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Damien Miller57c30112006-03-26 14:24:48 +11001/* $OpenBSD: match.c,v 1.24 2006/03/25 13:17:02 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
40#include <ctype.h>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100041
Ben Lindstrom226cfa02001-01-22 05:34:40 +000042#include "match.h"
Ben Lindstromb9be60a2001-03-11 01:49:19 +000043#include "xmalloc.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100044
Damien Miller5428f641999-11-25 11:54:57 +110045/*
46 * Returns true if the given string matches the pattern (which may contain ?
47 * and * as wildcards), and zero if it does not match.
48 */
Damien Miller95def091999-11-25 00:26:21 +110049
Damien Miller4af51302000-04-16 11:18:38 +100050int
Damien Miller95def091999-11-25 00:26:21 +110051match_pattern(const char *s, const char *pattern)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100052{
Damien Miller95def091999-11-25 00:26:21 +110053 for (;;) {
54 /* If at end of pattern, accept if also at end of string. */
55 if (!*pattern)
56 return !*s;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100057
Damien Miller95def091999-11-25 00:26:21 +110058 if (*pattern == '*') {
59 /* Skip the asterisk. */
60 pattern++;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100061
Damien Miller95def091999-11-25 00:26:21 +110062 /* If at end of pattern, accept immediately. */
63 if (!*pattern)
64 return 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100065
Damien Miller95def091999-11-25 00:26:21 +110066 /* If next character in pattern is known, optimize. */
67 if (*pattern != '?' && *pattern != '*') {
Damien Miller5428f641999-11-25 11:54:57 +110068 /*
69 * Look instances of the next character in
70 * pattern, and try to match starting from
71 * those.
72 */
Damien Miller95def091999-11-25 00:26:21 +110073 for (; *s; s++)
74 if (*s == *pattern &&
75 match_pattern(s + 1, pattern + 1))
76 return 1;
77 /* Failed. */
78 return 0;
79 }
Damien Miller5428f641999-11-25 11:54:57 +110080 /*
81 * Move ahead one character at a time and try to
82 * match at each position.
83 */
Damien Miller95def091999-11-25 00:26:21 +110084 for (; *s; s++)
85 if (match_pattern(s, pattern))
86 return 1;
87 /* Failed. */
88 return 0;
89 }
Damien Miller5428f641999-11-25 11:54:57 +110090 /*
91 * There must be at least one more character in the string.
92 * If we are at the end, fail.
93 */
Damien Miller95def091999-11-25 00:26:21 +110094 if (!*s)
95 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100096
Damien Miller5428f641999-11-25 11:54:57 +110097 /* Check if the next character of the string is acceptable. */
Damien Miller95def091999-11-25 00:26:21 +110098 if (*pattern != '?' && *pattern != *s)
99 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000100
Damien Miller5428f641999-11-25 11:54:57 +1100101 /* Move to the next character, both in string and in pattern. */
Damien Miller95def091999-11-25 00:26:21 +1100102 s++;
103 pattern++;
104 }
105 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000106}
Damien Miller450a7a12000-03-26 13:04:51 +1000107
108/*
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000109 * Tries to match the string against the
Damien Miller450a7a12000-03-26 13:04:51 +1000110 * comma-separated sequence of subpatterns (each possibly preceded by ! to
Damien Millerd3a18572000-06-07 19:55:44 +1000111 * indicate negation). Returns -1 if negation matches, 1 if there is
112 * a positive match, 0 if there is no match at all.
Damien Miller450a7a12000-03-26 13:04:51 +1000113 */
114
115int
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000116match_pattern_list(const char *string, const char *pattern, u_int len,
117 int dolower)
Damien Miller450a7a12000-03-26 13:04:51 +1000118{
119 char sub[1024];
120 int negated;
121 int got_positive;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000122 u_int i, subi;
Damien Miller450a7a12000-03-26 13:04:51 +1000123
124 got_positive = 0;
125 for (i = 0; i < len;) {
126 /* Check if the subpattern is negated. */
127 if (pattern[i] == '!') {
128 negated = 1;
129 i++;
130 } else
131 negated = 0;
132
133 /*
134 * Extract the subpattern up to a comma or end. Convert the
135 * subpattern to lowercase.
136 */
137 for (subi = 0;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100138 i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
139 subi++, i++)
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000140 sub[subi] = dolower && isupper(pattern[i]) ?
