1 /*- 2 * Copyright (c) 1998-2014 Dag-Erling Smørgrav 3 * Copyright (c) 2013 Michael Gmelin <freebsd@grem.de> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer 11 * in this position and unchanged. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * $FreeBSD: head/lib/libfetch/common.c 266291 2014-05-17 03:39:56Z des $ 29 */ 30 31 #include <sys/cdefs.h> 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 <netdb.h> 43 #include <poll.h> 44 #include <pwd.h> 45 #include <stdarg.h> 46 #include <stdlib.h> 47 #include <stdio.h> 48 #include <string.h> 49 #include <unistd.h> 50 51 #ifdef WITH_SSL 52 #include <openssl/x509v3.h> 53 #endif 54 55 #include "fetch.h" 56 #include "common.h" 57 58 59 /*** Local data **************************************************************/ 60 61 /* 62 * Error messages for resolver errors 63 */ 64 static struct fetcherr netdb_errlist[] = { 65 #ifdef EAI_NODATA 66 { EAI_NODATA, FETCH_RESOLV, "Host not found" }, 67 #endif 68 { EAI_AGAIN, FETCH_TEMP, "Transient resolver failure" }, 69 { EAI_FAIL, FETCH_RESOLV, "Non-recoverable resolver failure" }, 70 { EAI_NONAME, FETCH_RESOLV, "No address record" }, 71 { -1, FETCH_UNKNOWN, "Unknown resolver error" } 72 }; 73 74 /* End-of-Line */ 75 static const char ENDL[2] = "\r\n"; 76 77 78 /*** Error-reporting functions ***********************************************/ 79 80 /* 81 * Map error code to string 82 */ 83 static struct fetcherr * 84 fetch_finderr(struct fetcherr *p, int e) 85 { 86 while (p->num != -1 && p->num != e) 87 p++; 88 return (p); 89 } 90 91 /* 92 * Set error code 93 */ 94 void 95 fetch_seterr(struct fetcherr *p, int e) 96 { 97 p = fetch_finderr(p, e); 98 fetchLastErrCode = p->cat; 99 snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string); 100 } 101 102 /* 103 * Set error code according to errno 104 */ 105 void 106 fetch_syserr(void) 107 { 108 switch (errno) { 109 case 0: 110 fetchLastErrCode = FETCH_OK; 111 break; 112 case EPERM: 113 case EACCES: 114 case EROFS: 115 case EAUTH: 116 case ENEEDAUTH: 117 fetchLastErrCode = FETCH_AUTH; 118 break; 119 case ENOENT: 120 case EISDIR: /* XXX */ 121 fetchLastErrCode = FETCH_UNAVAIL; 122 break; 123 case ENOMEM: 124 fetchLastErrCode = FETCH_MEMORY; 125 break; 126 case EBUSY: 127 case EAGAIN: 128 fetchLastErrCode = FETCH_TEMP; 129 break; 130 case EEXIST: 131 fetchLastErrCode = FETCH_EXISTS; 132 break; 133 case ENOSPC: 134 fetchLastErrCode = FETCH_FULL; 135 break; 136 case EADDRINUSE: 137 case EADDRNOTAVAIL: 138 case ENETDOWN: 139 case ENETUNREACH: 140 case ENETRESET: 141 case EHOSTUNREACH: 142 fetchLastErrCode = FETCH_NETWORK; 143 break; 144 case ECONNABORTED: 145 case ECONNRESET: 146 fetchLastErrCode = FETCH_ABORT; 147 break; 148 case ETIMEDOUT: 149 fetchLastErrCode = FETCH_TIMEOUT; 150 break; 151 case ECONNREFUSED: 152 case EHOSTDOWN: 153 fetchLastErrCode = FETCH_DOWN; 154 break; 155 default: 156 fetchLastErrCode = FETCH_UNKNOWN; 157 } 158 snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno)); 159 } 160 161 162 /* 163 * Emit status message 164 */ 165 void 166 fetch_info(const char *fmt, ...) 167 { 168 va_list ap; 169 170 va_start(ap, fmt); 171 vfprintf(stderr, fmt, ap); 172 va_end(ap); 173 fputc('\n', stderr); 174 } 175 176 177 /*** Network-related utility functions ***************************************/ 178 179 /* 180 * Return the default port for a scheme 181 */ 182 int 183 fetch_default_port(const char *scheme) 184 { 185 struct servent *se; 186 187 if ((se = getservbyname(scheme, "tcp")) != NULL) 188 return (ntohs(se->s_port)); 189 if (strcasecmp(scheme, SCHEME_FTP) == 0) 190 return (FTP_DEFAULT_PORT); 191 if (strcasecmp(scheme, SCHEME_HTTP) == 0) 192 return (HTTP_DEFAULT_PORT); 193 return (0); 194 } 195 196 /* 197 * Return the default proxy port for a scheme 198 */ 199 int 200 fetch_default_proxy_port(const char *scheme) 201 { 202 if (strcasecmp(scheme, SCHEME_FTP) == 0) 203 return (FTP_DEFAULT_PROXY_PORT); 204 if (strcasecmp(scheme, SCHEME_HTTP) == 0) 205 return (HTTP_DEFAULT_PROXY_PORT); 206 return (0); 207 } 208 209 210 /* 211 * Create a connection for an existing descriptor. 212 */ 213 conn_t * 214 fetch_reopen(int sd) 215 { 216 conn_t *conn; 217 int opt = 1; 218 219 /* allocate and fill connection structure */ 220 if ((conn = calloc(1, sizeof(*conn))) == NULL) 221 return (NULL); 222 fcntl(sd, F_SETFD, FD_CLOEXEC); 223 setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof opt); 224 conn->sd = sd; 225 ++conn->ref; 226 return (conn); 227 } 228 229 230 /* 231 * Bump a connection's reference count. 