme, SCHEME_HTTP) == 0)
268 return (HTTP_DEFAULT_PROXY_PORT);
269 return (0);
270 }
271
272
273 /*
274 * Create a connection for an existing descriptor.
275 */
276 conn_t *
fetch_reopen(int sd)277 fetch_reopen(int sd)
278 {
279 conn_t *conn;
280 int flags;
281 int opt = 1;
282
283 /* allocate and fill connection structure */
284 if ((conn = calloc(1, sizeof(*conn))) == NULL)
285 return (NULL);
286 flags = fcntl(sd, F_GETFD);
287 if (flags != -1 && (flags & FD_CLOEXEC) == 0)
288 (void)fcntl(sd, F_SETFD, flags | FD_CLOEXEC);
289 (void)setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
290 conn->sd = sd;
291 ++conn->ref;
292 return (conn);
293 }
294
295
296 /*
297 * Bump a connection's reference count.
298 */
299 conn_t *
fetch_ref(conn_t * conn)300 fetch_ref(conn_t *conn)
301 {
302
303 ++conn->ref;
304 return (conn);
305 }
306
307
308 /*
309 * Resolve an address
310 */
311 struct addrinfo *
fetch_resolve(const char * addr,int port,int af)312 fetch_resolve(const char *addr, int port, int af)
313 {
314 char hbuf[256], sbuf[8];
315 struct addrinfo hints, *res;
316 const char *hb, *he, *sep;
317 const char *host, *service;
318 int err, len;
319
320 /* first, check for a bracketed IPv6 address */
321 if (*addr == '[') {
322 hb = addr + 1;
323 if ((sep = strchr(hb, ']')) == NULL) {
324 errno = EINVAL;
325 goto syserr;
326 }
327 he = sep++;
328 } else {
329 hb = addr;
330 sep = strchrnul(hb, ':');
331 he = sep;
332 }
333
334 /* see if we need to copy the host name */
335 if (*he != '\0') {
336 len = snprintf(hbuf, sizeof(hbuf),
337 "%.*s", (int)(he - hb), hb);
338 if (len < 0)
339 goto syserr;
340 if (len >= (int)sizeof(hbuf)) {
341 errno = ENAMETOOLONG;
342 goto syserr;
343 }
344 host = hbuf;
345 } else {
346 host = hb;
347 }
348
349 /* was it followed by a service name? */
350 if (*sep == '\0' && port != 0) {
351 if (port < 1 || port > 65535) {
352 errno = EINVAL;
353 goto syserr;
354 }
355 if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
356 goto syserr;
357 service = sbuf;
358 } else if (*sep != '\0') {
359 service = sep + 1;
360 } else {
361 service = NULL;
362 }
363
364 /* resolve */
365 memset(&hints, 0, sizeof(hints));
366 hints.ai_family = af;
367 hints.ai_socktype = SOCK_STREAM;
368 hints.ai_flags = AI_ADDRCONFIG;
369 if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
370 netdb_seterr(err);
371 return (NULL);
372 }
373 return (res);
374 syserr:
375 fetch_syserr();
376 return (NULL);
377 }
378
379
380 /*
381 * Bind a socket to a specific local address
382 */
383 int
fetch_bind(int sd,int af,const char * addr)384 fetch_bind(int sd, int af, const char *addr)
385 {
386 struct addrinfo *cliai, *ai;
387 int err;
388
389 if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
390 return (-1);
391 for (ai = cliai; ai != NULL; ai = ai->ai_next)
392 if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
393 break;
394 if (err != 0)
395 fetch_syserr();
396 freeaddrinfo(cliai);
397 return (err == 0 ? 0 : -1);
398 }
399
400
401 /*
402 * SOCKS5 connection initiation, based on RFC 1928
403 * Default DNS resolution over SOCKS5
404 */
405 int
fetch_socks5_init(conn_t * conn,const char * host,int port,int verbose)406 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
407 {
408 /*
409 * Size is based on largest packet prefix (4 bytes) +
410 * Largest FQDN (256) + one byte size (1) +
411 * Port (2)
412 */
413 unsigned char buf[BUFF_SIZE];
414 unsigned char *ptr;
415 int ret = 1;
416
417 if (verbose)
418 fetch_info("Initializing SOCKS5 connection: %s:%d", host, port);
419
420 /* Connection initialization */
421 ptr = buf;
422 *ptr++ = SOCKS_VERSION_5;
423 *ptr++ = SOCKS_CONNECTION;
424 *ptr++ = SOCKS_RSV;
425
426 if (fetch_write(conn, buf, 3) != 3) {
427 ret = SOCKS5_ERR_SELECTION;
428 goto fail;
429 }
430
431 /* Verify response from SOCKS5 server */
432 if (fetch_read(conn, buf, 2) != 2) {
433 ret = SOCKS5_ERR_READ_METHOD;
434 goto fail;
435 }
436
437 ptr = buf;
438 if (ptr[0] != SOCKS_VERSION_5) {
439 ret = SOCKS5_ERR_VER5_ONLY;
440 goto fail;
441 }
442 if (ptr[1] == SOCKS_NOMETHODS) {
443 ret = SOCKS5_ERR_NOMETHODS;
444 goto fail;
445 }
446 else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
447 ret = SOCKS5_ERR_NOTIMPLEMENTED;
448 goto fail;
449 }
450
451 /* Send Request */
452 *ptr++ = SOCKS_VERSION_5;
453 *ptr++ = SOCKS_CONNECTION;
454 *ptr++ = SOCKS_RSV;
455 /* Encode all targets as a hostname to avoid DNS leaks */
456 *ptr++ = SOCKS_ATYP_DOMAINNAME;
457 if (strlen(host) > FQDN_SIZE) {
458 ret = SOCKS5_ERR_HOSTNAME_SIZE;
459 goto fail;
460 }
461 *ptr++ = strlen(host);
462 memcpy(ptr, host, strlen(host));
463 ptr = ptr + strlen(host);
464
465 port = htons(port);
466 *ptr++ = port & 0x00ff;
467 *ptr++ = (port & 0xff00) >> 8;
468
469 if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
470 ret = SOCKS5_ERR_REQUEST;
471 goto fail;
472 }
473
474 /* BND.ADDR is variable length, read the largest on non-blocking socket */
475 if (!fetch_read(conn, buf, BUFF_SIZE)) {
476 ret = SOCKS5_ERR_REPLY;
477 goto fail;
478 }
479
480 ptr = buf;
481 if (*ptr++ != SOCKS_VERSION_5) {
482 ret = SOCKS5_ERR_NON_VER5_RESP;
483 goto fail;
484 }
485
486 switch(*ptr++) {
487 case SOCKS_SUCCESS:
488 break;
489 case SOCKS_GENERAL_FAILURE:
490 ret = SOCKS5_ERR_GENERAL;
491 goto fail;
492 case SOCKS_CONNECTION_NOT_ALLOWED:
493 ret = SOCKS5_ERR_NOT_ALLOWED;
494 goto fail;
495 case SOCKS_NETWORK_UNREACHABLE:
