1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2017, 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 https://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_OPENSSL) \
26 || defined(USE_AXTLS) \
27 || defined(USE_GSKIT) \
28 || (defined(USE_SCHANNEL) && defined(_WIN32_WCE))
29 /* these backends use functions from this file */
30
31 #ifdef HAVE_NETINET_IN_H
32 #include <netinet/in.h>
33 #endif
34 #ifdef HAVE_NETINET_IN6_H
35 #include <netinet/in6.h>
36 #endif
37
38 #include "hostcheck.h"
39 #include "strcase.h"
40 #include "inet_pton.h"
41
42 #include "curl_memory.h"
43 /* The last #include file should be: */
44 #include "memdebug.h"
45
46 /*
47 * Match a hostname against a wildcard pattern.
48 * E.g.
49 * "foo.host.com" matches "*.host.com".
50 *
51 * We use the matching rule described in RFC6125, section 6.4.3.
52 * https://tools.ietf.org/html/rfc6125#section-6.4.3
53 *
54 * In addition: ignore trailing dots in the host names and wildcards, so that
55 * the names are used normalized. This is what the browsers do.
56 *
57 * Do not allow wildcard matching on IP numbers. There are apparently
58 * certificates being used with an IP address in the CN field, thus making no
59 * apparent distinction between a name and an IP. We need to detect the use of
60 * an IP address and not wildcard match on such names.
61 *
62 * NOTE: hostmatch() gets called with copied buffers so that it can modify the
63 * contents at will.
64 */
65
hostmatch(char * hostname,char * pattern)66 static int hostmatch(char *hostname, char *pattern)
67 {
68 const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
69 int wildcard_enabled;
70 size_t prefixlen, suffixlen;
71 struct in_addr ignored;
72 #ifdef ENABLE_IPV6
73 struct sockaddr_in6 si6;
74 #endif
75
76 /* normalize pattern and hostname by stripping off trailing dots */
77 size_t len = strlen(hostname);
78 if(hostname[len-1]=='.')
79 hostname[len-1] = 0;
80 len = strlen(pattern);
81 if(pattern[len-1]=='.')
82 pattern[len-1] = 0;
83
84 pattern_wildcard = strchr(pattern, '*');
85 if(pattern_wildcard == NULL)
86 return strcasecompare(pattern, hostname) ?
87 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
88
89 /* detect IP address as hostname and fail the match if so */
90 if(Curl_inet_pton(AF_INET, hostname, &ignored) > 0)
91 return CURL_HOST_NOMATCH;
92 #ifdef ENABLE_IPV6
93 if(Curl_inet_pton(AF_INET6, hostname, &si6.sin6_addr) > 0)
94 return CURL_HOST_NOMATCH;
95 #endif
96
97 /* We require at least 2 dots in pattern to avoid too wide wildcard
98 match. */
99 wildcard_enabled = 1;
100 pattern_label_end = strchr(pattern, '.');
101 if(pattern_label_end == NULL || strchr(pattern_label_end + 1, '.') == NULL ||
102 pattern_wildcard > pattern_label_end ||
103 strncasecompare(pattern, "xn--", 4)) {
104 wildcard_enabled = 0;
105 }
106 if(!wildcard_enabled)
107 return strcasecompare(pattern, hostname) ?
108 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
109
110 hostname_label_end = strchr(hostname, '.');
111 if(hostname_label_end == NULL ||
112 !strcasecompare(pattern_label_end, hostname_label_end))
113 return CURL_HOST_NOMATCH;
114
115 /* The wildcard must match at least one character, so the left-most
116 label of the hostname is at least as large as the left-most label
117 of the pattern. */
118 if(hostname_label_end - hostname < pattern_label_end - pattern)
119 return CURL_HOST_NOMATCH;
120
121 prefixlen = pattern_wildcard - pattern;
122 suffixlen = pattern_label_end - (pattern_wildcard + 1);
123 return strncasecompare(pattern, hostname, prefixlen) &&
124 strncasecompare(pattern_wildcard + 1, hostname_label_end - suffixlen,
125 suffixlen) ?
126 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
127 }
128
Curl_cert_hostcheck(const char * match_pattern,const char * hostname)129 int Curl_cert_hostcheck(const char *match_pattern, const char *hostname)
130 {
131 char *matchp;
132 char *hostp;
133 int res = 0;
134 if(!match_pattern || !*match_pattern ||
135 !hostname || !*hostname) /* sanity check */
136 ;
137 else {
138 matchp = strdup(match_pattern);
139 if(matchp) {
140 hostp = strdup(hostname);
141 if(hostp) {
142 if(hostmatch(hostp, matchp) == CURL_HOST_MATCH)
143 res = 1;
144 free(hostp);
145 }
146 free(matchp);
147 }
148 }
149
150 return res;
151 }
152
153 #endif /* OPENSSL, AXTLS, GSKIT or schannel+wince */
154