232 */ 233 conn_t * 234 fetch_ref(conn_t *conn) 235 { 236 237 ++conn->ref; 238 return (conn); 239 } 240 241 242 /* 243 * Bind a socket to a specific local address 244 */ 245 int 246 fetch_bind(int sd, int af, const char *addr) 247 { 248 struct addrinfo hints, *res, *res0; 249 int err; 250 251 memset(&hints, 0, sizeof(hints)); 252 hints.ai_family = af; 253 hints.ai_socktype = SOCK_STREAM; 254 hints.ai_protocol = 0; 255 if ((err = getaddrinfo(addr, NULL, &hints, &res0)) != 0) 256 return (-1); 257 for (res = res0; res; res = res->ai_next) 258 if (bind(sd, res->ai_addr, res->ai_addrlen) == 0) 259 return (0); 260 return (-1); 261 } 262 263 264 /* 265 * Establish a TCP connection to the specified port on the specified host. 266 */ 267 conn_t * 268 fetch_connect(const char *host, int port, int af, int verbose) 269 { 270 conn_t *conn; 271 char pbuf[10]; 272 const char *bindaddr; 273 struct addrinfo hints, *res, *res0; 274 int sd, err; 275 276 DEBUG(fprintf(stderr, "---> %s:%d\n", host, port)); 277 278 if (verbose) 279 fetch_info("looking up %s", host); 280 281 /* look up host name and set up socket address structure */ 282 snprintf(pbuf, sizeof(pbuf), "%d", port); 283 memset(&hints, 0, sizeof(hints)); 284 hints.ai_family = af; 285 hints.ai_socktype = SOCK_STREAM; 286 hints.ai_protocol = 0; 287 if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) { 288 netdb_seterr(err); 289 return (NULL); 290 } 291 bindaddr = getenv("FETCH_BIND_ADDRESS"); 292 293 if (verbose) 294 fetch_info("connecting to %s:%d", host, port); 295 296 /* try to connect */ 297 for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) { 298 if ((sd = socket(res->ai_family, res->ai_socktype, 299 res->ai_protocol)) == -1) 300 continue; 301 if (bindaddr != NULL && *bindaddr != '\0' && 302 fetch_bind(sd, res->ai_family, bindaddr) != 0) { 303 fetch_info("failed to bind to '%s'", bindaddr); 304 close(sd); 305 continue; 306 } 307 if (connect(sd, res->ai_addr, res->ai_addrlen) == 0 && 308 fcntl(sd, F_SETFL, O_NONBLOCK) == 0) 309 break; 310 close(sd); 311 } 312 freeaddrinfo(res0); 313 if (sd == -1) { 314 fetch_syserr(); 315 return (NULL); 316 } 317 318 if ((conn = fetch_reopen(sd)) == NULL) { 319 fetch_syserr(); 320 close(sd); 321 } 322 return (conn); 323 } 324 325 #ifdef WITH_SSL 326 /* 327 * Convert characters A-Z to lowercase (intentionally avoid any locale 328 * specific conversions). 329 */ 330 static char 331 fetch_ssl_tolower(char in) 332 { 333 if (in >= 'A' && in <= 'Z') 334 return (in + 32); 335 else 336 return (in); 337 } 338 339 /* 340 * isalpha implementation that intentionally avoids any locale specific 341 * conversions. 342 */ 343 static int 344 fetch_ssl_isalpha(char in) 345 { 346 return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z')); 347 } 348 349 /* 350 * Check if passed hostnames a and b are equal. 351 */ 352 static int 353 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b, 354 size_t blen) 355 { 356 size_t i; 357 358 if (alen != blen) 359 return (0); 360 for (i = 0; i < alen; ++i) { 361 if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i])) 362 return (0); 363 } 364 return (1); 365 } 366 367 /* 368 * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9 369 * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha- 370 * numeric characters. Double hyphens (like they're found in IDN a-labels 371 * 'xn--') are not allowed. Empty labels are invalid. 372 */ 373 static int 374 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok) 375 { 376 size_t i; 377 378 if (!len || l[0] == '-' || l[len-1] == '-') 379 return (0); 380 for (i = 0; i < len; ++i) { 381 if (!isdigit(l[i]) && 382 !fetch_ssl_isalpha(l[i]) && 383 !(l[i] == '*' && wcok) && 384 !(l[i] == '-' && l[i - 1] != '-')) 385 return (0); 386 } 387 return (1); 388 } 389 390 /* 391 * Check if host name consists only of numbers. This might indicate an IP 392 * address, which is not a good idea for CN wildcard comparison. 393 */ 394 static int 395 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len) 396 { 397 size_t i; 398 399 for (i = 0; i < len; ++i) { 400 if (!((hostname[i] >= '0' && hostname[i] <= '9') || 401 hostname[i] == '.')) 