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