Coverage Report

Created: 2025-06-20 06:24

/src/openssh/match.c
Line
Count
Source (jump to first uncovered line)
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/* $OpenBSD: match.c,v 1.45 2024/09/06 02:30:44 djm Exp $ */
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/*
3
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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 *                    All rights reserved
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 * Simple pattern matching, with '*' and '?' as wildcards.
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 *
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 * As far as I am concerned, the code I have written for this software
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 * can be used freely for any purpose.  Any derived versions of this
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 * software must be clearly marked as such, and if the derived work is
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 * incompatible with the protocol description in the RFC file, it must be
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 * called by a name other than "ssh" or "Secure Shell".
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 */
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/*
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 * Copyright (c) 2000 Markus Friedl.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#include "includes.h"
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#include <sys/types.h>
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#include <ctype.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include "xmalloc.h"
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#include "match.h"
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#include "misc.h"
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/*
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 * Returns true if the given string matches the pattern (which may contain ?
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 * and * as wildcards), and zero if it does not match.
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 */
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int
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match_pattern(const char *s, const char *pattern)
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5.38M
{
59
8.34M
  for (;;) {
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    /* If at end of pattern, accept if also at end of string. */
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8.34M
    if (!*pattern)
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604
      return !*s;
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8.33M
    if (*pattern == '*') {
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      /* Skip this and any consecutive asterisks. */
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340k
      while (*pattern == '*')
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170k
        pattern++;
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      /* If at end of pattern, accept immediately. */
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170k
      if (!*pattern)
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13.0k
        return 1;
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      /* If next character in pattern is known, optimize. */
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156k
      if (*pattern != '?' && *pattern != '*') {
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        /*
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         * Look instances of the next character in
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         * pattern, and try to match starting from
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         * those.
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         */
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2.94M
        for (; *s; s++)
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2.78M
          if (*s == *pattern &&
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2.78M
              match_pattern(s + 1, pattern + 1))
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0
            return 1;
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        /* Failed. */
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156k
        return 0;
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156k
      }
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      /*
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       * Move ahead one character at a time and try to
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       * match at each position.
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       */
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0
      for (; *s; s++)
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0
        if (match_pattern(s, pattern))
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0
          return 1;
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      /* Failed. */
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0
      return 0;
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0
    }
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    /*
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     * There must be at least one more character in the string.
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     * If we are at the end, fail.
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     */
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8.16M
    if (!*s)
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402k
      return 0;
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    /* Check if the next character of the string is acceptable. */
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7.76M
    if (*pattern != '?' && *pattern != *s)
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4.80M
      return 0;
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    /* Move to the next character, both in string and in pattern. */
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2.95M
    s++;
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2.95M
    pattern++;
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2.95M
  }
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  /* NOTREACHED */
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5.38M
}
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/*
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 * Tries to match the string against the
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 * comma-separated sequence of subpatterns (each possibly preceded by ! to
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 * indicate negation).  Returns -1 if negation matches, 1 if there is
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 * a positive match, 0 if there is no match at all.
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 */
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int
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match_pattern_list(const char *string, const char *pattern, int dolower)
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2.00M
{
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2.00M
  char sub[1024];
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2.00M
  int negated;
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2.00M
  int got_positive;
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2.00M
  u_int i, subi, len = strlen(pattern);
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2.00M
  got_positive = 0;
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7.29M
  for (i = 0; i < len;) {
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    /* Check if the subpattern is negated. */
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5.28M
    if (pattern[i] == '!') {
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0
      negated = 1;
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0
      i++;
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0
    } else
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5.28M
      negated = 0;
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    /*
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     * Extract the subpattern up to a comma or end.  Convert the
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     * subpattern to lowercase.
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     */
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5.28M
    for (subi = 0;
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75.5M
        i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
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70.2M
        subi++, i++)
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70.2M
      sub[subi] = dolower && isupper((u_char)pattern[i]) ?
