hostcheck.c (6623B)
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 26 COPYRIGHT AND PERMISSION NOTICE 27 28 Copyright (c) 1996 - 2013, Daniel Stenberg, <daniel@haxx.se>. 29 30 All rights reserved. 31 32 Permission to use, copy, modify, and distribute this software for any purpose 33 with or without fee is hereby granted, provided that the above copyright 34 notice and this permission notice appear in all copies. 35 36 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 37 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 38 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN 39 NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 40 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 41 OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE 42 OR OTHER DEALINGS IN THE SOFTWARE. 43 44 Except as contained in this notice, the name of a copyright holder shall not 45 be used in advertising or otherwise to promote the sale, use or other dealings 46 in 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. */ 54 static 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 */ 122 123 static 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 } 137 138 static 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 */ 162 163 static 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 } 204 205 int 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 }