496 ret = SOCKS5_ERR_NET_UNREACHABLE;
497 goto fail;
498 case SOCKS_HOST_UNREACHABLE:
499 ret = SOCKS5_ERR_HOST_UNREACHABLE;
500 goto fail;
501 case SOCKS_CONNECTION_REFUSED:
502 ret = SOCKS5_ERR_CONN_REFUSED;
503 goto fail;
504 case SOCKS_TTL_EXPIRED:
505 ret = SOCKS5_ERR_TTL_EXPIRED;
506 goto fail;
507 case SOCKS_COMMAND_NOT_SUPPORTED:
508 ret = SOCKS5_ERR_COM_UNSUPPORTED;
509 goto fail;
510 case SOCKS_ADDRESS_NOT_SUPPORTED:
511 ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
512 goto fail;
513 default:
514 ret = SOCKS5_ERR_UNSPECIFIED;
515 goto fail;
516 }
517
518 return (ret);
519
520 fail:
521 socks5_seterr(ret);
522 return (0);
523 }
524
525 /*
526 * Perform SOCKS5 initialization
527 */
528 int
fetch_socks5_getenv(char ** host,int * port)529 fetch_socks5_getenv(char **host, int *port)
530 {
531 char *socks5env, *endptr, *ext;
532 const char *portDelim;
533 size_t slen;
534
535 portDelim = ":";
536 if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
537 *host = NULL;
538 *port = -1;
539 return (-1);
540 }
541
542 /*
543 * IPv6 addresses begin and end in brackets. Set the port delimiter
544 * accordingly and search for it so we can do appropriate validation.
545 */
546 if (socks5env[0] == '[')
547 portDelim = "]:";
548
549 slen = strlen(socks5env);
550 ext = strstr(socks5env, portDelim);
551 if (socks5env[0] == '[') {
552 if (socks5env[slen - 1] == ']') {
553 *host = strndup(socks5env, slen);
554 } else if (ext != NULL) {
555 *host = strndup(socks5env, ext - socks5env + 1);
556 } else {
557 socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
558 return (0);
559 }
560 } else {
561 *host = strndup(socks5env, ext - socks5env);
562 }
563
564 if (*host == NULL) {
565 fprintf(stderr, "Failure to allocate memory, exiting.\n");
566 return (-1);
567 }
568 if (ext == NULL) {
569 *port = 1080; /* Default port as defined in RFC1928 */
570 } else {
571 ext += strlen(portDelim);
572 errno = 0;
573 *port = strtoimax(ext, (char **)&endptr, 10);
574 if (*endptr != '\0' || errno != 0 || *port < 0 ||
575 *port > 65535) {
576 free(*host);
577 *host = NULL;
578 socks5_seterr(SOCKS5_ERR_BAD_PORT);
579 return (0);
580 }
581 }
582
583 return (2);
584 }
585
586
587 /*
588 * Establish a TCP connection to the specified port on the specified host.
589 */
590 conn_t *
fetch_connect(const char * host,int port,int af,int verbose)591 fetch_connect(const char *host, int port, int af, int verbose)
592 {
593 struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
594 const char *bindaddr;
595 conn_t *conn = NULL;
596 int err = 0, sd = -1;
597 char *sockshost;
598 int socksport;
599
600 DEBUGF("---> %s:%d\n", host, port);
601
602 /*
603 * Check if SOCKS5_PROXY env variable is set. fetch_socks5_getenv
604 * will either set sockshost = NULL or allocate memory in all cases.
605 */
606 sockshost = NULL;
607 if (!fetch_socks5_getenv(&sockshost, &socksport))
608 goto fail;
609
610 /* Not using SOCKS5 proxy */
611 if (sockshost == NULL) {
612 /* resolve server address */
613 if (verbose)
614 fetch_info("resolving server address: %s:%d", host,
615 port);
616 if ((sais = fetch_resolve(host, port, af)) == NULL)
617 goto fail;
618
619 /* resolve client address */
620 bindaddr = getenv("FETCH_BIND_ADDRESS");
621 if (bindaddr != NULL && *bindaddr != '\0') {
622 if (verbose)
623 fetch_info("resolving client address: %s",
624 bindaddr);
625 if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
626 goto fail;
627 }
628 } else {
629 /* resolve socks5 proxy address */
630 if (verbose)
631 fetch_info("resolving SOCKS5 server address: %s:%d",
632 sockshost, socksport);
633 if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
634 socks5_seterr(SOCKS5_ERR_BAD_HOST);
635 goto fail;
636 }
637 }
638
639 /* try each server address in turn */
640 for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
641 /* open socket */
642 if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0)
643 goto syserr;
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 if (verbose)
653 fetch_info("failed to bind to %s", bindaddr);
654 goto syserr;
655 }
656 /* attempt to connect to server address */
657 if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
658 break;
659 /* clean up before next attempt */
660 close(sd);
661 sd = -1;
662 }
663 if (err != 0) {
664 if (verbose && sockshost == NULL) {
665 fetch_info("failed to connect to %s:%d", host, port);
666 goto syserr;
667 } else if (sockshost != NULL) {
668 if (verbose)
669 fetch_info(
670 "failed to connect to SOCKS5 server %s:%d",
671 sockshost, socksport);
672 socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
673 goto fail;
674 }
675 goto syserr;
676 }
677
678 if ((conn = fetch_reopen(sd)) == NULL)
679 goto syserr;
680
681 if (sockshost)
682 if (!fetch_socks5_init(conn, host, port, verbose))
683 goto fail;
684 free(sockshost);
685 if (cais != NULL)
686 freeaddrinfo(cais);
687 if (sais != NULL)
688 freeaddrinfo(sais);
689 return (conn);
690 syserr:
691 fetch_syserr();
692 fail:
693 free(sockshost);
694 /* Fully close if it was opened; otherwise just don't leak the fd. */
695 if (conn != NULL)
696 fetch_close(conn);
697 else if (sd >= 0)
698 close(sd);
699 if (cais != NULL)
700 freeaddrinfo(cais);
701 if (sais != NULL)
702 freeaddrinfo(sais);
703 return (NULL);
704 }
705
706 #ifdef WITH_SSL
707 /*
708 * Convert characters A-Z to lowercase (intentionally avoid any locale
709 * specific conversions).