402 return (0); 403 } 404 return (1); 405 } 406 407 /* 408 * Check if the host name h passed matches the pattern passed in m which 409 * is usually part of subjectAltName or CN of a certificate presented to 410 * the client. This includes wildcard matching. The algorithm is based on 411 * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280. 412 */ 413 static int 414 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m, 415 size_t mlen) 416 { 417 int delta, hdotidx, mdot1idx, wcidx; 418 const char *hdot, *mdot1, *mdot2; 419 const char *wc; /* wildcard */ 420 421 if (!(h && *h && m && *m)) 422 return (0); 423 if ((wc = strnstr(m, "*", mlen)) == NULL) 424 return (fetch_ssl_hname_equal(h, hlen, m, mlen)); 425 wcidx = wc - m; 426 /* hostname should not be just dots and numbers */ 427 if (fetch_ssl_hname_is_only_numbers(h, hlen)) 428 return (0); 429 /* only one wildcard allowed in pattern */ 430 if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL) 431 return (0); 432 /* 433 * there must be at least two more domain labels and 434 * wildcard has to be in the leftmost label (RFC6125) 435 */ 436 mdot1 = strnstr(m, ".", mlen); 437 if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4) 438 return (0); 439 mdot1idx = mdot1 - m; 440 mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1); 441 if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2) 442 return (0); 443 /* hostname must contain a dot and not be the 1st char */ 444 hdot = strnstr(h, ".", hlen); 445 if (hdot == NULL || hdot == h) 446 return (0); 447 hdotidx = hdot - h; 448 /* 449 * host part of hostname must be at least as long as 450 * pattern it's supposed to match 451 */ 452 if (hdotidx < mdot1idx) 453 return (0); 454 /* 455 * don't allow wildcards in non-traditional domain names 456 * (IDN, A-label, U-label...) 457 */ 458 if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) || 459 !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1)) 460 return (0); 461 /* match domain part (part after first dot) */ 462 if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1, 463 mlen - mdot1idx)) 464 return (0); 465 /* match part left of wildcard */ 466 if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx)) 467 return (0); 468 /* match part right of wildcard */ 469 delta = mdot1idx - wcidx - 1; 470 if (!fetch_ssl_hname_equal(hdot - delta, delta, 471 mdot1 - delta, delta)) 472 return (0); 473 /* all tests succeded, it's a match */ 474 return (1); 475 } 476 477 /* 478 * Get numeric host address info - returns NULL if host was not an IP 479 * address. The caller is responsible for deallocation using 480 * freeaddrinfo(3). 481 */ 482 static struct addrinfo * 483 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len) 484 { 485 struct addrinfo hints, *res; 486 char *host; 487 488 host = (char *)malloc(len + 1); 489 memcpy(host, hostname, len); 490 host[len] = '\0'; 491 memset(&hints, 0, sizeof(hints)); 492 hints.ai_family = PF_UNSPEC; 493 hints.ai_socktype = SOCK_STREAM; 494 hints.ai_protocol = 0; 495 hints.ai_flags = AI_NUMERICHOST; 496 /* port is not relevant for this purpose */ 497 getaddrinfo(host, "443", &hints, &res); 498 free(host); 499 return res; 500 } 501 502 /* 503 * Compare ip address in addrinfo with address passes. 504 */ 505 static int 506 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost, 507 size_t rhostlen) 508 { 509 const void *left; 510 511 if (lhost->ai_family == AF_INET && rhostlen == 4) { 512 left = (void *)&((struct sockaddr_in*)(void *) 513 lhost->ai_addr)->sin_addr.s_addr; 514 #ifdef INET6 515 } else if (lhost->ai_family == AF_INET6 && rhostlen == 16) { 516 left = (void *)&((struct sockaddr_in6 *)(void *) 517 lhost->ai_addr)->sin6_addr; 518 #endif 519 } else 520 return (0); 521 return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0); 522 } 523 524 /* 525 * Compare ip address in addrinfo with host passed. If host is not an IP 526 * address, comparison will fail. 527 */ 528 static int 529 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r, 530 size_t rlen) 531 { 532 struct addrinfo *raddr; 533 int ret; 534 char *rip; 535 536 ret = 0; 537 if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL) 538 return 0; /* not a numeric host */ 539 540 if (laddr->ai_family == raddr->ai_family) { 541 if (laddr->ai_family == AF_INET) { 542 rip = (char *)&((struct sockaddr_in *)(void *) 543 raddr->ai_addr)->sin_addr.s_addr; 544 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4); 545 #ifdef INET6 546 } else if (laddr->ai_family == AF_INET6) { 547 rip = (char *)&((struct sockaddr_in6 *)(void *) 548 raddr->ai_addr)->sin6_addr; 549 ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16); 550 #endif 551 } 552 553 } 554 freeaddrinfo(raddr); 555 return (ret); 556 } 557 558 /* 559 * Verify server certificate by subjectAltName. 