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3c0ef626 | 1 | /* |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * Simple pattern matching, with '*' and '?' as wildcards. | |
6 | * | |
7 | * 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". | |
12 | */ | |
13 | /* | |
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 | */ | |
36 | ||
37 | #include "includes.h" | |
38 | RCSID("$OpenBSD: match.c,v 1.14 2001/06/27 04:48:53 markus Exp $"); | |
39 | ||
40 | #include "match.h" | |
41 | #include "xmalloc.h" | |
42 | ||
43 | /* | |
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 | */ | |
47 | ||
48 | int | |
49 | match_pattern(const char *s, const char *pattern) | |
50 | { | |
51 | for (;;) { | |
52 | /* If at end of pattern, accept if also at end of string. */ | |
53 | if (!*pattern) | |
54 | return !*s; | |
55 | ||
56 | if (*pattern == '*') { | |
57 | /* Skip the asterisk. */ | |
58 | pattern++; | |
59 | ||
60 | /* If at end of pattern, accept immediately. */ | |
61 | if (!*pattern) | |
62 | return 1; | |
63 | ||
64 | /* If next character in pattern is known, optimize. */ | |
65 | if (*pattern != '?' && *pattern != '*') { | |
66 | /* | |
67 | * Look instances of the next character in | |
68 | * pattern, and try to match starting from | |
69 | * those. | |
70 | */ | |
71 | for (; *s; s++) | |
72 | if (*s == *pattern && | |
73 | match_pattern(s + 1, pattern + 1)) | |
74 | return 1; | |
75 | /* Failed. */ | |
76 | return 0; | |
77 | } | |
78 | /* | |
79 | * Move ahead one character at a time and try to | |
80 | * match at each position. | |
81 | */ | |
82 | for (; *s; s++) | |
83 | if (match_pattern(s, pattern)) | |
84 | return 1; | |
85 | /* Failed. */ | |
86 | return 0; | |
87 | } | |
88 | /* | |
89 | * There must be at least one more character in the string. | |
90 | * If we are at the end, fail. | |
91 | */ | |
92 | if (!*s) | |
93 | return 0; | |
94 | ||
95 | /* Check if the next character of the string is acceptable. */ | |
96 | if (*pattern != '?' && *pattern != *s) | |
97 | return 0; | |
98 | ||
99 | /* Move to the next character, both in string and in pattern. */ | |
100 | s++; | |
101 | pattern++; | |
102 | } | |
103 | /* NOTREACHED */ | |
104 | } | |
105 | ||
106 | /* | |
107 | * Tries to match the host name (which must be in all lowercase) against the | |
108 | * comma-separated sequence of subpatterns (each possibly preceded by ! to | |
109 | * indicate negation). Returns -1 if negation matches, 1 if there is | |
110 | * a positive match, 0 if there is no match at all. | |
111 | */ | |
112 | ||
113 | int | |
114 | match_hostname(const char *host, const char *pattern, u_int len) | |
115 | { | |
116 | char sub[1024]; | |
117 | int negated; | |
118 | int got_positive; | |
119 | u_int i, subi; | |
120 | ||
121 | got_positive = 0; | |
122 | for (i = 0; i < len;) { | |
123 | /* Check if the subpattern is negated. */ | |
124 | if (pattern[i] == '!') { | |
125 | negated = 1; | |
126 | i++; | |
127 | } else | |
128 | negated = 0; | |
129 | ||
130 | /* | |
131 | * Extract the subpattern up to a comma or end. Convert the | |
132 | * subpattern to lowercase. | |
133 | */ | |
134 | for (subi = 0; | |
135 | i < len && subi < sizeof(sub) - 1 && pattern[i] != ','; | |
136 | subi++, i++) | |
137 | sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i]; | |
138 | /* If subpattern too long, return failure (no match). */ | |
139 | if (subi >= sizeof(sub) - 1) | |
