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 * $FreeBSD: head/lib/libfetch/common.c 358227 2020-02-21 18:21:57Z kevans
32 */
33
34 #include <sys/cdefs.h>
35
36 #include <sys/param.h>
37 #include <sys/socket.h>
38 #include <sys/time.h>
39 #include <sys/uio.h>
40
41 #include <netinet/in.h>
42
43 #include <ctype.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <inttypes.h>
47 #include <netdb.h>
48 #include <poll.h>
49 #include <pwd.h>
50 #include <stdarg.h>
51 #include <stdlib.h>
52 #include <stdio.h>
53 #include <string.h>
54 #include <unistd.h>
55
56 #ifdef WITH_SSL
57 #include <openssl/x509v3.h>
58 #endif
59
60 #include "fetch.h"
61 #include "common.h"
62
63
64 /*** Local data **************************************************************/
65
66 /*
67 * Error messages for resolver errors
68 */
69 static struct fetcherr netdb_errlist[] = {
70 #ifdef EAI_NODATA
71 { EAI_NODATA, FETCH_RESOLV, "Host not found" },
72 #endif
73 { EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" },
74 { EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" },
75 { EAI_NONAME, FETCH_RESOLV, "No address record" },
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 opt = 1;
281
282 /* allocate and fill connection structure */
283 if ((conn = calloc(1, sizeof(*conn))) == NULL)
284 return (NULL);
285 fcntl(sd, F_SETFD, FD_CLOEXEC);
286 setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt);
287 conn->sd = sd;
288 ++conn->ref;
289 return (conn);
290 }
291
292
293 /*
294 * Bump a connection's reference count.
295 */
296 conn_t *
fetch_ref(conn_t * conn)297 fetch_ref(conn_t *conn)
298 {
299
300 ++conn->ref;
301 return (conn);
302 }
303
304
305 /*
306 * Resolve an address
307 */
308 struct addrinfo *
fetch_resolve(const char * addr,int port,int af)309 fetch_resolve(const char *addr, int port, int af)
310 {
311 char hbuf[256], sbuf[8];
312 struct addrinfo hints, *res;
313 const char *hb, *he, *sep;
314 const char *host, *service;
315 int err, len;
316
317 /* first, check for a bracketed IPv6 address */
318 if (*addr == '[') {
319 hb = addr + 1;
320 if ((sep = strchr(hb, ']')) == NULL) {
321 errno = EINVAL;
322 goto syserr;
323 }
324 he = sep++;
325 } else {
326 hb = addr;
327 sep = strchrnul(hb, ':');
328 he = sep;
329 }
330
331 /* see if we need to copy the host name */
332 if (*he != '\0') {
333 len = snprintf(hbuf, sizeof(hbuf),
334 "%.*s", (int)(he - hb), hb);
335 if (len < 0)
336 goto syserr;
337 if (len >= (int)sizeof(hbuf)) {
338 errno = ENAMETOOLONG;
339 goto syserr;
340 }
341 host = hbuf;
342 } else {
343 host = hb;
344 }
345
346 /* was it followed by a service name? */
347 if (*sep == '\0' && port != 0) {
348 if (port < 1 || port > 65535) {
349 errno = EINVAL;
350 goto syserr;
351 }
352 if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
353 goto syserr;
354 service = sbuf;
355 } else if (*sep != '\0') {
356 service = sep + 1;
357 } else {
358 service = NULL;
359 }
360
361 /* resolve */
362 memset(&hints, 0, sizeof(hints));
363 hints.ai_family = af;
364 hints.ai_socktype = SOCK_STREAM;
365 hints.ai_flags = AI_ADDRCONFIG;
366 if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
367 netdb_seterr(err);
368 return (NULL);
369 }
370 return (res);
371 syserr:
372 fetch_syserr();
373 return (NULL);
374 }
375
376
377 /*
378 * Bind a socket to a specific local address
379 */
380 int
fetch_bind(int sd,int af,const char * addr)381 fetch_bind(int sd, int af, const char *addr)
382 {
383 struct addrinfo *cliai, *ai;
384 int err;
385
386 if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
387 return (-1);
388 for (ai = cliai; ai != NULL; ai = ai->ai_next)
389 if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
390 break;
391 if (err != 0)
392 fetch_syserr();
393 freeaddrinfo(cliai);
394 return (err == 0 ? 0 : -1);
395 }
396
397
398 /*
399 * SOCKS5 connection initiation, based on RFC 1928
400 * Default DNS resolution over SOCKS5
401 */
402 int
fetch_socks5_init(conn_t * conn,const char * host,int port,int verbose)403 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
404 {
405 /*
406 * Size is based on largest packet prefix (4 bytes) +
407 * Largest FQDN (256) + one byte size (1) +
408 * Port (2)
409 */
410 unsigned char buf[BUFF_SIZE];
411 unsigned char *ptr;
412 int ret = 1;
413
414 if (verbose)
415 fetch_info("Initializing SOCKS5 connection: %s:%d", host, port);
416
417 /* Connection initialization */
418 ptr = buf;
419 *ptr++ = SOCKS_VERSION_5;
420 *ptr++ = SOCKS_CONNECTION;
421 *ptr++ = SOCKS_RSV;
422
