/* $NetBSD: match.c,v 1.1.1.6 2001/09/27 02:00:44 itojun Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * Simple pattern matching, with '*' and '?' as wildcards. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" RCSID("$OpenBSD: match.c,v 1.14 2001/06/27 04:48:53 markus Exp $"); #include "match.h" #include "xmalloc.h" /* * Returns true if the given string matches the pattern (which may contain ? * and * as wildcards), and zero if it does not match. */ int match_pattern(const char *s, const char *pattern) { for (;;) { /* If at end of pattern, accept if also at end of string. */ if (!*pattern) return !*s; if (*pattern == '*') { /* Skip the asterisk. */ pattern++; /* If at end of pattern, accept immediately. */ if (!*pattern) return 1; /* If next character in pattern is known, optimize. */ if (*pattern != '?' && *pattern != '*') { /* * Look instances of the next character in * pattern, and try to match starting from * those. */ for (; *s; s++) if (*s == *pattern && match_pattern(s + 1, pattern + 1)) return 1; /* Failed. */ return 0; } /* * Move ahead one character at a time and try to * match at each position. */ for (; *s; s++) if (match_pattern(s, pattern)) return 1; /* Failed. */ return 0; } /* * There must be at least one more character in the string. * If we are at the end, fail. */ if (!*s) return 0; /* Check if the next character of the string is acceptable. */ if (*pattern != '?' && *pattern != *s) return 0; /* Move to the next character, both in string and in pattern. */ s++; pattern++; } /* NOTREACHED */ } /* * Tries to match the host name (which must be in all lowercase) against the * comma-separated sequence of subpatterns (each possibly preceded by ! to * indicate negation). Returns -1 if negation matches, 1 if there is * a positive match, 0 if there is no match at all. */ int match_hostname(const char *host, const char *pattern, u_int len) { char sub[1024]; int negated; int got_positive; u_int i, subi; got_positive = 0; for (i = 0; i < len;) { /* Check if the subpattern is negated. */ if (pattern[i] == '!') { negated = 1; i++; } else negated = 0; /* * Extract the subpattern up to a comma or end. Convert the * subpattern to lowercase. */ for (subi = 0; i < len && subi < sizeof(sub) - 1 && pattern[i] != ','; subi++, i++) sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i]; /* If subpattern too long, return failure (no match). */ if (subi >= sizeof(sub) - 1) return 0; /* If the subpattern was terminated by a comma, skip the comma. */ if (i < len && pattern[i] == ',') i++; /* Null-terminate the subpattern. */ sub[subi] = '\0'; /* Try to match the subpattern against the host name. */ if (match_pattern(host, sub)) { if (negated) return -1; /* Negative */ else got_positive = 1; /* Positive */ } } /* * Return success if got a positive match. If there was a negative * match, we have already returned -1 and never get here. */ return got_positive; } /* * returns 0 if we get a negative match for the hostname or the ip * or if we get no match at all. returns 1 otherwise. */ int match_host_and_ip(const char *host, const char *ipaddr, const char *patterns) { int mhost, mip; /* negative ipaddr match */ if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1) return 0; /* negative hostname match */ if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1) return 0; /* no match at all */ if (mhost == 0 && mip == 0) return 0; return 1; } /* * match user, user@host_or_ip, user@host_or_ip_list against pattern */ int match_user(const char *user, const char *host, const char *ipaddr, const char *pattern) { char *p, *pat; int ret; if ((p = strchr(pattern,'@')) == NULL) return match_pattern(user, pattern); pat = xstrdup(pattern); p = strchr(pat, '@'); *p++ = '\0'; if ((ret = match_pattern(user, pat)) == 1) ret = match_host_and_ip(host, ipaddr, p); xfree(pat); return ret; } /* * Returns first item from client-list that is also supported by server-list, * caller must xfree() returned string. */ #define MAX_PROP 20 #define SEP "," char * match_list(const char *client, const char *server, u_int *next) { char *sproposals[MAX_PROP]; char *c, *s, *p, *ret, *cp, *sp; int i, j, nproposals; c = cp = xstrdup(client); s = sp = xstrdup(server); for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0'; (p = strsep(&sp, SEP)), i++) { if (i < MAX_PROP) sproposals[i] = p; else break; } nproposals = i; for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0'; (p = strsep(&cp, SEP)), i++) { for (j = 0; j < nproposals; j++) { if (strcmp(p, sproposals[j]) == 0) { ret = xstrdup(p); if (next != NULL) *next = (cp == NULL) ? strlen(c) : cp - c; xfree(c); xfree(s); return ret; } } } if (next != NULL) *next = strlen(c); xfree(c); xfree(s); return NULL; }