1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, 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.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 #include "curl_memrchr.h"
37
38 #include "hostcheck.h"
39 #include "strcase.h"
40 #include "hostip.h"
41
42 #include "curl_memory.h"
43 /* The last #include file should be: */
44 #include "memdebug.h"
45
46 /* check the two input strings with given length, but do not
47 assume they end in nul-bytes */
pmatch(const char * hostname,size_t hostlen,const char * pattern,size_t patternlen)48 static bool pmatch(const char *hostname, size_t hostlen,
49 const char *pattern, size_t patternlen)
50 {
51 if(hostlen != patternlen)
52 return FALSE;
53 return strncasecompare(hostname, pattern, hostlen);
54 }
55
56 /*
57 * Match a hostname against a wildcard pattern.
58 * E.g.
59 * "foo.host.com" matches "*.host.com".
60 *
61 * We use the matching rule described in RFC6125, section 6.4.3.
62 * https://datatracker.ietf.org/doc/html/rfc6125#section-6.4.3
63 *
64 * In addition: ignore trailing dots in the host names and wildcards, so that
65 * the names are used normalized. This is what the browsers do.
66 *
67 * Do not allow wildcard matching on IP numbers. There are apparently
68 * certificates being used with an IP address in the CN field, thus making no
69 * apparent distinction between a name and an IP. We need to detect the use of
70 * an IP address and not wildcard match on such names.
71 *
72 * Only match on "*" being used for the leftmost label, not "a*", "a*b" nor
73 * "*b".
74 *
75 * Return TRUE on a match. FALSE if not.
76 *
77 * @unittest: 1397
78 */
hostmatch(const char * hostname,size_t hostlen,const char * pattern,size_t patternlen)79 static bool hostmatch(const char *hostname,
80 size_t hostlen,
81 const char *pattern,
82 size_t patternlen)
83 {
84 const char *pattern_label_end;
85
86 DEBUGASSERT(pattern);
87 DEBUGASSERT(patternlen);
88 DEBUGASSERT(hostname);
89 DEBUGASSERT(hostlen);
90
91 /* normalize pattern and hostname by stripping off trailing dots */
92
93 if(hostname[hostlen-1]=='.')
94 hostlen--;
95 if(pattern[patternlen-1]=='.')
96 patternlen--;
97
98 if(strncmp(pattern, "*.", 2))
99 return pmatch(hostname, hostlen, pattern, patternlen);
100 /* detect IP address as hostname and fail the match if so */
101 else if(Curl_host_is_ipnum(hostname))
102 return FALSE;
103
104 /* We require at least 2 dots in the pattern to avoid too wide wildcard
105 match. */
106 pattern_label_end = memchr(pattern, '.', patternlen);
107 if(!pattern_label_end ||
108 (memrchr(pattern, '.', patternlen) == pattern_label_end))
109 return pmatch(hostname, hostlen, pattern, patternlen);
110 else {
111 const char *hostname_label_end = memchr(hostname, '.', hostlen);
112 if(hostname_label_end) {
113 size_t skiphost = hostname_label_end - hostname;
114 size_t skiplen = pattern_label_end - pattern;
115 return pmatch(hostname_label_end, hostlen - skiphost,
116 pattern_label_end, patternlen - skiplen);
117 }
118 }
119 return FALSE;
120 }
121
Curl_cert_hostcheck(const char * match_pattern,const char * hostname)122 int Curl_cert_hostcheck(const char *match_pattern, const char *hostname)
123 {
124 int res = 0;
125 if(!match_pattern || !*match_pattern ||
126 !hostname || !*hostname) /* sanity check */
127 ;
128 else {
129 char *matchp = strdup(match_pattern);
130 if(matchp) {
131 char *hostp = strdup(hostname);
132 if(hostp) {
133 size_t hostlen = strlen(hostp);
134 size_t matchlen = strlen(matchp);
135 if(hostmatch(hostp, hostlen, matchp, matchlen) == TRUE)
136 res = 1;
137 free(hostp);
138 }
139 free(matchp);
140 }
141 }
142
143 return res;
144 }
145
146 #endif /* OPENSSL, GSKIT or schannel+wince */
147