423 if (fetch_write(conn, buf, 3) != 3) {
424 ret = SOCKS5_ERR_SELECTION;
425 goto fail;
426 }
427
428 /* Verify response from SOCKS5 server */
429 if (fetch_read(conn, buf, 2) != 2) {
430 ret = SOCKS5_ERR_READ_METHOD;
431 goto fail;
432 }
433
434 ptr = buf;
435 if (ptr[0] != SOCKS_VERSION_5) {
436 ret = SOCKS5_ERR_VER5_ONLY;
437 goto fail;
438 }
439 if (ptr[1] == SOCKS_NOMETHODS) {
440 ret = SOCKS5_ERR_NOMETHODS;
441 goto fail;
442 }
443 else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
444 ret = SOCKS5_ERR_NOTIMPLEMENTED;
445 goto fail;
446 }
447
448 /* Send Request */
449 *ptr++ = SOCKS_VERSION_5;
450 *ptr++ = SOCKS_CONNECTION;
451 *ptr++ = SOCKS_RSV;
452 /* Encode all targets as a hostname to avoid DNS leaks */
453 *ptr++ = SOCKS_ATYP_DOMAINNAME;
454 if (strlen(host) > FQDN_SIZE) {
455 ret = SOCKS5_ERR_HOSTNAME_SIZE;
456 goto fail;
457 }
458 *ptr++ = strlen(host);
459 strncpy(ptr, host, strlen(host));
460 ptr = ptr + strlen(host);
461
462 port = htons(port);
463 *ptr++ = port & 0x00ff;
464 *ptr++ = (port & 0xff00) >> 8;
465
466 if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
467 ret = SOCKS5_ERR_REQUEST;
468 goto fail;
469 }
470
471 /* BND.ADDR is variable length, read the largest on non-blocking socket */
472 if (!fetch_read(conn, buf, BUFF_SIZE)) {
473 ret = SOCKS5_ERR_REPLY;
474 goto fail;
475 }
476
477 ptr = buf;
478 if (*ptr++ != SOCKS_VERSION_5) {
479 ret = SOCKS5_ERR_NON_VER5_RESP;
480 goto fail;
481 }
482
483 switch(*ptr++) {
484 case SOCKS_SUCCESS:
485 break;
486 case SOCKS_GENERAL_FAILURE:
487 ret = SOCKS5_ERR_GENERAL;
488 goto fail;
489 case SOCKS_CONNECTION_NOT_ALLOWED:
490 ret = SOCKS5_ERR_NOT_ALLOWED;
491 goto fail;
492 case SOCKS_NETWORK_UNREACHABLE:
493 ret = SOCKS5_ERR_NET_UNREACHABLE;
494 goto fail;
495 case SOCKS_HOST_UNREACHABLE:
496 ret = SOCKS5_ERR_HOST_UNREACHABLE;
497 goto fail;
498 case SOCKS_CONNECTION_REFUSED:
499 ret = SOCKS5_ERR_CONN_REFUSED;
500 goto fail;
501 case SOCKS_TTL_EXPIRED:
502 ret = SOCKS5_ERR_TTL_EXPIRED;
503 goto fail;
504 case SOCKS_COMMAND_NOT_SUPPORTED:
505 ret = SOCKS5_ERR_COM_UNSUPPORTED;
506 goto fail;
507 case SOCKS_ADDRESS_NOT_SUPPORTED:
508 ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
509 goto fail;
510 default:
511 ret = SOCKS5_ERR_UNSPECIFIED;
512 goto fail;
513 }
514
515 return (ret);
516
517 fail:
518 socks5_seterr(ret);
519 return (0);
520 }
521
522 /*
523 * Perform SOCKS5 initialization
524 */
525 int
fetch_socks5_getenv(char ** host,int * port)526 fetch_socks5_getenv(char **host, int *port)
527 {
528 char *socks5env, *endptr, *ext;
529 const char *portDelim;
530 size_t slen;
531
532 portDelim = ":";
533 if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
534 *host = NULL;
535 *port = -1;
536 return (-1);
537 }
538
539 /*
540 * IPv6 addresses begin and end in brackets. Set the port delimiter
541 * accordingly and search for it so we can do appropriate validation.
542 */
543 if (socks5env[0] == '[')
544 portDelim = "]:";
545
546 slen = strlen(socks5env);
547 ext = strstr(socks5env, portDelim);
548 if (socks5env[0] == '[') {
549 if (socks5env[slen - 1] == ']') {
550 *host = strndup(socks5env, slen);
551 } else if (ext != NULL) {
552 *host = strndup(socks5env, ext - socks5env + 1);
553 } else {
554 socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
555 return (0);
556 }
557 } else {
558 *host = strndup(socks5env, ext - socks5env);
559 }
560
561 if (*host == NULL) {
562 fprintf(stderr, "Failure to allocate memory, exiting.\n");
563 return (-1);
564 }
565 if (ext == NULL) {
566 *port = 1080; /* Default port as defined in RFC1928 */
567 } else {
568 ext += strlen(portDelim);
569 errno = 0;
570 *port = strtoimax(ext, (char **)&endptr, 10);
571 if (*endptr != '\0' || errno != 0 || *port < 0 ||
572 *port > 65535) {
573 free(*host);
574 *host = NULL;
575 socks5_seterr(SOCKS5_ERR_BAD_PORT);
576 return (0);
577 }
578 }
579
580 return (2);
581 }
582
583
584 /*
585 * Establish a TCP connection to the specified port on the specified host.
586 */
587 conn_t *
fetch_connect(const char * host,int port,int af,int verbose)588 fetch_connect(const char *host, int port, int af, int verbose)
589 {
590 struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
591 const char *bindaddr = NULL;
592 conn_t *conn = NULL;
593 int err = 0, sd = -1;
594 char *sockshost;
595 int socksport;
596
597 DEBUGF("---> %s:%d\n", host, port);
598
599 /*
600 * Check if SOCKS5_PROXY env variable is set. fetch_socks5_getenv
601 * will either set sockshost = NULL or allocate memory in all cases.
