1 /* $OpenBSD: match.c,v 1.27 2008/06/10 23:06:19 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * Simple pattern matching, with '*' and '?' as wildcards.
8 * 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".
15 * Copyright (c) 2000 Markus Friedl. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
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.
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.
40 #include <sys/types.h>
49 * Returns true if the given string matches the pattern (which may contain ?
50 * and * as wildcards), and zero if it does not match.
54 match_pattern(const char *s, const char *pattern)
57 /* If at end of pattern, accept if also at end of string. */
61 if (*pattern == '*') {
62 /* Skip the asterisk. */
65 /* If at end of pattern, accept immediately. */
69 /* If next character in pattern is known, optimize. */
70 if (*pattern != '?' && *pattern != '*') {
72 * Look instances of the next character in
73 * pattern, and try to match starting from
78 match_pattern(s + 1, pattern + 1))
84 * Move ahead one character at a time and try to
85 * match at each position.
88 if (match_pattern(s, pattern))
94 * There must be at least one more character in the string.
95 * If we are at the end, fail.
100 /* Check if the next character of the string is acceptable. */
101 if (*pattern != '?' && *pattern != *s)
104 /* Move to the next character, both in string and in pattern. */
112 * Tries to match the string against the
113 * comma-separated sequence of subpatterns (each possibly preceded by ! to
114 * indicate negation). Returns -1 if negation matches, 1 if there is
115 * a positive match, 0 if there is no match at all.
119 match_pattern_list(const char *string, const char *pattern, u_int len,
128 for (i = 0; i < len;) {
129 /* Check if the subpattern is negated. */
130 if (pattern[i] == '!') {
137 * Extract the subpattern up to a comma or end. Convert the
138 * subpattern to lowercase.
141 i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
143 sub[subi] = dolower && isupper(pattern[i]) ?
144 (char)tolower(pattern[i]) : pattern[i];
145 /* If subpattern too long, return failure (no match). */
146 if (subi >= sizeof(sub) - 1)
149 /* If the subpattern was terminated by a comma, skip the comma. */
150 if (i < len && pattern[i] == ',')
153 /* Null-terminate the subpattern. */
156 /* Try to match the subpattern against the string. */
157 if (match_pattern(string, sub)) {
159 return -1; /* Negative */
161 got_positive = 1; /* Positive */
166 * Return success if got a positive match. If there was a negative
167 * match, we have already returned -1 and never get here.
173 * Tries to match the host name (which must be in all lowercase) against the
174 * comma-separated sequence of subpatterns (each possibly preceded by ! to
175 * indicate negation). Returns -1 if negation matches, 1 if there is
176 * a positive match, 0 if there is no match at all.
179 match_hostname(const char *host, const char *pattern, u_int len)
181 return match_pattern_list(host, pattern, len, 1);
185 * returns 0 if we get a negative match for the hostname or the ip
186 * or if we get no match at all. returns -1 on error, or 1 on
190 match_host_and_ip(const char *host, const char *ipaddr,
191 const char *patterns)
195 /* error in ipaddr match */
196 if ((mip = addr_match_list(ipaddr, patterns)) == -2)
198 else if (mip == -1) /* negative ip address match */
201 /* negative hostname match */
202 if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1)
204 /* no match at all */
205 if (mhost == 0 && mip == 0)
211 * match user, user@host_or_ip, user@host_or_ip_list against pattern
214 match_user(const char *user, const char *host, const char *ipaddr,
220 if ((p = strchr(pattern,'@')) == NULL)
221 return match_pattern(user, pattern);
223 pat = xstrdup(pattern);
224 p = strchr(pat, '@');
227 if ((ret = match_pattern(user, pat)) == 1)
228 ret = match_host_and_ip(host, ipaddr, p);
235 * Returns first item from client-list that is also supported by server-list,
236 * caller must xfree() returned string.
241 match_list(const char *client, const char *server, u_int *next)
243 char *sproposals[MAX_PROP];
244 char *c, *s, *p, *ret, *cp, *sp;
245 int i, j, nproposals;
247 c = cp = xstrdup(client);
248 s = sp = xstrdup(server);
250 for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
251 (p = strsep(&sp, SEP)), i++) {
259 for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
260 (p = strsep(&cp, SEP)), i++) {
261 for (j = 0; j < nproposals; j++) {
262 if (strcmp(p, sproposals[j]) == 0) {
265 *next = (cp == NULL) ?
266 strlen(c) : (u_int)(cp - c);