560 */ 561 static int 562 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames, 563 const char *host, struct addrinfo *ip) 564 { 565 const GENERAL_NAME *name; 566 size_t nslen; 567 int i; 568 const char *ns; 569 570 for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) { 571 #if OPENSSL_VERSION_NUMBER < 0x10000000L 572 /* 573 * This is a workaround, since the following line causes 574 * alignment issues in clang: 575 * name = sk_GENERAL_NAME_value(altnames, i); 576 * OpenSSL explicitly warns not to use those macros 577 * directly, but there isn't much choice (and there 578 * shouldn't be any ill side effects) 579 */ 580 name = (GENERAL_NAME *)SKM_sk_value(void, altnames, i); 581 #else 582 name = sk_GENERAL_NAME_value(altnames, i); 583 #endif 584 ns = (const char *)ASN1_STRING_data(name->d.ia5); 585 nslen = (size_t)ASN1_STRING_length(name->d.ia5); 586 587 if (name->type == GEN_DNS && ip == NULL && 588 fetch_ssl_hname_match(host, strlen(host), ns, nslen)) 589 return (1); 590 else if (name->type == GEN_IPADD && ip != NULL && 591 fetch_ssl_ipaddr_match_bin(ip, ns, nslen)) 592 return (1); 593 } 594 return (0); 595 } 596 597 /* 598 * Verify server certificate by CN. 599 */ 600 static int 601 fetch_ssl_verify_cn(X509_NAME *subject, const char *host, 602 struct addrinfo *ip) 603 { 604 ASN1_STRING *namedata; 605 X509_NAME_ENTRY *nameentry; 606 int cnlen, lastpos, loc, ret; 607 unsigned char *cn; 608 609 ret = 0; 610 lastpos = -1; 611 loc = -1; 612 cn = NULL; 613 /* get most specific CN (last entry in list) and compare */ 614 while ((lastpos = X509_NAME_get_index_by_NID(subject, 615 NID_commonName, lastpos)) != -1) 616 loc = lastpos; 617 618 if (loc > -1) { 619 nameentry = X509_NAME_get_entry(subject, loc); 620 namedata = X509_NAME_ENTRY_get_data(nameentry); 621 cnlen = ASN1_STRING_to_UTF8(&cn, namedata); 622 if (ip == NULL && 623 fetch_ssl_hname_match(host, strlen(host), cn, cnlen)) 624 ret = 1; 625 else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen)) 626 ret = 1; 627 OPENSSL_free(cn); 628 } 629 return (ret); 630 } 631 632 /* 633 * Verify that server certificate subjectAltName/CN matches 634 * hostname. First check, if there are alternative subject names. If yes, 635 * those have to match. Only if those don't exist it falls back to 636 * checking the subject's CN. 637 */ 638 static int 639 fetch_ssl_verify_hname(X509 *cert, const char *host) 640 { 641 struct addrinfo *ip; 642 STACK_OF(GENERAL_NAME) *altnames; 643 X509_NAME *subject; 644 int ret; 645 646 ret = 0; 647 ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host)); 648 altnames = X509_get_ext_d2i(cert, NID_subject_alt_name, 649 NULL, NULL); 650 651 if (altnames != NULL) { 652 ret = fetch_ssl_verify_altname(altnames, host, ip); 653 } else { 654 subject = X509_get_subject_name(cert); 655 if (subject != NULL) 656 ret = fetch_ssl_verify_cn(subject, host, ip); 657 } 658 659 if (ip != NULL) 660 freeaddrinfo(ip); 661 if (altnames != NULL) 662 GENERAL_NAMES_free(altnames); 663 return (ret); 664 } 665 666 /* 667 * Configure transport security layer based on environment. 668 */ 669 static void 670 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose) 671 { 672 long ssl_ctx_options; 673 674 ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_TICKET; 675 if (getenv("SSL_ALLOW_SSL2") == NULL) 676 ssl_ctx_options |= SSL_OP_NO_SSLv2; 677 if (getenv("SSL_NO_SSL3") != NULL) 678 ssl_ctx_options |= SSL_OP_NO_SSLv3; 679 if (getenv("SSL_NO_TLS1") != NULL) 680 ssl_ctx_options |= SSL_OP_NO_TLSv1; 681 if (verbose) 682 fetch_info("SSL options: %lx", ssl_ctx_options); 683 SSL_CTX_set_options(ctx, ssl_ctx_options); 684 } 685 686 687 /* 688 * Configure peer verification based on environment. 