602 */
603 sockshost = NULL;
604 if (!fetch_socks5_getenv(&sockshost, &socksport))
605 goto fail;
606
607 /* Not using SOCKS5 proxy */
608 if (sockshost == NULL) {
609 /* resolve server address */
610 if (verbose)
611 fetch_info("resolving server address: %s:%d", host,
612 port);
613 if ((sais = fetch_resolve(host, port, af)) == NULL)
614 goto fail;
615
616 /* resolve client address */
617 bindaddr = getenv("FETCH_BIND_ADDRESS");
618 if (bindaddr != NULL && *bindaddr != '\0') {
619 if (verbose)
620 fetch_info("resolving client address: %s",
621 bindaddr);
622 if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
623 goto fail;
624 }
625 } else {
626 /* resolve socks5 proxy address */
627 if (verbose)
628 fetch_info("resolving SOCKS5 server address: %s:%d",
629 sockshost, socksport);
630 if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
631 socks5_seterr(SOCKS5_ERR_BAD_HOST);
632 goto fail;
633 }
634 }
635
636 /* try each server address in turn */
637 for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
638 /* open socket */
639 if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0)
640 goto syserr;
641 /* attempt to bind to client address */
642 for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
643 if (cai->ai_family != sai->ai_family)
644 continue;
645 if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
646 break;
647 }
648 if (err != 0) {
649 if (verbose)
650 fetch_info("failed to bind to %s", bindaddr);
651 goto syserr;
652 }
653 /* attempt to connect to server address */
654 if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
655 break;
656 /* clean up before next attempt */
657 close(sd);
658 sd = -1;
659 }
660 if (err != 0) {
661 if (verbose && sockshost == NULL) {
662 fetch_info("failed to connect to %s:%d", host, port);
663 goto syserr;
664 } else if (sockshost != NULL) {
665 if (verbose)
666 fetch_info(
667 "failed to connect to SOCKS5 server %s:%d",
668 sockshost, socksport);
669 socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
670 goto fail;
671 }
672 goto syserr;
673 }
674
675 if ((conn = fetch_reopen(sd)) == NULL)
676 goto syserr;
677
678 if (sockshost)
679 if (!fetch_socks5_init(conn, host, port, verbose))
680 goto fail;
681 free(sockshost);
682 if (cais != NULL)
683 freeaddrinfo(cais);
684 if (sais != NULL)
685 freeaddrinfo(sais);
686 return (conn);
687 syserr:
688 fetch_syserr();
689 fail:
690 free(sockshost);
691 /* Fully close if it was opened; otherwise just don't leak the fd. */
692 if (conn != NULL)
693 fetch_close(conn);
694 else if (sd >= 0)
695 close(sd);
696 if (cais != NULL)
697 freeaddrinfo(cais);
698 if (sais != NULL)
699 freeaddrinfo(sais);
700 return (NULL);
701 }
702
703 #ifdef WITH_SSL
704 /*
705 * Convert characters A-Z to lowercase (intentionally avoid any locale
706 * specific conversions).
707 */
708 static char
fetch_ssl_tolower(char in)709 fetch_ssl_tolower(char in)
710 {
711 if (in >= 'A' && in <= 'Z')
712 return (in + 32);
713 else
714 return (in);
715 }
716
717 /*
718 * isalpha implementation that intentionally avoids any locale specific
719 * conversions.
720 */
721 static int
fetch_ssl_isalpha(char in)722 fetch_ssl_isalpha(char in)
723 {
724 return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
725 }
726
727 /*
728 * Check if passed hostnames a and b are equal.
729 */
730 static int
fetch_ssl_hname_equal(const char * a,size_t alen,const char * b,size_t blen)731 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
732 size_t blen)
733 {
734 size_t i;
735
736 if (alen != blen)
737 return (0);
738 for (i = 0; i < alen; ++i) {
739 if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
740 return (0);
741 }
742 return (1);
743 }
744
745 /*
746 * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
747 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
748 * numeric characters. Double hyphens (like they're found in IDN a-labels
749 * 'xn--') are not allowed. Empty labels are invalid.
750 */
751 static int
fetch_ssl_is_trad_domain_label(const char * l,size_t len,int wcok)752 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
753 {
754 size_t i;
755
756 if (!len || l[0] == '-' || l[len-1] == '-')
757 return (0);
758 for (i = 0; i < len; ++i) {
759 if (!isdigit(l[i]) &&
760 !fetch_ssl_isalpha(l[i]) &&
761 !(l[i] == '*' && wcok) &&
762 !(l[i] == '-' && l[i - 1] != '-'))
763 return (0);
764 }
765 return (1);
766 }
767
768 /*
769 * Check if host name consists only of numbers. This might indicate an IP
770 * address, which is not a good idea for CN wildcard comparison.
771 */
772 static int
fetch_ssl_hname_is_only_numbers(const char * hostname,size_t len)773 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
774 {
775 size_t i;
776
777 for (i = 0; i < len; ++i) {
778 if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
779 hostname[i] == '.'))
780 return (0);
781 }
782 return (1);
783 }
784
785 /*
786 * Check if the host name h passed matches the pattern passed in m which
787 * is usually part of subjectAltName or CN of a certificate presented to
788 * the client. This includes wildcard matching. The algorithm is based on
789 * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
790 */
791 static int
fetch_ssl_hname_match(const char * h,size_t hlen,const char * m,size_t mlen)792 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
793 size_t mlen)
794 {
795 int delta, hdotidx, mdot1idx, wcidx;
796 const char *hdot, *mdot1, *mdot2;
797 const char *wc; /* wildcard */
798
799 if (!(h && *h && m && *m))
800 return (0);
801 if ((wc = strnstr(m, "*", mlen)) == NULL)
802 return (fetch_ssl_hname_equal(h, hlen, m, mlen));
803 wcidx = wc - m;
804 /* hostname should not be just dots and numbers */
805 if (fetch_ssl_hname_is_only_numbers(h, hlen))
806 return (0);
807 /* only one wildcard allowed in pattern */
808 if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
809 return (0);
810 /*
811 * there must be at least two more domain labels and
812 * wildcard has to be in the leftmost label (RFC6125)
813 */
814 mdot1 = strnstr(m, ".", mlen);
815 if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
816 return (0);
817 mdot1idx = mdot1 - m;
818 mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
819 if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
820 return (0);
821 /* hostname must contain a dot and not be the 1st char */
822 hdot = strnstr(h, ".", hlen);
823 if (hdot == NULL || hdot == h)
824 return (0);
825 hdotidx = hdot - h;
826 /*
827 * host part of hostname must be at least as long as
828 * pattern it's supposed to match
829 */
830 if (hdotidx < mdot1idx)
831 return (0);
832 /*
833 * don't allow wildcards in non-traditional domain names
834 * (IDN, A-label, U-label...)
835 */
836 if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
837 !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
838 return (0);
839 /* match domain part (part after first dot) */
840 if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
841 mlen - mdot1idx))
842 return (0);
843 /* match part left of wildcard */
844 if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
845 return (0);
846 /* match part right of wildcard */
847 delta = mdot1idx - wcidx - 1;
848 if (!fetch_ssl_hname_equal(hdot - delta, delta,
849 mdot1 - delta, delta))
850 return (0);
851 /* all tests succeeded, it's a match */
852 return (1);
853 }
854
855 /*
856 * Get numeric host address info - returns NULL if host was not an IP
857 * address. The caller is responsible for deallocation using
858 * freeaddrinfo(3).
