1 /* $OpenBSD: match.c,v 1.30 2015/05/04 06:10:48 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>
50 * Returns true if the given string matches the pattern (which may contain ?
51 * and * as wildcards), and zero if it does not match.
55 match_pattern(const char *s
, const char *pattern
)
58 /* If at end of pattern, accept if also at end of string. */
62 if (*pattern
== '*') {
63 /* Skip the asterisk. */
66 /* If at end of pattern, accept immediately. */
70 /* If next character in pattern is known, optimize. */
71 if (*pattern
!= '?' && *pattern
!= '*') {
73 * Look instances of the next character in
74 * pattern, and try to match starting from
79 match_pattern(s
+ 1, pattern
+ 1))
85 * Move ahead one character at a time and try to
86 * match at each position.
89 if (match_pattern(s
, pattern
))
95 * There must be at least one more character in the string.
96 * If we are at the end, fail.
101 /* Check if the next character of the string is acceptable. */
102 if (*pattern
!= '?' && *pattern
!= *s
)
105 /* Move to the next character, both in string and in pattern. */
113 * Tries to match the string against the
114 * comma-separated sequence of subpatterns (each possibly preceded by ! to
115 * indicate negation). Returns -1 if negation matches, 1 if there is
116 * a positive match, 0 if there is no match at all.
119 match_pattern_list(const char *string
, const char *pattern
, int dolower
)
124 u_int i
, subi
, len
= strlen(pattern
);
127 for (i
= 0; i
< len
;) {
128 /* Check if the subpattern is negated. */
129 if (pattern
[i
] == '!') {
136 * Extract the subpattern up to a comma or end. Convert the
137 * subpattern to lowercase.
140 i
< len
&& subi
< sizeof(sub
) - 1 && pattern
[i
] != ',';
142 sub
[subi
] = dolower
&& isupper((u_char
)pattern
[i
]) ?
143 tolower((u_char
)pattern
[i
]) : pattern
[i
];
144 /* If subpattern too long, return failure (no match). */
145 if (subi
>= sizeof(sub
) - 1)
148 /* If the subpattern was terminated by a comma, skip the comma. */
149 if (i
< len
&& pattern
[i
] == ',')
152 /* Null-terminate the subpattern. */
155 /* Try to match the subpattern against the string. */
156 if (match_pattern(string
, sub
)) {
158 return -1; /* Negative */
160 got_positive
= 1; /* Positive */
165 * Return success if got a positive match. If there was a negative
166 * match, we have already returned -1 and never get here.
172 * 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.
178 match_hostname(const char *host
, const char *pattern
)
180 return match_pattern_list(host
, pattern
, 1);
184 * returns 0 if we get a negative match for the hostname or the ip
185 * or if we get no match at all. returns -1 on error, or 1 on
189 match_host_and_ip(const char *host
, const char *ipaddr
,
190 const char *patterns
)
194 /* error in ipaddr match */
195 if ((mip
= addr_match_list(ipaddr
, patterns
)) == -2)
197 else if (mip
== -1) /* negative ip address match */
200 /* negative hostname match */
201 if ((mhost
= match_hostname(host
, patterns
)) == -1)
203 /* no match at all */
204 if (mhost
== 0 && mip
== 0)
210 * match user, user@host_or_ip, user@host_or_ip_list against pattern
213 match_user(const char *user
, const char *host
, const char *ipaddr
,
219 if ((p
= strchr(pattern
,'@')) == NULL
)
220 return match_pattern(user
, pattern
);
222 pat
= xstrdup(pattern
);
223 p
= strchr(pat
, '@');
226 if ((ret
= match_pattern(user
, pat
)) == 1)
227 ret
= match_host_and_ip(host
, ipaddr
, p
);
234 * Returns first item from client-list that is also supported by server-list,
235 * caller must free the returned string.
240 match_list(const char *client
, const char *server
, u_int
*next
)
242 char *sproposals
[MAX_PROP
];
243 char *c
, *s
, *p
, *ret
, *cp
, *sp
;
244 int i
, j
, nproposals
;
246 c
= cp
= xstrdup(client
);
247 s
= sp
= xstrdup(server
);
249 for ((p
= strsep(&sp
, SEP
)), i
=0; p
&& *p
!= '\0';
250 (p
= strsep(&sp
, SEP
)), i
++) {
258 for ((p
= strsep(&cp
, SEP
)), i
=0; p
&& *p
!= '\0';
259 (p
= strsep(&cp
, SEP
)), i
++) {
260 for (j
= 0; j
< nproposals
; j
++) {
261 if (strcmp(p
, sproposals
[j
]) == 0) {
264 *next
= (cp
== NULL
) ?
265 strlen(c
) : (u_int
)(cp
- c
);