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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11003 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11005 * Simple pattern matching, with '*' and '?' as wildcards.
Damien Miller4af51302000-04-16 11:18:38 +10006 *
Damien Millere4340be2000-09-16 13:29:08 +11007 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
Damien Miller95def091999-11-25 00:26:21 +110012 */
Ben Lindstromb9be60a2001-03-11 01:49:19 +000013/*
14 * Copyright (c) 2000 Markus Friedl. All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100036
37#include "includes.h"
Damien Miller9f0f5c62001-12-21 14:45:46 +110038RCSID("$OpenBSD: match.c,v 1.16 2001/12/19 07:18:56 deraadt Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100039
Ben Lindstrom226cfa02001-01-22 05:34:40 +000040#include "match.h"
Ben Lindstromb9be60a2001-03-11 01:49:19 +000041#include "xmalloc.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100042
Damien Miller5428f641999-11-25 11:54:57 +110043/*
44 * Returns true if the given string matches the pattern (which may contain ?
45 * and * as wildcards), and zero if it does not match.
46 */
Damien Miller95def091999-11-25 00:26:21 +110047
Damien Miller4af51302000-04-16 11:18:38 +100048int
Damien Miller95def091999-11-25 00:26:21 +110049match_pattern(const char *s, const char *pattern)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100050{
Damien Miller95def091999-11-25 00:26:21 +110051 for (;;) {
52 /* If at end of pattern, accept if also at end of string. */
53 if (!*pattern)
54 return !*s;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100055
Damien Miller95def091999-11-25 00:26:21 +110056 if (*pattern == '*') {
57 /* Skip the asterisk. */
58 pattern++;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100059
Damien Miller95def091999-11-25 00:26:21 +110060 /* If at end of pattern, accept immediately. */
61 if (!*pattern)
62 return 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100063
Damien Miller95def091999-11-25 00:26:21 +110064 /* If next character in pattern is known, optimize. */
65 if (*pattern != '?' && *pattern != '*') {
Damien Miller5428f641999-11-25 11:54:57 +110066 /*
67 * Look instances of the next character in
68 * pattern, and try to match starting from
69 * those.
70 */
Damien Miller95def091999-11-25 00:26:21 +110071 for (; *s; s++)
72 if (*s == *pattern &&
73 match_pattern(s + 1, pattern + 1))
74 return 1;
75 /* Failed. */
76 return 0;
77 }
Damien Miller5428f641999-11-25 11:54:57 +110078 /*
79 * Move ahead one character at a time and try to
80 * match at each position.
81 */
Damien Miller95def091999-11-25 00:26:21 +110082 for (; *s; s++)
83 if (match_pattern(s, pattern))
84 return 1;
85 /* Failed. */
86 return 0;
87 }
Damien Miller5428f641999-11-25 11:54:57 +110088 /*
89 * There must be at least one more character in the string.
90 * If we are at the end, fail.
91 */
Damien Miller95def091999-11-25 00:26:21 +110092 if (!*s)
93 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100094
Damien Miller5428f641999-11-25 11:54:57 +110095 /* Check if the next character of the string is acceptable. */
Damien Miller95def091999-11-25 00:26:21 +110096 if (*pattern != '?' && *pattern != *s)
97 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100098
Damien Miller5428f641999-11-25 11:54:57 +110099 /* Move to the next character, both in string and in pattern. */
Damien Miller95def091999-11-25 00:26:21 +1100100 s++;
101 pattern++;
102 }
103 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000104}
Damien Miller450a7a12000-03-26 13:04:51 +1000105
106/*
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000107 * Tries to match the string against the
Damien Miller450a7a12000-03-26 13:04:51 +1000108 * comma-separated sequence of subpatterns (each possibly preceded by ! to
Damien Millerd3a18572000-06-07 19:55:44 +1000109 * indicate negation). Returns -1 if negation matches, 1 if there is
110 * a positive match, 0 if there is no match at all.
Damien Miller450a7a12000-03-26 13:04:51 +1000111 */
112
113int
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000114match_pattern_list(const char *string, const char *pattern, u_int len,
115 int dolower)
Damien Miller450a7a12000-03-26 13:04:51 +1000116{
117 char sub[1024];
118 int negated;
119 int got_positive;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000120 u_int i, subi;
Damien Miller450a7a12000-03-26 13:04:51 +1000121
122 got_positive = 0;
123 for (i = 0; i < len;) {
124 /* Check if the subpattern is negated. */
125 if (pattern[i] == '!') {
126 negated = 1;
127 i++;
128 } else
129 negated = 0;
130
131 /*
132 * Extract the subpattern up to a comma or end. Convert the
133 * subpattern to lowercase.