710 */
711 static char
fetch_ssl_tolower(char in)712 fetch_ssl_tolower(char in)
713 {
714 if (in >= 'A' && in <= 'Z')
715 return (in + 32);
716 else
717 return (in);
718 }
719
720 /*
721 * isalpha implementation that intentionally avoids any locale specific
722 * conversions.
723 */
724 static int
fetch_ssl_isalpha(char in)725 fetch_ssl_isalpha(char in)
726 {
727 return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
728 }
729
730 /*
731 * Check if passed hostnames a and b are equal.
732 */
733 static int
fetch_ssl_hname_equal(const char * a,size_t alen,const char * b,size_t blen)734 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
735 size_t blen)
736 {
737 size_t i;
738
739 if (alen != blen)
740 return (0);
741 for (i = 0; i < alen; ++i) {
742 if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
743 return (0);
744 }
745 return (1);
746 }
747
748 /*
749 * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
750 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
751 * numeric characters. Double hyphens (like they're found in IDN a-labels
752 * 'xn--') are not allowed. Empty labels are invalid.
753 */
754 static int
fetch_ssl_is_trad_domain_label(const char * l,size_t len,int wcok)755 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
756 {
757 size_t i;
758
759 if (!len || l[0] == '-' || l[len-1] == '-')
760 return (0);
761 for (i = 0; i < len; ++i) {
762 if (!isdigit(l[i]) &&
763 !fetch_ssl_isalpha(l[i]) &&
764 !(l[i] == '*' && wcok) &&
765 !(l[i] == '-' && l[i - 1] != '-'))
766 return (0);
767 }
768 return (1);
769 }
770
771 /*
772 * Check if host name consists only of numbers. This might indicate an IP
773 * address, which is not a good idea for CN wildcard comparison.
774 */
775 static int
fetch_ssl_hname_is_only_numbers(const char * hostname,size_t len)776 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
777 {
778 size_t i;
779
780 for (i = 0; i < len; ++i) {
781 if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
782 hostname[i] == '.'))
783 return (0);
784 }
785 return (1);
786 }
787
788 /*
789 * Check if the host name h passed matches the pattern passed in m which
790 * is usually part of subjectAltName or CN of a certificate presented to
791 * the client. This includes wildcard matching. The algorithm is based on
792 * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
793 */
794 static int
fetch_ssl_hname_match(const char * h,size_t hlen,const char * m,size_t mlen)795 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
796 size_t mlen)
797 {
798 int delta, hdotidx, mdot1idx, wcidx;
799 const char *hdot, *mdot1, *mdot2;
800 const char *wc; /* wildcard */
801
802 if (!(h && *h && m && *m))
803 return (0);
804 if ((wc = strnstr(m, "*", mlen)) == NULL)
805 return (fetch_ssl_hname_equal(h, hlen, m, mlen));
806 wcidx = wc - m;
807 /* hostname should not be just dots and numbers */
808 if (fetch_ssl_hname_is_only_numbers(h, hlen))
809 return (0);
810 /* only one wildcard allowed in pattern */
811 if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
812 return (0);
813 /*
814 * there must be at least two more domain labels and
815 * wildcard has to be in the leftmost label (RFC6125)
816 */
817 mdot1 = strnstr(m, ".", mlen);
818 if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
819 return (0);
820 mdot1idx = mdot1 - m;
821 mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
822 if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
823 return (0);
824 /* hostname must contain a dot and not be the 1st char */
825 hdot = strnstr(h, ".", hlen);
826 if (hdot == NULL || hdot == h)
827 return (0);
828 hdotidx = hdot - h;
829 /*
830 * host part of hostname must be at least as long as
831 * pattern it's supposed to match
832 */
833 if (hdotidx < mdot1idx)
834 return (0);
835 /*
836 * don't allow wildcards in non-traditional domain names
837 * (IDN, A-label, U-label...)
838 */
839 if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
840 !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
841 return (0);
842 /* match domain part (part after first dot) */
843 if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
844 mlen - mdot1idx))
845 return (0);
846 /* match part left of wildcard */
847 if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
848 return (0);
849 /* match part right of wildcard */
850 delta = mdot1idx - wcidx - 1;
851 if (!fetch_ssl_hname_equal(hdot - delta, delta,
852 mdot1 - delta, delta))
853 return (0);
854 /* all tests succeeded, it's a match */
855 return (1);
856 }
857
858 /*
859 * Get numeric host address info - returns NULL if host was not an IP
860 * address. The caller is responsible for deallocation using
861 * freeaddrinfo(3).
