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djm@openbsd.orga5ad3a92016-09-21 16:55:42 +00001/* $OpenBSD: match.c,v 1.32 2016/09/21 16:55:42 djm Exp $ */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002/*
Damien Miller95def091999-11-25 00:26:21 +11003 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11004 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11006 * Simple pattern matching, with '*' and '?' as wildcards.
Damien Miller4af51302000-04-16 11:18:38 +10007 *
Damien Millere4340be2000-09-16 13:29:08 +11008 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
Damien Miller95def091999-11-25 00:26:21 +110013 */
Ben Lindstromb9be60a2001-03-11 01:49:19 +000014/*
15 * Copyright (c) 2000 Markus Friedl. All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100037
38#include "includes.h"
Damien Millerc7b06362006-03-15 11:53:45 +110039
Damien Millerd7834352006-08-05 12:39:39 +100040#include <sys/types.h>
41
Damien Millerc7b06362006-03-15 11:53:45 +110042#include <ctype.h>
Darren Tuckera627d422013-06-02 07:31:17 +100043#include <stdlib.h>
Damien Millere3476ed2006-07-24 14:13:33 +100044#include <string.h>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100045
Ben Lindstromb9be60a2001-03-11 01:49:19 +000046#include "xmalloc.h"
Damien Millerd7834352006-08-05 12:39:39 +100047#include "match.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100048
Damien Miller5428f641999-11-25 11:54:57 +110049/*
50 * Returns true if the given string matches the pattern (which may contain ?
51 * and * as wildcards), and zero if it does not match.
52 */
Damien Miller95def091999-11-25 00:26:21 +110053
Damien Miller4af51302000-04-16 11:18:38 +100054int
Damien Miller95def091999-11-25 00:26:21 +110055match_pattern(const char *s, const char *pattern)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100056{
Damien Miller95def091999-11-25 00:26:21 +110057 for (;;) {
58 /* If at end of pattern, accept if also at end of string. */
59 if (!*pattern)
60 return !*s;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100061
Damien Miller95def091999-11-25 00:26:21 +110062 if (*pattern == '*') {
63 /* Skip the asterisk. */
64 pattern++;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100065
Damien Miller95def091999-11-25 00:26:21 +110066 /* If at end of pattern, accept immediately. */
67 if (!*pattern)
68 return 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100069
Damien Miller95def091999-11-25 00:26:21 +110070 /* If next character in pattern is known, optimize. */
71 if (*pattern != '?' && *pattern != '*') {
Damien Miller5428f641999-11-25 11:54:57 +110072 /*
73 * Look instances of the next character in
74 * pattern, and try to match starting from
75 * those.
76 */
Damien Miller95def091999-11-25 00:26:21 +110077 for (; *s; s++)
78 if (*s == *pattern &&
79 match_pattern(s + 1, pattern + 1))
80 return 1;
81 /* Failed. */
82 return 0;
83 }
Damien Miller5428f641999-11-25 11:54:57 +110084 /*
85 * Move ahead one character at a time and try to
86 * match at each position.
87 */
Damien Miller95def091999-11-25 00:26:21 +110088 for (; *s; s++)
89 if (match_pattern(s, pattern))
90 return 1;
91 /* Failed. */
92 return 0;
93 }
Damien Miller5428f641999-11-25 11:54:57 +110094 /*
95 * There must be at least one more character in the string.
96 * If we are at the end, fail.
97 */
Damien Miller95def091999-11-25 00:26:21 +110098 if (!*s)
99 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000100
Damien Miller5428f641999-11-25 11:54:57 +1100101 /* Check if the next character of the string is acceptable. */
Damien Miller95def091999-11-25 00:26:21 +1100102 if (*pattern != '?' && *pattern != *s)
103 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000104
Damien Miller5428f641999-11-25 11:54:57 +1100105 /* Move to the next character, both in string and in pattern. */
Damien Miller95def091999-11-25 00:26:21 +1100106 s++;
107 pattern++;
108 }
109 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000110}
Damien Miller450a7a12000-03-26 13:04:51 +1000111
112/*
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000113 * Tries to match the string against the
Damien Miller450a7a12000-03-26 13:04:51 +1000114 * comma-separated sequence of subpatterns (each possibly preceded by ! to
Damien Millerd3a18572000-06-07 19:55:44 +1000115 * indicate negation). Returns -1 if negation matches, 1 if there is
116 * a positive match, 0 if there is no match at all.