Damien Miller1d2b6702006-03-26 14:09:54 +1100141 (char)tolower(pattern[i]) : pattern[i];
Damien Miller450a7a12000-03-26 13:04:51 +1000142 /* If subpattern too long, return failure (no match). */
143 if (subi >= sizeof(sub) - 1)
144 return 0;
145
146 /* If the subpattern was terminated by a comma, skip the comma. */
147 if (i < len && pattern[i] == ',')
148 i++;
149
150 /* Null-terminate the subpattern. */
151 sub[subi] = '\0';
152
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000153 /* Try to match the subpattern against the string. */
154 if (match_pattern(string, sub)) {
Damien Miller450a7a12000-03-26 13:04:51 +1000155 if (negated)
Damien Millerd3a18572000-06-07 19:55:44 +1000156 return -1; /* Negative */
Damien Miller450a7a12000-03-26 13:04:51 +1000157 else
Damien Millerd3a18572000-06-07 19:55:44 +1000158 got_positive = 1; /* Positive */
Damien Miller450a7a12000-03-26 13:04:51 +1000159 }
160 }
161
162 /*
163 * Return success if got a positive match. If there was a negative
Damien Millerd3a18572000-06-07 19:55:44 +1000164 * match, we have already returned -1 and never get here.
Damien Miller450a7a12000-03-26 13:04:51 +1000165 */
166 return got_positive;
167}
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000168
Ben Lindstromf0c50292001-06-25 05:17:53 +0000169/*
Ben Lindstrom9eab2622001-12-06 18:06:05 +0000170 * Tries to match the host name (which must be in all lowercase) against the
171 * comma-separated sequence of subpatterns (each possibly preceded by ! to
172 * indicate negation). Returns -1 if negation matches, 1 if there is
173 * a positive match, 0 if there is no match at all.
174 */
175int
176match_hostname(const char *host, const char *pattern, u_int len)
177{
178 return match_pattern_list(host, pattern, len, 1);
179}
180
181/*
Ben Lindstromf0c50292001-06-25 05:17:53 +0000182 * returns 0 if we get a negative match for the hostname or the ip
183 * or if we get no match at all. returns 1 otherwise.
184 */
185int
186match_host_and_ip(const char *host, const char *ipaddr,
187 const char *patterns)
188{
189 int mhost, mip;
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000190
Ben Lindstromf0c50292001-06-25 05:17:53 +0000191 /* negative ipaddr match */
192 if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1)
193 return 0;
194 /* negative hostname match */
195 if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1)
196 return 0;
197 /* no match at all */
198 if (mhost == 0 && mip == 0)
199 return 0;
200 return 1;
201}
202
203/*
Ben Lindstrom60260022001-07-04 04:56:44 +0000204 * match user, user@host_or_ip, user@host_or_ip_list against pattern
205 */
206int
Ben Lindstrom3fb5d002002-03-05 01:42:42 +0000207match_user(const char *user, const char *host, const char *ipaddr,
Ben Lindstrom60260022001-07-04 04:56:44 +0000208 const char *pattern)
209{
210 char *p, *pat;
211 int ret;
212
213 if ((p = strchr(pattern,'@')) == NULL)
214 return match_pattern(user, pattern);
215
216 pat = xstrdup(pattern);
217 p = strchr(pat, '@');
218 *p++ = '\0';
219
220 if ((ret = match_pattern(user, pat)) == 1)
Ben Lindstrom3fb5d002002-03-05 01:42:42 +0000221 ret = match_host_and_ip(host, ipaddr, p);
Ben Lindstrom60260022001-07-04 04:56:44 +0000222 xfree(pat);
223
224 return ret;
225}
226
227/*
Ben Lindstromf0c50292001-06-25 05:17:53 +0000228 * Returns first item from client-list that is also supported by server-list,
229 * caller must xfree() returned string.
230 */
Damien Millerafc7a5d2002-02-13 13:55:30 +1100231#define MAX_PROP 40
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000232#define SEP ","
233char *
234match_list(const char *client, const char *server, u_int *next)
235{
236 char *sproposals[MAX_PROP];
237 char *c, *s, *p, *ret, *cp, *sp;
238 int i, j, nproposals;
239
240 c = cp = xstrdup(client);
241 s = sp = xstrdup(server);
242
243 for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100244 (p = strsep(&sp, SEP)), i++) {
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000245 if (i < MAX_PROP)
246 sproposals[i] = p;
247 else
248 break;
249 }
250 nproposals = i;
251
252 for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100253 (p = strsep(&cp, SEP)), i++) {
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000254 for (j = 0; j < nproposals; j++) {
255 if (strcmp(p, sproposals[j]) == 0) {
256 ret = xstrdup(p);
257 if (next != NULL)
258 *next = (cp == NULL) ?
Damien Millereccb9de2005-06-17 12:59:34 +1000259 strlen(c) : (u_int)(cp - c);
Ben Lindstromb9be60a2001-03-11 01:49:19 +0000260 xfree(c);
261 xfree(s);
262 return ret;
263 }
264 }
265 }
266 if (next != NULL)
267 *next = strlen(c);
268 xfree(c);
269 xfree(s);
270 return NULL;
271}