862 */
863 static struct addrinfo *
fetch_ssl_get_numeric_addrinfo(const char * hostname,size_t len)864 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
865 {
866 struct addrinfo hints, *res;
867 char *host;
868
869 host = (char *)malloc(len + 1);
870 memcpy(host, hostname, len);
871 host[len] = '\0';
872 memset(&hints, 0, sizeof(hints));
873 hints.ai_family = PF_UNSPEC;
874 hints.ai_socktype = SOCK_STREAM;
875 hints.ai_protocol = 0;
876 hints.ai_flags = AI_NUMERICHOST;
877 /* port is not relevant for this purpose */
878 if (getaddrinfo(host, "443", &hints, &res) != 0)
879 res = NULL;
880 free(host);
881 return res;
882 }
883
884 /*
885 * Compare ip address in addrinfo with address passes.
886 */
887 static int
fetch_ssl_ipaddr_match_bin(const struct addrinfo * lhost,const char * rhost,size_t rhostlen)888 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
889 size_t rhostlen)
890 {
891 const void *left;
892
893 if (lhost->ai_family == AF_INET && rhostlen == 4) {
894 left = (void *)&((struct sockaddr_in*)(void *)
895 lhost->ai_addr)->sin_addr.s_addr;
896 #ifdef INET6
897 } else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
898 left = (void *)&((struct sockaddr_in6 *)(void *)
899 lhost->ai_addr)->sin6_addr;
900 #endif
901 } else
902 return (0);
903 return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
904 }
905
906 /*
907 * Compare ip address in addrinfo with host passed. If host is not an IP
908 * address, comparison will fail.
909 */
910 static int
fetch_ssl_ipaddr_match(const struct addrinfo * laddr,const char * r,size_t rlen)911 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
912 size_t rlen)
913 {
914 struct addrinfo *raddr;
915 int ret;
916 char *rip;
917
918 ret = 0;
919 if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
920 return 0; /* not a numeric host */
921
922 if (laddr->ai_family == raddr->ai_family) {
923 if (laddr->ai_family == AF_INET) {
924 rip = (char *)&((struct sockaddr_in *)(void *)
925 raddr->ai_addr)->sin_addr.s_addr;
926 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
927 #ifdef INET6
928 } else if (laddr->ai_family == AF_INET6) {
929 rip = (char *)&((struct sockaddr_in6 *)(void *)
930 raddr->ai_addr)->sin6_addr;
931 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
932 #endif
933 }
934
935 }
936 freeaddrinfo(raddr);
937 return (ret);
938 }
939
940 /*
941 * Verify server certificate by subjectAltName.
942 */
943 static int
fetch_ssl_verify_altname(STACK_OF (GENERAL_NAME)* altnames,const char * host,struct addrinfo * ip)944 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
945 const char *host, struct addrinfo *ip)
946 {
947 const GENERAL_NAME *name;
948 size_t nslen;
949 int i;
950 const char *ns;
951
952 for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
953 name = sk_GENERAL_NAME_value(altnames, i);
954 ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
955 nslen = (size_t)ASN1_STRING_length(name->d.ia5);
956
957 if (name->type == GEN_DNS && ip == NULL &&
958 fetch_ssl_hname_match(host, strlen(host), ns, nslen))
959 return (1);
960 else if (name->type == GEN_IPADD && ip != NULL &&
961 fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
962 return (1);
963 }
964 return (0);
965 }
966
967 /*
968 * Verify server certificate by CN.
969 */
970 static int
fetch_ssl_verify_cn(X509_NAME * subject,const char * host,struct addrinfo * ip)971 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
972 struct addrinfo *ip)
973 {
974 ASN1_STRING *namedata;
975 X509_NAME_ENTRY *nameentry;
976 int cnlen, lastpos, loc, ret;
977 unsigned char *cn;
978
979 ret = 0;
980 lastpos = -1;
981 loc = -1;
982 cn = NULL;
983 /* get most specific CN (last entry in list) and compare */
984 while ((lastpos = X509_NAME_get_index_by_NID(subject,
985 NID_commonName, lastpos)) != -1)
986 loc = lastpos;
987
988 if (loc > -1) {
989 nameentry = X509_NAME_get_entry(subject, loc);
990 namedata = X509_NAME_ENTRY_get_data(nameentry);
991 cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
992 if (ip == NULL &&
993 fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
994 ret = 1;
995 else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
996 ret = 1;
997 OPENSSL_free(cn);
998 }
999 return (ret);
1000 }
1001
1002 /*
1003 * Verify that server certificate subjectAltName/CN matches
1004 * hostname. First check, if there are alternative subject names. If yes,
1005 * those have to match. Only if those don't exist it falls back to
1006 * checking the subject's CN.
1007 */
1008 static int
fetch_ssl_verify_hname(X509 * cert,const char * host)1009 fetch_ssl_verify_hname(X509 *cert, const char *host)
1010 {
1011 struct addrinfo *ip;
1012 STACK_OF(GENERAL_NAME) *altnames;
1013 X509_NAME *subject;
1014 int ret;
1015
1016 ret = 0;
1017 ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1018 altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1019 NULL, NULL);
1020
1021 if (altnames != NULL) {
1022 ret = fetch_ssl_verify_altname(altnames, host, ip);
1023 } else {
1024 subject = X509_get_subject_name(cert);
1025 if (subject != NULL)
1026 ret = fetch_ssl_verify_cn(subject, host, ip);
1027 }
1028
1029 if (ip != NULL)
1030 freeaddrinfo(ip);
1031 if (altnames != NULL)
1032 GENERAL_NAMES_free(altnames);
1033 return (ret);
1034 }
1035
1036 /*
1037 * Configure transport security layer based on environment.
1038 */
1039 static void
fetch_ssl_setup_transport_layer(SSL_CTX * ctx,int verbose)1040 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1041 {
1042 long ssl_ctx_options;
1043
1044 ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1045 if (getenv("SSL_NO_TLS1") != NULL)
1046 ssl_ctx_options |= SSL_OP_NO_TLSv1;
1047 if (getenv("SSL_NO_TLS1_1") != NULL)
1048 ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1049 if (getenv("SSL_NO_TLS1_2") != NULL)
1050 ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1051 if (getenv("SSL_NO_TLS1_3") != NULL)
1052 ssl_ctx_options |= SSL_OP_NO_TLSv1_3;
1053 if (verbose)
1054 fetch_info("SSL options: %lx", ssl_ctx_options);
1055 SSL_CTX_set_options(ctx, ssl_ctx_options);
1056 }
1057
1058
1059 /*
1060 * Configure peer verification based on environment.
