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