859 */
860 static struct addrinfo *
fetch_ssl_get_numeric_addrinfo(const char * hostname,size_t len)861 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
862 {
863 struct addrinfo hints, *res;
864 char *host;
865
866 host = (char *)malloc(len + 1);
867 memcpy(host, hostname, len);
868 host[len] = '\0';
869 memset(&hints, 0, sizeof(hints));
870 hints.ai_family = PF_UNSPEC;
871 hints.ai_socktype = SOCK_STREAM;
872 hints.ai_protocol = 0;
873 hints.ai_flags = AI_NUMERICHOST;
874 /* port is not relevant for this purpose */
875 if (getaddrinfo(host, "443", &hints, &res) != 0)
876 res = NULL;
877 free(host);
878 return res;
879 }
880
881 /*
882 * Compare ip address in addrinfo with address passes.
883 */
884 static int
fetch_ssl_ipaddr_match_bin(const struct addrinfo * lhost,const char * rhost,size_t rhostlen)885 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
886 size_t rhostlen)
887 {
888 const void *left;
889
890 if (lhost->ai_family == AF_INET && rhostlen == 4) {
891 left = (void *)&((struct sockaddr_in*)(void *)
892 lhost->ai_addr)->sin_addr.s_addr;
893 #ifdef INET6
894 } else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
895 left = (void *)&((struct sockaddr_in6 *)(void *)
896 lhost->ai_addr)->sin6_addr;
897 #endif
898 } else
899 return (0);
900 return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
901 }
902
903 /*
904 * Compare ip address in addrinfo with host passed. If host is not an IP
905 * address, comparison will fail.
906 */
907 static int
fetch_ssl_ipaddr_match(const struct addrinfo * laddr,const char * r,size_t rlen)908 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
909 size_t rlen)
910 {
911 struct addrinfo *raddr;
912 int ret;
913 char *rip;
914
915 ret = 0;
916 if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
917 return 0; /* not a numeric host */
918
919 if (laddr->ai_family == raddr->ai_family) {
920 if (laddr->ai_family == AF_INET) {
921 rip = (char *)&((struct sockaddr_in *)(void *)
922 raddr->ai_addr)->sin_addr.s_addr;
923 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
924 #ifdef INET6
925 } else if (laddr->ai_family == AF_INET6) {
926 rip = (char *)&((struct sockaddr_in6 *)(void *)
927 raddr->ai_addr)->sin6_addr;
928 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
929 #endif
930 }
931
932 }
933 freeaddrinfo(raddr);
934 return (ret);
935 }
936
937 /*
938 * Verify server certificate by subjectAltName.
939 */
940 static int
fetch_ssl_verify_altname(STACK_OF (GENERAL_NAME)* altnames,const char * host,struct addrinfo * ip)941 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
942 const char *host, struct addrinfo *ip)
943 {
944 const GENERAL_NAME *name;
945 size_t nslen;
946 int i;
947 const char *ns;
948
949 for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
950 #if OPENSSL_VERSION_NUMBER < 0x10000000L
951 /*
952 * This is a workaround, since the following line causes
953 * alignment issues in clang:
954 * name = sk_GENERAL_NAME_value(altnames, i);
955 * OpenSSL explicitly warns not to use those macros
956 * directly, but there isn't much choice (and there
957 * shouldn't be any ill side effects)
958 */
959 name = (GENERAL_NAME *)SKM_sk_value(void, altnames, i);
960 #else
961 name = sk_GENERAL_NAME_value(altnames, i);
962 #endif
963 #if OPENSSL_VERSION_NUMBER < 0x10100000L
964 ns = (const char *)ASN1_STRING_data(name->d.ia5);
965 #else
966 ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
967 #endif
968 nslen = (size_t)ASN1_STRING_length(name->d.ia5);
969
970 if (name->type == GEN_DNS && ip == NULL &&
971 fetch_ssl_hname_match(host, strlen(host), ns, nslen))
972 return (1);
973 else if (name->type == GEN_IPADD && ip != NULL &&
974 fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
975 return (1);
976 }
977 return (0);
978 }
979
980 /*
981 * Verify server certificate by CN.
982 */
983 static int
fetch_ssl_verify_cn(X509_NAME * subject,const char * host,struct addrinfo * ip)984 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
985 struct addrinfo *ip)
986 {
987 ASN1_STRING *namedata;
988 X509_NAME_ENTRY *nameentry;
989 int cnlen, lastpos, loc, ret;
990 unsigned char *cn;
991
992 ret = 0;
993 lastpos = -1;
994 loc = -1;
995 cn = NULL;
996 /* get most specific CN (last entry in list) and compare */
997 while ((lastpos = X509_NAME_get_index_by_NID(subject,
998 NID_commonName, lastpos)) != -1)
999 loc = lastpos;
1000
1001 if (loc > -1) {
1002 nameentry = X509_NAME_get_entry(subject, loc);
1003 namedata = X509_NAME_ENTRY_get_data(nameentry);
1004 cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
1005 if (ip == NULL &&
1006 fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
1007 ret = 1;
1008 else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
1009 ret = 1;
1010 OPENSSL_free(cn);
1011 }
1012 return (ret);
1013 }
1014
1015 /*
1016 * Verify that server certificate subjectAltName/CN matches
1017 * hostname. First check, if there are alternative subject names. If yes,
1018 * those have to match. Only if those don't exist it falls back to
1019 * checking the subject's CN.
1020 */
1021 static int
fetch_ssl_verify_hname(X509 * cert,const char * host)1022 fetch_ssl_verify_hname(X509 *cert, const char *host)
1023 {
1024 struct addrinfo *ip;
1025 STACK_OF(GENERAL_NAME) *altnames;
1026 X509_NAME *subject;
1027 int ret;
1028
1029 ret = 0;
1030 ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1031 altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1032 NULL, NULL);
1033
1034 if (altnames != NULL) {
1035 ret = fetch_ssl_verify_altname(altnames, host, ip);
1036 } else {
1037 subject = X509_get_subject_name(cert);
1038 if (subject != NULL)
1039 ret = fetch_ssl_verify_cn(subject, host, ip);
1040 }
1041
1042 if (ip != NULL)
1043 freeaddrinfo(ip);
1044 if (altnames != NULL)
1045 GENERAL_NAMES_free(altnames);
1046 return (ret);
1047 }
1048
1049 /*
1050 * Configure transport security layer based on environment.
