[openssh.git] / match.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, 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 1.19 2002/03/01 13:12:10 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 string 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_pattern_list(const char *string, const char *pattern, u_int len,
    int dolower)
{
	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] = dolower && 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 string. */
		if (match_pattern(string, 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;
}

/*
 * 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)
{
	return match_pattern_list(host, pattern, len, 1);
}

/*
 * 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	40
#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;
}
Commit	Line	Data
8efc0c15	1	/*
5260325f	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5260325f	4	* All rights reserved
5260325f	5	* Simple pattern matching, with '*' and '?' as wildcards.
6ae2364d	6	*
bcbf86ec	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".
5260325f	12	*/
cab80f75	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	*/
8efc0c15	36
8efc0c15	37	#include "includes.h"
6805fc56	38	RCSID("$OpenBSD: match.c,v 1.19 2002/03/01 13:12:10 markus Exp $");
8efc0c15	39
42f11eb2	40	#include "match.h"
cab80f75	41	#include "xmalloc.h"
8efc0c15	42
aa3378df	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	*/
8efc0c15	47
6ae2364d	48	int
5260325f	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;
8efc0c15	55
5260325f	56	if (pattern == '') {
	57	/* Skip the asterisk. */
	58	pattern++;
8efc0c15	59
5260325f	60	/* If at end of pattern, accept immediately. */
	61	if (!*pattern)
	62	return 1;
8efc0c15	63
5260325f	64	/* If next character in pattern is known, optimize. */
5260325f	65	if (pattern != '?' && pattern != '*') {
aa3378df	66	/*
	67	* Look instances of the next character in
	68	* pattern, and try to match starting from
	69	* those.
	70	*/
5260325f	71	for (; *s; s++)
	72	if (s == pattern &&
	73	match_pattern(s + 1, pattern + 1))
	74	return 1;
	75	/* Failed. */
	76	return 0;
	77	}
aa3378df	78	/*
	79	* Move ahead one character at a time and try to
	80	* match at each position.
	81	*/
5260325f	82	for (; *s; s++)
	83	if (match_pattern(s, pattern))
	84	return 1;
	85	/* Failed. */
	86	return 0;
	87	}
aa3378df	88	/*
	89	* There must be at least one more character in the string.
	90	* If we are at the end, fail.
	91	*/
5260325f	92	if (!*s)
5260325f	93	return 0;
8efc0c15	94
aa3378df	95	/* Check if the next character of the string is acceptable. */
5260325f	96	if (pattern != '?' && pattern != *s)
5260325f	97	return 0;
8efc0c15	98
aa3378df	99	/* Move to the next character, both in string and in pattern. */
5260325f	100	s++;
	101	pattern++;
	102	}
	103	/* NOTREACHED */
8efc0c15	104	}
4fe2af09	105
4fe2af09	106	/*
6a92533a	107	* Tries to match the string against the
4fe2af09	108	* comma-separated sequence of subpatterns (each possibly preceded by ! to
fa649821	109	* indicate negation). Returns -1 if negation matches, 1 if there is
fa649821	110	* a positive match, 0 if there is no match at all.
4fe2af09	111	*/
	112
	113	int
6a92533a	114	match_pattern_list(const char string, const char pattern, u_int len,
6a92533a	115	int dolower)
4fe2af09	116	{
	117	char sub[1024];
	118	int negated;
	119	int got_positive;
1e3b8b07	120	u_int i, subi;
4fe2af09	121
	122	got_positive = 0;
	123	for (i = 0; i < len;) {
	124	/* Check if the subpattern is negated. */
	125	if (pattern[i] == '!') {
	126	negated = 1;
	127	i++;
	128	} else
	129	negated = 0;
	130
	131	/*
	132	* Extract the subpattern up to a comma or end. Convert the
	133	* subpattern to lowercase.
	134	*/
	135	for (subi = 0;
184eed6a	136	i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
184eed6a	137	subi++, i++)
6a92533a	138	sub[subi] = dolower && isupper(pattern[i]) ?
