text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at http://curl.haxx.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  
  #include "curl_setup.h"
  
  #if defined(USE_SSLEAY) || defined(USE_AXTLS)
  /* these two backends use functions from this file */
  
  #include "hostcheck.h"
  #include "rawstr.h"
  
  /*
   * Match a hostname against a wildcard pattern.
   * E.g.
   *  "foo.host.com" matches "*.host.com".
   *
   * We use the matching rule described in RFC6125, section 6.4.3.
   * http://tools.ietf.org/html/rfc6125#section-6.4.3
   */
  
  static int hostmatch(const char *hostname, const char *pattern)
  {
    const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
    int wildcard_enabled;
    size_t prefixlen, suffixlen;
    pattern_wildcard = strchr(pattern, '*');
    if(pattern_wildcard == NULL)
      return Curl_raw_equal(pattern, hostname) ?
        CURL_HOST_MATCH : CURL_HOST_NOMATCH;
  
    /* We require at least 2 dots in pattern to avoid too wide wildcard
       match. */
    wildcard_enabled = 1;
    pattern_label_end = strchr(pattern, '.');
    if(pattern_label_end == NULL || strchr(pattern_label_end+1, '.') == NULL ||
       pattern_wildcard > pattern_label_end ||
       Curl_raw_nequal(pattern, "xn--", 4)) {
      wildcard_enabled = 0;
    }
    if(!wildcard_enabled)
      return Curl_raw_equal(pattern, hostname) ?
        CURL_HOST_MATCH : CURL_HOST_NOMATCH;
  
    hostname_label_end = strchr(hostname, '.');
    if(hostname_label_end == NULL ||
       !Curl_raw_equal(pattern_label_end, hostname_label_end))
      return CURL_HOST_NOMATCH;
  
    /* The wildcard must match at least one character, so the left-most
       label of the hostname is at least as large as the left-most label
       of the pattern. */
    if(hostname_label_end - hostname < pattern_label_end - pattern)
      return CURL_HOST_NOMATCH;
  
    prefixlen = pattern_wildcard - pattern;
    suffixlen = pattern_label_end - (pattern_wildcard+1);
    return Curl_raw_nequal(pattern, hostname, prefixlen) &&
      Curl_raw_nequal(pattern_wildcard+1, hostname_label_end - suffixlen,
                      suffixlen) ?
      CURL_HOST_MATCH : CURL_HOST_NOMATCH;
  }
  
  int Curl_cert_hostcheck(const char *match_pattern, const char *hostname)
  {
    if(!match_pattern || !*match_pattern ||
        !hostname || !*hostname) /* sanity check */
      return 0;
  
    if(Curl_raw_equal(hostname, match_pattern)) /* trivial case */
      return 1;
  
    if(hostmatch(hostname,match_pattern) == CURL_HOST_MATCH)
      return 1;
    return 0;
  }
  
  #endif /* SSLEAY or AXTLS */
  