1051 */
1052 static void
fetch_ssl_setup_transport_layer(SSL_CTX * ctx,int verbose)1053 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1054 {
1055 long ssl_ctx_options;
1056
1057 ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_TICKET;
1058 if (getenv("SSL_ALLOW_SSL3") == NULL)
1059 ssl_ctx_options |= SSL_OP_NO_SSLv3;
1060 if (getenv("SSL_NO_TLS1") != NULL)
1061 ssl_ctx_options |= SSL_OP_NO_TLSv1;
1062 if (getenv("SSL_NO_TLS1_1") != NULL)
1063 ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1064 if (getenv("SSL_NO_TLS1_2") != NULL)
1065 ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1066 if (verbose)
1067 fetch_info("SSL options: %lx", ssl_ctx_options);
1068 SSL_CTX_set_options(ctx, ssl_ctx_options);
1069 }
1070
1071
1072 /*
1073 * Configure peer verification based on environment.
1074 */
1075 #define LOCAL_CERT_FILE "/usr/local/etc/ssl/cert.pem"
1076 #define BASE_CERT_FILE "/etc/ssl/cert.pem"
1077 static int
fetch_ssl_setup_peer_verification(SSL_CTX * ctx,int verbose)1078 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1079 {
1080 X509_LOOKUP *crl_lookup;
1081 X509_STORE *crl_store;
1082 const char *ca_cert_file, *ca_cert_path, *crl_file;
1083
1084 if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1085 ca_cert_file = getenv("SSL_CA_CERT_FILE");
1086 if (ca_cert_file == NULL &&
1087 access(LOCAL_CERT_FILE, R_OK) == 0)
1088 ca_cert_file = LOCAL_CERT_FILE;
1089 if (ca_cert_file == NULL &&
1090 access(BASE_CERT_FILE, R_OK) == 0)
1091 ca_cert_file = BASE_CERT_FILE;
1092 ca_cert_path = getenv("SSL_CA_CERT_PATH");
1093 if (verbose) {
1094 fetch_info("Peer verification enabled");
1095 if (ca_cert_file != NULL)
1096 fetch_info("Using CA cert file: %s",
1097 ca_cert_file);
1098 if (ca_cert_path != NULL)
1099 fetch_info("Using CA cert path: %s",
1100 ca_cert_path);
1101 if (ca_cert_file == NULL && ca_cert_path == NULL)
1102 fetch_info("Using OpenSSL default "
1103 "CA cert file and path");
1104 }
1105 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1106 fetch_ssl_cb_verify_crt);
1107 if (ca_cert_file != NULL || ca_cert_path != NULL)
1108 SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1109 ca_cert_path);
1110 else
1111 SSL_CTX_set_default_verify_paths(ctx);
1112 if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1113 if (verbose)
1114 fetch_info("Using CRL file: %s", crl_file);
1115 crl_store = SSL_CTX_get_cert_store(ctx);
1116 crl_lookup = X509_STORE_add_lookup(crl_store,
1117 X509_LOOKUP_file());
1118 if (crl_lookup == NULL ||
1119 !X509_load_crl_file(crl_lookup, crl_file,
1120 X509_FILETYPE_PEM)) {
1121 fprintf(stderr,
1122 "Could not load CRL file %s\n",
1123 crl_file);
1124 return (0);
1125 }
1126 X509_STORE_set_flags(crl_store,
1127 X509_V_FLAG_CRL_CHECK |
1128 X509_V_FLAG_CRL_CHECK_ALL);
1129 }
1130 }
1131 return (1);
1132 }
1133
1134 /*
1135 * Configure client certificate based on environment.
1136 */
1137 static int
fetch_ssl_setup_client_certificate(SSL_CTX * ctx,int verbose)1138 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1139 {
1140 const char *client_cert_file, *client_key_file;
1141
1142 if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1143 client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1144 getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1145 if (verbose) {
1146 fetch_info("Using client cert file: %s",
1147 client_cert_file);
1148 fetch_info("Using client key file: %s",
1149 client_key_file);
1150 }
1151 if (SSL_CTX_use_certificate_chain_file(ctx,
1152 client_cert_file) != 1) {
1153 fprintf(stderr,
1154 "Could not load client certificate %s\n",
1155 client_cert_file);
1156 return (0);
1157 }
1158 if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1159 SSL_FILETYPE_PEM) != 1) {
1160 fprintf(stderr,
1161 "Could not load client key %s\n",
1162 client_key_file);
1163 return (0);
1164 }
1165 }
1166 return (1);
1167 }
1168
1169 /*
1170 * Callback for SSL certificate verification, this is called on server
1171 * cert verification. It takes no decision, but informs the user in case
1172 * verification failed.
1173 */
1174 int
fetch_ssl_cb_verify_crt(int verified,X509_STORE_CTX * ctx)1175 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1176 {
1177 X509 *crt;
1178 X509_NAME *name;
1179 char *str;
1180
1181 str = NULL;
1182 if (!verified) {
1183 if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1184 (name = X509_get_subject_name(crt)) != NULL)
1185 str = X509_NAME_oneline(name, 0, 0);
1186 fprintf(stderr, "Certificate verification failed for %s\n",
1187 str != NULL ? str : "no relevant certificate");
1188 OPENSSL_free(str);
1189 }
1190 return (verified);
1191 }
1192
1193 #endif
1194
1195 /*
1196 * Enable SSL on a connection.