1061 */
1062 static int
fetch_ssl_setup_peer_verification(SSL_CTX * ctx,int verbose)1063 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1064 {
1065 X509_LOOKUP *crl_lookup;
1066 X509_STORE *crl_store;
1067 const char *ca_cert_file, *ca_cert_path, *crl_file;
1068
1069 if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1070 ca_cert_file = getenv("SSL_CA_CERT_FILE");
1071 ca_cert_path = getenv("SSL_CA_CERT_PATH");
1072 if (verbose) {
1073 fetch_info("Peer verification enabled");
1074 if (ca_cert_file != NULL)
1075 fetch_info("Using CA cert file: %s",
1076 ca_cert_file);
1077 if (ca_cert_path != NULL)
1078 fetch_info("Using CA cert path: %s",
1079 ca_cert_path);
1080 if (ca_cert_file == NULL && ca_cert_path == NULL)
1081 fetch_info("Using OpenSSL default "
1082 "CA cert file and path");
1083 }
1084 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1085 fetch_ssl_cb_verify_crt);
1086 if (ca_cert_file != NULL || ca_cert_path != NULL)
1087 SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1088 ca_cert_path);
1089 else
1090 SSL_CTX_set_default_verify_paths(ctx);
1091 if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1092 if (verbose)
1093 fetch_info("Using CRL file: %s", crl_file);
1094 crl_store = SSL_CTX_get_cert_store(ctx);
1095 crl_lookup = X509_STORE_add_lookup(crl_store,
1096 X509_LOOKUP_file());
1097 if (crl_lookup == NULL ||
1098 !X509_load_crl_file(crl_lookup, crl_file,
1099 X509_FILETYPE_PEM)) {
1100 fprintf(stderr,
1101 "Could not load CRL file %s\n",
1102 crl_file);
1103 return (0);
1104 }
1105 X509_STORE_set_flags(crl_store,
1106 X509_V_FLAG_CRL_CHECK |
1107 X509_V_FLAG_CRL_CHECK_ALL);
1108 }
1109 }
1110 return (1);
1111 }
1112
1113 /*
1114 * Configure client certificate based on environment.
1115 */
1116 static int
fetch_ssl_setup_client_certificate(SSL_CTX * ctx,int verbose)1117 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1118 {
1119 const char *client_cert_file, *client_key_file;
1120
1121 if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1122 client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1123 getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1124 if (verbose) {
1125 fetch_info("Using client cert file: %s",
1126 client_cert_file);
1127 fetch_info("Using client key file: %s",
1128 client_key_file);
1129 }
1130 if (SSL_CTX_use_certificate_chain_file(ctx,
1131 client_cert_file) != 1) {
1132 fprintf(stderr,
1133 "Could not load client certificate %s\n",
1134 client_cert_file);
1135 return (0);
1136 }
1137 if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1138 SSL_FILETYPE_PEM) != 1) {
1139 fprintf(stderr,
1140 "Could not load client key %s\n",
1141 client_key_file);
1142 return (0);
1143 }
1144 }
1145 return (1);
1146 }
1147
1148 /*
1149 * Callback for SSL certificate verification, this is called on server
1150 * cert verification. It takes no decision, but informs the user in case
1151 * verification failed.
1152 */
1153 int
fetch_ssl_cb_verify_crt(int verified,X509_STORE_CTX * ctx)1154 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1155 {
1156 X509 *crt;
1157 X509_NAME *name;
1158 char *str;
1159
1160 str = NULL;
1161 if (!verified) {
1162 if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1163 (name = X509_get_subject_name(crt)) != NULL)
1164 str = X509_NAME_oneline(name, 0, 0);
1165 fprintf(stderr, "Certificate verification failed for %s\n",
1166 str != NULL ? str : "no relevant certificate");
1167 OPENSSL_free(str);
1168 }
1169 return (verified);
1170 }
1171
1172 #endif
1173
1174 /*
1175 * Enable SSL on a connection.
1176 */
1177 int
fetch_ssl(conn_t * conn,const struct url * URL,int verbose)1178 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1179 {
1180 #ifdef WITH_SSL
1181 int ret, ssl_err;
1182 X509_NAME *name;
1183 char *str;
1184
1185 conn->ssl_meth = SSLv23_client_method();
1186 conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
1187 SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1188
1189 fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1190 if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1191 return (-1);
1192 if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1193 return (-1);
1194
1195 conn->ssl = SSL_new(conn->ssl_ctx);
1196 if (conn->ssl == NULL) {
1197 fprintf(stderr, "SSL context creation failed\n");
1198 return (-1);
1199 }
1200 SSL_set_fd(conn->ssl, conn->sd);
1201
1202 #if !defined(OPENSSL_NO_TLSEXT)
1203 if (!SSL_set_tlsext_host_name(conn->ssl,
1204 __DECONST(struct url *, URL)->host)) {
1205 fprintf(stderr,
1206 "TLS server name indication extension failed for host %s\n",
1207 URL->host);
1208 return (-1);
1209 }
1210 #endif
1211 while ((ret = SSL_connect(conn->ssl)) == -1) {
1212 ssl_err = SSL_get_error(conn->ssl, ret);
1213 if (ssl_err != SSL_ERROR_WANT_READ &&
1214 ssl_err != SSL_ERROR_WANT_WRITE) {
1215 ERR_print_errors_fp(stderr);
1216 return (-1);
1217 }
1218 }
1219 conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1220
1221 if (conn->ssl_cert == NULL) {
1222 fprintf(stderr, "No server SSL certificate\n");
1223 return (-1);
1224 }
1225
1226 if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1227 if (verbose)
1228 fetch_info("Verify hostname");
1229 if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1230 fprintf(stderr,
1231 "SSL certificate subject doesn't match host %s\n",
1232 URL->host);
1233 return (-1);
1234 }
1235 }
1236
1237 if (verbose) {
