1 /* $NetBSD: hostcheck.c,v 1.1.1.1 2017/01/31 21:14:53 christos Exp $ */
2 /***************************************************************************
3 * _ _ ____ _
4 * Project ___| | | | _ \| |
5 * / __| | | | |_) | |
6 * | (__| |_| | _ <| |___
7 * \___|\___/|_| \_\_____|
8 *
9 * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
10 *
11 * This software is licensed as described in the file COPYING, which
12 * you should have received as part of this distribution. The terms
13 * are also available at http://curl.haxx.se/docs/copyright.html.
14 *
15 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
16 * copies of the Software, and permit persons to whom the Software is
17 * furnished to do so, under the terms of the COPYING file.
18 *
19 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
20 * KIND, either express or implied.
21 *
22 ***************************************************************************/
23
24 /* This file is an amalgamation of hostcheck.c and most of rawstr.c
25 from cURL. The contents of the COPYING file mentioned above are:
26
27 COPYRIGHT AND PERMISSION NOTICE
28
29 Copyright (c) 1996 - 2013, Daniel Stenberg, <daniel@haxx.se>.
30
31 All rights reserved.
32
33 Permission to use, copy, modify, and distribute this software for any purpose
34 with or without fee is hereby granted, provided that the above copyright
35 notice and this permission notice appear in all copies.
36
37 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
38 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
39 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN
40 NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
41 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
42 OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
43 OR OTHER DEALINGS IN THE SOFTWARE.
44
45 Except as contained in this notice, the name of a copyright holder shall not
46 be used in advertising or otherwise to promote the sale, use or other dealings
47 in this Software without prior written authorization of the copyright holder.
48 */
49
50 #include "hostcheck.h"
51 #include <string.h>
52
53 /* Portable, consistent toupper (remember EBCDIC). Do not use toupper() because
54 its behavior is altered by the current locale. */
Curl_raw_toupper(char in)55 static char Curl_raw_toupper(char in)
56 {
57 switch (in) {
58 case 'a':
59 return 'A';
60 case 'b':
61 return 'B';
62 case 'c':
63 return 'C';
64 case 'd':
65 return 'D';
66 case 'e':
67 return 'E';
68 case 'f':
69 return 'F';
70 case 'g':
71 return 'G';
72 case 'h':
73 return 'H';
74 case 'i':
75 return 'I';
76 case 'j':
77 return 'J';
78 case 'k':
79 return 'K';
80 case 'l':
81 return 'L';
82 case 'm':
83 return 'M';
84 case 'n':
85 return 'N';
86 case 'o':
87 return 'O';
88 case 'p':
89 return 'P';
90 case 'q':
91 return 'Q';
92 case 'r':
93 return 'R';
94 case 's':
95 return 'S';
96 case 't':
97 return 'T';
98 case 'u':
99 return 'U';
100 case 'v':
101 return 'V';
102 case 'w':
103 return 'W';
104 case 'x':
105 return 'X';
106 case 'y':
107 return 'Y';
108 case 'z':
109 return 'Z';
110 }
111 return in;
112 }
113
114 /*
115 * Curl_raw_equal() is for doing "raw" case insensitive strings. This is meant
116 * to be locale independent and only compare strings we know are safe for
117 * this. See http://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for
118 * some further explanation to why this function is necessary.
119 *
120 * The function is capable of comparing a-z case insensitively even for
121 * non-ascii.
122 */
123
Curl_raw_equal(const char * first,const char * second)124 static int Curl_raw_equal(const char *first, const char *second)
125 {
126 while(*first && *second) {
127 if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second))
128 /* get out of the loop as soon as they don't match */
129 break;
130 first++;
131 second++;
132 }
133 /* we do the comparison here (possibly again), just to make sure that if the
134 loop above is skipped because one of the strings reached zero, we must not
135 return this as a successful match */
136 return (Curl_raw_toupper(*first) == Curl_raw_toupper(*second));
137 }
138
Curl_raw_nequal(const char * first,const char * second,size_t max)139 static int Curl_raw_nequal(const char *first, const char *second, size_t max)
140 {
141 while(*first && *second && max) {
142 if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second)) {
143 break;
144 }
145 max--;
146 first++;
147 second++;
148 }
149 if(0 == max)
150 return 1; /* they are equal this far */
151
152 return Curl_raw_toupper(*first) == Curl_raw_toupper(*second);
153 }
154
155 /*
156 * Match a hostname against a wildcard pattern.
157 * E.g.
158 * "foo.host.com" matches "*.host.com".
159 *
160 * We use the matching rule described in RFC6125, section 6.4.3.
161 * http://tools.ietf.org/html/rfc6125#section-6.4.3
162 */
163
hostmatch(const char * hostname,const char * pattern)164 static int hostmatch(const char *hostname, const char *pattern)
165 {
166 const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
167 int wildcard_enabled;
168 size_t prefixlen, suffixlen;
169 pattern_wildcard = strchr(pattern, '*');
170 if(pattern_wildcard == NULL)
171 return Curl_raw_equal(pattern, hostname) ?
172 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
173
174 /* We require at least 2 dots in pattern to avoid too wide wildcard
175 match. */
176 wildcard_enabled = 1;
177 pattern_label_end = strchr(pattern, '.');
178 if(pattern_label_end == NULL || strchr(pattern_label_end+1, '.') == NULL ||
179 pattern_wildcard > pattern_label_end ||
180 Curl_raw_nequal(pattern, "xn--", 4)) {
181 wildcard_enabled = 0;
182 }
183 if(!wildcard_enabled)
184 return Curl_raw_equal(pattern, hostname) ?
185 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
186
187 hostname_label_end = strchr(hostname, '.');
188 if(hostname_label_end == NULL ||
189 !Curl_raw_equal(pattern_label_end, hostname_label_end))
190 return CURL_HOST_NOMATCH;
191
192 /* The wildcard must match at least one character, so the left-most
193 label of the hostname is at least as large as the left-most label
194 of the pattern. */
195 if(hostname_label_end - hostname < pattern_label_end - pattern)
196 return CURL_HOST_NOMATCH;
197
198 prefixlen = pattern_wildcard - pattern;
199 suffixlen = pattern_label_end - (pattern_wildcard+1);
200 return Curl_raw_nequal(pattern, hostname, prefixlen) &&
201 Curl_raw_nequal(pattern_wildcard+1, hostname_label_end - suffixlen,
202 suffixlen) ?
203 CURL_HOST_MATCH : CURL_HOST_NOMATCH;
204 }
205
Curl_cert_hostcheck(const char * match_pattern,const char * hostname)206 int Curl_cert_hostcheck(const char *match_pattern, const char *hostname)
207 {
208 if(!match_pattern || !*match_pattern ||
209 !hostname || !*hostname) /* sanity check */
210 return 0;
211
212 if(Curl_raw_equal(hostname, match_pattern)) /* trivial case */
213 return 1;
214
215 if(hostmatch(hostname,match_pattern) == CURL_HOST_MATCH)
216 return 1;
217 return 0;
218 }
219