1197 */
1198 int
fetch_ssl(conn_t * conn,const struct url * URL,int verbose)1199 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1200 {
1201 #ifdef WITH_SSL
1202 int ret, ssl_err;
1203 X509_NAME *name;
1204 char *str;
1205
1206 /* Init the SSL library and context */
1207 if (!SSL_library_init()){
1208 fprintf(stderr, "SSL library init failed\n");
1209 return (-1);
1210 }
1211
1212 SSL_load_error_strings();
1213
1214 conn->ssl_meth = SSLv23_client_method();
1215 conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
1216 SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1217
1218 fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1219 if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1220 return (-1);
1221 if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1222 return (-1);
1223
1224 conn->ssl = SSL_new(conn->ssl_ctx);
1225 if (conn->ssl == NULL) {
1226 fprintf(stderr, "SSL context creation failed\n");
1227 return (-1);
1228 }
1229 SSL_set_fd(conn->ssl, conn->sd);
1230
1231 #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
1232 if (!SSL_set_tlsext_host_name(conn->ssl,
1233 __DECONST(struct url *, URL)->host)) {
1234 fprintf(stderr,
1235 "TLS server name indication extension failed for host %s\n",
1236 URL->host);
1237 return (-1);
1238 }
1239 #endif
1240 while ((ret = SSL_connect(conn->ssl)) == -1) {
1241 ssl_err = SSL_get_error(conn->ssl, ret);
1242 if (ssl_err != SSL_ERROR_WANT_READ &&
1243 ssl_err != SSL_ERROR_WANT_WRITE) {
1244 ERR_print_errors_fp(stderr);
1245 return (-1);
1246 }
1247 }
1248 conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1249
1250 if (conn->ssl_cert == NULL) {
1251 fprintf(stderr, "No server SSL certificate\n");
1252 return (-1);
1253 }
1254
1255 if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1256 if (verbose)
1257 fetch_info("Verify hostname");
1258 if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1259 fprintf(stderr,
1260 "SSL certificate subject doesn't match host %s\n",
1261 URL->host);
1262 return (-1);
1263 }
1264 }
1265
1266 if (verbose) {
1267 fetch_info("%s connection established using %s",
1268 SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1269 name = X509_get_subject_name(conn->ssl_cert);
1270 str = X509_NAME_oneline(name, 0, 0);
1271 fetch_info("Certificate subject: %s", str);
1272 OPENSSL_free(str);
1273 name = X509_get_issuer_name(conn->ssl_cert);
1274 str = X509_NAME_oneline(name, 0, 0);
1275 fetch_info("Certificate issuer: %s", str);
1276 OPENSSL_free(str);
1277 }
1278
1279 return (0);
1280 #else
1281 (void)conn;
1282 (void)verbose;
1283 (void)URL;
1284 fprintf(stderr, "SSL support disabled\n");
1285 return (-1);
1286 #endif
1287 }
1288
1289 #define FETCH_READ_WAIT -2
1290 #define FETCH_READ_ERROR -1
1291 #define FETCH_READ_DONE 0
1292
1293 #ifdef WITH_SSL
1294 static ssize_t
fetch_ssl_read(SSL * ssl,char * buf,size_t len)1295 fetch_ssl_read(SSL *ssl, char *buf, size_t len)
1296 {
1297 ssize_t rlen;
1298 int ssl_err;
1299
1300 rlen = SSL_read(ssl, buf, len);
1301 if (rlen < 0) {
1302 ssl_err = SSL_get_error(ssl, rlen);
1303 if (ssl_err == SSL_ERROR_WANT_READ ||
1304 ssl_err == SSL_ERROR_WANT_WRITE) {
1305 return (FETCH_READ_WAIT);
1306 } else {
1307 ERR_print_errors_fp(stderr);
1308 return (FETCH_READ_ERROR);
1309 }
1310 }
1311 return (rlen);
1312 }
1313 #endif
1314
1315 static ssize_t
fetch_socket_read(int sd,char * buf,size_t len)1316 fetch_socket_read(int sd, char *buf, size_t len)
1317 {
1318 ssize_t rlen;
1319
1320 rlen = read(sd, buf, len);
1321 if (rlen < 0) {
1322 if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls))
1323 return (FETCH_READ_WAIT);
1324 else
1325 return (FETCH_READ_ERROR);
1326 }
1327 return (rlen);
1328 }
1329
1330 /*
1331 * Read a character from a connection w/ timeout
1332 */
1333 ssize_t
fetch_read(conn_t * conn,char * buf,size_t len)1334 fetch_read(conn_t *conn, char *buf, size_t len)
1335 {
1336 struct timeval now, timeout, delta;
1337 struct pollfd pfd;
1338 ssize_t rlen;
1339 int deltams;
1340
1341 if (fetchTimeout > 0) {
1342 gettimeofday(&timeout, NULL);
1343 timeout.tv_sec += fetchTimeout;
1344 }
1345
1346 deltams = INFTIM;
1347 memset(&pfd, 0, sizeof pfd);
1348 pfd.fd = conn->sd;
1349 pfd.events = POLLIN | POLLERR;
1350
1351 for (;;) {
1352 /*
1353 * The socket is non-blocking. Instead of the canonical
1354 * poll() -> read(), we do the following:
1355 *
1356 * 1) call read() or SSL_read().
1357 * 2) if we received some data, return it.
1358 * 3) if an error occurred, return -1.
1359 * 4) if read() or SSL_read() signaled EOF, return.
1360 * 5) if we did not receive any data but we're not at EOF,
1361 * call poll().
1362 *
1363 * In the SSL case, this is necessary because if we
1364 * receive a close notification, we have to call
1365 * SSL_read() one additional time after we've read
1366 * everything we received.
1367 *
1368 * In the non-SSL case, it may improve performance (very
1369 * slightly) when reading small amounts of data.