689 */ 690 #define LOCAL_CERT_FILE "/usr/local/etc/ssl/cert.pem" 691 #define BASE_CERT_FILE "/etc/ssl/cert.pem" 692 static int 693 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose) 694 { 695 X509_LOOKUP *crl_lookup; 696 X509_STORE *crl_store; 697 const char *ca_cert_file, *ca_cert_path, *crl_file; 698 699 if (getenv("SSL_NO_VERIFY_PEER") == NULL) { 700 ca_cert_file = getenv("SSL_CA_CERT_FILE"); 701 if (ca_cert_file == NULL && 702 access(LOCAL_CERT_FILE, R_OK) == 0) 703 ca_cert_file = LOCAL_CERT_FILE; 704 if (ca_cert_file == NULL) 705 ca_cert_file = BASE_CERT_FILE; 706 ca_cert_path = getenv("SSL_CA_CERT_PATH"); 707 if (verbose) { 708 fetch_info("Peer verification enabled"); 709 if (ca_cert_file != NULL) 710 fetch_info("Using CA cert file: %s", 711 ca_cert_file); 712 if (ca_cert_path != NULL) 713 fetch_info("Using CA cert path: %s", 714 ca_cert_path); 715 } 716 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, 717 fetch_ssl_cb_verify_crt); 718 SSL_CTX_load_verify_locations(ctx, ca_cert_file, 719 ca_cert_path); 720 if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) { 721 if (verbose) 722 fetch_info("Using CRL file: %s", crl_file); 723 crl_store = SSL_CTX_get_cert_store(ctx); 724 crl_lookup = X509_STORE_add_lookup(crl_store, 725 X509_LOOKUP_file()); 726 if (crl_lookup == NULL || 727 !X509_load_crl_file(crl_lookup, crl_file, 728 X509_FILETYPE_PEM)) { 729 fprintf(stderr, 730 "Could not load CRL file %s\n", 731 crl_file); 732 return (0); 733 } 734 X509_STORE_set_flags(crl_store, 735 X509_V_FLAG_CRL_CHECK | 736 X509_V_FLAG_CRL_CHECK_ALL); 737 } 738 } 739 return (1); 740 } 741 742 /* 743 * Configure client certificate based on environment. 744 */ 745 static int 746 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose) 747 { 748 const char *client_cert_file, *client_key_file; 749 750 if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) { 751 client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ? 752 getenv("SSL_CLIENT_KEY_FILE") : client_cert_file; 753 if (verbose) { 754 fetch_info("Using client cert file: %s", 755 client_cert_file); 756 fetch_info("Using client key file: %s", 757 client_key_file); 758 } 759 if (SSL_CTX_use_certificate_chain_file(ctx, 760 client_cert_file) != 1) { 761 fprintf(stderr, 762 "Could not load client certificate %s\n", 763 client_cert_file); 764 return (0); 765 } 766 if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file, 767 SSL_FILETYPE_PEM) != 1) { 768 fprintf(stderr, 769 "Could not load client key %s\n", 770 client_key_file); 771 return (0); 772 } 773 } 774 return (1); 775 } 776 777 /* 778 * Callback for SSL certificate verification, this is called on server 779 * cert verification. It takes no decision, but informs the user in case 780 * verification failed. 781 */ 782 int 783 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx) 784 { 785 X509 *crt; 786 X509_NAME *name; 787 char *str; 788 789 str = NULL; 790 if (!verified) { 791 if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL && 792 (name = X509_get_subject_name(crt)) != NULL) 793 str = X509_NAME_oneline(name, 0, 0); 794 fprintf(stderr, "Certificate verification failed for %s\n", 795 str != NULL ? str : "no relevant certificate"); 796 OPENSSL_free(str); 797 } 798 return (verified); 799 } 800 801 #endif 802 803 /* 804 * Enable SSL on a connection. 805 */ 806 int 807 fetch_ssl(conn_t *conn, const struct url *URL, int verbose) 808 { 809 #ifdef WITH_SSL 810 int ret, ssl_err; 811 X509_NAME *name; 812 char *str; 813 814 /* Init the SSL library and context */ 815 if (!SSL_library_init()){ 816 fprintf(stderr, "SSL library init failed\n"); 817 return (-1); 818 } 819 820 SSL_load_error_strings(); 821 822 conn->ssl_meth = SSLv23_client_method(); 823 conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth); 824 SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY); 825 826 fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose); 827 if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose)) 828 return (-1); 829 if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose)) 830 return (-1); 831 832 conn->ssl = SSL_new(conn->ssl_ctx); 833 if (conn->ssl == NULL) { 834 fprintf(stderr, "SSL context creation failed\n"); 835 return (-1); 836 } 837 SSL_set_fd(conn->ssl, conn->sd); 838 839 #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) 840 if (!SSL_set_tlsext_host_name(conn->ssl, 841 __DECONST(struct url *, URL)->host)) { 842 fprintf(stderr, 843 "TLS server name indication extension failed for host %s\n", 844 URL->host); 845 return (-1); 846 } 847 #endif 848 while ((ret = SSL_connect(conn->ssl)) == -1) { 849 ssl_err = SSL_get_error(conn->ssl, ret); 850 if (ssl_err != SSL_ERROR_WANT_READ && 851 ssl_err != SSL_ERROR_WANT_WRITE) { 852 ERR_print_errors_fp(stderr); 853 return (-1); 854 } 855 } 856 conn->ssl_cert = SSL_get_peer_certificate(conn->ssl); 857 858 if (conn->ssl_cert == NULL) { 859 fprintf(stderr, "No server SSL certificate\n"); 860 return (-1); 861 } 862 863 if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) { 864 if (verbose) 865 fetch_info("Verify hostname"); 866 if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) { 867 fprintf(stderr, 868 "SSL certificate subject doesn't match host %s\n", 869 URL->host); 870 return (-1); 871 } 872 } 873 874 if (verbose) { 875 fetch_info("SSL connection established using %s", 876 SSL_get_cipher(conn->ssl)); 877 name = X509_get_subject_name(conn->ssl_cert); 878 str = X509_NAME_oneline(name, 0, 0); 879 fetch_info("Certificate subject: %s", str); 880 OPENSSL_free(str); 881 name = X509_get_issuer_name(conn->ssl_cert); 882 str = X509_NAME_oneline(name, 0, 0); 883 fetch_info("Certificate issuer: %s", str); 884 OPENSSL_free(str); 885 } 886 887 return (0); 888 #else 889 (void)conn; 890 (void)verbose; 891 fprintf(stderr, "SSL support disabled\n"); 892 return (-1); 893 #endif 894 } 895 896 #define FETCH_READ_WAIT -2 897 #define FETCH_READ_ERROR -1 898 #define FETCH_READ_DONE 0 899 900 #ifdef WITH_SSL 901 static ssize_t 902 fetch_ssl_read(SSL *ssl, char *buf, size_t len) 903 { 904 ssize_t rlen; 905 int ssl_err; 906 907 rlen = SSL_read(ssl, buf, len); 908 if (rlen < 0) { 909 ssl_err = SSL_get_error(ssl, rlen); 910 if (ssl_err == SSL_ERROR_WANT_READ || 911 ssl_err == SSL_ERROR_WANT_WRITE) { 912 return (FETCH_READ_WAIT); 913 } else { 914 ERR_print_errors_fp(stderr); 915 return (FETCH_READ_ERROR); 916 } 917 } 918 return (rlen); 919 } 920 #endif 921 922 static ssize_t 923 fetch_socket_read(int sd, char *buf, size_t len) 924 { 925 ssize_t rlen; 926 927 rlen = read(sd, buf, len); 928 if (rlen < 0) { 929 if (errno == EAGAIN || (errno == EINTR && fetchRestartCalls)) 930 return (FETCH_READ_WAIT); 931 else 932 return (FETCH_READ_ERROR); 933 } 934 return (rlen); 935 } 936 937 /* 938 * Read a character from a connection w/ timeout 939 */ 940 ssize_t 941 fetch_read(conn_t *conn, char *buf, size_t len) 942 { 943 struct timeval now, timeout, delta; 944 struct pollfd pfd; 945 ssize_t rlen; 946 int deltams; 947 948 if (fetchTimeout > 0) { 949 gettimeofday(&timeout, NULL); 950 timeout.tv_sec += fetchTimeout; 951 } 952 953 deltams = INFTIM; 954 memset(&pfd, 0, sizeof pfd); 955 pfd.fd = conn->sd; 956 pfd.events = POLLIN | POLLERR; 957 958 for (;;) { 959 /* 960 * The socket is non-blocking. Instead of the canonical 961 * poll() -> read(), we do the following: 962 * 963 * 1) call read() or SSL_read(). 964 * 2) if we received some data, return it. 965 * 3) if an error occurred, return -1. 966 * 4) if read() or SSL_read() signaled EOF, return. 967 * 5) if we did not receive any data but we're not at EOF, 968 * call poll(). 969 * 970 * In the SSL case, this is necessary because if we 971 * receive a close notification, we have to call 972 * SSL_read() one additional time after we've read 973 * everything we received. 974 * 975 * In the non-SSL case, it may improve performance (very 976 * slightly) when reading small amounts of data. 977 */ 978 #ifdef WITH_SSL 979 if (conn->ssl != NULL) 980 rlen = fetch_ssl_read(conn->ssl, buf, len); 981 else 982 #endif 983 rlen = fetch_socket_read(conn->sd, buf, len); 984 if (rlen >= 0) { 985 break; 986 } else if (rlen == FETCH_READ_ERROR) { 987 fetch_syserr(); 988 return (-1); 989 } 990 // assert(rlen == FETCH_READ_WAIT); 991 if (fetchTimeout > 0) { 992 gettimeofday(&now, NULL); 993 if (!timercmp(&timeout, &now, >)) { 994 errno = ETIMEDOUT; 995 fetch_syserr(); 996 return (-1); 997 } 998 timersub(&timeout, &now, &delta); 999 deltams = delta.tv_sec * 1000 + 1000 delta.tv_usec / 1000;; 1001 } 1002 errno = 0; 1003 pfd.revents = 0; 1004 if (poll(&pfd, 1, deltams) < 0) { 1005 if (errno == EINTR && fetchRestartCalls) 1006 continue; 1007 fetch_syserr(); 1008 return (-1); 1009 } 1010 } 1011 return (rlen); 1012 } 1013 1014 1015 /* 1016 * Read a line of text from a connection w/ timeout 1017 */ 1018 #define