Damien Miller450a7a12000-03-26 13:04:51 +1000117 */
Damien Miller450a7a12000-03-26 13:04:51 +1000118int
djm@openbsd.orge661a862015-05-04 06:10:48 +0000119match_pattern_list(const char *string, const char *pattern, int dolower)
Damien Miller450a7a12000-03-26 13:04:51 +1000120{
121 char sub[1024];
122 int negated;
123 int got_positive;
djm@openbsd.orge661a862015-05-04 06:10:48 +0000124 u_int i, subi, len = strlen(pattern);
Damien Miller450a7a12000-03-26 13:04:51 +1000125
126 got_positive = 0;
127 for (i = 0; i < len;) {
128 /* Check if the subpattern is negated. */
129 if (pattern[i] == '!') {
130 negated = 1;
131 i++;
132 } else
133 negated = 0;
134
135 /*
136 * Extract the subpattern up to a comma or end. Convert the
137 * subpattern to lowercase.
138 */
139 for (subi = 0;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100140 i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
141 subi++, i++)
Damien Millerfdb23062013-11-21 13:57:15 +1100142 sub[subi] = dolower && isupper((u_char)pattern[i]) ?
143 tolower((u_char)pattern[i]) : pattern[i];
Damien Miller450a7a12000-03-26 13:04:51 +1000144 /* If subpattern too long, return failure (no match). */
145 if (subi >= sizeof(sub) - 1)
146 return 0;
147
148 /* If the subpattern was terminated by a comma, skip the comma. */
149 if (i < len && pattern[i] == ',')
150 i++;
151
152 /* Null-terminate the subpattern. */
153 sub[subi] = '\0';
154
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000155 /* Try to match the subpattern against the string. */
156 if (match_pattern(string, sub)) {
Damien Miller450a7a12000-03-26 13:04:51 +1000157 if (negated)
Damien Millerd3a18572000-06-07 19:55:44 +1000158 return -1; /* Negative */
Damien Miller450a7a12000-03-26 13:04:51 +1000159 else
Damien Millerd3a18572000-06-07 19:55:44 +1000160 got_positive = 1; /* Positive */
djm@openbsd.orga5ad3a92016-09-21 16:55:42 +0000161 }
Damien Miller450a7a12000-03-26 13:04:51 +1000162 }
163
164 /*
165 * Return success if got a positive match. If there was a negative
Damien Millerd3a18572000-06-07 19:55:44 +1000166 * match, we have already returned -1 and never get here.
Damien Miller450a7a12000-03-26 13:04:51 +1000167 */
168 return got_positive;
169}
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000170
Ben Lindstromf0c50292001-06-25 05:17:53 +0000171/*
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000172 * Tries to match the host name (which must be in all lowercase) against the
173 * comma-separated sequence of subpatterns (each possibly preceded by ! to
174 * indicate negation). Returns -1 if negation matches, 1 if there is
175 * a positive match, 0 if there is no match at all.
176 */
177int
djm@openbsd.orge661a862015-05-04 06:10:48 +0000178match_hostname(const char *host, const char *pattern)
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000179{
djm@openbsd.orge661a862015-05-04 06:10:48 +0000180 return match_pattern_list(host, pattern, 1);
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000181}
182
183/*
Ben Lindstromf0c50292001-06-25 05:17:53 +0000184 * returns 0 if we get a negative match for the hostname or the ip
Darren Tucker896ad5a2008-06-11 09:34:46 +1000185 * or if we get no match at all. returns -1 on error, or 1 on
186 * successful match.
