1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2019, 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_GSKIT) \
27 || defined(USE_SCHANNEL)
28 /* these backends use functions from this file */
29
30 #ifdef HAVE_NETINET_IN_H
31 #include <netinet/in.h>
32 #endif
33 #ifdef HAVE_NETINET_IN6_H
34 #include <netinet/in6.h>
35 #endif
36
37 #include "hostcheck.h"
38 #include "strcase.h"
39 #include "inet_pton.h"
40
41 #include "curl_memory.h"
42 /* The last #include file should be: */
43 #include "memdebug.h"
44
45 /*
46 * Match a hostname against a wildcard pattern.
47 * E.g.
48 * "foo.host.com" matches "*.host.com".
49 *
50 * We use the matching rule described in RFC6125, section 6.4.3.
51 * https://tools.ietf.org/html/rfc6125#section-6.4.3
52 *
53 * In addition: ignore trailing dots in the host names and wildcards, so that
54 * the names are used normalized. This is what the browsers do.
55 *
56 * Do not allow wildcard matching on IP numbers. There are apparently
57 * certificates being used with an IP address in the CN field, thus making no
58 * apparent distinction between a name and an IP. We need to detect the use of
59 * an IP address and not wildcard match on such names.
60 *
61 * NOTE: hostmatch() gets called with copied buffers so that it can modify the
62 * contents at will.
63 */
64
hostmatch(char * hostname,char * pattern)65 static int hostmatch(char *hostname, char *pattern)
66 {
67 const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
68 int wildcard_enabled;
69 size_t prefixlen, suffixlen;
70 struct in_addr ignored;
71 #ifdef ENABLE_IPV6
72 struct sockaddr_in6 si6;
73 #endif
74
75 /* normalize pattern and hostname by stripping off trailing dots */
76 size_t len = strlen(hostname);
77 if(hostname[len-1]=='.')
78 hostname[len-1] = 0;
79 len = strlen(pattern);
80 if(pattern[len-1]=='.')
81 pattern[len-1] = 0;
82
83 pattern_wildcard = strchr(pattern, '*');
84 if(pattern_wildcard == NULL)
85 return strcasecompare(pattern, hostname) ?
86 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
87
88 /* detect IP address as hostname and fail the match if so */
89 if(Curl_inet_pton(AF_INET, hostname, &ignored) > 0)
90 return CURL_HOST_NOMATCH;
91 #ifdef ENABLE_IPV6
92 if(Curl_inet_pton(AF_INET6, hostname, &si6.sin6_addr) > 0)
93 return CURL_HOST_NOMATCH;
94 #endif
95
96 /* We require at least 2 dots in pattern to avoid too wide wildcard
97 match. */
98 wildcard_enabled = 1;
99 pattern_label_end = strchr(pattern, '.');
100 if(pattern_label_end == NULL || strchr(pattern_label_end + 1, '.') == NULL ||
101 pattern_wildcard > pattern_label_end ||
102 strncasecompare(pattern, "xn--", 4)) {
103 wildcard_enabled = 0;
104 }
105 if(!wildcard_enabled)
106 return strcasecompare(pattern, hostname) ?
107 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
108
109 hostname_label_end = strchr(hostname, '.');
110 if(hostname_label_end == NULL ||
111 !strcasecompare(pattern_label_end, hostname_label_end))
112 return CURL_HOST_NOMATCH;
113
114 /* The wildcard must match at least one character, so the left-most
115 label of the hostname is at least as large as the left-most label
116 of the pattern. */
117 if(hostname_label_end - hostname < pattern_label_end - pattern)
118 return CURL_HOST_NOMATCH;
119
120 prefixlen = pattern_wildcard - pattern;
121 suffixlen = pattern_label_end - (pattern_wildcard + 1);
122 return strncasecompare(pattern, hostname, prefixlen) &&
123 strncasecompare(pattern_wildcard + 1, hostname_label_end - suffixlen,
124 suffixlen) ?
125 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
126 }
127
Curl_cert_hostcheck(const char * match_pattern,const char * hostname)128 int Curl_cert_hostcheck(const char *match_pattern, const char *hostname)
129 {
130 int res = 0;
131 if(!match_pattern || !*match_pattern ||
132 !hostname || !*hostname) /* sanity check */
133 ;
134 else {
135 char *matchp = strdup(match_pattern);
136 if(matchp) {
137 char *hostp = strdup(hostname);
138 if(hostp) {
139 if(hostmatch(hostp, matchp) == CURL_HOST_MATCH)
140 res = 1;
141 free(hostp);
142 }
143 free(matchp);
144 }
145 }
146
147 return res;
148 }
149
150 #endif /* OPENSSL, GSKIT or schannel+wince */
151