MIN_BUF_SIZE 1024 1019 1020 int 1021 fetch_getln(conn_t *conn) 1022 { 1023 char *tmp; 1024 size_t tmpsize; 1025 ssize_t len; 1026 char c; 1027 1028 if (conn->buf == NULL) { 1029 if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL) { 1030 errno = ENOMEM; 1031 return (-1); 1032 } 1033 conn->bufsize = MIN_BUF_SIZE; 1034 } 1035 1036 conn->buf[0] = '\0'; 1037 conn->buflen = 0; 1038 1039 do { 1040 len = fetch_read(conn, &c, 1); 1041 if (len == -1) 1042 return (-1); 1043 if (len == 0) 1044 break; 1045 conn->buf[conn->buflen++] = c; 1046 if (conn->buflen == conn->bufsize) { 1047 tmp = conn->buf; 1048 tmpsize = conn->bufsize * 2 + 1; 1049 if ((tmp = realloc(tmp, tmpsize)) == NULL) { 1050 errno = ENOMEM; 1051 return (-1); 1052 } 1053 conn->buf = tmp; 1054 conn->bufsize = tmpsize; 1055 } 1056 } while (c != '\n'); 1057 1058 conn->buf[conn->buflen] = '\0'; 1059 DEBUG(fprintf(stderr, "<<< %s", conn->buf)); 1060 return (0); 1061 } 1062 1063 1064 /* 1065 * Write to a connection w/ timeout 1066 */ 1067 ssize_t 1068 fetch_write(conn_t *conn, const char *buf, size_t len) 1069 { 1070 struct iovec iov; 1071 1072 iov.iov_base = __DECONST(char *, buf); 1073 iov.iov_len = len; 1074 return fetch_writev(conn, &iov, 1); 1075 } 1076 1077 /* 1078 * Write a vector to a connection w/ timeout 1079 * Note: can modify the iovec. 1080 */ 1081 ssize_t 1082 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt) 1083 { 1084 struct timeval now, timeout, delta; 1085 struct pollfd pfd; 1086 ssize_t wlen, total; 1087 int deltams; 1088 1089 memset(&pfd, 0, sizeof pfd); 1090 if (fetchTimeout) { 1091 pfd.fd = conn->sd; 1092 pfd.events = POLLOUT | POLLERR; 1093 gettimeofday(&timeout, NULL); 1094 timeout.tv_sec += fetchTimeout; 1095 } 1096 1097 total = 0; 1098 while (iovcnt > 0) { 1099 while (fetchTimeout && pfd.revents == 0) { 1100 gettimeofday(&now, NULL); 1101 if (!timercmp(&timeout, &now, >)) { 1102 errno = ETIMEDOUT; 1103 fetch_syserr(); 1104 return (-1); 1105 } 1106 timersub(&timeout, &now, &delta); 1107 deltams = delta.tv_sec * 1000 + 1108 delta.tv_usec / 1000; 1109 errno = 0; 1110 pfd.revents = 0; 1111 if (poll(&pfd, 1, deltams) < 0) { 1112 if (errno == EINTR && fetchRestartCalls) 1113 continue; 1114 return (-1); 1115 } 1116 } 1117 errno = 0; 1118 #ifdef WITH_SSL 1119 if (conn->ssl != NULL) 1120 wlen = SSL_write(conn->ssl, 1121 iov->iov_base, iov->iov_len); 1122 else 1123 #endif 1124 wlen = writev(conn->sd, iov, iovcnt); 1125 if (wlen == 0) { 1126 /* we consider a short write a failure */ 1127 /* XXX perhaps we shouldn't in the SSL case */ 1128 errno = EPIPE; 1129 fetch_syserr(); 1130 return (-1); 1131 } 1132 if (wlen < 0) { 1133 if (errno == EINTR && fetchRestartCalls) 1134 continue; 1135 return (-1); 1136 } 1137 total += wlen; 1138 while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) { 1139 wlen -= iov->iov_len; 1140 iov++; 1141 iovcnt--; 1142 } 1143 if (iovcnt > 0) { 1144 iov->iov_len -= wlen; 1145 iov->iov_base = __DECONST(char *, iov->iov_base) + wlen; 1146 } 1147 } 1148 return (total); 1149 } 1150 1151 1152 /* 1153 * Write a line of text to a connection w/ timeout 1154 */ 1155 int 1156 fetch_putln(conn_t *conn, const char *str, size_t len) 1157 { 1158 struct iovec iov[2]; 1159 int ret; 1160 1161 DEBUG(fprintf(stderr, ">>> %s\n", str)); 1162 iov[0].iov_base = __DECONST(char *, str); 1163 iov[0].iov_len = len; 1164 iov[1].iov_base = __DECONST(char *, ENDL); 1165 iov[1].iov_len = sizeof(ENDL); 1166 if (len == 0) 1167 ret = fetch_writev(conn, &iov[1], 1); 1168 else 1169 ret = fetch_writev(conn, iov, 2); 1170 if (ret == -1) 1171 return (-1); 1172 return (0); 1173 } 1174 1175 1176 /* 1177 * Close connection 1178 */ 1179 int 1180 fetch_close(conn_t *conn) 1181 { 1182 int ret; 1183 1184 if (--conn->ref > 0) 1185 return (0); 1186 #ifdef WITH_SSL 1187 if (conn->ssl) { 1188 SSL_shutdown(conn->ssl); 1189 SSL_set_connect_state(conn->ssl); 1190 SSL_free(conn->ssl); 1191 conn->ssl = NULL; 1192 } 1193 if (conn->ssl_ctx) { 1194 SSL_CTX_free(conn->ssl_ctx); 1195 conn->ssl_ctx = NULL; 1196 } 1197 if (conn->ssl_cert) { 1198 X509_free(conn->ssl_cert); 1199 conn->ssl_cert = NULL; 1200 } 1201 #endif 1202 ret = close(conn->sd); 1203 free(conn->buf); 1204 free(conn); 1205 return (ret); 1206 } 1207 1208 1209 /*** Directory-related utility functions *************************************/ 1210 1211 int 1212 