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70.2M
          tolower((u_char)pattern[i]) : pattern[i];
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    /* If subpattern too long, return failure (no match). */
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5.28M
    if (subi >= sizeof(sub) - 1)
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0
      return 0;
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    /* If the subpattern was terminated by a comma, then skip it. */
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5.28M
    if (i < len && pattern[i] == ',')
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3.27M
      i++;
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    /* Null-terminate the subpattern. */
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5.28M
    sub[subi] = '\0';
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158
    /* Try to match the subpattern against the string. */
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5.28M
    if (match_pattern(string, sub)) {
160
13.6k
      if (negated)
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0
        return -1;   /* Negative */
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13.6k
      else
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13.6k
        got_positive = 1; /* Positive */
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13.6k
    }
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5.28M
  }
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167
  /*
168
   * Return success if got a positive match.  If there was a negative
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   * match, we have already returned -1 and never get here.
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   */
171
2.00M
  return got_positive;
172
2.00M
}
173
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/* Match a list representing users or groups. */
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int
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match_usergroup_pattern_list(const char *string, const char *pattern)
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0
{
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#ifdef HAVE_CYGWIN
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  /* Windows usernames may be Unicode and are not case sensitive */
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  return cygwin_ug_match_pattern_list(string, pattern);
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#else
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  /* Case sensitive match */
183
0
  return match_pattern_list(string, pattern, 0);
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0
#endif
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0
}
186
187
/*
188
 * Tries to match the host name (which must be in all lowercase) against the
189
 * comma-separated sequence of subpatterns (each possibly preceded by ! to
190
 * indicate negation).  Returns -1 if negation matches, 1 if there is
191
 * a positive match, 0 if there is no match at all.
192
 */
193
int
194
match_hostname(const char *host, const char *pattern)
195
0
{
196
0
  char *hostcopy = xstrdup(host);
197
0
  int r;
198
199
0
  lowercase(hostcopy);
200
0
  r = match_pattern_list(hostcopy, pattern, 1);
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0
  free(hostcopy);
202
0
  return r;
203
0
}
204
205
/*
206
 * returns 0 if we get a negative match for the hostname or the ip
207
 * or if we get no match at all.  returns -1 on error, or 1 on
208
 * successful match.
209
 */
210
int
211
match_host_and_ip(const char *host, const char *ipaddr,
212
    const char *patterns)
213
0
{
214
0
  int mhost, mip;
215
216
0
  if ((mip = addr_match_list(ipaddr, patterns)) == -2)
217
0
    return -1; /* error in ipaddr match */
218
0
  else if (host == NULL || ipaddr == NULL || mip == -1)
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0
    return 0; /* negative ip address match, or testing pattern */
220
221
  /* negative hostname match */
222
0
  if ((mhost = match_hostname(host, patterns)) == -1)
223
0
    return 0;
224
  /* no match at all */
225
0
  if (mhost == 0 && mip == 0)
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0
    return 0;
227
0
  return 1;
228
0
}
229
230
/*
231
 * Match user, user@host_or_ip, user@host_or_ip_list against pattern.
232
 * If user, host and ipaddr are all NULL then validate pattern/
233
 * Returns -1 on invalid pattern, 0 on no match, 1 on match.
234
 */
235
int
236
match_user(const char *user, const char *host, const char *ipaddr,
237
    const char *pattern)
238
0
{
239
0
  char *p, *pat;
240
0
  int ret;
241
242
  /* test mode */
243
0
  if (user == NULL && host == NULL && ipaddr == NULL) {
244
0
    if ((p = strrchr(pattern, '@')) != NULL &&
245
0
        match_host_and_ip(NULL, NULL, p + 1) < 0)
246
0
      return -1;
247
0
    return 0;
248
0
  }
249
250
0
  if (user == NULL)
251
0
    return 0; /* shouldn't happen */
252
253
0
  if (strrchr(pattern, '@') == NULL)
254
0
    return match_pattern(user, pattern);
255
256
0
  pat = xstrdup(pattern);
257
0
  p = strrchr(pat, '@');
258
0
  *p++ = '\0';
259
260
0
  if ((ret = match_pattern(user, pat)) == 1)
261
0
    ret = match_host_and_ip(host, ipaddr, p);
262
0
  free(pat);
263
264
0
  return ret;
265
0
}
266
267
/*
268
 * Returns first item from client-list that is also supported by server-list,
269
 * caller must free the returned string.
