1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "curl_setup.h"
24
25#if defined(USE_SSLEAY) || defined(USE_AXTLS) || defined(USE_QSOSSL) || \
26    defined(USE_GSKIT)
27/* these backends use functions from this file */
28
29#ifdef HAVE_NETINET_IN_H
30#include <netinet/in.h>
31#endif
32
33#include "hostcheck.h"
34#include "rawstr.h"
35#include "inet_pton.h"
36
37#include "curl_memory.h"
38/* The last #include file should be: */
39#include "memdebug.h"
40
41/*
42 * Match a hostname against a wildcard pattern.
43 * E.g.
44 *  "foo.host.com" matches "*.host.com".
45 *
46 * We use the matching rule described in RFC6125, section 6.4.3.
47 * http://tools.ietf.org/html/rfc6125#section-6.4.3
48 *
49 * In addition: ignore trailing dots in the host names and wildcards, so that
50 * the names are used normalized. This is what the browsers do.
51 *
52 * Do not allow wildcard matching on IP numbers. There are apparently
53 * certificates being used with an IP address in the CN field, thus making no
54 * apparent distinction between a name and an IP. We need to detect the use of
55 * an IP address and not wildcard match on such names.
56 *
57 * NOTE: hostmatch() gets called with copied buffers so that it can modify the
58 * contents at will.
59 */
60
61static int hostmatch(char *hostname, char *pattern)
62{
63  const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
64  int wildcard_enabled;
65  size_t prefixlen, suffixlen;
66  struct in_addr ignored;
67#ifdef ENABLE_IPV6
68  struct sockaddr_in6 si6;
69#endif
70
71  /* normalize pattern and hostname by stripping off trailing dots */
72  size_t len = strlen(hostname);
73  if(hostname[len-1]=='.')
74    hostname[len-1]=0;
75  len = strlen(pattern);
76  if(pattern[len-1]=='.')
77    pattern[len-1]=0;
78
79  pattern_wildcard = strchr(pattern, '*');
80  if(pattern_wildcard == NULL)
81    return Curl_raw_equal(pattern, hostname) ?
82      CURL_HOST_MATCH : CURL_HOST_NOMATCH;
83
84  /* detect IP address as hostname and fail the match if so */
85  if(Curl_inet_pton(AF_INET, hostname, &ignored) > 0)
86    return CURL_HOST_NOMATCH;
87#ifdef ENABLE_IPV6
88  else if(Curl_inet_pton(AF_INET6, hostname, &si6.sin6_addr) > 0)
89    return CURL_HOST_NOMATCH;
90#endif
91
92  /* We require at least 2 dots in pattern to avoid too wide wildcard
93     match. */
94  wildcard_enabled = 1;
95  pattern_label_end = strchr(pattern, '.');
96  if(pattern_label_end == NULL || strchr(pattern_label_end+1, '.') == NULL ||
97     pattern_wildcard > pattern_label_end ||
98     Curl_raw_nequal(pattern, "xn--", 4)) {
99    wildcard_enabled = 0;
100  }
101  if(!wildcard_enabled)
102    return Curl_raw_equal(pattern, hostname) ?
103      CURL_HOST_MATCH : CURL_HOST_NOMATCH;
104
105  hostname_label_end = strchr(hostname, '.');
106  if(hostname_label_end == NULL ||
107     !Curl_raw_equal(pattern_label_end, hostname_label_end))
108    return CURL_HOST_NOMATCH;
109
110  /* The wildcard must match at least one character, so the left-most
111     label of the hostname is at least as large as the left-most label
112     of the pattern. */
113  if(hostname_label_end - hostname < pattern_label_end - pattern)
114    return CURL_HOST_NOMATCH;
115
116  prefixlen = pattern_wildcard - pattern;
117  suffixlen = pattern_label_end - (pattern_wildcard+1);
118  return Curl_raw_nequal(pattern, hostname, prefixlen) &&
119    Curl_raw_nequal(pattern_wildcard+1, hostname_label_end - suffixlen,
120                    suffixlen) ?
121    CURL_HOST_MATCH : CURL_HOST_NOMATCH;
122}
123
124int Curl_cert_hostcheck(const char *match_pattern, const char *hostname)
125{
126  char *matchp;
127  char *hostp;
128  int res = 0;
129  if(!match_pattern || !*match_pattern ||
130      !hostname || !*hostname) /* sanity check */
131    ;
132  else {
133    matchp = strdup(match_pattern);
134    if(matchp) {
135      hostp = strdup(hostname);
136      if(hostp) {
137        if(hostmatch(hostp, matchp) == CURL_HOST_MATCH)
138          res= 1;
139        free(hostp);
140      }
141      free(matchp);
142    }
143  }
144
145  return res;
146}
147
148#endif /* SSLEAY or AXTLS or QSOSSL or GSKIT */
149