fetch_add_entry(struct url_ent **p, int *size, int *len, 1213 const char *name, struct url_stat *us) 1214 { 1215 struct url_ent *tmp; 1216 1217 if (*p == NULL) { 1218 *size = 0; 1219 *len = 0; 1220 } 1221 1222 if (*len >= *size - 1) { 1223 tmp = realloc(*p, (*size * 2 + 1) * sizeof(**p)); 1224 if (tmp == NULL) { 1225 errno = ENOMEM; 1226 fetch_syserr(); 1227 return (-1); 1228 } 1229 *size = (*size * 2 + 1); 1230 *p = tmp; 1231 } 1232 1233 tmp = *p + *len; 1234 snprintf(tmp->name, PATH_MAX, "%s", name); 1235 memcpy(&tmp->stat, us, sizeof(*us)); 1236 1237 (*len)++; 1238 (++tmp)->name[0] = 0; 1239 1240 return (0); 1241 } 1242 1243 1244 /*** Authentication-related utility functions ********************************/ 1245 1246 static const char * 1247 fetch_read_word(FILE *f) 1248 { 1249 static char word[1024]; 1250 1251 if (fscanf(f, " %1023s ", word) != 1) 1252 return (NULL); 1253 return (word); 1254 } 1255 1256 /* 1257 * Get authentication data for a URL from .netrc 1258 */ 1259 int 1260 fetch_netrc_auth(struct url *url) 1261 { 1262 char fn[PATH_MAX]; 1263 const char *word; 1264 char *p; 1265 FILE *f; 1266 1267 if ((p = getenv("NETRC")) != NULL) { 1268 if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) { 1269 fetch_info("$NETRC specifies a file name " 1270 "longer than PATH_MAX"); 1271 return (-1); 1272 } 1273 } else { 1274 if ((p = getenv("HOME")) != NULL) { 1275 struct passwd *pwd; 1276 1277 if ((pwd = getpwuid(getuid())) == NULL || 1278 (p = pwd->pw_dir) == NULL) 1279 return (-1); 1280 } 1281 if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn)) 1282 return (-1); 1283 } 1284 1285 if ((f = fopen(fn, "r")) == NULL) 1286 return (-1); 1287 while ((word = fetch_read_word(f)) != NULL) { 1288 if (strcmp(word, "default") == 0) { 1289 DEBUG(fetch_info("Using default .netrc settings")); 1290 break; 1291 } 1292 if (strcmp(word, "machine") == 0 && 1293 (word = fetch_read_word(f)) != NULL && 1294 strcasecmp(word, url->host) == 0) { 1295 DEBUG(fetch_info("Using .netrc settings for %s", word)); 1296 break; 1297 } 1298 } 1299 if (word == NULL) 1300 goto ferr; 1301 while ((word = fetch_read_word(f)) != NULL) { 1302 if (strcmp(word, "login") == 0) { 1303 if ((word = fetch_read_word(f)) == NULL) 1304 goto ferr; 1305 if (snprintf(url->user, sizeof(url->user), 1306 "%s", word) > (int)sizeof(url->user)) { 1307 fetch_info("login name in .netrc is too long"); 1308 url->user[0] = '\0'; 1309 } 1310 } else if (strcmp(word, "password") == 0) { 1311 if ((word = fetch_read_word(f)) == NULL) 1312 goto ferr; 1313 if (snprintf(url->pwd, sizeof(url->pwd), 1314 "%s", word) > (int)sizeof(url->pwd)) { 1315 fetch_info("password in .netrc is too long"); 1316 url->pwd[0] = '\0'; 1317 } 1318 } else if (strcmp(word, "account") == 0) { 1319 if ((word = fetch_read_word(f)) == NULL) 1320 goto ferr; 1321 /* XXX not supported! */ 1322 } else { 1323 break; 1324 } 1325 } 1326 fclose(f); 1327 return (0); 1328 ferr: 1329 fclose(f); 1330 return (-1); 1331 } 1332 1333 /* 1334 * The no_proxy environment variable specifies a set of domains for 1335 * which the proxy should not be consulted; the contents is a comma-, 1336 * or space-separated list of domain names. A single asterisk will 1337 * override all proxy variables and no transactions will be proxied 1338 * (for compatability with lynx and curl, see the discussion at 1339 * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>). 1340 */ 1341 int 1342 fetch_no_proxy_match(const char *host) 1343 { 1344 const char *no_proxy, *p, *q; 1345 size_t h_len, d_len; 1346 1347 if ((no_proxy = getenv("NO_PROXY")) == NULL && 1348 (no_proxy = getenv("no_proxy")) == NULL) 1349 return (0); 1350 1351 /* asterisk matches any hostname */ 1352 if (strcmp(no_proxy, "*") == 0) 1353 return (1); 1354 1355 h_len = strlen(host); 1356 p = no_proxy; 1357 do { 1358 /* position p at the beginning of a domain suffix */ 1359 while (*p == ',' || isspace((unsigned char)*p)) 1360 p++; 1361 1362 /* position q at the first separator character */ 1363 for (q = p; *q; ++q) 1364 if (*q == ',' || isspace((unsigned char)*q)) 1365 break; 1366 1367 d_len = q - p; 1368 if (d_len > 0 && h_len >= d_len && 1369 strncasecmp(host + h_len - d_len, 1370 p, d_len) == 0) { 1371 /* domain name matches */ 1372 return (1); 1373 } 1374 1375 p = q + 1; 1376 } while (*q); 1377 1378 return (0); 1379 } 1380