lib/libfetch/common.c

   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 }