140 | return 0; | |
141 | ||
142 | /* If the subpattern was terminated by a comma, skip the comma. */ | |
143 | if (i < len && pattern[i] == ',') | |
144 | i++; | |
145 | ||
146 | /* Null-terminate the subpattern. */ | |
147 | sub[subi] = '\0'; | |
148 | ||
149 | /* Try to match the subpattern against the host name. */ | |
150 | if (match_pattern(host, sub)) { | |
151 | if (negated) | |
152 | return -1; /* Negative */ | |
153 | else | |
154 | got_positive = 1; /* Positive */ | |
155 | } | |
156 | } | |
157 | ||
158 | /* | |
159 | * Return success if got a positive match. If there was a negative | |
160 | * match, we have already returned -1 and never get here. | |
161 | */ | |
162 | return got_positive; | |
163 | } | |
164 | ||
165 | /* | |
166 | * returns 0 if we get a negative match for the hostname or the ip | |
167 | * or if we get no match at all. returns 1 otherwise. | |
168 | */ | |
169 | int | |
170 | match_host_and_ip(const char *host, const char *ipaddr, | |
171 | const char *patterns) | |
172 | { | |
173 | int mhost, mip; | |
174 | ||
175 | /* negative ipaddr match */ | |
176 | if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1) | |
177 | return 0; | |
178 | /* negative hostname match */ | |
179 | if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1) | |
180 | return 0; | |
181 | /* no match at all */ | |
182 | if (mhost == 0 && mip == 0) | |
183 | return 0; | |
184 | return 1; | |
185 | } | |
186 | ||
187 | /* | |
188 | * match user, user@host_or_ip, user@host_or_ip_list against pattern | |
189 | */ | |
190 | int | |
191 | match_user(const char *user, const char *host, const char *ipaddr, | |
192 | const char *pattern) | |
193 | { | |
194 | char *p, *pat; | |
195 | int ret; | |
196 | ||
197 | if ((p = strchr(pattern,'@')) == NULL) | |
198 | return match_pattern(user, pattern); | |
199 | ||
200 | pat = xstrdup(pattern); | |
201 | p = strchr(pat, '@'); | |
202 | *p++ = '\0'; | |
203 | ||
204 | if ((ret = match_pattern(user, pat)) == 1) | |
205 | ret = match_host_and_ip(host, ipaddr, p); | |
206 | xfree(pat); | |
207 | ||
208 | return ret; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Returns first item from client-list that is also supported by server-list, | |
213 | * caller must xfree() returned string. | |
214 | */ | |
215 | #define MAX_PROP 20 | |
216 | #define SEP "," | |
217 | char * | |
218 | match_list(const char *client, const char *server, u_int *next) | |
219 | { | |
220 | char *sproposals[MAX_PROP]; | |
221 | char *c, *s, *p, *ret, *cp, *sp; | |
222 | int i, j, nproposals; | |
223 | ||
224 | c = cp = xstrdup(client); | |
225 | s = sp = xstrdup(server); | |
226 | ||
227 | for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0'; | |
228 | (p = strsep(&sp, SEP)), i++) { | |
229 | if (i < MAX_PROP) | |
230 | sproposals[i] = p; | |
231 | else | |
232 | break; | |
233 | } | |
234 | nproposals = i; | |
235 | ||
236 | for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0'; | |
237 | (p = strsep(&cp, SEP)), i++) { | |
238 | for (j = 0; j < nproposals; j++) { | |
239 | if (strcmp(p, sproposals[j]) == 0) { | |
240 | ret = xstrdup(p); | |
241 | if (next != NULL) | |
242 | *next = (cp == NULL) ? | |
243 | strlen(c) : cp - c; | |
244 | xfree(c); | |
245 | xfree(s); | |
246 | return ret; | |
247 | } | |
248 | } | |
249 | } | |
250 | if (next != NULL) | |
251 | *next = strlen(c); | |
252 | xfree(c); | |
253 | xfree(s); | |
254 | return NULL; | |
255 | } |