1370 */
1371 #ifdef WITH_SSL
1372 if (conn->ssl != NULL)
1373 rlen = fetch_ssl_read(conn->ssl, buf, len);
1374 else
1375 #endif
1376 rlen = fetch_socket_read(conn->sd, buf, len);
1377 if (rlen >= 0) {
1378 break;
1379 } else if (rlen == FETCH_READ_ERROR) {
1380 fetch_syserr();
1381 return (-1);
1382 }
1383 // assert(rlen == FETCH_READ_WAIT);
1384 if (fetchTimeout > 0) {
1385 gettimeofday(&now, NULL);
1386 if (!timercmp(&timeout, &now, >)) {
1387 errno = ETIMEDOUT;
1388 fetch_syserr();
1389 return (-1);
1390 }
1391 timersub(&timeout, &now, &delta);
1392 deltams = delta.tv_sec * 1000 +
1393 delta.tv_usec / 1000;;
1394 }
1395 errno = 0;
1396 pfd.revents = 0;
1397 if (poll(&pfd, 1, deltams) < 0) {
1398 if (errno == EINTR && fetchRestartCalls)
1399 continue;
1400 fetch_syserr();
1401 return (-1);
1402 }
1403 }
1404 return (rlen);
1405 }
1406
1407
1408 /*
1409 * Read a line of text from a connection w/ timeout
1410 */
1411 #define MIN_BUF_SIZE 1024
1412
1413 int
fetch_getln(conn_t * conn)1414 fetch_getln(conn_t *conn)
1415 {
1416 char *tmp;
1417 size_t tmpsize;
1418 ssize_t len;
1419 char c;
1420
1421 if (conn->buf == NULL) {
1422 if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) {
1423 errno = ENOMEM;
1424 return (-1);
1425 }
1426 conn->bufsize = MIN_BUF_SIZE;
1427 }
1428
1429 conn->buf[0] = '\0';
1430 conn->buflen = 0;
1431
1432 do {
1433 len = fetch_read(conn, &c, 1);
1434 if (len == -1)
1435 return (-1);
1436 if (len == 0)
1437 break;
1438 conn->buf[conn->buflen++] = c;
1439 if (conn->buflen == conn->bufsize) {
1440 tmp = conn->buf;
1441 tmpsize = conn->bufsize * 2 + 1;
1442 if ((tmp = realloc(tmp, tmpsize)) == NULL) {
1443 errno = ENOMEM;
1444 return (-1);
1445 }
1446 conn->buf = tmp;
1447 conn->bufsize = tmpsize;
1448 }
1449 } while (c != '\n');
1450
1451 conn->buf[conn->buflen] = '\0';
1452 DEBUGF("<<< %s", conn->buf);
1453 return (0);
1454 }
1455
1456
1457 /*
1458 * Write to a connection w/ timeout
1459 */
1460 ssize_t
fetch_write(conn_t * conn,const char * buf,size_t len)1461 fetch_write(conn_t *conn, const char *buf, size_t len)
1462 {
1463 struct iovec iov;
1464
1465 iov.iov_base = __DECONST(char *, buf);
1466 iov.iov_len = len;
1467 return fetch_writev(conn, &iov, 1);
1468 }
1469
1470 /*
1471 * Write a vector to a connection w/ timeout
1472 * Note: can modify the iovec.
1473 */
1474 ssize_t
fetch_writev(conn_t * conn,struct iovec * iov,int iovcnt)1475 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1476 {
1477 struct timeval now, timeout, delta;
1478 struct pollfd pfd;
1479 ssize_t wlen, total;
1480 int deltams;
1481
1482 memset(&pfd, 0, sizeof pfd);
1483 if (fetchTimeout) {
1484 pfd.fd = conn->sd;
1485 pfd.events = POLLOUT | POLLERR;
1486 gettimeofday(&timeout, NULL);
1487 timeout.tv_sec += fetchTimeout;
1488 }
1489
1490 total = 0;
1491 while (iovcnt > 0) {
1492 while (fetchTimeout && pfd.revents == 0) {
1493 gettimeofday(&now, NULL);
1494 if (!timercmp(&timeout, &now, >)) {
1495 errno = ETIMEDOUT;
1496 fetch_syserr();
1497 return (-1);
1498 }
1499 timersub(&timeout, &now, &delta);
1500 deltams = delta.tv_sec * 1000 +
1501 delta.tv_usec / 1000;
1502 errno = 0;
1503 pfd.revents = 0;
1504 if (poll(&pfd, 1, deltams) < 0) {
1505 /* POSIX compliance */
1506 if (errno == EAGAIN)
1507 continue;
1508 if (errno == EINTR && fetchRestartCalls)
1509 continue;
1510 return (-1);
1511 }
1512 }
1513 errno = 0;
1514 #ifdef WITH_SSL
1515 if (conn->ssl != NULL)
1516 wlen = SSL_write(conn->ssl,
1517 iov->iov_base, iov->iov_len);
1518 else
1519 #endif
1520 wlen = writev(conn->sd, iov, iovcnt);
1521 if (wlen == 0) {
1522 /* we consider a short write a failure */
1523 /* XXX perhaps we shouldn't in the SSL case */
1524 errno = EPIPE;
1525 fetch_syserr();
1526 return (-1);
1527 }
1528 if (wlen < 0) {
1529 if (errno == EINTR && fetchRestartCalls)
1530 continue;
1531 return (-1);
1532 }
1533 total += wlen;
1534 while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1535 wlen -= iov->iov_len;
1536 iov++;
1537 iovcnt--;
1538 }
1539 if (iovcnt > 0) {
1540 iov->iov_len -= wlen;
1541 iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1542 }
1543 }
1544 return (total);
1545 }
1546
1547
1548 /*
1549 * Write a line of text to a connection w/ timeout
1550 */
1551 int
fetch_putln(conn_t * conn,const char * str,size_t len)1552 fetch_putln(conn_t *conn, const char *str, size_t len)
1553 {
1554 struct iovec iov[2];
1555 int ret;
1556
1557 DEBUGF(">>> %s\n", str);
1558 iov[0].iov_base = __DECONST(char *, str);
1559 iov[0].iov_len = len;
1560 iov[1].iov_base = __DECONST(char *, ENDL);
1561 iov[1].iov_len = sizeof(ENDL);
1562 if (len == 0)
1563 ret = fetch_writev(conn, &iov[1], 1);
1564 else
1565 ret = fetch_writev(conn, iov, 2);
1566 if (ret == -1)
1567 return (-1);
1568 return (0);
1569 }
1570
1571
1572 /*
1573 * Close connection
1574 */
1575 int
fetch_close(conn_t * conn)1576 fetch_close(conn_t *conn)
1577 {
1578 int ret;
1579
1580 if (--conn->ref > 0)
1581 return (0);
1582 #ifdef WITH_SSL
1583 if (conn->ssl) {
1584 SSL_shutdown(conn->ssl);
1585 SSL_set_connect_state(conn->ssl);
1586 SSL_free(conn->ssl);
1587 conn->ssl = NULL;
1588 }
1589 if (conn->ssl_ctx) {
1590 SSL_CTX_free(conn->ssl_ctx);
1591 conn->ssl_ctx = NULL;
1592 }
1593 if (conn->ssl_cert) {
1594 X509_free(conn->ssl_cert);
1595 conn->ssl_cert = NULL;
1596 }
1597 #endif
1598 ret = close(conn->sd);
1599 free(conn->buf);
1600 free(conn);
1601 return (ret);