184eed6a	139	tolower(pattern[i]) : pattern[i];
4fe2af09	140	/* If subpattern too long, return failure (no match). */
	141	if (subi >= sizeof(sub) - 1)
	142	return 0;
	143
	144	/* If the subpattern was terminated by a comma, skip the comma. */
	145	if (i < len && pattern[i] == ',')
	146	i++;
	147
	148	/* Null-terminate the subpattern. */
	149	sub[subi] = '\0';
	150
6a92533a	151	/* Try to match the subpattern against the string. */
6a92533a	152	if (match_pattern(string, sub)) {
4fe2af09	153	if (negated)
fa649821	154	return -1; /* Negative */
4fe2af09	155	else
fa649821	156	got_positive = 1; /* Positive */
4fe2af09	157	}
	158	}
	159
	160	/*
	161	* Return success if got a positive match. If there was a negative
fa649821	162	* match, we have already returned -1 and never get here.
4fe2af09	163	*/
	164	return got_positive;
	165	}
cab80f75	166
6a92533a	167	/*
	168	* Tries to match the host name (which must be in all lowercase) against the
	169	* comma-separated sequence of subpatterns (each possibly preceded by ! to
	170	* indicate negation). Returns -1 if negation matches, 1 if there is
	171	* a positive match, 0 if there is no match at all.
	172	*/
	173	int
	174	match_hostname(const char host, const char pattern, u_int len)
	175	{
	176	return match_pattern_list(host, pattern, len, 1);
	177	}
	178
2cee8a25	179	/*
	180	* returns 0 if we get a negative match for the hostname or the ip
	181	* or if we get no match at all. returns 1 otherwise.
	182	*/
	183	int
	184	match_host_and_ip(const char host, const char ipaddr,
	185	const char *patterns)
	186	{
	187	int mhost, mip;
	188
	189	/* negative ipaddr match */
	190	if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1)
	191	return 0;
	192	/* negative hostname match */
	193	if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1)
	194	return 0;
	195	/* no match at all */
	196	if (mhost == 0 && mip == 0)
	197	return 0;
	198	return 1;
	199	}
cab80f75	200
80f8f24f	201	/*
	202	* match user, user@host_or_ip, user@host_or_ip_list against pattern
	203	*/
	204	int
6805fc56	205	match_user(const char user, const char host, const char *ipaddr,
80f8f24f	206	const char *pattern)
	207	{
	208	char p, pat;
	209	int ret;
	210
	211	if ((p = strchr(pattern,'@')) == NULL)
	212	return match_pattern(user, pattern);
	213
	214	pat = xstrdup(pattern);
	215	p = strchr(pat, '@');
	216	*p++ = '\0';
	217
	218	if ((ret = match_pattern(user, pat)) == 1)
6805fc56	219	ret = match_host_and_ip(host, ipaddr, p);
80f8f24f	220	xfree(pat);
	221
	222	return ret;
	223	}
	224
2cee8a25	225	/*
	226	* Returns first item from client-list that is also supported by server-list,
	227	* caller must xfree() returned string.
	228	*/
fa869228	229	#define MAX_PROP 40
cab80f75	230	#define SEP ","
	231	char *
	232	match_list(const char client, const char server, u_int *next)
	233	{
	234	char *sproposals[MAX_PROP];
	235	char c, s, p, ret, cp, sp;
	236	int i, j, nproposals;
	237
	238	c = cp = xstrdup(client);
	239	s = sp = xstrdup(server);
	240
	241	for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
184eed6a	242	(p = strsep(&sp, SEP)), i++) {
cab80f75	243	if (i < MAX_PROP)
	244	sproposals[i] = p;
	245	else
	246	break;
	247	}
	248	nproposals = i;
	249
	250	for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
184eed6a	251	(p = strsep(&cp, SEP)), i++) {
cab80f75	252	for (j = 0; j < nproposals; j++) {
	253	if (strcmp(p, sproposals[j]) == 0) {
	254	ret = xstrdup(p);
	255	if (next != NULL)
	256	*next = (cp == NULL) ?
	257	strlen(c) : cp - c;
	258	xfree(c);
	259	xfree(s);
	260	return ret;
	261	}
	262	}
	263	}
	264	if (next != NULL)
	265	*next = strlen(c);
	266	xfree(c);
	267	xfree(s);
	268	return NULL;
	269	}