1238 fetch_info("%s connection established using %s",
1239 SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1240 name = X509_get_subject_name(conn->ssl_cert);
1241 str = X509_NAME_oneline(name, 0, 0);
1242 fetch_info("Certificate subject: %s", str);
1243 OPENSSL_free(str);
1244 name = X509_get_issuer_name(conn->ssl_cert);
1245 str = X509_NAME_oneline(name, 0, 0);
1246 fetch_info("Certificate issuer: %s", str);
1247 OPENSSL_free(str);
1248 }
1249
1250 return (0);
1251 #else
1252 (void)conn;
1253 (void)verbose;
1254 (void)URL;
1255 fprintf(stderr, "SSL support disabled\n");
1256 return (-1);
1257 #endif
1258 }
1259
1260 #define FETCH_READ_WAIT -2
1261 #define FETCH_READ_ERROR -1
1262 #define FETCH_READ_DONE 0
1263
1264 #ifdef WITH_SSL
1265 static ssize_t
fetch_ssl_read(SSL * ssl,char * buf,size_t len)1266 fetch_ssl_read(SSL *ssl, char *buf, size_t len)
1267 {
1268 ssize_t rlen;
1269 int ssl_err;
1270 struct timeval tv;
1271
1272 if (fetchTimeout > 0) {
1273 tv.tv_sec = fetchTimeout;
1274 tv.tv_usec = 0;
1275 setsockopt(SSL_get_fd(ssl), SOL_SOCKET, SO_RCVTIMEO,
1276 &tv, sizeof(tv));
1277 }
1278
1279 rlen = SSL_read(ssl, buf, len);
1280 if (rlen < 0) {
1281 ssl_err = SSL_get_error(ssl, rlen);
1282 if (ssl_err == SSL_ERROR_WANT_READ ||
1283 ssl_err == SSL_ERROR_WANT_WRITE) {
1284 return (FETCH_READ_WAIT);
1285 } else {
1286 ERR_print_errors_fp(stderr);
1287 return (FETCH_READ_ERROR);
1288 }
1289 }
1290 return (rlen);
1291 }
1292 #endif
1293
1294 static ssize_t
fetch_socket_read(int sd,char * buf,size_t len)1295 fetch_socket_read(int sd, char *buf, size_t len)
1296 {
1297 ssize_t rlen;
1298
1299 rlen = read(sd, buf, len);
1300 if (rlen < 0) {
1301 if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
1302 return (FETCH_READ_WAIT);
1303 else
1304 return (FETCH_READ_ERROR);
1305 }
1306 return (rlen);
1307 }
1308
1309 /*
1310 * Read a character from a connection w/ timeout
1311 */
1312 ssize_t
fetch_read(conn_t * conn,char * buf,size_t len)1313 fetch_read(conn_t *conn, char *buf, size_t len)
1314 {
1315 struct timeval now, timeout, delta;
1316 struct pollfd pfd;
1317 ssize_t rlen;
1318 int deltams;
1319
1320 if (fetchTimeout > 0) {
1321 gettimeofday(&timeout, NULL);
1322 timeout.tv_sec += fetchTimeout;
1323 }
1324
1325 deltams = INFTIM;
1326 memset(&pfd, 0, sizeof pfd);
1327 pfd.fd = conn->sd;
1328 pfd.events = POLLIN | POLLERR;
1329
1330 for (;;) {
1331 /*
1332 * The socket is non-blocking. Instead of the canonical
1333 * poll() -> read(), we do the following:
1334 *
1335 * 1) call read() or SSL_read().
1336 * 2) if we received some data, return it.
1337 * 3) if an error occurred, return -1.
1338 * 4) if read() or SSL_read() signaled EOF, return.
1339 * 5) if we did not receive any data but we're not at EOF,
1340 * call poll().
1341 *
1342 * In the SSL case, this is necessary because if we
1343 * receive a close notification, we have to call
1344 * SSL_read() one additional time after we've read
1345 * everything we received.
1346 *
1347 * In the non-SSL case, it may improve performance (very
1348 * slightly) when reading small amounts of data.
1349 */
1350 #ifdef WITH_SSL
1351 if (conn->ssl != NULL)
1352 rlen = fetch_ssl_read(conn->ssl, buf, len);
1353 else
1354 #endif
1355 rlen = fetch_socket_read(conn->sd, buf, len);
1356 if (rlen >= 0) {
1357 break;
1358 } else if (rlen == FETCH_READ_ERROR) {
1359 fetch_syserr();
1360 return (-1);
1361 }
1362 // assert(rlen == FETCH_READ_WAIT);
1363 if (fetchTimeout > 0) {
1364 gettimeofday(&now, NULL);
1365 if (!timercmp(&timeout, &now, >)) {
1366 errno = ETIMEDOUT;
1367 fetch_syserr();
1368 return (-1);
1369 }
1370 timersub(&timeout, &now, &delta);
1371 deltams = delta.tv_sec * 1000 +
1372 delta.tv_usec / 1000;
1373 }
1374 errno = 0;
1375 pfd.revents = 0;
1376 if (poll(&pfd, 1, deltams) < 0) {
1377 if (errno == EINTR && fetchRestartCalls)
1378 continue;
1379 fetch_syserr();
1380 return (-1);
1381 }
1382 }
1383 return (rlen);
1384 }
1385
1386
1387 /*
1388 * Read a line of text from a connection w/ timeout
1389 */
1390 #define MIN_BUF_SIZE 1024
1391
1392 int
fetch_getln(conn_t * conn)1393 fetch_getln(conn_t *conn)
1394 {
1395 char *tmp;
1396 size_t tmpsize;
1397 ssize_t len;
1398 char c;
1399
1400 if (conn->buf == NULL) {
1401 if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
1402 errno = ENOMEM;
1403 return (-1);
1404 }
1405 conn->bufsize = MIN_BUF_SIZE;
1406 }
1407
1408 conn->buf[0] = '\0';
1409 conn->buflen = 0;
1410
1411 do {
1412 len = fetch_read(conn, &c, 1);
1413 if (len == -1)
1414 return (-1);
1415 if (len == 0)
1416 break;
1417 conn->buf[conn->buflen++] = c;
1418 if (conn->buflen == conn->bufsize) {
1419 tmp = conn->buf;
1420 tmpsize = conn->bufsize * 2 + 1;
1421 if ((tmp = realloc(tmp, tmpsize)) == NULL) {
1422 errno = ENOMEM;
1423 return (-1);
1424 }
1425 conn->buf = tmp;
1426 conn->bufsize = tmpsize;
1427 }
1428 } while (c != '\n');
1429
1430 conn->buf[conn->buflen] = '\0';
1431 DEBUGF("<<< %s", conn->buf);
1432 return (0);
1433 }
1434
1435
1436 /*
1437 * Write to a connection w/ timeout
1438 */
1439 ssize_t
fetch_write(conn_t * conn,const char * buf,size_t len)1440 fetch_write(conn_t *conn, const char *buf, size_t len)
1441 {
1442 struct iovec iov;
1443
1444 iov.iov_base = __DECONST(char *, buf);
1445 iov.iov_len = len;
1446 return fetch_writev(conn, &iov, 1);
1447 }
1448
1449 /*
1450 * Write a vector to a connection w/ timeout
1451 * Note: can modify the iovec.