270
 */
271
1.16M
#define MAX_PROP  40
272
3.61M
#define SEP ","
273
char *
274
match_list(const char *client, const char *server, u_int *next)
275
754k
{
276
754k
  char *sproposals[MAX_PROP];
277
754k
  char *c, *s, *p, *ret, *cp, *sp;
278
754k
  int i, j, nproposals;
279
280
754k
  c = cp = xstrdup(client);
281
754k
  s = sp = xstrdup(server);
282
283
1.91M
  for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
284
1.16M
      (p = strsep(&sp, SEP)), i++) {
285
1.16M
    if (i < MAX_PROP)
286
1.16M
      sproposals[i] = p;
287
0
    else
288
0
      break;
289
1.16M
  }
290
754k
  nproposals = i;
291
292
1.69M
  for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
293
1.06M
      (p = strsep(&cp, SEP)), i++) {
294
2.48M
    for (j = 0; j < nproposals; j++) {
295
1.54M
      if (strcmp(p, sproposals[j]) == 0) {
296
129k
        ret = xstrdup(p);
297
129k
        if (next != NULL)
298
0
          *next = (cp == NULL) ?
299
0
              strlen(c) : (u_int)(cp - c);
300
129k
        free(c);
301
129k
        free(s);
302
129k
        return ret;
303
129k
      }
304
1.54M
    }
305
1.06M
  }
306
625k
  if (next != NULL)
307
0
    *next = strlen(c);
308
625k
  free(c);
309
625k
  free(s);
310
625k
  return NULL;
311
754k
}
312
313
/*
314
 * Filter proposal using pattern-list filter.
315
 * "denylist" determines sense of filter:
316
 * non-zero indicates that items matching filter should be excluded.
317
 * zero indicates that only items matching filter should be included.
318
 * returns NULL on allocation error, otherwise caller must free result.
319
 */
320
static char *
321
filter_list(const char *proposal, const char *filter, int denylist)
322
302
{
323
302
  size_t len = strlen(proposal) + 1;
324
302
  char *fix_prop = malloc(len);
325
302
  char *orig_prop = strdup(proposal);
326
302
  char *cp, *tmp;
327
302
  int r;
328
329
302
  if (fix_prop == NULL || orig_prop == NULL) {
330
0
    free(orig_prop);
331
0
    free(fix_prop);
332
0
    return NULL;
333
0
  }
334
335
302
  tmp = orig_prop;
336
302
  *fix_prop = '\0';
337
1.20k
  while ((cp = strsep(&tmp, ",")) != NULL) {
338
906
    r = match_pattern_list(cp, filter, 0);
339
906
    if ((denylist && r != 1) || (!denylist && r == 1)) {
340
302
      if (*fix_prop != '\0')
341
0
        strlcat(fix_prop, ",", len);
342
302
      strlcat(fix_prop, cp, len);
343
302
    }
344
906
  }
345
302
  free(orig_prop);
346
302
  return fix_prop;
347
302
}
348
349
/*
350
 * Filters a comma-separated list of strings, excluding any entry matching
351
 * the 'filter' pattern list. Caller must free returned string.
352
 */
353
char *
354
match_filter_denylist(const char *proposal, const char *filter)
355
302
{
356
302
  return filter_list(proposal, filter, 1);
357
302
}
358
359
/*
360
 * Filters a comma-separated list of strings, including only entries matching
361
 * the 'filter' pattern list. Caller must free returned string.
362
 */
363
char *
364
match_filter_allowlist(const char *proposal, const char *filter)
365
0
{
366
0
  return filter_list(proposal, filter, 0);
367
0
}