134 */
135 for (subi = 0;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100136 i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
137 subi++, i++)
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000138 sub[subi] = dolower && isupper(pattern[i]) ?
Damien Miller9f0f5c62001-12-21 14:45:46 +1100139 tolower(pattern[i]) : pattern[i];
Damien Miller450a7a12000-03-26 13:04:51 +1000140 /* If subpattern too long, return failure (no match). */
141 if (subi >= sizeof(sub) - 1)
142 return 0;
143
144 /* If the subpattern was terminated by a comma, skip the comma. */
145 if (i < len && pattern[i] == ',')
146 i++;
147
148 /* Null-terminate the subpattern. */
149 sub[subi] = '\0';
150
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000151 /* Try to match the subpattern against the string. */
152 if (match_pattern(string, sub)) {
Damien Miller450a7a12000-03-26 13:04:51 +1000153 if (negated)
Damien Millerd3a18572000-06-07 19:55:44 +1000154 return -1; /* Negative */
Damien Miller450a7a12000-03-26 13:04:51 +1000155 else
Damien Millerd3a18572000-06-07 19:55:44 +1000156 got_positive = 1; /* Positive */
Damien Miller450a7a12000-03-26 13:04:51 +1000157 }
158 }
159
160 /*
161 * Return success if got a positive match. If there was a negative
Damien Millerd3a18572000-06-07 19:55:44 +1000162 * match, we have already returned -1 and never get here.
Damien Miller450a7a12000-03-26 13:04:51 +1000163 */
164 return got_positive;
165}
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000166
Ben Lindstromf0c50292001-06-25 05:17:53 +0000167/*
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000168 * Tries to match the host name (which must be in all lowercase) against the
169 * comma-separated sequence of subpatterns (each possibly preceded by ! to
170 * indicate negation). Returns -1 if negation matches, 1 if there is
171 * a positive match, 0 if there is no match at all.
172 */
173int
174match_hostname(const char *host, const char *pattern, u_int len)
175{
176 return match_pattern_list(host, pattern, len, 1);
177}
178
179/*
Ben Lindstromf0c50292001-06-25 05:17:53 +0000180 * returns 0 if we get a negative match for the hostname or the ip
181 * or if we get no match at all. returns 1 otherwise.
182 */
183int
184match_host_and_ip(const char *host, const char *ipaddr,
185 const char *patterns)
186{
187 int mhost, mip;
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000188
Ben Lindstromf0c50292001-06-25 05:17:53 +0000189 /* negative ipaddr match */
190 if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1)
191 return 0;
192 /* negative hostname match */
193 if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1)
194 return 0;
195 /* no match at all */
196 if (mhost == 0 && mip == 0)
197 return 0;
198 return 1;
199}
200
201/*
Ben Lindstrom60260022001-07-04 04:56:44 +0000202 * match user, user@host_or_ip, user@host_or_ip_list against pattern
203 */
204int
205match_user(const char *user, const char *host, const char *ipaddr,
206 const char *pattern)
207{
208 char *p, *pat;
209 int ret;
210
211 if ((p = strchr(pattern,'@')) == NULL)
212 return match_pattern(user, pattern);
213
214 pat = xstrdup(pattern);
215 p = strchr(pat, '@');
216 *p++ = '\0';
217
218 if ((ret = match_pattern(user, pat)) == 1)
219 ret = match_host_and_ip(host, ipaddr, p);
220 xfree(pat);
221
222 return ret;
223}
224
225/*
Ben Lindstromf0c50292001-06-25 05:17:53 +0000226 * Returns first item from client-list that is also supported by server-list,
227 * caller must xfree() returned string.
228 */
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000229#define MAX_PROP 20
230#define SEP ","
231char *
232match_list(const char *client, const char *server, u_int *next)
233{
234 char *sproposals[MAX_PROP];
235 char *c, *s, *p, *ret, *cp, *sp;
236 int i, j, nproposals;
237
238 c = cp = xstrdup(client);
239 s = sp = xstrdup(server);
240
241 for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100242 (p = strsep(&sp, SEP)), i++) {
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000243 if (i < MAX_PROP)
244 sproposals[i] = p;
245 else
246 break;
247 }
248 nproposals = i;
249
250 for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100251 (p = strsep(&cp, SEP)), i++) {
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000252 for (j = 0; j < nproposals; j++) {
253 if (strcmp(p, sproposals[j]) == 0) {
254 ret = xstrdup(p);
255 if (next != NULL)
256 *next = (cp == NULL) ?
257 strlen(c) : cp - c;
258 xfree(c);
259 xfree(s);
260 return ret;
261 }
262 }
263 }
264 if (next != NULL)
265 *next = strlen(c);
266 xfree(c);
267 xfree(s);
268 return NULL;
269}