1452 */
1453 ssize_t
fetch_writev(conn_t * conn,struct iovec * iov,int iovcnt)1454 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1455 {
1456 struct timeval now, timeout, delta;
1457 struct pollfd pfd;
1458 ssize_t wlen, total;
1459 int deltams;
1460
1461 memset(&pfd, 0, sizeof pfd);
1462 if (fetchTimeout) {
1463 pfd.fd = conn->sd;
1464 pfd.events = POLLOUT | POLLERR;
1465 gettimeofday(&timeout, NULL);
1466 timeout.tv_sec += fetchTimeout;
1467 }
1468
1469 total = 0;
1470 while (iovcnt > 0) {
1471 while (fetchTimeout && pfd.revents == 0) {
1472 gettimeofday(&now, NULL);
1473 if (!timercmp(&timeout, &now, >)) {
1474 errno = ETIMEDOUT;
1475 fetch_syserr();
1476 return (-1);
1477 }
1478 timersub(&timeout, &now, &delta);
1479 deltams = delta.tv_sec * 1000 +
1480 delta.tv_usec / 1000;
1481 errno = 0;
1482 pfd.revents = 0;
1483 if (poll(&pfd, 1, deltams) < 0) {
1484 /* POSIX compliance */
1485 if (errno == EAGAIN)
1486 continue;
1487 if (errno == EINTR && fetchRestartCalls)
1488 continue;
1489 return (-1);
1490 }
1491 }
1492 errno = 0;
1493 #ifdef WITH_SSL
1494 if (conn->ssl != NULL)
1495 wlen = SSL_write(conn->ssl,
1496 iov->iov_base, iov->iov_len);
1497 else
1498 #endif
1499 wlen = writev(conn->sd, iov, iovcnt);
1500 if (wlen == 0) {
1501 /* we consider a short write a failure */
1502 /* XXX perhaps we shouldn't in the SSL case */
1503 errno = EPIPE;
1504 fetch_syserr();
1505 return (-1);
1506 }
1507 if (wlen < 0) {
1508 if (errno == EINTR && fetchRestartCalls)
1509 continue;
1510 return (-1);
1511 }
1512 total += wlen;
1513 while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1514 wlen -= iov->iov_len;
1515 iov++;
1516 iovcnt--;
1517 }
1518 if (iovcnt > 0) {
1519 iov->iov_len -= wlen;
1520 iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1521 }
1522 }
1523 return (total);
1524 }
1525
1526
1527 /*
1528 * Write a line of text to a connection w/ timeout
1529 */
1530 int
fetch_putln(conn_t * conn,const char * str,size_t len)1531 fetch_putln(conn_t *conn, const char *str, size_t len)
1532 {
1533 struct iovec iov[2];
1534 int ret;
1535
1536 DEBUGF(">>> %s\n", str);
1537 iov[0].iov_base = __DECONST(char *, str);
1538 iov[0].iov_len = len;
1539 iov[1].iov_base = __DECONST(char *, ENDL);
1540 iov[1].iov_len = sizeof(ENDL);
1541 if (len == 0)
1542 ret = fetch_writev(conn, &iov[1], 1);
1543 else
1544 ret = fetch_writev(conn, iov, 2);
1545 if (ret == -1)
1546 return (-1);
1547 return (0);
1548 }
1549
1550
1551 /*
1552 * Close connection
1553 */
1554 int
fetch_close(conn_t * conn)1555 fetch_close(conn_t *conn)
1556 {
1557 int ret;
1558
1559 if (--conn->ref > 0)
1560 return (0);
1561 #ifdef WITH_SSL
1562 if (conn->ssl) {
1563 SSL_shutdown(conn->ssl);
1564 SSL_set_connect_state(conn->ssl);
1565 SSL_free(conn->ssl);
1566 conn->ssl = NULL;
1567 }
1568 if (conn->ssl_ctx) {
1569 SSL_CTX_free(conn->ssl_ctx);
1570 conn->ssl_ctx = NULL;
1571 }
1572 if (conn->ssl_cert) {
1573 X509_free(conn->ssl_cert);
1574 conn->ssl_cert = NULL;
1575 }
1576 #endif
1577 ret = close(conn->sd);
1578 free(conn->buf);
1579 free(conn);
1580 return (ret);
1581 }
1582
1583
1584 /*** Directory-related utility functions *************************************/
1585
1586 int
fetch_add_entry(struct url_ent ** p,int * size,int * len,const char * name,struct url_stat * us)1587 fetch_add_entry(struct url_ent **p, int *size, int *len,
1588 const char *name, struct url_stat *us)
1589 {
1590 struct url_ent *tmp;
1591
1592 if (*p == NULL) {
1593 *size = 0;
1594 *len = 0;
1595 }
1596
1597 if (*len >= *size - 1) {
1598 tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1599 if (tmp == NULL) {
1600 errno = ENOMEM;
1601 fetch_syserr();
1602 return (-1);
1603 }
1604 *size = (*size * 2 + 1);
1605 *p = tmp;
1606 }
1607
1608 tmp = *p + *len;
1609 snprintf(tmp->name, PATH_MAX, "%s", name);
1610 memcpy(&tmp->stat, us, sizeof(*us));
1611
1612 (*len)++;
1613 (++tmp)->name[0] = 0;
1614
1615 return (0);
1616 }
1617
1618
1619 /*** Authentication-related utility functions ********************************/
1620
1621 static const char *
fetch_read_word(FILE * f)1622 fetch_read_word(FILE *f)
1623 {
1624 static char word[1024];
1625
1626 if (fscanf(f, " %1023s ", word) != 1)
1627 return (NULL);
1628 return (word);
1629 }