1602 }
1603
1604
1605 /*** Directory-related utility functions *************************************/
1606
1607 int
fetch_add_entry(struct url_ent ** p,int * size,int * len,const char * name,struct url_stat * us)1608 fetch_add_entry(struct url_ent **p, int *size, int *len,
1609 const char *name, struct url_stat *us)
1610 {
1611 struct url_ent *tmp;
1612
1613 if (*p == NULL) {
1614 *size = 0;
1615 *len = 0;
1616 }
1617
1618 if (*len >= *size - 1) {
1619 tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1620 if (tmp == NULL) {
1621 errno = ENOMEM;
1622 fetch_syserr();
1623 return (-1);
1624 }
1625 *size = (*size * 2 + 1);
1626 *p = tmp;
1627 }
1628
1629 tmp = *p + *len;
1630 snprintf(tmp->name, PATH_MAX, "%s", name);
1631 memcpy(&tmp->stat, us, sizeof(*us));
1632
1633 (*len)++;
1634 (++tmp)->name[0] = 0;
1635
1636 return (0);
1637 }
1638
1639
1640 /*** Authentication-related utility functions ********************************/
1641
1642 static const char *
fetch_read_word(FILE * f)1643 fetch_read_word(FILE *f)
1644 {
1645 static char word[1024];
1646
1647 if (fscanf(f, " %1023s ", word) != 1)
1648 return (NULL);
1649 return (word);
1650 }
1651
1652 static int
fetch_netrc_open(void)1653 fetch_netrc_open(void)
1654 {
1655 struct passwd *pwd;
1656 char fn[PATH_MAX];
1657 const char *p;
1658 int fd, serrno;
1659
1660 if ((p = getenv("NETRC")) != NULL) {
1661 DEBUGF("NETRC=%s\n", p);
1662 if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1663 fetch_info("$NETRC specifies a file name "
1664 "longer than PATH_MAX");
1665 return (-1);
1666 }
1667 } else {
1668 if ((p = getenv("HOME")) == NULL) {
1669 if ((pwd = getpwuid(getuid())) == NULL ||
1670 (p = pwd->pw_dir) == NULL)
1671 return (-1);
1672 }
1673 if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1674 return (-1);
1675 }
1676
1677 if ((fd = open(fn, O_RDONLY)) < 0) {
1678 serrno = errno;
1679 DEBUGF("%s: %s\n", fn, strerror(serrno));
1680 errno = serrno;
1681 }
1682 return (fd);
1683 }
1684
1685 /*
1686 * Get authentication data for a URL from .netrc
1687 */
1688 int
fetch_netrc_auth(struct url * url)1689 fetch_netrc_auth(struct url *url)
1690 {
1691 const char *word;
1692 int serrno;
1693 FILE *f;
1694
1695 if (url->netrcfd < 0)
1696 url->netrcfd = fetch_netrc_open();
1697 if (url->netrcfd < 0)
1698 return (-1);
1699 if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1700 serrno = errno;
1701 DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1702 close(url->netrcfd);
1703 url->netrcfd = -1;
1704 errno = serrno;
1705 return (-1);
1706 }
1707 rewind(f);
1708 DEBUGF("searching netrc for %s\n", url->host);
1709 while ((word = fetch_read_word(f)) != NULL) {
1710 if (strcmp(word, "default") == 0) {
1711 DEBUGF("using default netrc settings\n");
1712 break;
1713 }
1714 if (strcmp(word, "machine") == 0 &&
1715 (word = fetch_read_word(f)) != NULL &&
1716 strcasecmp(word, url->host) == 0) {
1717 DEBUGF("using netrc settings for %s\n", word);
1718 break;
1719 }
1720 }
1721 if (word == NULL)
1722 goto ferr;
1723 while ((word = fetch_read_word(f)) != NULL) {
1724 if (strcmp(word, "login") == 0) {
1725 if ((word = fetch_read_word(f)) == NULL)
1726 goto ferr;
1727 if (snprintf(url->user, sizeof(url->user),
1728 "%s", word) > (int)sizeof(url->user)) {
1729 fetch_info("login name in .netrc is too long");
1730 url->user[0] = '\0';
1731 }
1732 } else if (strcmp(word, "password") == 0) {
1733 if ((word = fetch_read_word(f)) == NULL)
1734 goto ferr;
1735 if (snprintf(url->pwd, sizeof(url->pwd),
1736 "%s", word) > (int)sizeof(url->pwd)) {
1737 fetch_info("password in .netrc is too long");
1738 url->pwd[0] = '\0';
1739 }
1740 } else if (strcmp(word, "account") == 0) {
1741 if ((word = fetch_read_word(f)) == NULL)
1742 goto ferr;
1743 /* XXX not supported! */
1744 } else {
1745 break;
1746 }
1747 }
1748 fclose(f);
1749 url->netrcfd = -1;
1750 return (0);
1751 ferr:
1752 serrno = errno;
1753 fclose(f);
1754 url->netrcfd = -1;
1755 errno = serrno;
1756 return (-1);
1757 }
1758
1759 /*
1760 * The no_proxy environment variable specifies a set of domains for
1761 * which the proxy should not be consulted; the contents is a comma-,
1762 * or space-separated list of domain names. A single asterisk will
1763 * override all proxy variables and no transactions will be proxied
1764 * (for compatibility with lynx and curl, see the discussion at
1765 * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1766 */
1767 int
fetch_no_proxy_match(const char * host)1768 fetch_no_proxy_match(const char *host)
1769 {
1770 const char *no_proxy, *p, *q;
1771 size_t h_len, d_len;
1772
1773 if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1774 (no_proxy = getenv("no_proxy")) == NULL)
1775 return (0);
1776
1777 /* asterisk matches any hostname */
1778 if (strcmp(no_proxy, "*") == 0)
1779 return (1);
1780
1781 h_len = strlen(host);
1782 p = no_proxy;
1783 do {
1784 /* position p at the beginning of a domain suffix */
1785 while (*p == ',' || isspace((unsigned char)*p))
1786 p++;
1787
1788 /* position q at the first separator character */
1789 for (q = p; *q; ++q)
1790 if (*q == ',' || isspace((unsigned char)*q))
1791 break;
1792
1793 d_len = q - p;
1794 if (d_len > 0 && h_len >= d_len &&
1795 strncasecmp(host + h_len - d_len,
1796 p, d_len) == 0) {
1797 /* domain name matches */
1798 return (1);
1799 }
1800
1801 p = q + 1;
1802 } while (*q);
1803
1804 return (0);
1805 }
1806