Ben Lindstromf0c50292001-06-25 05:17:53 +0000187 */
188int
189match_host_and_ip(const char *host, const char *ipaddr,
190 const char *patterns)
191{
192 int mhost, mip;
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000193
Darren Tucker896ad5a2008-06-11 09:34:46 +1000194 /* error in ipaddr match */
195 if ((mip = addr_match_list(ipaddr, patterns)) == -2)
196 return -1;
197 else if (mip == -1) /* negative ip address match */
Ben Lindstromf0c50292001-06-25 05:17:53 +0000198 return 0;
Darren Tucker896ad5a2008-06-11 09:34:46 +1000199
Ben Lindstromf0c50292001-06-25 05:17:53 +0000200 /* negative hostname match */
djm@openbsd.orge661a862015-05-04 06:10:48 +0000201 if ((mhost = match_hostname(host, patterns)) == -1)
Ben Lindstromf0c50292001-06-25 05:17:53 +0000202 return 0;
203 /* no match at all */
204 if (mhost == 0 && mip == 0)
205 return 0;
206 return 1;
207}
208
209/*
Ben Lindstrom60260022001-07-04 04:56:44 +0000210 * match user, user@host_or_ip, user@host_or_ip_list against pattern
211 */
212int
Ben Lindstrom3fb5d002002-03-05 01:42:42 +0000213match_user(const char *user, const char *host, const char *ipaddr,
Ben Lindstrom60260022001-07-04 04:56:44 +0000214 const char *pattern)
215{
216 char *p, *pat;
217 int ret;
218
219 if ((p = strchr(pattern,'@')) == NULL)
220 return match_pattern(user, pattern);
221
222 pat = xstrdup(pattern);
223 p = strchr(pat, '@');
224 *p++ = '\0';
225
226 if ((ret = match_pattern(user, pat)) == 1)
Ben Lindstrom3fb5d002002-03-05 01:42:42 +0000227 ret = match_host_and_ip(host, ipaddr, p);
Darren Tuckera627d422013-06-02 07:31:17 +1000228 free(pat);
Ben Lindstrom60260022001-07-04 04:56:44 +0000229
230 return ret;
231}
232
233/*
Ben Lindstromf0c50292001-06-25 05:17:53 +0000234 * Returns first item from client-list that is also supported by server-list,
Darren Tuckera627d422013-06-02 07:31:17 +1000235 * caller must free the returned string.
Ben Lindstromf0c50292001-06-25 05:17:53 +0000236 */
Damien Millerafc7a5d2002-02-13 13:55:30 +1100237#define MAX_PROP 40
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000238#define SEP ","
239char *
240match_list(const char *client, const char *server, u_int *next)
241{
242 char *sproposals[MAX_PROP];
243 char *c, *s, *p, *ret, *cp, *sp;
244 int i, j, nproposals;
245
246 c = cp = xstrdup(client);
247 s = sp = xstrdup(server);
248
249 for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100250 (p = strsep(&sp, SEP)), i++) {
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000251 if (i < MAX_PROP)
252 sproposals[i] = p;
253 else
254 break;
255 }
256 nproposals = i;
257
258 for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100259 (p = strsep(&cp, SEP)), i++) {
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000260 for (j = 0; j < nproposals; j++) {
261 if (strcmp(p, sproposals[j]) == 0) {
262 ret = xstrdup(p);
263 if (next != NULL)
264 *next = (cp == NULL) ?
Damien Millereccb9de2005-06-17 12:59:34 +1000265 strlen(c) : (u_int)(cp - c);
Darren Tuckera627d422013-06-02 07:31:17 +1000266 free(c);
267 free(s);
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000268 return ret;
269 }
270 }
271 }
272 if (next != NULL)
273 *next = strlen(c);
Darren Tuckera627d422013-06-02 07:31:17 +1000274 free(c);
275 free(s);
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000276 return NULL;
277}