1630
1631 static int
fetch_netrc_open(void)1632 fetch_netrc_open(void)
1633 {
1634 struct passwd *pwd;
1635 char fn[PATH_MAX];
1636 const char *p;
1637 int fd, serrno;
1638
1639 if ((p = getenv("NETRC")) != NULL) {
1640 DEBUGF("NETRC=%s\n", p);
1641 if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1642 fetch_info("$NETRC specifies a file name "
1643 "longer than PATH_MAX");
1644 return (-1);
1645 }
1646 } else {
1647 if ((p = getenv("HOME")) == NULL) {
1648 if ((pwd = getpwuid(getuid())) == NULL ||
1649 (p = pwd->pw_dir) == NULL)
1650 return (-1);
1651 }
1652 if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1653 return (-1);
1654 }
1655
1656 if ((fd = open(fn, O_RDONLY)) < 0) {
1657 serrno = errno;
1658 DEBUGF("%s: %s\n", fn, strerror(serrno));
1659 errno = serrno;
1660 }
1661 return (fd);
1662 }
1663
1664 /*
1665 * Get authentication data for a URL from .netrc
1666 */
1667 int
fetch_netrc_auth(struct url * url)1668 fetch_netrc_auth(struct url *url)
1669 {
1670 const char *word;
1671 int serrno;
1672 FILE *f;
1673
1674 if (url->netrcfd < 0)
1675 url->netrcfd = fetch_netrc_open();
1676 if (url->netrcfd < 0)
1677 return (-1);
1678 if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1679 serrno = errno;
1680 DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1681 close(url->netrcfd);
1682 url->netrcfd = -1;
1683 errno = serrno;
1684 return (-1);
1685 }
1686 rewind(f);
1687 DEBUGF("searching netrc for %s\n", url->host);
1688 while ((word = fetch_read_word(f)) != NULL) {
1689 if (strcmp(word, "default") == 0) {
1690 DEBUGF("using default netrc settings\n");
1691 break;
1692 }
1693 if (strcmp(word, "machine") == 0 &&
1694 (word = fetch_read_word(f)) != NULL &&
1695 strcasecmp(word, url->host) == 0) {
1696 DEBUGF("using netrc settings for %s\n", word);
1697 break;
1698 }
1699 }
1700 if (word == NULL)
1701 goto ferr;
1702 while ((word = fetch_read_word(f)) != NULL) {
1703 if (strcmp(word, "login") == 0) {
1704 if ((word = fetch_read_word(f)) == NULL)
1705 goto ferr;
1706 if (snprintf(url->user, sizeof(url->user),
1707 "%s", word) > (int)sizeof(url->user)) {
1708 fetch_info("login name in .netrc is too long");
1709 url->user[0] = '\0';
1710 }
1711 } else if (strcmp(word, "password") == 0) {
1712 if ((word = fetch_read_word(f)) == NULL)
1713 goto ferr;
1714 if (snprintf(url->pwd, sizeof(url->pwd),
1715 "%s", word) > (int)sizeof(url->pwd)) {
1716 fetch_info("password in .netrc is too long");
1717 url->pwd[0] = '\0';
1718 }
1719 } else if (strcmp(word, "account") == 0) {
1720 if ((word = fetch_read_word(f)) == NULL)
1721 goto ferr;
1722 /* XXX not supported! */
1723 } else {
1724 break;
1725 }
1726 }
1727 fclose(f);
1728 url->netrcfd = -1;
1729 return (0);
1730 ferr:
1731 serrno = errno;
1732 fclose(f);
1733 url->netrcfd = -1;
1734 errno = serrno;
1735 return (-1);
1736 }
1737
1738 /*
1739 * The no_proxy environment variable specifies a set of domains for
1740 * which the proxy should not be consulted; the contents is a comma-,
1741 * or space-separated list of domain names. A single asterisk will
1742 * override all proxy variables and no transactions will be proxied
1743 * (for compatibility with lynx and curl, see the discussion at
1744 * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1745 */
1746 int
fetch_no_proxy_match(const char * host)1747 fetch_no_proxy_match(const char *host)
1748 {
1749 const char *no_proxy, *p, *q;
1750 size_t h_len, d_len;
1751
1752 if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1753 (no_proxy = getenv("no_proxy")) == NULL)
1754 return (0);
1755
1756 /* asterisk matches any hostname */
1757 if (strcmp(no_proxy, "*") == 0)
1758 return (1);
1759
1760 h_len = strlen(host);
1761 p = no_proxy;
1762 do {
1763 /* position p at the beginning of a domain suffix */
1764 while (*p == ',' || isspace((unsigned char)*p))
1765 p++;
1766
1767 /* position q at the first separator character */
1768 for (q = p; *q; ++q)
1769 if (*q == ',' || isspace((unsigned char)*q))
1770 break;
1771
1772 d_len = q - p;
1773 if (d_len > 0 && h_len >= d_len &&
1774 strncasecmp(host + h_len - d_len,
1775 p, d_len) == 0) {
1776 /* domain name matches */
1777 return (1);
1778 }
1779
1780 p = q + 1;
1781 } while (*q);
1782
1783 return (0);
1784 }
1785